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Selection of alternative fuel taxis: A hybridized approach of life cycle sustainability assessment and multi-criteria decision making with neutrosophic sets
(Taylor & Francis Online, 2021) Aboushaqra, Nour N. M.; Onat, Nuri Cihat; Kucukvar, Murat; Hamouda, A.M.S.; Kuşakçı, Ali Osman; Ayvaz, Berk
This study presents a combined application of hybrid life cycle sustainability assessment and multi-criteria decision-making, aiming to further advance an integrated sustainability assessment and decision-making for the selection of alternative-fuel taxis. First, a multiregional hybrid life cycle sustainability assessment model is built to evaluate macro-level sustainability impacts of various vehicle types: conventional gasoline vehicles, compressed natural gas vehicles, hybrid, and battery electric vehicles. Second, considering the subjective nature of the evaluation process, the intervalvalued neutrosophic sets-based analytic hierarchy process is suggested to assess the results obtained from the life cycle model to determine the weight of each evaluation criterion. Then, the technique for order preference by similarity to the ideal solution is used to rank the sustainability performance. Two different charging scenarios are also tested. The results show that solar-powered BEVs are the best in the environmental impacts with the exceptions of water consumption and land use. Solar-powered BEVs are superior in human health impact, while, ICVs are the best in compensation and employment generations. The ranking results reveal that solar-powered BEVs are the best alternatives when all indicators are considered, followed by CNG vehicles. The proposed method provides a practical and life cycle-based decision-making approach to support and prioritize effective policies for more sustainable transportation.
Risk assessment of corona virus: Implementing hierarchy of hazard control in workplaces
(Peertechz Publications, 2021) Yıldırım, Fatma Demircan; Ekmekçi, İsmail
The novel coronavirus or the other name Severe Acute Respiratory Syndrome coronavirus-2 (SARS-CoV-2), was fi rst identifi ed in Wuhan, China, in December 2019 among a group of patients that have the same symtoms of viral pneumonia. Due to the socio-economic factors in Zhuhai, Wuhan and globalization have also accelerated the spread of infectious diseases to the other parts of China and the world [1,2], The World Health Organisation (WHO) declared Covid-19 a public health emergency of international concern as of 1 February 2020 and epidemic as pandemic on 12 March 2020. The virus spreads very rapidly and globally, as of 25 February 2021, there have been more than 113 million confi rmed cases of Covid-19, including more than 2.5 million deaths, reported to WHO. Although initation of vaccination have raised hopes of bringing the pandemic under control, the recent news about the mutated variant of the novel coronavirus associated with recent infections make governments and people concerned about the future. WHO is warning that back to old normals is likely to take a long time, possibly several years due to the time required to manufacture and distribute millions of doses of vaccine.
Ömrünü tamamlamış araçların geri kazanımı için belirsizlik altında ağ tasarımı
(Haliç Üniversitesi, 2020) Erdoğan, Duygu; Ayvaz, Berk
Dünya genelinde doğal kaynakların küçümsenemeyecek boyutlarda tükenmeye başlaması ve yenilenebilmenin mümkün olmadığı bu zamanda, en ufak bir ürünün geri dönüşümünün çevresel faydası çok fazladır. Ömrünü tamamlamış araçların (ÖTA) geri kazanımı çevresel faydasının yanı sıra, içerdikleri geri dönüştürülebilir malzemeler nedeniyle ekonomik faydasıyla da dikkat çeken önemli kaynaklardır. Bu çalışmada, ÖTA için açık döngü tersine lojistik ağ tasarım problemi ele alınmıştır. Ele alınan problemi modellemek için ilk aşamada ağdaki tüm parametreler belirli olarak kabul edilip karma tam sayılı doğrusal programlama modeli geliştirilmiştir. İkinci aşamada ise son kullanıcılardan gelen ömrünü tamamlamış araçların miktarı belirsiz olarak kabul edilip deterministik model iki aşamalı stokastik programlama modeli olarak genişletilmiştir. İlk aşamada model söküm tesisleri ve işleme tesislerinin açılması gibi stratejik kararlar alınmıştır. Stokastik modelin ikinci aşamasında ise modele belirsizlik dahil edilerek toplama maliyetleri, taşıma maliyetleri, işleme maliyetleri gibi kararlar alınmıştır. Geliştirilen her iki modelin uygulaması Türkiye’nin Ankara ilinde yapılmış ve sonuçlar değerlendirilmiştir.
A Fuzzy integer programming model to locate temporary medical facilities as part of pre-disaster management
(IGI Global, 2019) Ayvaz, Berk; Kuşakçı, Ali Osman
The number and the scale of natural disasters have drastically increased over the last decades. One of the most vital stages of disaster preparedness is disaster response planning, and it plays an important role in limiting material and immaterial consequences, such as those caused by large scale earthquakes. In order to minimize human suffering and death, the aim of establishing a well-designed humanitarian relief chain must be to provide medicine, water, shelter, emergency food and supplies to the affected areas. From a holistic perspective, providing timely first aid and rapid transfer of injured victims to a medical facility is one of the most essential component of such chain. Thus, the location of first aid hospitals must be determined following a careful thought and planning process. This study presents a fuzzy integer programming model to determine the best location of the temporary hospitals which are expected to support extant state hospitals after a major earthquake. This study applies the proposed fuzzy model to the Üsküdar province of Istanbul and identifies optimum number and locations of field hospitals for a severe earthquake scenario.
Type-2 fuzzy TOPSIS model for green third party logistics provider performance evaluation
(International University of Sarajevo, 2019) Atasever, C.; Ayvaz, Berk
ABSTRACT: Green supplier selection, along with the environmental dimension in the supply chain, has attracted great interest both in the academic and institutional framework however, the supplier selection as well as the evaluation the performance of the current supplier affects the performance of the company and is important. In the real life, uncertainties in decision integral part of this process. are things that exist in the nature of decision making. Fuzzy set theory with the linguistic preferences was used to transform subjective decision-maker perceptions into a tangible net value. In this paper, it is proposed an interval type-2 fuzzy TOPSIS approach for green performance evaluation in GSCM. Then, it is applied in the performance evaluati Party Logistics (3PL) providers to validate the presented model.
Biyoyakıt tedarik zinciri ağ tasarımı çalışmaları için öz düzenleyici haritalar
(Süleyman Demirel Üniversitesi, 2020) Öztürk, Fatih; Kuşakçı, Ali Osman; Ayvaz, Berk; Sırakaya Karakoç, Melike
Son yıllarda çevre dostu yenilenebilir enerji kaynaklarına ilgi artmaktadır. Ülkemizde Enerji Piyasası Düzenleme Kurumu (EPDK) tarafından, 2013 yılından itibaren benzine ve motorine yerli katkı olarak, oranları her yıl arttırılmak üzere biyodizel ve etanol ilave zorunluluğu getirilmiştir. Bu da yenilenebilir enerji kaynakları için etkin ve optimal yeşil tedarik zinciri ağı tasarımı çalışmalarının yapılmasını gerekli kılmaktadır. Bu bağlamda karar vericiler, ekonomik gelişme sağlayan, çevre hassasiyeti olan ve sosyal refahı sağlayan sürdürülebilir çözümler üretmek için biyoenerji, rüzgâr, güneş, dalga, gelgit vs. gibi yenilenebilir enerjilere odaklanmışlardır Bu çalışmada biyoyakıtların tedarik zinciri ağ tasarımları ile ilgili yapılmış geçmiş çalışmalara yer verilmiş ve çalışmalar; amaçları, karar değişkenleri, kısıtları, kullanılan optimizasyon metodu ve sonuçları açısından analiz edilerek değerlendirilmiştir. İncelenen çalışmalar, yapay sinir ağlarının özel bir çeşidi olan öz düzenleyici haritalar (Self Organizing Maps-SOM) yöntemi kullanılarak kümelenmiş ve literatürdeki boşluklar tartışılmıştır. Literatürün incelemesi ve çalışmaların kümelenmesini içeren bu makale, biyoyakıt tedarik zinciri ağ tasarımı ile ilgili çalışma yapacak araştırmacılar için yol gösterici niteliktedir.
Risk assessment and mitigation for unmanned aerial vehicles
(M. B. Mondal, 2020) Yazıcıoğlu, Osman; Borat, Oğuz
UAVs performance is improved, in addition to GPS, they can find routes with artificial intelligence and various techniques, and can fly autonomously. The global UAV market was US$ 25.59 billion in 2018. It is estimated that the market will reach US$70.28 billion by 2029. The first three UAV manufacturers were DCL (USA), Parrot (France) and Yuneec (PRC) and are now being produced in many countries. Aircrafts are exposed to various risks: an aerodynamic stall due to inconsistent sensor readings and inadequate response, hitting a flock of geese or flying objects, pilot being unable to prevent the plane repeatedly nosediving despite following procedures. Therefore, procedures issued by aviation agency for aircraft type certification require an aircraft manufacturer (“applicant”) to demonstrate that its design complies with all applicable agency’s regulations and requirements. Safety risk management is a key component of a safety management system and involves fundamental activities such as identifying safety hazards, and assessing the risks and mitigation. Risk management is an integral component of safety management and involves some essential steps.Take into account any current mitigation measures and assess the seriousness in terms of the worst possible realistic scenario. The risk assessment considered five operational environments; remote, rural, suburban, urban, and congested. Reliability, availability, maintainability, and safety assessment are important study in the development of UAVs. This kind of study is mandatory to increase the reliability of the UAV, its availability, and to reduce repair and maintenance costs.
Thermal optimization of partitioned electric water heaters for energy conservation
(Ms. M. B. Mondal, 2020) Kar, A.K.; Yazicioglu, R.; Yazıcıoğlu, O.
Optimum design and selection of storage type electric water heaters were analyzed for energy conservation. The thermal performance of a single tank electric water heater is compared with that of partitioned electric water heater for the same average domestic hourly hot water use pattern according to Becker’s profile. Both water heaters have the same volume capacity and total power rating while the temperature of the hot water was kept between 60 and 65oC. It is concluded that a partitioned electric water heater provides more hot water and reduces energy consumption whereas the upper part of the tank has 25% of the total volume and 75% of the total power rating. To evaluate single tank and partitioned electric water heaters transient energy balance equations have been derived and solved. Some assumptions made and thermodynamic properties received to use the evaluate differential equations. To represent water heater models equations required data obtained from literature.
Efficiency and productivity analysis in Turkish banking sector with data envelopment analysis and malmquist index
(International University of Sarajevo, 2020) Balcı, Emine; Ayvaz, Berk
ABSTRACT: The aim of this study is to analyze the efficiency and productivity of 3 public, 6 private and 6 foreign deposit banks operating in the Turkish banking sector with the help of data envelopment analysis and Malmquist index.For this purpose, the efficiency of 15 deposit banks operating in the Turkish banking sector between 2014 and 2018 was measured and whether the efficiency of Malmquist productivity index changed over the years. input-oriented Charnes Cooper and Rhodes (CCR) model was used under the assumption of constant return to scale and 4 input 2 output variables were selected. Inputs in efficiency and productivity measurement are defined as; personnel expenses / total assets (%), total loans / total assets (%), equity / total assets (%), total deposits / total assets (%), outputs are defined as; the earning power of assets (net profit / total assets), the earning power of equity (net profit / equity) (%). The Windows Data Envelopment Analysis Program package program was used in the analysis and brokerage approach was adopted. While 4 banks were active under the Constant Return to between 2014 and 2018, 8 banks were found active under the assumption of Variable Return to Scale (VRS).Inefficient banks; target values were calculated by slacks movement and radial movement values to their original values and it was found that the lambda values calculated by Win4Deap program and which banks are peers. The changes observed in Malmquist total factor productivity, technical efficiency, technological efficiency, pure efficiency, scale efficiency and total factor productivity were analyzed as a whole and decision experienced improvement in the 2016-2017 period.

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