• Journal of architectural history
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• v.18 no.5
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• pp.25-39
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• 2009

The examples of developing a building site after the Woongjin period are mainly found in temple sites, tile-roofed building sites of unidentified features, and palace remains including the pavilion site with the river in the front(임류각지) inside the Castle of Gongsan, Gongjoo. In case of the Hanseong period, a glimpase of the features has gained in Poongnab mud castle and Mongchon mud castle, but the excavated relics are not yet enough to make some date out of them. After the Woongjin period of Baejae, the earth-ramming development method was used mostly to construct a building site, which is divided into horizontal and slant raising of the ground level. Both are used simultaneously, but there are the significant differences in the way of raising the ground level between them. Particularly, in case of the Wanggoong-ri relics in Iksan, the ground level was raised in a narrow line slantly, which is differentiated from other slant raising of the ground level, and its time of construction also is after that of others. In addition, the board-building development method used for narrow space is usually found in the remains since the seventh century. However, there are not enough the relics of Baekjae to reveal the whole aspect of building site development. It should be studied later through the subsequent excavation and research.

• Journal of the Korea Safety Management & Science
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• v.14 no.1
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• pp.101-108
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• 2012

In this study was conducted numerical analysis to evaluate the stability of BTR(Built-in Timber Roof Tunneling Method), which is one of construction methods of underground structures in the non-opening state. The discretion method was applied to individually model reinforcing members of BTR, and the homogeneity analysis technic by area ratio was used to verify the feasibility comparing this result with that from conventional analysis method. The parameter study was performed to evaluate the effect varying ground depth, distance length of reinforcing supports and to verify the field applicability of new analysis method. The results showed the very precise value with allowable error, so this method can be applied in the field, The more length of supporting members caused the more vertical displacement and the top displacement increment of support members is larger than that of ground surace. The effect of ground depth was more impressive than that of distance length of reinforcing supports.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.6
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• pp.603-610
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• 2009

Ice load is one of the important design parameters for the construction of icebreaking vessels. In this paper, the design ice load prediction for the icebreaking vessels under normal operating condition in ice-covered sea is discussed. The ice loads under normal operating condition are expected from sea trials in moderate ice conditions. In this sense the extreme ice loads during heavy ramming or accidental collision are not considered. Current study describes the global ice load on the hull of the icebreaking vessels. Available ice load data from full-scale sea trials are collected and analyzed according to various ship-ice interaction parameters including displacement, stem angle, speed of a ship and flexural strength and thickness of sea ice. The ice load prediction formula is compared with the collected full-scale sea trials data and it shows a good agreement.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.109.2-109.2
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• 2010

세라믹 필터는 여러 종류의 분진제거 시스템에서 연소 배가스 정제를 위한 가장 적절한 소재로 알려져 있다. 현재까지 다양한 형태의 세라믹 필터가 개발되고 있는데, 캔들 타입(candle type), 튜브 타입(tubular type), 평판 타입(parallel flow type) 등이 그 예이다. 통상적으로 세라믹 캔들 필터는 가압유동층복합발전(PFBC, Pressurize Fluidized-Bed Combustion), 석탄가스화복합발전(IGCC, Integrated coal Gasification Combined Cycle), 석탄가스화연료전지복합발전(IGFC, Integrated coal Gasification Fuel cell Combined cycle)에서 고온 배가스 정제용으로 사용되고 있다. 일반적으로 IGCC나 CTL 합성가스 정제시스템의 경우에는 높은 고압(약 25기압)과 미세분진이 함유되어 있는 분위기에서 운전된다. 그러므로 이때 사용되는 초청정용 세라믹 집진필터는 고온, 고압 및 부식 환경에서 50 MPa 이상을 갖는 높은 강도와 내식성을 갖도록 개발되어야 하기 때문에 SiC(Silicon Carbide)가 가장 적절한 캔들 필터 소재로 적용되고 있다. 이에 따라 집진용 SiC 세라믹 캔들 필터를 개발하기 위해서는 고온에서 내산화성이 우수하고, 부피팽창에 의한 균열이 발생하지 않는 무기결합재의 선정 및 이를 통한 소재의 특성 최적화가 가장 중요한 부분이라 할 수 있다. 본 연구에서는 IGCC나 CTL 공정에 적용하기 위한 SiC 캔들 필터 소재 개발을 위해 래밍성형 공정으로 1m급의 탄화규소 캔들 필터 시작품을 제작하여 SiC 출발입자 크기와 무기계 결합재인 스트론튬 카보네이트의 첨가량 변화에 따른 필터 소재의 특성 평가를 수행하였다.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.537-558
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• 2005

This paper addresses the results of HAUSAT-2 radiation environment and effect analyses, including TID and SEE analyses. Trapped proton and electron, solar proton, galactic cosmic ray models were considered for HAUSAT-2 TID radiation environment analysis. TID was analyzed through total dose-depth curve and the radiation tolerance of TID for HAUSAT-2 components was verified by using DMBP method and sectoring analysis. HAUSAT-2 LET spectrum for heavy ion and proton were also analyzed for SEE investigation. SEE(SEU, SEL) analyses were accomplished for MPC860T2B microprocessor and K6X8008T2B memory. It was estimated that several SEUs may occur without SEL during the HAUSAT-2 mission life(2 years). Software Hamming Code EDAC has been implemented to detect and correct the SEU. In this study, all radiation analyses were conducted by using SPENVIS software.

• Journal of the Korean Institute of Navigation
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• v.21 no.2
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• pp.47-58
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• 1997

The purpose of this study is to find out the impacts of VTS on the marine safety and users' opinion on the VTS which have been being operated in the port of Pohang for the last 3 years and is to suggest a guideline to the successful operation of VTS in the future. This study is based upon the questionnaire survey and the respondents include 236 masters/mates of merchant vessels who have visited the port of Pohang and 6 pilots who have been working in the port. From the questionnaire results, this study notes the following conclusions related to the VTS operations. (1) A few of the respondents (mainly foreigners) do not understand the entering procedure of the port and the fundamental concept of VTS. Accordingly, the more active VTS services have to be provided for the mariners. (2) It was found that themost dangerous factors in tehvicinity of the port were the floating materials, fishing nets, andillegal fishing activities inthe fairway. Therefore, the proper surveillance, stricter enforcement of Acts and the instructive education for the fishermen are required to avoid the risks. (3) A majority of the respondents agreed the VTS has contributed to the safety of vessel traffic, and they pointed out ' the assiatances in reduced visibililty conditions' is the most important task of VTS. The amount of 75.6% of the respondents answered that they have experienced the assistance from VTS more than 1 time since the system was established in the port of Pohang . Also 44.2% of the respondents considered they were able to avoid marine casualties such as collision, ramming or agrounding with the VTS assistances. (4) 49.2% of the respondents preferred the passive information services , while, 38.8% of them preferred the positive control advices in the case of encountering any potential risks. VTS iperators have to consider seriously when they provide the positive control advices of ship's course and speed. (5) A majority of the respondents confirmed that the prot and its approaches is suitable for the VTS coverge . To extend the service areas of the VTS and to improve radar detecting ability, the use of radar transponders are seen as the ideal method. (6) A minority of the respondents pointed out 'the improper orders or recommendatinos caused by the poor decision making' firstly, ' the language problem(sea-speaking in English)' secondly, as the deficiency of personal qualification. It seems, therefore, theat the personal efforts of the operators and systematic training programmes for them are necessary to solve the problems.

• Journal of Conservation Science
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• v.6 no.1 s.7
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• pp.31-60
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• 1997

Stone-cultural-properties, distributed in Naju, Hwasun and a part of Jangheung, have been investigated and studied on the characteristics, rock weathering and phases in the geological and conservational points of view. The properities involve pagoda and twelve stupas, four stone-buddha, three stone monuments, two stone-lantern, four stone-Jangseung, one and flag-pole. The rocks used are mainly pebble-bearing tuffaceous rocks of the Cretaceous age which are widely distributed in the area. However, granites are also used in some properties. These rocks are strongly influenced by weathering and pervasive moss. The mottled rock surfaces in some properties are in colors due to pervasive moss different. Parts of some cultural properties are broken which results in structurally unstable. Cultural properties in the area are relatively well conserved at the earth consolidated by ramming and by iron fence. However some cultural properties are partly repaired by using other hinds of rock phases which results in different colors in weathered rock surface. For conservation, rock phases, weathered surface colors, and relationships with original parts must be scientifically considered in repairment forward.