간행물
Journal of Korean Navigation and Port Reserch KCI 등재 한국항해항만학회지
- 발행기관 한국항해항만학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1598-5725 (Print)2093-8470 (Online)
- 수록기간 1977 ~ 2020
- 주제분류 농수해양 > 해상운송학 농수해양 분류의 다른 간행물
- 십진분류KDC 559DDC 629
권호리스트/논문검색
Vol.19 No.2 (1995년 5월) 7건
1.
1995.05
서비스 종료(열람 제한)
The final aim of our research project is a study on assessment of automatic steering system of ships in open seas. In order to achieve this aim, we need to know the characteristics of each component of the system, and also to know the characteristics of disturbance to ship dynamics. In this paper, we provide calculation method of irregular disturbance to ships in autopilot navigation in open seas, and also show calculation examples about two kinds of ship, ore carrier and fishing boat. The disturbance consists of irregular wave and random wind. The disturbance is calculated as equivalent yaw angular velocity. Each spectrum and time history of disturbance are reasonably evaluated. Further investigation concerning to performance index of autopilot system and energy loss related to automatic course keeping, will be dealt with in another paper.
2.
1995.05
서비스 종료(열람 제한)
This paper presents the numerical analysis results of the viscous flow for a full ship model. The mass and momentum conservation equations are used for governing equations, and the flow field is discretized by the Finite-Volume Method for the numerical calculation. An algebraic grid and elliptic grid generation techniques are adopted for generation of the body-fitted coordinates system, which is suitable to ship's hull forms. Time-marching procedure is used to solve the three-dimensional unsteady problem, where the convection terms are approximated by the QUICK scheme and the 2nd-order central differencing scheme is used for other spatial derivatives. A Sub-Grid Scale turbulence model is used to approximate the turbulence, and the wall function is used at the body surface. Pressure and velocity fields are calculated by the simultaneous iteration method. Numerical calculations were accomplished for the Crude Oil Tanker(DWT 95,000tons, Cb=0.805) model. Calculation results are compared to the experimental results and show good agreements.
3.
1995.05
서비스 종료(열람 제한)
A major change occuring in the workplace is the willingness of union leaders, managers, and workers to experiment with various work schedules and to work toward the improvement in the QWL(quality of work life). In this study, the writer measures the level of QWL, embodies components of QWL, testifies the difference of QWL according to the demographical traits, and develops some scales to measure QWL in merchant ships. To achieve objectives of the paper, 11 hypotheses were established and a questionnaire was used, 894 proper data was obtained from 2, 910 Korean seamen working in merchant ships. Results of analyses are as follows : 1) The components of QWL in merchant ships are job, employee satisfaction, wage, welfare, working condition, supervise, colleague relations, initiative, and organization management. 2) Seamen of merchant ships are satisfied with job, supervise, colleague relations, and organization management. They are dissatisfied employee satisfaction, wage, welfare, and working condition. 3) According to demographical traits, the number of the factors significant difference(P<0.05) among components of QWL are 9 for type of ships, 8 ages of seamen, 7 for married or single, nationality of ships, and education level respectively, 5 for seamen career, for 4 rank on board and trading route of ships respectively, 2 for whether union or not and whether union involvement or not respectively, and 1 for department on board. 4) Results which tested hypotheses are as follows : For the components of QWL, married men are more satisfactory than an unmarried men, officers are more dissatisfactory than ratings, old men are more satisfactory than young men, men in high education level are more dissatisfactory than men in low education level, those who are much careers as a seaman are more satisfactory than those who are little careers as a seaman. There are significant differences in the components of QWL according to nationality and type of ships. There are insignificant differences in the components of QWL according to the shipboard department, whether union is or not, whether union involvement is or not, and trading route of ships.
4.
1995.05
서비스 종료(열람 제한)
The protection of the marine environment is one of the main international legal problems in recent years. In parallel with the industrial development, a great quantity of chemical materials were used and in consequence, mass transportation of oil and other dangerous materials was required on the one hand, and discharge of industrial wasters drew also the attention on the other hand. Furthermore, oil tankers accidents, mass use of nuclear materials, sea-bed exploration and exploitation stimulated further deep human concern on the marine environment. The expansion of international concern to new and more dangerous sources of marine pollution regarded more strict and legal control on the Oil Tanker(DWT 95, 000tons, Cb=0.805) model. Calculation results are compared to the international, especially regional level. In particular, this study is concerned with the preservation of the Northeast Asian Seas surrounded by Japan, the Russian Far East, South Korea, North Korea, China and Taiwan. These adjacent countries must intensify cooperation regarding the prevention, reduction and control of the contamination of the sea. And this cooperation between the States concerned should, as much as possible, be aimed at maximizing the effectiveness of measures to prevent or abate transboundary environmental pollution. To achieve this purpose, States concerned should be imposed upon duties such as duty to assess the environmental impact, duty to inform, duty to consult and duty to assist on the basis of general principle of international law, international customary law and other various resolutions of international bodies. Depending on the nature and extent of actual or potential transboundary pollution with the use of a natural resource or the environment in general the establishment of some form of institutionalized cooperation between the States concerned may become useful or indispensable. The functions of this Organization are, inter alia, to keep the implementation of the Convention and the protocals under continuous observation, to make recommendations on regional or sub-regional rules and standards to be elaborated and on measures to be taken by the Contracting Parties, to be notified of any grave and imminent danger from pollution or threat of pollution by the Contracting Parties and to promote in close cooperation with appropriate governmental bodies additional measures to protect the marine environment of the Northeast Asian Seas, and so on. Above mentioned countries, first of all, are located within the Northeast Asian Seas geographically and, therefore, take responsibilities of preserving the clean sea against marine interferences regardless of any difference of the social, political and economic systems. They must be followed under the UNCLOS and other marine conventions. Under the present circumstances, Northeast Asian Seas will become dead seas in case that there is no instant and prompt action against pollution. Hence we have an absolute obligation to promote the development of the mandatory international environmental law, which in turn can faciliate more effective implementation of the regional cooperation by the neighbouring states within this area.
5.
1995.05
서비스 종료(열람 제한)
A wide band design method of an electromagnetic wave absorber with square ferrite cylinders in the second layer, which has very wide band frequency characteristics, is proposed and discussed. A theoretical model using the equivalent material constants method is also evaluated and proposed for its accuracy by comparison with Hashin-Shtrikman formulas. Based on the developed model, wide band electromagnetic wave absorbers with excellent reflective frequency characteristics in the frequency range of 30MHz to 3, 690MHz were designed.
6.
1995.05
서비스 종료(열람 제한)
Since the most of the mal-functions in the industrial equipments controlled by processors have been occured by the Electrical Fast Transient(EFT), the International Electrotechnical Commision(IEC) prepare the dummy signal to test the immunity level of the equipments controlled by processors and recommend it for the measuring. In this paper, the defined dummy EFT signal by IEC are analyzed by the spectrum analyzer in the frequency domain and studied the developed countermeasuring parts. The new developed parts are consist of the feedthrough capacitors ( Cy type ) in the input and materials with high permeaility which was wound or inserted in the second layer of the Power Cable in order to increase Common Mode inductance. And it is compared inserted Permalloy to material with high permeability increasing Common Mode inductance. We could gotten a excellent insertion loss on the wide band against EFT signal. Especially, we confirm that countermeasuring Power Cable have been an excellent dynamic characteristics in computer system above the 3.6Kv. This new parts could be effectively used for industrial, MIL, and medical equipments to reduce a mal-functions on the site. Furthermore, these parts also have a good characteristics for EMI countermeasuring over the 60MHz up to several GHz band, they are also expected to be used for all kind of EMS test with IEC801-2, 3, 5 and 6 on the power distributed line.
7.
1995.05
서비스 종료(열람 제한)
Recently, the ship automation technology(SAT) has received great attention for the efficient management of the ship with minimum human efforts. Among the SAT, a distance measuring system, the key element is the signal processing unit for the interpretion of the received signal from the remote sensing of the oil tank. In this paper, the tank monitoring system using FM-CW is described for the oil tank level guage measurement with an emphsis of signal processing unit.
