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DSpace at MIT (78,720 recursos)
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Electrical Engineering and Computer Sciences - Master's degree

Mostrando recursos 1 - 20 de 5,611

1. Design of tool for the optimization of deck area assignments with integration into existing naval ship design programs - Oslebo, Damian G
Many tasks in the early stages of ship design are manual and repetitive processes. One such task is in the realm of deck area arrangements. The allocation and assignment of areas in early stage ship design involves tracking the difference of total ship area envelope and all required areas to be placed for habitability, mission support, and propulsion capability among many. The problem becomes more complex with the addition of constraints involving required separation zones between other areas, affinities for certain areas or deck levels, and compartment subdivision. The Leading Edge Architecture for Prototyping Systems (LEAPS) database structure output from...

2. Design of an Autonomous Underwater Vehicle (AUV) charging system for underway, underwater recharging - Ewachiw, Mark Alexander, Jr
Modern robotics have enabled the rapid proliferation of Autonomous Underwater Vehicles (AUVs) throughout the marine environment. As autonomy algorithms increase in robustness, complexity, and reliability, so too does the ability of AUVs to perform an even-increasing array of complex missions. Maritime tasks that once required a fleet of ships, months to complete, and numerous mariners are now being performed by AUVs with little to no logistical support elements. Despite the many AUV technology advances that have been made, power remains a limiting factor. Most AUVs use onboard stored electric energy and electric drive to perform their various missions. The current...

3. Development of MIT geospatial data to CityGML workflows - Wu, Bradley
BlindAid is a virtual environment system that helps blind people learn in advance about places they plan to visit. A core component of the BlindAid system is the actual set of virtual models that represent physical locations. In order for BlindAid to be useful, there must be a means to generate new virtual environments. The research in this thesis explores the process of translating geospatial data received from MIT into the CityGML data format, which will then be used to generate virtual environments for BlindAid. We discuss the main challenge of preserving both geometry and semantic information with respect to...

4. CyberVisual : designing user environments for large scale networks and simulations - Workie, Nahoin Hailemariam
The growth of data collection within the technology sector has been increasing at an astounding rate over the last decade. This growth has given rise to techniques and statistical tools for computation that enable us to see trends and answer queries; however, most of this information has been in the form of numbers in a data set resulting from these computations. As this trend towards data collection and analysis continues, it becomes increasingly important to show and present this information to users and non-data scientists with quantifiable and concise methods. With respect to large data in the field of networks...

5. Design and implementation of a fiber optic doppler optical coherence microscopy system for cochlear imaging - Williams, Logan P
In this thesis, the design and implementation of a fiber optic Doppler optical coherence microscopy (FO-DOCM) system for cochlear imaging applications is presented. The use of a fiber optic design significantly reduces system size and complexity and the construction of a novel alignment and micropositioning apparatus increases ease of use for the researcher performing the imaging. To enable precise measurements of tissue motion, a time domain DOCM approach is used, utilizing an acousto-optic modulator (AOM) based optical heterodyne system to generate a stationary interference carrier frequency. By referencing this interference signal against the AOM drive signals, measurements of motions with...

6. EMGRIE : Ergonomic Microgesture Recognition and Interaction Evaluation, a case study - Way, David (David H.)
Given the recent success of hand pose gesture recognition via wrist-worn camera based sensors, specific hand pose interaction evaluation is needed. In order to evaluate such interactions, we built EMGRIE: a quick-prototype wrist-worn vision-based gesture recognition system that applies necessary feature extraction and training data collection techniques to facilitate user customization of specific hand pose gestures. We use EMGRIE to extract differences in microgesture task times, perceived effort, and perceived command associations across users, gestures, gesture performance iterations, and various applications. This thesis gives a summary of past wrist-worn gesture recognition systems and past gestural application design research, EMGRIE system...

7. Local versus global tables in Minimax Game Search - Wattanawaroon, Tana
Minimax Game Search with alpha-beta pruning can utilize heuristic tables in order to prune more branches and achieve better performance. The tables can be implemented using different memory models: global tables, worker-local tables and processor-local tables. Depending on whether each heuristic table depends on locality in the game tree, a memory model might be more suitable than others. This thesis describes an experiment that shows that local tables are generally preferable to global tables for two game heuristics used in chess-like games: killer move and best move history. The experiment is evidence that local tables might be useful for multithreaded...

8. Geometric modeling and optimization in 3D solar cells : implementation and algorithms - Wan, Jin Hao, M. Eng. Massachusetts Institute of Technology
Conversion of solar energy in three-dimensional (3D) devices has been essentially untapped. In this thesis, I design and implement a C++ program that models and optimizes a 3D solar cell ensemble embedded in a given landscape. The goal is to find the optimum arrangement of these solar cells with respect to the landscape buildings so as to maximize the total energy collected. On the modeling side, in order to calculate the energies generated from both direct and reflected sunlight, I store all the geometric inputs in a binary space partition tree; this data structure in turn efficiently supports a crucial...

9. Development of a powered transtibial prosthesis for ball room dancing - Villagaray-Carski, Nathan (Nathan C.)
Research on lower extremity prostheses has primarily focused on activities of daily living, such as walking and running, but has largely overlooked less common activities. As a result, traditional prosthetic devices are designed for a walking/running gait, and are difficult to use for other activities. This study aims to take the first steps to determine if a bionic prosthesis can enable alternate activity modes, not driven by traditional activities of daily living. Specifically, we aim to modify the BiOM, a commercial robotic ankle prosthesis, to allow a professional dancer and below-knee amputee to dance the Rumba. The movements of an...

10. Predictive ability of cerebrospinal fluid biomarkers in diagnosing and evaluating Parkinson's disease - Wang, Michelle J
Currently, there are a variety of clinical assessments and rating scales used in the research and treatment of Parkinson's disease (PD). Despite the widespread use and reliance on these scales, they do not offer a uniform, objective measure. Many previous studies have indicated promising relationships between various biomarkers and Parkinsonian symptoms that could lead to objective measures by using statistical methods and providing p-values. However, we could not find any literature that uses machine learning or directly tests predictive value. The goal of this thesis was to determine whether or not cerebrospinal fluid (CSF) biomarker data could predict incidence of...

11. Fast bug finding in lock-free data structures with CB-DPOR - Van den Hooff, Jelle (Jelle August)
This thesis describes CB-DPOR, an algorithm for quickly finding bugs in lock-free data structures. CB-DPOR is a combination of the CHESS and DPOR model checking algorithms. CB-DPOR performs similar to the concurrently developed preemption-bounded BPOR algorithm. CODEX is a tool for finding bugs in lock-free data structures. CODEX implements CBDPOR and this thesis demonstrates how to use CODEX to find bugs. This thesis describes new bugs in open-source lock-free data structures, and compares the performance of CBDPOR with the earlier model checking algorithms CHESS, DPOR, and PCT. CB-DPOR find bugs one to two orders of magnitude faster than earlier algorithms.

12. Building blocks of a 250MHz bandwidth, 10-bit continuous-time delta-sigma analog to digital converter
This thesis examines the design of a continuous time Delta-Sigma Analog to Digital Converter with the target performance to be 10-bit, 250MHz bandwidth with 200mW power dissipation.The design process involves choosing a top-level architecture and designing transistor-level blocks. The architecture is selected to be second-order, 3-bit with a 32 oversampling rate based on the ideal model simulation in MATLAB. The transistor-level circuits are designed in a BiCMOS technology. The SQNR result is 63.3dB and the power is 140mW.

13. Electrical stimulation of the ventral lateral periaqueductal gray induces antinociception in rats - Zheng, Shu, M. Eng. Massachusetts Institute of Technology
Despite the central role of general anesthesia in modern healthcare, the frequency of anesthesia-related morbidity resulting from the toxicity and non-specificity of anesthetic drugs remains high. Among the key behavioral states of general anesthesia is antinociception (reduced sensitivity to pain). Within the nociceptive pathway in the brain and the central nervous system, the periaqueductal gray (PAG) has been shown to be a key site that modulates antinociception responses. We hypothesize that electrical stimulation of the ventral lateral periaqueductal gray (vIPAG) in rodents reliably induces antinociception in a physiology-derived way. Rectangular electrical stimuli were applied at the vlPAG of rats at...

14. Learning time series data using cross correlation and its application in bitcoin price prediction - Zhang, Kang, M. Eng. Massachusetts Institute of Technology
In this work, we developed an quantitative trading algorithm for bitcoin that is shown to be profitable. The algorithm establishes a framework that combines parametric variables and non-parametric variables in a logistical regression model, capturing information in both the static states and the evolution of states. The combination improves the performance of the strategy. In addition, we demonstrated that we can discovery curve similarity of time series using cross correlation and L2 distance. The similarity metrics can be efficiently computed using convolution and can help us learn from the past instance using an ensemble voting scheme.

15. Representation discovery in non-parametric reinforcement learning - Zewdie, Dawit (Dawit Habtamu)
Recent years have seen a surge of interest in non-parametric reinforcement learning. There are now practical non-parametric algorithms that use kernel regression to approximate value functions. The correctness guarantees of kernel regression require that the underlying value function be smooth. Most problems of interest do not satisfy this requirement in their native space, but can be represented in such a way that they do. In this thesis, we show that the ideal representation is one that maps points directly to their values. Existing representation discovery algorithms that have been used in parametric reinforcement learning settings do not, in general, produce...

16. Secure communication through free-space channel using quantum illumination - Yune, Jiwon
Secure communication based on quantum illumination (QI) provides high-speed direct communication in the presence of loss and noise and is secure against passive eavesdropping. Recently, the QI based communication protocol has been demonstrated in a fiber channel. In this thesis, we extend the QI secure communication protocol to a free-space propagation channel. Unlike a fiber channel, a free-space channel is susceptible to air turbulence. Because a single spatial mode of light is essential in the QI protocol, if the beam path is affected by air turbulence, the power and phase may fluctuate, which can affect the interferometric measurement performance of...

17. Efficient wireless charging with gallium nitride FETs - Yeh, Theresa (Theresa I.)
Though wireless charging is more convenient than traditional wired charging methods, it is currently less efficient. This not only wastes power but can also result in a longer charging time. Improving the efficiency of wireless charging systems is equivalent to reducing the sources of loss in the system. In this work, we focus on losses originating from the transistor. Resonant inductive wireless charging systems were designed and implemented for efficiency comparisons. We show in our experiments that replacing the traditional Silicon MOSFET with a Gallium Nitride FET can increase the overall system efficiency by 5%.

18. Old man coyote stories : cross-cultural story understanding in the Genesis story understanding system - Yarlott, Wolfgang Victor Hayden
The original question was: "Can machines think?" Alan Turing asked: "Does there exist a digital computer that can do sufficiently well at the imitation game?" Patrick Winston asked: "What makes human intelligence different from that of other primates?" Winston's answer came in the form of four hypotheses that are the core behind the vision of the Genesis group at MIT's Computer Science and Artificial Intelligence Laboratory, which has developed the Genesis story understanding system. The key focus behind this system is: stories are an essential component of what makes human intelligence so remarkably different from that of other animals. I...

19. Cilkprof : a scalability profiler for Cilk programs - Xing, Kerry (Kerry K.)
This thesis describes the design and implementation of Cilkprof, a profiling tool that helps programmers to diagnose scalability problems in their Cilk programs. Cilkprof provides in-depth information about the scalability of programs, without adding excessive overhead. Cilkprof's output can be used to find scalability bottlenecks in the user's code. Cilkprof makes profiling measurements at the fork and join points of computations, which typically limits the amount of overhead incurred by the profiler. In addition, despite recording in-depth information, Cilkprof does not generate large log files that are typical of trace-based profilers. In addition, the profiling algorithm only incurs constant amortized...

20. Fault prophet : a fault injection tool for large scale computer systems - Tchwella, Tal
In this thesis, I designed and implemented a fault injection tool, to study the impact of soft errors for large scale systems. Fault injection is used as a mechanism to simulate soft errors, measure the output variability and provide analysis of the impact of soft errors on the program. The underlying framework for the tool is based on LLFI, a LLVM fault injection tool, which I modified to support an end-to-end scenario for program testing purposes. The modifications and addition provide greater modularity of the tool by abstracting the input and output of the different components of the tool, support...

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