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One-step estimation for varying coefficient models

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science china Mathematics 2005年第2期48卷 198-213页

作者： TANG Qingguo & WANG Jinde Department of Mathematics, nanjing univ.r.ity, nanjing 210093, china inst.tute of sciences, pla univ.r.ity of science and technology, nanjing 210007, china Department of Mathematics Nanjing University Nanjing China inst.tute of sciences PLA University of Science and Technology Nanjing China

A one-step method is proposed to estimate the unknown functions in the varying coefficient models, in which the unknown functions admit different degrees of smoothness. In this method polynomials of different orders are used to approximate unknown functions with different degrees of smoothness. As only one minimization operation is employed, the required computation burden is much less than that required by the existing two-step estimation method. It is shown that the one-step estimators also achieve the optimal convergence rate. Moreover this property is obtained under conditions milder than that imposed in the two-step estimation method. More importantly, as only one minimization operation is employed, the full asymptotic properties, not only the asymptotic bias and variance, but also the asymptotic distributions of the estimators can be derived. The asymptotic distribution results will play a key role for making statistical inference.

关键词： varying coefficient model, one-step estimation, asymptotic distribution, optimal convergence rate.

Intuitionistic fuzzy hierarchical clustering algorithms

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Journal of Systems Engineering and Electronics 2009年第1期20卷 90-97页

作者： Xu Zeshui1,2 1. Coll. of Economics and Management, Southeast univ., nanjing 210096, P. r. china 2. inst. of sciences, pla univ. of science and technology, nanjing 210007, P. r. china Coll. of Economics and Management Southeast Univ. Nanjing 210096 P. R. China inst. of sciences PLA Univ. of Science and Technology Nanjing 210007 P. R. China

Intuitionistic fuzzy set （IFS） is a set of 2-tuple arguments, each of which is characterized by a membership degree and a nonmembership degree. The generalized form of IFS is interval-valued intuitionistic fuzzy set （IVIFS）, whose components are intervals rather than exact numbers. IFSs and IVIFSs have been found to be very useful to describe vagueness and uncertainty. However, it seems that little attention has been focused on the clustering analysis of IFSs and IVIFSs. An intuitionistic fuzzy hierarchical algorithm is introduced for clustering IFSs, which is based on the traditional hierarchical clustering procedure, the intuitionistic fuzzy aggregation operator, and the basic distance measures between IFSs： the Hamming distance, normalized Hamming, weighted Hamming, the Euclidean distance, the normalized Euclidean distance, and the weighted Euclidean distance. Subsequently, the algorithm is extended for clustering IVIFSs. Finally the algorithm and its extended form are applied to the classifications of building materials and enterprises respectively.

关键词： intuitionistic fuzzy set interval-valued intuitionistic fuzzy set hierarchical clustering intuitionisticfuzzy aggregation operator distance measure.

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

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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 univ.r.ity,nanjing 210096,P.r.china 2.inst.tute of sciences,univ.r.ity of science and technology of the pla,nanjing 210007,P.r.china College of Economics and Management Southeast University Nanjing 210096 P. R. China inst.tute 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.

Effective capacity region of two-user opportunistic spectrum access

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science china(Information sciences) 2011年第9期54卷 1928-1937页

作者： XU YuHua,WANG JinLong & WU QiHui inst.tute of Communications Engineering,pla univ.r.ity of science and technology,nanjing 210007,china inst.tute of Communications Engineering PLA University of Science and Technology Nanjing China

The effective capacity region of the two-user opportunistic spectrum access (OSA) system in rayleigh fading environment is derived in this *** OSA is a contemporary research topic,little attention has been given to the capacity analysis under quality-of-service (QoS) ***,we use the effective capacity,which is a powerful tool to analyze the QoS requirements in wireless communication systems,to study the sustainable packet arrival rate of the secondary users while meeting statistical QoS *** derive the effective capacity region of the two-user OSA system and propose a method to obtain the capacity region *** addition,by combining the finite state channel model and the activity of the primary user,an extended finite state channel model for the two-user OSA system is also proposed.

关键词： cognitive radio opportunistic spectrum access effective capacity

A novel multicluster V-MIMO PCr scheme in large-scale Ad Hoc networks

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science china(Information sciences) 2010年第10期53卷 2097-2105页

作者： ZHOU Yao, CAI YueMing & PAN ChengKang Department of Wireless Communication, inst.tute of Communications Engineering, pla univ.r.ity of science and technology, nanjing 210007, china Department of Wireless Communication Institute of Communications Engineering PLA University of Science and Technology Nanjing China

A multicluster packet collision resolution (PCr) scheme is a kind of recently proposed virtualMIMO techniques. In existing multicluster PCr schemes, a large-scale wireless Ad Hoc network is divided into clusters and the single cluster PCr scheme is applied independently to resolve collisions in each cluster. However, there are still some flaws in existing multicluster PCr schemes. In this paper, by presenting a concise theoretical analysis model and a new CNS algorithm, a novel multicluster PCr scheme is proposed. Analysis and simulation results show that the proposed scheme can obtain high performance gain with low complexity. The proposed scheme is more robust and applicable than existing schemes.

关键词： packet collision resolution virtual-MIMO cooperative communication cooperative nodes selection

A new smoothing scheme for mathematical programs with complementarity constraints

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science china Mathematics 2010年第7期53卷 1881-1890页

作者： YAN TaoDepartment of Information and Computational sciences, College of science, nanjing univ.r.ity of science and technology, nanjing 210094, china Department of Information and Computational sciences College of Science Nanjing University of Science and Technology Nanjing China

In this paper, we consider a mathematical program with complementarity constraints (MPCC). We present a new smoothing scheme for this problem, which makes the primal structure of the complementarity part unchanged mostly. For the new smoothing problem, we show that the linear independence constraint qualification (LICQ) holds under some conditions. We also analyze the convergence behavior of the smoothing problem, and get some sufficient conditions such that an accumulation point of stationary points of the smoothing problems is C (M, B)-stationarity respectively. Based on the smoothing problem, we establish an algorithm to solve the primal MPCC problem. Some numerical experiments are given in the paper.

关键词： mathematical program with complementarity constrains MPEC-LICQ B-stationarity C-stationarity M-stationarity

Optimal MAC based cooperative spectrum sensing in cognitive radio networks

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science china(Information 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 science and technology,Department of Automation,Tsinghua univ.r.ity,Beijing 100084,china 2 inst.tute of Command Automation,pla univ.r.ity of science and technology,nanjing 210007,china State Key Laboratory of Intelligent technology and Systems Tsinghua National Laboratory for Information Science and Technology Department of Automation Tsinghua University Beijing China inst.tute of Command Automation PLA University of Science and Technology Nanjing China

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

rESEArCH ON CONSTrUCTING SYNTHETIC MATrIX IN AHP

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Journal of Systems science & Complexity 2002年第4期15卷 407-415页

作者： XU Zeshui inst.tute of

This paper presents a new method for constructing synthetic matrix which is obtained by extending the given judgement matrices in the Analytic Hierarchy Process (AHP). The consistency relationship among the given matrices and their synthetic matrix is studied. The method can be used to deal with situations where the number of the given alternatives is larger than nine, and needs less pairwise comparisons than any others. Thus it will aid in the design of the AHP, which will reduce the information overload of decision maker, a major drawback of the original AHP algorithm. Finally, a numerical example is given to show the feasibility and effectiveness of the method.

关键词： AHP synthetic matrix consistency index.

NEW ACHIEVEMENTS ON THE THEOrY AND technology OF EXPLOSIVE WELDING

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Acta Metallurgica Sinica(English Letters) 2003年第6期16卷 531-537页

作者： C.G. Shi, Y.H. Wang, L.G. Cai and C.H. ZhouEngineering inst.tute of Engineering Corps, pla univ.r.ity of science and technology, nanjing 210007, china Engineering inst.tute of Engineering Corps PLA University of Science and Technology

There are four new achievements of this work on the theory and technology of explosive welding.(1) It has been found and defined three kinds of bonding interfaces: big wavy, small wavy and micro wavy, and the micro wavy interface is the best. In a cladding plate, it is for the first time to find that the form of interface presents regular distribution.(2) Although the interface has the features of melt, diffusion and pressure welding in the mean time, the seam and 'hole' brought by the melt weaken the bonding strength of interface greatly, and the effect of melt on interface must be eliminated in explosive welding, so explosive welding is not a melt weld. The diffusion welding is a kind of form of pressure welding, and the diffusion is not the reason of the bonding of interface but the result of interface high pressure. So the diffusion welding cannot also explain the bonding mechanism of it. The experiment and theory make clear that explosive welding is a special pressure one.(3) To get good interface of no melt, explosive charge must be selected on the low limit of welding windows. In explosive welding, the drive plate should be treated as the viscous and plastoelastic body, not incompressible fluid. The bending moment under the explosive welding loading must be greater than that under dynamic limit of drive plate. According to the condition, the lower limit of explosive welding is obtained. It is about 20% less than that obtained by tradition calculation, and suitable for engineering application.(4) It is for the first time to test and study on soil anvil characteristics and change regularity under explosive welding impact loading. Through soil anvil parameter optimization analysis, it is the best for explosive welding with sandy soil of water content 17.00% and density 1.74q/cm3.

关键词： explosive welding bonding interface pressure welding low limit