Commodity brain-computer interfaces (BCI) are beginning to accompany everything from toys and games to sophisticated health care devices. These contemporary interfaces allow for varying levels of interaction with a computer. Not surprisingly, the more intimately BCIs are integrated into the nervous system, the better the control a user can exert on a system. At one end of the spectrum, implanted systems can enable an individual with full body paralysis to utilize a robot arm and hold hands with their loved ones [28, 62]. On the other end of the spectrum, the untapped potential of commodity devices supporting electroencephalography (EEG) and electromyography (EMG) technologies require innovative approaches and further research. This thesis proposes a modularized software architecture designed to build flexible systems based on input from commodity BCI devices. An exploratory study using a commodity EEG provides concrete assessment of the potential for the modularity of the system to foster innovation and exploration, allowing for a combination of a variety of algorithms for manipulating data and classifying results. Specifically, this study analyzes a pipelined architecture for researchers, starting with the collection of spatio temporal brain data (STBD) from a commodity EEG device and correlating it with intentional behaviour involving keyboard and mouse input. Though classification proves troublesome in the preliminary dataset considered, the architecture demonstrates a unique and flexible combination of a liquid state machine (LSM) and a deep belief network (DBN). Research in methodologies and techniques such as these are required for innovation in BCIs, as commodity devices, processing power, and algorithms continue to improve. Limitations in terms of types of classifiers, their range of expected inputs, discrete versus continuous data, spatial and temporal considerations and alignment with neural networks are also identified. / Graduate / 0317 / 0984 / jasoncummer@gmail.com

Made available in DSpace on 2015-03-05T13:53:45Z (GMT). No. of bitstreams: 0 Previous issue date: 11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho é proposto um método de extração de conhecimento a partir de Redes Neurais Recorrentes. Expressar formalmente o conhecimento armazenado dentro de uma Rede Neural Artificial representa um grande desafio, já que tal conhecimento precisa ser reformulado e apresentado de uma maneira simples e inteligível. Três formalismos simbólicos são abordados para a representação deste conhecimento: Autômatos Finitos Difusos, Cadeias de Markov e Autômatos Finitos Determinísticos. Para as extrações de conhecimento utilizadas no trabalho, atribui-se significado às regiões do espaço de atividade dos neurônios. O método proposto utiliza a clusterização do espaço neural para obtenção dos estados do autômato, sendo utilizados para isso, o algoritmo K-means e a clusterização difusa. A obtenção do conhecimento é feita utilizando-se Redes Neurais Recorrentes para aprender o comportamento de dois sistemas dinâmicos não lineares e, a partir das redes treinadas, extrair os estados e possíveis transições do autômato. Os sis / ln this work a method ofknowledge extraction from Recurrent Neural Network is proposed. Express formally the knowledge stored inside an Artificial Neural Network is a great challenge, because such knowledge has to be reformulated and presented by simple and understandable means. Three symbolic formats are presented for the representation of this knowledge: Fuzzy Finite Automata, Markov Chains and Deterministic Finite Automata. For the knowledge extraction used in this work, each space region of the neuron activity is associated to a meaning. The considered method uses clusterization of the neural space in order to obtain the automata states, using the K-means algorithm and the fuzzy clustering. The knowledge acquisition is made using Recurrent Neural Networks to learn the behavior of the two non linear dynamic systems and, from the trained nets, to extract the states and possible automata transitions. The dynamic systems are the lnverse Pendulum system and the Lorenz system. The presented extraction method wa

Made available in DSpace on 2016-04-29T14:23:06Z (GMT). No. of bitstreams: 1 Luciano Gaspar.pdf: 1342989 bytes, checksum: 2adb8081f31a71914dc0e2627497482b (MD5) Previous issue date: 2012-05-10 / The aspects that affect the complexity in the development of systems are, also, barriers to the teaching and learning process of software modeling. Many techniques, tools and processes are adopted in this specific kind of teaching, although, one of the greatest issues found in this task is to create conditions in order to make the student experiment such a complexity in the classroom. The adoption of criteria for software quality analysis is an option that, into the architectural prospect, can reveal that, even the algorithm with few code lines are fragile and, along their life cycle, may present problems of scalability, maintenance and reuse. In this aspect, the purpose of this research is to evaluate if the codes produced by the student, supported by the concepts and techniques of the State Model, will express the initial characteristics of a modularized structure. A tool which extends the functions of the BlueJ teaching environment was developed and it is presented in this paper. That tool, associated with the BlueJ native resources and the State Machines learning make it possible for the student to accomplish software model descriptions according to the structural and environmental code prospects / Os aspectos que afetam a complexidade no desenvolvimento de sistemas também são barreiras para o processo de ensino-aprendizagem de modelagem de software. Muitas técnicas, ferramentas e processos são adotados nesse tipo específico de ensino, porém, uma das dificuldades encontradas é criar condições para que o aluno vivencie tal complexidade em sala de aula. Como alternativa, a adoção de critérios de análise da qualidade de software, sob a perspectiva arquitetural, pode revelar que mesmo os algorítmos com poucas linhas de código são frágeis e ao longo do seu ciclo de vida apresentam problemas de escalabilidade, manutenção e reuso. Nesse sentido, o propósito desta pesquisa é avaliar se o código produzido pelo aluno, apoiado nos conceitos e técnicas do Modelo de Estados, manifestará características iniciais de uma estrutura modularizada. Uma ferramenta que estende as funcionalidades do ambiente de ensino BlueJ foi desenvolvida e é apresentada neste trabalho. Esta ferramenta, associada aos recursos nativos do BlueJ e aos conhecimentos de Máquina de Estados, permite que o aluno elabore descrições de modelos de software dentro das perspectivas estrutural e comportamental do código

<p>An Adaptive Cruise Controller (ACC) is an extension of an ordinary cruise controller. In addition to maintaining a desired set velocity, an ACC can also maintain a desired time gap to the vehicle ahead. For this end, both the engine andthe brakes are controlled. </p><p>The purpose with this thesis has been to develop control strategies for an ACC used in heavy vehicles. The focus of the work has been the methods used for switching between the use of engine and brake. Two different methods have been studied, a hybrid controller and an MPC-controller. </p><p>For the hybrid controller, the main contribution has been to use the influence of the surroundings on the acceleration of the truck. This consists of several parts such as wind drag, road slope and rolling resistance. The estimated influence of the surroundings is used as a switch point between the use of engine and brakes. Ideally, these switch points give bumpless actuator switches. </p><p>The interest in the MPC-controller as an alternative solution was to achieve automatic actuator switching, thus with no explicitly defined switch points. The MPC-controller is based on a model of the system including bounds on the control signals. Using this knowledge, the MPC-controller will choose the correct actuator for the current driving situation. </p><p>Results from simulations show that both methods solve the actuator switch problem. The advantages with the hybrid controller are that it is implementable in a truck with the hardware used today and that it is relatively simple to parameterise. A drawback is that explicit switch points between the uses of the different actuators have to be included. The advantages with the MPC-controller are that no explicit switch points have to be introduced and that constraints and time delays on signals in the system can be handled in a simple way. Among the drawbacks, it can be mentioned that the variant of MPC, used in this thesis, is too complex to implement in the control system currently used in trucks. One further important drawback is that MPC demands a mathematical model of the system.</p>

An Adaptive Cruise Controller (ACC) is an extension of an ordinary cruise controller. In addition to maintaining a desired set velocity, an ACC can also maintain a desired time gap to the vehicle ahead. For this end, both the engine andthe brakes are controlled. The purpose with this thesis has been to develop control strategies for an ACC used in heavy vehicles. The focus of the work has been the methods used for switching between the use of engine and brake. Two different methods have been studied, a hybrid controller and an MPC-controller. For the hybrid controller, the main contribution has been to use the influence of the surroundings on the acceleration of the truck. This consists of several parts such as wind drag, road slope and rolling resistance. The estimated influence of the surroundings is used as a switch point between the use of engine and brakes. Ideally, these switch points give bumpless actuator switches. The interest in the MPC-controller as an alternative solution was to achieve automatic actuator switching, thus with no explicitly defined switch points. The MPC-controller is based on a model of the system including bounds on the control signals. Using this knowledge, the MPC-controller will choose the correct actuator for the current driving situation. Results from simulations show that both methods solve the actuator switch problem. The advantages with the hybrid controller are that it is implementable in a truck with the hardware used today and that it is relatively simple to parameterise. A drawback is that explicit switch points between the uses of the different actuators have to be included. The advantages with the MPC-controller are that no explicit switch points have to be introduced and that constraints and time delays on signals in the system can be handled in a simple way. Among the drawbacks, it can be mentioned that the variant of MPC, used in this thesis, is too complex to implement in the control system currently used in trucks. One further important drawback is that MPC demands a mathematical model of the system.

In formal language theory, studying shortest strings in languages, and variations thereof, can be useful since these strings can serve as small witnesses for properties of the languages, and can also provide bounds for other problems involving languages. For example, the length of the shortest string accepted by a regular language provides a lower bound on the state complexity of the language. In Chapter 1, we introduce some relevant concepts and notation used in automata and language theory, and we show some basic results concerning the connection between the length of the shortest string and the nondeterministic state complexity of a regular language. Chapter 2 examines the effect of the intersection operation on the length of the shortest string in regular languages. A tight worst-case bound is given for the length of the shortest string in the intersection of two regular languages, and loose bounds are given for two variations on the problem. Chapter 3 discusses languages that are defined over a free group instead of a free monoid. We study the length of the shortest string in a regular language that becomes the empty string in the free group, and a variety of bounds are given for different cases. Chapter 4 mentions open problems and some interesting observations that were made while studying two of the problems: finding good bounds on the length of the shortest squarefree string accepted by a deterministic finite automaton, and finding an efficient way to check if a finite set of finite words generates the free monoid. Some of the results in this thesis have appeared in work that the author has participated in \cite{AngPigRamSha,AngShallit}.

In formal language theory, studying shortest strings in languages, and variations thereof, can be useful since these strings can serve as small witnesses for properties of the languages, and can also provide bounds for other problems involving languages. For example, the length of the shortest string accepted by a regular language provides a lower bound on the state complexity of the language. In Chapter 1, we introduce some relevant concepts and notation used in automata and language theory, and we show some basic results concerning the connection between the length of the shortest string and the nondeterministic state complexity of a regular language. Chapter 2 examines the effect of the intersection operation on the length of the shortest string in regular languages. A tight worst-case bound is given for the length of the shortest string in the intersection of two regular languages, and loose bounds are given for two variations on the problem. Chapter 3 discusses languages that are defined over a free group instead of a free monoid. We study the length of the shortest string in a regular language that becomes the empty string in the free group, and a variety of bounds are given for different cases. Chapter 4 mentions open problems and some interesting observations that were made while studying two of the problems: finding good bounds on the length of the shortest squarefree string accepted by a deterministic finite automaton, and finding an efficient way to check if a finite set of finite words generates the free monoid. Some of the results in this thesis have appeared in work that the author has participated in \cite{AngPigRamSha,AngShallit}.

Modeliais paremtos architektūros (MDA) technologijos panaudojimo tikslas – automatizuoti kuriamos programų sistemos kuriamų modelių transformavimą ir kodo generavimą. Norint atlikti sukurtų modelių korektišką transformavimą, reikia užtikrinti modelių pilnumą ir suderinamumą tarpusavyje. Šie modeliai aprašomi UML modeliavimo kalba. Magistriniame darbe nagrinėjama nuo platformos nepriklausančio modelio kūrimo stadija, modelio klasių ir būsenų mašinų suderimo galimybės ir būsenų mašinų korektiškumo ir išbaigtumo metodikos. Taip pat bus pateikiamas sprendimas atliktas MagicDraw aplinkoje įskiepio pagalba. / The main goal of Model Driven Architecture (MDA) is the automation of software development process. According this technology, we need to create platform independent model (PIM), after that transform it to platform specific model (PSM); from PSM model we can generate program code. To do that, we need to ensure static and dynamic completeness of PIM. All these models are described using UML modeling language. In this work correctness and completeness of PIM is achieved by analyzing compatibility of class diagrams and state machines, as well as correctness and completeness of state machines themselves. To solve this problem, algorithms were created and implemented in a plug-in for MagicDraw CASE tool.

Made available in DSpace on 2014-06-11T19:22:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-30Bitstream added on 2014-06-13T20:09:43Z : No. of bitstreams: 1 almeida_ts_me_ilha.pdf: 5032122 bytes, checksum: ba20bdd1ce902754e7b772b2be3cc785 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho, apresenta-se o desenvolvimento e a avaliação de duas ferramentas que auxiliam projetos de circuitos eletrônicos, sejam eles projetos de sistemas digitais ou de sistemas mistos (sinais digitais e sinais analógicos). A partir de um diagrama de transição de estados, modelado em ambiente Stateflow®, a primeira ferramenta, denominada SF2HDL, realiza a extração de linguagens de descrição de hardware, podendo ser VHDL ou Verilog HDL. Sendo ainda capaz de extrair uma tabela de transição de estados padronizada, que, posteriormente, foi utilizada como entrada pelo programa TABELA, o qual realiza a minimização do sistema digital. A máquina de estados finitos, alvo da tradução, pode ser descrita tanto pelo modelo de Mealy como pelo modelo de Moore. Como estudos de caso, foram utilizados quatro códigos de linhas empregados em sistemas de telecomunicações. A segunda ferramenta é um aperfeiçoamento de uma ferramenta já existente, denominada MS2SV, empregada na síntese de sistemas mistos. O MS2SV é capaz de gerar uma descrição em VHDL-AMS estrutural, a partir de um modelo descrito em alto nível de abstração no ambiente Simulink®. Toda a estrutura de projeto necessária para a simulação e análise do sistema no ambiente SystemVision™, também é gerado pelo MS2SV. Foram utilizados quatro modelos de conversor de dados do tipo DAC (Digital to Analog Conversor), para avaliar o desempenho da ferramenta. Nesse contexto, as duas ferramentas permitem maior flexibilidade ao projetista, traduzindo descrições em níveis de abstração diferentes, o que permite uma análise mais detalhada do funcionamento do sistema e facilitando a sua implementação física / In this work, it’s shown the development and evaluation of two tools to aid in electronic circuits projects, be them digital systems projects or for mixed systems (digital and analogical signs). From a states transition diagram modeled in Stateflow® environment, the first tool, named SF2HDL, performs the extraction of hardware description languages, which could be VHDL or Verilog HDL. It is also capable of extracting states transition table standardized, which later was used as a TABELA program, which accomplishes the minimization of the digital system. The target finite state machine of the translated can be described by the Mealy model as much as the Moore model. As case studies were used four code lines employed in telecommunications systems. The second tool is an improvement of an already existent tool, known as MS2SV, used in the synthesis of mixed systems. The MS2SV is able to generate a description in structural VHDL-AMS, from a model described in high level of abstraction in the Simulink® environment. The whole project structure necessary for the simulation and analysis of the system by the SystemVision™ environment is also generated by MS2SV. Four DAC (Digital to Analog Converter) were used to evaluate the tool is performance. In that context, both tools allow a greater flexibility to the planner, translating descriptions in different abstraction levels, which allows a more detailed analysis of the systems behavior and making its physical implementation easier

This thesis work investigates how to represent protocols for asynchronous communication in the Scala programming language and the Akka actor framework, to be run on Java Virtual Machine (JVM). Further restrictions from the problem domain - the coexistence of multiple protocol instances sharing the same Java thread - imply that neither an asynchronous call waiting for response nor anything else can block the underlying Java threads. A common way to represent asynchronous communication protocols is to use state machines. This thesis seeks a way to shrink the size of and to reduce the complexity of the protocol implementations by representing sequences of asynchronous communication calls (i.e. sequences of sent and received messages) as a type of procedure. The idea is find a way to make the procedures that contain asynchronous calls look like synchronous communication procedures by hiding the asynchronous details. In other words, the resulting procedure code should show what to do and not so much focus on how to overcome the impediment of the asynchronous calls. With the help of an asynchronous communication protocol toy example, this report shows how such an protocol can be implemented with a combination of a state machine and a procedure representation in Scala and Akka. The procedure representation hides away the asynchronous details by using the Scala capability to use CPS-transformed delimited continuations. As a sub-problem, this thesis also shows how to safely schedule asynchronous communication timeouts with help of Scala and Akka within the restrictions of the thesis problem domain.