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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.
181

Data Acquisition System Central Multiplexer

Anderson, William, Carro, Eduardo 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The Central Multiplexer is a versatile data multiplexer designed to address emerging test requirements for recording data from many sources on digital rotary head recorders at high data rates. A modular design allows easy reconfiguration for airborne or laboratory use; simultaneous data input from 63 sources of data in any combination of PCM commutators, ARINC 429 buses, ARINC 629 buses, MIL- STD-1553 buses, and general-purpose high-speed serial data packets; simultaneous, independent programmable outputs to high-speed digital data recorders, quick-look displays, and engineering monitor and analysis systems; and setup and control from a remote panel, a dumb terminal, a laptop personal computer, a standalone test system, or a large control computer.
182

A Rugged, Low-Cost, Advanced Data-Acquisition System for Field Test Projects

Simms, D. A., Cousineau, K. L. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The National Renewable Energy Laboratory (NREL) has teamed up with Zond Systems, Inc., to provide a rugged, low-cost, advanced data-acquisition system (ADAS) for use in field test projects. The ADAS simplifies the process of making accurate measurements on mechanical equipment exposed to harsh environments. It provides synchronized, time-series measurement data from multiple, independent sources. The ADAS is currently being used to acquire data from large wind turbines in operational wind-plant environments. ADAS modules are mounted on rotating blades, turbine towers, nacelles, control modules, meteorological towers, and electrical stations. The ADAS has the potential to meet the testing and monitoring needs of many other technologies as well, including vehicles, heavy equipment, piping and power transmission networks, and building energy systems.
183

Making TOFu : Fusion Plasma Neutron Emission Spectrometry with a Fully Digital Data Acquisition System

Skiba, Mateusz January 2016 (has links)
TOFu (Time-Of-Flight upgrade) is a fully digital data acquisition system based on 1 GSPS, 12 bit digitisers for the TOFOR (Time-Of-Flight spectrometer Optimised for Rate) fusion neutron spectrometer at JET. The system has been assessed, developed and subsequently tested during experimental campaigns at JET. A detailed presentation is provided, describing the electronics setup, as well as solutions to challenges related to time-alignment and synchronisation of the signal lines and digitisers. The system enables kinematic discrimination of spectral background, based on associated time and energy measurements. This technique has been tested with synthetic data, evaluated, and compared to experimental results. The kinematic background discrimination method is shown to provide improvements in signal-to-background ratio of up to 500 % in certain spectral regions. TOFOR is optimised for spectrometry of deuterium-deuterium fusion neutron emission at JET. The primary purpose of TOFu is to enable TOFOR to retain these spectrometric capabilities in the presence of a strong background of high-energy deuterium-tritium fusion emission neutrons, in a forthcoming deuterium-tritium fusion plasma campaign at JET. However, the improvement in signal-to-background ratio also allows for detailed studies of low-intensity spectral components, such as the contribution due to neutrons scattering off the internal wall of the JET tokamak before impinging on the TOFOR sight line. Satisfying experimental results pertaining to this aspect of spectral analysis with TOFu data are shown. Finally, a conceptual backscattering time-of-flight spectrometer, based on deuterated scintillator detectors is presented. The backscattering time-of-flight technique is shown to be able to provide high-resolution spectrometric capabilities of deuterium-tritium fusion plasma neutron emission. Studies with synthetic data are used to demonstrate these capabilities and the effects of the developed background discrimination techniques on deuterium-tritium fusion neutron spectra obtained with the instrument.
184

Projeto e construção de sistema de aquisição e processamento de dados para espectroscopia por transformada rápida de Fourier / Project and building of data acquisition system for fast Fourier transform spectrometer.

Encinas Junior, Walter Soto 03 April 1995 (has links)
No presente trabalho procurou-se desenvolver um sistema computacional para a automação de um Espectrofotômetro de Varredura Refrativa. Este sistema é baseado em um computador hospedeiro da linha IBM-PC, que pode ser de qualquer modelo, desde que possua barramento ISA de 16 bits. O sistema se divide em dois módulos - aquisição e processamento. O modulo de aquisição e capaz de atingir taxas de aquisição de ate 200 KHz, com resolução de 12 bits. É independente de controle do hospedeiro pois possui lógica de controle e sistema de armazenamento próprio. O módulo de processamento envolve o uso de um processador vetorial de sinais digitais ZORAN ZR34161 dedicado a efetuar eficientemente a Transformada Rápida de Fourier (FFT). Também opera independentemente do computador hospedeiro. Este módulo é capaz de efetuar a FFT em um vetor real de 4096 pontos em 19,64 ms / This work was intended to develop a computational system to control a fast Fourier spectrophotometer. This system is based in an IBM-PC type host computer, with ISA bus 16 bits wide. The system has two modules - acquisition and processing. The acquisition module works at 200 KHz sample rate, with 12 bits of resolution, and also works without host control, due to its own memory system and control logic. The processing module uses a ZORAN ZR34161 vector signal processor, dedicated to do the Fast Fourier Transform (FFT) in the most efficient way. No management of host is required, and it can compute a FFT of a 4096 points real vector in 19,64 ms
185

Desenvolvimento de dispositivo para calibraÃÃo de sensor de umidade do solo e aplicaÃÃo em sensores tipo tensiÃmetro eletrÃnico e resistÃncia elÃtrica / Development of apparatus for soil moisture calibration was developed and built (DCSUS) and application in sensors electronic type an electronic tensiometer and electric resistance.

Raimundo AlÃpio de Oliveira LeÃo 01 September 2004 (has links)
FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / Um dispositivo para calibraÃÃo de sensores de umidade do solo (DCSUS) foi desenvolvido. Para o controle da umidade do solo foram instalados um sistema de sucÃÃo tipo funil de placa porosa e um sistema de pressÃo tipo cÃmara de pressÃo. Foi construÃda uma estrutura de ferro de 3,0 m de altura, no topo da qual, uma balanÃa de braÃos conteve, em uma das extremidades, a coluna de solo horizontal com os sensores de umidade a serem calibrados e, na outra, uma cÃlula de carga com capacidade nominal de 490,33 N, para obtenÃÃo da variaÃÃo do peso da coluna decorrente da perda de umidade. Os dados dos sensores de umidade, da cÃlula de carga e de um sensor de temperatura foram coletados em tempo real, no perÃodo de 15/01 a 27/05/2004, a uma freqÃÃncia de 3 Hz, por um sistema de aquisiÃÃo de dados, cujo conversor analÃgico digital possuÃa canais de 12 bits. Os dados foram armazenados diariamente em um arquivo de texto para posterior processamento. Foi realizada a calibraÃÃo do dispositivo para determinaÃÃo de sua sensibilidade. Realizou-se o monitoramento da umidade do solo atravÃs dos registros da cÃlula de carga; da tensÃo da Ãgua do solo, atravÃs de cinco sensores tipo tensiÃmetros eletrÃnicos e da resistÃncia elÃtrica do solo, atravÃs de trÃs sensores de matriz granular (Watermark). Os dados da temperatura ambiente foram coletados pelo sensor de temperatura FM51. Foram analisadas as saÃdas obtidas na cÃlula de carga e nos sensores de umidade do solo quanto à variaÃÃo da temperatura ao longo do dia. O DCSUS apresentou sensibilidade para variaÃÃo de umidade correspondente à perda de 13,33 mL de Ãgua. A cÃlula de carga utilizada apresentou sensibilidade à temperatura ambiente ao longo do dia, com erro em torno de 0,25%. Nas condiÃÃes experimentais estabelecidas, os sensores Watermark nÃo apresentaram erro devido à temperatura ambiente. Os tensiÃmetros apresentaram erro devido à variaÃÃo da temperatura acima de 3,5% quando em potenciais mÃtricos mais elevados (-3,87 kPa) e acima de 5,5 % quando em potenciais mÃtricos mais baixos (-44,50 e 51,00 kPa). O DCSUS desenvolvido foi eficaz quanto à determinaÃÃo da umidade do solo, com sensibilidade à variaÃÃo de 4,244.10-4 cm3.cm-3. / Na apparatus for soil moisture calibration was developed and built (DCSUS). The moisture was controlled indirectly by controlling the soil water matrix potenctial using both a porous plate funnel and a pressure chamber system. A 3.0 m high tower wal built in steel and a scale installed on its top. The scale components were an I-bean articulated in its center by a set of bearings and bushings and a shaft. The bian was welded in its middle point to the shaft and a horizontal soil column with undisturbed soil contained by an acrylic cylinder installed on one of its ends, and a 50 N capacy load cell on the other end. The following sensors were installed: a granular matrix sensor (Watermark), an electronic tensiometer sensor, air temperature sensors and soil temperature sensors. Moisture sensor readings, as well as from the load cell and temperature sensor were taken in real time at a 3 Hz frequency from 01/15 to 05/27/2004. The data acquisition system was made of a 12-bit analog/digital coverter, an AMD188 microcontroller and an RS232 interface. Data was stored daily and applied to obtain the parameters of calibrations, sensitivity and the effect of temperature on the system. The apparatus resulted in sensitivity to moisture change of 13,33 mL of water. The load cell displayed some sensitivity to daily temperature variation, with an error of 0,25%. The Watermark sensors were not affected by air temperature variation, but displayed sensitivity to variation on the supplied voltage. The electronic tensiometers, however, were more sensitive to temperature with errors of 3.5% for higher matric potentials (-3.82 to -3.92 kPa) and 5.5% for lower matric potentials (-44.5 to -51 kPa). The DCSUS showed to be efficient in monitoring variations soil moisture, displaying a minimum reading 4.244E-4 cm3.cm-3.
186

A DETECTION AND DATA ACQUISITION SYSTEM FOR PRECISION BETA DECAY SPECTROSCOPY

Jezghani, Aaron P. 01 January 2019 (has links)
Free neutron and nuclear beta decay spectroscopy serves as a robust laboratory for investigations of the Standard Model of Particle Physics. Observables such as decay product angular correlations and energy spectra overconstrain the Standard Model and serve as a sensitive probe for Beyond the Standard Model physics. Improved measurement of these quantities is necessary to complement the TeV scale physics being conducted at the Large Hadron Collider. The UCNB, 45Ca, and Nab experiments aim to improve upon existing measurements of free neutron decay angular correlations and set new limits in the search for exotic couplings in beta decay. To achieve these experimental goals, a highly-pixelated, thick silicon detector with a 100 nm entrance window has been developed for precision beta spectroscopy and the direct detection of 30 keV beta decay protons. The detector has been characterized for its performance in energy reconstruction and particle arrival time determination. A Monte Carlo simulation of signal formation in the silicon detector and propagation through the electronics chain has been written to develop optimal signal analysis algorithms for minimally biased energy and timing extraction. A tagged-electron timing test has been proposed and investigated as a means to assess the validity of these Monte Carlo efforts. A universal platform for data acquisition (DAQ) has been designed and implemented in National Instrument's PXIe-5171R digitizer/FPGA hardware. The DAQ retains a ring buffer of the most recent 400 ms of data in all 256 channels, so that a waveform trace can be returned from any combination of pixels and resolution for complete energy reconstruction. Low-threshold triggers on individual channels were implemented in FPGA as a generic piecewise-polynomial filter for universal, real-time digital signal processing, which allows for arbitrary filter implementation on a pixel-by-pixel basis. This system is universal in the sense that it has complete flexible, complex, and debuggable triggering at both the pixel and global level without recompiling the firmware. The culmination of this work is a system capable of a 10 keV trigger threshold, 3 keV resolution, and maximum 300 ps arrival time systematic, even in the presence of large amplitude noise components.
187

Low Power Real-time Video and Audio Embedded System Design for Naturalistic Bicycle Study

Karri, Janardhan Bhima Reddy 05 March 2015 (has links)
According to NHTSA Traffic Safety Facts [9], bicyclist deaths and injuries in 2013 are recorded as 732 and 48,000, respectively. In the State of Florida the safety of bicyclists is of particular concern as the bicycle fatality rates are nearly triple the national average. Further Florida ranks #1 on bicycle fatality rate in the nation for several years. To determine the cause of near-misses and crashes, a detailed study of bicyclist behavior and environmental conditions is needed. In a Florida Department of Transport (FDOT) funded project, USF CUTR has proposed naturalistic bicycle study based on ride data collected from 100 bicyclists for 3000 hrs. To this end, Bicycle Data Acquisition System (BDAS) is being researched and developed. The main objective of this thesis work is to design and implement low power video and audio subsystems of BDAS as specified by domain experts (USF CUTR researchers). This work also involves design of graphical user interface (Windows application) to visualize the data in a synchronized manner. Selection of appropriate hardware to capture and store data is critical as it should meet several criteria like low power consumption, low cost, and small form factor. Several Camera controllers were evaluated in terms of their performance and cost. The major challenges in this design are synchronization between collected data, storage of the video and sensor data, and design of low power embedded subsystems.
188

Multi-spectral remote sensing of native vegetation condition

Sheffield, Kathryn Jane, kathryn.sheffield@dpi.vic.gov.au January 2009 (has links)
Native vegetation condition provides an indication of the state of vegetation health or function relative to a stated objective or benchmark. Measures of vegetation condition provide an indication of the vegetation's capacity to provide habitat for a range of species and ecosystem functions through the assessment of selected vegetation attributes. Subsets of vegetation attributes are often combined into vegetation condition indices or metrics, which are used to provide information for natural resource management. Despite their value as surrogates of biota and ecosystem function, measures of vegetation condition are rarely used to inform biodiversity assessments at scales beyond individual stands. The extension of vegetation condition information across landscapes, and approaches for achieving this, using remote sensing technologies, is a key focus of the work presented in this thesis. The aim of this research is to assess the utility of multi-spectral remotely sensed data for the recovery of stand-level attributes of native vegetation condition at landscape scales. The use of remotely sensed data for the assessment of vegetation condition attributes in fragmented landscapes is a focus of this study. The influence of a number of practical issues, such as spatial scale and ground data sampling methodology, are also explored. This study sets limitations on the use of this technology for vegetation condition assessment and also demonstrates the practical impact of data quality issues that are frequently encountered in these types of applied integrated approaches. The work presented in this thesis demonstrates that while some measures of vegetation condition, such as vegetation cover and stem density, are readily recoverable from multi-spectral remotely sensed data, others, such as hollow-bearing trees and log length, are not easily derived from this type of data. The types of information derived from remotely sensed data, such as texture measures and vegetation indices, that are useful for vegetation condition assessments of this nature are also highlighted. The utility of multi-spectral remotely sensed data for the assessment of stand-level vegetation condition attributes is highly dependent on a number of factors including the type of attribute being measured, the characteristics of the vegetation, the sensor characteristics (i.e. the spatial, spectral, temporal, and radiometric resolution), and other spatial data quality considerations, such as site homogeneity and spatial scale. A series of case studies are presented in this thesis that explores the effects of these factors. These case studies demonstrate the importance of different aspects of spatial data and how data manipulation can greatly affect the derived relationships between vegetation attributes and remotely sensed data. The work documented in this thesis provides an assessment of what can be achieved from two sources of multi-spectral imagery in terms of recovery of individual vegetation attributes from remotely sensed data. Potential surrogate measures of vegetation condition that can be derived across broad scales are identified. This information could provide a basis for the development of landscape scale multi-spectral remotely sensed based vegetation condition assessment approaches, supplementing information provided by established site-based vegetation condition assessment approaches.
189

Design and Development of a Marine Data Acquisition System for Inertial Measurement in Wind Powered Yachts

Bergeron, Alexandre 27 July 2012 (has links)
This thesis presents the design of an inertial measurement data acquisition system intended for use in sailboats. The variables of interest are 3-axis acceleration, 3-axis rotation, GPS position/velocity, magnetic compass bearing and wind speed/direction. The design focus is on low-cost micro-electromechanical systems (MEMS) based technology and demonstrating the validity of these technologies in a scientific application. A prototype is constructed and submitted to a series of tests to demonstrate functionality and soundness of the design. These tests range from bench tests to full scale application. Contributions of this thesis include the novel application of inertial measurement unit (IMU) technology to a sailboat racing application, the integration of all instrumentation, creative ruggedised packaging and emphasising the use of low-cost commercial off-the-shelf (COTS) technology.
190

A PC-based data acquisition system for sub-atomic physics measurements

Chabot, Daron 23 July 2008
Modern particle physics measurements are heavily dependent upon automated data acquisition systems (DAQ) to collect and process experiment-generated information. One research group from the University of Saskatchewan utilizes a DAQ known as the Lucid data acquisition and analysis system. This thesis examines the project undertaken to upgrade the hardware and software components of Lucid. To establish the effectiveness of the system upgrades, several performance metrics were obtained including the system's dead time and input/output bandwidth.<p>Hardware upgrades to Lucid consisted of replacing its aging digitization equipment with modern, faster-converting Versa-Module Eurobus (VME) technology and replacing the instrumentation processing platform with common, PC hardware. The new processor platform is coupled to the instrumentation modules via a fiber-optic bridging-device, the sis1100/3100 from Struck Innovative Systems.<p>The software systems of Lucid were also modified to follow suit with the new hardware. Originally constructed to utilize a proprietary real-time operating system, the data acquisition application was ported to run under the freely available Real-Time Executive for Multiprocessor Systems (RTEMS). The device driver software provided with sis1100/3100 interface also had to be ported for use under the RTEMS-based system. <p>Performance measurements of the upgraded DAQ indicate that the dead time has been reduced from being on the order of milliseconds to being on the order of several tens of microseconds. This increased capability means that Lucid's users may acquire significantly more data in a shorter period of time, thereby decreasing both the statistical uncertainties and data collection duration associated with a given experiment.

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