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Öğe AN APPLICATION OF EFFECTIVE GENETIC ALGORITHMS FOR SOLVING HYBRID FLOW SHOP SCHEDULING PROBLEMS(ATLANTIS PRESS, 2008) Kahraman, Cengiz; Engin, Orhan; Kaya, İhsan; Yılmaz, Mustafa KerimThis paper addresses the Hybrid Flow Shop (HFS) scheduling problems to minimize the makespan value. In recent years, much attention is given to heuristic and search techniques. Genetic algorithms (GAs) are also known as efficient heuristic and search techniques. This paper proposes an efficient genetic algorithm for hybrid flow shop scheduling problems. The proposed algorithm is tested by Carlier and Neron's (2000) benchmark problem from the literature. The computational results indicate that the proposed efficient genetic algorithm approach is effective in terms of reduced total completion time or makespan (C-max) for HFS problems.Öğe Fuzzy Acceptance Sampling and Characteristic Curves(Atlantıs Press, 2012) Turanoğlu, Ebru; Kaya, İhsan; Kahraman, CengizAcceptance sampling is primarily used for the inspection of incoming or outgoing lots. Acceptance sampling refers to the application of specific sampling plans to a designated lot or sequence of lots. The parameters of acceptance sampling plans are sample sizes and acceptance numbers. In some cases, it may not be possible to define acceptance sampling parameters as crisp values. These parameters can be expressed by linguistic variables. The fuzzy set theory can be successfully used to cope with the vagueness in these linguistic expressions for acceptance sampling. In this paper, the main distributions of acceptance sampling plans are handled with fuzzy parameters and their acceptance probability functions are derived. Then the characteristic curves of acceptance sampling are examined under fuzziness. Illustrative examples are given.Öğe Fuzzy Acceptance Sampling Plans(Springer-Verlag Berlin, 2010) Kahraman, Cengiz; Kaya, İhsanAcceptance sampling is one of the major components of the field of statistical quality control. It is primarily used for the inspection of incoming or outgoing lots. In recent years, it has become typical to work with suppliers to improve their process performance through the use of statistical process control (SPC). Acceptance sampling refers to the application of specific sampling plans to a designated lot or sequence of lots. Acceptance sampling procedures can, however, be used in a program of acceptance control to achieve better quality at lower cost, improved control, and increased productivity. In some cases, it may not be possible to define acceptance sampling parameters as crisp values. Especially in production environments, it may not be easy to define the parameters fraction of nonconforming, acceptance number, or sample size as crisp values. In these cases, these parameters can be expressed by linguistic variables. The fuzzy set theory can be used successfully to cope the vagueness in these linguistic expressions for acceptance sampling. In this paper, the two main distributions of acceptance sampling plans which are binomial and Poisson distributions are handled with fuzzy parameters and their acceptance probability functions are derived. Then fuzzy acceptance sampling plans are derived based on these distributions.Öğe Fuzzy and Grey Forecasting Techniques and Their Applications in Production Systems(Springer-Verlag Berlin, 2010) Kahraman, Cengiz; Yavuz, Mesut; Kaya, İhsanForecasting is an important part of decision making as many of our decisions are based on predictions of future unknown events. Forecast is an interesting research topic that has received attention from many researchers in the past several decades. Forecasting has many application areas including but not limited to stock markets, futures markets, enrollments of a school, demand of a product and/or service. Management needs to reduce the risks associated with decision-making, which can be done by anticipating the future more clearly. Accurate forecasts are therefore essential for risk reduction. Forecasting provides critical inputs to various manufacturing-related processes, such as production planning, inventory management, capital budgeting, purchasing, work-force scheduling, resource allocation and other important parts of the production system operation. Accurate forecasts are crucial for successful manufacturing and can lead to considerable savings when implemented efficiently. Forecasting literature contains a large variety of techniques from simple regression to complex metaheuristics such as neural networks and genetic algorithms. Fuzzy set theory is also another useful tool to increase forecast efficiency and effectiveness. This chapter summarizes and classifies forecasting techniques based on crisp logic, fuzzy logic and the grey theory. The chapter also presents numerical examples of fuzzy simple linear regression and grey forecasting methodology.Öğe A fuzzy approach to define sample size for attributes control chart in multistage processes: An application in engine valve manufacturing process(ELSEVIER, 2008) Engin, Orhan; Çelik, Ahmet; Kaya, İhsanControl charts are a basic means for monitoring the quality characteristics of processes to ensure the required quality level. Determine the sample size is a problem for attribute control charts (ACC). Kaya and Engin [I. Kaya, O. Engin, A new approach to define sample size at attributes control chart in multistage processes: an application in engine piston manufacturing process, J. Mater. Process. Technol. 183 (2007) 38-48] developed a model to determine sample size in multistage process and it was solved by Genetic Algorithms (GAs). In their model, the parameters such as defective item rates for raw materials and benches were assumed to be known exactly. But in many real world applications, these parameters may be changed very dynamically due to material, human factors or operating faults. In this study a fuzzy approach for ACC in multistage process is presented and it is solved by GAs. Formulations of this model are calculated based on acceptance sampling approach and, two main parameters are determined for every stage by GAs. These are: sample size, n, and acceptance number, c. The sample size, n, is suggested for ACC. The main contributions of this paper are to develop a fuzzy model for ACC in multistage processes. The proposed approach is applied in an engine valve manufacturing firm and the model is solved by GAs. (c) 2008 Elsevier B.V. All rights reserved.Öğe Fuzzy Process Capability Analysis and Applications(Springer-Verlag Berlin, 2010) Kahraman, Cengiz; Kaya, İhsanProcess capability indices (PCIs) are very useful statistical analysis tools to summarize process' dispersion and location through process capability analysis (PCA). PCIs are mainly used in industry to measure the capability of a process to produce products meeting specifications. Traditionally, the specifications are defined as crisp numbers. Sometimes, the specification limits (SLs) can be expressed in linguistic terms. Traditional PCIs cannot be applied for this kind of data. There are also some limitations which prevent a deep and flexible analysis because of the crisp definition of SLs. In this chapter, the fuzzy set theory is used to add more sensitiveness to PCA including more information and flexibility. The fuzzy PCA is developed when the specifications limits are represented by triangular or trapezoidal fuzzy numbers. Crisp SLs with fuzzy normal distribution are used to calculate the fuzzy percentages of conforming (FCIs) and nonconforming (FNCIs) items by taking into account fuzzy process mean, (mu) over tilde and fuzzy variance, (sigma) over tilde (2). Then fuzzy SLs are used together with (mu) over tilde and (sigma) over tilde (2) to produce fuzzy PCIs (FPCIs). FPCIs are analyzed under the existence of correlation and thus fuzzy robust process capability indices are obtained. Then FPCIs are improved for six sigma approach. And additionally, process accuracy index is analyzed under fuzzy environment. The results show that fuzzy estimations of PCIs have much more treasure to evaluate the process when it is compared with the crisp case.Öğe Information systems outsourcing decisions using a group decision-making approach(PERGAMON-ELSEVIER SCIENCE LTD, 2009) Kahraman, Cengiz; Engin, Orhan; Kabak, Özgür; Kaya, İhsanOutsourcing refers to a company that contracts with another company to provide services that might otherwise be performed by in-house employees. Information system (IS) outsourcing policies define the criteria that organizations utilize to decide upon the scope and degree of reliance of their IS capabilities upon external sources. IS outsourcing is an innovative organizational tool for IS management in both private and public sector organizations. In this paper, an interactive group decision-making methodology is proposed to select/rank 15 providers under multiple criteria. A measure for the consensus level of the group preferences is developed to satisfy an acceptable level of group agreement and reliability. The Spearman coefficients for both the aggregated rank order and each DM's rank order have also been calculated. The group and the individual evaluations are gathered through a fuzzy TOPSIS approach. The proposed methodology is applied in the largest office furniture manufacturer in Konya-Turkey. Eight alternative IS providers are evaluated based on seven criteria by five decision makers. Sensitivity analyses are also provided to see the effects of parameter changes on the final decision. (c) 2008 Elsevier Ltd. All rights reserved.Öğe Kalite İyileştirme Sürecinin Yedi Temel Aracı ve Motor-Traktör İmalatı Yapan Bir İşletmede Uygulanması(Selçuk Üniversitesi, 2004) Kaya, İhsan; Ağa, Abdullahİstatistiksel Proses Kontrol (İPK) bir ürünün en ekonomik ve yararlı biçimde üretilmesini sağlamak amacı ile istatistiksel prensip ve tekniklerin, üretimin tüm aşamasında kullanılmasıdır. Bu anlamda en çok bilinen yöntemler “Ishikawa’nın Yedi Temel Aracı” olarak da bilinen; sınıflandırma, çetele, histogram, pareto analizi, neden-sonuç diyagramları, serpilme ve kontrol grafikleridir. Bu çalışmada bu yedi temel araç ele alınarak motor ve traktör imalatı yapan bir işletmede bu tekniklerin kalite iyileştirme çalışmalarındaki kullanımları incelenmiştir. Yapılan literatür incelenmesinden sonra, işletmede istatistiksel proses kontrol araçlarının kullanılması ile kalite iyileştirme ve geliştirme süreci incelenerek, bu teknikler yardımı ile işletmenin kalite gelişimini olumsuz yönde etkileyen faktörler belirlenmiş ve bu faktörlerin ortadan kaldırılması için sebep-sonuç diyagramları geliştirilerek çeşitli önerilerde bulunulmuştur. Ayrıca kontrol diyagramları yardımı ile proseslerin kontrol altında olup olmadıkları incelenmiş ve kontrol dışı durumlar için sebep-sonuç diyagramları geliştirilmiştir.Öğe Kalite Kontrol Problemlerinin Çözümünde Uzman Sistemlerin Kullanımı(2004) Kaya, İhsan; Gözen, Şerife; Engin, Orhanİşletmeler, artan rekabetle birlikte pazar yapısının değişmesi ve müşteri isteklerinin ekonomik bir şekilde karşılanması amacıyla kalite ve kontrol çalışmalarında büyük değişimler göstermektedir. Firmalar, yapay zeka tekniklerini üretim planlama, kalite kontrol gibi alanlarda kullanarak verimliliklerini artırmayı ve problemlere en kısa zamanda çözüm üretmeyi amaçlamaktadırlar. Bu teknikler, bir çok problemin çözümünde etkin olarak kullanılmaktadır. Çalışmada yapay zeka tekniklerinden olan uzman sistemlerin kalite kontrol problemlerinin çözümündeki kullanımı incelenmiştir. Veri analizi, tahmin, yorumlama, hata teşhisi gibi pek çok kalite kontrol problemi için uzman sistemler kullanılmaktadır. Uzman sistem ile birlikte kalite kontrol faaliyetleri daha etkin uygulanmakta ve kontrol süreleri minimize edilebilmektedir. Çalışmada, son on yılda kalite kontrol problemlerinin çözümü için geliştirilen uzman sistemler incelenmiştir.Öğe Konya sanayisinde endüstri mühendisliği tekniklerinin uygulanma etkinliğinin araştırılması ve endüstri mühendislerinin durumunun analizi(2004) Kaya, İhsan; Engin, Orhan; Nazik, Zümrütİşletmeler arası rekabetin hızla artması ve boyut değiştirmesi ile beraber firmaların ileri teknoloji kullanılmaları da zorunlu hale gelmiştir. Gelişen teknolojilerin işletmelerimizde etkin olarak kullanılması, verimlilik ve kalitenin iyileştirilmesi sürecinde, endüstri mühendisleri önemli görevler üstlenmektedirler. Bu çalışmada Konya Sanayisinde endüstri mühendislerinin çalışma etkinliklerinin araştırılmasına yönelik olarak bir anket çalışması yapılmıştır. Ankette, firmalara toplam 21 adet soru yöneltilmiştir. Çalışma; birinci, ikinci, üçüncü organize sanayi bölgeleri ile BÜSAN sanayinde toplam 99 işletmede yapılmıştır. Anket sonuçlarına göre, büyük çoğunluğunu KOBİ’lerin ve aile şirketlerinin oluşturduğu Konya Sanayisinde endüstri mühendislerinin etkin olarak istenilen düzeyde kullanılamadığı gözlenmiştir.Öğe Multiprocessor Task Scheduling in Multistage Hybrid Flow-Shops: A Parallel Greedy Algorithm Approach(ELSEVIER, 2010) Kahraman, Cengiz; Engin, Orhan; Kaya, İhsan; Öztürk, R. ElifHybrid flow shop scheduling problems have a special structure combining some elements of both the flow shop and the parallel machine scheduling problems. Multiprocessor task scheduling problem can be stated as finding a schedule for a general task graph to execute on a multiprocessor system so that the schedule length can be minimized. Hybrid Flow Shop Scheduling with Multiprocessor Task (HFSMT) problem is known to be NP-hard. In this study we present an effective parallel greedy algorithm to solve HFSMT problem. Parallel greedy algorithm (PGA) is applied by two phases iteratively, called destruction and construction. Four constructive heuristic methods are proposed to solve HFSMT problems. A preliminary test is performed to set the best values of control parameters, namely population size, subgroups number, and iteration number. The best values of control parameters and operators are determined by a full factorial experimental design using our PGA program. Computational results are compared with the earlier works of Oguz et al. [1,3], and Oguz [2]. The results indicate that the proposed parallel greedy algorithm approach is very effective in terms of reduced total completion time or makespan (C-max) for the attempted problems.Öğe A New Approach For Rule Estımatıon Of Fuzzy Inference System: A Case Study For Publıc Transport Maıntenance System(Selçuk Üniversitesi Mühendislik Fakültesi, 2020) Erdoğan, Melike; Kaya, İhsanThe increase in the population and the high amount of individual vehicle usage in the big cities brought traffic congestion and environmental problems. Additionally, these issues have also some negative effects on the public transport systems (PTSs). In this respect, the analysis of PTS is critical and important for both city life and people. It is possible that the failures in PTS can lead to many problems. Disruption of daily life, loss of lives and property or damage to the environment are only just a few of these problems. In this context, effective maintenance planning for PTSs is so crucial. In this study, the rule estimation for a fuzzy rule-based system (FRBS) which takes into consideration many factors for the maintenance planning of PTSs is discussed. The rule-based system for maintenance planning of Bus Rapid Transit System (BRT) will be highly effective for the prediction of failures for PTSs and the correct actions to be taken. Rule estimation for this system is aimed to increase the precision and flexibility of maintenance procedures. In this context, a model based on artificial neural networks (ANNs) has been developed and used in rule estimation for FRBS. For this aim, ten cases that are not in the rule base system are estimated and the results of the fuzzy rule-based maintenance inference system for the relevant inputs are revealed. Thus, it has been shown that ANNs can be used effectively for the analysis of rules that are not included in the current rule-based maintenance system.Öğe A new approach to define sample size at attributes control chart in multistage processes: An application in engine piston manufacturing process(ELSEVIER SCIENCE SA, 2007) Kaya, İhsan; Engin, OrhanDefining sample size in attribute control charts (ACC) is a problem, though it is one of the important techniques in process control. Solution of this problem is investigated in this paper. For this purpose, a model is developed in multistage processes and it is solved by genetic algorithms (GAs). The aim of the model is to determine the sample size for ACC. The model has two main goals: first is to determine the best acceptance probability and second is to provide the minimum cost in every stage. Formulations of this model are calculated based on acceptance sampling approach. When GA solves the model, two main parameters are determined for every stage. These are: sample size, n, and acceptance number, c. This approach is applied in an engine piston manufacturing firm and sample size, n, which is determined in model by GA, is suggested for ACC. (c) 2006 Elsevier B.V. All rights reserved.Öğe Personel Seçi?m Süreci?nde Uzman Si?stem Yaklaşımı ve Konya Büyükşehi?r Beledi?yesi?nde Bi?r Uygulama(Selçuk Üniversitesi, 2005) Kaya, İhsan; Gözen, ŞerifeBu çalışmada, yapay zekanın bir alt disiplini olan uzman sistemler (US) incelenmiş ve personel seçimine yönelik “Expert-Personel” adında bir uzman sistem geliştirilmiştir. Sistem, Konya Büyükşehir Belediyesinde, Belediye Başkan Yardımcısı, Çevre Koruma Daire Başkanı ve Çevre Şube Müdürü seçimine yönelik olarak uygulanmıştır. Bu birimler için iş analizi ve görev tanımları yapıldıktan sonra uygun bir iş başvuru formu oluşturulmuştur. Ayrıca adayların kişilik özelliklerini belirlemeye yönelik kişilik belirleme soruları oluşturulmuş ve en uygun adaylar “Expert-Personel” uzman sistemi yardımı ile belirlenmiştir.Öğe Renewable Energy System Selection Based on Computing With Words(Atlantis Press, 2010) Kahraman, Cengiz; Kaya, İhsan; Çebi, SelçukRenewable energy is the energy generated from natural resources such as sunlight, wind, rain, tides and geothermal heat. Turkey has a great renewable energy potential with its natural resources such as biomass, geothermal, hydropower, solar, and wind. Selection among energy alternatives is a multicriteria decision-making problem with conflicting and interactive criteria. In this paper, the best energy alternative of Turkey is determined by taking into interactions among criteria by using Choquet integral methodology.Öğe Trafik Kazalarının Önlenmesinde Hata Modu ve Etkileri Analizi (HMEA) Modeli(2004) Engin, Orhan; Kaya, İhsanTrafik kazaları, sebep oldukları maddi ve manevi kayıplar nedeni ile sürekli olarak toplumumuzun gündeminde yer edinen önemli problemlerden biridir. 1997, 1998 ve 1999 yıllarında sırası ile trafik kazalarında 5181, 4935 ve 4596 vatandaşımız hayatını kaybetmiştir. Trafik kazalarını azaltmak için bugüne kadar değişik kurum ve kuruluşlar tarafından farklı çalışmalar yapılmıştır. Son yıllarda yapılan yoğun çalışmalara rağmen hala kaza oranı istenilen düzeylere düşürülememiştir. Bu çalışmada, ülkemizde son on yılda karayollarında meydana gelen trafik kazaları incelenmiştir. Hata Modu ve Etkileri Analizi (HMEA) yardımı ile trafik kazalarını azaltmaya yönelik bir model önerilmiştir. Bu model ile kazaların azaltılmasının mümkün olacağı düşünülmektedir.Öğe A two phased fuzzy methodology for selection among municipal projects(VILNIUS GEDIMINAS TECH UNIV, 2015) Baysal, Mehmet Emin; Kaya, İhsan; Kahraman, Cengiz; Sarucan, Ahmet; Engin, OrhanA municipality improves the quality of community life through its projects and actions. However, project selection and prioritization by municipalities are highly complex processes. Therefore, multicriteria decision making (MCDM) methodologies are very suitable for determining the best alternative. Recently, some studies have concentrated on the selection of the best project alternatives. In this paper, a two phased fuzzy MCDM methodology is proposed for the selection among municipal projects. In the first phase, fuzzy TOPSIS method is used to select the main project group and then fuzzy AHP is used to select the best sub-municipal project. The application of the suggested methodology has been made at the central district municipality in Konya, Turkey.Öğe Yüksek Öğretimde Kalite İyileştirme Sürecinde Öğrenci Memnuniyetinin Ölçülmesine Yönelik Bir Araştırma(2007) Kaya, İhsan; Engin, OrhanYüksek öğretimde kalite iyileştirme sürecinde yapılacak olan iki temel faaliyet vardır. Bunlar, eğitim programlarının akreditasyonunu sağlamak ve eğitim sürecinin çıktılarının nitelik ve niceliğini artırmaktır. Yüksek öğretim kurumlarında temel çıktı, eğitim almış ve programı başarıyla tamamlamış mezunlardır. Bu çalışmada, yüksek öğretim sisteminin çıktılarından olan öğrencilerin, eğitim sürecinde almış oldukları derslerdeki memnuniyet düzeyinin belirlenmesi için bir araştırma yapılmıştır. Araştırma, lisans ve yüksek lisans düzeyinde ders alan öğrenciler üzerinde, toplam 6 ders için, 26 sorudan oluşan bir anket yardımı ile 269 öğrenciye sorular yöneltilerek gerçekleştirilmiştir. Elde edilen sonuçlar SPSS 12.0 paket programı yardımı ile değerlendirilerek öğrencilerin ortalama memnuniyet puanları çıkartılmıştır.
