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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The structure of a multi-service operating system

Roscoe, Timothy January 1995 (has links)
No description available.
2

EOSDIS TEST SYSTEM (ETS) HIGH-RATE SYSTEM (HRS)

Mirchandani, Chandru, Daniel, Kenneth Jr, Nguyen, Diem, Hilinski, Stan 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / NASA’s use of high bandwidth packetized Consultative Committee for Space Data Systems (CCSDS) telemetry in the Earth Observing System (EOS) mission presents a great challenge to ground data system developers. The EOS mission calls for high data rate interfaces and small packet sizes which would dramatically increase the real-time workload on ground packet processing systems. NASA’s Goddard Space Flight Center (GSFC) has been developing packet processing subsystems for over a decade. This paper will discuss the design of a high-rate telemetry test system and a simulation software package. The system will support CCSDS telemetry formats and perform frame synchronization, error detection and correction, packet reassembly and sorting, error checking, and data set creation. In addition, a highly automated operation environment is designed to minimize human intervention in control and monitoring, and data distribution. The design is based on a Very Large Scale Integration (VLSI) Level Zero Processing (LZP) System technologies, VLSI telemetry data simulation and processing functional components, Object-Oriented Design methodologies, C++ programming environment, shareware and Open Software Foundation (OSF)/Motif-based Graphical User Interfaces (GUI).
3

Integration of multiple and asynchronous acoustic cues to word initial fricatives and context compensation in 7-year-olds, 12-year-olds and adults

Galle, Marcus Edward 01 July 2014 (has links)
For any speech category there are multiple sources of information (both acoustic and contextual) that are relevant to categorization. Complicating matters further, these sources of information are not always available simultaneously, but present themselves over the course of several hundred milliseconds. These features of spoken language complicate an already difficult task, and raise three important questions: 1) how do listeners weight different cues to the same speech category, 2) how do listeners integrate asynchronous information during speech perception and 3) how do listeners cope with contextual variability. While these questions have been explored, to varying degrees, with adults, there have been very few attempts to explore these questions from a developmental perspective. Furthermore, some of the more complex interactions between these factors remain uncharted territory even in the adult literature. For example, while adult listeners compensate for context when categorizing speech, and utilize acoustic cues as soon as they become available, we still do not know how this process is affected by context. This dissertation addresses these lingering issues by assessing 7-year-olds', 12-year-olds' and adults' perception of the /s-ʃ/ contrast (one that is influenced by multiple acoustic cues and context) using eye-tracking and the visual world paradigm. This work demonstrates that there is considerable development between 7 and 12 years of age for the /s-ʃ/ contrast in terms of real-time cue integration, cue-weighting and context compensation, and that development likely continues beyond these ages. In addition, the adult work demonstrates, for the first time, a pattern of real-time cue integration in which listeners' (both adult and child) buffer acoustic cues. Finally, several hypotheses are considered that may account for these findings, including the possibility that the unique developmental pattern of fricative perception may play an important role in understanding why adults buffer this contrast, and the implications of buffered speech perception are discussed.
4

High-Speed Probe Card Analysis Using Real-time Machine Vision and Image Restoration Technique

Shin, Bonghun January 2013 (has links)
There has been an increase in demand for the wafer-level test techniques that evaluates the functionality and performance of the wafer chips before packaging them, since the trend of integrated circuits are getting more sophisticated and smaller in size. Throughout the wafer-level test, the semiconductor manufacturers are able to avoid the unnecessary packing cost and to provide early feedback on the overall status of the chip fabrication process. A probe card is a module of wafer-level tester, and can detect the defects of the chip by evaluating the electric characteristics of the integrated circuits(IC's). A probe card analyzer is popularly utilized to detect such a potential probe card failure which leads to increase in the unnecessary manufacture expense in the packing process. In this paper, a new probe card analysis strategy has been proposed. The main idea in conducting probe card analysis is to operate the vision-based inspection on-the- y while the camera is continuously moving. In doing so, the position measurement from the encoder is rstly synchronized with the image data that is captured by a controlled trigger signal under the real-time setting. Because capturing images from a moving camera creates blurring in the image, a simple deblurring technique has been employed to restore the original still images from blurred ones. The main ideas are demonstrated using an experimental test bed and a commercial probe card. The experimental test bed has been designed that comprises a micro machine vision system and a real-time controller, the con guration of the low cost experimental test bed is proposed. Compared to the existing stop-and-go approach, the proposed technique can substantially enhance the inspection speed without additional cost for major hardware change.
5

Performance Enhancement of Space-Time Adaptive Processing for GPS and Microstrip Antenna Design Using Ferrite Rings

January 2013 (has links)
abstract: Global Positioning System (GPS) is a navigation system widely used in civilian and military application, but its accuracy is highly impacted with consequential fading, and possible loss of communication due to multipath propagation and high power interferences. This dissertation proposes alternatives to improve the performance of the GPS receivers to obtain a system that can be reliable in critical situations. The basic performance of the GPS receiver consists of receiving the signal with an antenna array, delaying the signal at each antenna element, weighting the delayed replicas, and finally, combining the weighted replicas to estimate the desired signal. Based on these, three modifications are proposed to improve the performance of the system. The first proposed modification is the use of the Least Mean Squares (LMS) algorithm with two variations to decrease the convergence time of the classic LMS while achieving good system stability. The results obtained by the proposed LMS demonstrate that the algorithm can achieve the same stability as the classic LMS using a small step size, and its convergence rate is better than the classic LMS using a large step size. The second proposed modification is to replace the uniform distribution of the time delays (or taps) by an exponential distribution that decreases the bit-error rate (BER) of the system without impacting the computational efficiency of the uniform taps. The results show that, for a BER of 0.001, the system can operate with a 1 to 2 dB lower signal-to-noise ratio (SNR) when an exponential distribution is used rather than a uniform distribution. Finally, the third modification is implemented in the design of the antenna array. In this case, the gain of each microstrip element is enhanced by embedding ferrite rings in the substrate, creating a hybrid substrate. The ferrite rings generates constructive interference between the incident and reflected fields; consequently, the gain of a single microstrip element is enhanced by up to 4 dB. When hybrid substrates are used in microstrip element arrays, a significant enhancement in angle range is achieved for a given reflection coefficient compared to using a conventional substrate. / Dissertation/Thesis / Ph.D. Electrical Engineering 2013
6

Assessing the intelligibility and acoustic changes of time-processed speech

Taleb, Nardine 02 June 2020 (has links)
No description available.
7

A Low Cost, Quick Reaction TM Acquisition System Solution for Deployed Testing

Pozmantier, Ronald 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / Design, development, fabrication, and deployment of an austere, deployable telemetry (TM) system, in only 3 1/2 weeks, will be discussed. This austere approach will be compared to a standard approach. TM candidate systems will be discussed along with exigencies and limitations (test geometry, link analysis, multiple test areas, schedule, cost, fabrication ...) that shaped their selection. Utilization of existing Radio Frequency (RF) systems in "unintended" applications will be discussed. System setup and BER testing with a simulated 'aircraft' will be presented, including observed multipath effects during testing, versus actual performance. Finally, benefits and test efficiencies garnered by having vehicle TM, real- time TM acquisition, processing and display, while deployed to a test area with no range instrumentation, will be presented.
8

AN ADVANCED DISTRIBUTED ARCHITECTURE FOR REAL-TIME PROCESSING AND DISPLAY OF TELEMETRY AND SPACE POSITIONING DATA

Rhea, Donald C., Scardello, Michael A., Moore, Archie L. 11 1900 (has links)
International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Rapid technology growth in the aerospace industry continues to manifest in increasingly complex weapons systems and system driven weapons systems platforms which must be supported in the flight test environment. This growth in complexity often surpasses the capabilities of many ground based real-time and post-flight processing and display systems, leaving these systems perpetually behind the power curve when compared to data/information processing, presentation and distribution requirements set forth by today’s flight test engineering community. Many flight test programs are accepting less than optimal results from these systems, therefore, the amount of information presently obtained (per flight hour) limits the results acquired during a test program, creating a more costly test and evaluation budget. As an integral participant in the development and testing of high technology aircraft and weapons systems, the U.S. Air Force Flight Test Center’s (AFFTC) Advanced Data Acquisition and Processing Systems (ADAPS) development is bridging the gap between requirements and capability by distributing current system architectures to provide incremental performance upgrades in specific areas of need in lieu of entire system replacements. This paper will discuss the current real-time processing, distribution and display capability that exists at the AFFTC and the planned phased upgrade of this tightly coupled system to a more flexible and extensible distributed architecture that will be increasingly responsive to the dynamic nature of test and evaluation of modern weapons systems and weapons systems platforms.
9

GULF RANGE DRONE CONTROL UPGRADE SYSTEM MOBILE CONTROL SYSTEM

Wagner, Steven M., Goodson, John H. 11 1900 (has links)
International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Gulf Range Drone Control Upgrade System (GRDCUS) Mobile Control System (GMCS) is an integral part of the test ranges located on the Gulf of Mexico. This paper begins with a brief overview of the current Gulf Range systems. These systems consist of five major components: ground stations, ground computer systems, data link/transponders, consoles, and software. The GMCS van contains many of these components to provide a stand-alone range capability for remote operations. This paper describes the development and assembly of the GMCS van and focuses on the on-board computer systems, consoles, and data link technology. An overall system engineering approach was used during GMCS development and is highlighted through the use of rapid prototyping. This methodology and the lessons learned are presented in the paper. Suggestions for future applications are considered.
10

RTPS Telemetry - Simulator Link at Naval Air Warfare Center

McNamara, William G., Stanley, Page, Nichols, Jay 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / Over the last 3 years the Naval Air Warfare Center Aircraft Division (NAWCAD), Patuxent River, MD, has been in the process of developing a link between its secure Manned Flight Simulator (MFS) and Real Time Processing System (RTPS) facilities. The MFS hosts a wide variety of high fidelity fixed and rotary wing aircraft simulation models. The RTPS is used as a telemetry ground station for conduct of Navy flight testing at Patuxent River MD. The ability to integrate simulation with flight testing in a real time environment provides new potential for increased flight safety, enhanced engineering training, optimized flight test planning, real time simulation fidelity assessments, improved engineering analysis and other applications for enhanced flight testing, data analysis and data processing. A prototype system has been successfully designed and operated at NAWCAD in support of an F/A-18C flight test project which required simultaneous merging and display of real time and simulation data to reduce the risk of departure from controlled flight. As currently designed the link (encryption and decryption gear in the loop) can be operated in three modes: (1) Simulation sending data to RTPS (e.g. pilot-engineer pre-first flight preparation/training scenario, (2) simulation is driven by real aircraft control surface inputs and response is compared with that of the real aircraft for simulation fidelity assessments and (3) simulation "rides along" with the real aircraft and data are extracted from the simulation which are otherwise unavailable from the aircraft (e.g. flight control law interconnect signals, control law feedback signals, aerodynamic data, propulsion model data, avionics model data, other model data etc.). This paper discusses, design and implementation aspects of the RTPS-Simulator link, and includes a description of how the link was used to support a real time flight test program by providing critical safety of flight data. Other potential uses for the link will also be highlighted.

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