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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.
171

Transmission of vector quantization over a frequency-selective Rayleigh fading CDMA channel

Nguyen, Son Xuan 19 December 2005
Recently, the transmission of vector quantization (VQ) over a code-division multiple access (CDMA) channel has received a considerable attention in research community. The complexity of the optimal decoding for VQ in CDMA communications is prohibitive for implementation, especially for systems with a medium or large number of users. A suboptimal approach to VQ decoding over a CDMA channel, disturbed by additive white Gaussian noise (AWGN), was recently developed. Such a suboptimal decoder is built from a soft-output multiuser detector (MUD), a soft bit estimator and the optimal soft VQ decoders of individual users. <p>Due to its lower complexity and good performance, such a decoding scheme is an attractive alternative to the complicated optimal decoder. It is necessary to extend this decoding scheme for a frequency-selective Rayleigh fading CDMA channel, a channel model typically seen in mobile wireless communications. This is precisely the objective of this thesis. <p>Furthermore, the suboptimal decoders are obtained not only for binary phase shift keying (BPSK), but also for M-ary pulse amplitude modulation (M-PAM). This extension offers a flexible trade-off between spectrum efficiency and performance of the systems. In addition, two algorithms based on distance measure and reliability processing are introduced as other alternatives to the suboptimal decoder. <p>Simulation results indicate that the suboptimal decoders studied in this thesis also performs very well over a frequency-selective Rayleigh fading CDMA channel.
172

Sjuksköterskors reflektioner kring ämnet sexualitet i omvårdnadsarbetet vid cytostatikabehandling : En kvalitativ intervjustudie

Stålberg, Desireé, Karlsson, Annethe January 2013 (has links)
Att drabbas av cancer och genomgå cytostatikabehandling kan inverka på patienters sexualitet. Sjuksköterskor bör se till patienters alla behov för att kunna ge en god omvårdnad. Syftet var att beskriva sjuksköterskors reflektioner kring ämnet sexualitet i omvårdnadsarbetet med cytostatikabehandlade vuxna patienter med cancer. Studiens metod var empirisk med deskriptiv design och kvalitativ ansats. Datainsamlingen skedde via semi-strukturerade intervjuer med sex sjuksköterskor från en onkologisk klinik i Mellansverige. I huvudresultatet presenteras två kategorier, information om sexualitet vid start av cytostatikabehandling och omständigheter som påverkade samtal om sexualitet. Sjuksköterskorna ansåg att det var deras ansvar att informera om sexualitet och att information om ämnet var betydelsefullt. Patienters intresse och behov styrde informationen, men alla patienter fick inte information om sexualitet. Anledning till detta kunde vara att sjuksköterskorna inte ville genera patienter. Sjuksköterskorna hade inte erhållit någon kunskap om sexualitet genom utbildning. Kunskapen hade sjuksköterskorna erhållit genom arbetslivserfarenhet. Slutsats, för att som sjuksköterska regelbundet kunna informera patienter om hur sexualiteten kan påverkas av cytostatikabehandling vid cancersjukdom behövs vidare kunskaper. Detta för att kunna minska den spänning som finns kring ämnet sexualitet. / To suffer from cancer and going through treatment with chemotherapy can affect patients’ sexuality. Nurses should pay regard to all needs of the patients to be able to provide good nursing care. The aim of the study was to describe the nurses’ reflections around sexuality as a part of their nursing practice, related to adult patients with cancer going through chemotherapy. The study is based on qualitative interviews with a descriptive design. The interviews were conducted through semi-structured questions and the study group consisted of six nurses who worked at an oncology clinic in the central part of Sweden. The main result showed two categories, information about sexuality at the start of chemotherapy and circumstances that could affect conversation about sexuality. The nurses considered it to be their responsibility to inform the patient about sexuality and that information was meaningful. The patient’s interest and need directed the information, but all patients’ did not get information about sexuality. A reason to this could be that the nurses did not want to embarrass the patients. The nurses had not gained any knowledge about sexuality through education. The knowledge the nurses had gained came from work experience. Conclusion, to inform patients about how their sexuality can be affected by going trough treatment with chemotherapy regularly, nurses need further knowledge. This could reduce the tension that exists around the topic sexuality.
173

複合応力下における木材 (ヒノキ) の破壊挙動 (載荷方式および載荷経路の影響)

山崎, 真理子, YAMASAKI, Mariko, 佐々木, 康寿, SASAKI, Yasutoshi 08 1900 (has links)
No description available.
174

Sensing characteristics of an optical three-axis tactile sensor under combined loading

Ohka, Masahiro, Mitsuya, Yasunaga, Matsunaga, Yasuaki, Takeuchi, Shuichi 03 1900 (has links)
No description available.
175

A Plan for Implementation of Hospital Information System in Developing Country: Recommendation from socio-technical perspective.

Bukhari, Sayyed Wasim Hussain, Zia, Qasim January 2011 (has links)
Hospital Information System (HIS) is considered as an important factor in health care sector for managing the administrative, financial and clinical aspects of a hospital. A large number of hospitals from both developing and developed countries are adopting hospital information system to bring efficiency in their current system. Current study is conducted to contribute to the literature regarding HIS implementation in developing country settings as there is scarce literature. This study attempts to improve the understanding of HIS implementation in developing countries.  In this study, socio technical model is used to understand the current working system of cardiology department of Combined Military Hospital (CMH). Qualitative case study is conducted for this research. Data is collected with the help of interviews done online via Skype and some secondary data resources to highlight the problems and solutions before HIS implementation. The data collection, generation of results and analysis is done on the basis of structure, people, technology, and process perspective originating from the socio-technical model. Findings of this study are presented in the form of recommendations which need to be considered for making a HIS implementation plan.
176

Simulation of Heat Recovery Steam Generator in a Combined Cycle Power Plant

Horkeby, Kristofer January 2012 (has links)
This thesis covers the modelling of a Heat Recovery Steam Generator (HRSG) in a Combined Cycle Power Plant(CCPP). This kind of power plant has become more and more utilized because of its high efficiency and low emissions. The HRSG plays a central role in the generation of steam using the exhaust heat from the gas turbine. The purpose of the thesis was to develop efficient dynamic models for the physical components in the HRSG using the modelling and simulation software Dymola. The models are then to be used for simulations of a complete CCPP.The main application is to use the complete model to introduce various disturbances and study their consequences inthe different components in the CCPP by analyzing the simulation results. The thesis is a part of an ongoingdevelopment process for the dynamic simulation capabilities offered by the Solution department at SIT AB. First, there is a theoretical explanation of the CCPP components and control system included in the scope of this thesis. Then the development method is described and the top-down approach that was used is explained. The structure and equations used are reported for each of the developed models and a functional description is given. Inorder to ensure that the HRSG model would function in a complete CCPP model, adaptations were made and tuning was performed on the existing surrounding component models in the CCPP. Static verifications of the models are performed by comparison to Siemens in-house software for static calculations. Dynamic verification was partially done, but work remains to guarantee the validity in a wide operating range. As a result of this thesis efficient models for the drum boiler and its control system have been developed. An operational model of a complete CCPP has been built. This was done integrating the developed models during the work with this thesis together with adaptations of already developed models. Steady state for the CCPP model is achieved during simulation and various disturbances can then be introduced and studied. Simulation time for a typical test case is longer than the time limit that has been set, mainly because of the gas turbine model. When using linear functions to approximate the gas turbine start-up curves instead, the simulation finishes within the set simulation time limit of 5 minutes for a typical test case.
177

Combined Visualization of Intracardiac Blood Flow and Wall Motion Assessed by MRI

Baeza Ortega, José Antonio January 2011 (has links)
MRI is a well known and widely spread technique to characterize cardiac pathologies due to its high spatial resolution, its accessibility and its adjustable contrast among soft tissues. In attempt to close the gap between blood flow, myocardial movement and the cardiac fucntion, researching in the MRI field addresses the quantification of some of the most relevant blood and myocardial parameters. During this proyect a new tool that allows reading, postprocessing, quantifying and visualizing 2D motion sense MR data has been developed. In order to analyze intracardiac blood flow and wall motion, the new tool quantifies velocity, turbulent kinetic energy, pressure and strain. In the results section the final tool is presented, describing the visualization modes, which represent the quantified parameters both individually and combined; and detailing auxiliary tool features as masking, thresholding, zooming, and cursors. Finally, thecnical aspects as the convenience of two dimensional examinations to create compact tools, and the challenges of masking as part of the relative pressure calculation, among others, are discussed; ending up with the proposal of some future developments.
178

Improving the Competitive Position in a Growing High Tech Industry : - Differentiation and Cost Leadership Strategies in Solar Photovoltaics -

Hrab, Dmytro, Yamkina, Oxana January 2011 (has links)
Background: The purpose of this master thesis was to investigate what generic strategies are utilized by big players in the solar photovoltaic industry to improve their competitive positions. The continuous expansion of the solar market indicated the significance of this research, since the correctly chosen strategy has a direct influence on the success and prosperity of the growing and developing high tech companies.Aim: The first aim of the study was to examine the applicability of Michael Porter‟s theory of generic strategies to the high tech industry, to be more precise the solar photovoltaic industry. The second aim of the study was to explore the cases, if any, when the simultaneous pursuit of more than one generic strategy was possible. The last but not the least aim was to deeply investigate the potential of the differentiation strategy and the effect it has on the companies.Definitions: The continuous utilization of the following concepts is present in the research: Generic strategies – the three different strategic approaches – cost leadership, differentiation, and focus – the companies can undertake to build a strong competitive advantage and outperform their competitors Differentiation – a case when a firm‟s offering is preferred, on some buying occasions (or by some customers all of the time) over rival firm‟s offerings Solar energy – alternative solutions of receiving energy directly from the sun – using solar modules which convert sunrays into electricityMethodology: Qualitative research methodology was used in this study. The in depth analyses of three case companies were done mainly by means of collecting the secondary data. In addition to that two out of three companies were contacted in order to conduct personal interviews via phone and email. Their answers were used as a supportive tool for the developed propositions.Results: The collected and analyzed secondary data together with the outcomes of the interviews revealed the flaws and limitations of Porter‟s theory. The simultaneous pursuit of two strategies was proven not only to be taking place, furthermore, to be leading to prosperity in some situations. The new model was developed which showed that the pursuit of two strategies is more of a necessity under certain circumstances. A thorough examination of the differentiation concept resulted in discovering the ways and methods which could be used by companies to strengthen their market positions.
179

Bulk electric system reliability simulation and application

Wangdee, Wijarn 19 December 2005 (has links)
Bulk electric system reliability analysis is an important activity in both vertically integrated and unbundled electric power utilities. Competition and uncertainty in the new deregulated electric utility industry are serious concerns. New planning criteria with broader engineering consideration of transmission access and consistent risk assessment must be explicitly addressed. Modern developments in high speed computation facilities now permit the realistic utilization of sequential Monte Carlo simulation technique in practical bulk electric system reliability assessment resulting in a more complete understanding of bulk electric system risks and associated uncertainties. Two significant advantages when utilizing sequential simulation are the ability to obtain accurate frequency and duration indices, and the opportunity to synthesize reliability index probability distributions which describe the annual index variability. <p>This research work introduces the concept of applying reliability index probability distributions to assess bulk electric system risk. Bulk electric system reliability performance index probability distributions are used as integral elements in a performance based regulation (PBR) mechanism. An appreciation of the annual variability of the reliability performance indices can assist power engineers and risk managers to manage and control future potential risks under a PBR reward/penalty structure. There is growing interest in combining deterministic considerations with probabilistic assessment in order to evaluate the system well-being of bulk electric systems and to evaluate the likelihood, not only of entering a complete failure state, but also the likelihood of being very close to trouble. The system well-being concept presented in this thesis is a probabilistic framework that incorporates the accepted deterministic N-1 security criterion, and provides valuable information on what the degree of the system vulnerability might be under a particular system condition using a quantitative interpretation of the degree of system security and insecurity. An overall reliability analysis framework considering both adequacy and security perspectives is proposed using system well-being analysis and traditional adequacy assessment. The system planning process using combined adequacy and security considerations offers an additional reliability-based dimension. Sequential Monte Carlo simulation is also ideally suited to the analysis of intermittent generating resources such as wind energy conversion systems (WECS) as its framework can incorporate the chronological characteristics of wind. The reliability impacts of wind power in a bulk electric system are examined in this thesis. Transmission reinforcement planning associated with large-scale WECS and the utilization of reliability cost/worth analysis in the examination of reinforcement alternatives are also illustrated.
180

Transmission of vector quantization over a frequency-selective Rayleigh fading CDMA channel

Nguyen, Son Xuan 19 December 2005 (has links)
Recently, the transmission of vector quantization (VQ) over a code-division multiple access (CDMA) channel has received a considerable attention in research community. The complexity of the optimal decoding for VQ in CDMA communications is prohibitive for implementation, especially for systems with a medium or large number of users. A suboptimal approach to VQ decoding over a CDMA channel, disturbed by additive white Gaussian noise (AWGN), was recently developed. Such a suboptimal decoder is built from a soft-output multiuser detector (MUD), a soft bit estimator and the optimal soft VQ decoders of individual users. <p>Due to its lower complexity and good performance, such a decoding scheme is an attractive alternative to the complicated optimal decoder. It is necessary to extend this decoding scheme for a frequency-selective Rayleigh fading CDMA channel, a channel model typically seen in mobile wireless communications. This is precisely the objective of this thesis. <p>Furthermore, the suboptimal decoders are obtained not only for binary phase shift keying (BPSK), but also for M-ary pulse amplitude modulation (M-PAM). This extension offers a flexible trade-off between spectrum efficiency and performance of the systems. In addition, two algorithms based on distance measure and reliability processing are introduced as other alternatives to the suboptimal decoder. <p>Simulation results indicate that the suboptimal decoders studied in this thesis also performs very well over a frequency-selective Rayleigh fading CDMA channel.

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