• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.5
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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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• v.14 no.4
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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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• s.33
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• pp.99-108
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• 2012

The white-rot fungus (Trametes versicolor) and brown-rot fungus (Tyromyces palustris), which cause damage to a variety of wooden cultural properties and buildings, such as drying of the wood tissue, decay and cracks, sponge, and discoloration, give rise to serious structural and aesthetic problems. Moreover, pest termites (Reticulitermes speratus kyushuensis Morimoto) can cause damages like hollowing the outdoor beams or pillars of wooden buildings and finally causing such buildings to collapse due to the termites' destruction of the inside of the beams or pillars, leaving only a thin layer on their surfaces. This study was conducted to determine the impact of the wood-decay fungus, a representative damage-causing microorganism, and of insects and termites on the termite ecology. The damage ratio was calculated as the weight of the timber, and the overall total mass was reduced from two kinds of rot fungi. The white-rot fungi reduced the total wood mass, but the brown-rot fungi were observed to have had an increasing tendency to do so. The wood mass was measured after drying to determine the destruction capacity of termites. As a result, the wood mass consumed by the brown-rot fungi was shown to be greater.

• Journal of Conservation Science
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• v.36 no.2
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• pp.103-111
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• 2020

To compare the cleaning effect of solvents such as water and ethanol used to clean lacquer relics, the components extracted with various solvents were analyzed. A freshly dried lacquer sample and a lacquer sample exposed to ultraviolet radiation for 24 days were treated with water, ethanol, acetone, and hexane, and the dissolved material was detected by pyrolysis-gas chromatography-mass spectrometry. The amount extracted was significantly higher in acetone and ethanol than in hexane, a nonpolar solvent. Water, a highly polar solvent, was relatively efficient for extracting low-molecular-weight materials. After experiencing 24 days of ultraviolet radiation, the lacquer exhibited a significant increase of extracted materials compared with the nonexposed one. This may be due to the degradation of the urushiol chain in the form of polymers, resulting in the formation of low-molecular-weight polar substances, including dicarboxylic acids. In addition to the deterioration status of lacquer relics, such solvent extraction properties will be a crucial consideration in selecting the appropriate cleaning solvent.

• Journal of Forest and Environmental Science
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• v.37 no.4
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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.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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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.

• Conservation Science in Museum
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• v.8
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• pp.81-95
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• 2007

The Conservation Science Team of National Museum of Korea has established the data base of lead isotope ratio as the scientific research of bronze patina, which was acquired from conservation process of metal objects, and based on this result, it intends to conduct the research related to the production places of raw material for the bronze objects. As the equipment for analysis of lead isotope ratio of the bronze patina, the thermal ionization mass spectrometer (TIMS) was used. As part of the research, in 2007, the 11 samples of the bronze Patina from the objects, believed to belong to of Nangnang(Lelang), the 6 items of bronze patina from the flower-shaped bronze dishes, belong to Unified Silla period and 4 items from the Goryeo bronze bell were acquired and analyzed the lead isotope ratio. Based on the data of the lead isotope ratio from the galena of Korea, China and Japan, the provenance raw materials were estimated through the comparison of their lead isotope ratios. In the future, the Conservation Science Team of the National Museum of Korea will collect as much bronze patina as possible from the process of conservation treatment of metal objects, and analyze them in order to conduct the study of provenance with the type, period and the region of the objects.

• Journal of Korean Public Health Nursing
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• v.31 no.2
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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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• v.16 no.3
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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.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.6
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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.