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Cost-Sensitive and Load-Balancing Gateway Placement in Wireless Mesh Networks with QoS Constraints
Feng Zeng Student Member,CCF,Zhi-Gang Chen Member,CCF School of Information Science,Engineering,Central South University,Changsha,China,

计算机科学技术学报 , 2009,
Abstract: In wireless mesh networks(WMNs),gateway placement is the key to network performance,QoS and construction cost.This paper focuses on the optimization of the cost and load balance in the gateway placement strategy,ensuring the QoS requirements.Firstly,we define a metric for load balance on the gateways,and address the minimum cost and load balancing gateway placement problem.Secondly,we propose two algorithms for gateway placement.One is a heuristic algorithm,which is sensitive to the cost,selects the gateway...
HEPAPS: A PCB automatic placement system
HEPAPS:A PCB Automatic Placement System

Jianguo Xu,Yuchai Gou,Zongkai Lin,
Xu Jianguo
,Gou Yuchai,Lin Zongkai

计算机科学技术学报 , 1992,
Abstract: HEPAPS is composed of constructive placement, improving placement, equivalence pins reassignment and same function elements reassignment. Based on practical demands, this paper implements the constructive procedure within a set of engineering constraints and resolves the reassignment problems of equivalence and same function elements. A new topological improving method combined min-cut algorithm with simulated annealing algorithm is presented. In addition, the two-dimensional relaxed method is introduced to solve the geometrical optimization problem.
Heuristic Replica Placement Algorithms in Content Distribution Networks  [cached]
Jing Sun,Suixiang Gao,Wenguo Yang,Zhipeng Jiang
Journal of Networks , 2011, DOI: 10.4304/jnw.6.3.416-423
Abstract: Content Distribution Networks have been attracted a great deal of attraction in recent years. Replica placement problems (RPPs) as one of the key technologies in the Content Distribution Networks have been widely studied. In this paper, we propose an optimization model with server storage capacity constraints for the RPPs. Furthermore, part of the objective function is represented as a Multiple Minimum Cost Flow Model for the first time. E
International Journal of Engineering Science and Technology , 2013,
Abstract: This paper presents a heuristic procedure for improving productivity in breweries companies. A case study of Champion brewery Plc, Uyo, Akwa Ibom State was adopted. The aim of this paper is to balance theProduction line of Champion lager beer. In the course of line balancing, the idle time and the number of workstations on the production line was minimized so as to maximize the efficiency of the production line. All the required data was measured and the parameters such as elapsed time at each work station, efficiencies,number of workers, time of each of the workstations etc. was calculated from the existing line. A new heuristic approach, the Longest Operation Time (LOT) method was used in designing the new production line. After set up of the new production line, the cost of production and effectiveness of the new line was computed and compared with those of the existing one. The new production line was found to have been increased by a significant amount reducing the overall production cost per unit.
Comparative Study on the Application of Modern Heuristic Techniques to SVC Placement Problem  [cached]
Mehdi Eghbal,Naoto Yorino,Yoshifumi Zoka
Journal of Computers , 2009, DOI: 10.4304/jcp.4.6.535-541
Abstract: This paper investigates the applicability and effectiveness of modern heuristic techniques for solving SVC placement problem. Specifically, Genetic Algorithm (GA), Particle Swarm Optimization (PSO) and Evolutionary PSO (EPSO) have been developed and successfully applied to find the optimal placement of SVC devices. The main objective of the proposed problem is to find the optimal number and sizes of the SVC devices to be installed in order to enhance the load margin when contingencies happen. SVC installation cost and load margin deviation are subject to be minimized. The proposed approaches have been successfully tested on IEEE 14 and 57 buses systems and a comparative study is illustrated. To evaluate the capability of the proposed techniques to solve large scale problems, they are also applied to a large scale mixed-integer nonlinear reactive power planning problem. Results of the application to IEEE 14 bus test system prove the feasibility of the proposed approaches and outperformance of PSO based techniques over GA.
Exact and Heuristic Methods for the Assembly Line Worker Assignment and Balancing Problem  [PDF]
Leonardo Borba,Marcus Ritt
Computer Science , 2013,
Abstract: In traditional assembly lines, it is reasonable to assume that task execution times are the same for each worker. However, in sheltered work centres for disabled this assumption is not valid: some workers may execute some tasks considerably slower or even be incapable of executing them. Worker heterogeneity leads to a problem called the assembly line worker assignment and balancing problem (ALWABP). For a fixed number of workers the problem is to maximize the production rate of an assembly line by assigning workers to stations and tasks to workers, while satisfying precedence constraints between the tasks. This paper introduces new heuristic and exact methods to solve this problem. We present a new MIP model, propose a novel heuristic algorithm based on beam search, as well as a task-oriented branch-and-bound procedure which uses new reduction rules and lower bounds for solving the problem. Extensive computational tests on a large set of instances show that these methods are effective and improve over existing ones.
Double four-bar crank-slider mechanism dynamic balancing by meta-heuristic algorithms  [PDF]
Habib Emdadi,Mahsa Yazdanian,Mir Mohammad Ettefagh,Mohammad-Reza Feizi-Derakhshi
Computer Science , 2013, DOI: 10.5121/ijaia.2013.4501
Abstract: In this paper, a new method for dynamic balancing of double four-bar crank slider mechanism by meta- heuristic-based optimization algorithms is proposed. For this purpose, a proper objective function which is necessary for balancing of this mechanism and corresponding constraints has been obtained by dynamic modeling of the mechanism. Then PSO, ABC, BGA and HGAPSO algorithms have been applied for minimizing the defined cost function in optimization step. The optimization results have been studied completely by extracting the cost function, fitness, convergence speed and runtime values of applied algorithms. It has been shown that PSO and ABC are more efficient than BGA and HGAPSO in terms of convergence speed and result quality. Also, a laboratory scale experimental doublefour-bar crank-slider mechanism was provided for validating the proposed balancing method practically.
Workload Balancing in Printed Circuit Board Assembly Shops = Baskili Devre Karti Dizgi At lyelerinde Hat Dengeleme  [cached]
Dogus University Journal , 2005,
Abstract: In assembling printed circuit boards (PCB), the use of numerically or computer controlled electronic component placement machines has become quite popular in the last decades. However, serious operations research problems arise through their use such as, allocation of component types to machines, board production schedule, feeder configuration and placement sequencing. In this study, the problem of allocation of component types to machines is taken up where two non-identical machines are deployed serially on a line to complete the assembly process of PCBs. For the solution of this problem three heuristic algorithms are suggested and their performances are investigated on experimental data.
EMinRET: Heuristic for Energy-Aware VM Placement with Fixed Intervals and Non-preemption  [PDF]
Nguyen Quang-Hung,Nam Thoai
Computer Science , 2015,
Abstract: Infrastructure-as-a-Service (IaaS) clouds have become more popular enabling users to run applications under virtual machines. This paper investigates the energy-aware virtual machine (VM) allocation problems in IaaS clouds along characteristics: multiple resources, and fixed interval times and non-preemption of virtual machines. Many previous works proposed to use a minimum number of physical machines, however, this is not necessarily a good solution to minimize total energy consumption in the VM placement with multiple resources, fixed interval times and non-preemption. We observed that minimizing total energy consumption of physical machines is equivalent to minimize the sum of total completion time of all physical machines. Based on the observation, we propose EMinRET algorithm. The EMinRET algorithm swaps an allocating VM with a suitable overlapped VM, which is of the same VM type and is allocated on the same physical machine, to minimize total completion time of all physical machines. The EMinRET uses resource utilization during executing time period of a physical machine as the evaluation metric, and will then choose a host that minimizes the metric to allocate a new VM. In addition, this work studies some heuristics for sorting the list of virtual machines (e.g., sorting by the earliest starting time, or the longest duration time first, etc.) to allocate VM. Using the realistic log-trace in the Parallel Workloads Archive, our simulation results show that the EMinRET algorithm could reduce from 25% to 45% energy consumption compared with power-aware best-fit decreasing (PABFD)) and vector bin-packing norm-based greedy algorithms. Moreover, the EMinRET heuristic has also less total energy consumption than our previous heuristics (e.g. MinDFT and EPOBF) in the simulations (using same virtual machines sorting method).
Pedro Palominos Belmar,Verónica Godoy Villalobos
Ingeniare : Revista Chilena de Ingeniería , 2010,
Abstract: El propósito de este trabajo es presentar una heurística para el problema de equilibrado de líneas para células conformadas en "U". Particularmente para el sistema de fabricación denominado Toyota Sewing System (TSS), que representa un nuevo concepto de organización en una línea de producción. Si bien este tipo de sistema ha sido abordado en la literatura bajo el título de sistemas de producción autoequilibrado, en donde el equilibrio se logra mediante la utilización de dos reglas básicas, creemos que estas reglas no son suficientes para lograr el autoequilibrio. Por lo cual incorporamos el concepto de zonas de enlace que facilita el equilibrado de la línea. De los resultados obtenidos mediante simulación, concluimos que la heurística es eficiente para este tipo de sistemas de producción. The purpose of this paper is to present a heuristic for the assembly line balancing problem in U-shaped cells, particularly for the manufacturing system called Toyota Sewing System (TSS), which represents a new production line organization concept. Although this type of system has been approached in the literature under the name of self-balanced production system, where the balance is achieved using two basic rules, we believe that these rules are not sufficient to achieve self-balance, so we have incorporated the concept of linkage zones that facilitate balancing the line. From the results obtained by simulation we conclude that the heuristic is efficient for this kind of production system.
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