Tabu Search Optimization Research Articles

A Multi-Agent Model and Tabu Search Optimization to Manage Agricultural Territories

This paper proposes a multi-agent model to manage agricultural territories in order to reduce damage caused by runoff and floods processes. The proposed approach consists in optimizing the distribution of crops in a territory based on a multi-agent optimization approach. A group of agents represents each type of crop. The objective of an agent group is to occupy a total surface of parcels to achieve its objectives of production while reducing the value of risk for the whole watershed. Some agronomic, economic and hydrologic constraints restrict the behavior of agents and must be satisfied during the optimization process. The value of runoff risk is evaluated by a spatial hydrological model at the level of the Digital Terrain Model. Three optimization strategies based on Tabu search are developed and tested using real data. They provide satisfactory solutions in various computation times.

AN IMPROVED ANT COLONY SYSTEM ALGORITHM FOR THE VEHICLE ROUTING PROBLEM

ABSTRACT The vehicle routing problem (VRP), a well-known combinatorial optimization problem, holds a central place in logistics management. Many meta-heuristic approaches like Simulated Annealing (SA), Genetic Algorithms (GA), Tabu Search (TS), and Ant Colony Optimization (ACO) have been proposed to solve VRP. Ant Algorithm is a distributed meta-heuristic approach that has been applied to various combinatorial optimization problems, including traveling salesman problem, quadratic assignment problem. In this research, we proposed an improved ant colony system (IACS) algorithm that possesses a new state transition rule, a new pheromone updating rule and diverse local search approaches. The computational results on 14 VRP benchmark problems show that our IACS yields better solutions than those of other ant algorithms in the literature and is competitive with other meta-heuristic approaches in terms of solution quality.

OPTIMAL ALLOCATION OF STATIC VAR COMPENSATORS USING MODAL ANALYSIS, SIMULATED ANNEALING AND TABU SEARCH

This paper investigates the ability of tabu search (TS) and simulated annealing (SA) optimization methods to deal with optimal placement of Static Var Compensators (SVC) in a large power system based on its primary function, where the optimization is made on two parameters: its location and size. The primary function of an SVC is improving transmission system voltage, thereby enhancing the maximum power transfer limit. Modal analysis is used to place several SVCs in the power system and the results obtained are compared with the results of applied TS and SA techniques. The results show that SA can give a good suboptimal placement while TS gives an optimal solution. Since by using the modal analysis alone SVCs may not be placed optimally in the power system, the study is carried out in two steps. In the first step, by using the modal analysis, the critical area of the power system is identified in view of the voltage instability. In the second step, once the weak area is identified, the SA technique is applied to get the level of compensation by the SVCs.

Tabu search optimization of horizontal and vertical alignments of forest roads

This article describes a program for optimizing horizontal and vertical alignments of forest roads using Tabu search, a modern heuristic technique. Once a series of intersection points (IPs) is selected manually, the program generates alternative horizontal and vertical alignments. The program precisely generates ground profile and cross sections using a high-resolution digital elevation model (DEM) derived from light detection and ranging (LiDAR) data. It accurately calculates earthwork volumes for curved roadways using the Pappus-based method. The program also estimates construction and maintenance costs. Tabu search optimizes forest road alignments based on the total costs. The application of the program to part of Capitol State Forest in Washington State, USA, indicated that the program successfully found better alignments than manually selected initial alignments. The effect of initial solutions and the number of iterations on the Tabu search process was examined. The result showed that the solutions were improved using the best solutions with the smaller number of grade change points as the initial solutions. It also showed that a small number of iterations could be used to reduce computation time due to the fact that Tabu search is based on a gradient search technique. Finally, the Dijkstra method was examined to find initial solutions without manually initialized solutions. The program, when combined with the Dijkstra method, could find similar-quality solutions from manually initialized solutions. The program will become useful with further tests and verifications.

A systems-based approach for generating quantitative models of microstructural evolution in silicon materials processing

A systematic approach based on multiple model regression to several distinct types of experimental data is used to create a robust modeling framework for defect and impurity evolution during crystalline silicon processing. The three experimental systems considered here are Czochralski single-crystal growth, zinc diffusion, and oxide precipitation during wafer thermal annealing. All three systems are intimately connected at the atomistic level by the thermodynamic and transport properties of single point defects. The present work demonstrates how this microscopic overlap in these macroscopically distinct systems can substantially reduce uncertainty in model regression to experimental data, leading to strict bounds on the transport, reaction, and thermodynamic properties of the various species present. The resulting parameters lead to a solid, quantitative basis for modeling a wide variety of technologically important defect-related phenomena in silicon processing. Several different stochastic global optimization methods are employed to perform the computationally expensive multi-objective function minimization, namely simulated annealing, genetic algorithms, Tabu search and particle swarm optimization. These methods are compared and contrasted as part of the investigation and it is shown that a hybrid genetic algorithm that periodically incorporates a local search is the most robust approach for the types of problems considered in this work.

Tabu-search simulation optimization approach for flow-shop scheduling with multiple processors — a case study

The flow shop with multiple processors (FSMP) environment is relatively common and has a variety of applications. The majority of academic authors solve the scheduling problem of FSMP using deterministic data that ignore the stochastic nature of a real-world problem. Discrete-event simulation can model a non-linear and stochastic problem and allows examination of the likely behaviour of a proposed manufacturing system under selected conditions. However, it does not provide a method for optimization. The present paper proposes to solve the FSMP scheduling problem by using a tabu-search simulation optimization approach. It features both the stochastically modelling capability of the discrete-event simulation and the efficient local-search algorithm of tabu search. A case study from a multilayer ceramic capacitor manufacturing illustrates the proposed solution methodology. Empirical results show promise for the practical application of the proposed methodologies. Future research opportunities are then addressed.

Tabu search synthesis of cascaded fiber Bragg gratings for linear phase filters

A new method for the synthesis of cascaded fiber Bragg gratings (FBGs) with complex characteristics is presented. The synthesis method involves the use of a transfer matrix method for calculating the frequency response of the cascade of apodized FBGs and a Tabu search optimization algorithm for obtaining an optimal fiber grating design. The proposed method enables dynamic weighting of different requirements to be made to both the reflective spectrum and the phase response of the filter. To demonstrate the effectiveness of the method, the synthesis of a linear phase filter with small in-band dispersion is presented.

メタヒューリスティク手法の電力·エネルギー分野への適用例

Considering deregulation in power systems and the energy conservation law, power and energy systems require more cost and energy reduction for system planning, operation, and control. Optimization techniques such as linear and nonlinear programming techniques have been utilized as one of the methods for realization of the reduction. Recently, meta-heuristics such as genetic algorithm, simulated annealing, tabu search, and particle swarm optimization have been paid attention as other options for realization of the reduction. In power and energy society, we had one technical committee and one special issue on applications of meta-heuristics for power system. Moreover, panel sessions and tutorials have been held in IEEE and IFAC. This paper presents applications of meta-heuristics to power and energy fields from the practical application point of view.

Multi-objective process design in multi-purpose batch plants using a Tabu Search optimization algorithm

Chemical batch processes are typically used for the production of speciality chemicals and pharmaceuticals. Due to the still growing importance of this type of processing, design methods are required that take into account the special requirements and constraints in the corresponding production facilities. We developed a method that optimizes the design of a single chemical process to be implemented in an existing multi-purpose batch plant, in which a well-defined set of equipment units is available for realizing this process. In the optimization, three objectives with different priorities are considered. A flexible metaheuristic algorithm, Tabu Search (TS), has been implemented to solve this multi-objective combinatorial non-linear problem. We started from a basic form of TS to determine the effectiveness of this version as well as establish the relative strengths and weaknesses of first level TS strategies. Our investigation includes a thorough examination of algorithm parameters and of implementation issues to identify algorithm settings that can handle the whole class of problems considered. Overall, we concluded that the basic form of TS—using fixed default settings—exhibits highly attractive performance features for solving the problems at hand. Moreover, comparison with a multi-start steepest descent algorithm shows that a basic TS approach conducts a global search more effectively. As illustrated by three case studies, the new method is well suited for identifying optimal designs of a chemical process to be implemented in an existing multi-purpose batch plant. The approach is particularly suited for considering multiple prioritized objectives and for enabling the use of external (e.g. commercial) batch process simulation software as a black-box model for the process evaluations.

<b>Emprego do Algoritmo Busca Tabu na determinação de principios ativos em fármacos</b>

A new methodology of analysis for the quantification of antihipertensive drugs is provided in this work, using tabu search optimization with infrared spectroscopy by diffuse reflectance Fourier transform (DRIFTS) and partial-least squares regression method (PLS). Firstly, through an experimental planning, samples with the active principle hidrochlorotiazide in starch were prepared, and the standard set of the spectra as well as of the validation samples were gotten in this process. A diffuse reflectance joined to a Nicolet Magna 550 spectrophotometry in the mid-infrared region was used. The examples were developed in a Matlab, spending the real data in shape of Log (1/R). The calibration was through PLS in order to use it as a pre-processing. The data were used in multiplicative signal correction (MSC). After the best wavelength selection, which results in models with better coefficient regression (R2), these were improved using routines based on tabu search heuristic method. For the evaluation of the optimization a standard error of validation (SEV) was used. The new technique using DRIFTS/PLS/TS shows an excellent choice for the quality control of the productive process of factories and drugstores that produce or handle these materials in large scale, presenting low time of analysis, no sample destruction and no wastes production. Keywords: Tabu Search, Pharmacological Formulations, multivariate regression.

Boiling Water Reactor Fuel Assembly Axial Design Optimization Using Tabu Search

In this paper the implementation of the tabu search (TS) optimization method to a boiling water reactor’s (BWR’s) fuel assembly (FA) axial design is described. The objective of this implementation is to test the TS method for the search of optimal FA axial designs. This implementation has been linked to the reactor core simulator CM-PRESTO in order to evaluate each design proposed in a reactor cycle operation. The evaluation of the proposed fuel designs takes into account the most important safety limits included in a BWR in-core analysis based on the Haling principle. Results obtained show that TS is a promising method for solving the axial design problem. However, it merits further study in order to find better adaptation of the TS method for the specific problem.

Eigenvalue assignments in multimachine power systems using tabu search algorithm

Applying tabu search (TS) optimization technique to multimachine power system stabilizer (PSS) design is presented in this paper. The proposed approach employs TS to search for optimal or near optimal settings of PSS parameters that shift the system eigenvalues associated with the electromechanical modes to the left of a vertical line in the s-plane. Incorporation of TS algorithm in PSS design significantly reduces the computational burden. One of the main advantages of the proposed approach is its robustness to the initial guess. The performance of the proposed PSS under different disturbances and loading conditions is investigated for multimachine power systems. The eigenvalue analysis and the nonlinear simulation results show the effectiveness of the proposed PSSs to damp out the local as well as the interarea modes of oscillations and work effectively over a wide range of loading conditions and system configurations.

Electric field optimization design of a vacuum interrupter based on the Tabu search algorithm

During interruption in the vacuum interrupter, the re-ignition between the contact and the shield is influenced by the shape of the contact and size of the shield. The design of the contact and the shield is an intricate optimization problem. In this paper, the Tabu search algorithm is applied to optimize the contacts of a 35 kV vacuum interrupter. The optimization design is based on electric field computation using the finite element method. By solving the inverse problem, the optimization of the contacts is achieved, and a reasonable distribution of the electric field is obtained. Based on the combinatorial optimization Tabu search algorithm, an improved universal algorithm for continuous variables global optimization is proposed.

Logical topologies design over WDM wavelength routed networks robust to traffic uncertainties

We develop a novel methodology for the design of the optimal logical topology configuration over a WDM wavelength routed network, when some or all the traffic relations are affected by a degree of uncertainty. Our optimal topology design algorithm relies on the application of the tabu search optimization meta-heuristic.

Robust design of multimachine power system stabilisers using tabu search algorithm

Robust design of multimachine power system stabilisers (PSSs) using the tabu search (TS) optimisation technique is presented. The proposed approach employs TS for optimal parameter settings of a widely used conventional fixed-structure lead-lag PSS (CPSS). The parameters of the proposed stabilisers are selected using TS in order to shift the system poorly damped electromechanical modes at several loading conditions and system configurations simultaneously to a prescribed zone in the left hand side of the s-plane. Incorporation of TS as a derivative-free optimisation technique in PSS design significantly reduces the computational burden. In addition, the quality of the optimal solution does not rely on the initial guess. The performance of the proposed PSSs under different disturbances and loading conditions is investigated for multimachine power systems. The eigenvalue analysis and the nonlinear simulation results show the effectiveness of the proposed PSSs in damping out the local, as well as the interarea, modes and enhance greatly the system stability over a wide range of loading conditions and system configurations.

Improving the finite element ordering for the frontal solver

ABSTRACT We present the structure of greedy methods used for reordering the nodes or the finite elements of a mesh and we propose two improvements that can be easily implemented in existing software. We investigate a wave reordering method which adapts the reordering strategy during the reordering process. Then, we propose an adaptation of the Tabu Search optimization technique for finite element reordering. The results show the efficiency of the improvements The wave reordering method and the Tabu Search provide very good solutions offering a motivation to carry on research for optimizing their computing time.

Tabu search and design optimization

Tabu search is a powerful optimization procedure that has been successfully applied to a number of combinatorial optimization problems, including integer-programming and quadratic-assignment problems. The procedure is simple to implement, sufficiently versatile to incorporate problem-specific constraints, and may also act as a control mechanism to monitor and direct the progress of other optimization routines. The paper explains the tabu-search mechanism, discusses the general procedure with the use of simple examples, and details the important computational considerations that affect the performance of the routine. An electronic-circuit design problem is used as an example of the application of tabu search. Finally, possible modifications to the basic search procedure are indicated, together with lines of further investigation.