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CHAOS SOLITONS & FRACTALS 2013年 56卷 45-52页

作者： Benson, Karyn Cebrian, Manuel Univ Calif San Diego Dept Comp Sci & Engn La Jolla CA 92093 USA

Biological evolution serves as a blueprint for the design of search and optimization algorithms, and has generated vast number of research prototypes as well as industrial implementations since it was first proposed to solve complex engineering problems the 1960s [1-3]. Underlying this is the idea that the evolutionary forces of mutation, recombination, reproduction and selection can drive the population towards better adapted solution over time, effectively solving an optimization problem by navigating the fitness landscape they inhabit. A much overlooked evolutionary force in the design of better algorithms so far has been cooperation, shown to be crucial to shape individual and group behavior at multiple scales of interaction. Here we explore the ability of cooperative dynamics to further increase the efficiency of evolutionary strategies. For this, we perform computer experiments on a variety of landscapes of increasing complexity. We present evidence suggesting that cooperative dynamics are able to naturally balance exploration and exploitation of local maxima, via endless cycles of cooperation (where local maxima are exploited) and defection (where new areas are explored). Cooperative strategies prove to be more robust to landscape ruggedness than evolutionary strategies which never cooperate, always cooperate, or cooperate randomly. Furthermore, our simulations show that the cooperative dynamics are invariant to the complexity of the landscape, hinting at the possibility that cooperation strategies may be able to absorb and exploit local information to keep the exploration-exploration tradeoff invariant across a range of environments. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： COOPERATIVENESS EVOLUTION (Biology) computer algorithms PROBLEM solving MATHEMATICAL optimization MUTATION (Biology)

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A two-loop sparse matrix numerical integration procedure for the solution of differential/algebraic equations: Application to multibody systems

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JOURNAL OF SOUND AND VIBRATION 2009年第3-5期327卷 557-563页

作者： Shabana, Ahmed A. Hussein, Bassam A. Univ Illinois Dept Mech & Ind Engn Chicago IL 60607 USA

In this paper, a two-loop implicit sparse matrix numerical integration (TLISMNI) procedure for the solution of constrained rigid and flexible multibody system differential and algebraic equations is proposed. The proposed method ensures that the kinematic constraint equations are satisfied at the position, velocity and acceleration levels. In this method, a sparse Lagrangian augmented form of the equations of motion that ensures that the constraints are satisfied at the acceleration level is first used to solve for all the accelerations and Lagrange multipliers. The independent coordinates and velocities are then identified and integrated using HTT or Newmark formulas, expressed in this paper in terms of the independent accelerations only. The constraint equations at the position level are then used within an iterative Newton-Raphson procedure to determine the dependent coordinates. The dependent velocities are determined by solving a linear system of algebraic equations. In order to effectively exploit efficient sparse matrix techniques and have minimum storage requirements, a two-loop iterative method is proposed. Equally important, the proposed method avoids the use of numerical differentiation which is commonly associated with the use of implicit integration methods in multibody system algorithms. Numerical examples are presented in order to demonstrate the use of the new integration procedure. (C) 2009 Elsevier Ltd. All rights reserved.

关键词： NUMERICAL solutions to differential-algebraic equations MULTIBODY systems NUMERICAL integration KINEMATICS ACCELERATION (Mechanics) MATRICES computer algorithms ITERATIVE methods (Mathematics) NEWTON-Raphson method MATHEMATICAL physics

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Variable Neighborhood Search for Parallel Machines Scheduling Problem with Step Deteriorating Jobs

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MATHEMATICAL PROBLEMS IN ENGINEERING 2012年第1期2012卷 1-20页

作者： Cheng, Wenming Guo, Peng Zhang, Zeqiang Zeng, Ming Liang, Jian SW Jiaotong Univ Sch Mech Engn Chengdu 610031 Peoples R China Xihua Univ Sch Mech Engn & Automat Chengdu 610039 Peoples R China

In many real scheduling environments, a job processed later needs longer time than the same job when it starts earlier. This phenomenon is known as scheduling with deteriorating jobs to many industrial applications. In this paper, we study a scheduling problem of minimizing the total completion time on identical parallel machines where the processing time of a job is a step function of its starting time and a deteriorating date that is individual to all jobs. Firstly, a mixed integer programming model is presented for the problem. And then, a modified weight-combination search algorithm and a variable neighborhood search are employed to yield optimal or near-optimal schedule. To evaluate the performance of the proposed algorithms, computational experiments are performed on randomly generated test instances. Finally, computational results show that the proposed approaches obtain near-optimal solutions in a reasonable computational time even for large-sized problems.

关键词： PRODUCTION scheduling INTEGER programming computer algorithms DYNAMIC programming LINEAR programming

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Capturing Uncertainty Information and Categorical Characteristics for Network Payload Grouping in Protocol Reverse Engineering

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MATHEMATICAL PROBLEMS IN ENGINEERING 2015年第1期2015卷 1-9页

作者： Luo, Jian-Zhen Yu, Shun-Zheng Cai, Jun Sun Yat Sen Univ Sch Informat Sci & Technol Guangzhou 510275 Guangdong Peoples R China Guangdong Polytech Normal Univ Sch Elect & Informat Guangzhou 510665 Guangdong Peoples R China

As a promising tool to recover the specifications of unknown protocols, protocol reverse engineering has drawn more and more attention in research over the last decade. It is a critical task of protocol reverse engineering to extract the protocol keywords from network trace. Since the messages of different types have different sets of protocol keywords, it is an effective method to improve the accuracy of protocol keyword extraction by clustering the network payload of unknown traffic into clusters and analyzing each clusters to extract the protocol keywords. Although the classic algorithms such as K-means and EM can be used for network payload clustering, the quality of resultant traffic clusters was far from satisfactory when these algorithms are applied to cluster application layer traffic with categorical attributes. In this paper, we propose a novel method to improve the accuracy of protocol reverse engineering by applying a rough set-based technique for clustering the application layer traffic. This technique analyze multidimension uncertain information in multiple categorical attributes based on rough sets theory to cluster network payload, and apply the Minimum Description Length criteria to determine the optimal number of clusters. The experiments show that our method outperforms the existing algorithms and improves the results of protocol keyword extraction.

关键词： UNCERTAINTY (Information theory) REVERSE engineering TRAFFIC engineering ROUGH sets computer algorithms

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Modeling for the Calcination Process of Industry Rotary Kiln Using ANFIS Coupled with a Novel Hybrid Clustering Algorithm

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MATHEMATICAL PROBLEMS IN ENGINEERING 2017年第1期2017卷 1-8页

作者： Cai, Yongchang Sch Elect & Informat Engn Shunde Polytechn Foshan 528300 Peoples R China Tech Univ Dresden D-01062 Dresden Germany

Rotary kiln is important equipment in heavy industries and its calcination process is the key impact to the product quality. Due to the difficulty in obtaining the accurate algebraic model of the calcination process, an intelligent modeling method based on ANFIS and clustering algorithms is studied. In the model, ANFIS is employed as the core structure, and aiming to improve both its performance in reduced computation and accuracy, a novel hybrid clustering algorithm is proposed by combining FCM and Subtractive methods. A quasi-random data set is then hired to test the new hybrid clustering algorithm and results indicate its superiority to FCM and Subtractive methods. Further, a set of data from the successful control activity of sophisticated workers in manufacturing field is used to train the model, and the model demonstrates its advantages in both fast convergence and more accuracy approaching.

关键词： ROTARY kilns CALCINATION (Heat treatment) computer algorithms WORKSTATION clusters (computer systems) FUZZY control systems

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HeNLM-LA: a locally adaptive non-local means algorithm based on hermite functions expansion

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PROGRAMMING AND computer SOFTWARE 2014年第4期40卷 199-207页

作者： Mamaev, N. V. Lukin, A. S. Yurin, D. V. Moscow MV Lomonosov State Univ Fac Computat Math & Cybernet Moscow 119991 Russia

A new noise reduction algorithm HeNLM-LA is proposed. It is a modification of the non-local means algorithm using Hermite functions expansion of pixel neighborhoods. The filtering strength parameter is automatically adjusted proportionally to the local noise level. An algorithm for local noise level estimation is based on edge modeling;it suppresses high-amplitude edges in the map of local image variance.

关键词： IMAGE denoising IMAGE processing RESEARCH CONTENT filters (computer science) INFORMATION storage & retrieval system security measures computer algorithms

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Efficient reconstruction of local heat fluxes in pool boiling experiments by goal-oriented adaptive mesh refinement

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HEAT AND MASS TRANSFER 2010年第10期46卷 1121-1135页

作者： Heng, Yi Mhamdi, Adel Marquardt, Wolfgang Rhein Westfal TH Aachen AVT Proc Syst Engn D-52056 Aachen Germany

In this paper, we consider the efficient estimation of local boiling heat fluxes from transient temperature measurements in the heater close to the heater surface. For accurate prediction, heat flux estimation is formulated as a transient three-dimensional (3D) inverse heat conduction problem (IHCP). This inverse problem is ill-posed and cannot be treated straightforwardly by established numerical methods. In order to obtain a regularized stable solution, a large-scale time-dependent PDE-constrained optimization problem has to be solved and an appropriate stopping criterion for the termination of the iterative solution process has to be chosen. Since the boiling heat flux is non-uniformly distributed on the heater surface due to the strong local activity of the boiling process, the use of a fixed uniform spatial discretization is not efficient. Instead, an adaptive mesh refinement strategy can be used to obtain an appropriate discretization which significantly reduces the total computational effort. In this work, we present an automatic algorithm incorporating an adaptive mesh refinement via a heat flux-based a-posteriori error estimation technique. The suggested algorithm can cope with both spatially point-wise or highly resolved temperature observations efficiently. It is applied to real measurement data obtained from two different types of pool boiling experiments. The numerical results show that the computational effort can be reduced significantly for given estimation quality. This adaptive IHCP solution technique can be also viewed as an efficient soft sensor to deduce unmeasurable local boiling heat fluxes.

关键词： HEAT transfer NUCLEATE boiling TEMPERATURE measurements HEATING -- Equipment & supplies HEAT conduction computer algorithms PARTIAL differential equations -- Numerical solutions BOUNDARY value problems -- Numerical solutions PHYSICS experiments

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Control and design of crystal growth furnace

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ISA TRANSACTIONS 1999年第1期38卷 73-85页

作者： Batur, C Duval, WMB Bennett, RJ Univ Akron Dept Mech Engn Akron OH 44325 USA

We present the control and design of a vertical transparent multizone furnace which can operate in the temperature range of 25-750 degrees C and deliver thermal gradients of 2-45 degrees C/cm for the commercial applications to crystal growth. A multivariable projective control algorithm is used for the temperature control. The controller accounts for the inevitable zone to zone thermal interactions. In addition, the control system operates such that the thermal profile is maintained under the thermal load of crystal, thus boundary conditions on crystal growth ampoules can be predetermined prior to crystal growth. Temperature profiles for the growth of crystals via directional solidification, vapor transport techniques, and multiple gradient applications can be easily implemented. The unique feature of its transparency and stable thermal profiles make the furnace useful for the determination of process parameters that optimize crystal growth conditions. (C) 1999 Elsevier Science Ltd. All rights reserved.

关键词： control systems Cutting parameters Furnaces crystals TEMPERATURE RANGE temperature gradients Transparency computer algorithms

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Near-computation-free image encoding scheme based on adaptive decimation

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IET IMAGE PROCESSING 2008年第4期2卷 175-184页

作者： Tsang, P. W. M. City Univ Hong Kong Dept Elect Engn Kowloon Hong Kong Peoples R China

Adaptive decimation ( AD) is a technique that aims at compressing images with a very small amount of computations and memory requirement. For images that contain moderate amounts of textural content, the method exhibits satisfactory performance and in general provides good visual quality and acceptable coding fidelity at low bit-rate of around 0.2 bpp. Although the complexity of the method is relatively light when compared with the existing compression methods, it still involves a considerable amount of computations that would require the use of medium-speed processors to achieve real-time operation. In the paper, a novel image encoder based on the principles of AD is reported. The scheme is near-computation-free as it involves on average a single fixed point multiplication plus a few other summing and logical operations for every four pixels. Experimental results reveal that, despite the substantial reduction in complexity, the performance of proposed method is similar to, if not better than, the existing AD encoding algorithms.

关键词： TELECOMMUNICATION DATA transmission systems OPTICAL communications computer algorithms DIGITAL communications

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Scheduling Method of Data-Intensive Applications in Cloud Computing Environments

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MATHEMATICAL PROBLEMS IN ENGINEERING 2015年第1期2015卷 1-8页

作者： Fu, Xiong Cang, Yeliang Zhu, Xinxin Deng, Song Nanjing Univ Posts & Telecommun Sch Comp Sci & Technol Nanjing 210023 Jiangsu Peoples R China Nanjing Univ Posts & Telecommun Inst Adv Technol Nanjing 210023 Jiangsu Peoples R China

The virtualization of cloud computing improves the utilization of resources and energy. And a cloud user can deploy his/her own applications and related data on a pay-as-you-go basis. The communications between an application and a data storage node, as well as within the application, have a great impact on the execution efficiency of the application. The locations of subtasks of an application and the data that transferred between the subtasks are the main reason why communication delay exists. The communication delay can affect the completion time of the application. In this paper, we take into account the data transmission time and communications between subtasks and propose a heuristic optimal virtual machine (VM) placement algorithm. Related simulations demonstrate that this algorithm can reduce the completion time of user tasks and ensure the feasibility and effectiveness of the overall network performance of applications when running in a cloud computing environment.

关键词： CLOUD computing computer scheduling VIRTUAL reality DATA transmission systems VIRTUAL machine systems computer algorithms

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