Endüstri Mühendisliği Bölümü Yayın Koleksiyonu
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Article Citation - Scopus: 12On Periodic Solutions of Linear Impulsive Delay Differential Systems(2008) Alzabut, Jehad; Akhmet, M.U.; Alzabut, J.O.; Zafer, A.; 351454; Matematik; 02.02. Matematik; 02. Fen-Edebiyat Fakültesi; 01. Çankaya ÜniversitesiA necessary and sufficient condition is established for the existence of periodic solutions of linear impulsive delay differential systems. Copyright © 2008 Watam Press.Conference Object Forecasting Day of Week Volume Fluctuations in the Intermodal Freight Transportation(Institute of Industrial Engineers, 2011) Ertem, M.A.; Ertem, Mustafa Alp; 52460; Endüstri Mühendisliği; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiAverage daily volume fluctuates intensely based on the day of week in the intermodal freight transportation. Shippers tend to peak around Thursdays and receivers tend to peak around Mondays. These fluctuations bring challenges to the industry in terms of capacity management and getting reliable service from the railroad companies. The purpose of this study is to forecast J. B. Hunt Transport Services, Inc.'s load volume on railroads. Load is meant to be the number of containers that will arrive at a rail ramp during a 24hrs time window. The end in mind is to have better service from the railroad companies and to manage the company owned equipment better. The forecasting model applied to tackle this problem is a multiple linear regression model and is based on the historical in-gate numbers. It uses the previous two year's data and day of week information as independent variables, and current year's data as the response variable. The results indicate better accuracy levels for the model when compared to the two week moving average.Article Citation - WoS: 7Citation - Scopus: 11A Warehouse Design With Containers for Humanitarian Logistics: A Real-Life Implementation From Turkey(Univ Cincinnati industrial Engineering, 2019) Sahin-Arslan, Aysenur; Ertem, Mustafa Alp; Ertem, Mustafa Alp; 52460; Endüstri Mühendisliği; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiThe purpose of this study is to investigate how and at what cost freight containers could be used as an inventory holding mechanism for humanitarian logistics. The layout and cost comparison of two alternatives are performed-stocking in a warehouse and material storage in containers. An optimum layout for storage in containers is proposed. It was found that container stockpiling uses the available area and space better than the warehouse option to stock the same number of material pallets. Leasing and purchasing costs of these alternatives are compared using present worth analysis. The results revealed that the container leasing option is not cost effective when land cost is included. Warehouse leasing results in the least setup cost, however, it incurs more operating costs, including lighting, ventilation, and maintenance as well as handling of the pallets. A real-life implementation of the proposed container stockpiling idea is presented for Turkey.Article Citation - WoS: 18Citation - Scopus: 34Comparison of Globoid and Cylindrical Shearer Drums' Loading Performance(South African inst Mining Metallurgy, 2006) Eyyuboğlu, E.Mustafa; Ayhan, M; Eyyuboglu, EM; 5072; Endüstri Mühendisliği; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiDrums of a modern longwall shearer are manufactured to include various constructional features conveying extracted material onto the face conveyor as efficiently as possible. Designing a drum with a conical shell or with reduced vane length, consequently with a stepper vane angle, is the most widely employed method in an attempt to increase loading efficiency. This study compares loading performances of two such drums, one having a conical shell with modified loading vanes, the other with a cylindrical shell with reduced vane length, Firstly, the loading performances of drums are predicted and the maximum haulage rate attainable with the drums are calculated. Then the performances of drum are compared by long-term comprehensive underground trials with coal shearers under similar conditions during the production operation of Park Termik Cayirhan coalmine in Turkey. Although higher loading performance is predicted for cylindrical drums, the in situ trials point out that Globoid drums have a slightly higher loading performance than cylindrical drums. Furthermore, the relationship between operational variables, i.e. extraction height, sumping depth, haulage rate and in situ loading performance, were investigated statistically on the basis of data gathered during the underground trials.Conference Object Citation - Scopus: 1Multi-Manned Assembly Line Balancing Problems With Sequence-Dependent Setup Times(Curran Associates Inc., 2017) Güner, F.; Güner, Funda; Kellegöz, T.; Toklu, B.; 17931; Çankaya Meslek Yüksekokulu; 08.02. Çankaya Meslek Yüksekokulu; 08. Meslek Yüksekokulları; 01. Çankaya ÜniversitesiIn the production of large-size products (such as automobiles, buses, trucks etc.), designing assembly lines with multi-manned workstations may provide decreasing number of total workstations, requirement of large plant area and product flow time. Depending on the characteristics of the tasks about to be started and the one just completed on the same worker, setup times may be significant. Therefore, in some real life situations, it is possible to see setup times between tasks processed successively. In this study, assembly line balancing problems with multi-manned workstations and sequence dependent setup times are addressed. The formal definition of the problem is firstly presented. Then, its mixed integer programming formulation and is developed. In the computational study, by using these formulations, a set of test instances is solved, and results are provided.Conference Object Differential Algebraic Equations in Primal Dual Interior Point Optimization Methods(Amer inst Physics, 2004) Kasap, S; Kasap, Suat; Trafalis, TB; Endüstri Mühendisliği; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiPrimal dual Interior Point Methods (IPMs) generate points that lie in the neighborhood of the central trajectory. The key ingredient of the primal dual IPMs is the parameterization of the central trajectory. A new approach to the parameterization of the central trajectory is presented. Instead of parameterizing the central trajectory by the barrier parameter, it is parameterized by the time by describing a continuous dynamical system. Specifically, a new update rule based on the solution of an ordinary differential equation for the barrier parameter of the primal dual IPMs is presented. The resulting ordinary differential equation combined with the first order Karush-Kuhn-Tucker (KKT) conditions, which are algebraic equations, are called differential algebraic equations (DAEs). By solving DAEs, we find an optimal solution to the given problem.Article Citation - Scopus: 1Enhanced Nutrients Removal in Conventional Anaerobic Digestion Processes(2009) Othman, M.Z.; Uludag-Demirer, S.; Demirer, G.N.; 01. Çankaya Üniversitesi; 06. Mühendislik Fakültesi; 06.04. Endüstri MühendisliğiOne of the main challenges for one phase anaerobic digestion processes is the high concentration of NH 4 + and PO 4 3- ions in the digested sludge supernatant. This project focuses on enhancing the removal of nutrients during the anaerobic digestion process through fixing both NH 4 + and PO 4 3- ions in the form of struvite (magnesium ammonium phosphate, MAP, MgNH 4PO 4.6H 2O) within the anaerobic sludge. Batch anaerobic digestion tests showed that Mg 2+ concentration in the range 279 - 812 mg/L had insignificant effect on CGP but incurred a slight increase in COD removal. The reactor that had soluble Mg 2+:NH 4 +:PO 4 3- at a molar ratio of 1.28:1:00:1:00 achieved the best performance enhancement of 8% increase in COD removal and 32% reduction in NH 4 + in the reactor supernatant. Overall, the results show that there is a potential to optimise conventional anaerobic digestion such that supernatant lean in P and N, and sludge rich in nutrients are obtained.Article Citation - Scopus: 7A Partial Coverage Hierarchical Location Allocation Model for Health Services(Inderscience Publishers, 2023) Karasakal, O.; Karasakal, E.; Töreyen, Ö.; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiWe consider a hierarchical maximal covering location problem (HMCLP) to locate health centres and hospitals so that the maximum demand is covered by two levels of services in a successively inclusive hierarchy. We extend the HMCLP by introducing the partial coverage and a new definition of the referral. The proposed model may enable an informed decision on the healthcare system when dynamic adaptation is required, such as a COVID-19 pandemic. We define the referral as coverage of health centres by hospitals. A hospital may also cover demand through referral. The proposed model is solved optimally for small problems. For large problems, we propose a customised genetic algorithm. Computational study shows that the GA performs well, and the partial coverage substantially affects the optimal solutions. © 2023 Inderscience Enterprises Ltd.Article Citation - WoS: 1Citation - Scopus: 1Naval Air Defense Planning Problem: a Novel Formulation and Heuristics(Wiley, 2024) Karasakal, Orhan; Kirca, Oemer; Arslan, Caner; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiThis article focuses on air defense in maritime environment, which involves protecting friendly naval assets from aerial threats. Specifically, we define and address the Naval Air Defense Planning (NADP) problem, which consists of maneuvering decisions of the ships and scheduling weapons and sensors to the threats in order to maximize the total expected survival probability of friendly units. The NADP problem is more realistic and applicable than previous studies, as it considers features such as sensor assignment requirements, weapon and sensor blind sectors, sequence-dependent setup times, and ship's infrared/radar signature. In this study, a mixed-integer nonlinear programming model of the NADP problem is presented and heuristic solution approaches are developed. Computational results demonstrate that these heuristic approaches are both fast and efficient in solving the NADP problem.Article Design of a Distribution Network for the School Lunch Program(Academic Publication Council, 2023) Aydemir-Karadag, Ayyuce; Akdere, Erol; 116059; 01. Çankaya ÜniversitesiThe national school lunch program (NSLP) is crucial for providing healthy, inexpensive, or free lunches to children, thus benefiting society. Designing a distribution network for the program requires solving a location and routing problem. In this paper, first, we formulate a multi -objective non-linear integer programming formulation of the problem. Next, we develop a two-step approach since the problem is Np-hard. The first stage presents a K -mean clustering method that deals with routing decisions by determining the locations of food processing centers and allocating schools to these centers. The second stage offers a multi -objective mixed -integer linear mathematical model for finding the locations of distribution centers. Besides economic and environmental factors, we optimize travel time in the network as perishable items are involved. A weighted sum approach is presented for different weights of objectives. We provide a real case study in Turkey to demonstrate the applicability of the two -stage approach proposed in this study. The numerical results provide valuable information for decision -makers and authorities to prioritize and prepare action plans.Article Citation - Scopus: 4Scheduling With Lot Streaming in a Two-Machine Re-Entrant Flow Shop(Regional Association for Security and crisis management, 2021) Duman, M.; Çetinkaya, F.C.; 50129; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiLot streaming is splitting a job-lot of identical items into several sublots (portions of a lot) that can be moved to the next machines upon completion so that operations on successive machines can be overlapped; hence, the overall performance of a multi-stage manufacturing environment can be improved. In this study, we consider a scheduling problem with lot streaming in a two-machine re-entrant flow shop in which each job-lot is processed first on Machine 1, then goes to Machine 2 for its second operation before it returns to the primary machine (either Machine 1 or Machine 2) for the third operation. For the two cases of the primary machine, both single-job and multi-job cases are studied independently. Optimal and near-optimal solution procedures are developed. Our objective is to minimize the makespan, which is the maximum completion time of the sublots and job lots in the single-job and multi-job cases, respectively. We prove that the single-job problem is optimally solved in polynomial-time regardless of whether the third operation is performed on Machine 1 or Machine 2. The multi-job problem is also optimally solvable in polynomial time when the third operation is performed on Machine 2. However, we prove that the multi-job problem is NP-hard when the third operation is performed on Machine 1. A global lower bound on the makespan and a simple heuristic algorithm are developed. Our computational experiment results reveal that our proposed heuristic algorithm provides optimal or near-optimal solutions in a very short time. © 2021 by the authors. Submitted for possible open access publication under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Article The equivalence of discrete convexity and the classical definition of convexity(2006) Yüceer, Ümit; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiThis article presents a proof of the fact that the classical definition of convexity of nondecreasing (increasing) first forward differences for discrete univariate functions is actually a special case of the concept of discrete convexity for functions defined on a discrete space. Consequently proving the discrete convexity of separable functions is simplified and becomes simply showing each univariate function is convex in the classical sense. An illustrative example is provided.Article Citation - WoS: 4Citation - Scopus: 3Optimum Bidding Strategy for Wind and Solar Power Plants in Day-Ahead Electricity Market(Springer Heidelberg, 2021) Keysan, Ozan; Satir, Benhur; Ozcan, Mehmet; 54700; 01. Çankaya Üniversitesi; 06. Mühendislik Fakültesi; 06.04. Endüstri MühendisliğiThere are two possible strategies for wind power plants (WPPs) and solar power plants (SPPs) to maximize their income in day ahead markets (DAM) in the presence of imbalance cost: joint bidding (JB) via collaboration by participating to balancing groups and deployment of storage technologies. There are limited studies in the literature covering the comparative analysis of "JB strategy" with "battery deployment (BD) strategy". In the existence of balancing responsibility, the comparative analysis of these strategies is the main contribution of this study to the literature. Our Second contribution is the analysis of the impact of different regulatory regimes, which are set by the regulatory authority, on total income. JBM (joint bidding model), which is the model for joint bidding via different collaboration groups, is developed for the analysis of JB strategy, BDM (battery deployment model), which is the model covering the deployment of storage technology, is developed for the analysis of BD strategy. The impact of each strategy on total income is analyzed. According to the analysis of the results of the models, while JB strategy, which is sensitive to the regulatory regime, increases the total annual income of the collaboration groups up to 0.65%, BD strategy seems not feasible and financially viable. On the other hand, extra income values per MW of battery for SPP is between $218 and $400 /MW-year, while these values are between $2460 and $6795/MW-year for the group of 15 WPPs. Therefore, deployment of battery for WPPs creates extra income more than tenfold of that of SPP. BD strategy can be viable provided that the levelized cost of deployment of battery drops below the extra income values achieved per MW of battery.Book İngilizce Türkçe Endüstri mühendisliği ve mühendislik terimleri sözlüğü(TMMOB, 2009) Çetinkaya, Ferda Can; 50129; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiArticle Marjinal Analiz Yoluyla Güvenilirlik Optimizasyonu(2005) Yüceer, Ümit; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiMarjinal analizin güvenilirlik redandansı optimizasyonuna bir uyarlaması anlatılmaktadır. Amaç fonksiyonu ayrışık hale dönüştürülüp, konkav olduğu gösterilecek ve marjinal analiz metodunun çok seri ve hızlı bir şekilde, optimal olmasa bile, optimala çok yakın çözümler ürettiği bir örnekle gösterilecektir.Conference Object TKİ-OAL çayırhan yeraltı işletmesinde hazırlık çalışmalarının değerlendirilmesi(2004) Eyyuboğlu, E. Mustafa; Bölükbaşı, Naci; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiOrta Anadolu Linyitleri (OAL) ülkemizde tam mekanizasyonun uygulandığı ilk yeraltı işletmesidir. 1977 yılında ilk olarak Galeri Açma Makinaları'nm (GAM) kullanımı ile başlayan mekanizasyon çalışmaları 1985-1986 yıllarında yeraltı ocağında makinaların montajı ile devam etmiş ve 1987 yılında mekanize üretim başlamıştır. OAL'nin işletmecilik hakları 2000 yılından itibaren Park Termik A.Ş'ye devredilmiş olup kömür üretimi bu şirket tarafından yürütülmektedir. Bu çalışmada OAL'nin mekanize üretim için hazırlık çalışmalarını başlattığı 1977 yılından, işletme haklarını devrettiği 2000 yılına kadarki sürede yaptığı galeri açma çalışmalarının kapsamlı bir değerlendirilmesi sunulmuştur. Sonuçlar, işletmede özellikle son yıllarda yeterli performansa ulaşılamadığını göstermektedir.Article Kamu Kurumlarında Risk Değerlendirmesi İçin Karar Destek Sistemi Önerisi(2018) Tok, Elif Gülce; Satır, Benhür; 54700; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi6331 Sayılı İş Sağlığı ve Güvenliği (İSG) Kanunu’nun 31.12.2012’de yürürlüğegirmesinden itibaren risk değerlendirmesi bütün işyerlerinde zorunlu halegelmiştir. Bu çalışmada iş sağlığı ve güvenliğinin önemli bir öğesi olan riskdeğerlendirmesinin kamu kurumlarında yapılmasını daha sağlıklı hale getirecekve kolaylaştıracak bir rehber hazırlanmıştır. Bu rehber bir kontrol listesi ve ilgilirisk tablosundan oluşmaktadır. Gerek ülkemizdeki 6331 Sayılı İSG Kanununda veilgili yönetmeliklerde, gerekse de OHSAS 18001 İSG Yönetim Sisteminde, sürekliiyileştirmenin önemi açıkça görülmektedir. Bu çalışmada hazırlanan rehberinuygulanmasında riskin kabul edilebilir seviyeye inene kadar risk değerlendirmesiniizlemeyi sistemli ve kolay hale getirerek sürekli iyileştirmenin gereklerini sağlamaküzere bir Karar Destek Sistemi önerilmiştir. Birim, kaynak ve tehlike parametreleribir bütün olarak ele alınarak BKT olarak değerlendirilmiş ve sistemin veri tabanıaltyapısı bunun üzerine kurulmuştur. Risk değerlendirmesinin ana öğeleri olan BKT,risk ve önlem ilişkilerinin Varlık-İlişki Çiziti hazırlanarak en büyük ve en küçükkardinallik oranları her ilişki arasında tanımlanmıştır. Fikir vermesi açısından bazı kullanıcı arayüzleri tasarlanmış ve önerilmiştir. Farklı sektörlerde yapılmış benzerçalışmalar mevcuttur ancak gerek kamu kurumları düşünüldüğünde gerekse deuygulama için önerilen karar destek sistemi düşünüldüğünde bu çalışma bilgimizdahilinde literatürdeki ilk çalışmadır.Conference Object Sector Selection for Cluster Formation at OSTİM Industrial Zone: An AHP Application(2009) Çetinkaya, Ferda Can; Kandiller, Levent; Satır, Benhür; Umutlu, Mehmet; 50129; 06.04. Endüstri Mühendisliği; 03.04. İşletme; 03. İktisadi ve İdari Birimler Fakültesi; 06. Mühendislik Fakültesi; 01. Çankaya ÜniversitesiConference Object Sansürlü veriler temelinde yeniden örnekleme tekniklerine dayalı tahmin edicilerin istatistiksel değerlendirilmesi(2003) Yıldırım, Fetih; Yıldırım, Gonca; 4590; 09.01. Ortak Dersler Bölümü; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 09. Rektörlük; 01. Çankaya ÜniversitesiConference Object PROMETHEE Yöntemini Beklenti Teorisi ile Uyumlandıran Bütünleşik bir Yaklaşım(2018) Karasakal, Orhan; Karasakal, Esra; 216553; 06.04. Endüstri Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
