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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
491

Assessing the Energy Consumption of Smartphone Applications

Abousaleh, Mustafa M. 27 August 2013 (has links)
Mobile devices are increasingly becoming essential in people's lives. The advancement in technology and mobility factor are allowing users to utilize mobile devices for communication, entertainment, financial planning, fitness tracking, etc. As a result, mobile applications are also becoming important factors contributing to user utility. However, battery capacity is the limiting factor impacting the quality of user experience. Hence, it is imperative to understand how much energy impact do mobile apps have on the system relative to other device activities. This thesis presents a systematic studying of the energy impact of mobile apps features. Time-series electrical current measurements are collected from 4 different modern smartphones. Statistical analysis methodologies are used to calculate the energy impact of each app feature by identifying and extracting mobile app-feature events from the overall current signal. In addition, the app overhead energy costs are also computed. Total energy consumption equations for each component is developed and an overall total energy consumption equation is presented. Minutes Lost (ML) of normal phone operations due to the energy consumption of the mobile app functionality is computed for cases where the mobile app is simulated to run on the various devices for 30 minutes. Tutela Technologies Inc. mobile app, NAT, is used for this study. NAT has two main features: QoS and Throughput. The impact of the QoS feature is indistinguishable, i.e. ML is zero, relative to other phone activities. The ML with only the TP feature enabled is on average 2.1 minutes. Enabling the GPS increases the ML on average to 11.5 minutes. Displaying the app GUI interface in addition to running the app features and enabling the GPS results in an average ML of 12.4 minutes. Amongst the various mobile app features and components studied, the GPS consumes the highest amount of energy. It is estimated that the GPS increases the ML by about 448%. / Graduate / 0544 / mustafa.abousaleh@gmail.com
492

The market for energy in China

Lee, Shu-Kam January 1999 (has links)
Since 1979, China embarked on an economic reform to modernize the country. The reform was so successful that China was able to grow by an impressive rate of 9 percent per anum between 1979 and 1997. The rapid development of the economy leads to a drastic increase in demand for energy. Since China has the largest population in the world, its energy demand is nothing but huge. Each year, for example, China needs to install as much as 10,000 MW of new electricity generation capacity, which equals the curent capacity of Netherlands. This increase in demand for energy, which is likely to continue, wil have implications for global energy markets, the world price of energy and for the global environment as emissions of greenhouse gases grow rapidly. Against this background, there is an urgent need for the country to better manage the energy sector so that the market can function in an orderly manner. To tackle this issue, I single out three important energy problems to study. First, I wil examine the current situation of the energy imbalance in China. Second, I wil forecast how rapid the energy demand wil grow in future so that the deficit between the demand and domestic supply can be identified. Lastly, I wil discuss some methods that can be used to manage the demand. My finding shows that energy-capital and energy-material inputs are complementary, whereas the relationship of energy and labour is insignificant. In addition, the simulation exercises also reveals that a high energy pricing policy might not be effective in mitigating the demand and in encouraging firms to employ labour intensive techniques. Also, rising energy prices may bring spiral inflation and deterioration in the balance of payments and foreign resources. Therefore, government should act cautiously when increasing energy prices.
493

The effects of protective clothing and its properties on energy consumption during different activities

Dorman, Lucy E. January 2007 (has links)
There are many situations where workers are required to wear personal protective clothing (PPC), to protect against a primary hazard, such as heat or chemicals. But the PPC can also create ergonomic problems and there are important side effects which typically increase with rising protection requirements. The most extensively studied side effect is that of increased heat strain due to reduced heat and vapour transfer from the skin. Less studied is the extra weight, bulk and stiffness of PPC garments which is likely to increase the energy requirements of the worker, reduce the range of movement and lead to impaired performance. Current heat and cold stress standards assume workers are wearing light, vapour permeable clothing. By failing to consider the metabolic effects of actual PPC garments, the standards will underestimate heat production and therefore current standards cannot be accurately applied to workers wearing PPC. Information on the effect of the clothing on the wearer and the interactions between PPC, wearer and environment is limited. Data was collected to quantify the effect of PPC on metabolic load based on the properties of the PPC for the EU THERMPROTECT project (GERD-CT-2002-00846). The main objective of the project was to provide data to allow heat and cold stress assessment standards to be updated so that they need no longer exclude specialised protective clothing. The aim of this thesis was to investigate the effect of PPC and its properties on energy consumption during work. For this purpose, the effects of a range of PPC garments (Chapter 3), weight (Chapter 4), number of layers and material friction (Chapter 5) and wet layers (Chapter 6) on energy consumption whilst walking, stepping and completing an obstacle course were studied. The impact of PPC on range of movement in the lower limbs was also investigated (Chapter 7). The main findings were; a) Increased metabolic cost of 2.4 - 20.9% when walking, stepping and completing an obstacle course in PPC compared to a control condition. b) An average metabolic rate increase of 2.7% per kg increase in clothing weight, with greater increases with clothing that is heavier on the limbs and in work requiring greater ranges of movement. c) 4.5 to 7.9% increase in metabolic cost of walking and completing an obstacle course wearing 4 layers compared to a single layer control condition of the same weight. d) Changes in range of movement in PPC due to individual behavioural adaptations. e) Garment torso bulk is the strongest correlate of an increased metabolic rate when working in PPC (r=0.828, p<0.001). f) Garment leg bulk (r=0.615), lower sleeve weight (r=0.655) and weight of the garment around the crotch (r=0.638) are also all positively correlated with an increased metabolic rate. Total clothing weight and clothing insulation had r values of 0.5 and 0.35 respectively. This thesis has confirmed the major effect of clothing on metabolic rate, and the importance of including this effect in standards and models.
494

Energy consumption and conservation in school foodservice systems

Kobliner, Victoria Rousso 06 May 1994 (has links)
Graduation date: 1994
495

Mechanisms for coordinated power management with application to cooperative distributed systems

Nathuji, Ripal 12 June 2008 (has links)
Computing systems are experiencing a significant evolution triggered by the convergence of multiple technologies including multicore processor architectures, expanding I/O capabilities (e.g., storage and wireless communication), and virtualization solutions. The integration of these technologies has been driven by the need to deliver performance and functionality for applications being developed in emerging mobile and enterprise systems. These accomplishments, though, have come at the cost of increased power and thermal signatures of computing platforms. In response to the resulting power issues, power centric policies have been deployed across all layers of the stack including platform hardware, operating systems, application middleware, and virtualization components. Effective active power management requires that these independent layers or components behave constructively to attain globally desirable benefits. Two choices are (1) to tightly integrate different policies using negotiated management decisions, and (2) to coordinate their use based on the localized policy decisions that are already part of modern computer architectures and software systems. Recognizing the realities of (2), the goal of this thesis is to identify, define, and evaluate novel system-level coordination mechanisms between diverse management components that exist across system layers. The end goal of these mechanisms, then, is to enable synergistic behaviors between management entities, across different levels of abstraction, and across different physical platforms to improve power management functionality. Contributions from this work include operating system level mechanisms that dynamically capture workload behavior thereby enabling power efficient scheduling, and system descriptor mechanisms that allow for improved workload allocation and resource management schemes. Finally, observing the strong need for coordination in managing virtualized systems due to the existence of multiple, independent system layers, a set of extensions to virtualization architectures for effectively coordinating VM management in datacenters are developed.
496

Patterns of energy use, energy cost increases and their impacts on crop production on the Big Island of Hawaii : a linear programming approach

Koffi-Tessio, Egnonto N January 1982 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii. / Bibliography: leaves 168-173. / Photocopy. / xiv, 173 leaves, bound ill., map 28 cm
497

An index to measure the influences of climate on residential natural gas demand

Sánchez-Lugo, Ahira M January 2007 (has links)
Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 69-71). / x, 71 leaves, bound ill., maps 29 cm
498

Investigation Cooling and Lubrication Strategies for Sustainable Machining of Titanium Alloys

Pervaiz, Salman January 2014 (has links)
The manufacturing sector is one of the most rapidly growing sectors in the industrialized world today. Manufacturing industry is concerned with being more competitive and profitable. Profit margins are directly related to the productivity of the company, and productivity improvements can be achieved by making manufacturing processes more efficient and sustainable. Knowledge of cutting conditions and their impact on machined surface and tool life enable productivity improvement.  These days the main emphasis is not only to increase productivity, but also to make processes cleaner and more environmental friendly.  This research aims to study machinability of difficult to cut, titanium alloys, in close reference to the application of different cooling/ lubrication strategies and their environmental impact. Total energy consumed (kWh) and carbon dioxide (CO2) emissions produced in machining are common environmental indicators. In this research project environmental implications of the cutting process were calculated in terms of carbon dioxide (CO2) emissions and energy consumption analysis. The experimental work consisted of controlled machining tests with cutting force, surface roughness, power, and flank wear measurements under dry, mist, combination of vegetable oil mist and cooled air (MQL+CA) and flood cutting environments. The current study provides better understanding of the cutting performance of TiAlN coated and uncoated carbide tools. The study also investigated tool failure modes, tool wear mechanisms, surface roughness and energy consumption to improve machinability of Titanium alloys.  The study revealed the promising behaviour of minimum quantity lubrication (MQL) under specific ranges of cutting speed for both coated and uncoated tools.  Variation in the cutting force showed close link with built up edge (BUE) formation. MQL based systems have huge potential to improve machinability of Titanium alloys and should be investigated further. / <p>QC 20140407</p>
499

Energy-related CO2 emissions in the Indonesian manufacturing sector

Sitompul, Rislima Febriani, Economics, Australian School of Business, UNSW January 2006 (has links)
This study is aimed at developing policies for energy efficiency by observing the past changes of energy use in Indonesia???s manufacturing sector over the period 1980???2000, and to investigate mitigation options for energy-related CO2 emissions in the sector. The first part of the study uses decomposition analysis to assess the effect of the changes in energy consumption and the level of CO2 emissions, while the second part investigates energy efficiency improvement strategies and the use of economic instruments to mitigate CO2 emissions in the manufacturing sector. Economic activity was the dominant factor in increasing energy consumption over the whole period of analysis, followed by the energy intensity effect and then the structural effect. The increase in aggregate energy intensity over the period 1980-2000 was mainly driven by the energy intensity effect. In turn, the technical effect was the dominant contributor to changes in energy intensity effect, with the fuel-mix effect being of lesser importance. Changes in CO2 emissions were dominated by economic activity and structural change. Sub-sectors that would benefit from fuel switching and energy efficiency improvements are the textile, paper, and non-metal sub-sectors. Three main options for reducing CO2 emissions from the manufacturing sector were considered: the imposition of a carbon tax, energy efficiency initiatives, and other mitigation measures. A carbon tax was found to reduce sectoral emissions from the direct use of oil, gas and coal, but increased the demand for electricity. At the practical level, energy efficiency improvements can be implemented by adopting energy efficient technologies that can reduce aggregate energy intensity up to 37.1 per cent from the base-year level, estimated after imposition of a carbon tax at $30 per tonne of carbon. A major priority for energy efficiency improvements was found to be in the textile and the paper and chemical sub-sectors. A mitigation measure such as the Clean Development Mechanisms could be encouraged in order to reduce projected emission levels. The preferred option would be the adoption of energy efficient technologies in the textile, chemical, paper and non-metal sub-sectors.
500

Assessment of energy efficiency in a passive solar housing development

Valenzuela, Brian, January 2007 (has links)
Thesis (M.S.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

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