Página 10 dos resultados de 100905 itens digitais encontrados em 0.154 segundos

‣ An automated web-based searchable archive for implantable cardioverter defibrillator data; Database systems for embedded data from implantable cardioverter defibrillators

Duh, Shin-Ning, 1979-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 95 leaves; 5889814 bytes; 5900573 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
This paper details the research, design, and implementation of a computer system built to archive electrograms and related patient data from implantable cardioverter defibrillators (ICDs) produced by Medtronic in particular. The archive will provide a central and stable repository for researchers looking for data originally stored in the ICDs. The Web interface to the system provides an easy means of searching for patients or episodes of interest. The database will also provide the functionality for appending comments onto a particular episode. Furthermore, the system allows the physicians to directly upload data from the ICDs into the database. Automatic detection and expansion functions will also allow data from new models and current models that have been modified to be inserted properly into the database.; by Shin-Ning Duh.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.; Includes bibliographical references (leaf 95).

‣ Advanced Faraday cage measurements of charge, short-circuit current and open-circuit voltage

Amin, M. Shahrooz, 1981-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 117 leaves; 7105429 bytes; 7119908 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
(cont.) above atmospheric pressure caused both positive current and negative current pulses with the negative pulse larger than the positive pulse. A pressure decrease of more than 10psi below atmospheric pressure also caused both positive current and negative current pulses with the positive current larger than the negative current pulse. Experiments showed that the negative current was generated by the galvanic action between the two dissimilar metals in the triaxial connector connecting the center electrode of the electrode chamber with the electrometer, as water condensed. Positive current could have been produced by the evaporation of moisture from the center electrode of the electrode chamber. Dew point analysis is performed to show that for water to condense on metallic surfaces, it is not necessary to reach the dew point. The calculated dew point temperature is lower than the temperature at which the water condenses upon the electrode surfaces. In the liquid and solid dielectric experiments, we use a patented Faraday cage which is composed of two identical in-line hollow, gold-plated Faraday cup electrodes that enclose the samples which move between them during each measurement under computer control. We conducted charge measurements using various electrometers to rule out the possibility of false instrument readings due to input offset voltage and other experimental effects. One wire mesh style of Faraday cage connected with an electrometer was also used to measure the charge. The liquid dielectrics are distilled water...

‣ 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
Português
Relevância na Pesquisa
66.571284%
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...

‣ Energy allocation and transmission scheduling for wireless and space communications

Fu, Alvin C
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 164 p.; 4820030 bytes; 4819839 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
This thesis presents two innovations to geophysical inversion. The first provides a framework and an algorithm for combining linear deconvolution methods with geostatistical interpolation techniques. This allows for sparsely sampled data to aid in image deblurring problems, or, conversely, noisy and blurred data to aid in sample interpolation. In order to overcome difficulties arising from high dimensionality, the solution must be derived in the correct framework and the structure of the problem must be exploited by an iterative solution algorithm. The effectiveness of the method is demonstrated first on a synthetic problem involving satellite remotely sensed data, and then on a real 3-D seismic data set combined with well logs. The second innovation addresses how to use wavelets in a linear geophysical inverse problem. Wavelets have lead to great successes in image compression and denoising, so it is interesting to see what, if anything, they can do for a general linear inverse problem. It is shown that a simple nonlinear operation of weighting and thresholding wavelet coefficients can consistently outperform classical linear inverse methods in terms of mean-square error across a broad range of noise magnitude in the data. Wavelets allow for an adaptively smoothed solution: smoothed more in uninteresting regions...

‣ Nonparametric statistical methods for image segmentation and shape analysis

Kim, Junmo, 1976-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 131 p.; 2294740 bytes; 2312676 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
Image segmentation, the process of decomposing an image into meaningful regions, is a fundamental problem in image processing and computer vision. Recently, image segmentation techniques based on active contour models with level set implementation have received considerable attention. The objective of this thesis is in the development of advanced active contour-based image segmentation methods that incorporate complex statistical information into the segmentation process, either about the image intensities or about the shapes of the objects to be segmented. To this end, we use nonparametric statistical methods for modeling both the intensity distributions and the shape distributions. Previous work on active contour-based segmentation considered the class of images in which each region can be distinguished from others by second order statistical features such as the mean or variance of image intensities of that region. This thesis addresses the problem of segmenting a more general class of images in which each region has a distinct arbitrary intensity distribution. To this end, we develop a nonparametric information-theoretic method for image segmentation. In particular, we cast the segmentation problem as the maximization of the mutual information between the region labels and the image pixel intensities. The resulting curve evolution equation is given in terms of nonparametric density estimates of intensity distributions...

‣ Rendering from unstructured collections of images

Buehler, Christopher James, 1974-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 163 p.; 6842427 bytes; 6842234 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
Computer graphics researchers recently have turned to image-based rendering to achieve the goal of photorealistic graphics. Instead of constructing a scene with millions of polygons, the scene is represented by a collection of photographs along with a greatly simplified geometric model. This simple representation allows traditional light transport simulations to be replaced with basic image-processing routines that combine multiple images together to produce never-before-seen images from new vantage points. This thesis presents a new image-based rendering algorithm called unstructured lumigraph rendering (ULR). ULR is an image-based rendering algorithm that is specifically designed to work with unstructured (i.e., irregularly arranged) collections of images. The algorithm is unique in that it is capable of using any amount of geometric or image information that is available about a scene. Specifically, the research in this thesis makes the following contributions: * An enumeration of image-based rendering properties that an ideal algorithm should attempt to satisfy. An algorithm that satisfies these properties should work as well as possible with any configuration of input images or geometric knowledge. * An optimal formulation of the basic image-based rendering problem...

‣ Efficient volumetric reconstruction from multiple calibrated cameras

Jethwa, Manish, 1976-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 142 p.; 8204361 bytes; 8223335 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
The automatic reconstruction of large scale 3-D models from real images is of significant value to the field of computer vision in the understanding of images. As a consequence, many techniques have emerged to perform scene reconstruction from calibrated images where the position and orientation of the camera are known. Feature based methods using points and lines have enjoyed much success and have been shown to be robust against noise and changing illumination conditions. The models produced by these techniques however, can often appear crude when untextured due to the sparse set of points from which they are created. Other reconstruction methods, such as volumetric techniques, use image pixel intensities rather than features, reconstructing the scene as small volumetric units called voxels. The direct use of pixel values in the images has restricted current methods to operating on scenes with static illumination conditions. Creating a volumetric representation of the scene may also require millions of interdependent voxels which must be efficiently processed. This has limited most techniques to constrained camera locations and small indoor scenes. The primary goal of this thesis is to perform efficient voxel-based reconstruction of urban environments using a large set of pose-instrumented images. In addition to the 3- D scene reconstruction...

‣ Cooperative checkpointing for supercomputing systems

Oliner, Adam Jamison
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 94 p.; 2455146 bytes; 2616682 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
A system-level checkpointing mechanism, with global knowledge of the state and health of the machine, can improve performance and reliability by dynamically deciding when to skip checkpoint requests made by applications. This thesis presents such a technique, called cooperative checkpointing, and models its behavior as an online algorithm. Where C is the checkpoint overhead and I is the request interval, a worst-case analysis proves a lower bound of (2 + [C/I])-competitiveness for deterministic cooperative checkpointing algorithms, and proves that a number of simple algorithms meet this bound. Using an expected-case analysis, this thesis proves that an optimal periodic checkpointing algorithm that assumes an exponential failure distribution may be arbitrarily bad relative to an optimal cooperative checkpointing algorithm that permits a general failure distribution. Calculations suggest that, under realistic conditions, an application using cooperative checkpointing may make progress 4 times faster than one using periodic checkpointing. Finally, the thesis suggests an embodiment of cooperative checkpointing for a large-scale high performance computer system and presents the results of some preliminary simulations. These results show that...

‣ A general-purpose pulse sequencer for quantum computing

Phạm, Paul Tân Thế
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 170 p.; 1906024 bytes; 1903939 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
Quantum mechanics presents a more general and potentially more powerful model of computation than classical systems. Quantum bits have many physically different representations which nonetheless share a common need for modulating pulses of electromagnetic waves. This thesis presents the design and evaluates the implementation of a general-purpose sequencer which supports fast, programmable pulses; a flexible, open design; and feedback operation for adaptive algorithms. The sequencer achieves a timing resolution, minimum pulse duration, and minimum delay of 10 nanoseconds; it has 64 simultaneously-switching, independent digital outputs and 8 digital inputs for triggering or feedback. Multiple devices can operate in a daisy chain to facilitate adding and removing channels. An FPGA is used to implement a firmware network stack and a specialized pulse processor core whose modules are all interconnected using the Wishbone bus standard. Users can write pulse programs in an assembly language and control the device from a host computer over an Ethernet network. An embedded web server provides an intuitive, graphical user interface, while a non-interactive, efficient UDP protocol provides programmatic access to third-party software. The performance characteristics...

‣ Optoelectronic fiber webs for imaging applications

Arnold, Jerimy Reeves
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 73 p.; 2459428 bytes; 2462252 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
We demonstrate the use of novel visible and infrared light-sensitive optoelectronic fiber in the development of large scale photodector arrays. Unlike conventional point photodetectors these one-dimensional linear photodectors are capable of sensing light along the entire length of the fiber and 360 radially. Multiple fibers can be arranged in an orthogonal grid to create a two-dimensional fiber web. The fiber web is capable of tracking a time-and space-varying beam, and output it onto a computer screen. Other imaging applications for the fiber web include image recovery for 2D images based on Computed Axial Tomography concepts. and lensless imaging. Lensless imaging is accomplished d using two fiber webs separated by a fixed distance, recovering the intensity distribution on each fiber web, and applying a phase retrieval algorithm to the two distributions. Furthermore, fiber webs consisting of six planar arrays forming a cube can be used to detect incident light in three dimensions.; by Jerimy Reeves Arnold.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.; Includes bibliographical references (p. 73).

‣ Performance, scalability, and flexibility in the RAW network router

DeGangi, Anthony M
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 46 p.; 2223111 bytes; 2223448 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
Conventional high speed Internet routers are built using custom designed microprocessors, dubbed network processors, to efficiently handle the task of packet routing. While capable of meeting the performance demanded of them, these custom network processors generally lack the flexibility to incorporate new features and do not scale well beyond that for which they were designed. Furthermore, they tend to suffer from long and costly development cycles, since each new generation must be redesigned to support new features and fabricated anew in hardware. This thesis presents a new design for a network processor, one implemented entirely in software, on a tiled, general purpose microprocessor. The network processor is implemented on the Raw microprocessor, a general purpose microchip developed by the Computer Architecture Group at MIT. The Raw chip consists of sixteen identical processing tiles arranged in a four by four matrix and connected by four inter-tile communication networks; the Raw chip is designed to be able to scale up merely by adding more tiles to the matrix. By taking advantage of the parallelism inherent in the task of packet forwarding on this inherently parallel microprocessor, the Raw network processor is able to achieve performance that matches or exceeds that of commercially available custom designed network processors. At the same time...

‣ Temporal analysis of stages in negotiation

Khilnani, Reshma P
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 46 leaves; 2396538 bytes; 2396729 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
This thesis investigates the problem of computer voice analysis as applied to the negotiation setting. In our study we collected audio recordings of negotiations in a controlled experiment, outlined distinct behaviors within the negotiations, and built a program that can automatically annotate a recorded negotiation. In addition, we analyzed patterns of behaviors within the samples we collected. We found seven distinct behaviors present in the voice signal, and found that the role of the participant in the negotiation affects behavior to some degree.; by Reshma P. Khilnani.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.; Includes bibliographical references (leaf 34).

‣ Large vocabulary continuous speech recognition using linguistic features and constraints

Tang, Min, Ph. D. Massachusetts Institute of Technology
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 123 leaves; 777354 bytes; 732301 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
Automatic speech recognition (ASR) is a process of applying constraints, as encoded in the computer system (the recognizer), to the speech signal until ambiguity is satisfactorily resolved to the extent that only one sequence of words is hypothesized. Such constraints fall naturally into two categories. One deals with the ordering of words (syntax) and organization of their meanings (semantics, pragmatics, etc). The other governs how speech signals are related to words, a process often termed as lexical access". This thesis studies the Huttenlocher-Zue lexical access model, its implementation in a modern probabilistic speech recognition framework and its application to continuous speech from an open vocabulary. The Huttenlocher-Zue model advocates a two-pass lexical access paradigm. In the first pass, the lexicon is effectively pruned using broad linguistic constraints. In the original Huttenlocher-Zue model, the authors had proposed six linguistic features motivated by the manner of pronunciation. The first pass classifies speech signals into a sequence of linguistic features, and only words that match this sequence - the cohort - are activated. The second pass performs a detailed acoustic phonetic analysis within the cohort to decide the identity of the word. This model differs from the lexical access model nowadays commonly employed in speech recognizers where detailed acoustic phonetic analysis is performed directly and lexical items are retrieved in one pass. The thesis first studies the implementation issues of the Huttenlocher-Zue model. A number of extensions to the original proposal are made to take advantage of the existing facilities of a probabilistic...

‣ An automated bench testing system for direct current parameters of instrumentation amplifiers

Musah, Arthur
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 93 p.; 11744612 bytes; 11748471 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
Electrical testing is performed at multiple stages in the production of analog integrated circuits (ICs). An efficient system for low-volume IC testing is one that automates bench tests and provides good measurement precision and accuracy, while costing far less than the standard automated test equipment (ATE) used for high-volume manufacturing purposes. This thesis describes the design and implementation of an automated bench system for measuring the important direct current parameters associated with analog instrumentation amplifiers: voltage offset, input bias currents, input offset current, output swing, common mode rejection, power supply rejection, quiescent current and gain error. The system is developed on the PXI platform and consists of measurement and signal generating hardware modules, a Windows-based computer, a resource printed circuit board (PCB), a test-configuration PCB and LabVIEW-based software. The system is versatile and supports the testing of different instrumentation amplifier types and pin- outs. The performance of the system is characterized with respect to ATE results for the Texas Instruments instrumentation amplifier INA 126.; by Arthur Musah.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science...

‣ The Symmetriad : a journey of discovery through the land of the polychora

Radul, Alexey
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 111 p.; 5561923 bytes; 5566514 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
I devised and implemented a method for constructing regular and semiregular geometric objects in n-dimensional Euclidean space. Given a finite reflection group (a Coxeter group) G, there is a standard way to give G a group action on n-space. Reflecting a point through this group action yields an object that exhibits the symmetries specified by G. If the point is chosen well, the object is guaranteed to be regular or semiregular, and many interesting regular and semiregular objects arise this way. By starting with the symmetry group, I can use the group structure both to simplify the actual graphics involved with displaying the object, and to illustrate various aspects of its structure. For example, subgroups of the symmetry group (and their cosets) correspond to substructures of the object. Conversely, by displaying such symmetric objects and their various substructures, I find that I can elucidate the structure of the symmetry group that gives rise to them. I have written The Symmetriad, the computer system whose name this document has inherited, and used it to explore 3- and 4-dimensional symmetric objects and their symmetry groups. The 3-dimensional objects are already well understood, but they serve to illustrate the techniques used on the 4-dimensional objects and make them more comprehensible. Four dimensions offers a treasure trove of intriguing structures...

‣ EClerk office assistant; Electronic Clerk office assistant

Wolfe, Jonathan Eric
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 83 p.; 3565034 bytes; 3568423 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
For decades, people have continued to collect an inordinate amount of paper documents containing important information that should be easily accessible. This paper clutter inhibits indexing this information and easily searching through it. This thesis presents the code architecture and user interface design of the Electronic Clerk, a proof-of-concept electronic office assistant. The Electronic Clerk (EClerk) is a device to assist in reducing paper clutter in the office environment. The device takes paper and speech as input, performs data binding between input streams in order to attach metadata to each document, and structures the data using the Resource Description Framework (RDF) standard. The hardware structure of EClerk consists of a dedicated computer, video camera, scanner, touchscreen, and microphone for capturing input. The software structure consists of the Galaxy speech recognition system, the Haystack information client for retrieval and modification of the collected data, optical character recognition, and a graphical user interface that provides continuous feedback to the user. Primary design principles for this device include providing continuous user feedback and robustness to imperfect input in order to provide a truly usable system.; by Jonathan Eric Wolfe.; Thesis (M. Eng.)--Massachusetts Institute of Technology...

‣ A software toolkit for acoustic respiratory analysis

Yi, Gina Ann
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 147 p.; 8625770 bytes; 8631931 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
Millions of Americans suffer from pulmonary diseases. According to recent statistics, approximately 17 million people suffer from asthma, 16.4 million from chronic obstructive pulmonary disease, 12 million from sleep apnea, and 1.3 million from pneumonia - not to mention the prevalence of many other diseases associated with the lungs. Annually, the mortality attributed to pulmonary diseases exceeds 150,000. Clinical signs of most pulmonary diseases include irregular breathing patterns, the presence of abnormal breath sounds such as wheezes and crackles, and the absence of breathing entirely. Throughout the history of medicine, physicians have always listened for such sounds at the chest wall (or over the trachea) during patient examinations to diagnose pulmonary diseases - a procedure also known as auscultation. Recent advancements in computer technology have made it possible to record, store, and digitally process breath sounds for further analysis. Although automated techniques for lung sound analysis have not been widely employed in the medical field, there has been a growing interest among researchers to use technology to understand the subtler characteristics of lung sounds and their potential correlations with physiological conditions. Based on such correlations...

‣ Mesh modification using deformation gradients

Sumner, Robert Walker, 1975-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 131 p.; 30355738 bytes; 30404763 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
66.571284%
Computer-generated character animation, where human or anthropomorphic characters are animated to tell a story, holds tremendous potential to enrich education, human communication, perception, and entertainment. However, current animation procedures rely on a time consuming and difficult process that requires both artistic talent and technical expertise. Despite the tremendous amount of artistry, skill, and time dedicated to the animation process, there are few techniques to help with reuse. Although individual aspects of animation are well explored, there is little work that extends beyond the boundaries of any one area. As a consequence, the same procedure must be followed for each new character without the opportunity to generalize or reuse technical components. This dissertation describes techniques that ease the animation process by offering opportunities for reuse and a more intuitive animation formulation. A differential specification of arbitrary deformation provides a general representation for adapting deformation to different shapes, computing semantic correspondence between two shapes, and extrapolating natural deformation from a finite set of examples.; (cont.) Deformation transfer adds a general-purpose reuse mechanism to the animation pipeline by transferring any deformation of a source triangle mesh onto a different target mesh. The transfer system uses a correspondence algorithm to build a discrete many-to-many mapping between the source and target triangles that permits transfer between meshes of different topology. Results demonstrate retargeting both kinematic poses and non-rigid deformations...

‣ Single antenna interference cancellation in asynchronous GSM/GPRS networks

Chan, Chung, Ph. D. Massachusetts Institute of Technology
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 74 p.
Português
Relevância na Pesquisa
66.571284%
In this project, we have proposed a decorrelator-based single antenna interference cancellation algorithm for the asynchronous GSM/GPRS network. The algorithm is tested according to the current SAIC/DARP performance requirement in the computer simulation, and is shown to give various gains in different test scenarios.; by Chung Chan.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.; Includes bibliographical references (p. 73-74).

‣ A low dispersion 2-GHz comparator; Low dispersion two-gigahertz comparator

Johnston, William F. (William Francis)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 41 leaves
Português
Relevância na Pesquisa
66.571284%
A low dispersion 2-GHz comparator is an essential part of the latest automated VLSI tester by Teradyne Inc. With each new and faster CMOS logic VLSI microchips, faster and more precise comparators are needed to verify that the static discipline is being met on the many pins of the integrated circuit. As the error in the comparator is lowered, the VLSI production yield is greatly increased because of greater certainty of the measurements. The comparator described within is designed to test a variety of CMOS logic levels at the expected logic levels and rise-times of the near future. The result is a Si-Ge integrated comparator with 12psec of dispersion by detailed simulation awaiting fabrication. Index Terms-Complementary metal oxide semiconductor transistor technology (CMOS technology), very large scale integration (VLSI), application specific integrated circuit (ASIC), silicon germanium (Si-Ge), integrated circuits (IC), automatic test equipment (ATE), personal computer (PC), digital signal processing (DSP), direct current (DC), alternating current (AC), device under test (DUT), pin electronics (PE), bipolar junction transistors (BJT), complementary metal oxide semiconductor field effect transistor (MOSFET).; by William F. Johnston.; Thesis (M. Eng. and S.B.)--Massachusetts Institute of Technology...