• 한국환경복원기술학회지
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• 제5권5호
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• pp.67-75
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• 2002

This study was carried out to introduce current status to discuss erosion control strategy for the conservation of stream valley ecosystem. To restore stream valley ecosystem, we should establish restoration plans to keep the original shape of stream. It is necessary to use environmentally sound materials with conservation of valley stability. Valley construction for erosion control works should be evaluated continuously based on concepts of conservation and development of stream valley ecology. It is categorized in point of the important of class of stream valley conservation ahead planning and constructure. We suggest that the development of stream valley construction needs to prevent mass movement of soil sediments. In addition, it is established the basal strategy to protect macro and micro aquatic organisms in stream valley ecosystem.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권4호
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• pp.1738-1756
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• 2020

To improve the accuracy and realism of the virtual surgical simulation system, this paper proposes an optimized mass-spring model with shape restoration ability based on volume conservation to simulate soft tissue deformation. The proposed method constructs a soft tissue surface model that adopts a new flexion spring for resisting bending and incorporates it into the mass-spring model (MSM) to restore the original shape. Then, we employ the particle swarm optimization algorithm to achieve the optimal solution of the model parameters. Besides, the volume conservation constraint is applied to the position-based dynamics (PBD) approach to maintain the volume of the deformable object for constructing the soft tissue volumetric model base on tetrahedrons. Finally, we built a simulation system on the PHANTOM OMNI force tactile interaction device to realize the deformation simulation of the virtual liver. Experimental results show that the proposed model has a good shape restoration ability and incompressibility, which can enhance the deformation accuracy and interactive realism.

• 보존과학연구
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• 통권33호
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• pp.99-108
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• 2012

백색부후균(Trametes versicolor)과 갈색부후균(Tyromyces palustris)은 목조문화재 및 건축물 등의 목재 조직의 건조, 부패과 균열, 스펀지화, 변색 등 다양한 손상을 발생시켜 구조적, 미학적인 관점에서 심각한 문제를 나타내고 있다. 그리고 가장 피해를 많이 주는 해충인 흰개미(Reticulitermes speratus Kyushuensis Morimoto)는 목조건축물의 옥외 기둥이나 대들보 등의 표층을 얇게 남겨두고 내부를 침해함으로써, 결국은 속이 빈 기둥이 되어 건축물이 무너져버리는 피해를 줄 수 있다. 대표적 피해 미생물인 목재부후 균이 흰개미의 서식에 미치는 영향을 파악하기 위하여 부후균이 만연된 곳에 흰개미를 넣어 공존 가능성을 실험해 보았다. 목재의 중량으로 피해율을 산정한 결과, 전반적인 총질량은 두 종류의 부후균에서 모두 감소하였다. 목재의 질량은 백색부후균에서는 모두 감소하였으나, 갈색부후균에서는 오히려 증가한 경향을 볼 수 있었다. 그리고 섭식량을 측정하기 위한 목재의 건조 후 질량에서는 갈색부후균에 넣었던 목재의 질량 감소가 더 크게 나타났다.

• 보존과학회지
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• 제36권2호
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• pp.103-111
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• 2020

건조칠기 유물 세척 시 사용되는 다양한 용매을 대상으로 클리닝 효과를 비교하기 위해 실험을 진행하였다. 건조칠과 자외선에 24일 노출시킨 건조칠에 물, 에탄올, 아세톤, 헥산을 가하여 녹아 나오는 물질을 열분해/GC/MS로 검출하였다. 용출되는 양은 아세톤과 에탄올에서 많았으며, 극성이 높은 용매인 물은 저분자량 용출에 비교적 효율이 좋았다. 비극성 용매인 헥산은 용출량이 매우 낮았다. UV에 24일 노출되어 열화가 많이 진행된 건조칠은 노출되기 전 건조칠에 비해 용출되는 물질이 크게 증가하였다. 열화가 되면서 고분자 형태의 우루시올 사슬이 절단되고 산화되는 과정을 거쳐 dicarboxylic acid를 포함한 저분자량의 극성 물질을 생성하기 때문인 것으로 보인다. 이와 같은 용출특성은 칠기유물을 클리닝하는 용매를 선택할 때 유물의 열화 상태와 더불어 중요한 참고자료가 될 것이다.

• Journal of Forest and Environmental Science
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• 제37권4호
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• pp.304-308
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• 2021

Iris koreana (Iridaceae) is an endangered plant native to Korea. In order to develop an in vitro propagation method, we investigated the effect of 2,4-dichlorophenoxy acetic acid (2,4-D) and a-naphthalene acetic acid (NAA) on callus induction in different I. koreana tissues. In addition, we also investigated the effect of 2,4-D and Benzyl aminopurine (BA) treatments on adventitious shoot induction in viable calli and the effect of indole-3-butyric acid (IBA) on root formation in viable shoots. We found that callus production was highest with 1.0 mg/L NAA (94.4% cultured rhizome explants), and adding low concentrations of 2,4-D to BA containing media significantly increased the frequency of shoot primordial formation. The best rooting results were obtained with 1.0 mg/L IBA, on which 98% of regenerated shoots developed roots and produced an average of 7.4 roots within 45 days. This in vitro propagation protocol will be useful for conservation, as well as for mass propagation.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1995년도 가을 학술발표회 논문집
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• pp.76-83
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• 1995

Estimation of blasting behavior of explosives is prerequisite in the numerical analysis of blasting works. In this study, blasting pressure is estimated by the finite difference method using the Flux-Corrected Transport Algorithm. To formulate the behavior of blasting gas, the mass conservation equation, the moment conservation equation, the energy conservation equation and the ideal gas state equation are used. The simplified species conservation equation is included to simulate the behavior of reacting explosives. To verify the calculation, the Sod's shock tube problem, the strong shock problem and the reacting problem we used. Numerical results show that the shock wave can be captured by means of the FCT algorithm in the reacting and nonreacting states.

• 박물관보존과학
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• 제8권
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• pp.81-95
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• 2007

국립중앙박물관 보존과학팀에서는 금속 유물의 보존처리 과정에서 얻은 청동 녹의 과학적 연구로서 납동위원소비 데이터를 구축하고 이로부터 청동기 원료의 산지와 관련된 연구를 수행하고자 한다. 청동 녹의 납동위원소비 분석을 위한 분석 장비는 기초과학지원연구소의 열이온화질량분석기(Thermal ionization mass spectromete ; TIMS)를 활용하였다. 본 연구의 일환으로 2007년에는 낙랑시대의 청동기 11 점, 통일신라시대의 청동화형접시 등 6점, 고려시대 동종에서 4점의 청동 녹을 입수하였고 납동위원소비를 분석하였다. 기 분석한 한국, 중국 및 일본의 방연석 납동위원소비 데이터를 기초로 산지를 추정하였다. 앞으로 보존과학팀에서는 금속 유물의 보존처리를 수행하면서 얻을 수 있는 청동 녹을 최대한 수집하고 분석하여 이들 자료를 모아 유물의 종류별, 시기별, 지역별 산지연구를 위한 자료로 활용할 것이다.

• 한국보건간호학회지
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• 제31권2호
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• pp.220-233
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• 2017

Purpose: This study compared the body composition and health conservation of low and high physical activity groups in professional retired elderly. Methods: The participants were 132 professional retired elders using a university of education for the elderly and senior welfare centers in D and K city. Data were collected through interviews from November to December in 2015. The body composition was measured using an Inbody 230 and the health conservation was measured using Sung's (2005) Health Conservation Scale. The low and high physical activity groups were divided by CHAMPS (The Community Healthy Activities Model Program for Seniors Questionnaire). The collected data were analyzed using a $x^2$ test, independentt-test, andbinary logistic regression using the SPSS/WIN 20.0 program. Results: The body composition (body mass index, body fat percentage, and fitness score) and health conservation score were higher in the high physical activity group than in the low physical activity group. The result shows that the body weight (OR=10.62) is the highest risk factor influencing the physical activity in professional career-retired elders. Conclusion: These results suggest that to induce physical activity level among professional retired elders, nursing interventions are needed to increase the health conservation and body composition, particularly in controlling the body weight.

• Journal of Mechanical Science and Technology
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• 제16권3호
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• pp.376-385
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• 2002

Spray impingement and fuel film formation models with cavitation have been developed and incorporated into the computational fluid dynamics code, STAR-CD. The spray/wall interaction process was modeled by considering the effects of surface temperature conditions and fuel film formation. The behavior of fuel droplets after impingement was divided into rebound, spread and splash using the Weber number and parameter K(equation omitted). The spray impingement model accounts for mass conservation, energy conservation, and heat transfer to the impinging droplets. The fuel film formation model was developed by integrating the continuity, momentum, and energy equations along the direction of fuel film thickness. Zero dimensional cavitation model was adopted in order to consider the cavitation phenomena and to give reasonable initial conditions for spray injection. Numerical simulations of spray tip penetration, spray impingement patterns, and the mass of film-state fuel matched well with the experimental data. The spray impingement and fuel film formation models have been applied to study spray/wall impingement in high-speed direct injection diesel engines.

• 대한기계학회논문집B
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• 제27권6호
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• pp.744-752
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• 2003

A level set method is combined with the volume-of-fluid method so that the coupled method can not only calculate an interfacial curvature accurately but also can achieve mass conservation well. The coupled level set and volume-of-fluid(CLSVOF) method is efficiently implemented by employing an interface reconstruction algorithm which is based on the explicit relationship between the interface configuration and the fluid volume function. The CLSVOF method is applied for numerical simulation of droplet impact on solid surfaces with variable contact angles. The numerical results are found to preserve mass conservation and to be in good agreement with the data reported in the literature. Also, the present method proved to be applicable to the complex phenomena such as breakup and rebound of a droplet.