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A flexible and innovative platform for autonomous mobile robots

Howe, Jessica Anne, 1978-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 106 p.; 3828921 bytes; 3828729 bytes; application/pdf; application/pdf
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The development of the CREAL programming language and the STACK hardware platform by the members of the CSAIL Living Machines research group has lead to a foundation upon which roboticists may build and control autonomous mobile robots. This platform, however, has been used only within this research group on a minimal number of projects. As is, there has been no published discussion on the application of CREAL and the STACK to various types of control architectures commonly used in controlling autonomous mobile robots, or any personal accounts of the successes or failures of using such a system on a hand-built robot. In this thesis I focus on these two points. I go into depth on the use and expansion of CREAL to support multiple control architectures, as well as a personal account of the construction and use of a robot that uses these architectures and hardware to accomplish various tasks. The work to be undertaken will describe the process of design, construction, debugging and implementation of a hand-built robot that performs example tasks that are similar in nature to tasks commonly performed by autonomous mobile robots within the robotic research community. Currently, CREAL does not provide any abstract framework to facilitate implementation of neural net architectures by users. The work described in this thesis includes a set of macros that expand the CREAL language to allow user-friendly creation of neural nets. This abstraction framework is then put into use in an implementation that uses the neural net tools developed in order to achieve a fixed goal The second architecture to be discussed is that of subsumption...

Language generation and speech synthesis in dialogues for language learning

Zhang, Julia, 1981-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 68 p.; 3079530 bytes; 3086387 bytes; application/pdf; application/pdf
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Since 1989, the Spoken Language Systems group has developed an array of applications that allow users to interact with computers using natural spoken language. A recent project of interest is to develop an interactive conversational system to assist students in mastering a foreign language. The Spoken Language Learning System (SLLS), the first such system developed in SLS, has many impressive capabilities and shows great potential to be used as a model for language learning. This thesis further develops and expands on SLLS towards the goal of a more sophisticated conversational system. We make extensive use of Genesis, a language generation tool, to complete a variety of natural language generation and translation tasks. We aim to generate natural, well-formed, grammatically correct sentences and produce high quality synthesized waveforms for language students to emulate. We hope to develop a system that will engage the user in a natural and realistic way, and our goal is to mimic human-to-human conversant interactions as closely as possible.; by Julia Zhang.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.; Includes bibliographical references (p. 67-68).

Vowel articulation and laryngeal control in the speech of the deaf

Bush, Marcia Ann
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 214 leaves; 10638231 bytes; 10637990 bytes; application/pdf; application/pdf
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by Marcia Ann Bush.; Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981.; MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.; Bibliography: leaves 185-192.

Towards a unified framework for sub-lexical and supra-lexical linguistic modeling

Mou, Xiaolong, 1973-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 178 p.; 8408900 bytes; 8408707 bytes; application/pdf; application/pdf
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Conversational interfaces have received much attention as a promising natural communication channel between humans and computers. A typical conversational interface consists of three major systems: speech understanding, dialog management and spoken language generation. In such a conversational interface, speech recognition as the front-end of speech understanding remains to be one of the fundamental challenges for establishing robust and effective human/computer communications. On the one hand, the speech recognition component in a conversational interface lives in a rich system environment. Diverse sources of knowledge are available and can potentially be beneficial to its robustness and accuracy. For example, the natural language understanding component can provide linguistic knowledge in syntax and semantics that helps constrain the recognition search space. On the other hand, the speech recognition component also faces the challenge of spontaneous speech, and it is important to address the casualness of speech using the knowledge sources available. For example, sub-lexical linguistic information would be very useful in providing linguistic support for previously unseen words, and dynamic reliability modeling may help improve recognition robustness for poorly articulated speech. In this thesis...

NPL : a graphical programming language for motor control and its application to bipedal walking; Neuronal Programming Language : a graphical programming language for motor control and its application to bipedal walking

Wessler, Michael Alan, 1970-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 126 p.; 5937472 bytes; 5937281 bytes; application/pdf; application/pdf
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Current methods for bipedal walking control include playback of recorded joint motion and the derivation of dynamic equations to map desired forces at the body to the required torques at the joints. Both methods require a significant amount of up-front knowledge about the structure and characteristics of the robot. This thesis presents an alternative method of control that removes the interdependence of the joint torques and simplifies the mathematics considerably. The simplification allows a programmer to create and tune a bipedal walk controller without requiring a complete model of the dynamics. The controller is implemented in a graphical programming language similar to fuzzy logic and neural networks, in which the algorithm is contained in the structure of the nodes rather than in the weights of the connections. The language and its development environment are specifically designed to assist the programmer to create and debug the algorithm in a live environment.; by Michael Alan Wessler.; Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.; Includes bibliographical references (p. 123-126).

LanguageLand : a multimodal conversational spoken language learning system; Language Land : a multimodal conversational spoken language learning system

Lee, Vivienne C. (Vivienne Catherine)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 98 leaves; 5852448 bytes; 5856329 bytes; application/pdf; application/pdf
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LanguageLand is a multimodal conversational spoken language learning system whose purpose is to help native English users learn Mandarin Chinese. The system is centered on a game that involves navigation on a simulated map. It consists of an edit and play mode. In edit mode, users can set up the street map with whichever objects (such as a house, a church, a policeman) they see in the toolbar. This can be done through spoken conversation over the telephone or typed text along with mouse clicks. In play mode, users are given a start and end corner and the goal is to get from the start to the end on the map. While the system only responds actively to accurate Mandarin phrases, the user can speak or type in English to obtain Mandarin translations of those English words or phrases. The LanguageLand application is built using Java and Swing. The overall system is constructed using the Galaxy Communicator architecture and existing SLS technologies including Summit for speech recognition, Tina for NL understanding, Genesis for NL generation, and Envoice for speech synthesis.; by Vivienne C. Lee.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.; Includes bibliographical references (leaves 96-98).

Semi-supervised learning for natural language

Liang, Percy
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 86 p.; 4273216 bytes; 4277241 bytes; application/pdf; application/pdf
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Statistical supervised learning techniques have been successful for many natural language processing tasks, but they require labeled datasets, which can be expensive to obtain. On the other hand, unlabeled data (raw text) is often available "for free" in large quantities. Unlabeled data has shown promise in improving the performance of a number of tasks, e.g. word sense disambiguation, information extraction, and natural language parsing. In this thesis, we focus on two segmentation tasks, named-entity recognition and Chinese word segmentation. The goal of named-entity recognition is to detect and classify names of people, organizations, and locations in a sentence. The goal of Chinese word segmentation is to find the word boundaries in a sentence that has been written as a string of characters without spaces. Our approach is as follows: In a preprocessing step, we use raw text to cluster words and calculate mutual information statistics. The output of this step is then used as features in a supervised model, specifically a global linear model trained using the Perception algorithm. We also compare Markov and semi-Markov models on the two segmentation tasks. Our results show that features derived from unlabeled data substantially improves performance...

Detecting and parsing embedded lightweight structures

Rha, Philip
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 72 p.; 2721231 bytes; 2724141 bytes; application/pdf; application/pdf
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Text documents, web pages, and source code are all documents that contain language structures that can be parsed with corresponding parsers. Some documents, like JSP pages, Java tutorial pages, and Java source code, often have language structures that are nested within another language structure. Although parsers exist exclusively for the outer and inner language structure, neither is suited for parsing the embedded structures in the context of the document. This thesis presents a new technique for selectively applying existing parsers on intelligently transformed document content. The task of parsing these embedded structures can be broken up into two phases: detection of embedded structures and parsing of those embedded structures. In order to detect embedded structures, we take advantage of the fact that there are natural boundaries in any given language in which these embedded structures can appear. We use these natural boundaries to narrow our search space for embedded structures. We further reduce the search space by using statistical analysis of token frequency for different language types. By combining the use of natural boundaries and the use of token frequency analysis, we can, for any given document, generate a set of regions that have a high probability of being an embedded structure.; (cont.) To parse the embedded structures...

LADDER : a perceptually-based language to simplify sketch recognition user interface development; Perceptually-based language to simplify sketch recognition user interface development

Hammond, Tracy Anne
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 495 p.
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Diagrammatic sketching is a natural modality of human-computer interaction that can be used for a variety of tasks, for example, conceptual design. Sketch recognition systems are currently being developed for many domains. However, they require signal-processing expertise if they are to handle the intricacies of each domain, and they are time-consuming to build. Our goal is to enable user interface designers and domain experts who may not have expertise in sketch recognition to be able to build these sketch systems. We created and implemented a new framework (FLUID - f acilitating user interface development) in which developers can specify a domain description indicating how domain shapes are to be recognized, displayed, and edited. This description is then automatically transformed into a sketch recognition user interface for that domain. LADDER, a language using a perceptual vocabulary based on Gestalt principles, was developed to describe how to recognize, display, and edit domain shapes. A translator and a customizable recognition system (GUILD - a generator of user interfaces using ladder descriptions) are combined with a domain description to automatically create a domain specific recognition system.; (cont.) With this new technology...

PHDL : a Python Hardware Design framework; Python Hardware Design Language : a Python Hardware Design framework

Mashtizadeh, Ali
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 87 p.
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is thesis presents PHDL, a new hardware design language (HDL). In PHDL digital hardware components can vary in input/output widths, target platform, and have optional inputs and outputs. PHDL enables developers to write software to make intelligent compile time decisions far beyond the capabilities of current HDLs. e approach taken is to build PHDL on the Python scripting language and to build a component library suciently large to design a microprocessor. As an example a microprocessor is designed in PHDL to show the practicality of the language. e example shows that on average designs can be written with less complexity than a corresponding Verilog implementation, while achieving better portability and platform specific optimizations.; by Ali Mashtizadeh.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.; This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.; Includes bibliographical references (p. 87).

Decoding algorithms for complex natural language tasks

Deshpande, Pawan
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 85 p.
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This thesis focuses on developing decoding techniques for complex Natural Language Processing (NLP) tasks. The goal of decoding is to find an optimal or near optimal solution given a model that defines the goodness of a candidate. The task is challenging because in a typical problem the search space is large, and the dependencies between elements of the solution are complex. The goal of this work is two-fold. First, we are interested in developing decoding techniques with strong theoretical guarantees. We develop a decoding model based on the Integer Linear Programming paradigm which is guaranteed to compute the optimal solution and is capable of accounting for a wide range of global constraints. As an alternative, we also present a novel randomized algorithm which can guarantee an arbitrarily high probability of finding the optimal solution. We apply these methods to the task of constructing temporal graphs and to the task of title generation. Second, we are interested in carefully investigating the relations between learning and decoding. We build on the Perceptron framework to integrate the learning and decoding procedures into a single unified process. We use the resulting model to automatically generate tables-of-contents, structures with deep hierarchies and rich contextual dependencies. In all three natural language tasks...

FITSL : a language for directed exploration and analysis of sequence data; Language for directed exploration and analysis of sequence data

Mumpower, Eric J. P
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 84 p.
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This thesis describes a sequence-data processing toolkit for analysis of Intelligent Tutoring System (ITS) log data, that unlike other tools allows directed exploration of sequence patterns. This system provides a powerful yet straightforward abstraction for sequence-data processing, and a set of high-level manipulation primitives which allow arbitrarily complex transformations of such data. Using this language, very sophisticated queries can be performed using only a few lines of code. Furthermore, queries can be constructed interactively, allowing for rapid development, refinement, and comparison of hypotheses. Importantly, this system is not limited to ITS logs, but is equally applicable to the manipulation of any form of (potentially multidimensional) sequence data.; by Eric J.P. Mumpower.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.; Includes bibliographical references (p. 81-84).

Web-based, speech-enabled games for vocabulary acquisition in a foreign language; Speech-enabled games for vocabulary acquisition in a foreign language

McGraw, Ian C. (Ian Carmichael)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 85 p.
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In this thesis, I present two novel ways in which speech recognition technology might aid students with vocabulary acquisition in a foreign language. While research in the applied linguistics field of second language acquisition (SLA) increasingly suggests that students of a foreign language should learn through meaningful interactions carried out in that language, teachers are rarely equipped with tools that allow them to provide interactive environments outside of the classroom. Fortunately, speech and language technologies are becoming robust enough to aid in this regard. This thesis presents two distinct speech-enabled systems to assist students with the difficult task of vocabulary acquisition in Mandarin Chinese. At the core of each system is a Mandarin speech recognizer that, when connected to a web-based graphical user interface, provides students with an interactive environment in which to acquire new Mandarin vocabulary.; by Ian C. McGraw.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.; Includes bibliographical references (p. 79-85).

Natural language search of structured documents

Oney, Stephen W
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 48 leaves
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This thesis focuses on techniques with which natural language can be used to search for specific elements in a structured document, such as an XML file. The goal is to create a system capable of being trained to identify features, of written English sentence describing (in natural language) part of an XML document, that help identify the sections of said document which were discussed. In particular, this thesis will revolve around the problem of searching through XML documents, each of which describes the play-by-play events of a baseball game. These events are collected from Major League Baseball games between 2004 and 2008, containing information detailing the outcome of every pitch thrown. My techniques are trained and tested on written (newspaper) summaries of these games, which often refer to specific game events and statistics. The choice of these training data makes the task much more complex in two ways. First, these summaries come from multiple authors. Each of these authors has a distinct writing style, which uses language in a unique and often complex way. Secondly, large portions of these summaries discuss facts outside of the context of the play-by-play events of the XML documents. Training the system with these portions of the summary can create a problem due to sparse data...

Image-based motion estimation in a stream programming language

Aziz, Abdulbasier
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 59 p.
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In this thesis, a computer vision application was implemented in the StreamIt language. The reference application was an image-based motion estimation algorithm written in MATLAB. The intent of this thesis is to contribute a case study of StreamIt, an architecture-independent language designed for stream programming. In particular, it observes StreamIt's ability to preserve block structure and to handle otherwise complicated functionality in an elegant fashion, especially in comparison to the reference implementation, coded in MATLAB. Furthermore, we observe a runtime of the StreamIt-coded application 2% faster than that of MATLAB. Lastly, the potentials of boosted performance with parallelization of subroutines within the program are discussed.; by Abdulbasier Aziz.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.; Includes bibliographical references (p. 57-59).

Indexical grounding for a mobile robot; Semantic grounding in a natural language interface

Kehoe, Charles W. (Charles Ward)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 27 p.; 1446546 bytes; 1445037 bytes; application/pdf; application/pdf
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We have outfitted a mobile research robot with several sensors and algorithms designed to facilitate small- and large-scale navigation and natural language interaction. We begin with a parser using a large, hand-crafted English grammar and lexicon. We then add a standard gradient navigation algorithm for local obstacle avoidance, and a line segment comparison algorithm for basic, high-performance location recognition. The result is a full end-to-end system for natural-language-driven, mobile robotics research. The theme of grounding-mapping linguistic references to the corresponding real-world entities-runs throughout our approach. After the parser simplifies linguistic symbols and structures, we must connect them to the basic concepts that they represent, and then to our system's specific sensor readings and motor commands, to make natural language interaction possible. Additionally, many of the symbols we must ground are indexicals with critical contextual dependencies. We must therefore handle the implicit context that spatial communication carries with it.; by Charles W. Kehoe.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.; Includes bibliographical references (p. 26-27).

A graph editing framework for the StreamIt language

Reyes, Juan C. (Juan Carlos), 1980-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 56 leaves; 2246808 bytes; 2251824 bytes; application/pdf; application/pdf
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A programming language is more useful if it provides a level of abstraction that makes programming more intuitive and also allows the development of tools that take advantage of the language's internal representation. StreamIt, a language for the development of streaming applications, has a hierarchical and structural nature that lends itself to a graphical programming tool. I created a prototype StreamIt Graph Editor (SGE) to facilitate the development of streaming applications using StreamIt. The SGE provides intuitive visualization tools that allow developers to work more efficiently by automating certain processes. Thus, the programmer can focus more on design issues than on low level details that slow down the development process.; by Juan C. Reyes.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.; Includes bibliographical references (leaves 55-56).

PLUTO : a preprocessor for multilingual spoken language generation; Preprocessor for multilingual spoken language generation

Cowan, Brooke A. (Brooke Alissa), 1972-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 115 p.; 4036555 bytes; 4036363 bytes; application/pdf; application/pdf
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Surface realization, a subtask of natural language generation, maps a meaning representation to a natural language string. This thesis presents an architecture for a surface realization component in a spoken dialogue system. The architecture divides the surface realization task in two: (1) modification of the meaning representation to adhere to the constraints of the target language, and (2) string production. Each subtask is handled by a separate module. PLUTO is a new module, responsible for meaning representation modification, that has been added to the Spoken Language Systems group's surface realization component. PLUTO acts as a preprocessor to the main processor, GENESIS, which is responsible for string production. We show how this new, decoupled architecture is amenable to a hybrid approach to machine translation that combines transfer and interlingua. We also present a policy for generation that specifies the roles of PLUTO, GENESIS, and the lexicon they share. This policy formalizes a way of writing robust, reusable grammars. The primary contribution of this work is to simplify the development of such grammars in multilingual speech-based applications.; by Brooke A. Cowan.; Thesis (S.M.)--Massachusetts Institute of Technology...

Starkiller : a static type inferencer and compiler for Python; Static type inferencer for dynamic languages

Salib, Michael, 1978-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 96 leaves; 436696 bytes; 435331 bytes; application/pdf; application/pdf
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Starkiller is a type inferencer and compiler for the dynamic language Python designed to generate fast native code. It analyzes Python source programs and converts them into equivalent C++ programs. Starkiller's type inference algorithm is based on the Cartesian Product Algorithm but has been significantly modified to support a radically different language. It includes an External Type Description Language that enables extension authors to document how their foreign code extensions interact with Python. This enables Starkiller to analyze Python code that interacts with foreign code written in C, C++, or Fortran. The type inference algorithm also handles data polymorphism in addition to parametric polymorphism, thus improving precision. Starkiller supports the entire Python language except for dynamic code insertion features such as eval and dynamic module loading. While the system is not yet complete, early numeric benchmarks show that Starkiller compiled code performs almost as well as hand made C code and substantially better than alternative Python compilers.; by Michael Salib.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.; Includes bibliographical references (leaves 93-96).; This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.