Дисертації з теми "Cyclist detection"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Cyclist detection.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Cyclist detection".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
De, Angelis Marco, Víctor Marín Puchades, Federico Fraboni, Luca Pietrantoni, and Gabriele Prati. "Negative attitudes towards cyclists influence the acceptance of an in-vehicle cyclist detection system." Elsevier, 2017. https://publish.fid-move.qucosa.de/id/qucosa%3A73236.
Повний текст джерелаАнотація:
The shift towards automation and safer vehicles will increasingly involve use of technological advancements such as Advanced Driver Assistance Systems (ADAS). Nevertheless, these technologies need to meet users’ perceived needs to be effectively implemented and purchased. Based on an updated version of the Technology Acceptance Model (TAM), this study analyses the main determinants of drivers’ intention to use an ADAS aimed at detecting cyclist and preventing potential collision with them through an auto-braking system. Even if the relevance of perceived usefulness, perceived ease of use and trust on the acceptance of a new system has been already discussed in literature, we considered the role of an external variable such as attitudes towards cyclists in the prediction of an ADAS aimed to improve the safety of cyclists. We administered a questionnaire measuring negative attitudes towards cyclists, trust, perceived usefulness, perceived ease of use and the behavioural intention to use the system to 480 Italian drivers. Path analysis using Bayesian estimation showed that perceived usefulness, trust in the system, and negative attitudes towards cyclists have a direct effect on the intention to use the ADAS. Considering the role of attitudes towards other road users in the intention to use new ADAS aimed to improve their safety could foster the user’s acceptance, especially for those people who express a negative representation of cyclists and are even more unlikely to accept the technology.
2
Heydorn, Matthew Ryan. "Increased Cyclist Safety Using an Embedded System." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7391.
Повний текст джерелаАнотація:
In order to reduce bicycle-vehicle collisions, we design and implement a cost effectiveembedded system to warn cyclists of approaching vehicles. The system uses an Odroid C2 singleboard computer (SBC) to do vehicle and lane detection in real time using only vision. The system warns cyclist are warned of approaching cars using both a smartphone app and an LED indicator. Due to the limited performance of the Odroid C2 and other low power and low cost SBCs,we found that existing detection algorithms run either too slowly or do not have sufficient accuracy to be practical. Our solution to these limitations is to create a custom fully convolutional network(FCN) which is small enough to run at real time speeds on the Odroid C2 but robust enough tohave decent accuracy. We show that this FCN runs significantly faster than Tiny YOLOv3 andMobileNetv2 while getting similar accuracy when all are trained on a limited dataset. Since no dataset exists that separates the fronts of vehicles from other poses and is in the context of city and country roads, we create our own. Creating a dataset to train any detector hastraditionally been time consuming. We present and implement a way to efficiently do this usingminimal hand annotation by generating semi-synthetic images by cropping relatively few positive images into many background images. This creates a wider background class variance than wouldotherwise be possible.
3
Bieshaar, Maarten [Verfasser]. "Cooperative intention detection using machine learning : advanced cyclist protection in the context of automated driving / Maarten Bieshaar." Kassel : kassel university press c/o Universität Kassel - Universitätsbibliothek, 2021. http://d-nb.info/1233244175/34.
Повний текст джерела
4
Abakar, Issakha Souleymane. "Algorithms for the detection and localization of pedestrians and cyclists using new generation automotive radar systems." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S159.
Повний текст джерелаАнотація:
En réponse au nombre toujours élevé de décès provoqués par les accidents routiers, l'industrie automobile a fait de la sécurité un sujet majeur de son activité global. Les radars automobiles qui étaient de simples capteurs pour véhicule de confort, sont devenus des éléments essentiels de la norme de sécurité routière. Le domaine de l’automobile est un domaine très exigent en terme de sécurité et les radars automobiles doivent avoir des performances de détection très élevées et doivent répondre à des nombreuses contraintes telles que la facilité de production et/ou le faible coût. Cette thèse concerne le développement d’algorithmes pour la détection et la localisation de piétons et de cyclistes pour des radars automobiles de nouvelle génération. Nous avons proposé une architecture de réseau d'antennes non uniforme optimale et des méthodes d'estimation spectrale à haute résolution permettant d’estimer avec précision la position angulaire des objets à partir de la direction d'arrivée (DoA) de leur réponse. Ces techniques sont adaptées à l'architecture du réseau d'antennes proposé et les performances sont évaluées à l'aide de données radar automobiles simulées et réelles acquises dans le cadre de scénarios spécifiques. Nous avons également proposé un détecteur de cible de collision, basé sur la décomposition en sous-espaces Doppler, dont l'objectif principal est d'identifier des cibles latérales dont les caractéristiques de trajectoire représentent potentiellement un danger de collision. Une méthode de calcul d'attribut de cible est également développée et un algorithme de classification est proposé pour discriminer les piétons, cyclistes et véhicules. Les différents algorithmes sont évalués et validés à l'aide de données radar automobiles réelles sur plusieurs scenariosIn response to the persistently high number of deaths provoked by road crashes, the automotive industry has promoted safety as a major topic in their global activity. Automotive radars have been transformed from being simple sensors for comfort vehicle, to becoming essential elements of safety standard. The design of new generations automotive radars has to face various constraints and generally proposes a compromise between reliability, robustness, manufacturability, high-performance and low cost. The main objective of this PhD thesis is to design algorithms for the detection and localization of pedestrians and cyclists using new generation automotive radars. We propose an optimal non-uniform antenna array architecture and some high resolution spectral estimation methods to accurately estimate the position of objects from the direction of arrival (DOA) of their responses to the radar. These techniques are adapted to the proposed antenna array architecture and the performance is evaluated using both simulated and real automotive radar data, acquired in the frame of specific scenarios. We propose a collision target detector, based on the orthogonality of angle-Doppler subspaces, whose main goal is to identify lateral targets, whose trajectory features represent potentially a danger of collision. A target attribute calculation method is also developed and classification algorithm is proposed to classify pedestrian, cyclists and vehicles. This classification algorithm is evaluated and validated using real automotive radar data with several scenarios
5
BAKKAL, Ahmet Tansu. "Acoustic Detection of Rear Approaching Vehicles for Cyclists." Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-25182.
Повний текст джерелаАнотація:
The project aims to detect rear approaching vehicles for cycslist with a low power consumption. Study focuses on acoustic features of the sound of rear approaching vehicles and examines the useful indicators to detect the vehicles. The project includes more then one correlation and reveals their success rates for as many as samples possible.
6
Soames, Kieron, and Jonas Lind. "Detecting Cycles in GraphQL Schemas." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-156174.
Повний текст джерелаАнотація:
GraphQL is a database handling API created by Facebook, that provides an effective al-ternative to REST-style architectures. GraphQL provides the ability for a client to spec-ify exactly what data it wishes to receive. A problem with GraphQL is that the freedomof creating customized requests allows data to be included several times in the response,growing the response’s size exponentially. The thesis contributes to the field of GraphQLanalysis by studying the prevalence of simple cycles in GraphQL schemas. We have im-plemented a locally-run tool and webtool using Tarjan’s and Johnson’s algorithms, thatparses the schemas, creates a directed graph and enumerates all simple cycles in the graph.A collection of schemas was analysed with the tool to collect empirical data. It was foundthat 39.73 % of the total 2094 schemas contained at least one simple cycle, with the averagenumber of cycles per schema being 4. The runtime was found to be on average 11 mil-liseconds, most of which consisted of the time for parsing the schemas. It was found that44 out of the considered schemas could not be enumerated due to containing a staggeringamount of simple cycles. It can be concluded that it is possible to test schemas for cyclicityand enumerate all simple cycles in a given schema efficiently.
7
Cronje, Mercia. "Engineering process model: Detection of cycles and determination of paths." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/2376.
Повний текст джерелаАнотація:
Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2006.In order to plan the engineering work of large construction projects efficiently, a model of the engineering process is required. An engineering process can be modelled by sets of persons, tasks, datasets and tools, as well as the relationships between the elements of these sets. Tasks are more often than not dependent on other tasks in the engineering process. In large projects these dependencies are not easily recognised, and if tasks are not executed in the correct sequence, costly delays may occur. The homogeneous binary relation “has to be executed before” in the set of tasks can be used to determine the logical sequence of tasks algebraically. The relation can be described by a directed graph in the set of tasks, and the logical sequence of tasks can be determined by sorting the graph topologically, if the graph is acyclic. However, in an engineering process, this graph is not necessarily acyclic since certain tasks have to be executed in parallel, causing cycles in the graph. After generating the graph in the set of tasks, it is important to fuse all the cycles. This is achieved by finding the strongly connected components of the graph. The reduced graph, in which each strongly connected component is represented by a vertex, is a directed acyclic graph. The strongly connected components may be determined by different methods, including Kosaraju’s, Tarjan’s and Gabow’s methods. Considering the “has to be executed before” graph in the set of tasks, elementary paths through the graph, i.e. paths which do not contain any vertex more than once, are useful to investigate the influence of tasks on other tasks. For example, the longest elementary path of the graph is the logical critical path. The solution of such path problems in a network may be reduced to the solution of systems of equations using path algebras. The solution of the system of equations may be determined directly, i.e. through Gauss elimination, or iteratively, through Jacobi’s or Gauss-Seidel’s methods or the forward and back substitution method. The vertex sequence of an acyclic graph can be assigned in such a way that the coefficient matrix of the system of equations is reduced to staggered form, after which the solution is found by a simple back substitution. Since an engineering process has a start and an end, it is more acyclic than cyclic. Consequently we can usually reduce a substantial part of the coefficient matrix to staggered form. Using this technique, modifications of the solution methods mentioned above were implemented, and the efficiency of the technique is determined and compared between the various methods.
8
O'Connor, Matthew. "Ruminant prion disease detection and characterisation using protein misfolding cyclic amplification." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/41599/.
Повний текст джерелаАнотація:
Prion diseases or transmissible spongiform encephalopathies (TSE) are characterised by the accumulation of a misfolded conformer (PrPSc) of a host encoded protein (PrPC). The misfolding event that leads to the formation PrPSc can be replicated in the in vitro amplification technique, protein misfolding cyclic amplification (PMCA). This thesis focuses on the application PMCA to study multiple aspects of prion misfolding in relation to ruminant prion diseases, specifically developing techniques to detect and characterise PrPSc in scrapie and BSE infections. Utilising recombinant hamster PrP (rPrP) as substrate in PMCA, multiple genotypes of scrapie were successfully amplified in an attempt to describe a quantifiable technique applicable to a wide range of scrapie isolates. Observations of non-specific protease resistant rPrP formation was investigated with modifications to the PMCA methodology, which ultimately proved unsuccessful in reducing non-specific protease resistant rPrP. Using brain PrPC as substrate, the quantitative PMCA technique was piloted with BSE to correlate in vitro replication efficiency with infectious titre in mouse bioassay, but no correlation was identified. Atypical forms of BSE occur primarily in older cattle, are asymptomatic and thought to be spontaneous diseases. None the less, infection models in rodents and primates have identified the zoonotic potential of H-type and L-type BSE. Therefore PMCA methods were developed which were able to successfully amplify both atypical forms of BSE. In particular, sensitive detection and discrimination from classical BSE was demonstrated for H-type BSE, which has not previously been amplified in PMCA. H-type BSE could be detected in 1x10¬-12 g brain material and was discriminated from classical BSE by increased protease sensitivity, relatively high molecular weight and antibody reactivity. Evidence exists for co-infection of TSE strains, yet scrapie and BSE co-infection in an ovine host remains unaddressed. To study the disease progression and tissue dissemination of co-infections a PMCA assay capable of specifically amplifying BSE PrPSc in the presence of excess scrapie was applied to artificially mixed brain homogenates containing BSE and scrapie, and compared to current statutory strain typing methods. The PMCA was found to have sensitivity and specificity of 100% in mixes containing 0.1% BSE and 99.9% scrapie brain material, which was more effective than conventional strain typing methods. The assay was then applied to the brain, spleen and lymph of scrapie and BSE experimental co-infections in two genotypes of sheep, and to animals which belonged to a flock with endemic natural scrapie and that also received experimental BSE infections. The PMCA data demonstrated that sheep with PRNP genotype ARQ/ARQ (at amino acid positions 134, 154 and 171) were resistant to BSE in a co-infection scenario. In sheep with PRNP genotype of VRQ/ARQ, mixed infections could occur, and animals with scrapie PrPSc only in the brain could harbour BSE PrPSc in peripheral tissues. Co-infection was also possible in sheep with natural scrapie infections. The assay was compared to conventional testing methods of western blotting, PrPd profiling and immunohistochemistry and displayed superior sensitivity in BSE detection. PMCA amplification of bovine BSE isolates in ovine substrates identified several instances in which the molecular characteristics of the PrPSc was scrapie-like in terms of molecular weight, antibody reactivity and glycoform profile, and in some cases PrPSc characteristic of BSE could no longer be recovered. This occurred in a genotype specific manner, ‘molecular switching’ was only apparent in ovine substrate VRQ/VRQ in accordance with previous findings. These results raise the possibility of such an event occurring in in vivo ovine BSE infections and the zoonotic potential of these scrapie like conformers are yet to be fully addressed.
9
Kolluri, Murali Mohan. "Non-parametric nonlinearity detection under broadband excitation." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573224392534571.
Повний текст джерела
10
Kalil, Haitham Fawzy Mohamed. "NANOMATERIALS-BASED SENSORS FOR PEROXYNITRITE DETECTION AND QUANTIFICATION." Cleveland State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=csu151336709631904.
Повний текст джерела
11
Makarov, Aleksej. "Non parametric data qualification : detection and separation of cyclic and acyclic changes /." Lausanne : EPFL, 1997. http://library.epfl.ch/theses/?nr=1715.
Повний текст джерела
12
Yeary, Amber J. "Cetyltrimethylammonium Halide-Coated Electrodes for the Detection of Dopamine in the Presence of Interferents." Wright State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=wright1323471405.
Повний текст джерела
13
Campbell, Mariam. "Cyclic universes & direct detection of cosmic expansion by holonomy in the McVittie spacetime." Master's thesis, Faculty of Science, 2019. http://hdl.handle.net/11427/31091.
Повний текст джерелаАнотація:
This dissertation consists of two parts. They are separate ideas, but both fall into the context of General Relativity using dynamical systems. Part one is titled Cyclic Universes. It is shown that a Friedmann model with positive spatial sections and a decaying dark energy term admits cyclic solutions which is shown graphically by the use of phase planes. Coupling the modified Friedmann model to a scalar field model with cross-sectional terms in order to model the reheating phase in the early universe, it is found that there is a violation of the energy condition, i.e.
when the universe is in the contracting phase and re-collapses again. We suspect that the cause for this violation is due to the asymmetry of the solution of w together with the cross-sectional terms at the bounce preceding slow-roll inflation. Part two is titled Thought Experiment to Directly Detect Cosmic Expansion by Holonomy. Two thought experiments are proposed to directly measure the expansion of the universe by the parallel transfer of a vector around a closed loop in a curved spacetime. Generally, expansion would cause a measurable deficit angle between the vector’s initial and final positions. Using the McVittie spacetime (which describes a spherically symmetric object in an expanding universe) as a backdrop to perform these experiments it is shown that the expansion of the universe can be directly detected by measuring changes in the components of a gyroscopic spin axis. We find these changes to be small but large enough (∆S ∼ 10−7 ) to be measured if the McVittie spacetime were a representation of our universe.
14
Zosiwe, Mlandeli Siphelele Ernest. "Cytochrome P450 2E1/Nickel-Poly(propylene imine) dendrimeric nanobiosensor for pyrazinamide - A first line TB Drug." University of the Western Cape, 2015. http://hdl.handle.net/11394/4703.
Повний текст джерелаАнотація:
>Magister Scientiae - MScThe tuberculosis (TB) disease to this day remains one of the world’s prominent killerdiseases. Pyrazinamide (PZA) is one of the most commonly prescribed anti- tuberculosis (anti-TB) drugs due to its ability to significantly shorten the TB treatment period from the former nine months to the current six months duration. However, excess PZA in the body causes hepatotoxicity and damages the liver. This hepatotoxicity, together with the resistance of the bacteria to treatment drugs, poor medication and inappropriate dosing, greatly contribute to the high incidents of TB deaths and diseases that are due to side effects (such as liver damage). This brings about the calls for alternative methods for ensuring reliable dosing of the drug, which will be specific from person to person due to inter-individual differences in drug metabolism. A novel biosensor system for monitoring the metabolism of PZA was prepared with a Ni-PPI-PPy star copolymer and cytochrome P450 2E1 (CYP2E1) deposited onto a platinum electrode. The nanobiosensor system exhibited enhanced electro-activity that is attributed to the catalytic effect of the incorporated star copolymer. The biosensor had a sensitivity of 0.142 µA.nM-1, and a dynamic linear range (DLR) of 0.01 nM-0.12 nM (1.231 – 7.386 ng/L PZA). The limit of detection of the biosensor was found to be 0.00114 nM (0.14 ng/L) PZA. From the HPLC peakconcentration (Cmax) of PZA determined 2 h after drug intake is 2.79 – 3.22 ng.L-1,which is very detectable with the nanobiosensor as it falls within the dynamic linear range.
15
Kollipara, Suresh Babu. "Organic Electrochemical Transistors for Fast Scan Cyclic Voltammetry." Thesis, Linköpings universitet, Fysik och elektroteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-98676.
Повний текст джерелаАнотація:
The work presented in the thesis is about the evaluation of Organic Electrochemical Transistors (OECTs) for fast scan cyclic voltammetry (FSCV). FSCV is a method which has been used for real time dopamine sensing both in vivo and in vitro. The method is sensitive to noise and could therefore benefit from signal preamplification at the point of sensing, which could be achieved by incorporation of OECTs. In this study the OECTs are based on the conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The gate consists of gold microelectrodes of different sizes to be used one at a time. When dopamine is reacted at the gate electrode, the redox state of the PEDOT:PSS OECT channel is modulated and the resulting change in drain current can be measured. The gate current, which contains the sensing information, is after filtering obtained by differentiating the channel potential with respect to time. The derived gate current is plotted in cyclic voltammogram for different dopamine concentrations and the amplitude of the oxidation/reduction peaks can be used to determine the dopamine concentration. In this thesis for the first time it is demonstrated that OECTs can be used for FSCV detection of dopamine. The results are discussed and an outlook on future work is given.
16
Rocker, Samantha Nicole. "Piezoresistivity Characterization of Polymer Bonded Energetic Nanocomposites under Cyclic Load Cases for Structural Health Monitoring Applications." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/91427.
Повний текст джерелаАнотація:
The strain and damage sensing abilities of randomly oriented multi-walled carbon nanotubes (MWCNTs) dispersed in the polymer binder of energetic composites were experimentally investigated. Ammonium perchlorate (AP) crystals served as the inert energetic and atomized aluminum as the metallic fuel, both of which were combined to create a representative fuel-oxidizer filler often used for aerospace propulsive applications. MWCNTs were dispersed within an elastomer binder of polydimethylsiloxane (PDMS), and hybrid energetics were fabricated from it, with matrix material comprised of the identified fillers. The nanocomposites were characterized based on their stress-strain response under monotonic uniaxial compression to failure, allowing for the assessment of effects of MWCNTs and aluminum powder on average compressive elastic modulus, peak stress, and strain to failure. The piezoresistive response was measured as the change in impedance with applied monotonic strain in both the mesoscopic and microscopic strain regimes of mechanical loading for each material system, as well as under ten cycles of applied compressive loading within those same strain regimes. Gauge factors were calculated to quantify the magnitude of strain and damage sensing in MWCNT-enhanced material systems. Electrical response of single-cycle thermal loading was explored with epoxy in place of the elastomer binder of the previously discussed studies. Piezoresistive response due to microscale damage from thermal expansion was observed exclusively in material systems enhanced by MWCNTs. The results discussed herein validate structural health monitoring (SHM) applications for embedded carbon nanotube sensing networks in polymer-based energetics under unprecedented cyclic loads.Master of Science
The ability to characterize both deformation and damage in real time within materials of high energetic content, such as solid rocket propellant, is of great interest in experimental mechanics. Common energetic ammonium perchlorate, in the fonn of crystal particles, was embedded in polymer binders (ie PDMS and epoxy) and investigated under a variety of mechanical and thermal loads. Carbon nanotubes, conductive tube-shaped molecular structures of carbon atoms, have been demonstrated in prior proofs of concept to induce substantial electrical response change when dispersed in composites which are experiencing strain. With the introduction of carbon nanotubes in the energetic composites investigated herein, the electrical response of the material systems was measured as a change in impedance with applied strain. Elastomer-bonded energel.ks were t.esl.ed under monotonic compression and cyclic compression, and expanded exploration was done on these material systems with the additional particulate of aluminum powder, allowing for varied particulate sizes and conductivity enhancement of the overall composite. The magnitude of the resulting piezoresistive change due to strain and microscale damage was observed to increase dramatically in material systems enhanced by MWCNT networks. Local heating was used to explore thermal loading on epoxy-bonded energetic material systems, and sensing of permanent damage to the material through its CNT network was proven through a permanent change in the electrical response which was exclusive to the CNT-enhanced material systems. These results demonstrate valid structural health monitoring (SHM) applications for embedded carbon nanotube sensing networks in particulate energetic composites, under a variety of load cases.
17
Yamada, Rei. "Hyperpolarization-activated cyclic-nucleotide gated cation channels regulate auditory coincidence detection in nucleus laminaris of the chick." Kyoto University, 2005. http://hdl.handle.net/2433/144385.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(医学)
甲第11938号
医博第2920号
新制||医||911(附属図書館)
23727
UT51-2006-B117
京都大学大学院医学研究科脳統御医科学系専攻
(主査)教授 金子 武嗣, 教授 河野 憲二, 教授 伊藤 壽一
学位規則第4条第1項該当
18
Etsassala, Ninon Geornest Eudes Ronauld. "Detection of selective tyrosinase inhibitors from some South African plant extracts of lamiaceae family." University of the Western Cape, 2016. http://hdl.handle.net/11394/5439.
Повний текст джерелаАнотація:
Magister Scientiae - MScVarious dermatological disorders, such as formation of black pigmented patches on the surface of the skin arise from the over-activity of tyrosinase enzyme's degenerative action. This enzyme is further implicated in the involvement of melanin in malignant melanoma, the most lifethreatening skin tumors. Although, synthetic products were found effective to combat this menace, nevertheless, overtime detrimental effect on human skin is a challenge. Investigation of natural tyrosinase inhibitors from methanol extracts of medicinal plants of Lamiaceae family using L-tyrosine as substrate on three different complementary assays (TLC bio-autography, spectrophotometry and cyclic voltammetry) was carried out accordingly. The result indicated Salvia chamelaeagnea, Salvia dolomitica, Plectranthus ecklonii, Plectranthus namaensis, and Plectranthus zuluensis, with significant zone of inhibition against tyrosinase on TLC bio-autography, spectrophotometry result showed that extracts of Plectranthus ecklonii (IC50 = 21.58 μg/mL), Plectranthus zuluensis (IC50 = 23.99 μg/mL), Plectranthus madagascariensis (IC50 = 23.99 μg/mL) and Salvia lanceolata (IC50 = 28.83) demonstrated good anti-tyrosinase activity when compared with kojic acid (IC50 = 3.607 μg/mL). On the other hand, cyclic voltammetry are in consonant with above results thereby supported the nomination of some of the extracts as strong anti-tyrosinase agents. Salvia chamelaeagnea showed strong activity in cyclic voltammetry and clear zone of inhibition on TLC bioautography, these reasons gave us justification for further chemical study to isolate the bioactive constituents. Phytochemical investigation of the bioactive extract of Salvia chamelaeagnea using different chromatographic methods including column chromatographic and semi preparative HPLC afforded six (6) known compounds viz carsonol (C1), carnosic acid (C2), 7- ethoxylrosmanol (C3), ursolic acid (C4), rosmanol (C5) and ladanein (C6). Their chemical structures were elucidated by analyses of spectroscopic (1H and 13C NMR) data as well as correlations with existing literature. The methanolic extract of S. chamelaeagnea (SC) showed moderate antityrosinase (IC50 = 267.4 μg/mL) activity, total antioxidant capacities measured as: Oxygen radicals absorbance capacity (ORAC; 14970 ± 5.16 μM TE/g), ferric-ion reducing antioxidant power (FRAP; 9869.43 ± 7.87 μM AAE/g) and trolox equivalent absorbance capacity (TEAC; 13706.5 ± 0.95 μM TE/g). Excellent total antioxidant capacities were demonstrated by C1 and C5 respectively as FRAP (9338.92 ± 1.72; 8622.73 ± 1.92) μM AAE/g; TEAC (16505 ± 0.86; 10641.5 ± 0.52) μM TE/g; ORAC (14550.5 ± 3.65; 14633.90 ± 3.84) μM TE/g and including the inhibition of Fe2+ -induced lipid peroxidation (IC50 = 32.5; 30.25) μg/mL. All the compounds except C4 are electro-active with well-defined oxidation-reduction peaks while C1 demonstrated the highest tyrosinase inhibitory activity by strongly decreased the inhibition current with time using cyclic voltammetry method. The isolated compounds especially C1, C2 and C5 are well known to combat with ageing problems and documented for their powerful activity against oxidative stress and alzheimer's diseases, which are ageing related symptoms. The isolation of such bioactive compounds indicated the synergetic effect of the results of the three methods used in this thesis. This is the first report on the evaluation of both anti-tyrosinase and total antioxidant capacities of the isolated compounds from S. chamelaeagnea. The findings therefore can be used as background information for exploitation of skin depigmentation and antioxidant agents from natural source.
19
Grymel, Martin-Thomas. "Error control with binary cyclic codes." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/error-control-with-binary-cyclic-codes(a5750b4a-e4d6-49a8-915b-3e015387ad36).html.
Повний текст джерелаАнотація:
Error-control codes provide a mechanism to increase the reliability of digital data being processed, transmitted, or stored under noisy conditions. Cyclic codes constitute an important class of error-control code, offering powerful error detection and correction capabilities. They can easily be generated and verified in hardware, which makes them particularly well suited to the practical use as error detecting codes.A cyclic code is based on a generator polynomial which determines its properties including the specific error detection strength. The optimal choice of polynomial depends on many factors that may be influenced by the underlying application. It is therefore advantageous to employ programmable cyclic code hardware that allows a flexible choice of polynomial to be applied to different requirements. A novel method is presented in this thesis to realise programmable cyclic code circuits that are fast, energy-efficient and minimise implementation resources.It can be shown that the correction of a single-bit error on the basis of a cyclic code is equivalent to the solution of an instance of the discrete logarithm problem. A new approach is proposed for computing discrete logarithms; this leads to a generic deterministic algorithm for analysed group orders that equal Mersenne numbers with an exponent of a power of two. The algorithm exhibits a worst-case runtime in the order of the square root of the group order and constant space requirements.This thesis establishes new relationships for finite fields that are represented as the polynomial ring over the binary field modulo a primitive polynomial. With a subset of these properties, a novel approach is developed for the solution of the discrete logarithm in the multiplicative groups of these fields. This leads to a deterministic algorithm for small group orders that has linear space and linearithmic time requirements in the degree of defining polynomial, enabling an efficient correction of single-bit errors based on the corresponding cyclic codes.
20
Lazarevic, Ljubica. "Improving the efficiency and accuracy of nocturnal bird Surveys through equipment selection and partial automation." Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/4155.
Повний текст джерелаАнотація:
Birds are a key environmental asset and this is recognised through comprehensive legislation and policy ensuring their protection and conservation. Many species are active at night and surveys are required to understand the implications of proposed developments such as towers and reduce possible conflicts with these structures. Night vision devices are commonly used in nocturnal surveys, either to scope an area for bird numbers and activity, or in remotely sensing an area to determine potential risk. This thesis explores some practical and theoretical approaches that can improve the accuracy, confidence and efficiency of nocturnal bird surveillance. As image intensifiers and thermal imagers have operational differences, each device has associated strengths and limitations. Empirical work established that image intensifiers are best used for species identification of birds against the ground or vegetation. Thermal imagers perform best in detection tasks and monitoring bird airspace usage. The typically used approach of viewing bird survey video from remote sensing in its entirety is a slow, inaccurate and inefficient approach. Accuracy can be significantly improved by viewing the survey video at half the playback speed. Motion detection efficiency and accuracy can be greatly improved through the use of adaptive background subtraction and cumulative image differencing. An experienced ornithologist uses bird flight style and wing oscillations to identify bird species. Changes in wing oscillations can be represented in a single inter-frame similarity matrix through area-based differencing. Bird species classification can then be automated using singular value decomposition to reduce the matrices to one-dimensional vectors for training a feed-forward neural network.
21
Saatci, Ebru. "Development Of A Glutathione-s-transferase-based Biosensor For The Detection Of Heavy Metals." Phd thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12606425/index.pdf.
Повний текст джерелаАнотація:
In the recent years, environmental pollution becomes a health threatening issue for human beings. Technological developments introduce industrial wastes and heavy metals, and developments in agriculture introduce pesticides into the world that we live. All these toxic wastes accumulate in drinking water and food consumed by humans. Therefore, detection of toxic wastes in all kinds of environmental samples, and development of new detection techniques become an important issue.
In this study, development of a protein-based biosensor for detection of heavy metals in environmental samples, by expressing genetically modified glutathione S-transferase (GST-(His)6) protein in E.Coli BL21 (DE3) expression system, was designed. Recombinant GST proteins was expressed in E.Coli BL21 (DE3) expression system and purified with Glutathione Sepharose 4B affinity column and Ni-NTA spin kit. GST activities were determined using the GST substrate 1-chloro-2,4-dinitrobenzene (CDNB). Protein expression was tested by SDS-PAGE and Western blot analysis. Product formation linearly increased up to 1 mM CDNB, 1 mM GSH, 1.7 µg proteins in 0.05 M, pH 6.9 phosphate buffer in the final volume of 1.0 ml at 25&
#9702
C. The Vmax and Km values for GST-(His)6 towards CDNB and GSH were calculated with Lineweaver-Burk as CDNB Vmax
22.88 µ
mol/min/mg, Km
4.29 mM,and as GSH Vmax
6.42 µ
mol/min/mg, 24.45 µ
mol/min/mg, Km
3.69 mM, respectively. Biosensor working electrode was prepared by immobilizing the GST-(His)6 by 1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride (EDC) coupling on the gold surface. Electrode preparation was confirmed by cyclic voltammetry measurements. The biosensor was inserted as the working electrode in the constructed three(four)-electrode flow cell. The conformational change resulting from the binding of the metal ions to the recombinant protein causing a capacitance change proportional to the concentration of the metal ions was determined. After the working electrode is standardized and calibrated, the heavy metal concentration in water samples was measured. The GST-(His)6 biosensor has a large operational range between 1 fM and 10 mM and a storage stability of approximately 2 weeks. The GST-(His)6 biosensor is very sensitive to, Cu+2>
Cd+2>
Zn+2>
Hg+2 metal ions, at low concentrations.
22
Siebritz, Robert Matthew. "The preparation of an immunosensor for the detection of microcystins and nodularins by immobilisation of a labelled antibody onto a polymer modified electrode." University of the Western Cape, 2011. http://hdl.handle.net/11394/5220.
Повний текст джерелаАнотація:
Masters of ScienceSouth African dams and reservoirs are increasingly showing the propensity to support sustained populations of Cyanobacteria (blue green algae). These photosynthetic bacteria occur throughout the world and can rapidly form blooms in eutrophic water systems. The occurrence of these photosynthetic bacteria, in our dwindling drinking water source dams, poses a serious, economic, as well as a health, threat to and arid country like South Africa due to is potential to produce of toxic metabolites like Microcystins and Nodularins (MCN). MCN's are cyclic peptides toxins, harmful to humans and animals, and its toxicological mechanism is based on a strong inhibition of protein phosphatises in the liver. This may lead to severe liver damage and increased tumour development. Rural communities consuming untreated water in South Africa are most at risk due the high toxicity of MCN’s at low doses.We endeavour to develop an immunosensor for the detection of Microcystins and nodularins using anti-sheep IgG antibody labelled with horseradish peroxidase (HRP) immobilised on a modified glassy-carbon polymer surface. The immunosensor will be applied to water samples for MCN’s as a group of compounds recognised by the ADDA moiety common to all MCN congeners. The immunosensor will provide immediate confirmation and quantification of MCN’s in situ. A competitive Enzyme Linked Immuno-Sorbant Assay (ELISA) and High Performance liquid Chromatography (HPLC) will be used to validate results of our immunosensor. Elisa's are widely used as a screening test method for MCN's. The antibody-antigen specificity forms the bases for the recognition of target compound (MCN's) by antibodies which bind to a compound which is labelled with a colour indicator, and quantified by spectrophotometry.
23
Badal, Mohammed Youssouf. "The development of a micro-total analysis system for gene detection and quantitation using cycling probe technology with capillary zone electrophoresis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ60272.pdf.
Повний текст джерела
24
Nqakala, Noniko Civilized. "Construction of an enzyme-free electrochemical sensor based on Ag-Fe2O3/POM/RGO novel nanocomposite for hydrogen peroxide detection." University of the Western Cape, 2018. http://hdl.handle.net/11394/6762.
Повний текст джерелаАнотація:
>Magister Scientiae - MScThe motivation to determine H2O2 lies in the fact that this chemical species plays a crucial role in diverse fields of practise such as cosmetic, food, diagnostic, pharmaceutical, clinical and environmental protection industries. Several methods such as chromatography, colorimetry, titrimetry and spectrophotometry have been developed for its detection. However, these methods are known to manifest underlying disadvantages such as high cost, time consuming, instability and complicated immobilization procedures. In this present study an enzyme-less electrochemical sensor based on Ag-Fe2O3/POM/RGO nanocomposite (POM stands for polyoxometalate and RGO stands for reduced graphene oxide) was successfully synthesised via a hydrothermal method and a photochemical reduction method for the detection of hydrogen peroxide (H2O2).
25
Wilson, Lindsay. "Electrochemical immunosensor based on cyclodextrin supramolecular interactions for the detection of human chorionic gonadotropin." Thesis, University of the Western Cape, 2012. http://hdl.handle.net/11394/3995.
Повний текст джерелаАнотація:
>Magister Scientiae - MScGlucose oxidase (GOx) and horseradish peroxidase (HRP) are important enzymes for the development of amperometric enzyme linked immunosensors. The selectivity of each enzyme towards its analyte deepens its importance in determining the sensitivity of the resultant immunosensor. In designing immunosensors that have customized transducer surfaces, the incorporation with FAD and iron based enzymes ensures that electron kinetics remains optimal for electrochemical measurement. Various different immobilization strategies are used to produce response signals directly proportional to the concentration of analyte with minimal interferences. The combination of self-assembled monolayers and supramolecular chemistry affords stability and simplicity in immunosensor design. In this work, two electrochemical strategies for the detection of human chorionic gonadotropin(hCG) is presented. This involves the modification of a gold surface with a thiolated β-cyclodextrin epichlorohydrin polymer (βCDPSH) to form a supramolecular inclusion complex with ferrocene (Fc)-functionalised carboxymethyl cellulose polymer (CMC). Cyclic voltammetry indicated that ferrocene is in close proximity to the electrode surface due to the supramolecular complex formed with βCDPSH. Furthermore, strategy (a) for the detection of hCG used α-antihCG labelled (HRP) as reporter conjugate. Strategy (b) maintained the CMC bifunctionalised with Fc and recognition antibody for hCG hormone. However, the system was functionalised with a HRP enzyme and detection is done by using GOx reporter conjugates for in situ production of hydrogen peroxide. The reduction of H2O2 was used for the amperometric detection of hCG by applying a potential of 200 mV. The sensitivity and limit of detection of both strategies were calculated from calibration plots. For strategy (a) the LOD was found to be 3.7283 ng/mL corresponding to 33.56 mIU/mL and a sensitivity of 0.0914 nA ng-1 mL-1. The corresponding values for strategy (b) are 700 pg/mL (6.3 mIU/mL) and 0.94 nA ng-1 mL-1.
26
Choi, Jungyoon. "Développement de molécules théranostiques ciblantes contre le cancer de la prostate Targeting tumors with cyclic RGD-conjugated lipid nanoparticles loaded with an IR780 NIR dye: In vitro and in vivo evaluation." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAV025.
Повний текст джерелаАнотація:
Depuis leur découverte en 1987, les peptides RGD ont été largement testés comme agents anti-angiogéniques et comme agents de contraste pour la détection et l’imagerie des tumeurs. En particulier pour l’imagerie optique, plusieurs vecteurs à base de RGD sont testés en préclinique car ils ciblent en même temps les tumeurs et leurs vaisseaux récemment formés.Le premier objectif de ma thèse était de développer un agent de contraste fluorescent dans le proche infra-rouge pour guider la prise de biopsies dans la prostate par imagerie optique. En tant que partenaire d’un programme ANR, notre objectif était de créer une nanoémulsion lipidique conjuguée avec des peptides RGD cycliques, chargée avec un fluorophore proche infra-rouge, et de les tester dans un modèle de cancer de la prostate chez la souris. Comme la plupart des nanoparticules qui présentent un diamètre de 50 nm, les nanoémulsions lipidiques (LNPs) peuvent s’accumuler passivement dans les tumeurs par effet EPR (Enhanced permeability and retention effect). Dans cette étude, nous développons des LNPs PEGylées en surface, chargées avec de l’oleyl-IR780 pour l’imagerie de fluorescence proche infra-rouge et greffées avec des peptides cRGD dans le but de cibler l’intégrine αvβ3. Sur les lignées cellulaires HEK293-β3, HEK293-β3-αvRFP, DU145 et PC3, nous démontrons un ciblage spécifique du récepteur avec les cRGD-LNPs mais pas avec les LNPs-cRAD et LNPs-standards. Nous démontrons aussi que les LNPs-cRGD se lient à l’intégrine αvβ3, interfèrent avec l’adhésion des cellules à la vitronectine et sont co-internalisées avec αvβ3 dans les cellules en moins d’une heure. Nous avons ensuite étudié leur biodistribution et leur capacité de ciblage dans les souris porteuses de tumeurs DU145 ou M21. Nous n’avons observé aucune différence significative au niveau de l’accumulation/rétention entre les LNP-cRGD et les LNP non-ciblées. Ceci suggère que, malgré une bonne formulation des NPs, le ciblage cRGD n’augmente pas la quantité totale de LNPs qui s’accumulent passivement dans les tumeurs sous-cutanées via l’effet EPR. Dans un second temps, nous avons essayé d’augmenter ce ciblage et avons travaillé sur une nanoparticule faite d’une matrice de silice couverte par un peptide cRGD combiné à un autre peptide ATWLPPR qui cible la neuropilin-1 (NRP1). NRP1 est un corécepteur de VEGFR2, aussi impliqué dans la néoangiogenèse et dans la croissance tumorale. Le double-ciblage cRGD/ATWLPPR devrait assurer un meilleur ciblage tumoral ainsi qu’une meilleure activité anti-angiogénique comparé aux NPs présentant uniquement le cRGD. Cependant, nous avons plutôt trouvé un effet antagoniste avec les NP-cRGD mais sans synergie apparente ou effet additionnel lorsque le deuxième ligand était présent. Au contraire, nos résultats préliminaires suggèrent que le double-ciblage déclencherait plutôt la prolifération cellulaire. Ceci mérite une investigation plus poussée pour mieux comprendre les mécanismes mis en jeu. De plus, l’utilisation de telles particules mais qui seraient aussi capables de délivrer des agents cytotoxiques pourrait entrainer une activité anti-tumorale puissanteSince the discovery of RGD peptides in 1987, they have been largely tested as anti-angiogenic agents as well as targeted contrast agents for tumor detection and imaging. In particular, several RGD-based optical contrast agents are currently being tested in preclinical studies because they target tumors and newly formed blood vessels at the same time.The first aim of my thesis work was to develop a near-infrared (NIR) fluorescent contrast agent for optically guided prostate biopsy. As partners of an ANR program, our objective was to provide a cRGD-targeted lipid nanoemulsion labeled with a NIR dye, which would target prostate tumors in a mouse model. Like several 50 nm-large nanocarriers, lipid nanoparticles (LNPs) can passively accumulate in tumors through the Enhanced Permeability and Retention (EPR) effect. In this study, we developed PEGylated LNPs loaded with oleyl-IR780 dye as a contrast agent for NIR fluorescence imaging, and modified them with cyclic RGD peptides in order to target integrin αvβ3. We demonstrate a specific targeting of the receptor with cRGD-LNPs but not with cRAD-LNP and standard LNP, using HEK293-β3, HEK293-β3-αvRFP, DU145 and PC3 cell lines. We also demonstrate that cRGD-LNPs bind to αvβ3, interfere with cell adhesion to vitronectin, and co-internalize with αvβ3 within one hour. We then investigated their biodistribution and tumor targeting in mice bearing DU145 or M21 tumors. We observed no significant differences between cRGD-LNP and non-targeted ones regarding their biodistribution and accumulation/retention in tumors. This suggested that despite an efficient formulation of the cRGD-LNPs, the cRGD-mediated targeting did not increase the total amount of LNP that could already accumulate passively in the subcutaneous tumors via the EPR effect.In a second objective, we tried to improve this targeting and worked on second generation nanoparticles made of a silica matrix covered by a cRGD peptide combined with another peptide, ATWLPPR, which targets Neuropilin-1 (NRP1). NRP1, a co-receptor of VEGFR2, is also involved in neo-angiogenesis and tumor growth. Dual-targeted cRGD/ATWLPPR-SiNPs were thus expected to provide a better tumor targeting as well as an improved anti-angiogenic activity as compared to cRGD-only-SiNPs. However, we found a possible antagonistic effect only with cRGD-SiNPs without synergy or additive effect despite the presence of the two ligands. In contrast, our preliminary results suggest that the dual-targeted SiNPs may trigger a cell proliferation and tumor-promoting effect. This should be further investigated, but one interesting consequence would be that the delivery of selected therapeutic agents using our dual-targeted SiNPs may provide an interesting antitumor activity
27
Sadli, Rahmad. "Étude et développement d'un dispositif routier d'anticollision basé sur un radar ultra large bande pour la détection et l'identification notamment des usagers vulnérables." Thesis, Valenciennes, 2019. http://www.theses.fr/2019VALE0005.
Повний текст джерелаАнотація:
Dans ce travail de thèse, nous présentons nos travaux qui portent sur l’identification des cibles en général par un radar Ultra-Large Bande (ULB) et en particulier l’identification des cibles dont la surface équivalente radar est faible telles que les piétons et les cyclistes. Ce travail se décompose en deux parties principales, la détection et la reconnaissance. Dans la première approche du processus de détection, nous avons proposé et étudié un détecteur de radar ULB robuste qui fonctionne avec des données radar 1-D (A-scan) à une dimension. Il exploite la combinaison des statistiques d’ordres supérieurs et du détecteur de seuil automatique connu sous le nom de CA-CFAR pour Cell-Averaging Constant False Alarm Rate. Cette combinaison est effectuée en appliquant d’abord le HOS sur le signal reçu afin de supprimer une grande partie du bruit. Puis, après avoir éliminé le bruit du signal radar reçu, nous implémentons le détecteur de seuil automatique CA-CFAR. Ainsi, cette combinaison permet de disposer d’un détecteur de radar ULB à seuil automatique robuste. Afin d’améliorer le taux de détection et aller plus loin dans le traitement, nous avons évalué l’approche des données radar 2-D (B-Scan) à deux dimensions. Dans un premier temps, nous avons proposé une nouvelle méthode de suppression du bruit, qui fonctionne sur des données B-Scan. Il s’agit d’une combinaison de WSD et de HOS. Pour évaluer les performances de cette méthode, nous avons fait une étude comparative avec d’autres techniques de suppression du bruit telles que l’analyse en composantes principales, la décomposition en valeurs singulières, la WSD, et la HOS. Les rapports signal à bruit -SNR- des résultats finaux montrent que les performances de la combinaison WSD et HOS sont meilleures que celles des autres méthodes rencontrées dans la littérature. A la phase de reconnaissance, nous avons exploité les données des deux approches à 1-D et à 2-D obtenues à partir du procédé de détection. Dans la première approche à 1-D, les techniques SVM et le DBN sont utilisées et évaluées pour identifier la cible en se basant sur la signature radar. Les résultats obtenus montrent que la technique SVM donne de bonnes performances pour le système proposé où le taux de reconnaissance global moyen atteint 96,24%, soit respectivement 96,23%, 95,25% et 97,23% pour le cycliste, le piéton et la voiture. Dans la seconde approche à 1-D, les performances de différents types d’architectures DBN composées de différentes couches ont été évaluées et comparées. Nous avons constaté que l’architecture du réseau DBN avec quatre couches cachées est meilleure et la précision totale moyenne peut atteindre 97,80%. Ce résultat montre que les performances obtenues avec le DBN sont meilleures que celles obtenues avec le SVM (96,24%) pour ce système de reconnaissance de cible utilisant un radar ULB. Dans l’approche bidimensionnelle, le réseau de neurones convolutifs a été utilisé et évalué. Nous avons proposé trois architectures de CNN. La première est le modèle modifié d’Alexnet, la seconde est une architecture avec les couches de convolution arborescentes et une couche entièrement connectée, et la troisième est une architecture avec les cinq couches de convolution et deux couches entièrement connectées. Après comparaison et évaluation des performances de ces trois architectures proposées nous avons constaté que la troisième architecture offre de bonnes performances par rapport aux autres propositions avec une précision totale moyenne qui peut atteindre 99,59%. Enfin, nous avons effectué une étude comparative des performances obtenues avec le CNN, DBN et SVM. Les résultats montrent que CNN a les meilleures performances en termes de précision par rapport à DBN et SVM. Cela signifie que l’utilisation de CNN dans les données radar bidimensionnels permet de classer correctement les cibles radar ULB notamment pour les cibles à faible SER et SNR telles que les cyclistes ou les piétonsIn this thesis work, we focused on the study and development of a system identification using UWB-Ultra-Wide-Band short range radar to detect the objects and particularly the vulnerable road users (VRUs) that have low RCS-Radar Cross Section- such as cyclist and pedestrian. This work is composed of two stages i.e. detection and recognition. In the first approach of detection stage, we have proposed and studied a robust UWB radar detector that works on one dimension 1-D radar data ( A-scan). It relies on a combination of Higher Order Statistics (HOS) and the well-known CA-CFAR (Cell-Averaging Constant False Alarm Rate) detector. This combination is performed by firstly applying the HOS to the received radar signal in order to suppress the noise. After eliminating the noise of the received radar signal, we apply the CA-CFAR detector. By doing this combination, we finally have an UWB radar detector which is robust against the noise and works with the adaptive threshold. In order to enhance the detection performance, we have evaluated the approach of using two dimensions 2-D (B-Scan) radar data. In this 2-D radar approach, we proposed a new method of noise suppression, which works on this B-Scan data. The proposed method is a combination of WSD (Wavelet Shrinkage Denoising) and HOS. To evaluate the performance of this method, we performed a comparative study with the other noise removal methods in literature including Principal Component Analysis (PCA), Singular Value Decomposition (SVD), WSD and HOS. The Signal-to-Noise Ratio (SNR) of the final result has been computed to compare the effectiveness of individual noise removal techniques. It is observed that a combination of WSD and HOS has better capability to remove the noise compared to that of the other applied techniques in the literature; especially it is found that it allows to distinguish efficiency the pedestrian and cyclist over the noise and clutters whereas other techniques are not showing significant result. In the recognition phase, we have exploited the data from the two approaches 1-D and 2-D, obtained from the detection method. In the first 1-D approach, Support Vector Machines (SVM) and Deep Belief Networks (DBN) have been used and evaluated to identify the target based on the radar signature. The results show that the SVM gives good performances for the proposed system where the total recognition accuracy rate could achieve up to 96,24%. In the second approach of this 1-D radar data, the performance of several DBN architectures compose of different layers have been evaluated and compared. We realised that the DBN architecture with four hidden layers performs better than those of with two or three hidden layers. The results show also that this architecture achieves up to 97.80% of accuracy. This result also proves that the performance of DBN is better than that of SVM (96.24%) in the case of UWB radar target recognition system using 1-D radar signature. In the 2-D approach, the Convolutional Neural Network (CNN) has been exploited and evaluated. In this work, we have proposed and investigated three CNN architectures. The first architecture is the modified of Alexnet model, the second is an architecture with three convolutional layers and one fully connected layer, and the third is an architecture with five convolutional layers and two fully connected layers. The performance of these proposed architectures have been evaluated and compared. We found that the third architecture has a good performance where it achieves up to 99.59% of accuracy. Finally, we compared the performances obtained using CNN, DBN and SVM. The results show that CNN gives a better result in terms of accuracy compared to that of DBN and SVM. It allows to classify correctly the UWB radar targets like cyclist and pedestrian
28
Lim, Christina Go. "Synthesis and characterization of poly(oxazoline) rotaxanes and literature review on separation, detection and identification of cyclic oligomers in poly(ethylene terephthalate) and poly(c̋aprolactam) /." This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-01202010-020257/.
Повний текст джерела
29
Souza, Evellyn Gonçalves de. "Desenvolvimento de um aptassensor para detecção do vírus da dengue." Universidade Federal de Goiás, 2017. http://repositorio.bc.ufg.br/tede/handle/tede/7766.
Повний текст джерелаАнотація:
Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-09-13T16:28:44Z
No. of bitstreams: 2
Dissertação - Evellyn Gonçalves de Souza - 2017.pdf: 2198173 bytes, checksum: 0e490bd8b1f7554afb334a3e27faf8ef (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-09-19T13:57:54Z (GMT) No. of bitstreams: 2 Dissertação - Evellyn Gonçalves de Souza - 2017.pdf: 2198173 bytes, checksum: 0e490bd8b1f7554afb334a3e27faf8ef (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Made available in DSpace on 2017-09-19T13:57:54Z (GMT). No. of bitstreams: 2 Dissertação - Evellyn Gonçalves de Souza - 2017.pdf: 2198173 bytes, checksum: 0e490bd8b1f7554afb334a3e27faf8ef (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-08-17
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Dengue is an endemic disease that causes wide concern both the health systems and to the patients. Thus, it is important that studies aiming at diagnoses faster and with possibility of field application can be developed for the medical intervention happens early, avoiding the worsening of the cases. Therefore, the aim of this work was to develop an electrochemical biosensor based on the use of aptamer as a bioelement for recognition on the surface of the boron doped diamond electrode (BDD) for the detection of each of the four serotypes of the dengue virus. Previously to the development of the biosensor, the dot-blot and apta-PCR techniques were used as validation methods for the interaction between aptamer B07 and target, the 5'UTR region present in the viral genome. The cyclic voltammetry technique was used in the analysis of redox reactions on the surface of the BDD electrode with and without modification of its surface with chitosan film. Ferrocene was used as the redox mediator and electroactive indicator of hybridization of the DNA strands formed in the sensor. The peaks of current indicated that the electrode with chitosan film modification on its surface presented greater stability. The redox compound had higher affinity for the double chains hybridized on the surface of the electrode, showing current values for DENV 1, 2, 3 and 4 of were 0.73; 0.69; 0.79 and 1.03 μA, respectively. These values were higher than the current found for the single-stranded aptamer (ssDNA), which was 0.62 μA, as well as for the current obtained from the aptamer hybridized with its complementary strand (dsDNA) whose value was 0.91 μA. Analyzes with time variations were performed showing a reduction in current values as a function of time, probably due to the reduction of the interaction of the electroactive material in the sensor. The aptasensor developed here showed good detection distinction between nucleic acid sequences, presenting potential for application in the detection of dengue virus.
A dengue é uma doença endêmica que causa grande preocupação tanto aos sistemas de saúde quanto aos pacientes. Dessa forma, é importante que estudos visando diagnósticos mais rápidos e com possibilidade de aplicação a campo possam ser desenvolvidos para que a intervenção médica possa ser precoce, evitando-se o agravamento dos casos. Neste sentido, buscou-se no presente trabalho desenvolver um biossensor eletroquímico baseado no uso de aptâmero como bioelemento reconhecedor na superfície do eletrodo de diamante dopado com boro (DDB) para a detecção de cada um dos quatro sorotipos do vírus da dengue. Previamente ao desenvolvimento do biossensor, as técnicas de dot-blot e apta-PCR foram utilizadas como métodos de validação da interação entre o aptâmero B07 e alvo, a região 5’UTR presente no genoma viral. A técnica de voltametria cíclica foi utilizada nas análises de reações redox na superfície do eletrodo DDB com e sem modificação de sua superfície com filme de quitosana. O composto ferroceno foi utilizado como mediador redox e indicador eletroativo de hibridização das cadeias de DNA formadas no sensor. Os picos de corrente indicaram que o eletrodo com modificação de filme de quitosana em sua superfície apresentou maior estabilidade, onde o composto redox teve maior afinidade pelas duplas cadeias hibridizadas na superfície do eletrodo, apresentando valores de correntes para DENV 1, 2, 3 e 4 de foram 0,73; 0,69; 0,79 e 1,03 μA, respectivamente. Esses valores foram superiores a corrente encontrada para o aptâmero em fita simples (ssDNA) que foi de 0,62 μA, assim como observada para corrente obtida do aptâmero hibridizado com sua fita complementar (dsDNA) cujo valor obtido foi de 0,91 μA. Análises com variações de tempo foram realizadas apresentando redução nos valores de correntes em função do tempo, provavelmente devido à redução da interação do material eletroativo no sensor. O aptasensor aqui desenvolvido apresentou boa detecção distinção entre sequências de ácidos nucleicos, apresentando potencial para aplicação na detecção do vírus da dengue.
30
Lim, Christina Go. "Synthesis and characterization of poly(oxazoline) rotaxanes and literature review on separation, detection and identification of cyclic oligomers in poly(ethylene terephthalate) and poly(ε-caprolactam)". Master's thesis, Virginia Tech, 1991. http://hdl.handle.net/10919/40712.
Повний текст джерелаАнотація:
Several methods have been developed to determine the cyclic oligomer content in PET. Isolation procedures can be classified as those involving extraction, such as with solvents like chloroform, dioxane, and xylene, and those involving dissolution followed by precipitation in solvents like dimethylformamide and 1-methylnaphthalene. The amount of cyclic oligomer obtained is largely dependent upon the method used, as well as the type, drawing, and thermal history of the PET used.Various methods for separation of cyclic oligomers have also been developed using GPC and thin-layer chromatography.Master of Science
31
Ngwanya, Olwethu. "Molecularly imprinted polymers for detection of volatile organics associated with fuel combustion." University of the Western Cape, 2018. http://hdl.handle.net/11394/6363.
Повний текст джерелаАнотація:
Magister Scientiae - MSc (Chemistry)Pollutants such as polycyclic aromatic hydrocarbons (PAHs) are known for their toxic effects which may lead to the cause of degenerative diseases in both humans and animals. PAHs are widespread in the environment, and may be found in water, food, automotive industry and petrochemical industries to name but a few sources. Literature reports have highlighted industrial workplace exposure to PAHs as a leading cause for development of cancer in workers. Particularly, workers in the petrochemical industry are adversely affected and the incidence of skin and lung cancer in this population group is high. The United States of America in its guidelines developed by environmental protection agency (EPA) has identified 18 PAHs as priority pollutants. Among these are anthracene, benzo[a]pyrene and pyrene which have been selected as the focal point of this study due to their significance in the petrochemical industry. Due to the carcinogenic and mutagenic properties reported in literature for certain PAHs, there have been monitoring procedures taken in most countries around the world. The commonly used analytical methods for the detection of PAHs from industrial samples are high performance liquid chromatography (HPLC) coupled to fluorescence detection, membrane filtration, ozonation and reverse osmosis. Analysis of PAHs from the petrochemical industry is typically performed by HPLC method as well as sono-degredation in the presence of oxygen and hydrogen peroxide.
32
Bouvier, des Noes Mathieu. "Détection itérative des séquences pseudo-aléatoires." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT068/document.
Повний текст джерелаАнотація:
Les séquences binaires pseudo-aléatoires sont couramment employées par les systèmes de transmissions numériques ou des mécanismes de chiffrement. On les retrouve en particulier dans les transmissions par étalement de spectre par séquence direct (e.g. 3G ou GPS)) ou pour construire des séquences d'apprentissage pour faciliter la synchronisation ou l'estimation du canal (e.g. LTE). Un point commun à toutes ces applications est la nécessité de se synchroniser avec la séquence émise. La méthode conventionnelle consiste à générer la même séquence au niveau du récepteur et la corréler avec le signal reçu. Si le résultat dépasse un seuil pré-défini, la synchronisation est déclarée acquise. On parle alors de détection par corrélation.Cette thèse aborde une autre voie : la détection des séquences binaires pseudo-aléatoire par des techniques de décodage canal. Ceci permet par exemple de détecter des séquences longues (e.g. de période 242), contrairement aux techniques par corrélation qui sont trop complexes à implémenter. Cela nécessite néanmoins que le récepteur connaisse au préalable le polynôme générateur de la séquence.Nous avons montré que le décodage d'une séquence pseudo-aléatoire est une problématique du type 'détecte et décode'. Le récepteur détecte la présence de la séquence et simultanément estime son état initial. Ceci correspond dans la théorie classique de la détection à un détecteur de type GLRT qui ne connaît pas la séquence émise, mais qui connaît sa méthode de construction. L'algorithme implémente alors un GLRT qui utilise un décodeur pour estimer la séquence reçue. Ce dernier est implémenté avec un algorithme de décodage par passage de messages qui utilise une matrice de parité particulière. Elle est construite avec des équations de parités différentes, chacune ayant un poids de Hamming valant t.Il correspond au nombre de variables participants à l'équation.Les équations de parité sont un constituant indispensable du décodeur. Nous avons donné leur nombre pour les m-séquences et les séquences de Gold. Pour le cas particulier des séquences de Gold, nous avons calculé le nombre d'équations de parité de poids t=5 lorsque le degré du polynôme générateur r est impair. Ce calcul est important car il n'y a pas d'équations de parité de poids t < 5 lorsque r est impair. Le nombre d'équations de parité est aussi utilisé pour estimer le degré minimal des équations d'un poids t donné. Nous avons montré que le modèle de prédiction estime correctement la valeur moyenne du degré minimal de l'ensemble des séquences de Gold. Nous avons néanmoins mis en évidence une grande variabilité du degré minimal des séquences autour de cette valeur moyenne.Nous avons ensuite identifié les ensembles absorbants complets de plus petite taille lorsque le décodeur emploie plusieurs polynômes de parité. Ces ensembles bloquent la convergence du décodeur lorsque celui-ci est alimenté avec du bruit. Ceci évite les fausses alarmes lors du processus de détection. Nous avons montré que des cycles 'transverses' détruisent ces ensembles absorbants, ce qui génère des fausses alarmes. Nous en avons déduit un algorithme qui minimise le nombre de cycles transverses de longueur 6 et 8, ce qui minimise la probabilité de fausse alarme lorsque le poids des équations de parité vaut t=3. Notre algorithme permet de sélectionner les équations de parité qui minimisent la probabilité de fausse alarme et ainsi réduire notablement le temps d'acquisition d'une séquence de Gold.Nous avons enfin proposé deux algorithmes de détection du code d'embrouillage pour les systèmes WCDMA et CDMA2000. Ils exploitent les propriétés des m-séquences constituant les séquences de Gold, ainsi que les mécanismes de décodage par passage de messages. Ces algorithmes montrent les vulnérabilités des transmissions par étalement de spectrePseudo-random binary sequences are very common in wireless transmission systems and ciphering mechanisms. More specifically, they are used in direct sequence spread spectrum transmission systems like UMTS or GPS, or to construct preamble sequences for synchronization and channel estimation purpose like in LTE. It is always required to synchronize the receiver with the transmitted sequence. The usual way consists in correlating the received signal with a replica of the sequence. If the correlation exceeds a predefined threshold, the synchronization is declared valid.This thesis addresses a different approach: the binary sequence is detected with a forward error correction decoding algorithm. This allows for instance to detect very long sequences.In this thesis, we show that decoding a pseudo-random sequence is a problematic of the kind ‘detect and decode'. The decoder detects the presence of the transmitted sequence and simultaneously estimates its initial state. In conventional detection theory, this corresponds to a GLRT detector that uses a decoder to estimate the unknown parameter which is the transmitted sequence. For pseudo-random sequences, the decoder implements an iterative message-passing algorithm. It uses a parity check matrix to define the decoding graph on which the algorithm applies. Each parity check equation has a weight t, corresponding to the number of variables in the equation.Parity check equations are thus an essential component of the decoder. The decoding procedure is known to be sensitive to the weight t of the parity check equations. For m-sequences, the number of parity check equations is already known. It is given by the number of codewords of weight t of the corresponding Hamming dual code. For Gold sequences, the number of parity check equations of weight t = 3 and 4 has already been evaluated by Kasami. In this thesis we provide an analytical expression for the number of parity check equations of weight t = 5 when the degree of the generator polynomial r is odd. Knowing this number is important because there is no parity check equation of weight t < 5 when r is odd. This enumeration is also used to provide an estimation of the least degree of parity check equations of weight t.We have then addressed the problem of selecting the parity check equations used by the decoder. We observed the probability of false alarm is very sensitive to this selection. It is explained by the presence or absence of absorbing sets which block the convergence of the decoder when it is fed only with noise. These sets are known to be responsible for error floor of LDPC codes. We give a method to identify these sets according to the parity check equations used by the decoder. The probability of false alarm can increase dramatically if these absorbing sets are destroyed. Then we propose an algorithm for selecting these parity check equations. It relies on the minimization of the number of cycles of length 6 and 8. Simulation show that the algorithm allows to improve significantly the probability of false alarm and the average acquisition time.Eventually, we propose 2 algorithms for the detection of the scrambling codes used in the uplink of UMTS-FDD and CDMA2000 systems. They highlights a new vulnerability of DSSS transmission systems. It is now conceivable to detect these transmission if the sequence's generator is known
33
Larignon, Céline. "Mécanismes d'endommagement par corrosion et vieillissement microstructural d'éléments de structure d'aéronef en alliage d'aluminium 2024-T351." Phd thesis, Toulouse, INPT, 2011. http://oatao.univ-toulouse.fr/6994/1/larignon_partie_1_sur_2.pdf.
Повний текст джерелаАнотація:
Cette thèse s'inscrit dans le cadre d'une collaboration avec EADS Innovation Works et AIRBUS. L'objectif des travaux est d'identifier les modes d'endommagements possibles d'éléments de structure métalliques d'aéronefs développés en service et d'en comprendre les mécanismes et les effets sur les propriétés des matériaux afin de contribuer au développement d'une méthode de contrôle non destructif innovante. Le matériau sélectionné est un alliage d'aluminium 2024-T351, l'un des matériaux constitutifs de la voilure et du fuselage d'avions civils. Les modes d'endommagement étudiés sont la corrosion et le vieillissement microstructural. La première partie de ces travaux est consacrée à l'analyse de l'influence des conditions d'exposition au milieu corrosif sur le développement de la corrosion intergranulaire et à l'identification des mécanismes de dégradation associés et de leurs cinétiques. Des conditions d'exposition originales alternant des phases d'immersion et d'émersion à différentes températures ont été explorées dans la mesure où elles semblent particulièrement représentatives des conditions d'exposition réelles. Les mécanismes proposés pour comprendre l'endommagement observé dans certaines de ces conditions d'exposition au milieu corrosif, impliquent un phénomène apparenté à de la fragilisation par l'hydrogène, phénomène qui n'est, à l'heure actuelle, pas encore reconnu pour les alliages d'aluminium de la série 2xxx. L'influence de l'hydrogène sur les propriétés physico-chimiques et mécaniques du matériau est donc étudiée dans la seconde partie de ces travaux. Enfin, l'influence d'un vieillissement microstructural sur les propriétés de l'alliage ainsi que les couplages possibles entre vieillissement microstructural et phénomènes de corrosion sont abordés dans une dernière partie. L'ensemble des résultats obtenus permet de révéler des pistes pour développer une méthode CND innovante permettant la caractérisation physique in-situ du niveau d'endommagement à l'échelle locale d'éléments de structures en alliages d'aluminium.
34
Jijana, Abongile Nwabisa. "Development of electrochemical ZnSe Quantam dots biosensors for low-level detection of 17β-Estradiol estrogenic endocrine disrupting compound". Thesis, University of the Western Cape, 2010. http://hdl.handle.net/11394/2310.
Повний текст джерелаАнотація:
Magister Scientiae - MScThe main thesis hub was on development of two electrochemical biosensors for the determination of 17β-estradiol-estradiol: an estrogenic endocrine disrupting compound. Endocronology have significantly shown that the endocrine disruptors contribute tremendously to health problems encountered by living species today, problems such as breast cancer, reproductive abnormalities, a decline in male population most significant to aquatic vertebrates, reduced fertility and other infinite abnormalities recurring in the reproductive system of mostly male species. The first biosensor developed for the detection of 17β-estradiol-estradiol endocrine disrupting compound; consisted of an electro-active polymeric 3-mercaptoprorionic acid capped zinc selenide quantum dots cross linked to horseradish peroxidase (HRP) enzyme as a bio-recognition element. The second biosensor developed was comprised of cysteamine self assembled to gold electrode, with 3-mercaptopropionic acid capped zinc selenide quantum dots cross linked to cytochrome P450-3A4 (CYP3A4) enzyme in the presence of 1-ethyl-3-(3- dimethylaminopropyl)carbodiimide hydrochloride and succinimide.
South Africa
35
Feleni, Usisipho. "Quantum dots-amplified electrochemical cytochrome P450 phenotype sensor for tamoxifen, a breast cancer drug." University of the Western Cape, 2017. http://hdl.handle.net/11394/5505.
Повний текст джерелаАнотація:
Philosophiae Doctor - PhDBreast cancer is regarded as the most common cancer in South Africa and its rate of occurrence is increasing. About one in every 31 South African women are at the risk of developing breast cancer and early diagnosis and treatment guarantee 90% survival rate. Tamoxifen is the drugs of choice for the treatment of all stages of breast cancer. The drug binds with estrogen receptor (ER) to minimize the transcription of estrogen dependent genes. However, nearly 50% of ER-positive breast cancer patients either become resistant or fail to respond to tamoxifen resulting in a serious clinical challenge in breast cancer management. The Grand Health Challenges of South Africa includes the development of cost effective diagnostic systems suitable for early detection of diseases and drug resistivity for timely invention and better patient management.
2020-08-31
36
Gajdoš, Libor. "Optimalizace elektrochemického senzoru pro měření v kapce." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-221034.
Повний текст джерелаАнотація:
This thesis describes optimization and modification of standard thick-film electrochemical sensor to be able to be used for detection in microvolumes. In the theoretical part, the thick film technology is described. The work is then focused on the wettability of surfaces followed by introduction to electrochemistry and electro-analytical methods. In the experimental part, screen-printing of various types of thick film pastes on ceramic substrates for determination of their wettability and the following modification of the sensors with thick-film paste and with Parylene vaporization can be found, as well as the basic electrochemical measurements in microvolume using the modified sensor. Finally the results are summarized in conclusion.
37
Victoria, Rosemary. "Development of luminescent ruthenium complexes for in-vitro fluorescence imaging of angiogenesis with the RGD peptide." Honors in the Major Thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/633.
Повний текст джерелаАнотація:
Herein we report the synthesis of an RGD-ruthenium bipyridine [Ru(Bpy)2(BpyRGD)]2+ complex aimed at the detection of angiogenesis. Angiogenesis plays a critical role in many pathophysiological processes, such as tumor growth. The αv-integrins (αv[beta]3, αv[beta]5) are currently used as molecular targeting sites for anti-angiogenic therapies. The [Ru(Bpy)2(BpyRGD)]2+ complex is an organometallic luminescent probe, which enables noninvasive, in vitro imaging of αv[beta]3 expression. Peptides containing the arginine-glycine-aspartic acid (RGD) sequence have been shown to bind strongly to the αvb3 integrin. The RuBpy probes are soluble in water, display long lifetimes, and are photochemically stable. These properties enable the Ru(tris-bpy) complexes to be useful in numerous applications in biophysical and cell biology. The [Ru(Bpy)2(BpyRGD)]2+ complex was synthesized by combining the succinimidyl ester on the RuBpy complex with the lysine of the c(RGDfK) peptide. The results of the one-photon fluorescence bioimaging showed selective binding of the cyclic RGD to αv[beta]3 integrin, which supports previous literature. The high luminescence intensity, long lifetimes, and low cell toxicity levels of dye [Ru(Bpy)2(BpyRGD)]2+, illustrates the potential usage of this probe for future biological applications.B.S.
Bachelors
Sciences
Biology
38
Ostovar, Pour Saeideh. "Advanced vibrational spectroscopic studies of biological molecules." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/advanced-vibrational-spectroscopic-studies-of-biological-molecules(2e77df15-e7e0-4def-85f4-da996fbb6671).html.
Повний текст джерелаАнотація:
Raman optical activity (ROA) is a powerful probe of the structure and behaviour of biomolecules in aqueous solution for a number of important problems in molecular biology. Although ROA is a very sensitive technique for studying biological samples, it is a very weak effect and the conditions of high concentration and long data collection time required limit its application for a wide range of biological samples. These limitations could possibly be overcome using the principle of surface enhanced Raman scattering (SERS). The combination of ROA with SERS in the form of surface enhanced ROA (SEROA) could be a solution for widening the application of ROA. In the last few years, the generation of reliable SEROA spectra of biomolecules has been problematic due to non-homogenous colloidal systems forming and low signal-to-noise ratios which complicated detection of the true SEROA signal from the analyte. L- and D-enantiomers give full or partially mirror image chiroptical spectra, this property of enantiomers can be employed to prove the chiroptical activity of the SEROA technique. In this thesis we employed a hydrophilic polycarbopol polymer as stabilising media which has led to the first report of mirror image SEROA bands for enantiomeric structures. This new technique of incorporating the hydrogel polymer as a means to stabilise the colloidal system has proven to be reliable in obtaining high quality SEROA spectra of D- and L-enantiomers of ribose and tryptophan. In an extension of the hydrogel-stabilised SEROA work, we also demonstrate that single nanoparticle plasmonic substrate such as silver silica nanotags can enhance the weak ROA effect. These dye tagged silica coated silver nanoparticles have enabled a chiral response to be transmitted from a chiral analyte to the plasmon resonance of an achiral metallic nanostructure. The measurement of mirror image SERROA bands for the two enantiomers of each of ribose and tryptophan was confirmed for this system. The generation of SEROA for both systems was achieved and confirmed SEROA as a new sensitive tool for analysis of biomolecular structure. In a related project, Raman and ROA spectra were measured for adenosine and seven of its derivative ribonucleotides. Both of these spectroscopic techniques are shown to be sensitive to the site and degree of phosphorylation, with a considerable number of marker bands being identified for these ribonucleotides. Moreover, the SERS studies of these ribonucleotides were also performed. The obtained SERS spectra were shown similar features that confirm these analytes interact with the surface in a similar manner, hence limiting the structural sensitivity of this method towards phosphate position. Short dipeptides such as diketopiperazine (DKP) have been investigated during the last decades as both natural and synthetic DKPs have a wide variety of biological activities. Raman and ROA spectra of linear and cyclic dialanine and diserine were measured to charecterize their solution structures. Density functional theory (DFT) calculations were carried out by a collaborator to assist in making vibrational band assignments. Considerable differences were observed between the ROA bands for the cyclic and linear forms of both dialanine and diserine that reflect large differences in the vibrational modes of the polypeptide backbone upon cyclicization. In this study, the ROA spectra of cyclic dialanine and diserine have been reported for the first time which demonstrated that ROA spectroscopy when utilised in combination with computational modelling clearly provides a potential tool for characterization of cyclic peptides.
39
Chen, Yi-Hsiang, and 陳逸祥. "A Nighttime Part-based Cyclist Detection System Using Spatial and Appearance Information." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/03306661490324974114.
Повний текст джерелаАнотація:
碩士國立臺灣大學
資訊工程學研究所
102
Obstacle on road detection is an important issue in the field of intelligent transportation system. The research of pedestrian detection attracts attention due to the weakness of feature and descriptor. Some other obstacles, such as the cyclists, having weaker descriptive features are seldom discussed. The cyclist, of course, is not a light source and there are seldom or even no light source fixed on the two-wheel vehicles. Hence, it is notable to build a nighttime cyclist detection system to assist the vehicle driver. Thus, in this thesis, we propose a cyclist detection method for a moving vehicle equipped with a near-infrared camera. It will increase the difficulty when the detected objects including two-wheel vehicles due to some inherent properties of the two-wheel vehicles. For example, the aspect ratio varies depending on different viewpoints. Namely, the occlusion effect between cyclist and two-wheel vehicle varies with the viewpoint. To solve this problem, we employ the part-based object detection in this thesis as the main stream solution approach. Moreover, we use two kinds of additional information to verify the part-based detection result. The first one is the obvious contour appearance of two-wheel vehicle and its interior spatial relation with high stability. The second is the primary characteristic of the NIR image. Finally, experiments show that our system is verified and demonstrated in a nice performance.
40
Hu, Qichang. "Dynamic Scene Understanding with Applications to Traffic Monitoring." Thesis, 2017. http://hdl.handle.net/2440/119678.
Повний текст джерелаАнотація:
Many breakthroughs have been witnessed in the computer vision community in recent years, largely due to deep Convolutional Neural Networks (CNN) and largescale datasets. This thesis aims to investigate dynamic scene understanding from images. The problem of dynamic scene understanding involves simultaneously solving several sub-tasks including object detection, object recognition, and segmentation. Successfully completing these tasks will enable us to interpret the objects of interest within a scene. Vision-based traffic monitoring is one of many fast-emerging areas in the intelligent transportation system (ITS). In the thesis, we focus on the following problems in traffic scene understanding. They are 1) How to detect and recognize all the objects of interest in street view images? 2) How to employ CNN features and semantic pixel labelling to boost the performance of pedestrian detection? 3) How to enhance the discriminative power of CNN representations for improving the performance of fine-grained car recognition? 4) How to learn an adaptive color space to represent vehicle images for vehicle color recognition? For the first task, we propose a single learning based detection framework to detect three important classes of objects (traffic signs, cars, and cyclists). The proposed framework consists of a dense feature extractor and detectors of these three classes. The advantage of using one common framework is that the detection speed is much faster, since all dense features need only to be evaluated once and then are shared with all detectors. The proposed framework introduces spatially pooled features as a part of aggregated channel features to enhance the robustness to noises and image deformations. We also propose an object subcategorization scheme as a means of capturing the intra-class variation of objects. To address the second problem, we show that by re-using the convolutional feature maps (CFMs) of a deep CNN model as visual features to train an ensemble of boosted decision forests, we are able to remarkably improve the performance of pedestrian detection without using specially designed learning algorithms. We also show that semantic pixel labelling can be simply combined with a pedestrian detector to further boost the detection performance. Fine-grained details of objects usually contain very discriminative information which are crucial for fine-grained object recognition. Conventional pooling strategies (e.g. max-pooling, average-pooling) may discard these fine-grained details and hurt the iii iv recognition performance. To remedy this problem, we propose a spatially weighted pooling (swp) strategy which considerably improves the discriminative power of CNN representations. The swp pools the CNN features with the guidance of its learnt masks, which measures the importance of the spatial units in terms of discriminative power. In image color recognition, visual features are extracted from image pixels represented in one color space. The choice of the color space may influence the quality of extracted features and impact the recognition performance. We propose a color transformation method that converts image pixels from the RGB space to a learnt space for improving the recognition performance. Moreover, we propose a ColorNet which optimizes the architecture of AlexNet and embeds a mini-CNN of color transformation for vehicle color recognition.Thesis (Ph.D.) -- University of Adelaide, School of Computer Science, 2017
41
Lee, Chien-Ming, and 李健銘. "Detection of Cyclic Alternating Pattern in Electroencephalographic Signals." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/57989722092478086244.
Повний текст джерелаАнотація:
碩士國立交通大學
資訊科學與工程研究所
100
The purpose of this study is to develop a cyclic alternating pattern (CAP) detection algorithm based on EEG signal and to improve the classification accuracy of the A-phase subtypes. In the past study, sleep-related researches have been a lot, in which there is a large part of the analysis on the quality of sleep. But most of researches are applied for macrostructure analysis of sleep stage. Sleep medical literature has demonstrated that microstructure such as CAP and A-phase subtypes can be used in the analysis of quality of sleep. However, because of CAP has been noticed for sleep quality analysis in recent years and its intensive labor requirement, there are very few studies for the microstructure of CAP. Our study has inherited advantages of previous methods. It employed the descriptor of power spectrum, because the descriptor of power spectrum can provide a normalized measure. It also made use of the improved variable length template to detect the most suitable A-phase length of CAP detection algorithm. In order to decide A-phases’ length and existence, our method made use of descriptor to compare with threshold. After the detection of A-phase, it is used for determining CAP cycle and CAP sequence by CAP scoring rule. In the classification of A-phase subtypes, our method has attempted to enhance classification accuracy by using Navona classification method, fractal dimension, and k-NN classifier. In our experiment, we applied sleep EEG features of two insomnia subject's brain waves as the testing data. The accuracy of the proposed method is 65% in the CAP detection and 70.30% in A1, 24.4% in A2, and 65.4% in A3 in the classification of A-phase of subtypes. The proposed method combines variable length template method and EXIST/LENGTH thresholds method. Compared to Barcaro method, the proposed method is superior because of its usage of variable length template. We also used sleep EEG of 147 obstructive sleep apnea syndrome (OSAS) subjects and 41 non-OSAS subjects as the testing data. The CAP rates of 188 OSAS patients obtained by the proposed method are higher than those of non-OSAS subjects, which is consistent to the literature. For the severe OSAS subjects, the CAP detection results show increased values of CAP rates.
42
Lan, Jian-Cheng, and 藍建成. "Implementation of Bi-phase Muscle Electrical Stimulation Chip and Pedaling Force Detection Cycling Device." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/60426394609495786114.
Повний текст джерелаАнотація:
碩士雲林科技大學
電子與資訊工程研究所
98
In such an era when people are suffering from modern diseases resulted from the advance of technology, the emphasis on the demand of health and healthcare has been increased. After a series of clinical experiments, stimulation is proved to have good curative effects on pain relief, nerve and pressure elimination and muscle restoration, without any side effects as medical care do. The study mainly introduces the development of a bi-phase electrical stimulation chip and pedaling force detection cycling device, that the electrical stimulation chip produces various bi-phase square waves as the electrical stimulation waveform with different control models to make the user flexibly and easily operate the electrical stimulation system collocating a simple operated and easy assessed pedaling as an auxiliary to form a more practical treatment. The electrical stimulation chip may provide different frequency, band width, and strength in various ranges, reduce the number of chip pins with the concept of encoder circuit, and control to direction output current to achieve the electrical stimulation function of bipolar pulse. The study completes the chip design with TSMC 0.18 UM CMOS 1P6M 1.8&3.3V. The functional electrical stimulation cycling system brings good effects for spinal cord injuries on maintaining normal functioning of their muscles, nerve system and other physical performance. With simple and easy control and high security, FES cycling is a perfect device for rehabilitation. The pedaling device chosen in this study is inexpensive and easy to operate. With encoder (MES-30-P) and load cell (MLP-100 Series) as the re-equipped pedaling and the bi-phase electrical stimulation chip, a complete functional electrical stimulation cycling system established by an electrical stimulator is formed.
43
Lin, Hung-Yi, and 林鴻藝. "An Automatic Sleep Stage Classification and Cyclic Alternating Pattern Detection Algorithm and Its Application." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/08494393311885885060.
Повний текст джерелаАнотація:
碩士國立成功大學
電機工程學系碩博士班
97
This thesis presents an automatic sleep stage classification and cyclic alternating pattern detection algorithm for sleep quality analysis. The proposed algorithm is applied to improve the performance of clinical therapy in obstructive sleep apnea issue. An automatic classification algorithm composed of a neural-network-based classifier, which constructed by the minimum description length (MDL) principle, is developed to classify the four types of sleep stages of electroencephalogram (EEG) signal. Subsequently, an automatic CAP detection algorithm with adaptive thresholds is utilized to evaluate the current sleep quality of the patient in the NREM stage. Finally, the abovementioned two algorithms are both applied to clinical therapy in sleep issues. The experimental results have successfully validated: 1) the proposed sleep stage classification algorithm can classify the four types of sleep stages of EEG signal efficiently; 2) the proposed CAP detection algorithm can reduce computational burden and achieve satisfactory performance; and 3) the novel therapy procedure combined with the above two algorithms can improve the performance and effectiveness of the conventional clinical therapy method in obstructive sleep apnea issue.
44
Hsieh, Nan-Shin, and 謝男鑫. "Initial Downlink Synchronization for LTE Systems with Emphasis on Detection of Cyclic Prefix Type." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/30552287072109327655.
Повний текст джерелаАнотація:
碩士國立交通大學
電子工程學系 電子研究所
102
This thesis introduces the topic about initial downlink synchronization, including problem formulation, algorithm derivation and program simulation, in LTE-A system. We develop an algorithm about the joint estimation of symbol timing offset (STO), carrier frequency offset (CFO), and detection of the cyclic prefix (CP) type used in signal transmission. We first establish the transmitted and received signal models of LTE-A system and then derive the solution based on the maximum likelihood (ML) criterion. It is a general solution over not only additive white Gaussian noise (AWGN) and single-path Rayleigh fading channels but also multipath fading channels. In estimating CFO, we consider an approximation so as to reduce computational complexity largely. Though it is the suboptimal solution under multipath fading channels, it is an optimal solution under AWGN and single-path Rayleigh fading channels because the approximate term has no effect on estimation process. In simulation, we establish a reasonable received signal model in LTE-A system, and then simulate our proposed estimator under AWGN channel to verify its performance. Moreover, we test it under single-path Rayleigh fading and different multipath fading channels, including Standford University Interim (SUI) and Pedestrian B (PB), at different mobility and different signal to noise ratio (SNR).
45
Hong, Zim-min, and 洪子閔. "All-Digital High Speed Wide-Range Linear Cyclic Binary Detection Pulse Width Locked Loops." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/01534836448466432599.
Повний текст джерелаАнотація:
碩士國立雲林科技大學
電子與光電工程研究所碩士班
101
In the high-speed system chip inside, because the internal clock signal transistor manufacturing process, temperature, voltage variations caused by clock signal distortion, and even circuit performance can not be improved or operational error. These show the clock signal pulsewidth stability, in the circuit requirements are also increasing, as in piping systems, high-speed dynamic circuits, double sampling system or need negative edge trigger circuit needs to have stable a pulsewidth. Therefore, a stable working cycle lockout circuit is now an important issue. This thesis presents a new fully digital pulsewidth control circuit, using a linear cyclic delay line used in this thesis proposed a linear cyclic binary pulse detector and pulse generator mechanism so that the circuit does not need to increase the delay line progression to the low operational frequency state. The proposed linear cyclic binary pulse detectors, delay line design is only sixteen stage, in a linear cycle technology, and special arrangements are arranged in ascending binary mode. The proposed pulse detection circuit that can detect linear continuous, rapid quantized pulse code and cycle detection code detect quantitative takes only three clock cycles to complete. In this thesis, the pulse generator for the two-stage delay line architecture, when operated at high frequency band, close the loop delay line, only four bit from low to generate pulsewidth controlled delay line multiplexer. When operating in low frequencies, the open loop delay line, a linear binary cycle, generate a lot of low-frequency output pulse required delay time. In this thesis is unbalanced delay error compensation circuit is proposed in order to self-calibration techniques, through the pulse code subtractor correction techniques detect only feedback correction twice to reach locked output clock. In this thesis, the performance of the proposed new architecture using TSMC 90nm CMOS analog, with 25%, 50%, 75% three output locked pulse width is available, the operating bandwidth of 100MHz ∼ 3GHz, lock time of 25 clock cycles.
46
Burešová, Helena. "Cyklická voltametrie jako detekční technika ve vysokoúčinné kapalinové chromatografii." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-340413.
Повний текст джерелаАнотація:
The aim of the thesis was to study the possibility of employment of cyclic voltammetry as a detection technique in liquid chromatography. The phenothiazine derivatives (chlorpromazine hydrochloride, diethazine hydrochloride, and thioridazine hydrochloride) were used as model compounds. Firstly, the comparison of two potential detectors (tubular detector and bulk "wall-jet" detector) was accomplished. Only bulk "wal-jet" detector satisfied. Next, the conditions for the separation and detection of studied phenothiazines on RP-select B LiChrospher® 60 (250×4 mm) column with cyclic voltammetry as the detection techniques were optimized. The best separation is achieved in mobile phase consisted from the solution of 0.1 mol dm-3 sodium perchlorate in acetonitrile-water (80:20) mixture. The effect of flow rate of mobile phase and scan rate of polarization of the electrode on the symmetry of chromatographic peak was also followed, and optimal values of 0.5 ml min-1 for flow rate, and of 0.5 V s-1 for scan rate, were found. Under optimized conditions the calibration dependences of studied phenothiazines were measured in the range from 5×10-5 to 1×10-3 mol dm-3 for chlorpromazine, and in the range from 8×10-5 to 1×10-3 mol dm-3 for diethazine and thioridazine. The developed method was applied to...
47
Braithwaite, Shannon Lynn. "Optimization, adaptation and application of protein misfolding cyclic amplification to detection of prions in blood plasma." Master's thesis, 2010. http://hdl.handle.net/10048/1407.
Повний текст джерелаАнотація:
The PMCA assay was optimized for adaptation to low level detection of PrPSc in hamster plasma. Evaluation of numerous key variables of the PMCA assay led to an optimized protocol capable of ~3 log10 amplification after 32 cycles (two 16 hour rounds). When commercially purchased normal hamster plasma was added to the PMCA reaction an accentuation in PrPSc amplification was observed (>6.75 log10 after 32 cycles). Only con-specific plasma appeared to enhance the conversion of PrPC to PrPSc, suggesting that a species-specific co-factor may be involved in assembly of protein aggregates. Serial PMCA in the presence of low level (10%) contiguous conspecific plasma resulted in the generation of de novo PrPSc after several rounds of PMCA. Although plasma significantly accentuated PrPSc amplification by PMCA, the formation of de novo PrPSc interfered with the ability of using the PMCA assay to detect prion infections in hamsters experimentally infected with 263K scrapie.Physiology, Cell and Developmental Biology
48
Luo, Yan-Xiang, and 羅彥翔. "Label-free fluorescent biosensor with dual cyclic amplification strategy for DNA sequence detection of HPV-16." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/fxw6pe.
Повний текст джерелаАнотація:
碩士國立交通大學
應用化學系碩博士班
107
In this work, a label-free fluorescence biosensor for HPV-16 feature DNA sequence detection is developed. Based on the assistance of exonuclease III (Exo III) and phi-29/Nb.BbvCI, a dual amplification strategy is applied and an ultra-high sensitivity with extreme low detection limit is achieved. In the presence of target sequence, the first artificial hairpin DNA probe is hybridized with target sequence, which leads a blunt end and initiates the Exo III digest reaction, hydrolyzing the hybridized hairpin probe as residue DNA and releases target sequence for another cycle, leads to the first stage of amplification. Subsequently, the residue DNA triggered the 2nd amplification cycle by hybridizing with another artificial template DNA as the primer for DNA polymerization. Due to the complementary region and poly T we inserted in template DNA, the phi-29 polymerase replicates for the sequence of poly A with nicking site just after the region of residue DNA. Accordingly, multiple duplex of poly A sequence are produced under the assistance of phi-29 and Nb.BbvCI, leads to a second amplification cycle. Finally, we add Hoechst 33342, a fluorescence dye that significantly enhanced by A-T base pair, for fluorescence response and used for quantitation of target concentration. After all, this DNA sensor shows wide availability applications for detection of different DNA sequences.
49
Chang, Jinho. "Detection of unstable intermediates and mechanistic studies in multisteps, two-electron transfer reactions by cyclic voltammetry and scanning electrochemical microscopy." Thesis, 2014. http://hdl.handle.net/2152/30489.
Повний текст джерелаАнотація:
Unstable Sn(III) intermediates generated in the Sn(IV)/Sn(II) redox reaction in 2 M HBr + 4 M NaBr media were detected by scanning electrochemical microscopy (SECM) and cyclic voltammetry (CV). In CV, the underpotential deposition of Sn(0) and its stripping peaks severely perturbed the analysis of diffusional reactions. In SECM, however, the detection of diffusional Sn(III) bromide species was clearly observed due to the absence of the perturbation from the surface reactions. The ECEC-DISP mechanism in both the reduction and oxidation reactions was proposed via Sn(III) bromide intermediates. CVs at different concentrations of Sn(IV) and at various scan rates were fit by numerical simulations based on the proposed mechanism with good agreement. Enhanced electrochemical reversibility in the Sn(IV)/Sn(II) redox reaction was observed at the elevated temperature of 80 °C. We attributed such observation to changes in the rate of bromide loss from Sn(IV)Br₆²⁻ to Sn(IV)Br₅⁻ based on the CV simulation. In a similar approach, a short-lived intermediate, presumably bromine anion radical Br₂⁻·, was detected in the Br⁻ /Br₃⁻ electro-oxidation reaction in nitrobenzene solution by SECM and CV. The reaction mechanism was proposed based on a detected Br₂⁻· intermediate as follows: (1) the one electron transfer of Br⁻ to Br·, (2) the dimerization of 2Br· to Br₂, (3) the bromide addition reaction of Br₂ to Br₃⁻ , (4) the bromide addition reaction of Br· to Br₂⁻·, and (5) the Br· addition reaction of Br₂⁻· to Br₃⁻. The simulation based on the proposed mechanism fitted well with the experimental SECM and CV results. At last, the applicability of the Sn/Br system as electrolyte for electrochemical energy storage was tested. A redox flow battery was constructed, where the Sn(IV)/Sn(II) reduction was carried out on the negative electrode, while the Br· /Br₂ oxidation was carried out on the positive electrode during charging. Cyclability was tested up to 35 charge/discharge cycles, and 100 % coulombic efficiency was observed in all cycles. However, only 40 % of voltage efficiency was obtained, mainly due to the large irreversibility of the Sn(IV)/Sn(II) redox reaction in the bromide media.
50
Lin, Yuh-cheng, and 林育成. "Detection of p53 gene mutation in human breast neoplasm with single-strand conformation polymorphism and direct cyclic sequencing." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/36528981266891361444.
Повний текст джерелаАнотація:
碩士國立成功大學
藥理學研究所
85
p53是一種癌症抑制基因(tumor supressor gene)，在人類常見的癌症當 中，可發現p53基因的等位基因缺失(allelic deletion)或點突變(point mutation)所造成的功能喪失。當DNA受到了損傷之後，p53蛋白的量在細 胞內急遽增加，隨之使細胞週期停留在G1期；細胞若包含突變的p53或缺 乏p53則不能誘導此種細胞週期停止。此外，突變的p53基因使細胞進行計 畫性細胞自殺(apoptosis)的能力降低，因此癌細胞內的p53基因若突變則 其對化學療法或放射線療法將具有抵抗性。在與其他種致癌基因比較之下 ，p53基因的突變或缺失是在乳房癌中最常見的基因變化。因此，若能建 立p53基因與乳房癌惡化程度之間的關係，將有助於診斷乳房癌或者評估 其在治療後復發的可能性。本實驗的目的在於偵測不同病期的乳房癌中其 p53基因突變的情形，藉此來推斷乳房癌的預後(prognosis)。我們首先利 用去氧核醣核酸單股結構多型性(single-stand conformation polymorphism)，偵測涵蓋了p53之exons 5~9的部分，篩選出具有突變的 片段，再據此進行直接循環去氧核糖核酸定序(direct-cyclic DNA sequencing)以建立p53基因在乳房癌中突變的圖譜。經篩選及定序之後， 我們發現了三個病人在exon 5的位置產生了突變。編號33的病人，其p53 基因的第175個密碼子(codon)由CGC變為TGC，即胺基酸由原本的arginine 變為cysteine。編號36的病人其p53基因第175個密碼子由原本的CGC變為 CAC，即胺基酸由正常的arginine變為histidine。編號54的病人p53基因 的第138個密碼子則由原本的GCC變為CCC，即胺基酸由正常的alanine變為 proline，而以上三者均屬於錯譯突變(missense mutation)，並且其第一 個等位基因發生突變後伴隨著第二個等位基因的缺失，此現象稱之為loss of heterozygosity，是p53基因常被發現的現象之一。若想根據以上三個 p53突變之病人，來找出其病程與預後之關係，則尚無法確切地下結論。 其原因為此三人目前仍繼續在門診，其中雖有一人有癌症轉移之現象，但 代表性不夠，故仍需進一步的觀察。 p53 is a tumor supressor gene whose inactivation, either by allelic deletion or point mutation, is one of the most common genetic changes in human malignancies. The P53 protein level is strongly increased after experimental DNA damage and this is followed by a specific arrest of the cell cycle in G1 phase. Cells containing mutated p53 or lacking P53 are unable to induce this cell cycle arrest; furthermore, these cells would have a reduced capacity to induce apoptosis after DNA damage incurred by ionizing radiotherapy or some therapeutic drugs, suggesting that cancer cells containing mutated p53 are more resistant to radiotherapy or chemotherapy. Compared with the other oncogenes, p53 gene mutations and deletions are the most frequently observed genetic change in breast cancer. Therefore, p53 gene mutations coupled with the disease status could provide an invaluable tumor marker for diagnosis and/or prognosis of breast neoplasm. This research project aims at detecting p53 gene mutations from breast tumor samples of various neoplastic stages and with these information to infer the prognosis of breast cancer. We first obtained genomic DNA from archival and frozen-breast cancer tissues, then amplified exons 5,6,7,8 and 9 of p53 gene by the method of polymerase chain reaction (PCR). We used single-strand conformation polymorphism (SSCP) as a means to prescreen mutations in some specific exon fragments. Eleven variant fragments was identified by their band shifting following polyacrylamide gel electrophoresis (PAGE). Those variants are subjected to direct-cyclic sequencing so as to establish the mutation spectrum of p53 gene. Out of 11 SSCP variants, 3 showed nucleotide mutations upon sequencing. In patient number 33, codon 175 was changed from CGC to TGC, and patient number 36 has the same mutation site in codon 175: CGC ->CAC. Patient number 54 has mutation in codon 138: GCC->CCC. In agreement with other studies, these point mutations are believed to lead to changes in the conformation of p53 protein and loss of its normal functions.