检索结果-南通市图书馆

self-organized Algorithm in LTE Networks： A Utility Function Based Optimal Power Control Scheme

在线全文

学校读者我要写书评

暂无评论

China Communications 2014年第A02期11卷 95-101页

作者： XU Haitao AN Jianwei School of Computer and Communication Engineering University of Science and Technology Beijing (USTB) Beijing 100083 ER. China

In this paper, transmission power control problem for uplink LTE network is investigated and a new autonomic uplink power control scheme was proposed based on utility function, which is a self- organized algorithm. The whole approach is based on the economic concept named utility function. Then a self-organized algorithm is distributed in each mobile users to control the transmission power and to maximize the transmission utility. The proposed scheme is solved through the Lagrange multiplier technique. It is proved that the utility function based algorithm optimal power level can be model. is applicable and the achieved based on our

关键词： self-organized power control utilityfunction LTE networks lagrange multiplier

self-organized criticality of forest fires in China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第13期46卷 1134-1137页

作者： Song Weiguo Fan Weicheng Wang Binghong Univ Sci & Technol China State Key Lab Fire Sci Hefei 230026 Peoples R China

self-organized criticality(SOC) of forest fires in China from 1950 to 1989 is studied. The stability, scale-invariant character of SOC and external effects on SOC of forest fires in China are analyzed in detail. Forest-fire cellular automata model is a typical model for the research of SOC. Based on the traditional forest-fire model, an improved model, in which effects of tree species, meteorological conditions and human efforts on forest fires are considered, is introduced. Actual forest fire data in China are compared with simulation results of the two models. It is shown that forest fire data in China have SOC behavior and simulation results of the improved model accord better with actual forest fire data than those of the traditional model.

关键词： self-organized criticality cellular automata forest-fire model fire science.

Distributed intelligent self-organized mission planning of multi-UAV for dynamic targets cooperative search-attack

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2019年第12期32卷 2706-2716页

作者： Ziyang ZHEN Ping ZHU Yixuan XUE Yuxuan JI College of Automation Engineering Nanjing University of Aeronautics and Astronautics

This article studies the cooperative search-attack mission problem with dynamic targets and threats, and presents a Distributed Intelligent self-organized Mission Planning(DISOMP)algorithm for multiple Unmanned Aerial Vehicles(multi-UAV). The DISOMP algorithm can be divided into four modules: a search module designed based on the distributed Ant Colony Optimization(ACO) algorithm, an attack module designed based on the Parallel Approach(PA)scheme, a threat avoidance module designed based on the Dubins Curve(DC) and a communication module designed for information exchange among the multi-UAV system and the dynamic environment. A series of simulations of multi-UAV searching and attacking the moving targets are carried out, in which the search-attack mission completeness, execution efficiency and system suitability of the DISOMP algorithm are analyzed. The simulation results exhibit that the DISOMP algorithm based on online distributed down-top strategy is characterized by good flexibility, scalability and adaptability, in the dynamic targets searching and attacking problem.

关键词： Ant Colony Optimization(ACO) Cooperative control Mission planning Search-attack integration self-organized Unmanned Aerial Vehicle(UAV)

Preparation and third-order nonlinear optical properties of self-organized complex oxide Ce: BaTiO_3 quantum dots

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2000年第5期43卷 527-532页

作者：师文生陈正豪刘宁宁吕惠宾周岳亮崔大复杨国桢 Laboratory of Optical Physics Institute of Physics and Center for Condensed Matter Physics Chinese Academy of Sciences Beijing 100080 China

Pulsed laser ablation epitaxial Strancky-Krastanow growth of self-organized complex oxide Ce:BaTiO3 quantum dots on MgO(100) substrates is demonstrated. Atomic force microscopy and X-ray diffraction are used to observe the structure and the growth process of the self-organized complex oxide quantum dots. The average dimension, height, and the density of self-organized complex oxide Ce:BaTiO3 quantum dots are given. The nonlinear refractive indexes of the wetting layer and the self-organized ordered quantum dots are determined by the single beam Z-scan method. The mechanisms of the nonlinear effect enhancement for these low-dimensional structure are discussed.

关键词： Ce:BeTiO3 self-organized complex oxide quantum dots nonlinear refractive index.

On power system blackout modeling and analysis based on self-organized criticality

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2008年第2期51卷 209-219页

作者： MEI ShengWei XUE AnCheng ZHANG XueMin State Key Lab of Power System Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Institute of Systems Science Chinese Academic of SciencesBeijing 100080China

This paper makes a comprehensive survey on power system blackout modeling and analysis based on SOC (self-organized criticality). Firstly,a generalized SOC theory from the viewpoint of cybernetics is introduced. Then the evolution model of power system and its relative mathematical description,which serves as a concrete example of the proposed generalized SOC,are given. Secondly,five blackout models capturing various critical properties of power systems in different time-scales are listed. Finally,this paper analyzes SOC in power systems,such as,the revelation of criticalities of proposed models in both micro-scale and macro-scale which can be used to assess the security of power system,and cas-cading failures process.

关键词： blackout model self-organized criticality (SOC) cascading failures

Controllable fabrication of self-organized nano-multilayers in copper–carbon films

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第3期28卷 309-316页

作者： Wei-Qi Wang Li Ji Hong-Xuan Li Xiao-Hong Liu Hui-Di Zhou Jian-Min Chen State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences

In order to clarify the influence of methane concentration and deposition time on self-organized nano-multilayers,three serial copper-carbon films have been prepared at various methane concentrations with different deposition times using a facile magnetron sputtering deposition system. The ratios of methane concentration(CH4/Ar+CH4) used in the experiments are 20%, 40%, and 60%, and the deposition times are 5 minutes, 20 minutes, and 40 minutes, *** the difference in the growth conditions, self-organizing multilayered copper-carbon films are prepared at different deposition times by changing methane concentration. The film composition and microstructure are investigated by x-ray photoelectron spectroscopy(XPS), x-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), and high-resolution transmission electron microscopy(HRTEM). By comparing the composition and microstructure of three serial films, the optimal growth conditions and compositions for self-organizing nano-multilayers in copper-carbon film are acquired. The results demonstrate that the self-organized nano-multilayered structure prefers to form in two conditions during the deposition process. One is that the methane should be curbed at low concentration for long deposition time,and the other condition is that the methane should be controlled at high concentration for short deposition time. In particular, nano-multilayered structure is self-organized in the copper-carbon film with copper concentration of 10-25 at.%.Furthermore, an interesting microstructure transition phenomenon is observed in copper-carbon films, that is, the nanomultilayered structure is gradually replaced by a nano-composite structure with deposition time and finally covered by amorphous carbon.

关键词： nano-multilayers self-organized controllable fabrication copper–carbon films

A self-organized locator obtaining method driven by local minima

在线全文

学校读者我要写书评

暂无评论

High Technology Letters 2015年第2期21卷 155-161页

作者：王永功 Xie Gaogang Institute of Computing Technology Chinese Academy of Sciences The Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory the 54th Research Institute of China Electronics Technology Group Corporation

The scalability of routing architectures for large networks is one of the biggest challenges that the Internet faces *** routing,in which each node is assigned a locator used as a distance metric,recently received increased attention from researchers and is considered as a potential solution for scalable *** this paper,LMD—a local minimum driven method is proposed to compute the topology-based *** eliminate the negative effect of the " quasi" greedy property—transfer routes longer than the shortest routes,a two-stage routing strategy is introduced,which combines the greedy routing with source *** greedy routing path discovered and compressed in the first stage is then used by the following source-routing *** extensive evaluations,based on synthetic topologies as well as on a snapshot of the real Internet AS(autonomous system)topology,it is shown that LMD guarantees 100%delivery rate on large networks with low stretch.

关键词： greedy routing locator self-organized local minimum topology

Influences of finite-size effects on the self-organized critical-ity of forest-fire model

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第3期47卷 177-180页

作者： Weiguo Song Weicheng Fan Binghong Wang Univ Sci & Technol China State Key Lab Fire Sci Hefei 230026 Peoples R China

The influences of finite-size effects on the self-organized criticality (SOC) of the traditional forest-fire model are investigated by means of a new method. The forest size is originally set to a value much greater than the correla-tion length of the forest. Finite-size effects are then studied by equally dividing the forest into more and more separate subsystems on condition that the forest size, igniting prob-ability and planting probability are invariant. A new phe-nomenon, i.e. the finite-size effects with one-side frequency peak, is observed. The boundary between two neighboring subsystems can be regarded as a firebreak. The concept of ’separation ability’ is introduced to represent the probability for the firebreak to block off the fire successfully. Restrain-ing effects of separation ability on finite-size effects are ana-lyzed. Finite-size effects and separation ability, as well as their relations are found to have practical importance to the actual forest-fire protection.

关键词： forest-fire model self-organized criticality cellular automata finite-size effects.

High-performance self-organized Si nanocomposite anode for lithium-ion batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2014年第3期23卷 291-300页

作者： Xiuyun Zhao Dingguo Xia Lin Gu Juncheng Yue Biao Li Hang Wei Huijun Yan Ruqiang Zou Yingxia Wang Xiayan Wang Ze Zhang Jixue Li College of Engineering Peking University Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences College of Chemistry and Molecular Peking University College of Environmental and Energy Engineering Beijing University of Technology Center of Electron Microscopy Zhejiang University

Silicon is being investigated extensively as an anodic material for next-generation lithium ion batteries for portable energy storage and electric ***,the large changes in volume during cycling lead to the breakdown of the conductive network in Si anodes and the formation of an unstable solid-electrolyte interface,resulting in capacity ***,we demonstrate nanoparticles with a Si@Mn22.6Si5.4C4@C double-shell structure and the formation of self-organized Si-Mn-C nanocomposite anodes during the lithiation/delithiation *** anode consists of amorphous Si particles less than 10 nm in diameter and separated by an interconnected conductive/buffer network,which exhibits excellent charge transfer kinetics and charge/discharge performances.A stable specific capacity of 1100 mAh·g-1 at 100 mA·g-1 and a coulombic efficiency of 99.2%after 30 cycles are ***,a rate capacity of 343 mAh·g-1 and a coulombic efficiency of 99.4%at 12000 mA·g-1 are also *** to its simplicity and applicability,this strategy for improving electrode performance paves a way for the development of high-performance Si-based anodic materials for lithium ion batteries.

关键词： cycling performance self-organized Si nanocomposite anode lithium ion batteries