• Current Optics and Photonics
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• 제2권5호
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• pp.431-435
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• 2018

A modified setup of a CMD technique for high power coherent beam combining was presented to address an issue of low damage threshold of electro-optic modulators. The feasibility of the modified setup was demonstrated by combining eight fiber beams, and it was successfully performed with ${\lambda}/44$ of residual phase error and 100 Hz of control bandwidth. It is expected that the modified CMD setup facilitates ultra-high power coherent beam combination without a limitation caused by the low damage threshold of electro-optic modulators.

• 한국학교수학회논문집
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• 제15권4호
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• pp.673-698
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• 2012

본 연구는 미래 수학 교실의 기준을 환경, 교사, 학생의 측면에서 총 20개로 제시하였다. 환경기준은 미래 수학 교실이 갖추어야 할 물적 자원이 수행해야 하는 역할과 기능의 측면을 중심으로 3개로 제시하였다. 교사 기준은 수업 전문성의 영역 4개, 학습자의 능력 신장 영역 4개로 제시하고. 학생 기준은 수학적 탐구와 문제 해결, 협력과 의사소통, 공학적 도구나 지원 시스템의 활용 및 조작, 윤리 의식과 디지털 시민 의식의 4개 영역에서 총 9 개로 제시하였다. 또한 미래 수학 수업 모형으로 융합 중심 수업 모형을 개발하고, 첨단 환경과 공학적 도구가 갖추어진 미래 수학교실에서의 수학 수업 구현 모습을 시나리오로 제시하였다. 그런 다음, 현재 수학교과와 타교과 간의 융합 중심 교육과정 개발이 강조되고 있는 현실을 고려하여 현재의 수업에 융합 중심 수업 모형을 적용하였을 때의 한계점을 분석하고 미래 수학 교실을 위한 발전 방향에 대한 시사점을 얻고자 하였다.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• 제1호
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• pp.37-42
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• 2001

In order to answer the challenge that development gave to environment, Chinese cities are making up and putting into effect the green space system planning. The planning main keys are: set down standards and scope of green space; bring the characteristics of every types of green space in to full play and made into basic units of the system; formed powerful links of the system; make full use of the natural system of city, constituted the urban and countryside as a organic whole green space system, therefore give full play their function and ecological effect. In fact, this green space system is a complex system. It is the main body of city ecological system, a main container of the citizen activities of leisure and recreation and a leading factor for making characteristic city landscape. Therefore it is a system carrying city's environment sustainable development.

• Journal of Astronomy and Space Sciences
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• 제27권1호
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• pp.43-54
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• 2010

This study was performed by the policy research project of Ministry of Land, Transport and Maritime Affairs, which title is "Developing safety standards and management of space radiation on the polar route". In this research, total six experiments were performed using Korean commercial flights (B747). Three of those are on the polar route and the other three are on the north pacific route. Space radiation exposure measured on the polar route is the average 84.7 uSv. The simulation result using CARI-6M program gives 84.9 uSv, which is very similar to measured value. For the departure flight using the north pacific route, the measured space radiation is the average 74.4 uSv. It seems that is not so different to use the polar route or not for the return flight because the higher latitude effect causing the increase of space radiation is compensated by the shortened flight time effect causing decreasing space radiation exposure.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1234-1242
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• 2010

In this study, the effect of noise and vibration, and influence of ground improvement are evaluated and its application is analyzed through the example of SCP designed at ground improvement in Song-Do international city. consequently, it showes even comfortable result that it is about 5.0m of inner space, when the LVSCP method is applied, rather than that it is about 30m of inner space when the existing SCP is applied in vibration control standards 2.0mm/sec. In the noise, now that the many differences according to environmental factors like other equipment noise, limited space and so on at the time of the construction by LVSCP method are coming out, so we think that appro itate measures are needed according to surroundings. By the way, when it comes to the estimation of the ground improvement work before and after an improvement of LVSCP method, its result shows that it is satisfacttion to all the standards of compaction control in dregded and reclaimed ground and sedimentary clay layer.

• Journal of the Optical Society of Korea
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• 제13권2호
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• pp.178-183
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• 2009

At the time that the Keck-I 10m telescope was constructed in 1993, the era of Very Large Telescopes (VLTs) was opened. Now thirteen VLTs are in operation, and the largest of the monolithic mirrors is 8.4 m in diameter. Such monolithic mirrors are mostly aspheric and require high accuracies on the surface figures, reaching up to the diffraction limit. At present, next generation telescopes, Giant telescopes, are being developed. One is the GMT (Giant Magellan Telescope) whose size is 25.4 m in diameter. The primary mirror consists of seven segments figuring elliptical shapes on the surface. The surrounding six segments are off-axis and the edges are steep, as the fast focal ratio is adopted. It means that testing of the mirrors is a challenging task. In this paper, testing methods for the GMT primary mirror are reviewed, and accuracy of measuring devices is assessed. Results and discussions follow.

• 한국실내디자인학회논문집
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• 제25권4호
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• pp.113-124
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• 2016

This research examines domestic and oversea's barrier-free design guidelines provided exclusively for children and their implementations in the common spaces of the outpatient clinics in two pediatric rehabilitation hospitals in Seoul. Based on literature review, a checklist was developed to compare various barrier-free design guidelines in consideration of children's accessibility in space. In addition, four spatial areas in the outpatient clinics of the two hospitals were investigated based on the checklist. As a result, the domestic and Japanese guidelines were aiming primarily to all user groups regardless of ages. Whereas in other oversea's guidelines, a number of barrier-free design standards exclusive for children were found in the facility items such as handrail, sink, urine, toilet, water fountain, chair, table, shelve, and so on, throughout the indoor waiting and sanitary spaces. Concerning implementations, most of the items in the indoor passage, waiting, and sanitary spaces of the two hospitals were not sufficiently facilitated enough to meet with the barrier-free design standards exclusive for children. As such, it is recommended to review and improve the current domestic barrier-free design guideline to accommodate various physical and spatial needs of children in all age groups and regardless of disability types, in the design of a pediatric rehabilitation hospital in the future.

• Journal of the Optical Society of Korea
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• 제17권6호
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• pp.525-532
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• 2013

Contrary to the academic interests of other existing studies elsewhere, this study deals with how the alignment algorithms such as sensitivity or Differential Wavefront Sampling (DWS) can be better used under effects from field, compensator positioning and environmental errors unavoidable from the shop-floor alignment work. First, the influences of aforementioned errors to the alignment state estimation was investigated with the algorithms. The environmental error was then found to be the dominant factor influencing the alignment state prediction accuracy. Having understood such relationship between the distorted system wavefront caused by the error sources and the alignment state prediction, we used it for simulated and experimental alignment runs for Infrared Optical System (IROS). The difference between trial alignment runs and experiment was quite close, independent of alignment methods; 6 nm rms for sensitivity method and 13 nm rms for DWS. This demonstrates the practical usefulness and importance of the prior error analysis using the alignment algorithms before the actual alignment runs begin. The error analysis methodology, its application to the actual alignment of IROS and their results are described together with their implications.

• 한국공간구조학회논문집
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• 제21권1호
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• pp.95-104
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• 2021

As people's living standards and cultural standards have developed, interest in culture and art has increased, and the demand for large space structures where people can enjoy art, music, and sports has increased. As it accommodates a large number of personnel, it is most important to ensure safety of large spatial structures, and can be used as a space where people can evacuate in case of a disaster. Large spatial structures should be prepared for earthquake loads rather than wind loads. In addition to damage to the structure due to earthquakes, there are cases in which it was not utilized as a space for evacuation due to the fall of objects installed on top of the structure. Therefore, in this study, the dome-shaped large spatial structure is generalized and the displacement response according to the number of installations, position and mass is analyzed using a tuned mass damper(TMD) that is representative vibration control device.

• 지적과 국토정보
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• 제46권2호
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• pp.225-237
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• 2016

최근 들어 공간정보를 비롯하여 다양한 정보와 관련된 정책 동향은 개방과 공유로 변화하고 있다. 이러한 정책 동향에 맞춰서 개별 시스템에서 관리하는 공간정보를 체계적으로 공유하기 위해서는 공간정보표준을 반드시 준수해야 한다. 공간정보표준을 준수할 경우, 정보에 대한 접근성과 가독성, 정보처리 및 시스템 간의 상호운용성을 향상시킬 수 있다. 하지만 이러한 표준의 이점에도 불구하고, 공간정보표준에 대한 체계적인 관리가 이루어지지 않아 공간정보사업자들은 표준 적용에 많은 어려움을 겪고 있다. 따라서 본 연구에서는 국내외 표준 제정 현황을 조사하고, 국내 공간정보표준이 갖는 표준의 중복성, 버전 간 불일치, 유사 표준 제정 등의 문제점을 다각적으로 분석하여 이러한 문제점을 개선하기 위한 정책 방안을 제시하였다. 본 연구의 결과는 향후 국가공간정보체계에서 공간정보표준의 관리 운영, 조직 구성, 법제도 개선 등을 위한 기초 연구 자료로 활용될 수 있을 것으로 판단된다.