检索结果-内蒙古大学图书馆

IET IMAGE PROCESSING 2012年第2期6卷 115-128页

作者： Yang, F. Lu, H. Zhang, W. Yang, G. Dalian Univ Technol Dept Elect Engn Dalian Peoples R China Northeastern Univ Sch Informat Sci & Engn Shenyang Peoples R China

In this paper, we propose a visual tracking approach based on 'bag of features' (BoF) algorithm. First we use incremental PCA visual tracking (IVT) in the first few frames and collect image patches randomly sampled within the tracked object region in each frame for constructing the codebook;the tracked object then can be converted to a bag. Second we construct two codebooks using color (RGB) features and local binary pattern (LBP) features instead of only one codebook in traditional BoF, thereby extracting more informative details. We also devise an updating mechanism to deal with pose and appearance changes of objects. In the tracking process, a constant number of candidates are generated by sampling technique in each frame. Image patches are then randomly sampled and candidates are represented as bags by codebooks. Thus, we can compute patch similarity of a candidate with the codewords and bag similarity with trained bags. The actual object is then located by finding the maximal combined similarity of patches and bags. Experiments demonstrate that our approach is robust in handling occlusion, scaling and rotation.

关键词： VISUAL perception computer algorithms IMAGE analysis EXPERIMENTS BINARY system (Mathematics) INFORMATION processing MATHEMATICAL constants

来源：评论

学校读者我要写书评

暂无评论

DERIVING PROGRAMS USING GENERIC algorithms

引用

IBM SYSTEMS JOURNAL 1994年第1期33卷 158-181页

作者： YAKHNIS, VR FARRELL, JA SHULTZ, SS IBM Large Scale Computing Division Endicott NY

We suggest a new approach to the derivation of programs from their specifications. The formal derivation and proof of programs as is practiced today is a very powerful tool for the development of high-quality software. However, its application by the software development community has been slowed by the amount of mathematical expertise needed to apply these formal methods to complex projects and by the lack of reuse within the framework of program derivation. To address these problems, we have developed an approach to formal derivation that employs the new concept of generic algorithms. A generic algorithm is one that has (1) a formal specification, (2) a proof that it satisfies this specification, and (3) generic identifiers representing types and operations. It may have embedded program specifications or pseudocode instructions describing the next steps in the stepwise refinement process. Using generic algorithms, most software developers need to know only how to pick and adapt them, rather than perform more technically challenging tasks such as finding loop invariants and deriving loop programs. The adaptation consists of replacing the generic identifiers by concrete types and operations. Since each generic algorithm can be used in the derivation of many different programs, this new methodology provides the developer with a form of reuse of program derivation techniques, correctness proofs, and formal specifications.

关键词： computer algorithms SOFTWARE engineering

来源：评论

学校读者我要写书评

暂无评论

Image Encryption Algorithm Based on Dynamic DNA Coding and Chen's Hyperchaotic System

引用

MATHEMATICAL PROBLEMS IN ENGINEERING 2016年第1期2016卷 1-11页

作者： Zhang, Jian Hou, Dezhi Ren, Honge Northeast Forestry Univ Coll Informat & Comp Engn Harbin 150040 Peoples R China

With the development of national information processes, specific image information from secret departments or individuals is often required to be confidentially transmitted. Numerous image encryption methods exist, especially since the initial value sensitivity and other characteristics of chaos theory and chaos theory-based encryption have become increasingly important in recent years. At present, DNA coding constitutes a new research direction of image encryption that uses the four base pairs of DNA code and image pixel values to establish a special correspondence, in order to achieve pixel diffusion. There are eight DNA encoding rules, and current methods of selecting the DNA encoding rules are largely fixed. Thus, the security of encoded data is not high. In this paper, we use the Lorenz chaotic system, Chen's hyperchaotic system, and the DNA encoding combination and present a new image encryption algorithm that can dynamically select eight types of DNA encoding rules and eight types of DNA addition and subtraction rules, with significant improvements in security. Through simulation experiments and histograms, correlations, and NPCR analyses, we have determined that the algorithm possesses numerous desirable features, including good encryption effects and antishear and antinoise performances.

关键词： IMAGE encryption (computer science) computer algorithms CHAOS theory INFORMATION processing SUBTRACTION (Mathematics) INITIAL value problems

来源：评论

学校读者我要写书评

暂无评论

Online Parallel Machine Scheduling to Maximize the Number of Early Jobs

引用

MATHEMATICAL PROBLEMS IN ENGINEERING 2012年第1期2012卷 1-7页

作者： Zheng, Feifeng Liu, Ming Chu, Chengbin Xu, Yinfeng Donghua Univ Glorious Sun Sch Business & Management Shanghai 200092 Peoples R China Xi An Jiao Tong Univ Sch Management Xian 710049 Shaanxi Provinc Peoples R China Tongji Univ Sch Econ & Management Shanghai 200092 Peoples R China Ecole Cent Paris Lab Genie Ind F-92295 Chatenay Malabry France

We study a maximization problem: online scheduling on m identical machines to maximize the number of early jobs. The problem is online in the sense that all jobs arrive over time. Each job's characteristics, such as processing time and due date, become known at its arrival time. We consider the preemption-restart model, in which preemption is allowed, while once a job is restarted, it loses all the progress that has been made on this job so far. If in some schedule a job is completed before or at its due date, then it is called early (or on time). The objective is to maximize the number of early jobs. For m identical machines, we prove an upper bound 1 - (1/2m) of competitive ratio and show that ECT (earliest completion time) algorithm is 1/2-competitive.

关键词： computer scheduling computer algorithms PRODUCTION scheduling SCHEDULING MACHINERY

来源：评论

学校读者我要写书评

暂无评论

A novel method for one-way hash function construction based on spatiotemporal chaos

引用

CHAOS SOLITONS & FRACTALS 2009年第4期42卷 2014-2022页

作者： Ren, Haijun Wang, Yong Xie, Qing Yang, Huaqian Chongqing Univ Coll Software Engn Chongqing 400044 Peoples R China Chongqing Univ Posts & Telecommun Key Lab Elect Commerce & Logist Chongqing Chongqing 400065 Peoples R China Chongqing Educ Coll Dept Comp & Modern Educ Technol Chongqing 400067 Peoples R China Chongqing Univ State Key Lab Power Transmiss Equipment & Syst Se Chongqing 400044 Peoples R China

A novel hash algorithm based on a spatiotemporal chaos is proposed. The original message is first padded with zeros if needed. Then it is divided into a number of blocks each contains 32 bytes. In the hashing process, each block is partitioned into eight 32-bit values and input into the spatiotemporal chaotic system. Then, after iterating the system for four times. the next block is processed by the same way. To enhance the confusion and diffusion effect, the cipher block chaining (CBC) mode is adopted in the algorithm. The hash value is obtained from the final state value of the spatiotemporal chaotic system. Theoretic analyses and numerical simulations both show that the proposed hash algorithm possesses good statistical properties, strong collision resistance and high efficiency, as required by practical keyed hash functions. (C) 2009 Elsevier Ltd. All rights reserved.

关键词： HASHING (computer science) FUNCTIONS (Mathematics) CHAOS theory computer algorithms MATHEMATICAL analysis computer simulation

来源：评论

学校读者我要写书评

暂无评论

Generation Scheduling problem by Intelligent Genetic Algorithm

引用

computerS & ELECTRICAL ENGINEERING 2013年第1期39卷 79-88页

作者： Sundararajan, Dhanalakshmi Subramanian, Baskar Subramanian, Kannan Krishnan, Mahadevan Kalasalingam Univ Dept Elect & Elect Engn Krishnankoil Tamil Nadu India Thiagarajar Coll Engn Dept Elect & Elect Engn Madurai Tamil Nadu India PSNA Coll Engn & Technol Dept Elect & Elect Engn Dindugal Tamil Nadu India Kalasalingam Univ Krishnankoil Tamil Nadu India

This paper presents a Genetic Algorithm (GA) solution to solve the Generation Scheduling (GS) problem with intelligent coding scheme. The intelligent coding scheme effectively handles minimum up/down time constraints of GS problem. GA with intelligent coding is called as Intelligent Genetic Algorithm (IGA). Penalty parameter-less constraint handling technique is used for satisfying power balance constraint. Performance of the IGA is tested on a 10-unit 24-h and 26-unit 24-h unit commitment test systems. The result obtained using IGA is compared with the results reported using Lagrangian Relaxation (LR), Enhanced Lagrangian Relaxation (ELR), LRGA, GA and Evolutionary Programming methods. Simulation results show the effects of intelligent coding scheme in obtaining feasible and minimum cost solution. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： computer scheduling computer algorithms PROBLEM solving PERFORMANCE computer programming GENETIC algorithms ARTIFICIAL intelligence COMPARATIVE studies

来源：评论

学校读者我要写书评

暂无评论

Switching Gain Reduction in Adaptive Sliding Mode Control for Rigid Spacecraft Attitude Maneuvers

引用

MATHEMATICAL PROBLEMS IN ENGINEERING 2013年第1期2013卷 1-9页

作者： Chen, Zhen Cong, Binglong Liu, Xiangdong Beijing Inst Technol Sch Automat Beijing 100081 Peoples R China Beijing Inst Technol Key Lab Intelligent Control & Decis Complex Syst Beijing 100081 Peoples R China

This paper investigates the overadaptation problem in current adaptive sliding mode control (ASMC) for rigid spacecraft attitude maneuvers. The inertia matrix uncertainty and external disturbance are taken into account, and an adaptive scheme is employed for the switching gain calculation. A detailed analysis of existing ASMC design reveals the fact that the switching gain would be overestimated if the ASMC algorithm is developed in the framework of conventional sliding mode control (SMC), owing to the unrelated adaptation caused by initial tracking error. The global sliding mode concept of integral sliding mode control (ISMC) is exploited to solve such a problem. The advantages of the proposed strategy are twofold. First, a much smaller switching gain is generated as compared to conventional ASMC. Second, the resulting small switching gain would not slow down the system response. The advantages of the proposed strategy are verified by both theoretical analysis and simulation results.

关键词： SLIDING mode control SPACE vehicles ADAPTIVE control systems SIMULATION methods & models PROBLEM solving computer algorithms

来源：评论

学校读者我要写书评

暂无评论

Hybrid meta-heuristic algorithm for the simultaneous optimization of the O-D trip matrix estimation

引用

computer-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING 2004年第6期19卷 421-435页

作者： Stathopoulos, A Tsekeris, T Natl Tech Univ Athens Sch Civil Engn Dept Transportat Planning & Engn Athens 15773 Greece

In the present article, the origin-destination (O-D) trip matrix estimation is formulated as a simultaneous optimization problem and is resolved by employing three different meta-heuristic optimization algorithms. These include a genetic algorithm (GA), a simulated annealing (SA) algorithm, and a hybrid algorithm (GASA) based on the combination of GA and SA. The computational performance of the three algorithms is evaluated and compared by implementing them on a realistic urban road network. The results of the simulation tests demonstrate that SA and GASA produce a more accurate final solution than GA, whereas GASA shows a superior convergence rate, that is, faster improvement from the initial solution, in comparison to SA and GA. In addition, GASA produces a final solution that is more robust and less dependent on the initial demand pattern, in comparison to that obtained from a greedy search algorithm.

关键词： HEURISTIC programming computer algorithms MATRICES ESTIMATION theory GENETIC algorithms PROGRAM transformation (computer programming) ROADS INFRASTRUCTURE (Economics)

来源：评论

学校读者我要写书评

暂无评论

A primal/dual representation for discrete Morse complexes on tetrahedral meshes

引用

computer GRAPHICS FORUM 2013年第3期32卷 361-370页

作者： Weiss, Kenneth Iuricich, Federico Fellegara, Riccardo De Floriani, Leila Lawrence Livermore Natl Lab Livermore CA 94550 USA Univ Genoa Dept Comp Sci Genoa Italy

We consider the problem of computing discrete Morse and Morse-Smale complexes on an unstructured tetrahedral mesh discretizing the domain of a 3D scalar field. We use a duality argument to define the cells of the descending Morse complex in terms of the supplied (primal) tetrahedral mesh and those of the ascending complex in terms of its dual mesh. The Morse-Smale complex is then described combinatorially as collections of cells from the intersection of the primal and dual meshes. We introduce a simple compact encoding for discrete vector fields attached to the mesh tetrahedra that is suitable for combination with any topological data structure encoding just the vertices and tetrahedra of the mesh. We demonstrate the effectiveness and scalability of our approach over large unstructured tetrahedral meshes by developing algorithms for computing the discrete gradient field and for extracting the cells of the Morse and Morse-Smale complexes. We compare implementations of our approach on an adjacency-based topological data structure and on the PR-star octree, a compact spatio-topological data structure.

关键词： DISCRETE systems THREE-dimensional display systems COMBINATIONS (Mathematics) computer algorithms DATA structures (computer science) VECTOR fields

来源：评论

学校读者我要写书评

暂无评论

Diagnosing Source Geometrical Complexity of Large Earthquakes

引用

PURE AND APPLIED GEOPHYSICS 2014年第10期171卷 2819-2840页

作者： Rivera, L. Kanamori, H. Univ Strasbourg CNRS Inst Phys Globe Strasbourg Strasbourg France CALTECH Seismol Lab Pasadena CA 91125 USA

We investigated the possible frequency dependence of the moment tensor of large earthquakes by performing W phase inversions using teleseismic data and equally-spaced narrow, overlapping frequency bands. We investigated frequencies from 0.6 to 3.8 mHz. Our focus was on the variation with frequency of the scalar moment, the amount of non-double-couple, and the focal mechanism. We applied this technique to 30 major events in the period 1994-2013 and used the results to detect source complexity. Based on the results, we classed them into three groups according to the variability of the source parameters with frequency: simple, complex and intermediate. Twelve of these events fell into the simple category: Bolivia-1994, Kuril-1994, Sanriku-1994, Antofagasta-1995, Andreanoff-1996, Peru-2001, Sumatra-2004, Sumatra-2005, Tonga-2006, Sumatra-2007, Japan-2011, and the recent Sea of Okhotsk-2013. Seven exhibited significant complexity: Balleny-1998, Sumatra-2000, Indian Ocean-2000, Macquarie Island-2004, Sichuan-2008, and Samoa-2009. The remaining 11 events showed a moderate degree of complexity. Here, we discuss the results of this study in light of independent observations of source complexity, made by various investigators.

关键词： EARTHQUAKES computer algorithms SCALAR field theory RADIATION EIGENVALUES

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：