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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.
231

AUTOMATIC DEPENDENT SURVEILLANCE (ADS) SYSTEM RESEARCH AND DEVELOPMENT

Boying, Lu, Jun, Zhang, Shuhui, Nie, Xinjian, Huang 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / This paper presents the basic concept, construction principle and implementation work for the Automatic Dependent Surveillance (ADS) system. As a part of ADS system, the ADS message processing system based on PC computer was given more attention. Furthermore, the paper introduces the ADS trial status and points out that the ADS implementation will bring tremendous economical and social efficiency.
232

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).
233

An Evaluation System for Airplane's Power Supply

Song, Jian, Luo, Ni, Cao, Liu, Xu, Min 10 1900 (has links)
ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / Power supply is the most critical unit in an airplane. A defect in a power supply might lead to a crash. Therefore, it is very useful and important to monitor the status of the airplane's power supply during flight. This paper presents a real-time evaluation system constructed by a central process unit for processing and detecting defects and several remote units for acquiring parameters. Because of the huge amount of data acquired, a combination of Ethernet and time division multiplexing technique has been applied for constructing a 2.5Gbps synchronous data transportation network for the system.
234

LINUX POWERED TELEMETRY PROCESSING

Ayala, Joseph, Sorton, Eric 10 1900 (has links)
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / Since its debut, the Linux operating system has garnered much attention in the software development community. This paper discusses the open source operating system, Linux, and it’s application as the operating system powering a commercial off-the-shelf telemetry processing system. The paper begins by discussing what are the real-time requirements of the operating system in a telemetry processing system. A discussion to the Linux system is then presented. Soft real-time features of Linux are discussed which allow it to meet the telemetry processing requirements. Linux is compared with the more traditional operating system products and points are made as to why open source software is just as capable, if not preferable, of handling mission critical applications. The paper also presents the authors’ view of future of Linux and open source software in the telemetry marketplace. The paper concludes with a summary of products available for Linux that support telemetry processing and the data acquisition environment.
235

Diagnosis and vaccination for Bovine Genital Campylobacteriosis in beef heifers

2015 October 1900 (has links)
Bovine Genital Campylobacteriosis is characterized by early pregnancy loss and temporary infertility in cattle. The purpose of this project was to compare diagnostic approaches to detect Campylobacter fetus subsp. venerealis and evaluate the efficacy of vaccination for Bovine Genital Campylobacteriosis. This thesis describes the results of two studies that compared different sample preparation methods for bovine vaginal mucus for real-time PCR and assessed a commercial vaccine in preventing infection and reproductive loss. The first study compared real-time PCR utilizing different bovine vaginal mucus sample preparation techniques to direct culture. The magnetic bead based protocol demonstrated higher sensitivity (48.4%, P=0.02) and lower specificity (78.9%, P=0.01) than the heat lysis protocol which involved an additional dilution step (Sens=29.4%, Spec=88.2%), but did not differ from the heat lysis protocol without sample dilution (Sens=35.0%, P=0.16; Spec=81.1%, P=0.62). The sample preparation method, designed for bovine preputial samples (Chaban et al. 2012. Can J of Vet Res; 76: 166), did not work well for vaginal mucus. All modifications of that method and magnetic bead based extraction technique had low sensitivity compared to culture probably due to the biophysical properties of vaginal mucus, which could cause loss of targeted DNA during processing, or repeated sample freezing and thawing. Release of DNA directly from vaginal mucus by a modified heat lysis protocol with consequent real-time PCR could be a promising rapid screening approach after validating on fresh samples. The second study compared the risk of infection and reproductive failure in heifers, vaccinated with a commercial multivalent vaccine containing C. fetus antigen, to heifers vaccinated with a comparable product without C. fetus, that were exposed to infected bulls. There was no significant difference between groups either in risk of Campylobacter fetus subsp. venerealis isolation (P>0.17) or in the proportion of heifers that cultured positive at least once (P=0.42), as well as in the median number times of cultured positive samples (P=0.24) and the time to first cultured positive (P=0.67). There was no difference by treatment in the weekly proportions of heifers diagnosed pregnant by either ultrasound (P>0.31) or serum concentration of pragnancy specific protein B (P>0.31) during the study, as well as in the time to first pregnancy for heifers ever diagnosed as pregnant (P=0.30) and those that remained pregnant at the end of the study (P=0.70). Similarly, the difference was not detected by treatment in the proportion of animals, ever detected pregnant during the study (P=0.57) and in pregnancy loss rates (P=0.28). However, heifers that aborted were 4 times more likely to be cultured positive than those that did not abort (P=0.01). Heifers that were not pregnant at the end of the study cultured positive 1.5 times more often than pregnant animals in treatment group (P=0.04), while in control group such difference was 4 times (P=0.01). Heifers that were not pregnant at the end of the study did not differ by treatment in the number of times cultured positive (P=0.14). In this study, the mean concentrations of ELISA antibodies to C. fetus after vaccination were more than 2 times higher in treatment group than in control group (P<0.02), but vaccination did not significantly reduce infection or improve pregnancy in heifers when exposed to Cfv-infected bulls. Sample preparation technique is important for successful real-time PCR; release of DNA directly from a CVM sample by a modified heat lysis protocol was easy to perform and could be promising as a rapid screening approach for Bovine Genital Campylobacteriosis after validating on fresh samples. Vaccinating of heifers with a polyvalent commercial vaccine, containing Campylobacter fetus antigen, according to the label, did not significantly reduce infection rate or improve reproductive performance when they were naturally challenged.
236

Realization of Fast Acquisition for Spread Spectrum Signal Based on FFT

Jian-zhong, Qi, Yan, Gong, Peng, Song 10 1900 (has links)
ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / Acquisition based on Fast Fourier Transform (FFT) can acquire Pseudo-random code phase quickly and improve the performance of the satellite navigation receivers. In the paper Real-time receiver adopts the FPGA to realize the function of FFT and uses DSP processor to control the implementation process of Acquisition. For increasing the sensitivity of Acquisition incoherent accumulation were used in the process. Also, in the paper we have discussed the process method for decreasing the negative influence of signal power changes and carrier's Doppler frequency.
237

A multi-modal device for application in microsleep detection

Knopp, Simon James January 2015 (has links)
Microsleeps and other lapses of responsiveness can have severe, or even fatal, consequences for people who must maintain high levels of attention on monotonous tasks for long periods of time, e.g., commercial vehicle drivers, pilots, and air-traffic controllers. This thesis describes a head-mounted system which is the first prototype in the process of creating a system that can detect (and possibly predict) these lapses in real time. The system consists of a wearable device which captures multiple physiological signals from the wearer and an extensible software framework for imple- menting signal processing algorithms. Proof-of-concept algorithms are implemented and used to demonstrate that the system can detect simulated microsleeps in real time. The device has three sensing modalities in order to get a better estimate of the user's cognitive state than by any one alone. Firstly, it has 16 channels of EEG (8 currently in use) captured by 24-bit ADCs sampling at 250 Hz. The EEG is acquired by custom-built dry electrodes consisting of spring-loaded, gold-plated pins. Secondly, the device has a miniature video camera mounted below one eye, providing 320 x 240 px greyscale video of the eye at 60 fps. The camera module includes infrared illumination so that it can operate in the dark. Thirdly, the device has a six-axis IMU to measure the orientation and movement of the head. These sensors are connected to a Gumstix computer-on-module which transmits the captured data to a remote computer via Wi-Fi. The device has a battery life of about 7.4 h. In addition to this hardware, software to receive and analyse data from the head-mounted device was developed. The software is built around a signal processing pipeline that has been designed to encapsulate a wide variety of signal processing algorithms; feature extractors calculate salient properties of the input data and a classifier fuses these features to determine the user's cognitive state. A plug-in system is provided which allows users to write their own signal processing algorithms and to experiment with different combinations of feature extractors and classifiers. Because of this flexible modular design, the system could also be used for applications other than lapse detection‒any application which monitors EEG, eye video, and head movement can be implemented by writing appropriate signal processing plug-ins, e.g., augmented cognition or passive BCIs. The software also provides the ability to configure the device's hardware, to save data to disk, and to monitor the system in real time. Plug-ins can be implemented in C++ or Python. A series of validation tests were carried out to confirm that the system operates as intended. Most of the measured parameters were within the expected ranges: EEG amplifier noise = 0.14 μVRMS input-referred, EEG pass band = DC to 47 Hz, camera focus = 2.4 lp/mm at 40 mm, and total latency < 100 ms. Some parameters were worse than expected but still sufficient for effective operation: EEG amplifier CMRR ≥ 82 dB, EEG cross-talk = -17.4 dB, and IMU sampling rate = 10 Hz. The contact impedance of the dry electrodes, measured to be several hundred kilohms, was too high to obtain clean EEG. Three small-scale experiments were done to test the performance of the device in operation on people. The first two demonstrated that the pupil localization algorithm produces PERCLOS values close to those from a manually-rated gold standard and is robust to changes in ambient light levels, iris colour, and the presence of glasses. The final experiment demonstrated that the system is capable of capturing all three physiological signals, transmitting them to the remote computer in real time, extracting features from each signal, and classifying simulated microsleeps from the extracted features. However, this test was successful only when using conventional wet EEG electrodes instead of the dry electrodes built into the device; it will be necessary to find replacement dry electrodes for the device to be useful. The device and associated software form a platform which other researchers can use to develop algorithms for lapse detection. This platform provides data capture hardware and abstracts away the low-level software details so that other researchers are free to focus solely on developing signal processing techniques. In this way, we hope to enable progress towards a practical real-time, real-world lapse detection system.
238

VISION BASED REAL-TIME MONITORING AND CONTROL OF METAL TRANSFER IN LASER ENHANCED GAS METAL

Shao, Yan 01 January 2013 (has links)
Laser enhanced gas metal arc welding (GMAW) is a novel welding process where a laser is applied to provide an auxiliary detaching force to help detach the droplet such that welds may be made in gas tungsten arc welding high quality at GMAW high speeds. The current needed to generate the electromagnetic (detaching) force is thus reduced. The reduction in the current helps reduce the impact on the weld pool and over-heat fumes/smokes. However, in the previous studies, a continuous laser is applied. Since the auxiliary is only needed each time the droplet needs to be detached and the detachment time is relatively short in the transfer cycle, the laser energy is greatly wasted in the rest of the transfer cycle. In addition, the unnecessary application of the laser on the droplet causes additional over-heat fumes. Hence, this study proposes to use a pulsed laser such that the peak pulse is applied only when the droplet is ready to detach. To this end, the state of the droplet development needs to be closely monitored in real-time. Since the metal transfer is an ultra-high speed process and the most reliable method to monitor should be based on visual feedback, a high imaging system has been proposed to monitor the real-time development of the droplet. A high-speed image processing system has been developed to real-time extract the developing droplet. A closed-loop control system has been established to use the real-time imaging processing result on the monitoring of the developing droplet to determine if the laser peak pulse needs to be applied. Experiments verified the effectiveness of the proposed methods and established system. A controlled novel process – pulsed laser-enhanced GMAW - is thus established for possible applications in producing high-quality welds at GMAW speeds.
239

Algorithmic Analysis of Complex Semantics for Timed and Hybrid Automata.

Doyen, Laurent 13 June 2006 (has links)
In the field of formal verification of real-time systems, major developments have been recorded in the last fifteen years. It is about logics, automata, process algebra, programming languages, etc. From the beginning, a formalism has played an important role: timed automata and their natural extension,hybrid automata. Those models allow the definition of real-time constraints using real-valued clocks, or more generally analog variables whose evolution is governed by differential equations. They generalize finite automata in that their semantics defines timed words where each symbol is associated with an occurrence timestamp. The decidability and algorithmic analysis of timed and hybrid automata have been intensively studied in the literature. The central result for timed automata is that they are positively decidable. This is not the case for hybrid automata, but semi-algorithmic methods are known when the dynamics is relatively simple, namely a linear relation between the derivatives of the variables. With the increasing complexity of nowadays systems, those models are however limited in their classical semantics, for modelling realistic implementations or dynamical systems. In this thesis, we study the algorithmics of complex semantics for timed and hybrid automata. On the one hand, we propose implementable semantics for timed automata and we study their computational properties: by contrast with other works, we identify a semantics that is implementable and that has decidable properties. On the other hand, we give new algorithmic approaches to the analysis of hybrid automata whose dynamics is given by an affine function of its variables.
240

The design and implementation of high level programming language features for pattern matching in real-time.

Nilsen, Kelvin Don. January 1988 (has links)
High-level programming language features simplify software development by eliminating many low-level programming concerns and by providing programmers with useful abstractions to simplify description and analysis of their programs. This dissertation discusses briefly some of the special needs of structural pattern-matching programs that must execute in real time and suggests language features to support these needs. These language features are implemented in an experimental version of the Icon programming language and examples of how these language features can be used are presented. This dissertation also presents and discusses the implementation of these language mechanisms, including the implementation of a new algorithm for garbage collecting linked data structures and strings in real time. One of the new language features is a stream data type, which allows programmers to perform pattern matching directly on sequences of data values produced by external sources, without requiring explicit read operations to bring the data into memory before analyzing it. Other new language features provide the ability to create and manipulate concurrent Icon processes, between which the stream data type serves as the principal mechanism for interprocess communication. Stream and concurrent process manipulation mechanisms integrate naturally with each other and with the existing mechanisms of the Icon programming language. Sequential Icon programs are, for the most part, unaffected by the new language capabilities.

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