Investigation of Traffic Accidents Involving Municipality Buses in Urban Public Transport By Logistic Regression

DergiPark: 773099trakyasobedTraffic accidents are one of the important problems for many developing countries. Although there are many studies in the literature evaluating traffic accidents from different perspectives, the number of studies related to traffic accidents involving city buses, which are frequently used in urban public transportation, is quite limited. This study has been prepared to contribute to filling this gap in the literature. In the study, the factors affecting the traffic accidents involving the city buses used in İzmir within a year were analyzed using logistic regression. In the first part of the study, the factors affecting injured / fatal traffic accidents were determined by binary logistic regression. According to this model, season and driver experience were found statistically significant. In the second part, the accidents were grouped according to their total costs to the institution and the factors affecting the magnitude of the accidents have been determined by using ordinal regression model. Finally, all findings obtained in the study were generally evaluated and interpreted.Trafik kazaları, birçok gelişmekte olan ülke için önemli sorunlardan bir tanesidir. Literatürde trafik kazalarını farklı açılardan değerlendiren birçok çalışma olmasına karşılık, kent içi toplu taşımada sıklıkla kullanılan belediye otobüslerinin karıştığı trafik kazaları ile ilgili çalışma sayısı oldukça sınırlıdır. Bu çalışma, literatürdeki bu boşluğun dolmasına katkı sağlamak amacıyla hazırlanmıştır. Çalışmada İzmir’de kullanılan belediye otobüslerinin bir yıl içinde karıştıkları trafik kazalarına etki eden faktörler lojistik regresyon kullanılarak analiz edilmiştir. Çalışmanın ilk kısmında, yaralamalı/ölümlü trafik kazalarına etki eden faktörler ikili lojistik regresyon ile belirlenmiştir. Bu modele göre mevsim ve şoför tecrübesi değişkenleri anlamlı bulunmuştur. İkinci kısımda ise, kazalar, kuruma olan toplam maliyetlerine göre gruplanmış ve kazanın maddi büyüklüğüne etki eden faktörler ordinal regresyon ile analiz edilmiştir ve elde edilen modele göre kazanın büyüklüğüne anlamlı etki eden faktörler belirlenmiştir. Son olarak ise, elde edilen tüm bulgular genel olarak değerlendirilmiş ve yorumlanmıştır

Otobüs Yedek Parça Üretiminde Ölçüm Sistem Analizi Uygulaması

Rekabet ortamının giderek artması sonucu işletmeler, maliyetlerini düşürmek ve aynı zamanda kalitelerini arttırmak zorunda kalmaktadır. Bu durum işletmeleri çeşitli kalite iyileştirme tekniklerinden yararlanmaya yönlendirmiştir. Altı Sigma başta olmak üzere çoğu kalite iyileştirme yöntemleri veri odaklı yaklaşımlar olup, bu yöntemlerin başarılı olmasının ilk şartı kullanılan verilerin güvenilir olmasıdır. Bu durum kalite iyileştirme çalışmalarında, ilk adım olarak verilerin elde edildiği ölçüm sistemlerinin güvenilirliğinden emin olunmasını gerekmektedir. Bu çalışmada, bir otobüs yedek parçasının ölçümünde kullanılan sistemin güvenilirliği iki farklı yöntem kullanılarak analiz edilmiştir. Her iki yönteme göre kullanılan ölçüm sisteminin kabul edilebilir seviyede yeterli olduğu fakat iyileştirme fırsatları içerdiği sonucuna varılmıştır

Classification of Provinces in Turkey in Terms of Health Indicators with Fuzzy Clustering Analysis

4th International Conference on Intelligent and Fuzzy Systems (INFUS) -- JUL 19-21, 2022 -- Bornova, TURKEYHealth services are critical indicators in determining countries' sustainable development and socio-economic development levels. Especially in the process of the Covid-19 pandemic, it has been understood how important countries' health systems are for their economic status. While the countries compare their health indicators, they also try to implement health policies to reduce the development differences. Therefore, determining and classifying the existing social and economic structures of provinces is very important in examining the development status and possible development trends of provinces and informing regional health policies in parallel. This study it is aimed to classify 81 provinces in Turkey with their health indicators using fuzzy clustering analysis. As a result of the study, homogeneous provincial groups with the same characteristics in terms of health indicators will be determined. In light of the results, policy suggestions will be made to eliminate the development differences between clusters in the proposed regional health policies

Applying Six Sigma in urban public transportation to reduce traffic accidents involving municipality buses

Although Six Sigma is a really effective methodology with its strong data-based decision-making aspect, the majority of Six Sigma applications have focused on the private industry and manufacturing sectors. Moreover, the number of case studies implemented in public service is very limited. Despite the fact that the urban public transport sector directly affects the quality of both citizens' economic and social lives, and is one of the most important indicators of modern cities, the literature has not provided any cases of Six Sigma applications in this sector. This paper presents a case study where Six Sigma DMAIC methodology was implemented in the urban public transport sector. The aim of the case study is to reduce traffic accidents as they constitute a critical problem in this sector. The application of DMAIC methodology and Six Sigma tools and principles were used to identify areas of improvements in specifying appropriate bus drivers for lines/routes and bus types, and also in determining the factors that increase risk overall. In this study, various statistical analyses like ANOVA, logistic regression, k-means cluster analysis, and other non-parametric tests were used. An improvement approximately at a rate of 20% was provided as a result of the gains achieved. The results of the study indicate that the application of systematic and data-driven quality improvement approaches such as Six Sigma or Lean with some simple changes and adjustments can contribute to the service quality of public firms

Minimization of fuel consumption in city bus transportation: A case study for Izmir

In this study, we handle a real life optimization problem of a metropolitan city bus service. The problem's focus is the fuel consumption due to dead mileage, given the bus requirements of all route schedules. We obtain the optimal route bus-garage allocations that minimize the total distance covered in all pull-out and pull-in trips, and reach significant improvement levels with respect to the current situation. We consider the midday demand fluctuations on each route, so that some of the buses have to make extra pull-in and pull-out trips before parking at their night garages after ending their last service trips. Moreover, we develop a multicriteria model which takes into account the fuzzy levels of passenger satisfaction and parking safety combined with the previous minimization objective. (C) 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of the Program Committe

Origin-destination matrix generation using smart card data: Case study for Izmir

In parallel with growing populations and the development of the cities, the traffic densities and respectively the need for public transportation increase. While the local authorities transport the passengers to most of the locations they want, they must also maintain a high-quality public transport system to keep passengers' satisfaction levels high. The most reliable way to conduct such a good transport planning study is to benefit from actual numerical data. The number of the studies related to public transport planning by using smart card data has increased along with the developing technology and widespread usage of electronic fare collection systems. In Izmir city, which has employed an electronic fare collection system since 1999, a fully integrated public transport system has been developed that includes bus, light rail system, metro and ferry modes. In this study, the stages of constructing an origin-destination (OD) matrix that shows the regions where passengers board and alight are evaluated, and an example OD matrix generated by using actual data is interpreted

Determining Six Sigma success factors in Turkey by using structural equation modeling

Since it includes strong statistical and executive techniques, Six Sigma (SS) succeeded in many countries and different sectors. Especially successful SS applications of many international companies have increased the interest of other companies. As a result of this, the number of implemented SS projects in various countries has increased. Although successful SS projects are often in mind, the number of failed projects because of various reasons is not as low as to be ignored. As well as there are many factors that affect the success level of SS projects, and these factors vary according to countries. In this study, a survey was applied to 117 people who have 1 of SS belts in order to determine success levels of the SS projects in Turkey. By using explanatory factor analysis and structural equation modeling, critical success factors were determined. According to the results, project selection and its scope, quality culture and defining and measuring of metrics were determined as the top factors that are affecting success levels of SS projects applied in Turkey. The results of the study were also compared with the results of similar projects implemented in other countries

Media representations of naturalized athletes: Sentiment variations and trends in Turkish media

Turkey has received consistent criticism from international media for having many naturalized athletes in its national squad, both in the Olympic Games and other major international sporting events. Similar criticisms have also been a feature of debates for a long time in domestic media, varying in views toward these athletes. This research focuses on media representations of naturalized athletes in Turkey between 2008 and 2020. We investigated the sentiments of news items from four major Turkish newspapers (Milliyet, Cumhuriyet, Sabah and Fanatik) on their stances toward naturalized athletes over the timespan of 2008-2020. Beside analyzing the sentiment of the media content both cumulatively and fragmentedly, we also identified the yearly trends and most featured sports in this context, combining qualitative and quantitative techniques. Our findings showed that sentiments in Turkish media toward naturalized athletes are mostly neutral and negative as well as with differences varying on the basis of the newspapers and news item types. The most criticism underlined pursuing "shortcut" success with naturalized athletes representing Turkey in the international arena. Among the featured sports, basketball, football, and track and field have been the most discussed ones in the naturalization context

A Novel Oxidative Stress Mediator in Acute Appendicitis: Thiol/Disulphide Homeostasis

Aim. To investigate the role of a novel oxidative stress marker, thiol/disulphide homeostasis, in patients diagnosed with acute appendicitis (AA). Methods. In this study, seventy-one (43 male and 28 female) patients diagnosed with AA and 71 (30 male and 41 female) healthy volunteers were included. Age, gender, body mass index (BMI), haemoglobin (Hb), white blood cell (WBC), c-reactive protein (CRP), and thiol/disulphide homeostasis parameters (native thiol, total thiol, disulphide, disulphide/native thiol, native thiol/total thiol, and disulphide/total thiol ratios) were compared between the groups. Thiol/disulphide homeostasis was determined by a newly developed method by Erel and Neselioglu. Results. The native thiol, total thiol, and the native thiol/total thiol ratio levels were statistically significantly decreased in the AA compared with the control group (p<0.001). Disulphide level and the ratios of disulphide/native thiol and disulphide/total thiol were higher in the AA group than in the control group (p<0.001). There was a negative correlation of CRP with native thiol, total thiol, and native thiol/total thiol ratio while there was a positive correlation of CRP with disulphide/native thiol and disulphide/total thiol in the AA group. In the stepwise regression model, risk factors as disulphide/native thiol (OR = 1.368; p=0.018) and CRP (OR = 1.635; p=0.003) were determined as predictors of perforated appendicitis compared to the nonperforated group. Conclusion. This is the first study examining the thiol/disulphide homeostasis as a diagnostic aid in AA and establishing thiol/disulphide homeostatis balance shifted towards the disulphide formation due to thiol oxidation. Further studies are needed to optimize the use of this novel oxidative stress marker in AA