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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.
311

Development of a decision making model for the assessment of electricity demand side management in the State of Kuwait

Al-Ajmi, Abdullah A. January 2014 (has links)
Kuwait’s per capita electrical energy consumption is among the largest in the world, reaching 13,663 kWh per person in 2011. The electricity demand in Kuwait is increasing, which requires additional investments in power generation. A particular challenge in Kuwait is the peak demand in summer, when extreme heat increases air conditioning loads. Peak demand reached 11,220 MW in 2011, with a fast growth rate averaging 5.6% over the last decade and a maximum production capacity of around 14,720 MW. It is not possible to cope with this demand simply by increasing generation capacity. Therefore, the only alternative available to Kuwait is to control electricity demand via demand-side management. The main objective of this research is to assess and select the optimal demand- side management (DSM) technologies for buildings in the governmental sector (office, religious and school buildings) and to investigate the key factors in the evaluation process. To achieve the research objective, a model was proposed using multi-criteria decision-making techniques to enable the forecasting and comparison of DSM alternatives that are suitable for buildings. The developed model includes environmental, economic, technical and social considerations. The research methodology is based on three main phases. Phase 1: Data collection through a mail questionnaire that was sent to 42 experts for the identification of criteria and demand-side management alternatives. Phase 2: Screening and narrowing of the data collected in Phase 1 using a set of questionnaires, including the identification of potential DSM alternatives and criteria suitable for further analysis. This phase was performed through the Delphi process, taking into consideration the opinions of 28 experts. Phase 3: Use of Multi-criteria Decision Making (MCDM) techniques, namely the Analytic Hierarchy Process (AHP) and Fuzzy Analytic Hierarchy Process (FAHP), to evaluate and rank the identified DSM alternatives and criteria. This was done using pairwise comparisons of 17 experts to evaluate the criteria and alternatives for the buildings (office, religious and school). The research showed that the experts identified six alternative technologies and five criteria for the selection and evaluation of governmental buildings (office, religious and school). After performing the three phases of this research project, a set of criteria and alternatives were ranked based on the information gathered from every group of experts. It was found that reduction in consumption, capital cost and ease of implementation were the three most recommended criteria for the selection of DSM technologies in Kuwait government buildings while high efficiency lighting and programmable thermostats were identified as the most recommended DSM technologies for these buildings. An important aspect of this research is that unlike engineering approaches which sometimes depend on expensive test equipment or, often for building design, expensive computer modelling exercises, the proposed framework can be easily adopted by anyone without any significant financial cost. The FAHP approach was also tested and its results compared with those of AHP. There was a slight difference between using AHP and FAHP in terms of ranking the criteria and alternatives but that the difference barely affects the ranking. It was found that the AHP provides a convenient MCDM approach for solving the complex problem of selecting the optimal DSM options for buildings. The contributions of this thesis are the development of a novel framework for systematic selection and ranking of DSM technologies in different types of buildings using the Delphi method and AHP; the identification of the most important DSM technologies and criteria for their selection for three types of governmental buildings in Kuwait; and establishing that results from using AHP and FAHP for the selection of appropriate DSM measures in these buildings are almost identical, so use of AHP is likely to be sufficient in most building studies of this type.
312

Latest Technology Advancements in Hydraulic Systems for Refuse Vehicle Applications: The Case of an Automated Side Loader

Altare, Gabriele, Franzoni, Germano, Harsia, Jarmo, Hickey, Thomas 03 May 2016 (has links) (PDF)
The present paper describes an innovative electro-hydraulic system developed for automated side loaders. The system is based on Intelligent Flow Control (IFC), a concept where open circuit electric displacement controlled pumps are coupled with EH directional control valves. IFC was selected in order to achieve the level of performance required, in terms of efficiency and productivity (i.e. cycle times), and also to provide the best possible control of the side loader arm. The paper describes the system layout and the basics of the controls: from the alghorithms of the arm actuators to the vehicle on board telemetry and diagnostic. The paper reports the comparison between the IFC system (implemented on the vehicle) and a more traditional approach based on a Load Sense Flow Sharing concept. The benefits of the IFC solution are highlighted focusing on the energy efficiency (very important especially in the case of CNG engines, where the torque available at idle is significantly lower than diesel engines), but also in terms of controlability and response (due to the lack of load sensing signal lines).
313

Management of adverse gastrointestinal events in patients with anti-platelet therapy

Ng, Fook-hong., 吳福康. January 2008 (has links)
published_or_final_version / Medicine / Master / Doctor of Medicine
314

A Socio-technical Investigation of the Smart Grid: Implications for Demand-side Activities of Electricity Service Providers

Corbett, JACQUELINE 21 January 2013 (has links)
Enabled by advanced communication and information technologies, the smart grid represents a major transformation for the electricity sector. Vast quantities of data and two-way communications abilities create the potential for a flexible, data-driven, multi-directional supply and consumption network well equipped to meet the challenges of the next century. For electricity service providers (“utilities”), the smart grid provides opportunities for improved business practices and new business models; however, a transformation of such magnitude is not without risks. Three related studies are conducted to explore the implications of the smart grid on utilities’ demand-side activities. An initial conceptual framework, based on organizational information processing theory, suggests that utilities’ performance depends on the fit between the information processing requirements and capacities associated with a given demand-side activity. Using secondary data and multiple regression analyses, the first study finds, consistent with OIPT, a positive relationship between utilities’ advanced meter deployments and demand-side management performance. However, it also finds that meters with only data collection capacities are associated with lower performance, suggesting the presence of information waste causing operational inefficiencies. In the second study, interviews with industry participants provide partial support for the initial conceptual model, new insights are gained with respect to information processing fit and information waste, and “big data” is identified as a central theme of the smart grid. To derive richer theoretical insights, the third study employs a grounded theory approach examining the experience of one successful utility in detail. Based on interviews and documentary data, the paradox of dynamic stability emerges as an essential enabler of utilities’ performance in the smart grid environment. Within this context, the frames of opportunity, control, and data limitation interact to support dynamic stability and contribute to innovation within tradition. The main contributions of this thesis include theoretical extensions to OIPT and the development of an emergent model of dynamic stability in relation to big data. The thesis also adds to the green IS literature and identifies important practical implications for utilities as they endeavour to bring the smart grid to reality. / Thesis (Ph.D, Management) -- Queen's University, 2013-01-21 12:04:43.652
315

Channel Capacity in the Presence of Feedback and Side Information

SEN, NEVROZ 12 July 2013 (has links)
This thesis deals with the Shannon-theoretic fundamental limits of channel coding for single-user channels with memory and feedback and for multi-user channels with side information. We first consider the feedback capacity of a class of symmetric channels with memory modelled as nite-state Markov channels. The symmetry yields the existence of a hidden Markov noise process that facilitates the channel description as a function of input and noise, where the function satisfies a desirable invertibility property. We show that feedback does not increase capacity for such class of finite-state channels and that both their non-feedback and feedback capacities are achieved by an independent and uniformly distributed input. As a result, the capacity is given as a difference of output and noise entropy rates, where the output is also a hidden Markov process; hence, capacity can be approximated via well known algorithms. We then consider the memoryless state-dependent multiple-access channel (MAC) where the encoders and the decoder are provided with various degrees of asymmetric noisy channel state information (CSI). For the case where the encoders observe causal, asymmetric noisy CSI and the decoder observes complete CSI, inner and outer bounds to the capacity region, which are tight for the sum-rate capacity, are provided. Next, single-letter characterizations for the channel capacity regions under each of the following settings are established: (a) the CSI at the encoders are non-causal and asymmetric deterministic functions of the CSI at the decoder (b) the encoders observe asymmetric noisy CSI with asymmetric delays and the decoder observes complete CSI; (c) a degraded message set scenario with asymmetric noisy CSI at the encoders and complete and/or noisy CSI at the decoder. Finally, we consider the above state-dependent MAC model and identify what is required to be provided to the receiver in order to get a tight converse for the sum-rate capacity. Inspired by the coding schemes of the lossless CEO problem as well as of a recently proposed achievable region, we provide an inner bound which demonstrates the rate required to transmit this information to the receiver. / Thesis (Ph.D, Mathematics & Statistics) -- Queen's University, 2013-07-12 13:48:59.849
316

Modernising underground compressed air DSM projects to reduce operating costs / Christiaan Johannes Roux Kriel

Kriel, Christiaan Johannes Roux January 2014 (has links)
Growing demand for electricity forces suppliers to expand their generation capacity. Financing these expansion programmes results in electricity cost increases above inflation rates. By reducing electricity consumption, additional supply capacity is created at lower costs than the building of conventional power stations. Therefore, there is strong justification to reduce electricity consumption on the supplier and consumer side. The mining and industrial sectors of South Africa consumed approximately 43% of the total electricity supplied by Eskom during 2012. Approximately 10% of this electricity was used to produce compressed air. By reducing the electricity consumption of compressed air systems, operating costs are reduced. In turn this reduces the strain on the South African electricity network. Previous energy saving projects on mine compressed air systems realised savings that were not always sustainable. Savings deteriorated due to, amongst others, rapid employee turnover, improper training, lack of maintenance and system changes. There is therefore a need to improve projects that have already been implemented on mine compressed air systems. The continuous improvement of equipment (such as improved control valves) and the availability of newer technologies can be used to improve existing energy saving strategies. This study provides a solution to reduce the electricity consumption and operating costs of a deep level mine compressed air system. This was achieved by modernising and improving an existing underground compressed air saving strategy. This improvement resulted in a power saving of 1.15 MW; a saving equivalent to an annual cost saving of R4.16 million. It was found that the improved underground compressed air DSM project realised significant additional electrical energy savings. This resulted in ample cost savings to justify the implementation of the project improvements. It is recommended that opportunities to improve existing electrical energy saving projects on surface compressed air systems are investigated. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014
317

Development of a Human Body Model for the Analysis of Side Impact Automotive Thoracic Trauma

Forbes, Patrick January 2005 (has links)
Occupant thoracic injury incurred during side impact automotive crashes constitutes a significant portion of all fatal and non-fatal automotive injuries. The limited space between the impacting vehicle and occupant can result in significant loads and corresponding injury prior to deceleration of the impacting vehicle. Within the struck vehicle, impact occurs between the occupant and various interior components. Injury is sustained to human structural components such as the thoracic cage or shoulder, and to the internal visceral components such as the heart, lungs, or aorta. Understanding the mechanism behind these injuries is an important step in improving the side impact crash safety of vehicles. This study is focused on the development of a human body numerical model for the purpose of predicting thoracic response and trauma in side impact automotive crash. <br /><br /> The human body model has been created using a previously developed thoracic numerical model, originally used for predicting thoracic trauma under simple impact conditions. The original version of the thorax model incorporated three-dimensional finite element representations of the spine, ribs, heart, lungs, major blood vessels, rib cage surface muscles and upper limbs. The present study began with improvements to the original thorax model and furthered with the development of remaining body components such that the model could be assessed in side impact conditions. <br /><br /> The improvements to the thoracic model included improved geometry and constitutive response of the surface muscles, shoulder and costal cartilage. This detailed thoracic model was complimented with a pelvis, lower limbs, an abdomen and a head to produce the full body model. These components were implemented in a simplified fashion to provide representative response without significant computational costs. The model was developed and evaluated in a stepwise fashion using experimental data from the literature including side abdominal and pelvic pendulum impact tests. <br /><br /> The accuracy of the model response was investigated using experimental testing performed on post mortem human subjects (PMHS) during side and front thoracic pendulum impacts. The model produced good agreement for the side thoracic and side shoulder pendulum impact tests and reasonable correlation during the frontal thoracic pendulum impact test. Complex loading via side sled impact tests was then investigated where the body was loaded unbelted in a NHTSA-type and WSU-type side sled test system. The thorax response was excellent when considering force, compression and injury (viscous criterion) versus time. Compression in the thorax was influenced by the arm position, which when aligned with the coronal plane produced the most aggressive form of compressive loading possible. The simplified components provided good response, falling slightly outside experimental response corridors defined as one standard deviation from the average of the experimental PMHS data. Overall, the predicted model response showed reasonable agreement with the experimental data, while at the same time highlighting areas for future developments. The results from this study suggested that the numerical finite element model developed herein could be used as a powerful tool for improving side impact automotive safety.
318

Immunological characterization and localization of cell cycle regulatory proteins in preimplantation mouse embryos

Leroy, Brendan A. January 1999 (has links)
The anticonvulsant drug, Dilantin, in many cases must be taken by epileptic mothers to control seizures during pregnancy, but unfortunately, it has been characterized as a human teratogen. It has also been demonstrated that many of the teratogenic effects of Dilantin occur during postimplantation, but some studies implicate a detrimental role for Dilantin during the preimplantation stages of development. Some of the postimplantation effects include congenital malformations and the potential'loss of the fetus. Our lab has proposed that in preimplantation mouse embryos the drug may be altering the timing of expression of cell cycle regulatory proteins and therefore, we have begun to examine the expression of these proteins. Thus, it was the goal of this study to characterize and localize various cell cycle proteins at specific time points in normal in vivo preimplantation mouse embryos, as this will provide important baseline information for studies on how anticonvulsant drugs may alter cell cycle regulation in embryos.Western blotting has confirmed the presence of cyclin BI in G1 of the first cell cycle. Both cyclin E and CDK2 were not detected in GI or G2/M of the first cell cycle or GI of the second cell cycle.From the immunogold TEM experiments, the density of cyclin B1 staining was observed to be the highest at G1 of the first cell cycle and declined at S and G2/M. Cyclin B 1 was detected in all regions of the embryo including the microvilli, cortical cytoplasm, interior cytoplasm, and was observed to be associated with vesicles and some filaments. The gold particles at GI, S, and G2/N4 of the first cell cycle and G1 of the second cell cycle appear to be associated with filamentous and membraneous structures and not free in the cytoplasmic spaces. Cyclin B 1 expression was more concentrated around vesicles at G1 of the first cell cycle and in general, was more concentrated around vesicles than in microvilli and cortical cytoplasm, interior cytoplasm, or around filaments at each cell cycle stage tested. / Department of Biology
319

Examination of Sexual Differences in the Acute Effects of Haloperidol on Licking

Shoemaker, Danton L. 12 1900 (has links)
Schizophrenia is a debilitating psychiatric condition affecting almost one percent of the US population. Typical antipsychotics (e.g., haloperidol) have been in use for several decades and are generally very effective in treating the emotional and cognitive effects of schizophrenia, but are used as the last line of treatment due to their severe extrapyramidal motor side effects under chronic exposure. The present study was conducted to investigate the role of sex in determining the oromotor side effects of typical antipsychotics via measuring different behavioral dimensions of male and female Sprague-Dawley rats licking sucrose after haloperidol treatment. The results showed a stronger sensitivity in female rats than male rats within total licking responses and inter-lick intervals. The present results suggest closer attention needs to be paid to the role that sexual hormones play in the motor slowing and behavior-reducing effects of antipsychotics.
320

Supply Side Risks Assessment of the Supply Chain : A case study of the Supply Side Risks Assessment in HUAWEI’s Supply Chain

Feng, Zekang, He, Rui, Zhu, Wen, Amin, Fazal January 2017 (has links)
Research questions 1. What kind of risks in the supply side of HUAWEI supply chain can be identified? 2. How can supply side risks of HUAWEI supply chain be assessed? 3. How can supply side risks of HUAWEI supply chain be mitigated? Purpose This paper describes supply side risks in HUAWEI in China, the types of risks identified, provides guidelines for assessment of these risks and suggestions for mitigation. Methodology In order to answer above research questions empirical data have been collected through observations, interviews at with logistics managers of HUAWEI in China, and from the official documents, annual reports and authentic web pages of the HUAWEI. Theoretical framework has been built through scientific articles, peer reviewed journals, authentic web based documents, and textbooks. The information is then assessed and analyzed, which result in conclusion and recommendations for the company. Conclusion There can be four major risks identified on the supply side. Manufacturing risk, logistics risk, information risk and inventory risk. The manufacturing risk include risks related to production, skill, and quality. The logistics risk further include delivery risk, lead time risk, and transportation risk. Production risk and skill risk are critical and they can be avoided by enhancing risk awareness, evaluating production feasibility, strengthen staff training, investing in high skills, strengthening R&amp;D, and analysis of the external environment. The quality and inbound delivery risks can be reduced through supplier inspection and establishing good supplier relations. Lead time risk and inventory risk can be reduced by vendor based managed inventory system and mass customization. Meanwhile, transportation risk can adopt risk transfer strategy. The information risk can be reduced by increasing information sharing levels and adopting modern communication technologies.

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