Recent Submissions

  • Assortment planning under non-linear cost structures 

    Shams, Farzad (Bilkent University, 2019-04)
    We first consider the assortment optimization problem with fixed product costs under the Mixtures of Multinomials (MMNL) Model. The problem is NP-hard even under the Multinomial Logit Model and the existing literature ...
  • Risk-averse multi-stage mixed-integer stochastic programming problems 

    Mahmutoğulları, Ali İrfan (Bilkent University, 2019-01-29)
    Risk-averse multi-stage mixed-integer stochastic programming problems form a class of extremely challenging problems since the problem size grows exponentially with the number of stages, they are non-convex due to ...
  • Computation of systemic risk measures: a mixed-integer linear programming approach 

    Meimanjanov, Nurtai (Bilkent University, 2019-01)
    In the scope of nance, systemic risk is concerned with the instability of a nancial system, where the members of the system are interdependent in the sense that the failure of some institutions may trigger defaults ...
  • Risk-averse multi-class support vector machines 

    Karagöz, Ayşenur (Bilkent University, 2018-12)
    A classification problem aims to identify the class of new observations based on the previous observations whose classes are known. It has many applications in a variety of disciplines such as medicine, finance and ...
  • Age and lifetime based policies for perishable items 

    Poormoaied, Saeed (Bilkent University, 2018-11)
    Many inventory systems hold items which perish after a specific time. Upon perishing, the inventory level falls down to zero which may incur irreparable costs to the system. Therefore, developing a genius control policy ...
  • Combinatorial multi-armed bandits: applications and analyses 

    Sarıtaç, Anıl Ömer (Bilkent University, 2018-09)
    We focus on two related problems: Combinatorial multi-armed bandit problem (CMAB) with probabilistically triggered arms (PTAs) and Online Contextual Influence Maximization Problem with Costly Observations (OCIMP-CO) ...
  • Assortment planning with premium services 

    Akçakuş, Emine İrem (Bilkent University, 2018-09)
    We consider the assortment planning problem of an online retailer who offers products with multiple service types which differ in delivery time. We assume that customers make their choices according to the multinomial ...
  • Generating evenly distributed equitably efficient solutions in multi-objective optimization problems 

    Bashir, Bashir Abdullahi (Bilkent University, 2018-09)
    We consider multi-objective optimization (MOP) problems where the decision maker (DM) has equity concerns. We assume that the preference model of the DM satisfies properties related to inequity-aversion, hence we focus ...
  • A mathematical modeling approach for managing regional blood bank operations 

    Dilaver, Halit Metehan (Bilkent University, 2018-09)
    Blood bank operations are complex affairs since they involve supply chain management of highly perishable goods such as whole blood and blood products. The Turkish Red Crescent (TRC), who is the main responsible organization ...
  • Multi-location assortment optimization under lead time effects 

    Karaca, Utku (Bilkent University, 2018-08)
    We have investigated the assortment planning problem for an online retailer that has multiple ful llment centers to maximize its expected pro t. Each ful llment center is responsible for a customer segment which has its ...
  • Multi-stage stochastic programming for demand response optimization 

    Şahin, Munise Kübra (Bilkent University, 2018-08)
    The increase in the energy consumption puts pressure on natural resources and environment and results in a rise in the price of energy. This motivates residents to schedule their energy consumption through demand response ...
  • Covering vehicle routing problem: applications for refugee related services 

    Buluç, Elfe Naz (Bilkent University, 2018-07)
    The world is facing a refugee crisis because of the ongoing war in Syria, and it is important to develop refugees' life conditions and increase their integration to the host communities. There are several services given ...
  • Post-disaster assessment routing problem 

    Ağlar, Buse Eylül Oruç (Bilkent University, 2018-07)
    Post-disaster assessment operations constitute the basis for the operations conducted in the response phase of the disaster management. Through the assessment of the road segments, the extent of damage and the amount of ...
  • Integrated production transportation and storage policies with carbon costs 

    Erman, Başak (Bilkent University, 2018-07)
    Governments adopt carbon policies such as taxation in order achieve carbon reduction targets set by global agreements. In this study, we analyze a two-echelon supply chain model where production and dispatching decisions ...
  • Stochastic shelter site location under multi-hazard scenarios 

    Özbay, Eren (Bilkent University, 2018-07)
    In some cases, natural disasters happen successively (e.g. a tsunami following an earthquake) in close proximity of each other, even if they are not correlated. This study locates shelter sites and allocates the a ected ...
  • Deblurring text images affected by multiple kernels 

    Dizdarer, Tolga (Bilkent University, 2018-06)
    Image deblurring is one of the widely studied and challenging problems in image recovery. It is an estimation problem dealing with restoration of a linearly transformed image that is additional disturbed with noise. In ...
  • Balance in resource allocation problems: a changing reference approach 

    Erkan, Hale (Bilkent University, 2018-06)
    Fairness has become one of the primary concerns in resource allocation problems, especially in settings which are associated with public welfare. Using a pure e ciency maximizing approach may not be applicable while ...
  • Two approaches for fair resource allocation 

    Yavuz, Mirel (Bilkent University, 2018-06)
    Fairness has become one of the primary concerns in several Operational Research (OR) problems, especially in resource allocation problems. It is crucial to ensure a fair distribution of the resources across the entities ...
  • Structural results for average-cost inventory models with partially observed Markov-modulated demand 

    Avcı, Harun (Bilkent University, 2018-05)
    We consider a discrete-time in nite-horizon inventory system with full backlogging, deterministic replenishment lead time, and Markov-modulated demand. The actual state of demand can only be imperfectly estimated based ...
  • Finite perturbation analysis methods for optimization of inventory systems with non-stationary Markov-modulated demand and partial information 

    Güleçyüz, Süheyl (Bilkent University, 2018-02)
    The state of the economy may fluctuate due to several factors, and the customer demand is a affected from the fluctuations of the state of the economy. Although the inventory holders can predict the state of the ...

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