• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1895-1897
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• 1996

Lightning impulse voltage is essential to evaluate the insulation performance of electric power apparatus. Recently international standard (IEC-60) on high voltage measurement techniques are being revised. In the draft of this standard, a new calibration method is introduced and the accuracy of most industrial measuring systems is maintained by means of comparison test against the reference measuring systems. Comparison tests of dividers for chopped lightning impulse measurement were rallied out by KERI. The 700kV shielded resisitive divider with and without compensation element were done comparison test with 300kV PTB divider which have the similar charateristics as that were circulated among the laboratories. This paper reports on the calculation results of response charateristics obtained by EMTP and the comparison test results with chopped lightning impulse voltages from 150kV to 250kV. It is demonstrated that KERI are capable of realizing the idea in the revision of the IEC standand, that is, to establish traceability.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.6
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• pp.689-698
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• 2007

Particular attention is paid to the validity of PM-10 measurement using beta attenuation method. In this study, the inter-comparison studies were undertaken for PM-10 sampler with different measuring methods. The three beta attenuation monitoring instruments (BAM1020, FH C-14, and DIGS-150) and filter based gravitational method using High Volume Air Sampler were collocated and mass concentrations were compared from August to November, 2006. The results of the investigation show that beta attenuation monitoring instruments are comparable with gravitational method within 10% of measurement error. For specific conditions under high humidity and high concentrations, the inter-comparison results also showed a relatively good agreement and this can be explained as the effect of inlet heating of beta attenuation instrument. Subsequently, this study shows that beta attenuation monitoring instruments can be equivalently used with reasonable validity when compared gravimetric method.

• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.1
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• pp.1-14
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• 2015

This study examines the effect of sociocultural attitude toward appearance and appearance comparison on appearance management behavior by adolescents. The study examines the differences of the effect relationships among the three variables according to adolescents' sex and school grade. The questionnaire was administrated to 575 middle school and high school students in Gwangju from September 2-8, 2011. Data were analyzed by descriptive statistical analysis, frequency analysis, factor analysis, reliability analysis, and regression analysis by SPSS for WIN program. The results were as follows. First, the sociocultural attitude toward appearance was composed of two factors: internalization and awareness. Adolescent's appearance management behavior was composed of four factors: hair and style, face, weight, and neatness. There are significant differences on sociocultural attitude toward appearance and appearance management behavior by gender, age (girl/middle, boy/middle, girl/high, boy/high). Second, the sociocultural attitude toward appearance significantly influenced appearance management behavior with significant differences among groups. Third, the sociocultural attitude toward appearance significantly influenced the appearance comparison and there are significant differences among groups. Fourth, appearance comparison significantly influenced appearance management behavior with significant differences among groups. Fifth, the sociocultural attitude toward appearance mediated by appearance comparison statistically did not influence appearance management behavior.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.1
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• pp.1-7
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• 2012

This paper describes the performance comparison results for current controller of a single-phase PFC converter with 1-switch voltage doubler strategy for single-phase double-conversion UPS(Uninterruptible Power Supply). A single-phase PFC converter with 1-switch voltage doubler strategy needs a diode bridge and one bidirectional active switch. Thus it is possible to reduce the material cost. However, the study results of current controller design and comparison of current control method has not been known after the converter circuit was proposed. For the performance comparison of current control, single-phase 3 kVA double-conversion UPS was tested. The performance of PI and PR current controller is experimentally confirmed with followings - input current reference tracking, input power factor correction and input current THD suppression.

• Journal of Acupuncture Research
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• v.23 no.3
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• pp.1-19
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• 2006

Objectives : This study was carried out to determine the effects of Gamidokwalgisaeng-tang(GDS) oral administration and electro-acupuncture at $BL_{52}$ & $GB_{39}$ on the postmenopausal osteoporosis. Methods: In order to study the effects of the Gamidokwalgisaeng-tang(GDS) oral administration and electro-acupuncture at $BL_{52}$, $GB_{39}$ on osteoporotic rats induced by ovariectomy, body weight, femur weight, uterine weight, serum level of osteocalcin, alkaline phosphatase(ALP), cholesterol, triglyceride, estradiol, androstenedione, testosterone and urinary excretions of calcium & phosphorus were measured. Results : 1. Body weight in all experimental group decreased significantly in comparison with ovariectomized group(OVX). 2. The weight of femur compared with body increased significantly in GDS oral administration and combination treatment group in comparison with ovariectomized group(OVX). 3. Uterine endometrial morphology is caused by ovariectomy and the weight of uterus decreased significantly in control and all experimental group in comparison with sham. 4. The serum level of osteocalcin decreased in all experimental group in comparison with OVX, but significantly in electro-acupuncture and combination treatment group. 5. The serum alkaline phosphatase(ALP) activity decreased in electro-acupuncture and combination treatment group in comparison with OVX, but only significantly in electro-acupuncture group. 6. The serum level of cholesterol increased significantly in OVX in comparison with sham and decreased in all experimental group in comparison with OVX, not insignificantly. The serum level of triglyceride increased in all experimental group in comparison with OVX, not insignificantly. 7. Urinary excretions of calcium and phosphorus decreased significantly in all experimental group in comparison with OVX. Conclusion : We suggest that GDS oral administration and electro-acupuncture at $BL_{52}$ & $GB_{39}$ are available for prevention and curing about the postmenopausal osteoporosis.

• PNF and Movement
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• v.19 no.2
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• pp.173-182
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• 2021

Purpose: The purpose of this study was to compare the effects of underwater and ground-based diagonal pattern exercises on the balance confidence and respiratory functions of chronic stroke patients. Methods: Thirty chronic stroke patients were assigned randomly to an experimental (n = 15) or control (n = 15) group. The experimental group performed an underwater diagonal pattern exercise. The control group performed a ground-based diagonal pattern exercise. Training was conducted once a day for 30 minutes, five days per week for six weeks. Balance confidence was measured using the Activities-Specific Balance Confidence Scale-Korea version. Respiratory function was measured using a spirometer. Results: In a comparison within groups, the experimental and control groups showed significant differences in balance confidence after the experiment (p < 0.05). In a comparison between the two groups, the experimental group showed a more significant difference in balance confidence than the control group (p < 0.05). In a comparison within groups, the experimental group showed a significant difference in respiratory functions after the experiment (p < 0.05). In a comparison between the two groups, the experimental group showed a more significant difference in respiratory functions than the control group (p < 0.05). Conclusion: Based on these results, underwater diagonal pattern exercises effectively improved the balance confidence and respiratory functions of chronic stroke patients.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.154-161
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• 1997

Several studies have developed upward flame spread models which use somewhat different features. However, the models have not considered the transient effects of the igniter and the burning rate. Thus, the objective of this study is to examine a generalized upward flame spread model which includes these effects. We shall compare the results with results from simpler models used in the past in order to examine the importance of the simplifying assumptions. We compare these results using PMMA, and we also include experimental results for comparison. The results of the comparison indicate that flame velocity depends on the thermal properties of a material, the specific model for flame length and transient burning rate, as well as other variables including the heat flux by igniter and flame itself. The results from the generalized upward flame spread model can provide a prediction of flame velocity, flame and pyrolysis height, burnout time and position, and rate of energy output as a function of time.

• Fashion & Textile Research Journal
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• v.23 no.2
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• pp.186-199
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• 2021

SNS (social networking service) plays an important role in delivering information regarding fashion brands and providing a space for communication between fashion retailers and SNS users, as well as between users. This study primarily focuses on exploring the relationships among the motivation of SNS users and social comparison, clothing purchasing behaviors and the difference in the relationships according to individual characteristics. An online survey was conducted on Chinese female consumers in their 20's and 30's who had experience in fashion SNS. A total of 297 women completed online survey. The results of the study revealed that: (1) consumers who have stronger motivation of information seeking and interpersonal communication through fashion SNS reached more active upward comparison and peer comparison accordingly; (2) upward comparison had a significant effect on conspicuous consumption and bandwagon, while peer comparison had no significant effect; and (3) the self-esteem of fashion SNS users significantly moderated the effect of social comparison on conspicuous consumption and conformity consumption. This study contributed to expanding the knowledge on the relationships among the motivations of SNS users and social comparison, and shed light on Chinese SNS users' characteristics and purchasing behaviors in the fashion SNS context. This study also provides vital implications to fashion brands and retailers.

• Journal of Environmental Impact Assessment
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• v.19 no.4
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• pp.431-441
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• 2010

In this study, inter-comparison for PM-2.5 was undertaken. The PM-2.5 mass concentrations using the gravimetric and beta-attenuation methods were compared during the winter in 2007. Two different types of conventional filter-based measurements (Cyclone type and Impactor type) were also collocated and the measurement data was compared with each other. As a result, continuous PM-2.5 data using beta attenuation method show a comparable mass concentration with gravimetric measurement when the inlet of beta-gauge sampler is heated. The results also showed that the cyclone type shows a little high PM-2.5 concentration than Impactor type. In all the sampling cases, the correlations between measurement methods are high. Subsequently, this study suggests that highly correlated relationship between PM-2.5 measurement instruments can be obtained through the inter-comparison results based on filterb-ased gravimetric method and more intensive measurement and theoretical studies are needed in order to clarify the measurement errors for different sampler types.

• Journal of Acupuncture Research
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• v.24 no.3
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• pp.145-161
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• 2007

Objectives : The purpose of this study is to investigate the effect of electroacupuncture at Joksanmi($ST_{36}$) on Rat's aging by experimental methods. Methods : The author performed several experimental procedures to observe the effects of the EC-HAS at the arthritis. First, I measured the cell survival rate of the mice lung fibroblasts. Second, the incidence rate of arthritis and arthritis index of CIA were analyzed. Third, the levels of IL-6, $INF-{\gamma}$ , $INF-{\alpha}$ , $IL-1{\beta}$, IgG, IgM and anti-collagen II were measured in serum and the level of $INF-{\gamma}$, $INF-{\gamma}$/IL-4 ratio in the CIA mouse spleen cell culture. Fourth, histological analysis of the mice joint was performed. Fifth, the expression ratio of $CD3e^+$ cells to $CD19^+$ cells, $CD4^+$ cells to $CD8^+$ cells, $CD11a^+CD19^+$ cells, $CD4^+CD25^+$ cells, $CD3^+CD69^+$ cells, and $CD11b^+Gr-1^+$ cells were checked. Results: 1. The hematocrit was meaningfully (p<0.01, p<0.05) decreased in $ST_{36}$ group in comparison with the control and sham group. 2. The glucose, ALP were meaningfully (p<0.05, p<0.05) decreased in $ST_{36}$ group in comparison with the control group. 3. In the activation of hepatic antioxidase, the catalase was meaningfully (p<0.01) increased in $ST_{36}$ group in comparison with the control group. 4. In the liver, the NO formation was meaningfully (p<0.001) decreased in $ST_{36}$ group in comparison with the nomal, control and sham group. 5. In the activation of splenetic antioxidase, the GSH was meaningfully (p<0.01) increased in $ST_{36}$ group in comparison with the sham group, and the catalase was meaningfully (p<0.001) increased in $ST_{36}$ group in comparison with the control group. 6. In the spleen, the MDA formation was meaningfully (p<0.01, p<0.05) decreased in $ST_{36}$ group in comparison with the control and sham group. 7. In the spleen cell culture, the levels of IL-6 was meaningfully (p<0.05) decreased in comparison with the sham group, $INF-{\gamma}$( was meaningfully (p<0.05) increased in comparison with the control group. Conclusions: According to the results, it is considered that electroacupuncture at Joksamni($ST_{36}$) is effective in increasing the activities of antioxidative enzyme and inhibiting lipid peroxides, and has an immunomodulatory reaction. In conclusion, it han an significant anti-aging effect and need more experimental study.