Assessment of the safety of ship's transit in the narrow channel consist of the maneuvering safety determined by the chance of running aground, the maneuvering difficulty determined by ship's workload and master's subjective evaluation. To examine the relation between master's subjective evaluation and maneuvering safety, this utilizes a real-time and full-mission shiphandling simulator in the Korea Marine Training & Research Institutes(KMTRI). The vessel chosen was 60,000-ton, Panamax-type ship. The findings regarding master's subjective evaluation were as follows: -Relation between master's subjective evaluation and common logarithms of stranding probability is linear. -Stranding probability with more than 0.001 is master's subjective evaluation with more than 5.
Final aim of this paper is a study on simulation of automatic steering of a ship in random seas. In order to achieve this aim, we need excitation due to random seas. The excitation may be estimated from energy spectrum of irregular waves and response functions of manoeuvring motion of a ship in regular waves. This paper deals with response functions of manoeuvring motion of a ship in regular waves. We discussed New Strip Method(NSM) of sway-yaw-roll coupled motions in regular waves. NSM is defined in space axes system and that has been used to predict seakeeping performance of a ship in waves. But ship manoeuvring is defined in body fixed axes system. So we cannot use NSM theory itself in predicting manoeuvring performance of a ship in waves. We introduced relationship between space axes system and body fixed axes system. And we developed modified NSM which was defined in body fixed axes system and was able to be used in manoeuvring motion of a ship in waves. We calculated sway and yaw response functions of manoeuvring motion of a bulk carrier in regular waves.
A theoretical scaling was made in order to acquire the ice resistance of ships in level ice. Ice resistance of ice-breaker Ermak was calculated by Kashteljan eequation and it's model test results were compared with full-scale measurements. Atkins's ice number and Norman Jones's dimensionless numbers were investigated and discussed.
On developing port system, the performance tests of system in relation to ship maneuver generally consists of the three parts: the channel transit, the manoeuvring in a turning basin and the docking/undocking. The quantifications of risk of an accident has priviously been difficult due to the low occurrence of accidents relative to the number of transits. Additionally, accident statistics could not be related port system because of the large number of factors contributing to the accident. such as human error, equipment failure, visibility, light, traffic. etc. In case of the channel transit, "Relative Risk Factor(RRF)" or "Relative Risk Factor for Meeting Traffic" was proposed as the as the measures derived to quantify the relative risk of accident by M.W.Smith. This factor measure the tracking performance, the turning performance and the passing performance at meeting traffic. On the other hand, the safety of berthing maneuver is not measured with a few evaluating factors as controlled due to complex controllabilites such as steering, engine, side thrusters or tugs. This work, therefore, aims to propose the evaluating measure by the Analytic Hierarchy Process(AHP). Six experimental scenarios were establised under the various environmental conditions as independent variables. In every simulation, the difficulty of maneuver was scored by captain and compared with AHP scores. The results show almost same and from which the weights of eight evaluating factors could be fixed. Additionally, the limit value of relative factor in berthing safety to six scenarios could be estimated to 0.11.e estimated to 0.11.
In marine transportation of bulk cargoes such as crude oil. ore, coal etc., a lot of full form ship which have poor manoeuvrability were presented in many countries. Since ship manoeuvrability depends upon many parameters namely hydrodynamic derivatives, interference factors etc., as external forces, it is of great importance that we investigate these values of parameters on analysis of manoeuvrability. In this paper, we investigated and analyzed interaction coefficients among hull-propeller-rudder for a full form ship by captive model test in circulating water channel, and then compared with experimental results by PMM test. A tanker model ship which has 0.83 as block coefficient and MMG mathematical models were used in this experiment. Almost same tendencies were found in qualitative analysis, even though more serial experiments were demanded in quantitative analysis.
Korean property and liability insurance companies have underwrited hull insurance without proper undrewriting ability. But after April 1996. in case of Korean insurance market being opened the companies have to make hull insurance rate by themselves. Accordingly, in this study, the writer embodies important factors in making hull insurance rate by an empirical survey. In empirical survey, the writer used a questionnaire, 74 proper data was obtained from 96 officers working in making hull insurance rate in 12 Korean property and liablity insurance companies and 24 the foreign companies at home. Reliability was tested by Cronbach's Alpha and a conceptual validity by Factor Analysis. Hypothesis estabilished in this study was tested by Correlation and Multiple Regression Analysis. Results of testing hypothesis are as follows: Firstly, the traits of insurer and the assured influence significantly(P<0.05) on making hull insurance rate. Secondly, expected loss ratio, ship manager, ship's age, insured amount, level of the cost of repairing and salvage, shipowner, period of insurance, level of overseas rating, profit and expense, trading limits, ship's classification, conditions of insurance, and ship's size influence significantly(P<0.05) on making hull insurance rate.
In this study, the writer embodies factors influencing on ship safety management by an empirical survey. In the empirical survey, the writer used a questionnaire. 1, 271 proper data was obtained from 4, 240 Korean seamen working in 152 domestic and 60 foreign merchant ships. Reliability was tested by Cronbach's Alpha and a conceptual validity by Factor Analysis. Hypotheses established in this study were tested by Correlation and Multiple Regression Analysis. Results of analysis are as follows: Firstly, three levels(i.e. planning, doing, and evaluation) of safety management and satisfaction level of shipboard life correlate significantly with level of ship safety management and between them(P<0.05) Secondly, satisfaction level of shipboard life, evaluation and planning levels of safety management influence significantly on level of ship safety management(P<0.05).
In Korea, the System of search and rescue in water have came into force on the basis of the Korea Life Saving and Rescue Act. 1961. But It's a premodern administration law which is not fit for an international system of the search and rescue and become disconnected with reality in Korea. Recently the marine casualties occur frequently in Korea coastal area, therefore, we need to amend the 1961 Act. The amendment which is carried out by the Korea Maritime Police Agency is a provision to receive International convention(SAR, 1979). The amendment of this Act will give a epoch-making change to Korean policy of the life-saving and rescue, security to marine safety and contribution to National positon on system of "Search and Rescue". In this thesis, I propose a development scheme to be conductive to original task on "Search and Rescue" of International Convention in Korea Life Saving and Rescue Act(Amendment, 1994).t(Amendment, 1994).
A practical application of a fuzzy control system is described for an air-conditioning system. Air-hadling units are being widely used for improving the performance of central air-conditioning systems. The fuzzy control system has two controlled variables, temperature and humidity, and three control elements, cooling, heating, and humidification. In order to achieve high efficiency and economical control, especially in large offices and industrial buildings, two controllable parameters, temperature and humidity, must be adequately controlled by the three final controlling elements. In this paper a fuzzy control system was described for controlling air-conditioning systems efficiently and economically.
The minimum temperatures are important element in the daily human life, the climatic classification, and so on. In this study, the authors aim to make an analysis the distribution characteristics of minimum temperatures of 95 weather stations in Korea by using the Climatological Standard Normals of Korea VolumeI, VolumeII, and the Climatological Standard Normals of North Korea. The important results are as follows 1) The daily, fifthly, and tenthly minimum temperatures show the highest rate of occurrance on 14th of January( Occurrance rate : 56.6% ), 16~20th of January( 37.6% ), and the middle ten days of January( 82.1% ) respectively. 2) In the regional distribution of minimum temperatures in winter, the values of northern part, inland area, and west coastal region are lower than those of southern, coastal, and east coastal regions respectively. And, bigger cities and industrial area( Seoul, Incheon, Daejeon, Daegu, etc. ) have larger values than the its vicinities. 3) When the daily minimum temperature is 0℃ and less, the days of northern part, inland area, and wests coastal region are higher than those of southern, coastal, and east coastal regions respectively.
Fiber optic gyroscopes must be a promising technology that can replace conventional mechanical ones based on the principle of inertia of spinning masses. The advantages of fiber optic gyroscopes over mechanical ones include low cost, light weight, compact size and fast turn-on time. We will apply them to fiber optic gyrocompass for ships. Fiber optic gyrocompass for ships requires the north-seeking accuracy of 15˚/hr, earth rotation rate, or better. This article introduces the fiber optic gyroscope as rotation sensor in the fiber optic gyrocompass system for ships that is planed to develop in our laboratory.