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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.
131

The determination of illumination

Quigley, Louis Leroy 01 January 1907 (has links)
No description available.
132

The effect of magnetic reluctance on the general transformer diagram

Champion, R. B. 01 January 1906 (has links)
No description available.
133

Full-Wave Analyses of Nano-Electromechanical Systems Integrated Multifunctional Reconfigurable Antennas

Yuan, Xiaoyan 01 May 2009 (has links)
This thesis work builds upon the theoretical studies and full-wave analysis of radio frequency micro- and nano-electromechanical systems (RF M/NEMS) integrated multi-functional reconfigurable antennas(MRAs). This is a part of the overall M/NEMS research efforts performed in the RF NEMS Laboratory at USU, which includes design, microfabrication, test, and characterization of M/NEMS integrated congitive wireless communication systems (fig. A.1). The thesis work focuses on two MRAs. 1) A triple bands patch antenna which can operate at 800, 2400, and 4900 MHz in response to public safety wireless communication systems. 2) A multi-frequency multi-polarization MRA for wireless personal area networking application (WPAN) operating at 57-64 GHz frequency range
134

Evaluation of Weak Relations in TracFeed

Gauffin, Fredrik January 2008 (has links)
<p>This report is a master degree thesis in electronics that examines if weak relations can be used in TracFeed. TracFeed is a simulation tool designed to aid in the dimensioning of the power supply</p><p>system for electrical railroads. The program was originally developed by Adtranz and is today further enhanced by Balfour Beatty Rail AB.</p><p>When using weak relations there will be fewer truncations of the steps and therefore the response time will decrease. The purpose of this thesis is to study how much time that can be gained in</p><p>different types of simulations and in which way the result is effected because of weak relations. The theoretical part explains the fundamentals concerning electrical trains and how trains are</p><p>modelled in TracFeed. The calculation kernel used by TracFeed is called SIMPOW and it is described as well as the modelling language which is used to create the train models.</p><p>Weak relations are tested in two simulations. The result from those simulations shows that if a displacement in simulated time of the output is acceptable and there are many trains active</p><p>simultaneously weak relations are an interesting alternative.</p>
135

Demonstrator av vinkelgivare

Kivinen, Jonne January 2009 (has links)
<p>Eskilstuna Elektronikpartner (EEPAB) är ett elektronikföretag som tillverkar vinkelgivare till bland annat kranar som är monterade på lastbilsflak.</p><p>För att EEPAB på ett intressant sätt ska kunna demonstrera sin produkt på mässor har en demonstrator tagits fram. Denna demonstrator består av en fjärrstyrd grävmaskin och en elektronikenhet, som hanterar den analoga signalen från vinkelgivaren. Resultatet, som är vinkelgivarens lutning i grader, presenteras på två sjusegmentdisplayer som är placerade på grävmaskinens bägge sidor. Vinkeln skickas även trådlöst från elektronikenheten, via Bluetooth, till en PC. Grävmaskinens batteri (7,2V) strömförsörjer all hårdvara, vilket gör att demonstratorn är helt portabel.</p><p>Denna rapport beskriver block för block de olika programfunktioner samt hårdvara, som behövs till en färdig och fungerande demonstrator.</p> / <p>Eskilstuna Elektronikpartner (EEPAB) is an electronics company located in Eskilstuna that produces angle sensors to, for instance, cranes mounted on truck beds.</p><p>For EEPAB to be able to demonstrate their product on fairs in an interesting way, a demonstrator has been made. The demonstrator consists of a remote controlled excavator and an electronic unit which handles the analog signal from the sensor. The result, which is the angle of the sensor in degrees, is presented on two sevensegment displays that are placed on both sides of the excavator. The angle is also sent wirelessly from the electronic unit via Bluetooth to a PC. The battery of the excavator powers all of the hardware, making the demonstrator fully portable.</p><p>This thesis report describes the various programfunctions and hardware, part by part, necessary for a complete and functioning demonstrator.</p>
136

Halvautomatisk styrning av järnvägskran

Skoog, Björn January 2009 (has links)
<p>En RMRC, Rail Mounted Railway Crane, är en kran för hantering av containertrafik till och från järnvägsvagnar. Kranen som är helt manuellt styrd utrustas med en semiautomatik som hjälper operatören att positionera kranen. Målpositionen för containern kommer från terminalens logistiksystem. För positioneringen har en lämplig regulator tagits fram som tar hänsyn till den mekaniska påverkan på motorer och växellådor som finns vid acceleration och retardation. Regulatorn har tagits fram och testats i en simuleringsmiljö. Den har sedan implementerats i ett PLC-system och provkörts i labmiljö med PLC och motorer. Regulatorn har förbättrad prestanda jämfört med den regulator som tidigare använts för andra typer av kranar. Den är också lättare att trimma in vid idriftsättning.För positionsåterföringen på de tre rörelserna lyft, tralla och kranåk, har olika typer av givare undersökts och rekommenderat.</p>
137

Development of a collision avoidance system for a videoconferencing robot.

Björkman, Patrik, Odens Hedman, Lars January 2010 (has links)
<p>The work presented in this paper is about the development of a collision avoidance systemfor a mobile telepresence robot developed by the company Gira technologies AB.The robot is designed to extend the length of time elderly can stay in their homes beforerequiring full-time staed care. The collision avoidance system is needed to help the userto avoid running in to objects or down a stairway. The design must be capable of beingimplemented at low cost, and should not look overtly "robotic" as this would not resultin an appealing industrial design.</p><p>Herein, dierent techniques are presented and analyzed to nd the best suitable solutionfor the robot. In particular a lot of work is done in taking measurements to nd theright characteristics for the sensors according dierent mounting angles, dierent objectsand distances. A solution is chosen and calculations are made to nd the best positionsto place the sensors to get the best results.</p><p>A complete solution is presented and implemented in the current system and testedto work as expected.</p>
138

Development of a Multi‐bus platform for automation testbed

Isaksson, Mathias, Knapik, Lukas January 2010 (has links)
<p>The task for this thesis was to develop, construct and evaluate a multi‐bus communication system,connected to a PC via USB and capable of communicating in CAN, I2C and SPI and develop drivers for itin National Instruments LabVIEW.In the beginning a study was made of the communication buses followed by an investigation of whattype of hardware that could accomplish this task. A microcontroller unit was selected andprogrammed in MikroElektronika MikroC Pro v.3.2 to act as the interface between the communicationbusses and PC. A PCB prototype of the system was constructed by using Eagle Cad software v.5.6.0. General drivers for this system where created in LabVIEW v.8.6.1 so the end‐user simply can createtheir own applications and control the compatible hardware depending on their type of purposes. Thesystem was tested on criteria’s such as: speed, power consumption, burst performance andtransmission length depending on which communication bus was used.</p>
139

Memory Synthesis for FPGA Implementation of Real-Time Video Processing Systems

Lawal, Najeem January 2006 (has links)
<p>In this thesis, both a method and a tool to enable efficient memory synthesis for real-time video processing systems on field programmable logic array are presented. In real-time video processing system (RTVPS), a set of operations are repetitively performed on every image frame in a video stream. These operations are usually computationally intensive and, depending on the video resolution, can also be very data transfer dominated. These operations, which often require data from several consecutive frames and many rows of data within each frame, must be performed accurately and under real-time constraints as the results greatly affect the accuracy of application. Application domains of these systems include object recognition, object tracking and surveillance.</p><p>Developments in field programmable gate array (FPGA) have been the motivation for choosing them as the platform for implementing RTVPS. Essential logic resources required in RTVPS operation are currently available optimized and embedded in modern FPGAs. One such resource is the embedded memory used for data buffering during real-time video processing. Each data buffer corresponds to a row of pixels in a video frame, which is allocated using a synthesis tool that performs the mapping of buffers to embedded memories. This approach has been investigated and proven to be inefficient. An efficient alternative employing resource sharing and allocation width pipelining will be discussed in this thesis.</p><p>A method for the optimal use of these embedded memories and, additionally, a tool supporting automatic generation of hardware descriptions language (HDL) codes for the synthesis of the memories according to the developed method are the main focus of this thesis. This method consists of the memory architecture, allocation and addressing. The central objective of this method is the optimal use of embedded memories in the process of buffering data on-chip for an RVTPS operation. The developed software tool is an environment for generating HDL codes implementing the memory sub-components.</p><p>The tool integrates with the Interface and Memory Modelling (IMEM) tools in such a way that the IMEM’s output - the memory requirements of a RTVPS - is imported and processed in order to generate the HDL codes. IMEM is based on the philosophy that the memory requirements of an RTVPS can be modelled and synthesized separately from the development of the core RTVPS algorithm thus freeing the designer to focus on the development of the algorithm while relying on IMEM for the implementation of memory sub-components.</p> / Sensible Things That Communicate
140

Ion current interface

Johansson, Morgan January 2005 (has links)
<p>Abstract</p><p>Abstract The reason to measure the ion current in a combustion engine is to extract combustion parameters in order to achieve closed loop control of the combustion i.e. control of the spark, fuel and air into the engine. By using the spark plug, in a spark-ignited engine, as a probe it is possible to measure the ion current.</p><p>The purpose with this thesis is to improve an existing ion current interface.</p><p>A ringing caused by the ignition coil will follow by the ion current signal. Now the need of energy in the spark increase. Since increased energy in the spark gives a longer burn time and a longer ringing the ringing will extend into the ion current signal. The problem with the old interface is that the ringing is not symmetrical which could cause problems when filtering the signal.</p><p>The aim of this thesis is to achieve a symmetrical ringing and a interface that can handle an ion current amplitude from 0,1µA to 1mA.</p>

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