Scopus İndeksli Yayınlar Koleksiyonu

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Wavelet Analyses of Oil Prices, USD Variations and Impact on Logistics
(American Institute of Physics, 2009) Melek, M.; Tokgozlu, A.; Asian, Z.
This paper is related with temporal variations of historical oil prices and Dollar and Euro in Turkey. Daily data based on OECD and Central Bank of Turkey records beginning from 1946 has been considered. IDcontinuous wavelets and wavelet packets analysis techniques have been applied on data. Wavelet techniques help to detect abrupt changing's, increasing and decreasing trends of data. Estimation of variables has been presented by using linear regression estimation techniques. The results of this study have been compared with the small and large scale effects. Transportation costs of track show a similar variation with fuel prices. The second part of the paper is related with estimation of imports, exports, costs, total number of vehicles and annual variations by considering temporal variation of oil prices and Dollar currency in Turkey. Wavelet techniques offer a user friendly methodology to interpret some local effects on increasing trend of imports and exports data. © 2009 American Institute of Pliysics.
Criticality Investigations for the Fixed Bed Nuclear Reactor Using Thorium Fuel Mixed with Plutonium or Minor Actinides
(Pergamon-Elsevier Science Ltd, 2009) Sahin, Suemer; Sahin, Haci Mehmet; Acir, Adem; Al-Kusayer, Tawfik Ahmed
Prospective fuels for a new reactor type, the so called fixed bed nuclear reactor (FBNR) are investigated with respect to reactor criticality. These are (1) low enriched uranium (LEU); (2) weapon grade plutonium + ThO2; (3) reactor grade plutonium + ThO2; and (4) minor actinides in the spent fuel of light water reactors (LWRs) + ThO2. Reactor grade plutonium and minor actinides are considered as highly radioactive and radio-toxic nuclear waste products so that one can expect that they will have negative fuel costs. The criticality calculations are conducted with SCALE5.1 using S-8-P-3 approximation in 238 neutron energy groups with 90 groups in thermal energy region. The study has shown that the reactor criticality has lower values with uranium fuel and increases passing to minor actinides, reactor grade plutonium and weapon grade plutonium. Using LEU, an enrichment grade of 9% has resulted with k(eff) = 1.2744. Mixed fuel with weapon grade plutonium made of 20% PuO2 + 80% ThO2 yields k(eff) = 1.2864. Whereas a mixed fuel with reactor grade plutonium made of 35% PuO2 + 65% ThO2 brings it to k(eff) = 1.267. Even the very hazardous nuclear waste of LWRs, namely minor actinides turn out to be high quality nuclear fuel due to the excellent neutron economy of FBNR. A relatively high reactor criticality of k(eff) = 1.2673 is achieved by 50% MAO(2) + 50% ThO2. The hazardous actinide nuclear waste products can be transmuted and utilized as fuel in situ. A further output of the study is the possibility of using thorium as breeding material in combination with these new alternative fuels. (C) 2009 Elsevier Ltd. All rights reserved.
Identifying Effective Variables Using Mutual Information and Building Predictive Models of Sulfur Dioxide Concentration with Support Vector Machines
(Foundation Environmental Protection & Research-FEPR, 2010) Sakar, C. Okan; Kursun, Olcay; Ozdemir, Huseyin; Demir, Goksel; Yalcin, Senay
Sulfur dioxide (SO2) is an issue of increasing public concern due to its recognized adverse effects on human health. Therefore, accurate SO2 prediction models are very important tools in developing public warning strategies. The goal of this study is to identify the relevance of meteorological and air pollutant variables using a classical and widely used measure of dependence, Shannon's Mutual Information (MI), and to build an accurate SO, prediction model using the relevant variables as inputs. Specifically, features ranked by MI measure are tested on how much joint predictive power they have of the target using a popular machine learning tool, support vector machines (SVM), and in comparison to multilayer perceptron (MLP), which is the most commonly used machine learning tool in previous studies for the prediction and analysis of air pollutants. It was found that the SVM model gave a higher correlation coefficient (r) and less root mean squared error (RMSE) than MLP for both test and validation sets. The predictive model used 6 input variables for both data sets as the relevant features for maximum SO, concentration prediction at time t+1, which are the average SO,, maximum SO2, outdoor temperature (OT), average nitrogen dioxide (NO2), average ozone (O-3), and average wind speed at time t. The results of this study indicate that MI can be used efficiently in determining the importance of input variables in the prediction of SO2 concentration and SVM is a popular machine learning tool well suited for use in air pollution modeling.
An Evaluation on Growth Potential of the Small and Medium Scale Enterprises (SME) in Turkish Furniture Industry
(Academic Journals, 2011) Aksu, Baki; Koc, K. Huseyin; Karademir, Devrim
With its increasingly expanding uses, the furniture industry has become a basic industrial sector in the world, especially in the developed countries, and it represents 2% of the total labour and 2% to 4% of the total production. The global foreign trade of furniture was around $174 billion in 2008. Though it has been growing fast, the furniture industry in Turkey is far from the level in the developed countries. In regard to the Turkish furniture industry, 99% of which consists of small and medium scale enterprises, just like all the other industries, few data are needed to be able to make accurate evaluations. The current conditions in the small and medium scale enterprises have been neatly described in this study. It tries to offer solutions to the problems, analyze the competition opportunities and shed light for future studies by eliminating inadequate data. It is the first study in the field since there has not been such research which covers the whole country except for the regional ones. Also, this project is supplementary to the studies carried out by the researchers on the large-scale enterprises, the whole industry is analyzed.
Feature Selection for the Prediction of Tropospheric Ozone Concentration Using a Wrapper Method
(Taylor & Francis Ltd, 2011) Sakar, C. Okan; Demir, Goksel; Kursun, Olcay; Ozdemir, Huseyin; Altay, Gokmen; Yalcin, Senay
High concentrations of ozone (O-3) in the lower troposphere increase global warming, and thus affect climatic conditions and human health. Especially in metropolitan cities like Istanbul, ozone level approximates to security levels that may threaten human health. Therefore, there are many research efforts on building accurate ozone prediction models to develop public warning strategies. The goal of this study is to construct a tropospheric (ground) ozone prediction model and analyze the effectiveness of air pollutant and meteorological variables in ozone prediction using artificial neural networks (ANNs). The air pollutant and meteorological variables used in ANN modeling are taken from monitoring stations located in Istanbul. The effectiveness of each input feature is determined by using backward elimination method which utilizes the constructed ANN model as an evaluation function. The obtained results point out that outdoor temperature (OT) and solar irradiation (Si) are the most important input features of meteorological variables, and total hydrocarbons (THC), nitrogen dioxide (NO2) and nitric oxide (NO) are those of air pollutant variables. The subset of parameters found by backward elimination feature selection method that provides the maximum prediction accuracy is obtained with six input features which are OT, SI, NO2, THC, NO, and sulfur dioxide (SO2) for both validation and test sets.
Production and Marketing Structure of Large Scale Forestry Products Industry Enterprises in Turkey
(2011) Aksu, B.; Hüseyin Koç, K.; Kurtoǧlu, A.
In Turkey, a country with 21.2 million ha of forest land, it is evident that the processed forest products have not been able to be developed to realize their potential with regards to the exports possibilities. It is obvious that the situation is to the disadvantage of Turkey in terms of the trading equilibrium when the exports and imports figures are examined. According to the results of the research carried out locally with respect to the Turkish Forest Products Industry, the emphasized problems emerge as the misapplication of incentives, the disability to catch up with the technological innovations, problems regarding raw material quality, undercapitalization, lack of qualified personnel, etc. By the help of this study which had been planned to cover the whole Turkish Forest Products Industry; the target is to reveal the structural situations of the large scale businesses in Turkey in the first few years of the 20th century, where modern management principles are assumed to be applied. The research had been finalized with the comments made upon the results of the questionnaires gathered through mostly faceto-face interviews with 415 large scale forest product firms where it was assumed that contemporary management principles and technological developments were applied relatively easier. As the questionnaire study was applied by the researchers themselves directly, it was also supported through observations. © 2011 Academic Journals.
Current State and Future of Shipping and Logistics
(Elsevier Science Bv, 2013) Tuna, Okan; Duru, Okan
A New Simulation Modelling Approach to Continuous Berth Allocation
(Taylor & Francis Ltd, 2013) Esmer, Soner; Yildiz, Gokalp; Tuna, Okan
Within the international supply chain and logistics system, ports are an important ring of the basic transport activities. Thus, any shortage in or lack of well-planned orders encountered in the port operation processes is most likely to affect the whole logistic system, which eventually will cause undesirable delays in deliveries. This study aims at developing a simulation modelling approach to continuous berth allocation in Port of Izmir Alsancak, which has continuous quayside with two main wharfs perpendicular to each other. The simulation models which serve to evaluate the proposed modelling approach have been developed in ARENA 10.0 Simulation Software. The results of the conducted computational experiments showed that the proposed modelling approach provides more accurate and realistic estimates of performance measures, such as average berth utilisation, average ship waiting time in a queue, and the average number of ships in queuing up to get container terminals.
Greening Logistics Centers: The Evolution of Industrial Buying Criteria Towards Green
(Elsevier Science Bv, 2013) Altuntas, Ceren; Tuna, Okan
The rapidly globalizing world trade requires longer supply chains with higher attention on the environmental effects of logistics activities. Latest international conventions related with environmental regulations reinforce governments and corporations to adhere to environmental protection precautions. An effort to decrease the negative environmental effects of logistics activity is the geographical concentration of logistics companies which are called logistics centers. This study aims to provide a green industrial service buying approach for the industrial customers of logistics centers. The study combines green purchasing literature with previousely developed environmental performance indicators (EPIs) and develops a green industrial buying model for logistics centers. The model provides a framework for potential residents of a logistics center and supports their industrial buying processes. The model also serves as an input for green industrial service design in a logistics center.
Consumer Boycotts as a Consequence of Consumerism
(IGI Global, 2014) Yener, D.
Consumerism is not a new concept for marketing, but it has grown in importance in the recent years. Researchers have studied consumerism from within different dimensions. However, its relationship with consumer boycotts has not been dealt with accurately. A consumer boycott is a type of consumer behaviour in which consumers collectively prefer not to use their purchasing power towards a product, brand, or all products of a country. Motivations for participating in boycotts differ in accordance with various factors such as consumers' beliefs, needs, or attitudes. Being boycotted by consumers may cause economic damage and decreased amount of reputation incurred in return. Organizing a boycott and calling for people's participation is much easier today than it used to be in the past. The Internet, especially social media, is an effective tool to inform people about boycotts and free of charge. However, that does not mean all the information circulating in the Internet is always of a reliable nature. In this chapter, the case of Danone in Turkey is thoroughly analyzed. Danone has been the target of Turkey's biggest Internet smear campaign which resulted in 26% shrinkage in its whole category sales. The aim of this chapter is to examine the case of Danone in Turkey as an example of the relationship between consumerism and consumer boycotts. The research for the case of Danone, which has a special importance in Turkey, uses secondary sources such as the daily newspapers, news pages in Internet, and Danone's web page. © 2014, IGI Global. All rights reserved.
Changing Masculinities and Femininities: A Comparative Analysis of Bridget Jones's Diary and Pride and Prejudice
(Peter Lang AG, 2015) Irmak, B.
The Prioritisation of Service Dimensions in Logistics Centres: A Fuzzy Quality Function Deployment Methodology
(Taylor & Francis Ltd, 2016) Vural, Ceren Altuntas; Tuna, Okan
This study takes a customer focus that prioritises the service-offering dimensions of logistics centres (LCs) by considering potential LC customer expectations. Applying a survey and a quality function deployment methodology to logistics service providers, the study explores, categorises and prioritises LC customer expectations and LC service characteristics. The results indicate that customer preferences mainly prioritise infrastructure, and warehouse and intermodal dimensions. However, when the cost dimension is included, higher utility values are delivered through soft service dimensions like value-added or standard services. LC investors or undertakers can use these results to guide their design of market offerings by using the same methodology to assess expectations in their target markets.
Efficacy of Organizational Learning and Social Capital in Online Communities of Practice: Dualities and Intersections
(IGI Global, 2017) Gürsoy S.; Yücelen M.
This chapter deals with the evolution of communities of practice by considering two key components which facilitate knowledge sharing: Organizational Learning and Social Capital. Dualities and intersections between the building blocks of these two components are investigated by discussing organizational learning in its explorative and exploitative forms, while considering social capital in its bridging and bonding forms. As a critical contemporary step of evolution, information and communication technologies are also elaborated in order to examine the impact of constant and instant tools on these facilitators of knowledge sharing. The study aims to derive proxies among these components of organizational learning and social capital in order to design an integrated framework that reflects the nature of online communities of practice. © 2018, IGI Global. All rights reserved.
Rapid First-Stage Tests of On-Ship Infection
(Springer Heidelberg, 2017) Jerome, Carlos; Howard, Lawrence A.; Uzel, Ezgi; Androulidakis, Jameela R.
Protection against on-ship infectious disease-whether due to mishap or to harmful purpose-faces special situational problems. Sometimes, when infection levels on board have reached threshold levels, emergency actions are required. Often, the most thorough strategies for responding to threat are not feasible. A rapid first-stage test (RFT) is a fast, minimally invasive procedure used to rule out from possible infection a large percentage of an infection-threatened group. Prevention and control of on-ship infection need to combine various interconnected tactics. When timely criterion tests are not possible, the medical team must adopt fast alternative measures. The methods used to summarize protection against on-ship infectious agents included a scientific literature review and a web search. The fields of the review were maritime, health, and technology sources. Special attention was paid to material dealing with risks and threats of on-ship penetration by infectious agents, on-ship infection prevalence thresholds, and rapid diagnostic screens. The Bayes rule and the law of large numbers were applied to the analysis, for large on-ship populations, of RFT indications of crossing of an infection prevalence threshold. The increasing risk of serious on-ship infection-either accidental or purposeful-calls for a multi-layered protection approach. RFTs are a key part of the outer layer of such a defense. Well-designed and well-administered RFTs provide several advantages for defense against on-ship infection: low-cost, non-invasive, fast, and focuses on a drastically smaller number of infection possibilities.
Is It Possible to Define Globalization in One Definition
(Springer, 2018) Kivilcim, Fulya
When approximately past 50 years of past experience considered; it can be defined as a period where bipolar system that dominates the world collapsed and instead, monopole system established and thus, depending on the development of communication and transportation technologies of capitalism, economic, political and cultural dimensions of the relations are changed and intensified among the societies. This period has led to the differentiation in the ways of perceiving the world and in the lifestyles of the societies. In this context, time-space perceptions of societies and the processes of meaning the world began to develop and differ. Thus, globalization emerged where the contrast between far-near is removed and dimension of cross-border interaction developed and the nation states which are important actors of the past periods left their power to local cities and regions. As it can be seen from this, the past time has been subject to a social transformation. Therefore, the concept of globalization has been formed where the contrast between far-near is removed and dimension of cross-border interaction developed. Definition of the concept of globalization in its simplest form is; convergence of countries and people by ignoring the distance between the distant and nearby places and having economic and social interaction with each other. An important element in the definition of globalization is; decisions taken at the local level and adopted policies has the power to pass other nations and influence them. Especially when the last three decades considered; the mankind history felt the power of globalization and it will continue to be felt more effective in the coming years due to the circumstances of the current period. Within this rapid change and development process; supranational organizations that are competitive in global market conditions have taken their place in the process as global actors with their areas of activity they are dominant, organizational structures, understanding of management, forms of competition and capital structures they have. In this study; access to the definition of globalization concept and its evaluation for the last five decades targeted within the framework of approaches to the concept of globalization by emphasizing rapid and radical change.
Territorial Stigmatization as a Process of Bio Politics: The Case of Hacihusrev
(Middle East Technical University, 2018) Yilgur, Egemen
This paper discusses the stigmatization of Hacihusrev Neighborhood as a criminal area utilizing concepts borrowed from Agamben's understanding of bio-politics and the territorial stigmatization of Wacquant. The stigmatization of Hacihusrev Neighborhood, where peripatetic Roma groups as homo sacers reduced to 'bare life' had settled, occurred by means of the popular narrative produced by the mass media of the era. The manipulative representation of the social transformation occurring in the neighborhood turned it into a place where the exception became the rule. There are two different late-peripatetic groups in Hacihusrev Neighborhood. Roma tobacco workers, who came to the neighborhood during the Turk-Greek Population Exchange of 1923-24, had had an intense experience of waged occupation due to massive labor demand in the geography from which they came, late Ottoman Macedonia. Roma tobacco workers thus became a part of a mainstream social process, participating in waged occupations and in the leftist politics of the era and so pushed the limits of the area in which the peripatetics had been placed historically by means of legal pretexts and social relations. The other late-peripatetics, who came to the neighborhood mainly after 1950 from Bursa and its surroundings, had almost no opportunity for waged occupations. Excluded from the mainstream social relations, they were forced to be a part of criminal activities. Popular crime narratives in the media in the 1960s increased the visibility of the late-peripatetics from Bursa and rendered the Roma tobacco workers invisible. Thus, Hacihusrev Neighborhood was perceived as the natural habitat of criminal suspects. The stigma that surrounded the neighborhood in this process imprisoned the Roma tobacco workers in the very area where they had partly escaped before and their historical distinctiveness as a productive force became less certain. This paper aims to reveal the mechanisms of the stigmatization process through content analysis of the related news published between 1930-2009 in Milliyet and Cumhuriyet newspapers, the review of relevant literature, and the data collected during field research.
Teneke Mahallesi in the Late Ottoman Capital: A Socio-Spatial Ground for the Co-Inhabitation of Roma Immigrants and the Local Poor
(Liverpool Univ Press, 2018) Yilgur, Egemen
The term teneke mahalle, literally "tin can neighbourhood," has been widely used since the Russo-Turkish War of 1877-1878 to describe a specific kind of urban fabrication, possibly poor and physically dilapidated, but also the sole, cheapest, and undoubtedly creative solution for the urgent housing needs of the poorest segments of the urban population. Even though these neighbourhoods were initially built at least partly by Muslim refugees, the Roma Mohadjirs,(1) teneke mahalles also welcomed other poor members of society seeking informal, easily accessible, and safe housing in late Ottoman Istanbul. This study discusses the role of the Roma in the formation of teneke mahalles, and the socio-historical dynamics that directed the non-Roma poor to co-inhabitation with Roma in these teneke mahalles, and outlines their socio-economic and cultural profile from various respects on the basis of the two oldest examples of this socio-spatial and perceptual phenomenon in Istanbul.
Competitive Advantage and Clusters: What Can We Learn from Nine Turkish Clusters
(Boğaziçi University bjournal@boun.edu.tr, 2018) Mutlucan, N.Ç.
Many researchers have studied the ability of clusters to promote innovation, regional economic development, and national prosperity; however, these studies had been mostly conducted at the cluster level, not at the firm level. This study attempts to bring the cluster discourse back to the firm by answering the following research question: how do firms create and defend competitive advantages through clusters? The theoretical model presumes positive relationships between several constructs and firm performance, namely, business ties, support ties, entrepreneurial orientation and strategic learning capability. Furthermore, these relationships are supposed to be enhanced by the moderating effect of the cluster construct. The Partial Least Squares path model analysis of data from 160 surveyed firms located in nine Turkish clusters revealed that only entrepreneurial orientation and support ties contributed significantly and positively to firm performance. © 2018 The Trustees of Indiana University. All rights reserved.
Introduction of a Spatio-Temporal Mapping Based POE Method for Outdoor Spaces: Suburban University Campus as a Case Study
(Pergamon-Elsevier Science Ltd, 2018) Gocer, Ozgur; Gocer, Kenan; Basol, Altug M.; Kirac, M. Furkan; Ozbil, Ayse; Bakovic, Mujesira; Ozcan, Baris
Outdoor spaces are important to sustainable cities because they establish a common identity for social life by improving quality of urban living. The relation between outdoor spaces and building groups, competency, use period, and interaction of micro-climatic factors are needed to be investigated from a holistic approach. Unfortunately, the limited and narrow scoped POE studies on outdoor spaces make an overall assessment without causality relation. Other existing studies in outdoor spaces are mostly grouped under the headings such as; user satisfaction, space syntax and behavioral mapping, and biometeorological assessments. The intention of this paper is to introduce a new post-occupancy evaluation (POE) method integrates these studies focusing on various problems in outdoor spaces using spatio-temporal mapping. The comprehensive methodology applied in this research attempted to overcome some of the shortcomings of related studies by conducting a longitudinal study (during a year, as opposed to a few days) and also by objectively analyzing the associations of user behavior and physical attributes as well as the configurational properties of the campus layout. With this method, outdoor spaces can be evaluated in the context of the interaction between the physical environment and its users' behavior and activities, level of satisfaction and perceptions of comfort. The method has been applied on a suburban university campus in Istanbul, Turkey. The main courtyard of the campus has been subjected for map creation and result discussions.
Efficient Shared Path Protection Routing for Survivable Optical WDM Networks
(Institute of Electrical and Electronics Engineers Inc., 2019) Erkan, O.F.; Erkan, O.
Sustainability of the service continuity provided in the optical wavelength division multiplexing (WDM) networks with dynamic traffic environment requires effective protection schemes in the connections. Various approaches have been introduced for path protection and wavelength assignment to ensure survivability in WDM networks. In this paper, we propose a two-step algorithm to designate dedicated-path and shared-path protection schemes. The heuristic-based algorithm utilizes a global labeling which considers service time and line protection information. Thus, the algorithm aims to increase resource utilization by improving the efficiency of shared path protection. The proposed algorithm is applied to USNET and EuropeNet networks and performance analysis in terms of blocking probability and resource utilization is carried out. © 2019 IEEE.

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