• Conservation Science in Museum
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• v.23
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• pp.31-48
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• 2020

Conservation treatment of stone cultural properties in the open air is mainly conducted by companies specialized in conservation treatment. This study presents cases of conservation treatment of stone cultural properties housed outdoors in Seoul, including the Three-story Stone Pagoda at Nakseongdae in Gwanak-gu. The present condition of and damage to stone cultural properties are investigated and the materials and techniques used for conservation treatment are presented. The contamination on the surface of stone cultural properties located in downtown areas shows features specific to the related areas, meaning each case requires tailored conservation techniques. This study is expected to serve as reference for future conservation treatment of stone cultural properties in Seoul as well as others in museum collections exhibited outdoors. It is hoped that the cases presented in this study can become widely known to people in charge of conservation treatment in the private and public sectors to improve the quality of conservation treatment applied to stone cultural properties.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.3
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• pp.73-82
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• 2003

This paper proposes a work procedure for generalizing large-scale digital maps ver. 2.0(1/5,000) into a small-scale digital map(1/25,000). Unlike a existent digital map, the digital map ver. 2.0 has a variety of attribute data as well as graphic data. To perform an efficient map generalization with these structural properties, we establish a work procedure as follow; firstly, delete layers which don't exist in small-scale digital map's feature code, and secondly, generalize features which have been classified into 8 layers, and finally merge 8 layers which have been generalized into 1 layer. Therefore, we expect that a work procedure which is proposed in this paper will play a fundamental role in automated generalization system and will contribute to small-scale digital mapping and thematic mapping.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.383-388
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• 2010

Lab scale experiment study was carried out for biological process development on cruise. SBR(Sequence Batch Reactor), MBR(Membrane Bioreactor), and MSBR(Membrane Sequence Batch Reactor) system were investigated for practical application on shipboard sewage treatment. From the results it was suggested that MSBR system might be suitable process for cruise in terms of pollutant removal efficiency, maintenance and special environmental conditions of cruise. About 99% of BOD, 98% of COD and 99% of SS were removed in MSBR system. In addition, about 76% of total nitrogen was reduced and the total phosphorus reduction averaged 59%.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.176-183
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• 1998

Background: The total and differential cell count of bronchoalveolar lavage(BAL) fluid are useful assessing activity, prognosis and response to therapy in diffuse interstitial lung disease. But controversy exist as to the appropriate method in processing BAL fluid. Therefore we investigated the effect of gauze filtration, centrifugation and different storage time of BAL fluid on the total and differential cell count. Methods: We obtained BAL fluid from 6 persons with no active lung lesion and divided pooled BAL fluid into several siliconized glass tubes and filtered through 0, 1, 2, 4 folds of cotton guaze(pore size: 1mm), and compared total cell count using hemocytometer after trypan blue staining and differential cell count after Wright-Giemsa staining of cytocentrifuged preparations. And we also counted total and differential cell count after centrifugation(400g for 30 min) and various storage time(2hr, 24hr, and 48hr). Results: There was no difference in total and differential cell count according to folds of gauze filtraion. But without gauze filtration, mucus threads that hampered total and differential cell count were found in 2 cases (33%). Centrifugation resulted in loss of total cell count($24{\pm}18%$) without change in differential cell count. There was no change in total cell count after 2hr storage but significant cell loss was found after 24hr storage time(24hr : $28{\pm}21%$, 48hr : $41{\pm}24%$). However there was no change in differential cell count with 48hr storage time. Conclusion: Total and differential cell count of BAL fluid may be best performed after cotton gauze filtration without centrifugation and within 2 hours.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.04a
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• pp.39-39
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• 2000

열간단조후 절삭가공하여 냉간 성형가공하는 알루미늄 제품은 열간단조하면 재료가 연화되어 있어 절삭가공시 연속적인 칩이 발생하여 공구와 피삭재를 감고 회전함으로서 가공면 손상, 공구파손 및 작업자의 안전을 초래함에 따라 가공이 어려워 단지 절삭성 개선 목적만을 위해 중간공정으로 T4 열처리하여 절삭가공하고 다시 어닐링처리하여 냉간성형을 하고 최종열처리를 한다. 따라서 본 연구는 열간단조후 제품을 급냉시키면 용제화처리의 효과를 얻어 재료가 경화됨으로써 절삭성이 개선될 수 있다는 이론에 근거하여 T4 열처리를 대체할 수 있는 후처리 방법에 대해 연구하였다. 최적의 후처리방법을 구하기 위해 열간단조후 수냉과 공냉처리를 비교 분석하였고, 열간단조후 냉각처리까지 지연된 시간과 수냉과정에서의 유지시간에 따른 분석을 통해 최적의 작업조건을 선정하였다.

• Nuclear Engineering and Technology
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• v.25 no.3
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• pp.480-496
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• 1993

원자력발전 핵연료주기에서 고려하여야 할 중요한 요소의 하나는 사용후핵연료에서 비롯되는 고준위 방사성핵종이다. 고준위 방사성핵종의 처분 방법으로서 심지층처분방식은 가장 손쉬운 방법이기는 하나 매우 장시간의 감시가 필요하며, 특히 자연환경으로의 누출가능성이 커서 이의 대안으로서 외국 몇 나라에서는 소위 소멸처리(Transmutation)방법에 대한 연구를 활발히 하고 있다. 현시점에서 소멸처리 방법으로 가장 타당성이 있는 것으로 여겨지는 것은 원자로를 이용하는 것과 가속기 구동 미임계 시스템 (Accelerator-Driven Subcritical System)을 이용하는 방법이다. 본 기고문에서는 이들 방법을 중심으로 다양한 소멸처리 방법의 소개와 기술적인 문제점(특히 핵 특성관점에서)에 대한 고찰 그리고 향후 연구과제 등에 대하여 기술하고자 한다. 비록 소멸처리 시스템의 현실화를 위해서는 해결되어야 할 과제가 많이 남아 있지만, 기술적인 가능성과 방사능의 소멸이란 면을 고려할 때 소멸처리시스템은 궁극적인 방사성핵종 처리기술로서 연구·개발할 충분한 가치가 있는 것으로 판단된다.

• Geophysics and Geophysical Exploration
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• v.4 no.4
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• pp.133-144
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• 2001

An effective seismic reflection technique for mapping the cavities and bedrock surface in carbonate rocks is described. The high resolution seismic reflection images were successfully registered by using the hydrophones employed in the stream-water driven trench, and were effectively focused by applying optimal data processing sequences. The strategy included enhancement of the signal interfered with the large-amplitude scattering noise, through pre- and post stack processing such as time-variant filtering, bad-trace editing, residual statics, velocity analysis, and careful muting after NMO (normal moveout) correction. The major reflections including the bedrock surface were mapped with the desired resolution and were correlated to the seismic crosshole tomographic data. Shallow major reflectors could be identified and analyzed on the AGC (auto gain control)-applied field records. Three subhorizontal layers were identified with their distinct velocities; overburden (<3000 m/s), sediments (3000-4000 m/s), limestone bedrock (>4000 m/s). Taking into account of no diffraction effects in the field records, gravel-rich overburdens and sediments are considered to be well sorted. Based on the images mapped consistently on the whole survey line and seismic velocity increasing with depth, this area probably lacks in sizable cavities (if any, no air-filled cavities).

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.628-630
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• 2004

정렬되지 않은 3차원 측정 점들로부터 이들을 근사하는 표면을 재구성하는 방법을 제안하였다. 제안된 방법은 경계면 축소포장 방식에 의한 표면 재구성 방법 (shrink-wrapped boundary face : SWBF)으로, 측정 점으로부터 경계셀과 경계면을 구해 초기 메쉬를 생성하고 이를 연속적으로 축소하는 방식에 의해 표면을 재구성한다 제안된 방법은 기존의 표면 축소포장 방식의 메쉬 생성 방법의 문제점인 물체의 토폴로지에 대한 제악이 없이 어떠한 형태의 표면 재구성에도 적용이 가능하며, 기존 방법이 축소 단계에서 각 메쉬 정점에 대한 최단거리 측정점을 찾는 전역 탐색을 해야 하는데 비해 지역 탐색만으로 최적의 측정 점을 찾을 수 있으므로 처리 시간 측면에서도 우월하다. 실험을 통해 제안된 표면 재구성 알고리즘이 측정 점들간의 관계를 알 수 없는 정렬되지 않은 3차원 정들에 대한 표면 재구성에 매우 안정적이고 효과적임을 확인할 수 있었다.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.76-80
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• 2007

반도체 제조공정에서 매엽식 습식 식각 공정은 기판을 회전하면서 상하 면에 약액을 분사하는 형태로 박막을 식각한다. 이 때 기판은 척을 이용하여 고정되는 데 기판과 척이 접촉하는 가장자리 부분에서 약액의 흐름이 정체되거나 일정하지 못해 잔류막질이 남게 되고, 후속 공정에서 기판 오염의 문제를 야기하게 된다. 본 논문에서는 이러한 문제를 해결하기 위해 기판을 파지하는 여러 개의 척을 2개조로 나누어 교대로 파지하도록 하는 기능을 제시하였다. 2개 조의 척들은 자성체를 사용하여 고속 회전 중에 비접촉 방식으로 구동하였고 실제 약액 처리론 수행하여 효과를 관찰하였다. 결과적으로 기존 고정형 파지 방식에 비해 교차형이 기판 베벨면이나 에지면에서의 잔류 막질 제거에 탁월한 효과가 있음을 확인하였다.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.3
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• pp.119-126
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• 2018

In this study, In this study, the Datum Level-based hydrography surveying system and the ellipsoid-based system were analyzed to acquire more consistent depth data. For the study, the ellipsoid-based surveying for hydrography was conducted twice for the same track line. And the depth was calculated by correcting rise and fall of water level (water level change by tidal energy and other marine environmental energies) respectively by the traditional water level correction method and ellipsoidally referenced water level correction method. there is able to check that Ellipsoid-based hydrographic surveying data is more improved than Datum Level-based hydrographic surveying data in aspect of level difference phenomenon in the same area (surveying line). This result shows that if the Ellipsoid-based hydrographic surveying is performed, the sea level change (tidal energy and other marine environmental energy) of the survey area in real time could be reflected to more consistent generating bathymetric data.