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1 - طراحی مدل ریاضی تعیین مکان بهینه ی استقرار شعب شرکت بیمه با استفاده از ترکیب روش های تصمیم گیری چند معیاره ی فازی
منصور صوفی فاطمه دین آراانتخاب مکان استقرار شعبه و یا دفتر بیمه، به عنوان مساله‌ی اصلی شرکت مادر، همواره مورد توجه بوده است. هدف این تحقیق تعیین محل استقرار شعبه جدید بیمه البرز در استان گیلان با استفاده از ترکیب چند مدل تصمیم‌گیری چند معیاره با داده‌های فازی است. در مدل طراحی شده، پنج معیار و أکثرانتخاب مکان استقرار شعبه و یا دفتر بیمه، به عنوان مساله‌ی اصلی شرکت مادر، همواره مورد توجه بوده است. هدف این تحقیق تعیین محل استقرار شعبه جدید بیمه البرز در استان گیلان با استفاده از ترکیب چند مدل تصمیم‌گیری چند معیاره با داده‌های فازی است. در مدل طراحی شده، پنج معیار و شش گزینه (مکان) وجود دارد. برای حل مساله‌ی اولویت‌بندی مکان در این پژوهش هفت گام اصلی برداشته شده است: 1) تعیین مکان‌های پیشنهادی و انتخاب خبرگان توسط مدیران شعبه، تعریف متغیرهای کلامی و تعیین اعداد فازی مربوط ؛ 2) انتخاب چند شاخص موثر از بین شاخص‌های مختلف با استفاده از تکنیک دلفی فازی؛ 3) مقایسه‌ی زوجی شاخص‌ها و گزینه‌ها با استفاده از تکنیک تحلیل سلسله‌مراتبی فازی؛ 4) محاسبه‌ی میانگین وزنی شاخص‌ها برای هر یک از خبرگان با استفاده از تکنیک کمترین مجذورات لگاریتمی فازی؛ 5) تشکیل ماتریس تصمیم جامع؛ 6) تشکیل تابع ترجیح فازی، ماتریس ترجیح کل، محاسبه‌ی جریان‌های مثبت و منفی، محاسبه‌ی جریان خالص با پرومته‌ی فازی و دیفازی کردن اعداد با روش چن؛ 7) تعیین درجه‌ی امکان و در نتیجه وزن هر گزینه. در نهایت با توجه به امتیاز هر گزینه، مکان 3 به عنوان اولویت اول و به ترتیب مکان‌های 4، 5، 6، 1 و 2 در اولویت‌های بعدی قرار گرفتند. در این پژوهش برای اجرای مدل‌ها از نرم‌افزارهای اکسل و لینگو استفاده شده است. تفاصيل المقالة -
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2 - ارائه یک مدل دوهدف تخصیص عضو مازاد برای بهینه سازی هزینه و قابلیت اطمینان یک سیستم سری –موازی و حل آن با استفاده
محمدرضا شهریاریبا توجه به افزایش عمومی توجه به مقوله کیفیت، توجه به بحث بهینه سازی قابلیت اطمینان در مرحله طراحی از اولویت بالایی برخوردار شده است. این تحقیق بر روی یکی از مدل­های موجود در علم قابلیت اطمینان به نام مسئله تخصیص افزونگی متمرکز شده و یک مدل دو هدفه برای این مسئله با أکثربا توجه به افزایش عمومی توجه به مقوله کیفیت، توجه به بحث بهینه سازی قابلیت اطمینان در مرحله طراحی از اولویت بالایی برخوردار شده است. این تحقیق بر روی یکی از مدل­های موجود در علم قابلیت اطمینان به نام مسئله تخصیص افزونگی متمرکز شده و یک مدل دو هدفه برای این مسئله با سیستم سری-موازی ارائه شده است که در آن نرخ خرابی اجزاء وابسته به تعداد اجزاء فعال می­باشد. اهداف این مسئله عباتند از افزایش قابلیت اطمینان سیستم و کاهش هزینه کل تخصی اجزاء. همچنین جهت نزدیک تر شدن این مسئله به جهان واقعی هزینه اتصال داخلی اجزاء نیز به مسئله اضافه شده است که در حوزه الکترونیک یک بحث بسیار متداول می­باشد. با توجه به آنکه مسئله تخصیص افزونگی متعلق به دسته مسائل NP. Hard می­باشد برای حل مسئله ارائه شده از الکوریتم NSGA-II استفاده شده و برای تنظیم پارامترهای مدل نیز از روش رویه پاسخ استفاده شده است. تفاصيل المقالة -
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3 - Using a Hybrid NSGA-II to Solve the Redundancy Allocation Mmodel of Series-Parallel Systems
Mohammadreza ShahriariThis paper develops an efficient non-dominated sorting genetic algorithm (NSGA-II) to solve the redundancy allocation problem (RAP) of series-parallel systems. The system consists of subsystem in series, where components are used in parallel for each subsystem. Both the أکثرThis paper develops an efficient non-dominated sorting genetic algorithm (NSGA-II) to solve the redundancy allocation problem (RAP) of series-parallel systems. The system consists of subsystem in series, where components are used in parallel for each subsystem. Both the system and its subsystems can only take two states of complete perfect and complete failure. Identical redundant components are included to achieve a desirable reliability. The components of each subsystem, which are chosen from a list that is available in the market, are characterized by their cost, weight, and reliability. To find the optimum combination of the number of components for each subsystem, the mathematical formulation for the maximal reliability and minimal cost of the system configuration under cost constraint is first obtained. Then, a modified NSGA-II is proposed to solve the model. In this algorithm, a heuristic method of generating a primary solution is integrated to achieve better solutions. Moreover, design of experiment approach is employed to calibrate the parameters of the algorithm. At the end, some numerical examples are used to validate the solution, to assess the performance of the proposed methodology under different configurations, and to compare the performance with the ones of two other meta-heuristic algorithms. The results of experiments are generally in favor of the proposed solution algorithm. تفاصيل المقالة -
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4 - Solving a Joint Availability-Redundancy Optimization Model with Multi-State Components with Meta-Heuristic
A. H. Borhani Alamdari‎‎‎ M. SharifiThis paper has been worked on a RAP with multi-state components and the performance rate of each component working state may increase by spending technical and organizational activities costs. Whereas RAP belongs to Np-Hard problems, we used Genetic algorithm (GA) and s أکثرThis paper has been worked on a RAP with multi-state components and the performance rate of each component working state may increase by spending technical and organizational activities costs. Whereas RAP belongs to Np-Hard problems, we used Genetic algorithm (GA) and simulated annealing (SA) and for solving the presented problem and calculating system reliability universal generating function (UGF) have been used. تفاصيل المقالة -
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5 - The Effects of Technical and Organizational Activities on Redundancy Allocation Problem with Choice of Selecting Redundancy Strategies Using the memetic algorithm
M. Sharifi MR. Shahriari A. ZaretalabRedundancy allocation problem is one of most important problems in reliability area. This problem involves with the suitable redundancy levels under certain strategies to maximizing system reliability under some constraints. Many changes have been made on this problem t أکثرRedundancy allocation problem is one of most important problems in reliability area. This problem involves with the suitable redundancy levels under certain strategies to maximizing system reliability under some constraints. Many changes have been made on this problem to draw the problem near to real situations. Selecting the redundancy strategy, using different system configuration are some of these changes. In this paper we considered the effects of technical and organizational activities on this problem and showed the difference between the system reliability with and without using these activities. In this paper we worked on a system containing s sub-systems connected serially together. Each sub-system contains parallel components that can be selected from different component types and all of each sub-system components must be the same. Because redundancy allocation problem belongs to Np. Hard problems, we used a new meta-heuristic algorithm called memetic competition algorithm for solving the presented problem and compared the result of this algorithm and other solving methods. تفاصيل المقالة -
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6 - A Bi-objective Capacitated Single-Allocation Hub Location Problem with Reliability Assumption on Paths
F. Moeen Moghadas F. FuladiThe hub location problems are highly crucial due to their applications in the transportation and distribution area. Today, the complexities of solving the real world problems using the single-objective techniques are challenging. For a more real model, the present study أکثرThe hub location problems are highly crucial due to their applications in the transportation and distribution area. Today, the complexities of solving the real world problems using the single-objective techniques are challenging. For a more real model, the present study considers a bi-objective capacitated single-allocation hub location problem assuming the reliability of paths. In addition to the capacity, the fixed costs for the hubs are considered, as well. Furthermore, while minimizing the cost, the reliability of the weakest path is making maximized. Three mathematical models are proposed for this problem. The performance of single-objective models is evaluated and then, the proposed bi-objective model is solved using the ε-constraint method. In the present study, the fixed cost is calculated using two different methods: one is based on the distance from the center of mass and another one depends on the hub capacity. The results reveal that the third model with the fixed cost based on the distance from the center of mass has the best performance. تفاصيل المقالة -
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7 - Redundancy Allocation Optimization Based on the Fuzzy Universal Generating Function approach in the Series-Parallel Systems
Mohammadreza ShahriariIn This paper we discuss about the redundancy allocation problem when uncertainty exists in the problem. The innovation of this paper is the use of fuzzy universal generating function for calculating the availability of system. The system consists of component in series أکثرIn This paper we discuss about the redundancy allocation problem when uncertainty exists in the problem. The innovation of this paper is the use of fuzzy universal generating function for calculating the availability of system. The system consists of component in series and for each component, elements are used in parallel. The system has the range of levels for performance from complete perfect to complete failure. Identical redundant elements are included in order to achieve a desirable reliability. The elements of each component are characterized by their cost, weight and availability. These elements are chosen from a list that available in market. To find optimum combination of elements for each component we calculate the system availability and then use proposed NSGA-III. The proposed NSGA-III heuristic determines the maximal availability system configuration base on weight constrain. تفاصيل المقالة -
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8 - Set a bi-objective redundancy allocation model to optimize the reliability and cost of the Series-parallel systems using NSGA II problem
M. R. Shahriari‎With the huge global and wide range of attention placed upon quality, promoting and optimize the reliability of the products during the design process has turned out to be a high priority. In this study, the researcher have adopted one of the existing models in the reli أکثرWith the huge global and wide range of attention placed upon quality, promoting and optimize the reliability of the products during the design process has turned out to be a high priority. In this study, the researcher have adopted one of the existing models in the reliability science and propose a bi-objective model for redundancy allocation in the series-parallel systems in accordance with the redundancy policy- given that failure rate depends on the number of the active elements. The objective behind the proposed model is to maximize the reliability and to minimize the total cost of the system. Internal connection cost, which is the most common parameter in electronic systems, put in this model in order to simulate the real-world conditions. As the proposed model is an NP-Hard one(for getting results), the researcher adopted a Non-dominated Sorting Genetic Algorithm (NSGA II) after optimizing its operators’ rate by using Response Surface Methodology (RSM)‎.‎ تفاصيل المقالة -
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9 - Classical Center Location Problem Under Uncertain Environment
A. Soltanpour‎‎ F. Baroughi‎‎ B. AlizadehThis paper investigates the $p$-center location problem on a network in which vertex weights and distances between vertices are uncertain. The concepts of the $\alpha$-$p$-center and the expected $p$-center are introduced. It is shown that the $\alpha$-$p$-center and th أکثرThis paper investigates the $p$-center location problem on a network in which vertex weights and distances between vertices are uncertain. The concepts of the $\alpha$-$p$-center and the expected $p$-center are introduced. It is shown that the $\alpha$-$p$-center and the expected $p$-center models can be transformed into corresponding deterministic models. Finally, linear time algorithms for finding the 1-center and \\2-center of uncertain unweighted trees are ‎proposed.‎ تفاصيل المقالة -
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10 - Stochastic Facilities location Model by Using Stochastic Programming
Ali Gholinezhad Devin Saeed Fayyaz Reza SadeghiFinding the location for plans like factories or warehousesfor any organization is an important and strategic decision. Costs oftransportation which are the main part of the price of the goods, is thefunction of the location of these projects. to find the optimum locati أکثرFinding the location for plans like factories or warehousesfor any organization is an important and strategic decision. Costs oftransportation which are the main part of the price of the goods, is thefunction of the location of these projects. to find the optimum locationof these projects, there have been various methods proposed which areusually defined (not random). In reality and in dealing with real worldconditions, taking into account influential and effective parameters leadsto unexpected results. In this research, while introducing these definedalgorithms, it been tried to random location model based on the existingmodels. Regarding this, by studying the models taken in randomlocation we tried to propose an efficient and effective model. For thispurpose, by using randomized planning and randomized constrainedplanning, we turn random model to defined model, which is solvable byusing the last algorithm or standard planning methods. تفاصيل المقالة -
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11 - Dynamic Facility Location with Stochastic Demand
Ali Gholinejad Devin Katayun Abedzade Ghuchani Reza Sadeghi Hamidreza KooshaDetermination of facilities, such as factories or warehouses, location and availability conditions is one of the important and strategic decisions for an organization to make. Transportation costs that form a major part of goods price are dependent to this decision maki أکثرDetermination of facilities, such as factories or warehouses, location and availability conditions is one of the important and strategic decisions for an organization to make. Transportation costs that form a major part of goods price are dependent to this decision making. There are verity of methods have been presented to achieve the optimal locations of these facilities which are generally deterministic. In real world accurate estimation of the effective parameters on this optimal location for single or multiple time periods is difficult and merely impossible.In this research, we try to achieve an efficient model with consideration of uncertainty demand over different time periods on the basis of previously presented models that we call stochastic dynamic facilities location problem. In order to do so we use stochastic constrain programming which convert the stochastic model to a deterministic one. According to this conversion we can use the cutting edge standard algorithm and methods of programing to solve the model. Next we implement the presented model for a case study and solve the problem with MATLAB software and examine the efficiency of model. Implementation the presented model and analyzing the results cause better management and better control of changing facility status تفاصيل المقالة -
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12 - مکان یابی سایت های مناسب بر پایه GIS با پوشش حداکثری برای توسعه شعب بانک
فاطمه دکامینی محمد احسانی فر سیدمحسن لطفیانتخاب مکان برای مکان یابی شرکت ها تصمیم بسیار مهمی است انتخاب نامناسب مکان ممکن است منجر به هزینه های بیش از حد حمل و نقل ، از دست دادن نیروی کار واجد شرایط ، مزیت رقابتی یا شرایط مشابه شود. این مقاله پیشنهاد یکپارچگی بین مدل MCDM ارائه شده توسط ANP با GIS برای پیشنهاد أکثرانتخاب مکان برای مکان یابی شرکت ها تصمیم بسیار مهمی است انتخاب نامناسب مکان ممکن است منجر به هزینه های بیش از حد حمل و نقل ، از دست دادن نیروی کار واجد شرایط ، مزیت رقابتی یا شرایط مشابه شود. این مقاله پیشنهاد یکپارچگی بین مدل MCDM ارائه شده توسط ANP با GIS برای پیشنهاد بهترین مکان برای ساخت یک شعبه جدید بانک و سپس استفاده از حداکثر مشکل محل پوشش برای انتخاب شعب که حداکثر تقاضا ممکن است در یک زمان از پیش تعیین شده سفر باشد.. موقعیت شعبه بانک یکی از مهمترین موضوعات استراتژیک در بازار رقابت است. در این مقاله ، یک مدل مبتنی بر سیستم اطلاعات جغرافیایی (GIS) برای مکان یابی سایت های مناسب برای ایجاد شاخه های جدید ارائه شده است ، و سپس از مسئله مکان حداکثر پوشش (MCLP) برای انتخاب شاخه ها استفاده می شود به طوری که حداکثر تقاضا در داخل زمان سفر هدف مشخص شده است. این مدل برای بانک مهر اقتصاد در شهر اراک ، ایران اجرا شد. برای تحقیقات آتی ، مطالعه بازسازی شعب بانک توصیه می شود. علاوه بر این ، استفاده از این مدل بر روی مشکلات پیچیده تر ، زمینه چالش برانگیزی برای مطالعات آینده است . تفاصيل المقالة -
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13 - مروری بر کاربرد روش فراابتکاری جستجوی ممنوعه در حل مسائل مکانیابی
علیرضا بیطرفدر این مقاله مروری، جزئیات کاربرد روش فراابتکاری جستجوی ممنوعه، در حل مسائل مکانیابی بررسی می‌شود. به این منظور، در ابتدا مفهوم مکانیابی و انواع مختلف مسایل مکانیابی معرفی شده و سپس جزئیات روش جستجوی ممنوعه، بطور تفصیلی شرح داده شده است. منظور از مکانیابی، یافتن مکان‌ها أکثردر این مقاله مروری، جزئیات کاربرد روش فراابتکاری جستجوی ممنوعه، در حل مسائل مکانیابی بررسی می‌شود. به این منظور، در ابتدا مفهوم مکانیابی و انواع مختلف مسایل مکانیابی معرفی شده و سپس جزئیات روش جستجوی ممنوعه، بطور تفصیلی شرح داده شده است. منظور از مکانیابی، یافتن مکان‌های جدید مناسب برای برپا کردن مراکز خدماتی است. امروزه به دلیل افزایش رقابت بین شرکت‌ها، مکانیابی علمی از اهمیت ویژه‌‌ای برخوردار شده است. روش‌های علمی مختلفی برای حل مسائل مکانیابی وجود دارد. در دهه‌های اخیر روش‌های فراابتکاری مختلفی برای حل مسائل مکانیابی معرفی شده‌‌اند. روش‌های فراابتکاری، برای حل مسائلی با داده‌ها و ابعاد زیاد، بدون نیاز به دانستن مسئله، با استفاده از ایده‌های ابتکاری، سرعت حل را افزایش می‌دهند. یکی از روش‌های فراابتکاری، الگوریتم جستجوی ممنوعه است که مبتنی بر جستجوی محلی است و در حل مسائل مکانیابی، نتایج مطلوبی به دست می‌دهد. این الگوریتم، مولفه‌ها و اجزای مختلفی دارد که در این مقاله، بطور مشروح معرفی شده‌‌اند. همچنین اصلاحات و افزوده‌هایی که برای بهبود الگوریتم، توسط محققین به آن اضافه شده است، نیز معرفی شده‌‌اند تفاصيل المقالة -
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14 - Joint Inspecting Interval Optimization and Redundancy Allocation Problem Optimization for Cold-Standby Systems with Non-Identical Components
Mani SharifiIn this paper, we study a redundancy allocation problem. The investigated problem has a system with s serially connected subsystems, which are under periodic inspection. In each subsystem, component failures are diagnosed by a perfect switching system, and the first com أکثرIn this paper, we study a redundancy allocation problem. The investigated problem has a system with s serially connected subsystems, which are under periodic inspection. In each subsystem, component failures are diagnosed by a perfect switching system, and the first component on the standby queue starts working as a replacement for the failed component. . The failures of the components are detected at inspection. The failed component(s) will be repaired during the next inspection interval and added to the standby queue. The subsystems can be in different states depending on their working component and the order of the components on the standby queue. We present an approach to calculate the subsystems-states transition probabilities. We used a two-phase approach to minimize the system cost. In the first phase, we minimize the subsystem's expected total cost by determining the optimal number of components and the optimal subsystem's inspection intervals. The expected total cost consists of downtime, repair, and inspection costs of the subsystems per unit time. Then, in the second phase, we determine the optimum allocated components to each subsystem under some constraints to find the optimal system inspection cost per unit time تفاصيل المقالة -
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15 - Developing a Decision Model as Budget Assignment Method for Locating Industrial Facilities: Real Case Study
Parsa Fallah Sheikhlari Seyed Habib A RahmatiIn today's world, due to the existence of several criteria in every decision, budgeting has become a complex issue. Applying decision-making methods significantly helps to make optimal decisions. Multiple criteria decision making (MCDM) is a branch of operational resear أکثرIn today's world, due to the existence of several criteria in every decision, budgeting has become a complex issue. Applying decision-making methods significantly helps to make optimal decisions. Multiple criteria decision making (MCDM) is a branch of operational research dealing with finding optimal results in complex scenarios including various indicators, conflicting objectives, criteria, and various indicators. The paper presents a location-allocation decision-making problem resulting in the selection of the most desirable location for the consulting service center in the Qazvin state of Iran. In the first stage, different location criteria are determined. Then, the decision-making matrix preparation is completed based on the criteria dimension and expert opinions. The decision problem is formulated as a multiple criteria ranking problem (MCDM). In the second stage, the decision-making is performed by using all three models of the PROMETHEE method. Finally, considered locations are ranked from the best choice to the worst one with the application of the PROMETHEE MCDM/A method. تفاصيل المقالة -
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16 - Using NSGA II Algorithm for a Three Objectives Redundancy Allocation Problem with k-out-of-n Sub-Systems
mani sharifi Pedram Pourkarim Guilani mohammadreza shahriariin the new production systems, finding a way to improving the product and system reliability in design is a very important. The reliability of the products and systems may improve using different methods. One of this methods is redundancy allocation problem. In this pro أکثرin the new production systems, finding a way to improving the product and system reliability in design is a very important. The reliability of the products and systems may improve using different methods. One of this methods is redundancy allocation problem. In this problem by adding redundant component to sub-systems under some constraints, the reliability improved. In this paper we worked on a three objectives redundancy allocation problem. The objectives are maximizing system reliability and minimizing the system cost and weight. The structure of sub-systems are k-out-of-n and the components have constant failure rate. Because this problem belongs to Np. Hard problems, we used NSGA II multi-objective Meta-heuristic algorithm to solving the presented problem. تفاصيل المقالة -
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17 - Optimization of Multi-period Three-echelon Citrus Supply Chain Problem
Navid Sahebjamnia Fariba Goodarzian Mostafa Hajiaghaei-KeshteliIn this paper, a new multi-objective integer non-linear programming model is developed for designing citrus three-echelon supply chain network. Short harvest period, product specifications, high perished rate, and special storing and distributing conditions make the mod أکثرIn this paper, a new multi-objective integer non-linear programming model is developed for designing citrus three-echelon supply chain network. Short harvest period, product specifications, high perished rate, and special storing and distributing conditions make the modeling of citrus supply chain more complicated than other ones. The proposed model aims to minimize network costs including waste cost, transportation cost, and inventory holding cost, and to maximize network’s profits. To solve the model, firstly the model is converted to a linear programming model. Then three multi-objective meta-heuristic algorithms are used including MOPSO, MOICA, and NSGA-II for finding efficient solutions. The strengths and weaknesses of MOPSO, MOICA, and NSGA-II for solving the proposed model are discussed. The results of the algorithms have been compared by several criteria consisting of number of Pareto solution, maximum spread, mean ideal distance, and diversification metric.Computational results show that MOPSO algorithm finds competitive solutions in compare with NSGA-II and MOICA. تفاصيل المقالة -
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18 - Developing a New Bi-Objective Functions Model for a Hierarchical Location-Allocation Problem Using the Queuing Theory and Mathematical Programming
Parham Azimi Abulfazl AsadollahiIn this research, a hierarchical location-allocation problem is modeled in a queue framework. The queue model is considered as M/M/1/k, in which system capacity is finite, equals to k. This is the main contribution of the current research. Customer's enters to the syste أکثرIn this research, a hierarchical location-allocation problem is modeled in a queue framework. The queue model is considered as M/M/1/k, in which system capacity is finite, equals to k. This is the main contribution of the current research. Customer's enters to the system in order to find the service according to a Poisson. In this problem, the hierarchical location-allocation model is considered in two levels. Also, the model has two objective functions: maximizing the total number of demand coverage and minimizing the waiting time of customers in queues to receive services. After modeling and verifying the validity of the presented model, it is solved using NSGA II and MOPSO meta-heuristics. تفاصيل المقالة -
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19 - Developing a Transfer Point Location Problem Considering Normal Demands Distribution
Ammar Mollaie Soroush Avakh Darestani Deneise Daddn the scope of center location problem, transfer point location problems (TPLP) are the ones which have been studied more recently to make models more applicable in real world. The contribution of this work is to develop a model in which demand points are weighted and h أکثرn the scope of center location problem, transfer point location problems (TPLP) are the ones which have been studied more recently to make models more applicable in real world. The contribution of this work is to develop a model in which demand points are weighted and have a normal distribution. As an assumption, there is no transformation directly from a demand point to the service facility location. This means that the transfer point is always engaged. The contribution of work is summarized in two models. In the first model, all the points are considered in an area while in the second one the points are considered in several areas. The problem is to find out the best location for the transfer point so that the maximum expected weighted distance to all demand points through the transfer point is minimized. A mathematical solution is employed when demand points follow normal distribution, with some points of demands being in regions. Then, this model was solved by replacing real number in a real condition. We used Maple software to solve this objective function as well as MATLAB software to solve this model numerically. تفاصيل المقالة -
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20 - Genetic Algorithm and Simulated Annealing for Redundancy Allocation Problem with Cold-standby Strategy
Aida Karimi Mani Sharifi Amirhossain ChambariThis paper presents a new mathematical model for a redundancyallocation problem (RAP) withcold-standby redundancy strategy and multiple component choices.The applications of the proposed model arecommon in electrical power, transformation,telecommunication systems,etc.M أکثرThis paper presents a new mathematical model for a redundancyallocation problem (RAP) withcold-standby redundancy strategy and multiple component choices.The applications of the proposed model arecommon in electrical power, transformation,telecommunication systems,etc.Manystudies have concentrated onone type of time-to-failure, butin thispaper, two components of time-to-failures which follow hypo-exponential and exponential distributionare investigated. The goal of the RAP is to select available components and redundancy level for each subsystem for maximizing system reliability under cost and weight constraints.Sincethe proposed model belongs to NP-hard class, we proposed two metaheuristic algorithms; namely, simulated annealing and genetic algorithm to solve it. In addition, a numerical example is presented to demonstrate the application of the proposed solution methodology. تفاصيل المقالة -
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21 - Reliability Modelling of the Redundancy Allocation Problem in the Series-parallel Systems and Determining the System Optimal Parameters
Mani Sharifi Mohsen YaghoubizadehConsidering the increasingly high attention to quality, promoting the reliability of products during designing process has gained significant importance. In this study, we consider one of the current models of the reliability science and propose a non-linear programming أکثرConsidering the increasingly high attention to quality, promoting the reliability of products during designing process has gained significant importance. In this study, we consider one of the current models of the reliability science and propose a non-linear programming model for redundancy allocation in the series-parallel systems according to the redundancy strategy and considering the assumption that the failure rate depends on the number of the active elements. The purpose of this model is to maximize the reliability of the system. Internal connection costs, which are the most common costs in electronic systems, are used in this model in order to reach the real-world conditions. To get the results from this model, we used meta-heuristic algorithms such as genetic algorithm and simulation annealing after optimizing their operators’ rates by using response surface methodology. تفاصيل المقالة -
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22 - A New Hybrid Algorithm to Optimize Stochastic-fuzzy Capacitated Multi-Facility Location-allocation Problem
Esmaeil Mehdizadeh Mohammad Reza Tavarroth Vahid HajipourFacility location-allocation models are used in a widespread variety of applications to determine the number of required facility along with the relevant allocation process. In this paper, a new mathematical model for the capacitated multi-facility location-allocation p أکثرFacility location-allocation models are used in a widespread variety of applications to determine the number of required facility along with the relevant allocation process. In this paper, a new mathematical model for the capacitated multi-facility location-allocation problem with probabilistic customer's locations and fuzzy customer’s demands under the Hurwicz criterion is proposed. This model is formulated as α-cost minimization model according to different criteria. Since our problem is strictly Np-hard, a new hybrid intelligent algorithm is presented to solve the stochastic-fuzzy model. The proposed algorithm is based on a vibration damping optimization (VDO) algorithm which is combined with the simplex algorithm and fuzzy simulation (SFVDO). Finally, a numerical example is presented to illustrate the capability of the proposed solving methodologies. تفاصيل المقالة -
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23 - Facility Location and Inventory Balancing in a Multi-period Multi-echelon Multi-objective Supply Chain: An MOEA Approach
Seyed Habib A. Rahmati Abbas Ahmadi Behrooz KarimiA comprehensive and integrated study of any supply chain (SC) environment is a vital requirement that can create various advantages for the SC owners. This consideration causes productive managing of the SC through its whole wide components from upstream suppliers to do أکثرA comprehensive and integrated study of any supply chain (SC) environment is a vital requirement that can create various advantages for the SC owners. This consideration causes productive managing of the SC through its whole wide components from upstream suppliers to downstream retailers and customers. On this issue, despite many valuable studies reported in the current literature, considerable gaps still prevail. These gaps include integration and insertion of basic concepts, such as queuing theory, facility location, inventory management, or even fuzzy theory, as well as other new concepts such as strategic planning, data mining, business intelligence, and information technology. This study seeks to address some of these gaps. To do so, it proposes an integrated four-echelon multi-period multi-objective SC model. To make the model closer to the real world problems, it is also composed of inventory and facility location planning, simultaneously. The proposed model has a mixed integer linear programming (MILP) structure. The objectives of the model are reducing cost and minimizing the non-fill rate of customer zones demand. The cost reduction part includes cost values of raw material shipping from suppliers to plants, plant location, inventory holding costs in plants, distribution cost from plants to warehouses or distribution centers (DCs), and shipping costs from DCs to customer zones. Finally, since the literature of SC lacks efficient Pareto-based multi-objective evolutionary algorithms (MOEAs), a new multi-objective version of the biogeography-based optimization algorithm (MOBBO) is introduced to the literature of the SC. The efficiency of the algorithm is proved through its comparison with an existing algorithm called multi-objective harmony search (MOHS). تفاصيل المقالة -
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24 - A New Approach for Solving Fuzzy Single Facility Location Problem Under L1 Norm
Nemat Allah Taghi-Nezhad Fatemeh TaleshianThe location allocation problem is one of the most attractive optimization problems that is widely used in the real world. Therefore, any attempt to bring this problem closer to real-world conditions would be significant and useful. In this paper, we utilize fuzzy logic أکثرThe location allocation problem is one of the most attractive optimization problems that is widely used in the real world. Therefore, any attempt to bring this problem closer to real-world conditions would be significant and useful. In this paper, we utilize fuzzy logic due to the uncertainty of parameters in the real world. That is the weights (the amounts of demands of customers) and variables (the coordinates of the optimal place) are both considered fuzzy numbers. If these variables are considered definitively, due to various conditions and reasons, it may not be possible to acquire land or build a facility center in it, so we also considered this variable in a fuzzy way and a facility center area was obtained, that certainly, the decision maker can find the right place more easily. To solve the fuzzy problem a new approach based on presenting the problem in the form of equivalent expressions is proposed. This equivalent problem is solved using fuzzy arithmetic. تفاصيل المقالة -
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25 - Uncertain Location of Network Structured Production Units
Azam Azodi Jafar Fathali Mojtaba Ghiyasi Tahere SayarFacility location problems are one of the most important issues for healthcare organizations and centers to achieve social welfare and respond to customer needs. Proper distribution of health and treatment facilities in cities is vital to minimize costs and improve the أکثرFacility location problems are one of the most important issues for healthcare organizations and centers to achieve social welfare and respond to customer needs. Proper distribution of health and treatment facilities in cities is vital to minimize costs and improve the efficiency of health centers. The main contribution of the current article is dealing with the uncertainty issue in the p-median location-efficient problem. In this article, the p-median location problem along with network data envelopment analysis (Network DEA) is used in parallel mode to calculate the efficiency of health and treatment centers. In this issue, health centers are considered as parallel networks with two departments that operate independently. Due to the precision of the input and output values, triangular fuzzy numbers and the α-level fuzzy method have been used. The primary results that consider the uncertainty provide efficient solution and suggestions for the potential location of health centers in our case study. تفاصيل المقالة -
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26 - Use whale algorithm and neighborhood search metaheuristics with fuzzy values to solve the location problem
مهدی فضلی فرزین مدرس خیابانی بهروز دانشیانIn this paper, a facility location model with fuzzy value parameters based on the meta-heuristic method is investigated and solved. The proposed method and model uses fuzzy values to investigate and solve the problem of location allocation. The hypotheses of the problem أکثرIn this paper, a facility location model with fuzzy value parameters based on the meta-heuristic method is investigated and solved. The proposed method and model uses fuzzy values to investigate and solve the problem of location allocation. The hypotheses of the problem in question are considered as fuzzy random variables and the capacity of each facility is assumed to be unlimited. This article covers a modern, nature-inspired method called the whale algorithm and the neighborhood search method. The proposed method and related algorithm are tested with practical optimization problems and modeling problems. To evaluate the efficiency and performance of the proposed method, we apply this method to our location models in which fuzzy coefficients are used. The results of numerical optimization show that the proposed method performs better than conventional methods. تفاصيل المقالة -
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27 - A Multi-Objective Decision-Based Solution for Facility Location-Allocation Problem Using Cuckoo Search And Genetic Algorithms
Amir Shimi Mohammad Reza Ebrahimi Dishabi Mohammad Abdollahi AzgomiConsidering the significant advancements in autonomous vehicle technology, research in this field is of interest to researchers. To automatic parking, controlling steer angle, gas hatch, and brakes need to be learned. Due to the increase in the number of cars and road t أکثرConsidering the significant advancements in autonomous vehicle technology, research in this field is of interest to researchers. To automatic parking, controlling steer angle, gas hatch, and brakes need to be learned. Due to the increase in the number of cars and road traffic, car parking space has decreased. Its main reason is information error. Because the driver does not receive the necessary information or receives it too late, he cannot take appropriate action against it. This paper uses two phases: the first phase, for goal coordination, was used genetic algorithms and the Cuckoo search algorithm was used to increase driver information from the surroundings. Using the Cuckoo search algorithm and considering the limitations, it increases the driver’s level of information from the environment. Also, by exchanging information through the application, it enables the information to reach the driver much more quickly and the driver reacts appropriately at the right time. The suggested protocol is called the multi-objective decision-based solution (MODM)-based solution. Here, the technique is assessed through extensive simulations performed in the NS-3 environment. Based on the simulation outcomes, it is indicated that the parking system performance metrics are enhanced based on the detection rate, false-negative rate, and false-positive rate. تفاصيل المقالة -
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28 - A Multi-Period Berth Allocation-Scheduling Model with Different Terminals and Irregular Layouts Under Uncertainty
S. Farid Mousavi Zahra Mahdavi Kaveh Khalili-Damghani Arezoo Gazori-NishaboriAs global trade flourishes, terminals endeavor to get higher income while adapting to an expanded intricacy concerning terminal administration tasks. Perhaps the most common issues such terminals encounter is the Berth Allocation Problem (BAP), which involves allotting أکثرAs global trade flourishes, terminals endeavor to get higher income while adapting to an expanded intricacy concerning terminal administration tasks. Perhaps the most common issues such terminals encounter is the Berth Allocation Problem (BAP), which involves allotting vessels to a bunch of berths and time allotments while at the same time limiting goals, for example, total stay time or total assignment cost. Complex formats of actual terminals present spatial constraints that restrict the mooring and departure of vessels. In spite of the fact that significant research has been carried out with regard to the BAP, these real-world limitations have not been considered in an overall manner. In this paper, a stochastic Multi-Period Berth Allocation-Scheduling Problem in Different Terminals with Irregular Layouts (SBAP) considering multi-Period modes, generalized precedence relations are developed. To solve the (SBAP), a solution approach based on Stochastic Chance Constraint Programming (SCCP) and a solution approach based on Two-Stage Stochastic Linear Programming with Recourse (TSSLPR) is proposed. A mathematical model is solved to show the applicability of the suggested model and solution approach. تفاصيل المقالة -
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29 - Reliability optimization problems with multiple constraints under fuzziness
Neha Gupta Sanam Haseen Abdul BariIn reliability optimization problems diverse situation occurs due to which it is not always possible to get relevant precision in system reliability. The imprecision in data can often be represented by triangular fuzzy numbers. In this manuscript, we have considered dif أکثرIn reliability optimization problems diverse situation occurs due to which it is not always possible to get relevant precision in system reliability. The imprecision in data can often be represented by triangular fuzzy numbers. In this manuscript, we have considered different fuzzy environment for reliability optimization problem of redundancy. We formulate a redundancy allocation problem for a hypothetical series-parallel system in which the parameters of the system are fuzzy. Two different cases are then formulated as non-linear programming problem and the fuzzy nature is defuzzified into crisp problems using three different defuzzification methods viz. ranking function, graded mean integration value andα-cut. The result of the methods is compared at the end of the manuscript using a numerical example. تفاصيل المقالة -
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30 - Exact algorithms for solving a bi-level location–allocation problem considering customer preferences
Ehsan Mirzaei Mahdi Bashiri Hossein Shams ShemiraniThe issue discussed in this paper is a bi-level problem in which two rivals compete in attracting customers and maximizing their profits which means that competitors competing for market share must compete in the centers that are going to be located in the near future. أکثرThe issue discussed in this paper is a bi-level problem in which two rivals compete in attracting customers and maximizing their profits which means that competitors competing for market share must compete in the centers that are going to be located in the near future. In this paper, a nonlinear model presented in the literature considering customer preferences is linearized. Customer behavior means that the customer patronizes the most attractive (most comfort) location that he/she wants to be served among the locations of the first-level decision maker (Leader) and the second-level decision maker (Follower). Four types of exact algorithms have been introduced in this paper which include three types of full enumeration procedures and a developed branch-and-bound procedure. Moreover, a clustering-based algorithm has been presented that can provide a good approximation (a good lower bound) to the mentioned binary problem. For this purpose, the numerical results obtained are compared with the results of the full enumeration, heuristic and the branch-and-bound procedure. تفاصيل المقالة -
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31 - A hybrid DEA-based K-means and invasive weed optimization for facility location problem
Farshad Faezy RaziIn this paper, instead of the classical approach to the multi-criteria location selection problem, a new approach was presented based on selecting a portfolio of locations. First, the indices affecting the selection of maintenance stations were collected. TheK-means mod أکثرIn this paper, instead of the classical approach to the multi-criteria location selection problem, a new approach was presented based on selecting a portfolio of locations. First, the indices affecting the selection of maintenance stations were collected. TheK-means model was used for clustering the maintenance stations. The optimal number of clusters was calculated through the Silhouette index. The efficiency of each cluster of stations was determined using the Charnes, Cooper and Rhodes input-oriented data envelopment analysis model. A bi-objective zero one programming model was used to select a Pareto optimal combination of rank and distance of stations. The Pareto solutions for the presented bi-objective model were determined using the invasive weed optimization method. Although the proposed methodology is meant for the selection of repair and maintenance stations in an oil refinery Company, it can be used in multi-criteria decision-making problems. تفاصيل المقالة -
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32 - Redundancy allocation problem for k-out-of-n systems with a choice of redundancy strategies
Mahsa Aghaei Ali Zeinal Hamadani Mostafa Abouei ArdakanTo increase the reliability of a specific system, using redundant components is a common method which is called redundancy allocation problem (RAP). Some of the RAP studies have focused onk-out-of-nsystems. However, all of these studies assumed predetermined active or s أکثرTo increase the reliability of a specific system, using redundant components is a common method which is called redundancy allocation problem (RAP). Some of the RAP studies have focused onk-out-of-nsystems. However, all of these studies assumed predetermined active or standby strategies for each subsystem. In this paper, for the first time, we propose ak-out-of-nsystem with a choice of redundancy strategies. Therefore, ak-out-of-nseries–parallel system is considered when the redundancy strategy can be chosen for each subsystem. In other words, in the proposed model, the redundancy strategy is considered as an additional decision variable and an exact method based on integer programming is used to obtain the optimal solution of the problem. As the optimization of RAP belongs to the NP-hard class of problems, a modified version of genetic algorithm (GA) is also developed. The exact method and the proposed GA are implemented on a well-known test problem and the results demonstrate the efficiency of the new approach compared with the previous studies. تفاصيل المقالة -
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33 - A robust optimization model for distribution and evacuation in the disaster response phase
Meysam Fereiduni Kamran ShahanaghiNatural disasters, such as earthquakes, affect thousands of people and can cause enormous financial loss. Therefore, an efficient response immediately following a natural disaster is vital to minimize the aforementioned negative effects. This research paper presents a n أکثرNatural disasters, such as earthquakes, affect thousands of people and can cause enormous financial loss. Therefore, an efficient response immediately following a natural disaster is vital to minimize the aforementioned negative effects. This research paper presents a network design model for humanitarian logistics which will assist in location and allocation decisions for multiple disaster periods. At first, a single-objective optimization model is presented that addresses the response phase of disaster management. This model will help the decision makers to make the most optimal choices in regard to location, allocation, and evacuation simultaneously. The proposed model also considers emergency tents as temporary medical centers. To cope with the uncertainty and dynamic nature of disasters, and their consequences, our multi-period robust model considers the values of critical input data in a set of various scenarios. Second, because of probable disruption in the distribution infrastructure (such as bridges), the Monte Carlo simulation is used for generating related random numbers and different scenarios; the p-robust approach is utilized to formulate the new network. The p-robust approach can predict possible damages along pathways and among relief bases. We render a case study of our robust optimization approach for Tehran’s plausible earthquake in region 1. Sensitivity analysis’ experiments are proposed to explore the effects of various problem parameters. These experiments will give managerial insights and can guide DMs under a variety of conditions. Then, the performances of the “robust optimization” approach and the “p-robust optimization” approach are evaluated. Intriguing results and practical insights are demonstrated by our analysis on this comparison. تفاصيل المقالة -
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34 - Developing a new stochastic competitive model regarding inventory and price
Reza Rashid Ali Bozorgi-Amiri S. M . SeyedhoseiniWithin the competition in today’s business environment, the design of supply chains becomes more complex than before. This paper deals with the retailer’s location problem when customers choose their vendors, and inventory costs have been considered for reta أکثرWithin the competition in today’s business environment, the design of supply chains becomes more complex than before. This paper deals with the retailer’s location problem when customers choose their vendors, and inventory costs have been considered for retailers. In a competitive location problem, price and location of facilities affect demands of customers; consequently, simultaneous optimization of the location and inventory system is needed. To prepare a realistic model, demand and lead time have been assumed as stochastic parameters, and queuing theory has been used to develop a comprehensive mathematical model. Due to complexity of the problem, a branch and bound algorithm has been developed, and its performance has been validated in several numerical examples, which indicated effectiveness of the algorithm. Also, a real case has been prepared to demonstrate performance of the model for real world. تفاصيل المقالة -
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35 - Models, solution, methods and their applicability of dynamic location problems (DLPs) (a gap analysis for further research)
Seyed Mohammad Seyedhosseini Ahmad Makui Kamran Shahanaghi Sara Sadat TorkestaniDetermining the best location to be profitable for the facility’s lifetime is the important decision of public and private firms, so this is why discussion about dynamic location problems (DLPs) is a critical significance. This paper presented a comprehensive revi أکثرDetermining the best location to be profitable for the facility’s lifetime is the important decision of public and private firms, so this is why discussion about dynamic location problems (DLPs) is a critical significance. This paper presented a comprehensive review from 1968 up to most recent on published researches about DLPs and classified them into two parts. First, mathematical models developed based on different characteristics: type of parameters (deterministic, probabilistic or stochastic), number and type of objective function, numbers of commodity and modes, relocation time, number of relocation and relocating facilities, time horizon, budget and capacity constraints and their applicability. In second part, It have been also presented solution algorithms, main specification, applications and some real-world case studies of DLPs. At the ends, we concluded that in the current literature of DLPs, distribution systems and production–distribution systems with simple assumption of the tackle to the complexity of these models studied more than any other fields, as well as the concept of variety of services (hierarchical network), reliability, sustainability, relief management, waiting time for services (queuing theory) and risk of facility disruption need for further investigation. All of the available categories based on different criteria, solution methods and applicability of them, gaps and analysis which have been done in this paper suggest the ways for future research. تفاصيل المقالة -
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36 - Scenario-based modeling for multiple allocation hub location problem under disruption risk: multiple cuts Benders decomposition approach
Mohsen Yahyaei Mahdi BashiriThe hub location problem arises in a variety of domains such as transportation and telecommunication systems. In many real-world situations, hub facilities are subject to disruption. This paper deals with the multiple allocation hub location problem in the presence of f أکثرThe hub location problem arises in a variety of domains such as transportation and telecommunication systems. In many real-world situations, hub facilities are subject to disruption. This paper deals with the multiple allocation hub location problem in the presence of facilities failure. To model the problem, a two-stage stochastic formulation is developed. In the proposed model, the number of scenarios grows exponentially with the number of facilities. To alleviate this issue, two approaches are applied simultaneously. The first approach is to apply sample average approximation to approximate the two stochastic problem via sampling. Then, by applying the multiple cuts Benders decomposition approach, computational performance is enhanced. Numerical studies show the effective performance of the SAA in terms of optimality gap for small problem instances with numerous scenarios. Moreover, performance of multi-cut Benders decomposition is assessed through comparison with the classic version and the computational results reveal the superiority of the multi-cut approach regarding the computational time and number of iterations. تفاصيل المقالة -
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37 - A redundancy allocation problem with the choice of redundancy strategies by a memetic algorithm
J Safari R Tavakkoli-MoghaddamThis paper proposes an efficient algorithm based on memetic algorithm (MA) for a redundancy allocation problem without component mixing (RAPCM) in a series-parallel system when the redundancy strategy can be chosen for individual subsystems. Majority of the solution met أکثرThis paper proposes an efficient algorithm based on memetic algorithm (MA) for a redundancy allocation problem without component mixing (RAPCM) in a series-parallel system when the redundancy strategy can be chosen for individual subsystems. Majority of the solution methods for the general RAPCM assume that the type of a redundancy strategy for each subsystem is pre-determined and known a priori. In general, active redundancy has traditionally received greater attention; however, in practice both active and cold-standby redundancies may be used within a particular system design. The choice of the redundancy strategy then becomes an additional decision variable. Thus, the problem is to select the best redundancy strategy, component and redundancy level for each subsystem in order to maximize the system reliability under system-level constraints. Due to its complexity and NP-hardness, it is so difficult to optimally solve such a problem by using traditional optimization tools. To validate the performance of the proposed MA in terms of solution quality, a number of test problems are examined and the robustness of this algorithm is then discussed. Finally, the related results are reported and it is shown that the proposed MA performs well. تفاصيل المقالة -
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38 - Robust uncapacitated multiple allocation hub location problem under demand uncertainty: minimization of cost deviations
Aleksejs Lozkins Mikhail Krasilnikov Vladimir BureThe hub location–allocation problem under uncertainty is a real-world task arising in the areas such as public and freight transportation and telecommunication systems. In many applications, the demand is considered as inexact because of the forecasting inaccuraci أکثرThe hub location–allocation problem under uncertainty is a real-world task arising in the areas such as public and freight transportation and telecommunication systems. In many applications, the demand is considered as inexact because of the forecasting inaccuracies or human’s unpredictability. This study addresses the robust uncapacitated multiple allocation hub location problem with a set of demand scenarios. The problem is formulated as a nonlinear stochastic optimization problem to minimize the hub installation costs, expected transportation costs and expected absolute deviation of transportation costs. To eliminate the nonlinearity, the equivalent linear problem is introduced. The expected absolute deviation is the robustness measure to derive the solution close to each scenario. The robust hub location is assumed to deliver the least costs difference across the scenarios. The number of scenarios increases size and complexity of the task. Therefore, the classical and improved Benders decomposition algorithms are applied to achieve the best computational performance. The numerical experiment on CAB and AP dataset presents the difference of resulting hub networks in stochastic and robust formulations. Furthermore, performance of two Benders decomposition strategies in comparison with Gurobi solver is assessed and discussed. تفاصيل المقالة
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