{"title":"“Liner shipping”","authors":"O. Drozhzhyn, Y. Koskina, Iryna Tykhonina","doi":"10.31217/p.35.2.18","DOIUrl":"https://doi.org/10.31217/p.35.2.18","url":null,"abstract":"The aim of the study was to analyze the scientific views on the definition of liner shipping at various stages of its development. For this, literary sources for more than a hundred years of research on this issue were analyzed. The analysis emphasizes the lack of systemic studies on this issue and the scientific approach to the definition of the concept in question. As a result of the study, the stages of development of liner shipping are presented and the main characteristic features for the concept are given, its boundaries are established. The resulting research also synthesizes the scientific papers in the field of liner shipping, which represents an important supporting tool for future theoretical and applied studies. Taking into account the exceptional role of liner shipping in intermodal delivery systems, the presented analysis is useful for all involved transport modes.","PeriodicalId":44047,"journal":{"name":"Pomorstvo-Scientific Journal of Maritime Research","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42299102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flow visualization and analytical study on the exhaust gas diffusion of a frigate","authors":"E. Dobrucalı","doi":"10.31217/p.35.2.13","DOIUrl":"https://doi.org/10.31217/p.35.2.13","url":null,"abstract":"Wind tunnel flow visualization tests were conducted to analyse the efflux velocity impacts and the yaw angle on the smoke dispersion of the exhaust for a generic frigate. An analytical study was also implemented to obtain the exhaust plume trajectories. The 1/100 scale generic frigate, having a platform for helicopters on the aft of the ship, was built and employed during the experimental study. The forward and astern cruises of the frigate were considered. It is found that the plume height and the exhaust gases momentum increase with the velocity ratio. The problem of smoke nuisance was observed for the ratios with low velocity such as K=0.2. The plume was also directed towards the helicopter platform when the yaw angles are higher than 10°. The experimental results are compared with the analytical solutions for three different velocity ratios. The compliance between the experimental and analytical results is found to be consistent.","PeriodicalId":44047,"journal":{"name":"Pomorstvo-Scientific Journal of Maritime Research","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44063733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Jeevan, Loke Keng Bin, Mohamad Rosni Othman, N. H. Mohd Salleh, Raja Somu, Sun Ming Ming
{"title":"Cross-border freight movement between Thailand-Malaysia-Singapore","authors":"J. Jeevan, Loke Keng Bin, Mohamad Rosni Othman, N. H. Mohd Salleh, Raja Somu, Sun Ming Ming","doi":"10.31217/p.35.2.16","DOIUrl":"https://doi.org/10.31217/p.35.2.16","url":null,"abstract":"Trade plays an important role in economic growth. Thence, a smooth cross-border transaction between Thailand-Malaysia-Singapore provides a significant implication in international trade. Currently, cross-border transactions face several issues during the crossing of borders between countries and, specifically, happens during the transactions of cargo. A very rigid documentation process within the custom clearance and theresulting severe congestion will affect the trade flow in this particular zone. Inconsistency of freight transaction documents at the cross-border also makes the transaction procedure more complicated and affects the performance of the manufacturer’s competitiveness. Thus, this paper explores the current issues at the borders involving Thailand-Malaysia-Singapore. This paper also initiates to figure out the challenges and some key success factors in modelling efficiency for cross-border transactions amongst these countries. A qualitative approach has been adapted to answer the proposed research questions. The initial results stressed that congestion, thorough and repetitious documentation procedures, involvement of many documents, as well as the time-consuming clearance of documents are key issues encountered during cross-border freight movement. This situation has caused several issues such as delays in freight delivery, losses in tax collection due to delays, reluctance to share information, and effects on the competitiveness of the freight supply chain. Development in infrastructure, information sharing, regulations, logistics performance, and customs clearance procedure can overcome the problems during cross-border Thailand-Malaysia-Singapore activities. The model outcome is expected to be smoother for the administrative process during customs clearance and it is expected to be able to efficiently reduce costs.","PeriodicalId":44047,"journal":{"name":"Pomorstvo-Scientific Journal of Maritime Research","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43533352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Methodology for composite materials shrinkage definition for use in shipbuilding and marine technology","authors":"D. Bolf, M. Hadjina, A. Zamarin, T. Matulja","doi":"10.31217/p.35.2.9","DOIUrl":"https://doi.org/10.31217/p.35.2.9","url":null,"abstract":"Deformations of steel material in shipbuilding and marine technology applications as a result of mechanical or temperature influences are a well-known problem. However, in the modern shipbuilding industry, the application of alternative materials, especially composite materials, in the structure and for the equipment of the ship is increasingly represented. Consequently, there is a need to determine the deformation and change of characteristics of such composite materials as a result of various mechanical, and especially temperature influences that cause the so-called shrinkage. The basic composite production process involves connecting the matrix with a catalyst and accelerators that create temperature, then the material shrinks by cooling when it can change its dimensions and characteristics. Also, in order to achieve the best possible mechanical properties, composite materials are specially heated and then cooled according to strictly defined processes and curves. The ability to predict the characteristics and parameters of such deformations is important in the context of the application of composite materials. To define such deformations, different methods are used within individual numerical solvers, whose results can differ significantly from each other. Therefore, the authors in this paper present an established methodology for predicting mechanical and temperature deformations, and modelling of composite materials, based on the analysis of analytical methods and numerical solvers with the aim of defining the most accurate numerical solver. By applying the presented methodology, it is expected to raise the level of accuracy and quality of composite materials production as well as to raise the quality of design solutions and efficiency of production procedures during shipbuilding in particular, but also within different marine technology applications and during the product’s life cycle.","PeriodicalId":44047,"journal":{"name":"Pomorstvo-Scientific Journal of Maritime Research","volume":"18 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69635825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A multi-objective integrated procurement, production, and distribution problem of supply chain network under fuzziness uncertainties","authors":"K. Douaioui, Mouhsene Fri, C. Mabrouki, E. Semma","doi":"10.31217/p.35.2.1","DOIUrl":"https://doi.org/10.31217/p.35.2.1","url":null,"abstract":"In this paper, we devoted a design under uncertainty of a four-echelon supply chain network including multiple suppliers, multiple plants, multiple distributors and multiple customers. The proposed model is a bi-objective mixed integer linear programming which considers several constraints and aims to minimize the total costs including the procurement, production, storage and distribution costs as well as to maximize on-time deliveries (OTD). To bring the model closer to real-world planning problems, the objective function coefficients (e.g. procurement cost, production cost, inventory holding and transport costs) and other parameters (e.g., demand, production capacity and safety stock level), are all considered triangular fuzzy numbers. Besides, a hybrid mathematical model-based on credibility approach is constructed for the problem, i.e., expected value and chance constrained models. Moreover, to build the crisp equivalent model, we use different property of the credibility measure. The resulted crisp equivalent model is a bi-objective mixed integer linear programs (BOMILP). To transform this crisp BOMILP into a single objective mixed integer linear programs (MILP) model, we apply three different aggregation functions. Finally, numerical results are reported for a real case study to demonstrate the efficiency and applicability of the proposed model.","PeriodicalId":44047,"journal":{"name":"Pomorstvo-Scientific Journal of Maritime Research","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41344334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tetyana Теreschenko, Iuliia Yamnenko, O. Melnychenko, Maryna Panchenko, Liudmyla Laikova
{"title":"Analysis of image compression methods based on wavelet transforms for maritime applications","authors":"Tetyana Теreschenko, Iuliia Yamnenko, O. Melnychenko, Maryna Panchenko, Liudmyla Laikova","doi":"10.31217/p.35.2.21","DOIUrl":"https://doi.org/10.31217/p.35.2.21","url":null,"abstract":"The purpose of the article is to develop recommendations for choosing image compression method based on wavelet transformation, depending on image type, quality and compression requirements. Among the wavelet image compression methods, Embedded Zerotree Wavelet coder (EZW) and Set Partition In Hierarchical Trees (SPIHT) are considered, and the Haar wavelet and wavelet transformation in the oriented basis with the first, third, fifth and seventh decomposition levels is used as the base wavelet transform. These compression methods were compared with each other and with the standard JPEG method on the following parameters: mean square error, maximum error, peak to noise ratio, number of bits per pixel, compression ratio, and image size. The proposed methods can be successfully applied in the transmission of seabed relief images obtained from satellites or sea buoys.","PeriodicalId":44047,"journal":{"name":"Pomorstvo-Scientific Journal of Maritime Research","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49515393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ana Grbčić, Svjetlana Hess, Mirano Hess, Tomislav Krljan
{"title":"The impact of seasonality on efficient airport capacity utilization","authors":"Ana Grbčić, Svjetlana Hess, Mirano Hess, Tomislav Krljan","doi":"10.31217/p.35.2.3","DOIUrl":"https://doi.org/10.31217/p.35.2.3","url":null,"abstract":"The major cause of under-capacity or overcapacity at smaller airports is seasonality. Such airports are finding it difficult to determine the capacity to meet the demand and adequately handle passengers in both high and low season. If the capacity is not optimally defined, excessive congestions and waiting times occur, resulting in lower service quality. Airports greatly benefit from capacity utilization analysis in terms of more accurate planning, designing, and adjusting capacity to the current demand in order to encourage further development as well as to reduce additional costs. Using queuing theory, this paper aims to answer the following question: is the passenger capacity at Rijeka International Airport (Croatia) optimally determined to meet the demand promptly, both in high and low season, without causing excessive congestions and waiting times. The results obtained indicate the occurrence of overcapacity since high season demand can be well served, even with reduced capacity used in the low season when demand is significantly lower.","PeriodicalId":44047,"journal":{"name":"Pomorstvo-Scientific Journal of Maritime Research","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49613505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sandi Baressi Baressi Šegota, I. Lorencin, Mario Šercer, Z. Car
{"title":"Determining residuary resistance per unit weight of displacement with Symbolic Regression and Gradient Boosted Tree algorithms","authors":"Sandi Baressi Baressi Šegota, I. Lorencin, Mario Šercer, Z. Car","doi":"10.31217/p.35.2.11","DOIUrl":"https://doi.org/10.31217/p.35.2.11","url":null,"abstract":"Determining the residuary resistance per unit weight of displacement is one of the key factors in the design of vessels. In this paper, the authors utilize two novel methods – Symbolic Regression (SR) and Gradient Boosted Trees (GBT) to achieve a model which can be used to calculate the value of residuary resistance per unit weight, of displacement from the longitudinal position of the center of buoyancy, prismatic coefficient, length-displacement ratio, beam-draught ratio, length-beam ratio, and Froude number. This data is given as results of 308 experiments provided as a part of a publicly available dataset. The results are evaluated using the coefficient of determination (R2) and Mean Absolute Percentage Error (MAPE). Pre-processing, in the shape of correlation analysis combined with variable elimination and variable scaling, is applied to the dataset. The results show that while both methods achieve regression results, the result of regression of SR is relatively poor in comparison to GBT. Both methods provide slightly poorer, but comparable results to previous research focussing on the use of “black-box” methods, such as neural networks. The elimination of variables does not show a high influence on the modeling performance in the presented case, while variable scaling does achieve better results compared to the models trained with the non-scaled dataset.","PeriodicalId":44047,"journal":{"name":"Pomorstvo-Scientific Journal of Maritime Research","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47928039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Risk assessment and exemption approval procedure for the semi-closed seas according to the International Convention for the Control and Management of Ships’ Ballast Water and Sediments, 2004","authors":"Katarina Balić, D. Zec","doi":"10.31217/p.35.2.2","DOIUrl":"https://doi.org/10.31217/p.35.2.2","url":null,"abstract":"The paper analyses statutory foundations applicable to ships requiring to be exempted from the mandatory installation of the ballast water management system. In particular, it deals with ships sailing on regular international lines but within the semi-closed seas, such as the Adriatic Sea. The legal framework is set out in the International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM, 2004), the IMO Guidelines for Risk Assessment A-4 (G7), and the Croatian Ordinance on Ballast Water Control and Management, 2012 [Pravilnik o upravljanju i nadzoru balastnih voda]. The paper presents the model procedure to be followed by main stakeholders, mainly national maritime administrations and shipping companies. The paper outlines the main advantages and disadvantages of the whole process and analyses several cases of good practice. Furthermore, the main stakeholders in the approval procedure and their responsibilities are described, available risk assessment models are analysed, with the particular emphasis on the species-specific risk assessment method as the most preferred method. Finally, the need for cooperation between the involved states and their maritime administrations is considered.\u0000It is concluded that bilateral and regional cooperations are an essential element in preserving the marine environment of any sea area. In that respect, the proposed model of the BWM system exemption approval in closed and semi-closed seas, such as the Adriatic Sea, is essential for shipping companies connecting ports in different countries on regular routes. Although demanding in respect of efforts and time, a procedure is viable and may be carried out in due time and with satisfactory outcomes.","PeriodicalId":44047,"journal":{"name":"Pomorstvo-Scientific Journal of Maritime Research","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45724722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deviations and errors review on measuring and calculating heavy fuel oil consumption and fuel stock onboard vessels equipped with volumetric fuel consumption flowmeters","authors":"J. Dujmović, Dean Bernecic","doi":"10.31217/p.35.2.12","DOIUrl":"https://doi.org/10.31217/p.35.2.12","url":null,"abstract":"A common way of measuring heavy fuel oil consumption on board a vessel is to use volumetric fuel flow meters installed at fuel systems inlets for each of the major fuel consumers. At each stage of the fuel processing cycle, certain mass fuel losses or deviations and calculation errors occur that are not counted accurately into fuel consumption figures. The goal of this paper is to identify those fuel mass losses and measuring/calculating errors and perform their quantitative numerical analysis based on actual data. Fuel mass losses defined as deviations identified during the fuel preparation process are evaporation of volatile organic compounds, water drainage, fuel separation, and leakages while errors identified are flow meter accuracy and volumetric/mass flow conversion accuracy. By utilizing statistical analysis of obtained data from engine logbook extracts from three different ships numerical models were generated for each fuel mass loss point. Measuring errors and volumetric/mass conversion errors are numerically analyzed based on actual equipment and models used onboard example vessels. By computational analysis of the obtained models, approximate percentage losses and errors are presented as a fraction of fuel quantity on board or as a fraction of fuel consumed. Those losses and errors present between 0,001% and 5% of fuel stock or fuel consumption figures for each identified loss/error point. This paper presents a contribution for more accurate heavy fuel oil consumption calculation and consequently accurate declaration of remaining fuel stock onboard. It also presents a base for possible further research on the possible influence of fuel grade, fuel water content on the accuracy of consumption calculation.","PeriodicalId":44047,"journal":{"name":"Pomorstvo-Scientific Journal of Maritime Research","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43337156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}