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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

Determination of traffic responsive plan selection factors and thresholds using artificial neural networks

Sharma, Anuj 15 November 2004 (has links)
Traffic congestion has become a menace to civilized society. It degrades air quality, jeopardizes safety and causes delay. Traffic congestion can be alleviated by providing an effective traffic control signal system. Closed-loop traffic control systems are an example of such a system. Closed-loop traffic control systems can be operated primarily in either of two modes: Time of Day Mode (TOD) or Traffic Responsive Plan Selection Mode (TRPS). TRPS mode, if properly configured, can easily handle time independent variation in traffic volumes. It can also reduce the effect of timing plan aging. Despite these advantages, TRPS mode is not used as frequently as TOD mode. The reason being a lack of methodologies and formal guidelines for predicting the factors and thresholds associated with TRPS mode. In this research, a new methodology is developed for determining the thresholds and factors associated with the TRPS mode. This methodology, when tested on a closed-loop system in Odem, Texas, produced a classification accuracy of 94%. The classification accuracy can be increased to 98% with a proposed TRPS architecture.
2

Modeling and Control Design of a Bidirectional PWM Converter for Single-phase Energy Systems

Dong, Dong 02 September 2009 (has links)
This thesis proposes a complete modeling and control design methodology for a multifunctional single-phase bidirectional PWM converter in renewable energy systems. There is a generic current loop for different modes of operation to ease the transition between different modes, including stand-alone inverter mode, grid-tied inverter mode, grid-tied rectifier mode and grid-tied charger/discharger mode. Under stand-alone mode operation, ac voltage regulation is of importance because of the sensitive loads. In this thesis, different multi-loop-based control schemes are investigated and compared, especially between the load current feedback control, PR control and capacitor current loop control. It shows that PR controller reduces the steady-state error, while load current feedback controller improves the transient response. However, the load current feedback controller and capacitor current loop controller presents unstable outputs under some filter load condition. Single-phase d-q frame control is also studied. In order to ease the implementation effort, an unbalanced d-q frame control is proposed to achieve zero steady-state error voltage regulation without generating β-axis component. Based on the same principle, a d-q frame-based single-phase PLL is also proposed to achieve the fast dynamic response with the zero steady-state error phase tracking. The entire control system is verified on a modified 7 kW single-phase PWM converter prototype with a simple DSP-based digital implementation. The load step response test is presented under different modes of operation. The controllers for stand-alone mode are also done under no load, 1 kW resistive load, 1kVar capacitive load, and non-linear load conditions verifying that the single-phase d-q achieves 70% steady-state error improvement if taking the normal PID controller as the baseline design. In the end, the proposed PLL is compared with the standard PLL by experiments showing that the steady-state error can be reduced by 80%. / Master of Science
3

"Det bästa med intraprenaden är friheten den ger oss" : En kvalitativ och kvantitativ studie av intraprenaden i Halmstads kommun

Kovijanic, Isidora, Jemc, Sasa January 2020 (has links)
Intrapreneur driven units in the municipal administration in Halmstad is a fairly new phenomenon that has not existed for more than seven years. In the study, employees and managers experience  about differences and similarities between the traditional mode of operation and intrapreneur were examined as well as their views on the application of the policy in practice. Quantitative and qualitative methods have been used to investigate managers and employees experience of both modes of operation. Empirical materials have been collected using previous research, interviews with the managers and a survey of the employees. Content of the municipality's policy for intraprenades has been linked to various theories and models, which form the basis for the study's questions. The study highlights the policy's personnel and operational perspectives.  The result shows several similarities between the operating modes. Positive differences are experienced in respondents participation, motivation and influence. What both professions feel is that these opportunities are not used by all employees. Positive effects with intrapreneurs from an economic perspective are reflected in, among other things, increased financial awareness of the staff. What is perceived negatively by both managers and employees is that they feel limited by the municipality's acquisition agreement. Some employees think that there may be too much of a financial hassle at their meetings. Policy is complied with on all of the units, except that it is the Home Care Board that originally wanted the formation of intrapreneur mode of operation and not the staff themselves.  The study shows no connection between employees experiences of motivation and their age, but motivation depends on whether they feel seen and confirmed by their manager. / Intraprenad i Hemvårdsförvaltningen i Halmstad är ett tämligen nytt fenomen som inte funnits längre än sju år. I studien har medarbetares och chefers erfarenheter och upplevelser kring skillnader och likheter mellan den traditionella driftsformen och intraprenad undersökts samt deras syn på policys tillämpning i praktiken. Kvantitativa och kvalitativa metoder har använts för att undersöka chefers och medarbetares erfarenheter av de båda driftsformerna. Empiriska material har samlats in med hjälp av tidigare forskning, intervjuer med cheferna och enkätundersökning av medarbetarna. Innehåll i kommunens policy för intraprenader har kopplats till olika teorier och modeller vilket utgör grunden för studiens frågeställningar. I studien belyses personal- och verksamhetsperspektiv i policy. Resultatet visar på flera likheter mellan driftsformerna. Positiva skillnader upplevs i respondenternas delaktighet, motivation och inflytande. Det som båda yrkesgrupperna upplever negativt är att dessa möjligheter inte utnyttjas av alla anställda. Positiva effekter med intraprenad ur ett ekonomiskt perspektiv visar sig bland annat i ökad ekonomisk medvetenhet hos personalen. Det som uppfattas negativt av både chefer och medarbetare är att de känner sig begränsade av kommunens uppköpsavtal. En del anställda tycker att det kan bli för mycket ”ekonomisnack”. Policy för intraprenader efterföljs på samtliga enheter förutom att det är Hemvårdsnämnden som ursprungligen önskat bildande av intraprenader och inte personalen själva.   Studien visar inget samband mellan medarbetarnas upplevelser av motivation och deras ålder. Motivationen beror snarare på om de känner sig sedda och bekräftade av sin chef.
4

Analysis Of Protein Purification By Affinity Chromatography

Sridhar, P 05 1900 (has links) (PDF)
No description available.
5

Implementace symetrické blokové šifry AES na moderních procesorech / Implementation of symmetric bloc cipher AES in modern processors

Škoda, Martin January 2014 (has links)
The main aim of master's thesis is usage of new instructions from instruction set called Intel® Advanced Encryption Standard New Instructions (AES-NI), which is available on processors with code name Westmere and newer. In theoretical part, there are described symmetric block ciphers and their operational modes. Cipher AES is described in details, especially used block transformations, key expansion and equivalent inverse cipher. Next topic is description of instructions of AES-NI instruction set – their function is explained using pseudo codes of instructions and there are examples of their usage in code. Further in work, dynamic-link library is created, which implements cipher AES with key sizes 128, 192 and 256 bites and implements operational modes described in theoretical part. Library functions are called from Matlab by scripts and their functionality is proved by checking test vectors values, which are provided in publications of National Institute of Standards and Technology.

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