Unmanned Ship Identification Based on Improved YOLOv8s Algorithm

Aiming at defects such as low contrast in infrared ship images,uneven distribution of ship size,and lack of texture details,which will lead to unmanned ship leakage misdetection and slow detection,this paper proposes an infrared ship detection model based on the improved YOLOv8 algorithm(R_YOLO).The algorithm incorporates the Efficient Multi-Scale Attention mechanism(EMA),the efficient Reparameterized Generalized-feature extraction module(CSPStage),the small target detection header,the Repulsion Loss function,and the context aggregation block(CABlock),which are designed to improve the model’s ability to detect targets at multiple scales and the speed of model inference.The algorithm is validated in detail on two vessel datasets.The comprehensive experimental results demonstrate that,in the infrared dataset,the YOLOv8s algorithm exhibits improvements in various performance metrics.Specifically,compared to the baseline algorithm,there is a 3.1%increase in mean average precision at a threshold of 0.5(mAP(0.5)),a 5.4%increase in recall rate,and a 2.2%increase in mAP(0.5:0.95).Simultaneously,while less than 5 times parameters,the mAP(0.5)and frames per second(FPS)exhibit an increase of 1.7%and more than 3 times,respectively,compared to the CAA_YOLO algorithm.Finally,the evaluation indexes on the visible light data set have shown an average improvement of 4.5%.

Improved Formula for Estimating Added Resistance of Ships in Engineering Applications

The authors previously introduced a semi-empirical formula that enabled fast estimation of the added resistance of ships in head waves, and in this study the formula is further refined for easy use in engineering applications. It includes an alternative ship draft correction coefficient, which better accounts for the wave pressure decay with ship’s draft. In addition, it only uses the speed and main characteristics of the ship and wave environment as input, and has been simplified to the extent that it can be readily processed using a pocket calculator. Extensive validations are conducted for different ship types at low to moderate speeds in various typical irregular sea conditions, and encouraging results are obtained. This relevant and topical research lies within the framework of the recent IMO MEPC.232（65） （2013） EEDI guidelines for estimating the minimum powering of ships in adverse weather conditions, which specify for the use of simple methods in current Level 2 assessment within engineering applications.Keywords： added resistance, minimum power, IMO regulation, EEDI regulation, weather coefficient, semi-empirical formulas, ships, head waves

A Non-geometrically Similar Model for Predicting the Wake Field of Full-scale Ships

The scale effect leads to large discrepancies between the wake fields of model-scale and actual ships, and causes differences in cavitation performance and exciting forces tests in predicting the performance of actual ships. Therefore, when test data from ship models are directly applied to predict the performance of actual ships, test results must be subjected to empirical corrections. This study proposes a method for the reverse design of the hull model. Compared to a geometrically similar hull model, the wake field generated by the modified model is closer to that of an actual ship. A non-geometrically similar model of a Korean Research Institute of Ship and Ocean Engineering （KRISO）’s container ship （KCS） was designed. Numerical simulations were performed using this model, and its results were compared with full-scale calculation results. The deformation method of getting the wake field of full-scale ships by the non-geometrically similar model is applied to the KCS successfully.

Experimental Investigation of the Decay from A Ship’s Propeller

In the present study, an experimental investigation of the decay of the maximum velocity and its turbulent characteristics behind a ship propeller, in ＂bollard pull＂ condition （zero speed of advance）, is reported. Velocity measurements were performed in laboratory by use of a Laser Doppler Anemometry （LDA） measurement system. Earlier researchers described that the maximum axial velocity is constant at the initial stage of a ship＇s propeller jet （Fuehrer and Romisch, 1977; Blaauw and van de Kaa, 1978; Berger et al, 1981; Verhey, 1983） as reported in a pure water jet （Albertson et al., 1950; Lee et al., 2002; Dai, 2005）, but a number of researchers disagreed with the constant velocity assumption. The present study found that the maximum axial velocity decays in the zone of flow establishment and the zone of established flow with different rates. The investigation provides an insight into the decays of both the maximum velocity and the maximum turbulent fluctuation in axial, tangential and radial components and the decay of the maximum turbulent kinetic energy. Empirical equations are proposed to allow coastal engineers to estimate the jet characteristics from a ship＇s propeller.

Fuzzy Optimal Control Design for Ship Steering

This paper presents a method to design a control scheme for nonlinear systems using fuzzy optimal control.In the design process,the nonlinear system is first converted into local subsystems using sector non linearity approach of Takagi Sugeno(T S)fuzzy modeling.For each local subsystem,an optimal control is designed.Then,the parameters of local controllers are defuzzified to construct a global optimal controller.To prove the effectiveness of this control scheme,simulations are performed using the mathematical model of Esso Osaka tanker ship for set point regulation with and without disturbance and reference tracking.In addition,the simulation results are compared with that of a PID controller for further verification and validation.It has been shown that the proposed optimal controller can be used for the nonlinear ship steering with good rise time,zero steady state error and fast settling time.

A Mathematical Model of a Ship with Wings Propelled by Waves

This paper discusses mathematical modeling of a ship equipped with energy-saving wing devices.Therewith,the ship is mathematically represented by an elongated hull with high-aspect-ratio wings mounted near its bow and stern.Equations,describing ship motions in regular oncoming waves,are written in the spirit of strip theory with account of inertial and damping influence of energy-saving wing elements with the use of linear expansion of wing-related forces with respect to heave and pitch perturbations.This approach readily yields fast numerical solutions for the propulsion of a ship with wings in waves.The latter solutions are then used as an input for calculation of thrust on wing elements on the basis of classical unsteady foil theories corrected for finite aspect ratio.To evaluate speed of the ship in the modes which allow cruising exclusively by wave power,it is hypothetically assumed that in this case,the wave-generated thrust on the wings equals total drag of the ship-plus-wings system,the latter being defined as a sum of its viscous,wave-making,induced(for wing elements)and added-wave components.Excepting the added-wave term and wings’contributions,the total drag is calculated herein by Holtrop method whereas added-wave resistance is evaluated with Beukelman-Gerritsma formula involving kinematic parameters of heaving and pitching motions of the ship calculated both without and with account of the wings.Also discussed in the paper is a decrease of added wave resistance for a ship with wings as compared to that of ship without wings.Finally,the energy efficiency design index(EEDI)introduced by the International Maritime Organization(IMO)is discussed for representative sea conditions as a measure of ship environmental friendliness.

Powership＇s Identity and MARPOL Convention Application

The concept, although it is not new, came to surface in the last ten years with significant technological improvement and became a temporary solution for the port cities where the supply of electricity is in need. A ship shaped floatable structure with a huge power generator on board becomes the temporary but effective solution. However, these converted ex-ships are still legally ships in order to admit them sufficiently within the scope of a leading convention, which applies to marine and air pollution from ships. This issue needs research on the legal definition of the ＂ship＂ to clarify if it is a ship and to determine whether that would also fall within the concept of MARPOL.

Calculate Thermal Infrared Intensity of the Hull’s Military Ship

Stealth technology emphasizes on the reduction in reflection and radiation energies, the surface of target's body in the range of visual, radar, thermal and near IR and so on. Providing solutions to reduce thermal IR intensity radiation is one of the appropriate actions in passive defense for identifying power and targeting enemy. Therefore, questions are brought up: How much is the thermal IR intensity radiation of surface of the hall’s vessel? How much is the effect of each parameter? This thesis tries to provide the software to answer these questions. The provided software measures thermal IR intensity radiation of the surface of the hall’s vessel by the material substance, the temperature of the surface of the hall’s vessel, the situation and characteristic of the thermal detector, noticing the coefficient of environment atmospheric transmittal. This software by changing the effective parameters on thermal IR radiation calculates the thermal radiation on thermal detector in different situations.

China's Shipping Market

Since the New China, the nation’s ports have been under the centralized control and development program of the Ministry of Traffic, with a separate shipping line. With the growth of the national economy and foreign trade after reform and opening to the outside world, it has become more evident that construction of coastal ports has lagged behind. To catch up, China is opening

A Full Mission Simulator of the Ship＇s Automated Electric Power System for Training and Competence Testing of Marine Engineers

This article describes practical preparation of marine engineers on the full mission simulator complex of the ship＇s automated electrical power plant. A full mission simulator complex of the ship＇s automated power management system meets International Convention STCW （Standards of Training, Certification and Watchkeeping） 78 （with Manila amendments 2010） requirements in part of adequate reproduction of its operational modes corresponding to the actual configuration and layout of the ship＇s automated power management system with real consumers and typical loads. The simulator is fully consistent with the goals and objectives of the practical training, as well as the goals and objectives of proficiency testing engine department officers on issues of technical maintenance of real ship＇s equipment （high voltage installations included） and means of automation. The simulator＇s complex is designed for training and proficiency testing of cadets and students of maritime educational institutions, as well as training and proficiency testing of marine specialists （mechanics and electricians） by watch-keeping and maintenance of modem integrated automated control systems of ship＇s electric power plant and the individual ship electromechanical systems, including high-voltage systems. A simulator＇s complex provides adequate reproduction of operational situations on technical side of real ship electric and automation equipment provides training on monitoring, control and management diesel-generator sets in hand, semi-automatic and automatic modes of power station, control and management of electromechanical systems, as well as the set of tasks upon parameterization, visualization and etc. Besides number of combinations of monitoring, control and management tasks, the simulator＇s complex provides an opportunity to simulate various practical fault conditions. It allows students to focus on the work of automatic control system in emergency situations and to work out correct actions for a watch-keeper on searching, localizing of faults and troubleshooting of equipment.

Shipping Giant Launches New Line between Tianjin,U.S East Coast

The Grand Alliance group, one of the world＇s shipping giants, has launched a new route betweennorth China＇s port city of Tianjin and the U.S. east coast.

Granny's Ship

Throughout~*the Depression years^1,mybrothers,sisters and I often heard our grannysay,“One of these days,my ship is comingin.”Of course Granny s ship was just a~*dream—her escape from the reality of beingpoor^2 most of her life.But to us it was veryreal.~*Our family got by with the barest of ne-cessities;there rarely was enough left over forspecial desires.~3 So if we wished for

和平海运与HACHIMAN SHIPPING S.A.等船舶碰撞损害赔偿纠纷案

一、当事人名称 原告汕头市和平海运有限公司. 被告HACHIMAN SHIPPING S.A.. 被告DORVAL KAIUN K.K.. 二、当事人诉辨 原告汕头市和平海运有限公司诉称,2000年7月3日,原告所属"和平"轮在长江口水域正常出口航行时,相向行驶的被告所属"金亚马"轮突然违章穿越航道,在"和平"轮的正常水道上碰撞了"和平"轮的首部,造成船艏左舷严重受损,原告营运被迫中止,损失达90万元人民币.原告认为,本起事故是由于"金亚马"轮违章航行穿越航道避让措施严重不当所致,被告对此应负90%的责任.据此,原告向本院起诉,请求判令两被告赔偿原告经济损失人民币81万元及利息,并承担诉讼费用及律师费用.

The Cradle of China's First Class Seafarers:Qingdao Ocean Shipping Mariners College——by Lin Jinhe,President of Qingdao Ocean Shipping Mariners College

Qingdao Ocean Shipping Mariners College is a College subordinate to China Ocean Shipping (Group) Company under the Ministry of Communications. In our college there are the Department of Marine Navigation,Department of Marine Engineering, Department of Shipping Management and Department of Foreign Languages, offering speciahies of Marine Navigation, Marine Engine Control, Marine Electrical Equipment Control, Marine Radio Communication, International Shipping Management and International Finance and Accounting. We have 3 types of education: the education of formal college schooling, the training for implementation of the 95 revised STCW Convention and the continuation education. Meanwhile we undertake different training of COSCO’s contracted seafarers overseas and other managerial per-

REGULATIONS OF THE PEOPLE'S REPUBLIC OF CHINA GOVERNING REGISTRATION OF SHIPS

Chapter Ⅴ Registration of Bareboat Charter Article 25 In any of the following cases,the shipowner and the charterer shall apply for the registration of barehoat charter: a. A ship of Chinese nationality hareboat chartered to a Chinese enterprise; b. A ship of foreign nationality hareboat chartered to a Chinese enterprise; c. A ship of Chinese nationality

REGULATIONS OF THE PEOPLE'S REPUBLIC OF CHINA GOVERNING REGISTRATION OF SHIPS

Chapter Ⅲ Nationality of Ships Article 15 A shipowner applying for the nationality of a ship shall, in addition to the Certificate of Registration of Ship’s Ownership, submit the following docu-ments according to the ship’s navigation zone: 1. For ships engaged in international voyages, the valid technical documents of the ship issued by an authorized organization for survey of ships in accordance with

中国船舶科学研究中心关于EEDI的研究进展(英文)

介绍了中国船舶科学研究中心(CSSRC)关于EEDI的若干研究成果,包括EEDI衡准基面、船舶失速系数分析和水动力节能装置的研究成果,同时介绍了正在开发的EEDI验证评估软件平台。

关于EEDI衡准基线的研究

EEDI(能效设计指数)是衡量船舶在航行中CO_2排放量的考核指标,EEDI衡准基线则是船舶CO_2排放量合格与否的分界线。通过对EEDI的本质和影响因素的详细分析研究,提出了以装载量为自变量、以船速为参变量、按不同船舶类别表达和生成EEDI衡准基线的方法。实例验证结果表明,该方法合理、实用、有效,与目前不计船速影响的方法相比,准确性有了明显的改善,可以作为EEDI衡准基线正确表达和生成的一种新方法。

EEDI中船舶失速系数fw的计算方法与软件开发

近来IMO提出的新船能效设计指数(EEDI)将会对我国船舶工业产生重大影响。针对该指数计算公式中的船舶失速系数fw进行了研究,提出了一个系统的fw计算方法并形成软件,将计算结果与试验值和NMRI方法计算结果进行比较,证明计算方法具有工程实用性,为近一步开展相关研究工作奠定了理论基础。

船舶余热利用sCO_2布雷顿循环发电技术综述

在船舶动力系统能量转换和利用过程中,实现烟气余热的最大效率回收是降低船舶能效设计指数(EEDI)的有效途径。超临界二氧化碳(sCO_2)发电系统在船舶余热循环利用方面所具有的技术优势已引起全球船舶行业的高度关注,而如何将其与船舶动力系统有机集成并实现高效、稳定联合循环运行发电,正是当前制约该新型技术实船应用的瓶颈。概述了sCO_2布雷顿循环发电的基本原理、典型技术特点及循环结构,分析了国内外研究机构针对sCO_2发电系统在船舶余热循环利用方面的研究现状,探讨了现阶段面向船舶主机余热发电工程化应用所存在的关键技术问题,从而为推进sCO_2布雷顿循环发电技术在船舶烟气余热回收利用领域的基础理论研究和工程方案设计提供理论参考。