For the vibration analysis of floating structures, fluid-structure coupled analysis method which combine the added mass matrix into FEM has been used since many years ago. However, this method has some problems.
In the first problem, it is well known, preparations for FE-model are time consuming works. In second, designers are at a loss how to deliberate the result because too many eigenvalue are obtained. In third problem, the natural frequency in water condition is sometimes different between experiment and calculation though the natural frequency in air condition is equivalent. To solve those problems, reduced added mass matrix method was proposed and this method needed the rotation vector for vibration analysis of higher order modes.
In this paper, the method of extracting rotation vector in experiment is used by rigid connection theory. The modal structural modification analysis is done by using the eigenvectors in 6 directions which contain the extracted rotation vector. This calculation is compared with the experiment in water condition, and the importance of eigenvector on the fluid-structure coupled vibration analysis is shown.

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In the analysis of 3 dimensional solid structure, the mesh generation is always the most time consuming and sometimes makes the analysis impossible. Here, the authors have developed the boundary fitted voxel element to reduce the cost of mesh generation in 3D solid analysis. The shape functions that satisfy the continuity between elements are proposed, and integration method to compute the stiffness matrix, mass matrix and load vector of complicated shape is proposed. The element are implemented to MSC/NASTRAN as user defined element, and the unified numbering method of element and nodes for voxel elements are proposed. Also, the postprocessing technique, which does not use the finite element mesh, is proposed, and implemented using VRML. The analysis examples of static and eigenfrequency problems are shown.

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The concept of cover is employed from manifold method into voxel analysis and applied to 3D solid analysis to make the accuracy control possible. For the mathematical cover, regular square or cubic cover is used, and appropriate weight functions and cover functions that keep the linear independency between approximate functions are proposed. Mathematical proofs are given for the sufficiency of some conditions. The integration method of stiffness matrix and load vector using geometric voxels is proposed. The example problem with analytical solution is solved, and it was shown that with cover functions with higher order polynomial, the error becomes smaller. Also local arrangement of higher order cover functions are carried out, and almost same error norm with the case higher order cover function is used all over.

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Fiber optic sensors were applied to vibration and strain monitoring of ship structures. Fiberoptic LDV sensor was used to monitor vibration at a bow of a ship in the field tests and its response to random vibration of CFRP plate on which fiber-optic LDV sensor was bonded was investigated in the laboratory. Fiber-optic LDV sensor could detect vibration of CFRP plate accurately and monitor an impact of the ship due to slamming. Fiber Bragg Grating sensor (FBG) was used to monitor strain at an upper deck of the ship in the field tests and to measure strain of a tensile specimen in the laboratory. Strain of the tensile specimen was well measured by FBG and strain of the ship which was running was monitored by FBG successfully. Tensile strength and durability of fiber optic sensor bonded on a steel specimen were confirmed in tensile tests and fatigue tests with fiber-optic LDV sensor. Structural integrity assessment with FBG was carried out using rainflow counting methods and thermal compensation of FBG was needed to monitor the structural integrity precisely.

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Subcritical damages sucn as Tatigue cracks ana corrosion usually occur in snip structures cturing tne service period. Such damages do not immediately cause a loss of serviceability or serious disaster such as oil spill from tankers. However, the maintenance of ship structures is very important to avoid such casualties. In this paper, the concept of the information system for damages of ship structures is proposed in order to improve the safety and to support the maintenance of ships in service. In the proposed system, all information of damages in a certain ship is managed in one database, and appropriate action could be taken based on the assessment of these damages. Three possible ways of the situation of application of the proposed system are also discussed. Secondly, the object oriented data model of crack and corrosion damages with the structural data model of a single-hull tanker is proposed. The data structure includes the information of the time when the damage is detected so that the life assessment of the damage is possible. Finally, the prototype system is constructed on the object oriented database based on the proposed data model by using the internet environment. The validity of the proposed concept and data model is illustrated by the examples of the assessment of damages such as life assessment of a fatigue crack. The validity of the proposed concept and data model is illustrated.

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In this paper, a new efficient method to solve the structural optimization problems with the static and dynamic constraints using Genetic Algorithms (GAs) was proposed. With this method, the static equilibrium equation and dynamic equation have no need to be solved by conventional methods resulting in saving the huge computing time which accounts for the most part of the computation in structural optimization. In order to achieve this goal, the concept of generalized design variables was introduced. The number of the variables becomes larger when the new method is applied to real-world engineering problems. To save the computing storage, in this paper, the floating point representation to the string of solution was used. Since many problems reach their optimal point on or near the boundary of constraints, the boundary mutation was introduced to speed up the convergence of the method. To improve the fine local tuning capabilities of this method, the non-uniform mutation was also used. The effect of the boundary mutation and non-uniform mutation on the performance of the GA was examined. A simple numerical example was given to illustrate applicability of this method.

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This is a proposal for the adoption of a simplified means for structural strength calculation based on energy method. Adopting this approach, we may, during initial planning stages, evaluate the strength characteristics of double hull structures by using Lagrange's Multiplier Method to guarantee the continuity of deflection angles with adjoining structures.
The calculation is accomplished by multiplying the nondimensional element stiffness matrix that remains constant for various combinations of structural dimensions by the stiffness ratio. This method makes data inputs and calculation of the stiffness matrix simpler and more expeditious.
The results of calculations using this method have been compared with theoretical values and numerical results obtained through the finite element method (FEM) and have proved to produce results accurate enough to be of practical use, from the perspective of grasping general strength parameters in initial hull planning.Furthermore, we have performed hull structure weight optimization by combining these calculations with genetic algorithms, thereby additionally verifying their validity for the applications addressed here.

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In this paper, the nonlinear programming system is proposed for preliminary planning of area curve for high speed ships. The system is composed of 4 neural networks ; the Estimating Net, Descriptive Net, Integrating Net, and Optimizing Net.
The Optimizing Net proposes an area curve based on the design condition, i. e. target Froude number F_n, target Prismatic coefficient C_P, Length Breadth ratio L/B, and Breadth draft ratio B / d. Its output is connected to the inputs of other three forward model networks, which calculate resulted C_P, wave making resistance coefficient r _w, and teaching-data density parameter δ. The Optimizing Net is adjusted to minimize the evaluation function J, whose elements are the outputs of three forward model networks using the error-back propagation method. Finally, the Optimizing Net proposes the optimum area curve for the given design condition.
Since the definition of J includes the output of Descriptive Net, the resulted area curve is certificated that it is inside of the domain of teaching data which are adopted for generation of the forward model networks. The introduction of Descriptive net's output to the evaluation function is one of the important features of the proposed system.
The proposed optimizing system involves non-linear effects on design parameters and their crossinteraction, so that it could recommend an innovative idea for ship design.
It should be emphasized that the forward model networks were generated based on the tank test data of Series60. When the other data are available, it is possible to make the system to cover much wider variety of ship hull form.

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Generation of Lines, the underwater hull form of ships is an essential process in the initial designof ships.
Technology innovation in the field of ship engineering has not changed the generation of lines. It may be because that the generation of lines requires an analogized information - process ability that can discriminate the fine distinction of underwater hull form. This kind of ability is quite metaphysical and has been piled up only in the memory of experienced designers. And, one of the most important is that propulsive performance of ships has been improved by ship designers' efforts based on their individual experiences.
In order to take over the sophisticated ability of experienced designers, it is necessary to extract metaphysical relations between hull form and ship performance.
In the 1st report, the authors showed that it is possible to obtain information about hull form by means of Fourier Descriptors (FD's). They applied the FD's for expressing/discriminating fine difference of underwater hull form and its effect on hydrodynamic characteristics of 2-dimensional oscillating bodies.
In the present paper, they apply the FD's for expressing and understanding the relations between hull form and propulsive performance of ships. Using published results of self propulsion experiments in a towing tank, they show relations between self-propulsion factors and hull form for 123 model ships by means of FD's. As the results, they show that hull form configuration and self-propulsion factor (1-w) have close relations that have not been explained positively. It may mean that experienced/skilled ship designers have taken over the metaphysical ability for discriminating/evaluating fine changes of underwater hull form.

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It is necessary for risk evaluation of ship, to estimate lives lost at several accidents such as collision, fire etc.. We are developing an evacuation simulation program for this purpose. Generally an evacuation simulation program is composed of three elemental models which are a space model, an evacuee's model and a disaster model. In the simulation program we use coordinate model which deals with coordinate of point of ship directly, as a space model. An individual model which deals with every evacuee differently, is used as an evacuee's model, and time histories of several type of ship condition such as smoke concentration of corridor, slant of decks, are used as a disaster model. These data are the outputs of disaster simulation programs such as smoke movement simulation program, flooding simulation program. To construct the evacuation simulation program, frame based programming approach has been taken, so that characteristics of evacuees can be modeled precisely and representation of ship structure can be easily modeled. By applying this program to analyze evacuation of tested ship and by using outputs from the smoke movement program, several evacuation simulations were carried out varying start time of evacuees. In the results of these simulations situation of evacuation in the ship was thought to be reasonable. This result shows that this program is appropriate for estimation of lives lost under some kinds of disasters caused by accidents of ship.
This paper shows the modeling of the evacuation simulation, and the result of the simulations by using the program.

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It may be difficult to establish the methodology for safe evacuation in the case of outbreak of a marine fire, by originating in the intricacies of the fire spread phenomena and the uncertain behaviors of evacuation based on human factors without uniformity. The suitable countermeasures have to be taken to cope with rapid spreading smoke that is apt to endanger even for personnel away from the division of fire outbreak. Besides, the existence of un-measurable factors such as the ambiguity of human behavioral patterns should be necessary to be considered the redundancy system for safe evacuation. Accordingly, the designing criteria for the safety of evacuation system consisted in evacuating routes and human flow control, is desirably instituted by grasping the personnel behavior based on the associated in simulations of smoke diffusion and evacuation.
The evacuation movement can be predicted considering the decrease of walking speed and the occurrence of self-isolation in psychological action with lowering smoke layer by the proposed method in this paper. The measured index of risk for the evacuation system is defined by using the results of a simultaneous simulation of smoke diffusion and evacuation. This risk index may be used the comparison between various safety systems and its validity is confirmed using the model of a common space in a typical cruising ship.

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Human elements in marine affairs have been discussed in IMO MSC/MEPC, and IMO have intended to introduce the human elements into FSA (Formal Safety Assessment) of future probabilistic rules assessment.
The human in marine is a complex multi-dimentional issue that is affected by three complex systems of human activities, ship apparatuses and misterious marine environments.
To get the solution of the human in marine seems far away from knowledges now. This is out of the range of ergonomics or man-machine interface problems.
The aim of this paper is to get a clue of the solution of the problem. The author investigated human actions in grounding and collision accidents based on the materials of marine accidents inquiry. By the investigation, probabilities of human actions affecting the accidents are summarized in a part of reliability data seas.
To get a more theoretical assessment of human actions, the author figured out a way to introduce the human elements to probabilistic safety assessments of grounding and collision accidents. In the assessments, human actions are treated by clausal form logic equations to introduce human actions, that is described by words in the inquiry materials, into reliability analyses for structures and environments. By this, human elements can be treated in a same ring as structure and environment problems.
The reliability assessments in this paper are based on simple normal distributions with a certain measure of a proof.

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One of the most important information that may make it possible to analyse / evaluate the motion sickness incidence is subject's facial expressions during the whole-body exposure to low-frequency oscillations. Measurements of facial expression have to be carried out by means of non-invasive instruments.
The authors used recorded video pictures for the analysis of facial expressions. After detailed observations of many records, they selected several parameters that were closely related to motion sickness incidence.
Some statistical method such as multiple regression analysis, cluster analysis, etc. and fuzzy integral method with fuzzy measures were applied for the analysis of facial expressions.
The authors show that analysis of facial expressions is possible and may give an effective tool for the evaluation of motion sickness incidence.

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The container cargo flow is now growing, especially in Asia. Coping with this growth, the size of container ships become bigger and the container cargo flow network is changing to, for example, hub and spokes network. The present paper proposes a design method of the container cargo flow network. The network problem is dealt with as a minimum cost problem in this paper. The main OD cargo flow and the distance table give the optimized network and this network can be used as a first plan. The characteristic of this method is to use some mathematical programming and to be designed on a step-by-step basis. An example of the design of the container cargo flow network is presented to show the effectiveness of this method.

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There is a transport form of the multiple seed multiple states of freight transport in such cases as the Hub-Spokes type transport, the direct delivery type transport between two points, the round type transport. In this, do an examination about the Hub-Spokes type transport form by this research.
Devise a macro-model most as a fundamental model. Then, demand density, an area, a form, the homogeneity of the demand are made to change by using this macro-model, and do an examination about an influence to exert on the number of the base and the position. Put the fundamental characters in order quantitatively, and try application to the transport system design.

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More than 80% of the material movements, except raw materials, between Japan and its trade countries are conducted today in the containerized mode.
In recent years, the transportation sector has been undergoing very rapid and multifarious changes due to the alliances between shipping companies, introduction of larger ships as a cost reduction measure and the application of integrated logistics to satisfy the needs of customers.
However, many shipping companies tend to avoid calling a port in Japan due to the inadequate terminal facilities and other services, insufficient channel depth, inefficient handling and the high cost of port fees and dues.
In this paper, an evaluation of the container handling efficiency of terminals is made and a functional assessment of some terminal facilities is conducted. A Petri net model of the container terminal operations is constructed for numerical simulations. Also, a practical simulation is attempted through field measurements conducted on the operational performance of some handling devices being used in a modern container terminal.

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Berthing control is one of the most important phase of ship control, and its automation is desired for a long time. Some approaches for centralistic control have already proposed, but the complexity of the control process makes it almost impossible to design and implement, . In the area of autonomous agent research, research for generating coherent, robust, useful, and adaptive autonomous agents is becoming increasingly active.
In this paper, berthing system was modeled as a multi-agent system, which consists of multiple tugboat agents and one propeller agent. Modelling and implementation technique for Müller's three-layered autonomous agent is proposed. Implementation results show the independency of numbers of the agents in the multi-agent system produces robustness, extensiveness, flexibility of the system architecture.

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Accompanying gradual increase of consuming coal as inexpensive energy, a great deal of coal which has tendency to generate methane-gas spontaneously by oxidizing heat is transported overseas by many bulk carriers. The problem of methane-gas generation originating from coal self-heating is induced greatly the concern in the coal transportation as bulk cargo for the reason that the accidents of gas explosion is apprehensive to occur. Consequently, it needs to take counter-measures to cope with preventing from accumulating surplus explosive gas beyond the lower limit of explosive concentration in void spaces of cargo holds. For this purpose, the hold ventilation is a way of controlling the gas concentration to take account into the fact that quantity of oxidizing heat of fine coal depends upon its temperature and surrounding oxygen concentration which could be expressed by the Arrheniuse's formula.
The generated methane-gas by oxidizing heat of stored coal and the variation of gas concentration in cargo hold with ventilation are clarified in the present study. Firstly, the measurement of generating quantity of methane-gas based on coal temperature is carried out experimentally using the gas-tight steel box in the electric furnace. Secondly, the variation of temperature and gas concentration in a cargo hold are simulated numerically for the coals having combined properties of thermal and gas characteristic, by using the thermal conductivity equation and the gas diffusion equations with the selfgenerating source. By the results of simulation, the gas accumulation in a cargo hold must depend upon the properties of coal in regard to methane-gas generation and it may be difficult to control the gas concentration within the safety range only by hold ventilation in a case of carrying the coal with high gas generation.

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