• Journal of Preventive Medicine and Public Health
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• v.35 no.3
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• pp.214-220
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• 2002

Objectives : To investigate the relationship of serum uric acid to cardiovascular risk factors in Korean male workers. Methods : We screened 522 male workers at an electrical manufacturing company by a periodic health examination and a questionnaire survey in 2000. We collected data relating to age, smoking status, alcohol drinking status, body mass index (BMI), blood pressure, serum lipid, fasting blood glucose and serum uric acid. The data were analyzed using a variety of methods, including ANOVA, Pearson's correlation, and multivariate regression analyses. to examine the association between uric acid and cardiovascular risk factors with a cross-sectional study design. Results : The concentration of serum uric acid showed positive associations with BMI, total cholesterol, triglyceride, and LDL-cholesterol; it was also significantly correlated to systolic and diastolic blood pressures. Life-style characteristics, such as smoking and alcohol drinking showed no significant association. From the multivariate regression analyses, BMI, total cholesterol and fasting blood glucose levels were found to be independent positive predictors of uric acid; while age, blood pressure and smoking status give no independent contribution explaining the variability of serum uric acid levels. Conclusions : This study demonstrates that serum uric acid level have a significant association with cardiovascular risk factors, such as BMI, total cholesterol and blood glucose in some Korean male workers.

• Journal of Biosystems Engineering
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• v.30 no.2 s.109
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• pp.81-88
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• 2005

Manual transplanting Chinese cabbage needs 184 hours per ha in Korea. Mechanization of Chinese cabbage transplanting operation has been highly required because it needs highly intensive labor during peak season. This study was conducted to developed walking-type Chinese cabbage transplanter. In order to find out design factor of the transplanter, a kinematic analysis software, RecurDyn, was used. The prototype was tested in the circular soil bin and its operating motion was captured and analyzed using high speed camera system. Prototype was one row type which utilized original parts of engine, transmission and etc. from walking-type rice transplanter in order to save the manufacturing cost. Success ratio of pick-up device of hole-pin type and latch type were $96.0\%$ and $99.2\%$, respectively. which was highly affected by feeding accuracy of feeding device of seedling. Transplanting device of the prototype produced a elliptic loci which were coincident with those produced by the computer simulation. Prototype proved good performance in transplanting with mulching and without mulching operation, either. Working performance of prototype was 22 hours per ha and operation cost of the prototype was 961,757 won per ha. So, it would reduce $88\%$ of the labor and $29\%$ of operation cost.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.2
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• pp.137-146
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• 2014

The practice of sustainability is an important subject to integrate into the management, product planning, manufacturing by textile and fashion companies as well as consumption by end-users. This study shows an evaluation scale designed to assess the practical cases in order to suggest efficient and systematic methods to fulfill the practice of sustainability in textile and fashion companies. First, companies should practice environmental sustainability to use eco-friendly material and cleaner production, protect the environment, and save natural resources. Second, social sustainability is required to fulfill social responsibility and ethical needs. Third, companies should perform various innovative activities, transparency in management, fair competition and economic contribution in the local community in order to maintain economic sustainability to survive in industry. Finally, cultural sustainability should be fulfilled by textile and fashion companies as part of the intellectual-cultural industry in a way that increases the importance of ethnic and cultural diversity. Textile and fashion companies should fulfill four environmental, social, and economic cultural sustainable subjects in a balanced method to accomplish sustainability. The concerns and practices of environmental sustainability are comparatively highly rated due to the analysis of the evaluation scale. However, cultural sustainability (a need of the times) is poorly rated and needs more attention. Therefore, the evaluation scale can be used as a standard tool to fulfill the sustainability of companies and brands from the viewpoint of improving poor and insufficiently sustainable items as well as balancing sustainability management.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.25-28
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• 2007

In this study we measured the changes according to time respectively on the basis of 0, 30, 60 and 90 minutes, taking into consideration the decline in fluidity of concrete according to elapsed time to analyze manufacturing capability of batcher plant according to elapsed time of ready-mixed concrete manufactured in batcher plant, and offer basic data for mixture design of ultra-high strength concrete. The proportion of water-binder was 23.55, water content was 160kg/m3, proportion of replacement of crushed sand was 0, 20 and 40% at 3 level, and we applied to the same condition of triaxial component using blast furnace slag powder and silica fume as admixture. And to meet the demand of certain fluidity, we measured respectively on property before and after hardening of ultra-high strength concrete using superplasticizer. As a result of experiment, before hardening of ultra-high strength concrete showed the best fluidity in conditions of crushed sand replacement rates of 20% and superplasticizer composition of 1.95%, but it appeared that fluidity drops as time goes by in the same composition condition. And it appeared that when it comes to hardened, the changes of compression strength according to elapsed time by crushed sand replacement rates were within 1MPa. Therefore, it turned out that the difference of strength according to elapsed time was low and compression strength of 280dys in composition mentioned above appeared highly as 88MPa.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.3-5
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• 2001

Racetrack coils are used in many areas of superconductivity applications such as generators, motors, maglev, wiggler magnets and so on. The fabrication and characteristics of race-track type High Tc Superconducting (HTS) magnets were carried out. The Magnet is composed of 3 pancake coils wound by 37-filamental Bi-2223/ Ag-alloy tapes. Quench current ($I_q$) of both whole magnet and 3 pancake coils were measured. At 77K under the self-field, $I_q$ of magnet was 12A, while in the case of middle pancake coil, $I_q$ was 15A. The upper pancake coils of racetrack magnet with iron plates, magnet having optimized current distribution and initial magnet are compared with each other through 3D FEA, manufacturing and testing these magnets. The measured performance of the upper pancake coil #3 with iron plates improved by 50% on the basis of initial pancake coil #3. Quench current ($I_q$) of field winding was 12A. In addition, the fabrication processes and the characteristics of HTS magnet are described.

• Polymer(Korea)
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• v.35 no.1
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• pp.1-6
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• 2011

Pressurized high temperature plastic resin flows into the cavity of mold and is solidified in injection molding process. Residual stress is being developed in injection molded part because of high temperature variations and high pressure. Developed residual stress relaxes as time goes. Consequently this makes part deformed and deteriorates quality of product. A measurement method of residual stress for injection molded transparent articles has been investigated using photoelasticity. Light, a composite of electromagnetic waves, is purified into a single wave by a polarized film. When this wave passes through the specimen, birefringence is developed according to the level of residual stress in the specimen and color fringed pattern appears after the second polarized film. Residual stress in the injection molded transparent flat a part has been measured quantitatively using the color fringed pattern. Optical characteristics have been a part also predicted by computer simulation and compared with experimental results.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.282-286
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• 2011

The artificial increase in the solar intensity incident on solar cells using lenses or mirrors can allow solar cells to generate equivalent power with a lower cost. In application areas of Fresnel lenses as solar concentrators, several variations of design were devised and tested. Some PV systems still use commercially available flat Fresnel lenses as concentrators. In this study, we designed and optimized flat Fresnel lens and the 'light pipe' to develop 500X concentrated solar PV system. We performed rigorous ray tracing simulation of the flat Fresnel lens and light-pipe. The light-pipe can play imporatant roles of redistributing solar energy at the solar cell and increase the mechanical tolerance so that it can increase the lifetime of the high-concentration solar PV system and decrease the cost of manufacturing. To investigate the sensitivity of the solar power generated by the concentrated solar PV according to the performance of lens and light pipe, we performed raytracing and executed a simulation of electrical performance of the solar cell when it is exposed to the non-uniform illumination. We could conclude that we can generate 95 % or more energy compared with the energy that can be generated by perfectly uniform illumination once the total energy is given the same.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.997-1000
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• 2008

Strength development of concrete subjected to cold weather is generally delayed due to its low temperature. In case of soil nailing method, it is necessary to apply the shotcrete. However, the shotcrete placement under low temperature experiences retardation of strength development due to delayed hydration reaction. Therefore, in this paper, the use of fine particle cement which is produced through particle classification in cement manufacturing process, is discussed to enhance the strength development of the shotcrete under low temperature. According to the results, the concrete containing 100% of fine particle cement had excellent strength development even at $-9^{\circ}C$ of temperature and at 5days, it reached design strength with PE film curing. It is thought that more than 70% of fine particle cement can secure required strength of the shotcrete even at low temperature condition.

• Fashion & Textile Research Journal
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• v.8 no.3
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• pp.317-325
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• 2006

The purposes of this study are to examine clothing businesses which are using dress forms and grasp the problems in apparel manufacturing process, to verify the size and shape of the dress forms for uniformity, to ascertain the uniformity between the dress forms being sold today and the somatotype of the target consumers. The following results were obtained. First, most of the clothing businesses used the existing dress forms in the company. The dress forms didn't reflect the somatotype of the current consumers. And the users satisfaction was below the average. Second, the size and shape of the dress forms being sold today had lack of uniformity between themselves. Third, the dress forms didn't reflect the shape characteristics as well as the size of the target consumers. Consequently, The dress forms need to have the following. First, It is necessary that the dress forms have various functions in a dress form in the future. Second, to get high satisfaction of clothing fit, we need to build up the data base of the consumers somatotype. The data base have to consist of not only circumference but also width, thickness, angle of the current consumers. Last, the further studies of the dress forms need to meet the clothing businesses demand.

• Composites Research
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• v.33 no.4
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• pp.220-227
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• 2020

When curing the composite, the fibers have little thermal deformation, but the resin changes its properties with time and temperature, which leads to residual stress in the product. Residual stress is caused by the difference in the coefficient of thermal expansion of the fibers and resin during the curing process and the chemical shrinkage of the resin. This difference causes thermal deformation such as spring-in and warpage. Thermal deformation of composite structure is important issue on quality of product, and it should be considered in manufacturing process. In this study, a subroutine was developed to predict thermal deformation by applying 3-D viscoelastic model. The finite element analysis was verified by comparing the results of the plate analysis of the 2-D viscoelastic model. Spring-in of L-shaped structure was predicted and analyzed by applying the 3-D viscoelastic model.