• 보존과학회지
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• 제34권5호
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• pp.333-343
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• 2018

부여 능산리고분군 동하총 벽화의 보존상태를 진단하고자 2년간 온 습도 모니터링을 실시하여 고분 내부 보존환경 평가 및 벽화의 잔존안료 지도화(Mapping)를 실시하였다. 고분 내부의 온 습도 모니터링 결과로 결로 발생의 특성을 평가하고, 2008년 조사결과와 비교하여 벽화의 상태변화를 진단하였다. 고분 현실의 온도는 국내 지하 5 m 깊이의 연간 평균 지중온도 분포인 $13{\sim}18^{\circ}C$와 근사한 온도분포를 유지하고 있다. 현실 공기의 일교차 범위는 $0.1^{\circ}C$미만, 최대 $0.5^{\circ}C$의 범위로 나타나고 여름철(6월~9월)과 겨울철(12월~1월)의 일교차가 가장 크다. 현실보다 온도가 높은 외기가 유입되는 여름철에는 일교차의 변화로 결로가 집중적으로 발생하는 것으로 판단된다. 동하총 벽화의 잔존안료 성분과 안료입자 분포를 지도화한 결과, 벽체 면적의 36.72~39.53% 범위로 존재하였다. 자외선 형광반응 및 적외선 촬영을 통하여 채색안료 범위가 2008년과 동일하게 나타남을 확인하였다. 따라서 동하총은 여름철에 결로가 발생하는 지하환경이지만 선행조사 이후 벽화가 안정한 상태로 유지되고 있음을 알 수 있다. 그러나 발굴 이후 개방된 환경으로 인해 벽화의 열화가 진행되어 잔존하는 채색안료가 미량이기 때문에 지속적인 모니터링이 필요하다.

• 한국농공학회논문집
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• 제53권5호
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• pp.1-7
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• 2011

The objective of this study is to decide a spatial interpolation method on temperature data for the suitability analysis of garlic cultivation. In Korea, garlic is the second most cultivated condiment vegetable after red pepper. Nowadays warm-temperate garlic faces potential shift of its arable area according to warmer temperature in the Korean Peninsula, and the change can be drawn with the precise temperature map derived from interpolation on point-measured data. To find the preferable interpolation method in cases of germination and vegetative period of the garlic, different approaches were tested as follows: Inverse Distance Weighted (IDW), Spline, Ordinary Kriging (OK), and Universal Kriging (UK). As a result, IDW and UK show the lowest root mean square errors as for the germination and vegetative seasons, respectively. However, statistically significant difference was not revealed among the applied methods regarding the germinating period. Eventually this will contribute to mapping the suitable lands for the cultivation of warm-temperate garlic reasonably.

• 대한기계학회논문집
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• 제10권1호
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• pp.50-55
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• 1986

본 연구에서는 경계면에 맞춘 좌표계를 이용한 mapping을 통하여 37개봉으로 구성된 유로에서의 전달현상을 분석하였다.

• 대한기계학회논문집
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• 제18권6호
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• pp.1455-1464
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• 1994

A new and efficient algorithm for the integration of the thermal-elasto-plastic constitutive equation is proposed. While it falls into the category of the return mapping method, the algorithm adopts the three point approximation of plastic corrector within one time increment step. The results of its application to a von Mises-type thermal-elasto-plastic model with combined hardening and temperature-dependent material properties show that the accurate iso-error maps are obtained for both angular and radial errors. The accuracy achieved is because the predicted stress increment in a single step calculation follows the exact value closely not only at the end of the step but also through the whole path. Also, the comparison of the computational time for the new and other algorithms shows that the new one is very efficient.

• Structural Engineering and Mechanics
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• 제75권1호
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• pp.101-108
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• 2020

The present study intends to analyze damage in thin-walled steel cylinders undergoing constant internal pressure and thermal cycles through use of anisotropic continuum damage mechanics (CDM) model coupled with nonlinear kinematic hardening rule of Chaboche. Materials damage in each direction was defined based on plastic strain and its direction. Stress and strain distribution over wall-thickness was described based on the CDM model and the return mapping algorithm was employed based on the consistency condition. Plastic zone expansion across the wall thickness of cylinders was noticeably affected with change in internal pressure and temperature gradients. Expansion of plastic zone over wall-thickness at inner and outer surfaces and their boundaries demarking elastic and plastic regions was attributed to the magnitude of damage induced over thermomechanical cycles on the thin-walled samples tested at various pressure stresses.

• Geomechanics and Engineering
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• 제32권3호
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• pp.293-305
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• 2023

To ensure the safety of underground infrastructures, ground can sometimes be first treated by cement slurry and then stabilized using artificial ground freezing (AGF) technique before excavation. The hydration heat produced by cement slurry increases the soil temperature before freezing and results in an extension of the active freezing time (AFT), especially when the Metro Jet System (MJS) treatment is adopted due to a high cement-soil ratio. In this paper, by taking advantage of an on-going project, a case study was performed to evaluate the influence of MJS and AGF on the ground temperature variation through on-site measurement and numerical simulation. Both on-site measurement and simulation results reveal that MJS resulted in a significant increase in the soil temperature after treatment. The ground temperature gradually decreases and then stabilized after completion of MJS. The initiation of AGF resulted in a quick decrease in ground temperature. The ground temperature then slowly decreased and stabilized at later freezing. A slight difference in ground temperature exists between the on-site measurements and simulation results due to limitations of numerical simulation. For the AGF system, numerical simulation is still strongly recommended because it is proven to be cost-effective for predicting the ground temperature variation with reasonable accuracy.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.283-283
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• 2022

Abiotic stresses such as high/low temperature, drought, salinity, and submergence directly or indirectly influence the physiological status and molecular mechanisms of rice which badly affect yield. Especially, the low temperature causes harmful influences in the overall process of rice growth such as uneven germination and the establishment of seedlings, which has become one of the main limiting factors affecting rice production in the world. It is of great significance to find the candidate genes controlling low-temperature tolerance during seed germination and study their functions for breeding new rice cultivars with immense low-temperature tolerance during seed germination. In this study, 120 lines of Cheongcheong/Nagdong double haploid population were used for quantitative trait locus analysis of low-temperature germinability. The results showed significant difference in germination under low different temperature conditions. In total, 4 QTLs were detected on chromosome 3, 6, and 8. A total of 41 genes were identified from all the 4 QTLs, among them, 25 genes were selected by gene function annotation and further screened through quantitative real time polymerase chain reaction. Based on gene function annotation and level of expression under low-temperature, our study suggested OsGPq3 gene as a candidate gene controlling viviparous germination, ABA and GA signaling under low-temperature. This study will provide a theoretical basis for marker-assisted breeding.

• 항공우주시스템공학회지
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• 제12권4호
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• pp.57-63
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• 2018

적외선 온도 측정 기법은 비접촉식 방법으로 모형의 표면 온도를 가시화할 수 있는 기법이다. 그러나 획득할 수 있는 결과는 2차원 온도 결과로 정량적인 결과를 획득하기에는 한계가 있다. 본 연구는 3차원 매핑 기법을 적외선 온도 측정 기법에 적용하는 것이 목표이다. 풍동 실험은 국방과학연구소에서 보유하고 있는 중형 아음속 풍동에서 수행했으며, 대상 모형은 오자이브 실린더이다. 시험 조건은 유속 20 m/s에서 80 m/s, 받음각은 $0^{\circ}{\sim}90^{\circ}$이다. 3차원 매핑 기법은 마커를 이용하여 실제 모형의 위치정보와 적외선 이미지 상의 위치 정보를 대응시키는 방법을 사용하였다. 그 결과, 모형의 박리점이 이론적인 값과 매우 일치하는 것을 확인하였다.

• 한국측량학회지
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• 제38권3호
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• pp.247-257
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• 2020

구제역과 같은 가축 전염병은 강한 전염력으로 인해 막대한 경제적 손실을 초래하고 있다. 가축의 전염성 질병은 조기 감지가 매우 중요하나, 개별 농가에서 조기 진단이 어렵고, 수의사나 사료 공급 차량 등의 농장간 이동을 통해서 전파되는 사례도 빈번하다. 본 연구에서는 발병 초기단계에서 유비쿼터스 기반의 정보통신기술을 이용하여 가축의 체온을 자동으로 모니터링 하여 실시간 전송함으로써 수의사의 농장방문 없이 빠른 진단이 가능하고 추가 확산을 방지하는 기술을 연구하였다. 자동으로 수집된 정보와 연계된 원격진료시스템을 활용하여 농장단위, 지역단위, 국가단위에서 가축전염병을 커뮤니티 매핑 기법을 이용하여 체계적으로 관리하는 기술을 제시하였다. 이 과정에서 사용자 참여형 공간정보기술 적용을 위한 각 단계별, 주체별 커뮤니티 매핑 항목을 도출하였다.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.121-124
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• 2001

The research results on the superconducting magnet for whole body MRI are presented. The magnet consists of main coil with 6 solenoid coils, shielding coil with 2 solenoid coils and 6 sets of cryogenic shim coil. The ferromagnetic shim assembly is installed on the inside wall of the room temperature bore for shimming inhomogeneous field components generated due to manufacturing tolerances, installation misalignments and external ferromagnetic materials near the magnet. Also, the magnet is enclosed with the horizontal type cryostat with 80cm room temperature bore to keep the magnet under the operating temperature. The magnetic field distributions within the imaging volume were measured by the NMR field mapping system. Through the test, the central field of magnet was 1.5 Tesla and the field homogeneity of 9.3 ppm has been obtained on 40cm DSV(the diameter of spherical volume) and using this magnet, comparatively good images for human body, fruits and water phantoms have been achieved.