Dissertations / Theses on the topic 'Biometrical method'

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1

Holeksa, David. "Návrh audio-vizuální databáze pro extrakci sekundárních biometrických a ne-biometrických znaků." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-220544.

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The aim of this semester project is to design a suitable database structure for the audio-visual data, parts extracted from the data corresponding to secondary biometric and non-biometric characteristics and description of these characters. The resulting database will be used for research into the identification of audio-visual content of multimedia data.
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Fransson, Linda, and Therese Jeansson. "Biometric methods and mobile access control." Thesis, Blekinge Tekniska Högskola, Avdelningen för programvarusystem, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-5023.

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Our purpose with this thesis was to find biometric methods that can be used in access control of mobile access. The access control has two parts. Firstly, to validate the identity of the caller and, secondly, to ensure the validated user is not changed during the session that follows. Any solution to the access control problem is not available today, which means that anyone can get access to the mobile phone and the Internet. Therefore we have researched after a solution that can solve this problem but also on how to secure that no one else can take over an already validated session. We began to search for biometric methods that are available today to find them that would be best suited together with a mobile phone. After we had read information about them we did choose three methods for further investigation. These methods were Fingerprint Recognition, Iris Scan and Speaker Verification. Iris Scan is the method that is best suited to solve the authentication problem. The reasons for this are many. One of them is the uniqueness and stability of the iris, not even identical twins or the pair of the same individual has the same iris minutiae. The iris is also very protected behind eyelids, cornea and the aqueous humor and therefore difficult to damage. When it comes to the method itself, is it one of the most secure methods available today. One of the reasons for this is that the equal error rate is better than one in a million. However, this rate can be even better. It all depends on the Hamming Distance, which is a value that show how different the saved and temporarily template are, and what it is set to. To solve our session authentication, which was to make sure that no one else could take over a connected mobile phone, a sensor plate is the answer. This sensor will be able to sense for touch, heat and pulse. These three sensor measurements will together secure a validated session since the mobile phone will disconnect if the sensor looses its sensor data. There are, however, technological and other challenges to be solved before our proposed solutions will become viable. We address some of these issues in our thesis.
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Betschart, Willie. "Applying intelligent statistical methods on biometric systems." Thesis, Blekinge Tekniska Högskola, Avdelningen för signalbehandling, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-1694.

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This master’s thesis work was performed at Optimum Biometric Labs, OBL, located in Karlskrona, Sweden. Optimum Biometric Labs perform independent scenario evaluations to companies who develop biometric devices. The company has a product Optimum preConTM which is surveillance and diagnosis tool for biometric systems. This thesis work’s objective was to develop a conceptual model and implement it as an additional layer above the biometric layer with intelligence about the biometric users. The layer is influenced by the general procedure of biometrics in a multimodal behavioural way. It is working in an unsupervised way and performs in an unsupervised manner. While biometric systems are increasingly adopted the technologies have some inherent problems such as false match and false non-match. In practice, a rejected user can not be interpreted as an impostor since the user simply might have problems using his/her biometric feature. The proposed methods in this project are dealing with these problems when analysing biometric usage in runtime. Another fact which may give rise to false rejections is template aging; a phenomenon where the enrolled user’s template is too old compared towards the user’s current biometric feature. A theoretical approach of template aging was known; however since the analysis of template aging detection was correlated with potential system flaws such as device defects or human generated risks such as impostor attacks this task would become difficult to solve in an unsupervised system but when ignoring the definition of template aging, the detection of similar effects was possible. One of the objectives of this project was to detect template aging in a predictive sense; this task failed to be carried out because the absence of basis performing this kind of tasks. The developed program performs abnormality detection at each incoming event from a biometric system. Each verification attempt is assumed to be from a genuine user unless any deviation according to the user's history is found, an abnormality. The possibility of an impostor attack depends on the degree of the abnormality. The application makes relative decisions between fraud possibilities or if genuine user was the source of what caused the deviations. This is presented as an alarm with the degree of impostor possibility. This intelligent layer has increased Optimum preCon´s capacity as a surveillance tool for biometrics. This product is an efficient complement to biometric systems in a steady up-going worldwide market.
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Anderson, Niall Hay. "Methods for the investigation of spatial clustering, with epidemiological applications." Thesis, University of Glasgow, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364260.

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Fakhir, Mahammad Majed. "Biometric fusion methods for adaptive face recognition in computer vision." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/4001.

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Face recognition is a biometric method that uses different techniques to identify the individuals based on the facial information received from digital image data. The system of face recognition is widely used for security purposes, which has challenging problems. The solutions to some of the most important challenges are proposed in this study. The aim of this thesis is to investigate face recognition across pose problem based on the image parameters of camera calibration. In this thesis, three novel methods have been derived to address the challenges of face recognition and offer solutions to infer the camera parameters from images using a geomtric approach based on perspective projection. The following techniques were used: camera calibration CMT and Face Quadtree Decomposition (FQD), in order to develop the face camera measurement technique (FCMT) for human facial recognition. Facial information from a feature extraction and identity-matching algorithm has been created. The success and efficacy of the proposed algorithm are analysed in terms of robustness to noise, the accuracy of distance measurement, and face recognition. To overcome the intrinsic and extrinsic parameters of camera calibration parameters, a novel technique has been developed based on perspective projection, which uses different geometrical shapes to calibrate the camera. The parameters used in novel measurement technique CMT that enables the system to infer the real distance for regular and irregular objects from the 2-D images. The proposed system of CMT feeds into FQD to measure the distance between the facial points. Quadtree decomposition enhances the representation of edges and other singularities along curves of the face, and thus improves directional features from face detection across face pose. The proposed FCMT system is the new combination of CMT and FQD to recognise the faces in the various pose. The theoretical foundation of the proposed solutions has been thoroughly developed and discussed in detail. The results show that the proposed algorithms outperform existing algorithms in face recognition, with a 2.5% improvement in main error recognition rate compared with recent studies.
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Iqbal, K. "Image detection and retrieval for biometric security from an image enhancement perspective." Thesis, Coventry University, 2011. http://curve.coventry.ac.uk/open/items/ed5b98d3-84e6-4070-89cb-7ede2f0e9c0b/1.

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Security methods based on biometrics have been gaining importance increasingly in the last few years due to recent advances in biometrics technology and its reliability and efficiency in real world applications. Also, several major security disasters that occurred in the last decade have given a new momentum to this research area. The successful development of biometric security applications cannot only minimise such threats but may also help in preventing them from happening on a global scale. Biometric security methods take into account humans’ unique physical or behavioural traits that help to identify them based on their intrinsic characteristics. However, there are a number of issues related to biometric security, in particular with regard to surveillance images. The first issue is related to the poor visibility of the images produced by surveillance cameras and the second issue is concerned with the effective image retrieval based on user query. This research addresses both issues. This research addresses the first issue of low quality of surveillance images by proposing an integrated image enhancement approach for face detection. The proposed approach is based on contrast enhancement and colour balancing methods. The contrast enhancement method is used to improve the contrast, while the colour balancing method helps to achieve a balanced colour. Importantly, in the colour balancing method, a new process for colour cast adjustment is introduced which relies on statistical calculation. It can adjust the colour cast and maintain the luminance of the whole image at the same level. The research addresses the second issue relating to image retrieval by proposing a content-based image retrieval approach. The approach is based on the three welliii known algorithms: colour histogram, texture and moment invariants. Colour histogram is used to extract the colour features of an image. Gabor filter is used to extract the texture features and the moment invariant is used to extract the shape features of an image. The use of these three algorithms ensures that the proposed image retrieval approach produces results which are highly relevant to the content of an image query, by taking into account the three distinct features of the image and the similarity metrics based on Euclidean measure. In order to retrieve the most relevant images the proposed approach also employs a set of fuzzy heuristics to improve the quality of the results further. The integrated image enhancement approach is applied to the enhancement of low quality images produced by surveillance cameras. The performance of the proposed approach is evaluated by applying three face detection methods (skin colour based face detection, feature based face detection and image based face detection methods) to surveillance images before and after enhancement using the proposed approach. The results show a significant improvement in face detection when the proposed approach was applied. The performance of the content-based image retrieval approach is carried out using the standard Precision and Recall measures, and the results are compared with wellknown existing approaches. The results show the proposed approach perform s better than the well-known existing approaches.
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Mráček, Štěpán. "Biometric Recognition of 3D Faces." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2010. http://www.nusl.cz/ntk/nusl-237237.

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Diplomová práce byla vypracována na studijním pobytu na "Gjovik University College" v Norsku, a je zpracována v angličtině. Tato práce se zabývá rozpoznáváním 3D obličejů. Je zde popsán obecný biometrický systém a také konkrétní postupy používané při rozpoznávání 2D i 3D obličejů. Následně je navžena metoda pro rozpoznávání 3D obličejů. Algoritmus je vyvíjen a testován pomocí databáze Face Recognition Grand Challenge (FRGC). Během předzpracování jsou nalezeny význačné body v obličeji a následně je trojrozměrný model zarovnán do referenční polohy. Dále jsou vstupní data porovnávána s biometrickými šablonami uloženými v databázi, a to je zajištěno využitím tří základních technik pro rozpoznávání obličejů -- metoda eigenface (PCA), rozpoznávání založené na histogramu obličeje a rozpoznávání založené na anatomických rysech. Nakonec jsou jednotlivé metody spojeny do jednoho systému, jehož celková výsledná výkonnost převyšuje výkonnost jednotlivých použitých technik.
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Subramanian, Ravichandran. "Orientation Invariance Methods for Inertial Gait." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7369.

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Intelligent devices such as smart phones, smart watches, virtual reality (VR) headsets and personal exercise devices have become integral elements of accessories used by many people. The ability of these devices to verify or identify the user could be applied for enhanced security and user experience customization among other things. Almost all these devices have built-in inertial sensors such as accelerometer and gyroscope. These inertial sensors respond to the movements made by the user while performing day to day activities like walking, getting up and sitting down. The response depends on the activity being performed and thus can be used for activity recognition. The response also captures the user's unique way of doing the activity and can be used as a behavioral biometric for verification or identification. The acceleration (accelerometer) and rate of rotation (gyroscope) are recorded in the device coordinate frame. But to determine the user's motion, these need to be converted to a coordinate frame relative to the user. In most situations the orientation of the device relative to the user can neither be controlled nor determined reliably. The solution to this problem requires methods to remove the dependence on device orientation while comparing the signals collected at different times. In a vast of majority of research to date, the performance of authentication algorithms using inertial sensors have been evaluated on small datasets with few tens of subjects, collected under controlled placement of the sensors. Very often stand alone inertial sensors have been used to collect the data. Stand alone sensors afford better calibration, while the sensors built into smart devices offer little or no means of calibration. Due to these limitations of the datasets used, it is difficult to extend the results from these research to realistic performance with a large number subjects and natural placement of off-the-shelf smart devices. This dissertation describes the Kabsch algorithm which is used to achieve orientation invariance of the recorded inertial data, enabling better authentication independent of device orientation. It also presents the Vector Cross Product (VCP) method developed to achieve orientation invariance. Details of a realistic inertial dataset (USF-PDA dataset) collected with commercial smart phones placed in natural positions and orientations using 101 subjects are given. The data includes sessions from different days on a subset of 56 subjects. This would enable realistic evaluation of authentication algorithms. This dataset has been made publicly available. The performance of five methods that address the orientation dependence of signals are compared to a baseline that performs no compensation for orientation of the device. The methods as a part of a overall gait authentication algorithm are evaluated on the USF-PDA dataset mentioned above and another large dataset with more than 400 subjects. The results show that the orientation compensation methods are able to improve the authentication performance on data with uncontrolled orientation to be close to performance on data collected with controlled orientation. The Kabsch method shows the highest improvement.
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9

Robertson, Joshua. "The application of the human-biometric sensor interaction method to automated border control systems." Thesis, University of Kent, 2017. https://kar.kent.ac.uk/66822/.

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Biometrics components are used in many different systems and technologies to verify that the user is whom they say they are. In Automated Border Control systems, biometrics components used in conjunction with a traveller's documents to make sure the user is whom they say they are so that they can cross into a countries borders. The systems are expected to verify the identity with a higher degree than officers who manually check travellers. Each year the number of travellers crossing through a country borders increases and so systems are expected to handle bigger demands; through improving the user experience to ensuring accuracy and performance standards increase. While the system does bring its benefits through increased speed and higher security, there are drawbacks. One of the main issues with the systems is a lack of standardisation across implementations. Passing through an automated process at Heathrow may be different to Hong Kong. The infrastructure, information, environment and guidance given during the transaction will all greatly differ for the user. Furthermore, the individual components and subsequent processing will be evaluated using a different methodology too. This thesis reports on the contrasts between implementations, looking at solutions which utilise different biometric modalities and travel documents. Several models are devised to establish a process map which can be applied to all systems. Investigating further, a framework is described for a novel assessment method to evaluate the performance of a system. An RGB-D sensor is implemented, to track and locate the user within an interactive environment. By doing so, the user's interaction is assessed in real-time. Studies then report on the effectiveness of the solution within a replicated border control scenario. Several relationships are studied to improve the technologies used within the scenario. Successful implementation of the automated assessment method may improve the user's experience with systems, improving information and guidance, increasing the likelihood of successful interaction while maintaining a high level of security and quicker processing times.
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10

Bin, Safie Sairul Izwan. "Pulse domain novel feature extraction methods with application to ecg biometric authentication." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=17829.

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This thesis presents the concept of representing finite signals in terms of sequential output pulses called pulse domain to extract Electrocardiogram (ECG) features for biometric authentication systems. Two novel methods based on the pulse domain philosophy namely Pulse Active (PA) and Adaptive Pulse Active (APA) techniques are presented in this thesis. A total of 11 algorithms are derived from these two methods and used to generate novel ECG feature vectors. Six algorithms of the PA technique are named as Pulse Active Bit (PAB), Pulse Active Width (PAW), Pulse Active Area (PAA), Pulse Active Mean (PAM), Pulse Active Ratio (PAR) and Pulse Active Harmonic (PAH). Five APA algorithms are named as Adaptive Pulse Active Bit (APAB), Adaptive Pulse Active Width (APAW), Adaptive Pulse Active Area (APAA), Adaptive Pulse Active Mean (APAM) and Adaptive Pulse Active Harmonic (APAH). The proposed techniques are validated using ECG experimental data from 112 subjects. Simulation results indicate that APAW generates the best biometric performance of all 11 algorithms. Selected ranges of PA and APA parameters are determined in this thesis that generates approximate similar biometric performance. Using this suggested range, these parameters are than used as a personal identification number (PIN) which are a part of the proposed PA-APA ECG based multilevel security biometric authentication system.
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11

Silva, Ana Paula Tasquetto da. "BIOMETRIA CUTÂNEA COM FORMULAÇÕES SEMISSÓLIDAS CONTENDO NANOCÁPSULAS DE PALMITATO DE ASCORBILA." Universidade Franciscana, 2012. http://tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/201.

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Made available in DSpace on 2018-06-27T18:56:18Z (GMT). No. of bitstreams: 2 Ana Paula Tasquetto da Silva.pdf: 1732740 bytes, checksum: 47edd54cda91b699dcfb391a5d278658 (MD5) Ana Paula Tasquetto da Silva.pdf.jpg: 3416 bytes, checksum: 36b42ef9fce8470da16904c695c43fe1 (MD5) Previous issue date: 2012-03-29
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Aging is a natural occurring process in our body, resulting in a series of structural changes in our skin, such as transepidermal water loss, senile xerosis (dry skin) and hyperpigmentation disorders. Vitamin C is a powerful antioxidant and have ability to inhibit melanogenesis, and skin bleaching agent. However, his low stability is a serious limitation. Thus, ascorbyl palmitate (AP), lipid-soluble derivative, appears as a promising agent for incorporation in topical formulations. Thus, this study aim to develop, characterize and determine the physical-chemical stability of topical semisolid formulations containing nanocapsules of the ascorbyl palmitate, with the oily nucleus of the Rosehip oil. Associated to this, the safety of the active in vivo by non-invasive biophysical analysis was verified. Suspensions containing the PA associated to the nanocapsules (NCPA) and suspensions without the active (NCBC) were developed and characterized, and stability was evaluated for 90 days (25 °C ± 2 °C and 3 °C ± 2 °C). Inicially, the NCPA suspensions presented content equal to 82,95 %, pH 4,21, average particle diameter of 269,7 nm, polydispersity index of around 0,2 and zeta potential of -47,03 mV. After, the active in the free form (GPA) and associated to the nanocapsules (GNCPA) were incorporated in semi-solid basis of Carbopol® gel and stored, for 90 days, for stability studies, by determination of the pH, active content quantification, organoleptic characteristics determination, viscosity determination and spreadability. All formulations presented slightly acidic pH and a homogeneous aspect. We obtained a higher concentration of active GNCPA, suggesting that nanocapsules may exert a greater protection of the PA. However, in both formulations in different temperatures, after 90 days analysis a decrease was observed and the GNCPA remain with a higher concentration of PA. Regarding to the rheological behavior, independently of drug dispersion, all formulations showed a non-Newtonian character and pseudoplastic behavior together with an adequate spreadability during the analysis period. For the bioengineering skin measurements, twenty healthy volunteers were selected, and during 90 days, every week, were performed biometric skin tests including stratum corneum water content (hydration), pH, transepidermal water loss, color and erythema. According to the results observed in relation to the determination of skin hydration, there was pronounced reduction (24 %) of the values of the stratum corneum water content in the areas treated with GPA, while GNCPA obtained an increased in hydration (21 %). The skin pH values not change significant during the experiment for both formulations, and this values are into the satisfactory limits for the use in topical products. We observed an increase in transepidermal water loss for both gels, however, to the GPA, this increased was slightly larger (39 %). Thus, it was evident that the nanocapsules have a tendency to avoid the transepidermal water loss, favoring the skin hydration degree and maintain the integrity of the stratum corneum. In the results obtained for melanin content, there was a decrease in this parameter during the experiment for both formulations, being more pronounced in GNCPA (23 %). The GNCPA and GPA did not cause erythema, configuring security in the use of these formulations.
O envelhecimento é um processo que ocorre naturalmente em nosso organismo, resultando em uma série de mudanças estruturais em nossa pele, como a perda transepidérmica de água, aparecimento de xerose senil (pele seca) e distúrbios de hiperpigmentação. A vitamina C é um poderoso antioxidante e possui comprovada capacidade de inibição da melanogênese, torna-se um agente clareador cutâneo. Entretanto, sua baixa estabilidade é uma séria limitação. Assim, o palmitato de ascorbila (PA), seu derivado lipossolúvel, surge como um promissor agente para incorporação em formulações tópicas. Desta forma, o presente trabalho teve como objetivo desenvolver, caracterizar e determinar a estabilidade físico-química de formulações tópicas semissólidas contendo nanocápsulas de palmitato de ascorbila, tendo como núcleo oleoso o óleo de rosa mosqueta. Associado a isso, foi verificada a segurança do ativo in vivo, através de ensaios de biometria cutânea. Foram desenvolvidas e caracterizadas suspensões contendo PA associado à nanocápsulas (NCPA) e uma suspensão de nanocápsulas sem o ativo (NCBC), sendo que a estabilidade foi avaliada durante 90 dias (25 ºC ± 2 ºC e 3 ºC ± 2 ºC). As suspensões de NCPA apresentaram inicialmente um teor de 82,95 %, pH 4,21, diâmetro de partícula de 269,7 nm, índice de polidispersão em torno de 0,2 e potencial zeta de -47,03 mV. Posteriormente, foram incorporados em bases semissólidas de gel de Carbopol® o ativo na forma livre (GPA) e associado à nanocápsulas (GNCPA), sendo armazenados, por 90 dias, para estudo de estabilidade, através das determinações de pH, quantificação do teor de ativo, determinação das características organolépticas, determinação da viscosidade e espalhabilidade. Todas as formulações apresentaram inicialmente um pH levemente ácido e um aspecto homogêneo. Obteve-se uma maior concentração de ativo no GNCPA, sugerindo que as nanocápsulas possam estar exercendo uma maior proteção do PA. Contudo, foi possível observar uma diminuição em ambas as formulações, nas diferentes temperaturas, após 90 dias de análise; sendo que, ao final deste período, o GNCPA permaneceu com uma maior concentração de PA. Quanto aos aspectos reológicos, independente da forma de dispersão do fármaco, as formulações apresentaram um caráter não-newtoniano e comportamento pseudoplástico, e uma espalhabilidade adequada durante todo o período de análise. Para o ensaio de biometria cutânea, foram selecionados vinte voluntários saudáveis, sendo que a cada semana foram realizados testes de avaliação do conteúdo aquoso do estrato córneo (hidratação), pH, perda transepidérmica de água, melanina e eritema, durante 90 dias. De acordo com os resultados observados com relação à determinação da hidratação cutânea, observou-se uma redução mais pronunciada (24 %) dos valores do conteúdo aquoso do estrato córneo nas regiões tratadas com GPA, enquanto que com o GNCPA obteve-se um aumento na hidratação (21 %). Os valores de pH cutâneo não sofreram alterações significativas durante o experimento para ambas formulações, sendo que estes valores encontram-se dentro dos limites considerados satisfatórios para o uso de produtos tópicos. Foi observado um aumento na perda transepidérmica de água para ambos os géis, entretanto, para o GPA este aumento foi um pouco maior (39 %). Desta forma, evidenciou-se que as nanocápsulas apresentam uma tendência para evitar a perda transepidérmica de água, o que favorece o grau de hidratação cutânea e mantêm a integridade do estrato córneo. Nos resultados obtidos para conteúdo de melanina, verificou-se uma redução deste parâmetro no decorrer do experimento para ambas as formulações, sendo mais pronunciado no GNCPA (23 %). Os GNCPA e GPA não causaram eritema, configurando a segurança na utilização destes produtos.
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Johnson, Amos Y. Jr. "A method for human identification using static, activity-specific parameters." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/15793.

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Blommé, Johan. "Evaluation of biometric security systems against artificial fingers." Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1145.

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Verification of users’ identities are normally carried out via PIN-codes or ID- cards. Biometric identification, identification of unique body features, offers an alternative solution to these methods.

Fingerprint scanning is the most common biometric identification method used today. It uses a simple and quick method of identification and has therefore been favored instead of other biometric identification methods such as retina scan or signature verification.

In this report biometric security systems have been evaluated based on fingerprint scanners. The evaluation method focuses on copies of real fingers, artificial fingers, as intrusion method but it also mentions currently used algorithms for identification and strengths and weaknesses in hardware solutions used.

The artificial fingers used in the evaluation were made of gelatin, as it resembles the surface of human skin in ways of moisture, electric resistance and texture. Artificial fingers were based on ten subjects whose real fingers and artificial counterpart were tested on three different fingerprint scanners. All scanners tested accepted artificial fingers as substitutes for real fingers. Results varied between users and scanners but the artificial fingers were accepted between about one forth and half of the times.

Techniques used in image enhancement, minutiae analysis and pattern matching are analyzed. Normalization, binarization, quality markup and low pass filtering are described within image enhancement. In minutiae analysis connectivity numbers, point identification and skeletonization (thinning algorithms) are analyzed. Within pattern matching, direction field analysis and principal component analysis are described. Finally combinations of both minutiae analysis and pattern matching, hybrid models, are mentioned.

Based on experiments made and analysis of used techniques a recommendation for future use and development of fingerprint scanners is made.

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Nelson, Jonas. "Methods for Locating Distinct Features in Fingerprint Images." Thesis, Linköping University, Department of Science and Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1147.

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With the advance of the modern information society, the importance of reliable identity authentication has increased dramatically. Using biometrics as a means for verifying the identity of a person increases both the security and the convenience of the systems. By using yourself to verify your identity such risks as lost keys and misplaced passwords are removed and by virtue of this, convenience is also increased. The most mature and well-developed biometric technique is fingerprint recognition. Fingerprints are unique for each individual and they do not change over time, which is very desirable in this application. There are multitudes of approaches to fingerprint recognition, most of which work by identifying so called minutiae and match fingerprints based on these.

In this diploma work, two alternative methods for locating distinct features in fingerprint images have been evaluated. The Template Correlation Method is based on the correlation between the image and templates created to approximate the homogenous ridge/valley areas in the fingerprint. The high-dimension of the feature vectors from correlation is reduced through principal component analysis. By visualising the dimension reduced data by ordinary plotting and observing the result classification is performed by locating anomalies in feature space, where distinct features are located away from the non-distinct.

The Circular Sampling Method works by sampling in concentric circles around selected points in the image and evaluating the frequency content of the resulting functions. Each images used here contains 30400 pixels which leads to sampling in many points that are of no interest. By selecting the sampling points this number can be reduced. Two approaches to sampling points selection has been evaluated. The first restricts sampling to occur only along valley bottoms of the image, whereas the second uses orientation histograms to select regions where there is no single dominant direction as sampling positions. For each sampling position an intensity function is achieved by circular sampling and a frequency spectrum of this function is achieved through the Fast Fourier Transform. Applying criteria to the relationships of the frequency components classifies each sampling location as either distinct or non-distinct.

Using a cyclic approach to evaluate the methods and their potential makes selection at various stages possible. Only the Circular Sampling Method survived the first cycle, and therefore all tests from that point on are performed on thismethod alone. Two main errors arise from the tests, where the most prominent being the number of spurious points located by the method. The second, which is equally serious but not as common, is when the method misclassifies visually distinct features as non-distinct. Regardless of the problems, these tests indicate that the method holds potential but that it needs to be subject to further testing and optimisation. These tests should focus on the three main properties of the method: noise sensitivity, radial dependency and translation sensitivity.

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15

Farias, Gabriela D'avila. "FORMULAÇÕES SEMISSÓLIDAS CONTENDO NANOCÁPSULAS DE ADAPALENO: DETERMINAÇÃO DA ESTABILIDADE, AVALIAÇÃO DA LIBERAÇÃO IN VITRO E ENSAIOS UTILIZANDO BIOMETRIA CUTÂNEA." Universidade Franciscana, 2011. http://tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/260.

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Acne vulgaris is a genetic hormone disease, located in the hair follicle. Adapalene a third-generation retinoid, and it is a topical alternative for acne treatment, but may have some adverse effects, irritation and dryness of the skin are the most common. Due to this, and knowing the nanocarriers potential, the object of this study was determine the physicochemical stability of semisolid formulations containing adapalene-loaded nanocapsules (NC) incorporated in Aristoflex AVL®, evaluate the release profiles in semisolid formulations containing nanocapsules containing adapalene incorporated in Carbopol 940® and verify the safety of the formulation in vivo by noninvasive biophysical analysis. For the determination of the stability, samples were subjected to freeze-thaw cycle, completing a cycle of 21 days. The in vitro release studies were performed comparing the drug-loaded NC (GCNCA) with the gel containing adapalene in its free form (GCA). For the skin bioengineer techniques, twenty healthy volunteers were selected. Each week were performed biometric skin tests including stratum corneum water content (hydration), pH, color, erythema and transepidermal water loss for 63 days. In stability studies, we observed that the average particle size, polydispersity and zeta potential of cream gel containing NC without adapalene (CGNC) and cream gel containing adapaleneloaded NC (CGNCA) showed no change after being subjected to the freeze-thaw cycle. Semisolid formulations showed non-Newtonian flow and pseudoplastic behavior during the study period. The initial adapalene content in CGNCA did not change compared with the result obtained at the end of the experiment. However, for the cream gel containing free adapalene (CGA), there was a reduction in the drug concentration, whereas the initial content decreased to below 90% after 21 days of analysis. According to release studies, we can observe that the GCNCA showed total concentration and release rate less than the GCA, which demonstrates the ability of nanoparticles to control the drug release. According to the results observed for the non-invasive method in relation to the determination of melanin content, there was a decrease in this parameter during the experiment for both formulations. The GCNCA did not cause erythema, configuring security in the use of the formulation. However, the GCA increased the index of erythema of the skin of volunteers. We observed an increase in transepidermal water loss to the GCA while in GCNCA there is a reduction of this parameter. The results obtained for skin hydration, there was a more pronounced reduction of the values of the stratum corneum water content in the treated areas with GCA. Thus, it was evident that the polymeric nanocapsules are able to decrease transepidermal water loss, favoring the skin hydration degree and keeping the stratum corneum integrity.
A acne vulgar é uma doença genética hormonal, de localização pilo-sebácea. O adapaleno, retinóide de terceira geração, é uma alternativa tópica para o tratamento da acne, podendo apresentar alguns efeitos indesejáveis, sendo a irritação e o ressecamento da pele os mais comuns. Em vista disso, e conhecendo as potencialidades dos nanocarreadores, o presente trabalho tem como objetivo determinar a estabilidade físico-química de formulações semissólidas contendo adapaleno nanoestruturado incorporado em Aristoflex AVL®, avaliar os perfis de liberação em formulações semissólidas contendo nanocápsulas (NC) de adapaleno incorporadas em Carbopol 940® e verificar a segurança do fármaco nanoencapsulado in vivo, através de análises biofísicas não invasivas. Para a determinação da estabilidade as amostras foram submetidas ao ciclo gelo-degelo, completando-se um ciclo de 21 dias. Os estudos de liberação in vitro foram realizados comparando-se as formulações contendo nanocápsulas de adapaleno (GCNCA) com o gel contendo o fármaco na forma livre (GCA). Para o ensaio utilizando biometria cutânea, foram selecionados vinte voluntários saudáveis. A cada semana foram realizados testes de bioengenharia cutânea, incluindo avaliação do conteúdo aquoso do estrato córneo (hidratação), pH, coloração, eritema e perda transepidérmica de água durante 63 dias. Nos estudos de estabilidade, observou-se que o diâmetro médio das partículas, índice de polidispersão e potencial zeta do creme gel contendo NC sem adapaleno (CGNC) e do creme gel contendo NC de adapaleno (CGNCA) não apresentaram alterações após serem submetidos ao ciclo gelodegelo. As formulações semissólidas independente da forma de dispersão do fármaco apresentaram fluxo não-newtoniano e comportamento pseudoplástico durante todo o período de análise. O teor inicial de adapaleno no CGNCA não sofreu alteração, quando comparado com o teor obtido no término do experimento. Entretanto, para o creme gel contendo adapaleno livre (CGA) houve uma redução na concentração de adapaleno, visto que o teor inicial decaiu para valores abaixo de 90% após 21 dias de análise. Com relação aos estudos de liberação, pode-se observar que o GCNCA apresentou concentração total e taxa de liberação menor do que o GCA, o que demonstra a capacidade das nanopartículas em controlar a liberação do fármaco. De acordo com os resultados observados para o ensaio de bioengenharia cutânea, com relação à determinação do conteúdo de melanina, verificouse uma redução deste parâmetro no decorrer do experimento para ambas as formulações. O GCNCA não causou eritema, configurando a segurança na utilização da formulação. Entretanto, o GCA aumentou, de maneira estatisticamente significativa, o índice de eritema da pele dos voluntários. Foi observado um aumento na perda transepidérmica de água para o GCA enquanto no GCNCA observa-se uma redução deste parâmetro. Nos resultados obtidos para hidratação cutânea, observou-se uma redução mais pronunciada dos valores do conteúdo aquoso do estrato córneo nas regiões tratadas com GCA. Desta forma, evidenciou-se que as nanocápsulas poliméricas são capazes de diminuir a perda transepidérmica de água, favorecendo o grau de hidratação cutânea e mantendo a integridade do estrato córneo.
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16

Farias, Gabriela D'Avila. "FORMULAÇÕES SEMISSÓLIDAS CONTENDO NANOCÁPSULAS DE ADAPALENO: DETERMINAÇÃO DA ESTABILIDADE, AVALIAÇÃO DA LIBERAÇÃO IN VITRO E ENSAIOS UTILIZANDO BIOMETRIA CUTÂNEA." Centro Universitário Franciscano, 2011. http://www.tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/495.

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Acne vulgaris is a genetic hormone disease, located in the hair follicle. Adapalene a third-generation retinoid, and it is a topical alternative for acne treatment, but may have some adverse effects, irritation and dryness of the skin are the most common. Due to this, and knowing the nanocarriers potential, the object of this study was determine the physicochemical stability of semisolid formulations containing adapalene-loaded nanocapsules (NC) incorporated in Aristoflex AVL®, evaluate the release profiles in semisolid formulations containing nanocapsules containing adapalene incorporated in Carbopol 940® and verify the safety of the formulation in vivo by noninvasive biophysical analysis. For the determination of the stability, samples were subjected to freeze-thaw cycle, completing a cycle of 21 days. The in vitro release studies were performed comparing the drug-loaded NC (GCNCA) with the gel containing adapalene in its free form (GCA). For the skin bioengineer techniques, twenty healthy volunteers were selected. Each week were performed biometric skin tests including stratum corneum water content (hydration), pH, color, erythema and transepidermal water loss for 63 days. In stability studies, we observed that the average particle size, polydispersity and zeta potential of cream gel containing NC without adapalene (CGNC) and cream gel containing adapaleneloaded NC (CGNCA) showed no change after being subjected to the freeze-thaw cycle. Semisolid formulations showed non-Newtonian flow and pseudoplastic behavior during the study period. The initial adapalene content in CGNCA did not change compared with the result obtained at the end of the experiment. However, for the cream gel containing free adapalene (CGA), there was a reduction in the drug concentration, whereas the initial content decreased to below 90% after 21 days of analysis. According to release studies, we can observe that the GCNCA showed total concentration and release rate less than the GCA, which demonstrates the ability of nanoparticles to control the drug release. According to the results observed for the non-invasive method in relation to the determination of melanin content, there was a decrease in this parameter during the experiment for both formulations. The GCNCA did not cause erythema, configuring security in the use of the formulation. However, the GCA increased the index of erythema of the skin of volunteers. We observed an increase in transepidermal water loss to the GCA while in GCNCA there is a reduction of this parameter. The results obtained for skin hydration, there was a more pronounced reduction of the values of the stratum corneum water content in the treated areas with GCA. Thus, it was evident that the polymeric nanocapsules are able to decrease transepidermal water loss, favoring the skin hydration degree and keeping the stratum corneum integrity.
A acne vulgar é uma doença genética hormonal, de localização pilo-sebácea. O adapaleno, retinóide de terceira geração, é uma alternativa tópica para o tratamento da acne, podendo apresentar alguns efeitos indesejáveis, sendo a irritação e o ressecamento da pele os mais comuns. Em vista disso, e conhecendo as potencialidades dos nanocarreadores, o presente trabalho tem como objetivo determinar a estabilidade físico-química de formulações semissólidas contendo adapaleno nanoestruturado incorporado em Aristoflex AVL®, avaliar os perfis de liberação em formulações semissólidas contendo nanocápsulas (NC) de adapaleno incorporadas em Carbopol 940® e verificar a segurança do fármaco nanoencapsulado in vivo, através de análises biofísicas não invasivas. Para a determinação da estabilidade as amostras foram submetidas ao ciclo gelo-degelo, completando-se um ciclo de 21 dias. Os estudos de liberação in vitro foram realizados comparando-se as formulações contendo nanocápsulas de adapaleno (GCNCA) com o gel contendo o fármaco na forma livre (GCA). Para o ensaio utilizando biometria cutânea, foram selecionados vinte voluntários saudáveis. A cada semana foram realizados testes de bioengenharia cutânea, incluindo avaliação do conteúdo aquoso do estrato córneo (hidratação), pH, coloração, eritema e perda transepidérmica de água durante 63 dias. Nos estudos de estabilidade, observou-se que o diâmetro médio das partículas, índice de polidispersão e potencial zeta do creme gel contendo NC sem adapaleno (CGNC) e do creme gel contendo NC de adapaleno (CGNCA) não apresentaram alterações após serem submetidos ao ciclo gelodegelo. As formulações semissólidas independente da forma de dispersão do fármaco apresentaram fluxo não-newtoniano e comportamento pseudoplástico durante todo o período de análise. O teor inicial de adapaleno no CGNCA não sofreu alteração, quando comparado com o teor obtido no término do experimento. Entretanto, para o creme gel contendo adapaleno livre (CGA) houve uma redução na concentração de adapaleno, visto que o teor inicial decaiu para valores abaixo de 90% após 21 dias de análise. Com relação aos estudos de liberação, pode-se observar que o GCNCA apresentou concentração total e taxa de liberação menor do que o GCA, o que demonstra a capacidade das nanopartículas em controlar a liberação do fármaco. De acordo com os resultados observados para o ensaio de bioengenharia cutânea, com relação à determinação do conteúdo de melanina, verificouse uma redução deste parâmetro no decorrer do experimento para ambas as formulações. O GCNCA não causou eritema, configurando a segurança na utilização da formulação. Entretanto, o GCA aumentou, de maneira estatisticamente significativa, o índice de eritema da pele dos voluntários. Foi observado um aumento na perda transepidérmica de água para o GCA enquanto no GCNCA observa-se uma redução deste parâmetro. Nos resultados obtidos para hidratação cutânea, observou-se uma redução mais pronunciada dos valores do conteúdo aquoso do estrato córneo nas regiões tratadas com GCA. Desta forma, evidenciou-se que as nanocápsulas poliméricas são capazes de diminuir a perda transepidérmica de água, favorecendo o grau de hidratação cutânea e mantendo a integridade do estrato córneo.
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17

Pinto, Allan da Silva 1984. "A countermeasure method for video-based face spoofing attacks : Detecção de tentativas de ataque com vídeos digitais em sistemas de biometria de face." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275616.

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Orientador: Anderson de Rezende Rocha
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação
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Abstract: The complete abstract is available with the full electronic document
Mestrado
Ciência da Computação
Mestre em Ciência da Computação
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18

Alejo, Willy, Daniel Rodriguez, Guillermo Kemper, and Universidad Peruana de Ciencias Aplicadas (UPC). "A biometric method based on the matching of dilated and skeletonized IR images of the veins map of the dorsum of the hand." IEEE, 2015. http://hdl.handle.net/10757/556175.

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Article
This work proposes a biometric identification system that works together with a palm vein reader sensor and a hand-clenching support, designed to perform the capture the back of the hand. Several processing steps were performed: extraction of the region of interest, binarization, dilation, noise filtering, skeletonization, as well as extraction and verification of patterns based on the measurment of coincidence of vertical and horizontal displacements of skeletonized and dilated images. The proposed method achieved the following results: processing time post capture of 1.8 seconds, FRR of 0.47% and FAR of 0,00%, with a referential database of 50 people from a total of 1500 random captures.
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19

Gustavsson, Linnéa. "Ansiktsrekonstruktion : Mannen från den medeltida kyrkoruinen S:t Hans, Visby." Thesis, Uppsala universitet, Arkeologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-386062.

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Facial reconstructions, like archaeology, consists of many layers that one must get through to understand the whole picture. The development of the methods that reconstructions rely on, occurred during the 20th century. By focusing on the various elements such as studies of tissue depth, chemical processes (DNA and isotope analysis), solid craftsmanship and the development of computer technology, researchers around the world have been able to build a method that can give us an extended understanding of history. However, a lot of opinions have risen for the subject, people begin to question it ́s accuracy and what the real purpose really is. Besides the reliability of facial reconstruction, the experience of how a facial reconstruction is perceived by another person is equally important, the ethical principles have been brought up to discussion because it involves human remains. Discussions may occur during cases when facial reconstructions are inevitable, one example could be with minority groups that have a different view on how a body should be handled and treated after death. These scenarios are more likely to develop in the identification in forensic contexts, but the problem may also increase in archaeological contexts if the remains are from more recent times and the individuals as a population group has suffered repression. Therefore, this paper aims to discuss such questions but also embark on a mission to perform a facial reconstruction of an individual from the medieval church of St. Hans and the challenges that may occur during the way. The American method used in this essay shows that you can get a good result by following the instructions and guidelines that are displayed in various books and articles.
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20

Melin, Håkan. "Automatic speaker verification on site and by telephone: methods, applications and assessment." Doctoral thesis, KTH, Tal, musik och hörsel, TMH, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4242.

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Speaker verification is the biometric task of authenticating a claimed identity by means of analyzing a spoken sample of the claimant's voice. The present thesis deals with various topics related to automatic speaker verification (ASV) in the context of its commercial applications, characterized by co-operative users, user-friendly interfaces, and requirements for small amounts of enrollment and test data. A text-dependent system based on hidden Markov models (HMM) was developed and used to conduct experiments, including a comparison between visual and aural strategies for prompting claimants for randomized digit strings. It was found that aural prompts lead to more errors in spoken responses and that visually prompted utterances performed marginally better in ASV, given that enrollment data were visually prompted. High-resolution flooring techniques were proposed for variance estimation in the HMMs, but results showed no improvement over the standard method of using target-independent variances copied from a background model. These experiments were performed on Gandalf, a Swedish speaker verification telephone corpus with 86 client speakers. A complete on-site application (PER), a physical access control system securing a gate in a reverberant stairway, was implemented based on a combination of the HMM and a Gaussian mixture model based system. Users were authenticated by saying their proper name and a visually prompted, random sequence of digits after having enrolled by speaking ten utterances of the same type. An evaluation was conducted with 54 out of 56 clients who succeeded to enroll. Semi-dedicated impostor attempts were also collected. An equal error rate (EER) of 2.4% was found for this system based on a single attempt per session and after retraining the system on PER-specific development data. On parallel telephone data collected using a telephone version of PER, 3.5% EER was found with landline and around 5% with mobile telephones. Impostor attempts in this case were same-handset attempts. Results also indicate that the distribution of false reject and false accept rates over target speakers are well described by beta distributions. A state-of-the-art commercial system was also tested on PER data with similar performance as the baseline research system.
QC 20100910
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21

Holušová, Kateřina. "Standardizace a harmonizace znalecké metodiky pro potřeby Forenzní ekotechniky: les a dřeviny." Doctoral thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-234301.

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In the presented thesis is an overview of the current state solved the problem, specifying the inclusion of Forensic Ecotechnique: forest and trees into the forensic sciences in the world and its description as part of special methods of forensic engineering. The results focus on the design of standardized and harmonized processes according to the type of expert opinions. As another of the key results of the work are designed functional biometric parameters for evaluating trees in the functional diagnosis of Methods of contact flora assessment (“CFA”). Application of some methods of measurement and selected functional biometric parameters are listed in the examples in the measurement of selected forest stands of beech in the National Nature Reserve Voděradské bučiny and in Chřiby hills. As a general supplement usable in Forensic ecotechnique: forest and trees are given the limits for functional diagnostics. In another series of work includes a discussion on the proposed standards and the measurement results. The work is concluded by summarizing the results and the benefits.
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22

Marnell, Joseph. "An Empirical Investigation of Factors Affecting Resistance to Using Multi-Method Authentication Systems in Public-Access Environments." NSUWorks, 2016. http://nsuworks.nova.edu/gscis_etd/970.

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Over the course of history, different means of object and person identification as well as verification have evolved for user authentication. In recent years, a new concern has emerged regarding the accuracy of verifiable authentication and protection of personal identifying information (PII), because previous misuses have resulted in significant financial loss. Such losses have escalated more noticeably because of human identity-theft incidents due to breaches of PII within multiple public-access environments. Although the use of various biometric and radio frequency identification (RFID) technologies is expanding, resistance to using these technologies for user authentication remains an issue. This study addressed the effect of individuals’ perceptions on their resistance to using multi-method authentication systems (RMS) in public-access environments and uncovered key constructs that may significantly contribute to such resistance. This study was a predictive study to assess the contributions of individuals’ perceptions of the importance of organizational protection of their PII, noted as Perceived Value of Organizational Protection of PII (PVOP), authentication complexity (AC), and invasion of privacy (IOP) on their resistance to using multi-method authentication systems (RMS) in public-access environments. Moreover, this study also investigated if there were any significant differences on the aforementioned constructs based on age, gender, prior experience with identity theft, and acquaintance experience with identity theft. As part of this study, a rollout project was implemented of multi-factor biometric and RFID technologies for system authentication prior to electronic-commerce (e-commerce) use in public-access environments. The experimental group experienced the multi-factor authentication and also was trained on its use. Computer users (faculty & students) from a small, private university participated in the study to determine their level of PVOP, IOP, and AC on their resistance to using the technology in public-access environments. Multiple Linear Regression (MLR) was used to formulate a model and test predictive power along with the significance of the contribution of the aforementioned constructs on RMS. The results show that all construct measures demonstrated very high reliability. The results also indicate that the experimental group of the multi-factor authentication had lower resistance than the control group that didn’t use the technology. The mean increases indicate an overall statistically significant difference between the experimental and control groups overall. The results also demonstrate that students and participants’ increased levels of education indicate an overall statistically significant decrease in resistance. The findings demonstrate that overall computer authentication training do provide added value in the context of measuring resistance to using newer multi-method authentication technology.
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23

Soldera, John. "Reconhecimento facial com projeções ortogonais preservadoras de localidade customizadas para maximizar margens suaves." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/131030.

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Atualmente, o reconhecimento facial por técnicas automáticas é ainda uma tarefa desafiadora uma vez que as imagens faciais podem ser afetadas por mudanças na cena, tais como na iluminação, na pose da cabeça, ou na expressão facial. Além disso, a representação de faces por feições faciais geralmente requer diversas dimensões, o que impõe desafios adicionais ao reconhecimento facial. Nessa tese, é proposto um novo método de reconhecimento facial com o objetivo de ser robusto a muitos dos fatores que podem afetar as feições faciais na prática e se baseia em determinar transformações do espaço original de feições faciais de alta dimensionalidade para um espaço de baixa dimensionalidade que apresenta maior discriminação das classes de dados faciais (indivíduos). Isso é realizado através da aplicação de um método Projeções Ortogonais Preservadoras de Localidade (Orthogonal Locality Preserving Projections - OLPP) modificado, que usa esquemas de definição de localidade supervisionados que têm o objetivo de preservar a estrutura das classes de dados faciais no espaço resultante de baixa dimensionalidade, diferentemente do método OLPP típico que preserva a estrutura dos dados faciais. Dessa forma, as classes se tornam mais compactas, preservando a métrica de classificação. O método proposto pode trabalhar tanto com representações densas como esparsas de imagens faciais (ou seja, ele pode usar subconjuntos ou todos os pixels das imagens faciais), sendo proposto nessa tese um método de extração de feições faciais esparsas e um método de extração de feições faciais densas que preservam a informação de cor das imagens faciais apresentando melhora em relação ao método OLPP típico que usa imagens em escalas de cinza em baixa resolução. Novas imagens faciais de teste são classificadas no espaço de baixa dimensionalidade obtido usando Máquinas de Vetores de Suporte (Support Vector Machines - SVM) treinadas com margens suaves, apresentando maior eficiência do que a regra do vizinho mais próximo usada no método OLPP típico. Um conjunto de experimentos foi projetado para avaliar o método proposto sob várias condições encontradas na prática (como mudanças na pose, expressão facial, iluminação e a presença de artefatos que causam oclusão facial). Os resultados experimentais foram obtidos usando cinco bases de imagens faciais públicas (a PUT, a FEI, a FERET, a Yale e a ORL). Esses experimentos confirmam que os esquemas propostos de extração de feições faciais integrados à transformação proposta para um espaço discriminativo de baixa dimensionalidade empregando o esquema alternativo de classificação usando SVM com margens suaves obtêm maiores taxas de reconhecimento do que o próprio método OLPP e métodos representativos do estado da arte mesmo quando são usadas imagens coloridas em alta resolução (das bases de imagens faciais PUT, FEI e FERET) como imagens faciais em escalas de cinza em baixa resolução (das bases Yale e ORL).
Nowadays, face recognition by automatic techniques still is a challenging task since face images may be affected by changes in the scene, such as in the illumination, head pose or face expression. Also, face feature representation often requires several dimensions, which poses additional challenges for face recognition. In this thesis is proposed a novel face recognition method with the objective of to be robust to many issues which can affect the face features in practice and it is based on projections of high dimensional face image representations into lower dimensionality and highly discriminative spaces. This is achieved by a modified Orthogonal Locality Preserving Projections (OLPP) method that uses a supervised alternative locality definition scheme designed to preserve the face class (individuals) structure in the obtained lower dimensionality face feature space unlike the typical OLPP method which preserves the face data structure. Besides, a new kernel equation is proposed to calculate affinities among face samples, presenting better class structure preservation when compared to the heat kernel used by the typical OLPP method. The proposed method can work with sparse and dense face image representations (i.e. it can use sub-sets or all face image pixels), and a sparse and a dense feature extraction methods are proposed, which preserve the color information during the feature extraction process from the facial images improving on the typical OLPP method which uses grayscale low-resolution face images. New test face images are classified in the obtained lower dimensionality feature space using a trained soft margins Support Vector Machine (SVM), so it performs better than the nearest neighbor rule used in the typical OLPP method. A set of experiments was designed to evaluate the proposed method under various conditions found in practice (such as changes in head pose, face expression, illumination, and in the presence of occlusion artifacts). The experimental results were obtained using five challenging public face databases (namely, PUT, FEI, FERET, Yale and ORL). These experiments confirm that the proposed feature extraction method integrated to the proposed transformation to a discriminative lower dimensionality space using the alternative classification scheme with SVM and soft margins obtains higher recognition rates than the OLPP method itself and methods representative of the state-ofthe- art even when are used color (RGB) face images in high resolution (PUT, FEI and FERET face databases) as well as grayscale face images in low resolution (Yale and ORL face databases).
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24

Silva, Heyder Diniz. "Aspectos biométricos da detecção de QTL'S ("Quantitative Trait Loci") em espécies cultivadas." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/11/11134/tde-18102002-162652/.

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O mapeamento de QTL's difere dos demais tipos de pesquisas conduzida em genética. Por se tratar basicamente de um procedimento de testes múltiplos, surge, neste contexto, um problema que se refere ao nível de significância conjunto da análise, e consequentemente, seu poder. Deste modo, avaliou-se, via simulação computacional de dados, o poder de detecção de QTL's da análise de marcas simples, realizada por meio de regressão linear múltipla, utilizando o procedimento stepwise" para seleção das marcas e procedimentos baseados em testes individuais, utilizando os critérios FDR e de Bonferroni para determinação nível de significância conjunto. Os resultados mostraram que o procedimento baseado em regressão múltipla, utilizando o procedimento stepwise" foi mais poderoso em identificar as marcas associadas a QTL's e, mesmo nos casos em que este procedimento apresentou poder ligeiramente inferior aos demais, verificou-se que o mesmo tem como grande vantagem selecionar apenas as marcas mais fortemente ligadas aos QTL's. Dentre os critérios FDR e de Bonferroni, o primeiro mostrou-se, em geral, mais poderoso, devendo ser adotado nos procedimentos de mapeamento por intervalo. Outro problema encontrado na análise de QTL's refere-se µa abordagem da interação QTL's x ambientes. Neste contexto, apresentou-se uma partição da variância da interação genótipos x ambientes em efeitos explicados pelos marcadores e desvios, a partir da qual obtiveram-se os estimadores da proporção da variância genética (pm), e da variância da interação genótipos x ambientes (pms), explicadas pelos marcadores moleculares. Estes estimadores independem de desvios das frequências alélicas dos marcadores em relação µ as esperadas (1:2:1 em uma geração F2, 1:1 em um retrocruzamento, etc.), porém, apresentam uma alta probabilidade de obtenção de estimativas fora do intervalo paramétrico, principalmente para valores elevados destas proporções. Contudo, estas probabilidades podem ser reduzidas com o aumento do número de repetições e/ou de ambientes nos quais as progênies são avaliadas. A partir de um conjunto de dados de produtividade de grãos, referentes µ a avaliação de 68 progênies de milho, genotipadas para 77 marcadores moleculares codominantes e avaliadas em quatro ambientes, verificou-se que as metodologias apresentadas permitiram estimar as proporções pm e pms, bem como classificar as marcas associadas a QTL's, conforme seu nível de interação. O procedimento permitiu ainda a identificação de regiões cromossômicas envolvidas no controle genético do caractere sob estudo conforme sua maior ou menor estabilidade ao longo dos ambientes.
In general terms, QTL mapping di®ers from other research ac-tivities in genetics. Being basically a multiple test procedure, problems arise which are related to the joint level of signi¯cance of the analysis, and consequently, to its power. Using computational simulation of data, the power of simple marker analysis, carried out through multiple linear regression, using stepwise procedures to select the markers was obtained. Procedures based on single tests, using both the FDR and the Bonferroni criteria to determinate the joint level of signi¯cance were also used. Results showed that the procedure based on multiple regression, using the stepwise technique, was the most powerful in identifying markers associated to QTL's. However, in cases where its power was smaller, its advantage was the ability to detect only markers strongly associates with QTL's. In comparision with the Bonferroni method, the FDR criterion was in general more powerful, and should be adopted in the interval mapping procedures. Additional problems found in the QTL analysis refer to the QTL x environment interaction. We consider this aspect by par-titioning the genotype x environment interaction variance in components explained by the molecular markers and deviations. This alowed estimating the proportion of the genetic variance (pm), and genotype x environment variance (pms), explained by the markers. These estimators are not a®ected by deviations of allelic frequencies of the markers in relation to the expected values (1:2:1 in a F2 generation, 1:1 in a backcross , etc). However, there is a high probability of obtaining estimates out of the parametric range, specially for high values of this proportion. Nevertheless, these probabilities can be reduced by increasing the number of replications and/or environments where the progenies are evaluated. Based on a set of grain yield data, obtained from the evaluation of 68 maize progenies genotyped for 77 codominant molecular markers, and evaluated as top crosses in four environments, the presented methodologies allowed estimating proportions pm and pms as well the classification of markers associated to QTL's, with respect to its level of genotype x environment interaction. The procedure also allowed the identification of chromosomic regions, involved in the genetical control of the considered trait, according to its stability, in relation to the observed environmental variation.
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25

Chada, Kinnera. "COMPUTATIONAL ANALYSES OF THE UPTAKE AND DISTRIBUTION OF CARBON MONOXIDE (CO) IN HUMAN SUBJECTS." UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_diss/224.

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Carbon monoxide (CO) is an odorless, colorless, tasteless gas that binds to hemoglobin with high affinity. This property underlies the use of low doses of CO to determine hemoglobin mass (MHb) in the fields of clinical and sports medicine. However, hemoglobin bound to CO is unable to transport oxygen and exposure to high CO concentrations is a significant environmental and occupational health concern. These contrasting aspects of CO—clinically useful in low doses but potentially lethal in higher doses—mandates a need for a quantitative understanding of the temporal profiles of the uptake and distribution of CO in the human body. In this dissertation I have (i) used a mathematical model to analyze CO-rebreathing techniques used to estimate total hemoglobin mass and proposed a CO-rebreathing procedure to estimate hemoglobin mass with low errors, (ii) enhanced and validated a multicompartment model to estimate O2, CO and CO2 tensions, bicarbonate levels, pH levels, blood carboxyhemoglobin (HbCO) levels, and carboxymyoglobin (MbCO) levels in all the vascular (arterial, mixed venous and vascular subcompartments of the tissues) and tissue (brain, heart and skeletal muscle) compartments of the model in normoxia, hypoxia, CO hypoxia, hyperoxia, isocapnic hyperoxia and hyperbaric oxygen, and (iii) used this developed mathematical model to propose a treatment to improve O2 delivery and CO removal by comparing O2 and CO levels during different treatment protocols administered for otherwise-healthy CO-poisoned subjects.
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26

Laranja, Danitiele Cristina França. "Estudo de parâmetros populacionais de plantios clonais de Eucalyptus spp. a partir de nuvens de pontos obtidos com escaneamento a laser aerotransportado." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-09082016-165442/.

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As florestas plantadas contribuem para o desenvolvimento econômico, social e ambiental brasileiro, e o setor florestal busca plantios cada vez mais produtivos e melhor aproveitados. A tecnologia a laser aerotransportada (ALS - Airborne Laser Scanning), capaz de gerar informações tridimensionais precisas em extensas áreas e em pequeno intervalo de tempo, tem se destacado nas aplicações florestais, sendo utilizada na quantificação e caracterização de florestas. Neste estudo foram utilizados dados ALS obtidos em dois sobrevoos (2013 e 2014), cobrindo uma área de plantio do gênero Eucalyptus com diferentes clones e idades, localizada no estado de São Paulo. Esta dissertação é dividida em três partes. A primeira buscou avaliar a combinação de métricas ALS e de dupla amostragem nas estimativas de volume e na redução da intensidade amostral, comparando seus resultados aos de métodos amostrais tradicionais. Os resultados mostraram que a dupla amostragem obteve o menor erro de amostragem dentre os delineamentos, permitindo a redução do esforço amostral. A segunda parte visou caracterizar as diferenças estruturais existentes entre clones de eucalipto, com diferentes idades, a partir de métricas ALS e perfis de altura do dossel (CHP). O estudo mostrou que é possível distinguir a estrutura do dossel dos clones, o que pode contribuir com melhorias nas estimativas e no gerenciamento dos plantios comerciais. Na última parte, foram avaliados dois algoritmos de detecção de árvores individuais quanto à quantificação dos indivíduos e os efeitos da composição (tamanho de célula e filtragem) do modelo digital de alturas (CHM) no desempenho desses algoritmos. Verificou-se que as características do CHM influenciam na detecção. A estratégia com melhor desempenho resultou em um erro médio relativo de 11% no número de indivíduos.
Planted forests contribute to the economic, social and environmental development of Brazil, and the forest industry aims to increase productivity and the efficient use of these plantations. Airborne Laser Scanning (ALS) technology, capable of generating accurate three-dimensional information, covering large areas in a short time, has highlighted potential in forestry applications and has been applied in forests quantification and characterization. In this study, ALS data were obtained from two flights (2013 and 2014), covering a Eucalyptus plantation area with different clones and ages, in the state of São Paulo. This thesis comprises three parts. The first study aimed to evaluate the combination of ALS metrics and double sampling design for volume estimates and reducing sampling intensity, comparing the results to traditional sampling methods. Results showed that the double sampling had the lowest error from the designs, allowing the reduction of the sampling effort. The second part was proposed to characterize the structural differences between Eucalyptus clones with different ages, based on metrics ALS and canopy height profiles (CHP). The study showed that it is possible to distinguish the canopy structure of the clones, which can contribute to improvements in estimates and management of commercial plantations. In the last study, two individual tree detection algorithms were evaluated for quantification of individuals, and the effect of the canopy height model (CHM) composition at the performance of these algorithms was analyzed. It was found that the CHM characteristics influence the tree detection. The strategy with better performance resulted in an average relative error of 11% in number of trees.
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27

Girabent, i. Farrés Montserrat. "Aplicació dels models de Thrustone i de Bradely-Terry a l’anàlisi de dades “ranking” obtingudes de mesures de preferència en escala ipsativa." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/277566.

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La recerca va néixer de l’interès de mesurar les preferències dels individus quan se’ls demana que ordenin una llista d’opcions, ja siguin conductes o objectes, obtenint així dades rànquing. Això determina que l’individu està forçat a establir un ordre entre les seves preferències, donant lloc al que es coneix com a escala de mesura ipsativa ordinal. Aquest tipus de mesura té com a avantatge front a la d’escala normativa, com Likert, que disminueix la probabilitat del conegut problema d’ “acquiescense bias” i s’elimini l’efecte “halo and horn”. Per altre banda, la principal característica del vector de respostes es que la suma dels seus components serà sempre una mateixa constant i això dificulta l’anàlisi de les dades. El primer objectiu fou el de revisar els models estadístics per analitzar dades rànquing mesurades en escala ipsativa que donen informació sobre el procés discriminador. El segon fou estendre aquests quan es tenen mesures repetides de l’elecció dels individus respecte les seves preferències i/o quan es consideren covariables referents a característiques dels propis individus o de les alternatives a ordenar. La primera teoria que marca l’ús d’una escala ipsativa és la llei dels judicis comparatius de Thurstone (1927), on es postula que quan a un individu se li demana que emeti un judici es produeix un procés discriminador en el contínuum psicològic. És en aquesta escala continua no observada en la que rau el interès a fi de veure el perfil de preferències en termes d’ordre i distància entre les opcions. La metodologia avaluada per a trobar les solucions en escala d’interval continua, es va fonamentar en dues aproximacions. La primera, treballada per el grup de Böckenholt (1991-2006) es base en els models clàssics desenvolupats per Thurstone al 1931. En aquesta les observacions ordenades s’expressen com a diferències de les variables latents subjacents a cada un dels ítems de comparació. Així, imposant les restriccions proposades per Maydeu-Olivares (2005) a la matriu de covariàncies, s’obté un cas particular d’un model d’equacions estructural (SEM). Aquest permet estimar les mitjanes de les variables latents que correspondran a la posició de cada opció en l’escala continua d’interval. Si bé, la solució depèn de que es compleixi la condició de normalitat de les variables latents i l’algorisme no troba solució a partir de cert nombre d’opcions. A més el model no permet modelar situacions de mesures repetides. En la segona aproximació es troben els treballs del grup de Dittrich (1998-2012) basats en els models de Bradley-Terry (BTM) del 1952. Els BTM consideren que la distribució de cada un dels judicis aparellats segueix una llei Binomial. Així, treballant directament amb la taula de contingències, es pot expressar la funció de versemblança com un model log-lineal general (LLBTM). És a partir d’aquest segon model, i de les seves extensions per a covariables que proposem l’extensió pel cas de mesures repetides. Les diferents propostes metodològiques es van provar tant per dades simulades com en dos exemples reals de l’àmbit de l’educació en ciències de la salut. En un, s’estudien les preferències sobre l’estil d’aprenentatge (Test Canfield) d’estudiants de medicina i en l’altre es valora si l’opinió dels estudiants de fisioteràpia sobre les activitats d’autoaprenentatge és diferent abans i després de realitzar-les. Com a conclusions, • La diferència entre les aproximacions de Thurstone y Bradley-Terry rau en la distribució que segueix la funció de versemblança. • El model LLBTM permet incorporar modificacions a les condicions d’aplicació que donen lloc a cada una de les extensions del model que incorporen covariables. • El model LLBTM permet una extensió en la que la comparació entre les opcions no sigui independent donant lloc als models per a mesures repetides.
The research focus on measuring individual preferences when people are asked to sort a list of options, thus obtaining data ranking. This determines that the subject is forced to establish an order between their preferences, resulting in what is known as ordinal Ipsative measurement scale.The advantage of this type of measure over the normative measurement scale such as Likert, which reduces the likelihood of problems known as "acquiescence bias" and removed the effect "halo and horn". However, they statistical analysis is difficult because the vector-response sums always a constant.The objectives were to review the statistical models to analyze the preferences measured in Ipsative scale, to give information about the discriminating process and to extend these models when we had repeated measures and / or covariates.The law of comparative judgments (Thurstone, 1927) postulated that this process occurs in discriminatory psychological continuum. This continuum scale allows finding the distance between the options.The methodology evaluated based on two approaches. First, the working of Böckenholt group (1991-2006) based on classical models developed by Thurstone in 1931. They expressed the ranking data as differences in the latent variables underlying each of items for comparison. So imposing the Maydeu-Olivares (2005) restrictions on the covariance matrix, we obtain a special case of a structural equation model to estimate the means of the latent variables that correspond to the position each option in the continuous interval scale. While the answer depends on the Normality of the latent variables. In addition, the model not allows to have repeated measurements. The second approach is the work of the Dittrich group (1998-2012) based on Bradley-Terry model (1952), which assumes a binomial distribution of the pairs of comparison. Thus, the likelihood function expressed as a general log-linear model (LBTM). The extension we developed is from LBTM.The aim of first applied study was to known the learning style preferences of medical students. The purpose of the second study was assessed whether physiotherapy students' opinions about self-learning is different before and after perform them.Conclusions:• The difference between the approaches of Thurstone and Bradley-Terry lies in the likelihood function distribution.• The model BTM allows incorporate modifications to the application conditions that give rise the extensions incorporating covariates and consider repeated measures.
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28

Tayah, David. "Componentes oculares em anisometropia." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/5/5149/tde-10032008-153020/.

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Objetivo: Em anisométropes, comparar os valores médios individuais dos componentes oculares de ambos os olhos (poder da córnea, profundidade da câmara anterior, poder equivalente do cristalino e comprimento axial), correlacionar as diferenças dos componentes oculares com as diferenças de refração de ambos os olhos; verificar a contribuição total e a seqüência geral de influência das variáveis na diferença refrativa; e identificar o menor número de fatores que contenham o mesmo grau de informações expressas no conjunto de variáveis que influenciam na diferença refrativa. Métodos: Realizou-se um estudo transversal analítico em população de 77 anisométropes de duas ou mais dioptrias, atendida no ambulatório de Oftalmologia do Hospital Universitário da Faculdade de Medicina Nilton Lins, Manaus, Amazonas. Os anisométropes foram submetidos à refração estática objetiva e subjetiva, ceratometria e biometria ultra-sônica A-scan. A análise dos dados foi feita por meio dos seguintes modelos estatísticos: análise univariada, multivariada, de regressão múltipla e fatorial. Resultados: Não houve diferenças significativas na comparação dos valores médios individuais dos componentes oculares entre os olhos. Houve correlação negativa média entre a diferença refrativa e a diferença de comprimento axial (r=-0,64) (P<0,01) e correlação negativa fraca entre a diferença refrativa e a diferença de poder do cristalino (r=-0,34) (p<0,01). As variáveis analisadas responderam, no seu conjunto, por 78% da variação total para a diferença refrativa. A seqüência geral de influência das variáveis na diferença refrativa foi a seguinte: comprimento axial, poder do cristalino, poder da córnea e profundidade da câmara anterior. Foram identificados três fatores para a diferença refrativa: a) fator 1 (refração, comprimento axial); b) fator 2 (profundidade da câmera anterior, poder da córnea) e c) fator 3 (poder do cristalino). Conclusões: O estudo conduzido em 77 indivíduos com anisometropias variando de 2,00 a mais de 19,00 dioptrias, realizado para avaliar a influência dos componentes oculares, mostrou que o comprimento axial foi o principal fator causador das anisometropias, seguido pelo cristalino que contribuiu menos, depois pela córnea e profundidade da câmara anterior, com contribuições ainda menores. A investigação sugere falência no mecanismo adaptativo normal em anisometropia, o que poderia produzir não só descontrole do alongamento do comprimento axial (fator 1), mas também falência no controle do aplanamento da córnea e do aprofundamento da câmara anterior (fator 2) e no achatamento do cristalino (fator 3).
Purpose: To compare the individual means of ocular components of both eyes (corneal power, anterior chamber depth, crystalline lens power and axial length) in patients with anisometropia; to correlate the differences of the ocular components with refractive differences in both eyes; to verify total contribution and the sequence of influence that variables have in refractive differences, and to identify the smallest number of factors that contain the same level of information expressed in the set of variables that influence refractive difference. Methods: An analytical transversal study was carried out in 77 patients with anisometropia of two or more dioptres seen at the Ophthalmologic Clinic, University Hospital, Medical School Nilton Lins, Manaus, Amazon state. All participants were submitted to ophthalmologic exam which included objective and subjective cycloplegic refractometry, keratometry and ultrasonic biometry. Data analysis comprised the following statistical models: univariate, multivariate, multiple and factorial regression analyses. Results: There were no significant differences in the comparison of the individual means of the ocular components. There was negative correlation between refractive difference and difference of axial length (r=- 0.64; p<0.01) and weak negative correlation between refractive difference and crystalline lens power difference (r=-0.34; p< 0.01). The analyzed variables amounted to 78% of the total variation of refractive difference. The general sequence of variables influencing refractive difference was: axial length, crystalline lens power, cornea power, and anterior chamber depth. There were three factors identified for refractive differences: a) factor 1 (refraction, axial length); b) factor 2 (anterior chamber depth, cornea power), and c) factor 3 (crystalline lens power). Conclusions: Seventy-seven cases of anisometropia ranging from 2,00 to over 19,00 dioptres, examined for the individual components of refraction, showed that axial length was the major causative factor; crystalline lens have contributed less, followed by cornea and anterior chamber length. This study has suggested deficit of the normal adaptive mechanism in anisometropia that could produce not only axial elongation (factor 1), but also failure to control flattening of the cornea, deepening of the anterior chamber length (factor 2) and flattening of crystalline lens (factor 3).
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29

Suutala, J. (Jaakko). "Learning discriminative models from structured multi-sensor data for human context recognition." Doctoral thesis, Oulun yliopisto, 2012. http://urn.fi/urn:isbn:9789514298493.

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Abstract In this work, statistical machine learning and pattern recognition methods were developed and applied to sensor-based human context recognition. More precisely, we concentrated on an effective discriminative learning framework, where input-output mapping is learned directly from a labeled dataset. Non-parametric discriminative classification and regression models based on kernel methods were applied. They include support vector machines (SVM) and Gaussian processes (GP), which play a central role in modern statistical machine learning. Based on these established models, we propose various extensions for handling structured data that usually arise from real-life applications, for example, in a field of context-aware computing. We applied both SVM and GP techniques to handle data with multiple classes in a structured multi-sensor domain. Moreover, a framework for combining data from several sources in this setting was developed using multiple classifiers and fusion rules, where kernel methods are used as base classifiers. We developed two novel methods for handling sequential input and output data. For sequential time-series data, a novel kernel based on graphical presentation, called a weighted walk-based graph kernel (WWGK), is introduced. For sequential output labels, discriminative temporal smoothing (DTS) is proposed. Again, the proposed algorithms are modular, so different kernel classifiers can be used as base models. Finally, we propose a group of techniques based on Gaussian process regression (GPR) and particle filtering (PF) to learn to track multiple targets. We applied the proposed methodology to three different human-motion-based context recognition applications: person identification, person tracking, and activity recognition, where floor (pressure-sensitive and binary switch) and wearable acceleration sensors are used to measure human motion and gait during walking and other activities. Furthermore, we extracted a useful set of specific high-level features from raw sensor measurements based on time, frequency, and spatial domains for each application. As a result, we developed practical extensions to kernel-based discriminative learning to handle many kinds of structured data applied to human context recognition
Tiivistelmä Tässä työssä kehitettiin ja sovellettiin tilastollisen koneoppimisen ja hahmontunnistuksen menetelmiä anturipohjaiseen ihmiseen liittyvän tilannetiedon tunnistamiseen. Esitetyt menetelmät kuuluvat erottelevan oppimisen viitekehykseen, jossa ennustemalli sisääntulomuuttujien ja vastemuuttujan välille voidaan oppia suoraan tunnetuilla vastemuuttujilla nimetystä aineistosta. Parametrittomien erottelevien mallien oppimiseen käytettiin ydinmenetelmiä kuten tukivektorikoneita (SVM) ja Gaussin prosesseja (GP), joita voidaan pitää yhtenä modernin tilastollisen koneoppimisen tärkeimmistä menetelmistä. Työssä kehitettiin näihin menetelmiin liittyviä laajennuksia, joiden avulla rakenteellista aineistoa voidaan mallittaa paremmin reaalimaailman sovelluksissa, esimerkiksi tilannetietoisen laskennan sovellusalueella. Tutkimuksessa sovellettiin SVM- ja GP-menetelmiä moniluokkaisiin luokitteluongelmiin rakenteellisen monianturitiedon mallituksessa. Useiden tietolähteiden käsittelyyn esitetään menettely, joka yhdistää useat opetetut luokittelijat päätöstason säännöillä lopulliseksi malliksi. Tämän lisäksi aikasarjatiedon käsittelyyn kehitettiin uusi graafiesitykseen perustuva ydinfunktio sekä menettely sekventiaalisten luokkavastemuuttujien käsittelyyn. Nämä voidaan liittää modulaarisesti ydinmenetelmiin perustuviin erotteleviin luokittelijoihin. Lopuksi esitetään tekniikoita usean liikkuvan kohteen seuraamiseen. Menetelmät perustuvat anturitiedosta oppivaan GP-regressiomalliin ja partikkelisuodattimeen. Työssä esitettyjä menetelmiä sovellettiin kolmessa ihmisen liikkeisiin liittyvässä tilannetiedon tunnistussovelluksessa: henkilön biometrinen tunnistaminen, henkilöiden seuraaminen sekä aktiviteettien tunnistaminen. Näissä sovelluksissa henkilön asentoa, liikkeitä ja astuntaa kävelyn ja muiden aktiviteettien aikana mitattiin kahdella erilaisella paineherkällä lattia-anturilla sekä puettavilla kiihtyvyysantureilla. Tunnistusmenetelmien laajennuksien lisäksi jokaisessa sovelluksessa kehitettiin menetelmiä signaalin segmentointiin ja kuvaavien piirteiden irroittamiseen matalantason anturitiedosta. Tutkimuksen tuloksena saatiin parannuksia erottelevien mallien oppimiseen rakenteellisesta anturitiedosta sekä erityisesti uusia menettelyjä tilannetiedon tunnistamiseen
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30

Válková, Jana. "Formy zadávání a zpracování textových dat a informací v podnikových IS - trendy a aktuální praxe." Master's thesis, Vysoká škola ekonomická v Praze, 2011. http://www.nusl.cz/ntk/nusl-114263.

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This thesis introduces readers to the basic types of the text and information inputs and processing to the computer. Thesis also includes historical contexts, current trends and future perspective of computer data input technologies and their use in practice. The first part of the thesis is a summary of a particular forms of entering and processing of the text data and information. The following part presents technological trends on the market concentrated on the automatic speech recognition systems along with the possibilities of their application in the business sphere. The rest of the thesis consists of a survey between Czech IT companies and based on it's results comes a suggestion of which technologies should be used as a part of the information systems.
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31

Cerda, III Cruz. "Medical Identity Theft and Palm Vein Authentication: The Healthcare Manager's Perspective." ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/4778.

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The Federal Bureau of Investigation reported that cyber actors will likely increase cyber intrusions against healthcare systems and their concomitant medical devices because of the mandatory transition from paper to electronic health records, lax cyber security standards, and a higher financial payout for medical records in the deep web. The problem addressed in this quantitative correlational study was uncertainty surrounding the benefits of palm vein authentication adoption relative to the growing crime of medical identity theft. The purpose of this quantitative correlational study was to understand healthcare managers' and doctors' perceptions of the effectiveness of palm vein authentication technology. The research questions were designed to investigate the relationship between intention to adopt palm vein authentication technology and perceived usefulness, complexity, security, peer influence, and relative advantage. The unified theory of acceptance and use of technology was the theoretical basis for this quantitative study. Data were gathered through an anonymous online survey of 109 healthcare managers and doctors, and analyzed using principal axis factoring, Pearson's product moment correlation, multiple linear regression, and 1-way analysis of variance. The results of the study showed a statistically significant positive correlation between perceived usefulness, security, peer influence, relative advantage, and intention to adopt palm vein authentication. No statistically significant correlation existed between complexity and intention to adopt palm vein authentication. These findings indicate that by effectively using palm vein authentication, organizations can mitigate the risk of medical fraud and its associated costs, and positive social change can be realized.
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32

Gavrus, Ion Alina. "Interacciones y patrones evolutivos de los caracteres de historia de vida en humanos. Influencia de los factores sociales y culturales sobre el patrón reproductivo." Doctoral thesis, Universitat de Barcelona, 2021. http://hdl.handle.net/10803/673461.

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En nuestra especie, los hombres y las mujeres presentan un patrón reproductivo diferenciado: los hombres retienen el potencial reproductivo hasta edades avanzadas, mientras que las mujeres ven restringida su vida reproductiva por la menarquia y la menopausia. Los caracteres de historia de vida (LHT, del inglés Life History Traits) son aquellos caracteres relacionados con la supervivencia y la reproducción, tales como la longevidad, el período reproductivo, el número de hijos y su supervivencia. Estos caracteres están determinados por la selección sexual y están relacionados con diferentes factores ambientales. El objetivo principal de esta tesis es ahondar en los patrones evolutivos de los LHT y la influencia de los factores sociales y culturales en el patrón reproductivo humano. La historia familiar de Hallstatt (Austria) reconstruida gracias a los registros parroquiales de nacimientos, matrimonios y defunciones de 1602 a 1900 para católicos y de 1783 a 1906 para protestantes ha permitido alcanzar este propósito. Los resultados obtenidos se detallan en tres manuscritos. En el primer manuscrito se evaluó y comparó la heredabilidad de los LHT y de los caracteres morfológicos (MT); en el segundo se compararon la supervivencia y la reproducción de los católicos y los protestantes para determinar la influencia de la religión sobre los LHT; mientras que en el tercero se analizó la influencia de factores ambientales y de historia de vida sobre la supervivencia infantil a un año. En el primer artículo, los LHT mostraron una baja heredabilidad (h2) en comparación con los MT debido a una alta influencia de los factores ambientales en los LHT. En el segundo trabajo, se observaron diferencias entre católicos y protestantes en cuanto a la mortalidad y supervivencia, seguramente debido a diferencias a nivel socioeconómico entre los miembros de ambas congregaciones. Y, finalmente, en el tercer manuscrito, se destacó el papel fundamental de la supervivencia de la madre en la supervivencia del niño al año así como de otros factores relacionados con la historia de vida y factores ambientales. En conclusión, la baja heredabilidad de los LHT sugiere un papel relevante de los factores ambientales en los mismos, sin descartar su potencial evolutivo. La religión como indicador de estatus socioeconómico ha jugado un rol significativo en la supervivencia y el patrón reproductivo de los habitantes de Hallstatt durante los tres siglos estudiados.
In our species, men and women present a differentiated reproductive pattern: men retain reproductive potential until advanced ages, a fact that enable them to increase fitness in old ages, while women have their reproductive life restricted by menarche and menopause. Life history traits (LHT) are related to survival and reproduction, such as longevity, reproductive period, the number of offspring and their survival. These traits are determined by sexual selection and are related to different environmental factors. The main objective of this thesis is to address the evolutionary patterns of LHT and the influence of social and cultural factors on the human reproductive pattern. Familiar history of Hallstatt (Austria) reconstructed thanks to the parish records of births, marriages and deaths from 1602 to 1900 for Catholics and from 1783 to 1906 for Protestants has enabled this purpose to be achieved. The results obtained are detailed in three manuscripts. The first manuscript evaluated and compared the heritability of LHT and morphological traits (MT); the second compared the survival and reproduction of Catholics and Protestants in order to determine the influence of religion on LHT; while the third analyzed the influence of environmental and life history factors on infant survival. In the first manuscript, LHT showed low heritability (h2) compared to MT due to a high influence of environmental factors. Regarding the second manuscript, differences between Catholics and Protestants in terms of mortality and survival, were probably due to differences at the socioeconomic level between the members of both congregations. And, finally, in the third manuscript, the critical role of the mother's survival in infant’s survival at one year was highlighted, as well as the influence of other factors related to life history and environmental factors. In conclusion, the low heritability of LHT suggests a relevant role of environmental factors on them, without ruling out their evolutionary potential. Religion as an indicator of socioeconomic status has played a significant role in the survival and reproductive pattern of Hallstatt inhabitants during the three centuries studied.
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33

Valencia, Cruz José María. "Paràsits de mol·luscs bivalves a les Illes Balears: Detecció de Marteilia refringens i Perkinsus mediterraneus mitjançant tècniques moleculars." Doctoral thesis, Universitat de les Illes Balears, 2016. http://hdl.handle.net/10803/396224.

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Una de les principals limitacions a la que s‘enfronta la producció de mol·luscs bivalves és la prevenció i control de malalties, que es dispersen, principalment, pel moviment d‘estocs. A les Balears, hem trobat paràsits de bivalves poc patogènics com Bucephalus haimeanus, Mytilicola intestinalis, i metacercàries de tremàtodes. També altres que suposen un risc per a la producció, com Marteilia refringens, Perkinsus mediterraneus i P. olseni. La presència de M. refringens és una greu amenaça, doncs produeix desordres fisiològics que poden matar l‘hoste. Probablement, als anys 80, la desaparició dels bancs ostrícoles va ser causada per aquesta malaltia. Els musclos també són susceptibles a la infecció per M. refringens, però són resistents a la malaltia. L‘any 2004, es va detectar una mortalitat al banc de la rossellona (Chamelea gallina) de s‘Arenal de Palma de Mallorca. Per detectar l‘espècie causant de la malaltia es va recórrer a tècniques histològiques, hibridació in situ, PCR i PCR niada. La seqüència obtinguda a partir d‘un bloc de parafina va mostrar un 99,1 % de similitud amb les M. refringens tipus O. D‘aquesta manera es va concloure que l‘agent etiològic era M. refringens i posteriorment que la prevalença era del 55,1%. La ubicació específica de les cèl·lules de Marteilia refringens en els teixits de la rossellona es va determinar per hibridació in situ, trobant totes les fases conegudes, inclosa la d‘esporulació, el que demostra que el paràsit completa la infecció a la rossellona. Perkinsus mediterraneus infecta a una gran varietat de mol·luscs bivalves a l‘arxipèlag balear: Ostrea edulis, Mimachlamys varia, Arca noae, Chamelea gallina, Pinna nobilis i Venus verrucosa, sense mortalitats associades a aquest paràsit. Perkinus olseni sols s‘ha detectat en V. verrucosa, però en el present estudi no l‘hem trobat. La recerca de Perkinsus spp. s‘ha realitzat mitjançant RFTM i la determinació de l‘espècie per PCR-RFLP i seqüenciació. La prevalença de P. mediterraneus ha estat semblant a la d‘altres espècies de Perkinsus i la dinàmica de la seva infecció es semblant a la de P. marinus en la badia de Chesapeake, amb valors màxims de detecció del paràsit al setembre i octubre, després del màxim estival de temperatura, i regressió de la infecció a l‘hivern. Hem trobat 12 haplotips de P. mediterraneus amb una elevada similitud genètica. Les diferències es fan majors en incloure seqüències procedents de la bases de dades del GenBank, augmentant el nombre d‘haplotips a 24. Les anàlisis filogenètiques han detectat, en conjunt, tres grups diferents d‘O. edulis de Menorca, que es diferencien d‘altres llinatges coespecífics. Les anàlisis recolzen aquesta diferenciació entre les poblacions de Menorca i Mallorca, la qual sembla, en bona part deguda a l‘aïllament geogràfic del port de Maó. Malgrat això, altres factors, com la variabilitat ambiental, diferents localitats i dates de detecció, la translocació d‘animals, l‘activitat humana, etc, poden tenir certa influència. Al Mediterrani occidental es troben tres espècies de Perkinsus. Malgrat que es coneix que es produeixen co-infeccions a l‘escopinya gravada del port de Maó amb P. olseni i P. mediterraneus, no hem trobat cap cas, ni tampoc bivalves afectats per P. chesapeaki, espècie que s'ha trobat al delta de l'Ebre. A diferents mostreigs de C. gallina hem detectat la presència de M. refringens i P. mediterraneus. Encara que no hem trobat co-infecció, aquesta no es pot descartar, perquè els individus són molt joves i possiblement ambdós patògens estiguin a fases inicials d‘infecció.Tenint en compte que l‘esporulació de M. refringens s‘inicia quan la temperatura de l‘aigua és de 17ºC (mes de maig), que les zoospores de P. mediterraneus apareixen més tard (setembre-octubre) i que les mortalitats es detecten al juny-juliol, és més probable que la causa de la mortalitat sigui la marteiliosi.
Una de las principales limitaciones a la que se enfrenta la producción de moluscos bivalvos es la prevención y control de enfermedades, dispersadas, principalmente, por movimiento de partidas. En las Baleares, hemos encontrado parásitos de bivalvos poco patogénicos como Bucephalus haimeanus, Mytilicola intestinalis y metacercarias de tremátodos. También otros que suponen un riesgo para la producción, como Marteilia refringens, Perkinsus mediterraneus y P. olseni. La presencia de M. refringens es una grave amenaza, pues produce desórdenes fisiológicos que pueden matar al huésped. Probablemente, en los años 80, la desaparición de los bancos ostrícolas fue causada por esta enfermedad. Los mejillones también són susceptibles a la infección por M. refringens, pero són resistentes a la enfermedad. En 2004, se detectó una mortalidad en el banco de la chirla (Chamelea gallina) de s‘Arenal de Palma de Mallorca. Para detectar la especie causante de la enfermedad se recurrió a técnicas histológicas, hibridación in situ, PCR y PCR anidada. La secuencia obtenida a partir de un bloque de parafina mostró un 99,1% de similitud con M. refringens tipo O. De esta manera se concluyó que el agente etiológico era M. refringens y posteriormente, que la prevalencia era del 55,1%. La ubicación específica de las células de Marteilia refringens en los tejidos de la chirla se determinó por hibridación in situ, encontrando todas las fases conocidas, incluida la de esporulación, lo que demuestra que el parásito completa la infección en la chirla. Perkinsus mediterraneus infecta a una gran variedad de moluscos bivalvos en el archipiélago balear: Ostrea edulis, Mimachlamys varia, Arca noae, Chamelea gallina, Pinna nobilis y Venus verrucosa, sin mortalidades asociadas a este parásito. Perkinsus olseni sólo se ha detectado en V. verrucosa, pero en el presente estudio no lo hemos encontrado. La búsqueda de Perkinsus spp. se ha realizado mediante RFTM y la determinación de la especie por PCR-RFLP y secuenciación. La prevalencia de P. mediterraneus ha sido similar a la de otras especies de Perkinsus y la dinámica de su infección es similar a la de P. marinus en la bahía de Chesapeake, con valores máximos de detección del parásito en septiembre y octubre, después del máximo estival de temperatura, y regresión de la infección en invierno. Hemos encontrado 12 haplotipos de P. mediterraneus con una elevada similitud genética. Las diferencias se hacen mayores al incluir secuencias procedentes de la bases de datos del GenBank, aumentando el número de haplotipos a 24. Los análisis filogenéticos han detectado, en conjunto, tres grupos diferentes de O. edulis de Menorca, que se diferencian de otros linajes coespecíficos. Los análisis apoyan esta diferenciación entre las poblaciones de Menorca y Mallorca, la cual parece, en buena parte debida al aislamiento geográfico del puerto de Mahón. Sin embargo, otros factores, como la variabilidad ambiental, diferentes localidades y fechas de detección, la translocación de animales, la actividad humana, etc, pueden tener cierta influencia. En el Mediterráneo occidental se encuentran tres especies de Perkinsus. Aunque se conoce que se producen coinfecciones en la escupiña grabada del puerto de Mahón con P. olseni y P. mediterraneus, no hemos encontrado ningún caso, ni tampoco bivalvos afectados por P. chesapeaki, especie que se ha detectado en el delta del Ebro. En diferentes muestreos de C. gallina hemos detectado la presencia de M. refringens y P. mediterraneus. Aunque no hemos encontrado coinfección, ésta no se puede descartar, porque los individuos són muy jóvenes y posiblemente ambos patógenos estén en las fases iniciales de infección. Teniendo en cuenta que la esporulación de M. refringens se inicia cuando la temperatura del agua es de 17ºC (mes de mayo), que las zoosporas de P. mediterraneus aparecen más tarde (septiembre-octubre) y que la mortalidad se detecta en junio-julio, lo más probable es que la causa sea la marteiliosis
One of the main issues in bivalve mollusc production is the prevention and control of diseases, scattered mainly by stock movements. In the Balearic Islands, we found low pathogenic bivalve parasites as Bucephalus haimeanus, Mytilicola intestinalis and trematode metacercariae. Furthermore, we found others that are a threat for their welfare, like Marteilia refringens, Perkinsus mediterraneus and P. olseni. M. refringens is a serious threat, because it causes physiological disorders that could kill the host. Presumably, in the 80s, this disease was the agent of oyster banks die out. Mussels are susceptible to the infection, but they are resistant to the disease. Mass mortality was detected in 2004 at the striped Venus shell (Chamelea gallina) bed in S‘Arenal beach. We use histological techniques, in situ hybridization, PCR and nested PCR to detect the disease agent. From a paraffin block we retrieved a sequence which showed 99.1% similarity with M. refringens type O. Thus, it was concluded that the aetiological agent was M. refringens. Subsequently, we found a prevalence of 55.1%. Marteilia refringens specific location in striped Venus shell tissues was determined by in situ hybridization. We observed all known stages, including sporulation, thus this parasite could complete its vital cycle in C. gallina, and so striped Venus shell should be considered as a new host of M. refringens. A wide bivalve mollusc variety is infected by Perkinsus mediterraneus in Balearic Islands: Ostrea edulis, Mimachlamys varia, Arca noae, Chamelea gallina, Pinna nobilis and Venus verrucosa, but they are not killed by this parasite. Perkinsus olseni has only been detected in V. verrucosa from Mahon harbour, although we have not detected it in another bivalve species. Perkinsus spp. search was performed using RFTM and species was established by PCR-RFLP and sequencing. P. mediterraneus prevalence was similar to other Perkinsus species and their infection dynamics is like P. marinus’ in Chesapeake Bay, with maximum detection values in September and October, after summer peak temperature with infection regression in winter. We have found 12 P. mediterraneus haplotypes, all of them sharing a high similarity. Differences grow up when we added GenBank sequences. Then, the haplotype number raised 24. Three groups of O. edulis from Minorca were revealed by phylogenetic analyses which are different from other co-specifics lineages. Analysis supported this differentiation among populations from Minorca and Majorca. This differentiation could be due to Mahon harbour geographic isolation. Nevertheless, another factors, such environmental variability, different detection locations and dates, animal translocations, human activity, etc., might also have some influence. There are three Perkinsus species at the western Mediterranean. Although it is known that co-infections between P. olseni and P. mediterraneus can happen in warty Venus shell from Mahon harbour, we have not found any occurrence. Furthermore, we have not detected infection by P. chesapeaki, although it has been found in the Ebro delta. We have found out M. refringens and P. mediterraneus presence in different C. gallina samples. Although coinfection has not been found, we cannot discard it, because individuals are very young and perhaps both pathogens are in early infection stages. Given that M. refringens sporulation starts when water temperature is 17ºC (May), P. mediterraneus zoospores appear later (September-October) and mortality is detected in June-July, in this way, marteiliosis might be the candidate.
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34

JENG, REN-HE, and 鄭仁和. "Multimodal Biometric Recognition: Methods and Applications." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/yr83aw.

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博士
國立暨南國際大學
電機工程學系
104
Unimodal biometric systems have some challenges in a variety of problems such as noisy data, intra-class variations, restricted degrees of freedom, non-universality, spoof attacks, and unacceptable error rates. Some of these problems can be addressed by using multimodal biometric systems that explore the evidences presented by multiple sources of information. Aimed at improving the reliability of biometric authentication, we present a novel approach based on feature-level biometric modality fusion. This thesis proposes a two-stage transformation which produces an efficient code to feature amalgamation in which the variance of each bit is maximized and the bits are pairwise uncorrelated. We combine two contactless biometric modalities: one is face modality and another is the iris modality. For the feature extraction part, we extract both global and local features for combination which can provide complementary information, in order to excel the performance of applying single modality. Experiments in this thesis are tested on the dataset 1 (CASIA-Distance-Iris) and dataset 2 (extended Yale B face database and UBIRIS v1 eye database). The recognition system structure is divided into four parts: (i) preprocessing module, (ii) feature extraction module, (iii) fusion module, and (iv) classification and learning module. The preprocessing module detects and segments the region of interest of face and iris inside a noisy image. In the feature extraction step, we introduce a novel real local binary pattern (RLBP) histogram for global statistical features and sharpening convolutional neural network for local iris structure representation. In the feature fusion step, we use the two-stage transformation to analyze features in order to perform feature amalgamation. Finally, a classifier generated by bagged decision trees is processed to complete the classification. After comparing with several state-of-the-art multimodal biometric systems, our system achieves a equal error rate of less than 1% for verification tasks. For identification, the proposed system achieves error less than 10% using 10% feature vectors. Experimental results reveal that feature amalgamation of multimodal biometric system is better than existing feature fusion scheme, i.e., sereial/parallel feature fusion and weighted sum rule.
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35

"Classification and fusion methods for multimodal biometric authentication." 2007. http://library.cuhk.edu.hk/record=b5893313.

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Ouyang, Hua.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (leaves 81-89).
Abstracts in English and Chinese.
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Biometric Authentication --- p.1
Chapter 1.2 --- Multimodal Biometric Authentication --- p.2
Chapter 1.2.1 --- Combination of Different Biometric Traits --- p.3
Chapter 1.2.2 --- Multimodal Fusion --- p.5
Chapter 1.3 --- Audio-Visual Bi-modal Authentication --- p.6
Chapter 1.4 --- Focus of This Research --- p.7
Chapter 1.5 --- Organization of This Thesis --- p.8
Chapter 2 --- Audio-Visual Bi-modal Authentication --- p.10
Chapter 2.1 --- Audio-visual Authentication System --- p.10
Chapter 2.1.1 --- Why Audio and Mouth? --- p.10
Chapter 2.1.2 --- System Overview --- p.11
Chapter 2.2 --- XM2VTS Database --- p.12
Chapter 2.3 --- Visual Feature Extraction --- p.14
Chapter 2.3.1 --- Locating the Mouth --- p.14
Chapter 2.3.2 --- Averaged Mouth Images --- p.17
Chapter 2.3.3 --- Averaged Optical Flow Images --- p.21
Chapter 2.4 --- Audio Features --- p.23
Chapter 2.5 --- Video Stream Classification --- p.23
Chapter 2.6 --- Audio Stream Classification --- p.25
Chapter 2.7 --- Simple Fusion --- p.26
Chapter 3 --- Weighted Sum Rules for Multi-modal Fusion --- p.27
Chapter 3.1 --- Measurement-Level Fusion --- p.27
Chapter 3.2 --- Product Rule and Sum Rule --- p.28
Chapter 3.2.1 --- Product Rule --- p.28
Chapter 3.2.2 --- Naive Sum Rule (NS) --- p.29
Chapter 3.2.3 --- Linear Weighted Sum Rule (WS) --- p.30
Chapter 3.3 --- Optimal Weights Selection for WS --- p.31
Chapter 3.3.1 --- Independent Case --- p.31
Chapter 3.3.2 --- Identical Case --- p.33
Chapter 3.4 --- Confidence Measure Based Fusion Weights --- p.35
Chapter 4 --- Regularized k-Nearest Neighbor Classifier --- p.39
Chapter 4.1 --- Motivations --- p.39
Chapter 4.1.1 --- Conventional k-NN Classifier --- p.39
Chapter 4.1.2 --- Bayesian Formulation of kNN --- p.40
Chapter 4.1.3 --- Pitfalls and Drawbacks of kNN Classifiers --- p.41
Chapter 4.1.4 --- Metric Learning Methods --- p.43
Chapter 4.2 --- Regularized k-Nearest Neighbor Classifier --- p.46
Chapter 4.2.1 --- Metric or Not Metric? --- p.46
Chapter 4.2.2 --- Proposed Classifier: RkNN --- p.47
Chapter 4.2.3 --- Hyperkernels and Hyper-RKHS --- p.49
Chapter 4.2.4 --- Convex Optimization of RkNN --- p.52
Chapter 4.2.5 --- Hyper kernel Construction --- p.53
Chapter 4.2.6 --- Speeding up RkNN --- p.56
Chapter 4.3 --- Experimental Evaluation --- p.57
Chapter 4.3.1 --- Synthetic Data Sets --- p.57
Chapter 4.3.2 --- Benchmark Data Sets --- p.64
Chapter 5 --- Audio-Visual Authentication Experiments --- p.68
Chapter 5.1 --- Effectiveness of Visual Features --- p.68
Chapter 5.2 --- Performance of Simple Sum Rule --- p.71
Chapter 5.3 --- Performances of Individual Modalities --- p.73
Chapter 5.4 --- Identification Tasks Using Confidence-based Weighted Sum Rule --- p.74
Chapter 5.4.1 --- Effectiveness of WS_M_C Rule --- p.75
Chapter 5.4.2 --- WS_M_C v.s. WS_M --- p.76
Chapter 5.5 --- Speaker Identification Using RkNN --- p.77
Chapter 6 --- Conclusions and Future Work --- p.78
Chapter 6.1 --- Conclusions --- p.78
Chapter 6.2 --- Important Follow-up Works --- p.80
Bibliography --- p.81
Chapter A --- Proof of Proposition 3.1 --- p.90
Chapter B --- Proof of Proposition 3.2 --- p.93
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36

Chen, Yung-Chih, and 陳勇志. "An EAP Method with Biometrics Privacy Preserving in IEEE802.11 Wireless LANs." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/28992333391793756590.

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Abstract:
碩士
國立中山大學
資訊工程學系研究所
97
It is necessary to authenticate users when they want to access services in WLANs. Extensible Authentication Protocol (EAP) is an authentication framework widely used in WLANs. Authentication mechanisms built on EAP are called EAP methods. The requirements for EAP methods in WLAN authentication have been defined in RFC 4017. Besides, low computation cost and forward secrecy, excluded in RFC 4017, are noticeable requirements in WLAN authentication. However, all EAP methods and authentication schemes designed for WLANs so far do not satisfy all of the above requirements. Therefore, we will propose an EAP method which utilizes three factors, stored secrets, passwords, and biometrics, to verify users. Our proposed method fully satisfies 1) the requirements of RFC 4017, 2) forward secrecy, and 3) lightweight computation. Moreover, the privacy of biometrics is protected against the authentication server, and the server can flexibly decide whether passwords and biometrics are verified in each round or not.
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37

Chang, Chia-Kai, and 張家愷. "Face Recognition Method by Integrating the Techniques of Biometrics and Principal Component Analysis." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/56719495701817415015.

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Abstract:
碩士
朝陽科技大學
資訊管理系
102
This study proposes a face recognition method by integrating the techniques of biometrics and principal component analysis (PCA). Based on this method, we construct a multi-face recognition system which is based on fourteen biometric features. In this system, improve the detection process by using two color space models to extract face regions from the picture. We capture the biometric features from every candidate of face image, calculate the difference of facial feature vector (DFFV) and find weights of feature vector by PCA. Then, these data are stored in facial database for face recognition. When a new face image is coming, we capture the biometric features can be captured from the coming face image, calculate DFFV, and compare them with DFFVs in database by progressively use the weights which obtained from the PCA to find the closest face. Finally, we continued test and regulate the experimental procedure, we obtain initial recognition success rate and confirmed our face recognition method which used PCA and biometrics can be used. And because this method use only some biometrics features to detection face, therefore, we can save more calculation time and amount of data. In the future, we need to study more the other research on biometrics and improve amount of features, we think it can be improve success rate make the face recognition both fast and accurately.
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38

Wu, Jia-Yang, and 吳家揚. "Non-Invasive Blood Glucose Estimation and Biometric Recognition Method Based on Photoplethysmography Signal." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/mbermw.

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39

CHAO, HSIN-YIN, and 趙梓吟. "Development of Ticket Reservation Model based on Biometric Identification Method and Blockchain Technology." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/97t764.

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Abstract:
碩士
世新大學
資訊管理學研究所(含碩專班)
107
Scalper in the modern is also endless, with the emergence of blockchain, bring people a significant impact, the use of blockchain characteristics to join biometric authentication, the ticketing system, greatly increased convenience, and effectively prevent scalpers from earning illegal benefits, so that the rights and interests of buyers and sellers can be protected. Several characteristics of blockchain like immutable, difficult to counterfeit, decentralized, traceable, automatic contract execution, privacy, fast transaction clearing, correctness and integrity. Its emergence provides a more convenient mechanism for society. Cryptography technology in order to protect personal information security, which ensure their rights and protection of their property and safety. We have previously had keys and door cards such as portable equipment or set passwords to verify their identity, but with biometric authentication high-end identity verification appeared.Their own body is the password. People can protect their own security and interests more effectively. This study combines blockchain, smart contracts, cryptography and biometrics to create a fair and notarized ticket ingress system, hoping to root out the problem of scalpers and effectively solve the complex problem of refund, so that people can enjoy the best price.
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40

Chang, Chin-Kai, and 張智凱. "A Study on Using RFID and Biometric Identification Method to Improve Mobilization Call Management." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/91653812696053155839.

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Abstract:
碩士
國防管理學院
國防資訊研究所
96
With the progressive technology, the wireless Radio Frequency Identification (RFID) has promoted the researches of object recognition and tracing technique. Although mobilization call in military has become more and more convenient by means of information processing, it still relies on lots of paperwork and manpower to finish. Therefore, the unit commander can’t get or use the real-time and exactly correct data of the working process. The main research goal of this thesis is to discuss how do we use RFID technology in military mobilization call environment. Besides of understanding RFID is capable of tracing moving objects and gathering data, we also design a complete and effective working process to save massive manpower. Our system can precisely control the condition of person-summoned, calculate the equipment to be used, analyze the registration rate of person-summoned and the status of salary received, and truly reduce the work for daily person checking. Furthermore, we integrate Biometric Identification to enhance the insufficient part of RFID in order to strengthen recognition function. We hope the system could be helpful for military mobilization call in the future.
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41

Wu, Jonathan. "Gesture passwords: concepts, methods and challenges." Thesis, 2016. https://hdl.handle.net/2144/17090.

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Abstract:
Biometrics are a convenient alternative to traditional forms of access control such as passwords and pass-cards since they rely solely on user-specific traits. Unlike alphanumeric passwords, biometrics cannot be given or told to another person, and unlike pass-cards, are always “on-hand.” Perhaps the most well-known biometrics with these properties are: face, speech, iris, and gait. This dissertation proposes a new biometric modality: gestures. A gesture is a short body motion that contains static anatomical information and changing behavioral (dynamic) information. This work considers both full-body gestures such as a large wave of the arms, and hand gestures such as a subtle curl of the fingers and palm. For access control, a specific gesture can be selected as a “password” and used for identification and authentication of a user. If this particular motion were somehow compromised, a user could readily select a new motion as a “password,” effectively changing and renewing the behavioral aspect of the biometric. This thesis describes a novel framework for acquiring, representing, and evaluating gesture passwords for the purpose of general access control. The framework uses depth sensors, such as the Kinect, to record gesture information from which depth maps or pose features are estimated. First, various distance measures, such as the log-euclidean distance between feature covariance matrices and distances based on feature sequence alignment via dynamic time warping, are used to compare two gestures, and train a classifier to either authenticate or identify a user. In authentication, this framework yields an equal error rate on the order of 1-2% for body and hand gestures in non-adversarial scenarios. Next, through a novel decomposition of gestures into posture, build, and dynamic components, the relative importance of each component is studied. The dynamic portion of a gesture is shown to have the largest impact on biometric performance with its removal causing a significant increase in error. In addition, the effects of two types of threats are investigated: one due to self-induced degradations (personal effects and the passage of time) and the other due to spoof attacks. For body gestures, both spoof attacks (with only the dynamic component) and self-induced degradations increase the equal error rate as expected. Further, the benefits of adding additional sensor viewpoints to this modality are empirically evaluated. Finally, a novel framework that leverages deep convolutional neural networks for learning a user-specific “style” representation from a set of known gestures is proposed and compared to a similar representation for gesture recognition. This deep convolutional neural network yields significantly improved performance over prior methods. A byproduct of this work is the creation and release of multiple publicly available, user-centric (as opposed to gesture-centric) datasets based on both body and hand gestures.
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42

Acharya, Bibhudendra. "On the Development of Novel Encryption Methods for Conventional and Biometric Images." Thesis, 2015. http://ethesis.nitrkl.ac.in/6758/1/50709003.pdf.

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Information security refers to the technique of protecting information from unauthorized access, use, disclosure, disruption and modification. Governments, military, corporations, financial institutions, hospitals, and private businesses amass a great deal of confidential information about their employees, customers, products, research, and financial status. Most of this information is now collected, processed and stored on electronic media and transmitted across networks to other computers. Encryption clearly addresses the need for confidentiality of information, in process of storage and transmission. Popular application of multimedia technology and increasingly transmission ability of network gradually leads us to acquire information directly and clearly through images and hence the security of image data has become inevitable. Moreover in the recent years, biometrics is gaining popularity for security purposes in many applications. However, during communication and transmission over insecure network channels it has some risks of being hacked, modified and reused. Hence, there is a strong need to protect biometric images during communication and transmission. In this thesis, attempts have been made to encrypt image efficiently and to enhance the security of biometrics images during transmission. In the first contribution, three different key matrix generation methods invertible, involuntary, and permutation key matrix generation have been proposed. Invertible and involuntary key matrix generation methods solves the key matrix inversion problem in Hill cipher. Permutation key matrix generation method increases the Hill system’s security. The conventional Hill cipher technique fails to encrypt images properly if the image consists of large area covered with same colour or gray level. Thus, it does not hide all features of the image which reveals patterns in the plaintext. Moreover, it can be easily broken with a known plaintext attack revealing weak security. To address these issues two different techniques are proposed, those are advanced Hill cipher algorithm and H-S-X cryptosystem to encrypt the images properly. Security analysis of both the techniques reveals superiority of encryption and decryption of images. On the other hand, H-S-X cryptosystem has been used to instil more diffusion and confusion on the cryptanalysis. FPGA implementation of both the proposed techniques has been modeled to show the effectiveness of both the techniques. An extended Hill cipher algorithm based on XOR and zigzag operation is designed to reduce both encryption and decryption time. This technique not only reduces the encryption and decryption time but also ensures no loss of data during encryption and decryption process as compared to other techniques and possesses more resistance to intruder attack. The hybrid cryptosystem which is the combination of extended Hill cipher technique and RSA algorithm has been implemented to solve the key distribution problem and to enhance the security with reduced encryption and decryption time. Two distinct approaches for image encryption are proposed using chaos based DNA coding along with shifting and scrambling or poker shuffle to create grand disorder between the pixels of the images. In the first approach, results obtained from chaos based DNA coding scheme is shifted and scrambled to provide encryption. On the other hand in the second approach the results obtained from chaos based DNA coding encryption is followed by poker shuffle operation to generate the final result. Simulated results suggest performance superiority for encryption and decryption of image and the results obtained have been compared and discussed. Later on FPGA implementation of proposed cryptosystem has been performed. In another contribution, a modified Hill cipher is proposed which is the combination of three techniques. This proposed modified Hill cipher takes advantage of all the three techniques. To acquire the demands of authenticity, integrity, and non-repudiation along with confidentiality, a novel hybrid method has been implemented. This method has employed proposed modified Hill cipher to provide confidentiality. Produced message digest encrypted by private key of RSA algorithm to achieve other features such as authenticity, integrity, and non-repudiation To enhance the security of images, a biometric cryptosystem approach that combines cryptography and biometrics has been proposed. Under this approach, the image is encrypted with the help of fingerprint and password. A key generated with the combination of fingerprint and password and is used for image encryption. This mechanism is seen to enhance the security of biometrics images during transmission. Each proposed algorithm is studied separately, and simulation experiments are conducted to evaluate their performance. The security analyses are performed and performance compared with other competent schemes.
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43

Al-Waisy, Alaa S., Rami S. R. Qahwaji, Stanley S. Ipson, Shumoos Al-Fahdawi, and Tarek A. M. Nagem. "A multi-biometric iris recognition system based on a deep learning approach." 2017. http://hdl.handle.net/10454/15682.

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Yes
Multimodal biometric systems have been widely applied in many real-world applications due to its ability to deal with a number of significant limitations of unimodal biometric systems, including sensitivity to noise, population coverage, intra-class variability, non-universality, and vulnerability to spoofing. In this paper, an efficient and real-time multimodal biometric system is proposed based on building deep learning representations for images of both the right and left irises of a person, and fusing the results obtained using a ranking-level fusion method. The trained deep learning system proposed is called IrisConvNet whose architecture is based on a combination of Convolutional Neural Network (CNN) and Softmax classifier to extract discriminative features from the input image without any domain knowledge where the input image represents the localized iris region and then classify it into one of N classes. In this work, a discriminative CNN training scheme based on a combination of back-propagation algorithm and mini-batch AdaGrad optimization method is proposed for weights updating and learning rate adaptation, respectively. In addition, other training strategies (e.g., dropout method, data augmentation) are also proposed in order to evaluate different CNN architectures. The performance of the proposed system is tested on three public datasets collected under different conditions: SDUMLA-HMT, CASIA-Iris- V3 Interval and IITD iris databases. The results obtained from the proposed system outperform other state-of-the-art of approaches (e.g., Wavelet transform, Scattering transform, Local Binary Pattern and PCA) by achieving a Rank-1 identification rate of 100% on all the employed databases and a recognition time less than one second per person.
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44

"A new model for the generation of photoplethysmographic signal with its application to the analysis of beat-to-beat blood pressure variability." 2004. http://library.cuhk.edu.hk/record=b5891881.

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Gu Yingying.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (leaves 155-164).
Abstracts in English and Chinese.
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- IPFM Model --- p.1
Chapter 1.1.1 --- Description of IPFM Model --- p.1
Chapter 1.1.2 --- Background of IPFM Related Modeling --- p.3
Chapter 1.2 --- Windkessel Model --- p.8
Chapter 1.2.1 --- Background of the Windkessel Model --- p.8
Chapter 1.2.2 --- Windkessel Related Modeling --- p.13
Chapter 1.3 --- Photoplethysmogram (PPG) --- p.14
Chapter 1.3.1 --- Principle of PPG --- p.14
Chapter 1.3.2 --- Characteristics of PPG Signal --- p.16
Chapter 1.4 --- A Study on the Beat-to-Beat BPV --- p.18
Chapter 1.5 --- Main Purposes of the Study --- p.19
Chapter 1.6 --- Organization of the Thesis --- p.20
Chapter 2 --- Spectral Analysis on the IPFM Process --- p.22
Chapter 2.1 --- Introduction --- p.22
Chapter 2.2 --- A Theoretical Study on the Neural Firing Rate Function --- p.23
Chapter 2.2.1 --- Mathematical Derivation of the Neural Firing Rate --- p.23
Chapter 2.2.2 --- Spectral Analysis of the IPFM Process --- p.27
Chapter 2.2.3 --- Reconstruction of Neural Firing Rate through LPF --- p.30
Chapter 2.3 --- Effects of Neural Dynamics --- p.33
Chapter 2.4 --- Discussion & Conclusion --- p.35
Chapter 3 --- A New Model for the Generation of PPG --- p.37
Chapter 3.1 --- Introduction --- p.37
Chapter 3.2 --- Principles of PPG --- p.38
Chapter 3.2.1 --- Relationship between Pressure and Flow --- p.38
Chapter 3.2.2 --- Peripheral Pressure and Flow Curves --- p.41
Chapter 3.2.3 --- Generation of PPG signal --- p.43
Chapter 3.3 --- Model Description --- p.44
Chapter 3.3.1 --- IPFM model --- p.45
Chapter 3.3.2 --- Windkessel model --- p.46
Chapter 3.3.3 --- New Model for the Generation of PPG --- p.49
Chapter 3.4 --- Simulation --- p.51
Chapter 3.4.1 --- Generation of ECG --- p.51
Chapter 3.4.2 --- Generation of PPG --- p.57
Chapter 3.4.3 --- Effects of the Modulation Depth on the Output --- p.65
Chapter 3.4.4 --- Effects of Mean Autonomic Tone on HRV --- p.72
Chapter 3.5 --- Discussion & Conclusion --- p.75
Chapter 4 --- A Correlation Study on the Beat-to-Beat Features of Photoplethysmographic Signals --- p.80
Chapter 4.1 --- Introduction --- p.80
Chapter 4.2 --- Methodology --- p.81
Chapter 4.2.1 --- Experimental Conditions --- p.81
Chapter 4.2.2 --- Definition of the Parameters --- p.82
Chapter 4.3 --- Data Analysis --- p.85
Chapter 4.3.1 --- At Normal Relaxed State --- p.85
Chapter 4.3.2 --- At Different Levels of Contacting Force --- p.87
Chapter 4.3.3 --- At Different Levels of Local Skin Finger Temperature --- p.90
Chapter 4.3.4 --- At Dynamic State --- p.93
Chapter 4.3.5 --- Repeatability Study --- p.95
Chapter 4.3.6 --- Spectral Analysis --- p.96
Chapter 4.4 --- Discussion --- p.98
Chapter 5 --- The Estimation of the Beat-to-Beat Blood Pressure Variability --- p.103
Chapter 5.1 --- Introduction --- p.103
Chapter 5.2 --- BP Estimation using FY Interval --- p.104
Chapter 5.2.1 --- Multi-Beat BP Estimation under Different Levels of Contacting Force --- p.104
Chapter 5.2.2 --- Beat-to-Beat BP Estimation --- p.108
Chapter 5.2.3 --- Repeatability Study --- p.112
Chapter 5.3 --- A Study on the Beat-to-Beat BPV --- p.113
Chapter 5.3.1 --- Background of the Beat-to-Beat BPV --- p.113
Chapter 5.3.2 --- Analysis of the Beat-to-Beat BPV --- p.115
Chapter 5.4 --- Improving the PPG Model with the Time-Varying BP --- p.120
Chapter 5.4.1 --- Modification of the Model --- p.121
Chapter 5.4.2 --- Simulation --- p.127
Chapter 5.4.3 --- Application of the PPG Model --- p.132
Chapter 5.5 --- Discussion & Conclusion --- p.134
Chapter 6 --- A Novel Biometric Approach --- p.139
Chapter 6.1 --- Introduction --- p.139
Chapter 6.2 --- Human Verification by PPG Signal --- p.140
Chapter 6.2.1 --- Experiment --- p.141
Chapter 6.2.2 --- Feature Extraction --- p.142
Chapter 6.2.3 --- Decision-making --- p.143
Chapter 6.2.4 --- Results --- p.146
Chapter 6.3 --- Discussion --- p.149
Chapter 7 --- Conclusions --- p.151
Chapter 7.1 --- Conclusions of Major Contributions --- p.151
Chapter 7.2 --- Work to Be Done --- p.154
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45

"The statistical evaluation of minutiae-based automatic fingerprint verification systems." Thesis, 2006. http://library.cuhk.edu.hk/record=b6074180.

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Basic technologies for fingerprint feature extraction and matching have been improved to such a stage that they can be embedded into commercial Automatic Fingerprint Verification Systems (AFVSs). However, the reliability of AFVSs has kept attracting concerns from the society since AFVSs do fail occasionally due to difficulties like problematic fingers, changing environments, and malicious attacks. Furthermore, the absence of a solid theoretical foundation for evaluating AFVSs prevents these failures from been predicted and evaluated. Under the traditional empirical AFVS evaluation framework, repeated verification experiments, which can be very time consuming, have to be performed to test whether an update to an AFVS can really lead to an upgrade in its performance. Also, empirical verification results are often unable to provide deeper understanding of AFVSs. To solve these problems, we propose a novel statistical evaluation model for minutiae-based AFVSs based on the understanding of fingerprint minutiae patterns. This model can predict the verification performance metrics as well as their confidence intervals. The analytical power of our evaluation model, which makes it superior to empirical evaluation methods, can assist system developers to upgrade their AFVSs purposefully. Also, our model can facilitate the theoretical analysis of the advantages and disadvantages of various fingerprint verification techniques. We verify our claims through different and extensive experiments.
Chen, Jiansheng.
"November 2006."
Adviser: Yiu-Sang Moon.
Source: Dissertation Abstracts International, Volume: 68-08, Section: B, page: 5343.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2006.
Includes bibliographical references (p. 110-122).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstracts in English and Chinese.
School code: 1307.
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46

Пясецький, Володимир Богданович, and Vladimir Pyasetsky. "Розробка інформаційної системи для збору та аналізу сигналів біометричної ідентифікації на прикладі відбитків пальців." Master's thesis, 2021. http://elartu.tntu.edu.ua/handle/lib/35205.

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Дипломна робота присв’ячена розробці інформаційної системи для збору та аналізу сигналів біометричної ідентифікації на прикладі відбитків пальців. В першому розділі дипломної роботи описані біометричні засоби. Висвітлено інформаціні системи для біометричної аутентифікації користувачів на основі відбитків пальців. Розглянуто методи опрацювання відбитків пальців. Проаналазовано публікацій в предметній області. В другому розділі дипломної роботи методи автоматизації процесів ідентифікації відбитків пальців. Досліджено методи індексування відбитків пальців. Подано порівняльний опис системи ідентифікації відбитків пальців. В третьому розділі дипломної роботи описано програмне забезпечення інформаційної системи. наведена архітектура розробленої інформаційної системи. Проаналізовано методи індексування з широкоширеним розподілом цінності. Проведено обчислювальний експеримент. Об’єкт дослідження: процеси збирання та опрацювання біометричних сутностей на прикладі відбитків пальців. Предмет дослідження: методи збирання та аналітичного опрацювання быометричних сутностей на прикладі відбитків пальців.
Thesis is devoted to the development of an information system for the collection and analysis of biometric identification signals on the example of fingerprints. The first section of the thesis describes biometric tools. Information systems for biometric authentication of users based on fingerprints are highlighted. Methods of fingerprint processing are considered. Publications in the subject area are analyzed. In the second section of the thesis methods of automation of fingerprint identification processes. Methods of indexing fingerprints are investigated. A comparative description of the fingerprint identification system is given. The third section of the thesis describes the software of the information system. the architecture of the developed information system is given. Indexing methods with a wide distribution of value are analyzed. A computational experiment was performed. Object of research: processes of collecting and processing biometric entities on the example of fingerprints. Subject of research: methods of collection and analytical processing of biometric entities on the example of fingerprints.
ВСТУП ...8 1 АНАЛІЗ ПРЕДМЕТНОЇ ОБЛАСТІ ...10 1.1 Біометричні засоби ...10 1.2 Інформаціні системи для біометричної аутентифікації користувачів на основі відбитків пальців ...11 1.3 Методи опрацювання відбитків пальців ...13 1.3.1 Методи отримання відбитків пальців з пористих поверхонь ...14 1.3.2 Методи отримання відбитків пальців з пористих поверхонь ...14 1.4 Аналіз публікацій в предметній області ...15 1.5 Висновок до першого розділу ...17 2 АНАЛІЗ МЕТОДІВ, СИСТЕМ ТА ПРОЄКТУВАННЯ СИСТЕМИ БІОМЕТРИЧНОЇ ІДЕНТИФІКАЦІЇ ВІДБИТКІВ ПАЛЬЦІВ ...18 2.1 Методи автоматизації процесів ідентифікації відбитків пальців ...18 2.1.1 Сегментація відбитків пальців ...18 2.1.2 Оцінка та покращення якості відбитків пальців ...21 2.1.3 Структурні елементи відбитків пальців ...24 2.1.4 Збіг відбитків пальців ...28 2.2 Методи індексування відбитків пальців ...30 2.3 Системи ідентифікації відбитків пальців ...32 2.3.1 Ручний аналіз відбитків пальців ...32 2.3.2 Напівавтоматизований аналіз відбитків пальців ...33 2.3.3 Автоматизована система ідентифікації відбитків пальців ...34 2.4 Висновок до другого розділу ...35 3 ОБЧИСЛЮВАЛЬНИЙ ЕКСПЕРИМЕНТ ...36 3.1 Програмне забезпечення інформаційної системи ...36 3.2 Архітектура розробленої інформаційної системи ...36 3.3 Методи індексування з широкоширеним розподілом цінності ...37 3.3.1 Тріангуляція Делауні ...37 3.3.2 Розширена триангуляція Делауні ...40 3.3.3 Покоління індексної цілісності ...40 3.4 Обчислювальний експеримент ..44 3.4.1 Підготовка експерименту ...44 3.4.2 Бази даних відбитків пальців ...45 3.4.3 Метрики виконання ...46 3.4.4 Аналіз виконання експерименту ...47 3.4.5 Обчислювальна складність ...50 3.5 Висновок до третього розділу ...50 4 ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ ...51 4.1 Небезпечні й шкідливі фактори при виконанні робіт за комп’ютером ...51 4.2 Створення і функціонування системи моніторингу довкілля з метою інтеграції екологічних інформаційних систем, що охоплюють певні території ...54 ВИСНОВКИ ...57 ПЕРЕЛІК ДЖЕРЕЛ ...58 ДОДАТКИ
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47

Mohammadzade, Narges Hoda. "Two- and Three-dimensional Face Recognition under Expression Variation." Thesis, 2012. http://hdl.handle.net/1807/32773.

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In this thesis, the expression variation problem in two-dimensional (2D) and three-dimensional (3D) face recognition is tackled. While discriminant analysis (DA) methods are effective solutions for recognizing expression-variant 2D face images, they are not directly applicable when only a single sample image per subject is available. This problem is addressed in this thesis by introducing expression subspaces which can be used for synthesizing new expression images from subjects with only one sample image. It is proposed that by augmenting a generic training set with the gallery and their synthesized new expression images, and then training DA methods using this new set, the face recognition performance can be significantly improved. An important advantage of the proposed method is its simplicity; the expression of an image is transformed simply by projecting it into another subspace. The above proposed solution can also be used in general pattern recognition applications. The above method can also be used in 3D face recognition where expression variation is a more serious issue. However, DA methods cannot be readily applied to 3D faces because of the lack of a proper alignment method for 3D faces. To solve this issue, a method is proposed for sampling the points of the face that correspond to the same facial features across all faces, denoted as the closest-normal points (CNPs). It is shown that the performance of the linear discriminant analysis (LDA) method, applied to such an aligned representation of 3D faces, is significantly better than the performance of the state-of-the-art methods which, rely on one-by-one registration of the probe faces to every gallery face. Furthermore, as an important finding, it is shown that the surface normal vectors of the face provide a higher level of discriminatory information rather than the coordinates of the points. In addition, the expression subspace approach is used for the recognition of 3D faces from single sample. By constructing expression subspaces from the surface normal vectors at the CNPs, the surface normal vectors of a 3D face with single sample can be synthesized under other expressions. As a result, by improving the estimation of the within-class scatter matrix using the synthesized samples, a significant improvement in the recognition performance is achieved.
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