A spread mooring system (SMS) allows a ship or a floating platform to moor the seafloor using multiple mooring lines at a restricted region with a fixed heading in harsh weather. These systems can be used for the operations of ships of different tonnage at different sea depths. The optimal design of these systems is a challenging engineering problem because of the effects of many design parameters and changing environmental conditions. Modern soft computing techniques allow difficult engineering problems to be solved easily and precisely and are becoming more and more popular. In this paper, Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) as soft computation techniques have been chosen to estimate the hawser tensions and displacements of a spread mooring system. The attained results show both techniques can give consistent indicators for the modelling of dynamic systems. Although these techniques performed very well, the ANFIS model is relatively superior to the ANN technique, considering the accuracy of hawser tensions and displacements in terms of the relative errors and coefficient of correlation obtained for the ANN and ANFIS.
{"title":"AN APPLICATION OF SOFT COMPUTING TECHNIQUES TO PREDICT DYNAMIC BEHAVIOUR OF MOORING SYSTEMS","authors":"A. Mentes, M. Yetkin","doi":"10.21278/brod73207","DOIUrl":"https://doi.org/10.21278/brod73207","url":null,"abstract":"A spread mooring system (SMS) allows a ship or a floating platform to moor the seafloor using multiple mooring lines at a restricted region with a fixed heading in harsh weather. These systems can be used for the operations of ships of different tonnage at different sea depths. The optimal design of these systems is a challenging engineering problem because of the effects of many design parameters and changing environmental conditions. Modern soft computing techniques allow difficult engineering problems to be solved easily and precisely and are becoming more and more popular. In this paper, Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) as soft computation techniques have been chosen to estimate the hawser tensions and displacements of a spread mooring system. The attained results show both techniques can give consistent indicators for the modelling of dynamic systems. Although these techniques performed very well, the ANFIS model is relatively superior to the ANN technique, considering the accuracy of hawser tensions and displacements in terms of the relative errors and coefficient of correlation obtained for the ANN and ANFIS.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42653496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
After introducing an energy efficiency design index (EEDI) in 2011, International Maritime Organization (IMO) pursued their short- and long-term goals to reduce greenhouse gas (GHG) emissions from ships by presenting, among others, an energy efficiency existing ship index (EEXI). Contrary to EEDI which is used for new ships solely, EEXI is addressing an energy efficiency of already built ships and is set to become formally applicable starting from 2023. Existing designs cannot be essentially and rapidly changed to comply the criterion. The only main particular from the preliminary design phase that can be meaningly optimized “post festum” is a required engine power, and thus, the speed. Therefore, the paper explores the effect of EEXI policy on a fleet of 153 bulk carriers built between 2000 and 2020 in order to address their near future and prompt design changes, specifically considering the power reduction. For that purpose, an attained and a required EEXI are calculated for each ship. The results showed that only 15% of the ships built in 2000-2012 satisfied 2013-2014 IMO criterion. This impacted the design of ships built in 2013-2022, as they complied the same criterion by 88% of share. However, no ship from the whole database satisfied the present day EEDI requirement and only one ship fulfilled the contemporary EEXI requirement meaning that the current designs are not able to match the emerging criteria to a large extent. In order to meet an energy efficiency criterion, a main engine power reduction and speed are predicted assuming that the engine power and shaft limiter are installed. The investigation showed that MCR reduction of the total fleet taken into account had to be reduced by 50% and speed by 15% on average in order for ships to meet current requirements. Moreover, a graphic method is developed for the estimation of EEXI by using only deadweight (DWT) and maximum continuous rating (MCR). The proposed simplified method based on average values could be used on existing bulk carriers with an aim to satisfy novel regulation with application of “easy to use” approach. Additionally, authors discussed other options to reliably evaluate an energy efficiency of existing ships.
{"title":"POWER REDUCTION CONSIDERATIONS FOR BULK CARRIERS WITH RESPECT TO NOVEL ENERGY EFFICIENCY REGULATIONS","authors":"M. Kalajdžić, Matija Vasilev, N. Momčilović","doi":"10.21278/brod73205","DOIUrl":"https://doi.org/10.21278/brod73205","url":null,"abstract":"After introducing an energy efficiency design index (EEDI) in 2011, International Maritime Organization (IMO) pursued their short- and long-term goals to reduce greenhouse gas (GHG) emissions from ships by presenting, among others, an energy efficiency existing ship index (EEXI). Contrary to EEDI which is used for new ships solely, EEXI is addressing an energy efficiency of already built ships and is set to become formally applicable starting from 2023. Existing designs cannot be essentially and rapidly changed to comply the criterion. The only main particular from the preliminary design phase that can be meaningly optimized “post festum” is a required engine power, and thus, the speed. Therefore, the paper explores the effect of EEXI policy on a fleet of 153 bulk carriers built between 2000 and 2020 in order to address their near future and prompt design changes, specifically considering the power reduction. For that purpose, an attained and a required EEXI are calculated for each ship. The results showed that only 15% of the ships built in 2000-2012 satisfied 2013-2014 IMO criterion. This impacted the design of ships built in 2013-2022, as they complied the same criterion by 88% of share. However, no ship from the whole database satisfied the present day EEDI requirement and only one ship fulfilled the contemporary EEXI requirement meaning that the current designs are not able to match the emerging criteria to a large extent. In order to meet an energy efficiency criterion, a main engine power reduction and speed are predicted assuming that the engine power and shaft limiter are installed. The investigation showed that MCR reduction of the total fleet taken into account had to be reduced by 50% and speed by 15% on average in order for ships to meet current requirements. Moreover, a graphic method is developed for the estimation of EEXI by using only deadweight (DWT) and maximum continuous rating (MCR). The proposed simplified method based on average values could be used on existing bulk carriers with an aim to satisfy novel regulation with application of “easy to use” approach. Additionally, authors discussed other options to reliably evaluate an energy efficiency of existing ships.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47647869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. A. Ismail, N. Shaharuddin, O. Yaakob, M. Jamal, F. A. Adnan, A. H. M. Rashidi, W. A. H. W. Azhary, Mohd Kamarul Huda Samion, A.N.D. Bachok, B. Ahmad, Nur Shafira Ahmad
This paper presents the model testing of an 8.23m boat with hard chine planning hull generated waves at the Kilim recreational park. Wake is considered one of the main causes of riverbank erosion due to the energy carried by waves hitting the riverbank. Initially, ship particulars were measured from actual boats to generate a hull form using MAXSURF software. A lines plan was then generated to fabricate the model using fibreglass. Experiments were conducted in the National Hydraulic Research Institute of Malaysia (NAHRIM) at various speeds at a constant operating draft. The wave patterns generated by the modelled boats at different speeds were recorded for analysis. Wave attenuation for deep water conditions was studied and it was found that the wave exponent, n ranged from -0.36 to -0.75 for all depth Froude number (Fnh) condition. Wave decay analysis was used to estimate wave height for defined water depth. For 11 people with an average mass of 65 kg on board, the produced wave height was greater than the permissible wave wake height of 75 mm. The generated energy exceeded 60 Joules/m for nearly all measured speeds. A boat speed of less than 5 knots was suggested for boats loaded with the maximum passenger limit of 11 people. Other recommendations were made to minimize the wave wake height produced by the modelled boat.
{"title":"WAKE WASH OF A FAST SMALL BOAT IN RESTRICTED WATERS: MODEL TESTS AND FULL-SCALE MEASUREMENTS","authors":"M. A. Ismail, N. Shaharuddin, O. Yaakob, M. Jamal, F. A. Adnan, A. H. M. Rashidi, W. A. H. W. Azhary, Mohd Kamarul Huda Samion, A.N.D. Bachok, B. Ahmad, Nur Shafira Ahmad","doi":"10.21278/brod73206","DOIUrl":"https://doi.org/10.21278/brod73206","url":null,"abstract":"This paper presents the model testing of an 8.23m boat with hard chine planning hull generated waves at the Kilim recreational park. Wake is considered one of the main causes of riverbank erosion due to the energy carried by waves hitting the riverbank. Initially, ship particulars were measured from actual boats to generate a hull form using MAXSURF software. A lines plan was then generated to fabricate the model using fibreglass. Experiments were conducted in the National Hydraulic Research Institute of Malaysia (NAHRIM) at various speeds at a constant operating draft. The wave patterns generated by the modelled boats at different speeds were recorded for analysis. Wave attenuation for deep water conditions was studied and it was found that the wave exponent, n ranged from -0.36 to -0.75 for all depth Froude number (Fnh) condition. Wave decay analysis was used to estimate wave height for defined water depth. For 11 people with an average mass of 65 kg on board, the produced wave height was greater than the permissible wave wake height of 75 mm. The generated energy exceeded 60 Joules/m for nearly all measured speeds. A boat speed of less than 5 knots was suggested for boats loaded with the maximum passenger limit of 11 people. Other recommendations were made to minimize the wave wake height produced by the modelled boat.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49616929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Preliminary prediction of resistance and power is a fundamental aspect of the ship design process since they directly influence the developments of the design process, fuel consumption and costs, and environmental impact from the early design stage. Parametric predictions of resistance and power, based mainly on statistical regression models that are also ideal for computer programming, are often performed during initial design stages, providing rapid predictions and optimisations for minimum resistance. The paper aims to present the results of the comparative analysis on some conventional hulls of the predictive accuracy of a computer program developed by the author for parametric predictions of resistance and power of ships. The program (entitled Ship Power V 1.0) is developed in the Visual Basic 6.0 environment based on two well-known regression models Holtrop and Van Oortmerssen. The program can perform detailed predictions of resistance and power, resistance coefficients, propeller thrust, hull efficiency, wake, and trust fractions, with no restriction on the number of velocities. In this study, only the analysis of the accuracy of resistance and power prediction is considered. Results of the comparative analysis of the computational procedures of Ship Power V 1.0 versus experimental data, and against results of another well-known commercial software, performed on three models of the Ridgely-Nevitt trawler series and KCS hull have shown a good level of accuracy and reliability as other well-known commercial software.
阻力和功率的初步预测是船舶设计过程的一个基本方面，因为它们直接影响设计过程的发展，燃料消耗和成本，以及从早期设计阶段对环境的影响。电阻和功率的参数预测，主要基于统计回归模型，也是理想的计算机编程，通常在初始设计阶段进行，提供最小电阻的快速预测和优化。本文介绍了笔者开发的船舶阻力和动力参数预测计算机程序对一些常规船体预测精度的对比分析结果。该程序(名为Ship Power V 1.0)是在Visual Basic 6.0环境下基于两个著名的回归模型Holtrop和Van Oortmerssen开发的。该程序可以执行阻力和功率、阻力系数、螺旋桨推力、船体效率、尾流和信任分数的详细预测，对速度的数量没有限制。在本研究中，只考虑电阻和功率预测的准确性分析。通过对ridgly - nevitt系列拖网渔船和KCS船体三种型号的计算结果，对比分析了Ship Power V 1.0的计算过程与实验数据，并与另一知名商业软件的计算结果进行了对比分析，结果表明该软件的准确性和可靠性与其他知名商业软件相当。
{"title":"INVESTIGATION ON SOME CONVENTIONAL HULLS FORMS OF THE PREDICTIVE ACCURACY OF A PARAMETRIC SOFTWARE FOR PRELIMINARY PREDICTIONS OF RESISTANCE AND POWER","authors":"Blenard Xhaferaj","doi":"10.21278/brod73101","DOIUrl":"https://doi.org/10.21278/brod73101","url":null,"abstract":"Preliminary prediction of resistance and power is a fundamental aspect of the ship design process since they directly influence the developments of the design process, fuel consumption and costs, and environmental impact from the early design stage. Parametric predictions of resistance and power, based mainly on statistical regression models that are also ideal for computer programming, are often performed during initial design stages, providing rapid predictions and optimisations for minimum resistance. The paper aims to present the results of the comparative analysis on some conventional hulls of the predictive accuracy of a computer program developed by the author for parametric predictions of resistance and power of ships. The program (entitled Ship Power V 1.0) is developed in the Visual Basic 6.0 environment based on two well-known regression models Holtrop and Van Oortmerssen. The program can perform detailed predictions of resistance and power, resistance coefficients, propeller thrust, hull efficiency, wake, and trust fractions, with no restriction on the number of velocities. In this study, only the analysis of the accuracy of resistance and power prediction is considered. Results of the comparative analysis of the computational procedures of Ship Power V 1.0 versus experimental data, and against results of another well-known commercial software, performed on three models of the Ridgely-Nevitt trawler series and KCS hull have shown a good level of accuracy and reliability as other well-known commercial software.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42880262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Energy extraction capacity of controllably flexible hydrofoil was studied under two identified deformation modes. Deformation modes, flexure parameters (flexure amplitude and flexure coefficient ) and motion parameters (reduced frequency f* and pitching amplitude 0) were investigated to understand the effects of controllably flexible deformation on energy extraction. The results reveal that deformation modes affect the effective angle of attack and vortex structure, which influence hydrodynamic performance. The energy extraction capacity improves from the deformation mode 2 to the rigid hydrofoil and then to the deformation mode 1. Under the deformation mode 1, lift, moment and power coefficients are increased obviously with the increase of , while they increase slightly with . Power coefficients and efficiency are sensitive to , which influences the development of leading-edge vortices. The flexible coefficient affects the wake structure, which has less impact on variation of force coefficient. As the increase in f*, averaged power coefficients firstly increase and then decrease. Further, the optimal f* is subjected to 0. Interestingly, a critical reduced frequency f*s, which is generally increase with increasing 0, was found under three modes. The condition that f* > f*s. is a prerequisite for subsequent adjustments of flexure modes and parameters according to different requirement of power coefficient under different tidal currents. The range of high efficiency () is: deformation mode 1 (36.1%<<54.3%) > rigid hydrofoils (34.2%<<41%) > deformation mode 2 (26.9%<<30.3%).
{"title":"EFFECTS OF TWO TYPES OF CONTROLLABLE DEFORMATION ON ENERGY EXTRACTION OF A FLEXIBLE HYDROFOIL","authors":"Yubing Zhang, Yong Wang, Guangyong Sun, Jiazhen Han, Yudong Xie","doi":"10.21278/brod73106","DOIUrl":"https://doi.org/10.21278/brod73106","url":null,"abstract":"Energy extraction capacity of controllably flexible hydrofoil was studied under two identified deformation modes. Deformation modes, flexure parameters (flexure amplitude and flexure coefficient ) and motion parameters (reduced frequency f* and pitching amplitude 0) were investigated to understand the effects of controllably flexible deformation on energy extraction. The results reveal that deformation modes affect the effective angle of attack and vortex structure, which influence hydrodynamic performance. The energy extraction capacity improves from the deformation mode 2 to the rigid hydrofoil and then to the deformation mode 1. Under the deformation mode 1, lift, moment and power coefficients are increased obviously with the increase of , while they increase slightly with . Power coefficients and efficiency are sensitive to , which influences the development of leading-edge vortices. The flexible coefficient affects the wake structure, which has less impact on variation of force coefficient. As the increase in f*, averaged power coefficients firstly increase and then decrease. Further, the optimal f* is subjected to 0. Interestingly, a critical reduced frequency f*s, which is generally increase with increasing 0, was found under three modes. The condition that f* > f*s. is a prerequisite for subsequent adjustments of flexure modes and parameters according to different requirement of power coefficient under different tidal currents. The range of high efficiency () is: deformation mode 1 (36.1%<<54.3%) > rigid hydrofoils (34.2%<<41%) > deformation mode 2 (26.9%<<30.3%).","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44688491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Generally, cell guides are installed in the cargo hold of container ships, which improve the loading and unloading efficiency of containers and fix containers when the ship is sailing. However, in actual production, due to the low accuracy of ship loading in sections, and the deviation of welding shrinkage and expansion in relevant sections, errors occur in the loading process of containers, resulting in hidden safety risks or significant economic losses. Given the above situation, it is particularly important to find a high-efficiency cell guide accuracy inspection method for construction monitoring. 3D scanner to obtain three-dimensional data is presented in this paper, based on this paper proposes a new method, this method will be used based on improved instances of 3 d point cloud segmentation model to cell guide the segmentation, and fitting container ship cell guide structure, and then realize the function of container simulation test box, cell guide after the segmentation precision inspection at the same time, for the practicality review, we compared the accuracy data gained from inspection simulation and the measured data. As a result, it was confirmed that both values were within about ±1.5mm. The validity, and reliability of the method are further verified.
{"title":"CONTAINER SHIP CELL GUIDE ACCURACY CHECK TECHNOLOGY BASED ON IMPROVED 3D POINT CLOUD INSTANCE SEGMENTATION","authors":"Chengjie Zong, Zhibo Wan","doi":"10.21278/brod73102","DOIUrl":"https://doi.org/10.21278/brod73102","url":null,"abstract":"Generally, cell guides are installed in the cargo hold of container ships, which improve the loading and unloading efficiency of containers and fix containers when the ship is sailing. However, in actual production, due to the low accuracy of ship loading in sections, and the deviation of welding shrinkage and expansion in relevant sections, errors occur in the loading process of containers, resulting in hidden safety risks or significant economic losses. Given the above situation, it is particularly important to find a high-efficiency cell guide accuracy inspection method for construction monitoring. 3D scanner to obtain three-dimensional data is presented in this paper, based on this paper proposes a new method, this method will be used based on improved instances of 3 d point cloud segmentation model to cell guide the segmentation, and fitting container ship cell guide structure, and then realize the function of container simulation test box, cell guide after the segmentation precision inspection at the same time, for the practicality review, we compared the accuracy data gained from inspection simulation and the measured data. As a result, it was confirmed that both values were within about ±1.5mm. The validity, and reliability of the method are further verified.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46903304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Trimaran hull forms have been popular recently in both commercial and military usage due to reduction in resistance at high speeds, better stability, and greater deck area compared to conventional monohull vessels. Determination of the location of the side hulls is most critical to get higher hydrodynamic performance. Therefore, many studies in the literature are related to defining the location of the side hulls for trimaran vessels. Most of the studies have been carried out experimentally or numerically. In this study, an artificial neural network (ANN) model was used to predict the residual resistance coefficient of a trimaran model. The model uses four parameters which are the transverse and longitudinal positions of the side hulls, the longitudinal centre of buoyancy and the Froude number to predict the residual resistance of the trimaran model. The experimental data of the trimaran model were used to train the neural network model in order to develop a more reliable model. Several neural network models were developed and tested to find the one with minimum error. The study showed that the residual resistance coefficients of the trimaran model were predicted with high accuracy levels compared to the model experimental data. It was also shown that an ANN is a useful alternative method to model tests and numerical simulations. The developed model can be used to reduce the number of model tests or numerical simulations as well as to obtain the optimum location of the side hulls in terms of resistance.
{"title":"PREDICTION OF RESIDUAL RESISTANCE OF A TRIMARAN VESSEL BY USING AN ARTIFICIAL NEURAL NETWORK","authors":"Burak Yıldız","doi":"10.21278/brod73107","DOIUrl":"https://doi.org/10.21278/brod73107","url":null,"abstract":"Trimaran hull forms have been popular recently in both commercial and military usage due to reduction in resistance at high speeds, better stability, and greater deck area compared to conventional monohull vessels. Determination of the location of the side hulls is most critical to get higher hydrodynamic performance. Therefore, many studies in the literature are related to defining the location of the side hulls for trimaran vessels. Most of the studies have been carried out experimentally or numerically. In this study, an artificial neural network (ANN) model was used to predict the residual resistance coefficient of a trimaran model. The model uses four parameters which are the transverse and longitudinal positions of the side hulls, the longitudinal centre of buoyancy and the Froude number to predict the residual resistance of the trimaran model. The experimental data of the trimaran model were used to train the neural network model in order to develop a more reliable model. Several neural network models were developed and tested to find the one with minimum error. The study showed that the residual resistance coefficients of the trimaran model were predicted with high accuracy levels compared to the model experimental data. It was also shown that an ANN is a useful alternative method to model tests and numerical simulations. The developed model can be used to reduce the number of model tests or numerical simulations as well as to obtain the optimum location of the side hulls in terms of resistance.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48967646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The demand analysis method of maritime emergency resources is the key technology to promote a reasonable emergency resource allocation during maritime emergency management. It is widely used to improve the efficiency of maritime emergency rescue and reduce the loss of maritime accidents. However, it requires a scientific and effective method of the demand analysis of maritime emergency resources. This paper aims to analyze the underlying modeling paradigms and to assess the extent to which the demand analysis methods of maritime emergency resources can meet the requirements. Focusing on the demand analysis methods, this paper provides a broad overview of the current literature on maritime emergency resources of the last decades, by considering the models’ purposes, theoretical frameworks, factors, and outputs. The results indicate that the existing methods can be classified into three concepts: the linear regression theory, Back Propagation (BP) Neural Network, and Case-based Reasoning (CBR) technology. Combined with the characteristics of China's maritime emergency management field, the interaction between theoretical framework and applications is not sufficiently understood and thus needs to be further studied. Being familiar with knowledge gaps acts as a catalyst for further research on scientific and efficient demand analysis methods of maritime emergency resources in various navigation conditions.
{"title":"REVIEW AND COMPARISON OF THE DEMAND ANALYSIS METHODS OF MARITIME EMERGENCY RESOURCES","authors":"Quandang Ma, Yang Zhou, Lei Liu","doi":"10.21278/brod73108","DOIUrl":"https://doi.org/10.21278/brod73108","url":null,"abstract":"The demand analysis method of maritime emergency resources is the key technology to promote a reasonable emergency resource allocation during maritime emergency management. It is widely used to improve the efficiency of maritime emergency rescue and reduce the loss of maritime accidents. However, it requires a scientific and effective method of the demand analysis of maritime emergency resources. This paper aims to analyze the underlying modeling paradigms and to assess the extent to which the demand analysis methods of maritime emergency resources can meet the requirements. Focusing on the demand analysis methods, this paper provides a broad overview of the current literature on maritime emergency resources of the last decades, by considering the models’ purposes, theoretical frameworks, factors, and outputs. The results indicate that the existing methods can be classified into three concepts: the linear regression theory, Back Propagation (BP) Neural Network, and Case-based Reasoning (CBR) technology. Combined with the characteristics of China's maritime emergency management field, the interaction between theoretical framework and applications is not sufficiently understood and thus needs to be further studied. Being familiar with knowledge gaps acts as a catalyst for further research on scientific and efficient demand analysis methods of maritime emergency resources in various navigation conditions.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45956560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents the development of autonomy capability for an unmanned surface vehicle (USV). The development mainly focuses on the high-level autonomy on perception, path planning, guidance and control to achieve real sea applications of the USV. First, visual recognition and point cloud data processing techniques are utilized to achieve a real-time perception of the object in the sea environment. Second, detailed path planning strategies are illustrated to plan the easily reachable path for different missions, and the classic guidance and heading controller are adopted to implement the path following algorithm. Subsequently, these autonomy algorithms run in the high-level computer and render the actuator commands for the low-level embedded control system. Finally, sea trials of the USV are conducted by attending the 2020 Zhuhai Wanshan International Intelligent Vessel Competition (IIVC) in Dong Ao Island of South China Sea. The USV accomplish three missions: 1) path following, 2) navigating around the obstacle, and 3) rescuing the drowning. Sea trial results verify the autonomy of the USV in terms of the achieved performances.
{"title":"DEVELOPMENT OF USV AUTONOMY: ARCHITECTURE, IMPLEMENTATION AND SEA TRIALS","authors":"Chuan Liu, Xianbo Xiang, Jian Huang, Shaolong Yang, Zhang Shaoze, Xiang Su, Yunfei Zhang","doi":"10.21278/brod73105","DOIUrl":"https://doi.org/10.21278/brod73105","url":null,"abstract":"This paper presents the development of autonomy capability for an unmanned surface vehicle (USV). The development mainly focuses on the high-level autonomy on perception, path planning, guidance and control to achieve real sea applications of the USV. First, visual recognition and point cloud data processing techniques are utilized to achieve a real-time perception of the object in the sea environment. Second, detailed path planning strategies are illustrated to plan the easily reachable path for different missions, and the classic guidance and heading controller are adopted to implement the path following algorithm. Subsequently, these autonomy algorithms run in the high-level computer and render the actuator commands for the low-level embedded control system. Finally, sea trials of the USV are conducted by attending the 2020 Zhuhai Wanshan International Intelligent Vessel Competition (IIVC) in Dong Ao Island of South China Sea. The USV accomplish three missions: 1) path following, 2) navigating around the obstacle, and 3) rescuing the drowning. Sea trial results verify the autonomy of the USV in terms of the achieved performances.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48380126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Andalusian Agency of Energy has identified three areas of major interest for harnessing wave energy, in their plan of “Marine Energy and Energy Resources of Andalusia”. One of these areas is located on the Atlantic coast, the bay of Cádiz. Considering this initial interest, the objective of this work is to carry out an evaluation of the performance provided by various technologies of wave energy conversion in the bay of Cádiz. The data for the wave climate in the target area are obtained from the Spanish Agency Puertos del Estado. Diagrams for bivariate distributions of the sea states occurrences, defined by the significant wave height and the energy period, are shown. On this basis, the output of nine different technologies for the conversion of wave energy is assessed in the reference locations in the bay of Cádiz. According to the results obtained, it can be said that the bay of Cádiz is a suitable place for wave energy extraction.
安达卢西亚能源局在其“安达卢西娅海洋能源和能源资源”计划中确定了利用波浪能的三个主要兴趣领域。其中一个地区位于大西洋沿岸的加的斯湾。考虑到这一最初的兴趣，这项工作的目标是对加的斯湾波浪能转换的各种技术所提供的性能进行评估。目标地区的波浪气候数据来自西班牙Puertos del Estado机构。显示了由有效波高和能量周期定义的海况出现的双变量分布图。在此基础上，在加的斯湾的参考地点评估了九种不同的波浪能转换技术的输出。根据获得的结果，可以说加的斯湾是提取波浪能量的合适地点。
{"title":"EVALUATION OF VARIOUS WAVE ENERGY CONVERTERS IN THE BAY OF CÁDIZ","authors":"M. J. Legaz, Carlos Soares","doi":"10.21278/brod73104","DOIUrl":"https://doi.org/10.21278/brod73104","url":null,"abstract":"The Andalusian Agency of Energy has identified three areas of major interest for harnessing wave energy, in their plan of “Marine Energy and Energy Resources of Andalusia”. One of these areas is located on the Atlantic coast, the bay of Cádiz. Considering this initial interest, the objective of this work is to carry out an evaluation of the performance provided by various technologies of wave energy conversion in the bay of Cádiz. The data for the wave climate in the target area are obtained from the Spanish Agency Puertos del Estado. Diagrams for bivariate distributions of the sea states occurrences, defined by the significant wave height and the energy period, are shown. On this basis, the output of nine different technologies for the conversion of wave energy is assessed in the reference locations in the bay of Cádiz. According to the results obtained, it can be said that the bay of Cádiz is a suitable place for wave energy extraction.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43660997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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