• Journal of the Korean Society for Marine Environment & Energy
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• v.2 no.1
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• pp.90-101
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• 1999

This paper is concerned with the design of automatic ship maneuvering system including automatic path tracking controller and automatic berthing controller. The optimal control technique is employed to design the automatic path tracking controller, which is based on the linearized equations of ship motion. The numerical example shows that the automatic path tracking controller is capable of tracking the line between way points which are determined by pilot a priori. The decentralized control technique is employed to design the automatic berthing controller. In addition to the automatic path tracking controller, the fuzzy logic controller is used to control the forward speed. The numerical example shows that the automatic berthing controller can be successfully implemented.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.4
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• pp.72-77
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• 1984

A placement program in LSI layout is developed and the results of test are discussed in this paper. In order to achieve 100% wiring, this paper introduces, as a virtual routing method, an algorithm which is close to the real routing. This algorithm is reflected to calculate the channel density. An object function is introduced to achieve minimization of total wire length, number of cuts, and maximum channel density simultaneously. The time complexity for the proposed virtual routing algorithm is O(n2). The time required for the algorithm is very short. This algorithm represents the routing state which is close to minimum wire length. So this algorithm is very proper to the application of placement problem. An auto-placement program is developed by the use of this algorithm. The efficiency of the proposed algorithm is shown in the test of the developed program.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.6
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• pp.906-915
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• 1986

This study reviewed the theory of acoustic emission applying generation of acoustic emission in metal cutting and proposed a relationship between fundamental cutting parameters and the root mean square (RMS) voltage of the acoustic emission on the basis of the mechanics of the orthogonal cutting operation. Experimental results are presented for 6063-T5 Auminum and the validity of this relationship is evaluated by a series of tests varying cutting speed, feed rate and rake angle in orthogonal cutting. The original formula derived theoretically has been modified in order to utilize independent of fundamental cutting parameters. RMS voltage of acoustic emission depends on cutting speed and strain rate, but it is not much affected by feed rate. Applying lubricant, the drop of RMS level has been observed.

• Fire Science and Engineering
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• v.24 no.2
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• pp.178-184
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• 2010

In this study, a smoke or a heat which occurs by a fire is perceived by wireless detector, this signal is transmitted to the receiving device by the wireless installation which is not the wire device and wire/wireless integration system which sends this signal to main server via wire system is proposed. In addition wireless heat/smoke detector, wireless module, firmware and wire/wireless integration controller were developed and for verifying regarding the efficiency and applicability of wire/wireless installation actual place application experiment was really accomplished with a transmission tower, a multipurpose building, and a station etc of the subway. The experimental result, it could operate the system which is proposed normally with all experimental object ones and, future actual place application possibility could verify.

• Journal of Radiation Protection and Research
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• v.14 no.1
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• pp.66-70
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• 1989

In routine testing, the radioactive neutron sources are particularly suitable for producing standard. neutron fields. The ISO TC-85 has proposed neutron reference radiation for the calibration of neutron measuring devices used for radiation protection purposes. Radiation laboratory of KSRI has installed a standard irradiation facility using $^{252}Cf$ and $^{241}Am-Be$ sources for calibrating personal dosimeters according to the recommendations given in ISO TC-85. In this study, correction factors for calibration related to neutron scattering and anisotropy are obtained by experiments with commercial rem meter for demonstration purposes.

• Nuclear Engineering and Technology
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• v.27 no.3
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• pp.447-452
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• 1995

경·중수로 연계 핵연료 주기 (Direct Use of Spent PWR Fuel in CANDU : DUPIC ) 기술개발의 핵물질 보장조치(Safeguards)는 경수로 사용후 핵연료를 중수로에 재 활용하기 위한 DUPIC 공정에 대한 최적 보장조치 시스템을 구축하여, 국제 원자력 기구(IAEA) 및 국제 원자력 사회에서 핵 투명성확보 및 신뢰도를 향상시키는 것을 기술개발의 목적으로 하고 있다. DUPIC 공정은 고립된 차폐시설내의 고준위 방사선장 하에서 가동되므로 타 시설에 비해 핵 물질 전용 가능성은 희박하지만, 전 공정이 원격제어 되야 하고, 조업조건이 정복해야 하므로 기존의 보장조치 기술보다 더욱 발전된 계량관리시스템, 측정시스템 및 감시시스템 등을 개발하여야 한다. 이를 위해 본 연구에서는 각 항목에 대한 요소 분석 및 각 항목별 향후 연구방향에 대해 분석하였다. DUPIC 공정 전반에 대한 핵물질 계량관리를 위해 물질수지구역 (Material Balance Area : MBA) 및 주요측정 지점 (Key Measurement Point : KMP )을 설정하여 각 측정지점별 측정방법 및 재고검증(Inventory Verification) 방법을 분석하였다. 최적 측정시스템을 개발하기 위해 적용 가능한 비파괴분석 방법들을 분석한 결과, 핵분열성 물질 함량을 정량적으로 측정할 수 있는 수동적 중성자 측정법이 가장 적합하다는 결론을 얻었다. 또한, 감시시스템을 개발하기 위해 전용전략의 주요 요소 및 전용경로 등을 분석하였으며, 핵물질 및 시설에 대한 물리적 방호체제를 DUPIC시설에 적용하기 위하여 물리적 방호에 필요한 방호체제 요소를 분석하여 DUPIC 시설을 위한 가상적인 방호체제를 구축하였다.

• Nuclear Engineering and Technology
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• v.12 no.3
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• pp.171-179
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• 1980

This paper presentss flux-to-dose conversion factors for neutrons and gamma-rays based on the concept of the maximum absorbed dose. Neutron flux-to-does-rate conversion factors for energies from 2.5$\times$10$^{-8}$ to 20 MeV are presented while the conversion factors for gamma-rays are given in the energy range of 0.01 to 15MeV. Flux-to-does-rate conversion factors, which were calculated under the assumption that the radiation energy distribution has nonlinearity in phantom, are different from those values obtained by monoenergetic radiation. Especially, these values obtained here were determined for the cross section libray such as DLC-23, DLC-27, and DLC-31. The flux-to-dose-rate conversion factors obtained in this work are in a good agreement with the values presented by American National Standard Institute (ANSI) N666. These results are used to calculate the dose rate distribution of neutron and gamma-ray in any radiation fields, and will be useful for the radiation shielding analysis, radiation protection and radiation dosimetry concerned with problems of continuous energy distribution.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.47-53
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• 2022

A person who intends to become a maritime pilot shall have sea experience as a master, pass the apprentice pilot test and pilot test, and obtain a license from the Minister of Oceans and Fisheries. In Korea, the government limits the number of pilot licenses, considering the demand for pilotage. An inherent problem exist in the apprentice pilot test system as it conducts a relative evaluation based on test scores without an absolute evaluation standard. The purpose of this study is to identify problems of the current pilot test system and to suggest ways to improve the pilot certification system. In this study, the history of amendments of the pilot certification system in the Pilotage Act was investigated, and implications were derived by examining international standards for pilot certification, and a survey was conducted on 77 incumbent pilots. Consequently, a plan to improve the domestic apprentice pilot test and a step-by-step implementation plan for pilot certification system improvement were presented. The results of this study are expected to be utilized not only for the development of the government policy on pilot certification and for related academic basic data.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.4
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• pp.303-307
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• 2008

The tug boat is restricted in her maneuvering ability due to the towed barge, and tug-barge has been strongly affected by the external forces, i.e. the wind, wave, currents, and so on. Therefore, it is difficult to get the safety of tug-barge operation. It is necessary for the captain of tug boat, VTS and operation department to develope the system which can keep observing the course, speed and position of the towed barge in actual sea and prevent the marine accidents in advance. In this study, we proposed the basic method to develope the safety towing system for barge using portable GPS which was easily movable and relatively inexpensive. Then we conducted the test on the real barge. As a result, we could obtain diverse navigation data to make a safety towing work. It was noted that these data could be used for carious purposes.

• Journal of Navigation and Port Research
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• v.42 no.3
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• pp.195-200
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• 2018

When a ship accident occurs, it is imperative that the captain makes a prompt decision because the accident directly leads to the loss of human lives. The purpose of this study is to quantitatively analyze the main factors and to provide basic data for making decisions in case of ship related contingencies. Experts were surveyed using questionnaires containing eight main factors. The priorities based on relative importance of those factors were determined using the analytic hierarchy process (AHP). As a result, the main priority factors were capsizing (heeling occurs), and fire/explosion, which could have the greatest impact on decision making. We plan to do a larger, more detailed scale survey to improve the reliability of the results. The results above will be used as a basis for the main factors of ships and passenger evacuation decision-making procedures.