检索结果-南通市图书馆

Communication network designing:Transmission capacity,cost and scalability

在线全文

学校读者我要写书评

暂无评论

science china({2. sciences) 2012年第11期55卷 2454-2465页

作者： ZHANG GuoQiang1,2.3.& ZHANG GuoQing1 1Institute of Computing technology,Chinese Academy of sciences,Beijing 100190,{2. 2.chool of Computer science and technology,nanjing Normal university,nanjing 2.0046,{2. 3.rovincial Key Laboratory for Computer information Processing technology,Soochow university,Suzhou 2.5000,{2. Institute of Computing technology Chinese Academy of Sciences Beijing China School of Computer science and technology Nanjing Normal University Nanjing China Provincial Key Laboratory for Computer information Processing technology Soochow University Suzhou China

Despite the growing number of works centering around the traffic dynamics on complex networks,these researches still have some common shortcomings,e.g.,too simple traffic flow model and lack of considerations for the designing cost and scalability *** paper builds on a more realistic traffic flow model,and offers a holistic view on the network designing *** addition to the extensively studied transmission capacity,this paper takes designing cost and scalability as two other designing objectives,and presents a quantitative study of how different designing choices independently and collectively influence these objectives by the introduction of a cartesian coordinate *** is shown that different kinds of network topologies display different shapes of achievable solution spaces and exhibit different abilities to achieve cost-effective and scalable *** particular,we find the philosophy underlying empirical network designing and engineering today fails to meet the cost-effective and scalable designing requirements,and propose a cost-effective and scalable designing scheme for BA-like networks,i.e.,the efficient routing combined with effective betweenness based link bandwidth *** addition,when designing a thoroughly new network from the beginning,we find that ER network is a good candidate to achieve cost-effective and scalable designing in most settings.

关键词： cost-effective communication network designing network transmission efficiency network topology traffic dynamics next generation network scalable network designing

A LAW OF ITERATED LOGARITHM FOR THE MLE IN A RANDOM CENSORING MODEL WITH INCOMPLETE information

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2008年第3期28卷 501-512页

作者：宋凤丽刘禄勤 School of Mathematics and Statistics Wuhan University

In this article, a law of iterated logarithm for the maximum likelihood estimator in a random censoring model with incomplete information under certain regular conditions is obtained.

关键词： Random censoring model maximum likelihood estimator law of iterated logarithm

Optimal MAC based cooperative spectrum sensing in cognitive radio networks

在线全文

学校读者我要写书评

暂无评论

science china({2. sciences) 2012年第6期55卷 1388-1396页

作者： CHEN Zhong 1,ZHANG XianDa 1 & YANG LanJuan 2.1 State Key Laboratory of Intelligent technology and Systems,Tsinghua National Laboratory for information {2. and technology,Department of Automation,Tsinghua university,Beijing 100084,china 2.Institute of Command Automation,PLA university of {2. and technology,nanjing 2.0007,china State Key Laboratory of Intelligent technology and Systems Tsinghua National Laboratory for Information Science and Technology Department of Automation Tsinghua University Institute of Command Automation PLA University of Science and Technology

This paper considers a cognitive radio (CR) system in non-ideal fading wireless channels and pro-poses cooperative spectrum sensing schemes based on coherent multiple access channels (MAC),serving as an alternative way to improve the cooperative spectrum sensing performance and provide space diversity for spec-trum *** statistics are transmitted using a common channel from the secondary users (SUs) to a fusion center (FC) where the global decision is *** optimal scaling factors of the proposed schemes are obtained by maximizing the detection probability under a target false alarm probability and a transmit power *** the proposed optimal MAC scheme has high computational complexity,a sub-optimal solu-tion based on maximization of the deflection coefficient (DC) is also *** results show that the proposed algorithms can significantly improve the spectrum sensing performance and approach the detection baseline.

关键词： cognitive radio (CR) spectrum sensing multiple access channel (MAC) deflection coefficient optimization

Spatial teleconnection pattern between Indian Ocean Dipole and the southern high-latitude sea level pressure field

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2005年第12期15卷 1143-1147页

作者： LIU Na,CHEN Hongxia,MIN Jinzhong,HUA Feng and BIAN Hongcun Jiangsu Key Laboratory of Meteorological Disaster,nanjing university of {2. {3. & technology,nanjing 210044,china Key Laboratory of Marine {3. and Numerical Modeling,State Oceanic Administration,Qingdao 2.6061,china First Institute of Oceanography,Qingdao 2.6061,china Jiangsu Key Laboratory of Meteorological Disaster Nanjing University of Information Science & Technology Nanjing 210044 China. Key Laboratory of Marine science and Numerical Modeling State Oceanic Administration Qingdao 266061 China. First Institute of Oceanography Qingdao 266061 China

Sea level pressure (SLP) anomalies over the southern high latitudes associated with the Indian Ocean Dipole Mode (IOD) are *** correlation and composite analysis depict,for the first time,the seasonal spatial variability in the relationship of SLP field in Southern Ocean with *** suggest that the IOD signal exists in the southern high latitudes and it is enhanced in boreal autumn,an active season of *** interannual to subdecadal timescales,the spatial teleconnection pattern exhibits a wavenum-ber-3.pattern around the circumpolar Southern Ocean and the lead-lag correlation analysis shows that there are about 3.months of SLP anomalies in southern high latitudes lagging IOD,which indicates that the response time is almost instantaneous.

关键词： IOD SLP teleconnection southern high latitudes

Decentralized H-infinity state feedback control for discrete-time singular large-scale systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2010年第2期8卷 200-204页

作者： Songlin WO 1 , Yun ZOU 2., Shengyuan XU 2.(1.School of Electrical and information Engineering, Jiangsu Teachers {3. of {2., Changzhou Jiangsu 2.3.01, china 2.School of Automation, nanjing {3. of science and {2., nanjing Jiangsu 2.0094, china) School of Electrical and information Engineering Jiangsu Teachers University of Technology Changzhou Jiangsu China School of Automation Nanjing University of Science and Technology Nanjing Jiangsu China

The decentralized H-infinity control problem for discrete-time singular large-scale systems is considered. Based on the bounded real lemma of discrete-time singular systems, a sufficient condition for the existence of decentralized H-infinity controller for discrete-time singular large-scale systems is presented in terms of the solvability to a certain system of linear matrix inequalities by linear matrix inequality (LMI) approach, and the feasible solutions to the system of LMIs provide a parameterized representation of a set of decentralized H-infinity controller. The given example shows the application of the method.

关键词： Discrete-time singular large-scale system Linear matrix inequality (LMI) Decentralized H-infinity control

Interactive group decision making procedure based on uncertain multiplicative linguistic preference relations

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2010年第3期21卷 408-415页

作者： Zeshui Xu1,2.1.College of Economics and Management,Southeast university,nanjing 2.0096,P.R.{2. 2.Institute of sciences,university of science and technology of the PLA,nanjing 2.0007,P.R.{2. College of Economics and Management Southeast University Nanjing 210096 P. R. China Institute of sciences University of Science and Technology of the PLA Nanjing 210007 P. R. China

Group decision making problems are investigated with uncertain multiplicative linguistic preference *** unbalanced multiplicative linguistic label set is introduced,which can be used by the experts to express their linguistic preference information over *** uncertain linguistic weighted geometric mean operator is utilized to aggregate all the individual uncertain multiplicative linguistic preference relations into a collective one,and then a simple approach is developed to determine the experts＇ weights by utilizing the consensus degrees among the individual uncertain multiplicative linguistic preference relations and the collective uncertain multiplicative linguistic preference ***,a practical interactive procedure for group decision making is proposed based on uncertain multiplicative linguistic preference relations,in which a possibility degree formula and a complementary matrix are used to rank the given ***,the proposed procedure is applied to solve the group decision making problem of a manufacturing company searching the best global supplier for one of its most critical parts used in assembling process.

关键词： group decision making uncertain multiplicative linguistic preference relations unbalanced multiplicative linguistic label set consensus degree interaction.

Prediction method for October 2.03.solar storm

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2006年第5期49卷 629-640页

作者： XIE Yanqiong1, 2. 3. WEI Fengsi1, FENG Xueshang1 & ZHONG Dingkun1, 2.1. State Key Laboratory of space Weather, Center for space {2. and Applied Research, Chinese Academy of {2.s, Beijing 100080, china 2. Graduate School, Chinese Academy of {2.s, Beijing 10003., china 3. Institute of Meteorology, PLA university of {2. and technology, {13. 2.1101, china State Key Laboratory of space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Graduate School Chinese Academy of Sciences

Aiming at two intense shock events on October 2. and 2., 2.03. this paper presents a two-step method, which combines synoptic analysis of {3. weather ——“observing” and quantitative prediction ——“palpating”, and then uses it to test predictions. In the first step of “observing”, on the basis of observations of the solar source surface magnetic field, interplanetary scintillation (IPS) and ACE {3.craft, we find that the propagation of the shocks is asymmetric relative to the normal direction of their solar sources, and the Earth is located near the direction of the fastest speed and the greatest energy of the shocks. As the two fast ejection shock events, the fast explosion of coronal mass of the extremely high temperature, the strong magnetic field, and the high speed background solar wind are also helpful to their rapid propagation. In the second step of “palpating”, we adopt a new membership function of the fast shock events for the ISF method. The predicted results show that for the onset time of the geomagnetic disturbance, the relative errors between the observational and the predicted results are 1.8% and 6.7%; and for the magnetic disturbance magnitude, the relative errors are 4.1% and 3.1%, re- spectively. Furthermore, the comparison among the predicted results of our two-step method with those of five other prevailing methods shows that the two-step method is advantageous. The results tell us that understanding the physical features of shock propagation thoroughly is of great importance in improving the prediction precision.

关键词： solar storm, interplanetary shock, interplanetary scintillation, two-step method, ISF method.

CHARACTERISTICS OF THE INTERANNUAL AND INTERDECADAL TIMESCALES OF EVAPORATION IN NORTHERN china IN THE RECENT 115 YEARS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2006年第5期18卷 593-596页

作者： RONG Yan-shu TU Qi-pu DUAN Li-yao College of Water Resources and Environment Hohai University Nanjing 210098 China Tianjin Institute of Meteorological Science Tianjin 300074 China Tianjin Institute of Meteorological science Tianjin 300074 China nanjing university of {2. {3. and technology Nanjing 210044 China Tianjin Climate Centre Tianjin 300074 China

Evaporation plays an important role in water balance on the land surface. In Northern china, the evaporation series of the recent 115 years was reconstructed on the basis of Yhornthwaite evaporation formula. The characteristics of the reconstructed series were analyzed using 10-year running mean filter, power spectrum method, and running t-text of abrupt changes on the paper. The results showed that there were remarkable interannual fluctuations with timescales of about quasi-8-year, 3.4-year, and quasi-2.year, and interdecadal oscillations with timescales of 57.5-year, quasi-2.-year, and l l.5-year. Meanwhile, the abrupt changes of the evaporation series were also of interdecadal timescale. Either interannual fluctuations or interdecadal oscillations of evaporation were closely related to variations in air temperatures and precipitation.

关键词： reconstructed evaporation series interannual timescale interdecadal timescale Northern china

The structural analysis of fuzzy measures

在线全文

学校读者我要写书评

暂无评论

science china({2. sciences) 2011年第1期54卷 38-50页

作者： ZHANG Ling1,ZHANG Bo2.& ZHANG YanPing1 1 Computer science College,Anhui university,Hefei 2.003.,{2. 2.tate Key Lab of Intelligent technology & Systems Tsinghua National Lab for information science & technology information science & technology College,Computer science & technology,Tsinghua university,Beijing 100084,{2. Computer science College Anhui University State Key Lab of Intelligent technology & Systems Tsinghua National Lab for information science & {2. Information Science & Technology College Computer Science & Technology Tsinghua University

From quotient space based granular computing theory we explore the fuzzy measures of fuzzy sets. Based on the structural analysis of fuzzy sets,we present an"isotropism"*** this assumption we achieved the following insights:(1)the uniqueness of a fuzzy measure being isotropic on a finite complete semi-ordered set;(2.the necessary and suffcient condition of the isomorphism for fuzzy measure functions in fuzzy mathematics;(3.the necessary and suffcient condition that fuzzy measures have fuzzy and granular monotonicity;(4)under a certain assumption,the analytic expression for fuzzy *** results clarify the relationship between fuzzy measures and granular computing,reveal the essence of fuzzy measures,and provide a simple way of constructing fuzzy measures.

关键词： quotient space fuzzy set fuzzy measure rough set structural analysis