Information models and functions for CIM in shipbuilding

In order to make significant progress in design and manufacturing systems, all industries must consider integration. This paper considers information models and functions for a computer integrated design and manufacturing system in shipbuilding. The authors propose the product model and several alterative functions for designing a ship's structure, and develop a “ship definition system for computer integrated design and manufacturing.” This system is called SODAS (System of Design and Assembly for Shipbuilding). An object-oriented concept is used to develop this system. In order to define a ship's structure, the authors propose the product models of “parts member” and “parts connection,” and the product models of “Room,” “Unit,” and “Module” are introduced to define the compartments, internal structures and intermediate products of a ship. Therefore, all information about a product from the design to the production stage is stored in the product model. As well as the product model, the “design function,” “cutting function,” and “virtual assembling function” are introduced. By using the design function, any type of ship's structure can be designed, and by using the cutting function, the design of a ship's structure can be cut into smaller elements. By using the virtual assembling function, a simulation of the manufacture of a ship's structure can be carried out.     

弯曲航道平面尺度研究

在弯道实船试验基础上,结合已有研究成果和有关标准及规范,分析研究了弯曲段航道的最小弯曲半径、航道度及其加宽位置。指出现行有关航道最小弯曲半径的规定基本适合于自航船舶并略偏于安全,现行弯道加宽公式计算值偏小比较并推荐了弯曲航道宽度计算公式和相应参数,弯顶采用凹岸加宽既必要又可行。     

Market based framework for multiple AUVs cooperation

A“Market” based framework for multiple AUVs team is introduced in this paper. It is a distributed meta-level task allocation framwork. The formulation and the basic concepts of the “Market” such as “goods” and “price” are discussed first, then the basic algorithm of the “auction”. The loosely coupled v-MDTSP tasks are considered as an example of the task allocation mission. A multiple AUV team controller and a detailed algorithm are developed for such applications. The simulation results show that the controller has the advantages such as robustness and low complexity and it can achieve better optimization results than the classical central controller （ such as GA） in some tasks. And the comparison of two different local solvers also implies that we should get the reasonable task allocation even not using the high quality algorithm, which can considerably decrease the cooperation computation.     

GAUSS曲率数值计算及其在船体外板展开中的应用

本文对按照离散型值描述的船体外形,提出了一种Gauss曲率的数值算法,以判别船体曲面的可展性,以解决外板的分段展开问题。 Gauss曲率的数值计算是:把船体曲面按照水线和分段线划分成若干小块曲面,判别每一个小块曲面的可展性可推广到较大曲面的可展性。在小块曲面内,首先计算某一定点处的各个方向上的法曲率,然后求出该点的Gauss曲率数值,并由这一数值大小来判定小块曲面可展的几何特性。 本方法避免了复杂的曲面方程,只采用一些简单的表达式计算,对船舶设计和建造收到了一定的效益。     

Second-order sum-frequency wave diffraction by a truncated surface-piercing cylinder in bichromatic waves

This work considers the second-order sum-frequency diffraction problem for a stationary truncated surface-piercing circular cylinder in bichromatic waves. The solution method was based on a semianalytical formulation of the second-order sum-frequency diffraction potential. The boundary conditions were properly satisfied by introducing the “locked” and the “free” wave components of the nonlinear velocity potential. The method was validated by comparing the calculated results with numerical data previously reported by other authors. Particular attention was paid to the second-order sum-frequency heave forces and the change in the wave run-up configuration due to the existence of the lower fluid domain underneath the truncated cylinder.     

Computer-based support for the evaluation of ship handling exercise results

One of the most important parts of the simulator exercise is the evaluation of the students’ results by the instructor both during and after the training session. This should be performed in two ways: first, during the exercise run to ensure that the training objective can be achieved and second after exercise completion in order to give the students an indication of their performance during the simulation run. For these purposes software tools have been created and implemented at the Maritime Simulation Centre in Warnemünde: the “Surveillance Tool”, allows for a monitoring during the run and the “Evaluation Tool” will enable a detailed evaluation by the instructor after the run. It allows for in-depth search within the replay data and at the same time facilitates the calculation of the final score for the student’s performance based on measurement factors as penalties for exceeding quality limits. Within this paper a brief overview of the principles of these methods is high-lighted and selected examples of applications are described.     

Goal-based standards

The development of goal-based new ship construction standards is a new subject matter of high importance for IMO which has been included in the Organization’s strategic and long-term work plans and also in the work programme of its Maritime Safety Committee. This paper briefly describes the meaning of “goal-based” regulation in general and looks at its application to ship construction. The on-going work at IMO is presented, results achieved to date are explained and an outlook is given regarding the work still to be carried out.     

S^2 BHCA Multiple AUVs cooperation oriented control architecture

Oceanographic survey, or other similar applications should be the applications of multiple AUVs. In this paper, the skill ＆ simulation based hybrid control architecture （S^2BHCA） as the controller＇s design reference was proposed. It is a multi-robot cooperation oriented intelligent control architecture based on hybrid ideas. The S^2BHCA attempts to incorporate the virtues of the reactive controller and of the deliberative controller by introducing the concept of the ＂skill＂. The additional online task simulation ability for cooperation is supported, too. As an application, a multiple AUV control system was developed with three ＂skills＂ for the MCM mission including two different cooperative tasks. The simulation and the sea trials show that simple task expression, fast reaction and better cooperation support can be achieved by realizing the AUV controller based on the S^2BHCA.     

Ship inspection support system using a product model

 Recently, the significance of ship inspections has been increasingly recognized because sea pollution and safety problems are occurring more and more frequently. However, current ship inspections rely on the experience of the workers. Therefore, it is difficult to understand, and hence to improve, the state of ship inspections. In this paper, ship inspection is directed into three stages (plan, do, and check), and the configurations of a total system to support ship inspections are discussed. A prototype system for the “plan” and “do” stages is developed. This is realized by organizing the information that relates to inspection, and defining data models for damage and inspection states. Then the proposed system is integrated with a shipbuilding computer integrated manufacturing (CIM) system so that the ship's structural information can be used effectively. In addition, functions to calculate the damage-finding probability, and functions to generate information about damage and the inspection state are introduced. Therefore, in the planning stage, as inspector can execute a virtual ship inspection, and then the damage-finding probability of each hull part and oversight areas are calculated automatically. Further, by carrying this system into an inspection, an inspector can generate damage information and inspection information simply and easily. Some examples of the proposed system are shown at the end of the paper. Received: November 12, 2001 / Accepted: January 30, 2002     

Outline of scientific ocean drilling and specifications of riser drilling vessel Chikyu

 The Japan Marine Science and Technology Center (JAMSTEC) has been, and is now promoting the “OD21” program (i.e., “Ocean drilling in the 21st century”). This is the first plan in the world to utilize deep-water riser-drilling technologies for scientific drilling. One of the important factors for the success of this program is the development of a high-performance drilling vessel. Since 1990, JAMSTEC has been continuing a technological study of a riser-drilling vessel for scientific studies with an operational capability in waters up to 4000 m deep. It was decided to start the construction with a two-phase plan: a vessel with a riser operation for waters up to 2500 m deep will be constructed in the initial stage, and then the vessel will be modified to a 4000-m depth capability. In the development process of the vessel, named Chikyu, many new technical developments have taken place, such as drilling/coring equipment, a dynamic positioning system, etc. Thus, the Chikyu is expected to contribute to ocean engineering and other work, in addition to scientific advances. Received: June 15, 2002 / Accepted: November 11, 2002 Address correspondence to: Y. Yano (e-mail: yanoy@jamstec.go.jp)     

Fuzzy logic based decision making system for collision avoidance of ocean navigation under critical collision conditions

This paper focuses on a fuzzy logic based intelligent decision making system that aims to improve the safety of marine vessels by avoiding collision situations. It can be implemented in a decision support system of an oceangoing vessel or included in the process of autonomous ocean navigation. Although Autonomous Guidance and Navigation (AGN) is meant to be an important part of future ocean navigation due to the associated cost reduction and improved maritime safety, intelligent decision making capabilities should be an integrated part of the future AGN system in order to improve autonomous ocean navigational facilities. In this study, the collision avoidance of the Target vessel with respect to the vessel domain of the Own vessel has been analyzed and input, and output fuzzy membership functions have been derived. The if–then rule based decision making process and the integrated novel fuzzy inference system are formulated and implemented on the MATLAB software platform. Simulation results are presented regarding several critical collision conditions where the Target vessel fails to take appropriate actions, as the “Give way” vessel to avoid collision situations. In these situations, the Own vessel is able to take critical actions to avoid collisions, even when being the “Stand on” vessel. Furthermore, all decision rules are formulated in accordance with the International Maritime Organization Convention on the International Regulations for Preventing Collisions at Sea (COLREGs), 1972, to avoid conflicts that might occur during ocean navigation.     

Predicting parametric rolling in irregular head seas with added resistance taken into account

Parametric rolling in irregular head seas is investigated using numerical simulation in the time domain in this paper. The effect of the change in speed due to added resistance on parametric rolling is taken into account. Three methods of calculating the added resistance in irregular head seas are applied to this problem, and then Pinkster’s method, which considers the time-varying added resistance in irregular head seas, is extended for further investigations in this paper. Furthermore, the Froude–Krylov component of restoring variation is estimated with coupling from heave and pitch motions, and the hydrodynamic effects are extrapolated nonlinearly with regards to roll angle. Finally, the “practical non-ergodicity” of parametric roll is investigated with a model experiment at zero forward speed and using the simulation, and the effect of added resistance is investigated with the simulation.     

Private maritime security company (PMSC) in the Strait of Malacca

Recently, maritime security issues in the Strait of Malacca have been in the limelight. Statistics highlighting the risk of piracy faced by shipping in the Strait of Malacca and the possibility of a terrorist attack have led to an enhanced awareness of the need for heightened security. The declaration by Lloyd’s Joint War Committee (JWC) of the Strait as a “war risk area” has strengthened the perception that the littoral states have not done enough to make the Strait secure for international trade.     

Numerical simulations of fatigue crack initiation and propagation based on re-tensile plastic zone generating load criterion for in-plane gusset welded joints

Many accidents are caused by fatigue in welded built-up steel structures, and so it is important to estimate the fatigue lives of such structures quantitatively for safety reasons. By assuming that fatigue cracks cannot grow without an accumulation of alternating tensile/compressional plastic strain, one of the authors identified an improved effective stress intensity factor range ΔK _RPG based on the re-tensile plastic zone generating (RPG) load, which represents the driving force for fatigue cracks, and suggested that ΔK _RPG should be used as the parameter to describe fatigue crack growth behavior. The “FLARP” numerical simulation code in which ΔK _RPG is implemented as the fatigue crack growth parameter, was developed in order to predict fatigue crack initiation and propagation behavior. In this paper, it is demonstrated that FLARP gives accurate estimates for fatigue life by comparing the estimated fatigue crack growth curves and S–N curves with the experimental results for in-plane gusset welded joints, which are used in many welded steel structures. Moreover, the effect of induced bending moment due to the linear misalignment in the out of plane direction on the fatigue strength of in-plane gusset welded joints is investigated through numerical simulations.     

Potential and benefits of AIS to Ships and Maritime Administrations

The Universal Automatic Identification System (AIS) provides a huge variety of potential applications and services which exceed the well known ship-to-ship data exchange. The purpose of this paper is to address the most important AIS services, in particular the AIS position report and the AIS safety-related and binary messages (“AIS telegrams”). The main issue is the impact of this new technology on the on-board use of AIS in collision avoidance (and its limitations) as well as the impact on shore-based services such as Vessel Traffic Service (VTS), port management and the need of an effective AIS network.     

EU maritime transport

The purpose of this paper is to summarize the European maritime transport policy within the context of maritime politics at large. At the outset the legal framework conditions and supportive instruments for the shipping and port industries are presented. Against the background of recent accidents at sea, such as the sinking of ERIKA and PRESTIGE, the EU legislation on maritime safety is of particular interest as it is both complex and rapid in reaction to environmental needs and political pressure. Finally, the sensible relationship between the EU as a regional organization and the IMO as “the competent international organization” is discussed with a view to reconcile possible rivalry and to suggest a complementary cooperation between the two organizations.     

The enforcement of shipping standards under UNCLOS

This article discusses the enforcement of shipping standards, with a particular focus on Part XII of UNCLOS. Section 6 of Part XII contains the only comprehensive set of vessel-related enforcement provisions in the Convention, but the Part’s scope is limited to “the preservation and protection of the marine environment.” Therefore, not all shipping standards fall clearly within Part XII’s ambit, including those centered on safety, security, and crewing considerations. The enforcement provisions of Section 6 are favorable to flag states and their vessels, and Section 7 contains a number of safeguards for their benefit, so it is in the interests of these parties to have coastal state enforcement governed by Part XII. However, the ability of coastal states to establish and enforce shipping standards that apply within the territorial sea extends to more than just environmental matters. The result is that different standards give rise to different enforcement powers, depending on the maritime zone in which a vessel is located, even if those standards arise from the same international agreement. It is suggested that to remedy these problems, UNCLOS would need to be amended in order to provide a comprehensive enforcement regime for the enforcement of shipping standards.     

Universal jurisdiction as obligation to prosecute or extradite

Before searching for new legal solutions to manage maritime piracy problems, especially those related to jurisdiction, it is essential to examine and analyse the existing international legal framework to determine whether current international legal instruments are already appropriate to face off this threat. One such principle is the “Aut dedere aut iudicare” principle, which has been also codified into SUA Convention, at art. 6 par. 4. This obligation comes from an international treaty, so it cannot be disregarded by any state (short of becoming susceptible to international liability), neither can it be amended by a national law. If a state party has inadequate law resources to establish its jurisdiction, or if unable or unwilling to prosecute the pirate, then such state party has no choice but extradite the pirate. If we consider the above principle as a conventional obligation, then it should be limited only to state parties, and it should be applied only under conditions stated by SUA Convention. Instead, if we consider it as a customary law principle, because piracy—as crimen iuris gentium—offends international community as a whole, then such principle shall be binding without any limit or condition.     

集束塔式立管总体强度分析(英文)

Bundled hybrid offset riser (BHOR) global strength analysis, which is more complex than single line offset riser global strength analysis, was carried out in this paper. At first, the equivalent theory is used to deal with BHOR, and then its global strength in manifold cases was analyzed, along with the use of a three-dimensional nonlinear time domain finite element program. So the max bending stress, max circumferential stress, and max axial stress in the BHOR bundle main section (BMS) were obtained, and the values of these three stresses in each riser were obtained through the "stress distribution method". Finally, the Max Von Mises stress in each riser was given and a check was made whether or not they met the demand. This paper provides a reference for strength analysis of the bundled hybrid offset riser and some other bundled pipelines.