• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.12
• /
• pp.2199-2201
• /
• 2008

Sulfur hexafluoride($SF_6$) is a gaseous dielectric used in high voltage electrical equipment such as an insultor or arc quenching medium in the transmission and distribution of electricity. however, $SF_6$ is one of the greenhouse gases(GHG) with a global warming potential that is 23,900 times greater than that of carbon dioxide($CO_2$). for this reason, $SF_6$ emissions in electric equipment shall be controlled to reduce GHG and improve cost-effective use of $SF_6$ for economical benefits. Until recently there has not been any investigation on $SF_6$ emission characteristics and inventory in Korea. To understand emission characteristics during the use-phase, the scope of this study was limited to the following closed pressure system equipment from 10 substations in Korea. This study highlights (1) the investigation of sampling/analysis methodology for $SF_6$ emissions in high voltage equipment, (2) the estimation of $SF_6$ emissions in the use-phase, and (3) the comparison between the emission ratio and the mass-balance applied to inventory study. According to this study, the majority of emissions were related to electric equipment nameplates and the rest of the emissions were related to the handling of $SF_6$ during operations. from this result, emission ratios estimated from this study were similar; GIS was 14% and GCB was 13%, as maintenance process conditions were the same as manual process conditions for both equipment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.05a
• /
• pp.65-68
• /
• 2003

Interconnected power system operation has given rise to the problem of increased fault levels and leads to over stressing of all the components. Use have been made of recently developed high Tc superconductor in devising a superconducting fault current limiter (SFCL) that promises optimum performance in terms of capital cost, size, auto sensing, operational losses, response time and reliability. Recently, research about the application of the SFCL is actively progressing in Korea. To be applied for SFCL practically, the electrical insulation design of SFCL must be developed. Therefore, this paper presents the result of an investigation of the dielectric characteristics of turn-to-turn insulation for SFCL in liquid nitrogen. The dielectric characteristics of turn-to-turn insulation models of SFCL were investigated. We obtained following results. The breakdown voltages increased as the spacer thickness and length increased. And the breakdown voltages of turn-to-turn model without spacer were higher than the breakdown voltages of turn-to-turn model with spacer under impulse as well as AC voltages. The information gathered in this test series should be helpful in the design of liquid nitrogen filled SFCL.

• Genomics & Informatics
• /
• v.6 no.3
• /
• pp.117-125
• /
• 2008

Recently, obesity has become a worldwide public health concern and the use of anorectic drugs has drastically increased. In this study, sibutramine and phendimetrazine, representative marketed anorectics, were repeatedly administered per os on a daily basis into C57BL/6 mice and the effects of these drugs on food intakes, body weight changes and gene expression profiles were monitored for up to following 7 days. Methamphetamine, which has a potent anorectic effect, was used as a positive control. Anorectic effects were sustained only for two days by phendimetrazine or methamphetamine, but for six days by sibutramine. The modulations of gene expressions in the hypothalamus and the striatum were investigated using microarrays on day 2 and day 7 post-administration, which corresponded to the anorectic period and a return of appetite respectively, for all three drugs tested. Differences in overall gene expression profiles in the stratum on day 2 for sibutramine and phendimetrazine seems to reflect difference between the two in terms of the onsets of drug tolerance. According to microarray findings, the Ankrd26 gene appears to have an important anorectic role, whereas the up-regulation of the olfaction system appeared to be involved in the drug tolerance of anorectics. The microarray data presented in this study demonstrates the usefulness of gene expression analysis for gathering information on the efficacy and safety of anorectic drugs.

• Computational Structural Engineering
• /
• v.10 no.4
• /
• pp.281-290
• /
• 1997

Current seismic design code is based on the assumption that the designed structures would be behaved inelastically during a severe earthquake ground motion. For this reason, seismic design forces calculated by seismic codes are much lower than the forces generated by design earthquakes which makes structures responding elastically. Present procedures for calculating seismic design forces are based on the use of elastic spectra reduced by a strength reduction factors known as "response modificaion factor". Because these factors were determined empirically, it is difficult to know how much inelastic behaviors of the structures exhibit. In this study, lateral strength required to maintain target ductility ratio was first calculated from nonlinear dynamic analysis of the single degree of freedom system. At the following step, base shear foeces specified in seismic design code compare with above results. If the base shear force required to maintain target ductility ratio was higher than the code specified one, the lack of required strength should be filled by overstrength and/or redundancy. Therefore, overstrength of moment resisting frame structure will be estimated from the results of push-over analysis.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.30 no.6
• /
• pp.515-522
• /
• 2017

In this paper, an isogeometric analysis for multipatch problem is investigated, in which two or more geometries are connected at the interface in a conforming or non-conforming conditions. To express higher continuity at the patch interface, two approaches such as Nitsche based method and master-slave method are formulated for the linear elasticity problem and discretized using the isogeometric approach using NURBS basis functions. A short comparison between two approaches in formulations reveals the pros and cons of them with the applicability in the isogeometric multipatch problem. In addition, a NURBS based stress recovery is adopted to express a better stress continuity through the post-processing. Numerical examples indicate the effectiveness of Nitsche method in the non-conforming patch, following the exact solution well. For the stress concentration problem with the conforming patch, introduced two methodologies show comparative results, meanwhile the NURBS based stress recovery presents an improved smooth stress contour in the whole domain including the patch interface.

• Journal of Digital Convergence
• /
• v.13 no.9
• /
• pp.49-56
• /
• 2015

Korea government has established clear cost estimation standard based on a survey of e-learning contents development cost and presented 'e-Learning Contents Development Cost Estimation Guidelines' that reflect the characteristics of the e-learning industry. However, if there is no institutional support, this guideline and system fails to achieve the purposes and objectives. And it is likely to be facing a dead document. Therefore, the policy foundation is required. This study suggested the following policy; stepwise activation of cost estimation standard, enact announcement and periodically adjustment of cost estimation standard, installation and operation of cost estimation standard operational committee, conjunction with the e-learning industry survey, cultural diffusion of co-owned copyright, systematic monitoring of the e-learning contents development process, research on activating policy of cost estimation standard, conjunction with the standard contract for enhancing policy effectiveness.

• Journal of Digital Convergence
• /
• v.12 no.10
• /
• pp.541-556
• /
• 2014

study on Storytelling advertisement, this study examined its own characteristics and distinctive qualities, compared to other advertisements. For this purpose, not only previous discussions about Storytelling genre and theoretical system about its narrative are examined; but also, from actual advertisements, its classification and the distinction of their characteristics are established. According to the Storytelling advertisements, it is also examined that each impact on the field of consumer's response of sympathy, perception, and emotion; and on the process of advertising effect. Below is the results of each research. Through the comparison of Storytelling advertisement's clarification, the following was suggested: there are distinctive advertising strategies, the relationship between advertising strategies and advertisement forms, and the consideration for causing the consumer's response, depending on the advertisement form. Also, the concept of explaining how consumers perceive, in the process of advertising effect, the main concept of the drama advertisement, that is the constituents of drama genre, such as characters, plot, conflict, transition, helps achieve the deeper understanding toward advertising.

• Journal of Digital Convergence
• /
• v.11 no.7
• /
• pp.19-26
• /
• 2013

This research sought to study viewers' perception of migrant women who wed Korean men following these women's level of specialty as shown on multi-cultural TV program by focusing on university students. Post test control group design method was utilized to conduct analysis, which demonstrates that there was a significant difference between the viewers on the professional migrant women and on the non-professional migrant women when it comes to the categories such as, 'Migrant women have specialized skills', 'migrant women have outstanding communication skills' and 'migrant women are independent minded.' Because of the existence (or non-existence) of professional careers as shown on TV program can affect viewers' perception of migrant women, it is necessary to develop measures such as development of expert group's advising system and to guarantee migrant women's diversity.

• Journal of Haehwa Medicine
• /
• v.12 no.1
• /
• pp.1-9
• /
• 2003

This experimental study was carried out to evaluate the effects of Kimchi intake of Acanthopanacis cortex extract (APCE) supplementation on cytokine-induction and immune response in mice. To study in experiments using male Balb/c mice fed Kimchi and Kimchi of APCE supplementation (addition of 2% of total Kimchi weight) containing fed experimental diet during 2 weeks. Experimental mice were fed control diet or diet containing freeze-dried Kimchi at the level of 5%(w/w) or 5% freeze-dried Kimchi with 2% APCE supplementation. The main ingredient of Kimchi was Korean cabbage and fermentation was carried out at $4^{\circ}C$ for three weeks. Freeze-dried 2% APCE supplementation was added to Kimchi at the begining of fermentation. In order to investigate the effect of Kimchi intake of APCE supplementation (5%Kimchi-2%APCE), the following was performed; body weight, food intake, hematological parameter, serum level of mouse interleukin-4 (mlL-4) and mouse interferon-$\gamma$ (mIFN-$\gamma$ ), and, the percentage of CD3+/CD4+, CD3+/CD8+, B220+ in splenic cells. The results of final body weight, and food diet intake of two Kimchi groups were lower than those of the control group (not supplemented experimental diet). The hematology change obtained from the level of WBC (white blood cell) and platelet were not affected by feeding different dietary regiments, but the level of RBC (red blood cells) HB (hemoglobin), and spleen weight of two Kimchi groups were increased significantly than those of the control group. The serum level of IL-4 and IFN-$\gamma$ of two Kimchi groups were increased significantly than those of the control group, also enhanced the percentages of the CD3+/CD4+ and CD3+/CD8+ by 5% freeze-dried Kimchi, and 5%Kimchi-2%APCE group were 43.9 and 65.2%, and 96.0 and 208% than those of the control group, respectively. From these results, it can be concluded that Kimchi itself has an immuno-stimulatory effect and Kimchi contaning 2% APCE supplementation has the more pronounced effect in vivo system.

• BMB Reports
• /
• v.38 no.3
• /
• pp.328-333
• /
• 2005

A human homologue of Sar1, named Sara2, was shown to be preferentially expressed during erythropoiesis in a culture stimulated by EPO. Previous studies, in yeast, have shown that secretion-associated and Ras-related protein (Sar1p) plays an essential role in protein transport from the endoplasmic reticulum to the Golgi apparatus. Here, we report the molecular analysis of Sara2 in erythroid cell culture. A 1250 bp long cDNA, encoding a 198 amino-acid protein very similar to Sar1 proteins from other organisms, was obtained. Furthermore, we also report a functional study of Sara2 with Real-time quantitative PCR analysis, demonstrating that expression of Sara2 mRNA increases during the initial stages of erythroid differentiation with EPO and that a two-fold increase in expression occurs following the addition of hydroxyurea (HU). In K562 cells, Sara2 mRNA was observed to have a constant expression and the addition of HU also up-regulated the expression in these cells. Our results suggest that Sara2 is an important gene in processes involving proliferation and differentiation and could be valuable for understanding the vesicular transport system during erythropoiesis.