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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.
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Showing 11 to 20 of 21 (0.023 seconds)| 11 |
Automatisk mätning och detektering av röjande signaler / Automatic measuring and detection of compromising emanationsEkman, Anders January 2003 (has links)
<p>This master thesis has been performed at Sectra Communications AB in Linköping where they manufacture electronic encryption devices. In cryptology it is essential that an eavesdropper cannot find the plain text. To assure that a system is safe, all devices are thoroughly examined so that they don’t emit any secret information, so called Compromising Emanations (CE). This is done by comparing the secret signal with measured signals on the screen of an oscilloscope, a process that is very time consuming and furthermore, the risk of missing compromising emanations is high. The purpose of this thesis is to investigate the possibilities to let a computer do this job. Two methods for comparing the signals have been suggested and implemented; cross covariance and model estimation. In the cross covariance method, the cross covariance is calculated and its highest value determine how well the signals match. In the model estimation method, a number of ARX models are estimated, and if the best model is successful in explaining the output signal, it is assumed that there exists CE. </p><p>The work shows that both these methods are functional for solving the task, yet with a few limitations. Both methods announce CE for clock signals, which really aren’t compromising. The cross covariance method is limited only to find compromising emanations that look like the secret signal or certain frequently occurring non-linearities of it. The model estimation method is more general and detects CE for all linear systems, along with the known non-linearities. However, this method has a flaw: the time delay in the system must be known approximately. Further, the results show that the model estimation method is considerably more time consuming than the cross covariance method. The measurement is carried out with a computer communicating with oscilloscope and spectrum analyzer via the GPIB interface. The implementation has been done in LabView with calculation modules coded in C++.</p>
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Spacecraft Interface Standards Analysis and Simple BreadboardingLjunggren, Birgitta January 2005 (has links)
<p>This report is a result of a thesis work done for Linköping University at Contraves Space AG in Zürich, Switzerland. The aim was to perform an analysis of 12 interface standards and construct a simple breadboard, which should function as a testsystem for the data communication interface MIL-STD-1553. </p><p>The conclusion of the extensive analysis is that SpaceWire, MIL-STD-1553 and CAN are the most interesting interfaces for future data communication in spacecrafts. In the breadboard part of the work, a test system was built and data gathered with help from a demonstration program that came with one of the components.</p>
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Automatisk mätning och detektering av röjande signaler / Automatic measuring and detection of compromising emanationsEkman, Anders January 2003 (has links)
This master thesis has been performed at Sectra Communications AB in Linköping where they manufacture electronic encryption devices. In cryptology it is essential that an eavesdropper cannot find the plain text. To assure that a system is safe, all devices are thoroughly examined so that they don’t emit any secret information, so called Compromising Emanations (CE). This is done by comparing the secret signal with measured signals on the screen of an oscilloscope, a process that is very time consuming and furthermore, the risk of missing compromising emanations is high. The purpose of this thesis is to investigate the possibilities to let a computer do this job. Two methods for comparing the signals have been suggested and implemented; cross covariance and model estimation. In the cross covariance method, the cross covariance is calculated and its highest value determine how well the signals match. In the model estimation method, a number of ARX models are estimated, and if the best model is successful in explaining the output signal, it is assumed that there exists CE. The work shows that both these methods are functional for solving the task, yet with a few limitations. Both methods announce CE for clock signals, which really aren’t compromising. The cross covariance method is limited only to find compromising emanations that look like the secret signal or certain frequently occurring non-linearities of it. The model estimation method is more general and detects CE for all linear systems, along with the known non-linearities. However, this method has a flaw: the time delay in the system must be known approximately. Further, the results show that the model estimation method is considerably more time consuming than the cross covariance method. The measurement is carried out with a computer communicating with oscilloscope and spectrum analyzer via the GPIB interface. The implementation has been done in LabView with calculation modules coded in C++.
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Spacecraft Interface Standards Analysis and Simple BreadboardingLjunggren, Birgitta January 2005 (has links)
This report is a result of a thesis work done for Linköping University at Contraves Space AG in Zürich, Switzerland. The aim was to perform an analysis of 12 interface standards and construct a simple breadboard, which should function as a testsystem for the data communication interface MIL-STD-1553. The conclusion of the extensive analysis is that SpaceWire, MIL-STD-1553 and CAN are the most interesting interfaces for future data communication in spacecrafts. In the breadboard part of the work, a test system was built and data gathered with help from a demonstration program that came with one of the components.
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Automatický přepínač rozsahů pro AC-DC etalon Fluke 792A / Automatic switch range for AC-DC etalon Fluke 792ATrojan, Martin January 2010 (has links)
The main topic of this Master's Thesis is design and implementation of mechanical connection between the automatic range switch unit and the AC-DC Transfer Standart Fluke 792A. This Master's Thesis contains theoretical analysis of the the AC-DC Transfer Standart Fluke 792A and of stepper motors. Followed the choosing of appropriate drive. In next chapter is the theoretical analysis of automatic range switch unit, used microcontroller and the description of the GPIB. Last part of this Master's Thesis describes design of mechanical connecting part and the selection of appropriate sensors for sensing the current position of the shading component.
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Řídicí jednotka k automatickému přepínači / Automatic switch control unitZlý, Marián January 2009 (has links)
The main topic of this Master's Thesis is design and implementation of automatic range switch AC/DC Transfer Standart Fluke 792A. In the first part is introduce and description of character and the parameters AC/DC trasfer Standart Fluke 792A and design of the Automatic range switch for this equipment. In the next part is introduce design and description of realize automatic switch control unit it has comunication faculty witch PC over GPIB bus. In the finish part is show of the theoretic description for GPIB bus and her realization with helped microcontroller Atmega16.
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Automatizace měření odchylek a stability generátorů / Meaurement process automatization of deviations and stability of oscilatorsČermák, Jan January 2010 (has links)
This Master´s thesis on a topic ,,Meaurement process automatization of deviations and stability of oscilators‘‘ describes methods for measuring the difference of time scales. Using this method, calculates the parameters of the oscillator, which is also describes in this work. Parameters of the oscillator means inning and stability. Describes is the procedure for calculating the uncertainties and their presentation in the final calibration sheet. This Master´s thesis also describes the practical measurement with this method in the Czech metrology institute in Brno. Measurement of the parameters of oscillator by the method of measurement of the difference of time scales is carried out automatically by computer. This Master´s thesis deals with the creation and development of new software and thus the automation of the entire task.
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Webové rozhraní pro on-line správu laboratorních úloh / Web interface for on-line administration of laboratory tasksBelko, Jakub January 2011 (has links)
The present work describes the current trends and e-learning methods using the Internet in the educational process on Czech and foreign universities. The main objective is to create a web interface for on-line administrations of laboratory tasks named "Laboratorě UETE". Practical work is focused on programming web applications and modules for management of instrumentation for laboratory protocols administration including implementation of the IP video cameras outputs and sensor atmospheric conditions. An integral part of this work is to create a module for simulation of physical quantities using commercially available software components based on client – server system.
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Modelování diferenčního proudového zesilovače / Modelling of differential current amplifierPolák, Josef January 2013 (has links)
The aim of my diploma thesis was programming of systems for measuring AC, DC and impedance measurements. Each measuring system measures selected characteristics of current amplifier with controllable amplification DACA_N. Control programs I have created in Agilent VEE Pro 9.2. The measured data are stored to executable files in MS Excel for further processing. With created measurement programs I made measurements of eight current amplifiers. The results of individual measurements I compiled into graphs and compared with each other circuit characteristics of amplifiers. Then there is described controlling and connection of current amplifier and its construction. At the end the diploma thesis describes amplifiers with the worst and the best measured circuit characteristics. The measured values show that the amplifier DACA_N with slight differences works by theoretical assumptions and measurement systems suggested by me work with no problem.
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The modernization of a DOS-basedtime critical solar cell LBICmeasurement system.Hjern, Gunnar January 2019 (has links)
LBIC is a technique for scanning the local quantum efficiency of solar cells. This kind of measurements needs a highly specialized, and time critical controlling software. In 1996 the client, professor Markus Rinio, constructed an LBIC system, and wrote the controlling software as a Turbo-Pascal 7.0 application, running under the MS-DOS 6.22 operating system. By now (2018) both the software and several hardware components are in dire need to be modernized. This thesis thoroughly describes several important aspects of this work, and the considerations needed for a successful result. This includes both very foundational choices about the software architecture, the choice of suitable operating system, the threading model, and the adaptation to new hardware with vastly different behavior. The project also included a new hardware module for position reports and instrument triggering, as well as several adaptations to transform the DOS-based LBIC software into a pleasant modern GUI application.
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