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Low-Cost Insulation for Energy Efficient Buildings in Terai Region of Nepal
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作者 Abhishek Karn 《Journal of Civil Engineering and Architecture》 2024年第1期38-50,共13页
There is a huge amount of energy savings potential in public building sector that has yet to be realized.By prioritizing energy efficiency in its own buildings and thus promoting the development of required knowledge ... There is a huge amount of energy savings potential in public building sector that has yet to be realized.By prioritizing energy efficiency in its own buildings and thus promoting the development of required knowledge in terms of new technology and construction methods,the public sector will lead the way in efforts to increase the rate of renovations.The low-cost insulation strategies and a comparison of cost with existing insulation materials has been described in this study.We have repeatedly faced energy crises and will continue to do so in the future if appropriate action is not taken in a timely manner.Properly implementing energy-saving initiatives in for achieving thermal comfort in buildings as well as reducing the energy costs would undoubtedly inspire the residential sector,resulting in significant reductions in energy usage.Simulations were carried out to study insulation layers on various building components like exterior walls,floor and roofs,generating different scenarios for a building as a base model,which were then compared and analysed to verify the literature used to develop the cases.The proposed recommendations,which have been validated,are certain to increase building energy efficiency,achieve thermal comfort in low cost than what is currently being used. 展开更多
关键词 BUILDINGS energy energy efficient thermal comfort
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A Traffic-Aware and Cluster-Based Energy Efficient Routing Protocol for IoT-Assisted WSNs
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作者 Hina Gul Sana Ullah +1 位作者 Ki-Il Kim Farman Ali 《Computers, Materials & Continua》 SCIE EI 2024年第8期1831-1850,共20页
The seamless integration of intelligent Internet of Things devices with conventional wireless sensor networks has revolutionized data communication for different applications,such as remote health monitoring,industria... The seamless integration of intelligent Internet of Things devices with conventional wireless sensor networks has revolutionized data communication for different applications,such as remote health monitoring,industrial monitoring,transportation,and smart agriculture.Efficient and reliable data routing is one of the major challenges in the Internet of Things network due to the heterogeneity of nodes.This paper presents a traffic-aware,cluster-based,and energy-efficient routing protocol that employs traffic-aware and cluster-based techniques to improve the data delivery in such networks.The proposed protocol divides the network into clusters where optimal cluster heads are selected among super and normal nodes based on their residual energies.The protocol considers multi-criteria attributes,i.e.,energy,traffic load,and distance parameters to select the next hop for data delivery towards the base station.The performance of the proposed protocol is evaluated through the network simulator NS3.40.For different traffic rates,number of nodes,and different packet sizes,the proposed protocol outperformed LoRaWAN in terms of end-to-end packet delivery ratio,energy consumption,end-to-end delay,and network lifetime.For 100 nodes,the proposed protocol achieved a 13%improvement in packet delivery ratio,10 ms improvement in delay,and 10 mJ improvement in average energy consumption over LoRaWAN. 展开更多
关键词 Internet of Things wireless sensor networks traffic load CLUSTERING ROUTING energy efficiency
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Priority Based Energy Efficient MAC Protocol by Varying Data Ratefor Wireless Body Area Network
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作者 R.Sangeetha Usha Devi Gandhi 《Computer Systems Science & Engineering》 2024年第2期395-411,共17页
Wireless Body Area Network(WBAN)is a cutting-edge technology that is being used in healthcare applications to monitor critical events in the human body.WBAN is a collection of in-body and on-body sensors that monitor ... Wireless Body Area Network(WBAN)is a cutting-edge technology that is being used in healthcare applications to monitor critical events in the human body.WBAN is a collection of in-body and on-body sensors that monitor human physical parameters such as temperature,blood pressure,pulse rate,oxygen level,body motion,and so on.They sense the data and communicate it to the Body Area Network(BAN)Coordinator.The main challenge for the WBAN is energy consumption.These issues can be addressed by implementing an effective Medium Access Control(MAC)protocol that reduces energy consumption and increases network lifetime.The purpose of the study is to minimize the energy consumption and minimize the delay using IEEE 802.15.4 standard.In our proposed work,if any critical events have occurred the proposed work is to classify and prioritize the data.We gave priority to the highly critical data to get the Guarantee Tine Slots(GTS)in IEEE 802.15.4 standard superframe to achieve greater energy efficiency.The proposed MAC provides higher data rates for critical data based on the history and current condition and also provides the best reliable service to high critical data and critical data by predicting node similarity.As an outcome,we proposed a MAC protocol for Variable Data Rates(MVDR).When compared to existing MAC protocols,the MVDR performed very well with low energy intake,less interruption,and an enhanced packet-sharing ratio. 展开更多
关键词 Wireless Body Area Network(WBAN) IEEE 802.15.4 energy efficiency MAC protocol ZIGBEE
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Energy Efficient Unequal Fault Tolerance Clustering Approach
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作者 Sowjanya Ramisetty Divya Anand +4 位作者 Kavita Sahil Verma NZ Jhanjhi Mehedi Masud Mohammed Baz 《Computer Systems Science & Engineering》 SCIE EI 2023年第5期1971-1983,共13页
For achieving Energy-Efficiency in wireless sensor networks(WSNs),different schemes have been proposed which focuses only on reducing the energy consumption.A shortest path determines for the Base Station(BS),but faul... For achieving Energy-Efficiency in wireless sensor networks(WSNs),different schemes have been proposed which focuses only on reducing the energy consumption.A shortest path determines for the Base Station(BS),but fault tolerance and energy balancing gives equal importance for improving the network lifetime.For saving energy in WSNs,clustering is considered as one of the effective methods for Wireless Sensor Networks.Because of the excessive overload,more energy consumed by cluster heads(CHs)in a cluster based WSN to receive and aggregate the information from member sensor nodes and it leads to failure.For increasing the WSNs’lifetime,the CHs selection has played a key role in energy consumption for sensor nodes.An Energy Efficient Unequal Fault Tolerant Clustering Approach(EEUFTC)is proposed for reducing the energy utilization through the intelligent methods like Particle Swarm Optimization(PSO).In this approach,an optimal Master Cluster Head(MCH)-Master data Aggregator(MDA),selection method is proposed which uses the fitness values and they evaluate based on the PSO for two optimal nodes in each cluster to act as Master Data Aggregator(MDA),and Master Cluster Head.The data from the cluster members collected by the chosen MCH exclusively and the MDA is used for collected data reception from MCH transmits to the BS.Thus,the MCH overhead reduces.During the heavy communication of data,overhead controls using the scheduling of Energy-Efficient Time Division Multiple Access(EE-TDMA).To describe the proposed method superiority based on various performance metrics,simulation and results are compared to the existing methods. 展开更多
关键词 energy-EFFICIENCY unequal fault tolerant clustering approach particle swarm optimization master data aggregator energy efficient time division multiple access optimal nodes
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Coati Optimization-Based Energy Efficient Routing Protocol for Unmanned Aerial Vehicle Communication 被引量:1
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作者 Hanan Abdullah Mengash Hamed Alqahtani +5 位作者 Mohammed Maray Mohamed K.Nour Radwa Marzouk Mohammed Abdullah Al-Hagery Heba Mohsen Mesfer Al Duhayyim 《Computers, Materials & Continua》 SCIE EI 2023年第6期4805-4820,共16页
With the flexible deployment and high mobility of Unmanned Aerial Vehicles(UAVs)in an open environment,they have generated con-siderable attention in military and civil applications intending to enable ubiquitous conn... With the flexible deployment and high mobility of Unmanned Aerial Vehicles(UAVs)in an open environment,they have generated con-siderable attention in military and civil applications intending to enable ubiquitous connectivity and foster agile communications.The difficulty stems from features other than mobile ad-hoc network(MANET),namely aerial mobility in three-dimensional space and often changing topology.In the UAV network,a single node serves as a forwarding,transmitting,and receiving node at the same time.Typically,the communication path is multi-hop,and routing significantly affects the network’s performance.A lot of effort should be invested in performance analysis for selecting the optimum routing system.With this motivation,this study modelled a new Coati Optimization Algorithm-based Energy-Efficient Routing Process for Unmanned Aerial Vehicle Communication(COAER-UAVC)technique.The presented COAER-UAVC technique establishes effective routes for communication between the UAVs.It is primarily based on the coati characteristics in nature:if attacking and hunting iguanas and escaping from predators.Besides,the presented COAER-UAVC technique concentrates on the design of fitness functions to minimize energy utilization and communication delay.A varied group of simulations was performed to depict the optimum performance of the COAER-UAVC system.The experimental results verified that the COAER-UAVC technique had assured improved performance over other approaches. 展开更多
关键词 Artificial intelligence unmanned aerial vehicle data communication routing protocol energy efficiency
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FSE2R:An Improved Collision-Avoidance-based Energy Efficient Route Selection Protocolin USN
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作者 Prasant Ku.Dash Lopamudra Hota +3 位作者 Madhumita Panda N.Z.Jhanjhi Kshira Sagar Sahoo Mehedi Masud 《Computer Systems Science & Engineering》 SCIE EI 2023年第3期2225-2242,共18页
The 3D Underwater Sensor Network(USNs)has become the most optimistic medium for tracking and monitoring underwater environment.Energy and collision are two most critical factors in USNs for both sparse and dense regio... The 3D Underwater Sensor Network(USNs)has become the most optimistic medium for tracking and monitoring underwater environment.Energy and collision are two most critical factors in USNs for both sparse and dense regions.Due to harsh ocean environment,it is a challenge to design a reliable energy efficient with collision free protocol.Diversity in link qualities may cause collision and frequent communication lead to energy loss;that effects the network performance.To overcome these challenges a novel protocol Forwarder Selection Energy Efficient Routing(FSE2R)is proposed.Our proposal’s key idea is based on computation of node distance from the sink,Residual Energy(RE)of each node and Signal to Interference Noise Ratio(SINR).The node distance from sink and RE is computed for reliable forwarder node selection and SINR is used for analysis of collision.The novel proposal compares with existing protocols like H2AB,DEEP,and E2LR to achieve Quality of Service(QoS)in terms of through-put,packet delivery ratio and energy consumption.The comparative analysis shows that FSE2R gives on an average 30%less energy consumption,24.62%better PDR and 48.31%less end-to-end delay compared to other protocols. 展开更多
关键词 USN energy efficiency collision avoidance MAC SINR
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Hybridization of Metaheuristics Based Energy Efficient Scheduling Algorithm for Multi-Core Systems
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作者 J.Jean Justus U.Sakthi +4 位作者 K.Priyadarshini B.Thiyaneswaran Masoud Alajmi Marwa Obayya Manar Ahmed Hamza 《Computer Systems Science & Engineering》 SCIE EI 2023年第1期205-219,共15页
The developments of multi-core systems(MCS)have considerably improved the existing technologies in thefield of computer architecture.The MCS comprises several processors that are heterogeneous for resource capacities,... The developments of multi-core systems(MCS)have considerably improved the existing technologies in thefield of computer architecture.The MCS comprises several processors that are heterogeneous for resource capacities,working environments,topologies,and so on.The existing multi-core technology unlocks additional research opportunities for energy minimization by the use of effective task scheduling.At the same time,the task scheduling process is yet to be explored in the multi-core systems.This paper presents a new hybrid genetic algorithm(GA)with a krill herd(KH)based energy-efficient scheduling techni-que for multi-core systems(GAKH-SMCS).The goal of the GAKH-SMCS tech-nique is to derive scheduling tasks in such a way to achieve faster completion time and minimum energy dissipation.The GAKH-SMCS model involves a multi-objectivefitness function using four parameters such as makespan,processor utilization,speedup,and energy consumption to schedule tasks proficiently.The performance of the GAKH-SMCS model has been validated against two datasets namely random dataset and benchmark dataset.The experimental outcome ensured the effectiveness of the GAKH-SMCS model interms of makespan,pro-cessor utilization,speedup,and energy consumption.The overall simulation results depicted that the presented GAKH-SMCS model achieves energy effi-ciency by optimal task scheduling process in MCS. 展开更多
关键词 Task scheduling energy efficiency multi-core systems fitness function MAKESPAN
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Green Networking Based Energy Efficient Communications 被引量:2
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作者 Wang Wennai Mi Zhengkun Wang Bin 《China Communications》 SCIE CSCD 2012年第2期22-30,共9页
The mainstream approaches to green networking are discussed first from the view of engineering,including resource consolidation,server virtualization,selective connectedness,and proportional computing.A brief introduc... The mainstream approaches to green networking are discussed first from the view of engineering,including resource consolidation,server virtualization,selective connectedness,and proportional computing.A brief introduction to network virtualization techniques is given then and a virtual node embedding approach is provided.Finally,three kinds of enhanced green networking schemes by network virtualization are proposed,that is enhancement to sever virtualization,resource consolidation and Adaptive Link Rate(ALR).Examples are included to show the virtue of network virtualization to green networking in terms of energy efficient communications. 展开更多
关键词 energy efficient communications greennetworking network virtualization green of Infor-mation and Communications Technology (ICT)
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Invited Paper: Antenna Selection in Energy Efficient MIMO Systems: A Survey 被引量:7
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作者 Zhou Xingyu Bai Bo Chen Wei 《China Communications》 SCIE CSCD 2015年第9期162-173,共12页
With the explosive growth and need for high-speed wireless communications, more and more energy is consumed to support the required quality of service. Therefore, energy efficient or green communication has become a v... With the explosive growth and need for high-speed wireless communications, more and more energy is consumed to support the required quality of service. Therefore, energy efficient or green communication has become a very hot topic under the ground of limited energy resource and environmentally friendly transmission schemes. MIMO technique is capable of reducing the transmission power thanks to its diversity and multiplexing gain. Moreover, antenna selection(AS) is an alternative to extract many of the benefits in MIMO systems with a reduced cost of complexity and power. Although many works including several survey papers have investigated AS in MIMO systems, the goal of these works is only the capacity maximization or error rate minimization, which fails to guarantee the optimality of the energy efficiency in MIMO systems. In this paper, we overview the state of the art in the AS schemes in energy efficient MIMO systems, the goal of which is to optimize the energy efficiency of the whole system. Specifically, we introduce energy efficient AS in point-to-point MIMO, cooperative MIMO, multiuser MIMO and largescale MIMO systems, respectively. Several challenging and practical issues in this area are also addressed. 展开更多
关键词 antenna selection energy efficient holistic power model MIMO
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Energy Efficient MAC Protocol for Wireless Full-Duplex Networks 被引量:2
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作者 Yu Song Wangdong Qi Wenchi Cheng 《China Communications》 SCIE CSCD 2018年第1期35-44,共10页
The wireless full-duplex(FD) nodes can transmit and receive at the same time using the same frequency-band. Currently, the latest FD media access control(MAC) protocols mainly focus on how to convert the physical laye... The wireless full-duplex(FD) nodes can transmit and receive at the same time using the same frequency-band. Currently, the latest FD media access control(MAC) protocols mainly focus on how to convert the physical layer gains of FD nodes to the throughput gain of wireless FD networks, but pay little attention to the energy consumptions of FD nodes. In this paper, we propose an energy efficient FD MAC protocol. According to the values of self-interference cancellation coefficients corresponding to the nodes of each FD pair and the signal propagation attenuation, the proposed protocol can adaptively select the communication mode of the FD pair between the full-duplex and half-duplex. Also, the minimum transmit power for FD nodes can be obtained to achieve high energy efficiency. We develop an analytical model to characterize the performance of our protocol. The numerical results show that the proposed MAC protocol can optimize the system throughput and reduce the transmission energy consumptions of nodes simultaneously as compared with those of the existing works. 展开更多
关键词 wireless full-duplex networks MAC protocol energy efficient self-interference cancellation coefficient
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Energy Efficient Relay Positioning and Power Allocation for One-Way N-Relay Channel 被引量:1
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作者 周健 朱灿焰 +1 位作者 王东林 季爱明 《Journal of Donghua University(English Edition)》 EI CAS 2016年第1期127-133,共7页
Two end-users which have symmetric traffic requirements in terms of data rate are considered. They exchange information in Rayleigh flat-fading channels and multiple serial half-duplex relay nodes are employed to exte... Two end-users which have symmetric traffic requirements in terms of data rate are considered. They exchange information in Rayleigh flat-fading channels and multiple serial half-duplex relay nodes are employed to extend the communication coverage and assist the bidirectional communication between them using the analog network coding( ANC) protocol. With the objective of minimizing the sum transmit energy at the required data rate c,the optimal relay positioning and power allocation problem is firstly investigated and then the sub-optimal solutions for a two-relay channel are proposed,due to no close-form optimal solution. Furthermore,a sub-optimal scheme of relay positioning and power allocation,called equal-distance equal-transmit-power( EDEP) for an arbitrary Nrelay channel,N > 1 is proposed. Simulation results demonstrate a consistence with our proposed scheme. 展开更多
关键词 analog network coding(ANC) energy efficient communication relay positioning and power allocation N-relay channel
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A Solution for Scalable Routing in Depth Divisions-Based DUSNs via Adding a Scalable Parameter to Control Depth Clusters: Creating an Energy Efficient and Low Delay NI-Independent Communication Protocol 被引量:3
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作者 Mohammad Reza Khosravi Reza Salari Habib Rostami 《Journal of Computer and Communications》 2016年第7期55-61,共7页
Due to effectiveness of network layer on general performance of networks, designing routing protocols is very important for lifetime and traffic efficiency in wireless sensor networks. So in this paper, we are going t... Due to effectiveness of network layer on general performance of networks, designing routing protocols is very important for lifetime and traffic efficiency in wireless sensor networks. So in this paper, we are going to represent an efficient and scalable version of depth-based routing (DBR) protocol that is limited by depth divisions-policy. In fact the new version is a network information independent routing protocol for acoustic communications. Proposed method by use of depth clustering is able to reduce consumed energy and end-to-end delay in dense underwater sensor networks (DUSNs) and this issue is proved by simulation. 展开更多
关键词 Network Information (NI) Depth-Based Routing (DBR) Dense Underwater Sensor Networks (DUSNs) energy efficient and Low Delay-DBR (EELD-DBR)
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Energy Efficient Resource Allocation in Timesharing Multiuser Systems with Hybrid Energy Harvesting Transmitter 被引量:1
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作者 Jinming Hu Wei Heng +1 位作者 Guodong Zhang Xiang Li 《China Communications》 SCIE CSCD 2017年第8期83-92,共10页
An energy effi cient resource allocation scheme in timesharing multiuser system with a hybrid energy harvesting transmitter is studied in this paper. Specially, the operation energy of system is supplied by constant e... An energy effi cient resource allocation scheme in timesharing multiuser system with a hybrid energy harvesting transmitter is studied in this paper. Specially, the operation energy of system is supplied by constant energy and energy harvesting, which harvests energy from external environment. Our goal is to maximize the energy effi ciency of timesharing multiuser systems by considering jointly allocation of transmission time and power control in an off-line manner. The original nonconvex objective function is transformed into convex optimization problem via the fractional programming approach. Then, we solve the convex problem by Lagrange dual decomposition method. Simulation results show that the proposed energy efficient resource allocation scheme has a better performance than the scheme which decomposes optimization problem into two parts(power allocation, time allocation) to solve iteratively. 展开更多
关键词 energy harvesting energy efficient resource allocation fractional programming
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Echo Location Based Bat Algorithm for Energy Efficient WSN Routing
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作者 Anwer Mustafa Hilal Siwar Ben Haj Hassine +5 位作者 Jaber S.Alzahrani Masoud Alajmi Fahd N.Al-Wesabi Mesfer Al Duhayyim Ishfaq Yaseen Abdelwahed Motwakel 《Computers, Materials & Continua》 SCIE EI 2022年第6期6351-6364,共14页
Due to the wide range of applications,Wireless Sensor Networks(WSN)are increased in day to day life and becomes popular.WSN has marked its importance in both practical and research domains.Energy is the most significa... Due to the wide range of applications,Wireless Sensor Networks(WSN)are increased in day to day life and becomes popular.WSN has marked its importance in both practical and research domains.Energy is the most significant resource,the important challenge in WSN is to extend its lifetime.The energy reduction is a key to extend the network’s lifetime.Clustering of sensor nodes is one of the well-known and proved methods for achieving scalable and energy conserving WSN.In this paper,an energy efficient protocol is proposed using metaheuristic Echo location-based BAT algorithm(ECHO-BAT).ECHO-BAT works in two stages.First Stage clusters the sensor nodes and identifies tentativeCluster Head(CH)along with the entropy value using BAT algorithm.The second stage aims to find the nodes if any,with high residual energy within each cluster.CHs will be replaced by the member node with high residual energy with an objective to choose the CH with high energy to prolong the network’s lifetime.The performance of the proposed work is compared with Low-Energy Adaptive Clustering Hierarchy(LEACH),Power-Efficient Zoning Clustering Algorithm(PEZCA)and Chaotic Firefly Algorithm CH(CFACH)in terms of lifetime of network,death of first nodes,death of 125th node,death of the last node,network throughput and execution time.Simulation results show that ECHO-BAT outperforms the other methods in all the considered measures.The overall delivery ratio has also significantly optimized and improved by approximately 8%,proving the proposed approach to be an energy efficient WSN. 展开更多
关键词 Wireless sensor networks BAT algorithm energy efficient CLUSTERING cluster head energy consumption
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Energy Efficient Thermal Comfort Control for Residential Building Based on Nonlinear EMPC
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作者 Xucheng Chang Bing Kong +3 位作者 Yong Li GaofengRen Chao Zhang ZhengheWang 《Energy Engineering》 EI 2022年第5期1941-1966,共26页
For purpose of achieving the desired thermal comfort level and reducing the economic cost of maintaining the thermal comfort of green residential building,an energy efficient thermal comfort control strategy based on ... For purpose of achieving the desired thermal comfort level and reducing the economic cost of maintaining the thermal comfort of green residential building,an energy efficient thermal comfort control strategy based on economic model predictive control(EMPC)for green residential buildings which adopts household heat metering is presented.Firstly,the nonlinear thermal comfort model of heating room is analyzed and obtained.A practical nonlinear thermal comfort prediction model is obtained by using an approximation method.Then,the economic cost function and optimization problem of energy-saving under the necessary thermal comfort requirements are constructed to realize the optimal economic performance of the dynamic process.The energy efficient thermal comfort MPC(EETCMPC)is designed.Finally,the comparison and analysis between EETCMPC and Double-layer Model Predictive Control(DMPC)is simulated.The simulation results reveal that when the clothing insulation is typical,the energy efficiency of EETCMPC is 8.9%and 11.6%,respectively,in the two simulation scenarios.When the clothing insulation varies with temperature,the energy efficiency of EETCMPC is 7.29%and 9.15%,respectively,and the total energy consumption is reduced by about 1.65%and 14.6%,respectively,compared with the typical clothing insulation.The economic performance is improved in the thermal comfort dynamic process of heating room. 展开更多
关键词 Household control and heat metering EMPC PMV(Predicted Mean Vote)thermal comfort energy efficient
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EcoShopping: Energy Efficient and Cost Competitive Retrofitting Solutions for Retail Buildings in Europe
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作者 Andy Lewry Ed Suttie 《Journal of Civil Engineering and Architecture》 2017年第9期811-830,共20页
The "EcoShopping" project aims to produce a practical holistic retrofitting solution for commercial buildings, reduce primary energy consumption to less than 80 kWh/(m2.year) and increase the proportion of RES (r... The "EcoShopping" project aims to produce a practical holistic retrofitting solution for commercial buildings, reduce primary energy consumption to less than 80 kWh/(m2.year) and increase the proportion of RES (renewable energy systems) to more than 50% by using state of the art solutions. The project intends to use and integrate available products and technologies; along with a network to accurately monitor the environmental and occupancy parameters to allow the building management system to have better control of the building and fully exploit the thermal mass. This paper introduces the EcoShopping project and the consortium carrying out the work, describes the case study building and the initial targets for carbon reduction, and discusses the results of Work Package 2: which is an assessment of national building codes, EPBD (energy performance buildings directive) implementation, performance standards and good practice. 展开更多
关键词 EcoShopping energy efficient retrofitting retail sector shopping buildings.
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A Novel Energy Efficient MAC Protocol for Wireless Body Area Network
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作者 LIU Jing LI Ming +1 位作者 YUAN Bin LIU Wenlong 《China Communications》 SCIE CSCD 2015年第2期11-20,共10页
Wireless Body Area Network(WBAN) is the most promising technology in e-health applications.Energy efficiency stands out as the paramount issue for WBAN.In this paper,an energy efficient MAC protocol named Quasi-Sleep-... Wireless Body Area Network(WBAN) is the most promising technology in e-health applications.Energy efficiency stands out as the paramount issue for WBAN.In this paper,an energy efficient MAC protocol named Quasi-Sleep-Preempt-Supported(QSPS) is proposed.The protocol is mainly TDMA-based:nodes transmit packets in the allocated slots,while entering the Q-Sleep mode in other slots.Moreover,for a node with emergency packet,it can broadcast a special designed Awakening Message to wake up the whole network and preempts the right to use the current slot to transmit that emergency packet,thus decreasing delay.Compared with relevant protocols,QS-PS can achieve high energy efficiency and decrease the delay of both normal packets and emergency packets. 展开更多
关键词 WBAN energy efficient delay Quasi-Sleep TDMA preemption
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Energy Efficient
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作者 Denis Green 《ChinAfrica》 2014年第12期59-59,共1页
CHINA has become the most prominent user and producer of coal in the world and also the largest emitter of carbon dioxide and other greenhouse gases. However, it is currently establishing the world's largest renewabl... CHINA has become the most prominent user and producer of coal in the world and also the largest emitter of carbon dioxide and other greenhouse gases. However, it is currently establishing the world's largest renewable energy system. This. by 2013, came in at over 1 trillion kilowatt-hours, more than the total elec- trical energy produced by the power systems of France and Germany As part of this drive toward renewable energy. photovoltaic (PV) technology is at the forefront of the battle to reduce pollution and make China greener. 展开更多
关键词 energy efficient PV
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Energy Efficient Power Allocation for Relay-Aided D2D Communications in 5G Networks 被引量:13
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作者 Ru Wang Jia Liu +2 位作者 Guopeng Zhang Shuanghong Huang Ming Yuan 《China Communications》 SCIE CSCD 2017年第6期54-64,共11页
As one of the key technologies for the fifth generation(5G) wireless networks,device-to-device(D2D) communications allow user equipment(UE) in close proximity to communicate with each other directly.Forwarded by a rel... As one of the key technologies for the fifth generation(5G) wireless networks,device-to-device(D2D) communications allow user equipment(UE) in close proximity to communicate with each other directly.Forwarded by a relay,the relay-aided D2D(RA-D2D) communications can not only be applied to communications in much longer distance but also achieve a high quality of service(Qo S) .In this paper,we first propose a two-layer system model allowing RA-D2 D links to underlay traditional cellular uplinks.Then we maximize the energy efficiency of the RA-D2 D link while satisfying the minimum data-rate of the cellular link.The optimal transmit power at both D2 D transmitter and D2 D relay sides is obtained by transforming the nonlinear fractional programming into a nonlinear parameter programming.Simulation results show that our proposed power allocation method is more energy efficient than the existing works,and the proposed RA-D2 D scheme outperformed direct D2 D scheme when the distance between two D2 D users is longer. 展开更多
关键词 D2D communication relay-aided underlay green communication energy efficiency power allocation
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Energy Efficient Multi-Antenna UAV-Enabled Mobile Relay 被引量:8
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作者 Qingheng Song Fuchun Zheng 《China Communications》 SCIE CSCD 2018年第5期41-50,共10页
In this paper, we study an energy efficient multi-antenna unmanned aerial vehicle(UAV)-enabled half-duplex mobile relaying system under Rician fading channels. By assuming that the UAV follows a circular trajectory at... In this paper, we study an energy efficient multi-antenna unmanned aerial vehicle(UAV)-enabled half-duplex mobile relaying system under Rician fading channels. By assuming that the UAV follows a circular trajectory at fixed altitude and applying the decode-and-forward relaying strategy, we maximize the energy efficiency by jointly designing beamforming, power allocation, circular radius and flight speed, subject to the sum transmit power constraint on source node and UAV relay node. First, we maximize the end-to-end signal-to-noise ratio by jointly designing beamforming and statistical power allocation. Based on the obtained beamforming and power allocation results, we then obtain a semi closed-form expression of energy efficiency, and finally maximize energy efficiency by optimizing flight speed and circular radius, allowing optimal circular radius to be obtained via numerical computation. Numerical results demonstrate that the proposed scheme can effectively enhance the system energy efficiency. 展开更多
关键词 UAV mobile relay energy efficiency statistical power allocation circular radius flight speed
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