Murat Şahin - Academia.edu (original) (raw)
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Papers by Murat Şahin
Engineering Optimization, 2016
Standardize edilmis urunlerin uretiminde yaygin olarak kullanilan montaj hatlari onemli bir akis ... more Standardize edilmis urunlerin uretiminde yaygin olarak kullanilan montaj hatlari onemli bir akis tipi uretim seklidir. Bu hatlarin dengelenme problemleri uretim ve kaynak yatirimi maliyetlerinin minimizasyonu acisindan buyuk onem arz etmektedir. NP-zor bir yapiya sahip olan probleme endustriyel ortamlarda yaygin olarak karsilasilmasina karsin makul sureler icerisinde kesin cozum yontemleri ile cozumu mumkun olmayabilmektedir. Bu calismada yenilenebilir kaynak yatirimi maliyetini de dikkate alan cok iscili montaj hatti dengeleme problemine yonelik yeni bir algoritma sunulmustur. Onerilen algoritmada tamsayili dogrusal programlama ile cozulecek olan alt problemler tavlama benzetimi yontemi ile belirlenmistir. Literaturde montaj hatti dengeleme problemlerinde siklikla tercih edilen rassal sayilar dizisi kullanilarak gorevlerin hangi onceliklerle atanacagi belirlenmistir. Tavlama benzetimi ve tamsayili dogrusal programlamanin birlikte kullanimina dayanan algoritmanin etkinligi test prob...
Educational institutions generally present a timetable to students in which the scheduling of cou... more Educational institutions generally present a timetable to students in which the scheduling of courses and classes have been arranged before. Generating an appropriate timetable in which all classes do not conflict each other is quite difficult. Students use this timetable to choose the courses and classes according to their requirements. A selected course class may be conflict with another selected one in timetable. Therefore, students are generally forced in selecting the classes without course conflict or minimum and acceptable course conflict. In this study a computer aided system for engineering students of Industrial Engineering Department at Gazi University is proposed to define the classes for selected courses. The system takes the courses from users and presents them appropriate classes by using a mathematical model in background. The aims of the mathematical model are minimizing the course conflict, assigning student to classes desired by department and minimizing total day...
International Journal of Production Research, 2019
Assembly lines are widely used in industrial environments that produce standardised products in h... more Assembly lines are widely used in industrial environments that produce standardised products in high volumes. Multimanned assembly line is a special version of them that allows simultaneous operation of more than one worker at the same workstation. These lines are widely used in large-sized product manufacturing since they have many advantages over the simple one. This article has dealt with multi-manned assembly line balancing problem with walking workers for minimising the number of workers and workstations as the first and second objectives, respectively. A linear mixed-integer programming formulation of the problem has been firstly addressed after the problem definition is given. Besides that, a metaheuristic based on electromagnetic field optimisation algorithm has been improved. In addition to the classical electromagnetic field optimisation algorithm, a regeneration strategy has been applied to enhance diversification. A particle swarm optimisation algorithm from assembly line balancing literature has been modified to compare with the proposed algorithm. A group of test instances from many precedence diagrams were generated for evaluating the performances of all solution methods. Deviations from lower bound values of the number of workers/workstations and the number of optimal solutions obtained by these methods are concerned as performance criteria. The results obtained by the proposed programming formulations have been also compared with the solutions obtained by the traditional mathematical model of the multi-manned assembly line. Through the experimental results, the performance of the metaheuristic has been found very satisfactory according to the number of obtained optimal solutions and deviations from lower bound values.
Engineering Optimization, 2016
Standardize edilmis urunlerin uretiminde yaygin olarak kullanilan montaj hatlari onemli bir akis ... more Standardize edilmis urunlerin uretiminde yaygin olarak kullanilan montaj hatlari onemli bir akis tipi uretim seklidir. Bu hatlarin dengelenme problemleri uretim ve kaynak yatirimi maliyetlerinin minimizasyonu acisindan buyuk onem arz etmektedir. NP-zor bir yapiya sahip olan probleme endustriyel ortamlarda yaygin olarak karsilasilmasina karsin makul sureler icerisinde kesin cozum yontemleri ile cozumu mumkun olmayabilmektedir. Bu calismada yenilenebilir kaynak yatirimi maliyetini de dikkate alan cok iscili montaj hatti dengeleme problemine yonelik yeni bir algoritma sunulmustur. Onerilen algoritmada tamsayili dogrusal programlama ile cozulecek olan alt problemler tavlama benzetimi yontemi ile belirlenmistir. Literaturde montaj hatti dengeleme problemlerinde siklikla tercih edilen rassal sayilar dizisi kullanilarak gorevlerin hangi onceliklerle atanacagi belirlenmistir. Tavlama benzetimi ve tamsayili dogrusal programlamanin birlikte kullanimina dayanan algoritmanin etkinligi test prob...
Educational institutions generally present a timetable to students in which the scheduling of cou... more Educational institutions generally present a timetable to students in which the scheduling of courses and classes have been arranged before. Generating an appropriate timetable in which all classes do not conflict each other is quite difficult. Students use this timetable to choose the courses and classes according to their requirements. A selected course class may be conflict with another selected one in timetable. Therefore, students are generally forced in selecting the classes without course conflict or minimum and acceptable course conflict. In this study a computer aided system for engineering students of Industrial Engineering Department at Gazi University is proposed to define the classes for selected courses. The system takes the courses from users and presents them appropriate classes by using a mathematical model in background. The aims of the mathematical model are minimizing the course conflict, assigning student to classes desired by department and minimizing total day...
International Journal of Production Research, 2019
Assembly lines are widely used in industrial environments that produce standardised products in h... more Assembly lines are widely used in industrial environments that produce standardised products in high volumes. Multimanned assembly line is a special version of them that allows simultaneous operation of more than one worker at the same workstation. These lines are widely used in large-sized product manufacturing since they have many advantages over the simple one. This article has dealt with multi-manned assembly line balancing problem with walking workers for minimising the number of workers and workstations as the first and second objectives, respectively. A linear mixed-integer programming formulation of the problem has been firstly addressed after the problem definition is given. Besides that, a metaheuristic based on electromagnetic field optimisation algorithm has been improved. In addition to the classical electromagnetic field optimisation algorithm, a regeneration strategy has been applied to enhance diversification. A particle swarm optimisation algorithm from assembly line balancing literature has been modified to compare with the proposed algorithm. A group of test instances from many precedence diagrams were generated for evaluating the performances of all solution methods. Deviations from lower bound values of the number of workers/workstations and the number of optimal solutions obtained by these methods are concerned as performance criteria. The results obtained by the proposed programming formulations have been also compared with the solutions obtained by the traditional mathematical model of the multi-manned assembly line. Through the experimental results, the performance of the metaheuristic has been found very satisfactory according to the number of obtained optimal solutions and deviations from lower bound values.