• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.6
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• pp.639-644
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• 2015

A cylindrical secondary Li-ion cell is a device in which stored chemical energy is converted to electrical energy via an electrochemical reaction. These cells are widely used for applications that require high capacity and rate power, such as notebooks, power tools, and electric vehicles. The role of a center pin is to retain the channel for gas release, preventing blockage of the hollow of the jelly roll during a charge-discharge cycle, and to prevent an internal short circuit for tearing of separator under mechanical free fall. In this paper, two experiments are conducted with and without the center pin to experimentally verify the importance of the role of the center pin. The first experiment is a 50-cycle charge-discharge cycle test, and the second is a free fall test conducted according to the Underwriters Laboratories (UL) standards. Based on these experiments, we demonstrate that the center pin in a cylindrical cell is a very important component in terms of safety.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.187-196
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• 2011

This study aimed to estimate the economic impact of the '2011 Seoul Motor Show' using a direct survey-based regional input-output(I-O) model. Based on the regional I-O table, Exhibition multipliers were derived with respect to output, income, employment, value-added and indirect tax. Attendees' survey was conducted to estimate per capita expenditure. The results of this study indicated that all attendees of '2011 Seoul Motor Show' generated 53.1 billion Won of output impact, 11.7 billion Won of income impact, 24.1 billion Won of Value-added impact, 2.6 billion Won of tax impact, and 1,030 part-time and full-time jobs throughout direct and indirect effects. Another result of this study was that output multiplier of the exhibition industry was similar with other industries, however, income, employment and value-added multipliers were relatively larger than those of other industries.

• Korean Journal of Materials Research
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• v.9 no.5
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• pp.452-459
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• 1999

To develop advanced cladding materials, the effect of Nb addition on the microstructure and corrosion characteristics of Zr-0.8Sn-xNb alloys was investigated. As the Nb content increased, the grain size decreased and the volume fraction of precipitates increased. It was observed from the corrosion test at $360^{\circ}C$ that the corrosion resistance increased with decreasing Nb content. The best corrosion resistance was obtained in Zr-0.8Sn-0.2Nb alloy with high volume fraction of tetra-$ZrO_2$in the oxide. Therefore, it is suggested that Nb in theZr-0.85Sn-xNb system should be added within the solubility limit of Nb from the viewpoint of alloy design.

• Journal of the Korea Institute of Building Construction
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• v.20 no.2
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• pp.163-169
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• 2020

Construction is a typical labor-dependent industry. However, problems related to wage payment, which directly affects the livelihood of workers, have caused other problems in maintaining skilled workers, such as increasing the turnover rate of skilled workers, resulting in a shortage of skilled workers. Against this backdrop, this study was conducted to develop measures to improve the conventional wage payment systems in order to prevent skilled workers from leaving their jobs and to maintain them as workers. It is necessary to make the registration of non-registered small-sized construction companies in Korea mandatory, and to introduce means by which construction companies that hire workers through non-registered agents can be penalized. In addition, the project bank account (PBA) system used in the domestic banking sector can be benchmarked in operating payment systems, an approach that is expected to effectively prevent delayed wage payments in the construction industry.

• Journal of Oriental Neuropsychiatry
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• v.19 no.2
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• pp.223-230
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• 2008

소합향원 (蘇合香元) 가감방(加減方) 정유향기의 진통효과가 투여방법에 따라 어떤 차이가 있는지를 비교, 검토함으로서 본 약재의 새로운 적용방법을 탐색해 보고자 한다. 방법 : 가감소합향원에서 추출한 정유향기를 실험동물을 대상으로 7일간 경구 (50mg/kg, 100mg/kg), 흡입 (매일 3시간씩 1일 2회), 또는 피부도찰 (10mg) 방법으로 투여하여 페닐퀴논-유도 writhing test, 아세트산-유도 writhing test 및 hot-plate test를 실시하였다. 결과 : 가감소합향원 정유향기는 페닐퀴논-유도 writhing test에서는 피부도찰이 가장 효과적 이었으며 그 효과는 양성 대조약물인 아세트아미노펜 보다 약간 더 우수하였다 (p<0.05). 아세트산-유도 writhing test에서도 피부도찰법이 가장 좋은 효과를 나타내었으며 양성대조 약물인 아미노피린보다는 좀 더 좋은 효과를 보여주었다 (p<0.05). 그러나 hot-plate test에서는 경구투여가 가장 좋은 진통효과를 나타내었는데 고용량 (100mg/kg)에서는 양성 대조약물인 아세트아미노펜보다 유의적으로 더 효과적이었으나 저용량 (50mg/kg )에서는 이보다 다소 약하였다. 이상의 연구결과, 가감소합향원의 정유향기는 피부도찰시에는 비특이적 화학자극제인 페닐퀴논이나 아세트산에 의한 통증의 완화에 보다 효과적이며, 경구투여시에는 중추신경계에 영향을 미치는 hot plate에 의한 열자극성 통증에 더 유효함을 의미한다. 결론 : 가감소합향원의 정유향기액은 향기흡입보다는 피부흡수나 경구투여방법으로 진통의 목적으로 응용될 수 있을 것으로 사료된다.

• Korean Journal of Veterinary Pathology
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• v.1 no.2
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• pp.97-106
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• 1997

This study was carried out to investigate the testicular toxicity of environmental toxicant, 2-bromopropane(2-BP) recently caused occupational intoxication in Korea by light microscopy and electron microscopy. To evaluate the effect on spermatogenesis and find target germ cell 10 weeks old male Sprague-Dawley rats were treated with 5g/10m ℓ/kg/day of 2-bromopropane for 3 consecutive days orally and observed on day 1 or day 7 after treatment. 2-BP induced depletion of spermatogonia and early spermatocytes on stages I-IX or extensive degeneration of germ cells on the other stages on day 1. But extensive degeneration of germ cells without stage specificity was observed and round spermatid formed multinucleated giant cells in the lumen of seminiferous tubules on day 7. Electron microscopically Sertoli cells showed irregular shape of nucleus and cytoplasmic vauolation. And spermatocyte showed a extensive heterochromatin and cytoplasmic vacuolation. But there was no histopathological changes in the interstial cells. On the base of the results the target germ cell was spermatogonia in the early of the study but Srtoli cells also effected by high-dosed 2-BP in the late of the study.

• Tunnel and Underground Space
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• v.19 no.4
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• pp.348-354
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• 2009

Slug test is a common characterization method that estimates aquifer hydraulic conductivity rapidly and economically. To characterize the hydraulic property near the borehole YS-4 in the Korea Atomic Energy Research Institute (KAERI) site, slug tests were performed, and oscillatory hydraulic responses were observed. We analyzed the observations with the modified Hvorslev and Bouwer&Rice methods considering the casing inertia, and then the results were compared with those from the general Hvorslev and Bouwer&Rice methods. The estimated hydraulic conductivities from the modified methods are ranged from $4.85{\times}10^{-6}$ to $5.44{\times}10^{-6}$ m/sec, but those from the general ones are ranged from $3.10{\times}10^{-6}$ to $3.63{\times}10^{-5}$ m/s, which shows that the oscillatory responses should be analyzed with consideration of the flowing water inertia effect.

• Journal of Technology Innovation
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• v.22 no.2
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• pp.31-50
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• 2014

Recent efforts of government to improve economic performance and increase employment through industrial convergence are being promoted actively. However, unfortunately, we have little of quantitative study on the following questions; (1) what is the rate of industrial convergence progressed?, and (2) what is the rate of total effects of industrial convergence spreaded?, and (3) which is the No. 1 industry in the magnitude of inductive effect of industrial convergence? In this study, we have measured and analyzed quantitatively the following questions using patent citation; (1) how is industrial convergence progressed?, and (2) how much has industrial convergence a effect on all industry?, and (3) what is the rate of the inductive effect of industrial convergence? In doing so, decision about industrial convergence has been made using patent citation and the effect of industrial convergence is drawn from convergence I/O table which made by patent citation.

• Korean Journal of Materials Research
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• v.7 no.1
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• pp.50-56
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• 1997

급냉응고법을 이용하여 고용한도 이상으로 Mn량을 첨가할 때 Mn량에 따른 인장특성의 변화와 시효특성을 조사하였다. 원심분무법으로 AI-4.7%Zn-2.5%Mg-0.2%Zr합금에 Mn량을 각기 달리 첨가한 급냉응고 분말을 제조 하였다. 이 분말을 냉간압축, 진공 탈가스처리를 한 후 15:1로 압출하여 봉상 시편을 만들었다. 분말의 미세조직은 $\alpha$-AI수지상과 수지상간 편석부로 이루어져 있으며 Mn첨가에 따라 조직의 변화는 관찰되지 않았다. 빠른 냉각속도로 인하여 2.0%Mn을 첨가한 경우에도 초정 Mn상을 발견할 수 없었다. 압출재의 미세조직은 아결정립으로 이루어져 있으며 약간의 제2상들이 관찰되었다. 대부분의 Mn 분산상은 압출후 용체화처리 과정에서 형성되었으며 시효경화량은 Mn양에 관계없이 일정하였다. 46$0^{\circ}C$에서 1시간 용체화처리하고 12$0^{\circ}C$에서 24시간 시효처리한 경우 최대의 시효경도값을 나타내었다. 인장강도는 Mn첨가량에 따라 증가 하였는데 이것은 Mn분산상의 밀도증가에 의한 것으로 확인되었다. 2.0%Mn을 첨가한 합금의 시효후 인장강도는 590MPa, 연산율은 4%를 보였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4749-4755
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• 2014

In this study, to maximize the heat release from the heat generating environment, such as a high-capacity inverter, the heat release performance of the extruded-type heat sinks with the variation of the base thickness were investigated using the experimental and numerical methods. The base thickness was varied from 5 to 14 mm. The heat release was characterized by the amount of heat released through the heat sink, the surface temperature of heat sink base between the heat sources, and temperature of heat sources. The surface temperatures between heat sources and the amounts of heat release were improved more as the base thickness was decreased. In contrast, the temperatures of the heat sources decreased with increasing base thickness. Based on the case study of these heat sinks, it is believed that a heat sink with a 9.5mm-thick base was optimized for the heat release.