Analysis of potential gain from using hybrid vehicles in public transportation

In the last two decades, the pollution in major cities was a growing concern. A significantly large contribution was made by road transportation sources to this problem. EU regulations on emissions and improvements in fu el quality sustained an improvement in air quality through reduction in pollutants. Latest trend taking the environmental issues into consideration in consumer car industry is hybrid vehicles, which use a conventional inner combustion engine using petroleum or diesel fuel, alongside with an electric engine, selectively using the necessary one depending on the current speed and power needs. As the vehicles equipped with this technology create less emission and consume less fuel, investigation o f the potential gain when used public transportation is inevitable. In this study, a comparison-based study will be done between traditional busses using fossil fu el and new technology busses that the Istanbul Municipality selected as candidate fleet, utilizing energy, finance, environment and social responsibility aspects.Doğuş Üniversitesi; TÜBİTA

Logistics process improvement of Kapıkule Border crossing

Çekyay, Bora (Dogus Author) -- Önsel Ekici, Şule (Dogus Author) -- Özaydın, Özay (Dogus Author) -- Toktaş Palut, Peral (Dogus Author)In this study, logistics process improvement of Kapikule Border Crossing, one of the largest customs gates, has been evaluated. It is obvious that, any decrease in trade time is expected to realize positive impact on the logistics competitiveness of a specific country. In order to reduce time across all dimensions of the border process, the improvement of physical infrastructure and the proliferation of procedures are the most important issues that should be focused on. The aim of the study is to improve the Kapikule border crossing by reducing the process time. For this purpose, first, in-depth interviews were conducted with the Kapikule customs gate authorities in order to reveal explicitly the process flows. Subsequently, the current situation at the gate was simulated using the Arena simulation software. Finally, several improvement scenarios were tested to identify the ones that will have the highest impact on reducing the queues and the delays at the border

Fire station location selection for İstanbul

Makale Endüstri Mühendisliği dergisinin "YA/EM 2009 özel sayısı"nda yayımlanmıştır.Özellikle acil hizmetler veren polis, hastane, itfaiye gibi kurumlar için yer seçimi büyük önem taşımaktadır. Uygun bir yer seçimi gerçekleştirilmediği takdirde bunun sonuçları insan hayatını tehlikeye atabilir niteliktedir. İstanbul gibi büyük metropollerde, artan nüfus ve trafik yoğunluğunun yanı sıra bir de metropolün deprem kuşağında olması durumunda, itfaiye araçlarının olay yerine en hızlı şekilde ulaşması hayati önem taşımakta; bu da itfaiye istasyonu yerinin etkin seçimine kritik bir rol yüklemektedir. Bu çalışma; İstanbul Büyükşehir Belediyesi tarafından kararlaştırıldığı gibi, itfaiye teşkilatının her bölgeye en çok beş dakikada erişebilmesi ve kapsama alanının %100 olması hedeflenerek yeni kurulacak olan itfaiye istasyonlarının küme kapsama modeli yardımıyla konumlandırılmasını içermektedir. Bu amaçla bir tamsayı programlama modeli kurulmuş, coğrafi bilgi sistemlerinden elde edilen verilerle model çözülmüş, seçilen yerler için itfaiye kurulması durumunda yangın hizmet düzeyinin değişimi incelenmiştir.For emergency services such as ambulance systems and fire departments, location selection plays a critical role due to the direct impact of these services on human lives. Timeliness plays a primary role in location selection decision of fire stations for large metropolitan cities such as Istanbul with increasing population with a high level of congestion coupled with an imminent earthquake risk. This study is based on a set-covering model for locating new fire stations, which target to serve each area at most in five minutes and improve their coverage area to 100% for Istanbul Municipality Fire Department. Accordingly, a set-covering model is built and solved using the data retrieved from geographical information systems. Finally the change in service level with proposed fire station locations is investigated and further suggestions are provided

A decision support methodology to enhance the competitiveness of the Turkish automotive industry

This is the post-print (final draft post-refereeing) version of the article. Copyright @ 2013 Elsevier B.V. All rights reserved.Three levels of competitiveness affect the success of business enterprises in a globally competitive environment: the competitiveness of the company, the competitiveness of the industry in which the company operates and the competitiveness of the country where the business is located. This study analyses the competitiveness of the automotive industry in association with the national competitiveness perspective using a methodology based on Bayesian Causal Networks. First, we structure the competitiveness problem of the automotive industry through a synthesis of expert knowledge in the light of the World Economic Forum’s competitiveness indicators. Second, we model the relationships among the variables identified in the problem structuring stage and analyse these relationships using a Bayesian Causal Network. Third, we develop policy suggestions under various scenarios to enhance the national competitive advantages of the automotive industry. We present an analysis of the Turkish automotive industry as a case study. It is possible to generalise the policy suggestions developed for the case of Turkish automotive industry to the automotive industries in other developing countries where country and industry competitiveness levels are similar to those of Turkey

Are road transportation investments in line with demand projections? A gravity-based analysis for Turkey

This is the post-print version of the article which has been published and is available at the link below.In this research, an integrated gravity-based model was built, and a scenario analysis was conducted to project the demand levels for routes related to the highway projects suggested in TINA-Turkey. The gravity-based model was used to perform a disaggregated analysis to estimate the demand levels that will occur on the routes which are planned to be improved in specific regions of Turkey from now until 2020. During the scenario development phase for these gravity-based models, the growth rate of Turkey's GDP, as estimated by the World Bank from now until 2017, was used as the baseline scenario. Besides, it is assumed that the gross value added (GVA) of the origin and destination regions of the selected routes will show a pattern similar to GDP growth rates. Based on the estimated GDP values, and the projected GVA growth rates, the demand for each selected route was projected and found that the demand level for some of these road projects is expected to be very low, and hence additional measures would be needed to make these investments worthwhile

Optimizing fire station locations for the Istanbul metropolitan municipality

Copyright @ 2013 INFORMSThe Istanbul Metropolitan Municipality (IMM) seeks to determine locations for additional fire stations to build in Istanbul; its objective is to make residences and historic sites reachable by emergency vehicles within five minutes of a fire station’s receipt of a service request. In this paper, we discuss our development of a mathematical model to aid IMM in determining these locations by using data retrieved from its fire incident records. We use a geographic information system to implement the model on Istanbul’s road network, and solve two location models—set-covering and maximal-covering—as what-if scenarios. We discuss 10 scenarios, including the situation that existed when we initiated the project and the scenario that IMM implemented. The scenario implemented increases the city’s fire station coverage from 58.6 percent to 85.9 percent, based on a five-minute response time, with an implementation plan that spans three years

Effects of quotas on Turkish foreign trade: a gravity model

As stated by a European Union Commission Report (2009), Turkey's role as a world trade participant has grown in recent years, particularly as the country has been capitalizing more on its unique geopolitical position. Given the substantial trade volume and deep-rooted relations between Turkey and the EU, due attention should be paid to their trade and economic relations, and steps should be taken to improve these relations. Turkey is the biggest economy that is in a Customs Union (CU) with the EU, but not a member of the EU, along with Andorra, Monaco, and San Marino. When it joined the CU in 1996, Turkey removed all customs duties and equivalent charges as well as quantitative restrictions. However, some EU countries impose quota limits on Turkish road transporters that may indirectly restrict trade between Turkey and the country in question. This study has investigated the effect of road-transport quotas on Turkish foreign trade with EU countries. A gravity model estimated using panel data from 18 selected EU countries between 2005 and 2012 was used for this purpose. Furthermore, as one of the leading sectors using road transportation for Turkish exports to EU countries, the textile sector was analyzed as a case study. The results indicated that quotas have significant effects on total Turkish exports by road transport as well as Turkish textile exports to EU countries. The estimated loss of Turkish exports to the selected countries in the time period analyzed was 10.6 billion dollars of Turkey's total exports by road transport and 5.65 billion dollars of Turkey's total textile exports. Therefore, it can be concluded that the quota limitations are against CU regulations because they limit not only road transportation, but also trade between parties

Logistics process improvement of Kapikule border crossing

Önsel Ekici, Şule (Dogus Author) -- Çekyay, Bora (Dogus Author) -- Özaydın, Özay (Dogus Author) -- Toktaş Palut, Peral (Dogus Author) -- Conference full title: The 15th International Logistics and Supply Chain Congress (LMSCM), October 19, 2017 through October 20, 2017 in Istanbul, TurkeyIn this study, logistics process improvement of Kapikule Border Crossing, one of the largest customs gates, has been evaluated. It is obvious that, any decrease in trade time is expected to realize positive impact on the logistics competitiveness of a specific country. In order to reduce time across all dimensions of the border process, the improvement of physical infrastructure and the proliferation of procedures are the most important issues that should be focused on. The aim of the study is to improve the Kapikule border crossing by reducing the process time. For this purpose, first, in-depth interviews were conducted with the Kapikule customs gate authorities in order to reveal explicitly the process flows. Subsequently, the current situation at the gate was simulated using the Arena simulation software. Finally, several improvement scenarios were tested to identify the ones that will have the highest impact on reducing the queues and the delays at the border

A Gis-based Decision Support Model For Prioritizing Critical Structures Of Istanbul Transportation Network

Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2011Thesis (PhD) -- İstanbul Technical University, Institute of Science and Technology, 2011Afet, toplum üzerinde fiziksel, ekonomik, sosyal ve çevresel kayıplara neden olan, normal yaşamı durdurarak veya kesintiye uğratarak toplulukları etkileyen doğal, teknolojik ve insan kökenli olayların sonuçlarıdır. Sonucun etkisinin azaltılması birçok açıdan insanlara bağlıdır. Birçok fay hattının bulunduğu ülkemiz de deprem kuşağında sayılmaktadır. Gerek nüfus yoğunluğu gerekse yarattığı ekonomik katmadeğer ile ülkemizin en önemli ili olan İstanbul’da da önümüzdeki 50 yıl içerisinde büyük ölçekli bir deprem beklenmektedir. Olası bu deprem sonucunda, 15 milyonun üzerindeki nüfusunun hayati tehlikesini azaltmak, yaşanacak ekonomik kayıpları en aza indirmek, bireyden, devlet seviyesine kadar herkesin bazı hazırlıklar yapmasını gerektirmektedir. 17 Ağustos ve 12 Kasım depremleri, afet yönetimi konusunda dünyadaki başarılı örnekler arasında olmadığımızı göstermiştir. Binalarımızın yapısal kalitesinin düşüklüğü kadar, gerekli yardımın gerektiği zamanda gerekli yerlere ulaştırılmasında yaşanan sorunlar, afet lojistiğinde de başarılı olamadığımızı göstermiştir. Yaşananların tekrarlanmaması için İstanbul ili ulaşım ağı bütünüyle incelenmiş ve kritik yapıların belirlenmesi için bir model kurulmuştur. İdeal olan durumda tüm yapıların kontrolü ve yeniden inşası gerekmektedir ancak bu finansal, insan kaynağı ve zaman açısından mümkün değildir. Bu nedenle bir önceliklendirme yapılması gerekmektedir. Ulaşım ağının önemini belirlemek için İstanbul Büyükşehir Belediyesi’nden (İBB) farklı birimlerden uzmanlar ile birlikte dört temel kriterli bir model geliştirilmiştir. Modele girdi olacak veriler ise İBB Ulaşım Koordinasyon Merkezi (UKOME), İBB Coğrafi Bilgi Sistemleri (CBS) Daire Başkanlığı’ndan alınan CBS veriler kullanılarak yapılan analizler sonucunda oluşturulmuştur. Sonuç olarak, 897’si köprü ve viyadük, 2027’i yol parçası olmak üzere toplamda incelenen 2924 ulaşım ağı elemanından 32’sinin yüksek derecede, 375’inin ise daha düşük derecede kritik öneme sahip olduğu belirlenmiştir.Disasters are the consequences of a natural or man made events that create physical, economical, social and natural loss, disrupt normal life and effect civilizations. Hence, people can mitigate its effects. With many fault lines located under, Turkey is considered to be on an earthquake zone. With its population and economical input, Istanbul is the most important city in Turkey, and expecting a major earthquake in 50 years. Decreasing the fatal risk of 15 million people living in Istanbul and economical risks require precautions to be taken from individual level to state level. August 17, and November 12 Earthquakes showed that Turkey is not amongst the countries that show successful disaster management examples. In addition to the low build quality of our buildings, problems faced in transporting required supplies to required destionations in required time, showed that we have failed in disaster logistics as well. In order to prevent the mishaps to occur, the transportation network of Istanbul has been investigated thoroughly and a model is presented to determine critical network elements. As financial, human resource and time resources are limited, a prioritization is needed. To determine the important network elements, a model with four main criteria is developed with decision makers from Istanbul Metropolitan Municipality. Data that will act as input to the model is obtained from Transportation Coordination Center and analysis results from Geographical Information Systems data. 2924 network elements are investigated and 32 of them found to have highest critical importance and 375 to have critical importance.DoktoraPh

A Decision Support Model For Airline Crew Scheduling

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2005Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2005Havayolu ekip çizelgelemesi, uçuş ekiplerinin, kanunlarca belirlenmiş yasak ve kısıtlara uyarak, tarifelenmiş tüm uçuşları gerçekleştirmek üzere en düşük maliyetle atanması problemidir. Geleneksel olarak bu problem, küme bölümleme problemi olarak modellenmiştir. Bu çalışmada karar modeli iki aşamalı olarak kurulmuş ve modelin karmaşık bir hal alması engellenmiştir. İlk aşamada tarifelenmiş uçuşları kapsayacak ve maliyeti en düşükleyecek uçuş dizileri oluşturulmuştur. İkinci aşamada da bu uçuş dizilerini hangi ekiplerin gerçekleştireceği bulunmuştur. İlk aşamadaki uçuş dizilerinin oluşturulması problemindeki modelin çözümü için sütun oluşumu, küme bölümleme ve küme kapsama yöntemleri, ikinci bölümdeki atamalar için de macar yöntemi önerilmiştir. Önerilen yöntemler, yerel bir havayolu şirketinin ekip çizelgelemesi problemini çözmede kullanılmış ve şu anda kullanılan yöntemlerden çok daha hızlı ve verimli olduğu görülmüştür.Airline crew scheduling is concerned with finding a minimum cost assignment of flight crews to a given flight schedule while satisfying restrictions of aviation authorities and legal agreements of the airline companies with unions. Traditionally, the problem has been modeled as a set partitioning problem. In this work, the decision model is divided into two stages to prevent complexity. In the first stage a set of duty periods that cover the flights in schedule is constructed. Then, in the second stage, the crew members are individually assigned to every duty period created in the first stage. Column generation, set partitioning and set covering methods are used for enumerating the duty periods in first stage. For assignment of crew members, the hungarian method is suggested. These suggested methods are used to solve a crew scheduling problem for a national airline company and the results are much more rapid and efficient than that of the current manual and heuristic methods used.Yüksek LisansM.Sc