• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.427-438
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• 2004

Cosmeceuticals products we not the products simply for moisturizing and protecting skin but the ones for encouraging to make improvements on wrinkles and helping to whiten, tan, and protect skin against ultraviolet light. In a broader sense, they refer to products with aiming to maintain healthy condition of skin such that skin troubles could be improved or aging of skin could be delayed. However, cosmeceuticals should not have any side effects because they are applied to the whole body for a long period of time differing from medical products which are used on specific areas for a short time. The number of such cosmeceuticals has increased from 500 in 2001 to 2300 in 2003. In order to develop and broaden the scope of cosmeceuticals, the concept of cosmetics needs to be changed from caring skin to delaying aging of the skin and reviving cells. For this purpose, high-valued materials should be developed through basic researches related to the biological function of skin, in vivo experiment and reaction of skin in response to various stimuli using biotechnologies and bioengineering methods. At the same time, it should be proceeded to develop new nano materials for overcoming skin barriers and transfer matericals for helping to absorb effective substances and maintaining stability.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.49-52
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• 2013

Seed coat of hairy vetch is very thick and hard, and difficult to absorb water during germination. It requires much time that cotyledon comes out from seed coat. Therefore this experiment was carried out to increase the germination rate by enhancing water absorption through water-soaking of seed, chemical scarification by sulfuric acid, and mechanical scarification on seed coat. Water-soaking for 5 hours seemed to be highly effective in enhancing germination rate. Although not significant, water-soaking resulted in increase of germination rate by 9%. Effect of soaking temperature was not significant, but early germination rate was increased to be 5.0%, 31.7% and 48.3% at $10^{\circ}C$, $20^{\circ}C$ and $30^{\circ}C$, respectively. Mechanical scarification of seed coat led to a germination rate of 97% whereas intact seed showed that of 65%. Chemical scarification by sulfuric acid for 10min, 20min and 30min resulted in a germination rate of 76.7%, 74.7% and 96.0% respectively. It is clear that scarification increased germination rate.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.3 s.55
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• pp.87-96
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• 2007

A new Energy-Dissipating Sacrificial Device (EDSD) is developed for steel plate girders, which can effectively dissipate the energy stored in the structures during seismic actions. To verify the performance of the EDSD, various seismic responses of a sample bridge with the EDSD are analyzed in terms of energy, member forces and deformation. The full scale model tests are conducted to certify the performance of the EDSD when it is applied on existing bridges. Using the improved hysteretic model of the sacrificial member, the seismic analysis for an example bridge is performed. The results show that the proposed EDSD under seismic excitations can significantly decrease the energy stored in the bridge structures and reduce the relative displacements of each superstructure to the ground. The EDSD is also found to function as a structural fuse under strong ground motions, sacrificing itself to absorb the excessive energy. Consequently, economical enhancement of the seismic performance of bridges can be achieved by employing the newly developed energy-dissipating sacrificial device.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.1
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• pp.53-60
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• 2010

In constructing ILM(Incremental Launching Method) bridges, a launching nose is generally used in order to absorb temporary stress occurring during launching. The sectional forces of superstructure of ILM bridges, which occurs during launching, varies significantly according to the length, weight and stiffness of the launching nose. Thus in order to guarantee the safety of section of ILM bridges, the change of stress according to interaction behavior between launching nose and superstructure should be considered. However, the span division and span length are often decided based on previous cases in practice. It makes the design sections of launching nose are similar in spite of different projects. The designer's anxiety to optimize the launching nose to affect the optimum design of superstructure is also weak. In this study, an design formular to optimize the nose is proposed by using the analysis formular of nose-deck interaction and the design level of ILM bridges constructed on 00 Expressway is examined. According to the result of this study, the proposed design formulas are expected to make a significant contribution to section design that is economically efficient and at the same time guarantees the safety of the superstructure and launching noses of ILM bridges regardless of span length.

• Journal of Adhesion and Interface
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• v.19 no.3
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• pp.113-117
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• 2018

Boron carbide is lower in hardness than diamond or boron nitride but has a hardness of more than 30 GPa and is used for manufacturing tank armors and ammo shells due to its high hardness. It is also used as a neutron absorber due to its ability to absorb neutrons, which is increasing its use in nuclear power projects. Neutrons have no interaction with electrons and are known to pass through the material without interactions. Along with boron carbide, the atoms with high interaction with neutrons are hydrogen, and high hydrogen concentration polyesters and epoxy polymers including boron are used as materials for manufacturing products for nuclear power generation waste. In this paper, the surface of boron carbide is treated with iron oxide and tungsten to improve interaction between modified boron carbide and epoxy polymer. XRD and XPS were used to confirm that iron oxide and tungsten are well attached on the surface of boron carbide, respectively. The mechanical strength of the surface treated boron carbide was measured by a universal testing machine (UTM) and the dynamic characteristics of the cured product were observed by using a dynamic analyzer (DMA).

• Journal of Environmental Science International
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• v.2 no.2
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• pp.123-133
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• 1993

Shingal reservoir is a relatively small (211ha) and shallow impoundment, and approximately 25 ha of its sediment is exposed after spring drawdown. At least 14 vascular p13n1 species germinate on the exposed sediment, but Persimria vulgaris Webb et Moq. quickly dominates the vegetation. In order to estimate the role of the vegetation in the dynamics of heavy metal pollutants in the reservoir, Cu concentration of water, fallout particles, exposed sediment, and tissues of p. vulgaris, Ivas analyzed. Cu content in reservoir water decreased from $13.10mg/m^2$ on May 15 (before dralvdown) to $3.08mg/m^2$ in June 1 (after drawdown), mainly due to the loiwering of water level. Average atmospheric deposition of Cu by fallout particles was $10.84 {\mu}g/m^2/day$. Cu content in the surface 15cm of exposed sediment decreased from $5.094g1m^2$ right after drawdown, to $0.530g/m^2$ in 41 days, which is a 89.6% decrease. Therefore up to 99.7% of Cu in the reservoir appears to exist in the sediment. only 0.3% in water If the rate of atmospheric Input by fallout particles is assumed to have been the same since 1958, when the reservoir was completed, cumulative input of Cu during the 38 years would have been $150.35mg/m^2$, which is only 3.0% of Cu content in sediment right after drawdown. Therefore, most of Cu in the Shingal reservoir must have been transported by the Shingal-chun flowing into the reservoir, Standing crop of vegetation on the exposed sediment 41 days after drawdown was $730.67g/m^2$, of which 630.91g/m2 was p. vulgaris alone, and Cu content in P vulgaris at this time was $6.612mg/m^2$. This was only 0.13% of Cu in the exposed sediment, but was 50.5% of Cu in water before drawdown, or 167% of the average annual input of Cu by atmospheric deposition. If other plants were assumed to absorb Cu to the same concentration as p. vulgaris, total amount of Cu absorbed in 41 days by vegetation on the exposed sediment is estimated to be 1913.3 g, which is a considerable contribution to the purification of the reservoir water.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.68-74
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• 2007

Critical Chain Project Management(CCPM) is a new project management system paradigm which maintains the advantages of PERT/CPM and improves the shortcomings of it. In CCPM the task durations are determined as 50% time estimates, ie average time discarding the their contingency. CCPM determines the critical chain the constraint of a projects considering the logical precedence relationship and resource conflict resolution. Project buffer is located at the end of critical chain to absorb the variations of critical chain. The size of project buffer is usually calculated as the half of the sum of critical chain length. Also feeding buffer is inserted after each non-critical chain which feeding into the critical chain to prevent the time delay of critical chain from uncertainties of non-critical chains. Resource buffer can be utilized to improve the availability of resources of critical chain. Buffer management is a project execution and control mechanism. Buffers are classified into 3 zones. They are OK zone, Watch and Plan zone and Expediting zone. If the project status is within Watch and Plan zone, contingency plan is established. And if it changes into Expediting zone, the preplanned contingency plan are executed to recover the time delay. In CCPM the workers are asked to work with relay runner work mechanism that they work fast if possible and report their completion to project manager for the succeeding task to start as soon as possible. The task durations are not considered as the promised time schedule. The multi-tasking is prohibited.

• Journal of Environmental Science International
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• v.2 no.2
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• pp.29-29
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• 1993

Shingal reservoir is a relatively small (211ha) and shallow impoundment, and approximately 25 ha of its sediment is exposed after spring drawdown. At least 14 vascular p13n1 species germinate on the exposed sediment, but Persimria vulgaris Webb et Moq. quickly dominates the vegetation. In order to estimate the role of the vegetation in the dynamics of heavy metal pollutants in the reservoir, Cu concentration of water, fallout particles, exposed sediment, and tissues of p. vulgaris, Ivas analyzed. Cu content in reservoir water decreased from $13.10mg/m^2$ on May 15 (before dralvdown) to $3.08mg/m^2$ in June 1 (after drawdown), mainly due to the loiwering of water level. Average atmospheric deposition of Cu by fallout particles was $10.84 {\mu}g/m^2/day$. Cu content in the surface 15cm of exposed sediment decreased from $5.094g1m^2$ right after drawdown, to $0.530g/m^2$ in 41 days, which is a 89.6% decrease. Therefore up to 99.7% of Cu in the reservoir appears to exist in the sediment. only 0.3% in water If the rate of atmospheric Input by fallout particles is assumed to have been the same since 1958, when the reservoir was completed, cumulative input of Cu during the 38 years would have been $150.35mg/m^2$, which is only 3.0% of Cu content in sediment right after drawdown. Therefore, most of Cu in the Shingal reservoir must have been transported by the Shingal-chun flowing into the reservoir, Standing crop of vegetation on the exposed sediment 41 days after drawdown was $730.67g/m^2$, of which 630.91g/m2 was p. vulgaris alone, and Cu content in P vulgaris at this time was $6.612mg/m^2$. This was only 0.13% of Cu in the exposed sediment, but was 50.5% of Cu in water before drawdown, or 167% of the average annual input of Cu by atmospheric deposition. If other plants were assumed to absorb Cu to the same concentration as p. vulgaris, total amount of Cu absorbed in 41 days by vegetation on the exposed sediment is estimated to be 1913.3 g, which is a considerable contribution to the purification of the reservoir water.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.4
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• pp.17-23
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• 2013

The purpose of this study was to provide information on management and apply it to a roadside ground cover plant understanding the capacity of calcium chloride in the plant. The experimental group was composed of the ratio control group of calcium chloride, 0.5%, 1.0%, and 3.0% in 500g of soil. Plant materials were selected and measured according to their ecological characteristics such as ground cover plant, Pachysandra terminalis, Hosta plantaginea, Trachelospermum asiaticum, Vitex rotundifolia, Euonymus japonica and Callicarpa japonica. The acidity of the amended soil was increased gradually depending on the treatment and conductivity was continually decreased. The EX-Ca increased after the treatment, but decreased in the middle of the experiment. Pachysandra terminalis, Trachelospermum asiaticum and Euonymus japonica were able to grow and survive at the ratio of 0.5%. Hosta plantaginea and Vitex rotundifolia were able to survive at the ratio of 1.0%. Hosta plantaginea, the possible state can absorb salts due to moisture and, can be applied to ground cover plants in the roadside. The growth and development of Callicarpa japonica was poor and the leaves were open to grow for calcium chloride treatment except the control group. It was concluded that Callicarpa japonica was very sensitive to calcium chloride.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.1
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• pp.49-57
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• 2002

The possibility of a transmission noise reduction of piezoelectric smart panels using piezoelectric shunt damping is experimentally studied. Piezoelectric smart panel is basically a plate structure on which piezoelectric patch with shunt circuits is mounted and sound absorbing materials are bonded on the surface of the structure. Sound absorbing materials can absorb the sound transmitted at mid frequency region effectively while the use of piezoelectric shunt damping can reduce the transmission at resonance frequencies of the panel structure. To be able to reduce the sound transmission at low panel resonances, piezoelectric damping using the measured electrical impedance model is adopted. Resonant shunt circuit for piezoelectric shunt damping is composed of register and inductor in series, and they are determined by maximizing the dissipated energy throughout the circuit. The transmitted noise reduction performance of smart panels is investigated using an acoustic tunnel. The tunnel is a tube with square crosses section and a loud-speaker is mounted at one side of the tube as a sound source. Panels are mounted in the middle of the tunnel and the transmitted sound pressure across panels is measured. Noise reduction performance of a smart panels possessing absorbing material and/or air gap shows a good result at mid frequency region but little effect in the resonance frequency. By enabling the piezoelectric shunt damping, noise reduction of 10dB, 8dB is achieved at the resonance frequencise as well. Piezoelectric smart panels incorporating passive method and piezoelectric shunt damping are a promising technology for noise reduction in a broadband frequency.