The transport of cargoes carried by coastal and ocean-going vessels has increased with the rapid growth of the Korean economy these days. This increase of the sea-borne cargoes has made the Korean coastal traffic so congested that this can be a cause of large pollution as well as great marine casualties such as loss of human lives and properties. Marine casualties generally result from the complicated interaction of natural and human factors; the former being the topographic, marine traffic volume and meteorological conditions, and the latter being the quality of seafares. In this paper, the authors analyse the trend of marine casualties in the Korean coastal and clear up the cause of accidents and examine closely the mutual relations among sea accidents, weather conditions, and marine traffic volume. These accidents are classified into several patterns on hte point of view of ship's size, ship's type and ship's age and its characteristics of each pattern are described in detail. Also, the authors estimate the amount of economical losses resulting from marine casualties which are classified into the accident patterns, and clarify the effects of those losses on B/B(Balance Sheet) and P/L(Profit & Loss) of Korean shipping companies and Korean national economy. The analyzed results of marine casualties are summarized as follows: 1) The average number of sea accidents is 248 cases per year with the loss of 107 persons during last 13 years. 2) Collision is the top of causes of sea accidents (approx. 36.4%), shipwreck the second (approx. 20.3%), agroung the third rank (approx. 18.2%). 3) The ship's number under 1, 000G/T is approx. 74% of total ship's number of accidents. 4) 80% of total number of marine accidents is taken plact at the coastal waters. (involved ports & narrow channels) 5) Marine casualties are occur likely to in the night, the winter and the summer. 6) The average amount of economical losses is approx. 18.5 billion won. (approx. 0.14% of GNP) 7) Shipwreck is the top of the amount of economical losses (approx. 60.4%), collision the second (aprox. 24.5%), aground the third (approx. 9.9%). 8) The amount of economical losses is approx. 5.24% of gross capital of shipping co., 1.24% of shipping revenue, 1.38% of shipping total income in 1983.

Tidal phenomenon can be utilized by the wise and cautious mariner to safely perform his duties as pilot and navigator. It can be either a help or hindrance to the mariner. The principle of MULDAE which expresses the determination of the state of the tide based upon knowledge of the lunar date and it has been used in Korea since ancient times. The folk method of calculation was essentially based on an unsystematic division of the lunar month, traditionally using the numbers 7 or 8. As the lunar cycle is complete in 15 days the tidal cycle should also correspondence closely to the lunar date. This paper represents the first scientific attempt to systematically investigate this unique traditional method of tidal calculation and contains a comparison of the MULDAE and ordinary (solar based) tide calculation methods. MULDAE was compared with the standard tide table for standard and island ports in Korea from 1982 to 1985. This study concluded that MULDAE was indeed an accurate adn reliable predictor of tidal activity. Furthermore, the number 6 was found to be the correct divisor upon which to base MULDAE calculations Also a formula expressing MULDAE as a function was discovered. This research show that MULDAE can be applied nationwide and is a reliable and easy way to predict tides based upon mean figures for certain ports and island A calender showing MULDAE is presented here for the first time. A clear relationship between the MULDAE method of calculating tides and the use of ordinary tide tables is proven.

Sea casulties involving tankers, compared with those incurred by other type of vessels, have become particularly threatening to port State in terms of environmental as well as property damages. As a result, most of developed countries including the U.S.A. and Japan have shown a strong interest in implementing the policy of the Port State Control more rigorously in an attempt to protect themselves from irreparable damages caused by sea casualties involving large vessels. In this paper, the problems associated with the implementation of the Port State Control are analysed and then following recommendations and suggestions are made: ⅰ) The flag nation is urged to improve the quality of personnel associated with the operation of a ship. ⅱ) A closer cooperation between developing nations operating vessels and developed nations adopting the Port State Control is required for a successful implementation of this policy. ⅲ) Port states are advised to give a special attention to vessels carrying hazardous cargoes.

It has been generally known that the chattering of an AC electromagnetic contactor due to the fluctuation of attracting force is the primary cause of its abrasion and noise. To reduce this chattering effect, an AC electromagnetic contactor is mostly fitted with a shading coil which works the role to make difference in phases of two distinct components of attracting force. The theoretical interpretation of an AC electromagnetic contactor with shading coil and the equation of its attracting force per unit wattage consumed have already been proposed, however, few explications so far have been made on the determination of optimal circuit constants of shading coil. In this paper, the auther constructs a circuit model of an AC electromagnetic contactor with shading coil which is based on the theoretical interpretation of shading coil examined to be valid by experiments under some assumptions, and defines the equation of attracting force without chattering per unit wattage consumed as a performance function for determining the optimal circuit constants of shading coil. And then, the optimal circuit constants maximizing the performance function are determined by means of computer simulation founded on the above circuit model and the characteristics of those circuit constants are examined with special attention to the coupling coefficient.

The Maritime Commercial Part, which based on the CMI Conventions before 1950s, of the Korea Commercial Code has some critical issues to be improper to the morden internaitonal sea trade. This paper, therefore, has proposed a legislative policy and draft articles in order to make a reasonable and proper shipping law.