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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.
11

Syntetiska Instrument

Borg, Daniel, Mantling, Ulf January 2009 (has links)
This thesis aims to investigate SAAB AB´s possibilities to use synthetic instruments in their test systems. The reason for this is reducing costs and the risk of obsolescence which is common when test systems operate for several decades. The market around synthetic instruments has been explored in the search for suitable hardware and software. Software has been developed in LabVIEW and synthetic instruments have been created with the help of IVI-drivers. The hardware consisted of PXI-instruments (Waveform generator and Digitizer), connected to a computer using a fiber optic link and PXI-chassi. The created instruments was then compared to common instruments used today, and the comparison turned out well. Advantages, disadvantages and the theory surrounding synthetic instruments is also covered. This thesis is only an introduction and further work will be necessary to implement synthetic instruments at SAAB. The thesis also purposes suitable hardware and further development based on the test systems used today, and how it is possible to solve the layer structure. / Detta examensarbete har som mål att undersöka möjligheterna för SAAB AB att börja använda sig av syntetiska mätinstrument i sina testsystem. Anledningen till detta är att SAAB AB vill minska kostnaderna och riskerna för obsolescens som finns när testsystem är i drift i flera decennier. Detta har inneburit att marknaden har sonderats efter lämplig hårdvara och mjukvara för tillämpningen. Förutom detta har mjukvara tagits fram i LabVIEW och syntetiska instrument skapats med hjälp av IVI-drivrutiner. Som hårdvara användes PXI-instrument (vågformsgenerator och digitizer) med tillhörande chassi och fiberoptisk länk från National Instruments. De framtagna instrumenten har jämförts med vanliga reella instrument och visat sig fungera väl, men även fördelar och nackdelar belyses samt teori kring hur syntetiska instrument fungerar. Examensarbetet är endast en introduktion i ämnet och kräver ytterligare arbete innan det är praktiskt genomförbart. Förutom detta ges även förslag på lämplig hårdvara och vidareutveckling baserat på hur testsystemen ser ut i dag, och förslag på hur lageruppbyggnaden skulle kunna lösas.
12

Reliability assessment of non-utility generation and demand-side management In composite power systems

Adzanu, Steve Kwaku 01 January 1998 (has links)
The last two decades have brought about significant changes in the resource planning environment of electric power utilities throughout the world. The conventional generation technologies that have been the backbone of every electric utility i.e., coal, hydro, nuclear, oil and natural gas, are being re-examined to address environmental concerns and resource utilization. The research described in this thesis focuses on the adequacy and economic assessment of non-utility generation (NUG) and demand-side management (DSM) initiatives within a typical power system. The main objective was to examine and extend the ability of the contingency enumeration approach to evaluate the economic reliability benefits of incorporating NUG and DSM options separately or jointly in composite system adequacy assessment. Two test systems were employed in the evaluations. The studies undertaken in this thesis demonstrate the need for accurate load model representations which clearly reflect the mix of customer sectors at each bus.Chronological hourly load curves were developed for each load bus in the test systems recognizing the individual load profiles of the customers. The adequacy and economic implications of demand-side management initiatives in the test systems were examined at each load point in the composite generation and transmission configuration. This thesis illustrates the development of techniques by which system planners and operators can incorporate reliability cost/worth assessment power system applications. Focus is placed in the thesis on the utilization of reliability cost/worth concepts in integrated resource planning in the form of NUG additions and DSM initiatives. Methods for the joint implementation of NUG and DSM options in a composite power system are presented and examples from the studies conducted are used to illustrate the procedures. Studies are presented which illustrate the impacts of NUG additions and DSM initiatives on the test system planning reserve margins (PRM) and on the total societal cost of electrical energy. The total evaluated cost incorporates the explicit cost associated with customer failures but does not include the cost associated with DSM program implementation. The results of the studies conducted show that NUG facilities and DSM programs can have considerable reliability and economic impacts on electric power systems.
13

The effects of ITO surface modification on lifetime in organic photovoltaic devices and a test setup for measuring lifetime

Sutcu, Sinan Mahmut 07 July 2010 (has links)
Though relatively young, the field of organic electronics is a rapidly growing market and considerable research is being done in creating a whole range of devices from organic molecules from organic field effect transistors to LEDs to photovoltaic devices. The field of organic photovoltaic in particular has become important in recent years with the push for newer, renewable sources of energy to end the dependence on fossil fuels. While the efficiencies of organic photovoltaic devices continue to rise, one barrier to their commercial adoption has been the limited lifetimes of these devices. While certain degradation methods of organic photovoltaics, such as photo-oxidation, have been extensively studied and solutions to these problems, such as encapsulation, are being researched, certain other degradation mechanisms are less understood and studied. The focus of this thesis is on one such degradation mechanism, UV degradation, specific to the ITO-pentacene interface in pentacene/C60 organic photovoltaic devices. Attempts were made to increase the lifetime of the devices by using phosphonic acids or oxygen plasma to modify the surface of the ITO. While conducting these experiments, the lack of a system to test the lifetime of multiple devices for long periods of time became apparent. As such as system was a requirement for future research into the lifetimes of organic photovoltaic devices a system was designed and built. The system would operate the photovoltaic device in a way comparable to its end-use and would allow over 100 devices to be tested simultaneously for durations exceeding 10,000 hours if necessary. This system would allow for statistically significant lifetime testing to be carried out in the future.
14

Loginių įtaisų testavimo sistemos tyrimas / Investigation the test sytem of logic devices

Nerlikas, Arūnas 23 June 2006 (has links)
The analysis of logic device characterization have been performed. Logic device sorts and its characterization analysis was made. The analysis of other logic device test system was performed. The logic test system requirements was made. The hardware project of logic device test system and system hardware mounting was made. The software for the logic device test system was made. Experimentation of logic device test system was performed. The results of experimentation was given. Graphs about logic test system analysis of trustiness research was given. Performed finding about the logic device test system accordance for technical requirements, trustiness and universality.
15

Testovací systém pro zařízení V-mux / The V-mux test system

Morávek, Patrik January 2008 (has links)
An optical network technology is the network technology that meets given requirements for a fast and reliable long-distance information transmission. Optical fibres can offer undoubted features where other communication technologies are near their limits or stand in front of insurmountable problems. The intensive research of last years is focused on optical transmission features utilization in the optimal way. Especially an optical signal processing in active network devices without a need for electrical conversation is a topic of high interest. V-Mux is an optical network device that accomplishes above mentioned requirements for modern optical network devices. It is a device that multiplexes and drops an optical signal in its native light form into or from optical fibre. Basic micro electro-mechanical components, which the V-Mux is built from, are high end precise devices. The whole complex V-Mux has to meet strict rules and specifications as the components itself. That is why a control system has to be included in the production process to keep quality and right functionality. This diploma thesis is focused on a development of the testing system that will help in the automated control procedure in the V-Mux production. A brief introduction to optical network technologies and a description of the GPIB bus form a first part of the thesis. The next part focuses on the V-Mux itself and the proposal of the test station with its component description. The last part deals with a developing of the software for the V-Mux testboard and a user application that will be used for the test system initialization.
16

An investigation of the use of Broyden's method in load flow analysis

Selim, Asif January 1994 (has links)
No description available.
17

Psychomotor ability and learning potential as predictors of driver and machine operator performance in a road construction company

Olivier, Louis Petrus 06 1900 (has links)
The changing nature of work and its competitive characteristics are global phenomena and are mainly fuelled by ongoing technological advancement. This creates unique challenges for talent attraction and the retention of high performing individuals. In addition, the global workforce is becoming more diverse due to demographic, societal and cultural changes and companies are placing greater demands on employee competency and performance. Managing the human factor as a strategic asset in organisations remains a primary challenge in securing a competitive advantage. The road construction industry in South Africa is no different. There is growing competition between civil engineering contractors to secure tenders and to maximise profitability. This is only possible with a sufficient and sustainable labour force. Valid selection processes are therefore required to ensure that the most productive individuals are selected for the most suitable jobs. Reliable and valid performance predictors will assist employers in making appropriate selection decisions. Selecting high performing individuals will support and enhance overall organisational performance. ix In this study the investigation focused on whether psychomotor ability and learning potential are statistically significant predictors of work performance - with specific reference to drivers and machine operators in a road construction company. A quantitative approach was followed to investigate the relationships between variables, or then the prediction of one dependent variable (driver and machine operator performance) by means of two independent variables (psychomotor ability and learning potential). Results from the study did not indicate any statistically significant relationships between the variables. Only scientifically validated assessment instruments were used in the study - which means the findings led to a renewed focus on the importance of performance measurement and the psychometric quality (reliability and validity) of performance data. / Industrial and Organisational Psychology / M.A. (Industrial and Organisational Psychology)
18

Psychomotor ability and learning potential as predictors of driver and machine operator performance in a road construction company

Olivier, Louis Petrus 06 1900 (has links)
The changing nature of work and its competitive characteristics are global phenomena and are mainly fuelled by ongoing technological advancement. This creates unique challenges for talent attraction and the retention of high performing individuals. In addition, the global workforce is becoming more diverse due to demographic, societal and cultural changes and companies are placing greater demands on employee competency and performance. Managing the human factor as a strategic asset in organisations remains a primary challenge in securing a competitive advantage. The road construction industry in South Africa is no different. There is growing competition between civil engineering contractors to secure tenders and to maximise profitability. This is only possible with a sufficient and sustainable labour force. Valid selection processes are therefore required to ensure that the most productive individuals are selected for the most suitable jobs. Reliable and valid performance predictors will assist employers in making appropriate selection decisions. Selecting high performing individuals will support and enhance overall organisational performance. ix In this study the investigation focused on whether psychomotor ability and learning potential are statistically significant predictors of work performance - with specific reference to drivers and machine operators in a road construction company. A quantitative approach was followed to investigate the relationships between variables, or then the prediction of one dependent variable (driver and machine operator performance) by means of two independent variables (psychomotor ability and learning potential). Results from the study did not indicate any statistically significant relationships between the variables. Only scientifically validated assessment instruments were used in the study - which means the findings led to a renewed focus on the importance of performance measurement and the psychometric quality (reliability and validity) of performance data. / Industrial and Organisational Psychology / M.A. (Industrial and Organisational Psychology)
19

Endocrine Disruption in Amphibians : Developmental Effects of Ethynylestradiol and Clotrimazole on the Reproductive System

Gyllenhammar, Irina January 2008 (has links)
Amphibian populations are declining world-wide and one of the suggested reasons is environmental pollutants. Studies of long-term effects on the reproductive system in frogs following larval exposure to environmental pollutants are scarce. It is therefore important to develop methods to study developmental reproductive toxicity in amphibians. In this thesis the usefulness of Xenopus tropicalis (the West African clawed frog) as a model species for a test system was investigated. Effects on the reproductive system after larval exposure to the pharmaceuticals ethynylestradiol (EE2) and clotrimazole were evaluated. The susceptibility to EE2 exposure was compared between the model species and a wild species, the European common frog (Rana temporaria). Larval exposure to EE2 caused female-biased sex ratios in both examined frog species, indicating male-to-female sex-reversal. In adult Xenopus tropicalis, male frogs that were not sex-reversed had reduced fertility and decreased amount of mature spermatozoa in the seminiferous tubules. The proportion of frogs with ovaries but lacking oviducts increased with increasing EE2-concentrations. A female frog without oviducts is sterile. The development of ovaries in sex-reversed male frogs was implied to be similar to control females. The combination of a reduced number of males, due to sex-reversal, and impaired fertility could have severe effects on frog populations. Larval exposure to clotrimazole modulated aromatase activity in gonads and brain in Xenopus tropicalis. Brain aromatase activity was decreased at the time for gonadal differentiation and gonadal aromatase activity was increased at metamorphosis. The findings in this thesis indicate that reproduction in wild frogs might be impaired by estrogenic compounds in the environment. The results combined with the short generation time supports the use of Xenopus tropicalis as a model species when evaluating long term effects of endocrine disruptors on the reproductive system in amphibians.
20

Smart Grid Technologies for Efficiency Improvement of Integrated Industrial Electric System

Balani, Spandana 20 May 2011 (has links)
The purpose of this research is to identify the need of Smart Grid Technologies in communication between industrial plants with co-generation capability and the electric utilities in providing the most optimum scheme for buying and selling of electricity in such a way that the fuel consumption is minimized, reliability is increased, and time to restore the system is reduced. A typical industrial plant load profile based on statistical mean and variance of industrial plants' load requirement is developed, and used in determining the minimum cost of producing the next megawatt-hours by a typical electric utility. The 24-hour load profile and optimal power flow program are used to simulate the IEEE 39 Bus Test System. The methodology for the use of smart grid technology in fuel saving is documented in the thesis. The results obtained from this research shall be extended to include several industrial plants served by electric utilities in future work by the UNO research team.

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