期刊文献+
任意字段
题名或关键词
题名
关键词
摘要
作者
第一作者
机构
刊名
分类号
参考文献
作者简介
基金资助
栏目信息
共找到76篇文章
< 1 2 … 4 >
每页显示 20 50 100
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
显示方式：
ELASTIC WAVEFIELD CALCULATION FOR HETEROGENEOUS ANISOTROPIC POROUS MEDIA USING THE 3-D IRREGULAR-GRID FINITE-DIFFERENCE 认领 引用 被引量：4
1
作者 SunWeitao YangHuizhu 《Acta Mechanica Solida Sinica》 SCIE 2003年第4期283-299,共17页
Basedonthe first-order Biot-equation with simplified coefficients,astaggered irregu- lar-grid finite difference method(FDM)is developed to simulate elastic wave propagation in 3-D heterogeneous anisotropic porous medi... Basedonthe first-order Biot-equation with simplified coefficients,astaggered irregu- lar-grid finite difference method(FDM)is developed to simulate elastic wave propagation in 3-D heterogeneous anisotropic porous media.The ‘slow’P wave in porous media wave simulation is highly dispersive.Finer grids are needed to get a precise wavefield calculation for models with curved interface and complex geometric structure.Fine grids in a global model greatly increase computation costs of regular grids scheme.Irregular fine or coarse grids in local fields not only cost less computing time than the conventional velocity-stress FDM,but also give a more accu- rate wavefield description.A dispersion analysis of the irregular-grid finite difference operator has confirmed the stability and high efficiency.The absorbing boundary condition is used to elimi- nate artificial reflections.Numerical examples show that this new irregular-grid finite difference method is of higher performance than conventional methods using regular rectangular grids in simulating elastic wave propagation in heterogeneous anisotropic porous media. 展开更多
关键词 elastic wave anisotropic porous media finite difference irregular-grid
暂未订购 下载PDF
Angular distribution of sputtered atoms induced by low-energy heavy ion bombardment 认领 引用 被引量：2
2
作者 ZHANGLai ZHANGZhu-Lin 《Nuclear Science and Techniques》 EI CAS 2004年第6期340-343,共4页
The sputtering yield angular distributions have been calculated based on the ion energy dependence of to- tal sputtering yields for Ni and Mo targets bombarded by low-energy Hg+ ion. The calculated curves show excelle... The sputtering yield angular distributions have been calculated based on the ion energy dependence of to- tal sputtering yields for Ni and Mo targets bombarded by low-energy Hg+ ion. The calculated curves show excellent agreement with the corresponding Wehner’s experimental results of sputtering yield angular distribution. The fact clearly demonstrated the intrinsic relation between the ion energy dependence of total sputtering yields and the sput- tering yield angular distribution. This intrinsic relation had been ignored in Yamamura’s papers (1981,1982) due to some obvious mistakes. 展开更多
关键词 溅射当量 辐角分布 各向异性效应 原子物理学
暂未订购 下载PDF
Addition Sequence Method of Scalar Multiplication of Elliptic Curve over OEF 认领 引用 被引量：2
3
作者 LIUDuo DAIYi-qi 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第1期174-178,共5页
A new elliptic curve scalar multiplication algorithm is proposed. Thealgorithm uses the Frobenius map on optimal extension field (OEF) and addition sequence We introducea new algorithm on generating addition sequence ... A new elliptic curve scalar multiplication algorithm is proposed. Thealgorithm uses the Frobenius map on optimal extension field (OEF) and addition sequence We introducea new algorithm on generating addition sequence efficiently and also give some analysis about it.Based on this algorithm, a new method of computing scalar multiplication of elliptic curve over anOEF is presented. The new method is more efficient than the traditional scalar multiplicationalgorithms of elliptic curve over OEF. Thecomparisons of traditional method and the new method arealso given. 展开更多
关键词 cryptology elliptic curve optimal extension field Frobenius additionsequence
暂未订购 下载PDF
Multiple constraints-based QoS multicast routing: model and algorithms 认领 引用 被引量：6
4
作者 SunBaolin LiLayuan 《Journal of Systems Engineering and Electronics》 2005年第1期187-193,共7页
Constraint-based multicast routing, which aims at identifying a path that satisfies a set of quality of service (QoS) constraints, has became a very important research issue in the areas of networks and distributed sy... Constraint-based multicast routing, which aims at identifying a path that satisfies a set of quality of service (QoS) constraints, has became a very important research issue in the areas of networks and distributed systems. In general, multi-constrained path selection with or without optimization is a NP-complete problem that can not be exactly solved in polynomial time. Hence, accurate constraints-based routing algorithms with a fast running time are scarce, perhaps even non-existent. The expected impact of such a constrained-based routing algorithm has resulted in the proposal of numerous heuristics and a few exact QoS algorithms. This paper aims to give a thorough, concise and fair evaluation of the most important multiple constraint-based QoS multicast routing algorithms known today, and it provides a descriptive overview and simulation results of these multi-constrained routing algorithms. 展开更多
关键词 multicast routing algorithm multiple constraints QoS routing NP-complete.
暂未订购 下载PDF
A Geometrical Transformations Resistant Digital Watermarking Based on Quantization 认领 引用
5
作者 SHILei HONGFan +2 位作者 LIUWei-qun HUYu-ping CHENZhuo 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第1期319-323,共5页
A geometrical transformations resistant digital image watermarking based on quantization is described. Taking advantage of the rotation, scale and translation invariants of discrete Fourier transform (DFT), each water... A geometrical transformations resistant digital image watermarking based on quantization is described. Taking advantage of the rotation, scale and translation invariants of discrete Fourier transform (DFT), each watermark bit is embedded into each homocentric circles around the zero frequency term in DFT domain by quantizing the magnitude vector of Fourier spectrum. The embedded sequence can be extracted by “majority principles” without restoring to the original unmarked image. The experimental results show that the watermark is invisible and robust to any combination of geometrical transformations or common image processing techniques. 展开更多
关键词 Key words digital watermarking quantization geometrical transformation Fourier transform
暂未订购 下载PDF
A class of integrable expanding model for the coupled AKNS-Kaup-Newell soliton hierarchy 认领 引用 被引量：1
6
作者 杨洪祥 徐西祥 《Chinese Physics B》 CAS 2005年第5期869-874,共6页
暂未订购 下载PDF
Semi-Fragile Watermarking for Copyright Protection and Image Authentication 认领 引用
7
作者 HUANGJi-feng 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第1期284-288,共5页
In this paper, we propose a semi-fragile wattr-marking technology forcopyright protection and image authentication We transform the image into wavelet domain and groupthe four adjacent wavelet coefficients Utilizing t... In this paper, we propose a semi-fragile wattr-marking technology forcopyright protection and image authentication We transform the image into wavelet domain and groupthe four adjacent wavelet coefficients Utilizing the characteristics of the humanvisual system, weembed a digital signal into the average of the four adjacent wavelet coefficients since the mean hasbetter stability than single wavelet coefficient. This method neednt original image when extractsthe watermark. Experimental results show the effectiveness of this method which is robust to commonimage process and fragile to malicious attack. 展开更多
关键词 semi-fiagile watermark image authentication copyright protection wavelettransform
暂未订购 下载PDF
WSAP: provide loss rate differentiation with active queue management 认领 引用
8
作者 章淼 WuJianping XuKe 《High Technology Letters》 EI CAS 2005年第2期118-123,共6页
How to provide service differentiation in the Internet is a hot research topic. One proposal is to provide loss rate differentiation by assigning levels of dropprecedence to IP packets. This paper proposes a new Activ... How to provide service differentiation in the Internet is a hot research topic. One proposal is to provide loss rate differentiation by assigning levels of dropprecedence to IP packets. This paper proposes a new Active Queue Management (AQM) mechanism, Weighted SAP (WSAP) to achieve this goal. WSAP is based on a new AQM algorithm called Simple Adaptive Proportional (SAP). WSAP can approximate proportional loss rate differentiation, while keeping high link utilization and short queuing delay. Compared with Weighted RED(WRED) and RED In and Out (RIO), WSAP is easier to configure and can provide better performance. Furthermore, an architecture for differentiated service is proposed. In the design of this architecture, more attention is paid to the characte of network traffic in the Internet and an attempt is made to preserve the Internet's oringinal design principles. 展开更多
关键词 WSAP 因特网 网络管理 损失率比较 IP协议
暂未订购 下载PDF
Ant Colony Algorithm for Solving QoS Routing Problem 认领 引用 被引量：3
9
作者 SUNLi-iuan WANGLiang-jun WANGRu-chuan 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第4期449-453,共5页
Based on the state transition rule, the local updating rule and the global updating rule of ant colony algorithm, we propose an improved ant colony algorithm of the least\|cost quality of service (QoS) unicast routing... Based on the state transition rule, the local updating rule and the global updating rule of ant colony algorithm, we propose an improved ant colony algorithm of the least\|cost quality of service (QoS) unicast routing. The algorithm is used for solving the routing problem with delay, delay jitter, bandwidth, and packet loss\|constrained. In the simulation, about 52.33% ants find the successful QoS routing , and converge to the best. It is proved that the algorithm is efficient and effective. 展开更多
关键词 ant colony algorithm QoS unicast routing
暂未订购 下载PDF
Circle quorum system-based non-stop network service model 认领 引用 被引量：1
10
作者 宋平 孙建伶 何志均 《Journal of Zhejiang University Science》 2004年第5期550-557,共8页
Rapid developments in network systems of business service have resulted in more reliance on distributed computing, typified by “subscriber/push” architectures. Unfortunately, frequent and unexpectable network failur... Rapid developments in network systems of business service have resulted in more reliance on distributed computing, typified by “subscriber/push” architectures. Unfortunately, frequent and unexpectable network failures were routine, and downtime was not in hours, but in days. High availability has become the most important factor decreasing business risk and improving Quality of Service. Cluster technology has solved the non-stop problem on Local Area Network. However, most technologies including cluster today fail to ensure the non-stop Internet service based on Routers. With good performance on high availability and fault tolerance, quorum systems are very suitable for application to distributed business service networks. In this work, we modeled and developed a non-stop Internet service system based on a new quorum system, circle quorum system, for Boston Mutual Fund Broker, US. With five protocols, it provided highly available data services for clients on Internet. 展开更多
关键词 Non-stop network Quorum system Distributed computation Fault-tolerance
暂未订购 下载PDF
A Role-Based PMI Security Model for E-Government 认领 引用 被引量：2
11
作者 WULi-jun SUKai-le YANGZhi-hua 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第1期329-332,共4页
We introduce the general AC( atlribure certificate), the role specificationAC and the rolt assignment AC We discuss the rolt-based PMI(Privilege Management Infrastructure)architecture. The role-based PMT(Public-Kty In... We introduce the general AC( atlribure certificate), the role specificationAC and the rolt assignment AC We discuss the rolt-based PMI(Privilege Management Infrastructure)architecture. The role-based PMT(Public-Kty In-frastructure) secure model forE-govcrnment isresearehed by combining the role-bastd PMI with PKI architeclure (Public Key Infrastructure). Themodel has advantages of flexibility, convenience, less storage space and less network consumptionetc. We are going to ust iht secure modelin the E-govern-ment system. 展开更多
关键词 E-govemment public key certificate role-specification AC role-assignmentAC ihe security model for E- government
暂未订购 下载PDF
Robustness Proof on A United Watermarking Based on CRT Theorem 认领 引用
12
作者 LIULi-gang CHENXiao-su XIAODao-ju HULei 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第1期307-310,共4页
A new method of embedding and detecting a joint watermarking is proposed. Itapplies the asmuth-bloom secret sharing scheme, which is based on CRT (Chinese remainder theorem)theorem, to the digital watermarking technol... A new method of embedding and detecting a joint watermarking is proposed. Itapplies the asmuth-bloom secret sharing scheme, which is based on CRT (Chinese remainder theorem)theorem, to the digital watermarking technology. On the base of describing the watermarkingembedding proceeding and analyzing the watermarking detection proceeding, a series of experiments isdone. The experiments emphasize on the method's robust proving and security analysis. And theexperiments show that the method can resistthe attacks of JPEG compress, geometry, noise and grayadjusting. The results of the experiments show that the method has a nice recognition of copyrightfor joint ownership. 展开更多
关键词 united digital watermarking Chinese remainder theorem robustness proof
暂未订购 下载PDF
A Grafted Genetic Algorithm for the Job-Shop Scheduling Problem 认领 引用 被引量：1
13
作者 LIXiang-jun WANGShu-zhen XUGuo-hua 《International Journal of Plant Engineering and Management》 EI 2004年第2期91-96,共6页
The standard genetic algorithm has limitations of a low convergence rate and premature convergence in solving the job-shop scheduling problem.To overcome these limitations,this paper presents a new improved hybrid gen... The standard genetic algorithm has limitations of a low convergence rate and premature convergence in solving the job-shop scheduling problem.To overcome these limitations,this paper presents a new improved hybrid genetic algorithm on the basis of the idea of graft in botany.Through the introduction of a grafted population and crossover probability matrix,this algorithm accelerates the convergence rate greatly and also increases the ability to fight premature convergence.Finally,the approach is tested on a set of standard instances taken from the literature and compared with other approaches.The computation results validate the effectiveness of the proposed algorithm. 展开更多
关键词 grafted genetic algorithm job-shop scheduling problem premature convergence hy brid optimization strategy
暂未订购 下载PDF
Incremental frequent tree-structured pattern mining from semi-structured data 认领 引用
14
作者 ChenEnhong LinLe WuGongqing 《High Technology Letters》 EI CAS 2005年第1期6-8,共3页
The paper studies the problem of incremental pattern mining from semi-structrued data. When a new dataset is added into the original dataset, it is difficult for existing pattern mining algorithms to incrementally upd... The paper studies the problem of incremental pattern mining from semi-structrued data. When a new dataset is added into the original dataset, it is difficult for existing pattern mining algorithms to incrementally update the mined results. To solve the problem, an incremental pattern mining algorithm based on the rightmost expansion technique is proposed here to improve the mining performance by utilizing the original mining results and information obtained in the previous mining process. To improve the efficiency, the algorithm adopts a pruning technique by using the frequent pattern expansion forest obtained in mining processes. Comparative experiments with different volume of initial datasets, incremental datasets and different minimum support thresholds demonstrate that the algorithm has a great improvement in the efficiency compared with that of non-incremental pattern mining algorithm. 展开更多
关键词 网页 计算机技术 XML文件 命令树 传输协议
暂未订购 下载PDF
Methods for behavior descriptions of structure-complex Petri nets 认领 引用
15
作者 QingtianZENG ZhehuiWU 《控制理论与应用（英文版）》 2004年第1期93-98,共6页
Petri net language is a powerful tool for describing dynamic behaviors of physical systems. However, it is not easy to obtain the language expression for a given Petri net especially a structure-complex net. In this p... Petri net language is a powerful tool for describing dynamic behaviors of physical systems. However, it is not easy to obtain the language expression for a given Petri net especially a structure-complex net. In this paper, we first analyze the behaviors of S-nets, which are structure-simple. With the decomposition method based on a given index function on the place set, a given structure-complex Petri net can be decomposed into a set of structure-simple S-nets. With the language relationships between the original system and the decomposed subnets, an algorithm to obtain the language expression of a given structure-complex net system is presented, which benefits the analysis of physical systems based on the Petri net language. 展开更多
关键词 Petri net S-net Decomposition Index of places Petri net language Behavior description Synchronous intersection of languages
暂未订购 下载PDF
Visualization of the first chinese visible human male and female 认领 引用
16
作者 ShaoxiangZhang PhengannHeng +21 位作者 ZhengjinLiu LiwenTan MingguoQiu QiyuLi KaiLi GaoyuCui YanliGuo GuangjiuLiu JingluShan JijunLiu WeiguoZhang JinhuaChen JianWang WeiChen MingLu JianYou XueliPang HongXiao YongmingXie ZhongxinXu YushuWang ZeshengTang 《中国组织化学与细胞化学杂志》 CAS 2004年第3期330-330,共1页
关键词 造影术 计算机 男性 女性 人类 器官
暂未订购 下载PDF
The Application of Levenberg-Marquartb Algorithm in EEG Inverse Problem 认领 引用
17
作者 ZOULing MAZheng-hua 《Chinese Journal of Biomedical Engineering(English Edition)》 CAS 2005年第1期32-40,共9页
EEG inverse problem has great significance and importance for both cli nical and research applications. It discusses EEG dipole source localization pro blems solved by nonlinear local optimization methods, such as Lev... EEG inverse problem has great significance and importance for both cli nical and research applications. It discusses EEG dipole source localization pro blems solved by nonlinear local optimization methods, such as Levenberg-Marquar t b. This paper presents the relation between location errors and noise level on c ondition that the source number is known; if the source number is not known, the selected number in model may not equal to the actual one, and a computation is carried out and a corresponding discrimination criteria is proposed. Computer si mulation demonstrates that Levenberg-Marquardt algorithm is better than global methods if the source number is small. 展开更多
关键词 EEG inverse problem Levenberg-marquart Equivalen t current dipole
暂未订购 下载PDF
Highly accurate SVM model with automatic feature selection for word sense disambiguation 认领 引用
18
作者 WangHao ChenGuilin XuLianxian 《Journal of Systems Engineering and Electronics》 2004年第4期723-727,共5页
A novel algorithm for word sense disambiguation(WSD) that is based on SVM model improved with automatic feature selection is introduced. This learning method employs rich contextual features to predict the proper sens... A novel algorithm for word sense disambiguation(WSD) that is based on SVM model improved with automatic feature selection is introduced. This learning method employs rich contextual features to predict the proper senses for specific words. Experimental results show that this algorithm can achieve an execellent performance on the set of data released during the SENSEEVAL-2 competition. We present the results obtained and discuss the transplantation of this algorithm to other languages such as Chinese. Experimental results on Chinese corpus show that our algorithm achieves an accuracy of 70.0% even with small training data. 展开更多
暂未订购 下载PDF
A Difference Hamiltonian Operator and a Hierarchy of Generalized Toda Lattice Equations 认领 引用 被引量：1
19
作者 XUXi-Xiang YANGHong-Xiang DINGHai-Yong 《Communications in Theoretical Physics》 SCIE CAS 2005年第1X期1-7,共7页
A difference Ha-miltonian operator with three arbitrary constants is presented. When the arbitrary constants -in the Hamiltonian operator are suitably chosen, a pair of Hamiltonian operators are given. The resulting H... A difference Ha-miltonian operator with three arbitrary constants is presented. When the arbitrary constants -in the Hamiltonian operator are suitably chosen, a pair of Hamiltonian operators are given. The resulting Hamiltonian pair yields a difference hereditary operator. Using Magri scheme of bi-Hamiltonian formulation, a hierarchy of the generalized Toda lattice equations is constructed. Finally, the discrete zero curvature representation is given for the resulting hierarchy. 展开更多
关键词 Hamiltonian算子 微分函数 Hamiltonian公式 遗传算子 离散弯曲函数
暂未订购 下载PDF
Leakage Current Estimation of CMOS Circuit with Stack Effect 认领 引用 被引量：4
20
作者 Yong-JunXu Zu-YingLuo +2 位作者 Xiao-WeiLi Li-JianLi Xian-LongHong 《Journal of Computer Science & Technology》 SCIE EI 2004年第5期708-717,共10页
Leakage current of CMOS circuit increases dramatically with the technologyscaling down and has become a critical issue of high performance system. Subthreshold, gate andreverse biased junction band-to-band tunneling (... Leakage current of CMOS circuit increases dramatically with the technologyscaling down and has become a critical issue of high performance system. Subthreshold, gate andreverse biased junction band-to-band tunneling (BTBT) leakages are considered three maindeterminants of total leakage current. Up to now, how to accurately estimate leakage current oflarge-scale circuits within endurable time remains unsolved, even though accurate leakage modelshave been widely discussed. In this paper, the authors first dip into the stack effect of CMOStechnology and propose a new simple gate-level leakage current model. Then, a table-lookup basedtotal leakage current simulator is built up according to the model. To validate the simulator,accurate leakage current is simulated at circuit level using popular simulator HSPICE forcomparison. Some further studies such as maximum leakage current estimation, minimum leakage currentgeneration and a high-level average leakage current macromodel are introduced in detail.Experiments on ISCAS85 and ISCAS89 benchmarks demonstrate that the two proposed leakage currentestimation methods are very accurate and efficient. 展开更多
关键词 computer-aided design leakage current estimation stack effect macromodeling propagation of signal probability
暂未订购 下载PDF
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
上一页 1 2 … 4 下一页 到第 页
在线咨询 使用帮助 返回顶部 意见反馈