The DGPS is used to improve the accuracy of the GPS by determining the positioning error data known locatio and subsequently transmitting the determined error, or corrective factors, to users of the GPS operating in the same geographical area. The accuracy of the DGPS available to real0time users is published in the Federal Radio-Navigation Plan to be better than 10 meters, although users often experience accuracies of better than 3 meters. USA recently decided to expand the marine DGPS service for land applications and initiated the Nationwide DGPS chain. Korea is processing for improving the marine DGPS. We have not achieved Full Operational Capability. But after announcing FOC, we have to begin expansion of DGPS into land. This paper investigate the availability of marine DGPS in land. The results will provide a basic guide for estimation of a propagation loss of the marine DGPS frequency in land.

As the increasing demand of the radio wave communication and teh progreessing of communication system, the radio interference of neighbor nations is rising in the improtant matter. This problem is a delicate matter which must be dealt diplomatically with by having a distinct technical basis. For our country, after the radio interference has been occurred in TRS service on the south seashore due to the base stations located at Fukuoka in Japan, the radio interference problem of neighbor nations has risen importantly. In this paper, therefore, we has measured the radio wave that reach from Fukuoka in Japan to Pusan in Korea and also collected dat by real-time.

The paper deals with the implementation of prototype Risk Visualization Sytem (RVS). The RVS is one of the sub-system of Risk Management System (RMS) of National Maritime Police Agency in Korea. In this work, prototype RVS was constructed with virtual reality techniques. Using the prototype RVS, we carried out some performance tests for the various environmental conditions at sea. As results from tests, the prototype RVS can provide immersible virtual world. The results gave rise to the user interaction with 3D objects that give realistic reproduction of sear environments. Thus, we found that the prototype RVS should be a immersible visualization system of Risk Management System.

The purpose of this study is the optimum modification of dynamic characteristics of stiffened plate structure. In the method of the optimization ,finite element method (FEM), sensitivity analysis and optimum structural modification method are used. To begin with, using FEM, the dynamic characteristics of stiffened plate structure is analyzed. Next, rate of change of dynamic characteristic by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using this sensitivity value and optimum structural modification method. The change of natural frequency is made to be an objective function. Thickness of plate and cross section moment become a design variable. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure.

Recently, marine traffic engineering has been developed until that possible to estimate a change in traffic flow caused from some transformations of the traffic condition and to assess whether changed traffic condition is can be accepted as a useful thing in navigation or not by compute simulation. This paper's main substance is assessment of the present marine traffic safety at these area adjacent to Pusan harbor. Also in this study, it was carried out in order to be convinced of validity of round about TSS to expect changing in traffic flows by the institution of round about TSS and to assess expected traffic flows by using Environmental Stress assessment model.

The hull form of $\boxDr$Tamna Sullyokto$\boxUl$ ancient envoy ship for shipping and foreign trade in Choson period were transformed and developed in accordance with their voyage and regional routes. It is not easy to presume the hull form and the structural form of Envoy ship of choson period. This paper aims to present material concerning the ancient ship of $\boxDr$Tamna Sullyokto$\boxUl$ by analysing ancient voyage sea route and war ship history of Chosun period of the $\boxDr$Tamna Sullyokto$\boxUl$ ancient ship.

In this paper, we proposed a simulator for reconstructing and analyzing vessel collision accidents happened at sea and we verified validity of the system by applying it to some collision accidents. This system will offer us to advantage of time and human power by contributing to automation of judge's decision.

The most important thing in the ship is safety. In this paper, we discussed a development of the education system on various equipments concerned to safety. It may increase the effect of the education for the equipment by showing the details of safety equipments, general account, a manual, LSA(Life Saving Appliance) Code and SOLAS convention through an image on a screen.

1. Instruction. 2. Investigation about holding power in Da san mooring area. 3. Weather condition in Da san anchorge. 4. Calculation of Externer power. a. Calculation of Container ship' holding power in mooring. 6. Comparison of Container ship' External power and holding power. 7. Conclusion.

The paper deals with the design and implementation of Navigational Aids Training Simulator (VR-NATS) by Virtual Reality (VR). To gave interaction and immersible training situation to the user, prototype VR-NATS was developed based on the object-oriented operating system with 3D objects of navigational aids. Using the VR-NATS we created virtual navigational aids. As results from the assessment tests, students can obtain IALA (International Association of Lighthouse Authorities) rules of the navigational aids exactly and quickly comparing with conventional education methods. Thus, we found that he proposed VR-NAT is very effective for the next-generation simulation system.

As Internet has been spreading and popularizing, lots of industries of he society are changing their industries to be compatible to the internet. In other works may companies are investing for Electronic Commerce to change their industries....so there are lots of company to introduce electronic commerce in his industrial fields and this kind of tendency is increasing now, because electronic commerce has a lot of advantages this kind of tendency has been trying in the shipping industrial fields... so we an find lots of marine electronic commerce sites in the internet by a searching engine. these sites insist their site is real portal in the shipping field.. But actually their sites just e-commericalize a field or some fields of shipping, So they cann't insist their site is a real portal site But in this kind of tendency, real shipping portal site will be made someday but not so long.. so we want to show contents and strategy real shipping portal site should possess by comparison and generalization with existing shipping portal sites.

An expert system for a ship medical manager is presented in this paper where it si planned to improve the medical environment of the crew. The proposed system includes a information retrieval system that is based on the knowledge database organizing important experiences of first-aiders and is intended to be used effectively by the inexpert member. Moreover, this system of which the purpose is to computerize the medical work of each ship medical manager that the third officer give an affirmative guide for the execution of their duty from the medical treatment database of the disease occurring frequently on many crews.

More and more people have suffered from the environmental pollution caused by the rapid development of our industry. They wat to be compensated for loss an furthermore hope to prevent their neighbor circumstances from being polluted. It's the reason why the environmental action occurred. Our team will clarify our environmental right, the process of environmental action and general problems of our current system. On the basis of them we will present several improvable methods.