Department of Management

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Open Access
A dynamic multi-level iterative algorithm for clearing European electricity day-ahead markets: an application to the Turkish market
(Taylor and Francis Ltd., 2023-05-12) Büke, B.; Sayın, M.; Tanrısever, Fehmi
Designing and clearing day-ahead electricity market auctions have recently received significant attention from academia and practice alike. Given the size and the complexity of day-ahead market auctions, clearing them within the time limits imposed by the market is a major practical concern. In this paper, we model all the practical details of the Turkish day-ahead electricity market and provide a new multi-level iterative heuristic to clear the market. We compare our results with a commercial solver using data provided by Energy Exchange Istanbul. Our heuristic achieves an average optimality gap less than 0.09%, with an average solution time of just 14 s; whereas the commercial solver takes, on average, 18 min (and in some cases up to three hours) to find the optimal solution. We also demonstrate that using our heuristic solution to warm-start the commercial solver further reduces the solution time by 25%, on average. Overall, our heuristic proves to be very efficient in clearing the Turkish day-ahead market. We also test the performance of our algorithm as the problem size grows.
Embargo
A fuzzy cognitive map approach to understand agricultural system and food prices in Türkiye: policy recommendations for national food security
(John Wiley & Sons Ltd., 2023-11-16) Ekici, Ahmet; Önsel Ekici, Ş.; Yumurtacı Hüseyinoğlu, I. Ö.; Watson, F.
Once one of the few self-sufficient food countries in the world, Turkey has become dependent on imports to feed its population. Food prices have climbed to among the highest in the world, severely threatening the food security of the country. Most researchers generally attributed the high prices to the increased input costs of agriculture. Although the role of input prices cannot be denied, this paper focuses on a neglected problem that can account for food price inflation: the attitudes and behaviours of farming communities towards agriculture. Through fuzzy cognitive map methodology, known to be very effective in understanding complex networks of problems, we identify and map the relationships among the factors affecting the agriculture system, develop interview and literature-driven scenarios, and test these scenarios to demonstrate their role in explaining the relationship between attitudes and behaviours of farming communities and food prices in Turkey. Our findings provide recommendations to policymakers.
Open Access
Accounting for materialism in four cultures
(1999) Ger, G.; Belk, R. W.
Accounts for materialism are examined based on qualitative research in Romania, Turkey, the USA, and Western Europe. Various spontaneously offered accounts reconcile the discrepancy between the belief that materialism is bad and materialistic consumption behavior and aspirations. These accounts include justifications - passionate connoisseurship, instrumentalism, and altruism - and excuses - the compelling external forces, the ways of the modern world, and deservingness. The differences in accounts can be understood culturally and historically. In negotiating the 'bad' material world with their own consumption worlds, informants draw from various ethics prevalent in their cultures to moralize their personal materialistic consumption. Our findings suggest ways in which materialism, moralized by local accounts, is able to grow globally in spite of its condemnation.
Open Access
Accounting in Turkey
(Routledge, 1995) Simga‐Mugan, C.
Turkey is a developing country in the Middle East, and is attracting an increasing number of foreign investments and joint ventures. However, the Turkish accounting system is not one of the topics that is studied in detail, the language barrier perhaps being the main reason. As the amount of foreign investment and the number of joint ventures increase and the Turkish stock market develops, a new responsibility will fall on accountants to disclose and discuss the current accounting system in Turkey. This paper attempts to fill this gap by describing the current accounting system and state of the profession in Turkey. .
Open Access
Acculturation and overseas assignments: a review and research agenda
(Pergamon Press, 2015) Gonzalez-Loureiro, M.; Kiessling, T.; Dabic, M.
This review analyzes two streams of literature that are exploring a similar phenomenon from separate perspectives and only recently have they began to overlap; that of migrant acculturation (from the psychology, sociology and anthropology research) and international assignee adjustment (from the international business research stream). We conducted a multiple correspondence analysis on a sample of 389 articles to provide the intellectual structure of the research in these fields. Our research indicates that: (1) the standard 2 × 2 matrix of acculturation is insufficient; (2) most past research focuses on USA to other countries and vice versa, suggesting there is much work left to explore other pairs of cultures (“there and back again” is not the same globally); (3) as global organizations are dominating the marketplace with many various staffing forms, variables such as corporate culture and management interaction will need to be incorporated; (4) research needs to include dynamics over time as many individuals who have worked outside of their home country often become multi-cultural with a global mindset and the typical acculturation framework is insufficient; (5) past acculturation research focuses on the work or the sociocultural context separately, while both need to be included; (6) and the extended family (parents, relatives, close friends, etc.) need to be considered.
Open Access
Actual, ideal, and expected relatedness with parents across and within cultures
(John Wiley & Sons, 2006) Imamoǧlu, E. O.; Karakitapoǧlu-Aygün, Z.
Differences in actual, ideal, and expected relatedness with mothers and fathers were explored across two cultural groups (i.e., university students from the U.S. and Turkey) in Study 1, and across two socioeconomic status (SES) groups (i.e., high school students from the upper and lower SES in Turkey) in Study 2. In both studies associations of perceived relatedness with individualistic and collectivistic value orientations as well as with self-construal types were also explored. Results indicated cultural groups to be quite similar in actual relatedness, but to differ in expected and ideal relatedness, with Turks reporting more relatedness. In Turkey, lower SES adolescents reported more relatedness in ideal and actual conditions than upper SES adolescents, while they did not differ in expected relatedness. Results involving self-types and value orientations pointed to both cross-cultural similarities and within-cultural diversity in relatedness. Theoretical implications of the differential impact of culture, SES, self-construals, and value orientations on actual, ideal, and expected relatedness are discussed.
Open Access
Ad Hoc Reviewers-Journal of Macromarketing Volume 33, Number 4, December 2013
(2013) Desmond, John; Dorsch, Michael; Kravets, Olga; Leonidou, Leonidas; Lewin, Jeff; Stöttinger, Barbara; Vargo, Stephen; Veeck, Ann
[No abstract available]
Open Access
Adverse selection in cryptocurrency markets
(Wiley, 2023-01-11) Tiniç, M.; Şensoy, Ahmet; Akyıldırım, Erdinç; Corbet, S.
In this article we investigate the influence that information asymmetry may have on future volatility, liquidity, market toxicity, and returns within cryptocurrency markets. We use the adverse-selection component of the effective spread as a proxy for overall information asymmetry. Using order and trade data from the Bitfinex exchange, we first document statistically significant adverse-selection costs for major cryptocurrencies. Also, our results suggest that adverse-selection costs, on average, correspond to 10% of the estimated effective spread, indicating an economically significant impact of adverse-selection risk on transaction costs in cryptocurrency markets. Finally, we document that adverse-selection costs are important predictors of intraday volatility, liquidity, market toxicity, and returns.
Open Access
Advertising agency scene in Saudi Arabia
(1998) Erdem, Orham; Tuncalp, Seçil
Looks at advertising agencies in Saudi Arabia and describes their strengths and the facilities they can offer. Focuses on five major advertising agencies – Tihama for Advertising, Public Relations and Marketing; United Outdoor Advertising Company Ltd.; Raed Marketing and Advertising; Narwah Public Relations, Advertising and Marketing; and Transworld Publicity Limited – and mentions five others. Explores the history of advertising in Saudi Arabia; it's a relatively new industry built on the crude oil boom of 1973, when the Saudis embarked on an intensive economic development programme. © 1998, MCB UP Limited
Open Access
Advertising and the public sphere
(Association for Consumer Research, 2004) Sandikci, Ö.
Open Access
Affect-based stock investment decision : the role of affective self-affinity
(Elsevier Inc., 2017) Usul, N.; Özdemir, Ö.; Kiessling, T.
This paper studies the role of affective self-affinity for a company in the stock investment decision by investigating the factors triggering it. Based on the social identity theory and the affect literature we hypothesize that three types of identifications, namely group related, company-people related and idea/ideal related, trigger affective self-affinity for a company which results in extra affect-based motivation to invest in the company's stock. The two ideas included in the idea/ideal related affective self-affinity are socially responsible investing and nationality related ideas. Based on the survey data of 133 active individual investors, we find that the more the investors perceive the company supports/represents a specific group or idea or employ a specific person, with which the investors identify themselves, the higher is the investors’ affective self-affinity for the company. This results in higher extra affective motivation to invest in the company's stock over and beyond financial indicators. Thus, investors’ identification with groups, people, or ideas such as socially responsible investing and nationality results in higher affect-based investment motivation through affective self-affinity aroused in the investors. Moreover, positive attitude towards the company is another factor that explains the affect-based extra investment motivation. © 2017 Elsevier Inc.
Open Access
Age-based vs. stock level control policies for a perishable inventory system
(2001) Tekin, E.; Gürler Ü.; Berk, E.
In this study, we investigate the impact of modified lotsize-reorder control policy for perishables which bases replenishment decisions on both the inventory level and the remaining lifetimes of items in stock. We derive the expressions for the key operating characteristics of a lost sales perishable inventory model, operating under the proposed age-based policy, and examine the sensitivity of the optimal policy parameters with respect to various system parameters. We compare the performance of the suggested policy to that of the classical (Q,r) type policy through a numerical study over a wide range of system parameters. Our findings indicate that the age-based policy is superior to the stock level policy for slow moving perishable inventory systems with high service levels.
Open Access
Aggregate volatility expectations and threshold CAPM
(Elsevier Inc., 2015) Arisoy, Y. E.; Altay-Salih, A.; Akdeniz, L.
We propose a volatility-based capital asset pricing model (V-CAPM) in which asset betas change discretely with respect to changes in investors' expectations regarding near-term aggregate volatility. Using a novel measure to proxy uncertainty about expected changes in aggregate volatility, i.e. monthly range of the VIX index (RVIX), we find that portfolio betas change significantly when uncertainty about aggregate volatility expectations is beyond a certain threshold level. Due to changes in their market betas, small and value stocks are perceived as riskier than their big and growth counterparts in bad times, when uncertainty about aggregate volatility expectations is high. The proposed model yields a positive and significant market risk premium during periods when investors do not expect significant uncertainty in near-term aggregate volatility. Our findings support a volatility-based time-varying risk explanation.
Open Access
An algorithm based on facial decomposition for finding the efficient set in multiple objective linear programming
(Elsevier, 1996) Sayın, S.
We propose a method for finding the efficient set of a multiple objective linear program based on the well-known facial decomposition of the efficient set. The method incorporates a simple linear programming test that identifies efficient faces while employing a top-down search strategy which avoids enumeration of efficient extreme points and locates the maximally efficient faces of the feasible region. We suggest that discrete representations of the efficient faces could be obtained and presented to the Decision Maker. Results of computational experiments are reported.
Open Access
Aligning strategic orientation with local market conditions: Implications for subsidiary knowledge management
(2012) Griffith, D.A.; Kiessling, T.; Dabic, M.
Purpose: One role of a foreign subsidiary within a multinational corporation's (MNC's) global portfolio is to connect the MNC to foreign customers. To examine this key customer contact point, this study aims to examine the linkages between local market conditions and strategic orientation, and how strategic orientation influences knowledge management capabilities of MNC subsidiaries, employing the Miles and Snow strategic orientation perspective. Design/methodology/approach: A survey was conducted of 112 managers in foreign MNC subsidiaries in Croatia. Data were analyzed with both discriminant analysis and MANCOVA. Findings: The results indicate that in highly dynamic and competitively intense markets, MNC subsidiaries primarily employ a Prospector orientation. Furthermore, the results indicate that there is a significant difference in knowledge management capabilities among subsidiaries depending on their strategic orientation, with the Prospector orientation most closely aligned with knowledge acquisition, knowledge conversion and knowledge application. Practical implications: The findings highlight the importance of strategic orientation in MNC subsidiaries tailoring to local market conditions. The results suggest that MNC subsidiaries undertaking a Prospector strategic orientation develop greater knowledge acquisition, conversion and application capabilities. Originality/value: This study conceptualizes the MNC subsidiary as a key marketing element of the global MNC whole and examines the nuanced relationships between the host environment and MNC foreign subsidiary strategic orientation as well as MNC subsidiary strategic orientation and knowledge management relationship. © Emerald Group Publishing Limited.
Open Access
Alliance orientation: conceptualization, measurement, and impact on market performance
(Springer, 2006) Kandemir, D.; Yaprak, A.; Cavusgil, S. T.
Interfirm collaborations have inspired a rich literature in marketing and strategy during the past two decades. Building on this extant work, the authors developed a new construct, alliance orientation, and explored its influence on firms' alliance network performance and market performance. The authors drew on data collected from 182 U.S. firms with extensive experience in forming, developing, and managing strategic alliances in marketing, new product development, distribution, technology, and manufacturing projects. Using structural equations modeling, the authors demonstrate that alliance orientation significantly affects alliance network performance, which in turn enhances market performance. The findings also suggest that market turbulence exerts a significant moderating influence on the relationship between alliance orientation and alliance network performance, whereas the moderating role of technological turbulence on that relationship does not appear to be significant. The study provides evidence that firms' alliance orientations positively affect their performance in strengthening their alliance network relationships and in managing conflicts with their alliance partners.
Open Access
Amme İdaresi Dergisi’nde yayınlanan makaleler ve Türk Yönetim Bilimi
(Eskişehir Osmangazi Üniversitesi İktisadi ve İdari Bilimler Fakültesi, 2009) Berkman, A. Ümit
Bu araştırmada, Türkiye ve Ortadoğu Amme İdaresi Enstitüsü (TODAİE) tarafından 20 yıldır sürekli olarak yayınlanan ve Türk yönetim bilimine önemli katkılarda bu‐ lunan Amme İdaresi Dergisi’nde yayınlanan makalelerin konu, veri‐türü, yazarı gibi bazı yönlerden incelenmesine çalışılacaktır 1 . Süreli yayınların benzer biçimler‐ de incelenmeleri diğer ülkelerde ve disiplinlerde sıkça görülmektedir Bu tür çalış‐ maların bir bölümü akademik kurumları bilimsel dergilere katkıları açısından, diğer bir bölümü de seçilmiş dergilerde yayınlanan makaleleri ilgili disiplinin gelişimine katkıları açısından incelemektedir.
Open Access
Analyses of serial production line systems for interdeparture time variability and WIP inventory systems
(International Journal of Operations and Quantitative Management, 2004) Erel, E.; Sabuncuoglu, I.; Kok, G. A.
This paper investigates the well-known and extensively studied unpaced production line problem for the interdeparture time variability and work-in-process (WIP) inventory. The primary objective is to examine the relationships between the interdeparture time variability and some system design factors such as the number of stations, buffer capacity, and location of a bottleneck station. The performance of the system is also evaluated for average and variance of WIP inventory. Simulation is used as a modeling and analysis tool with the results being tested by appropriate statistical procedures. The analysis of the results reveals several important findings on the interdeparture time variability and WIP inventory. We confirm and strengthen some of the previous findings on throughput. In this paper, we also discuss managerial implications and suggest further research areas.
Open Access
Analysis of assembly systems for interdeparture time variability and throughput
(Taylor & Francis, 2002) Sabuncuoğlu, İ.; Erel, E.; Kok, A. G.
This paper studies the effect of the number of component stations (parallelism), work transfer, processing time distributions, buffers and buffer allocation schemes on throughput and interdeparture time variability of assembly systems, As an alternative to work transfer, variability transfer is introduced and its effectiveness is assessed. Previous research has indicated that the optimal throughput displays an anomaly at certain processing time distributions and, this phenomenon is now thoroughly analyzed and the underlying details are uncovered. This study also yields several new findings that convey important practical implications.
Open Access
Analysis of Lagrangian lower bounds for a graph partitioning problem
(Institute for Operations Research and the Management Sciences (INFORMS), 1999) Adil, G. K.; Ghosh, J. B.
Recently, Ahmadi and Tang (1991) demonstrated how various manufacturing problems can be modeled and solved as graph partitioning problems. They use Lagrangian relaxation of two different mixed integer programming formulations to obtain both heuristic solutions and lower bounds on optimal solution values. In this note, we point to certain inconsistencies in the reported results. Among other things, we show analytically that the first bound proposed is trivial (i.e., it can never have a value greater than zero) while the second is also trivial for certain sparse graphs. We also present limited empirical results on the behavior of this second bound as a function of graph density.