이 논문에서는 가상현실로 잘 알려진 인간과 컴퓨터 상호 작용에서의 3차원 음장 재생을 위한 요소 기술을 논하였다. 이 연구의 목적은 가상 공간과 같은 가상 환경을 갖는 선박 조종 시뮬레이터의 구현 가능성을 검토하는데 있다. 이 연구에서는 머리 전달 함수(HRTF)를 이용한 3차원 음장 재생에서의 몇가지 핵심 기술을 고찰하고, 필터 탭수를 줄이기 위한 방법과 3차원 음장에서의 불연속 영역을 보간하기 위한 방법을 기술하였다.
This work aims at examining the navigational safety of the entrance channels of Masan harbour and suggesting the way to improve ships' navigational safety through the channels. It has been found, from the on-scene investigation of the navigational safety at Masan, that the depth of the Budo-Sudo channel is not deep enough to cater for the largest vessel visiting the harbour, and that the No.2 navigational channel is not wide enough for the vessel. An additional new waterway, therefore, has been recommended to be established in the south of the Budo-Sudo channel so that the deep draft vessel can detour. The No.2 navigational channel has been recommended to be widen. The width of the channel was suggested to be 280 meters. A waterway design simulation methodology has been applied to examine the safety of the newly suggested channels. New channels have been proved to be safe from the experiment.
One of the most important missons that are imposed on merchant ship at sea is to accomplish the safe transportation of cargo loaded. Recently, a study on the seakeeping performance has been carried out on the development of evaluation system related to the synthetic safety of a ship at sea. The seakeeping performance is the ship's ability sailing at, and executing its misson against adverse environmental factors successfully and safely. Until now, however, there has not been any method of quantitative evaluation on the dynamic safety of the ship's cargo loaded. In this regards, this paper has introduced the evaluation method of dynamic safety of the ship's cargo. In order to evaluate the dynamic safety of cargo, the vertical and lateral acceleration which causes the collapse, racking and local structure failure of cargo was adopted as the evaluation factors in the ship's motions. The response amplitude of ship's motions in regular waves is manipulated by NSM (New Strip Method) on a given 2,700 TEU full container vessel under the wind forces of 7, 8 and 9 Beaufort scale. Each response of ship's motions induced by NSM was applied to short-crested irregular waves for stochastic process on evaluation factors and then vertical and lateral acceleration of each cargo was compared with significant amplitude of each acceleration. A representative dangerous factor was determined by comparing permissible values of stacking and racking forces occurred typically to the vertical and transverse directions with the container strength required on ISO 1496 at the positions of forecastle, poop and ship's midship respectively. Through the occurrence probability of the determined factor by Rayleigh's probability density function, the dangerousness which limits loads on container's side wall as an evaluation was applied in judging of the danger of the ship's cargo loaded.
As passenger ship accidents so frequently have occurred, crisis consciousness is highly aroused in Korean society. Although bombastic policy guidlines were suggested in accordance with every passenger ship accident, there remains a still high possibility of such an accident reoccurring because passenger ship accidents occur from the perspective of non-compliance. The research objective of this study is to government's safety regulatory policies. Data for the analysis was collected from literature review. A Case study related to passenger ship accident is adopted for the analysis. The research methods utilized in this study consist of extensive quantitative analysis of 138 passenger ship accidents which had happened over last 10 years from 1984 to 1993 in Korea and a qualitative analysis of the passenger ship accident of the Seohae Ferry in October 1993. The results of the quantitive analysis on the 138 passenger ship accidents are as follows; Seeing the accidents yearly, the accidents which occurred by policy non-compliance are still exist, only somewhat reduced as years gone by. Seeing the accidents from the perspective of types of accident, fire accidents and death and injury accidents had more non-compliance factors than contact accidents and one-side collision accidents, etc. had. Seeing the accidents from the perspectives of types of passenger ship, large ships like car ferries and general passenger ship accidents had more non-compliance factors than any other kinds of ships had. Seeing the accidents from the perspectives of tons of passenger ships, large ships weighing more than 1, 000 tons and small ships weighing less than 50tons contained a lots of non-compliance factors. The results of the qualitative analysis of the passenger ship accident of the Seohae Ferry in Octovber 1993 are as follows; From the viewpoint of the human factor, there were non-compliance to the recruiting of required number of qualified crew members and non-compliance to the rule which prohibited them from leaving port in bad weather and high wave conditions. From the viewpoint of the ship factor, there were defects in the ship. So we might say that there was non-compliance which was aroused from the lacks of technical skills. From the viewpoint of the administrative factor, there were many non-compliance factors such as sailor education, shipping management, rescue, safety equipment. From the viewpoint of the passenger factor, there were passengers' threats which compelled the crews to leave the port under bad weather conditions. In conclusion, the principal non-compliances factors are passenger ship company did not follow safety rules such as shipping the permitted number of passengers, loading permitted tons of freight and fastening freights properly and recruiting required number of qualified crew. In order to reduce accidents, firstly we should find out the causes which play key roles in passenger ship companies' non-compliance to the government's safety regulations. Secondly we should tackle the causes.
It is well known that simulation study in the preliminary design stage of harbors or berths is of great use, since it can provide helpful informations to the designer from the view point of ship navigations. In this paper, a brief review is made in the safety assessment of ship navigation for a 320,000 DWT VLCC entering Yecocheon harbor area, which is carried out by shiphandling simulator system. The geographic data base for the harbor as well as the mathematical models of the ship and environmental effects are designed and developed. Based in the on-site inspections and interviews with pilots in Yeocheon area, basic maneuvering plans and consistence with real operation conditions. Berthing and deberthing maneuvering simulations as well as approaching and departing simulations are carried out by 3 experienced navigators according to the maneuvering plans and environmental scenarios. The simulation results are analysed in various ways to evaluate the quantitative and qualitative maneuvering difficulties and thereby to assess the safety of ship navigation in that area.
To predict the oil-spill dispersion in marine waters, the oil-spill dispersion model based on Lagrangian particle-tracking method was developed and applied to Kwangyang and Jinju Bay. The tidal current movements to be required as input data of the oil-spill dispersion model were obtained by a two-dimensional numerical tidal model. Evaluation of tidal current movements using mean tide was successful. Modelling results were compared with the field data obtained at spill site. There were some descrepancies between modeling results and field data. However, the general pattern of modelling results was similar to that of field data. Provided the real-time tidal currents and more accurate wind data are supported, more favorable results can be obtained.
the observations in situ and the seawater analyses were conducted in July and August, 1996 for the purpose of evaluating the characteristics of seawater quality centered on eutrophication in Mokpo harbour. By applying the OECD standards of trophic classification to the parameters such as secchi depth, total inorganic nitrogen, phosphate phosphorus and chlorophyll-a, the trophic level of seawater in Mokpo harbour was evaluated to be in eutrophic state in summer. By the estimation of pollution index with relation to eutrophication, the seawater quality of Mokpo harbour was evaluated to be under the regular grades and this evaluation was found to be different from the results of evaluation obtained by the environmental index of single parameter, chemical oxygen demand. By the estimation of eutrophication index, the seawaters of Mokpo harbour were shown to have the high potentiality of red tide occurrence.
To understand the dynamics of a drifting object, an analysis based on fluid dynamics theory is presented. A simplified analysis shows a consistency with the linear formula currently used for search and rescue mission. Also an experiment using miniatured human models has been conducted to study the drift characteristics of Person-in-Water. The tests were carried out at the water channel facility and the models were tested in different positions and styles. The measured drag coefficients for human body ranged over 0.4-1.2.
When navigating at sea, informations like other ship's particular are very important to navigator who should make a safe maneuvering. Most of all is obtained through the optical observation and/or the radiotelephone communication, but it is not easy to perceive them when the visibility is restricted or there is some hardness in communication. In this study, we suggest the algorithm that measures the ship's length and speed on the radar screen and estimates the ship's particular such as gross tonnage, breath and type on the base of above two factors.
The in situ observations and the seawater analyses were conducted in July and August, 1996 for the purpose of describing the characteristics of organic pollution, dissolved oxygen distributions, and the evaluation of water quality in Mokpo harbour. The vertical density distribution of water column was found to be in stable structure with higher water temperature and lower salinity on surface layer at ebb tide in summer. In July, dissolved oxygen was shown to be oversaturated on surface and bottom layers, while in August, which was shown to be oversaturated on surface layer, and to be unsaturated on bottom layer as 68∼93% of saturation percentage. Dissolved oxygen of bottom layer in August was evaluated to be under the regular grades, based on Korean standards of seawater quality. In view of COD, the seawater quality of Mokpo harbour in summer was evaluated to be deteriorated due to organic wastes and graded to be the third class, and TSS of Mokpo harbour in summer was graded to be the second class, based on Korean standards of seawater quality. In particular, COD of surface layer in August was found to be under the regular grades. It is, therefore, necessary to take measures for the control of pollution loads and the proper management of seawater quality in Mokpo harbour. The distribution patterns of DO, COD, VSS and Chlorophyll-a on surface layer along the downstream center line from inner harbour to harbour entrance were similar to one another at ebb tide in August.
The application of all regulations during building phase, plus constant vigilance in operation is essential to reducing the risk of fire aboard. A Safety by design approach is increasingly important. Fire safety regulation can solve problems which are hard to be solved by HSC code(International Code of Safety for High Speed Craft). Recently HSC code is applied for ship design development or guidance to the designer and demonstrates many advantages. In this pages, ship fire Safety are realistically modeled as ship design and the shipboard fires & muster stations are analyzed using HSC Code