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O código de obras como instrumento regulatório de eficiência energética em edificações residenciais: proposições para o município de São Paulo; The Building Code as a Energy Efficiency Regulatory Instrument in Residential Buildings: Propositions to São Paulo Municipality

Teodoro, Maria Inês Tavares de Matos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 19/04/2012 PT
Relevância na Pesquisa
76.1%
A conjuntura nacional de crescimento econômico e populacional aliada aos programas habitacionais de combate ao déficit de moradias deixa antever o contínuo aumento da demanda energética no setor residencial, que deve ser alvo de políticas públicas de promoção de eficiência energética. O objetivo da presente dissertação é investigar o potencial do Código de Obras e Edificações (COE) do Município de São Paulo enquanto instrumento regulatório de promoção de eficiência energética e apresentar sugestões com vista à revisão do atual documento. Para tal dividiu-se a pesquisa em três temas: fatores que explicam o consumo energético (direto e indireto) das edificações e estratégias de minimização desse consumo; caracterização dos códigos de eficiência energética em edificações (CEEE), com destaque para o Código de Obras, e panorama internacional e brasileiro relativamente à sua adoção; caracterização do consumo energético do Município de São Paulo e análise dos requisitos de eficiência energética no atual COE. Atendendo à elevada taxa de novas construções e ao estoque de edifícios obsoletos com potencial de retrofitting defende-se que o Código de Obras, pela sua abrangência e obrigatoriedade...

Reliable and energy efficient routing for ad hoc networks; Encaminhamento confiável e energeticamente eficiente para redes ad hoc

Talooki, Vahid Nazari
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Tese de Doutorado
Relevância na Pesquisa
56.01%
In Mobile Ad hoc NETworks (MANETs), where cooperative behaviour is mandatory, there is a high probability for some nodes to become overloaded with packet forwarding operations in order to support neighbor data exchange. This altruistic behaviour leads to an unbalanced load in the network in terms of traffic and energy consumption. In such scenarios, mobile nodes can benefit from the use of energy efficient and traffic fitting routing protocol that better suits the limited battery capacity and throughput limitation of the network. This PhD work focuses on proposing energy efficient and load balanced routing protocols for ad hoc networks. Where most of the existing routing protocols simply consider the path length metric when choosing the best route between a source and a destination node, in our proposed mechanism, nodes are able to find several routes for each pair of source and destination nodes and select the best route according to energy and traffic parameters, effectively extending the lifespan of the network. Our results show that by applying this novel mechanism, current flat ad hoc routing protocols can achieve higher energy efficiency and load balancing. Also, due to the broadcast nature of the wireless channels in ad hoc networks...

Increasing energy efficiency in OCDMA network via distributed power control

Durand,Fábio R.; Angélico,Bruno A.; Abrão,Taufik
Fonte: Sociedade Brasileira de Microondas e Optoeletrônica e Sociedade Brasileira de Eletromagnetismo Publicador: Sociedade Brasileira de Microondas e Optoeletrônica e Sociedade Brasileira de Eletromagnetismo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 EN
Relevância na Pesquisa
55.95%
In this work, we investigate the utilization of transmission power control as mechanism to increase the energy efficiency in optical code division multiplexing access (OCDMA) networks. We have modeled the energy efficiency considering the optical fiber transmission and network infrastructure as encoders, decoders and star coupler. In the analyzed scenario, this model confirms that the energy consumption of the network infrastructure is larger than the energy consumption of the transmission infrastructure; On the other hand, we have proposed a scheme to define the energy efficiency according to the BER level accomplished with the quality of service (QoS) requirements. The main results showed that it is possible to save 70% of the transmitted energy per bit with the penalty of one order of magnitude of BER.

Transient and permanent error management for networks-on-chip

Yu, Qiaoyan (1979 - ); Ampadu, Paul
Fonte: University of Rochester Publicador: University of Rochester
Tipo: Tese de Doutorado Formato: Number of Pages:xviii, 251 leaves; Illustrations:ill. (some col.)
ENG
Relevância na Pesquisa
45.84%
Thesis (Ph. D.)--University of Rochester. Dept. of Electrical and Computer Engineering, 2011.; Reliability has become one of the most important metrics for on-chip communications infrastructures in nanoscale technologies. Reduced supply voltages and high clock frequency exacerbate the impact of noise sources such as particle strikes and crosstalk, which can cause transient errors in transmitted data. Manufacturing defects and aging issues can cause permanent errors in the communication links. The modularity of the Networks-on-Chip (NoCs) approach facilitates the exploration of error control techniques for on-chip interconnects and many-cores systems. Unfortunately, error control is not free. Worst-case error management methods are simple but waste energy and bandwidth in favorable noise conditions. Consequently, cost-effective techniques for improving link error resilience are needed. In this work, we propose configurable error control methods to tackle variable transient errors and exploit existing transient error control redundancy for permanent error management, achieving high reliability and low average energy consumption with minor area overhead. To adapt to the variable transient error rates, a configurable error control coding (ECC) scheme is proposed for datalink-layer transient error management. The proposed method can adjust both error detection and error correction capability at runtime by varying the number of redundant wires for parity check bits. The obtained error resilience makes the proposed method suitable for a range of link error rates. Configuring the number of redundant wires to match the noise conditions reduces the average energy consumption in the ECC codec and interconnect link. A hardware efficient implementation for the configurable ECC is presented...

Energy efficiency with runtime models for energy-aware embedded systems.

Karakehayov, Z.; Vassev, Emil
Fonte: IEEE Computer Society Publicador: IEEE Computer Society
Tipo: Conference item; all_ul_research; none
ENG
Relevância na Pesquisa
55.79%
non-peer-reviewed; Reducing power consumption is an important design objective in energy-constrained embedded and mobile systems. Such systems must be designed to meet functional and often timing requirements facing the challenge of energy restriction. This paper presents a new approach for power management based on ZETA, a mathematical framework that utilizes computational and energy models to provide proofs for optimal clock rate control. Special runtime models are developed to provide optimal values for the CPU clock rate under real-time requirements. The method is suitable for embedded systems which utilize a single task real-time computational model and linear energy models. A special tool called CASTLE is developed to support this approach. CASTLE helps us integrate power management into the operating system or to automatically insert power management into the application code. The tool utilizes as input application-specific data which is conveyed via comments in the source file.

Status of Energy Efficiency in the Western Balkans : A Stocktaking Report

World Bank
Fonte: World Bank Publicador: World Bank
Relevância na Pesquisa
65.97%
Across the Western Balkan region, countries exhibit relatively high levels of energy intensity, a high energy savings potential among energy end-users, and heavy dependence on imported hydrocarbons. Energy markets would benefit from enhanced demand-side efforts and integrated energy efficiency measures across all sectors. Since most energy infrastructure was built during the 1960s and 1970s, inadequately maintained since the 1990s, and reaching the end of its useful lifespan, now is a crucial time to consider the way forward in the energy sector. The signing of the Energy Community Treaty in 2003 marked the beginning of systematic energy sector liberalization among Western Balkan countries, allowing them to deal with widespread energy sector problems that included, on the demand side, low energy tariffs, lack of payment discipline and, hence, little incentive for energy users to invest in energy efficiency measures. Building each component of the strong enabling environment required for increased Energy Efficiency (EE) across the Western Balkan countries will need cooperation among decision makers at multiple government levels...

Mainstreaming Building Energy Efficiency Codes in Developing Countries : Global Experiences and Lessons from Early Adopters

Liu, Feng; Meyer, Anke S.; Hogan, John F.
Fonte: World Bank Publicador: World Bank
Relevância na Pesquisa
66.06%
This report summarizes the findings of an extensive literature survey of the experiences of implementing BEECs in developed countries. It also includes case studies of four developing countries- China, Egypt, India, and Mexico and the state of California in the United States of America. It aims to inform both the World Bank Group and its client countries about global best practices and emerging lessons from developing countries in the design and implementation of BEECs. The report also serves as a primer on the basic features of BEECs and the commonly adopted compliance and enforcement approaches. The key challenges to improving compliance enforcement in developing countries include the level of government commitment to energy efficiency, the effectiveness of government oversight of the construction sector, the compliance capacity of domestic/local building supply chain, and the financing constraints. These challenges are surmountable in countries where economic growth is sustained and energy efficiency is pursued as a key element of national energy strategy.

Egypt : Improve Energy Efficiency

World Bank
Fonte: Washington, DC Publicador: Washington, DC
EN_US
Relevância na Pesquisa
65.98%
Egypt has an overall low efficiency in using energy resources to create economic wealth. Egypt is among the most energy intensive economies in the Middle East North Africa region as well as in the world. The Egyptian energy intensity is almost twice as high as in some neighboring countries like Morocco and Tunisia and four times as high as industrialized countries like Japan and Germany. On the sector level, most industrial processes, equipment and consumer appliances in Egypt have 20 percent or higher energy consumption than the best international practices. Therefore, Egypt has a great opportunity to improve the efficiency of its energy resource utilization across all segments of economic activities. The objective of this report is to take stock of the past/ongoing energy efficiency initiatives and activities and to recommend a set of the principal strategic actions which could be undertaken by the Government of Egypt to promote and sustain energy efficiency improvements. The first part of the report presents the following topics: a brief general overview of energy use in Egypt; an analysis of the current institutional framework for energy efficiency; a review of the past...

Integrating Variable Renewable Energy into Power System Operations

Nikolakakis, Thomas; Chatopadhyay, Debabrata
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
45.82%
Wind and solar energy is a fast-growing share of the global energy mix. But integrating them into power-system operations requires significant adaptations to compensate for their variability. Solutions include increasing the amount of flexible generation within the system, combining, and dispersing variable resources to smooth aggregate output, expanding the transmission network, using smart technology to control supply and demand, and storing electricity.

A study of the user behaviours in dwellings of earth construction

Daniel, L.; Williamson, T.
Fonte: University of Sydney; Australia Publicador: University of Sydney; Australia
Tipo: Conference paper
Publicado em //2011 EN
Relevância na Pesquisa
45.88%
Occupant behaviours are cited as a significant factor in residential energy use, in a report prepared for the Department of Climate Change and Energy Efficiency in 2010. The Nationwide House Energy Rating Scheme (NatHERS), that determines the Star Rating for the Building Code of Australia (BCA) Energy Efficiency compliance, allows just a single user profile. This research explores the postulation that; occupants of earth dwellings may have different behaviours to the generic profile prescribed by the NatHERS protocol and that these alternative behaviour profiles may affect greater household energy savings. If true, this indicates that the NatHERS method of Energy Efficiency compliance may be biased against occupants with ecocentric dispositions, shown to result in energy saving behaviours. This study provides empirical evidence on the occupancy behaviour profiles of a cohort of earth building users and gauges the critical effect this has on star rating output and compliance with the BCA Energy Efficiency requirements. Questionnaire results corroborate the previously acknowledged ecocentric dispositions of occupants of dwellings incorporating earth components, whilst thermal simulation reveals the potential energy savings these behavioural trends may affect.; http://www.adelaide.edu.au/directory/terence.williamson; Lyrian Daniel and Terence Williamson

A Market Transformation Programme for Improving Energy Efficiency in Data Centres

BERTOLDI PAOLO
Fonte: ACEEE Publicador: ACEEE
Tipo: Contributions to Conferences Formato: CD-ROM
ENG
Relevância na Pesquisa
45.97%
The European Code of Conduct for Data Centres is a voluntary market transformation programme addressing primarily data centre owners and operators, and secondly the supply chain. The Data Centres Code of Conduct has been created in response to increasing energy consumption in data centres and the need to reduce the related environmental, economic and energy supply impacts. The aim is to inform and stimulate operators and owners to reduce energy consumption in a cost-effective manner without hampering the critical function of data centres. It also introduces a set of metrics to measure the energy efficiency. The data centre supply industry can join the programme by offering products and solution to help achieving the energy savings. Since the start of the programme in 2008, 220 Data Centres have been certified as Participant. The core of the programme is the commitment by the participant to carry out an initial energy audit to identify the major energy saving opportunities; to prepare an Action Plan; to implement the Action Plan; and to monitor energy consumption. The paper reports on the results achieved so far in terms of energy savings and technologies adopted, the participant motivations to join the programme and it suggests additional market transformation measures to improve data centres energy efficiency.; JRC.F.7-Renewables and Energy Efficiency

Towards an energy efficient 10 Gb/s optical ethernet: performance analysis and viability

Larrabeite, D.; Hernández, José Alberto; Reviriego, Pedro; Maestro, J. A.; Urueña, Manuel
Fonte: Elsevier Publicador: Elsevier
Tipo: info:eu-repo/semantics/acceptedVersion; info:eu-repo/semantics/article Formato: application/pdf
Publicado em /07/2011 ENG
Relevância na Pesquisa
55.8%
The new IEEE 802.3az Energy Efficient Ethernet (EEE) standard will improve significantly the energy efficiency of 10 Gbps copper transceivers by the introduction of a sleep mode for idle transmission times. The next step towards energy saving seems to be the application of similar concepts to Optical Ethernet, both for short and long range links. To this aim, this paper starts by proposing an analytical model to estimate the energy consumption of a link that uses a sleep-mode power saving mechanism. This model can be useful to answer a number of questions that need to be carefully studied. Otherwise, the complexity of optical components could be increased for the sake of an energy saving that could turn out negligible. In the rest of the paper we analyze three key questions to try to shed some light on this design decision: (a) is the new copper EEE actually outperforming the current regular optical Ethernet in terms of energy saving in such a way that optical PHYs (transceivers) actually need a green upgrade to remain more energy efficient than their copper counterparts? (b) How much energy saving could be actually achieved by EE optical Ethernet? (c) What is the transition time required to achieve a substantial energy saving at medium traffic loads on EE 10 Gb/s optical Ethernet links? The answer to the latter question sets a concrete goal for short-term research in fast on–off laser technology.; This work has been supported by a Google Research Award...

Accelerating Energy Conservation in China's Provinces

World Bank
Fonte: World Bank Publicador: World Bank
Tipo: Economic & Sector Work :: Energy Study
ENGLISH
Relevância na Pesquisa
45.96%
China's comprehensive 2006-10 energy conservation drive has succeeded in both delivering strong results to date and laying policy and program foundations for delivering more energy savings well into the future. The policies, program concepts, and implementation platforms created over the last four years will serve China well to achieve further energy conservation results during the next five-year planning cycle, and to help achieve China's target to reduce the carbon intensity of its economy by 40-45 percent by 2020. However, much work remains to be done, to improve, adjust, and strengthen the programs further, and to continue to interject new and creative solutions. This report seeks to provide provincial agencies and groups in China, and those that support them, with some outside perspectives and ideas on further development of provincial-level energy conservation programs over the next several years. The report also describes the provincial energy conservation programs developed during the last four years in some detail...

The Residential Energy Efficiency Program in Lithuania

Sirvydis, Viktoras
Fonte: World Bank Group, Washington, DC Publicador: World Bank Group, Washington, DC
Tipo: Publications & Research :: Working Paper; Publications & Research
ENGLISH
Relevância na Pesquisa
65.92%
This case study, which describes the residential Lithuanian energy efficiency (EE) program and lessons learned, was prepared in support of the Energy Sector Management Assistance Program (ESMAP)-funded technical assistance activity Scaling Up of Energy Efficiency in Building in the Western Balkans. During the first period (1996-2004), the World Bank- and donor-funded Energy Efficiency Housing Pilot Project was implemented around investments of US$28.6 million. In addition, technical assistance (TA) was included to facilitate energy auditor market development, establish centers to provide legal advice to homeowner associations (HOAs), train bank officials, and develop a housing agency to further promote EE investments in the residential sector. These changes accelerate the modernization process in Lithuania from about 70 apartment buildings a year to 490 buildings a year. Subsidy procedures for low-income persons were also revised: a May 2013 law to provide support to low-income families was amended to require eligible households to implement a renovation project or risk a cut in their state subsidy from 50 percent to 0 percent for heating costs for a period of three years. This has facilitated the renovation decision-making process among low-income apartment owners.

Financing Energy Efficiency Measures for Residential Building Stock : Scaling Up Energy Efficiency in Buildings in the Western Balkans

Kalkum, Bernd
Fonte: World Bank Group, Washington, DC Publicador: World Bank Group, Washington, DC
Tipo: Publications & Research; Publications & Research :: Working Paper
ENGLISH; EN_US
Relevância na Pesquisa
55.93%
Within the Western Balkans region, a secure energy supply is critical to sustaining economic growth. Currently, the region relies heavily on imported hydrocarbons and maintains high energy intensity relative to Gross Domestic Product, or GDP. This places a huge burden on companies, which require affordable and reliable infrastructure services to be competitive; the public sector, which spends significant budgetary resources on energy; and households, which have to pay a high portion of their income for energy services. As energy pricing is further rationalized, a higher burden will be placed on all sectors, especially poorer households. The residential sector is a significant energy consumer. Its share of total final energy consumption ranges from 28 percent to 32 percent (compared with the EU average of 27 percent). Fairly simple renovations such as insulation, heating system upgrades, and improvements to windows and lighting could reduce consumption in this sector by some 9 percent, with payback periods generally less than 8 years. Such improvements could help ease the impact of future tariff increases while helping reduce the region's projected energy supply and demand gap.

Energy Efficiency and Reliability in Wireless Biomedical Implant Systems

Abouei, Jamshid; Brown, J. David; Plataniotis, Konstantinos N.; Pasupathy, Subbarayan
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 05/01/2011
Relevância na Pesquisa
45.87%
The use of wireless implant technology requires correct delivery of the vital physiological signs of the patient along with the energy management in power-constrained devices. Toward these goals, we present an augmentation protocol for the physical layer of the Medical Implant Communications Service (MICS) with focus on the energy efficiency of deployed devices over the MICS frequency band. The present protocol uses the rateless code with the Frequency Shift Keying (FSK) modulation scheme to overcome the reliability and power cost concerns in tiny implantable sensors due to the considerable attenuation of propagated signals across the human body. In addition, the protocol allows a fast start-up time for the transceiver circuitry. The main advantage of using rateless codes is to provide an inherent adaptive duty-cycling for power management, due to the flexibility of the rateless code rate. Analytical results demonstrate that an 80% energy saving is achievable with the proposed protocol when compared to the IEEE 802.15.4 physical layer standard with the same structure used for wireless sensor networks. Numerical results show that the optimized rateless coded FSK is more energy efficient than that of the uncoded FSK scheme for deep tissue (e.g....

On the Latency and Energy Efficiency of Erasure-Coded Cloud Storage Systems

Kumar, Akshay; Tandon, Ravi; Clancy, T. Charles
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.9%
The increase in data storage and power consumption at data-centers has made it imperative to design energy efficient Distributed Storage Systems (DSS). The energy efficiency of DSS is strongly influenced not only by the volume of data, frequency of data access and redundancy in data storage, but also by the heterogeneity exhibited by the DSS in these dimensions. To this end, we propose and analyze the energy efficiency of a heterogeneous distributed storage system in which $n$ storage servers (disks) store the data of $R$ distinct classes. Data of class $i$ is encoded using a $(n,k_{i})$ erasure code and the (random) data retrieval requests can also vary across classes. We show that the energy efficiency of such systems is closely related to the average latency and hence motivates us to study the energy efficiency via the lens of average latency. Through this connection, we show that erasure coding serves the dual purpose of reducing latency and increasing energy efficiency. We present a queuing theoretic analysis of the proposed model and establish upper and lower bounds on the average latency for each data class under various scheduling policies. Through extensive simulations, we present qualitative insights which reveal the impact of coding rate...

On the Energy Efficiency of LT Codes in Proactive Wireless Sensor Networks

Abouei, Jamshid; Brown, J. David; Plataniotis, Konstantinos N.; Pasupathy, Subbarayan
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 03/12/2009
Relevância na Pesquisa
45.86%
This paper presents the first in-depth analysis on the energy efficiency of LT codes with Non Coherent M-ary Frequency Shift Keying (NC-MFSK), known as green modulation [1], in a proactive Wireless Sensor Network (WSN) over Rayleigh flat-fading channels with path-loss. We describe the proactive system model according to a pre-determined time-based process utilized in practical sensor nodes. The present analysis is based on realistic parameters including the effect of channel bandwidth used in the IEEE 802.15.4 standard, and the active mode duration. A comprehensive analysis, supported by some simulation studies on the probability mass function of the LT code rate and coding gain, shows that among uncoded NC-MFSK and various classical channel coding schemes, the optimized LT coded NC-MFSK is the most energy-efficient scheme for distance $d$ greater than the pre-determined threshold level $d_T$, where the optimization is performed over coding and modulation parameters. In addition, although uncoded NC-MFSK outperforms coded schemes for $d < d_T$, the energy gap between LT coded and uncoded NC-MFSK is negligible for $d < d_T$ compared to the other coded schemes. These results come from the flexibility of the LT code to adjust its rate to suit instantaneous channel conditions...

On the Energy Efficiency of LT Codes in Proactive Wireless Sensor Networks

Abouei, Jamshid; Brown, J. David; Plataniotis, Konstantinos N.; Pasupathy, Subbarayan
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 13/11/2010
Relevância na Pesquisa
45.87%
This paper presents an in-depth analysis on the energy efficiency of Luby Transform (LT) codes with Frequency Shift Keying (FSK) modulation in a Wireless Sensor Network (WSN) over Rayleigh fading channels with pathloss. We describe a proactive system model according to a flexible duty-cycling mechanism utilized in practical sensor apparatus. The present analysis is based on realistic parameters including the effect of channel bandwidth used in the IEEE 802.15.4 standard, active mode duration and computation energy. A comprehensive analysis, supported by some simulation studies on the probability mass function of the LT code rate and coding gain, shows that among uncoded FSK and various classical channel coding schemes, the optimized LT coded FSK is the most energy-efficient scheme for distance d greater than the pre-determined threshold level d_T , where the optimization is performed over coding and modulation parameters. In addition, although the optimized uncoded FSK outperforms coded schemes for d < d_T , the energy gap between LT coded and uncoded FSK is negligible for d < d_T compared to the other coded schemes. These results come from the flexibility of the LT code to adjust its rate to suit instantaneous channel conditions, and suggest that LT codes are beneficial in practical low-power WSNs with dynamic position sensor nodes.; Comment: accepted for publication in IEEE Transactions on Signal Processing

Building an Energy Efficiency Supply Curve: A Case Study of Rubenstein Hall at Duke University

Devoy, Kealy
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 17/04/2012 EN_US
Relevância na Pesquisa
66.08%
Duke University has a deep commitment to sustainability and a clear track record of constructing highly efficient buildings. The new North Carolina Building Energy Conservation Code requires that new construction be 30 percent more efficient than the ASHRAE 90.1-2007 standard. To determine the impact of meeting this new code, an energy model of Rubenstein Hall was constructed as if the building were being built new today. This model was used to assess the effect of energy efficiency projects on the building’s overall energy use. Projects fell into four categories: heating ventilating and air conditioning, thermal performance, solar gain, and lighting. The results of the analysis found that the entirety of the new NC Building Energy Conservation Code could be met through four projects, each with no upfront costs: reducing the minimum percentage of outside air to 15 percent (from 17-21 percent), altering the time at which thermostats return to set points from 5am to 7am, reducing the lighting power density to 0.9 watts per square foot (from 1.8 watts per square foot), and maximizing the window area at 30 percent of total wall area. These projects will result in a building that uses 43 percent less energy use than the ASHRAE 90.1-2007 standard...