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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.
31

A Power Saving Mechanism for Web Traffic in IEEE 802.11 Wireless LAN

Jiang, Jyum-Hao 26 July 2010 (has links)
Web browsing via Wi-Fi wireless access networks has become a basic function on a variety of consumer mobile electronic devices, such as smart phones, PDAs, and the Apple iPad. It has been found that in terms of energy consumption, wireless communications/networking plays an important role in mobile devices. Since the power-saving mode (PSM) of the IEEE 802.11 a/b/g standard is not tailored for the HTTP protocol, we propose a novel power saving scheme that exploits the characteristics of web applications. After sending HTTP requests, the proposed power saving scheme updates the estimated value of RTT based on the information contained in the TCP timestamp header field. Next, the proposed scheme adjusts the value of the listening period based on the estimated value of RTT. When all TCP connections have been closed, the wireless network card could enter the deep-sleeping mode. In this case, the value of the listening period could be larger than one second, since the user is reading the webpage and is unlikely to send another HTTP request within one second. The usage of the deep-sleeping mode can significantly reduce the power consumption of mobile devices.
32

Power-Saving Design in Android Platform

Wang, Ruei-Sheng 03 May 2011 (has links)
The well-known software company, Google,announced a new handset platform named Android on 5 November 2007, which makes a dramatic impact on the mobile platform market. Later, Open Handset Alliance (OHA) continues to develop Android platform, and to date, the mobile development platform has become the most popular one. However, how to save the power and extend the waiting time are important issues to both academic and industrial communities. Currently, there are few intelligent programs developed to save the power at the Android Market, and these programs are usually short of some functions. Moreover,the Android SDK provides no setting functions to adjust the CPU state. So this paper studies and develops several kernel programs. The targets of our programs are to not only monitor common-use programs on the background, but also dynamically adjust the CPU frequency on the platform according to application programs on executing.Several interfaces are provided such that users can manually adjust the mode and frequency of CPU, view the statistic information, and so on. Furthermore, we also collect many settings of saving the power into our program, which makes users straightforward and easy to manipulate.
33

The study of energy saving and pollution reduction by H2/O2 addition to the diesel engine combustion chamber

Cheng, Chia-Yu 07 August 2012 (has links)
Hydrogen is generally acknowledged to have a high heat value and emit few pollutants. It has been identified as the fuel with the most potential for the twenty-first century. This study investigates energy saving and pollutant reduction for polycyclic aromatic hydrocarbons (PAHs), hydrocarbons (HCs), carbon monoxide (CO), carbon dioxide (CO2), particulate matter (PM), and nitrogen oxides and a hydrogen (H2) and oxygen (O2) mixture (H2/O2) mixed in a diesel engine combustion chamber. Experimental parameters included a speed of 1600 rpm and a torque of 145 Nm in the steady-state condition. These operating conditions represent a speed of 40km/hr, roughly vehicle speed in an urban area. In this study, premium diesel fuel (PDF) was mixed with H2/O2 at different injection rates. When mixed with PDF, the H2/O2 injection rate was set to 60L/min, while different biodiesel injection rates were used in the diesel engine combustion chamber. In addition, this study used mathematical simulation to model the combustion temperature, combustion efficiency, and combustion gas distribution in the combustion chamber. The results of PDF mixed under different H2/O2 injection rates showed that the brake thermal efficiency (BTE) did not significantly change when the H2/O2 injection rate rose from 0 L/min to 40L/min, but markedly increased when the H2/O2 injection rate increased from 50 L/min to 70L/min. The best BTE of the diesel engine was 35.4% at an H2/O2 injection rate of 60 L/min, roughly 12.6% higher than PDF. The brake specific fuel consumption (BSFC) was 16.287 g/bhp-hr at an H2/O2 injection rate of 60 L/min, 11.72% lower than PDF. The results of the BTE and BSFC showed that an H2/O2 injection rate of 60 L/min enabled the best performance of the diesel engine. Emissions of CO, CO2, THC, PM, and PAHs fell as the H2/O2 injection rate increased, while the NOx emission increased as the H2/O2 injection rate increased. This was because the addition of H2/O2 improved the combustion efficiency of the fuel. The total oil equivalent saving was about 22.13% compared to neat diesel at an H2/O2 injection rate of 70 L/min. The BTE decreased from 37.0% to 35.5% while the BSFC increased to 149.75 g/bhp-hr when the PDF was mixed with biodiesel and the injection rate of H2/O2 was set at 60 L/min. These results showed that the performance of the diesel engine declined slightly. The BTE of the 30% biodiesel + PDF decreased roughly 1.5% compared to pure PDF. The emissions of CO, THC, and PAHs decreased as the percentage of biodiesel mixed with PDF increased, but CO2, NOx, and PM increased as the proportion of biodiesel rose. In the mathematical simulation, H2/O2 was mixed with combustion air at injection rates of 0, 30, 60, and 70 L/min, using C12H26 as the main fuel. The simulation investigated the combustion flame temperature, fuel combustion efficiency, and combustion gas distribution in the diesel engine combustion chamber. The results showed that the combustion temperature and combustion efficiency improved as the H2/O2 injection rate increased.
34

The Confirmation of Two TPB-Based Energy Saving Models

Lin, Shis-ping 03 September 2012 (has links)
The reduction green house gases (GHG) and migitation of climate change have become great challenges to mankind. Taiwan¡¦s households, which account for about 13% of the GHG emissions in Taiwan, are certainly a target for GHS and energy reduction. Based on the theory of planned behavior and Stern and Gardner's (1981) typology of energy saving behavior, this study proposed a model of curtailment behavior toward climate change (CCC model) and a model of efficiency action toward climate change (ECC model). Results of confirmatory factor analysis showed that both models were useful. The CCC model could predict people's intent to take curtailment actions and actual behavior, whereas the ECC model could predict people's intent to take efficiency actions. However, the functions of independent variables were different by gender in both models. Subjective norm influnce the dependent variable significantly only in ECC model. This study suggests some energy saving methods, according to the literatures and the findings.
35

Energy-Efficient Multicasting in Mobile Networks

Liu, Tian-You 06 August 2008 (has links)
In this thesis, we focus on mobile networks consist of a single base station as the source transceiver, and multiple mobile stations as the receiving party. Applying energy management on multicasting between the base station and mobile stations, network users can conserve the energy consumed while wating for subscribing data contents to come. We referenced the SMBC-D (Scheduling over Multiple Broadcast Channels--the dynamic model) algorithm proposed by R. Cohen et al., grouping users with high request similarity, partitioning channels with a time-division duplexing scheme, and putting mobile stations into sleep mode during channels that include no subscribing data contents. Since SMBC-D statically schedules fixed size channels, groups request fewer data items will idle their channels after finishing their transmision, while groups request more data items take longer time to finish their transmission. For such problem, we propose a heuristic algorithm that makes use of these idle channels by combining adequate consecutive idle channels, to improve channel utility, and lower the overall energy consumed. We also process relevant computer simulations, verifying that our method has better performance.
36

Εξοικονόμηση ενέργειας κτιρίων με χρήση ευφυούς ελέγχου / Energy efficiency of buildings using fuzzy logic

Μπελογιάννη, Βασιλική 05 February 2015 (has links)
Η εξοικονόμηση ενέργειας σε ένα κτίριο μέσω της αποτελεσματικής χρήσης του κτιριακού αυτοματισμού και των ενεργειακών βελτιώσεων που πρέπει να γίνουν σε αυτό είναι δυο τομείς που συγκεντρώνουν μεγάλο ενδιαφέρον τα τελευταία χρόνια. Ειδικά αν η προσπάθεια αυτή συνδυαστεί με τη χρήση μεθόδων της Ασαφούς Λογικής και των Ασαφών Γνωστικών Δικτύων (ΑΓΔ) τότε αναμένουμε πολλά και αξιόλογα αποτελέσματα τα οποία υπόσχονται μια ραγδαία βελτίωση του τρόπου ζωής μας. Στόχος της παρούσας διπλωματικής εργασίας είναι να χρησιμοποιούν προηγμένες θεωρίες ελέγχου για να διαμορφωθεί τη συνολική ενεργειακή συμπεριφορά ενός κτιρίου για οικιστική ή εμπορική χρήση. Η προτεινόμενη μέθοδος είναι η χρήση ασαφούς λογικής και ο έξυπνος έλεγχος για να διαμορφωθούν τέτοια έξυπνα κτίρια. Για το σκοπό αυτό κατασκευάζονται ένα σύστημα Ασαφούς Λογικής και ένα Ασαφές Γνωστικό Δίκτυο και μελετώνται οι ενεργειακές απαιτήσεις ενός κτιρίου από το νότιο τμήμα της Ελλάδας. Το προτεινόμενο έξυπνο λογισμικό που διαμορφώνεται αποτελείται από δύο μέρη: Α) Το Ασαφές Σύστημα Συμπερασμού, το οποίο λαμβάνοντας υπόψη τα μετεωρολογικά δεδομένα της περιοχής (ηλιακή ακτινοβολία, θερμοκρασία κλπ) ελέγχει τον αυτοματισμό του κτιρίου (HVAC και φωτισμός), προκειμένου να επιτευχθεί πιο αποτελεσματική χρήση του. Β) Το Ασαφές Γνωστικό Δίκτυο (ΑΓΔ), το οποίο βάσει της χρήσης του κάθε στοιχείου του αυτοματισμού κτιρίου, ανιχνεύει αν το κτίριο χρειάζεται ενεργειακές βελτιώσεις και εάν ναι, προτείνει τις κατάλληλες λύσεις με βάση την κατανάλωση ενέργειας. Οι μελέτες προσομοίωσης διεξήχθησαν χρησιμοποιώντας και τις δύο μεθόδους. Τα ληφθέντα αποτελέσματα έδειξαν ότι και οι δύο μέθοδοι μπορούν να συνεισφέρουν θετικά στη βελτίωση του αυτοματισμού κτιρίων, καθώς και στη συνολική ενεργειακή συμπεριφορά του κτιρίου. / Reducing the energy consumption of a building through the effective use of its automation and the necessary energy improvements that can be made, are two scientific areas that gathered a lot of interest in recent years, especially, if this effort is combined with the use of advanced system and control theories such as fuzzy logic, intelligent control and Fuzzy Cognitive Maps (FCM). The purpose of this diploma thesis is to use advanced control theories to model the total energy behavior of an autonomous building for residential or commercial use. The proposed method is using fuzzy logic and intelligent control to model such intelligent buildings. A Fuzzy Logic and a Fuzzy Cognitive Map are constructed. The energy requirements for a building from the southern part of Greece are determined using the Design Builder software. The proposed intelligent software tool is composed of two parts: A)The Fuzzy Inference System (FIS) which taking into account the weather data of the area (sun radiation, temperature etc.) controls the building automation (HVAC and lighting) in order to achieve its most effective use. Β)The Fuzzy Cognitive Map (FCM) which based on the use of each element of the building automation, detects whether the building needs energy improvements and if so, proposes appropriate solutions based on its energy consumption. Simulation studies were conducted using both methods. The obtained results have shown that both methods can contribute positively to the improvement of the building automation as well to the overall energy behavior of the building.
37

Acquiring combat capability through innovative uses of public private partnerships

Buchanan, Steven M., Cabell, Jayson W., McCrary, Daniel C. 06 1900 (has links)
MBA Professional Report / Approved for public release; distribution in unlimited. / The purpose of this research is to study the federal government's historical use of public-private partnerships (PPPs) and their view on the issue. Then we study recent applications (case studies) of innovative financing arrangements by Hannon Armstrong, LLC, an Annapolis, Maryland based financial services firm. The intention is to build upon previous Naval Postgraduate School research efforts is this subject; specifically, expanding upon the efforts of Professor San Miguel, Shank and Summers by investigating current examples of PPPs. First, we examine Hannon Armstrong's "fee for service contract" solution to the lack of appropriated capital funds needed for a vital fiber-optic link near the Arctic Circle. Then, we will explore the history of the Energy Saving Performance Contracts (ESPCs), which have been a useful tool in reducing the energy consumption throughout the federal government. Historically, this program has only been used for fixed assets. There is little debate over the success of these contracts in reducing energy consumption. The authors believe that applying Energy Saving Performance Contracts to mobile assets could further reduce the energy consumption of the Department of Defense (DoD) and save tax-payers millions of dollars.
38

Energy audit of an industrial facility,Hagby waste management plant

Kunytsia, Maksym January 2016 (has links)
In order to answer modern challenges, which come from increasing needs in energy forprivate persons and industries as well as in order to decrease negative environmentalimpacts, caused by the processes of energy generation, it is important to constantly searchfor untapped energy efficiency potential. Moreover, nowadays, energy efficiency hasbecome one of the prerequisites of successful market competitiveness for any type ofindustry on local and global levels.An energy audit is an instrument, which can be used for understanding how the energy isused and identify possible energy-saving opportunities. It can be applied to a facility as awhole, as well as individually to equipment, system(s) or process(es). Moreover, energysaving measures can be both cross-cutting and sector-specific.The purpose of this project was to conduct a detailed energy audit of the Hagby wasterecycling plant and to identify beneficial energy saving opportunities from economic,environmental and social perspectives.In the frames of a preliminary energy audit 10 focus areas for further analysis wereidentified. For every area a baseline assessment of the current energy performance wasconducted, possible energy management opportunities were identified and evaluated aswell as results of each analysis were summarized. According to the results of the study, with the implementation of the suggestions, whichrequire no, low or medium investments it is possible to save 3,2% of the energy per year,which corresponds to 76 846 kWh. Energy consumption can further be decreased byimplementing measures, which need high initial financial investment. In that case totalsavings will be 468 846 kWh or 19,4% of total annual energy consumption. Additionalenergy might be saved just by introducing energy housekeeping measures. Finally,implementation of all the proposed EMO can bring 14,46 tons of 2 CO savings annually.Additional benefits of implementing the energy saving opportunities come from decreasingenvironmental impacts, improving working conditions of the plant employees and higherenergy security at the plant.The results of the energy audit can be a solid base for establishing an energy managementprogram at the plant, which will include performance targets, required resources and aclear procedure of realization of improvements. However, since some of the calculations inthe current study are based on various assumptions, after the company forms the energymanagement program, it is necessary to invite experts from industry in order to giveaccurate calculations for each of the focus areas.
39

Systematic Structure Synthesis of Distillation-Based Separation Processes / 蒸留を基軸とした分離プロセスの系統的構造合成手法

Takase, Hiroshi 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21130号 / 工博第4494号 / 新制||工||1698(附属図書館) / 京都大学大学院工学研究科化学工学専攻 / (主査)教授 長谷部 伸治, 教授 大嶋 正裕, 教授 佐野 紀彰 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
40

Městský polyfunkční dům na ulici Křížová, Brno / Multipurpose Town House on Křížová Street, Brno

Poruba, Martin January 2011 (has links)
Design Theory 1st WHAT IS THE TOWN HOUSE By Town House (the only no MD) is undoubtedly the "parterre". The parterre is meant the space where the public associates with a freelancer (the owner of the house rules), which produces original products and original services. The advantage of this arrangement is just the comfort of home owners who meet only a few steps and is in its own business. Up to then follow the floors for residential owners and floor suitable for extended family living or for rent. The building can be rented for parts. The bottom line is that at least one of the apartments will be permanently residing owner. This is achieved by real form MD. The possibility of phased construction, in principle, helps to achieve optimal distribution of project funding (see figure below), ie. There is no need to invest at a time. It is important to fill the empty land in the streets of the city the right partner, with a gradual hill floor living, creating and MD. Just like in nature and in grow houses in the same way. Live to see if any of them, it is easy to replace by a new town house in a relatively short period of time. 2nd TRANSPORT VISION January 2 The need for transport for the urban man City man living in MD would be able to travel virtually anywhere on foot. Common goals, which during the day or week Stakes should be available nearby. She would arise from the need to own a personal vehicle for city driving. So the MD automatically receives the imaginary top of the pyramid forms of housing. Living it has many advantages. I would venture to say that owning a house might be the goal of each of us. As the owner of MD do not happen to work, ie. carry him away from home. All comfort is located in the vicinity. This form of housing support retail development and maintenance of interpersonal relationships. It is a healthy way of life. Basically I'm trying to point out the long years of proven experience. February 2 Future Transport When thinking about the future of transportation, I think of flying caps, with automatic navigation. Today we may seem too fantasy, but it can be assumed that this direction for the future traffic will develop. Such a concept of urban transport is therefore clear that it will be necessary to invest large sums in building road corridors and the streets will again become a pleasant place for people to meet. Just imagine the morning when you come to lift the roof of the MD and sit at sunrise in your hovercraft ... amazing! If you stay in the country, even today there are solutions that will relieve traffic in the city. Good public transport will solve many. Congestion nodes not in the inner cities, what to do. MHD What should be: efficient, clean, for an annual pass with the support price At least busy line should be abolished and congested lines strengthened, leading to migration of people into urban centers. It is a challenge for city planners. A sufficient number of seats in vehicles is a necessary condition for successful public transport. Cars with low starting edge and in good technical condition are showcase quality public transport. Bicycle hire Following the example of many EU countries, we should consider for transportation by bicycle wheels. Bike rentals should be the norm. RENTAL MOTOR UNIVERSAL MINI carts Likewise, the creation of citywide rental carts with electric motor at low speed 25 km / h would be very beneficial.

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