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Performance of iteratively decoded bit-interleaved coded modulation with chaos based interleaving strategies

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science china({2. sciences) 2010年第4期53卷 833-841页

作者： ZOU XueLan1*, LIU WeiYan2.& FENG GuangZeng3.1Department of Electronic and information engineering, Zhejiang Institute of Media and Communications, Hangzhou 3.0018, {2. 2.epartment of information engineering, Jiangsu City Vocation College, Nanjing 2.003., {2. 3.ollege of Communication and information engineering, Nanjing University of Posts and Telecommunications, Nanjing 2.0003. {2. 1. Department of Electronic and information engineering Zhejiang Institute of Media and Communications Hangzhou 310018 China2. Department of Information Engineering Jiangsu City Vocation College Nanjing 210036 China3. College of Communication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China

Bit-interleaved coded modulation with iterative decoding (BICM-ID) is a bandwidth efficient trans- mission scheme which is well suitable for next-generation mobile communications. The interleaver design is critical to the high performance of BICM-ID. In this paper we investigate the application of the chaos theory to the interleaver design to further improve the performance of BICM-ID. A new interleaving scheme based on the chaos theory is proposed. Compared with the random interleaver, the proposed approach has the ad- vantages including lower system delay and higher transmission efficiency. Simulation results in both additive white Gaussian noise (AWGN) channel and Rayleigh fading channel are provided, which demonstrates that the new interleaver is better than the random interleaver and exhibits excellent performance when applied to the BICM-ID system.

关键词： chaos interleaving bit-interleaved coded modulation (BICM) iterative decoding

Seasonal variation of global stratosphere-troposphere mass exchange

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Progress in Natural science:Materials International 2007年第12期17卷 1466-1475页

作者： Guo Dong1,2. Lu Daren2.and Sun Zhaobo1(1. Institute of Atmospheric sciences, Nanjing University of {3. science and Technology, Nanjing 2.0044, china 2. LAGEO, Institute of Atmospheric Physics, Chinese Academy of sciences, Beijing 10002., china) Institute of Atmospheric sciences Nanjing University of Information Science and Technology Nanjing 210044 China LAGEO Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

By Wei formula in pressure coordinate, the stratosphere-troposphere mass exchange (STME) is diagnosed globally for 44 years from 1958 to 2.01 using the European Center for Medium-Range Weather Forecasts (ECMWF) reanalysis datasets. Regions of mass flux into the stratosphere are found over Indonesia, bay of Bangladesh and the mid-west coast of South Africa. Compensating mass outflow from the stratosphere appears mainly over mid-latitudes near large-scale troughs. Upward and downward transport of mass at the middle and high latitudes accompany with each other. Mass flux into troposphere is stronger in autumn and winter than in spring and summer. Strong downward mass flux into the troposphere occurs in eastern Asia the whole year with nearly stable sites. Although the area of eastern Asia accounts for only 5.6% of that of the northern hemisphere (NH), its net mass exchange reaches 15.83. of that of the NH, which means that research on STME of eastern Asia is greatly important to that of the NH and even the global areas. Air across the tropopause enters more from stratosphere to troposphere than that from troposphere to stratosphere, which is possibly related with systematic bias of the assimilated datasets and with persistent rise of the tropopause height. Contributions of the mass exchange and the mass flux exchange in the NH and southern hemisphere (SH) on their latitudes increase from equator to pole, with larger contributions in the NH. Mass exchange and mass flux exchange per areas at high latitudes are larger than that at low latitudes, which means greater mass exchange efficiency at high latitudes.

关键词： stratosphere troposphere mass exchange seasonal variation.

The Young's moduli prediction of random distributed short-fiber-reinforced polypropylene foams using finite element method

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science china(Technological sciences) 2009年第1期52卷 72-78页

作者： WANG Bo1, WANG RongXiu2.& WU Yong1 1 School of Mathematic science, Chongqing Institute of Technology, Chongqing 400050, {2. 2.Department of Computer science and information engineering, Chongqing Technology and Business University, Chongqing 400067, {2. School of Mathematic science Chongqing Institute of Technology Chongqing 400050 China Department of Computer science and information {2. Chongqing Technology and Business University Chongqing 400067 China

The elastic moduli of short-fiber-reinforced foams depend critically on the fiber content and fiber length, as well as on the fiber orientation distribution. Based on periodic tetrakaidecahedrons, the finite element models with short-fiber reinforcement were proposed in this paper to examine the effects of the fiber content and fiber length on Young's modulus. The fiber length distribution and fiber orientation distribution were also considered. The proposed models featured in a three-dimensional diorama with random short-fiber distribution within or on the surfaces of the walls and edges of the closed-cells of polypropylene (PP) foams. The fiber length/orientation distributions were modeled by Gaussian prob-ability density functions. Different fiber volume fractions, different lengths, and different distributions were investigated. The predicted Young's moduli of the PP foams with short-glass-fiber or short-carbon-fiber reinforcement were compared with other theoretic and experimental results, and the agreement was found to be satisfactory. The proposed finite element models were proved to be acceptable to predict the Young's moduli of the grafted closed-cell PP foams with short-fiber reinforcement.

关键词： short-fiber reinforcement Young’s modulus finite element Gaussian distribution

The new interpretation of support vector machines on statistical learning theory

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science china Mathematics 2010年第1期53卷 151-164页

作者： ZHANG ChunHua 1 , TIAN YingJie 2.& DENG NaiYang 3.1 School of information, Renmin University of {2., Beijing 100872. {2. 2.Research Center on Fictitious Economy and Data science, Chinese Academy of sciences, Beijing 100080, {2. 3.College of science, {2. Agricultural University, Beijing 100083. {2. 1. School of information Renmin University of China Beijing 100872 China2. Research Center on Fictitious Economy and Data Science Chinese Academy of Sciences Beijing 100080 China3. College of Science China Agricultural University Beijing 100083 China

This paper is concerned with the theoretical foundation of support vector machines (SVMs). The purpose is to develop further an exact relationship between SVMs and the statistical learning theory (SLT). As a representative, the standard C-support vector classification (C-SVC) is considered here. More precisely, we show that the decision function obtained by C-SVC is just one of the decision functions obtained by solving the optimization problem derived directly from the structural risk minimization principle. In addition, an interesting meaning of the parameter C in C-SVC is given by showing that C corresponds to the size of the decision function candidate set in the structural risk minimization principle.

关键词： C-support vector classification the minimization principle of the structural risk KKT conditions

11-Round Impossible Differential Algebraic Attack for Serpent Encryption Algorithm

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Wuhan University Journal of Natural sciences 2010年第3期15卷 232-236页

作者： HU Zhihua1,2. QIN Zhongping3.1. School of Computer, Wuhan University, Wuhan 43.072. Hubei, {3. 2. College of Mathematical and {2. sciences,Huanggang Normal University, Huanggang 43.000, Hubei, {3. 3. School of Software engineering, Huazhong University of science and Technology, Wuhan 43.074, Hubei, {3. School of Computer Wuhan University Wuhan Hubei China College of Mathematical and information sciences Huanggang Normal University Huanggang Hubei China School of Software engineering Huazhong University of Science and Technology Wuhan Hubei China

This paper explored algebraic features of nonlinear parts in Serpent encryption algorithm and offered an 11-round Serpent-12. impossible differential algebraic attack through utilizing the method in constructing S-box algebraic equations. The new method analyzed block ll-round Serpent with 2.2. selected plaintexts and 2.2. bytes memory space at the same time of giving a new design principle of S-box anti-algebraic attack.

关键词： impossible differential Serpent algebraic equation

Analysis of the co-seismic responses of the fluid well pattern system in Jiangsu Province to the Wenchuan and Tohoku earthquakes

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Earthquake science 2012年第3期25卷 263-274页

作者： Jiangrong Zheng1, Haolin Jiang1 and Zhengran He2.1 Earthquake Administration of Jiangsu Province, Nanjing 2.0014, china 2.School of {2. science and engineering, southeast University, Nanjing 2.0049, china 1. Earthquake Administration of Jiangsu Province Nanjing 210014 China2. School of Information Science and Engineering Southeast University Nanjing 210049 China

This thesis discusses the earthquake reflecting ability of the observation well pattern system of Jiangsu Province, china, which has been digitally renovated, and probes into the cause of the major differences in the earthquake reflecting abilities of well holes at different measurement points. This is achieved through the analysis of the co-seismic responses to the Wenchuan (2.08; Ms8.0, china) and Tohoku (2.11; Ms9.0, Japan) earthquakes. We found that the co-seismic response of water level from regional well holes in Jiangsu Province was stronger than that of water temperature. The water-level co-seismic response follows a consistent law and is closely related to the earthquake magnitude. The co-seismic response of water temperature strongly varied among well points, and was more often manifested as a slow restorative change. The co-seismic responses also varied based on tectonic elements. The response in central and northern Jiangsu was weaker than that of southern Jiangsu, possibly due to the thicker loess cover layer in central Jiangsu which makes it less effective at capturing the micro-changes of stress-strain states relative to the hilly land in the south. The more complicated geological structure in southern Jiangsu makes it contribute to greater changes in the state of underground water after a minor disturbance.

关键词： fluid well pattern system 2.08 Ms8.0 Wenchuan earthquake 2.11 MS9.0 Tohoku earthquake features of co-seismic responses

The optimization of replica distribution in the unstructured overlays

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science china({2. sciences) 2012年第3期55卷 714-722页

作者： FENG GuoFu1,2., LI WenZhong2. LU SangLu2. CHEN DaoXu2.& BUYYA Rajkumar3.1School of information {2., Nanjing Audit University, Nanjing 2.002., china 2.tate Key Laboratory of Novel Software Technology, Nanjing University, Nanjing 2.0093. china 3.epartment of Computer {2. and Software engineering, The University of Melbourne, Victoria 3.10, Australia 1. School of information {2. Nanjing Audit University Nanjing 210029 China2. State Key Laboratory of Novel Software Technology Nanjing University Nanjing 210093 China3. Department of Computer Science and Software Engineering The University of Melbourne Victoria 3010 Australia

Replication is a widely used technique in unstructured overlays to improve content availability or system performance. A fundamental question often addressed by previous work focused on: how many replicas ought to be allocated for each data item given the fixed query rates and limited storage capability? In this paper, we have put forth two optimal replica distributions to achieve the highest success rate and the lowest message consumption. Especially, we have investigated the influence of item size on replica distribution. Our results show that Square-Root Replication, which is traditionally considered to be optimal, is not always the best choice. Our study offers a new deep understanding of resource managment in self-organized unstructured overlays.

关键词： unstructured overlay item size distribution query rate success rate expected search size

On the number of rotation symmetric Boolean functions

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science china({2. sciences) 2010年第3期53卷 537-545页

作者： FU ShaoJing1, LI Chao1,2.& QU LongJiang1,3.1science College of National University of Defense Technology, Changsha 410073. china 2.tate Key Laboratory of {2. Security, Beijing 10003., china 3.ational Mobile Communications Research Laboratory, southeast University, Nanjing 2.0096, china 1. science College of National University of Defense Technology Changsha 410073 China2. State Key Laboratory of Information Security Beijing 100039 China3. National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China

Rotation symmetric Boolean functions (RSBFs) have been used as components of different cryptosystems. This class of functions are invariant under circular translation of indices. In this paper, we investigated balanced RSBFs and 1st order correlation immune RSBFs. Based on constructive techniques, we give an accurate enumeration formula for n-variable balanced RSBFs when n is a power of a prime. Furthermore, an original and efficient method to enumerate all n-variable (n prime) 1st order correlationimmune functions is presented. The exact number of 1st order correlation immune RSBFs with 11 variables is 692.04715655047882.2.52.03.412.764511077684773.0552.800 and the number of 13.variables has 189 digits. Then for more variables, we also provide a significant lower bound on the number of 1st order correlation immune RSBFs.

关键词： cryptography rotation symmetry correlation immunity balancedness

Notifiable infectious disease surveillance with data collected by search engine

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Journal of Zhejiang University-science C(Computers and Electronics) 2010年第4期11卷 241-248页

作者： Xi-chuan ZHOU1,Hai-bin SHEN2.(1Department of information science and Electronic {2.,Zhejiang University,Hangzhou 3.002.,china) (2.chool of Electrical {2.,Zhejiang University,Hangzhou 3.002.,china) Department of information science and Electronic {2. Zhejiang University Hangzhou China School of Electrical engineering Zhejiang University Hangzhou China

Notifiable infectious diseases are a major public health concern in china,causing about five million illnesses and twelve thousand deaths every *** detection of disease activity,when followed by a rapid response,can reduce both social and medical impact of the *** aim to improve early detection by monitoring health-seeking behavior and disease-related news over the ***,we counted unique search queries submitted to the Baidu search engine in 2.08 that contained disease-related search *** we counted the news articles aggregated by Baidu's robot programs that contained disease-related *** found that the search frequency data and the news count data both have distinct temporal association with disease *** adopted a linear model and used searches and news with 1–2.0-day lead time as explanatory variables to predict the number of infections and deaths attributable to four notifiable infectious diseases,i.e.,scarlet fever,dysentery,AIDS,and *** the search frequency data and news count data,our approach can quantitatively estimate up-to-date epidemic trends 10–40 days ahead of the release of Chinese Centers for Disease Control and Prevention(Chinese CDC)*** approach may provide an additional tool for notifiable infectious disease surveillance.

关键词： Notifiable infectious diseases Disease surveillance Search engine