@article {1437, title = {Influence maximization with deactivation in social networks}, journal = {European Journal of Operational Research}, volume = {278}, year = {2019}, pages = {105-119}, abstract = {

In this paper, we consider an extension of the well-known Influence Maximization Problem in a social network which deals with finding a set of k nodes to initiate a diffusion process so that the total number of influenced nodes at the end of the process is maximized. The extension focuses on a competitive variant where two decision makers are involved. The first one, the leader, tries to maximize the total influence spread by selecting the most influential nodes and the second one, the follower, tries to minimize it by deactivating some of these nodes. The formulated bilevel model is solved by complete enumeration for small-sized instances and by a matheuristic for large-sized instances. In both cases, the lower level problem, which is a stochastic optimization problem, is approximated via the Sample Average Approximation method.

}, keywords = {Bilevel modeling, Influence maximization, Matheuristics, Metaheuristics, Stochastic optimization}, issn = {0377-2217}, doi = {https://doi.org/10.1016/j.ejor.2019.04.010}, url = {https://www.sciencedirect.com/science/article/pii/S0377221719303303}, author = {K{\"u}bra Tan{\i}nm{\i}{\c s} and Necati Aras and I. Kuban Altinel} } @article {1444, title = {An integrated disaster preparedness model for retrofitting and relief item transportation}, journal = {Networks and Spatial Economics}, volume = {19}, year = {2019}, pages = {1031{\textendash}1068}, author = {D{\"o}yen, Alper and Necati Aras} } @article {1474, title = {Impacts of Regulatory Transformation Processes to the Downstream Oil Market in Turkey}, journal = {International Journal of Energy Economics and Policy}, volume = {8}, year = {2018}, pages = {141{\textendash}149}, issn = {2146-4553}, author = {Metin, Erol and G{\"u}rkan Kumbaro{\u g}lu} } @article {1435, title = {Integer Programming Formulations and Benders Decomposition for the Maximum Induced Matching Problem}, journal = {INFORMS Journal on Computing}, volume = {30}, year = {2018}, pages = {43-56}, abstract = {

We investigate the maximum induced matching problem (MIM), which is the problem of finding an induced matching having the largest cardinality on an undirected graph. The problem is known to be NP-hard for general graphs. We first propose a vertex-based integer programming formulation for MIM, which is more compact compared to an edge-based formulation found in the literature. We also introduce the maximum weight induced matching problem (MWIM), which generalizes MIM so that vertices and edges have weights. We adapt the edge-based formulation to MWIM, and propose a quadratic programming formulation of MWIM based on our vertex-based formulation. We then linearize our quadratic programming formulation, and devise a Benders decomposition algorithm that exploits a special structure of the linearized formulation. We also propose valid inequalities and formulation tightening procedures to improve the efficiency of our approach. Our computational tests on a large suite of randomly generated graphs show that our vertex-based formulation and decomposition approach significantly improve the solvability of MIM and MWIM, especially on dense graphs. The online appendix and data are available at https://doi.org/10.1287/ijoc.2017.0764.

}, doi = {10.1287/ijoc.2017.0764}, url = {https://doi.org/10.1287/ijoc.2017.0764}, author = {Ahat, Bet{\"u}l and Ekim, Tinaz and Z C Ta{\c s}k{\i}n} } @proceedings {1181, title = {The Impact of Orbit Dependent Return Rate on the Control Policies of a Hybrid Production System}, journal = {11th SMMSO Conference }, year = {2017}, author = {Aybek Korugan and S. Ata and M. Fad{\i}lo{\u g}lu} } @article {1159, title = {Influence maximization based on partial network structure information: A comparative analysis on seed selection heuristics}, journal = {International Journal of Modern Physics C}, volume = {28}, year = {2017}, pages = {1750122}, author = {{\c S}irag Erkol and G{\"o}nen{\c c} Y{\"u}cel} } @article {1174, title = {Innovation race under revenue and technology uncertainty of heterogeneous firms where the winner does not take all}, journal = {IIE Transactions}, volume = {48}, year = {2016}, pages = {527{\textendash}540}, author = {Taner Bilgi{\c c} and Refik G{\"u}ll{\"u}} } @article {1466, title = {INVESTIGATING THE POTENTIAL OF STATE-TRUNCATIONAPPROXIMATIONS FOR PRODUCTION LINES}, journal = {Stochastic Modelling and Applications}, volume = {20}, year = {2016}, month = {Dec}, pages = {91{\textendash}109}, author = {Durmu{\c s}, Deniz and YERALAN, SENCER and Aybek Korugan} } @proceedings {ekcsiougluinvestigation, title = {An Investigation of User-Experience Design of E-Commerce Websites}, year = {2015}, author = {Mahmut Ek{\c s}io{\u g}lu and Varol, Sevgican and Duman, Yusuf} } @article {Yavas2014, title = {Impact of Homophily on Diffusion Dynamics Over Social Networks}, journal = {Social Science Computer Review}, volume = {32}, number = {3}, year = {2014}, month = {mar}, abstract = {

The purpose of this study is to analyze the impact of homophily on diffusion over social networks. An agent-based simulation model is developed to serve as the experimental ground for this analysis. Diffusion dynamics of a nonsticky innovation is investigated by varying homophily levels in the social network depicted in the model as the primary control variable. First of all, the results show that homophily is self-reinforcing. Second, starting from a nonhomophilous network, early increases in the level of homophily have a positive effect on the extent of diffusion, whereas further increases have a negative impact. Finally, several local minima and maxima are observed in the relation between the homophily level and the extent of diffusion. Our analysis focuses on node properties such as connect- edness and average degrees in order to explain the observed regular relationship between homophily and diffusion. We argue that (i) homophily increases the connectedness of different status groups separately and (ii) increasing levels of homophily decreases the marginal importance of a single homo- philous tie by increasing the sources of valuable information. Future research involves investigating the coevolution of social behavior and networks by allowing the adopted innovation to lead to value homophily, exploration of different diffusion initiation types, and different adoption heuristics.

}, issn = {0894-4393}, doi = {10.1177/0894439313512464}, url = {http://ssc.sagepub.com/cgi/doi/10.1177/0894439313512464}, author = {Yava{\c s}, Mustafa and G{\"o}nen{\c c} Y{\"u}cel} } @article {671, title = {An Integer Programming-Based Search Technique for Error-Prone Substructures of LDPC Codes}, journal = {AEU - International Journal of Electronics and Communications}, volume = {68}, year = {2014}, pages = {1097-1105}, doi = {10.1016/j.aeue.2014.05.012}, author = {Abdullah Sar{\i}duman and Ali Emre Pusane and Z C Ta{\c s}k{\i}n} } @article {keccici2012incorporating, title = {Incorporating the threat of terrorist attacks in the design of public service facility networks}, journal = {Optimization Letters}, volume = {6}, number = {6}, year = {2012}, pages = {1101{\textendash}1121}, publisher = {Springer-Verlag}, author = {Ke{\c c}ici, Serhat and Necati Aras and Verter, Vedat} } @article {TaskinEkim2012, title = {Integer Programming Formulations for the Minimum Weighted Maximal Matching Problem}, journal = {Optimization Letters}, volume = {6(6)}, year = {2012}, pages = {1161-1171}, doi = {http://dx.doi.org/10.1007/s11590-011-0351-x}, author = {Z C Ta{\c s}k{\i}n and Ekim, Tinaz} } @conference {yasarcan2011information, title = {Information Sharing in Supply Chains: A Systemic Approach}, booktitle = {The 29th International System Dynamics Conference, Washington, DC, USA}, year = {2011}, publisher = {System Dynamics Society (http://www.systemdynamics.org/conferences/2011/index.htm)}, organization = {System Dynamics Society (http://www.systemdynamics.org/conferences/2011/index.htm)}, author = {Yasarcan, Hakan} } @article {yasarcan2010improving, title = {Improving understanding, learning, and performances of novices in dynamic managerial simulation games}, journal = {Complexity}, volume = {15}, number = {4}, year = {2010}, pages = {31{\textendash}42}, publisher = {John Wiley \& Sons, Ltd}, author = {Yasarcan, Hakan} } @article {ekcsiouglu2009iyi, title = {{\.I}yi Ergonomi {\.I}yi Ekonomidir}, journal = {End{\"u}stri {\.I}{\c s}letme M{\"u}hendisli{\u g}i Meslek Dal{\i} Ana Komisyonu B{\"u}lteni}, number = {129}, year = {2009}, pages = {22{\textendash}25}, author = {Mahmut Ek{\c s}io{\u g}lu} } @conference {ekcsiouglu2008isometric, title = {Isometric grip strength distribution of a Turkish sample}, booktitle = {Proceedings of the XX Annual International Occupational Ergonomics and Safety Conference}, year = {2008}, pages = {20{\textendash}24}, publisher = {International Society of Occupational Ergonomics and Safety ISBN \# 97809654506-4-5}, organization = {International Society of Occupational Ergonomics and Safety ISBN \# 97809654506-4-5}, author = {Mahmut Ek{\c s}io{\u g}lu and Silahl{\i}, Baykar} } @conference {eksioglu1999search, title = {In search of relative optimum grip span}, booktitle = {CD-ROM Proceedings of CybErg 1999: The Second International Cyberspace Conference on Ergonomics}, year = {1999}, pages = {494{\textendash}504}, publisher = {The International Ergonomics Association Press}, organization = {The International Ergonomics Association Press}, author = {Mahmut Ek{\c s}io{\u g}lu} }