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Öğe Analysis of patent documents with weighted association rules(Elsevier Inc., 2015) Altuntas S.; Dereli T.; Kusiak A.Analysis of relationship among various technologies may result in technology maximizing profits. Weighted association rules are proposed to determine dependencies across technologies. The proposed approach recognizes uneven importance of patents and technology class in terms of their technological impact and commercial significance. The proposed analysis approach is illustrated with a case study. © 2014 Elsevier Inc.Öğe A causal and effect model for knowledge flow analysis among firms(Computers and Industrial Engineering, 2014) Dereli T.; Altuntas S.Examination of the relations among firms with respect to knowledge flows is essential for sustainable development and creative economy in global competition as well as for governments, investors and decision makers. Knowing the causal relations among firms provides answers to questions such as: (1) which firms have strong associations? (2) which firms are in the cause group and (3) which firms are in the effect group? The knowledge flow among firms shows the relations among firms directly. Patent citation analysis is extensively conducted to measure the knowledge flow in the literature. The decision making trial and evaluation laboratory (DEMATEL) method is also extensively used to construct causal relations among variables. In this study, the DEMATEL method based patent citation analysis is utilized to construct causal relations among firms. An illustrative example is presented to find relations among firms which operate business method technologies. The results of the example show that the DEMATEL based patent citation analysis can be performed to construct causal relations among firms.Öğe An evaluation index system for prediction of technology commercialization of investment projects(2012) Altuntas S.; Dereli T.Technology commercialization is a hot topic for governments, entrepreneurs, marketers and researchers due to the fact that its measurement is quite important for decision makers to know their possible growth potential in a dynamic and competitive environment. Having a high technology commercialization potential for invested technology is the engine of national development and growth as well. However, the measuring technology commercialization of any investment project is difficult because of the fact that there are some difficult questions, which should be answered exactly. For example, 'how will the technology be marketed in own sector?' 'Which factors are important for considered technology and affect technology commercialization?' 'Which scientific methods should be used for predication of technology commercialization potential properly?' and so on. The purpose of this study is to develop an evaluation index system for predicting the technology commercialization of the investment project. At the beginning of this study, a review of the technology commercialization literature is performed to address the factors which affect technology commercialization. Then, the evaluation index system proposed in this study can be used to prioritize investment projects in terms of their technology commercialization potential. It uses fuzzy multi-criteria decision making (FMCDM) methods and beta distribution to estimate the mean of each factor. Next, a solution approach to find an index value which shows technology commercialization potential is proposed. The proposed approach firstly finds interrelationships among the factors under fuzziness by using the fuzzy decision-making trial and evaluation laboratory (Fuzzy DEMATEL) method. Subsequently, it makes use of the fuzzy Analytic Network Process (Fuzzy ANP) method to determine the weights of factors. The values of all factors are then predicted by experts and assessed by beta distribution to estimate the mean of each factor with respect to the experts' opinion. Finally, a case study is presented to demonstrate the usefulness of the proposed approach. © 2012 - IOS Press and the authors. All rights reserved.Öğe A fuzzy DEMATEL-based solution approach for facility layout problem: A case study(Springer-Verlag London Ltd, 2014) Altuntas S.; Selim H.; Dereli T.Facility layout in production systems is a difficult activity since both qualitative and quantitative factors affect the location decision, and also influence and causal relationship between these factors should be determined for a better location. In this respect, it is demonstrated in this study that fuzzy decision-making trial and evaluation laboratory (fuzzy DEMATEL) method can effectively be used in handling facility layout problems in practice. The qualitative factors that described by linguistic terms can be taken into account through fuzzy structure of the method. Considering this, a fuzzy DEMATEL-based solution approach for facility layout problem is proposed in this study. The proposed approach takes into account both qualitative and quantitative location factors. To address the need in practice, six important location factors are considered in this study. These are material flow, information flow, personnel flow, equipment flow, environmental condition, and supervision of personnel. This study differs from the previous works in that it applies fuzzy DEMATEL method to facility layout problem. To explore the viability of the proposed approach, a real world problem in a machinery industry firm is handled. © 2014 Springer-Verlag London.Öğe Fuzzy weighted association rule based solution approaches to facility layout problem in cellular manufacturing system(2013) Altuntas S.; Dereli T.; Selim H.This study aims to propose new solution approaches based on fuzzy weighted association rules for facility layout problem in a cellular manufacturing system. The facility layout problem under concern has two important aspects, namely; fuzzy product route and fuzzy machine weight. Number of machine types as well as the number of machines in each type is determined in order to define a fuzzy product route. A fuzzy set is then assigned for each machine type to match them with appropriate products. Alternative routes for each product and machine weights are defined by fuzzy functions. Market demand is also used to assign weights to the machines. Three solution approaches, namely fuzzy weighted association rule mining (FWARM), Gyenesei's weighted quantitative association rules (WQAR) and normalised weighted association rule mining (NWARM) based approaches, are proposed in this study. To the authors' best knowledge, this is the first attempt which considers fuzzy weighted association rule-based data mining approaches to the facility layout problem. An illustrative example is presented to demonstrate the usefulness of the proposed approaches. Copyright © 2013 Inderscience Enterprises Ltd.Öğe Multi-criteria decision making methods based weighted SERVQUAL scales to measure perceived service quality in hospitals: A case study from Turkey(2012) Altuntas S.; Dereli T.; Yilmaz M.K.The main objectives of this study are to: (i) measure hospital service quality by using analytic hierarchy process (AHP) and analytic network process (ANP) as a multi-criteria decision making method to acquire the relationship and the level of the importance among service quality measurement (SERVQUAL) dimension; (ii) find perceived service quality with respect to different hospital classes (A, B and C) in Istanbul, Turkey; (iii) compare AHP- and ANP-based weighted SERVQUAL scales with the unweighted SERVQUAL scale for public hospital service quality in terms of different hospital classes (A-B and C). First, four hospitals are selected randomly for each class and then, a questionnaire based on the SERVQUAL model is conducted for each class to measure perceived service quality with respect to five major criteria, namely tangible, reliability, responsiveness, assurance and empathy, from patients' viewpoints at hospitals. Next, the second questionnaire based on ANP is developed to evaluate the importance of criteria and construct the relations among the criteria. The study sample contains 281 outpatients totally. Three important findings are obtained in this study. First, there is a significant difference among different hospital classes regarding the perceived service quality. Second, according to the patients, the most important service quality dimensions are empathy, the knowledge of employees, sympathetic and reassuring employees, services provided at the time promised to do so, and safe feeling of patients in interactions with hospital employees. Thirdly, the, perceived service quality through the AHP- and ANP-based SERVQUAL scale is higher than that with the unweighted SERVQUAL scale. © 2012 Copyright Taylor and Francis Group, LLC.Öğe A novel approach based on DEMATEL method and patent citation analysis for prioritizing a portfolio of investment projects(Elsevier Ltd, 2015) Altuntas S.; Dereli T.The aim of this article is to propose a novel approach based on a method called Decision-Making Trial and Evaluation Laboratory (DEMATEL) and patent citation analysis for prioritizing the portfolio of investment projects. The proposed approach reflects the government's perspective and takes into account two important prioritization criteria. They are: (i) the decreasing rate of foreign trade deficits in the country and (ii) the potential to attract new investments which are not considered in the literature before. A case study from Turkey is presented to demonstrate the benefits of the proposed approach. The findings show that the proposed approach can be used easily and efficiently to prioritize investment projects among available project proposals. © 2014 Elsevier Ltd. All rights reserved.
