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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.
1

Introducing C-Band Operations Using a Low Cost Test Platform

Mueller, Guenter 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 / Changing from L/S-Band to C-Band requires not only new equipment. Even the characteristics of the new frequencies just as the new frequency environment are a challenge for the operations in this bands when changing from a well-known frequency environment to a unknown new one. This paper describes the way used at Airbus Defense and Space Flight Test Ground Station to get experience with new equipment and to learn more about the new environment. Repeatable and comparable tests allowed training for the operators and the optimization of the equipment and procedures with the new environment. Although many of the problems or features observed during the tests where expected in advance, but even unexpected results could be identified.
2

Critical path tracing as a diagnostic evaluation method for sequential systems

Mann, Timothy Lee, 1950- January 1988 (has links)
Diagnostic tests are designed to detect and isolate faults in sequential systems. The problem is to evaluate the effectiveness of the design. For stuck faults a diagnostic model can be used. A fault simulation strategy is presented for generating this model. First, definitions, for identifying critical inputs are derived. A definition is a statement of the conditions to sensitize an input. Then a fault free simulation is used to generate a critical value array. A critical path is traced through the sensitized inputs marked in the array using a critical value array tracing algorithm that is developed. This algorithm traces a path back in time, as required for a sequential system, to identify detectable faults for the model.
3

Acquisition and analysis of performance data for mobile devices

Luiro, V. (Vesa) 18 October 2003 (has links)
Abstract Electronic industry is developing advanced and versatile products to satisfy customers' needs. It is also creating new needs, which expand the market further. This highly competitive field forces companies to produce continuously better, and hence more complex, products at an increasingly fast rate. This is particularly true of the mobile phone industry, which pursues higher volumes and penetration rates throughout the world. Very high volumes and extreme complexity require intensive research and a commitment to high product quality. Mobile phone manufacturers must commit themselves to strict quality standards and programs, which ultimately enable high customer satisfaction. Both quality assessment and product management generally need a method of feedback to be able to react to the manufactured output. This thesis concentrates on this aspect of feedback. A preliminary customer survey revealed that the information received directly from customers might not be accurate enough to be used as primary feedback data. The quality of the information varies notably and depends entirely on the customers' ability to perceive the relevant parameters. This also affects greatly their ability to communicate the information to the customer interface and then all the way back to the manufacturer. Based on the findings, end customers' average level of knowledge of mobile phone technology is fair [C]. Therefore, it is recommended that more accurate means should be developed for acquiring feedback data. Also, based on other research findings, it would be important to minimize human intervention and to make the flow of information as direct as possible. Based on previous research and the present findings, a concept was designed which satisfies the specific need for accurate feedback from the performance of mobile phones in the field. The interfaces providing data throughout the whole product life cycle were also analyzed in detail. And finally, the concept was implemented and piloted with a mobile phone manufacturer. The pilot studies showed that an improved feedback capability would benefit not only product quality, but also various functions of the company producing mobile devices. The increased knowledge of device performance obtained from the system can be utilized in, for example, testing, design, marketing, and management and also at all customer interfaces in the field.
4

Optimalizace hydraulického systému a jeho prvků pro malá dopravní letadla / Optimization of Hydraulic System and its Components for Commuter Category Airplanes

Kameník, Luboš January 2012 (has links)
The dissertation thesis deals with optimization of the selected areas of the hydraulic system for small and medium transport aircrafts. Newly developed small aircraft EV-55 is a representative in the category of the small aircrafts . The selected areas of the hydraulic systems , important and useful for domestic producers of the hydraulic devices and whole hydraulic systems for the airplane EV-55 , are subjected to optimization efforts in the dissertation thesis. Design parameters of the hydraulic system (type of hydraulic source, level of pressure, weight of connecting tube), hydraulic devices ( tribology, machining process), simulation of the servomechanism and areas of diagnostic of technical status of the hydraulic system are optimized in the dissertation thesis.
5

Avaliação de conformidade de inversores para micro e mini geração fotovoltaica: a implantação da NBR 16150 e NBR IEC 62116 / onformity evaluation for micro and mini photovoltaic generation inverters: NBR 16150 and NBR IEC 62116 implementation

Almeida Neto, José Cesar de Souza 20 September 2017 (has links)
No Brasil, a necessidade crescente por sistemas de geração solar fotovoltaica conectados à rede de distribuição levou ao desenvolvimento de normas brasileiras para a conformidade de inversores. Assim, de forma a atender a população em geral, foi publicada a Portaria 357, de 01 de agosto de 2014, do Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), que inclui inversores para conexão à rede de potência nominal até 10 kW no Programa Brasileiro de Etiquetagem (PBE). Por possuir os equipamentos necessários para a realização dos ensaios de conformidade com a portaria 357, o Laboratório de Sistemas Fotovoltaicos (LSF) do Instituto de Energia e Ambiente da Universidade de São Paulo passa então a ser o primeiro laboratório acreditado pelo INMETRO para a realização desses ensaios. Este trabalho tem como objetivo resumir as experiências de aplicação das normas brasileiras no ensaio de inversores para o PBE no LSF, sendo levantados os resultados obtidos no ensaio de 15 inversores ao longo de três anos de operação da bancada de ensaio para sistemas conectados à rede. A partir deste levantamento conclui-se que, embora as normas brasileiras exijam rigor em seus requisitos, existem inversores capazes de atender aos requisitos normativos brasileiros, assim como existem inversores que necessitam de implementações nos respectivos firmware de controle para conseguirem atender todos os requisitos. Uma vez que as normas brasileiras são recentes, este trabalho também destaca pontos das normas que se beneficiariam de adequações no corpo do texto, a fim de melhorar as rotinas de ensaios em inversores e critérios de conformidade. / In Brazil, the increasing demand for grid-tie photovoltaic systems lead to the development of the Brazilian standards for inverter quality and evaluation. In order to meet the general population demand, the National Institute for Metrology, Quality and Technology (INMETRO) published the normative nº 357 01/08/2014 to include inverters up to 10 kW in the Brazilian Labeling Program (PBE). For having all the equipment needed for inverter conformity evaluation in accordance with the normative nº 357, the Laboratory of Photovoltaic Systems (LSF) of the Institute of Energy and Environment of the University of Sao Paulo becomes the first INMETRO accredited laboratory for conducting the inverter evaluation in Brazil. This works main goal is to summarize the experience acquired for the appliance of the Brazilian standards for inverter testing in the LSF. The results obtained for the test of 15 different inverters during the first three years operating the inverter test bench are showed. Using the data shown this work concludes that, although the Brazilian standards are rigorous on its criteria, there are inverters capable of complying with the standards requirements and there are inverters that need further software and hardware development in order to comply with all the requirements. Since the Brazilian standards are in its first version, this work also aims to point out aspects of the standard that would benefit from text revising in order to improve the test conditions and conformity criteria.
6

Avaliação de conformidade de inversores para micro e mini geração fotovoltaica: a implantação da NBR 16150 e NBR IEC 62116 / onformity evaluation for micro and mini photovoltaic generation inverters: NBR 16150 and NBR IEC 62116 implementation

José Cesar de Souza Almeida Neto 20 September 2017 (has links)
No Brasil, a necessidade crescente por sistemas de geração solar fotovoltaica conectados à rede de distribuição levou ao desenvolvimento de normas brasileiras para a conformidade de inversores. Assim, de forma a atender a população em geral, foi publicada a Portaria 357, de 01 de agosto de 2014, do Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), que inclui inversores para conexão à rede de potência nominal até 10 kW no Programa Brasileiro de Etiquetagem (PBE). Por possuir os equipamentos necessários para a realização dos ensaios de conformidade com a portaria 357, o Laboratório de Sistemas Fotovoltaicos (LSF) do Instituto de Energia e Ambiente da Universidade de São Paulo passa então a ser o primeiro laboratório acreditado pelo INMETRO para a realização desses ensaios. Este trabalho tem como objetivo resumir as experiências de aplicação das normas brasileiras no ensaio de inversores para o PBE no LSF, sendo levantados os resultados obtidos no ensaio de 15 inversores ao longo de três anos de operação da bancada de ensaio para sistemas conectados à rede. A partir deste levantamento conclui-se que, embora as normas brasileiras exijam rigor em seus requisitos, existem inversores capazes de atender aos requisitos normativos brasileiros, assim como existem inversores que necessitam de implementações nos respectivos firmware de controle para conseguirem atender todos os requisitos. Uma vez que as normas brasileiras são recentes, este trabalho também destaca pontos das normas que se beneficiariam de adequações no corpo do texto, a fim de melhorar as rotinas de ensaios em inversores e critérios de conformidade. / In Brazil, the increasing demand for grid-tie photovoltaic systems lead to the development of the Brazilian standards for inverter quality and evaluation. In order to meet the general population demand, the National Institute for Metrology, Quality and Technology (INMETRO) published the normative nº 357 01/08/2014 to include inverters up to 10 kW in the Brazilian Labeling Program (PBE). For having all the equipment needed for inverter conformity evaluation in accordance with the normative nº 357, the Laboratory of Photovoltaic Systems (LSF) of the Institute of Energy and Environment of the University of Sao Paulo becomes the first INMETRO accredited laboratory for conducting the inverter evaluation in Brazil. This works main goal is to summarize the experience acquired for the appliance of the Brazilian standards for inverter testing in the LSF. The results obtained for the test of 15 different inverters during the first three years operating the inverter test bench are showed. Using the data shown this work concludes that, although the Brazilian standards are rigorous on its criteria, there are inverters capable of complying with the standards requirements and there are inverters that need further software and hardware development in order to comply with all the requirements. Since the Brazilian standards are in its first version, this work also aims to point out aspects of the standard that would benefit from text revising in order to improve the test conditions and conformity criteria.
7

Hardware/Software Interface Assurance with Conformance Checking

Lei, Li 02 June 2015 (has links)
Hardware/Software (HW/SW) interfaces are pervasive in modern computer systems. Most of HW/SW interfaces are implemented by devices and their device drivers. Unfortunately, HW/SW interfaces are unreliable and insecure due to their intrinsic complexity and error-prone nature. Moreover, assuring HW/SW interface reliability and security is challenging. First, at the post-silicon validation stage, HW/SW integration validation is largely an ad-hoc and time-consuming process. Second, at the system deployment stage, transient hardware failures and malicious attacks make HW/SW interfaces vulnerable even after intensive testing and validation. In this dissertation, we present a comprehensive solution for HW/SW interface assurance over the system life cycle. This solution is composited of two major parts. First, our solution provides a systematic HW/SW co-validation framework which validates hardware and software together; Second, based on the co-validation framework, we design two schemes for assuring HW/SW interfaces over the system life cycle: (1) post-silicon HW/SW co-validation at the post-silicon validation stage; (2) HW/SW co-monitoring at the system deployment stage. Our HW/SW co-validation framework employs a key technique, conformance checking which checks the interface conformance between the device and its reference model. Furthermore, property checking is carried out to verify system properties over the interactions between the reference model and the driver. Based on the conformance between the reference model and the device, properties hold on the reference model/driver interface also hold on the device/driver interface. Conformance checking discovers inconsistencies between the device and its reference model thereby validating device interface implementations of both sides. Property checking detects both device and driver violations of HW/SW interface protocols. By detecting device and driver errors, our co-validation approach provides a systematic and ecient way to validate HW/SW interfaces. We developed two software tools which implement the two assurance schemes: DCC (Device Conformance Checker), a co-validation framework for post-silicon HW/SW integration validation; and CoMon (HW/SW Co-monitoring), a runtime verication framework for detecting bugs and malicious attacks across HW/SW interfaces. The two software tools lead to discovery of 42 bugs from four industry hardware devices, the device drivers, and their reference models. The results have demonstrated the signicance of our approach in HW/SW interface assurance of industry applications.
8

Waveform relaxation based hardware-in-the-loop simulation

Goulkhah, Mohammad (Monty) January 2015 (has links)
This thesis introduces an alternative potentially low cost solution for hardware-in-the-loop (HIL) simulation based on the waveform relaxation (WR) method. The WR tech-nique is extended so that, without the need for a real-time simulator, the behaviour of an actual piece of physical hardware can nevertheless be tested as though it were connected to a large external electrical network. This is achieved by simulating the external network on an off-line electromagnetic transients (EMT) simulation program, and utilizing iterative exchange of waveforms between the simulation and the hardware by means of a spe-cialized Real-Time Player/Recorder (RTPR) interface device. The approach is referred to as waveform relaxation based hardware-in-the-loop (WR-HIL) simulation. To make the method possible, the thesis introduces several new innovations for stabi-lizing and accelerating the WR-HIL algorithm. It is shown that the classical WR shows poor or no convergence when at least one of the subsystems is an actual device. The noise and analog-digital converters’ quantization errors and other hardware disturbances can affect the waveforms and cause the WR to diverge. Therefore, the application of the WR method in performing HIL simulation is not straightforward and the classical WR need to be modified accordingly. Three convergence techniques are proposed to improve the WR-HIL simulation con-vergence. Each technique is evaluated by an experimental example. The stability of the WR-HIL simulation is studied and a stabilization technique is proposed to provide suffi-cient conditions for the simulation stability. The approach is also extended to include the optimization of the parameters of power system controllers located in geographically distant places. The WR-HIL simulation technique is presented with several examples. At the end of the thesis, suggestions for the future work are presented. / February 2016
9

Optimalizace hydraulického systému a jeho prvků pro malá dopravní letadla / Optimization of Hydraulic System and its Components for Commuter Category Airplanes

Kameník, Luboš January 2012 (has links)
The dissertation thesis deals with optimization of the selected areas of the hydraulic system for small and medium transport aircrafts. Newly developed small aircraft EV-55 is a representative in the category of the small aircrafts . The selected areas of the hydraulic systems , important and useful for domestic producers of the hydraulic devices and whole hydraulic systems for the airplane EV-55 , are subjected to optimization efforts in the dissertation thesis. Design parameters of the hydraulic system (type of hydraulic source, level of pressure, weight of connecting tube), hydraulic devices ( tribology, machining process), simulation of the servomechanism and areas of diagnostic of technical status of the hydraulic system are optimized in the dissertation thesis.

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