Bulut, Önder

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Profile URL
https://gcris.yasar.edu.tr/handle/123456789/12603
Name Variants
Job Title
Doç.Dr.
Email Address
Main Affiliation
01.01.09.03. Endüstri Mühendisliği Bölümü
Status
Current Staff
Website
ORCID ID
0000-0003-1476-6333
Scopus Author ID
35168573500
Turkish CoHE Profile ID
Google Scholar ID
1273oisAAAAJ
WoS Researcher ID
GVQ-7522-2022
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onder.bulut.jpg (12.44 KB)

Sustainable Development Goals

NO POVERTY1
NO POVERTY
0
Research Products
ZERO HUNGER2
ZERO HUNGER
0
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GOOD HEALTH AND WELL-BEING3
GOOD HEALTH AND WELL-BEING
0
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QUALITY EDUCATION4
QUALITY EDUCATION
0
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GENDER EQUALITY5
GENDER EQUALITY
0
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CLEAN WATER AND SANITATION6
CLEAN WATER AND SANITATION
0
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AFFORDABLE AND CLEAN ENERGY7
AFFORDABLE AND CLEAN ENERGY
0
Research Products
DECENT WORK AND ECONOMIC GROWTH8
DECENT WORK AND ECONOMIC GROWTH
0
Research Products
INDUSTRY, INNOVATION AND INFRASTRUCTURE9
INDUSTRY, INNOVATION AND INFRASTRUCTURE
3
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REDUCED INEQUALITIES10
REDUCED INEQUALITIES
0
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SUSTAINABLE CITIES AND COMMUNITIES11
SUSTAINABLE CITIES AND COMMUNITIES
1
Research Products
RESPONSIBLE CONSUMPTION AND PRODUCTION12
RESPONSIBLE CONSUMPTION AND PRODUCTION
0
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CLIMATE ACTION13
CLIMATE ACTION
0
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LIFE BELOW WATER14
LIFE BELOW WATER
0
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LIFE ON LAND15
LIFE ON LAND
0
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PEACE, JUSTICE AND STRONG INSTITUTIONS16
PEACE, JUSTICE AND STRONG INSTITUTIONS
0
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PARTNERSHIPS FOR THE GOALS17
PARTNERSHIPS FOR THE GOALS
0
Research Products
Documents

35

Citations

213

h-index

8

Go to Scopus profile
Documents

27

Citations

165

Go to WoS profile
Scholarly Output

44

Articles

14

Views / Downloads

0/6

Supervised MSc Theses

11

Supervised PhD Theses

2

WoS Citation Count

92

Scopus Citation Count

135

Patents

0

Projects

1

WoS Citations per Publication

2.09

Scopus Citations per Publication

3.07

Open Access Source

7

Supervised Theses

13

JournalCount
International Symposium for Production Research ISPR 20233
An International Journal of Optimization and Control: Theories & Applications (IJOCTA)2
IEEE Congress on Evolutionary Computation (CEC)2
22nd International Symposium for Production Research ISPR 20222
4th International Conference on Intelligent and Fuzzy Systems (INFUS)2
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Scholarly Output Search Results

Now showing 1 - 10 of 44
  • Thumbnail Image
    Article
    Citation - WoS: 5
    Citation - Scopus: 5
    An embedded Markov chain approach to stock rationing under batch orders
    (ELSEVIER SCIENCE BV, 2019) Mehmet Murat Fadiloglu; Onder Bulut; Fadıloğlu, Mehmet Murat; Bulut, Önder
    We provide an extension to the embedded Markov chain approach of Fadiloglu and Bulut (2010) for the analysis of lot-per-lot inventory systems with backorders under rationing. This extension generalizes the method so that it can be used for the analysis under (Q R) policy. We introduce a new embedded Markov chain of higher dimensionality that keeps track of the ordering process. We finally provide a recursive procedure to generate the steady-state probabilities from the chain and obtain the steady-state distribution. (C) 2018 Elsevier B.V. All rights reserved.
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    Conference Object
    Citation - Scopus: 1
    A Genetic Algorithm for the Economic Lot Scheduling Problem under Extended Basic Period Approach and Power-of-Two Policy
    (SPRINGER-VERLAG BERLIN, 2012) Onder Bulut; M. Fatih Tasgetiren; M. Murat Fadiloglu; Tasgetiren, M. Fatih; Bulut, Onder; Fadiloglu, M. Murat; D Huang; Y Gan; P Gupta; MM Gromiha
    In this study we propose a genetic algorithm (GA) for the economic lot scheduling problem (ELSP) under extended basic period (EBP) approach and power-of-two (PoT) policy. The proposed GA employs a multi-chromosome solution representation to encode PoT multipliers and the production positions separately. Both feasible and infeasible solutions are maintained in the population through the use of some sophisticated constraint handling methods. Furthermore a variable neighborhood search (VNS) algorithm is also fused into GA to further enhance the solution quality. The experimental results show that the proposed GA is very competitive to the best performing algorithms from the existing literature under the EBP and PoT policy.
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    Article
    Control of M/Cox-2/s make-to-stock systems
    (2020) Özgün Yücel; Önder Bulut; Yücel, Özgün; Bulut, Önder
    This study considers a make-to-stock production system with multiple identicalparallel servers fixed production start-up costs and lost sales. Processing times are assumed to be two-phase Coxian random variables that allows us to model thesystems having rework or remanufacturing operations. First the dynamicprogramming formulation is developed and the structure of the optimal productionpolicy is characterized. Due to the highly dynamic nature of the optimal policy asa second contribution we propose an easy-to-apply production policy. Theproposed policy makes use of the dynamic state information and controlled byonly two parameters. We test the performance of the proposed policy at severalinstances and reveal that it is near optimal. We also assess the value of dynamicstate information in general by comparing the proposed policy with the wellknownstatic inventory position based policy.
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    Article
    Citation - WoS: 3
    Citation - Scopus: 5
    Exact analysis of production lines with Coxian-2-distributed processing times and parallel machines
    (Elsevier Ltd, 2021) Özgün Yücel; Önder Bulut; Yücel, Özgün; Bulut, Önder
    This study considers production lines where each station has parallel machines with 2-phase Coxian processing times. The setting in this paper is designed specifically for scrutiny of the replenishment of raw materials and finished goods inventories with intermediate buffers in-between stations. Each buffer has a limit of capacity. Raw material supply and demand for finished goods are generated according to independent stationary Poisson processes. Coxian-2 processing times can be utilized to model failure-prone machines with exponential service times times to failure and repair times. The second phase of Coxian-2 can also be considered as a rework operation visited with a predefined probability. We model the line as a continuous-time Markov chain and propose recursive algorithms to generate the transition rate matrix. Although the general recursive form is specific to 3-station 4-buffer lines routines for calculating the number of states and generating the states work for any M−station (M + 1)-buffer systems. The developed model allows obtaining steady-state distribution and performance metrics such as throughput the average number of items in the buffers and average system cost consisting of production holding and shortage costs. Furthermore we enrich our study with numerical experiments and analyze the impacts of buffer capacities processing rates of the machines and the number of parallel machines on the system performance. Moreover the exact analysis provided in this paper can also be used as the decomposition block for the performance analysis of longer lines. © 2021 Elsevier B.V. All rights reserved.
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    Article
    Citation - WoS: 4
    Citation - Scopus: 5
    A Framework for Capacity Expansion Planning in Failure-Prone Flow-Networks via Systemic Risk Analysis
    (Institute of Electrical and Electronics Engineers Inc., 2022) Nazlı Karatas Aygün; Önder Bulut; Emrah Biyik; Aygun, Nazl Karatas; Bulut, Onder; Biyik, Emrah
    In this article a capacity expansion framework is proposed for failure-prone flow-networks. A systemic risk measure that quantifies the risk of unsatisfied demand due to cascaded edge failures is considered. To minimize the total cost of additional edge capacities while keeping the risk of unsatisfied demand below a certain threshold a general stochastic optimization problem is formulated. The distribution of unsatisfied demand is calculated via Monte-Carlo simulations embodied within a grid search algorithm that identifies the feasible region. Thereafter the cost-optimal edge capacity expansion plan is computed by a differential evolution algorithm. Contributions of this article are: 1) consideration of both immediate investment and future risk costs of capacity expansion plans, 2) a generic flow-network model that can be tuned for different real-life applications, 3) addressing the stochastic nature of both supply and demand simultaneously within a systemic risk framework, 4) use of eigenvector centrality for edge grouping in systemic risk analysis. An extensive numerical study is performed to investigate the effects of different edge grouping methods characteristics of stochastic components and cost parameters on the feasible region and optimal solution. The proposed framework is also demonstrated on a case study adapted from ERCOT 13-bus test system. © 2022 Elsevier B.V. All rights reserved.
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    Doctoral Thesis
    Control and Performance Analysis of Three Station Make-to-Stock Production Lines
    (2021) Yücel, Özgün; Bulut, Önder
    Üretim sistemleri üzerine yapılan çalışmalar, on yıllardır rastgelelik, müşteri gereksinimleri, üretim süreçlerinin belirli özellikleri ve sistem maliyetleri ile başa çıkmaktadır. Stoğa üretim, müşteri hizmet düzeyini artırıp üretim, envanter ve kıtlıklarla ilişkili maliyetlerin dengelenmesini kolaylaştırır. Bu çalışma, stoğa üretim ortamında seri olarak düzenlenmiş üç istasyondan oluşan üretim sistemlerinin üretim kontrolü ve performans değerlendirmesini ele almaktadır. İlk olarak, tek makineli istasyonlar, istasyonlar arasında yer alan yarı mamül stokları ve bitmiş ürün stoğu içeren üretim sistemlerinin eniyi kontrol problemleri incelenmiştir. Taleplerin bir Poisson sürecine göre geldiği bu çalışmada, son ürün stoğundan anında karşılanamayan talepler için kayıp satış bedeli ödenir. Üstel olarak dağıtılmış işlem sürelerine sahip makinelerden oluşan sistem ana model olarak tanımlanırken, genişletilmiş modellerde arıza veya yeniden işleme oluşumları olan daha karmaşık sistemleri incelemek için iki fazlı Coxian işlem süreleri dikkate alınmıştır. Çalışmanın amacı, uzun vade ortalama sistem maliyetini en aza indiren eniyi kontrol politikasını bulmaktır. Markov karar süreci kullanılarak eniyi politikaların yapısı ortaya konmuş ve çalışma çeşitli sayısal örnekler ile zenginleştirilmiştir. İkinci olarak, eniyi kontrol politikaları bulmada karşılaşılan zorlukların üstesinden gelmek adına uygulaması kolay bir politika önerilmiştir. Önerilen politika birçok durumda eniyi politikaya yakın performans göstermektedir. Performansı eniyi politikadan uzak olan durumları iyileştirmek adına, önerilen yaklaşımın geliştirilmiş bir versiyonu da dikkate alınmıştır. Tez kapsamında yapılan son çalışma, iki-fazlı Coxian işlem süreleri, paralel makineler ve sonlu tamponlar içeren üretim hatlarının kesin bir Markov analizini sunar. Hammadde tedariği ve son ürün talebinin bağımsız Poisson süreçleri uyarınca geldiği bu problem, sürekli zamanlı bir Markov zinciri olarak modellenmiş ve geçiş hızı matrisini oluşturmak için özyinelemeli algoritmalar önerilmiştir. Genel özyinelemeli form 3-istasyon 4-tampon sistemlerine özgü olmasına rağmen, durum sayısını hesaplama ve durumları üretme rutinleri herhangi bir M-istasyon (M+1)-tampon sistemi için çalışmaktadır. Geliştirilen model, kararlı durum dağılımını ve verim, sistemdeki ürün sayısı ve ortalama sistem maliyeti gibi performans ölçütlerini hesaplamaya olanak sağlar. Önerilen metodoloji, daha uzun hatların performans analizi için bir ayrıştırma bloğu olarak da kullanılabilir.
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    Conference Object
    Citation - WoS: 5
    Citation - Scopus: 8
    A Dynamic Berth Allocation Problem with Priority Considerations under Stochastic Nature
    (SPRINGER-VERLAG BERLIN, 2012) Evrim Ursavas Guldogan; Onder Bulut; M. Fatih Tasgetiren; Tasgetiren, M. Fatih; Guldogan, Evrim Ursavas; Bulut, Onder; D Huang; Y Gan; P Gupta; MM Gromiha
    Stochastic nature of vessel arrivals and handling times adds to the complexity of the well-known NP-hard berth allocation problem. To aid real decision-making under customer differentiations a dynamic stochastic model designed to reflect different levels of vessel priorities is put forward. For exponential interarrival and handling times a recursive procedure to calculate the objective function value is proposed. To reveal the characteristics of the model numerical experiments based on heuristic approaches are conducted. Solution procedures based on artificial bee colony and genetic algorithms covering both global and local search features are launched to improve the solution quality. The practical inferences led by these approaches are shown to be helpful for container terminals faced with multifaceted priority considerations.
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    Master Thesis
    Paralel üretim kanallı ve hazırlık maliyetli stoğa-üretim sistemlerinin kontrolü
    (2016) Özkan, Sinem; Bulut, Önder
    This study considers production and inventory control problems for a make-to-stock queue with production setup costs, several customer classes and lost sales. At any system state, production decision is to specify whether to activate new production channels or to continue with the currently active ones. If the decision is to activate new channels, a fixed/setup cost is incurred per channel. At the decision epochs where the system experiences demand from any customer class, the controller should also decide whether to satisfy the arriving demand or to reject it. The literature of the control of make-to-stock queues is extended by considering fixed system costs and multiple servers at the same time. Firstly, the structure of the optimal production and rationing policies are characterized and then new/alternative policies that have well-defined structures and are easier to apply are proposed. Numerical and theoretical studies are carried out to assess the performances of the proposed policies. The expected average cost of the optimal production policy for the single-server make-to-stock queue is obtained conducting a renewal analysis.
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    Master Thesis
    Kopmalara eğilimli akış ağlarında sistemik risk analizi ile bir kapasite artış planlama çerçevesi
    (2020) Aygün, Nazlı Karataş; Bulut, Önder; Bıyık, Emrah
    We propose a capacity expansion framework to guarantee a certain service level in failure-prone flow-networks composed of supply, demand and intermediate nodes, and arcs in between. We formulate the problem as a general stochastic optimization model to minimize the total cost of additional edge capacities. Our model allows considering different cost structures corresponding to the nature of different real-life applications. We consider a non-linear cost structure that captures both the immediate cost of investment and the cost of future risk. The feasible region is composed of the additional edge capacities that satisfy a probabilistic constraint (certain service level) which is the probability of total demand-not-satisfied is greater than a predetermined level is less than a risk threshold and a boundary constraint which is the additional edge capacities are greater than or equal to 0. These constraints are based on a systemic risk measure. Systemic risk measure, in contrast to traditional risk analysis on the component level, captures a holistic view of the system-wide operation and calculates the risk of unsatisfied demand. The requirement for system-wide analysis arises from the complex and nonlinear relationship between components of the system. Systemic risk is due to initial edge failures and the cascade of these failures throughout the system. Due to the stochastic nature of initial failures and certain supply and demand nodes, the distribution of unsatisfied demand is calculated via simulations embodied within a Grid Search Algorithm that identifies the feasible region. Cost-optimal edge capacity expansion is computed by a population-based heuristic optimization algorithm, namely, Differential Evolution. Our methodology can be applied to numerous fields including financial systems, power systems and supply chains. We apply our proposed framework to a medium-size general flow-network, and conduct a comprehensive numerical study to investigate the effects of system parameters on the feasible region and optimal solution.
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    Conference Object
    Bus Spare Parts Demand Forecasting via Holt Winter’s Method and Support Vector Regression Algorithm
    (Springer Science and Business Media Deutschland GmbH, 2025) İlker Mutlu; Önder Bulut; Mutlu, İlker; Bulut, Önder; N.M. Durakbasa , K.G. Gülen
    Demand forecasting and spare parts availability are crucial in managing spare parts for public transport systems. The condition of public transport buses is critical for service quality. Regular maintenance and repair of buses can increase public transport usage. This case study focuses on forecasting spare parts demand for a public transport company with more than 1700 buses and five workshops. Considering the variety of bus models and wide range of parts effective demand forecasting is essential to avoid unnecessary holding costs or service interruptions. This study aims to apply two different demand forecasting methods Winter’s Method and Support Vector Regression to a public transport company that makes forecast demands based on experience and to interpret the results. While applying the Support Vector Regression method demand dates and bus ages were used as factors. Parameter optimization and demand forecasting methods were applied to the demand data using Weka software. Data were collected from the company's ERP software between 2019 and 2024. Spare parts were determined from five spare parts from different workshop units of the company. As a result of the study MAPE values were calculated. According to the calculated MAPE values it was determined that both methods gave similar results and successfully captured the demand structure. © 2025 Elsevier B.V. All rights reserved.