• Computational Structural Engineering
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• v.22 no.4
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• pp.89-94
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• 2009

최근에 선박의 도킹해석은 3차원 전선 구조 해석을 통해 수행되어 왔으나 도킹해석 모델을 구성하는데 많은 시간과 노력이 필요하였다. 전선구조해석 모벨을 만들기 위해 필요한 선박구조 도면이 완성되기 전인 초기 설계단계에서 도킹시 반목배치를 조기에 확정하고, 구조 안정성을 확보하기 위한 노력이 요구되어 왔기 때문에 간이화된 도킹 해석 프로그램을 개발하게 되었다. 2차원 격자구조를 이용한 도킹해석기법을 통해 얻은 반목에서의 지지력이 3차원 전선해석모델을 사용하여 얻은 반목에서의 반력 결과와 비교해 타당한 결과를 보여 주고 있음을 확인하였다. 간이화된 도킹용 해석 프로그램을 개발하였으며, 다음과 같은 기능을 갖추어 사용자가 쉽게 격자 구조 모델을 생생하고 해석을 수행할 수 있도록 구성하였다. 향후 각 요소의 단면 특성치를 자동으로 산정하는 기능이 추가되어야 한다. 그리고 부유식 도크(Floating dock)에서의 도킹해석은 본 개발의 대상이 된 건식 도크(Dry dock)에서의 경우와 다른 고려사항이 추가되어야 하기 때문에 향후 추가적인 연구와 개발을 통해 새로운 기능으로 포함될 것이다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.1
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• pp.58-66
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• 2003

This paper discusses the practical issue of the bias estimation of the KOREASAT ground tracking data. First, a batch filter based orbit determination algorithm including the turn around range measurement in addition to the range, azimuth and elevation measurement is presented. Then the estimation performance is analyzed through simulation studies. Additionally, this paper proposes a tracking antenna bias estimation strategies using accurately tuned secondary ground tracking station. Finally the relationship between antenna biases are analyzed to give comprehensive tool for estimation results evaluation.

• 공원문화
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• s.35
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• pp.33-39
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• 1987

1987년을 맞이하자 21세기가 또 한걸음 닥아선듯하다. 지난해 일본의 4개국립공원(십화전팔번평.부사상근이두.길야태야.대산은기)이 지정50주년을 맞았다. 1934년 2월1일에 지정되어 그후 구역의 확장, 타공원과의 통합등을 거처 오늘의 모습이 되었고 명칭도 바뀌었다. 그러나 모두가 일본을 대표하는 국립공원으로 국민의 사랑을 받고 있다. 일본의 국립공원지가 올신년호에 실은 특별기획물 "21세기의 국립공원에 기대한다"의 글가운데 우리에게 우리에게 감명을 주는 글을 모두 싣지 못한 것이 아쉽다. 일본은 연간6억의 이용자가 찾는 국립공원을 교화의 장으로도 이용되길 바라고 있으며 지구전분를 하나의 연방으로보아 공원배치를 멀리 내다보고 주장하는 소리도 있다. 여기에 수록한 글의 필자는 모두가 일본국립공원창설의 유공자인 전촌강전사의 이름으로 제정된 전촌상수상자임을 밝혀둔다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.248-249
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• 2023

빠르게 변화하는 해양 교통 환경은 항상 선박과 관련 산업 종사자 등의 안전을 위협하고 있다. 특히나 선박의 안전하고 효율적인 접이안을 지원하는 약 300여 명의 도선사와 70여 척의 도선선은 안전 운항의 최전방에 배치되어 있으며 관련 사고가 발생할 시 타 사고에 비해 그 피해가 극심하다. 따라서 본 연구는 국내외의 과거 도선선 충돌 사고 사례를 분석하고 이를 안전 문화의 관점을 통해 바라보면서 미래의 안전 도선 환경 마련을 위한 대응책을 모색하였다.

• Korean Journal of Optics and Photonics
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• v.32 no.1
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• pp.1-8
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• 2021

We have studied a tiled-aperture coherent-beam-combining system based on constructive interference, as a way to overcome the power limitation of a single laser. A 1-watt-level, 3-channel coherent fiber laser and a 3-channel fiber array of triangular tiling with tip-tilt function were developed. A monitoring system, phase controller, and 3-channel phase modulator formed a closed-loop control system, and the SPGD algorithm was applied. Eventually, phase-locking with a rate of 5-67 kHz and peak-intensity efficiency comparable to the ideal case of 53.3% was successfully realized. We were able to develop the essential elements for a tiled-aperture coherent-beam-combining system that had the potential for highest output power without any beam-combining components, and a multichannel coherent-beam-combining system with higher output power and high speed is anticipated in the future.

• The Journal of Sustainable Design and Educational Environment Research
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• v.16 no.3
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• pp.27-36
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• 2017

The purpose of this study is to provide a basis for determining when a school established long term school plans accepted by analyzing the trend of increase or decrease elementary school students 30 years to target of following city, 323 elementary schools in Busan - 16 administration zone for this purpose. Results of this study are as follows: First, type 5 occupies 55.4% of the total, followed by the second most, type 10, 21.4%> type 11> type 13> type 15, which is the most urgent object of the student placement plan Can be. Second, the results of the Conflict Model I and Conflict Model II showed that Type1 and Type7 were not needed to be adopted. Third, we can see through the case analysis that the effect of excessive school opening on the decrease of the number of students in the nearby school is serious. Fourth, as a result of analyzing the current number of students in Busan, the number of schools with less than 150 students accounted for 12.4% of the total 323 elementary schools, 30.0% for schools with less than 300 students, and 60.4% for students with less than 600 students. Fifth, when the elementary school student induction rate of urban redevelopment area in Busan was examined, the average induction rate was 0.37.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8745-8752
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• 2015

Since many accidents have occurred in Korea in these days, many people have lost their health and have been damaged. The damages caused by fires which occur to many buildings where many people always reside takes a substantial share of the total damages. And since the proportions of the domestic fire protection designing/supervising industries are relatively much disregarded compared to other kinds of work, it is in the situation that there are many cases of serious damages because the fire protection equipment didn't exert the proper functions on fire after a building is constructed since the supervision against the poor construction along with the inadequate design. In order to improve such situations, in case of the design industry, the criteria on registration and workforce placement, the scope of operation, the design documents required when requesting the agreement to the construction permits, the responsibilities and authorities about the jobs of the fire protection facility designers must be improved and, in case of supervising industry, the registration criteria, the operation scope and the kinds, methods, targets and criteria of supervision, the criteria on the additional placement of assistant supervisors, the contents and scope of work must be improved, the PQ system and Public Supervision System must be reviewed and the systems for preventing any poor supervision must be improved in order to pursue the security of the people and their properties at the same level as the other kinds of work by preparing for the firm position and foundation of the fire protection design and supervision.

• Journal of the Korean Society for information Management
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• v.36 no.4
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• pp.21-52
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• 2019

This study focused on the domestic hospital libraries, the policies and support projects for them, and the current operation status of them. To this end, a list of hospital libraries was established and the operation status was investigated by conducting telephone interviews with 73 libraries collected. As a result, it was found that hospital libraries were established through support projects of other institutions (foundations, enterprises, etc.) rather than by the parent institutions, most of which were barely maintained except for certain actively operated ones. In terms of space, hospital libraries equipped with independent space were mostly operated on a small scale, and bookshelves were deployed in space for other purposes such as lounge and hallway. In terms of operation, a dedicated department or personnel for the library operation hardly existed, and more than half of them did not purchase additional books, simply maintaining the donated books at the time of the establishment. It was also shown that for services and programs, only booklending services are provided, except for a few libraries. Therefore, national policies and support will be needed to revitalize hospital libraries in the future, and the government needs to seek ways to continuously operate them through links with local representative libraries and public libraries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.305-315
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• 2016

Due to the change from small volume production to small quantity batch production systems, individual companies have been attempting to produce a wide range of operating strategies, maximize their productivity, and minimize their WIP level by operating with the proper cycle time to defend their market share. In particular, using a complex workflow and process sequence in the manufacturing line has some drawbacks when it comes to designing the production strategy by applying analytical models, such as mathematical models and queueing theory. For this purpose, this paper uses three heuristic algorithms to solve the job release problem at the bottleneck workstation, product mix problem in multi-purpose machine(s), and batch size and sequence in batch machine(s). To verify the effectiveness of the proposed methods, a simulation analysis was performed. The experimental results demonstrated that the combined application of the proposed methods showed positive effects on the reduction of the cycle time and WIP level, and improvement of the throughput.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.297-302
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• 2004

This paper analyzed productivity of quay cranes on container terminal that have perpendicular yard layout block. In most existing container terminals, quay cranes of single trolley type are used to loading and unloading containers, but quay crane productivity of these type has many limitation about large size containership. For these reasons, recently quay cranes of various type that mn improve productivity are developed and as the representative example, dual trolley, double trolley, supertainer are developing. These cranes are realized that very high productivity bemuse their cycle time is short more than existent single trolley quay crane. Therefore, we analyzed productivity of these cranes that are realized by next generation crane alternatives and as result qf this research, mechaniml productivity by cycle time and net productivity by simulation were measured.