Rozprawy doktorskie na temat „ENHANCE SYSTEM PERFORMANCE”

Computer performance has become increasingly important at modern computer installations. At the same time, performance analysts have shown a strong interest in using expert system technology to meet these new demands. Because of the importance of the system sort product in improving overall system performance, a prototype expert system (KBSORT) was developed. When embedded in the system sort utility, KBSORT optimizes the CPU time performance of the sort applications generated by the system utility. A thorough search of the available literature revealed that no work had yet been done on applying expert system technology to enhancing sort performance. Because the research for this study is a first attempt in this area, a rigorous twelve step procedure was followed in developing the KBSORT prototype. The steps included formulating test cases, researching sort performance enhancement techniques, interviewing experts on sort performance, developing the rules for the expert system, embedding the prototype in the sort utility, and running the sort utility to study the difference in CPU time performance when the expert system was in use. Interviews with sort performance experts revealed that the expert system had to optimize in three areas. It had to choose (1) the best sorting algorithm for the current circumstances, (2) the optimal amount of core for the particular sort, and (3) the proper sort work allocation on the input/output devices available while taking into account the current level of contention for those devices. The results of this study support the original hypothesis that the use of a sort utility with an embedded expert system designed to improve CPU time performance generates applications that run more efficiently than sort applications generated by a sort utility without such an embedded expert system.

This thesis presents the initial exploratory research into an original and novel technique to enhance performance control in animatronics. An animatronic system is defined as a 3-D electro-mechanically driven facial model that can move in certain ways, when controlled by a human performer to create the "illusion of life" for a viewer. The vital elements in this form of performance are the synchronisation of lip movements to an acoustic speech signal and the animation of emotive expressions. A novel optical sensing technique is proposed based on the hypothesis that the input of distinctive articulatory or emotive movements from the performer's face would provide a more 'natural' form of control. The principle that the movement of a minimal set of points at key positions on the face can produce sufficient control information to describe the overall action is proposed to achieve this hypothesis. A comprehensive investigation into human communication, including visual speech perception and non-verbal facial expression, to define the optimum set of key points is described. Conclusions are also drawn on the primary facial actions required for successful lip synchronisation. Both the theoretical and practical aspects of the realisation of a prototype system are described. A methodology is presented for the assessment of the sensing system and the overall objectives based on the design and construction of an animatronic face, of the same dimensions as the researcher's, to produce animation of the desired actions with similar displacements. Objective analysis is achieved through the comparison of measurements by the sensor system from the performer's key point movements and those of the animatronic model. Perceptual data is generated through the visual analysis of the animated facial movement. The results and analysis of the investigations are presented in the thesis. The thesis discusses results obtained which indicate that, given certain valid assumptions, the sensor system is capable of consistent facial motion detection. It can provide sufficient control for the animatronic model to produce a limited set of facial actions in a realistic manner. Results indicate the possibilities for improved lip synchronisation and, hence, "overall character" performance.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2009.
Includes bibliographical references (p. 203-212).
In an attempt to improve their Product Development Processes (PDPs), many companies make considerable investments to have available cutting-edge technology such as virtual tools. While some companies have increased their productivity and time to market with them, some others have not. There seem to be fundamental factors above and beyond the use of these tools that can obstruct the PDP and one of them appears to be the misalignment between the product architecture and the organizational interactions of the actors working on it. While there has been significant work addressing the technical and social concerns of a PDP independently, the nature of the misalignment requires an integrated analysis of the product architecture and the organization. The present work studies them in an integrated approach by making use of network analyses. The research for this thesis was conducted in a Global Product Development (GPD) project of an automotive manufacturer. By first using as a reference the Multidisciplinary System Design Optimization (MSDO) to decompose the architecture of a product and then, using a specific type of Design Structure Matrix (DSM) [43] called N2 Diagram to identify the interfaces of the architecture, a network called theoretical sociogram was created. In addition, the relative sensitivity of some objectives describing the functioning of the product's systems was calculated to classify the strength of the ties in two levels: strong for those above an absolute relative sensitivity of 0.5, and weak for those with an absolute relative sensitivity lower or equal than 0.5.
(cont.) Furthermore, through surveys and interviews, the organizational interactions for two different phases of the project were mapped to construct a new set of networks called actual sociograms. By comparing the sociograms and utilizing metrics that deal with the centrality of the actors in the network, the misalignments were identified. The misalignments provided guidance to identify the enablers and obstacles influencing the PDP. It was observed that, in some cases, when the sensitivity among variables was weak, engineering teams tend to use intermediaries to share information. In some other circumstances the direct interaction doesn't occur, due to reasons including cultural aspects, complexity of the information, the way the information is structured and organizational fuzziness, among others. Based on these findings, some recommendations based on literature review, lessons learned from other industries and conversations with Product Development (PD) actors, are provided.
by J. Adrian Diaz Garcia.
S.M.

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2005.
Includes bibliographical references (leaves 51-52).
This thesis determines how to design the supply chain policies in a hospital for the wide array of products that exist there. This research was done through interviewing staff and analyzing data of two hospitals implementing automated point of use systems. This thesis argues that a hospital needs to implement more than one supply chain policy in order to achieve its objective of maximizing patient care while avoiding prohibitive costs. The research further proposes that a hospital should develop its supply chain for a specific product based on that product's unit cost, demand, variability, physical size, and criticality. The research analyzes demand data from two hospitals and demonstrates that hospital demand can be modeled using a variation of Croston's method for intermittent demand. This fact was used to generate an appropriate s, Q inventory policy that can be adjusted to fit any product and supply chain policy implemented within the hospital. Under simulation, the proposed inventory policy outperformed existing policies by over 50%. This research further argues current aggregate and "one-size-fits-all" strategies are inappropriate in a hospital and discusses the importance for hospitals to add physical size and criticality attributes to their product master files as these will enable further supply chain enhancements.
by Derek T. DeScioli.
M.Eng.in Logistics

Wastewater treatment is an energy intensive process and sustainable processes/technologies for the treatment of wastewaters need to be considered. One such contender might be the microbial fuel cell (MFC), a subset of bioelectrochemical system (BES) which generates electricity in the process of electrogenic (generating electrons) degradation of soluble organic contaminants present in the water (or wastewater) by electrogens (electron producing bacteria) at the anode in absence of oxygen. Several issues related to the power performance (also somewhat linked to the cost) of MFCs exist causing barriers in the deployment of up-scaled MFC system and the continual research from a multitude of discipline is focusing on overcoming these issues. Implementation of an MFC system for wastewater treatment would require a large array of MFCs to meet the treatment capacity of the wastewater treatment plant. Commissioning and continual operation of such MFCs would require rapid and cost-effective start-up and improvement in their performance. Optimisation of the power performance is addressed through a systems approach in this study, where improvement in the performance is sought through the system design and control strategies applied to the MFCs. The start-up rate of MFCs has been reduced by 45% using maximum power point tracking (MPPT), which is believed to be cost-effective as exogenous energy (such as in the case of poised-potential) is not required for the rapid start-up. The control of MFC power would need to be considered when up-scaled MFC system is realised. The controller implementation benefits from linearised system models. The viability of such piecewise linearisation of the nonlinear MFC system was demonstrated and the data were shown to be reasonably represented by the 1st order process models throughout its operating range. The occurrence of voltage reversal during stack operation of MFCs is a concern in large arrays particularly, and has been shown to be avoidable by adopting the hybrid stack connectivity. Further enhancement of the performance was sought through the detailed design and fluid dynamics modeling to obtain highly mixed anolyte at low input power, using improved helical anodes which increased the MFC performance at all the tested flow rates (1, 3 and 8 mL min-1) compared to previously studied helical anodes. The up-scaling of MFCs by modularisation was demonstrated and it was shown that the use of improved helical anodes can increase the modular length of the MFC without compromising the power performance. Aggregated power produced from the multi-module MFC (containing 5 modules) was 28.05 ± 3.5 mW (19.75 ± 2.47 W m-3) with an PhD Thesis – Hitesh Chandubhai Boghani 2014 V individual MFC power of 5.61 ± 0.7 mW, when fed with 10 mM sodium acetate at 3 mL min-1 flow rate and at 22 ± 3 °C. So, this thesis presents the strategies for improvement in the performance of MFCs for their applications in wastewater treatment and such strategies may also be transferable to their other applications.

With the depletion of non-renewable resources and growing public awareness about the advantages of green energy, alternative renewable sources are evolving as a significant source of energy since past few years. Furthermore, the electrical grid is on the verge of a paradigm shift, from centralized power generation, transmission, and huge power grids towards distributed generation (DG). DG fundamentally uses small-scale generators like photovoltaic (PV) panels, wind turbine, fuel cells, small and micro hydropower, diesel generator set, etc., and is limited to small distribution networks to produce power close to the end users. Renewable energy sources (RES) are essential components of DG because they are more environment friendly than conventional power generators and once established maintenance cost is also low. One of the most popular renewable energy source is solar energy because it is abundant, accessible and can be easily converted into electricity. The electricity produced from SPV system can be utilized by the local loads within the microgrid or it can be integrated with conventional grid. Microgrid (MG), which is a cluster of distributed generation, renewable sources, and local loads connected to the utility grid provides solution to manage local generations and loads as a single grid level entity. It has the potential to maximize overall system efficiency, power quality, and energy surety for critical loads. A microgrid can operate either in stand-alone mode or grid connected mode. Due to abundant availability of solar energy, an SPV based microgrid is widely used around the world. Due to intermittent nature of solar energy, stand-alone SPV based microgrid needs an energy storage system also, whereas in grid connected system, the microgrid is connected to conventional grid which takes care of the solar intermittency by having bi-directional flow of power. Depending on the technical specifications, grid-connected solar PV- based microgrid can be single-stage or double-stage. In single stage configuration, PV array is directly connected to a DC/AC converter whereas in double-stage configuration, DC/DC converter is coupled in between the solar PV array and PV inverter and provides the desired fixed DC voltage to the inverter. The present work aims at modelling, design, development and control of a solar PV vii based microgrid for enhanced performance. Also, the characterization studies of the developed system have been carried out. Modeling of the system is required in order to predict its behaviour under both steady and dynamic states. Characterization studies such as sensitivity and reliability analysis are used to evaluate the performance of the system. Sensitivity analysis is the performance evaluation technique for evaluating the change in the system’s performance with respect to the change in its parameters. The sensitivity functions for solar cell and boost converter with respect to influential parameters have been developed using first derivative of Taylor’s series. Reliability analysis for electrical and electronic components of the system have been performed using pareto analysis and reliability model of the PV based microgrid has been developed using reliability block diagram for different PV array configurations. The Fault tree analysis (FTA) model of the system has been developed to find the cause of failure and to step the events leading to failure serially. Further, Markov’s model has been used to develop the reliability functions of individual components and hence, the reliability of complete grid connected PV system has been calculated. Solar PV system gives maximum power under uniform shading. But many a times PV panels are non-uniformly irradiated and this condition is known as called partial shading condition (PSC). PSC occur due to shadow of big trees, nearby buildings and dense clouds etc. PSC in PV system is an inevasible situation and exhibits multiple peaks, consisting of a single global maximum power point and many local maximum power points, in its power-voltage curve. PSC makes tracking of global maximum power point more difficult and also reduces the efficiency of the system. The conventional MPPT control algorithms work well under uniform shading condition but under partial shading scenario, they may not be able to track global peak out of multiple peaks. Therefore, an efficient controller is required to overcome the raised issue. Further, various PV array configurations such as series, series-parallel, total cross tied, bridge linked etc. may be used to improve the system efficiency. In the present work, novel maximum power point control algorithms viz. an asymmetrical fuzzy logic control (AFLC) and asymmetrical interval type-2 FLC (AIT-2 FLC) are developed for stand-alone PV system under partial shading condition. The developed algorithms are tested for different PV array configurations. viii In stand-alone PV system, the power supplied to the load depends upon the available solar energy. The output of SPV is intermittent in nature as it depends on the environmental conditions. This intermittency problem can be addressed by adding an energy storage system along with PV system. Battery is the most commonly used energy storage device and is very pivotal in maintaining continuity of power to the load. But when two or more energy sources are connected, then control of dc link voltage at common coupling point (CCP) is an area of concern. Therefore, in a SPV system with BESS a controller is required which can maintain constant DC link voltage irrespective of system transients. The PI controller is commonly used controller for controlling dc- link voltage, but it cannot regulate DC-link voltage under dynamic operating conditions and have overshoots and long settling time in its response. Suitable intelligent controllers are designed to replace the conventional PI controller, as they provide a better transient response. In order to overcome the drawbacks of the conventional PI control algorithm, nonlinear autoregressive moving average-L2 (NARMA-L2) control algorithm is proposed and developed for the stand-alone PV system with BESS. The proposed control scheme maintains the voltage across DC-link under change in irradiation and load condition. In a grid connected SPV based microgrid, the output of boost converter i.e., DC link is connected to voltage source inverter which is connected to grid at the point of common coupling (PCC). Voltage source inverter converts the generated DC power from PV system to AC of required voltage and frequency, as well as maintains the balance of power between the SPV system, load, and grid. The inverter is regulated by the interfacing controllers for effective operation and grid synchronization. The interfacing controllers are used to control the output of PV inverter for its efficient utilization and for improving power quality at PCC by providing reactive power compensation, harmonics compensation and load balancing. Conventional control algorithm like synchronous reference frame theory (SRFT) uses proportional integral (PI) controller for DC-link voltage regulation. These controllers are not best suited for SPV based microgrid as the overshoots and long settling time in their response are inevitable. In order to overcome this, novel smooth Least Mean Square (SLMS), improved zero attracting LMS (IZALMS) and reweighted L0 norm variable step size continuous mixed p-norm (RL0-VSSCMPN) based adaptive interfacing control algorithms are proposed ix and developed for the PV based microgrid. The efficacy of the proposed control algorithms has been tested on hardware prototype developed in the laboratory using MicroLab box (dSPACE 1202). The developed prototype system acts as distribution static compensator (DSTATCOM) and consists of inverter that is tied in parallel to the grid at the point of common coupling. FLUKE power analyzer has been used to measure the response of the system. The research work presented in the thesis is expected to provide good exposure to design, development and control of the solar PV based microgrid.

Service companies today face new challenges arising from the widespread of technologies, which affects their relationships with customers. This is particularly true in the hospitality industry, where the emergence of Online Travel Agencies, such as Booking.com, today erodes the share of reservations directly done by guests through traditional channels. In the literature, in last decades several studies deepened effects of information technology on customer service systems, linking such benefits to concepts of service quality and value generated for and by customers. On this base, recent studies introduced the concept of customer experience management, a strategic process aimed to manage the entire experience perceived by guests while getting in touch with the company. Therefore, IT-enabled CEM strategies today represent a trend topic in both academia and industry, and personalization represents the core functionality offered by service companies to reach this goal. This dissertation contains three works. At first, a theoretical study offers a complete review of the studies which in several disciplines described elements and relationships among component of a customer service system. In this first article, 1030 articles have been reviewed, to finally coding and classifying 192 articles. The literature describes functionalities and the effect of technical and social attributes of customer service systems, and how each element translates into service quality provided and customer value perceived. The work therefore offers an interdisciplinary review, describing a paradigm of how all elements of an information system for customer management can generate value for both internal and external actors of the service chain. Based on this theoretical framework, and contextualizing it within the hospitality industry, two articles are then reported. The first one, entitled ―Information Systems for Customer Experience Management: effects of usage and users’ perceptions on satisfaction‖, shows how different patterns of usage, and different beliefs and attitudes of system users, translates into different benefits perceived by both customers and employees, and how top/medium management plays a critical role in advocating its usage. By conducting two surveys and collecting external data from Google Analytics and TripAdvisor online review platform, the work shows how an IT-enabled CEM strategy can sustain firms‘ competitiveness, levering on new technological innovations to generate value and loyalty among guests. The second article, entitled ―The Impact of IT-enabled Customer Experience Management on Service Perceptions and Performance‖ places the focus on individuals and firm level outcomes, making three contributions to the literature. First, it demonstrates a positive role played by signifiers in service system design. Second, it show how service personalization through CEM systems translates into enhanced service quality and comfort perceived by guests. Finally, it reports a firm-level service improvement in terms of revenue share-shift through disintermediation. iii Findings from the three chapters therefore describe what elements characterize a customer service system and how they can, from a theoretical and empirical standpoint, generate customer value and information system success through service personalization and system usage. This work can therefore contribute to both literature and industry offering a multi-disciplinary study of elements affecting the overall customer experience, and how firms can deal with today challenges by levering on IT.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2002.
Thesis advisor(s): John C. McEachen, R. Clark Robertson, Daniel M. Rosser. Includes bibliographical references (p. 73-75). Also available online.

Kyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第14935号
工博第3162号
新制||工||1474(附属図書館)
27373
UT51-2009-M849
京都大学大学院工学研究科建築学専攻
(主査)教授 中島 正愛, 教授 金子 佳生, 准教授 吹田 啓一郎
学位規則第4条第1項該当

This thesis aims to increase energy storage performance of supercapacitor devices by improving the energy density of supercapacitors without significantly compromising power density. Different strategies were used in this research, including using battery materials in place of electrodes, increasing the potential window of the supercapacitor, and employing soluble dual-redox additives. These strategies led to the discovery of several high power and high energy density energy-storage technology applications that have the promising potential to be commercialized.

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada
The integrated Network-Enhanced Telemetry (iNET) project conducted an assessment to determine how the Test and Training Enabling Architecture (TENA) would integrate into an iNET Telemetry Network System (TmNS), particularly across constrained environments on a resource constrained platform. Some of the key elements investigated were quality of service measures (throughput, latency, and reliability) in the face of projected characteristics of iNET Data Acquisition Unit (DAU) devices including size, weight, and power (SWAP), and processing capacity such as memory size and processor speed. This paper includes recommendations for both the iNET and TENA projects.

International Telemetering Conference Proceedings / October 13-16, 1986 / Riviera Hotel, Las Vegas, Nevada
In this paper we investigate the performance degradation of the NASA Deep Space Network (DSN) telemetry receiving system for two data channels in the presence of cross-modulation interference. It is shown that the sub-carrier waveforms and/or frequencies can be selected to suppress the cross-modulation interference for enhanced deep-space telemetry performance. The application of this study is suggested for a simultaneous telemetry and ranging as well as telecommand and ranging operations. Recommendations as to use of specific subcarrier waveforms and frequencies to suppress cross-modulation interference are made to the international Consultative Committee for Space Data Systems (CCSDS) for consideration in the future standards systems.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada
This paper baselines the performance of common, single band telemetry blade antennas in two telemetry bands and compares that performance to two very differing multi-band antenna designs. A description of each antenna is presented followed by flight testing results and conclusions. Results are in the form of received signal strength versus geographic location, derived in-flight antenna patterns, link availability, and bit error analysis.

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1999.
Includes bibliographical references (leaves 181-183).
by Domagoj J. Gotovac.
M.Eng.

Enhanced Biological Phosphorous Removal (EBPR) performance was found to be adequate with reduced Return Activated Sludge (RAS) flows (50% of available RAS) to the anaerobic tank and smaller than typical anaerobic zone volume (1.08 hours hydraulic retention time or HRT). Three identical parallel biological nutrient removal (BNR) pilot plants were fed with strong, highly fermented (160 mg/L VFAs), domestic/industrial wastewater from a full scale wastewater treatment facility (WWTF). The pilot plants were operated at 100%, 50%, 40% and 25% RAS (percent of available RAS) flows to the anaerobic tank with the remaining RAS to the anoxic tank. In addition, varying anaerobic HRT (1.08 and 1.5 hours), and increased hydraulic loading (35% increase) was examined. The study was divided in four Phases, and the effect of these process variations on EBPR were studied by having one different variable between two identical systems. The most significant conclusions were that only bringing part of the RAS to the anaerobic zone did not decrease EBPR performance, instead changing the location of P release and uptake. Bringing less RAS to the anaerobic and more to the anoxic tank decreased anaerobic P release and increased anoxic P release (or decreased anoxic P uptake). Equally important is that with VFA rich influent wastewater, excessive anaerobic volume was shown to hurt overall P removal even when it resulted in increased anaerobic P release. Computer modeling with BioWin and UCTPHO was found to predict similar results to the pilot test results. Modeling was done with reduced RAS flows to the anaerobic zone (100%, 50%, and 25% RAS), increased anaerobic volume, and increased hydraulic loading. The most significant conclusions were that both models predicted EBPR did not deteriorate with less RAS to the anaerobic zone, in fact, improvements in EBPR were observed. Additional scenarios were also consistent with pilot test data in that increased anaerobic volume did not improve EBPR and increased hydraulic loading did not adversely affect EBPR.
M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Environmental Engineering

[Truncated abstract] The application of reductionism, breaking down problems to simpler components that can be solved and then aggregating the results, is one of the bases of classical science. However, living organisms, ecosystems, social and economic structures are complex systems, characterised by non-linear interactions between their elements and exhibit emergent properties that are not directly traceable to their components. Sustainability assessment frameworks oversimplify system interactions, achieving limited predictive capacity and causing managerial behavior that may reduce system's ability to adapt to external disturbance. Intrigued by the importance of complexity, we explore the central theme of how complex thinking can influence the understanding and progress towards sustainability. The purpose is to conceptualize the relationship of key terms (such as sustainability, functionality and resilience), and consecutively develop new or adjust existing sustainability frameworks to take into account complex systems interactions. We aim at developing theory and frameworks that can be used to raise awareness of the pitfalls of the growth paradigm and direct towards modest positions when managing complex systems. We seek to define the structural elements that influence system adaptive capacity, allowing identification of early signs of system rigidity or vulnerability and the development of knowledge and techniques that can improve our predictive and managerial ability. The focus has been on a variety of system scales and dynamics. At the collective community level, a number of stakeholder engagement practices and frameworks are currently available. However, there is limited awareness of the complexity challenges among stakeholders, who are commonly directed to a triple bottom line analysis aiming at maximizing a combination of outputs. An attempt is conducted to measure the functionality of the processes underlying a standing stock, in contrast to sustainability measures that only assess the variations of the standing stock itself. We develop the Index of Sustainable Functionality (ISF), a framework for the assessment of complex systems interactions within a large-scale geographic domain and apply it to the State of Western Australia. '...' Finally, we focus on smaller systems scales and develop a methodology for the calculation of Product Ecological Footprint (PEF) including elements from the accounting method of activity based costing. We calculate PEF for three apple production systems and identify significant differences from first stage calculations within the same industry. Cross-industry application will provide a practical way to link individuals' consumption with their ecological impact, reduce misperceptions of products' ecological impacts and develop a market-driven approach to internalizing environmental externalities. At the firm level PEF can be compared with investment costs, resulting in the opportunity to optimize both functions of financial cost and ecological impact in decision making. We have developed methods for incorporating complexity in sustainability assessment frameworks. Further work is required in testing and validating these methodologies at multiple system scales and conditions. Integrating such tools in decision making mechanisms will enhance long-term management of socioecological systems performance.

The purpose of this thesis is to investigate the use of a course management system in a University learning environment and the factors that affect students' attitude and performance in such environments and to study the relationship between these factors. The course management system that was used in the research studies in this thesis was WebCT. Three in-field studies were carried out to achieve the aim of this research thesis. A mixture of qualitative and quantitative approaches was used in the studies. Data from participants were collected via questionnaires, interviews, and numerical data from the WebCT tracking system. First the relationship between the students' attitude towards using WebCT and their module leaders' attitude towards using it was studied. Then, the relationship between students' cognitive styles and their satisfaction, their achievement, and their way of using WebCT was investigated. Finally, a model of the critical factors affecting students‟ attitudes to WebCT, use of WebCT and achievement was developed and tested. The model is divided into three main dimensions. The three dimensions are 1) The learner dimension: students' interaction with their classmates, students' capability of using the internet, students' capability of using WebCT. 2) The instructor dimension: Instructor's technical competence, instructor's way of presenting materials on WebCT, interaction between students and their instructor. 3) The technology dimension: usefulness, ease of use, flexibility, quality. The results suggested that students have a positive attitude towards using a course management system (WebCT) on their courses. Also, the results indicated that students' use of WebCT is a positive indicator of their academic achievement (in terms of performance on specific modules). It was also found that instructor attitude and way of using WebCT affects students' attitude and performance when using WebCT. The Technology dimension was found to be a positive indicator of students' attitude and use of WebCT. The Instructor dimension was also found to be a positive indicator of students' attitude and achievement in WebCT. Moreover, the Learner dimension was found to be a positive indicator of students' attitude, use of WebCT and achievement.

The penetration of renewable energy sources has increased significantly in recent years due to the ongoing depletion of conventional resources and the transition to a low carbon energy system. Renewable energy sources such as wind energy are highly intermittent and unpredictable in nature, which makes the operation of the power grid more dynamic and therefore more complex. In order to operate the power system reliably under such conditions, Phasor Measurement Units (PMUs) through the use of satellite technology can offer a state-of-the-art Wide Area Monitoring System (WAMS) for improving power system monitoring, control and protection. They can improve the operation by providing highly precise and synchronised measurements near to real-time with higher frequency and accuracy. In order to achieve such objectives, a high-speed and reliable communications infrastructure is required to transfer time-critical PMU data from remote locations to the control centre. The signals measured by PMUs are transmitted across Local and Wide Area Networks, where they may encounter excessive delays. Signal delays can have a disruptive effect and make applications at best inefficient and at worse ineffective. The main research contribution of this thesis is the performance evaluation of communication infrastructures for WAMS. The evaluation begins from inside substations and continues over wide areas from substations to control centre. Through laboratory-based investigations and simulations, the performance of communications infrastructure in a typical power system substation has been analysed. In addition, the performance evaluation of WAMS communications infrastructure has been presented. In the modelling and analysis, an existing WAMS as installed on the GB transmission system has been considered. The actual PMU packets as received at the Phasor Data Concentrator (PDC) were captured for latency analysis. A novel algorithmic procedure has been developed and implemented to automate the large-scale latency calculations. Furthermore, the internal delays of PMUs have been investigated, determined and analysed. Subsequently, the WAMS has been simulated and detailed comparisons have been performed between the simulated model results and WAMS performance data captured from the actual WAMS. The validated WAMS model has been used for analysing possible future developments as well as to test newly proposed mechanisms, protocols, etc. in order to improve the communications infrastructure performance.

In recent years, global mobile data traffic has been increasing exponentially as mobile devices pervade our daily lives. To cope with the ever growing demands for higher data rates and seamless connectivity, one solution is to drastically increase the number of macro base stations in the conventional cellular architecture. However, this results in high deployment costs. Deploying low-power nodes such as relays that do not require a wired backhaul connection within a macrocell is one of cost-effective ways to extend high data rate coverage range. Relays are typically deployed to increase signal strength in poor coverage areas or to eliminate dead spots. But more importantly, relays provide a natural diversity, called cooperative diversity. In addition to a direct signal from a base station, extra copies of the same signal are forwarded from relays. Utilizing this diversity at the destination can yield significant performance enhancements. Thus, cooperative relay strategies need to be considered to enable high data rate coverage in a cost-effective manner. In this dissertation, we consider a simple single-relay network and present low-complexity and power-efficient cooperative relay designs that can achieve low error rate. We first study decode-and-forward (DF) relay networks with a single antenna at each node, where the relay decodes the received signal and forwards the re-encoded information to the destination. In DF relay scheme, decoding at the relay is not perfect and the error-propagation phenomenon is a detrimental problem, preventing the destination from collecting the cooperative diversity. To enable cooperative diversity in DF relay networks, we adopt link-adaptive power-scaling relay strategies where the relay scales the transmission power of the re-encoded signal based on the reliability of the source-relay link. We generalize power-profile designs and analyze the diversity order enabled by the general power-profile designs. We provide necessary and sufficient conditions for the designs to enable full cooperative diversity at the destination. In the second part of this dissertation, we extend the power-scaling relay strategy to DF multi-input multi-output (MIMO) relay networks, where multiple antennas are adopted at each node, and show that full cooperative diversity can also be achieved here. To collect spatial diversity provided by multiple antennas without using maximum-likelihood equalizers (MLEs) or near-ML detectors which exhibit high complexity, channel-controlled automatic repeat request (CC-ARQ) scheme is developed for DF MIMO relay networks to enable spatial diversity with linear equalizers (LEs) maintaining low-complexity. We also show that joint cooperative and spatial diversity can be achieved at the destination when the power-scaling strategy and the CC-ARQ with LEs are combined. Finally, amplify-and-forward (AF) MIMO relay designs, where the relay simply amplifies the received signal and forwards it to the destination, are studied with consideration of peak-power constraints at the relay. One practical concern for AF relaying is that the output signal at the relay may suffer from large peak-to-average power ratio (PAR), which may cause nonlinear distortion and/or saturation in the transmitted signal due to the limited linear range of power amplifiers. Thus, we first investigate peak-power constrained power-scaling strategies and find a sufficient condition to enable joint cooperative and spatial diversity at the destination. Based on this study, we propose simple and practical AF MIMO relay designs with peak-power constraint at the relay. CC-ARQ is also applied to AF MIMO relay networks to reduce the decoding complexity.

The energy trading system is an essential part of critical infrastructure systems. If adversaries were to exploit the vulnerabilities of energy trading systems that can disrupt electricity generation and supply nationally, resulting in a devastating chain reaction. This study designs an architecture to safeguard the trading system for Australia’s wholesale energy market. The outcome of this study is a roadmap of a viable and sustainable system architecture for the future development of energy trading systems. It includes a design of three achievable security control subsystems to record and protect energy trading and trading communications in a wholesale energy market context.

This thesis aims to explore learning management systems use and usefulness in Higher Education (HE) environments in a Middle Eastern developing country (Saudi Arabia) and gauge what factors influence the attitudes of the learners and by the same token investigate which of these, if any, do affect their performances in such environments. This study intends to delve into these factors and single out any relationships that might exist among these factors. The LMS (learning management system) chosen for the purpose of this research is the „Blackboard‟ LMS. To enable the researcher to look thoroughly at the issue, three separate studies were conducted to achieve comprehensive results. Qualitative and quantitative methodologies were combined for maximum Data collection from participants using questionnaires, interviews and numerical data from the Blackboard tracking system. A framework encompassing all the perceived critical variables that could play a part in affecting students' attitudes in the use of the Blackboard LMS and their overall achievements was designed, developed and then tested. The framework consists of four main parts, 1) Learners interaction with their peers; their ability to use the Internet and associated technologies, named 'learner dimension'. 2) Instructors‟ technical knowledge and competence, the manner in which they deliver lessons to learners using 'Blackboard' and the interactions taking place between the two parties named ' instructor variable or dimension'. 3) The technology itself variable or dimension: usability, flexibility and quality. 4) The HE institution's support dimension: training and technical support. The results have indicated that students were keen to adopt the LMS Blackboard for their courses. Instructor attitudes and behaviours when using Blackboard were found to play a major role in students' attitudes and performances. A major relationship was found in relation to student gender, academic specialization and attitude towards using the LMS, but not in the way the system is used. Students varied and various academic specializations were found to impact positively on their attitude towards the use of the system and in their learning (in terms of performance on a specific course). The learner variable was found to be a good indicator of how students behaved towards VLE and Blackboard and their achievements. The Instructor dimension was also found to be a positive indicator of students' attitudes, their use of Blackboard and achievements in its use. Similarly the technology and the HE institution variables were also found to be sound indicators of their attitudes.

Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.
Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Biomedical Engineering." Discipline: Biomedical Engineering; Department/School: Medicine.

Currently, there are various training machines that can support training of the muscles while the muscles are lengthened, also known as eccentric training. Training machines that are widely used to train the muscles eccentrically utilize a flywheel to generate load to the user. When training the muscles eccentrically with such a machine, there is a desire to accomplish eccentric overload, which is achieved when the muscles under training are exposed to a very high load during eccentric training of these muscles. To achieve this, the user needs to activate other muscles that are not in the focus of the training or be assisted by another person. In this study, a novel, smart flywheel training machine was developed by implementing electric motor and sensors, which could identify the exercise pattern of the user and help achieve desired eccentric overload. This study focused on how the system performance of such training machine interacting with human beings was affected by various grade of sensor feedback. With an increased resolution of the sensors and a lower sample time, the cost of the system is increased, and it was therefore of interest to study what grade of sensor feedback was required. More exactly, this study evaluated how the system performance was improved when sensor resolution was improved, what resolution and sample time were required for the system to perform correct and safely and last, how noise and disturbances affected the system. The study was conducted in a simulated environment in Matlab and Simulink, and some real tests and experiments were also performed on the existing flywheel training machine. An incremental encoder was implemented in the system and resolution of the encoder, as well as sample time, were tweaked in the simulation to test different combinations of these. The results showed that both resolution and sample time had an impact on the system performance. A higher resolution resulted in a smaller tracking error to some extent, but after a certain value the system became unstable if the sample time was not small enough. Noise and disturbances had a minor impact on the system performance. It was concluded that the best choice of encoder resolution was 0.0314 radians with a sample time of 0.01 ms. Even lower resolution such as 0.628 rad, 0.126 rad or 0.0571 rad with a sample time of 0.1 ms could be allowed and should be considered safe. However, the system might not perform as desired if these alternatives are chosen, although the alternatives might decrease the cost of the system.
I nuläget finns det olika träningsmaskiner som kan stödja träning av muskler där musklerna förlängs, även känt som excentrisk träning. Träningsmaskiner som idag används i stor utsträckning för att träna musklerna excentriskt använder ett svänghjul för att generera träningsmotstånd till användaren. När musklerna tränas excentriskt med en sådan maskin finns det en önskan att åstadkomma excentrisk överbelastning; detta uppnås när musklerna som tränas utsätts för en mycket hög belastning under den excentriska träningsfasen. För att uppnå detta måste användaren aktivera andra muskler som inte står i träningens fokus eller få hjälp av en annan person. I den här studien har en ny, smart, svänghjulsträningsmaskin utvecklats genom att implementera elmotor och sensorer som kan identifiera användarens träningsmönster och hjälpa till att uppnå önskvärd excentrisk överbelastning. Denna studie fokuserade på hur systemprestanda för en sådan träningsmaskin som interagerar med människor påverkades av olika grader av sensoråterkoppling. Med en ökad upplösning av sensorerna och en lägre samplingstid ökar kostnaden för systemet och det var därför av intresse att studera vilken grad av sensoråterkoppling som krävdes. Mer exakt utvärderar denna studie hur systemets prestanda förbättrades när sensorupplösningen var högre och vilken upplösning och samplingstid som krävdes för att systemet skulle fungera korrekt och säkert. Påverkan av brus och störningar på systemet utvärderades också. Studien genomfördes i simuleringsmiljö i Matlab och Simulink och verkliga tester och experiment utfördes på den befintliga svänghjulsträningsmaskinen. En inkrementell pulsgivare (incremental encoder) implementerades i systemet och dess upplösning, såväl som samplingstid, justerades i simuleringen för att testa olika kombinationer av dessa. Resultat visade att både upplösningen och samplingstiden påverkade systemets prestanda. En högre upplösning resulterade i ett mindre reglerfel till en viss del, men efter en viss ökad upplösning blev systemet instabilt om samplingstiden inte var tillräckligt liten. Brus och störningar hade en mindre inverkan på systemprestandan. Slutsatsen var att det bästa valet av pulsgivarupplösning var 0,0314 radianer med en samplingstid på 0,01 ms. Även lägre upplösning såsom 0,628 rad, 0,126 rad eller 0,0571 rad med en samplingstid på 0,1 ms kan tillåtas och bör betraktas som säkert. Systemet kan dock komma att inte fungera som önskat om dessa alternativ väljs, dock kan alternativen sänka kostnaden för systemet.

The widespread use of low friction PVD coatings on machine elements is limited by the high costs associated with fulfilling the demands on the surface quality of both the supporting substrate and the counter surface. In this work, an attempt is made at lowering these demands, by adding a sacrificial carbon overcoat to a TaC/aC low friction coating. Both coatings were deposited by planar magnetron DC sputtering, as separate steps in a single PVD-process. Coatings were deposited on substrates of two different surface roughnesses, in order to test the ability of this coating system to function on rougher substrates. Reciprocating ball on disc tests was performed, using balls with two different surface roughnesses. The worn surfaces were investigated using 3-D profilometry and SEM. The ability of the different overcoats to initially reduce the roughness of both the coated surface and the counter surface and to produce stable, low-friction conditions was examined for the different initial roughnesses. The implications for design of efficient run-in coatings for various systems are discussed.

Surfing the web has moved from the stationary computers to mobile devices such as smartphones and tablets. As the technology moves further and more devices comes out on the market this is a trend that will continue. This makes it more important for web developers to adapt and make their websites fit not only for one device. The website needs to fit all devices. Since many of these devices are using wireless connections, the website performance has also become even more important in order to give the users a good experience.   Responsive web design is an approach for designing and developing web pages. By using the three techniques of flexible grid layout, flexible images and media, and media queries, websites can get a design that fits all devices. Responsive web techniques will also make the web page perform better on each device since it makes the web page adapt to its environment. There are several performance techniques that can be applied to a website in order to increase performance and loading time. Responsive web design including performance techniques can together make a great impact on a website's loading speed and user experience.   This thesis embraces this approach for web development. By developing a design theory, a website emerges where these approaches of web development have been implemented. During the development of the website the experiences implementing this approach and techniques is discussed. The website developed for this thesis was able to finish loading below 4 seconds on a mobile device using a 3G connection. We argue that responsive web design and performance techniques can help a website immensely to increase its user experience and performance.

Dans cette thèse de doctorat, nous abordons trois défis auxquels sont confrontés les solveurs d'algèbres linéaires dans la perspective des futurs systèmes exascale: accélérer la convergence en utilisant des techniques innovantes au niveau algorithmique, en profitant des accélérateurs GPU (Graphics Processing Units) pour améliorer le calcul sur plusieurs systèmes, en évaluant l'impact des erreurs due à l'augmentation du parallélisme dans les superordinateurs. Nous nous intéressons à l'étude des méthodes permettant d'accélérer la convergence et le temps d'exécution des solveurs itératifs pour les grands systèmes linéaires creux. Le solveur plus spécifiquement considéré dans ce travail est le “parallel Algebraic Recursive Multilevel Solver (pARMS)” qui est un soldeur parallèle sur mémoire distribuée basé sur les méthodes de sous-espace de Krylov.Tout d'abord, nous proposons d'intégrer une technique de randomisation appelée “Random Butterfly Transformations (RBT)” qui a été proposée avec succès pour éliminer le coût du pivotage dans la résolution des systèmes linéaires denses. Notre objectif est d'appliquer cette technique dans le préconditionneur ARMS de pARMS pour résoudre plus efficacement le dernier système Complément de Schur dans l'application du processus à multi-niveaux récursif. En raison de l'importance considérable du dernier Complément de Schur pour certains problèmes de test, nous proposons également d'utiliser une variante creux de RBT suivie d'un solveur direct creux (SuperLU). Les résultats expérimentaux sur certaines matrices de la collection de Davis montrent une amélioration de la convergence et de la précision par rapport aux implémentations existantes.Ensuite, nous illustrons comment une approche non intrusive peut être appliquée pour implémenter des calculs GPU dans le solveur pARMS, plus particulièrement pour la phase de préconditionnement locale qui représente une partie importante du temps pour la résolution. Nous comparons les solveurs purement CPU avec les solveurs hybrides CPU / GPU sur plusieurs problèmes de test issus d'applications physiques. Les résultats de performance du solveur hybride CPU / GPU utilisant le préconditionnement ARMS combiné avec RBT, ou le préconditionnement ILU(0), montrent un gain de performance jusqu'à 30% sur les problèmes de test considérés dans nos expériences.Enfin, nous étudions l'effet des défaillances logicielles variable sur la convergence de la méthode itérative flexible GMRES (FGMRES) qui est couramment utilisée pour résoudre le système préconditionné dans pARMS. Le problème ciblé dans nos expériences est un problème elliptique PDE sur une grille régulière. Nous considérons deux types de préconditionneurs: une factorisation LU incomplète à double seuil (ILUT) et le préconditionneur ARMS combiné avec randomisation RBT. Nous considérons deux modèle de fautes logicielles différentes où nous perturbons la multiplication du vecteur matriciel et la phase de préconditionnement, et nous comparons leur impact potentiel sur la convergence
In this PhD thesis, we address three challenges faced by linear algebra solvers in the perspective of future exascale systems: accelerating convergence using innovative techniques at the algorithm level, taking advantage of GPU (Graphics Processing Units) accelerators to enhance the performance of computations on hybrid CPU/GPU systems, evaluating the impact of errors in the context of an increasing level of parallelism in supercomputers. We are interested in studying methods that enable us to accelerate convergence and execution time of iterative solvers for large sparse linear systems. The solver specifically considered in this work is the parallel Algebraic Recursive Multilevel Solver (pARMS), which is a distributed-memory parallel solver based on Krylov subspace methods.First we integrate a randomization technique referred to as Random Butterfly Transformations (RBT) that has been successfully applied to remove the cost of pivoting in the solution of dense linear systems. Our objective is to apply this method in the ARMS preconditioner to solve more efficiently the last Schur complement system in the application of the recursive multilevel process in pARMS. The experimental results show an improvement of the convergence and the accuracy. Due to memory concerns for some test problems, we also propose to use a sparse variant of RBT followed by a sparse direct solver (SuperLU), resulting in an improvement of the execution time.Then we explain how a non intrusive approach can be applied to implement GPU computing into the pARMS solver, more especially for the local preconditioning phase that represents a significant part of the time to compute the solution. We compare the CPU-only and hybrid CPU/GPU variant of the solver on several test problems coming from physical applications. The performance results of the hybrid CPU/GPU solver using the ARMS preconditioning combined with RBT, or the ILU(0) preconditioning, show a performance gain of up to 30% on the test problems considered in our experiments.Finally we study the effect of soft fault errors on the convergence of the commonly used flexible GMRES (FGMRES) algorithm which is also used to solve the preconditioned system in pARMS. The test problem in our experiments is an elliptical PDE problem on a regular grid. We consider two types of preconditioners: an incomplete LU factorization with dual threshold (ILUT), and the ARMS preconditioner combined with RBT randomization. We consider two soft fault error modeling approaches where we perturb the matrix-vector multiplication and the application of the preconditioner, and we compare their potential impact on the convergence of the solver

MBA Professional Report
With the release of next generation operating systems, network managers face the prospect of upgrading their systems based on the assumption that "newer is better". The Graduate School of Business and Public Policy is in the process of upgrading their network application server and one of the most important decisions to be made is which Server Operating System to use. Based on hands-on benchmark tests and analysis we aim to assist the GSBPP by providing benchmark metrics and a recommendation of which Operating Systems will provide the best solution.

An increased competitive climate has enhanced the importance for companies to differentiate from other companies. Today, the customer support within service organizations are often disregarded as a source of value due to the focus on costs. Further, it has become more important to leverage the contact with the customer at all encounters. New technological advancements within Business Intelligence have also enabled companies to increase their competitiveness through improved decision support. The objective of this thesis is through a case study investigate how an insurance company could leverage its customer support as a source of creating shareholder value as well as how to apply trends within Business Intelligence for increased decision support. This was done through developing a conceptual model based on academic theory in order to provide a tool for analysis and development of a customer support. The research questions intends to investigate how an customer support can contribute to, and balance a focus on service quality, costs and sales in order to enhance shareholder value. A business driven approach was further used in order to understand how a customer support could leverage the emerging trends of Business Intelligence. This since the thesis also aims to provide some first insights into how to leverage the trends of mobile- and Self-Service- Business Intelligence within the customer support within insurance companies. The research emphasizes the need to have a holistic view of what drives value and costs with regard to the retention, growth and acquisition of customers when viewing the customer support as a source of value. The thesis concludes that both the trends of mobile- and Self-Service- Business Intelligence could enable an insurance company to gain new insights through utilizing existing internal as well as external data in order to conduct a more continuous and flexible analysis of important matters.

The performance of an adaptive filter may be studied through the behaviour of the optimal and adaptive coefficients in a given environment. This thesis investigates the performance of finite impulse response adaptive lattice filters for two classes of input signals: (a) frequency modulated signals with polynomial phases of order p in complex Gaussian white noise (as nonstationary signals), and (b) the impulsive autoregressive processes with alpha-stable distributions (as non-Gaussian signals). Initially, an overview is given for linear prediction and adaptive filtering. The convergence and tracking properties of the stochastic gradient algorithms are discussed for stationary and nonstationary input signals. It is explained that the stochastic gradient lattice algorithm has many advantages over the least-mean square algorithm. Some of these advantages are having a modular structure, easy-guaranteed stability, less sensitivity to the eigenvalue spread of the input autocorrelation matrix, and easy quantization of filter coefficients (normally called reflection coefficients). We then characterize the performance of the stochastic gradient lattice algorithm for the frequency modulated signals through the optimal and adaptive lattice reflection coefficients. This is a difficult task due to the nonlinear dependence of the adaptive reflection coefficients on the preceding stages and the input signal. To ease the derivations, we assume that reflection coefficients of each stage are independent of the inputs to that stage. Then the optimal lattice filter is derived for the frequency modulated signals. This is performed by computing the optimal values of residual errors, reflection coefficients, and recovery errors. Next, we show the tracking behaviour of adaptive reflection coefficients for frequency modulated signals. This is carried out by computing the tracking model of these coefficients for the stochastic gradient lattice algorithm in average. The second-order convergence of the adaptive coefficients is investigated by modeling the theoretical asymptotic variance of the gradient noise at each stage. The accuracy of the analytical results is verified by computer simulations. Using the previous analytical results, we show a new property, the polynomial order reducing property of adaptive lattice filters. This property may be used to reduce the order of the polynomial phase of input frequency modulated signals. Considering two examples, we show how this property may be used in processing frequency modulated signals. In the first example, a detection procedure in carried out on a frequency modulated signal with a second-order polynomial phase in complex Gaussian white noise. We showed that using this technique a better probability of detection is obtained for the reduced-order phase signals compared to that of the traditional energy detector. Also, it is empirically shown that the distribution of the gradient noise in the first adaptive reflection coefficients approximates the Gaussian law. In the second example, the instantaneous frequency of the same observed signal is estimated. We show that by using this technique a lower mean square error is achieved for the estimated frequencies at high signal-to-noise ratios in comparison to that of the adaptive line enhancer. The performance of adaptive lattice filters is then investigated for the second type of input signals, i.e., impulsive autoregressive processes with alpha-stable distributions . The concept of alpha-stable distributions is first introduced. We discuss that the stochastic gradient algorithm which performs desirable results for finite variance input signals (like frequency modulated signals in noise) does not perform a fast convergence for infinite variance stable processes (due to using the minimum mean-square error criterion). To deal with such problems, the concept of minimum dispersion criterion, fractional lower order moments, and recently-developed algorithms for stable processes are introduced. We then study the possibility of using the lattice structure for impulsive stable processes. Accordingly, two new algorithms including the least-mean P-norm lattice algorithm and its normalized version are proposed for lattice filters based on the fractional lower order moments. Simulation results show that using the proposed algorithms, faster convergence speeds are achieved for parameters estimation of autoregressive stable processes with low to moderate degrees of impulsiveness in comparison to many other algorithms. Also, we discuss the effect of impulsiveness of stable processes on generating some misalignment between the estimated parameters and the true values. Due to the infinite variance of stable processes, the performance of the proposed algorithms is only investigated using extensive computer simulations.

La quinta generación de redes móviles (5G) se encuentra a la vuelta de la esquina. Se espera provea de beneficios extraordinarios a la población y que resuelva la mayoría de los problemas de las redes 4G actuales. El éxito de 5G, cuya primera fase de estandarización ha sido completada, depende de tres pilares: comunicaciones tipo-máquina masivas, banda ancha móvil mejorada y comunicaciones ultra fiables y de baja latencia (mMTC, eMBB y URLLC, respectivamente). En esta tesis nos enfocamos en el primer pilar de 5G, mMTC, pero también proveemos una solución para lograr eMBB en escenarios de distribución masiva de contenidos. Específicamente, las principales contribuciones son en las áreas de: 1) soporte eficiente de mMTC en redes celulares; 2) acceso aleatorio para el reporte de eventos en redes inalámbricas de sensores (WSNs); y 3) cooperación para la distribución masiva de contenidos en redes celulares. En el apartado de mMTC en redes celulares, esta tesis provee un análisis profundo del desempeño del procedimiento de acceso aleatorio, que es la forma mediante la cual los dispositivos móviles acceden a la red. Estos análisis fueron inicialmente llevados a cabo por simulaciones y, posteriormente, por medio de un modelo analítico. Ambos modelos fueron desarrollados específicamente para este propósito e incluyen uno de los esquemas de control de acceso más prometedores: access class barring (ACB). Nuestro modelo es uno de los más precisos que se pueden encontrar en la literatura y el único que incorpora el esquema de ACB. Los resultados obtenidos por medio de este modelo y por simulación son claros: los accesos altamente sincronizados que ocurren en aplicaciones de mMTC pueden causar congestión severa en el canal de acceso. Por otro lado, también son claros en que esta congestión se puede prevenir con una adecuada configuración del ACB. Sin embargo, los parámetros de configuración del ACB deben ser continuamente adaptados a la intensidad de accesos para poder obtener un desempeño óptimo. En la tesis se propone una solución práctica a este problema en la forma de un esquema de configuración automática para el ACB; lo llamamos ACBC. Los resultados muestran que nuestro esquema puede lograr un desempeño muy cercano al óptimo sin importar la intensidad de los accesos. Asimismo, puede ser directamente implementado en redes celulares para soportar el tráfico mMTC, ya que ha sido diseñado teniendo en cuenta los estándares del 3GPP. Además de los análisis descritos anteriormente para redes celulares, se realiza un análisis general para aplicaciones de contadores inteligentes. Es decir, estudiamos un escenario de mMTC desde la perspectiva de las WSNs. Específicamente, desarrollamos un modelo híbrido para el análisis de desempeño y la optimización de protocolos de WSNs de acceso aleatorio y basados en cluster. Los resultados muestran la utilidad de escuchar el medio inalámbrico para minimizar el número de transmisiones y también de modificar las probabilidades de transmisión después de una colisión. En lo que respecta a eMBB, nos enfocamos en un escenario de distribución masiva de contenidos, en el que un mismo contenido es enviado de forma simultánea a un gran número de usuarios móviles. Este escenario es problemático, ya que las estaciones base de la red celular no cuentan con mecanismos eficientes de multicast o broadcast. Por lo tanto, la solución que se adopta comúnmente es la de replicar e contenido para cada uno de los usuarios que lo soliciten; está claro que esto es altamente ineficiente. Para resolver este problema, proponemos el uso de esquemas de network coding y de arquitecturas cooperativas llamadas nubes móviles. En concreto, desarrollamos un protocolo para la distribución masiva de contenidos, junto con un modelo analítico para su optimización. Los resultados demuestran que el modelo propuesto es simple y preciso, y que el protocolo puede reducir el con
La cinquena generació de xarxes mòbils (5G) es troba molt a la vora. S'espera que proveïsca de beneficis extraordinaris a la població i que resolga la majoria dels problemes de les xarxes 4G actuals. L'èxit de 5G, per a la qual ja ha sigut completada la primera fase del qual d'estandardització, depén de tres pilars: comunicacions tipus-màquina massives, banda ampla mòbil millorada, i comunicacions ultra fiables i de baixa latència (mMTC, eMBB i URLLC, respectivament, per les seues sigles en anglés). En aquesta tesi ens enfoquem en el primer pilar de 5G, mMTC, però també proveïm una solució per a aconseguir eMBB en escenaris de distribució massiva de continguts. Específicament, les principals contribucions són en les àrees de: 1) suport eficient de mMTC en xarxes cel·lulars; 2) accés aleatori per al report d'esdeveniments en xarxes sense fils de sensors (WSNs); i 3) cooperació per a la distribució massiva de continguts en xarxes cel·lulars. En l'apartat de mMTC en xarxes cel·lulars, aquesta tesi realitza una anàlisi profunda de l'acompliment del procediment d'accés aleatori, que és la forma mitjançant la qual els dispositius mòbils accedeixen a la xarxa. Aquestes anàlisis van ser inicialment dutes per mitjà de simulacions i, posteriorment, per mitjà d'un model analític. Els models van ser desenvolupats específicament per a aquest propòsit i inclouen un dels esquemes de control d'accés més prometedors: el access class barring (ACB). El nostre model és un dels més precisos que es poden trobar i l'únic que incorpora l'esquema d'ACB. Els resultats obtinguts per mitjà d'aquest model i per simulació són clars: els accessos altament sincronitzats que ocorren en aplicacions de mMTC poden causar congestió severa en el canal d'accés. D'altra banda, també són clars en què aquesta congestió es pot previndre amb una adequada configuració de l'ACB. No obstant això, els paràmetres de configuració de l'ACB han de ser contínuament adaptats a la intensitat d'accessos per a poder obtindre unes prestacions òptimes. En la tesi es proposa una solució pràctica a aquest problema en la forma d'un esquema de configuració automàtica per a l'ACB; l'anomenem ACBC. Els resultats mostren que el nostre esquema pot aconseguir un acompliment molt proper a l'òptim sense importar la intensitat dels accessos. Així mateix, pot ser directament implementat en xarxes cel·lulars per a suportar el trànsit mMTC, ja que ha sigut dissenyat tenint en compte els estàndards del 3GPP. A més de les anàlisis descrites anteriorment per a xarxes cel·lulars, es realitza una anàlisi general per a aplicacions de comptadors intel·ligents. És a dir, estudiem un escenari de mMTC des de la perspectiva de les WSNs. Específicament, desenvolupem un model híbrid per a l'anàlisi de prestacions i l'optimització de protocols de WSNs d'accés aleatori i basats en clúster. Els resultats mostren la utilitat d'escoltar el mitjà sense fil per a minimitzar el nombre de transmissions i també de modificar les probabilitats de transmissió després d'una col·lisió. Pel que fa a eMBB, ens enfoquem en un escenari de distribució massiva de continguts, en el qual un mateix contingut és enviat de forma simultània a un gran nombre d'usuaris mòbils. Aquest escenari és problemàtic, ja que les estacions base de la xarxa cel·lular no compten amb mecanismes eficients de multicast o broadcast. Per tant, la solució que s'adopta comunament és la de replicar el contingut per a cadascun dels usuaris que ho sol·liciten; és clar que això és altament ineficient. Per a resoldre aquest problema, proposem l'ús d'esquemes de network coding i d'arquitectures cooperatives anomenades núvols mòbils. En concret, desenvolupem un protocol per a realitzar la distribució massiva de continguts de forma eficient, juntament amb un model analític per a la seua optimització. Els resultats demostren que el model proposat és simple i precís
The 5th generation (5G) of mobile networks is just around the corner. It is expected to bring extraordinary benefits to the population and to solve the majority of the problems of current 4th generation (4G) systems. The success of 5G, whose first phase of standardization has concluded, relies in three pillars that correspond to its main use cases: massive machine-type communication (mMTC), enhanced mobile broadband (eMBB), and ultra-reliable low latency communication (URLLC). This thesis mainly focuses on the first pillar of 5G: mMTC, but also provides a solution for the eMBB in massive content delivery scenarios. Specifically, its main contributions are in the areas of: 1) efficient support of mMTC in cellular networks; 2) random access (RA) event-reporting in wireless sensor networks (WSNs); and 3) cooperative massive content delivery in cellular networks. Regarding mMTC in cellular networks, this thesis provides a thorough performance analysis of the RA procedure (RAP), used by the mobile devices to switch from idle to connected mode. These analyses were first conducted by simulation and then by an analytical model; both of these were developed with this specific purpose and include one of the most promising access control schemes: the access class barring (ACB). To the best of our knowledge, this is one of the most accurate analytical models reported in the literature and the only one that incorporates the ACB scheme. Our results clearly show that the highly-synchronized accesses that occur in mMTC applications can lead to severe congestion. On the other hand, it is also clear that congestion can be prevented with an adequate configuration of the ACB scheme. However, the configuration parameters of the ACB scheme must be continuously adapted to the intensity of access attempts if an optimal performance is to be obtained. We developed a practical solution to this problem in the form of a scheme to automatically configure the ACB; we call it access class barring configuration (ACBC) scheme. The results show that our ACBC scheme leads to a near-optimal performance regardless of the intensity of access attempts. Furthermore, it can be directly implemented in 3rd Generation Partnership Project (3GPP) cellular systems to efficiently handle mMTC because it has been designed to comply with the 3GPP standards. In addition to the analyses described above for cellular networks, a general analysis for smart metering applications is performed. That is, we study an mMTC scenario from the perspective of event detection and reporting WSNs. Specifically, we provide a hybrid model for the performance analysis and optimization of cluster-based RA WSN protocols. Results showcase the utility of overhearing to minimize the number of packet transmissions, but also of the adaptation of transmission parameters after a collision occurs. Building on this, we are able to provide some guidelines that can drastically increase the performance of a wide range of RA protocols and systems in event reporting applications. Regarding eMBB, we focus on a massive content delivery scenario in which the exact same content is transmitted to a large number of mobile users simultaneously. Such a scenario may arise, for example, with video streaming services that offer a particularly popular content. This is a problematic scenario because cellular base stations have no efficient multicast or broadcast mechanisms. Hence, the traditional solution is to replicate the content for each requesting user, which is highly inefficient. To solve this problem, we propose the use of network coding (NC) schemes in combination with cooperative architectures named mobile clouds (MCs). Specifically, we develop a protocol for efficient massive content delivery, along with the analytical model for its optimization. Results show the proposed model is simple and accurate, and the protocol can lead to energy savings of up to 37 percent when compared to the traditional approach.
Leyva Mayorga, I. (2018). On reliable and energy efficient massive wireless communications: the road to 5G [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/115484
TESIS

碩士
國立臺北教育大學
資訊科學系碩士班
105
One of the reasons for the success of the enterprise is to be able to anticipate the development and signs of things, and to grasp the development trend of today's business opportunities. Therefore, the use of computer equipment and information systems to enhance business performance has become an inevitable trend for modern enterprises to enhance their competitiveness. Information technology plays an important role by building a set of information that can help companies analyze costs, master progress, risk, and customer satisfaction, as it provides faster access to real-time information for business decision making and forecasting. This reseach uses the “trust” and “altruistic” spirit of the social exchange theory to explore whether the Effectiveness Efficiency Quality System (EEQ) expected to improve the performance of the organization's members and organizations as they expected to introduce into the organization to explore the use of electronic systematization performance management system for practical use. We based on the information success model (DeLone & McLean Information Success Model). After discussing with the experts, we summarized the following constructs: system quality, information quality, intention to use, user satisfaction, the individual effect and the effect to organization as a research model and used to analyze the association of EEQ system to enhance organizational performance. This research based on the Delphi method, the research object is for the employees and operators of the industry, after trial system conducted a questionnaire survey. The analysis of the data shows that these two constructs: Intention to Use, User Satisfaction have moderately significant on the Individual Effect, and the Individual Effect has significant positive to Effect to Organization, which proves that the EEQ system can enhance individual and organizational performance.

碩士
元智大學
資訊工程學系
94
A procedure is submitted to reduce Context Switching to improve system performance for buffer management strategy of the embedded system. And a Task Deadline Monitor Mechanism in Kernel Space is carried to dynamically manage buffer strategy by checking Task Miss Deadline to increase the system efficiency. Besides, it can reduce the power consumptions due to the decreasing of Context Switching. For the management of power consumption, a way of Application Level DPM and MontaVista Power Policy to reduce the executing frequency for different application to save power consumption while system running.

碩士
國立臺北教育大學
資訊科學系碩士班
105
System integration (system integration) referred to as SI. SI to help enterprises to import information technology and system integration to improve business efficiency and competitiveness in the small and medium enterprises play an important role and in this enterprises environment changes and the number of information systems significantly Promotion, small and medium-sized enterprises have their own information system, the demand has been greatly changed, the demand for software systems has been much hardware needs, and in this system integration process, the risk factor is encountered in this study to explore. The results used as a reference for future import. The purpose of this study is to explore the risk factors that affect the system integration of the enterprise. Taking the Contingency Model as a research model to allow enterprises to integrate the system into the system can avoid the risk in advance, thereby enhancing the system integration benefits and increase customer satisfaction And trust.

碩士
國立臺北教育大學
資訊科學系碩士班
103
To reduce procurement costs and shorten the processing times have been the direction of the electronics manufacturing industry efforts. The enterprise use the dynamic purchasing system (DPS) who can find the cheapest material cost, significantly reduce procurement cost. However, the dynamic purchasing system (DPS) can be effective, the main reason is the users used and accept for the dynamic purchasing system (DPS). In order for find out what the most important reasons are affect the users use the dynamic purchasing system (DPS).This research is according to TAM model and designed a questionnaire. Data from users returns and analyze the main factors affecting users used and accept for the dynamic purchasing system (DPS), let enterprise improve weaknesses to enhance performance.

碩士
國立臺北教育大學
資訊科學系碩士班
106
The purpose of this study is to use robot arms to achieve the goal of saving queuing and obtaining drugs, thereby improving the accuracy and effectiveness of drug management. The structure is composed of a mechanical body, a controller, a servo mechanism, a sensor, a database comprising patient information, etc., and a certain designated action is set according to the work requirements to complete a series of work processes and improve patient and organization satisfaction. This study is to improve people's life efficiency and quality. Therefore, questionnaires are used to analyze the optimization that meets people's needs and meet the most effective organizational performance requirements. This study uses the results of the problem to cross-analyze the relevance and positive impact of the problem. The questionnaires were anonymously and randomly sampled from different ages, education levels, identities, and genders, and the average results of different personality traits were analyzed to understand the key factors. The study found that people like the fast and efficient quality of life and respond to the rapid and changing pace of life. Therefore, the use efficiency and ease of use of the system will directly affect people’s satisfaction. This study integrates smart technologies into reality and uses knowledge to improve and improve the quality of life in order to achieve organizational performance and social progress.

The current approach to performance measurement in British Columbia is to select and match performance measures with strategic goals and objectives so that health administrators and decision makers can evaluate the performance of different care sectors (e.g. primary, community and acute care) within the provincial health system. Although this approach offers basic understanding of system performance, it is static and considers the performance of organizational components in isolation from their interrelationships and external influences. The purpose of this research is to enhance the current performance measurement approach in BC by linking health system variables through causal relationships and feedback loops that can impact and lead to health system sustainability. The qualitative system dynamics method was applied to develop a conceptual performance measurement model. Fifteen interviews with stakeholders were conducted at the BC Ministry of Health to validate and improve the pre-validation model. A post-validation model was then created based on the feedback and comments from the 15 interview participants. As a product of this research, the post-validation model, Web of Measures 2.0, will explain how the identified cause and feedback mechanisms both internal and external to the BC health system may help determine policy levers for designing and developing quality improvement initiatives. Although quantitative analysis is out of scope for this research, potential benefits of inputting BC data into the proposed model are discussed at the end of this thesis.
Graduate
0769
0790
qi.william.yang@gmail.com

碩士
國立臺北教育大學
資訊科學系碩士班
105
In our country, there were 560,171 million pieces of road traffic accidents in 2016, involving about 12.24.2 million people each year facing criminal, civil and administrative responsibilities derived from road traffic accidents and consuming medical resources Up to 22 billion such as considering social costs more difficult to estimate, far-reaching impact, how to effectively and effectively analyze the road traffic accident by scientific method, as the basis for project improvement, traffic law enforcement strategy and education propaganda, so as to effectively prevent traffic accidents, reduce the damage of accidents, reduce the loss of personnel property, avoid social expenses, prevent the country The depletion of resources is important. The Ministry of the Interior Police Department, in order to collect information on road traffic accidents, to avoid the follow-up effects of human factors and to analyze the characteristics and trends of traffic accidents, to use the information technology technology to build road traffic accident information system (TAS), in addition to a complete collection of traffic accident information, reduce the personnel factors of the error situation, improve the efficiency of the staff to increase manpower and organizational efficiency, and can effectively reduce the probability of traffic accidents, and other administrative resources combined with the use of maximizing The benefits. In this study, the social exchange theory is used to verify whether the system achieves the goal and benefit of the expected construction. It collects papers, periodicals, books and articles, finds relevant theories and materials, and uses the science and technology acceptance model as the basis of this study. Field survey, use the relevant statistical software (spss software) to analyze the questionnaire data, view and verify the validity of the questionnaire data to analyze the statistical data, provide theoretical and model-related conclusions and recommendations to achieve the maximum benefit of the road traffic accident system (TAS), and further provide a blueprint for updating the system.