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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Aparatinės programų apsaugos metodų tyrimas ir paskirstytų skaičiavimų modelio panaudojimas apsaugos rakto realizacijai / Research on hardware-based software protection methods and distributed computing model for security dongle implementation

Valbasas, Hubertas 01 September 2011 (has links)
Programų apsaugą yra svarbus šių dienų klausimas. 2009 metais pasaulyje buvo užfksuotas 43% piratavimo lygis, o Rytų Europoje 64% lygis. Vienas iš būdų apsaugoti programas nuo neteisėto naudojimo yra aparatiniai apsaugos metodai. Atlikus aparatinių apsaugos metodų analizę nustatyta, kad pažeidžiamiausia apsaugos vieta yra komunikavimas tarp programos ir aparatinio įrenginio, todėl apsaugos raktai, kurie vykdo dalį programos, gali apsaugoti nuo daugumą apgrąžos inžinerijos atakų. Įrodymui buvo sukurtas simuliacinis paskirstytų skaičiavimų aparatinės apsaugos Matlab modelis ir atliktas eksperimentis jo patikrinimas parodė, kad siūlomas apsaugos modelis yra atsparus derinimo ir programos klonavimo atakoms. Tyrimo metu, buvo sukurtas eksperimentinis apsaugos rakto prototipas, kuri vykdo dalį programos, o apsauga ištirta su dviem eksperimentinėmis programomis nuo derinimo, dekompiliavimo ir programos klonavimo atakų. Eksperimentinis tyrimas parodė, kad galima rasti programos kreipinius į apsaugos raktą, tačiau jų apėjimas ar pakeitimas, sugadina programą, praneša apie nežinomus adresus. Taip pat buvo atliktas eksperimetinės programos, apsaugotos komerciniu apsaugos raktu, tyrimas, kuris parodė, kad tradiciniai apsaugos metodai neužtikrina apsaugos nuo apgrąžos inžinerijos, kaip tai buvo įrodyta su eksperimentiniu apsaugos rakto prototipu. / Software protection is important problem of nowaday. In 2009 the piracy rate reaches 43% of all globe softwares usage, especialy high piracy rate is in Eastern Europe, where 64% of softwares are illegal. This brings hardware-based protection to be one of the prime defense against illegal software usage. The analysis of hardware-based software protection showed that the weakest part of hardware-based protection is communication with software, so dongle method, which computes part of the software inside dongle, could withstand most of reverse engineer attack methods. To prove this Matlab model of distributed dongle-based protection scheme was created and its experimental evaluation showed, that suggested software protection model is resistant against deassembling, debbuging and software cloning attacks. Equally, experimental distributed computing protection dongle prototype was created and tested with two experimental programs against deassembling, debbuging, decompilation and software cloning attacks. This shows that attackers can find calls to the dongle, but can not jump or nop it, such it was done in experimental software protected with traditional commercial dongle.
132

Srities diskretizavimo baigtiniais elementais galimybių tyrimas / Feasibility Study on the Domain Discretization by Finite Elements

Sprainys, Kęstutis 31 October 2014 (has links)
Šiame darbe buvo analizuojama programinė įranga skirta diskretizuoti sritį į baigtinius elementus. Analizuotos MATLAB sistemos ir COMSOL programos diskretzavimo galimybės. Sukurta programa sujungianti COMSOL ir MATLAB, kuri leidžia diskretizuoti sritį į baigtinius elementus. / In this work was done study of software for domain discretization by finite elements. Created program that connects MATLAB and COMSOL, which allows domain discretization by finite elements.
133

Příprava výukového materiálu pro tvorbu GUI v MATLABu / Preparation of educational material for developing of GUI in MATLAB

ŠIMEK, Jakub January 2012 (has links)
The aim of this thesis is to create an educational material for creating graphical user interfaces in MATLAB. The reader will learn the basic procedures of the GUI creation, get to know the various graphic objects and learn about the GUIDE environment, which is intended for the actual application development. Text is supplemented by practical examples of source code fragments as much as possible. All material is accompanied by two functional sample applications with their source code.
134

Determinação das freqüências naturais e modos de vibrar de um veículo de dois eixos através de um programa computacional em Matlab-Simulink / Determination of the natural frequencies and ways to vibrate of a vehicle of two axles through a computational program in MatLab-Simulink

Hudson Tadeu Ferreira 10 December 2003 (has links)
Este trabalho obtém as frequências naturais e seus respectivos modos de vibrar da massa suspensa e não suspensa de um veículo comercial através de um programa computacional desenvolvido em MatLab Simulink. As rodas do veículo são excitadas no modelo teórico com sinais harmônicos de frequência continuamente variável de 0 a 40 Hz e de 0 a 4 Hz, faixas que contém as frequências naturais da massa suspensa e não suspensa. As frequências naturais foram obtidas analisando-se a amplitude máxima das forças normais nos pneus, ângulo de arfagem e rolamento da massa suspensa e outras variáveis (respostas do veículo à excitação imposta na roda dianteira esquerda). A roda esquerda dianteira do veículo foi excitada em laboratório com movimento harmônico aleatório cujo power spectral density mostra uma faixa relativamente plana na faixa de 0 a 22 Hz. As frequências naturais foram obtidas analisando-se o PSD da resposta do veículo medida nos eixos e na massa suspensa. As frequências naturais da massa suspensa e não suspensa obtidas teoricamente foram comparadas com as obtidas no ensaio em laboratório. O conhecimento das frequências naturais da massa suspensa e não suspensa é o primeiro passo para a análise do ride do veículo. Os resultados práticos e teóricos mostraram-se próximos mostrando que o programa computacional desenvolvido em MatLab Simulink é uma opção para o projeto e otimização da suspensão de veículos comerciais. / This study has the natural frequencies and its respective ways of vibration the lifted mass and not lifted of a commercial vehicle through a computerized program developed at MatLab Simulink. The wheels of this vehicle are excited on the theoretic model with harmonic frequency signals continuously variable from 0 to 40 Hz and from 0 to 4 Hz, ranges that have the natural frequencies of the lifted mass and not lifted. These natural frequencies were obtained by analyses of the maximum amplitude of the normal strength on the tires, pitch angle, riding of the lifted mass and variables (reaction of the vehicle to the excitement stressed on the front left wheel). The front left wheel was excited in lab in harmonic random motion of which the power spectral density shows a range reasonable steady at the range of 0 to 22 Hz. The natural frequencies were obtained by the analyses of the PSD the reaction of the vehicle measured on the axels and the lifted mass. The natural frequencies of the lifted and not lifted mass theoretically obtained were compared with the ones obtained at the lab. The data on the natural frequencies of the lifted and not lifted mass is the first step to the analyses of the ride of the vehicle. The practical and theoretical results appear to close showing that the computerized program developed at the MatLab Simulink is an option for the project and suspension upgrades on commercial vehicles.
135

Monitoramento do acesso de veículos de carga em vias urbanas / Monitoring of freight vehicles access on urban roads

Pamela Rosa Tancredi 04 May 2012 (has links)
O monitoramento do trânsito de veículos rodoviários de carga em vias urbanas é dependente do trabalho de profissionais que precisam estar integralmente atentos ao tráfego de uma determinada via, e assim, identificar a presença desses veículos em meio a cenas complexas. Sistemas automáticos de identificação de veículos em quadros de vídeos podem agregar valor na qualidade de vida das cidades, pois tendem a diminuir os congestionamentos e incrementam segurança ao trânsito. Nesta pesquisa, propõe-se um modelo capaz de identificar e segregar veículos rodoviários de carga em vias urbanas, por meio de técnicas de processamento e análise de vídeos, gravados por câmeras posicionadas em diversos ângulos em dispositivos de acessos a vias urbanas. O sistema foi desenvolvido em linguagem MATLAB® e foram abordadas técnicas referentes às etapas de detecção, segmentação e processamento de objetos em fundos complexos. Ao final do trabalho, o sistema é aplicado em cenários de filmagem na cidade de São Carlos - SP e os resultados obtidos são discutidos. / The monitoring of the road freight vehicles traffic on urban roads relies on the work of professionals who need to be fully aware of the traffic on a specific road, and thereby identify the presence of these vehicles in complex scenes. Automatic vehicle identification in video shots may add value to the city life quality, due to congestion diminishment and traffic security improvement. In this research, a model able to identify and segregate road freight vehicles on urban roads is proposed, by means of video analysis and processing, that were recorded by cameras positioned at different angles on highways accesses on urban roads. The system was developed using MATLAB®. Techniques related to detecting, targeting and processing steps have been used to identify objects in complex backgrounds. At the end of the work, the system is applied to several scenarios that have been filmed in the city of São Carlos - SP and the results are discussed.
136

LabSis : um ambiente para desenvovimento de aplicações sismicas Matlab

Marcolino, Cristiano da Silva 18 October 2004 (has links)
Orientadores: Martin Tygel, Rodrigo Portugal / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica, Instituto de Geociencias / Made available in DSpace on 2018-08-04T03:30:57Z (GMT). No. of bitstreams: 1 Marcolino_CristianodaSilva_M.pdf: 5526347 bytes, checksum: 572b0c9e072b07844652770f09e1225c (MD5) Previous issue date: 2004 / Resumo: O pacote computacional Matlab é uma ferramenta de uso generalizado no meio acadêmico pelas suas vantagens de programação simples e direta e uso fácil de gráficos e visualizações, permitindo rapidamente implementações iniciais de algoritmos e procedimentos em uma série de aplicações. Em contrapartida às facilidades operacionais, os programas Matlab não possuem a eficiência computacional exigidas das linguagens de programação propriamente ditas (tais como Fortran e C, por exemplo). Tais propriedades fazem com que o Matlab seja, por excelência, um pacote de obtenção de "primeiras versões", dedicadas a testes em "problemas pequenos". Numa segunda etapa, os programas Matlab devem ser submetidos aos procedimentos de praxe da engenharia de software, incluindo a mudança de linguagem de programação para uso final em problemas práticos. Tal característica explica porque o Matlab seja tão utilizado na academia, em particular no ensino e elaboração de dissertações e teses. No caso específico do Laboratório de Geofisica Computacional da Unicamp, uma variedade de programas Matlab foi desenvolvida, visando aplicações ao ensino e a pesquisa de métodos de processamento de dados geofisicos, com ênfase aos métodos sísmicos. Devido aos focos específicos e sem muita conexão entre si, os programas foram desenvolvidos sem uma unidade de concepção, resultando na dificuldade de sinergia e utilização dos programas por um público mais amplo ou mesmo por outros alunos e usuários do próprio Laboratório. O LabSis, desenvolvido nesta dissertação, surge como um pacote integrador destas funções, utilizando as ferramentas gráficas do Matlab para criar uma interface simplificada e intuitiva ao usuário. O LabSis é formado por "funções casca", as quais fazem a ponte entre os algoritmos originais e o usuário. O uso destas funções casca libera o programador da tarefa de alterar as funções externas que compõem o LabSis, mantendo assim a filosofia dos autores dos programas originais. O fato de ter sido escrito totalmente em Matlab, toma o Labsis um software de código aberto, permitindo a qualquer programador a introdução de novas funções e programas. Uma vez que não é compilado em nenhum sistema específico, podendo assim ser executado em qualquer sistema onde o Matlab esteja instalado, toma o LabSis um software multi-plataforma. Construído para ser um pacote que englobe funções presentes e futuras, o LabSis contém, em sua versão atual, algoritmos (simples) de modelagem por traçado de raios, aproximação de Bom e integral Kirchhoff, análise de velocidades NMO, transformada T - P e análise de variação de amplitude com afastamento (AVO), migração Kirchhoffem profundidade e demigração Kirchhoff. O dado pode ser a qualquer momento visualizado através de uma feITamenta de "plotagem" de dados sísmicos. O programa permite ao usuário trabalhar com vários dados sísmicos ao mesmo tempo, sendo possível alternar entre eles a qualquer momento. O programa é totalmente gráfico, liberando o usuário de recorrer à linha de comando. No entanto essa opção existe, sendo útil para o caso de sucessivas repetições com ligeira variação de parâmetros. O LabSis é integrado com o pacote InterSis, um software também desenvolvido no Laboratório de Geofisica Computacional da Unicamp, e que consiste de uma interface gráfica para programas de modelagem de dados sísmicos. Com auxílio do InterSis, é possível gerar um modelo geológico e exportá-lo para o LabSis onde o mesmo é utilizado nas suas várias funções. Uma outra possibilidade é a utilização do InterSis para a modelagem de dados sísmicos e transferi-Ios para o LabSis para tarefas de processamento ou imageamento. A importação de dados no formato Seismic Unix (SU), bem conhecido na comunidade geofisica acadêmica e profissional, faz com que o LabSis possa se comunicar sem dificuldades com o mundo externo, permitindo a utilização de dados gerados por outros softwares. LabSis é um software didático, desenvolvido primordialmente para o ensino e a pesquisa, com o objetivo de tomar possível o entendimento e a verificação, na prática, de conceitos teóricos expostos em sala de aula. Tais características fazem com que o LabSis seja um atraente pacote para ser utilizado em cursos de graduação e pós-graduação. Por ser um programa leve, o LabSis não requer grandes exigências de máquina (a não ser que o dado utilizado assim o exija). Finalmente, o caráter integrador do LabSis permite sua utilização como plataforma unificada paras várias aplicações, em particular na área de modelagem e imageamento de dados sísmicos / Abstract: The Matlab package is a tool of widespread use in the academic environment, because of its advantages in simple direct programming, graphs and visualization tools. It allows initial implementations of algorithms and procedures very quickly in a series of applications. As a counterpar to the above good qualities, Matlab programs do not exhibit the computational efficiency that is found in typical programming languages (such as Fortran and C), as required for "final production codes". Such properties make the Matlab a package for "prototype codes". On a later stage, Matlab programs can be submitted to standard software engineering procedures, that contemplate a more adequate programming language for final use in practical problems. This characteristic of Matlab illustrates why it is so widely used in academia, especially for teaching and research purposes. In the specific case of the Laboratory of Computational Geophysics at Unicamp, a variety of Matlab programs have been developed in the last few years, mainly in the area of seismic data processing. Due to their very specific focus and lack of a common interface, the programs did not benefit from any conceptual unity that would allow more widespread application, even for users of the Laboratory. LabSis, developed in this thesis, appears as an integrator package of these functions, using the graphic tools of Matlab to create a simplified and intuitive interface for the user. LabSis is composed as a series of "wrapper functions", which make the bridge between the original algorithms and the final user. The employment of these wrapper functions frees the programmer from the task of altering the external functions that compose LabSis, maintaining the author's original program philosophy. The fact of being totally written in Matlab tums LabSis software an open source application, allowing any user to introduce new functions and programs. Since LabSis it is not compiled in any specific system (namely, it can be executed on any system where Matlab is installed), it also a multi-platform software. Built to be a package to include present and future functions, LabSis contains, in the current version, programs designed for modelling (using ray tracing, Bom and Kirchhoffmethods), NMO velocity analysis, computation of T - P transforms, amplitude versus offset (AVO) analysis, kirchhofftrue-amplitude migration and demigration. Visualization of results is always available by means of a tool that plots seismic data. The program allows the user to work simultaneously with several data sets, switching between them at any moment. The program is a graphical user interface (GUI) application. The user does not need to use command lines, however, that option exists, being useful for the case of successive repetitions with small variation of parameters. LabSis is integrated with the InterSis package, a software also developed at the Laboratory of Computational Geophysics of Unicamp, that consists of a graphic interface for seismic data modelling programs. With the aid of InterSis, it is possible to generate a geological model and export it to LabSis. Another possibility is to use InterSis to produce synthetic seismograms and transfer the datasets to LabSis for processing or imaging tasks. The possibility to import data in the Seismic Unix (SD) format, enables LabSis to communicate with the external world, allowing the use of data generated by other softwares. LabSis is a didactic software, specifically developed for teaching and research, with the aim of verifying in practice, many theoretical concepts exposed in the c1assroom. Such characteristics make LabSis attractive to Undergraduate and Graduate Programs that have geophysical data processing among their topics of interest. LabSis has not heavy requirements of computational speed or memory, unless the volume of data used demands it. LabSis integrated structure, makes possible its use as a small developrnent an communication platform to a wide range of users / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo
137

Improvement of the numerical capacities of simulation tools for reactive transport modeling in porous media / Amélioration des capacités numériques des outils de simulation pour la modélisation du transport réactif dans les milieux poreux

Jara Heredia, Daniel 21 June 2017 (has links)
La modélisation du transport réactif dans les milieux poreux implique la simulation de plusieurs processus physico-chimiques : écoulement de phases fluides, transport de chaleur, réactions chimiques entre espèces en phases identiques ou différentes. La résolution du système d'équations qui décrit le problème peut être obtenue par une approche soit totalement couplée soit découplée. Les approches découplées simplifient le système d'équations en décomposant le problème sous-parties plus faciles à gérer. Chacune de ces sous-parties peut être résolue avec des techniques d'intégration appropriées. Les techniques de découplage peuvent être non‑itératives (operator splitting methods) ou itératives (fixed‑point iteration), chacunes ayant des avantages et des inconvénients. Les approches non‑iteratives génèrent une erreur associée à la séparation des sous­-parties couplées, et les approaches itératives peuvent présenter des problèmes de convergence. Dans cette thèse, nous développons un code sous licence libre en langage MATLAB (https://github.com/TReacLab/TReacLab) dédie à la modélisation du la problématique de la carbonatation atmosphérique du béton, dans le cadre du stockage de déchets de moyenne activité et longue vie en couche géologique profonde. Le code propose un ensemble d'approche découplée : classique, comme les approches de fractionnement séquentiel, alternatif ou Strang, et moins classique, comme les approches de fractionnement additif ou par répartition symétrique. En outre, deux approches itératives basées sur une formulation spécifique (SIA CC et SIA TC) ont également été implémentées. Le code été interfacé de manière générique avec différents solveurs de transport (COMSOL, pdepe MATLAB, FVTool, FD scripts) et géochimiques (iPhreeqc, PhreeqcRM). Afin de valider l'implémentations des différentes approches, plusieurs bancs d'essais classiques dans le domaine du transport réactif ont été utilises avec succès. L'erreur associée à la combinaison du fractionnement de l'opérateur et des techniques numériques étant complexe à évaluer, nous explorons les outils mathématiques existants permettant de l'estimer. Enfin, nous structurons le problème de la carbonatation atmosphérique et présentons des simulations préliminaires, en détaillant les problèmes pertinents et les étapes futures à suivre. / Reactive transport modeling in porous media involves the simulation of several physico‑chemical processes: flow of fluid phases, transport of species, heat transport, chemical reactions between species in the same phase or in different phases. The resolution of the system of equations that describes the problem can be obtained by a fully coupled approach or by a decoupled approach. Decoupled approaches can simplify the system of equations by breaking down the problem into smaller parts that are easier to handle. Each of the smaller parts can be solved with suitable integration techniques. The decoupling techniques might be non‑iterative (operator splitting methods) or iterative (fixed‑point iteration), having each its advantages and disadvantages. Non‑iterative approaches have an error associated with the separation of the coupled effects, and iterative approaches might have problems to converge. In this thesis, we develop an open‑source code written in MATLAB (https://github.com/TReacLab/TReacLab) in order to model the problematic of concrete atmospheric carbonation for an intermediate‑level long‑lived nuclear waste package in a deep geological repository. The code uses a decoupled approach. Classical operator splitting approaches, such as sequential, alternating or Strang splitting, and less classical splitting approaches, such as additive or symmetrically weighted splitting, have been implemented. Besides, two iterative approaches based on an specific formulation (SIA CC, and SIA TC) have also been implemented. The code has been interfaced in a generic way with different transport solvers (COMSOL, pdepe MATLAB, FVTool, FD scripts) and geochemical solvers (iPhreeqc, PhreeqcRM). In order to validate the implementation of the different approaches, a series of classical benchmarks in the field of reactive transport have been solved successfully and compared with analytical and external numerical solutions. Since the associated error due to the combination of operator splitting and numerical techniques may be complex to assess, we explore the existing mathematical tools used to evaluate it. Finally, we frame the atmospheric carbonation problem and run preliminary simulations, stating the relevant problems and future steps to follow.
138

Dynamic torque clutch control for heavy duty vehicles using a backlash size and position observer

Eliasson Godonou, Samuel January 2017 (has links)
This master's thesis investigated the possibility to control the clutch torque in order to better traverse a Scania vehicles powertrain backlash. When traversing a backlash the torque difference between the two gears will at the time of contact excite oscillations in the powertrain, and by controlling the torque these oscillations can be minimized. The master's thesis solves this issue in three major steps. First a Simulink model was created to mimic the actual vehicles powertrain as closely as possible. It was created using mostly Simdriveline components and then validated by comparing simulations to measurements from real drives. After that backlash position and backlash size observers were created in order to estimate them. Using the developed Simulink model these observers could then be evaluated, and the backlash position observer proved to be very precise while the backlash size observer was not as precise but still usable. Finally a control strategy was devised, by using the estimates from the developed observers it was supposed to control the clutch torque in a better way than previously done. The controller was a switching controller that simply used the full engine torque while the backlash was in contact, and a P controller to control the clutch torque while performing a backlash traverse. The controller proved to perform well and was robust to errors in the backlash size. Future work to be done could be to develop a shaft torque observer for use in the already developed observers.
139

Turbo kódy a jejich aplikace / Turbo codes and their applications

Ploštica, Stanislav January 2009 (has links)
This Diploma thesis aims to explain the data coding using turbo codes. These codes belong to the group of error correction codes. We can reach the high efficiency using these codes. The first part describes process of encoding and decoding. There are describes parts of encoder and decoder. Principle of encoding and decoding demonstrate a simple example. The end of this part contains description of two most frequently used decoding algorithms (SOVA and MAP). The second part contains description of computer program that was made for using as teaching aid. This program was created in Matlab GUI. This program enables to browse error correction process step by step. This program contains graphic interface with many options and display results. In the third part is described program created in Matlab Simulink that was implemented into the TMS320C6713 kit and there is description of measuring procedure. For verification of efficiency of turbo codes was measured any parameters. Some of these parameters are: number of decoding iterations, generating polynoms and using of puncturing. The last part contains measured value and result evaluation.
140

Simulace přenosu DVB-S2 / Simulation of the DVB-S2 Transmission

Klíma, Jindřich January 2011 (has links)
This thesis is focusing on the second satellite digital TV standard, DVB-S2. It deals with the principle of the digital TV and the first standard DVB-S. It also describes the very beginning and characteristics of the DVB-S2, new technologies in use, architecture and the individual topics are then explained more in detail. The thesis also contains the program of transmission simulation of DVB-S2 in MATLAB. In the laboratory of television technology UREL, two standards were measured and compared with the values obtained from the program. The functionality of the program and the benefits of DVB-S2 were verified afterwards.

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