@article {1537, title = {Semi-supervised extensions of multi-task tree ensembles}, journal = {Pattern Recognition}, volume = {123}, year = {2022}, pages = {108393}, abstract = {

Scale inconsistency is a widely encountered issue in multi-output learning problems. Specifically, target sets with multiple real valued or a mixture of categorical and real valued variables require addressing the scale differences to obtain predictive models with sufficiently good performance. Data transformation techniques are often employed to solve that problem. However, these operations are susceptible to different shortcomings such as changing the statistical properties of the data and increase the computational burden. Scale differences also pose problem in semi-supervised learning (SSL) models as they require processing of unsupervised information where distance measures are commonly employed. Classical distance metrics can be criticized as they lose efficiency when variables exhibit type or scale differences, too. Besides, in higher dimensions distance metrics cause problems due to loss of discriminative power. This paper introduces alternative semi-supervised tree-based strategies that are robust to scale differences both in terms of feature and target variables. We propose use of a scale-invariant proximity measure by means of tree-based ensembles to preserve the original characteristics of the data. We update classical tree derivation procedure to a multi-criteria form to resolve scale inconsistencies. We define proximity based clustering indicators and extend the supervised model with unsupervised criteria. Our experiments show that proposed method significantly outperforms its benchmark learning model that is predictive clustering trees.

}, keywords = {Ensemble learning, Multi-objective trees, Multi-task learning, Semi-supervised learning, Totally randomized trees}, issn = {0031-3203}, doi = {https://doi.org/10.1016/j.patcog.2021.108393}, url = {https://www.sciencedirect.com/science/article/pii/S0031320321005549}, author = {Esra Ad{\i}yeke and Mustafa Gokce Baydogan} } @article {1541, title = {Single Machine Campaign Planning under Sequence Dependent Family Setups and Co-Production}, journal = {Journal of the Operational Research Society}, volume = {72}, year = {2021}, pages = {2091{\textendash}2111}, doi = {https://doi.org/10.1080/01605682.2020.1772016}, author = {Serkan Kalay and Z C Ta{\c s}k{\i}n} } @article {1456, title = {Statistical inference using stratified judgment post-stratified samples from finite populations}, journal = {Environmental and Ecological Statistics}, volume = {27}, year = {2020}, pages = {73{\textendash}94}, author = {Ozturk, Omer and K{\"o}n{\"u}l Bayramo{\u g}lu Kavlak} } @article {1427, title = {A strong integer programming formulation for hybrid flowshop scheduling}, journal = {Journal of the Operational Research Society}, volume = {71}, year = {2020}, pages = {2042-2052}, doi = {10.1080/01605682.2019.1654414}, url = {https://doi.org/10.1080/01605682.2019.1654414}, author = {Ali Tamer {\"U}nal and Semra A{\u g}ral{\i} and Z C Ta{\c s}k{\i}n} } @article {1445, title = {SLA-aware optimal resource allocation for service-oriented networks}, journal = {Future Generation Computer Systems}, volume = {101}, year = {2019}, pages = {959-974}, abstract = {

The popularity of traditional network services and web content is succeeded by the recent trend in customized services proliferated by the smart devices and gadgets. Fall-risk assessment, augmented reality, ECG (electrocardiography) monitoring, virtual reality-based gaming and similar services are driven through data generated by multi-modal sensors embedded in the end-user equipment. These services may possess varying characteristics and requirements represented with performance metrics and Quality of Service (QoS) parameters. Even though the small form-factor end-user gadgets are getting powerful in terms of resource capacity, they are still incapable of executing complex routines, and thus these tasks should be offloaded to a remote machine. Service-Centric Networks (SCN) focus on delivering customized services to the users in a location-independent fashion. This is in parallel with previous vision put forward by the Information-Centric Networks (ICN) and Content Delivery Networks (CDN), which aim to enhance the end-user experience. The novel set of services for complementing the daily activities of the end-users mostly depicts a latency-intolerant attribute which ultimately calls for a full-fledged resource allocation scheme. Within this context, both computation and networking resources should be allocated optimally, and task assignments should be handled precisely for following the requirements specified by the Service Level Agreements (SLAs). This paper initially presents and discusses problem definitions that should be addressed by the service-centric multi-tier computing architecture that is composed of edge, metro, and cloud servers. In order to achieve this objective, an SLA-aware optimal resource allocation and task assignment model for service-oriented networks is proposed. This optimization model is based on a nonlinear delay formulation for accommodating service-centric network scenarios under various conditions. It is then reshaped as a mixed-integer linear model through piecewise linear approximation. Additionally, a heuristic implementation is presented to address the time and space complexities of the problem for which the aforementioned optimization models remain ineffective. Performance evaluation results show that the proposed solutions are able to find a good allocation of resources while taking the requirements of the services into account.

}, keywords = {Cloud computing, Edge computing, Network optimization, Service-centric networks, Task offloading}, issn = {0167-739X}, doi = {https://doi.org/10.1016/j.future.2019.07.050}, url = {https://www.sciencedirect.com/science/article/pii/S0167739X19306430}, author = {Ahmet Cihat Bakt{\i}r and Bet{\"u}l Ahat and Necati Aras and Atay {\"O}zg{\"o}vde and Cem Ersoy} } @article {1500, title = {Small 1-defective Ramsey numbers in perfect graphs}, journal = {Discrete Optimization}, volume = {34}, year = {2019}, pages = {100548}, abstract = {

In this paper, we initiate the study of defective Ramsey numbers for the class of perfect graphs. Let PG be the class of all perfect graphs and R1PG(i,j) denote the smallest n such that all perfect graphs on n vertices have either a 1-dense i-set or a 1-sparse j-set. We show that R1PG(3,j)=j for any j>=2, R1PG(4,4)=6, R1PG(4,5)=8, R1PG(4,6)=10, R1PG(4,7)=13, R1PG(4,8)=15 and R1PG(5,5)=13. We exhibit all extremal graphs for R1PG(4,7)=13 (there are exactly three). We also obtain the 1-defective Ramsey number of order (4,7) in triangle-free perfect graphs, namely R1ΔPG(4,7)=12.

}, keywords = {-dense, -dependent, -sparse, Extremal graphs}, issn = {1572-5286}, doi = {https://doi.org/10.1016/j.disopt.2019.06.001}, url = {https://www.sciencedirect.com/science/article/pii/S1572528618301622}, author = {Ekim, Tinaz and John Gimbel and Oylum {\c S}eker} } @article {1475, title = {Substitution elasticities in an energy-augmented CES production function An empirical analysis for Turkey}, journal = {Journal of Economics and Political Economy}, volume = {5}, year = {2018}, month = {Jun}, pages = {234{\textendash}249}, issn = {2148-8347}, author = {K{\"u}{\c c}{\"u}k, Merve and G{\"u}rkan Kumbaro{\u g}lu and SARICA, KEMAL} } @conference {1167, title = {A scale-space theory and bag-of-features based time series classification method}, booktitle = {Signal Processing and Communications Applications Conference (SIU), 2017 25th}, year = {2017}, publisher = {IEEE}, organization = {IEEE}, author = {Altay, Tayip and Mustafa Gokce Baydogan} } @article {1495, title = {The Shifting the Burden Archetype A Workforce and Task Backlog Management Game}, journal = {Korean System Dynamics Review}, volume = {4}, year = {2017}, month = {Feb}, pages = {81{\textendash}110}, author = {G{\"u}ran, Seniha Zeynep and Yasarcan, Hakan} } @article {1188, title = {The Shifting the Burden Archetype: A Workforce and Task Backlog Management Game}, journal = {Korean System Dynamics Review}, volume = {17}, year = {2017}, pages = {81-110}, author = {S.Z. G{\"u}ran and Hakan Ya{\c s}arcan} } @article {1189, title = {The Shifting the Burden Archetype: A Workforce and Task Backlog Management Game}, journal = {Korean System Dynamics Review}, volume = {18}, year = {2017}, pages = {81-110}, author = {A. Mutallip and Hakan Ya{\c s}arcan} } @article {1168, title = {Sensitivity analysis for models with multiple behavior modes: a method based on behavior pattern measures}, journal = {System Dynamics Review}, volume = {32}, year = {2016}, pages = {332{\textendash}362}, author = {Hekimo{\u g}lu, Mustafa and Yaman Barlas} } @article {1511, title = {On some applications of the selective graph coloring problem}, journal = {European Journal of Operational Research}, volume = {240}, year = {2015}, pages = {307-314}, abstract = {

In this paper we present the Selective Graph Coloring Problem, a generalization of the standard graph coloring problem as well as several of its possible applications. Given a graph with a partition of its vertex set into several clusters, we want to select one vertex per cluster such that the chromatic number of the subgraph induced by the selected vertices is minimum. This problem appeared in the literature under different names for specific models and its complexity has recently been studied for different classes of graphs. Here, we describe different models {\textendash} some already discussed in previous papers and some new ones {\textendash} in very different contexts under a unified framework based on this graph problem. We point out similarities between these models, offering a new approach to solve them, and show some generic situations where the selective graph coloring problem may be used. We focus on specific graph classes motivated by each model, and we briefly discuss the complexity of the selective graph coloring problem in each one of these graph classes and point out interesting future research directions.

}, keywords = {Combinatorial optimization, Computational complexity, Graph theory, partition coloring, Selective coloring}, issn = {0377-2217}, doi = {https://doi.org/10.1016/j.ejor.2014.05.011}, url = {https://www.sciencedirect.com/science/article/pii/S0377221714004184}, author = {Marc Demange and Ekim, Tinaz and Bernard Ries and Cerasela Tanasescu} } @article {ekcsiouglu2014save, title = {Save the Musicians! The Ergonomics of the Drumming}, journal = {Advances in Physical Ergonomics and Human Factors: Part II}, volume = {15}, year = {2014}, pages = {269}, publisher = {AHFE Conference}, author = {Mahmut Ek{\c s}io{\u g}lu and {\"O}zt{\"u}rk, N Kaan and {\c S}irin, Orkun} } @inbook {aras2014simultaneous, title = {Simultaneous Optimization of Berth Allocation, Quay Crane Assignment and Quay Crane Scheduling Problems in Container Terminals}, booktitle = {Operations Research Proceedings 2012}, year = {2014}, pages = {101{\textendash}107}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, author = {Necati Aras and T{\"u}rko{\u g}ullar{\i}, Yavuz and Z C Ta{\c s}k{\i}n and I. Kuban Altinel} } @article {35, title = {SMT: Sparse multivariate tree}, journal = {Statistical Analysis and Data Mining}, volume = {7}, year = {2014}, month = {02/2014}, pages = {53-69}, abstract = {

A multivariate decision tree attempts to improve upon the single variable split in a traditional tree. With the increase in datasets with many features and a small number of labeled instances in a variety of domains (bioinformatics, text mining, etc.), a traditional tree-based approach with a greedy variable selection at a node may omit important information. Therefore, the recursive partitioning idea of a simple decision tree combined with the intrinsic feature selection of L1 regularized logistic regression (LR) at each node is a natural choice for a multivariate tree model that is simple, but broadly applicable. This natural solution leads to the sparse multivariate tree (SMT) considered here. SMT can naturally handle non-time-series data and is extended to handle time-series classification problems with the power of extracting interpretable temporal patterns (e.g., means, slopes, and deviations). Binary L1 regularized LR models are used here for binary classification problems. However, SMT may be extended to solve multiclass problems with multinomial LR models. The accuracy and computational efficiency of SMT is compared to a large number of competitors on time series and non-time-series data.

}, keywords = {decision tree, feature extraction, fused Lasso, Lasso, time series classification}, issn = {1932-1872}, doi = {10.1002/sam.11208}, url = {http://dx.doi.org/10.1002/sam.11208}, author = {Houtao Deng and Mustafa Gokce Baydogan and George Runger} } @mastersthesis {857, title = {Solving Integrated Berth Allocation And Crane Assignment Problem Using A Tabu Search Metaheuristic}, year = {2013}, author = {Zeynep {\c S}uvak} } @article {ekim2013some, title = {Some Defective Parameters in Graphs}, journal = {Graphs and Combinatorics}, volume = {29}, number = {2}, year = {2013}, pages = {213{\textendash}224}, publisher = {Springer Japan}, author = {Ekim, Tinaz and Gimbel, John} } @article {1469, title = {A stochastic analysis of asynchronous demand in disassembly processes of remanufacturing systems}, journal = {European Journal of Industrial Engineering}, volume = {7}, year = {2013}, pages = {175{\textendash}205}, author = {Dinge{\c c} , Kemal Din{\c c}er and Aybek Korugan} } @article {Yucel2012, title = {A simulation-based analysis of transition pathways for the Dutch electricity system}, journal = {Energy Policy}, volume = {42}, year = {2012}, pages = {557{\textendash}568}, issn = {03014215}, doi = {10.1016/j.enpol.2011.12.024}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0301421511010299}, author = {G{\"o}nen{\c c} Y{\"u}cel and van Daalen, Cornelia} } @conference {yasarcan2012soft, title = {A Soft Landing Model and an Experimental Platform as an Introductory Control Design Tool}, 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 = {Yasarcan, Hakan and Tanyola{\c c}, Togay} } @proceedings {ozgun, title = {Systemic Complexity of a Growth Management Game: Comparative Analysis of Decision Heuristics and Experimental Results}, journal = {30th International Conference of the System Dynamics Society}, year = {2012}, author = {Onur {\"O}zg{\"u}n and Yaman Barlas} } @article {1479, title = {A sectoral decomposition analysis of Turkish CO2 emissions over 1990{\textendash}2007}, journal = {Energy}, volume = {36}, year = {2011}, pages = {2419-2433}, abstract = {

At a time of increased international concern and negotiations for greenhouse gas emission reduction, country studies on the underlying effects of greenhouse gas emission growth gain importance. The case of Turkey is particularly interesting due to rapidly growing emissions, accompanied by a political will and actions to reduce the quick growth. The refined Laspeyres method is used in this study to identify factors\ that accelerate or reduce the increase in Turkish CO2 emissions. A year-by-year decomposition over 1990{\textendash}2007 is carried out at sectoral level based on disaggregated data that is consistent over time and consistent with international standards. Various interesting results on the underlying effects of sectoral emission growth are found. Valuable insights are gained into CO2 impacts of sectoral policies including energy and emission intensities, fuel switching and activity changes. The results yield important hints for the planning of energy and climate policy.

}, keywords = {Carbon intensity, CO decomposition, Energy intensity, Sectoral emissions, Turkey}, issn = {0360-5442}, doi = {https://doi.org/10.1016/j.energy.2011.01.027}, url = {https://www.sciencedirect.com/science/article/pii/S0360544211000284}, author = {G{\"u}rkan Kumbaro{\u g}lu} } @article {aras2011selective, title = {Selective multi-depot vehicle routing problem with pricing}, journal = {Transportation Research Part C: Emerging Technologies}, volume = {19}, number = {5}, year = {2011}, pages = {866{\textendash}884}, publisher = {Elsevier}, author = {Necati Aras and Aksen, Deniz and Tu{\u g}rul Tekin, Mehmet} } @conference {tanyolacc2011soft, title = {A Soft Landing Model and a Mass Spring Damper Based Control Heuristic}, 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 = {Tanyola{\c c}, Togay and Yasarcan, Hakan} } @article {yasarcan2011stock, title = {Stock management in the presence of significant measurement delays}, journal = {System Dynamics Review}, volume = {27}, number = {1}, year = {2011}, pages = {91{\textendash}109}, publisher = {Wiley Online Library}, author = {Yasarcan, Hakan} } @conference {ekcsiouglusystems, title = {Systems-Based Approach to Safety and Health in the Small to Medium-sized Enterprises}, booktitle = {Proceedings of XIX World Congress on Safety and Health at Work}, year = {2011}, pages = {22{\textendash}23}, publisher = {http://app.csgb.gov.tr/isgum/safety2011turkey/kongresunumlaring.html}, organization = {http://app.csgb.gov.tr/isgum/safety2011turkey/kongresunumlaring.html}, author = {Mahmut Ek{\c s}io{\u g}lu} } @article {ekim2010split, title = {Split-critical and uniquely split-colorable graphs}, journal = {Discrete Mathematics and Theoretical Computer Science}, volume = {12}, number = {5}, year = {2010}, pages = {1{\textendash}24}, author = {Ekim, Tinaz and Ries, Bernard and de Werra, Dominique and others} } @inbook {Hoermann;Leydold:2009a, title = {Sampling from Linear Multivariate Densities}, booktitle = {Advancing the Frontiers of Simulation: A Festschrift in Honor of George Samuel Fishman}, year = {2009}, pages = {143{\textendash}152}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {Heidelberg}, author = {Wolfgang H{\"o}rmann and Leydold, Josef} } @article {ozkisacik2009solving, title = {Solving probabilistic multi-facility Weber problem by vector quantization}, journal = {OR spectrum}, volume = {31}, number = {3}, year = {2009}, pages = {533{\textendash}554}, publisher = {Springer-Verlag}, author = {{\"O}zk{\i}sac{\i}k, Kerem Can and I. Kuban Altinel and Necati Aras} } @booklet {erdincc2009student, title = {Student Specific Cornell Musculoskeletal Discomfort Questionnaires (SS-CMDQ) (Turkish)}, journal = {http://ergo.human.cornell.edu/ahSSCMDQquestTurkish.html}, year = {2009}, author = {Erdin{\c c}, O{\u g}uzhan and Mahmut Ek{\c s}io{\u g}lu} } @booklet {erdincc2009student, title = {Student Specific Cornell Musculoskeletal Discomfort Questionnaires (SS-CMDQ) (English)}, journal = {http://ergo.human.cornell.edu/ahSSCMDQquest.html}, year = {2009}, author = {Erdin{\c c}, O{\u g}uzhan and Mahmut Ek{\c s}io{\u g}lu} } @article {eksioglu2008steering, title = {Steering-wheel grip force characteristics of drivers as a function of gender, speed, and road condition}, journal = {International journal of industrial ergonomics}, volume = {38}, number = {3}, year = {2008}, pages = {354{\textendash}361}, publisher = {Elsevier}, author = {Mahmut Ek{\c s}io{\u g}lu and K{\i}z{\i}laslan, Kemal} } @article {Yucel2008, title = {Studying transition dynamics via focusing on underlying feedback interactions}, journal = {Computational and Mathematical Organization Theory}, volume = {14}, number = {4}, year = {2008}, pages = {320{\textendash}349}, issn = {1381-298X}, doi = {10.1007/s10588-008-9032-4}, url = {http://www.springerlink.com/index/10.1007/s10588-008-9032-4}, author = {G{\"o}nen{\c c} Y{\"u}cel and Chiong Meza, Catherine Miluska} } @article {Hoermann:2007a, title = {A simple Generator for the t-Distribution}, journal = {Computing}, volume = {81}, year = {2007}, author = {Wolfgang H{\"o}rmann} } @inbook {aras2007solving, title = {Solving the capacitated multi-facility Weber problem by simulated annealing, threshold accepting and genetic algorithms}, booktitle = {Metaheuristics}, year = {2007}, pages = {91{\textendash}112}, publisher = {Springer US}, organization = {Springer US}, author = {Necati Aras and Yumusak, Sadettin and I. Kuban Altinel} } @article {aras2006solving, title = {Solving the uncapacitated multi-facility Weber problem by vector quantization and self-organizing maps}, journal = {Journal of the Operational Research Society}, volume = {57}, number = {1}, year = {2006}, pages = {82{\textendash}93}, publisher = {Nature Publishing Group}, author = {Necati Aras and {\"O}zk{\i}sac{\i}k, KC and I. Kuban Altinel} } @article {ekim2006split, title = {On split-coloring problems (vol 10, pg 211, 2005)}, journal = {JOURNAL OF COMBINATORIAL OPTIMIZATION}, volume = {11}, number = {1}, year = {2006}, pages = {125{\textendash}125}, publisher = {SPRINGER VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, author = {Ekim, Tinaz and de Werra, Dominique} } @article {ekim2005split, title = {On split-coloring problems}, journal = {Journal of Combinatorial Optimization}, volume = {10}, number = {3}, year = {2005}, pages = {211{\textendash}225}, publisher = {Kluwer Academic Publishers}, author = {Ekim, Tinaz and de Werra, Dominique} } @conference {yasarcan2005stable, title = {Stable stock management heuristics when the outflow is proportional to the control stock}, booktitle = {The 23rd International System Dynamics Conference, Boston, MA, USA}, year = {2005}, publisher = {System Dynamics Society (http://www.systemdynamics.org/conferences/2005/index.htm)}, organization = {System Dynamics Society (http://www.systemdynamics.org/conferences/2005/index.htm)}, author = {Yasarcan, Hakan and Barlas, Yaman} } @article {Leydold;Hoermann:2004b, title = {Smoothed Transformed Density Rejection}, journal = {Monte Carlo Methods and Applications}, volume = {10}, number = {3{\textendash}4}, year = {2004}, pages = {393{\textendash}402}, author = {Leydold, Josef and Wolfgang H{\"o}rmann} } @conference {altmel2003self, title = {A self-organizing method for map reconstruction}, booktitle = {Neural Networks for Signal Processing, 2003. NNSP{\textquoteright}03. 2003 IEEE 13th Workshop on}, year = {2003}, pages = {677{\textendash}687}, publisher = {IEEE}, organization = {IEEE}, author = {I. Kuban Altinel and Necati Aras and Oommen, BJ} } @article {866098, title = {{Some aspects of using CASE tools in a Fusion-based application development project for production optimization}}, journal = {Industrial Management and Data Systems}, volume = {102}, year = {2002}, pages = {463{\textendash}471}, doi = {10.1108/02635570210445899}, author = {Nijaz Bajgoric and I. Kuban Altinel and Murat Draman and Ali Tamer {\"U}nal} } @inbook {oommen1999solving, title = {Solving the Travelling Salesman Problem using the Kohonen Network Incorporating Explicit Statistics}, booktitle = {Neural Nets WIRN VIETRI-98}, year = {1999}, pages = {273{\textendash}282}, publisher = {Springer London}, organization = {Springer London}, author = {Oommen, B John and Necati Aras and I. Kuban Altinel} } @article {Leydold;Hoermann:1998a, title = {A Sweep-Plane Algorithm for Generating random tuples in simple polytopes}, journal = {Mathematics of Computation}, volume = {67}, number = {224}, year = {1998}, pages = {1617{\textendash}1635}, keywords = {black box, multivariate log-concave distributions, polytope, rejection method, sweep-plane algorithm, T-concave, TDR, uniform distributions, universal method}, author = {Leydold, Josef and Wolfgang H{\"o}rmann} } @article {49169217, title = {{Scheduling of batch processes: An industrial application in paint industry}}, journal = {Computers \& Chemical Engineering}, volume = {21}, year = {1997}, doi = {10.1016/S0098-1354(97)87580-1}, author = {Seza Or{\c c}un and I. Kuban Altinel and {\"O}ner Horta{\c c}su} } @article {14551568, title = {{Scheduling of batch processes with operational uncertainties}}, journal = {Computers \& Chemical Engineering}, volume = {20}, year = {1996}, doi = {10.1016/0098-1354(96)00206-2}, author = {Seza Or{\c c}un and I. Kuban Altinel and {\"O}ner Horta{\c c}su} } @article {ulusoy1993simultaneous, title = {Simultaneous scheduling of machines and automated guided vehicles}, journal = {THE INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, volume = {31}, number = {12}, year = {1993}, pages = {2857{\textendash}2873}, publisher = {Taylor \& Francis}, author = {Ulusoy, G and {\"U}mit Bilge} }