Tufan Demirel

Multi-criteria warehouse location selection using Choquet integral

The location of a warehouse is generally one of the most important and strategic decision in the optimization of logistic systems. Warehouse location is a long-term decision and is influenced by many quantitative and qualitative factors. Among the main criteria taken into account in this paper, some are costs, labor characteristics, infrastructure, and markets. This paper also includes some sub-criteria because of the hierarchical structure of the problem, like tax incentives and tax structures, availability of labor force, quality and reliability of modes of transportation, and proximity to customers. The conventional approaches to warehouse location selection problem tend to be less effective in dealing with the imprecise or vague nature of the linguistic assessment. Under many situations, the values of the qualitative criteria are often imprecisely defined for the decision-makers. Choquet integral is a suitable multi-criteria method to capture this imprecise or vague nature. This paper shows a successful application of multi-criteria Choquet integral to a real warehouse location selection problem of a big Turkish logistic firm.

Prioritization of e-Government strategies using a SWOT-AHP analysis: the case of Turkey

The e-Government agenda is being pursued throughout the world to one degree or another, but it has added significance in Central Europe. The region is just beginning to emerge from a period of far-reaching political and economic transformation following the collapse of repressive communist systems. For these countries, e-Government is more than simply a new channel of delivering services; it offers an opportunity to achieve a quantum leap in transparency and efficiency of administration, which the regions leaders have promised their citizens since the early 1990s. Turkey is currently working hard to catch this opportunity. Turkish Government has initiated the Urgent Action Plan in December 2002 to remedy long-lasting economic problems and to improve social and well-being of the country. One of the basic components of this plan is ‘e-Transformation Turkey Project’ which aims to carry Turkey into Information society. One of the two purposes of this study is to define and to prioritize the strengths, weaknesses, opportunities, and threats (SWOT) groups and their subfactors for e-Government in Turkey. The other purpose is to determine and to evaluate the alternative strategies for e-Government applications at the national level in Turkey. We use the SWOT approach in combination with analytic hierarchy process (AHP) to achieve this task. The strategies have been prioritized and sensitivity analyses of the obtained results have been made using a software.

A SWOT-AHP Application Using Fuzzy Concept: E-Government in Turkey

E-government refers to the delivery of information and services online via the Internet. Many governmental units across the world have embraced the digital revolution and placed a wide range of materials on the web, from publications to databases. The purpose of this study is to evaluate and to determine the alternative strategies for e-government applications in Turkey. We use the strengths, weaknesses, opportunities, and threats (SWOT) approach in combination with the crisp and fuzzy analytic hierarchy process (AHP) to achieve this task. The strategies have been prioritized by using both methods comparatively and sensitivity analyses of the obtained results have been presented.

Fuzzy Analytic Hierarchy Process and its Application

The analytic hierarchy process (AHP) is one of the most widely-used multiattribute decision-making methods. In this section we overview the fuzzy AHP methods existing in the literature. We present the four different approaches of fuzzy AHP methods by giving numerical examples.

A fuzzy assessment framework to select among transportation investment projects in Turkey

Selecting the best transportation investment project (TIP) is often a difficult task, since many social, environmental and economic criteria have to be considered simultaneously. Evaluating a set of different projects, especially the best set of alternatives, portfolios, is even more complex. Pursuing the goal of selecting the best TIP portfolio, we propose a fuzzy assessment method to aid the selection process of a multi-criterion project by utilizing the concept of entropy and interval normalization procedure in a fuzzy analytic hierarchy process (F-AHP). Then, regarding this informative phase, we propose a fuzzy linear programming model to select the best TIP portfolio under uncertain cost pressure. A real case study is conducted to illustrate the efficiency of the proposed method.

Multi-Criteria Evaluation of Land Cover Policies Using Fuzzy AHP and Fuzzy ANP: The Case of Turkey

ABSTRACT Land cover and use strategies have gained importance with decreases in per capita availability of land worldwide. The food deficit is increasing as a result of increases in the population, more so in developing and under-developed countries. A multi-criteria decision-making method using fuzzy Analytic Hierarchy Process (AHP) and fuzzy Analytic Network Process (ANP) for the evaluation of alternate land cover policies under various confidence levels of the decision-makers has been proposed. Computations have been done by using fuzzy AHP in terms of reflection ambiguity and uncertainty of the real world. Comparisons were made with the results obtained by using fuzzy ANP.

Risk-Based Evaluation of Turkish Agricultural Strategies using Fuzzy AHP and Fuzzy ANP

ABSTRACT In this article, we propose a model for selection of an agricultural strategy for Turkey by using fuzzy analytical hierarchy process (AHP) and analytical network process (ANP) based on linguistic terms. Fuzzy AHP-based methodology will be discussed to tackle the different decision criteria such as risk factors, ecological structure, socioeconomic structure, and technological structure involved in the selection of an agricultural strategy for Turkey and ANP will represent an effective tool for providing a suitable solution for managers and government administrators of this case. The linguistic levels of comparisons produced by the experts for each comparison are tapped in the form of triangular fuzzy numbers in order to construct fuzzy pairwise comparison matrices. The implementation of the system is demonstrated by a problem having four stages of hierarchy that contains 4 criteria and 15 sub-criteria.

Multi-criteria Evaluation to Prioritize the Organic Farm Site Using Extended Vikor Method

The aim of the present study is to prioritize the sites in Turkey that organic farming is being practiced through extended VIKOR. The problem was considered as a multi-criteria decision making problem. Among the main criteria taken into account in this paper, some are ecological, technological, economic, and risk factors with the impacts of infrastructure and local community. Then, the problem was solved by using extended VIKOR method and the prioritization of the organic farming sites was determined.

Effects of Inflation under Fuzziness and Some Applications

This chapter presents the ways of incorporating the parameter fuzzy inflation to the engineering economy analyses. Inflation is a financial parameter difficult to estimate. The fuzzy set theory gives us the possibility of converting linguistic expressions about inflation estimates to numerical values. In the chapter, discounted cash flow techniques including these fuzzy expressions and some numerical examples are given. The obtained results show the interval of the worst and the best possible outcomes when fuzzy inflation rates are taken into account.

Determining the Suitability of Alternative Locations for Syrian Refugee Camps in Turkey using Extended VIKOR

As the conflict in Syria deepens, the number of displaced Syrians crossing the border into Turkey has dramatically risen. According to the United Nations Refugee Agency (UNHCR), there are 2,748,367 registered Syrian refugees in Turkey as of May 2016. On the other hand, the population of Syrian refugees in camps is estimated to be around 217,000 people, due to the lack of capacity. The demand for camps has surpassed the available spaces in the camps.On 22 October 2014, the Government of Turkey issued a regulation on protection, defining a status that refugees from Syria seeking international protection are admitted to Turkey and will not be sent back to Syria against his or her will. In addition, on 18 March 2016, EU and Turkey agreed to end the irregular migration from Turkey to the EU and replace it instead with legal channels of resettlement of refugees to the European Union. These two conditions lead to an urgent necessity to organize the situation of Syrian refugees in Turkey, who cannot be seen as temporary. For the settlement of Syrian refugees to Turkey, an adaptation process is necessary. Due to the lack of capacity and poor conditions in the current camps, new camps must be built. The aim of the present study is to analyze the alternative locations for building new refugee camps in Turkey, regarding the affecting factors, through Extended VIKOR.The problem is considered as a multi-criteria decision making problem. The factors affecting the suitability for new camps; mainly grouped as political, economic, demographic, and sociocultural; are taken into account as the main criteria. Alternatives are selected among a set of different locations that are already considered by the Turkish government and the UNHCR.The model developed uses experts? views to quantify the effects of the factors for each location with the aid of fuzzy approach. The problem is then solved using Extended VIKOR and the locations for new Syrian Refugee Camps in Turkey are evaluated. Afterwards, a sensitivity analysis is applied to analyze system?s behavior to changes.