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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.
291

Desenvolvimento de uma ferramenta computacional para aquisição via internet de dados de dispositivo de campo em ambiente Fieldbus / Developing a data acquisition software tool via Internet for field devices in fieldbus networks

Ricardo Luis Balieiro 16 October 2008 (has links)
A crescente utilização de equipamentos inteligentes na área de automação industrial tem assegurado eficiência e qualidade na produção. Em conseqüência deste crescimento, existe uma grande quantidade de equipamentos interligados abrangendo áreas geográficas distantes. Este cenário criou a demanda de sistemas que permitissem o acesso às informações geradas no chão de fábrica a partir de qualquer computador localizado na área industrial ou em qualquer outro ponto do planeta. A Internet propiciou uma nova opção para gerenciamento e monitoramento de equipamentos inteligentes a longa distância. Assim, este trabalho propõe um algoritmo para monitorar, via Internet, os eventos gerados por equipamentos inteligentes instalados em plantas industriais. Com o monitoramento contínuo, é possível analisar o desempenho dos equipamentos, detectar problemas e tomar decisões de forma a garantir que toda uma malha de controle não venha a parar inesperadamente. / The increasing usage of smart field devices in the industrial automation area has assured efficiency and quality of production. Thanks to this expansion, a large number of devices can be interconnected through distant geographical areas. This scenario created the need of computational systems that would make the information from the plant floor accessible to any computer in the local industrial area or any other earth wide location. The Internet has created a new possibility of remote managing and monitoring of smart devices. This work proposes an algorithm to monitor, via Internet, the events generated by smart devices installed in industrial plants. The continuous monitoring makes it possible to analyze the performance of the devices, detect problems and make decisions to ensure that an entire control loop does not come to an unexpected halt.
292

Mediação de parâmetro de escoamento bifásico gás-líquido utiizando sensores de impedância / Parameters measurement from a two-phase gas-liquid slug flow using impedance sensors

Danés, Leandro Henschel, 1986- 07 April 2012 (has links)
Orientador: Niederauer Mastelari / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-21T01:52:02Z (GMT). No. of bitstreams: 1 Danes_LeandroHenschel_M.pdf: 2871625 bytes, checksum: b9af585f9ca0d24b08f2435b57a913bc (MD5) Previous issue date: 2012 / Resumo: Uma mistura de gás e liquido escoando em um tubo em diferentes faixas de vazões se comporta como diferentes padrões de escoamento, em que interações cinemáticas e dinâmicas especificas de cada padrão, ocorrem entre gás e liquido. A estimação de dados sobre a velocidade media de deslocamento e a vazão de ambas as fases depende da aplicação de estratégias estatísticas de e de modelos de escoamento para calcular estas informações. Neste trabalho, um sensor de impedância que, se devidamente calibrado, possui sinal proporcional ao nível de liquido na seção transversal do duto, foi utilizado para a obtenção destes dados sendo desenvolvidas técnicas e estratégias para alcançar este objetivo. O estudo foi desenvolvido no regime de escoamento horizontal água-ar nos regimes de bolhas alongadas, estratificado intermitente. Foram utilizadas técnicas para a obtenção da velocidade media de deslocamento do escoamento bifásico a partir de um arranjo de dois sensores de impedância em serie. Foi utilizada a técnica da correlação cruzada e foram elaboradas e apresentadas como opção, uma técnica baseada no calculo numérico e outra na covariância entre os sinais como alternativa. As técnicas foram testadas e comparadas. Foram utilizados modelos de escoamento e levantadas hipóteses para a estimativa das vazões de gás e liquido. Foram realizadas estimativas para o padrão de bolhas alongadas, estratificado e intermitente. Para o regime intermitente, considerado foco do estudo, foram obtidas respectivamente para gás e liquido, margens de erro de 24.4% e 28% considerando um perfil de escoamento constante e margens de 12.5% e 20.5% para um perfil laminar / Abstract: A gas-liquid moisture flowing in a tube at different flow rates , behaves as different flow patterns, which cinematic and dynamic interactions occurs between the gas and liquid phases. The estimation of average displacement rate data and flow data for both phases depends of the application of statistical strategies and floe models for calculating the information. In this work, a impedance sensor which, is correctly calibrated, has a proportional out to the liquid level of the tube cross section, was used for obtaining these data with techniques and strategies developed to achieve this goal. The study was developed for horizontal air-water flow at the bubbles, stratified and slug patterns. It was used techniques for obtaining the average displacement speed of the flow between the two sensors. The cross-correlation technique was used and a numeric calculus based technique and a covariance based technique were elaborated and presented as an option. The techniques were tested and compared. Flow-models were used and hypothesis were take in order to make estimations of gas and liquid flow magnitude. Estimatives were done for the elongated bubbles , stratified and slug patterns. For the slug pattern ,focus of the work, it was obtained respectively for the gas and the liquid phase, error margins of 24,4% and 28% considering a constant flow profile and 12.5% and 20.5% margins considering a laminar flow profile / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica
293

Sequential-injection analysis

Marshall, Graham Dean 25 March 2010 (has links)
Please read the abstract in the section 00front of this document / Thesis (PhD)--University of Pretoria, 2010. / Chemistry / unrestricted
294

Methodical and technical aspects of functional-structural plant modelling

Henke, Michael 13 March 2017 (has links)
No description available.
295

Návrh elektronického subsystému pro simulátor dopadu ve snížené gravitaci / Design of electronic subsystem for reduced gravity impact simulator

Ostrý, Lubomír January 2020 (has links)
The focus of this thesis is development of an electronic subsystem for reduced gravity impact simulator. The research part of this thesis firstly covers methods used for simulation of microgravity or reduced gravity and compares them. Another part of research focuses on three selected potential approaches to creating the electronic subsystem for this device. The second, practical, part of this thesis describes the design and development of the electronic subsystem. The foundation of the electronic subsystem is a control unit which has been developed on the basis of an STMicroelectronics microcontroller. Using the control unit, the electronic subsystem measures pressure, position, acceleration and force in the system. Another task of the control unit is control of a stepper motor. Integration of individual elements into the electronic subsystem is described both in terms of software and hardware. Furthermore, a graphic user interface program for PC has been developed as a means to interact with the system. In the final part of the thesis, the operation of the electronic subsystem is described and lastly, the electronic subsystem is evaluated.
296

Virtuální laboratoř na bázi JAVA a LABVIEW / JAVA- and LABVIEW-based virtual laboratory

Bugla, Marek January 2008 (has links)
Dielektrické materiály jsou použivány v elektronice i v elektrotechnice. Jako jejich základní vlastnost může považovat změnu jejich charakteristik během jejich životnosti. Změny jsou způsobeny namáhaním materiálu vyvolané elektrickými či teplotími vlivy. Možnost jak určit průběh jejich charakteristik v závislosti na čase je měření proudu během aplikování elektrického napětí na materiál. Tyto experimenty vědci z LEMD provaděli ručně, tento postup ale není přílíš učinný pro vysokofrekvenční signály nebo pro experimenty s dlouhou periodou. Hlavním cílem této práce bylo vytvořit aplikaci v LabVIEW k ovládaní měřícího přístroje Keithley (generátor napětí) a k automatickému získavání měřených hodnot v pikoampérech. Tato aplikace nabízí uživateli různé funkce: - Zadání vystupního napětí. - Vyběr typu průběhu. - Definování délky periody. - Ovládaní přístroje. - Měření proudu, ukládaní dat do souboru vhodného pro jiné aplikace (textový soubor). - Analýzu naměřených dat.
297

LOW COST DATA ACQUISITION FOR AUTONOMOUS VEHICLE

Dong Hun Lee (9040400) 29 June 2020 (has links)
The study of this research has a challenge of learning data gathering sensor programming and design of electronic sensor circuit. The cost of autonomous vehicle development is expensive compared to purchasing an economy vehicle such as the Hyundai Elantra. Keeping the development cost down is critical to maintaining a competitive edge on vehicle pricing with newer technologies. Autonomous vehicle sensor integration was designed and then tested for the driving vision data-gathering system that requires the system to gather driving vision data utilizing area scan sensors, Lidar, ultrasonic sensor, and camera on real road scenarios. The project utilized sensors such as cheap cost LIDAR, which is that drone is used for on the road testing; other sensors include myRIO (myRIO Hardware), LabVIEW (LabVIEW software), LIDAR-Lite v3 (Garmin, 2019), Ultrasonic sensor, and Wantai stepper motor (Polifka, 2020). This research helps to reduce the price of usage of autonomous vehicle driving systems in the city. Due to resolution and Lidar detecting distance, the test environment is limited to within city areas. Lidar is the most expensive equipment on autonomous vehicle driving data gathering systems. This study focuses on replacing expensive Lidar, ultrasonic sensor, and camera to drone scale low-cost Lidar to real size vehicle. With this study, economic expense autonomous vehicle driving data acquisition is possible. Lowering the price of autonomous vehicle driving data acquisition increases involving new companies on the autonomous vehicle market. Multiple testing with multiple cars is possible. Since multiple testing at the same time is possible, collecting time reduces.
298

A Data Acquisition System Experiment for Gas Temperature and Pressure Measurements on a Liquid-Nitrogen-Powered Vehicle

Lui, Samson Sze-Sang 05 1900 (has links)
A data acquisition system was set up to measure gas temperatures and pressures at various points on a liquid-nitrogen-powered vehicle. The experiment was attempted to develop a data acquisition method for applications on engines that use liquid air as the fuel. Two thermocouples and a pressure transducer were connected using data acquisition instruments interfaced to a laptop computer to acquire data.
299

Array Analysis of Radio Frequency Interference Cancelation Requirements for a Land Mine Detection System

Pratt, Devin Baker 16 November 2005 (has links) (PDF)
Land mines are a major humanitarian problem with millions of active mines in place around the world. Since these mines can have little metal in them, novel detection techniques are needed. Nuclear Quadrupole Resonance (NQR) is one such technique. Unfortunately, NQR is highly succeptible to radio frequency interference (RFI). A significant contribution of this thesis is the development of a custom, experimental data acquisition system designed and built specifically for capturing RFI at frequencies significant to NQR land mine detection systems. Another major contribution is the development of data analysis techniques for determining the number of reference antennas required to effectively cancel out RFI at frequencies and in environments typical of an NQR land mine detection system.
300

Interactions of Tollmien-Schlichting Waves and Stationary Transient Disturbances

Gurun, Akif Murat January 2006 (has links)
No description available.

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