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复杂产品虚拟样机工程

计算机集成制造系统-CIMS 2002年第9期8卷 678-683页

作者：李伯虎柴旭东航天科工集团二院北京100854 清华大学国家CIMS工程技术研究中心北京100084

复杂产品虚拟样机技术是当前CIMS技术研究与应用的热点 ,其样机的开发工作已成为一项复杂的系统工程。复杂产品虚拟样机开发技术是融合与产品有关的专业领域技术与建模仿真技术、信息技术、多媒体虚拟现实技术、人工智能技术、系统... 详细信息

复杂产品虚拟样机技术是当前CIMS技术研究与应用的热点 ,其样机的开发工作已成为一项复杂的系统工程。复杂产品虚拟样机开发技术是融合与产品有关的专业领域技术与建模仿真技术、信息技术、多媒体虚拟现实技术、人工智能技术、系统技术和管理技术等多学科的一门综合性技术。基于笔者的研究与初步实践 ,本文提出了复杂产品虚拟样机工程的概念 ,并对其技术内涵、组成、运行模式、体系结构及其相关关键技术进行了探讨 ,以期促进复杂产品虚拟样机技术在我国企业的研究、实施与应用。

关键词：现代集成制造系统 CIMS 复杂产品虚拟样机虚拟样机工程

On an attack on RSA with small CRT-exponents

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Science china(information Sciences) 2010年第8期53卷 1511-1518页

作者： HAN LiDong 1,2 , WANG XiaoYun 3 & XU GuangWu 3,4 1 Key Laboratory of Cryptologic Technology and information security, Ministry of Education, Shandong University, Jinan 250100, china 2 School of Mathematics, Shandong University, Jinan 250100, china 3 Institute for Advanced Study, Tsinghua University, beijing 100084, china 4 Department of Electrical engineering and Computer Science, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA 1. Key Laboratory of Cryptologic Technology and information security Ministry of Education Shandong University Jinan 250100 China2. School of Mathematics Shandong University Jinan 250100 China3. Institute for Advanced Study Tsinghua University Beijing 100084 China4. Department of Electrical Engineering and Computer Science University of Wisconsin-Milwaukee Milwaukee WI 53201 USA

This paper concerns the RSA system with private CRT-exponents. Since Chinese remainder representation provides efficiency in computation, such system is of some practical significance. In this paper, an existing attack to small private CRT-exponents is analyzed. It is indicated that this attack makes nice use of lattice in RSA analysis, but some argument does not hold in general. Several counterexamples are constructed. Refinements and more precise statements of the attack are given.

关键词： RSA CRT cryptanalysis continued fraction lattice reduction

The Red Edge Parameters of Different Wheat Varieties Under Different Fertilization and Irrigation Treatments

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Agricultural Sciences in china 2002年第7期1卷 745-751页

作者： ZHAO Chun-Jiang, HUANG Wen-Jiang, WANG Ji-hua, YANG Min-hua and XUE Xu-zhang( national engineering center for information Technology in Agriculture , beijing 100089 , P. R . china) national engineering center for information Technology in Agriculture Beijing 100089 P.R. China

The dynamics of red edge parameters at different growth stages of wheat canopy was studied. The red edge position moved to the longer wavelength from erecting stage to heading stage, and returned to the original wavelength direction from grain-filling stage to maturity stage. The leaf total nitrogen content (LTN) is positively related to red edge amplitude (d λ red) and NIR platform amplitude (d λNIRP) and the correlation coefficient improved as growth stage extended. The chlorophyll content (TChl) is negatively related to d λ red from erecting stage to the elongation stage, and positively related to d λ red from heading stage to milky maturity stage. TChl is also positively related to d λNIRP. The leaf area index (LAI) is positively related to d λ red and d λNIRP, and the correlation coefficient improved as growth stage extended. It was concluded that d λ red and d λNIRP can be used as the indicators of winter wheat growth state, and guide the fertilization and irrigation decision making. The λNIRF is suitable for derivation of LTN, the d λ red for TChl, and the d λ red or d λNIRP for LAI.

关键词： Winter wheat Spectrum Red edge parameters (REP) Variety Fertilizer Water

Application of Multicast-based Video Conference on CERNET Backbone

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计算机工程 2002年第S1期28卷 133-136页

作者： ZHANG Xuan, WANG Yalei, LI Chongrong(Network research center of Tsinghua University, beijing 100084,china) Network research center of Tsinghua University Beijing 100084China

Multicast-based video conference is a representative application in advanced network. In multi-point video conference using multicast can get better efficiency facilitated by inner-group broadcast mechanism. In the application, the multicast-based network resources assignment, management and security should be considered together. This paper presents a framework model of multicast-based video conferencing application with three layers. And a practical multicast-based video conferencing is implemented in CERNET(china Education and research Network) backbone. The practice is valuable for the development of multicast-based video conferencing application in china.

关键词： Multicast Video conference Network application

Effects Evaluation on Sweep Jamming

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Effects Evaluation on Sweep Jamming

On the Organizational Dynamics of the Genetic Code

2011 IEEE International Conference on information Theory and information security(ICITIS 2011)

作者： Ying Zhu 1) 2) Qina Gao 1) 2) Zhanbin Jiang 2) 1) School of Electronics and information engineering Beihang University beijing china 2) beijing Aeronautical Technology research center beijing china

One method of effects evaluation on sweep jamming to conical-scan radar is discussed. Based on the analysis of operations performance of aircraft and weapons system, the relation between the ratio of input jamming power of radar which was oppressed in the minimal shot distance to the radar angle tracking error and the formula of shot error were obtained. The kill probability model was set up. In the end, using the model, the kill probability for an application example was computed, and the jamming effect was evaluated in terms of the results.

关键词： sweep jamming effects evaluation shot error kill probability

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Genomics,Proteomics & Bioinformatics 2011年第Z1期 21-29页

作者： Zhang Zhang1 and Jun Yu1,2* 1Plant Stress Genomics research center, Division of Chemical and Life Sciences and engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia 2CAS Key Laboratory of Genome Sciences and information, beijing Institute of Genomics, Chinese Academy of Sciences, beijing 100029, china.

The organization of the canonical genetic code needs to be thoroughly illuminated. Here we reorder the four nucleotides-adenine, thymine, guanine and cytosine-according to their emergence in evolution, and apply the organizational rules to devising an algebraic representation for the canonical genetic code. Under a framework of the devised code, we quantify codon and amino acid usages from a large collection of 917 prokaryotic genome sequences, and associate the usages with its intrinsic structure and classification schemes as well as amino acid physicochemical properties. Our results show that the algebraic representation of the code is structurally equivalent to a content-centric organization of the code and that codon and amino acid usages under different classification schemes were correlated closely with GC content, implying a set of rules governing composition dynamics across a wide variety of prokaryotic genome sequences. These results also indicate that codons and amino acids are not randomly allocated in the code, where the six-fold degenerate codons and their amino acids have important balancing roles for error minimization. Therefore, the content-centric code is of great usefulness in deciphering its hitherto unknown regularities as well as the dynamics of nucleotide, codon, and amino acid compositions.

关键词： genetic code codon GC content purine content organizational dynamics compositional dynamics

research ON APPLICATIONS OF STOCHASTIC PROCESS IN MODELING PLANT GROWTH

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RESEARCH ON APPLICATIONS OF STOCHASTIC PROCESS IN MODELING P...

第四届智能化农业信息技术国际学术会议

作者： Ying Xiong~(1 2) Changfeng Li~1 Shenglian Lu~1 Xinyu Guo~1 1 national engineering research center for information Technology in Agriculture beijing 100097 china 2 Capital Normal University beijing 100037 china

＜正＞This paper gives an overview to stochastic process,especially the mathematic definition, evolving history and applications of Markov stochastic ***,models and applications using Markov stochastic process to simulate and visualize plant growth are introduced in detail. Appraisal to these models are given following by a perspective to the simulating of plant growth.

关键词： Markov Process Plant Growth Modeling Stochastic L-System Reference Axis Dual-scale

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数字水印的研究进展和应用

通信学报 2001年第5期22卷 71-79页

作者：陈明奇钮心忻杨义先国家计算机网络与信息安全管理中心北京100031 北京邮电大学信息安全中心北京100876

随着社会的网络化、信息化的发展 ,对数字产品的版权保护迫在眉睫。数字水印是近年来出现的数字产品版权保护技术 ,可携带有版权信息和认证信息 ,保护数字产品的合法拷贝和传播 ,是当前国际学术界的研究热点。本文全面分析总结了数字水... 详细信息

随着社会的网络化、信息化的发展 ,对数字产品的版权保护迫在眉睫。数字水印是近年来出现的数字产品版权保护技术 ,可携带有版权信息和认证信息 ,保护数字产品的合法拷贝和传播 ,是当前国际学术界的研究热点。本文全面分析总结了数字水印的各种方案 ,讨论其种种应用 ,介绍了数字水印的研究现状 ,提出了数字水印下一步的发展方向 ,对数字水印技术的研究有着重要的指导意义。

关键词：产权保护数字水印信号处理算法设计保密通信

ON DECORRELATED FAST CIPHER

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Journal of Electronics(china) 2000年第1期17卷 94-96页

作者： Wu Wenling Li Bao Feng Denguo Qing Sihan(engineering research center for information security Technology,Chinese Academy of Sciences, beijing 100080)

Decorrelated Fast Cipher(DFC) is a candidate for the Advanced Encryption Standard (AES). It is shown that the cryptographic properties of the confusion permutation of DFC are weak in this paper. With the same F-function of DFC, a Feistel cipher VDFC which has no resistance against differential cryptanalysis is constructed. This demonstrates the importance of the key addition into DFC sufficiently. As a result, DFC may not be qualified candidate for the AES.

关键词： Round function Permutation Differential cryptanalysis Nonlinearity