检索结果-南通市图书馆

QoS-based optimal and fair resource allocation for energy-efficiency uplink NOMA networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2020年第3期27卷 83-92页

作者： Guo Yanyan Li Shuai Wu Chao College of Physics and Electronic Engineering Shanxi UniversityTaiyuan 030004China

The energy-efficiency(EE)optimization problem was studied for resource allocation in an uplink single-cell network,in which multiple mobile users with different quality of service(QoS)requirements operate under a non-orthogonal multiple access(NOMA)***,a multi-user feasible power allocation region is derived as a multidimensional body that provides an efficient scheme to determine the feasibility of original channel and power assignment ***,the size of feasible power allocation region was first introduced as utility function of the subchannel-user matching game in order to get high EE of the system and fairness among the ***,the power allocation optimization to the EE maximization is proved to be a monotonous decline *** simulation results show that compared with the conventional schemes,the network connectivity of the proposed scheme is significantly enhanced and besides,for low rate massive connectivity networks,the proposed scheme obtains performance gains in the EE of the system.

关键词： NOMA energy-efficiency multiple access D2D

Multi-hop routing for energy-efficiency enhancement in relay-assisted device-to-device communication

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2015年第2期22卷 1-6,51页

作者： Zhao Jingyi Li Xi Xu Quansheng Key Laboratory of Universal Wireless Communications Beijing University of Posts and Telecommunications

Financial and environment considerations present new trends in wireless network known as green communication. As one of the most promising network architectures, the device-to-device （D2D） communication should take seriously account to the energy-efficiency. Most of the existing work in the area of D2D communication only focus on the direct communication, however, the direct link D2D communication has to be limited in practice because of long distance, poor propagation medium and cellular interference, etc. A new energy-efficient multi-hop routing algorithm was investigated for multi-hop D2D system by jointly optimizing channel reusing and power allocation. Firstly, the energy-efficient multi-hop routing problem was formulated as a combinatorial optimization problem. Secondly, to obtain a desirable solution with reasonable computation cost, a heuristic multi-hop routing algorithm was presented to solve the formulated problem and to achieve a satisfactory energy-efficiency performance. Simulation shows the effectiveness of the proposed routing algorithm.

关键词： device-to-device (D2D) communication energy-efficiency multi-hop relay-assisted transmission routing algorithm

A Homeowner-Based Methodology for Economic Analysis of energy-efficiency Measures in Residences

在线全文

学校读者我要写书评

暂无评论

Open Journal of energy efficiency 2013年第2期2卷 97-106页

作者： Nelson Fumo Roy Crawford The University of Texas at Tyler Tyler USA

Residential energy-efficiency measures, besides energy savings, provide opportunities for improvement of thermal comfort, air quality, lighting quality, and operation. However, all these benefits sometimes are not enough to convince a homeowner to pay the incremental cost associated with the energy-efficiency measure. The objective of this work is to develop a methodology for the economic evaluation of residential energy-efficiency measures that can simplify the economic analysis for the homeowner while taking into consideration all factors associated with the purchase, ownership, and selling of the house with the energy-efficiency measure. The methodology accounts for direct and indirect economic parameters associated to an energy-efficiency measure;direct parameters such as the mortgage interest and fuel price escalation rate, and indirect parameters such as savings account interest and marginal income tax rate. The methodology also considers different cases based on the service life of the energy-efficiency measure and loss of efficiency through a derating factor. To estimate the market value, the methodology uses the future energy cost savings instead of the cost of the EEM. Results from the methodology offer to homeowner annual net savings and net assets. The annual net savings gives the homeowner a measure of the annual positive cash flow that can be obtained from an energy-efficiency project;but more important, the net assets offer a measure of the added net wealth. To simplify and increase the use of the methodology by homeowners, the methodology has been implemented in an Excel tool that can be downloaded from the TxAIRE’s website.

关键词： Methodology for Economic Analysis energy-efficiency Measures for Residences energy Savings in Residences

Asymptotic energy efficiency analysis for the state-of-the-art relaying protocols

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2011年第6期18卷 8-13页

作者： WANG Yu-ning ZHANG Jian-hua XU Wei Key Lab of Universal Wireless Communications Ministry of Education Wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing 100876 China

This article analyzes the energy-efficiency performances of fixed relaying schemes, selection relaying schemes and incremental relaying schemes in the three-node relay network. The closed-form asymptotic energy per good-bit （EPG） expressions for the state-of-the-art relaying protocols at high signal-to-noise ratio （SNR） regime are derived. In the formulation of the energy consumption model, the transmission, circuit and retransmission energies are all taken into account. To facilitate the comparison of energy-efficiency performances between different relaying protocols, the link reliabilities and retransmission probabilities are determined by the asymptotic outage probabilities at high SNR regime under the Rayleigh fading assumption. Computer simulations are carried out in both symmetric and asymmetric relay networks. The simulation results show the differences of system energy expenditure between these state-of-the-art relaying protocols. Finally some practical implications can be made from the observation.

关键词： green communication EPG relay energy-efficiency outage probability

energy-efficient and Secure Wireless Communication for Telemedicine in IoT

在线全文

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2022年第12期43卷 1111-1130页

作者： Shital Joshi S.Manimurugan Ahamed Aljuhani Umar Albalawi Amer Aljaedi Department of Computer Science Oklahoma State UniversityOklahomaUSA College of Computing and Information Technology University of TabukTabuk71491Saudi Arabia Industrial Innovation and Robotics Center University of TabukTabukSaudi Arabia

The Internet of Things (IoT) represents a radical shifting paradigm fortechnological innovations as it can play critical roles in cyberspace applications invarious sectors, such as security, monitoring, medical, and environmental sectors,and also in control and industrial applications. The IoT in E-medicine unleashedthe design space for new technologies to give instant treatment to patients whilealso monitoring and tracking health conditions. This research presents a systemlevel architecture approach for IoT energy efficiency and security. The proposedarchitecture includes functional components that provide privacy managementand system security. Components in the security function group provide securecommunications through Multi-Authority Ciphertext-Policy Attributes-BasedEncryption (MA-CPABE). Because MA-CPABE is assigned to unlimited devices,presuming that the devices are reliable, the user encodes data with AdvancedEncryption Standard (AES) and protects the ABE approach using the solutionsof symmetric key. The Johnson’s algorithm with a new computation measure isused to increase network lifetime since an individual sensor node with limitedenergy represents the inevitable constraints for the broad usage of wireless sensornetworks. The optimal route from a source to destination turns out as the cornerstone for longevity of network and its sustainability. To reduce the energy consumption of networks, the evaluation measures consider the node’s residualenergy, the number of neighbors, their distance, and the link dependability. Theexperiment results demonstrate that the proposed model increases network lifeby about 12.25% (27.73%) compared to Floyd–Warshall’s, Bellman–Ford’s,and Dijkstra’s algorithms, lowering consumption of energy by eliminating thenecessity for re-routing the message as a result of connection failure.

关键词： energy-efficiency energy consumption Internet of Things telemedicine wireless sensor networks

energy-Efficient Full-Duplex UAV Relaying with Trajectory Optimization and Power Control in Maritime Communication Environments

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2022年第12期19卷 216-231页

作者： Lili Guo Xiaodong Ji Shibing Zhang School of Information Science and Technology Nantong UniversityNantong 226019China Nantong University Xinglin College Nantong 226236China

This paper solves an energy-efficient optimization problem of a fixed-wing unmanned aerial vehicle(UAV) assisted full-duplex mobile relaying in maritime communication *** the speed and the acceleration of the UAV and the information-causality constraints into consideration,the energy-efficiency of the system under investigation is maximized by jointly optimizing the UAV’s trajectory and the individual transmit power levels of the source and the UAV relay *** optimization problem is non-convex and thus cannot be solved ***,it is decoupled into two *** sub-problem is for the transmit power control at the source and the UAV relay nodes,and the other aims at optimizing the UAV s flight *** using the Lagrangian dual and Dinkelbach methods,the two sub-problems are solved,leading to an iterative algorithm for the joint design of transmit power control and trajectory *** simulations demonstrated that by conducting the proposed algorithm,the flight trajectory of the UAV and the individual transmit power levels of the nodes can be flexibly adjusted according to the system conditions,and the proposed algorithm can achieve signiflcantly higher energy efficiency as compared with the other benchmark schemes.

关键词： UAV communication full-duplex relaying(FDR) energy-efficiency maritime communication

energy Efficient Unequal Fault Tolerance Clustering Approach

在线全文

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2023年第5期45卷 1971-1983页

作者： Sowjanya Ramisetty Divya Anand Kavita Sahil Verma NZ Jhanjhi Mehedi Masud Mohammed Baz Department of Computer Science and Engineering KG Reddy College of Engineering and TechnologyHyderabadIndia School of Computer Science and Engineering Lovely Professional UniversityPhagwaraIndia Department of Computer Science and Engineering Chandigarh UniversityMohaliIndia Department of Computer Science and Engineering Tailor’s UniversityMalaysia Department of Computer Science College of Computers and Information TechnologyTaif UniversityTaif21944Saudi Arabia Department of Computer Engineering College of Computer and Information TechnologyTaif UniversityTaif21994Saudi Arabia

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 *** saving energy in WSNs,clustering is considered as one of the effective methods for Wireless Sensor *** 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 *** increasing the WSNs’lifetime,the CHs selection has played a key role in energy consumption for sensor *** 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 *** 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 ***,the MCH overhead *** 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.

关键词： energy-efficiency unequal fault tolerant clustering approach particle swarm optimization master data aggregator energy efficient time division multiple access optimal nodes

In situ synthesis of chemically bonded NaTi2（PO4）3/rGO 2D nanocomposite for high-rate sodium-ion batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2016年第6期9卷 1844-1855页

作者： Ha-Kyung Roh Hyun-Kyung Kim Myeong-Seong Kim Dong-Hyun Kim Kyung Yoon Chung Kwang Chul Roh Kwang-Bum Kim Department of Material Science & Engineering Yonsei University 50 Yonsei-ro Seodaemun-gu Seou103722 Republic of Korea Department of Materials Science and Metallurgy University of Cambridge 27 Charles Babbage Road Cambridge CB30FS UK Center for energy Convergence Korea Institute of Science and Technology 5 Hwarang-ro 14-gil Seongbuk-gu Seou102792 Republic of Korea energy & Environmental Division Korea Institute of Ceramic Engineering & Technology 101 Soho-ro Jinju-si Gyeongsangnam-do 52851 Republic of Korea

A phase-pure NaTi2（PO4）3/reduced graphene oxide （rGO） nanocomposite was prepared using a microwave-assisted one-pot method and subsequent heat treatment. The well-crystallized NaTi2（PO4）3 nanoparticles （30-40 nm） were uniformly precipitated on rGO templates through Ti-O-C bonds. The chemical interactions between the NaTi2（PO4）3 nanoparticles and rGO could immobilize the NaTi2（PO4）3 nanoparticles on the rGO sheets, which might be responsible for the excellent electrochemical performance of the nanocomposite. The NaTi2（PO4）B/rGO nanocomposite exhibited a specific capacity of 128.6 mA-h.g-1 approaching the theoretical value at a 0.1 C-rate with an excellent rate capability （72.9% capacity retention at 50 C-rate） and cycling performance （only 4.5% capacity loss after 1,000 cycles at a high rate of 10 C）. These properties were maintained even when the electrodes were prepared without the use of an additional conducting agent. The excellent sodium storage properties of the NaTi2（PO4）B/rGO nanocomposite could be attributed to the nano-sized NaTi2（PO4）3 particles, which significantly reduced the transport lengths for Na＋ ions, and an intimate contact between the NaTi2（PO4）3 particles and rGO due to chemical bonding.

关键词： NaTi2(PO4)dreducedgraphene oxide (rGO)nanocomposite chemical bonding energy-efficiency in situ synthesis high-rate sodium-ion batteries

End-to-end energy-efficient resource allocation in device-to-device communication underlaying cellular networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2015年第1期22卷 24-30页

作者： Xu Quansheng Ji Hong Li Xi Xiong Danni Key Laboratory of Universal Wireless Communications Beijing University of Posts and Telecommunications

A proposed resource allocation （RA） scheme is given to device-to-device （D2D） communication underlaying cellular networks from an end-to-end energy-efficient perspective, in which, the end-to-end energy consumptions were taken into account. Furthermore, to match the practical situations and maximize the energy-efficiency （EE）, the resource units （RUs） were used in a complete-shared pattern. Then the energy-efficient RA problem was formulated as a mixed integer and non-convex optimization problem, extremely difficult to be solved. To obtain a desirable solution with a reasonable computation cost, this problem was dealt with two steps. Step 1, the RU allocation policy was obtained via a greedy search method. Step 2, after obtaining the RU allocation, the power allocation strategy was developed through quantum-behaved particle swarm optimization （QPSO）. Finally, simulation was presented to validate the effectiveness of the proposed RA scheme.

关键词： energy-efficiency resource allocation D2D communication mixed integer and non-convex optimization problem