In terms of economic development, internal availability of energy in a region means the capability to produce essential goods and services for the improvement in the quality of life of all the economic agents. Economic development consists in large part of harnessing increasing amounts of energy for productive purposes or by making more efficient use of available energy resources. In this dissertation, the future electricity supply and demand interactions are examined for seven countries in West Africa: Benin, Ghana, Ivory Coast, Niger, Nigeria, Togo, and Upper Volta. A description of the primary energy resources (coal, hydro, natural gas, and oil) available in each country is presented. The future demands for electricity in the medium term (1980-1989) are projected through econometric models developed in the study. Two sectorial models for each country's economy, the residential sector, and the commercial and industrial sector, are presented. Multiple regression analysis is applied in the estimation of all demand equations. Major determinants for electricity demand used in the estimation for the residential sector were average price of electricity, real personal income, and the number of households with access to electricity. Data on these variables were obtained from international organisations such as the United Nations and from government publications for the period 1960-1977. Each of these determinants was found to be significant for most countries; however, their relative importance differ across countries. Similarly, average price of electricity, real output, and employment were major determinants used and found to be significant in the demand for electricity in the commercial and industrial sector of all countries. Price and income elasticities were obtained from the estimated equations. A general multi-region supply model was developed to structure the future electricity supply possibilities in the countries involved. The objective of this model, using linear programming, was to seek the least-cost combination of resources (primary energy, capital, and technology) for the production of electricity. The impacts of various levels of resource availability on average cost of electricity were examined for each country, and for joint development efforts using a non-integer, deterministic, linear version of the general model. The application of the supply and demand models to West Africa over the decade to 1989 reveals that except for Nigeria, all countries in the region will require fossil fueled systems to supply additional demands for electricity, because all hydro resources would have to be exploited by the mid-1980s. This will lead to higher costs in producing electricity. However, Nigeria is expected to have excess electrical energy if plans initiated in its third development plan are completed. The extension of transmission lines between Nigeria and Benin could effectively distribute the relatively cheaper energy from Nigeria to other countries, since adequate transmission network already exists between most of the countries.

Large physical memory modules are necessary to meet performance demands of today's ap- plications but can be a major bottleneck in terms of power consumption during idle periods or when systems are running with workloads which do not stress all the plugged memory resources. Contribution of physical memory in overall system power consumption becomes even more signi cant when CPU cores run on low power modes during idle periods with hardware support like Dynamic Voltage Frequency Scaling. Our experiments show that even 10% of memory allocations can make references to all the banks of physical memory on a long running system primarily due to the randomness in page allocation. We also show that memory hot-remove or memory migration for large blocks is often restricted, in a long running system, due to allocation policies of current Linux VM which mixes movable and unmovable pages. Hence it is crucial to improve page migration for large contiguous blocks for a practical realization of power management support provided by the hardware. Operating systems can play a decisive role in effectively utilizing the power management support of modern DIMMs like PASR(Partial Array Self Refresh) in these situations but have not been using them so far. We propose three different approaches for optimizing memory power consumption by in- ducing bank boundary awareness in the standard buddy allocator of Linux kernel as well as distinguishing user and kernel memory allocations at the same time to improve the movability of memory sections (and hence memory-hotplug) by page migration techniques. Through a set of minimal changes in the standard buddy system of Linux VM, we have been able to reduce the number of active memory banks significantly (upto 80%) as well as to improve performance of memory-hotplug framework (upto 85%).

Thesis (MScIng)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Electricity theft in South Africa has become a major problem. This led to several developments from both industries and research institutes to counter these actions. Since equipment is already installed and major capital has been invested to provide electricity for a broad spectrum of consumers, the challenge is to find a low cost solution harnessing current investments and technology to detect electricity theft more accurately. This thesis investigates into the electricity theft topic. Two different methods, Time Domain Pulse Reflectometry and a data driven platform based on the Theory of Constraints philosophy, were investigated to provide means to detect and determine the impact of illegal electricity usage. Both methods required detailed designs to conduct preliminary proof of concept tests in a laboratory environment. These methods are evaluated against their economical viability, possible practical implications and applications. This thesis presents a practical approach to electricity theft detection and provides the basic tools for management of this ever-increasing problem. / AFRIKAANSE OPSOMMING: Suid Afrika se elektrisiteit diefstal statistiek het die afgelope jare skrikwekkend gegroei. Dit het die industrie genoop om baie meer navorsing in die area te doen. Met reeds gevestigde toerusting en tegnologie om di´e energie medium so effektief moontlik te versprei, is die uitdaging juis om ’n ekonomiese oplossing te vind om reeds beskikbare tegnologie¨e meer doeltreffend aan te wend. Die doel van die tesis is om die gebied van elektrisiteit diefstal na te vors. Twee verskillende metodes is ondersoek, naamlik Tydgebied-pulse-reflektometrie en ’n informasie gebaseerde stelsel wat op die Randvoorwaarde Teorie gebaseer is, om effektief die omvang van elektrisiteit diefstal in ’n mikro, asook makro omgewing te bepaal. Die twee metodes is in ’n beheerde omgewing getoets sodat die konsepte wat ontwikkel is bewys kon word. Die metodes is ge-evalueer in terme van die ekonomiese lewensvatbaarheid daarvan met inagneming van die praktiese implikasies. Die tesis bied bestuur die nodige kennis om elektrisiteit diefstal in die praktyk doeltreffend die hok mee te slaan.

Abu Dhabi, the Capital City of United Arab Emirates, evolved through various stages since its formation. However, unlike other Golf cities, policy makers, planners, and designers sought to guide its growth and development towards a sustainable responsive city. Sustainability has become a central theme of policy and practice, and the design of the built environment is playing a major role towards this. Abu Dhabi developed the World renowned City of Masdar, as a model of sustainable development and design, and established the Estidama Rating System to enforce specific sustainable applications. This aim of this study is to examine the cost-effectiveness of shifting the development of Abu Dhabi from a conventional approach to a sustainable one. In particular, it sought to determine whether vernacular design and architecture could help to address the quest for a sustainable city. The methodology adopted for this research was based on quantitative and qualitative approaches. Three buildings were selected to determine the cost-effectiveness of the proposed sustainable solutions. 1. Masdar building was studied to represent what is classified as a sustainable prototype. 2. Educational Building of Abu Dhabi Police Academy, which has an open courtyard at the centre of the building, represents a vernacular design. 3. Administrative Building of Abu Dhabi Police Academy, which has a closed atrium in the centre without any skylight, represents a conventional building design. The research involved an environmental investigation of power consumption, carbon dioxide emissions, indoor and outdoor temperature, indoor and outdoor relative humidity, and levels of indoor carbon dioxide. Monitors were installed in the three prototype buildings for a period of time, and the results of the readings were compared and analysed. In addition, a questionnaire survey was used to determine the impact of the three buildings on sustainable lifestyles and attitudes. Ninety users of the three buildings responded to the questionnaire. Their responses were also compared and analysed. The results of the monitoring of the thermal performance, power consumption and carbon dioxide levels indoors confirmed that most indoor temperature readings were similar due to the use of air-conditioning in the three buildings. However, cooler temperatures were recorded in similar rates in the alleyways of Masdar and in the courtyard of the Police Academy Educational building. In some cases, courtyard spaces in the Educational Building in the Police Academy recorded even lower temperatures than those of Masdar. These readings were much higher than those of the outdoor exposed temperature, whether in Masdar or in the Police Academy outdoor spaces. Considering that the cost per square meter of the Masdar prototype was almost the double of the other prototypes, these findings challenged the cost-effectiveness of the prevailing Masdar City approach. The results also highlighted the importance of the architectural heritage of Abu Dhabi to address the sustainability agenda, including its implications on planning and building regulations. The findings of the questionnaire survey revealed that there were no significant differences between user responses of Masdar and the Police Academy buildings. These also questioned the cost effectiveness of the Masdar prototype. However, the results also confirmed that the lack of awareness of the sustainability agenda for the users of the three buildings, thus highlighting the wider implications on the sustainability agenda.

Pressing demands for less power consumption of processors while delivering higher performance levels have put an extra attention on efficiency of the systems. Efficient management of resources in the current computing systems, given their increasing number of entities and complexity, requires accurate predictive models that can easily adapt to system and application changes. Through performance monitoring counter (PMC) events, in modern processors, a vast amount of information can be obtained from the system. This thesis provides a methodology to efficiently choose such events for power modeling purposes. In addition, exploiting the time-dependence of the data measured through PMCs and multi-meters, we build predictive multivariate time-series models that estimate the run-time power consumption of a system. In particular, we find an autoregressive moving average with exogenous inputs (ARMAX) model that is combined with a recursive least squares (RLS) algorithm as a good candidate for such purposes. Many of the available estimation or prediction models avoid using the metrics that are affected by the changes of the processor frequency. This thesis proposes a method to mitigate the impact of frequency scaling in a run-time model on power and PMC metrics. This method is based on a practical Gaussian approximation. Different segments of the trend of a metric that are associated with different frequencies are scaled and offset into a zero mean unit variance signal. This is an attempt to transform the variable frequency trend into a weakly stationary time-series. Using this approach, we have shown that power estimation of a system using PMCs can be done in a variable frequency environment. We extend the ARMAX-RLS model to predict the near future power consumption and PMCs of different applications in a variable frequency environment. The proposed method is adaptive, independent of the system and applications. We have shown that a run-time per core or aggregate system PMC event prediction, multiple-steps ahead of time, is feasible using an ARMAX-RLS model. This is crucial for progressing from the reactive power and performance management methods to more proactive algorithms. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2012-11-12 12:21:00.152

In recent years, advances in signal processing have led to small, low power, inexpensive Wireless Sensor Network (WSN). The signal processing in WSN is different from the traditional wireless networks in two critical aspects: firstly, the signal processing in WSN is performed in a fully distributed manner, unlike in traditional wireless networks; secondly, due to the limited computation capabilities of sensor networks, it is essential to develop an energy and bandwidth efficient signal processing algorithms. Target localisation and tracking problems in WSNs have received considerable attention recently, driven by the necessity to achieve higher localisation accuracy, lower cost, and the smallest form factor. Received Signal Strength (RSS) based localisation techniques are at the forefront of tracking research applications. Since tracking algorithms have been attracting research and development attention recently, prolific literature and a wide range of proposed approaches regarding the topic have emerged. This thesis is devoted to discussing the existing WSN-based localisation and tracking approaches. This thesis includes five studies. The first study leads to the design and implementation of a triangulation-based localisation approach using RSS technique for indoor tracking applications. The presented work achieves low localisation error in complex environments by predicting the environmental characteristics among beacon nodes. The second study concentrates on investigating a fingerprinting localisation method for indoor tracking applications. The proposed approach offers reasonable localisation accuracy while requiring a short period of offline computation time. The third study focuses on designing and implementing a decentralised tracking approach for tracking multiple mobile targets with low resource requirements. Despite the interest in target tracking and localisation issues, there are few systems deployed using ZigBee network standard, and no tracking system has used the full features of the ZigBee network standard. Tracking through the ZigBee is a challenging task when the density of router and end-device nodes is low, due to the limited communication capabilities of end-device nodes. The fourth study focuses on developing and designing a practical ZigBee-based tracking approach. To save energy, different strategies were adopted. The fifth study outlines designing and implementing an energy-efficient approach for tracking applications. This study consists of two main approaches: a data aggregation approach, proposed and implemented in order to reduce the total number of messages transmitted over the network; and a prediction approach, deployed to increase the lifetime of the WSN. For evaluation purposes, two environmental models were used in this thesis: firstly, real experiments, in which the proposed approaches were implemented on real sensor nodes, to test the validity for the proposed approaches; secondly, simulation experiments, in which NS-2 was used to evaluate the power-consumption issues of the two approaches proposed in this thesis.

D.Ing. (Electrical and Electronic Engineering) / The electricity shortage in South Africa has required the implementation of demand side management (DSM) projects. The DSM projects were implemented by installing energy monitoring and control systems to monitor certain mining aspects such as water pumping systems. Certain energy saving procedures and control systems followed by the mining industry are not sustainable and must be updated regularly in order to meet any changes in the water pumping system. In addition, the present water pumping, monitoring, and control system does not predict the energy consumption or the underground water dam levels. Hence, there is a need to introduce new monitoring system that could control and predict the energy consumption of the underground water pumping system and dam levels based on present and historical data. The work is undertaken to investigate the feasibility of using artificial intelligence in certain aspects of the mining industry. If successful, artificial intelligence systems could lead to improved safety and reduced electrical energy consumption, and decreased human error that could occur throughout the pump station monitoring and control process ...

Doctor of Philosophy / Department of Industrial and Manufacturing Systems Engineering / Zhijian Pei / Donghai Wang / The U.S. economy has been depending on petroleum-based liquid transportation fuels (such as gasoline, diesel, and jet fuels). Currently, about 50% of petroleum used in the U.S. is imported. Petroleum is a finite and non-renewable energy source and its use emits greenhouse gases. Therefore, it is extremely important to develop domestic sustainable alternatives for petroleum-based liquid transportation fuels. Ethanol produced from cellulosic biomass can be such an alternative. However, several technical barriers have hindered large-scale, cost-effective manufacturing of cellulosic ethanol. One such barrier is related to the low density of cellulosic feedstocks, causing high cost in their transportation and storage. Another barrier is low efficiency in conversion of cellulose to fermentable sugar (pretreatment and enzymatic hydrolysis are two major conversion processes), causing high cost in pretreatment and enzymatic hydrolysis of cellulosic biomass. Ultrasonic vibration-assisted (UV-A) pelleting increases both density and sugar yield of cellulosic feedstocks. Incorporating UV-A pelleting into cellulosic ethanol manufacturing may help realize cost-effective manufacturing of cellulosic ethanol. This PhD dissertation consists of 13 chapters. An introduction is given in Chapter 1. Chapter 2 presents a literature review on related topics. Experimental studies regarding effects of input parameters (such as particle size, pressure, and ultrasonic power) on output parameters (density, durability, stability, and sugar yield) are presented in Chapters 3–4. In Chapters 5–6, comparisons are made between UV-A pelleting and ring-die pelleting (a traditional pelleting method) in terms of pellet properties (density and durability), power consumption, and sugar yield under different conditions. Next, effects of input parameters (such as biomass type, particle size, moisture content, pelleting pressure, and ultrasonic power) on power consumption are studied in Chapters 7–9. Chapter 10 presents an investigation on biomass temperature in UV-A pelleting. Chapter 11 presents an investigation on effects of UV-A pelleting on sugar yield and chemical composition of cellulosic biomass. Chapter 12 presents an investigation on influence of UV-A pelleting on biomass characteristics (such as crystallinity index, thermal properties, and morphological structure). Finally, conclusions are presented in Chapter 13.

M.Com. (Business Management) / The residential demand profile for electricity shows that this segment of the market has. a great demand in the morning and early evening. Due to a shortage of generation capacity during these peak consumption periods, different strategies are now needed to persuade customers to use their electricity in the periods when there is not a great demand. One way in which this can be achieved is to give the customers a time differentiated tariff i.e. a time-of-use (TOU) tariff, whereby the customer will pay a high energy rate in the peak periods, and lower energy rates in the off-peak and standard periods. The overall goal of this study was to determine to what extent residential customers would respond to such a tariff The study covered three consumption groups i.e. customers using more than 1500 kWh per month, between 600 and 1000 kWh per month, and between 300 and 600 kWh per month. All the customers taking part in the study were direct Eskom customers. Once the customers had agreed to participate in the study, they had TOU measuring equipment installed in their homes, which measured their consumption according to the time of day it was consumed.

The subject of this work is comparing economic return and influence on environment by earth-sheltered house and classic house. Attention will be concentrated on construction process these houses from the beginning to approval of construction, the advantages and disadvantages resulting from the construction, which will be compared with neighboring states, especially with Germany and Austria. The work first briefly describes earth-sheltered houses, their history and use renewable energy sources, then focuses on comparing the two types of houses. The main objective of this work is to confirm the hypothesis about the benefits of building earth-sheltered houses, despite high initial costs and increased interest in population of these houses in recent years. To calculate the repayment time will be apply cost -- benefit analysis and questionnaire survey. At the conclusion work summarizes the results obtained and confirm of reject the hypothesis examined.