INTRODUCTION: The appropriate-use optimization of the limited spaces of the Iranian hospitals is believed to be a crucial step towards promoting the efficiency of these healthcare centers. The issue determining the optimization patterns of the layout of units has led to a lot of efforts by researchers as it increases the efficiency of the hospitals through patients’ improvement, changing the lo...

This paper attempts to improve the computational efficiency of the well known particle swarm optimization (PSO) algorithm for tackling discrete sizing optimization problems of steel frame structures. It is generally known that, in structural design optimization applications, PSO entails enormously time-consuming structural analyses to locate an optimum solution. Hence, in the present study it i...

This paper reports on preliminary numerical experiments in optimizing coolant flows in continuous casting of steel with respect to multiple objectives. For this purpose, Differential Evolution for Multiobjective Optimization (DEMO) coupled with a reliable numerical simulator of the casting process was applied. The algorithm parameters were initially tuned to balance between the quality of the e...

In engineering, it is often necessary to formulate problems in which there are several criteria or objectives. It is unlikely that a solution that optimizes one of the objectives will be optimal for any of the others. Compromise solutions are therefore sought such that no other solutions are better in any one objective while remaining no worse in the others. These types of problems are known as...

In this paper, we propose a sufficient condition for a solution to be optimal for a 2-additive Choquet integral in the context of multiobjective combinatorial optimization problems. A 2-additive Choquet optimal solution is a solution that optimizes at least one set of parameters of the 2-additive Choquet integral. We also present a method to generate 2-additive Choquet optimal solutions of mult...

During the flight, aircraft produces several pollutant emissions and the amount is deeply related to the atmospheric conditions (especially pressure, humidity, temperature, air density and wind), the aircraft performance and the phase of flight. In this paper an approach, based on Dijkstra algorithm, to calculate optimized trajectory in terms of several emission reduction (multi-objective traje...

in this paper, a multi-objective method is used to optimize a heat recovery steam generator (hrsg). two objective functions have been used in the optimization, which are irreversibility and hrsg equivalent volume. the former expresses the exergetic efficiency and the latter demonstrates the cost of the hrsg. decision variables are geometric and operational parameters of the hrsg. the results of...

the traveling salesman problem (tsp) is the problem of finding the shortest tour through all the nodes that a salesman has to visit. the tsp is probably the most famous and extensively studied problem in the field of combinatorial optimization. because this problem is an np-hard problem, practical large-scale instances cannot be solved by exact algorithms within acceptable computational times. ...

In this paper the piecewise level set method is combined with phase field method to solve the shape and topology optimization problem. First, the optimization problem is formed based on piecewise constant level set method then is updated using the energy term of phase field equations. The resulting diffusion equation which updates the level set function and optimization ...

Having the constant population size and crossover/mutation probability, standard genetic algorithm (SGA) has such disadvantages as premature convergence, low stability and optimization efficiency for large design variables situation. This paper presents an improved adaptive genetic algorithm (IAGA), which adjusts the population size and the crossover/mutation probability adaptively and linearly...