• Journal of Environmental Health Sciences
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• v.35 no.3
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• pp.235-238
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• 2009

In Korea, talc that has been widely used for a lot of consumer products as well as industrial usage until recently was found to be contaminated with asbestos. It becomes a major social issue. Critical health risk about both talc and talc contaminated with asbestos was summarized through literature review. It has been confirmed that talc can pose ovarian cancer when talc powder is used in the genital area. International Agency for Research on Cancer (IARC) already concluded that the perineal use of cosmetic talc can cause possibly carcinogenic to humane(Group 2B), although there was study reporting the lack of a consistent an established correlation between perineal dusting frequency and ovarian tissue talc concentrations and the lack of a consistent dose-response relationship with ovarian cancer risk. The association between talc exposure and ovarian cancer is as strong as in recent studies. The epidemiological studies to date provided inadequate evidence for the carcinogenicity of either inhaled or ingested talc that does not contain asbestos or asbestosiform fibers. Future studies should focus on seeking evidence in talc-exposed populations, collecting reliable information on age at initial used of body powder, exposure assessments related to talc use and dose response relationship in order to identify possible risk of talc ingested or inhaled.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.341-344
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• 2007

A major obstacle to classify and validate Land Cover maps is the high cost of generating reference data or multiple thematic maps for subsequent comparative analysis. In case of inaccessible area such as North Korea, the high resolution satellite imagery may be used as in situ data so as to overcome the lack of reliable reference data. The objective of this paper is to investigate the possibility of utilizing QuickBird (0.6m) of North Korea obtained from Google Earth data provided thru internet. Monthly NDVI images of nine months from the summer of 2004 were classified into L=54 cluster using ISODATA algorithm, and these L clusters were assigned to 7 classes; coniferous forest, deciduous forest, mixed forest, paddy field, dry field, water and built-up area. The overall accuracy and Kappa index were 85.98% and 0.82, respectively, which represents about 10% point increase of classification accuracy than our previous study based on GCP point data around North Korea. Thus we can conclude that Google Earth may be used to substitute the traditional in situ data collection on the site where the accessibility is severely limited.

• Journal of Environmental Impact Assessment
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• v.2 no.1
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• pp.39-55
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• 1993

The importance of urban and regional natural park increases because of the needs for preserving the natural resources and providing with natural recreation space in nature. This planning of natural park management should be established based on the research of the various natural resources in the park. But for the lack of effective data synthesizing methods and concepts, only some restricted factors for zoning plan are considered even though GIS computer system for large complex simulation is used. Therefore, in this study three ecological zoning models such as Basic Factor Model (BFM), Visual Landscape Model (VLM) and Comprehensive Ecological Model (CEM) are proposed and applied to Byounsan Peninsula Nature Park(BPNP) for comparison with the current natural park zoning. The BFM has three components -elevation, slope and vegetation. The VLM has applied with six components -elevation, slope, vegetation, road type, and the visual distance. Finally the CEM's modelling factors have included all of BFM, VLM components are added with the land use type, nature and historic resource factors. The zoning concept of BPNP was based on "Minimization" focused on the specific factors. But introduced modelling concept is "Optimization" based on the total ecological environment. So the result of the modelling has larger area for preservation and development zoning compared with the current zoning whose characteristics are ambiguous which allows the environmental destruction. The future study issues will be the determination of the weighting factor, component reconsideration based on the ground truth data and the agriculture residential area zoning.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.212-212
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• 2000

Since the first obserbvation of carbon nanotubes, extensive researches have been done for the synthesis using arc discharge, laser vaporization, and plasma-enhanced chemical vapor deposition. Carbon nanotubes have unique physical and chemical properties and can allow nanoscale devices. Vertically aligned carbon nanotubes with high quality on a large area is particularly important to enable both fundamental studies and applications, such as flat panel displays and vacuum microelectronics. we have grown vertically aligned carbon nanotubes on a large area of Si substrates by thermal chemical vapor deposition using C2H2 gas at 750-950$^{\circ}C$. we deposited catalytic metal on Si susbstrate using thermal evaporation. The nanotubes reveal highly purified surface. The carbon nanotubes have multi-wall structure with a hollow inside and it reveals bamboo structure agreed with base growth model. Figure 1 shows SEM micrograph showing vertically aligned carbon nanotubes whih were grown at 950$^{\circ}C$ on a large area (20mm${\times}$30mm) of Si substrates. Figure 2 shows TEM analysis was performed on the carbon nanotubes grown at 950$^{\circ}C$ for 10 min. The carbon nanotubes are multi-wall structure with bamboo shape and the lack of fringes inside the nanotube indicates that the core of the structure is hollow. In our experiment, carbon nanotubes grown by the thermal CVD indicate base growth model.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.5
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• pp.24-30
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• 2009

The Sin-Wol filtration plant was an urban infrastructure and off-limits to the public. It is recreated as a representative experiential theme park in the southwest area. It has not only provided places to relax, but has made a new model of urban park by reusing advantages. The current lack of easy access into the park area almost isolates it like a green island. The neighborhood surrounding the park does not have many physical connections to the park to be able to use it. By connecting the surrounding communities with numerous access points into the park and linking the hiking trails and bike paths, the city's need for open space and recreation would be far better satisfied than before. This would allow for the use of the valuable assets of the existing forest and open space.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.151-162
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• 2003

The purpose of this study was to investigate the frequency of sports injury among Korean junior elite golf players. The survey was made through the questionnaire which consist of eight categories and 280 valid answers were used to perform frequency analysis. The results indicated that 197 out of 280 participants experienced golf injuries (30%: during a game, 70%: during a practice) and 70% of them also experienced injuries within a year. The frequency analysis for the site of injury has shown that back was the most vulnerable area for all players(33%), followed by the right wrist, left shoulder and elbow for male players. Among female players, left wrist was the second weak site of injury, followed by the right wrist, right thoracic spine, and left shoulder. A few of them also have shown abnormal symptoms of ruptured lumbar disk, scoliosis, and lordosis and these injuries might be caused by the lack of flexibility and the fatigue due to over-practice. High frequency of wrist injury also demonstrated that excessive chopping or punching shot and poor environmental course conditions may cause this injury to be common. Overall, lack of warm up time, lack of strength and flexibility, and excessive amount of practice were the major reasons of injury for the junior elite golfers in Korea. The study also proved that these young Korean golfers actually had more chances to be faced with the injury than average. Thus, it is necessary to develop systematic and scientific methods of training, and prevention, treatment of these injuries with medical professionals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3231-3239
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• 2014

After 1970-80's rapid economic and urban development, nowadays the old downtown suffers from the deterioration of physical environment, outflow of its function and cavitation of population. And this phenomenon makes urban regeneration as a new paradigm in urban development. This is the case of Myeongdong area (Jungang-dong, Monsung-dong), old downtown of Cheonan around rail station, in the same way. City government has tried many regeneration/ redevelopment projects on this area but all failed due to lack of feasibility. This study intends to suggest new viable strategic regeneration scheme of this area through research and analysis of TOD development, existing condition and problems. As a result, the area needs to be considered as a node that links bus terminal complex and central market place with walkable street. For regeneration of this area, a strategic development scheme of this area is suggested deploying private capital invested rail station, underground shopping mall, transfer center, culture complex and nature park with Myeongdong street mall.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.3 s.110
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• pp.78-83
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• 2005

The purpose of this project is to create small parks in elementary schools in order to improve the educational environment and also to increase the amount of greenspace in the city. Above all, the main goal is to create space for local residents in which they can enjoy their leisure time. During a basic investigation and document investigation of elementary schools in Daegu, I placed the priority on choosing the schools that showed the most promise. Also, by doing a survey about the present conditions at schools, I verified, compared, and analyzed the validity of creating small parks in elementary schools. The summary of the results are as follows. The average area available for building small parte in Daegu elementary schools is $7,447m^2$. Even though this area is not as large as a neighborhood parti the difference is not that great. Therefore, I assumed that building small parks in schools would be as effective as building neighborhood parks. The standard size for a children's parks is $1,500m^2$, and if small parks were to be constructed in all school areas with available space larger than a children's park (i.e., larger than $1,500m^2$), the amount of added park greenspace would equal $1,217,953m^2$. The number of schools with areas under $1,500m^2$ is only 3% of all schools in which small parte can be created(5 schools). Schools that have between $1,500m^2$ and $8,000m^2$of greenspace make up 59.7% of all schools in which small parte can be created (98 schools). Schools that have greenspace of more than $8,000m^2$ make up 37% of all school in which small parks can be created (61 schools). The standard area for neighborhood parte is $10,000m^2$ (building-to-land ratio 20%). Schools that have areas that are larger than the standard area for neighborhood parte make up 31% of all elementary schools in Daegu (61 schools). Therefore city greenspace would increase to a total of $694,805m^2$ by making use of these schools, which would represent 7% of the park greenspace in Daegu.

• Journal of Welding and Joining
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• v.29 no.6
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• pp.71-76
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• 2011

Submerged arc welding method from both sides is generally applied to the welding of main panel manufacturing process during ship construction. The tandem SAW method is applied to improve the productivity. The various weld defects that occur during tandem SAW method are melt through, incomplete penetration, undercut and overlap etc. It could be thought that the reasons for these defects are mainly lack of prediction ability for penetration depth and deposited metal area. In this research, total 5 kinds of welding factors for experiment like current of lead pole, voltage of lead pole, current of trail pole, voltage of trail pole and welding speed are adopted. Weld tests are carried out for the analysis of variation effects of these factors on penetration depth and deposited metal area. Based on the test and analysis results, it is possible to obtain the prediction equation for the effect of these factors on the amount of deposited metal and penetration depth. As per the verification of the results by additional tests, it is confirmed that the prediction equation, include a error margin of ${\pm}2mm$ for penetration depth and ${\pm}10mm2$ for deposited metal area.

• Journal of Welding and Joining
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• v.33 no.1
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• pp.61-71
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• 2015

The effect of welding condition on microstructure and mechanical property of Plasma-MIG Hybrid Weld between Al 5083 plates(thickness : 10mm) was investigated. 1 pass weld without any defects such as puckering, undercut, and lack of fusion was obtained by 150~200A of plasma current and 5~7mm of welding speed. Gas porosities and shrinkage porosities were existed in the weld near fusion line. As welding speed and plasma current were decreasing, the area fraction of porosity was increasing. The hardness of the weld is increasing as welding speed. On the basis of microstructural analysis, Mg segregated region near dendrite boundaries tends to increase with the welding speed. In the result of hardness test, Distribution of hardness in fusion zone showed little change with the plasma current. However, when the welding speed increased, hardness in weld metal markdly increased. It could be considered that effect of heat input to growth of the dendritic solidification structures. Based on tensile test, tensile properties of weld metal was predominated by area fraction of porosities. Consequently, tensile properties can be controlled by formation site and area fraction of porosity.