Fatemeh Mehdizadeh Saradj,
Volume 18, Issue 6 (International Journal of Engineering science 2007)
Abstract
When a specific building is examined and analysed for its architectural merits, it is the visible, superficial aspects, which are considered, for example: aesthetics, function, spatial relationships, and landscape. One of the most important invisible factors that should be considered in the design process is the safety of buildings against natural hazards, particularly against earthquakes. While the provision of earthquake resistance is accomplished through structural means, the architectural designs and decisions play a major role in determining the seismic performance of a building. In other words, the seismic design is a shared architectural and engineering responsibility, which stems from the physical relationship between architectural forms and structural systems. It is economic to incorporate earthquake resistance in the stage of design than to add it later in the structural calculation or strengthening after completion. In addition, a building with proper earthquake-proof design will be more effective against earthquakes than the one with complementary strengthening. This paper will demonstrate that evidence for this lies in many historical buildings, which have withstood earthquakes throughout the hundreds of years without having been reinforced with special material. The fact is that the master builder or Mimar (traditional architect) of historic buildings was simultaneously designing the architecture as well as choosing the suitable form, proportion, and material for the best structural performance.
Esmaeil Mehdizadeh, Amir Fatehi-Kivi,
Volume 28, Issue 1 (IJIEPR 2017)
Abstract
In this paper, we propose a vibration damping optimization algorithm to solve a fuzzy mathematical model for the single-item capacitated lot-sizing problem. At first, a fuzzy mathematical model for the single-item capacitated lot-sizing problem is presented. The possibility approach is chosen to convert the fuzzy mathematical model to crisp mathematical model. The obtained crisp model is in the form of mixed integer linear programming (MILP) which can be solved by existing solver in crisp environment to find optimal solution. Due to the complexity and NP-hardness of the problem, a vibration damping optimization (VDO) is used to solve the model for large-scale problems. To verify the performance of the proposed algorithm, we computationally compared the results obtained by the VDO algorithm with the results of the branch-and-bound method and two other well-known meta-heuristic algorithms namely simulated annealing (SA) and genetic algorithm (GA). Additionally, Taguchi method is used to calibrate the parameters of the meta-heuristic algorithms. Computational results on a set of randomly generated instances show that the VDO algorithm compared with the other algorithms can obtain appropriate solutions.
Amir Nayeb, Esmaeil Mehdizadeh, Seyed Habib A. Rahmati,
Volume 34, Issue 2 (IJIEPR 2023)
Abstract
In the field of scheduling and sequence of operations, one of the common assumptions is the availability of machines and workers on the planning horizon. In the real world, a machine may be temporarily unavailable for a variety of reasons, including maintenance activities, and the full capacity of human resources cannot be used due to their limited number and/or different skill levels. Therefore, this paper examines the Dual Resource Constrained Flexible Job Shop Scheduling Problem (DRCFJSP) considering the limit of preventive maintenance (PM). Due to various variables and constraints, the goal is to minimize the maximum completion time. In this regard, Mixed Integer Linear Programming (MILP) model is presented for the mentioned problem. To evaluate and validate the presented mathematical model, several small and medium-sized problems are randomly generated and solved using CPLEX solver in GAMS software. Because the solving of this problem on a large scale is complex and time-consuming, two metaheuristic algorithms called Genetic Algorithm (GA) and Vibration Damping Optimization Algorithm (VDO) are used. The computational results show that GAMS software can solve small problems in an acceptable time and achieve an accurate answer, and also meta-heuristic algorithms can reach appropriate answers. The efficiency of the two proposed algorithms is also compared in terms of computational time and the value obtained for the objective function.