• 대한한약학회:학술대회논문집
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• 2007.11a
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• pp.129-144
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• 2007

In order for stable demand-supply and regularity of distribution, "The regulations for management of demand-supply and distribution of medicinal herbs" were established on 1995. Therefore, the medicinal herbs of good quality have been controled to be distributed in the market. However, to be wide of the purpose, the standardized sound distribution system was caused due to the governmental control on demand-supply to protect domestic farmers who produce the material for medicinal herbs, which results in the over distribution of non-standardized or illegally imported medicinal herbs. In addition, because of the distribution of faulty or poor medicinal herbs, there are chances of affecting bad effects on public health. The standardized medicinal herbs cover 514 different kinds in total, of which 69 products are specified to be standardized in the oriental medicine product companies. Also, in order to protect farmers who produce the materials for medicinal herbs, the amount of imported materials are regulated in normal times. The 14 different materials for medicinal herbs, which are allowed to be imported to a certain amount only when the shortage of goods or sudden rise of prices is to happen, are frequently introduced into domestic market as food not as medical usage, and the origin of those illegally changes to home cropped one for the distribution in the market. In addition, the system of distribution are to be disordered and the condition for the distribution of medicinal herbs of good quality can not be made since they illegally changes the usage of the materials for medicinal herbs from their original one and can not be regulated by the domestic laws.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.2
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• pp.255-261
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• 2002

Concrete structures stand in poor surrounding than it has ever been met before, because they are installed in severe conditions such as chloride penetration. $CO_2$ gas, water and so on. Therefore, the countermeasure to efficiently protect from the deterioration of concrete structures should be urgently considered. From this point of view, this study was aimed to develop surface treatment systems for concrete structures, which cover physical properties, long term durability and economic consideration. Developing the optimal surface treatment materials, powder type polymer or liquid type polymer was added to inorganic base materials. Three surface treatment materials which had shown best results in primary tests were selected and durability tests were fulfilled. Consequently optimum surface treatment material was developed. The surface treatment materials, which were developed through this study, can efficiently extend the service life of concrete structures. As a result, the life cycle cost should be reduced and the waste of material resources would be cut down.

• Corrosion Science and Technology
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• v.7 no.2
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• pp.85-91
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• 2008

By operation in aqueous environment at high temperature and pressure, the structural materials from Primary Heat Transport System (PHTS) cover with protective oxide films, which maintain the corrosion rate in admissible limits. A lot of potential factors exist, which conduct to degradation of the protective films and consequently to intensification of the corrosion processes. The existing experience of different nuclear reactors shows that the water chemistry has an important role in integrity maintaining of the protective oxide films. To investigate the influence of water chemistry (pH, O2 dissolved, $Cl^-$, $F^-$) on corrosion of some structural materials (carbon and martensitic steel, Zr and Ni alloys) and to establish the maximum permissible values, corrosion experiments by static autoclaving and electrochemical methods were performed. The experimental results allowed us to establish the contribution of the water chemistry in initiation and evolution of some accelerated corrosion processes.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.124.1-124.1
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• 2016

In this work, uniform thickness and good adhesion of electrodeposited copper layer were achieved on AZ91 Mg alloy in alkaline noncyanide copper solution containing pyrophosphate ion by employing appropriate zincate pretreatment. Without zincate pretreatment, the electrodeposited copper layer on AZ91 Mg alloy was porous and showed poor adhesion which was explained by small number of nucleation sites of copper due to rapid dissolution of the magnesium substrate in the pyrophosphate solution. The zincate pretreatment was found as one of the most important steps that can form a conducting layer to cover AZ91 surface which decreased the dissolution rate of AZ91 Mg alloy about 40 times in the copper pyrophosphate solution. Electrodeposited copper layer on AZ91 Mg alloy after an appropriate zincate pretreatment showed good adhesion and uniform thickness with bright surface appearance, independent of the deposition time but the surface roughness of the electrodeposited copper layer increased with increasing Cu deposition time.

• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.235-236
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• 2008

Charging of spacecraft occurs in plasma and radiation environment. Especially, we focused on an accident caused by internal charging in a glass material that was used as the cover plate of solar panel array, and tried to measure the charge distribution in glass materials under electron beam irradiation by using a PEA (Pulsed Electro-Acoustic method) system. In the case of a quartz glass (pure $SiO_2$), no charge accumulation was observed either during or after the electron beam irradiation. On the contrary, positive charge accumulation was observed in glass samples containing metal-oxide components. It is found that the polarity of the observed charges depends on the contents of the impurities. To identify which impurity dominates the polarity of the accumulated charge, we measured charge distributions in several glass materials containing various metal-oxide components and calculated the trap energy depths from the charge decay characteristics of all glass samples.

• Transactions of Materials Processing
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• v.13 no.3
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• pp.248-252
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• 2004

The mechanical properties of polycrystalline thin-films, critical for Micro-Electro-Mechanical Systems (MEMS) components, are known to have the size effect and the scatter in the length scale of microns by the numbers of intensive investigation by experiments and simulations. So, the consideration of the microstructure is essential to cover these length scale effects. The lattice based stochastic model for the microstructure evolution is used to simulate the actual microstructure, and the fast and reliable algorithm is described in this paper. The kinetics parameters, which are the key parameters for the microstructure evolution based on the nucleation and growth mechanism, are extracted from the given micrograph of a polycrystalline material by an inverse method. And the method is verified by the comparison of the quantitative measures, the number of grains and the grain size distribution, for the actual and simulated microstructures. Finite element mesh is then generated on this lattice based microstructure by the developed code. And the statistical finite element analysis is accomplished for selected microstructure.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.47-54
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• 2003

In this study, to achieve the optimal conditions for mechanical hyper-fine pattern fabrication process, deformation behavior of the materials during indentation was studied with numerical method by ABAQUS S/W. Polymer (PMMA) and brittle materials (Si, Pyrex glass) were used as specimens, and forming conditions to reduce the elastic re cover and pile-up were proposed. The indenter was modeled a rigid surface. Minimum mesh sizes of specimens are 1 -l0nm. Comparison between the experimental data and numerical result demonstrated that the finite element approach is capable of reproducing the loading-unloading behavior of a nanoindentation test. The result of the investigation will be applied to the fabrication of the hyper-fine pattern.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1527-1532
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• 2007

We have evaluated the toxicity of interior materials for the railway passenger car by checking the release of $CO_2$, CO, NOx, SO2, HCl, HF, HBr, HCN. The NOx is one of the most effective for the determination of Toxic Index R value. It is generally known that the mechanism of thermal NOx generation without the Interior Material nitrogen source. This study started from the idea to check the NOx difference according to the furnace temperature. But from the results, it was revealed that NOx is not so sensitive for the furnace temperature in case of solid burning. Other gases such as HCN, CO were more changeable to the furnace Temp. We reported the test result as for toxicity index r(x).

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2305-2306
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• 2008

Charging of spacecraft occurs in plasma and radiation environment. Especially, we focused on an accident caused by internal charging in a glass material that was used as the cover plate of solar panel array, and tried to measure the charge distribution in glass materials under electron beam irradiation by using a PEA (Pulsed Electro-Acoustic method) system. In the case of a quartz glass (pure $SiO_2$), no charge accumulation was observed either during or after the electron beam irradiation. On the contrary, positive charge accumulation was observed in glass samples containing metal-oxide components. It is found that the polarity of the observed charges depends on the contents of the impurities. To identify which impurity dominates the polarity of the accumulated charge, we measured charge distributions in several glass materials containing various metal-oxide components and calculated the trap energy depths from the charge decay characteristics of all glass samples.

• School Mathematics
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• v.2 no.2
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• pp.459-474
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• 2000

It has been said that concrete materials are useful and necessary when children learn mathematics. But it has been proved by several researches teachers don’t often use them even if they agree that they are useful. This article focuses on the lack of systematic and applicable research on manipulatives. Therefore, it tries to identify the state of current research and to present the concrete domains which need more study in the future, in order to induce both qualitative and quantitative research. The following nine domains cover almost all the research on manipulatives so far affect of manipulatives on achievement. types of learners, mathematical topics, subjects of operation, variety of mainipulatives, instructional method, degree of involvement of mainpulatives in class, selection criteria, and place for use.