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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.
11

Dynamic Voltage and Frequency Scaling Enhanced Task Scheduling Technologies Toward Greener Cloud Computing

Aldhahri, Eiman Ali 01 May 2014 (has links)
The skyrocketing amount of electricity consumed by many data centers around the globe has become a serious issue for the cloud computing and entire IT industry. The demand for data centers is rapidly increasing due to widespread usage of cloud services. It also leads to huge carbon emissions contributing to the global greenhouse effect. The US Environmental Protection Agency has declared that data centers represent a substantial portion of the energy consumption in the US and the whole world. Some of this energy consumption is caused by idle servers or servers running at higher-than-necessary frequencies. Due to the Dynamic Voltage and Frequency Scaling (DVFS) technology enabled in many CPUs, strategically reducing CPU frequency without affecting the Quality of Service (QoS) is desired. Our goal in this paper is to calculate and tune to the best CPU frequency for each running task combined with two commonly-used scheduling approaches, namely round robin and first fit algorithms, given the CPU configuration and the execution deadline. The effectiveness of our algorithms is evaluated under a CloudSim/CloudReport simulation environment as well as real hypervisor computer system with power gauge. The open source CloudReport, based on the CloudSim simulator, has been used to integrate our DVFS algorithm with the two scheduling algorithms to illustrate the efficiency of power saving in different scenarios. Furthermore, electricity consumption is measured and compared using power gauge of Watts Up meter.
12

Energy-efficient cooking systems, food preparation facilities, and human diets

Newborough, Marcus January 1987 (has links)
This thesis aims at identifying the opportunities for saving energy, which are available to those working within the final link of the UK food system (i. e. at, or in relation to, the points of consumption). Substantial prospective savings exist, because relatively little attention has, as yet, been given to energy-thrift in food-preparation facilities. Within the food-service industry, cooking systems are characterised by high thermal capacities, excessive external surface temperatures and poorly-designed control systems. Catering staff, who use such appliances, are rarely trained to use energy wisely when preparing foods, and kitchens (and their associated dining facilities) tend to be designed without sufficient regard to energy-thrift. Similar problems prevail in domestic kitchens, but to a lesser extent because the cooks there usually pay (or contribute towards) the fuel bills. However, manufacturers still provide household appliances, which are unnecessarily energy-profligate. Furthermore most people have insufficient knowledge of the nutritional suitabilities and the primary-energy costs of their diets. Thus a major educational need exists, which must be satisfied if industrialised food systems are to become more energy efficient. This thesis attempts to make a contribution to this requirement, by analysing cooking systems, food-preparation facilities, kitchen operatives, and human diets from an energy-thrift perspective. Long-term savings (i. e. those achieved as a result of implementing the recommendations within a 15-year period) of approximately £1O p. a. (at 1987 prices) are predicted, although this could be increased substantially if Britons adopt more energy-efficient, yet nutritionally-balanced, diets.
13

Analysis on EAC Application of VRV air-conditioning Systems

Su, Lun 26 June 2006 (has links)
In Green Building Evaluation Indexes, the EAC has been adapted as the central HVAC system energy consumption criteria, has been assigned an energy saving factor£\4 of 0.2, despite of the actual power consumption variations existed among various system. In this study, the PILV values of specific VRV systems were utilized, so that actual energy-saving factor £\4 can be evaluated. Furthermore, being lack of the chilled water distribution system, the weighting of power consumption percentages of a VRV system has also been changed into 0.9 vs. 0.1 for the outdoor and indoor units respectively. The methodology established in this study has been justified by suing the actual VRV projects under commercial operations, which can successfully discriminate different energy efficiencies among various systems.
14

The Design Analysis and Experimental Investigation on School Building Energy Conservation

Shiao, Ay-ling 21 June 2003 (has links)
Due to the energy crisis in 1970, the energy saving is more important for the human civilization. The energy-saving policy is important for the economic growth and competition of Taiwan. The energy of daily life and business consumes 17% of the total energy, especially the air conditioning of architectures on the peak hours occupying a third in summer. So the building energy-saving policy is the most important in Taiwan. The main of theme building energy saving is not only to save energy but also to consider the comfortable and healthy of the living environment. So that, the optimal design of the building energy saving of commercial buildings in Taiwan has been established in this paper. In this study, theoretical analysis and a full scale experiment has been performed to validate this design. Results showed this design is suitable for the NPTC building in the weather condition of south Taiwan, which also complies with the energy code of Taiwan.
15

Αντιλήψεις φοιτητών/τριών παιδαγωγικών τμημάτων προσχολικής ηλικίας σχετικά με την εξοικονόμηση ενέργειας

Μπαρμπέρη, Μαρία, Μηλιαρά, Καλλιόπη 01 December 2009 (has links)
Στα πλαίσια του θέματος της πτυχιακής εργασίας «Αντιλήψεις φοιτητών/τριών Παιδαγωγικών Τμημάτων Προσχολικής Ηλικίας σχετικά με την εξοικονόμηση ενέργειας», πραγματοποιήθηκε μια έρευνα προκειμένου να διαπιστωθεί σε φοιτητές/τριες των Παιδαγωγικών Τμημάτων Προσχολικής Ηλικίας Βόλου και Πάτρας κατά πόσο είναι εξοικειωμένοι με τις Φυσικές Επιστήμες, καθώς και με τη κατανόηση τις έννοιας «εξοικονόμηση ενέργειας μέσω λαμπτήρων». Μέσω της έρευνας, η οποία πραγματοποιήθηκε με την βοήθεια ερωτηματολογίου για τη συλλογή των δεδομένων μας, διατυπώνονται συγκεκριμένα ερωτήματα. Τα ερωτήματα αυτά, αφορούν τον τρόπο λειτουργίας λαμπτήρων πυρακτώσεως όσο και λαμπτήρων εξοικονόμησης ενέργειας. Παράλληλα, θέτονται μέσω του ερωτηματολογίου προβληματισμοί γύρω από τον τρόπο με τον οποίο μπορούμε να εξοικονομήσουμε ενέργεια μέσω της χρήσης λαμπτήρων εξοικονόμησης ενέργειας. Γενικότεροι Στόχοι της έρευνας είναι: • να διαπιστωθεί κατά πόσο επεκτείνεται η γνώση πάνω στη λειτουργία των λαμπτήρων τόσο των φοιτητών/τριών Βόλου όσο και φοιτητών/τριών Πάτρας. Σαν μέτρο σύγκρισης λαμβάνονται η διδασκαλία Φυσικών Επιστημών στο Πανεπιστήμιο, η κατεύθυνση που είχαν επιλέξει οι φοιτητές/τριες στο λύκειο (θετική, τεχνολογική, θεωρητική) καθώς και ο τόπος στον οποίο πραγματοποιούνται οι σπουδές των φοιτητών/τριών.(Βόλος ή Πάτρα). • Να διαπιστωθεί η στάση των φοιτητών/τριών απέναντι στην ανάγκη για εξοικονόμηση ενέργειας. Μέσω του ερωτηματολογίου θα μπορέσουμε να πάρουμε τα απαραίτητα στοιχεία προκείμενου να διαπιστώσουμε αν διεκπεραιώθηκαν οι παραπάνω στόχοι που έχουμε θέσει. Τα αποτελέσματα του ερωτηματολογίου αναλύονται μέσω του προγράμματος SPSS με αναλυτικούς πίνακες και διαγράμματα ενώ αναλύονται παρακάτω η στρατηγική, οι τεχνικές καθώς και το ακριβές δείγμα της έρευνας. Τέλος μέσω της έρευνας, μελετάται το διεθνές πρόγραμμα αξιολόγησης μαθητών PISA και η σχέση του με τις Φυσικές Επιστήμες, καθώς και οι επιδράσεις και τα αποτελέσματα του συγκεκριμένου προγράμματος στην Ελλάδα. / In terms of our diploma’s final project, concerning: “students’ of the Department of Education Sciences in Pre-school Ages, beliefs about energy saving”, we performed a research in order to ascertain how familiar these students are with physical sciences and the idea of saving energy using lamps. Through the research which took place using a questionnaire as a helping hand in collecting the data, several questions are phrased. These questions pertain to the incandescence lamps, as well as the energy saving type lamps. At the same time, some sobering thoughts are expressed through the questionnaire referring to the way energy can be saved by using the energy saving type lamps. General Goals of this research are: * To figure out in which way the knowledge on the function of the lamps extends to the students of the department of Volos, as well as the department of Patras. As a comparing point, we used the lectures taken place in science classes in the university, the branch that the students had picked during their high school years (scientific, technological, and theoretical) along with the area in which the students study. (University of Volos, University of Patras). * To find out how the students feel towards the need to save energy. Through the questionnaire, we would be able to get the data needed, in order to make sure if we succeeded to get the answers to the goals we had set. The questionnaire’s results were analyzed through the SPSS program using analyzing boards and diagrams, while the strategy, the techniques and the research’s exact sample are analyzed as well later on. Finally through the research, the program for international students’ assessment (PISA) is examined, along with its impact and results in Greece.
16

Μελέτη και τεχνικές εξοικονόμησης ενέργειας σε κτιριακές εγκαταστάσεις

Σιδέρης, Ευάγγελος 20 October 2010 (has links)
Στη διπλωματική αυτή εργασία εξετάζονται οι τρέχουσες τεχνικές εξοικονόμησης ενέργειας σε κτιριακές εγκαταστάσεις, το τρέχον νομικό πλαίσιο και γίνεται μια μελέτη εξοικονόμησης ενέργειας κατοικίας. / --
17

A methodology for evaluating energy efficient lighting technologies for their performance, power quality and environmental impacts

Choudhry, Mohammad A. 26 October 2005 (has links)
Recent developments in compact fluorescent lamps, electronic ballasts and adjustable speed drives have expedited the process of taping energy saving potential of these technologies. The proliferation of these. loads, however, has raised new concerns about the power quality in commercial buildings. Higher cost of repair and the reduction in average life of equipment, both on the supply and load sides, could become obvious if these issues are overlooked or ignored. As lighting loads are the largest fraction of the load in most of commercial buildings, a small increase in harmonic distortion level in commercial buildings may jeopardize other loads in the building or the loads connected to the same utility bus. As these devices were tested to quantify their energy saving potential, it was found that they can create undesirable harmonic problems. Such characteristics were quantified for different samples. It was observed that certain combinations of these lamps and ballasts are much more acceptable from power quality viewpoints than when tested individually. A generic algorithm was developed that can help to select certain energy efficient lighting technologies and will minimize the harmonic distortion level in the building. Results from the algorithm were validated on a building load model to test the accuracy of the algorithm results. The proposed algorithm helps to avoid the problems of selecting energy efficient technologies randomly during retrofitting of commercial buildings for energy savings. Pollution mitigation features, and a summary of environmental and power quality status of energy efficient lighting devices were also discussed. A brief description of other nonlinear loads, present in commercial facilities, was also given to evaluate their role in reaping the benefit of energy savings in new lighting technologies. Energy savings and environmental benefits of new lighting devices were highlighted in the presence of other nonlinear loads. This study provides a complete illustration of the benefits and power quality issues related to these technologies. / Ph. D.
18

Thermal Performance Comparison of Three Integrated Thermal Solar Roof Collectors

Xu, Zheng 29 December 2004 (has links)
The integrated solar roof collector system can bring the house year-round energy saving benefit. In heating season, part of the space heating and preheating domestic hot water demand can be met by this integrated system. In the cooling season, cooling load reduction and preheating domestic hot water can be achieved by operating this system. The traditional solar thermal system is an add-on system rather than integrated, which increases the cost-benefit ratio. The current system is integrated with the roof structure. Except for the energy collecting benefit, it will reduce the material cost, labor cost and construction period. The objectives of this research is to estimate the energy performance of three collector configurations including space heating saving, and preheat hot water saving. This study also compares energy performance for the three collectors on two types of evaluated houses in Roanoke, Virginia. / Master of Science
19

The research on the demand and investment willingness of energy-saving products and services for medium and small enterprises

Chang, Hung-sen 25 July 2011 (has links)
Taiwan lack natural and energy resource, need to import 99.3% energy. Due to the traditional high-carbon energy also supply from abroad, its supply will be impacted by international demand and production, price fluctuations, and the international politics. In recent years the international oil price surged upward, business costs were constantly raise. In this study, some small and medium businesses are taken as objects in Kaohsiung, Taiwan. In this investigation, understand the application of energy resource in those businesses, different industries have their attention to other items and differences, it can be seen on those small and medium enterprises in the concept and practice by measuring and computing power consumption. Research Methods: First, to explore the international and domestic energy and policy and the related energy research literature, interview the small and medium enterprises and observe the way of energy usage, and provide the improving solution, questionnaires and field measurements made on those enterprises, to record the response, investment willingness and problem for energy improving, statistical analysis and get the conclusion. The results showed that the prevalence among the small businesses¡¦ waste of energy, there is many invalid lighting, it is the room to improve the installation of reflective shade to effect the lighting, even replace the lamps (T8) to lamps (T5) with reflective shade, then reduce the use of lamps and power, indirectly to reduce the power consumption of air condition. This research also found there is considerable room to improve the light in the refrigerated cabinet. The traditional fluorescent lamps(T8) be used in the refrigerated cabinet. The performance is low and produce high temperature, then the refrigerated cabinet shall expand more power to reach the set temperature, if change those lamps to LED lamps could immediately reduce the loss of electricity bills. Extension of this study, there is a great improvement in the domestic building and enterprises on lighting application, it could reduce a lot of power consumption by detailed observing, detected, and improving engineer to remove lighting waste, and thus achieve carbon reduction targets by 20% of the electricity.
20

None

Yeh, Ching-te 29 July 2008 (has links)
In Taiwan, most of the energy relies on imports due to few natural resources. Further more, scientists estimate that crude oil will be depleted within 40 years. A high cost energy era has arrived. Skyrocketing oil prices have a severe negative impact on the cost structure of the Taiwan Power Company (TPC), which has an estimated deficit of NT$70 billion in 2007. TPC has faced a difficult dilemma: whether to raise the electricity rate or become bankrupt. Eventually, the government has to intervene. The Kyoto Protocol was in effect in February 2005. It is expected that the environmental convention of reducing of CO2 will become an international movement following ISO14000. With every one kilowatt hour of electricity is generated by TPC, 638g of CO2 were produced. The products of made-in-Taiwan will not received international approval and will be boycotted by the International market if the energy efficiency of national enterprise is too low. Air compressor system, which is as important as water and electricity, is popularly used in almost all industries. However, its high energy-consumption and low efficiency system is seldom noticed. The energy cost of air compressor system is about 80% of the total operational cost which includes the electricity costs of all the machinery and lightings. How to improve air compressor efficiency plays an important role in the manufacture¡¦s production cost and its competition against other industries. Facing fierce competition and low profit, the industries must not only continuously innovate and reduce the cost to enhance competition ability for keeping market share, but also increase energy efficiency and reduce the emission of greenhouse gases by the green production method meeting the environmental requirement. The report is the summary of the interviews with many industry leaders who are involved in the air compressor production or the government officials who are in charge of energy-saving promotion. It also combines with the data of actual measurement of the compressor systems to research if the investment willingness of manufacturers is reflected by their operation cost, operation strategy, the risky consideration when facing law and the information getting of compressor energy-saving. The results of the study are: Clarify the main factors which influence the investment willingness to compressor energy-saving. (A) The cost side: The investment willingness is influenced by the cognition of the leaders of manufacturer unit or business owner to compressor system cost. (B) The strategy side: The investment willingness is influenced by the cognition of the leaders of manufacturer unit or business owner to the operation strategy on compressor system. (C) The legal side: The investment willingness is influenced by the cognition of the leaders of manufacturer unit or business owner to the legal affection to business. (D) The information side: The investment willingness is influenced by getting the information of energy-saving of compressor system. Finally, the study proposes a feasible project to the industries and the government officials who promote energy saving.

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