LEE- Deniz Ulaştırma Mühendisliği-Doktora

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http://hdl.handle.net/11527/19252

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Modelling departure time, destination and travel mode choices by using the generalized nested logit model: an example for discretionary trips

( 2020) Elmorssy, Mahmoud Morssy Mohamed ; Tezcan, Hüseyin Onur ; 635767 ; İnşaat Mühendisliği Ana Bilim Dalı

Nowadays, understanding the influences of different temporal and spatial factors on individuals' travel choices becomes essential especially after the pandemic of COVID-19 that invaded the world in 2020. Such an outbreak had its own influences on the future transportation planning studies. By words, policy makers have directed their interests toward newly emergency transportation policies that aim to distribute travels over wider time and space spans in accordance with precautionary and preventive measures to counteract Corona virus or any other similar future virus attacks. However, transportation planning studies still rely on traditional demand modelling approaches such as the four-step model. The four-step model is still exposed to considerable criticism for its shortages in representing the potential correlations between temporal, spatial factors and different travel dimensions which leads to inaccurate representations of individuals' actual travel behaviour. In order to overcome that, some researches have directed their interests toward using choice modelling approach as an alternative to some stages in four-step model. Even though these approaches show better performance in terms of goodness of fit and predictability power, most of them have represented travel dimensions individually rather than jointly. As there is a gap in literature about representing a unified choice model that connect different travel demand dimensions and consider various potential inter-correlation among them, this dissertation contributes filling this gap through introducing three research papers that employ various types of discrete choice models for jointly representing three major travel dimensions; destination, departure time and travel mode. Such models contribute more to mathematical modelling literature of transportation demand models that provide more detailed and specific micro-policy analyses where traditional four-step model cannot. The presented papers introduce three discrete choice models that differ in the level of accounting for correlation of error terms within elementary alternatives and therefore differ in cross-elasticity pattern while offering computational simplicity. In the first paper, limited number of correlation patterns is introduced by adopting the three-level Nested Logit (NL) models. In the second paper, opposite to traditional NL models that was introduced in previous paper, this paper assesses the effect of considering spatial correlation of adjacent discretionary destinations on the choice of the two other travel dimensions by using the Ordered Generalized Extreme Value (OGEV) approach. The third paper, introduces a novel modelling methodology for using the Generalized Nested Logit (GNL) model to represent multi-dimensional potential correlations; between different travel dimensions (inter-correlation), inside the same travel dimension (inner-correlation) and correlation due to ordered nature travel dimensions (e.g. spatial correlation among destinations and temporal correlation between departure times). Overall, in the published papers, different levels of correlation between departure time, destination and travel mode choices and within each travel dimension are represented through different assumed correlation structures according to the nesting structure limitations provided by each model. Moreover, the associated formulas for each proposed model that reflect different patterns of correlation (cross-elasticity) are explicitly introduced. From a policy implications standpoint, a calibrated version of departure time, destination and travel mode model will provide policy makers very detailed analyses about the inter-relationships associated with the three travel dimensions (while traditional four-step model cannot provide at micro-level). That leads to more certain, specific, efficient and precise policy decisions. Thus, developing these models can be considered as a significant milestone toward obtaining a consistent, efficient and integrated full-scale model that can lie in all travel demand dimensions (e.g. number and duration of activities for activity and tour-based models). The developed models have been estimated and calibrated by using shopping and entertainment trips data of Eskisehir city, Turkey. The data have been collected through a household survey that was conducted in 2015 in the context of Eskisehir strategic master plan project which was operated by Eskisehir Metropolitan Municipality. Eskisehir is a city in north-western Turkey. It is considered as a medium sized city with a population of 799724 (2013 census) distributed over about 2678 km2 area. The collected data include variables that represent attributes of alternatives and individuals' characteristics to be used in models' utility functions. The first group of alternatives' attributes is travel time related attributes where, in vehicle time and out of vehicle time (egress time, at stop waiting time and access time) for each individual trip have been obtained. Moreover, related to travel cost, the fare of public transportation modes (for public transportation users), trip cost for private cars as well as parking fees (for private car users) have been observed for each individual trip. Within the collected revealed data, a good portion of socio-economic individual characteristics related observations are presented. These data include car ownership, individual's age, monthly income and student status (if respondent is a student or not). The total number of observations related to the determined alternatives has been found to be 529. The estimation results of each model have been explicitly interpreted in each paper and logical as well as statistical comparisons between pairs of models have been conducted in order to ensure the superiority of more advanced approaches (OGEV and GNL) over the lesser ones (NL). In the light of the estimation results, generally, individuals have been found to jointly decide on "at which departure time", "to which destination" and "by which mode" rather than doing this separately as assumed by traditional four-step model. Neglecting the potential correlation among alternatives of the three travel dimensions has led to inaccurate estimates of measurements' indicators such as Value of Time (VOT) which results finally in incorrect and improper policy decisions. From another hand gradual improvements in predictability have been observed as the level of the represented correlation increases. That is, three-level NL model was found to offer improvements over Multinomial Logit (MNL) model, OGEV model is prominent over NL model and GNL is superior over all models. It is possible to argue that the proposed GNL approach has distinct improvements over all other proposed approaches. Its simplicity along with the incomparable flexibility in representing a lot of correlation patterns within and among three vital travel dimensions all of that under a unified modest model qualify it to be prominent. The proposed GNL model has provided very detailed analyses about the inter-dependencies associated with various departure times, travel modes and discretionary destinations where other models cannot. The estimation results have expressed the powerful analytical ability of the proposed GNL approach where it has the power of capturing unusual correlation patterns. These patterns are thoroughly specific, unexpected, and very difficult to be observed in the market. By words, the dissertation argues that there is no other approach as simple as the proposed GNL and leads to such temporal and spatial specific analyses. The advantages associated with the proposed GNL approach qualify it to be a strong peer to the traditional four-step model in micro-disaggregate modelling scopes if applied for medium and small-scale planning studies that involve limited number of alternatives in each travel dimension. It may be used with a large number of alternatives in each travel dimensions as well, however, through stratifying the whole population to small segments based on one or more travel dimensions to produce small segments suitable for readily estimation process. Finally, the proposed GNL methodology represents a time of day-based trip-end distribution model that can reproduce a considerably more accurate transportation mode based origin-destination matrix dependent on time of day. Moreover, unlike traditional four-step models, parameter estimates produced from the GNL model can provide significant indications which precisely reflect the individuals' actual behaviour. Obviously, that can enormously help policy makers to reach a solid perception about the effects of applying various strategies to manage demands through different times of day and towards different destinations.
Fuzzy logic system applied to the optimization of BWMS with emphasis on stakeholders' management

( 2020) Da Silva Jorge, Sara ; Satır, Tanzer ; 625761 ; Deniz Ulaştırma Mühendisliği Ana Bilim Dalı

The International Convention for the Control and Management of Ships' Ballast Water and Sediments (IMO, 2018 Edition) was adopted in 2004 and came into force on 8 September 2017, aiming to produce global regulations to monitor and control the transfer of potentially invasive species. Large efforts have been made by the maritime industry in creating reliable strategies for the installation of systems on board (Register, 2014). Environmental considerations (INTERTANKO, 2018) and optimization of the management systems (IMO, 2017 Report) are the main factors considered to tackle this matter. These factors are translated into a wide range of solutions for retrofitting and new building services, which is evidenced through the substantial amount of data disclosed and analyzed by different parties showing that optimization processes will have an important role for management systems. The analysis of a BWMS project in terms of implementation involves a series of requests in both the initial and concept phases, which are operationally and technically based. The project feasibility, as the market becomes more competitive, is a major aspect to managing projects of this order with the highest levels of monitoring and process control. At a time when engineering processes are reliant on large sources of data, and multienvironmental constraints cannot be neglected, consistent analysis must be studied and applied in the maritime industry. The project management, on the sub field of stakeholders' management, (Bourne, 2016) brings a myriad of shipping agents connected to ballast water management matters with different levels of knowledge, experience and commitment - according to the engineering perspective. From an engineering perspective, categorizing the agents involved and assessing the outcomes are important matters. The stakeholders' expertise is considered at the BWM Convention and its amendments set an important call, in terms of deliverables, to the industry. Avoiding any delay in operation is not the only answer to this call; setting up an optimized and sustainable operation after the installation project for a BWMS is also important. A consistent implementation strategy must be stated before the BWM system installation project starts – the management of stakeholders' is an important aspect of this process. This relies on their expertise, which in turn results in a high level of engagement and supports the implementation plan into the organizations. Another aspect to be taken into account for this analysis is the oil tankers' unique characteristics of purpose and operation, which can be amplified by their hazardous atmosphere. This brings the application of specific classification areas and explosion proof to the system to be installed on board. In this thesis, this type of vessel isxxii highlighted, due to its high levels of regulation, compared to other segments, for example, bulk carriers. In the introduction, the establishment of a framework of management systems to be optimized, with the location of the main constraints, is addressed. Frameworking the process doesn't mean restricting the process, as the research is a dynamic entity, subject to revisions as the investigation advances. The framework provides an understanding of the research and the overall picture as to what it includes and where it starts and finishes. The study of the technical solutions for the management systems available is the first objective of the data analysis in this thesis. Understanding how the makers are presenting solutions according to the BWM Convention is important, because most of the consultants in the market are presenting their analysis for installation based on rankings offered by the same range of data (IMO provides a list of final approved makers). As the research progressed, the stakeholders' management analysis became the main point, where the expertise of the key stakeholders about the BWM Convention is measured, analyzed and translated into a group of coefficients, which are central to the optimization process. The data analyzed was obtained from a series of interviews made from January/2019 to August/2019. Then, the use of Fuzzy Logic principles (Mamdani) – as an instrument of evaluation from the rankings obtained by multi-criteria analysis (from the database of makers) accomplishes the main objective of this thesis, where the peculiarities about oil tankers' modelling are demonstrated through the analysis of 2 optimization case studies (Suezmax and Aframax)
Development of a dynamic navigational risk assessment model

( 2020) Şenol, Yunus Emre ; Arslan, Özcan ; 635623 ; Deniz Ulaştırma Mühendisliği Ana Bilim Dalı

Marine traffic, which has an increasing importance in terms of global freight and passenger transportation, has increased significantly in recent years and has brought some navigational safety problems. An increase was observed especially in collision and grounding accidents in especially dense waterways. In order to find solutions to this problem, many academic studies have been carried out that offer different sights and analysis methods. In the literature review stage made within the scope of the thesis, the studies on the subject were examined in detail, the factors included to calculations, the methods utilised and their applicability to the solution of the problem were evaluated. Although the studies in the literature constitute an academic value in terms of their proposed methods and approaches, it has been evaluated that many of them are insufficient in terms of applicability, namely the solution of the problem faced by the industry. As a matter of fact, there is no real-time dynamic risk analysis algorithm that can work onboard ship which is capable of corresponding the needs of the industry. In addition, many studies in the literature do not seem to address both the risks of collision and grounding at the same time. Studies in which only collision or grounding risk analysis was presented could not fully meet the expectations of the maritime sector. For this reason, it is aimed to develop a real-time dynamic risk analysis algorithm with some novel and strong aspects which can provide decision support to the officer on watch, can work integrated with real navigational equipment. The proposed algorithm consists of 4 main stages as Automatic Identification System (AIS) Module where AIS data are decode and parsed, Electronic Navigational Chart (ENC) Module that allows reading ENCs, Calculation Module where all risks and other required calculations are performed, and Visualisation Module where risk indicators are projected with AIS targets over the visualized ENCs. The National Marine Electronics Association (NMEA) 0183 infrastructure, which is the standard data exchange protocol of ship navigation equipment, has been added to the algorithm so that it can be integrated to navigation equipment for real-time calculations. All of the factors obtained from integrated navigation equipment used as data source and which may affect the risk of collision and grounding were included directly or indirectly as inputs. Information of Closest Point of Approach (CPA), Time to Closest Point of Approach (TCPA), relative bearing, relative speed, ship's length and ship's type are determined as the system inputs of the algorithm. Own ship and target ships perceived with AIS data are not considered as a single point as in the classical approaches in the literature. Instead, the actual dimensions of the ships are calculated by considering the position information of the Global Positioning System (GPS) receiver sent by OTS on the ship. Ship forms created in real dimensions are perceived as a set of multi-points consisting of points in which a distance of less than 10 meters between each one, and risk calculations of collision is carried out in real time by including all of these points in consideration. Similarly, shallow contour information obtained using ENC, which is dangerous in terms of vessel draft value, is perceived as a set of multi-points with a distance of less than 10 meters between them. Risk calculations have been conducted with the Fuzzy Inference System (FIS) method, which is widely used as one of artificial intelligence methods, from medicine to many branches of engineering. A case study was carried out by applying the AIS data of a ship navigating in the Istanbul Strait to the model. In this study, it is aimed to develop a model to reduce the risks of collision and grounding by increasing situational awareness and thus providing a decision support.
A quantitative approach on human factor analysis in maritime operations

(Lisansüstü Eğitim Enstitüsü, 2021) Erdem, Pelin ; Akyüz, Emre ; 686914 ; Deniz Ulaştırma Mühendisliği

The maritime authorities and international organizations have taken the issue of the pivotal role of the human element and its contribution to the safety of ship operations very seriously due to the growing global concern over maritime disasters. At this point, that at least 80 per cent of shipping casualties are related to the human element is underpinned by the conducted studies and investigation reports published by organizations such as IMO (International Maritime Organization), ILO (International Labour Organization) and experts in the field. Despite the economic and technological improvements, since tragic events had caused the worst environmental disasters in recent years, never has the human element been so crucial in the safe operation of ships. However, although the issue of human contribution to unsafe shipboard operations needs to be the focal point of the researches, there has not been a qualified novel study that can meet the gap of the maritime transportation industry. The purpose of this thesis is to develop a uniquely quantitative approach to evaluate the human error probabilities (HEPs) and to analyse the increasing operational risks due to human errors. In this context, a hybrid approach incorporating Fault Tree Analysis (FTA) and Interval type-2 fuzzy-based Success Likelihood Index Method (SLIM) is developed. The approach, additionally contributing to current human error probability assessment methods in academic literature, is applicable to all shipboard operations regardless of vessel type. With the study under this thesis, it is predicted to provide supportive guidance that enables shipping companies to undertake the early detection of unsafe cargo operations before they get out of control. With the risk assessment concentrated on the concept of the human-related operational failure by implementing the hybrid approach, system vulnerabilities that could result in an undesired event are considerably detected and the awareness in shipping safety management is increased. It is also predicted to reach solid targets by providing both qualitative and quantitative data to maritime container transportation safety as well as an insight into what measures may be necessary to reduce future losses. A hybrid approach that differs from a traditional HEP assessment, suitable customization to containership platform, a methodology that involves key risk and performance shaping factors (PSFs) based on the literature, industry standards, technical knowledge of marine experts and analysis of marine accident investigation reports, increased consistency in expert judgements, and analysis of the root causes of major risks to operational safety can be mentioned as original aspects of the thesis. Implementation of management of human error probability analysis integrating with risk analysis will provide a consistent tool for the maritime industry. As a result, the study offering proactive solutions to related issue of unsafe shipboard operations that closely related to both economic and environmental aspects of the maritime transportation industry will provide tangible contributions for enhancing safety.
Coğrafi veriye analitik bilgiye dayalı denizcilik okulları segmentasyonu ve kalite değerlendirmesi

(Lisansüstü Eğitim Enstitüsü, 2021-04-12) Güzel, Esat ; Bolat, Pelin ; 512152007 ; Deniz Ulaştırma Mühendisliği

Küresel ticarete konu malların taşınmasında % 90'dan daha fazla paya sahip olan denizcilik sektörünün işgücü kaynağı nitelikli gemiadamlarıdır. Her ne kadar insansız gemiler ve tam otomasyona sahip gemiler üzerinde çalışmalar devam etse de yakın gelecekte gemiadamına olan ihtiyacın azalması bir yana özellikle zabit sınıfı gemiadamları açığının giderek artacağı öngörülmektedir. Türkiye'de denizcilik eğitimi Yükseköğretim Kurulu (YÖK)'e bağlı fakülteler, yüksekokullar ve meslek yüksek okullarında, Milli Eğitim Bakanlığı (MEB)'e bağlı resmi ve özel meslek liseleri / denizcilik meslek liseleri ile özel denizcilik kurslarında icra edilmektedir. Gemiadamları eğitiminin, Türkiye'nin de taraf olduğu "Gemiadamlarının Eğitim Belgelendirme ve Vardiya Tutma Standartları Hakkında Uluslararası Sözleşme (STCW-1978)" hükümlerine uygunluğunu denetleme ve bu sözleşmeye göre gemiadamlarının belgelendirilmesi, Türkiye'nin denizcilikten sorumlu idaresi olan Ulaştırma ve Altyapı Bakanlığı tarafından yerine getirilmektedir. Dolayısı ile Türkiye'deki denizcilik eğitim kurumları kuruluş ve işleyiş bakımından eğitim seviyesine göre MEB'e ve YÖK'e bağlı olsa da gemiadamları eğitiminin akreditasyonu ve belgelendirilmesi açısından Ulaştırma ve Altyapı Bakanlığı'na tabidir. Bu yetkilendirme STCW-1978 Sözleşmesi gereklerine uygun olarak yürürlüğe konulan Gemiadamları ve Kılavuz Kaptanlar Eğitim ve Sınav Yönergesi hükümlerine göre yapılmaktadır. Yönergeye göre eğitim kurumlarının ekipman, müfredat, derslik, eğitici, simülatör, denizde güvenlik eğitimi tesisi, kalite yönetim sistemi gibi kriterleri sağlaması gerekmektedir. Aralık 2020 itibariyle Türkiye'de 20'si önlisans düzeyinde, 26'sı lisans düzeyinde, 52'si lise düzeyinde, 70'i kurs düzeyinde olmak üzere 168 denizcilik eğitim kurumu bulunmaktadır. Bu kurumlardan yalnızca 101 tanesi Ulaştırma ve Altyapı Bakanlığı tarafından akredite edilerek gemiadamı eğitimi vermek üzere yetkilendirilmiştir. Dünyada eğitim kurumlarının eğitim kalitesinin değerlendirilmesi ve sıralanması için bazı metodolojiler geliştirilmiş ve bu hususta yayımlanmış "en iyi" sıralamaları mevcut olsa da, denizcilik eğitim kurumlarının eğitim kalitesini ve sıralamasını bilimsel ve sistematik bir yaklaşımla ele alan bir çalışma bulunmamaktadır. Aynı şekilde bu alanda Coğrafi Bilgi Sistemleri'nden faydanılarak denizcilik eğitim kurumlarının segmentasyonu ile ilgili bir çalışmaya rastlanılmamıştır. Türkiye ölçeğinde de bu alanda yapılan çalışmalarda ağırlıklı olarak denizcilik eğitiminde karşılaşılan sorunlar, eğitim kurumlarındaki eğitimci profilleri, gemiadamlarının eğitimine yönelik diğer tespitler ve öneriler yer almaktadır. Yine bu çalışmalarda, denizcilik eğitim kurumlarında yapılan iç denetim, dış denetim veya idari denetim gibi nesnel bir izleme ve değerlendirme mekanizması sonucu elde edilen veriler ışığında yapılmış bir araştırmaya rastlanılmamış, ağırlıklı olarak eğitimci sayısı, öğrenci sayısı, akademik çalışma sayısı, altyapı olanakları gibi temel bilgiler irdelenmiştir. Türkiye'de denizcilik eğitim kurumlarının Gemiadamları ve Kılavuz Kaptanlar Eğitim ve Sınav Yönergesi çerçevesinde yapılan izleme ve değerlendirme faaliyetleri kapsamındaki denetlemelerinde elde edilen uygunsuzluklar, Ulaştırma ve Altyapı Bakanlığı'nın Gemiadamları Eğitim Bilgi Sistemi (GAEBS) bünyesinde kaydedilmektedir. Bu çalışmada, Coğrafi Bilgi Sistemlerinden faydalanılarak önce denizcilik eğitim kurumlarının coğrafi dağılım haritaları çıkarılmış ve ülkemizin denizcilik eğitim kapasite ihtiyaçlarının belirlenmesi amaçlanmıştır. Çalışmanın devamında 2011-2017 yılları arasında 117 denizcilik eğitim kurumunun denetlemesinde elde edilen uygunsuzluklara ilişkin entropi tabanlı gri ilişki analizi yapılarak kalite değerlendirmesine ilişkin ağırlık faktörleri hesaplanmış, bu sonuçlara göre Türk denizcilik eğitim kurumlarının uygunsuzluk faktörlerine göre coğrafi segmentasyonu yapılmıştır. Çalışmanın sonuç ve öneriler kısmında dünya gemiadamı piyasasından yeterli pay alabilmek için denizcilik eğitim politikalarının çağımızın gerektirdiği bilim, teknolojik gelişmeler, eğitim altyapısı, tecrübe ve yabancı dil eğitimi hususları ile uluslararası piyasada tercih edilme kriterleri göz önüne alınarak yeniden yapılandırılması önerilmiştir.
Lack of Arctic and Antarctic issues in international code for ships operating in polar waters (polar code) and suggesting positive improvements

(Graduate School, 2021-05-20) Karahalil, Meriç ; Özsoy, Burcu ; 512162006 ; Maritime Transportation Engineering ; Deniz Ulaştırma Mühendisliği

The effects of industrial activities have reached global dimensions over the last century. Global climate change triggered as a result of industrialization which has brought many global issues. Currently, the consequences of global climate change are observed dramatically in the polar regions. As a result, the Arctic has become more important in geopolitical and geoeconomic terms with the melting of ice and disappearance to a large extent. As the sea ice coverage has been decreasing, the number of maritime activities such as tourism, fishing, and maritime transportation increased in the Arctic Ocean. On the other hand, the Antarctic is currently subject to scientific research and activities like fishing and tourism, which increase over time as well. While the polar environment's harshness presents significant risks to the ships, maritime activities also threaten the sensitivity of polar ecosystems and marine wildlife and habitats' vulnerability. The lack of accurate charts and marine infrastructure, the harshness of the environment, the limitations of radio and satellite communications to monitor and control ship movements in polar waters are the main challenges of operations in polar regions. The International Maritime Organization (IMO) aimed to legalize Polar Regions' shipping measures, and the International Code for Ships Operating in Polar Waters (Polar Code) came into force, but there are question marks if Polar Code provides significant protection. This thesis consists of three articles on lack of Arctic and Antarctic issues in Polar Code. First one suggests the extention of the Polar Code application areas in the Arctic. While maritime activities are increasing in the Arctic, little attention is being paid to some of the northernmost regions that are greatly influenced by the Arctic climate and are excluded from the Polar Code. The marine boundaries of the Arctic region have been defined differently by the Arctic Council Working Groups based on physical, geographical, and ecological characteristics. However, the boundaries of the Polar Code are not compatible with any of them. In the first article, the extent of sea ice change and the maritime traffic in the high north and also maritime safety in the frame of the application of the Polar Code boundaries in the Arctic analyzed and extention of the Polar Code application areas in the Arctic suggested. In the second article, Arctic and Antarctic sea ice extent change, arisen maritime safety and security issues and legal instruments relevant to the scope are evaluated. It is considered that some significant differences regarding sea ice in the content of Polar Code is not evaluated. The main contribution of this paper is the assessment of the Arctic and Antarctic sea ice condition differences via remote sensing data analyzes in the scope of the Polar Code. Third paper, which evaluates the Polar Code within the survey scope conducted with the people who have sailed in these regions and make suggestions to develop the Polar Code further. The original value of this study to the literature is that it draws attention to the differences between Arctic and Antarctic and points out the deficiencies in Polar Code and suggests its further development. Additionally, it provides data regarding sea ice changes and maritime activities trends in polar regions and supported by the opinions of the people who are working in those regions according to the survey evaluations.
Design of seafarer-centric safety system; mental workload (MWL) prediction

(Lisansüstü Eğitim Enstitüsü, 2022) Özsever, Barış ; Tavacıoğlu, Leyla ; 711394 ; Deniz Ulaştırma Mühendisliği

It is known that human factor has a major effect on maritime casualties that cause great harm to environment, economy and maritime sector. It was stated that while human error is the primary contributor of accidents, a good part of collisions and groundings were related to mental workload (MWL) of watchkeeping officers. Automation, mechanization and the introduction of new technologies had changed the working conditions together with reducing the number of crew and increasing the MWL of operators. This clearly indicates that human element related issues will continue to be one of the major issues in marine transportation assets. In maritime-related studies, it has been analysed mostly how the ship's environment, working period and other factors affect the seafarers. Almost all maritime-related studies couldn't have a potential to develop MWL prediction system for maritime operations aspect. However, lots of studies on drivers and pilots, have produced successful results for MWL prediction. Taking into consideration the fact that MWL has major contribution to maritime casualties, the development of real-time MWL prediction system is vitally essential for ships. By implementing the similar measurement techniques used in the studies on drivers and pilots, to maritime transportation, this study aims to classify the physiological responses of the operators that can produce an output for state of officer on duty as "Safe" or "Risky" from the collected physiological data and task load data during the seaborn operations. This study predicates on the theories which are the statement "minimum performance requires sufficient behavioural activity" of Sheridan and Simpson (1979) together with inverted U function of Yerkes and Dodson (1908) which presents the relationship between arousal and performance. Moreover, the theory of Young et al. (2015) which presents the relationship among mental workload, performance, task demand and resource supply and indicates the overload region, guides this study in terms of building the structure of the experimental research. By being predicated on the above-mentioned theories, this study aimed to design Cognitive Seafarer - Ship Interface (CSSI) which is a main part of Seafarer-Centric Safety System. The physiological data of the 17 junior deck officers (12 subjects performed navigation scenario, 5 subjects performed cargo operation scenario) was recorded according to the design. By being correlated with the performance of the officer, the change of physiological responses of the subjects were analysed in low and high task load levels. The medical decision-making process, which deduced "Safe" or "Risky", was run for this change. For performance measurement that is a part of triangulated measurement strategy (Wierwille and Eggemeier, 1993), Officer Performance Model which is used for MWL classification, was developed for navigation and cargo operation tasks. Additionally, the inputs of Task Load Estimator were defined as data transcription from navigational aids according to results of classification. In summary, the following process were done and results were found. Firstly, the navigation and cargo operation scenarios were created to simulate ship environment. The difficulty level of navigation scenario was gradually adjusted (in order to prevent acquired skill) according to traffic density, visibility and geography by combining in 4 steps. The difficulty level of cargo operation scenario was gradually adjusted according to type and number of operation and operation period corresponding to a real cargo operation by combining in 3 steps. Task load assessments of the scenarios were carried out according to Operator Function Model (OFM-COG) and its sample implications in literature. The results of NASA-TLX scores of the subjects supported the increase of task load levels of the scenarios. ANOVA results showed that there are significant differences in the NASA-TLX scores of 5 different dimensions and in total, among 4 steps which have different task load levels for navigation scenario. Similarly, ANOVA results showed that there are significant differences in the NASA-TLX scores of 3 different dimensions and in total among 3 steps which have different task load levels for cargo operation scenario. According to the subjective assessments of the subjects, MWL increased during the both of navigation and cargo operation scenarios. Secondly, ROC curve analysis was performed for validation of developed officer performance model. Recorded performances of the participants were evaluated as "safe" and "risky" for each task by one ocean going Master expert for navigation tasks and by one ocean going Chief Officer for cargo operation tasks. According to the ROC curve analysis, developed officer performance model was validated with high significance and AUC values. These results showed that the developed officer performance model can be used in any study focused on performance measurement in navigation and chemical tanker cargo operations. Being validated measurement method, performances of the subjects showed that there is a negative significant correlation between performance score and task load in both of navigation and cargo operation tasks. With the distinction of the task load as high task load and low task load, the performance scores were also found significantly different in low and high task loads for both of navigation and cargo operation tasks. Thirdly, physiological responses of the subjects were often differentiated between low and high task loads. Although the change of time-based heart rate variability (HRV) features was not found meaningful according to literature during the increase of task load, the change of frequency-based, time-frequency and nonlinear HRV features were found significant and meaningful during the increase of task load. Moreover, the change of some electrodermal activity (EDA) features and some eye responses were found significant in this study. However, the change of EDA responses was not found strongly correlated with the increase of task load. This can be explained by the fact that electrodermal activity occurs in stressful conditions rather than mental workload. The "frustration" scores of the NASA-TLX supported the fact that the subjects didn't feel so stressed during the tasks. On the other hand, the change of pupil diameter features was found significant and meaningful during the increase of task load in navigation tasks but in cargo operation tasks. Additionally, the change of blink frequency features varied across the scenarios. The variable results of eye responses are thought that the selectivity of eye blinks and pupil diameter to MWL is low according to literature. Additionally, the reason of the fact that the change of some eye features was significant during the increase of task load is thought to be related with the characteristics of eye responses that pupil diameter change is correlated highly with error rate and blink rate increases in incorrect responses rather than correct responses. Therefore, these significances can be explained with the decrease of performance together arising from the increase of task load. On the other hand, the correlations between HRV and EDA features, HRV and eye features, EDA and eye features were found significant and meaningful in mental workload theory. Classification process was carried out with artificial neural network (ANN) code and "Classification Learner" tool of Matlab 2020a. Although the results of the classifications of the subjects' physiological responses on high and low task loads in this study did not give very good accuracies, compared with the studies in literature, they gave sufficient results. The classification accuracies, 75.7% in testing, 83.3% in all for navigation tasks, 80.0% in testing, 92.5% in all for cargo operation tasks and 61.3% in testing, 77.0% in all for cross-task classification have been found similar to those stated in the related studies whose mental workload and stress classification accuracies vary between 70.48% and 98%. According to classification efforts of physiological responses on high task load and low task load levels and performance scores of the subjects, the red lines of task demand became appear in this study. Continuing from the aim of Orlandi and Brooks (2018) and the contributions to MWL prediction in marine engine operations of Yan et al. (2019), the red lines of task demand in ship navigation was tried to determine in this study. Classification of physiological responses and the distinction of the task loads according to the performances of the subjects have ensured the task load to be separated as high task load and low task load. Thus, the inputs of the Cognitive Seafarer-Ship Interface (CSSI) were formed with the outputs of high task load details for navigation and the physiological responses given as features (classified in this study). CSSI processes the task loading together with physiological data of the officer and gives an output as "Risky" for safety of navigation in "The future Seafarer-Centric Safety System design" to be used on ships or at the Shore Control Centre for autonomous ships in future. Consequently, this study will contribute to literature, being the first study in terms of predicting MWL for navigation and cargo operations in maritime transportation. In addition, this study will be a guide for future studies as it reveals the design of the "Seafarer-Centric Safety System" to be developed in order to minimize maritime casualties.
Denizcilik aile işletmelerinde kurumsallaşma

(Lisansüstü Eğitim Enstitüsü, 2022) Demir, Barış ; Tavacıoğlu, Leyla ; 722198 ; Deniz Ulaştırma Mühendisliği

Kurumsallaşma gelişen pazar koşullarında işletmelerin hayatta kalabilmeleri için son derece önemlidir. Kurumsallaşabilen işletmeler, iş ve işlemleri standart hale getirerek, kişilerden bağımsız bir sistem içerisinde yönetim fonksiyonlarını gerçekleştirebilmektedirler. Bu da profesyonel bir yönetim anlayışının doğmasına sebep olmaktadır. Aile işletmeleri dünya ekonomisinde önemli bir rol oynamaktadır. Denizcilik sektörü incelendiğinde de işletmelerin büyük bir kısmının aile işletmesi olduğu görülmektedir. Genellikle babadan oğula geçen bir yönetim anlayışıyla yönetilen ve kurumsallaşmayı başaramayan bu işletmeler, sürdürülebilirlik açısından büyük sorunlar yaşamakta ve birçoğu ikinci kuşağa erişemeden faaliyetlerini durdurmaktadır. İşletmelerin mevcut kurumsal yapılarını ölçmek, işletmenin hangi kurumsal yönetim fonksiyonlarında eksikliklerin olduğunu anlamaya yaramaktadır. Bu sebeple bu çalışmada Türkiye'de faaliyet gösteren gemi işletmeciliği firmalarına yönelik bir kurumsallaşma seviyesi ölçeği geliştirilerek, işletmelerin mevcut kurumsal yapıları incelenmiştir. Kurumsallaşma süreçlerinden hangi aşamalarda eksikliklerin olduğu tespit edilmiştir. Ayrıca kurumsallaşma fonksiyonları arasındaki ilişkiler incelenerek birbirlerine etki eden faktörler analiz edilmiştir. Çalışmada İMEAK Deniz Ticaret Odasına kayıtlı, Türk Bayraklı gemilere sahip ve aile işletmesi konumunda olan 177 gemi işletmeciliği firmasında çeşitli pozisyonlarda çalışan 193 kara personeline anket uygulanmıştır. Anket sonuçları SPSS 23.0 istatistik programında analiz edilmiştir. Ölçek geliştirme sürecinde önce Keşfedici Faktör Analizi (KFA) yapılarak ölçekte yer alan ifadelerin faktörleşmeleri sağlanmıştır. Başta 18 olan ifade sayısı 14 ifadeye düşürülmüştür ve ifadeler 3 faktör altında toplanmıştır. Faktörler, literatür ve uzman görüşleri yardımıyla; etkin örgüt yapısı, iç denetim ve yetki devri olarak adlandırılmıştır. KFA ile birlikte güvenilirlik analizleri yapılan ölçeğin yapı geçerliliğini test etmek adına Doğrulayıcı Faktör Analizi (DFA) yapılmıştır. KFA ve DFA sonuçlarına göre ölçek güvenilir ve geçerli bulunmuştur. Ölçekte yer alan faktörler arasındaki ilişkileri test etmek için SPSS AMOS 23.0 istatistik paket programında Yapısal Eşitlik Modellemesi (YEM) uygulanmıştır. Yapısal Eşitlik Modeli ile yapılan hipotez testleri incelendiğinde, Türk denizcilik aile işletmelerinde etkin bir örgüt yapısının oluşturulmasının, yetki devri ve iç denetimi faaliyetlerini olumlu yönde etkilediği sonucuna varılmıştır. Yetki devrinin iç denetime doğrudan ve anlamlı bir etkisinin olmadığı görülmekle birlikte, aracı değişken analizi yapılarak elde edilen sonuca göre etkin örgüt yapısının yetki devri ve iç denetim arasında tam aracılık etkisiyle bir köprü görevi gördüğü anlaşılmıştır. İşletmelerin kuşaklarıyla kurumsallaşma seviyeleri arasında bir ilişki olup olmadığı Anova Analizi ile test edilmiştir. Analiz sonucuna göre işletmelerin kaçıncı kuşak bir işletme olduğuyla kurumsallaşma seviyeleri arasında istatiksel olarak bir anlamlılık olmadığını görülmüştür. Denizcilik aile işletmelerinin kurumsallaşma seviyelerini tespit etmek adına frekans analizi yapılmıştır. Frekans analizi sonuçlarına göre Türkiye'de faaliyet gösteren aile sahipli gemi işletme firmalarının 3,51'lik bir ortalamayla yarı/orta seviyede kurumsallaştıkları tespit edilmiştir. Bu çalışma, denizcilikte kurumsallaşma alanında yapılan ilk nicel çalışmadır. Ayrıca literatürden farklı olarak, armatörler ve işletme sahiplerinin görüşleri yerine kara personelinin görüşleri ele alınmıştır. Bu şekilde armatör ve işletme sahiplerinin kendi işletmelerini değerlendirirken oluşabilecek taraflı tutumların engellenmesi amaçlanmıştır.
Konteyner liman operasyonlarının makine öğrenmesi yöntemleri ile analizi

(Lisansüstü Eğitim Enstitüsü, 2022-01-28) Atak, Üstün ; Arslanoğlu, Yasin ; Kaya, Tolga ; 512182014 ; Deniz Ulaştırma Mühendisliği

Deniz taşımacılığında seyir planlaması ve operasyon ile ilgili tahmin yürütebilmek için farklı türde veri kullanılabilmektedir. Hava durumu, yük bilgileri ve gemi özellikleri gibi verilerin uygun sistemler ile toplanıp analiz edilmesi enerji verimliliği sağlanması açısından değerli çıkarımlar yapılabilmesine olanak sağlayabilmektedir. Tıpkı elektronik seyir sistemleri ve yardımcılarında olduğu gibi elde edilecek verinin yenilikçi yöntemler ile operasyon sürecine dahil edilmesiyle birlikte deniz taşımacılığının güvenli, emniyetli ve uygun maliyetli bir şekilde tamamlamasına katkı sağlanabilmektedir. Öte yandan, veri bilimi uygulamaları farklı sektör uygulamaları ile son yıllarda yaygınlığını artırmaya başlamıştır. Uzman ya da analiz yapan kişiler yeterli ve doğru veri ile hesaplamalar yapabilmek için farklı yöntemleri kullanabilmektedir. Bu doğrultuda, ekipman ya da insan tarafından üretilen veri ile sistem davranış modellemesi yapılabilmektedir. Büyük veri, müşteri deneyimi analizlerinden veri madenciliği araçlarına kadar paydaşlara çeşitli çözümler sunabilmektedir. Operasyon verimliliği, sürücü destek sistemleri, tahminleyici bakım ve makine öğrenmesi uygulamaları ile çeşitli uygulama alanlarında çalışmalar bulunmaktadır. Benzer şekilde denizcilik sektörü uygulamaları sayesinde akıllı çözümler paydaşlara enerji tasarrufu ile birlikte uygun maliyetli seçenekler sunabilmektedir. Ayrıca, veri madenciliği çözümleri sayesinde daha büyük miktarda verinin üretildiği liman operasyonları için değerli analizler ve geliştirme hedefleri sağlanabilmektedir. Limana varış ve bekleme süresi tahmini yanı sıra yakıt tüketim hesabı ile hava kirliliğini azaltmak için gerçek zamanlı veri uygulamaları konteyner terminallerinde etkin makine öğrenmesi çözümlerinin ana başlıkları olarak değerlendirilebilir.

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