Endüstri Mühendisliği Bölümü

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Citation - WoS: 0
A Petri Net-based inference network for design automation under nondeterminism applied to mechatronic systems
(Pergamon Press Ltd, 1998) Erden, Z; Erkmen, AM; Erden, A
This paper introduces the completed part of an ongoing research, in which a Petri Net-based design inference network is developed for the representation and analysis of the functions and their interrelationships through information flow for the conceptual design stage of mechatronic systems in order to facilitate design automation. The theoretical framework behind the network is based on transition of Hybrid Automata into Petri Nets and application of this framework is introduced by a mechatronic design example.
Citation - Scopus: 2
A Systems Approach for Technology Assessment and Selection
(2012) Demirkiran, Z.K.; Altunok, Taner; Altunok, T.; Makine Mühendisliği
Each system development project necessitates making decisions on the selection of technologies among available alternatives for the system and is covered in the technology assessment phase in the acquisition process. For the assessment very limited numbers of methodologies most of which are qualitative are defined in the literature. This study aims to propose a systematic model, which can be used as a guide by planners or system architects in the multi-criteria technology selection process. The model also proposes a method to define the critical technology elements for a system. A case study on Unmanned Aerial Vehicle (UAV) communication systems is presented to illustrate the applicability of the model. © 2012 IEEE.
Citation - WoS: 18
Citation - Scopus: 34
Comparison of globoid and cylindrical shearer drums' loading performance
(South African inst Mining Metallurgy, 2006) Ayhan, M; Eyyuboglu, EM; 5072
Drums 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.
Citation - WoS: 1
Comparison on Solving a Class of Nonlinear Systems of Partial Differential Equations and Multiple Solutions of Second Order Differential Equations
(Springer international Publishing Ag, 2019) Akgul, Ali; Baleanu, Dumitru; Akgul, Esra Karatas; Khan, Yasir; Baleanu, Dumitru; 56389; Matematik
Citation - WoS: 3
Cyclical Behavior of Stock ExchangeIndex By Sectors: A Case From Turkey
(Elsevier Science Bv, 2012) Yuksel, Ebru; Bayrak, Ozlem Turker; 18500
In this study, the relation between the cyclical behaviors of stock market indices of industry, service, finance and technology sectors at Istanbul Stock Exchange and gross domestic product of Turkey between the 1998 January and 2011 September, is analyzed. The results suggest that stock exchange indices move in the same direction with economic activity and stock market leads the economy by about one quarter. However, when the sectoral differences are considered, movements in technology sector index are transmitted to economy in two months whereas it is three months for the industrial and service sector. The slowest sector is the financial sector for which pass-through speed is four months. (C) 2012 Published by Elsevier Ltd. Selection and/or peer review under responsibility of Prof. Dr. Huseyin Arasli
Citation - Scopus: 1
Enhanced nutrients removal in conventional anaerobic digestion processes
(2009) Othman, M.Z.; Uludag-Demirer, S.; Demirer, G.N.
One 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.
Citation - Scopus: 0
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
Average 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.
Kamu Kurumlarında Risk Değerlendirmesi İçin Karar Destek Sistemi Önerisi
(2018) Tok, Elif Gülce; Satır, Benhür; Satır, Benhür; 54700; Endüstri Mühendisliği
6331 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.
Katı Atık Depolama Tesisi Yer Seçimi için Birleştirilmiş Hedef Programlama ve AHP Yaklaşımı
(2019) Aydemir-karadag, Ayyuce; 116059
Tüm dünyada, nüfus ve kentleşmenin artması ve gelişen teknoloji ile beraber üretilen atık miktarı da artmaktadır. Katı atıkların bertarafı, büyük oranda düzenli depolama yöntemiyle sağlanmaktadır. Bir düzenli depolama sahasının uygun şekilde projelendirilmesi ve işletilmesi için en önemli ön şart uygun kuruluş yeri seçiminin yapılmasıdır. Sağlıklı, verimli, uzun ömürlü, sürdürülebilir ve yasal düzenlere uygun düzenli depolama yer seçimi çok kriterli bir karar problemidir. Bu çalışmada; Ankara ili ve çevresinde kurulabilecek katı atık düzenli depolama tesisi kuruluş yeri alternatifleri, çevresel, ekonomik, sosyal ve zeminsel kriterler açısından Analitik Hiyerarşi Prosesi (AHP) ile değerlendirilmiştir. Ankara'nın yıllık depolanan atık talebini karşılayacak alternatiflerin arasından seçim yapılması, AHP ile hesaplanan kriter ağırlıklarını ve alternatif önceliklerini kullanan ve sistem gerçeklerini yansıtan hedef programlama (HP) modeli ile sağlanır.
Citation - Scopus: 1
Multi-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
In 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.
Citation - Scopus: 7
Toward Sustainability: A Review of Analytical Models for Circular Supply Chains
(Emerald Group Publishing Ltd., 2022) Ülkü, M.A.; Yıldırım, Gonca; Skinner, D.M.; Yildirim, G.; 45908; Endüstri Mühendisliği
The earth's carrying capacity cannot withstand the pace of consumption resulting from current economic models, mainly the linear economy (LE) built on a throwaway culture. In the last few decades, the concept of a circular economy (CE), aiming to design waste out of the economy and mimic ecosystems, emerged as a strong alternative to LE. Being at the heart of the economic landscape, supply chains (SCs) need to respond to the necessary shift to CE. In so doing, the planning and execution of circular supply chains (CSCs) require a broader comprehension of CE and more sophisticated and large-scale analytical decision models. This chapter surveys extant literature on available best practices and quantitative models for sustainable supply chains (SSCs) and offers a new definition of CSC. Mapping on the knowledge extracted from this classification, potential gaps and strengths in the literature are identified. Key research papers on the "closed-loop" and "open-loop" ends of CSCs are highlighted. Challenges in developing CSC performance indicators and prescriptive models are emphasized. © 2022 by Emerald Publishing Limited. All rights reserved.

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