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.25 No.4 (2001년 12월) 14건
1.
2001.12
서비스 종료(열람 제한)
This paper presents a decision making model for the cruise ship management. A network based optimization model has been developed for a single cruise ship operation. It gives optimal itinerary patterns over the planning period for the cruise ship managers wanting to maximize profit from the cruise ship operation. A network solution method to find the optimal solution is also developed. This network model can be equivalently transformed into a linear programming model, which makes the implementation of the model quite practical however complicated the given set of possible itineraries may be. The ship scheduling network developed in this study can also be used as a general framework to describe all possible cruise ship itineraries the cruise ship manager can figure out.
2.
2001.12
서비스 종료(열람 제한)
While recognizing that Loran-C is very important as a back-up for satellite systems, the introduction of EUROFIX, that it uses Loran-C system, was proposed and admitted at 9th FERNS(Far East Radio Navigation System) Meeting. But, the FERNS countries should consider whether the cost-effectiveness of the system could be improved by making use of its communication facilities to integrate more closely with satellite systems. And, the members were requested to give this proposal consideration before the l0th session of the Council. or this matter, Korea planned to demonstrate transmitting EUROFIX signals from Pohang Loran-C station (Master of 9930 Chain) during the l0th FERNS Meetings. Therefore, this thesis describes the analysis of EUROFIX datalink and progress of EUROFIX construction work. This thesis is the report with regard to the sequence of this demonstration of EUROFIX in Korea.
3.
2001.12
서비스 종료(열람 제한)
The purpose of this study is to find out the subjective and objective fatigue level and the characteristics of seamen's physical strength with the service period on board, to have a new understanding of the vocation, and to explore a physical exercising program for the seamen. The questionnaire survey for the seamen who had been in service on the ocean going vessels was conducted and the results are fumed out as the followings. Total number of seamen who had answered the questionnaire was 64 persons and the distribution status of service period group was identified as 16 persons for each of 4 groups； the group was classified as the group of less than 5 years, 5 - 10 years, 10 - 15 years, and more than 15 years. 1. Working conditions Working hours in a week was identified as 44－56 hours(45.3%) and the number of 45.3% of the seamen answered the working hours in week is more than 56 hours. The seamen of 25.0% are unsatisfied or very unsatisfied with their vocation. The seamen of 65.6% are smoking, and 45.3% of them drink. The seamen of 44.,3% drink once or more in a week. And the seamen of 67.2% do not take any exercise in a week. 2. Contribution to the seamen's fatigue and subjective symptom The most contributive factor to the seamen's fatigue was identified as the short of sleeping(21.5%), overwork(19.2%), poor working conditions (18.6%), and the friction in human relations also becomes one the contribution to the fatigue(14.0%). The subjective symptom by fatigue was identified as the feeling of languid, sleepy and tiredness of eyes. 3. Characteristics of the seamen's physical strength and Interrelations The grip strength and back strength of the seamen whose service period is less than 5 years were measured as 40.44kg and 127.8kg. The sit ups in the group of service period less than 5 years was measured as 36.84 times, and the vertical jump for the seamen in this group was measured as 46.55cm. The closed-eyes foot balance was measured as 33.64 seconds in the group of service period between 5 and 10 years, and side-step was measured as 35.31 times in the group of service period less than 5 years. The standing trunk flexion was measured as 10.54cm for the seamen whose service period is between 10-15 years, and the trunk extension was measured as 50.70cm for the seamen whose service period is less than 5 years. And the step test of the seamen whose service period is between 10-15 years was measured as 54.44 numbers, and the number of flickers of the seamen whose service period is less than 5 years was measured as 32.94.
4.
2001.12
서비스 종료(열람 제한)
This thesis describes the design of a stabilized algorithm for shipboard satellite antenna systems which can enhance the tracking performance. In order to overcome some drawbacks of the conventional step tracking algorithm, the proposed algorithm searches for the best tracking angles using gradient-based formulae and signal intensities measured according to a search pattern. The effectiveness of the proposed algorithm is demonstrated through simulation using real-world data.
5.
2001.12
서비스 종료(열람 제한)
We have reported the new measurement system which was substituted digital filter for the analog filter in order to develop the optimal system that could find the time delay between each sensors with high accuracy. And also we have confirmed through the experiments that the accuracy of measurements were differentiated by the methods what kind of digital filter had been adopted. This paper suggests two algorithms which approximate the sound source's bearing and distance. One is that sound source's relative bearing can be approximately regarded as the gradient of hyperbolic asymptote, the other is that the source's range can be approximated under the condition of a long range source relative to the sensor's interval. And a series of experiments were carried out with the source's distance 22.42meters and the random bearing interval within the limits of -90˚~+90˚. As a result, we have recognized that the approximation methods could measure the bearing and distance with higher accuracy than the method using trigonometric relation could do.
6.
2001.12
서비스 종료(열람 제한)
Marine Casualties cause the loss of hmm lives, properties and marine pollution. The prevention of marine accidents has been a major topic in marine society and various policies and countermeasures have been developed, applied to the industries. The coastal VTS and navigational aids are considered as one of the effective methods to promote marine safety but they need relatively huge amount of budgets to build. Thus prior to establishing these coastal VTS and navigational aids, it should be evaluated the navigational safety level in the coastal waterways in concern. So far as human beings are concerned, there are many types of fuzziness in the evaluation of navigational safety level. In order to reflect these fuzziness on this evaluation, this paper introduces the fuzzy measure and integral to represent the fuzziness in the evaluation process. Therefore this paper aims to develop the method for this evaluation using the fuzzy measure and integral. In this paper, Korean coastal area is divided into 8 sectors and evaluated the priority for the needs of coastal VTS and navigational aids. The results are found as order as Mokpo, Yosu, Pohang, Busan, Inchon, Geoje, Gunsan, Donghae coastal area.
7.
2001.12
서비스 종료(열람 제한)
In the present study, irregular disturbances to ship dynamics is proposed, where irregular disturbances implying irregular wave and the fluctuating component of wind for the evaluation of automatic steering system of ship in following seas. Prediction method based on the principle of linear superposition. Irregular wave disturbances in following seas is calculated by frequency variation method. The mathematical model of each element of an automatic steering system is derived, which takes account of a few non-linear mechanisms. PD(Proportional-Derivative) controller and low-pass filter with a weather adjustment are adopted to modelling the characteristics of an autopilot. Performance index is introduced from the viewpoint of energy saving, which derived from the concept of energy loss on ship propulsion. Finally, the present methods are applied to two typical types of ship ； an ore carrier and a fishing boat. The various effects of control constants of autopilot on propulsive energy loss are investigated
8.
2001.12
서비스 종료(열람 제한)
Every ship might be exposed to collision, grounding and/or various accidents. They may make some underwater holes on the hull. An underwater damage would cause her loss of buoyancy, trim, and inclination. Although a ship has some provisions against these accidents, if the circumstance is serious, she would be sunk or upsetted. Because of varieties of type of accidents, one could not prepare all of them. Many subdivision could prevent them, but it is difficult to realize it due to rising costs. This paper deals with physical phenomena of sinkage and an application on box type ship, and some results are earned as follows； 1. sinkage speed up to the level of the damage hole is increased proportionally, and is decreased proportionally after filling the level. 2. the curve of draft shows cup type of second order polynomial up to the damage hole level, and shows cap type of second order polynomial after filling the level. 3. if damage occurs beneath half of the draft, changes of head and displacement, and sinking speed follow almost straight lines. 4. by careful observation, sinkage speed could be predicted.
9.
2001.12
서비스 종료(열람 제한)
As a part of the development program of Ulsan Port, construction of detached breakwater is planned. In Ulsan Port, several oil-buoys exist. If the detached breakwaters have been constructed, these oil-buoys will be located within 1 km from the planned breakwaters. Construction of the breakwaters gives rise to changes of wave conditions on the sea areas, especially in front of the breakwater and it affects mooring of tankers, which supply oil to the oil-buoy In this study, in order to calculate standing wave distribution after construction of a breakwater, numerical model is proposed based on unsteady mild slope equation. Calculation is performed by testing different wave heights, directions and reflection coefficients of breakwater. In addition, the influence to working condition of tanker moored at the oil-buoy is evaluated by using measured wave conditions and calculated results.
10.
2001.12
서비스 종료(열람 제한)
A new technique to grow a manganese-doped zinc-sulfide(ZnS：Mn) has been proposed using the repeated deposition of the Hot Wall method. The optical characteristics and crystallinity for the ZnS and ZnS：Mn thin films deposited on a quartz glass substrate by the method were investigated. Also, The ZnS：Mn thin film elcetroluminescent devices were fabricated by the method to study luminescence characteristics. All films showed (111)-oriented cubic structure. By the repeated deposition, the deposition rates were decreased, and the optical characteristics and crystalline properties were improved, which clarifies that the method is effective to deposit the thin films with good crystallinity Futhermore, the crystallinity was more improved by the doping of Mn. Only one peak emission at around 585nm originating from Mn luminescent center is observed In the photoluminescent and electroluminescent spectra of ZnS：Mn films and the luminance of the ZnS：Mn-based thin film electroluminescent devices was obtained below 60cd/m2 . The optical and crystalline properties, luminescence characteristics are discussed in terms of the effects of the repeated deposition and Mn-doping.
11.
2001.12
서비스 종료(열람 제한)
본 연구에서는 방향성 결합기의 특성과 PIN다이오드의 특성을 이용하여 가변 감쇠기를 구현하였다. 기존의 Even-Odd Mode해석법이 아닌 간단한 2-port 기법으로 감쇠기를 분석하였으며, 산란 파라미터는 결합포트의 종단 임피던스가 동일한 경우와 동일하지 않은 경우에 있어서의 감쇠기의 동작특성을 평가하였다. 방향성 결합기의 결합포트는 가변종단을 HP사의 전류제어 소자인 HSMP-3864 PIN다이오드를 사용하였다. 구현된 가변감쇠기는 PCS 송신주파수 1.9 GHz에서 감쇠 범위가 30 dB 이상, 삽입손실 5 dB 이하, 입·출력 반사계수 -25 dB 이하의 특성을 나타내었으며, 이는 PCS와 셀룰러 이동통신 기지국용 전력 증폭기를 온도 등과 같은 외부의 환경변화에 따라서 이득을 가변 시킬 수 있으며, 또한 증폭기의 선형성을 향상시킬 것으로 사료된다.
12.
2001.12
서비스 종료(열람 제한)
The purpose of this paper is the optimum modification of dynamic characteristics of stiffened plate structure including the number of stiffener. This paper shows the optimum structural modification method by dynamic sensitivity analysis and quasi-least squares method and considers it's validity. In the method of the optimization, finite element method, sensitivity analysis and optimum structural modification method are used. The change of natural frequency and total weight are made to be an objective function. Thickness of plate, the number of stiffener and cross section moment of stiffener become a design variable. The dynamic characteristics of stiffened plate structure is analyzed using finite element method. Next, rate of change of dynamic characteristics by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using optimum structural modification method. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure including the number of stiffener.
13.
2001.12
서비스 종료(열람 제한)
Although the ports are actually competing with various strategies, the definition and structural understanding of port competitive power are not known very much. Therefore this study has launched from this fact, and has the objective of obtaining the structural model of the competitive power, and understanding the components of the port competitive power. The following are the results of the study. First, the process began by abstracting the components that composed the port competitive power through recent research, and grouping it by the most core components using the KJ method. Also, by using the FSM(Fuzzy Structural Modeling) method to understand the structure of the grouped components, and the structural model of the port competitive power was able to obtain as the result. Second, when analyzing the obtained structural model, port expenses, main trunk location, port congestion and port facility came out to be the most important component groups, and especially port expenses was the most effective component that effected all the other components overall. Third, the component groups that were relatively less important, effected by most of the other components, and located on the top level of the structure model were the hinterland accessibility, port ownership, customs duties speed, and large ship port entrance possibility etc. Fourth, the results of this study will be able to be used when establishing competing strategies for our country's ports by proposing the relatively important components with the port competitive rower considered.
14.
2001.12
서비스 종료(열람 제한)
In 1986, the People's Insurance Company of China(hereinafter called PICC) Hull Insurance Clauses, which were amended on the basis of the version 1972, were put into effect. Since PICC is the biggest state-owned insurance company in China, its hull insurance clauses have been used nationwide. In the clauses are included the following contents： scope of cover, exclusions, period of insurance, automatical termination of insurance, duty of assured, claim and indemnity, treatment of disputes and so on. However, this study is only limited to the legal interpretation of the most important clauses relating to indemnity of the insurer. The writers attempt to supply some basic materials necessary for the establishment and enforcement of the Korean hull insurance clauses.
