Fakülteler

Permanent URI for this communityhttps://hdl.handle.net/20.500.12469/28

Browse

Now showing 1 - 20 of 371

Citation - WoS: 3
Citation - Scopus: 4
A 2020 Vision for the Black Sea Region: the Commission on the Black Sea Proposes
(Routledge Journals Taylor & Francis Ltd, 2010) Aydın, Mustafa; Triantaphyllou, Dimitrios
The Black Sea region is coming into its own although it is at times a contested and dangerous neighbourhood. Despite heightened interest in the region its real priorities and needs are still being largely ignored by insiders and outsiders alike. What is needed are regional solutions for regional problems. The authors present the key findings and recommendations of the Commission on the Black Sea a civil society initiative comprising a number of current and former policy-makers scholars and practitioners both from within the region and from outside with the purpose of contributing to a joint vision and a common strategy for the Black Sea region by developing new knowledge in areas of key concern.
Citation - WoS: 5
Citation - Scopus: 6
(3+3+2) Warped-Like Product Manifolds With Spin(7) Holonomy
(Elsevier Science Bv, 2011) Uğuz, Selman; Bilge, Ayşe Hümeyra
We consider a generalization of eight-dimensional multiply warped product manifolds as a special warped product by allowing the fiber metric to be non-block diagonal. We define this special warped product as a (3 + 3 + 2) warped-like manifold of the form M = F x B. where the base B is a two-dimensional Riemannian manifold and the fibre F is of the form F = F-1 x F-2 where the F-i(i = 1 2) are Riemannian 3-manifolds. We prove that the connection on M is completely determined by the requirement that the Bonan 4-form given in the work of Yasui and Ootsuka [Y. Yasui and T. Ootsuka Spin(7) holonomy manifold and superconnection Class. Quantum Gravity 18(2001)807-816] be closed. Assuming that the F-i are complete connected and simply connected it follows that they are isometric to S-3 with constant curvature k > 0 and the Yasui-Ootsuka solution is unique in the class of (3 + 3 + 2) warped-like product metrics admitting a specific Spin(7) structure. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
Citation - WoS: 22
Citation - Scopus: 25
Absolute Configuration and Biological Profile of Pyrazoline Enantiomers as Mao Inhibitory Activity
(Wiley, 2019) Goksen, Umut Salgin; Sarıgül, Sevgi; Bultinck, Patrick; Herrebout, Wouter; Doğan, İlknur; Yelekçi, Kemal; Uçar, Gülberk; Kelekçi, Nesrin Gökhan
A new racemic pyrazoline derivative was synthesized and resolved to its enantiomers using analytic and semipreparative high-pressure liquid chromatography. The absolute configuration of both fractions was established using vibrational circular dichroism. The in vitro monoamine oxidase (MAO) inhibitory profiles were evaluated for the racemate and both enantiomers separately for the two isoforms of the enzyme. The racemic compound and both enantiomers were found to inhibit hMAO-A selectively and competitively. In particular the R enantiomer was detected as an exceptionally potent and a selective MAO-A inhibitor (K-i = 0.85 x 10(-3) +/- 0.05 x 10(-3) mu M and SI: 2.35 x 10(-5)) whereas S was determined as poorer compound than R in terms of K-i and SI (0.184 +/- 0.007 and 0.001). The selectivity of the enantiomers was explained by molecular modeling docking studies based on the PDB enzymatic models of MAO isoforms.
Citation - WoS: 1
Citation - Scopus: 1
Across Dimensions: Two- and Three-Dimensional Phase Transitions From the Iterative Renormalization-Group Theory of Chains
(2020) Keçoğlu, İbrahim; Berker, A. Nihat
Sharp two- and three-dimensional phase transitional magnetization curves are obtained by an iterative renormalization-group coupling of Ising chains, which are solved exactly. The chains by themselves do not have a phase transition or nonzero magnetization, but the method reflects crossover from temperaturelike to fieldlike renormalization-group flows as the mechanism for the higher-dimensional phase transitions. The magnetization of each chain acts, via the interaction constant, as a magnetic field on its neighboring chains, thus entering its renormalization-group calculation. The method is highly flexible for wide application.
Citation - WoS: 3
Citation - Scopus: 5
Activist Communication Design on Social Media: the Case of Online Solidarity Against Forced Islamic Lifestyle
(Sage Publications, 2021) Arda Güney, Talat Balca; Akdemir, Ayşegül
This article explores the relationship between connective and collective group identity through the example of “You Won’t Walk Alone,” a social media platform of solidarity for women suffering from the pressures of Islamic dress code in Turkey. While Turkey has a long history of conservative women’s initiatives against secular institutional code and of secular women against Islamic and misogynist social reactions, the social media platform You Won’t Walk Alone (Yalnız Yürümeyeceksin) illustrates a striking self-reflexivity of women mobilizing against their very own conservative communities. The research is based on multimodal content analysis of the posts including both images and texts in order to grasp to what extent social media offers a genuine public space for anonymous participants of the online platform as opposed to digitally networked movements which primarily reflect personalized agency. We analyze how connective and collective group identity can be correlated in this case in which online participants build solidarity by sharing content anonymously. Hence, this article questions the ways in which activist design of communication affects and shapes activism through this case study.
Citation - WoS: 6
Citation - Scopus: 10
An Adaptive Affinity Matrix Optimization for Locality Preserving Projection Via Heuristic Methods for Hyperspectral Image Analysis
(IEEE-Inst Electrıcal Electronıcs Engıneers Inc, 2019) Taşkın, Gülşen; Ceylan, Oğuzhan
Locality preserving projection (LPP) has been often used as a dimensionality reduction tool for hyperspectral image analysis especially in the context of classification since it provides a projection matrix for embedding test samples to low dimensional space. However, the performance of LPP heavily depends on the optimization of two parameters of the graph affinity matrix: k-nearest neighbor and heat kernel width, when one considers an isotropic kernel. These two parameters might be optimally chosen simply based on a grid search. In case of using a generalized heat kernel where each feature is separately weighted by a kernel width, the number of parameters that need to be optimized is related to the number of features of the dataset, which might not be very easy to tune. Therefore, in this article, we propose to use heuristic methods, including genetic algorithm (GA), harmony search (HS), and particle swarm optimization (PSO), to explore the effects of the heat kernel parameters aiming to analyze the embedding quality of LPP's projection in terms of various aspects, including 1-NN classification accuracy, locality preserving power, and quality of the graph affinity matrix. The results obtained with the experiments on three hyperspectral datasets show that HS performs better than GA and PSO in optimizing the parameters of the affinity matrix, and the generalized heat kernel achieves better performance than the isotropic kernel. Additionally, a feature selection application is performed by using the kernel width of the generalized heat kernel for each heuristic method. The results show that very promising results are obtained in comparison with the state-of-the-art feature selection methods.
Citation - WoS: 21
Citation - Scopus: 31
Adoption of Mobile Health Apps in Dietetic Practice: Case Study of Diyetkolik
(Jmır Publıcatıons, Inc, 130 Queens Quay E, 2020) Akdur, Görkem; Aydın, Mehmet Nafiz; Akdur, Gizdem
Background: Dietetics mobile health apps provide lifestyle tracking and support on demand. Mobile health has become a new trend for health service providers through which they have been shifting their services from clinical consultations to online apps. These apps usually offer basic features at no cost and charge a premium for advanced features. Although diet apps are now more common and have a larger user base, in general, there is a gap in literature addressing why users intend to use diet apps. We used Diyetkolik, Turkey's most widely used online dietetics platform for 7 years, as a case study to understand the behavioral intentions of users. Objective: The aim of this study was to investigate the factors that influence the behavioral intentions of users to adopt and use mobile health apps. We used the Technology Acceptance Model and extended it by exploring other factors such as price-value, perceived risk, and trust factors in order to assess the technology acceptance of users. Methods: We conducted quantitative research on the Diyetkolik app users by using random sampling. Valid data samples gathered from 658 app users were analyzed statistically by applying structural equation modeling. Results: Statistical findings suggested that perceived usefulness (P<.001), perceived ease of use (P<.001), trust (P<.001), and price-value (P<.001) had significant relationships with behavioral intention to use. However, no relationship between perceived risk and behavioral intention was found (P=.99). Additionally, there was no statistical significance for age (P=.09), gender (P=.98), or previous app use experience (P=.14) on the intention to use the app. Conclusions: This research is an invaluable addition to Technology Acceptance Model literature. The results indicated that 2 external factors (trust and price-value) in addition to Technology Acceptance Model factors showed statistical relevance with behavioral intention to use and improved our understanding of user acceptance of a mobile health app. The third external factor (perceived risk) did not show any statistical relevance regarding behavioral intention to use. Most users of the Diyetkolik dietetics app were hesitant in purchasing dietitian services online. Users should be frequently reassured about the security of the platform and the authenticity of the platform's dietitians to ensure that users' interactions with the dietitians are based on trust for the platform and the brand.
Citation - WoS: 18
Citation - Scopus: 25
After the Crimean Crisis: Towards a Greater Russian Maritime Power in the Black Sea
(Routledge Journals Taylor & Francis Ltd, 2014) Delanoe, Igor
The modernization of the Black Sea Fleet currently underway is believed to be one of the most ambitious parts of the Russian State Arms Procurement programme 2011-2020. Up to 18 units are being built and are expected to be commissioned in the Russian Black Sea Fleet by 2020 while new infrastructures are being developed. However Russia's annexation of Crimea in March 2014 has overthrown the Black Sea maritime context. It is likely to give substantial impetus to Russian naval plans in the Black Sea and by extension to sustain Moscow's resumption of naval activity in the Mediterranean. Yet whereas Russia's maritime power has been dramatically enhanced due to the takeover of Crimea Moscow's naval power in the Black Sea and in the Mediterranean remains challenged by a set of qualitative factors. Beyond the Ukrainian crisis has demonstrated the inability of the European Union to manage its Black Sea environment as well as it has highlighted the United States waning influence and interests in the region.
Citation - WoS: 41
Citation - Scopus: 50
Alevis and Alevism in the Changing Context of Turkish Politics: the Justice and Development Party's Alevi Opening
(Routledge Journals Taylor & Francis Ltd, 2011) Soner, Bayram Ali; Toktaş, Şule
The Justice and Development Party (JDP Adalet ve Kalkinma Partisi) has launched a rapprochement policy toward the Alevis. The JDP's Alevi Opening has presented a unique case in Turkey's latest identity politics not only because Alevi claims for the first time came to be involved in political processes for official recognition and accommodation but also because the process was handled by a political party which is regarded to have retained Islamist roots in Sunni interpretation. This article explores the JDP's Alevi Opening process and tries to explain the motivations behind the party's decision to incorporate the Alevi question in its political agenda. What is more the debate that the opening has caused is also under scrutiny with the positions and arguments held by the actors and the agencies involved in the process e. g. the Alevis (the secularist and the conservative wings) the General Directorate of Religious Affairs the National Security Council the JDP leadership and the Islamist intellectuals.
Citation - WoS: 6
Citation - Scopus: 6
Alone but Together Autonomous but Related: Self-Construal Effects on Happiness in Social Experiences
(Wiley, 2018) Merdin-Uygur, Ezgi; Hesapci, Ozlem
Communal tables and open workspaces have become popular servicescapes that is contemporary spaces for experiencing dining or working alone but together. Previous research demonstrates that experiencing with close others (e.g. with friends or family) increases happiness and satisfaction but experiences shared with strangers in contexts such as communal tables or workshops have not yet been thoroughly analyzed. Addressing this research gap from a social-psychological perspective we suggest that even though individuals are generally happier when they share experiences with loved ones self-construal plays a moderating role in the relationship. Individuals with high autonomy and high relatedness do not anticipate greater happiness from experiences shared with friends than with those shared with strangers. Three experimental studies (two online and one field) demonstrate this effect using different operationalizations of autonomy relatedness. Managerial implications are discussed and suggestions are made for future research.
The American Passport in Turkey: National Citizenship in the Age of Transnationalism
(Routledge Journals, Taylor & Francıs Ltd, 2020) Yanardağoğlu, Eylem
[Abstract Not Available]
Citation - WoS: 5
Citation - Scopus: 5
Analysis of Mixed-Element Structures Formed With Shunt Capacitors Separated by Transmission Lines
(IEEE-Inst Electrical Electronics Engineers Inc, 2019) Şengül, Metin Y.; Çakmak, Gökhan
In this brief, the analysis of mixed-element structures formed with shunt capacitors separated by commensurate transmission lines is performed first time in the literature. First, a low-pass lumped-element ladder network is considered. Then the series inductors are replaced with commensurate transmission lines. As a result, a practically important mixed-element structure is obtained. Then the description of the structure by means of two frequency variables (one for shunt capacitors and one for transmission lines) is detailed: Explicit expressions for the coefficients of the descriptive two-variable polynomials in terms of the coefficients of the single variable boundary polynomials are derived for various numbers of elements, which are obtained first time in the literature. Finally, a mixed-element broadband matching network is designed to illustrate the usage of the obtained expressions. If it is preferred not to have shunt capacitors, they can be replaced with open-ended stubs via Richard's transformation. So the resultant circuit is extremely suitable for microstrip fabrication.
Citation - WoS: 7
Citation - Scopus: 12
An Analysis of Price Spikes and Deviations in the Deregulated Turkish Power Market
(Elsevier, 2019) Gayretli, Gizem; Yücekaya, Ahmet; Bilge, Ayşe Hümeyra
The successful operation of a real time market is related to the planning in the day ahead market. We analyze the day ahead and real time market data for the Turkish power market for the period 2012-2015 to classify price spikes and their causes. We also focus on the levels of deviation between the day ahead market values and the real time market values. We define price deviation and load deviation ratios to measure the level of deviation both in price and demand. The analysis for the load is based on load shedding and cycling values. We analyze the mean and standard deviation in market prices and we determine the price spike as a two sigma deviation from the mean value. It is shown that 60% of the price deviation ratios are in the range of ( +/- 20%), while 44% are in the range of ( +/- 10%) and 35% are in the range of (+/- 5%). We also show that 56.9% of the spikes are due to problems in the generation of natural gas based power plants which affect the day ahead and real time prices. A total of 29.2% of the spikes are due to power plant and system failures that affect only real time prices. The share of high temperature based spikes is 13.9% which is a result of air conditioner usage.
Citation - Scopus: 88
An Analytic Network Process-Based Approach To Concept Evaluation in a New Product Development Environment
(Taylor & Francis, 2007) Ayağ, Zeki; Özdemir, Rifat Gürcan
Selecting the best product concept is one of the most critical tasks in a new product development (NPD) environment. Making decisions at this stage becomes very difficult due to imprecise and uncertain product requirements. So the evaluation process of determining the most satisfying conceptual design has been a very vital issue for companies to survive in fast-growing markets for a long time. Therefore most companies have used various methods to successfully carry out this difficult and time-consuming process. Of these methods an analytic hierarchy process (AHP) has been widely used in multiple-criteria decision-making problems (i.e. concept selection equipment evaluation). In this study however we use an analytic network process (ANP) a more general form of AHP due to the fact that AHP cannot accommodate the variety of interactions dependencies and feedback between higher and lower level elements. Briefly in this paper an ANP-based approach is presented to evaluate a set of conceptual design alternatives in order to reach to the best concept satisfying the needs and expectations of both customers and company. In addition a numerical example is presented to illustrate the proposed approach.
Citation - WoS: 33
Citation - Scopus: 37
Antecedents and Performance Outcomes of Value-Based Selling in Sales Teams: a Multilevel, Systems Theory of Motivation Perspective
(Springer, 2020) Mullins, Ryan; Mengüç, Bülent; Panagopoulos, Nikolaos G.
Firms are increasingly deploying a value-based selling (VBS) approach in their sales organizations to drive growth for new offerings. However, VBS adoption remains challenging, signaling that leaders need guidance to motivate VBS. Drawing from the systems theory of motivation, we examine motivational mechanisms at two levels-salesperson and sales team-to understand how to motivate, and benefit from, VBS. Using multisource data (i.e., salespeople, managers, archival performance) from 70 sales teams in a U.S.-based manufacturing and services provider, our findings illustrate drivers and outcomes of VBS. Specifically, we uncover a framework of salesperson, leader, customer, and team factors that help explain salesperson motivation for VBS. Importantly, we link VBS to customers' adoption of new products to support VBS's role for selling new products. Critical for sales team strategy, our model also integrates a team-level motivational mechanism to provide a comprehensive framework for salesperson and sales team motivations and outcomes.
Citation - WoS: 6
Citation - Scopus: 7
Are We at All Liberal at Heart? High-Powered Tests Find No Effect of Intuitive Thinking on Moral Foundations
(Academic Press Inc., 2021) Yılmaz, Onurcan;İşler, Ozan;Doğruyol, Burak
Two opposing views define the debate on the moral principles underlying human behavior. One side argues a central role for five moral foundations (care, fairness, loyalty, authority, sanctity), while the other argues that two of these (care, fairness) capture the essence of human moral concerns. In an experiment comparing these two views, Wright and Baril (2011) found that conservatives under cognitive load devalue loyalty, authority and sanctity, and become more liberal. Their finding of common intuitive concern with care and fairness supports the two-foundation perspective. In two high-powered preregistered experiments (N = 3275), we used time-pressure to induce intuitive thinking and tested Wright and Baril's finding that “we are all liberals at heart.” Although the manipulations worked as intended, Study 1 failed to identify an effect on the moral foundations questionnaire (MFQ). We conjectured that familiarity with standard survey items may weaken intuition manipulations by eliciting stable opinions. In Study 2, we therefore used not only the MFQ but also novel moral foundations vignettes. Study 2 failed to find an effect of time-pressure on either questionnaire type. An internal Bayesian meta-analysis indicated strong evidence against an effect of intuitive thinking on moral foundations.
Citation - WoS: 55
Citation - Scopus: 78
Assessing the Importance of International Tourism for the Turkish Economy: a Social Accounting Matrix Analysis
(Elsevier Science, 2012) Akkemik, K. Ali; Akkemik, K. Ali
The international tourism sector has grown rapidly in Turkey since the 1980s and Turkey ranks among the top ten countries in terms of tourist arrivals and receipts. Previous studies on international tourism in Turkey are partial equilibrium studies which emphasized the importance of the sector for foreign exchange earnings employment creation and economic growth. The social accounting matrix (SAM) modeling approach is superior to partial equilibrium analysis as it takes into account intersectoral linkages. This paper analyzes the contribution of international tourism to the Turkish economy using two SAMs for 1996 and 2002 respectively. Two analyses are conducted using the SAM impact model: (i) sectoral comparison of GDP elasticities and (ii) SAM impact analysis of international tourism on output value-added and employment. The results show that the GDP elasticity of international tourism is relatively low and the impact of foreign tourist expenditures on domestic production value-added (GDP) and employment in Turkey are modest. The results imply the possibility of leakage of foreign tourist expenditures out of the economy. (C) 2011 Elsevier Ltd. All rights reserved.
Citation - WoS: 4
Citation - Scopus: 4
An Assessment of Mining Efficiency in Turkish Lignite Industry
(Elsevier Science, 2015) Ediger, Volkan S.; Berk, Istemi; Ersoy, Mucella
This article focuses on the mining activities of Turkish Coal Enterprises (TKI) the major lignite supplier in Turkey. First we analyzed the lignite production and overburden removal activities of TKI from a historical perspective and then employed the Principle Component Analysis to build a mining efficiency index of TKI and investigated its historical development since the establishment of the company. We found that labor productivity and operational structure have been the most important factors positively affecting the index. The current article makes two important contributions: (1) by using the most comprehensive data set available on TKI for the first time and (2) by developing a Mining Efficiency Index (MEI) which can be used to analyze productivity in lignite mining activities in different countries. (C) 2015 Elsevier Ltd. All rights reserved.
The Association of Gvhd With Hla Dr Alleles, Ifn-Gamma, Tgf-Beta, and Mbl2 Gene Polymorphism
(Wiley, 2019) Oğuz, Rusdu; Çiftçi, Hayriye Şentürk; Gökçe, Muge; Öğret, Yeliz; Karadeniz, Sedat Tanju; Pehlivan, Sacide; Aydın, Filiz
[Abstract Not Available]
Citation - WoS: 6
Citation - Scopus: 7
Assortment Optimization With Log-Linear Demand: Application at a Turkish Grocery Store
(Elsevier, 2019) Hekimoğlu, Mustafa; Sevim, İsmail; Aksezer, Çağlar Sezgin; Durmuş, İpek
In retail sector product variety increases faster than shelf spaces of retail stores where goods are presented to consumers. Hence assortment planning is an important task for sustained financial success of a retailer in a competitive business environment. In this study we consider the assortment planning problem of a retailer in Turkey. Using empirical point-of-sale data a demand model is developed and utilized in the optimization model. Due to nonlinear nature of the model and integrality constraint we find that it is difficult to obtain a solution even for moderately large product sets. We propose a greedy heuristic approach that generates better results than the mixed integer nonlinear programming in a reasonably shorter period of time for medium and large problem sizes. We also proved that our method has a worst-case time complexity of O(n 2 )while other two well-known heuristics’ complexities are O(n 3 )and O(n 4 ). Also numerical experiments reveal that our method has a better performance than the worst-case as it generates better results in a much shorter run-times compared to other methods. © 2019 Elsevier Ltd

Browse

Browsing Fakülteler by WoS Q "Q1"