محمد محمدی
دانشیار، دانشگاه خوارزمی، گروه مهندسی صنایع، البرز، ایران(عهده دار مکاتبات)
[ 1 ] - برنامه ریزی خطوط هواپیمایی با در نظر گرفتن محدودیت‌های عملیاتی
از گذشته تا به امروز به علت بالا بودن هزینه‌های مربوط به صنعت هوایی و هواپیماها، برنامه‌ریزی برای این صنعت از اهمیت زیادی برخوردار بوده است. یکی از مسائل مربوط به صنعت هوایی، مسئله‌ی مسیریابی هواپیماها و تعیین تعداد هواپیماهای مورد نیاز در هر برنامه‌ی پروازی است. این مسائل، بخش قابل توجهی از هزینه‌های صنعت هوایی را برعهده دارند. از طرفی با توجه به یک سری محدودیت‌ها و قوانینی که شرکت‌های هواپیما...
[ 2 ] - مدل‌سازی و حل یک مسئلۀ موجودی چند محصولی با درنظرگرفتن وجود اقلام معیوب در محموله‌های سفارشی و گزینه‌های خرید یا تعمیر
در این پژوهش، یک مسئلة موجودی چند محصولی با فرض وجود اقلام معیوب ارائه شده است که دو رویکرد خرید یا تعمیر برای مواجهه با اقلام معیوب و تأمین تقاضا وجود دارد. در مدل‌سازی این مسئله از پژوهش جابر و همکاران ایده گرفته شده است. مدل ریاضی پیشنهادی، هزینة موجودی برای هر نوع محصول را در حالت خرید یا تعمیر اقلام معیوب محاسبه می‌کند و با توجه به هزینه‌های موجودی و شرایط عملیاتی، درمورد خرید یا تعمیر اقل...
[ 3 ] - Design of a reliable supply chain network with responsiveness considerations under uncertainty: case study of an Iranian tire manufacturer
This paper proposes a bi-objective reliable supply chain network design that immunizes the network against different sources of uncertainties. In this regard, scenario based stochastic programming method is applied to model different disruption scenarios affecting accurate performance of network stages. Also, reliable and unreliable facilities are suggested for lessening vulnerability of networ...
[ 4 ] - Multi objective organ transplant supply chain with effective location and time consideration
Nowadays, working alone on a context is not sufficient and reaching good and worthy results demands cooperation of multi sciences. Healthcare supply chain is one of these sciences that bridges engineering and healthcare sciences. This paper proposes a new multi–objective model for organ transplant supply chain, which is one of consequential fields in Healthcare supply chain, by aiming at having...
[ 5 ] - Location of Heath Care Facilities in Competitive and User Choice Environment
The location of facilities anywhere in an area in which several competing facilities already exist and serving the demand points has been brought to light in this work. Because of the great importance of health care systems in the health of the people, these systems have been studied in the present paper. Creation and maintenance of competitive advantage in health care systems requires optimizi...
[ 6 ] - Economic Lot Sizing and Scheduling in Distributed Permutation Flow Shops
This paper addresses a new mixed integer nonlinear and linear mathematical programming economic lot sizing and scheduling problem in distributed permutation flow shop problem with number of identical factories and machines. Different products must be distributed between the factories and then assignment of products to factories and sequencing of the products assigned to each factory has to be d...
[ 7 ] - Fuzzy Multi-objective Permutation Flow Shop Scheduling Problem with Fuzzy Processing Times under Learning and Aging Effects
In industries machine maintenance is used in order to avoid untimely machine fails as well as to improve production effectiveness. This research regards a permutation flow shop scheduling problem with aging and learning effects considering maintenance process. In this study, it is assumed that each machine may be subject to at most one maintenance activity during the planning horizon. The objec...
[ 8 ] - A Scheduling Model of Flexible Manufacturing System to Reduce Waste and Earliness/Tardiness Penalties
Nowadays, flexible manufacturing system (FMS) is introduced as a response to the competitive environment. Scheduling of FMS is more complex and more difficult than the other scheduling production systems. One of the main factors in scheduling of FMS is variable time of taking orders from customers, which leads to a sudden change in the manufacturing process. Also, some problems are created in p...
[ 9 ] - Solving a New Multi-objective Unrelated Parallel Machines Scheduling Problem by Hybrid Teaching-learning Based Optimization
This paper considers a scheduling problem of a set of independent jobs on unrelated parallel machines (UPMs) that minimizesthe maximum completion time (i.e., makespan or ), maximum earliness ( ), and maximum tardiness ( ) simultaneously. Jobs have non-identical due dates, sequence-dependent setup times and machine-dependentprocessing times. A multi-objective mixed-integer linear programmi...
[ 10 ] - Optimizing Flexible Manufacturing System: A Developed Computer Simulation Model
In recent years, flexible manufacturing system as a response to market demands has been proposed to increase product diversity, optimum utilization of machines andperiods of short-term products.The development of computer systems has provided the ability to build machines with high functionality and the necessary flexibility to perform various operations. However, due to the complexity and the ...
[ 11 ] - A Mathematical Model for Operating Room Scheduling Considering Limitations on Human Resources Access and Patient Prioritization
Operating room scheduling is an important task in healthcare sector. This study proposes a Mixed Integer Nonlinear Programming (MINLP) mathematical model for the scheduling of the operating rooms. In the presented model, apart from scheduling the patients’ surgery process, shifting of the medical staff is also carried out. The innovation considered in the proposed model is aimed at prioritizing...
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