@article {1602, title = {Column generation-based prototype learning for optimizing area under the receiver operating characteristic curve}, journal = {European Journal of Operational Research}, volume = {314}, year = {2024}, pages = {297{\textendash}307}, author = {Erhan C Ozcan and Berk G{\"o}rg{\"u}l{\"u} and Mustafa Gokce Baydogan} } @article {1498, title = {The complexity of the defensive domination problem in special graph classes}, journal = {Discrete Mathematics}, volume = {343}, year = {2020}, pages = {111665}, abstract = {

A k-attack on a graph G is a set of k distinct vertices {a1,{\textellipsis},ak} which are said to be under attack. A k-attack A can be countered or defended by a subset of defender vertices X if and only if there exists an injective function f from A to X, such that either f(ai)=ai or (ai,f(ai)) is an edge of G, for all i, 1<=i<=k. Given a graph G, a subset D of V is a k-defensive dominating set of G if and only if D can counter any k-attack in G. We consider the k-defensive dominating set problem. We start a systematic study on the complexity of the k-defensive dominating set problem. When k is not fixed, we show that it is already co-NP-hard to decide whether a given set of vertices is a k-defensive dominating set or not. However, if k is fixed, then we show that the problem is NP-complete even in split graphs. Subsequently, we consider special graph classes, namely paths, cycles, co-chain graphs and threshold graphs. We show that in each of these graph classes, a k-defensive dominating set of minimum size can be found in linear time even for non-fixed k.

}, keywords = {Domination, Networks, Security}, issn = {0012-365X}, doi = {https://doi.org/10.1016/j.disc.2019.111665}, url = {https://www.sciencedirect.com/science/article/pii/S0012365X19303437}, author = {Ekim, Tinaz and Arthur M. Farley and Andrzej Proskurowski} } @article {1428, title = {On the Construction of Regular QC-LDPC Codes With Low Error Floor}, journal = {IEEE Communications Letters}, volume = {24}, year = {2020}, pages = {25-28}, doi = {10.1109/LCOMM.2019.2953058}, author = {Sar{\i}duman, Abdullah and Pusane, Ali E. and Z C Ta{\c s}k{\i}n} } @article {1415, title = {Classification of generic system dynamics model outputs via supervised time series pattern discovery}, journal = {Turkish Journal of Electrical Engineering \& Computer Sciences}, volume = {27}, year = {2019}, pages = {832{\textendash}846}, author = {Edali, Mert and Mustafa Gokce Baydogan and G{\"o}nen{\c c} Y{\"u}cel} } @article {1433, title = {A column generation heuristic for {VMAT} planning with adaptive {CVaR} constraints}, journal = {Physics in Medicine {\&} Biology}, volume = {64}, year = {2019}, month = {oct}, pages = {205024}, abstract = {

In this study we develop an efficient computational procedure that generates medically acceptable treatment plans for volumetric modulated arc therapy with constant gantry speed. Our proposed method is a column generation heuristic based on a mixed integer linear programming model, where the objective function contains minimization of total monitor unit of the treatment plan and dose-volume requirements are included as conditional value-at-risk constraints. Our heuristic generates a full treatment arc for the restricted master problem and calibrates the right hand side parameters of the conditional value-at-risk constraints in the first phase. In the second phase, this initial solution is improved by performing column generation. This is a fully automated procedure and produces treatment plans in a single call without any human intervention. We evaluate its performance on real prostate cancer data by comparing the quality of the generated plans with those obtained by a widely used commercial treatment planning system. Our analysis shows that the results are promising, and the generated plans satisfy the prescription restrictions and require fewer monitor units on average compared to the ones obtained using Eclipse.

}, doi = {10.1088/1361-6560/ab416e}, url = {https://doi.org/10.1088/1361-6560/ab416e}, author = {P{\i}nar Dursun and Z C Ta{\c s}k{\i}n and I. Kuban Altinel and Hatice Bilge and Nazmiye D{\"o}nmez Kesen and Murat Okutan and Ethem Nezih Oral} } @inbook {1451, title = {Credibility, Validity and Testing of Dynamic Simulation Models}, booktitle = {Simulation and Modeling Methodologies, Technologies and Applications}, year = {2018}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {

Also called {\textquoteleft}model validity{\textquoteright} testing, model credibility evaluation has always been a controversial issue in any modeling methodology. We briefly discuss why this important notion is so controversial. To this end, we classify major types of models, particularly as they impact the notion of model credibility: i- Purely statistical forecasting (black box) models, and ii- Causal-descriptive policy (transparent) models. We then focus on what makes causal-descriptive model credibility and evaluation unique and quite difficult, compared to short-term forecasting models. One important result is that causal-descriptive model credibility consists of two different aspects: structural and behavioral. In most simulation modeling (particularly system dynamics policy simulation), establishing structure credibility must strictly precede behavior credibility; the latter has no value without the former. We thus discuss Structural tests and output behavior tests for dynamic simulation models separately. Structure tests can further be classified into direct and indirect structure tests. We place special emphasis on indirect structure tests. We also provide a quick overview of recent model testing software developed in SESDYN Laboratory at Bo{\u g}azi{\c c}i University. Finally we discuss model credibility in broader context and some implementation issues.

}, isbn = {978-3-319-69832-8}, author = {Yaman Barlas} } @article {1507, title = {Complexity of the Improper Twin Edge Coloring of Graphs}, journal = {Graphs and Combinatorics}, volume = {33}, year = {2017}, pages = {595{\textendash}615}, author = {Abedin, Paniz and Akbari, Saieed and Demange, Marc and Ekim, Tinaz} } @proceedings {1191, title = {A Conceptual Feedback Model of Performance Dynamics}, journal = {The 34th International Conference of the System Dynamics Society}, year = {2016}, address = {Delft, the Netherlands}, author = {Van den Berg, AR and Hakan Ya{\c s}arcan} } @article {785, title = {A column generation approach for evaluating delivery efficiencies of collimator technologies in IMRT treatment planning}, journal = {Physics in Medicine and Biology}, volume = {60}, year = {2015}, pages = {1989-2004}, author = {Merve G{\"o}ren and Z C Ta{\c s}k{\i}n} } @article {1459, title = {On Censored Bivariate Random Variables: Copula, Characterization, and Estimation}, journal = {Communications in Statistics - Simulation and Computation}, volume = {43}, year = {2014}, pages = {2173-2185}, abstract = {

{ Let (X, Y) be a bivariate random vector with joint distribution function FX, Y(x, y) = C(F(x), G(y)), where C is a copula and F and G are marginal distributions of X and Y, respectively. Suppose that (Xi, Yi)

}, doi = {10.1080/03610918.2012.748911}, url = {https://doi.org/10.1080/03610918.2012.748911}, author = {K{\"o}n{\"u}l Bayramo{\u g}lu Kavlak and Ismihan Bayramoglu (bairamov)} } @article {TaskinCevik2013, title = {Combinatorial Benders Cuts for Decomposing IMRT Fluence Maps Using Rectangular Apertures}, journal = {Computers and Operations Research}, volume = {40(9)}, year = {2013}, pages = {2178{\textendash}2186}, doi = {http://dx.doi.org/10.1016/j.cor.2011.07.005}, author = {Z C Ta{\c s}k{\i}n and Mucahit Cevik} } @article {dingecc2013control, title = {Control variates and conditional Monte Carlo for basket and Asian options}, journal = {Insurance: Mathematics and Economics}, volume = {52}, number = {3}, year = {2013}, pages = {421{\textendash}434}, publisher = {North-Holland}, author = {Dinge{\c c}, Kemal Din{\c c}er and Wolfgang H{\"o}rmann} } @article {kucukaydin2012ciftduzeyli, title = {Ciftduzeyli Bir Rekabetci Tesis Yer Secimi Problemi Icin Tabu Arama Sezgiseli}, journal = {Endustri Muhendisligi Dergisi}, volume = {23}, number = {1}, year = {2012}, publisher = {TMMOB Makina Muhendisleri Odasi}, author = {K{\"u}{\c c}{\"u}kayd{\i}n, Hande and Necati Aras and I. Kuban Altinel} } @inbook {ekim2012computing, title = {Computing minimum geodetic sets of proper interval graphs}, booktitle = {LATIN 2012: Theoretical Informatics}, year = {2012}, pages = {279{\textendash}290}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, author = {Ekim, Tinaz and Erey, Aysel and Heggernes, Pinar and van{\textquoteright}t Hof, Pim and Meister, Daniel} } @conference {tanyolacc2012control, title = {Control Heuristics for Soft Landing Problem}, booktitle = {The 30th International System Dynamics Conference, St. Gallen, Switzerland}, year = {2012}, publisher = {System Dynamics Society (http://www.systemdynamics.org/conferences/2012/index.html)}, organization = {System Dynamics Society (http://www.systemdynamics.org/conferences/2012/index.html)}, author = {Tanyola{\c c}, Togay and Yasarcan, Hakan} } @article {14445765, title = {{Competitive facility location problem with attractiveness adjustment of the follower: A bilevel programming model and its solution}}, journal = {European Journal of Operational Research}, volume = {208}, year = {2011}, pages = {206{\textendash}220}, doi = {10.1016/j.ejor.2010.08.009}, author = {Hande K{\"u}{\c c}{\"u}kaydin and Necati Aras and I. Kuban Altinel} } @article {13998331, title = {{A column generation based heuristic for sensor placement, activity scheduling and data routing in wireless sensor networks}}, journal = {European Journal of Operational Research}, volume = {207}, year = {2010}, pages = {1014{\textendash}1026}, doi = {10.1016/j.ejor.2010.05.020}, author = {Yavuz Boga{\c c} T{\"u}rkogullari and Necati Aras and I. Kuban Altinel and Cem Ersoy} } @conference {cseker2010controlling, title = {Controlling the Direction of a Model Helicopter}, booktitle = {The 28th International System Dynamics Conference, Seoul, Korea}, year = {2010}, publisher = {System Dynamics Society (http://www.systemdynamics.org/conferences/2010/index.htm)}, organization = {System Dynamics Society (http://www.systemdynamics.org/conferences/2010/index.htm)}, author = {Oylum {\c S}eker and Yasarcan, Hakan} } @article {4756711, title = {{A comparative analysis of several asymmetric traveling salesman problem formulations}}, journal = {Computers \& Operations Research}, volume = {36}, year = {2009}, pages = {637{\textendash}654}, doi = {10.1016/j.cor.2007.11.008}, author = {Temel {\"O}ncan and I. Kuban Altinel and Gilbert Laporte} } @article {guler2009coordinating, title = {On coordinating an assembly system under random yield and random demand}, journal = {European Journal of Operational Research}, volume = {196}, number = {1}, year = {2009}, pages = {342{\textendash}350}, publisher = {Elsevier}, author = {G{\"u}ler, M G{\"u}ray and Taner Bilgi{\c c}} } @article {TaskinEtAl2009a, title = {Cutting Plane Algorithms for Solving a Stochastic Edge-Partition Problem}, journal = {Discrete Optimization}, volume = {6}, number = {4}, year = {2009}, pages = {420-435}, doi = {http://dx.doi.org/10.1016/j.disopt.2009.05.004}, author = {Z C Ta{\c s}k{\i}n and J. Cole Smith and Shabbir Ahmed and Andrew J. Schaefer} } @article {1480, title = {CO2, GDP and RET: An aggregate economic equilibrium analysis for Turkey}, journal = {Energy Policy}, volume = {36}, year = {2008}, pages = {2694-2708}, abstract = {

There is a worldwide interest in renewable electricity technologies (RETs) due to growing concerns about global warming and climate change. As an EU candidate country whose energy demand increases exponentially, Turkey inevitably shares this common interest on RET. This study, using an aggregate economic equilibrium model, explores the economic costs of different policy measures to mitigate CO2 emissions in Turkey. The model combines energy demands, capital requirements and labor inputs at a constant elasticity of substitution under an economy-wide nested production function. Growing energy demand, triggered by economic growth, is met by increased supply and initiates new capacity additions. Investment into RET is encouraged via the incorporation of (a) endogenous technological learning through which the RET cost declines as a function of cumulative capacity, and (b) a willingness to pay (WTP) function which imposes the WTP of consumers as a lower bound on RET installation. The WTP equation is obtained as a function of consumer income categories, based on data gathered from a pilot survey in which the contingent valuation methodology was employed. The impacts of various emission reduction scenarios on GDP growth and RET diffusion are explored. As expected, RET penetration is accelerated under faster technological learning and higher WTP conditions. It is found that stabilizing CO2 emissions to year 2005 levels causes economic losses amounting to 17\% and 23\% of GDP in the years 2020 and 2030, respectively.

}, keywords = {Energy and environmental policy modeling, Learning (experience) curves, Willingness to pay for CO emission reduction}, issn = {0301-4215}, doi = {https://doi.org/10.1016/j.enpol.2008.03.026}, url = {https://www.sciencedirect.com/science/article/pii/S030142150800164X}, author = {G{\"u}rkan Kumbaro{\u g}lu and Nihan Karal{\i} and Y{\i}ld{\i}z Ar{\i}kan} } @inbook {barlas2008comprehensive, title = {A comprehensive model of goal dynamics in organizations: setting, evaluation and revision}, booktitle = {Complex Decision Making}, year = {2008}, pages = {295{\textendash}320}, publisher = {Springer}, organization = {Springer}, author = {Barlas, Yaman and Yasarcan, Hakan} } @article {geinoz2008construction, title = {Construction of balanced sports schedules using partitions into subleagues}, journal = {Operations Research Letters}, volume = {36}, number = {3}, year = {2008}, pages = {279{\textendash}282}, publisher = {North-Holland}, author = {Geinoz, A and Ekim, Tinaz and de Werra, Dominique} } @article {de2006construction, title = {Construction of sports schedules with multiple venues}, journal = {Discrete Applied Mathematics}, volume = {154}, number = {1}, year = {2006}, pages = {47{\textendash}58}, publisher = {North-Holland}, author = {de Werra, Dominique and Ekim, Tinaz and Raess, C} } @article {aras2006coordination, title = {Coordination and priority decisions in hybrid manufacturing/remanufacturing systems}, journal = {Production and Operations Management}, volume = {15}, number = {4}, year = {2006}, pages = {528{\textendash}543}, publisher = {Wiley Online Library}, author = {Necati Aras and Verter, Vedat and Boyaci, Tamer} } @inbook {aksen2006customer, title = {Customer selection and profit maximization in vehicle routing problems}, booktitle = {Operations Research Proceedings 2005}, year = {2006}, pages = {37{\textendash}42}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, author = {Aksen, Deniz and Necati Aras} } @article {Hoermann;Leydold:2003a, title = {Continuous Random Variate Generation by Fast Numerical Inversion}, journal = {ACMTOMACS}, volume = {13}, number = {4}, year = {2003}, pages = {347{\textendash}362}, author = {Wolfgang H{\"o}rmann and Leydold, Josef} } @article {14086928, title = {{A clone-based graphical modeler and mathematical model generator for optimal production planning in process industries}}, journal = {European Journal of Operational Research}, volume = {137}, year = {2002}, pages = {483{\textendash}496}, doi = {10.1016/S0377-2217(01)00066-2}, author = {Murat Draman and I. Kuban Altinel and Nijaz Bajgoric and Ali Tamer {\"U}nal and Burak Birg{\"o}ren} }