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Dongmo, Guy Blaise. "Rank matrix cascade algorithm, hermite interpolation." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/853.
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Thesis (DSc (Mathematical Sciences))--University of Stellenbosch, 2007.ENGLISH ABSTRACT: (Math symbols have changed) Wavelet and subdivision techniques have developed, over the last two decades, into powerful mathematical tools, for example in signal analysis and geometric modelling. Both wavelet and subdivision analysis are based on the concept of a matrix–refinable function, i.e. a finitely supported matrix function which is self-replicating in the sense that it can be expressed as a linear combination of the integer shifts of its own dilation with factor 2: F = TAF = å k∈Z F(2 ・ −k)Ak. The coefficients Ak, k ∈ Z of d × d matrices, of this linear combination constitute the so-called matrix- mask sequence. Wavelets are in fact constructed as a specific linear combination of the integer shifts of the 2-dilation of a matrix- refinable function cf. [2; 9], whereas the convergence of the associated matrix- subdivision scheme c0 = c, cr+1 = SAcr, r ∈ Z+, SA : c = (ck : k ∈ Z) 7→ SAc = å ℓ∈Z Ak−2ℓ cℓ : k ∈ Z ! , subject to the necessary condition that rank := dim \ ǫ∈{0,1} n y ∈ Rd : Qǫy = y o > 0, Qǫ := å j∈Z Aǫ+2j, ǫ ∈ {0, 1}, ( cf. [26]) , implies the existence of a finitely supported matrix- function which is refinable with respect to the mask coefficients defining the refinement equation and the subdivision scheme. Throughout this thesis, we investigate in time–domain for a given matrix mask sequence, the related issues of the existence of a matrix–refinable function and the convergence of the corresponding matrix– cascade algorithm, and finally we apply some results to the particular research area of Hermite interpolatory subdivision schemes. The dissertation is organized as follows: In order to provide a certain flexibility or freedom over the project, we established in Chapter 1 the equivalence relation between the matrix cascade algorithm and the matrix subdivision scheme, subject to a well defined class of initial iterates. Despite the general noncommutativity of matrices, we make use in the full rank case Qǫ = I, ǫ ∈ {0, 1}, of a symbol factorization, to develop in Chapter 2 some useful tools, yielding a convergence result which comes as close to the scalar case as possible: we obtained a concrete sufficient condition on the mask sequence based on the matrix version of the generating function introduced in [3, page 22] for existence and convergence. Whilst the conjecture on nonnegative masks was confirmed in 2005 by Zhou [29], our result on scalar case provided a progress for general mask sequences. We then applied to obtain a new one-parameter family of refinable functions which includes the cardinal splines as a special case, as well as corresponding convergent subdivision schemes. With the view to broaden the class of convergent matrix-masks, we replaced in chapter 3 the full rank condition by the rank one condition Qǫu = u, ǫ ∈ {0, 1}, u := (1, . . . , 1)T, then improved the paper by Dubuc and Merrien [13] by using the theory of rank subdivision schemes by Micchelli and Sauer [25; 26], and end up this improvement with a generalization of [13, Theorem 13, p.8] in to the context of rank subdivision schemes. In Chapter 4, we translated the concrete convergence criteria of the general theory from Theorem 3.2, based on the r-norming factor introduced in [13, Definition 6, p.6], into the context of rank, factorization and spectral radius (cf. [26]), and presented a careful analysis of the relationship between the two concepts. We then proceed with generalizations and improvements: we classified the matrix cascade algorithms in term of rank = 1, 2, . . . , d, and provided a complete characterization of each class with the use of a more general r−norming factor namely τ(r)-norming factor. On the other hand, we presented numerical methods to determine, if possible, the convergence of each class of matrix cascade algorithms. In both the scalar and matrix cases above, we also obtained explicitly the geometric constant appearing in the estimate for the geometric convergence of thematrix-cascade algorithm iterates to the matrix- refinable function. This same geometric convergence rate therefore also holds true for the corresponding matrix–cascade algorithm. Finally, in Chapter 5, we apply the theory and algorithms developed in Chapter 4 to the particular research area of Hermite interpolatory subdivision schemes: we provided a new convergence criterium, and end up with new convergence ranges of the parameters’ values of the famous Hermite interpolatory subdivision scheme with two parameters, due to Merrien [23].
AFRIKAANSE OPSOMMING :(Wiskundige simbole het verander) Golfie en subdivisietegnieke het oor die afgelope twee dekades ontwikkel in kragtige wiskundige gereedskap, byvoorbeeld in seinanalise en geometriesemodellering. Beide golfie en subdivisie analise is gebaseer op die konsep van ’n matriks-verfynbare funksie; oftewel ’n eindig-ondersteunde matriksfunksie F wat selfreproduserend is in die sin dat dit uitgedruk kan word as ’n lineêre kombinasie van die heelgetalskuiwe van F se eie dilasie met faktor 2: F = Σ F(2 · −α)A(α), met A(α), α ∈ Z, wat aandui die sogenaamde matriks-masker ry. Golfies kan dan gekonstrueer word as ’n spesifieke lineêre kombinasie van die funksie ry {F(2 · −α) : α ∈ Z} (sien [2; 9]), terwyl die konvergensie van die ooreenstemmende matriks-subdivisie skema cº = c, cr+1 =(Σ β∈Z A(α − 2β) cr(β) : α ∈ Z ! , r ∈ Z+, onderhewig aan die nodige voorwaarde dat rank := dim \ ǫ∈{0,1} n y ∈ Rd : Qǫy = y o > 0, Qǫ := å α∈Z A(ǫ + 2α), ǫ ∈ {0, 1}, (sien [27]) die bestaan impliseer van ’n eindig-ondersteunde matriksfunksie F wat verfynbaar ismet betrekking tot diemaskerko¨effisi¨entewat die subdivisieskema definieer, en in terme waarvan die limietfunksie F van die subdivisieskema uitgedruk kan word as F = å α∈Z F(· − α)c(α). Ons hoofdoel hier is om , in die tydgebied, en vir ’n gegewematriks-masker ry, die verwante kwessies van die bestaan van ’nmatriks-verfynbare funksie en die konvergensie van die ooreenstemmende matriks-kaskade algoritme, en matriks-subdivisieskema, te ondersoek, en om uiteindelik sommige van ons resultate toe te pas op die spesifieke kwessie van die konvergensie van Hermite interpolerende subdivisieskemas. Summary v Eerstens, in Hoofstuk 1, ondersoek ons die verwantskap tussen matriks-kaskade algoritmes en matriks-subdivisie skemas, met verwysing na ’n goedgedefinieerde klas van begin-iterate. Vervolgens beskou ons die volle rang geval Qǫ = I, ǫ ∈ {0, 1}, om, in Hoofstuk 2, nuttige gereedskap te ontwikkel, en wat daarby ’n konvergensie resultaat met ’n sterk konneksie ten opsigte van die skalaar-geval oplewer. Met die doelstelling om ons klas van konvergente matriks-maskers te verbreed, vervang ons, in Hoofstuk 3, die volle rang voorwaarde met die rang een voorwaarde Qǫu = u, ǫ ∈ {0, 1}, u := (1, . . . , 1)T, en verkry ons dan ’n verbetering op ’n konvergensieresultaat in die artikel [14] deur Dubuc en Merrien, deur gebruik te maak van die teorie van rang subdivisieskemas van Micchelli en Sauer [26; 27], waarna ons die resultaat [14, Stelling 13, page 8] na die konteks van rang subdivisieskemas veralgemeen. InHoofstuk 4 herlei ons die konkrete konvergensie kriteria van Stelling 3.2, soos gebaseer op die r-normerende faktor gedefinieer in [14, Definisie 6, page 6] , na die konteks van rang, faktorisering en spektraalradius (sien [27]), en gee ons ’n streng analise van die verwantskap tussen die twee konsepte. Verder stel ons dan bekend ’n nuwe klassifikasie van matriks-kaskade algoritmes ten opsigte van rang, en verskaf ons ’n volledige karakterisering van elke klasmet behulp van ’nmeer algemene r-normerende faktor, nl. die τ(r)-normerende faktor. Daarby gee ons doeltreffende numeriesemetodes vir die implementering van ons teoretiese resultate. Ons verkry ook eksplisiet die geometriese konstante wat voorkom in die afskatting van die geometriese konvergensie van die matriks-kaskade algoritme iterate na die matriks-verfynbare funksie. Ten slotte, in Hoofstuk 5, pas ons die teorie en algoritmes ontwikkel in Hoofstuk 4 toe om die konvergensie van Hermite-interpolerende subdivisieskemas te analiseer. Spesifiek lei ons ’n nuwe konvergensie kriterium af, wat ons dan toepas om nuwe konvergensie gebiede vir die parameter waardes te verkry vir die beroemde Hermite interpolerende subdivisieskema met twee parameters, soos toegeskryf aan Merrien [24].
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Lohiya, Paranjith Singh. "Detection of Nano Particles in TEM Images Using an Ensemble Learning Algorithm." Youngstown State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1432915612.
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Zhou, Hao, and 周浩. "An efficient algorithm for face sketch synthesis using Markov weight fields and cascade decomposition method." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B49618052.
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Great progress has been made in face sketch synthesis in recent years. State-of-the-art methods commonly apply a Markov Random Fields (MRF) model to select local sketch patches from a set of training data. Such methods, however, have two major drawbacks. Firstly, the MRF model used cannot synthesize new sketch patches. Secondly, the optimization problem in solving the MRF is NP-hard. In this thesis, a novel Markov Weight Fields (MWF) model is proposed. By applying linear combination of candidate patches, MWF is capable of synthesizing new sketch patches. The MWF model can be formulated into a convex quadratic programming (QP) problem to which the optimal solution is guaranteed. Based on the Markov property of MWF model, a cascade decomposition method (CDM) is further proposed for solving such a large scale QP problem efficiently. Experiments show that the proposed CDM is very efficient, and only takes about 2:4 seconds. To deal with illumination changes of input photos, five special shading patches are included as candidate patches in addition to the patches selected from the training data. These patches help keeping structure of the face under different illumination conditions as well as synthesize shadows similar to the input photos. Extensive experiments on the CUHK face sketch database, AR database and Chinese celebrity photos show that the proposed model outperforms the common MRF model used in other state-of-the-art methods and is robust to illumination changes.published_or_final_version
Computer Science
Master
Master of Philosophy
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Wood, Peter John, and drwoood@gmail com. "Wavelets and C*-algebras." Flinders University. Informatics and Engineering, 2003. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20070619.120926.
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A wavelet is a function which is used to construct a specific type of orthonormal basis.
We are interested in using C*-algebras and Hilbert C*-modules to study wavelets. A Hilbert C*-module is a generalisation of a Hilbert space for which the inner product takes its values in a C*-algebra instead of the complex numbers. We study wavelets in an arbitrary Hilbert space and construct some Hilbert C*-modules over a group C*-algebra which will be used to study the properties of wavelets.
We study wavelets by constructing Hilbert C*-modules over C*-algebras generated by groups of translations. We shall examine how this construction works in both the Fourier and non-Fourier domains. We also make use of Hilbert C*-modules over the space of essentially bounded functions on tori. We shall use the Hilbert C*-modules mentioned above to study wavelet and scaling filters, the fast wavelet transform, and the cascade algorithm. We shall furthermore use Hilbert C*-modules over matrix C*-algebras to study multiwavelets.
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Bernardo, Nariane Marselhe Ribeiro. "A semianalytical algorithm to retrieve the suspended particulate matter in a cascade reservoir system with widely differing optical properties /." Presidente Prudente, 2019. http://hdl.handle.net/11449/190950.
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Orientador: Enner Herenio de AlcântaraResumo: O Material Particulado em Suspensão (MPS) é o principal componente em sistemas aquáticos. Elevadas concentrações de MPS implicam na atenuação da luz, e ocasionam alterações das taxas fotossintéticas. Além disso, a presença de MPS no sistema aquático pode aumentar os níveis de turbidez, absorver poluentes e podem ser considerados como um indicativo de descargas de escoamento superficial. Portanto, monitorar as concentrações de MPS é essencial para a gerar informações técnicas que subsidiem o correto manejo dos recursos aquáticos, prevenindo colapsos hidrológicos. O sensoriamento remoto se mostra como uma eficiente ferramenta para monitorar e mapear MPS quando comparada às técnicas tradicionais de monitoramento, como as medidas in situ. Entretanto, diante de uma grande e complexa variabilidade de componentes óticos, desenvolver modelos de MPS por meio do sinal registrado em sensores remotos é um desafio. Diversos modelos foram desenvolvidos para reservatórios, lagos e lagoas específicos. Atualmente, não há um único modelo capaz de estimar MPS em reservatórios brasileiros em cascata. Com o objetivo de estimar as concentrações de MPS de forma acurada, o objetivo desta tese foi desenvolver um modelo semi-analítico capaz de estimar valores de coeficiente de atenuação, Kd, por meio do uso dos coeficientes de absorção e espalhamento e, consequentemente, utilizar os valores de Kd para estimar as concentrações de MPS. A adoção desta estratégica se baseou na atenuação da luz ao longo da... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Suspended particulate matter (SPM) is the main component presented within aquatic system. High levels of SPM concentration attenuate the light affecting the photosynthesis rates. Besides, can increase turbidity levels, absorb pollutions and is an indicative of runoff discharges. Therefore, monitoring SPM concentrations is essential to provide reliable information for a correct water management to prevent hydrological collapse. Remote sensing emerges as an efficient tool to map and monitor SPM when compared to traditional techniques, such as in situ measurements. Nevertheless, considering a widely range of optical components, modeling the remote sensing signal in terms of SPM is a challenge. Several models were developed for specific reservoirs, lakes or ponds. Up to our knowledge, there is not a single model capable to retrieve SPM in Brazilian linked reservoirs in a cascade system. In order to accurately estimate SPM, the aim of the thesis was developed a semianalytical model capable to estimate Kd via absorption and backscattering coefficients, and then, use Kd to derive SPM. This approach was adopted because SPM directly contributes to the light attenuation within the water column. Firstly, optical features were investigated. It was found that each reservoir presented a specific optical active component (OAC) dominance, such as Barra Bonita, the first reservoir in cascade is dominated by organic SPM, while Nova Avanhandava, the last reservoir in cascade is dominated by ino... (Complete abstract click electronic access below)
Doutor
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Age, Amber E. "A Survey of the Development of Daubechies Scaling Functions." Scholar Commons, 2010. https://scholarcommons.usf.edu/etd/1557.
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Wavelets are functions used to approximate data and can be traced back to several different areas, including seismic geology and quantum mechanics. Wavelets are applicable in many areas, including fingerprint and data compression, earthquake prediction, speech discrimination, and human vision. In this paper, we first give a brief history on the origins of wavelet theory. We will then discuss the work of Daubechies, whose construction of continuous, compactly supported scaling functions resulted in an explosion in the study of wavelets in the 1990's. These scaling functions allow for the construction of Daubechies' wavelets. Next, we shall use the algorithm to construct the Daubechies D4 scaling filters associated with the D4 scaling function. We then explore the Cascade Algorithm, which is a process that uses approximations to get possible representations for the D2N scaling function of Daubechies. Lastly, we will use the Cascade Algorithm to get a visual representation of the D4 scaling function.
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Paduru, Anirudh. "Fast Algorithm for Modeling of Rain Events in Weather Radar Imagery." ScholarWorks@UNO, 2009. http://scholarworks.uno.edu/td/1097.
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Weather radar imagery is important for several remote sensing applications including tracking of storm fronts and radar echo classification. In particular, tracking of precipitation events is useful for both forecasting and classification of rain/non-rain events since non-rain events usually appear to be static compared to rain events. Recent weather radar imaging-based forecasting approaches [3] consider that precipitation events can be modeled as a combination of localized functions using Radial Basis Function Neural Networks (RBFNNs). Tracking of rain events can be performed by tracking the parameters of these localized functions. The RBFNN-based techniques used in forecasting are not only computationally expensive, but also moderately effective in modeling small size precipitation events. In this thesis, an existing RBFNN technique [3] was implemented to verify its computational efficiency and forecasting effectiveness. The feasibility of modeling precipitation events using RBFNN effectively was evaluated, and several modifications to the existing technique have been proposed.
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Oloungha, Stephane B. "Convergence analysis of symmetric interpolatory subdivision schemes." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5268.
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Nagavelli, Sai Krishnanand. "Improve Nano-Cube Detection Performance Using A Method of Separate Training of Sample Subsets." Youngstown State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1485267005121308.
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Durand, Sylvain. "Étude de la vitesse de convergence de l'algorithme en cascade intervenant dans la construction des ondelettes." Paris 9, 1993. https://portail.bu.dauphine.fr/fileviewer/index.php?doc=1993PA090058.
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L'objet de cette thèse est l'étude de la vitesse de convergence des algorithmes de résolution d'une équation à deux échelles. Il s'agit d'algorithmes de point fixe, souvent appelés algorithme en cascade, qui sont utilisés dans la construction des ondelettes. Nous étudions leur vitesse de convergence dans les espaces de Lebesgue et de Besov, et montrons que la qualité de la convergence dépend de deux facteurs indépendants. Le premier, qui va de soi, est la régularité de la fonction d'échelle qui est la solution de l'équation. Le second facteur (qui est la découverte essentielle de cette thèse) concerne des propriétés algébriques spécifiques de la fonction servant à initialiser l'algorithme. Celle-ci doit satisfaire des conditions analogues à celles de fix et strang
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Barlow, Jacob L. "Hardware-in-the-Loop control of a cascaded multi-level converter." Thesis, Monterey, California. Naval Postgraduate School, 2004. http://hdl.handle.net/10945/1193.
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Approved for public release; distribution is unlimitedNext-generation U.S. Navy destroyers, known as DD(X), will use electric drive motors to meet their propulsion needs instead of the traditional mechanical drives. The use of electric drive motors in naval vessels has spurred the development of high power converters. This thesis examines the feasibility of using an advanced control algorithm known as Sine-triangle Pulse Width Modulation (SPWM) in combination with a Cascaded Multi-Level Converter (CMLC) in order to meet the U.S. Navy's strict requirements. The SPWM control algorithm was designed in Simulink and experimentally tested on a CMLC previously constructed at the Naval Postgraduate School. The controller and converter successfully powered a quarter horsepower three-phase induction motor.
Ensign, United States Navy
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Boudaoud, Boubkeur. "Une approche en cascade inversée pour l'allocation de ressources dans les réseaux inter domaines." Versailles-St Quentin en Yvelines, 2013. http://www.theses.fr/2013VERS0013.
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Les travaux de cette thèse portent sur la gestion de ressources avec une qualité de service garantie de bout en bout (source-destination) dans les réseaux inter-domaines. Notre principale contribution consiste en la proposition d'un nouveau modèle pour la réservation des stocks de capacité que nous avons appelé le modèle en stock. Le processus de négociation entre les différents domaines d'un réseau pour l'achat de capacité est basé sur l'approche en cascade inversée. Chaque domaine souhaitant acheter une route vers une destination donnée doit négocier avec son voisin fournisseur potentiel qui lui a proposé de la capacité vers cette destination. La réservation de capacité par un domaine est dans le but de satisfaire la demande de ses propres clients internes vers la destination de cette route et de revendre le reste aux domaines voisins. Chaque domaine cherche à réserver de la capacité d'une façon à augmenter son bénéfice. Afin d'étudier la validation du modèle en stock, nous avons proposé dans un premier temps un modèle dynamique qui permet de mettre en œuvre le protocole d'établissement des contrats basé sur le modèle en stock. Ce modèle dynamique est basé sur un processus itératif et des algorithmes distribués. Dans un deuxième temps, nous avons proposé un modèle statique basé aussi sur des algorithmes distribués, de la théorie des jeux et d'apprentissage. Ce modèle statique est aussi proposé afin de le comparer avec le modèle dynamiqueThis thesis focuses on provisioning and resource management with guaranteed end-to-end Quality of Service in the inter-domain networks. Our main contribution consists in proposing a new model for provisioning stocks of capacity that we have called Stock Model. The process of reservation between several domains for purchasing capacity is based on a reverse cascade approach. Each domain wishing to purchase a route to a given destination must negotiate with its potential provider neighbor that has offered capacity to this destination. Provisioning a stock of capacity on a given route by a domain aims to satisfy demands of its internal customers to the destination of this route and to sell the rest of capacity to its neighboring domains. Each domain purchases capacity in a way to increase its profit. In order to investigate Stock Model, we have proposed in a first time a dynamic model allowing the implementation of contracts establishment protocol that is based on Stock Model. This dynamic model is also based on an iterative process and distributed algorithms. In a second time, we have proposed a static model that is based on game and learning theory, and also based on distributed algorithms. The static model is also proposed in order to compare it with the dynamic model
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Coradine, Luis Claudius. "Filtragem adaptativa em cascata : proposta de estrutura e algoritmo, analise e aplicações." [s.n.], 1993. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260416.
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Orientador: João Marcos Travassos RomanoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica
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Resumo: A filtragem adaptativa utilizando estruturas na forma em cascata FIR se mostra mais eficaz do que na forma direta (transversal), quando se quer obter os polos de um modelo autoregressivo, estimando-se diretamente os zeros do preditor adaptativo, a partir dos parâmetros desse filtro, pela solução de equações de segundo grau. Este trabalho propõe uma técnica de filtragem adaptativa combinando o uso dos algoritmos dos mínimos quadrados recursivos em conjunto com estruturas na forma em cascata FIR. A abordagem consiste em transladar a original estrutura em cascata para uma configuração direta multidimensional FIR, de modo a atualizar os coeficientes do filtro através de um algoritmo dos mínimos quadrados rápido proposto, FLS-MD. A aplicação do algoritmo em cascata é de extrema importância em situações onde os parâmetros de interesse são os zeros dos filtros, como em predição de voz, detecção de freqüências, etc. Nesse sentido, esse algoritmo é proposto para estimação dos parâmetros LSP (Line Spectrum Pairs), utilizados em análise e modelagem de voz. A partir do estudo das relações entre os parâmetros LSP e a predição linear, chega-se a uma estrutura e mostra-se que o algoritmo multidimensional pode ser usado para adaptar seus coeficientes. Simulações são feitas com sinais de voz digitalizados. Também, no caso de detecção de freqüências, simulações mostram o bom desempenho da técnica proposta. A análise de convergência é feita a partir da relação entre as curvas de erro da estrutura proposta e da estrutura transversal, utilizando a seguir a técnica da equação diferencial associada (ODE)
Abstract: Adaptive filtering, using FIR cascade form, is more efficient than the direct (transversal) form when the poles of an autoregressive model are to be obtained, because it directly estimates the adaptive predictor zeros from the filter parameters by the solution of a second degree equation. This work proposes an adaptive filtering technique that combines the recursive least square algorithms and the FIR cascade form structures. The approach consists in translating the original structure in cascade form to a FIR multidimensional direct configuration, in such a way to update the filter coefficients by using the proposed fast least square multidimensional algorithm, FLS-MD. The application of this algorithm is very important in situations where the parameters of interest are the zeros of the filters, as in speech prediction, frequency detection, etc. In this way, this algorithm may be applied to estimate the LSP (Line Spectrum Pairs) parameters, used in speech analysis and speech modeling. From the study of the relation between the LSP parameters and the linear prediction, a structure is reached where the multidimensional algorithm can be used to adapt its coefficients. Simulations are carried out with digital speech signal. In the case of frequency detection, simulations also show a good performance of the proposed technique. The convergence analysis is made from the relation between the error surface of the proposed structure and the transversal structure, using the associated differential equation technique (DDE)
Doutorado
Doutor em Engenharia Elétrica
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Puppala, Ajith kumar. "Design of a Low Power Cyclic/Algorithmic Analog-to-Digital Converter in a 130nm CMOS Process." Thesis, Linköpings universitet, Elektroniksystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-80132.
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Analog-to-digital converters are inevitable in the modern communication systems and there is always a need for the design of low-power converters. There are different A/D architectures to achieve medium resolution at medium speeds and among all those Cyclic/Algorithmic structure stands out due to its low hardware complexity and less die area costs. This thesis aims at discussing the ongoing trend in Cyclic/Algorithmic ADCs and their functionality. Some design techniques are studied on how to implement low power high resolution A/D converters. Also, non-ideal effects of SC implementation for Cyclic A/D converters are explored. Two kinds of Cyclic A/D architectures are compared. One is the conventional Cyclic ADC with RSD technique and the other is Cyclic ADC with Correlated Level Shift (CLS) technique. This ADC is a part of IMST Design + Systems International GmbH project work and was designed and simulated at IMST GmbH. This thesis presents the design of a 12-bit, 1 Msps, Cyclic/Algorithmic Analog-to-Digital Converter (ADC) using the “Redundant Signed Digit (RSD)” algorithm or 1.5-bit/stage architecture with switched-capacitor (SC) implementation. The design was carried out in 130nm CMOS process with a 1.5 V power supply. This ADC dissipates a power of 1.6 mW when run at full speed and works for full-scale input dynamic range. The op-amp used in the Cyclic ADC is a two-stage folded cascode structure with Class A output stage. This op-amp in typical corner dissipates 631 uW power at 1.5 V power supply and achieves a gain of 77 dB with a phase margin of 64° and a GBW of 54 MHz at 2 pF load.
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Pereira, Rafael Cardoso. "T?cnica de rastreamento e persegui??o de alvo utilizando o algoritmo Haar cascade aplicada a rob?s terrestres com restri??es de movimento." PROGRAMA DE P?S-GRADUA??O EM ENGENHARIA MECATR?NICA, 2017. https://repositorio.ufrn.br/jspui/handle/123456789/23739.
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A habilidade de seguir ou de se mover acompanhando uma pessoa ou um objeto especificado, capaz de se deslocar, ? uma per?cia necess?ria em diversos agentes aut?nomos. Tais agentes s?o amplamente utilizados para realizar v?rias tarefas presentes no cotidiano, podendo ser aplicados tanto em tarefas corriqueiras, como em carrinhos de supermercado ou limpeza de ambientes, quanto ?s tarefas de mais alto risco, como em grandes ind?strias ou carros aut?nomos. A ideia apresentada aqui ? a de desenvolver um m?todo de rastreamento e persegui??o de alvo aplic?vel ? rob?s m?veis terrestres com rodas que possuem restri??es em sua movimenta??o, que fazem com que t?cnicas de controle padr?o nem sempre possam ser aplicadas. O trabalho desenvolvido aqui tamb?m leva em considera??o a utiliza??o de uma t?cnica de detec??o de alvo que possa se tornar adapt?vel a praticamente qualquer tipo de alvo estipulado pelo projetista de acordo com as necessidades de sua aplica??o. O desenvolvimento dos m?todos propostos foram realizados agregando t?cnicas de reconhecimento de padr?es utilizados em c?meras de padr?o RGB comuns, t?cnicas de estimativa de posi??o e orienta??o e algoritmos de controle inteligentes, que possuem baixo custo computacional, aplic?veis a rob?s com restri??es de movimenta??o.
The ability to follow or move along with a specified moving person or object, is a necessary skill in several autonomous agents. Such agents are widely used to perform various tasks in everyday life, and they can be applied either in everyday tasks, such as in supermarket carts or cleaning environments, as well in high-risk tasks like large industries or autonomous cars. The idea presented here is to develop a target tracking and following method applicable to mobile wheeled land robots that have restrictions on their movement, which means that standard control techniques cannot always be applied. The work developed here also takes into account the use of a target detection technique that can be adapted to practically any type of target stipulated by the designer according to the needs of its application. The development of the proposed methods is accomplished by adding standard recognition techniques used in common RGB type cameras, position estimation and orientation techniques, and intelligent control algorithms, with a low computational cost, applicable to robots with movement restrictions.
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Štaffa, Jan. "Jednofázový pulzní měnič DC/AC s digitálním řízením." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217881.
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This work is focused on single phase inverters, which are used for the conversion of the direct current to the alternating current and are nowdays used especially in systems of back-up power supply. The specific aim of this work is implementation of design hight power circuit of inverter include calculation of control algorithm. It describes the complete solution of power circuit. Next step is a analysis of problems concerning the digital control with help of signal processor which is used for solution of regulator structure. Check of the design and checkout of control algorithm is made in the form of simulation in the MATLAB Simulink. Debugged program algorithm is subsequently implemented into the signal microprocessor. The work results rate estimation functionality of inverter and solution of control algorithm.
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Bilokin, Sviatoslav. "Cascades hadroniques dans un calorimètre électromagnétique silicium-tungstène hautement granulaire et production des quarks top et bottom à l'ILC." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS599/document.
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Cette thèse présente des études pour l’International Linear Collider (ILC), un collisionneur électron-positron linéaire avec une énergie nominale dans le centre de masse de 250 GeV à 500 GeV. Les données analysées ont été enregistrées avec le prototype physique CALICE d’un calorimètre électromagnétique silice-tungstène (Si-W ECAL) à FermiLab en 2008. Au cours de cette thèse, un algorithme de recherche de traces a été développé, qui trouve des traces secondaires dans les événements hadroniques enregistrés par le prototype Si-W ECAL. Cet algorithme révèle des détails sur les interactions hadroniques dans le volume du détecteur et les résultats sont comparés avec des simulations basées sur le GEANT4 toolkit. Les recherches indirectes de nouvelle physique nécessitent une haute précision sur les mesures des paramètres de Modèle Standard. Théories de la physique au-delà de Modèle Standard, comme théories de dimensions supplémentaires ou modèles composite, impliquent des modifications des couplages électrofaibles des quarks lourds, top et bottom. La deuxième partie de la thèse est une étude de simulation complète des algorithmes de vertexing dans l’environnement ILD et la reconstruction de la charge de quark b. La reconstruction de la charge du quark bottom est essentielle pour de nombreux canaux de physique à l’ILC, particulièrement, pour les réactions e⁺e⁻ → bb̄ et e⁺e⁻ → tt̄ . L’algorithme développé améliore la performance de reconstruction de la charge du quark bottom. Les méthodes de reconstruction de la charge du quark bottom sont appliquées à l’analyse du mécanisme de production tt̄ . Cela permet d’augmenter la statistique pour l’estimation du facteur de forme électrofaible du quark top par rapport à une étude antérieure et donc de diminuer les incertitudes statistiques correspondantes. Les résultats de l’étude du détecteur permettent d’estimer la précision de l’ILC sur les couplages et les facteurs de forme électrofaibles du quark bottom. L’ILC sera capable de résoudre l’anomalie du LEP dans le processus de production bb̄. La précision de l’ILC sur le couplage droite Z⁰bb̄, un candidat majeur pour les effets de la nouvelle physique, est calculée et est au moins 5 fois mieux que celle des expériences de LEPThis thesis presents studies for the International Linear Collider (ILC),a linear electron-positron collider with a nominal center-of-mass energy of 500 GeV. Data are analysed that were recorded with the physics prototype of the CALICE silicon-tungsten electromagnetic calorimeter (Si-W ECAL) prototype at FermiLab in 2008. During this thesis, a track-finding algorithm was developed, which finds secondary tracks in hadronic events recorded by the Si-W ECAL physics prototype. This algorithm reveals details of hadronic interactions in the detector volume and the results are compared with simulations based on the geant4 toolkit.Indirect searches of New Physics require a high precision on the measurements of the Standard Model parameters. Many Beyond Standard Model theories, like extradimentional or composite models, imply modifications of electroweak couplings of the heavy quarks, top and bottom. The second part of the thesis is a full simulation study of vertexing algorithms in the ILD environment and the reconstruction of the b-quark charge. The b-quark charge reconstruction is essential for many physics channels at the ILC, particularly, for the e+ e− → bb̄ and the e+ e− → tt̄ channels. The developed algorithm improves the b-quark charge reconstruction performance.The b-quark charge reconstruction methods are applied to the tt̄ production process. This allows to increase statistics for the top quark electroweak form factor estimation w.r.t an earlier study and thus to decrease corresponding statistical uncertainties.The results of the detector study allow for an estimation of the ILC precision on the b-quark electroweak couplings and form factors. The ILC will be able to resolve the LEP anomaly in the bb̄ production process. The ILC precision on the right-handed Z⁰bb̄ coupling, a prime candidate for effects of new physics, is calculated to be at least 5 times better than theLEP experiments
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Muhammad, Hanif Shehzad. "Feature selection and classifier combination: Application to the extraction of textual information in scene images." Paris 6, 2009. http://www.theses.fr/2009PA066521.
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Dans cette thèse, nous avons traité le problème de la détection et de la localisation dans les images de scène. Notre système est composé de deux parties : le Détecteur de texte et le Localiseur de texte. Le détecteur de texte (une cascade de classifieurs boostés) emploie la méthode de dopage qui sélectionne et combine des descripteurs et des classifieurs faibles pertinents. Plus précisément, nous avons proposé une version régularisée de l’algorithme AdaBoost qui intègre la complexité (liée à la charge de calcul) des descripteurs et des classifieurs faibles dans la phase de sélection. Nous avons proposé des descripteurs hétérogènes pour coder l’information textuelle dans les images. Nos règles de classification appartiennent des différentes classes de classifieurs : discriminant, linéaire et non-linéaire, paramétrique et non-paramétrique. Le détecteur génère des régions candidates de texte qui servent d’entrées au localiseur de texte dont l’objectif est de trouver des rectangles englobants, autour des mots ou des lignes de texte dans l’image. Les résultats sur deux bases d’images difficiles montrent l’efficacité de notre approche.
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Susnjak, Teo. "Accelerating classifier training using AdaBoost within cascades of boosted ensembles : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Computer Sciences at Massey University, Auckland, New Zealand." Massey University, 2009. http://hdl.handle.net/10179/1002.
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This thesis seeks to address current problems encountered when training classifiers within the framework of cascades of boosted ensembles (CoBE). At present, a signifi- cant challenge facing this framework are inordinate classifier training runtimes. In some cases, it can take days or weeks (Viola and Jones, 2004; Verschae et al., 2008) to train a classifier. The protracted training runtimes are an obstacle to the wider use of this framework (Brubaker et al., 2006). They also hinder the process of producing effective object detection applications and make the testing of new theories and algorithms, as well as verifications of others research, a considerable challenge (McCane and Novins, 2003). An additional shortcoming of the CoBE framework is its limited ability to train clas- sifiers incrementally. Presently, the most reliable method of integrating new dataset in- formation into an existing classifier, is to re-train a classifier from beginning using the combined new and old datasets. This process is inefficient. It lacks scalability and dis- cards valuable information learned in previous training. To deal with these challenges, this thesis extends on the research by Barczak et al. (2008), and presents alternative CoBE frameworks for training classifiers. The alterna- tive frameworks reduce training runtimes by an order of magnitude over common CoBE frameworks and introduce additional tractability to the process. They achieve this, while preserving the generalization ability of their classifiers. This research also introduces a new framework for incrementally training CoBE clas- sifiers and shows how this can be done without re-training classifiers from beginning. However, the incremental framework for CoBEs has some limitations. Although it is able to improve the positive detection rates of existing classifiers, currently it is unable to lower their false detection rates.
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Cardozo, López Sergio Daniel. "Otimização de placas e cascas de materiais compósitos, utilizando algoritmos genéticos, redes neurais e elementos finitos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/18583.
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A otimização estrutural, utilizando ferramentas computacionais é um grande campo de pesquisa na atualidade. Os métodos utilizados, dependendo da complexidade do problema, demandam um grande custo computacional, e por isso vem sendo avaliandas várias técnicas para diminuí-lo. Uma delas é o emprego de técnicas de aproximação de análises, dentre as quais destacam-se as redes neurais, que combinadas aos métodos de otimização e de análises clássicos conseguem bons resultados e reduzem significativamente o tempo de processamento. O emprego dos compósitos laminados como material estrutural vem crescendo nos últimos tempos, incentivado pela suas excelentes propriedades mecânicas e baixo peso. Em consenso com todo o esforço científico dedicado a essa área, o presente trabalho visa a implementação de uma ferramenta computacional capaz de otimizar estruturas complexas fabricadas com tais materiais, a um baixo custo computacional. Com isto em mente, é desenvolvido um sistema de otimização, aproveitando módulos implementados previamente para a análise estática linear e não linear através do método dos elementos finitos (MEF), e o módulo de otimização por algoritmos genéticos. Serão desenvolvidos os módulos de análise modal, para otimizar também estruturas com critérios baseados em freqüências e modos, e o modulo de redes neurais de tipo perceptron para aproximações das análises feitas através do MEF. Alguns exemplos são apresentados para demonstrar que bons resultados são obtidos com a utilização de redes neurais artificiais, cujo treinamento permite poupar tempo computacional proveniente do grande número de análises usualmente necessárias no processo de otimização.Structural optimization using computational tools has become a major research field in recent years. Methods commonly used in structural analysis and optimization may demand considerable computational cost, depending on the problem complexity. Therefore, many techniques have been evaluated in order to diminish such impact. Among these various techniques, artificial neural networks may be considered as one of the main alternatives, when combined with classic analysis and optimization methods, to reduce the computational effort without affecting the final solution quality. Use of laminated composite structures has been continuously growing in the last decades due to the excellent mechanical properties and low weight characterizing these materials. Taken into account the increasing scientific effort in the different topics of this area, the aim of the present work is the formulation and implementation of a computational code to optimize manufactured complex laminated structures with a relatively low computational cost by combining the Finite Element Method (FEM) for structural analysis, Genetic Algorithms (GA) for structural optimization and Artificial Neural Networks (ANN) to approximate the finite element solutions. The modules for linear and geometrically non-linear static finite element analysis and for optimize laminated composite plates and shells, using GA, were previously implemented. Here, the finite element module is extended to analyze dynamic responses to optimize problems based in frequencies and modal criteria, and a module with perceptron ANN is added to approximate finite element analyses. Several examples are presented to show the effectiveness of ANN to approximate solutions obtained using the FEM and to reduce significatively the computational cost.
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Žůrek, Tomáš. "Řízení trojfázového sinusového zdroje." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220914.
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This thesis deals with control of three phase inverter as three phase sinusoidal voltage source for UPS application. Thesis is split to two parts, teoretical and practical. Teoretical part deals with three phase inverter topology analysis according requirement of neutral line wire and possibilities of generating sinusoidal PWM in depend of topology. There are also analysed properties of contorled system and designed 3 regulation methods with simulations. Second part of thesis deals with realisation of sinusoidal power source with inverter borrowed by Elcom company. To inverter control is used digital signal controler TMS320F28335 with implemented control algorithms. There are also presented the measurement results of the prototype of power source. In conclusion, simulation results are compared with measurements and achieved results are summarized.
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Bouges, Pierre. "Gestion de données manquantes dans des cascades de boosting : application à la détection de visages." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2012. http://tel.archives-ouvertes.fr/tel-00840842.
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Ce mémoire présente les travaux réalisés dans le cadre de ma thèse. Celle-ci a été menée dans le groupe ISPR (ImageS, Perception systems and Robotics) de l'Institut Pascal au sein de l'équipe ComSee (Computers that See). Ces travaux s'inscrivent dans le cadre du projet Bio Rafale initié par la société clermontoise Vesalis et financé par OSEO. Son but est d'améliorer la sécurité dans les stades en s'appuyant sur l'identification des interdits de stade. Les applications des travaux de cette thèse concernent la détection de visages. Elle représente la première étape de la chaîne de traitement du projet. Les détecteurs les plus performants utilisent une cascade de classifieurs boostés. La notion de cascade fait référence à une succession séquentielle de plusieurs classifieurs. Le boosting, quant à lui, représente un ensemble d'algorithmes d'apprentissage automatique qui combinent linéairement plusieurs classifieurs faibles. Le détecteur retenu pour cette thèse utilise également une cascade de classifieurs boostés. L'apprentissage d'une telle cascade nécessite une base d'apprentissage ainsi qu'un descripteur d'images. Cette description des images est ici assurée par des matrices de covariance. La phase d'apprentissage d'un détecteur d'objets détermine ces conditions d'utilisation. Une de nos contributions est d'adapter un détecteur à des conditions d'utilisation non prévues par l'apprentissage. Les adaptations visées aboutissent à un problème de classification avec données manquantes. Une formulation probabiliste de la structure en cascade est alors utilisée pour incorporer les incertitudes introduites par ces données manquantes. Cette formulation nécessite l'estimation de probabilités a posteriori ainsi que le calcul de nouveaux seuils à chaque niveau de la cascade modifiée. Pour ces deux problèmes, plusieurs solutions sont proposées et de nombreux tests sont effectués pour déterminer la meilleure configuration. Enfin, les applications suivantes sont présentées : détection de visages tournés ou occultés à partir d'un détecteur de visages de face. L'adaptation du détecteur aux visages tournés nécessite l'utilisation d'un modèle géométrique 3D pour ajuster les positions des sous-fenêtres associées aux classifieurs faibles.
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Twining, Erika. "Voltage compensation in weak distribution networks using shunt connected voltage source converters." Monash University, Dept. of Electrical and Computer Systems Engineering, 2004. http://arrow.monash.edu.au/hdl/1959.1/9701.
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Khalid-Naciri, Abdalilah. "Test par microcalculateur de réseaux arborescents de postes NAND, NOR, de multiplexeurs." Nancy 1, 1986. http://www.theses.fr/1986NAN10004.
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Chen, Hsu-Hung, and 陳旭宏. "A Study of Image Detail and Contrast Cascade Algorithm." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/97364352736578530456.
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碩士國立臺灣大學
電子工程學研究所
96
In this thesis, an advanced method which can improve detail and contrast of image in luminance is presented and associated hardware experimentation is developed. There are three major features in this thesis ,the first feature is CIEL*a*b* color space transformation which has better separation of luminance and chroma, the second is image processing method which is implemented by detail and contrast cascade, and the third is dynamic image processing. This thesis uses CIEL*a*b* color space which has proper perceptual image and it also can be easily analyzed and processed in linear format. Image detail and contrast cascade architecture has complementary design which could preserve detail and enhance contrast of image simultaneously. The presented approach of dynamic image analysis and parameter adjustment could help enhance the dynamic input images. From the theoretical basis and associated hardware implementation, the presented approach in this thesis has shown feasible and usable. We also expect this content could stimulate different thinking in image research.
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LIU, ZHEN-LONG, and 劉振隆. "Numerical investigation of turbine cascade flows by a locally implicit hybrid algorithm." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/32229183409332426508.
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Chou, Yu-Hsi, and 周玉璽. "Algorithm and Architecture Design for Monocular Forward Collision Warning System Based on A Cascade Classifier Using AdaBoost Algorithm." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/3t62n2.
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碩士國立中興大學
電機工程學系所
106
Automotive electronics has been a very hot market in recent years, autopilot is the major field to many car companies, which is due to the rapid growth and development of advanced driving assistance system. This paper uses the popularity of dash cam, developing the forward collision warning system based on monocular camera, and let the detection range in 50 meters to achieve real-time, stability and robustness as the goal. The system algorithm is divided into four blocks, Cascade classifier training, vehicle detection, vehicle tracking and collision judgment. We use the Harr-features with adaboost algorithm and Active-learning Framework to train a good Cascade classifier. Vehicle detection is two-steps framework, in the first step, cascade classifier using multi-scale search window to find vehicle candidates, in the second step, further screening to reduce the false detection, and if we confirm as vehicle objects, get better vehicle width information, so that the final collision judgement has a better performance. Then recognizing vehicles in sequential frames, tracking them. Last, we find the most priority vehicle in collision region, calculating the time to contact with vehicle widths and sampling time, if less than two seconds, the driver will be warned. We analysis consume time of each software algorithm, first-step vehicle detection is the most time-consuming part of the entire system, also the most front-end, so we select this part to design hardware architecture, to speed up the operation, the hardware architecture design including partition and scaler block, integral image generation block, line buffers block, search window registers block and parallel cascade classifier block. Partition and scaler block can greatly reduce the use of hardware resources. The use of two search window registers directly reduces a half of the overall processing time, and can also let the line buffers data have a higher reusability. Parallel cascade classifier block directly parallels the stages of cascade classifier, quickly determine whether the vehicle, to achieve our goal 60 FPS.
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Horng, Woan Jing, and 洪婉竟. "A Cascade Exponentiation Evaluation Scheme Based on the Lempel- Ziv-Weich Compression Algorithm." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/52715407585466315861.
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Dong, Fan-Yun, and 董凡昀. "A Multiscale Pedestrian Detection System Based on a Cascade Classifier Applying AdaBoost Algorithm." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/b2jt8w.
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碩士國立臺灣科技大學
電機工程系
104
People are among the most important role of the Human–Machine Interaction (HCI) applications, and endowing machines with ability to detect human is very significant. The relevant applications conclude interactive robots, advanced driver assist systems (ADAS), burglarproof systems, and care for the elderly and disabled. Pedestrian detection system can detect people from the input image by camera and provide the result for the relevant applications. The system architecture is composed of integral channel images transformation and fast multiscale detection. Channel images consist of YCbCr color channels, gradient magnitude channel and 6 quantized orientations channels. Aim at fast features extraction, we compute the integral channel images of 10 channel images. Different from rescaling the image several times in multiscale detection, fast multiscale detection rescales the detection windows to save the process time for computing the rescaled integral channel images. Our pedestrian detector is based on a cascade classifier applying AdaBoost algorithm, and can adjust the integral channel features’ thresholds with the empirical approximation function for different scale pedestrian. After fast multiscale detection, our system applies result clustering to reduce multiple detection results and demonstrates the multiscale pedestrian detection results.
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HUANG, BING-MING, and 黃炳明. "An algorithm for the design of programmable NAND logic network based on cascade digraph." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/61732901774980023843.
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Yeh, Yao-teng, and 葉曜謄. "A Cascade Classifier Using the Adaboosting Algorithm for Real-time On-road Motorcycle Detection and Tracking." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/6bh4gt.
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碩士國立臺灣科技大學
資訊工程系
102
With the rapid advancement of information technology, today computing power of computer is increased dramatically; making digital image processing technology has more extensive application in real life. For solving the traffic problems also produced the Intelligent Transportation Systems (ITS), ITS is an integrated hardware and software facilities of all kinds of transportation systems in order to achieve the automation and improve the quality of transport services, and one of the ring is an Advanced Vehicle Control and Safety Services (AVCSS), AVCSS is a combination of the sensors, computers, communications, electrical and control technology for vehicles and road infrastructure, to help drivers improve driving safety, using sensors to help drivers with visual sensory deficiencies reduce the risk which caused by improper driving behavior and negligence judgment. At the field of the sensors of motorcycle detection uses different technology to achieve, such as acoustic, laser, radar and camera, etc. Using laser radar can obtain a high detection rate, and can get information about the target, such as the target distance, azimuth, height, and speed, etc. But its expensive hardware also is a burden. The detection methods using the camera, because the inexpensive hardware costs, there are more and more relevant researches. This paper presents a use of camera sensors of method to implement real-time motorcycle detection and tracking. This method can be applied in a variety of road environment. For motorcycle detection, we use haar-like features as the digital image features of machine learning, and use adaboost and cascade classifier for training and detection, in order to achieve real-time detection purpose; For motorcycle tracking, we use the principle which the detection windows are neighboring and similar in the video. We conducted experiments in the different environments, such as urban streets of dynamic background, sunny and rainy city streets of static background. Our proposed method can effectively detect a variety of motorcycles, in sunny environment can achieve 92.9% precision rate and 94.2% recall rate, while in the high degree of complexity and the noise of the rainy environment can achieve 92.2% precision rate and 79.1% recall rate; And the proposed method of tracking in the urban streets also showed stable. The overall performance is 20 fps at 640×480 resolution.
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Tsau, Che-Wei, and 曹哲瑋. "A Vehicle Detection and Tracking System based on a Cascade Classifier applying AdaBoost Algorithm and Object Estimation." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/u9y4df.
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碩士國立交通大學
電控工程研究所
104
In recent years, the traffic accidents happen because drivers are not concentrating on the front vehicles. This thesis develops a vehicle detection and tracking system which can avoid traffic accidents. Unlike other complex hardware or software system, this dissertation uses USB camera and computer to build a hardware architecture. The software architecture contains an offline training model. This paper has three part: object estimation, object detection and object tracking In first part, the object estimation calculates the object probable position and scale size in processing image by offline training model .The offline model is combined with positive samples and negatives samples which using the BING(Binary Normal Gradient) and support vector machine. In second part , the several weak classifiers use AdaBoost algorithm to estimate the cascade classifiers, and then the weak classifier is calculated by five kinds of Haar like features which are described with offline positive and negative samples. In third part, the detection object tracked by particle filter, the particle filter’s likelihood function is yielded with the object’s color features. Finally, our method is combined with three parts and applied to vehicle detection and tracking system. The thesis has the highest 94% detection rate and the lowest 7% false alarm in our experiments
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Kohl, Nate F. "Learning in fractured problems with constructive neural network algorithms." 2009. http://hdl.handle.net/2152/10658.
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Evolution of neural networks, or neuroevolution, has been a successful approach to many low-level control problems such as pole balancing, vehicle control, and collision warning. However, certain types of problems — such as those involving strategic decision-making — have remained difficult to solve. This dissertation proposes the hypothesis that such problems are difficult because they are fractured: The correct action varies discontinuously as the agent moves from state to state. To evaluate this hypothesis, a method for measuring fracture using the concept of function variation of optimal policies is proposed. This metric is used to evaluate a popular neuroevolution algorithm, NEAT, empirically on a set of fractured problems. The results show that (1) NEAT does not usually perform well on such problems, and (2) the reason is that NEAT does not usually generate local decision regions, which would be useful in constructing a fractured decision boundary. To address this issue, two neuroevolution algorithms that model local decision regions are proposed: RBF-NEAT, which biases structural search by adding basis-function nodes, and Cascade-NEAT, which constrains structural search by constructing cascaded topologies. These algorithms are compared to NEAT on a set of fractured problems, demonstrating that this approach can improve performance significantly. A meta-level algorithm, SNAP-NEAT, is then developed to combine the strengths of NEAT, RBF-NEAT, and Cascade-NEAT. An evaluation in a set of benchmark problems shows that it is possible to achieve good performance even when it is not known a priori whether a problem is fractured or not. A final empirical comparison of these methods demonstrates that they can scale up to real-world tasks like keepaway and half-field soccer. These results shed new light on why constructive neuroevolution algorithms have difficulty in certain domains and illustrate how bias and constraint can be used to improve performance. Thus, this dissertation shows how neuroevolution can be scaled up from learning low-level control to learning strategic decision-making problems.text
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Tsai, Tsung Wei, and 蔡宗衞. "Real-Time Algorithm of Conduction Angle Minimizing THD for Cascade Multilevel Inverter and Its Hardware-in-the-loop Simulation." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/32974207204958013615.
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碩士國立聯合大學
電機工程學系碩士班
100
This thesis presents real-time calculation algorithms of switching conduction angles minimizing total harmonic distortion (THD) for cascade multilevel inverters based on optimized harmonic stepped waveform (OHSW). The proposed algorithms effectively reduce the computing time to achieve real-time control while minimizing THD. These algorithms are implemented not only in a digital real-time simulator (RT-LAB) but also in a Hardware-in-the-loop environment using FPGA for testing their effectiveness.
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Chen, Tsay-Juin, and 陳在鈞. "Neural Network Cascade Steepest Descendant Learning Algorithm with application on Precise Temperature Control Control of Injetion Molding Barrel System." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/97187407721790547040.
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碩士國立中興大學
機械工程學系
86
"類神經網路"以其良好之非線性映射能力，己經被廣泛的應用於系統模式 建立、模糊隸屬函數調整、文字辨識及複雜之非線性系統控制 ?等方面 。本論文主要目的乃是希望將類神經網路應用於極非線性之射出成型機料 管系統鑑別與精密溫度控制上。為了對料管系統做更完整之鑑別，本研究 嘗試在類神經網路EBP(誤差逆傳遞學習法則)架構之下，由一階逼進著手 ，在簡單的原則下，以最陡負梯度法則及參數上下限設定的方式，針對每 一次權值更新，找出增進模式或批次模式相對應之最佳學習參數 及學習 慣量 參數值，使得網路能在最少的次數下收斂，且能有不錯的重現性， 電腦模擬證明本研究所提出之新法則在收斂速度與學習成功率上，皆較其 他方法優異。在本研究之第二部分，我們先將所發展之新類神經網路學習 法則應用於射出成型機料管系統之模擬上，實際實驗結果證明，本研究所 提出之新方法確實可對複雜之料管系統做有效的鑑別。完成之類神經網路 料管模式則進一步用來做為類神經網路式參數自調PID控制器之依據，實 際實驗結果亦證明此參數自調PID控制器能將料管溫度控制於 +0.5~-0.5 度內 Artificial neural networks, with its high learning and nonlinear mapping ability, have been successfully applied to many system identification and control problems. The goal of this thesis is to apply the neural network techniques to the system identification and precise temperature control of the extremely nonlinear injection molding barrel system.In order to complete the system identification work as accuracy as possible, we propose a new and efficient multilayer neural network learning algorithm first. In this new learning algorithm (Cascade steepest descendant learning algorithm) the steepest descendant method is used to search the optimal learning constant ηand momentum term αfor each weights updating process. The well known Delta learning rule is then employed to modify the connecting weights in terms of the optimal ηand α. Computer simulations show that the proposed new algorithm outmatches other learning algorithms both in converging speed and success rate.In the second part of this research, we first apply the new neural network learning algorithm to the identification of the injection molding barrel system. Real experiment results demonstrate that the new algorithm can precisely identify the complicate barrel system. Further more, a self-tuning PID controller based on the trained neural network barrel model for precise temperature control is developed. Real experiments show that the proposed self-tuning PID controller can precisely control the barrel temperature within 0.5 degree.
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Mousavi, Nima. "Algorithmic Problems in Access Control." Thesis, 2014. http://hdl.handle.net/10012/8303.
Full textAbstract:
Access control is used to provide regulated access
to resources by principals. It is an important and foundational
aspect of information security. Role-Based Access Control (RBAC) is
a popular and widely-used access control model,
that, as prior work argues,
is ideally suited for enterprise settings. In this dissertation,
we address two problems in the context of RBAC.
One is the User Authorization Query (UAQ) problem, which relates
to sessions that a user creates to exercise permissions.
UAQ's objective is the identification of a
set of roles that a user needs to activate such that the session is
authorized to all permissions that the user wants to exercise in
that session. The roles that are activated must respect
a set of Separation of Duty constraints. Such constraints restrict the
roles that can be activated together in a session.
UAQ is known to be intractable (NP-hard).
In this dissertation, we give a precise formulation of UAQ as a
joint-optimization problem, and analyze it.
We examine the manner in which each input parameter contributes to its
intractability.
We then propose an approach to mitigate its intractability based on
our observation that a corresponding decision version of the problem
is in NP. We efficiently
reduce UAQ to Boolean satisfiability in conjunctive normal form
(CNF-SAT), a well-known
NP-complete problem for which solvers exist that are efficient for large
classes of instances. We also present results for UAQ posed
as an approximation problem; our results
suggest that efficient approximation is not promising for UAQ.
We discuss an open-source implementation of our approach and a
corresponding empirical assessment that we have conducted.
The other problem we consider in this dissertation regards
an efficient data structure for distributed
access enforcement. Access enforcement is the process of validating an access
request to a resource.
Distributed access enforcement has become important
with the proliferation of data, which requires access control systems
to scale to tens of thousands of resources and permissions.
Prior work has shown the effectiveness of a data structure called
the Cascade Bloom Filter (CBF) for this problem.
In this dissertation, we study the construction of instances
of the CBF.
We formulate the problem of finding an optimal instance of a
CBF, where optimality refers to the number of false positives
incurred and the number
of hash functions used. We prove that this problem
is NP-hard, and a meaningful decision version is in NP.
We then propose an approach to mitigate the intractability of
the problem by reducing it to
CNF-SAT, that allows us to use a SAT solver for instances that
arise in practice.
We discuss an open-source implementation of our approach
and an empirical assessment based on it.
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Dolenko, Brion K. "Performance and hardware compatibility of backpropagation and cascade correlation learning algorithms." 1993. http://hdl.handle.net/1993/17526.
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HOU, SHU-FEN, and 侯淑芬. "A design algorithm of a cascaded plants with plants modification." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/96781314528167994439.
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JIANG, KUN-NAN, and 江坤南. "Modified algorithms of adaptive recursive filters in cascade form and their applications." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/67377336129711452384.
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Chen, Hong-Shen, and 陳竑伸. "Cascaded Mach-Zehnder Directional Coupler Design Using Genetic Algorithm and Its Applications." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/27wyut.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
107
The wavelength-independent components is in high demand in the optical communication and optical sensing. In this thesis the cascaded Mach-Zehnder directional coupler (CMZDC) is demonstrated with 160-nm bandwidth on the silicon-on-insulator (SOI) platform. The Genetic Algorithm is further utilized to enhance the operating wavelength range. The phase shifter is replaced by waveguides with two different widths to reduce device size and improve simulation efficiency. The CMZDC can be any splitting ratios, and owns the advantages of large bandwidth and low loss. The CMZDC based Mach-Zehnder interferometer can be taken as the demultiplexer for 400-Gb/s fiber optic communications and biosensing. In this thesis a 1x4 wavelength demultiplexer with flat-top passband is demonstrated. Moreover, the CMZDC is also applied to the swept source of optical coherence tomography (OCT) for higher axial resolution. A 1x4 flat-top passband demultiplexer with 20-nm channel spacing demonstrates the crosstalk lower than 8-dB except one output due to the process error.
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Tsai, Yun-Feng, and 蔡勻豐. "Security Analysis and a Fast Algorithm for the Implementation of Gollmann Cascades Pseudorandom Number Generator." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/74865432684455768754.
Full textAbstract:
碩士國立雲林科技大學
電子與資訊工程研究所
93
The security of Gollmann Cascades pseudorandom number generator is analyzed in this paper. Additional, an algorithm is proposed to improve the software efficiency for generating keystreams. In the security analysis, Golomb’s three randomness postulates, linear complexity, and profile of linear complexity were utilized to analyze Gollmann Cascades. The degree of randomness by changing the amount of Stage, length of LFSR, and feedback functions is discussed. To attack a pseudorandom number generator is a part of security analysis. Some methods are developed to obtain the feedback functions with fewer information. The keystream of Gollmann Cascades is first divided into several blocks in these methods. Hence, these methods are called block attacks. Under the condition that the keystream is sufficiently long, block attacks can also be used on longer length of LFSR or longer cascades as well. Gollmann Cascades is generally implemented in hardware, every stage can operate at one clock cycle. If it is implemented in software, there is only one stage can operate at one clock cycle. In order to improve the software efficiency for generating keystreams, we propose an algorithm to generate a huge keystream faster.
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Thacher, Eric. "Simulation based design and performance assessment of a controlled cascaded pneumatic wave energy converter." Thesis, 2017. https://dspace.library.uvic.ca//handle/1828/8535.
Full textAbstract:
The AOE Accumulated Ocean Energy Inc. (AOE) wave energy converter (WEC) is a cascaded pneumatic system, in which air is successively compressed through three point absorber devices on the way to shore; this air is then used to drive an electricity generator. To better quantify the performance of this device, this thesis presents a dynamically coupled model architecture of the AOE WEC, which was developed using the finite element solver ProteusDS and MATLAB/Simulink. This model is subsequently applied for the development and implementation of control in the AOE WEC. At each control stage, comprehensive power matrix data is generated to assess power production as a function of control complexity.
The nature of the AOE WEC presented a series of novel challenges, centered on the significant residency time of air within the power take-off (PTO). As a result, control implementation was broken into two stages: passive and active control. The first stage, passive control, was realized as an optimization of eight critical PTO parameters with the objective of maximizing exergy output. After only 15 generations, the genetic algorithm optimization led to an increase of 330.4% over an initial, informed estimate of the optimal design, such that the annually-averaged power output was 29.37 kW. However, a disparity in power production between low and moderate energy sea-states was identified, which informed the development of an active control strategy for the increase of power production in low energy sea-states. To this aim, a recirculation-based control strategy was developed, in which three accumulator tanks were used to selectively pressurize and de-pressurize the piston at opportune times, thereby increasing the continuity of air throughput. Under the influence of active control, sea-states with significant wave heights between 0.75 m – 1.75 m, which on average encompass 55.93% of the year at the Amphitrite Bank deployment location, saw a 16.3% increase in energy production.Graduate
2018-08-18
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Gomes, Carlos Alberto Ferreira. "Use of generative algorithms and shape optimization strategies in structural design." Master's thesis, 2014. http://hdl.handle.net/1822/36155.
Full textAbstract:
Dissertação de mestrado integrado em Engenharia CivilThe aim of this work is to address the challenges and opportunities that are placed at the structural design by the availability of software applications with graphical capabilities able to obtain arbitrary geometries, usually called freeform, and its automatic interoperability with structural analysis tools. The focus of this dissertation is to establish methodologies and interfaces that enable the collaborative and integrated work in real time between Engineers and Architects for the design of freeform structures based in reinforced concrete membranes. In this context, the concepts of formfinding and morphogenesis are discussed and explored. The presented document also describes the implementation and use of a custom made application, developed as part of this dissertation, which enables real-times interoperability between a CAD software and a structural analysis software.
Pretende-se com este trabalho abordar os desafios e oportunidades que são colocados à conceção estrutural pela disponibilidade de aplicações informáticas com capacidades gráficas capazes de obter geometrias arbitrárias, usualmente designadas por freeform, e sua interoperabilidade automática com ferramentas de análise estrutural. A presente tese tem como enfoque especial o estabelecimento de metodologias e interfaces que permitam o trabalho colaborativo e integrado em tempo real entre Engenheiros e Arquitetos para a conceção de estruturas freeform baseadas em membranas de betão armado. Nesse contexto, são abordados e explorados os conceitos de formfinding e morfogênese. Este documento descreve ainda a implementação e utilização de uma aplicação, desenvolvida no âmbito desta tese, que permite a interoperabilidade em tempo real entre uma aplicação CAD e uma aplicação de cálculo estrutural.
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Rebelo, Fernando Manuel Dias. "Análise de sentimento em microblogues com base em cascatas de classificacao." Master's thesis, 2016. http://hdl.handle.net/10071/13040.
Full textAbstract:
Esta dissertação descreve uma plataforma de classificação que permite utilizar e aplicar classificadores binários em cascata. A plataforma utiliza algoritmos de aprendizagem automática existentes no software WEKA que disponibiliza uma API para esse efeito, tendo sido testada na classificação de sentimento de tweets e blogues. Esta plataforma permitiu também analisar e comparar diferentes cascatas de classificação com os classificadores Naive Bayes, Regressão Logística e Support Vector Machines que implementa o algoritmo Sequential Minimal Optimization para otimização da fase de treino. Neste caso de estudo foram exploradas várias arquiteturas de classificação com um máximo de três níveis, combinando diversos classificadores binários, para classificação em quatro e seis classes. Como entrada para os classificadores, foram extraídas características de cada um dos documentos e utilizados léxicos de polaridade associados às palavras. Em geral, as arquiteturas que utilizam Support Vector Machines obtêm os melhores resultados. Os diferentes classificadores obtêm os seus melhores resultados com diferentes arquiteturas.This thesis describes a classification platform that enables to use and apply binary classifiers in cascade. The platform uses existing machine learning algorithms from WEKA software that provides an API for this purpose, having been tested in sentiment classification of tweets and blogs. This platform allowed also to analyze and compare different classification cascades with the classifiers Naive Bayes, Logistic Regression and Support Vector Machines which implements the Sequential Minimal Optimization algorithm to optimize the training phase. In this case study were explored various classification architectures with a maximum of three levels, combining different binary classifiers for classification in four and six classes. As input for the classifiers, were extracted characteristics of each of the documents and utilized polarity lexicons associated to the words. In general, architectures based on Sequential Minimal Optimization get the best results. The different classifiers get their best results with different architectures.
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Hulett, David Alexander. "De Fourier a wavelets : un breve recorrido por el análisis tiempo-frecuencia." Bachelor's thesis, 2020. http://hdl.handle.net/11086/15941.
Full textAbstract:
Tesis (Lic. en Matemática)--Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía, Física y Computación, 2020.Un pequeño tour por el análisis de Fourier. Definimos a la transformada continua de Fourier, presentamos y estudiamos los resultados principales de la serie de Fourier y de la transformada de Fourier discreta. Analizamos cómo hacer la transición de serie a transformada continua y de transformada discreta a la serie. Para estudiar la estructura tiempo-frecuencia de una función presentamos a las transformadas atómicas y estudiamos dos ejemplos: la STFT y la transformada wavelet.
A small tour of Fourier analysis. We define the continuous Fourier transform, and we present and study the main results regarding the Fourier series and the discrete Fourier transform. We analyse how to transition from the series to the continuous transform and from the discrete transform to the series. In order to study the time-frequency structure of a function we introduce the atomic transforms and we focus our attention on two examples: the STFT and the wavelet transform.
Fil: Hulett, David Alexander. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía, Física y Computación; Argentina.
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Kumar, Pawan. "Memory Efficient Regular Expression Pattern Matching Architecture For Network Intrusion Detection Systems." Thesis, 2012. http://etd.iisc.ernet.in/handle/2005/2321.
Full textAbstract:
The rampant growth of the Internet has been coupled with an equivalent growth in cyber crime over the Internet. With our increased reliance on the Internet for commerce, social networking, information acquisition, and information exchange, intruders have found financial, political, and military motives for their actions. Network Intrusion Detection Systems (NIDSs) intercept the traffic at an organization’s periphery and try to detect intrusion attempts. Signature-based NIDSs compare the packet to a signature database consisting of known attacks and malicious packet fingerprints. The signatures use regular expressions to model these intrusion activities.
This thesis presents a memory efficient pattern matching system for the class of regular expressions appearing frequently in the NIDS signatures. Proposed Cascaded Automata Architecture is based on two stage automata. The first stage recognizes the sub-strings and character classes present in the regular expression. The second stage consumes symbol generated by the first stage upon receiving input traffic symbols. The basic idea is to utilize the research done on string matching problem for regular expression pattern matching. We formally model the class of regular expressions mostly found in NIDS signatures. The challenges involved in using string matching algorithms for regular expression matching has been presented. We introduce length-bound transitions, counter-based states, and associated counter arrays in the second stage automata to address these challenges. The system uses length information along with counter arrays to keep track of overlapped sub-strings and character class based transition. We present efficient implementation techniques for counter arrays. The evaluation of the architecture on practical expressions from Snort rule set showed compression in number of states between 50% to 85%. Because of its smaller memory footprint, our solution is suitable for both software based implementations on network chips as well as FPGA based designs.
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Roach, Lisa Aretha Nyala. "Temporal Variations in the Compliance of Gas Hydrate Formations." Thesis, 2012. http://hdl.handle.net/1807/44081.
Full textAbstract:
Seafloor compliance is a non-intrusive geophysical method sensitive to the shear modulus of the sediments below the seafloor. A compliance analysis requires the computation of the frequency dependent transfer function between the vertical stress, produced at the seafloor by the ultra low frequency passive source-infra-gravity waves, and the resulting displacement, related to velocity through the frequency. The displacement of the ocean floor is dependent on the elastic structure of the sediments and the compliance function is tuned to different depths, i.e., a change in the elastic parameters at a given depth is sensed by the compliance function at a particular frequency. In a gas hydrate system, the magnitude of the stiffness is a measure of the quantity of gas hydrates present. Gas hydrates contain immense stores of greenhouse gases making them relevant to climate change science, and represent an important potential alternative source of energy. Bullseye Vent is a gas hydrate system located in an area that has been intensively studied for over 2 decades and research results suggest that this system is evolving over time.
A partnership with NEPTUNE Canada allowed for the investigation of this possible evolution. This thesis describes a compliance experiment configured for NEPTUNE Canada’s seafloor observatory and its failure. It also describes the use of 203 days of simultaneously logged pressure and velocity time-series data, measured by a Scripps differential pressure gauge, and a Güralp CMG-1T broadband seismometer on NEPTUNE Canada’s seismic station, respectively, to evaluate variations in sediment stiffness near Bullseye. The evaluation resulted in a (- 4.49 x10-3± 3.52 x 10-3) % change of the transfer function of 3rd October, 2010 and represents a 2.88% decrease in the stiffness of the sediments over the period. This thesis also outlines a new algorithm for calculating the static compliance of isotropic layered sediments.