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A relationship between the nonexistence of generalized bent functions and class groups

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Science china Mathematics 2010年第1期53卷 213-222页

作者： LIU FengMei 1,& YUE Qin 21 Department of Information Research,college of Information Engineering,Information Engineering university,Zhengzhou 450002,china 2 Department of Mathematics,nanjing university of Aeronautics and Astronautics,nanjing 210016,china 1. Department of Information Research College of Information Engineering Information Engineering University Zhengzhou 450002 China2. Department of Mathematics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A new result on the nonexistence of generalized bent functions is presented by using properties of the decomposition law of primes in cyclotomic fields and properties of solutions of some Diophantine equations. At the same time,a method is given which can be used to simplify the known results. Then we give the bounds and the meaning in algebraic number theory of the parameters in our results.

关键词： generalized bent function integral basis class group genus theory

Low-complexity distributed differential spacetime coding scheme for amplify-and-forward cooperative networks

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Science in china(Series F) 2009年第8期52卷 1418-1427页

作者： YU XiangBin1,2, BI GuangGuo3 & XU WeiYe4 1 college of Information Science and Technology, nanjing university of Aeronautics and Astronautics, nanjing 210016, china 2 Department of Electronic Engineering, City university of Hong Kong, Hong Kong, china 3 National Mobile Communications Research Laboratory, Southeast university, nanjing 210096, china 4 Department of Communication Engineering, nanjing Institute of Technology, nanjing 211167, china college of Information Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Department of Electronic Engineering City University of Hong Kong Hong Kong China National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China Department of Communication Engineering Nanjing Institute of Technology Nanjing 211167 China

By introducing a space-time coding scheme based on amicable orthogonality, we develop a distributed differential space-time coding scheme with the amplify-and-forward （AF） method for wireless cooperative networks. The scheme requires no knowledge of the channel state information at both transmitters and receivers, and effectively decreases the realization complexity due to no channel estimation. Moreover, it has lower decoding complexity and higher coding advantage than the existing scheme, thus avoiding the shortcoming of exponential decoding complexity of some existing schemes. According to the pairwise error probability （PEP） analysis of the system, the power allocations of source and relay terminals are jointly optimized, and as a result, the PEP is minimized, which will provide a helpful guideline for system design. Numerical calculation and simulation results show that the developed scheme is superior to the existing scheme. Moreover, the scheme with optimal power allocation yields obvious performance improvement over that with equal power allocation.

关键词： differential space-time coding cooperative communication amplify-and-forward method power allocation

Back analysis of mechanical parameters of roller compacted concrete dam

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Science china(Technological Sciences) 2010年第3期53卷 848-853页

作者： GU ChongShi 1,2,3,LI Bo 1,XU GuangLei 4 &YU Hong 1,2,3 1 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai university,nanjing 210098,china 2college of Water Conservancy Hydropower,Hohai university,nanjing 210098,china 3National Engineering Research Center of Water Resources Engineering Safety,Efficient Utilization and nanjing 210098,china 4 nanjing Hydraulic Research Institute,nanjing 210029,china 1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China2. College of Water Conservancy Hydropower Hohai University Nanjing 210098 China3. National Engineering Research Center of Water Resources Engineering Safety Efficient Utilization and Nanjing Nanjing 210098 China4. Nanjing Hydraulic Research Institute Nanjing 210029 China

In view of the diversity and complexity of mechanical parameters of roller compacted concrete dam(RCCD),the uniform design method,partial least-squares regression(PLS)and least squares support vector machine(LSSVM)were applied to the back analysis of RCCD with the use of the complex nonlinear relationship between dam mechanical parameters and dam *** the process of back analysis,the initial samples of parameters were designed with uniform design ***,a transversely isotropic model of RCCD was established by *** *** this model,training samples of LSSVM model could be *** then,the complex nonlinear relationship between relative values of hydraulic components of dam displacements and mechanical parameters was ***,actual relative values of dam hydraulic components are isolated from the measured data of dam displacements by using *** inputting the isolated relative values into LSSVM model,the back analysis values of RCCD mechanical parameters can be *** example analysis showed that mechanical parameters obtained by the above-mentioned back analysis method are reasonable,and the back analysis method is feasible.

关键词： roller compacted concrete dam mechanical parameters back analysis

Facile Synthesis of Nanocrystalline Cr_2O_3 Thin Film

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Journal of Wuhan university of Technology(Materials Science) 2011年第6期26卷 1032-1035页

作者：杨明 School of Transportation Southeast University

A novel and facile synthesis route for the manufacture of transparent and uniform self-assembled nanocrystalline Cr2O3 （nc-Cr2O3） thin films with different morphology was reported, utilizing chromium nitrate as the inorganic source and triblock copolymer F127 as the morphology-directing agent by the evaporation-induced assembly （EIA） method. X-ray powder diffraction （XRD）, thermogravimetry-differential scanning calorimetry （TG-DSC）, N2-sorption, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） were used to characterize the as-prepared nc-Cr2O3 thin films. The Cr2O3 thin film with different morphology was obtained by changing the relative humidity. The possible formation mechanism of the nc-Cr2O3 thin films with different morphologies was discussed.

关键词： microstrucmre Cr2O3 thin film

On generalized k-syzygy modules

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Science china Mathematics 2007年第5期50卷 675-682页

作者： Chong-hui HUANG & Zhao-yong HUANG Department of Mathematics, nanjing university, nanjing 210093, china college of Mathematics and Physics, Nanhua university, Hengyang 421001, china Department of Mathematics Nanjing University Nanjing China college of Mathematics and Physics Nanhua University Hengyang China

In this paper, we first introduce the notion of generalized k-syzygy modules, and then give an equivalent characterization that the class of generalized k-syzygy modules coincides with that ofω-k-torsionfree modules. We further study the extension closure of the category consisting of generalized k-syzygy modules. Some known results are obtained as corollaries.

关键词： generalized k-syzygy module ω-k-torsionfree module extension closure

Image space analysis for variational inequalities with cone constraints and applications to traffic equilibria

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Science china Mathematics 2012年第4期55卷 851-868页

作者： LI Jun 1,& HUANG nanjing 2 1 college of Mathematics and Information,china West Normal university,Nanchong 637009,china 2 Department of Mathematics,Sichuan university,Chengdu 610064,china 1. college of Mathematics and Information China West Normal University Nanchong 637009 China2. Department of Mathematics Sichuan University Chengdu 610064 China

In this paper,the image space analysis (for short,ISA) is employed to investigate variational in- equalities (for short,VI) with cone *** separation for VI with cone constraints is characterized by using the normal cone to a regularization of the image,and saddle points of the generalized Lagrangian func- ***-type necessary and sufficient optimality conditions for VI with cone constraints are presented by using a separation *** functions and weak sharpness for VI with cone constraints are also investi- ***,the obtained results are applied to standard and time-dependent traffic equilibria introduced by Daniele,Maugeri and Oettli.

关键词： variational inequality image space analysis linear separation necessary and sufficient optimalitycondition traffic equilibrium

Theory and methods of global stability analysis for high arch dam

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Science china(Technological Sciences) 2011年第S1期54卷 9-17页

作者： REN QingWen 1,LI Qiang 1,JIANG YaZhou 2 & JIANG XiaoLan 3 1 Department of Engineering Mechanics,Hohai university,nanjing 210098,china 2 college of Water Conservation and Hydropower Engineering,Hohai university,nanjing 210098,china 3 Changjiang Academy of Sciences,Wuhan 430010,china 1. Department of Engineering Mechanics Hohai University Nanjing 210098 China2. College of Water Conservation and Hydropower Engineering Hohai University Nanjing 210098 China3. Changjiang Academy of Sciences Wuhan 430010 China

The global stability of high arch dam is one of the key problems in the safety study of arch dams,but no feasible method with theoretical basis is *** this paper,based on the stability theory of mechanical system,it is demonstrated that the global failure of high arch dams belongs to a physical instability starting from local strength failure,which is the extreme point instability according to the characteristics of load-displacement curve obtained from the failure process of dam-foundation system. So the global failure of dam-foundation system should be studied with the stability theory of mechanical *** is also pointed out that the current stability analysis methods used in engineering are consistent with the stability theory,but not established according to the mechanical system stability theory directly.A perfect method can be obtained through the study of physical disturbance equations.

关键词： high arch dam global stability physical instability extreme point instability

New data regarding acritarch biostratigraphy from the Early-Middle Cambrian Kaili Formation in Chuandong,Guizhou Province,china

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Progress in Natural Science:Materials International 2009年第1期19卷 107-114页

作者： Leiming Yin a,Ruidong Yang b,Jin Peng c,Fanfan Kong a a nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,nanjing 210008,china b college of Resource and Environment of Guizhou university,Guiyang 550003,china c Department of Sciences of nanjing university,nanjing 210093,china [a]nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China [b]College of Resource and Environment of Guizhou University Guiyang 550003 China [c]Department of Sciences of Nanjing University Nanjing 210093 China

Previous studies had evaluated acritarchs from the Balang and Pingzhai sections of the Early-Middle Cambrian Kaili Formation in east Guizhou,*** results of these studies suggest that the acritarchs in these sections have potential biostratigraphic *** recently,34 samples collected from 83 m lower part of the Lower-Middle Cambrian Kaili Formation in the Jianshan section of Chuandong,Guizhou Province were prepared for palynological *** of these samples revealed a distinct change in the acritarch assemblages at the bed,which was approximately 46 m above the bottom of the Kaili *** findings suggest a boundary represented by an important alteration of the ecological *** addition,the position of the acritarch biostratigraphic change is somewhat higher than the boundary between Cambrian Series 2 and Series 3 based on trilobites found in the same *** indicates that the distinct change in acritarch assemblages is similar to the change in trilobite assemblages that occurs around the boundary between Cambrian Series 2 and Series ***,acritarch biostratigraphy can provide data that can be used to define the base of Cambrian Series 3 in this region,and possibly worldwide.

关键词： Acritarchs Lower-Middle Cambrian Kaili Formation Jianshan section Chuandong

A novel multi-relay cross-layer cooperative communication strategy based on Jackson queuing model

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Science china(Information Sciences) 2010年第4期53卷 842-853页

作者： XU XiaoRong1,2* & ZHENG BaoYu1 1Institute of Signal Processing and Transmission, nanjing university of Posts and Telecommunications, nanjing 210003, china 2college of Telecommunication Engineering, Hangzhou Dianzi university, Hangzhou 310018, china Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing China college of Telecommunication Engineering Hangzhou Dianzi University Hangzhou China

A novel multi-relay cooperative communication strategy based on Jackson queuing model is pro-posed, which is implemented via a cross-layer design between the physical (PHY) layer and the medium access control (MAC) layer. In the PHY layer, we focus mainly on system outage performance by analyzing in detail the relationship between the SNR threshold and the outage probabilities. While in the MAC layer, system model is treated as a Jackson queuing network, and the queue discipline for each node is assumed to be GI/M/1 model. System throughput and delay performance for the proposed strategy are also illustrated. Simulation results of the proposed cross-layer scheme are presented to validate our theoretical derivations. It is revealed that, the number of cooperative nodes influences system outage performance at high spectral efficiency regimes in the PHY layer while the proposed strategy provides a better throughput and delay performance than conventional schemes in the MAC layer.

关键词： multi-relay cooperative communication cross-layer design Jackson queuing model outage prob- abilities GI/M/1 model system throughput delay performance