전기수용설비의 중성선 영상분고조파전류저감장치

강창원,최길수,한성배,김범수,정연해,이기철,Kang, Chang-Won,Choi, Gil-Soo,Han, Sung-Bae,Kim, Bum-Soo,Chung, Yeon-Hae,Lee, Ki-Cheol 한국전기기술인협회 2001 電力技術人 Vol.228 No.8

우리나라에서는 3 Θ 4w 배전방식을 채택하고 있는데 최근에는 컴퓨터 등 OA 기기 사용증가로 이때 발생하는 영상분 고조파에 의하여 중성선에 상전류 보다 큰 전류가 흐르게 된다. 고조파에 의한 중전선 과전류는 케이블, 변압기, 과열소손, 변압기, 발전기 출력저하, 역률저하, 전력손실 증가, ELB, MCCB 오동작, 유도장해, 중성선 대지전위 상승 등 심각한 장애를 일으키고 있다. Wide use of non-linear loads such as personal computers, monitors, laser printers, variable speed drives, UPS systems and other electronic equipment have led to harmonics becoming #1 issue in the electrical industry today. Commercial and Industrial building power distribution systems, designed for the old, linear-style loads especially when found in high densities. Some common power system problems include overloaded neutral conductors, overheated distribution transfOlmers, high neutral-to-ground voltage, poor power factor and distortion of the voltage waveform supplying these loads. The power quality problems, particularly high voltage distortion, have been known to cause equipment downtime due to malfunctions and component failure.

백서 간 관류모델에서 forskolin이 Insulin like growth factor-I의 분비에 미치는 효과

강창원,이대열,이호일,Kang, Chang-won,Lee, Dae-yeol,Lee, Ho-il 대한수의학회 1999 大韓獸醫學會誌 Vol.39 No.5

The insulin-like growth factor-I(IGF-I) is an important metabolic factor involved in cell growth and metabolism. Although secretion of IGF-I in rat liver is regulated by growth hormone, the effects of forskolin, adenylate cyclase activator, on secretion of IGF-I have not been reported. Therefore, a modified perfused rat liver model was used to investigate the regulatory effects of forskolin on IGF-I secretion in this experiment. The results were summerized as follows : 1. Modified perfused rat liver model was not changed to aspartate aminotransferase(AST), alanine aminotransferase(ALT) and lactic dehydrogenase(LDH) secretion in time. 2. The IGF-I secretion in hepatic cell was increased by forskolin($10^{-5}$, $10^{-6}$ and $10^{-7}M$) in a dose-dependent manner as compared with those of the controls, and significantly increased by $10^{-5}$ and $10^{-6}$ forskolin(p < 0.05). 3. Secretion of glucose in hepatic cell significantly was decreased by $10^{-5}$ forskolin as compared with those of controls(p < 0.05). These results suggest that forskolin may be involved in the regulation of IGF-I secretion in the perfused rat liver.

특별기고 - 생존을 넘어 성장을 위한 기본전략

강창원,Kang, Chang-Won 한국사료협회 2009 飼料 Vol.40 No.-

심방이뇨호르몬의 분비조절에 있어서 superoxide anion의 영향

강창원,김남수,이호일,Kang, Chang-won,Kim, Nam-soo,Lee, Ho-il 대한수의학회 1996 大韓獸醫學會誌 Vol.36 No.1

Atrial Natriuretic Peptide(ANP) is a hormone with potent natriuretic, diuretic and relaxing properties of vascular smooth muscle. Specific chemical modulator responsible for the ANP secretion has not yet been found. Although atrial stretch of stretch-release is to be a major stimulus for the secretion of ANP, the precise mechano-molecular transduction mechanism responsible for its evoked secretion remains to be elucidated. It is interested to clarify the effect of superoxide anion in the stretch-induced ANP secretion. In order to investigate the effectg of $H_2O_2$ in the regulation of ANP secretion, a perfused model of left atrium of rats was used. The results obtained were as follows; 1. The ANP secretion and the extracellular fluid(ECF) translocation were accentuated by the effect of repetitive atrial distension-reduction volume at atrial pressure($4cmH_2O$). 2. The dilution curve showed to be in parallel between pure atriopeptin III (AP III) and perfusated buffer. 3. $H_2O_2(5{\times}10^{-4}M)$ accenturated a strectch-release induced increase of the ANP secretion. The amount of released ANP was significantly(p<0.01) increased. These results suggest that the superoxide anion may be involved in the regulatory mechanism of mechanically activated ANP release.

심방 이뇨호르몬의 분비조절에서 Ca²⁺이 protein kinase C 활성화에 미치는 영향

강창원,김진상,이호일,Kang, Chang-won,Kim, Jin-shang,Lee, Ho-il 대한수의학회 1999 大韓獸醫學會誌 Vol.39 No.5

Atrial natriuretic peptide(ANP) is a hormone with potent natriuretic, diuretic and relaxing properties on vascular smooth muscle. Specific chemical modulator in response for the ANP secretion has not been found yet. Therefore, we have investigated the role of $Ca^{2+}$ responsible for the regulation of ANP induced by protein kinase C(PKC) on mechanically stretch-induced ANP secretion in the rat atria. The results obtained were as follows ; 1. ANP secretion and ANP concentration were increased to more in $Ca^{2+}$-free buffer than in the Kreb-Henseleit buffer on mechanically stretch-induced ANP secretion(p < 0.05), but extracellular fluid translocation(ECF) was not significant. Phorbol 12-myristate 13-acetate(PMA, $10^{-7}M$) induced ANP secretion and ANP concentration in $Ca^{2+}$-free buffer shown to more accentuate on mechanically stretch-induced ANP secretion than in the $Ca^{2+}$-free buffer(p < 0.05), but ECF translocation was not significant. 2. In the presence of ryanodine($3{\times}10^{-6}M$), PMA($10^{-7}M$) induced ANP secretion and ANP concentration in the Kreb-Henseleit buffer were shown to more increase on mechanically stretch-induced ANP secretion than in the ryanodine($3{\times}10^{-6}M$) with the Kreb-Henseleit buffer(p < 0.05), but ECF translocation was not significant. 3. In the presence of ryanodine($3{\times}10^{-6}M$), PMA($10^{-7}M$) induced ANP secretion and ANP concentration in the $Ca^{2+}$-free buffer was shown to more increase on mechanically stretch-induced ANP secretion than in the ryanodine($3{\times}10^{-6}M$) with the $Ca^{2+}$-free buffer on mechanically induced ANP secretion(p < 0.05), but ECF translocation was not significant. The results suggest that PKC-induced ANP secretion may not be related to the change of $Ca^{2+}$ on mechanically induced ANP secretion in the rat atria.

Effects of activation of protein kinase C on the regulation of atrial natriuretic peptide(ANP) by isolated perfused left atria

강창원,강형섭,이호일,Kang, Chang-won,Kang, Hyung-sub,Lee, Ho-il The Korean Society of Veterinary Science 1997 大韓獸醫學會誌 Vol.37 No.4

심방근 세포는 심방이뇨호르몬을 합성, 저장 그리고 분비하며, 세포내외 이온의 농도, 수분균형 및 혈압 등을 조절하는 것으로 알려져 있다. 또한 심방근의 인장자극에는 Atrial Natriuretic Peptide(ANP)를 2단계(분비, 유리)의 과정으로 이루어져 있으며, 이에 따른 심방이뇨호르몬의 분비 조절기전에 대하여서는 명확히 알려져 있지 않다. 따라서 본 연구는 백서의 심방근 적출관류 모델을 이용하여 protein kinase C와 ANP 조절의 상관관계를 밝히고 분비와 유리의 과정중 어떠한 과정을 이용하여 분비자극에 영향을 주는지를 관찰하기 위하여 본 실험을 실시하였다. PKC 활성제인 PMA(phorbol 12-mystrate 13-acetate)는 ANP의 유리를 현저하게 증가시켰으며, PKC 억제제인 H-7(1-(5-isoquinoline sulfonyl)-2-methyl piperazine dihydrochlo-ride)에 의해 유리를 억제시켰다. PMA와 H-7을 동시에 처리한 경우 PMA에 의하여 증가된 ANP의 유리가 H-7에 의하여 차단됨을 관찰할 수 있었다. 따라서 백서의 관류 심방에서의 ANP 분비 증가는 PKC 활성화에 의하여 이루어지며, ANP분비의 2단계중 ANP 유리에 영향을 줌을 알 수 있었다.

국제회계기준 도입이 재무회계의 투명성과 법인세에 미치는 영향

강창원(Kang Chang Won) 한국국제회계학회 2011 국제회계연구 Vol.0 No.35

본 연구는 기업현장의 재무 및 회계 담당자와 기업 대행 또는 CPA 의견을 제시하는 세무 및 회계 대리인 등, 회계시스템 내에 종사하는 자들이 인식하는 정도로 국제회계기준 도입이 기업의 재무제표 투명성과 법인세에 어떠한 영향을 미치는지 분석하고자 하였으며. 결과는 다음과 같다. 첫째, 회계 투명성의 인식에 대한 분석 결과, 국제회계기준 도입은 재무회계 자료의 신뢰도와 투명도가 높아지고, 기업의 재무제표와 경영성과를 적절하게 나타낼 수 있다고 인식하였다. 둘째, 국제회계기준 도입에 따른 기준차이의 중요도, 납세협력 비용의 증가도, 국제회계기준 수용 필요성, 그리고 국제회계기준 도입에 따른 회계투명성을 재고자산, 유형자산, 무형자산별로 파악한 결과, 국제회계기준을 수용하는 것에 대해서 매우 긍정적으로 평가하였다. 또한, 기업회계기준에 맞게 법인세법을 개정한다 해도 목적과 체계를 중요하게 훼손하지 않을 것이라 인식하였다. 더불어 현행 법인세법체계에서 납세협력비용이 과거대비 증가할 것이라 인식하는 것으로 나타났다. This study aimed at analyzing how the introduction of International Financial Reporting Standards(IFRS) has an effect upon the transparency of corporation, and the results of analysis are as follows. First, in the result of analysis on the recognition of accounting transparency, it was recognized that the introduction of IFRS heightens the reliability of accounting data more than the maintenance of the current tax law, lifts the transparency of accounting data and expresses the corporate financing state and management results appropriately. Secondly, when figuring out the importance of the reference differences according to the introduction of IFRS, the increase of tax compliance cost, the necessity of the acceptance of IFRS and the accounting transparency according to the introduction of FRS by the inventory assets, tangible assets and intangible assets, it could be known that the tax law accepting IFRS was affirmatively assessed. In addition, it was thought that even amending the tax law fitted for the corporate accounting standard didn't damage the objective and system of the tax law seriously. It was recognized that if the current tax law is maintained, the tax compliance cost will increase compared with the past.

자동차용 라디에이터 열유동 특성에 관한 수치해석

강창원(Chang Won Kang),김태준(Tae Joon Kim),이치우(Chi Woo Lee) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.6

The purpose of this study was to numerically analyze the heat flow characteristics of an automotive radiator. Heat flow analyses were conducted on the cooling water and outdoor air of the radiator, as well as the temperature distribution of the cooling water after heat transfer. The results of the study revealed that neither heat transfer nor radiator volume was affected by the position of the inlet of cooling water. However, temperature distribution was affected by the position of both the inlet and outlet. In case of heat transfer, three models underwent about 158 kW of heat transfer. The difference in cooling water temperature was about 10 ℃. In case of pressure drop, the core external air side was reduced to about 1,375 Pa, and the internal cooling water side about 14,570 Pa.

갑상샘 호르몬이 고양이 사구체 혈관사이세포의 증식, 수축력 및 prostaglandin E₂ 분비에 미치는 효과

강창원(Chang Won Kang),김송군(Song Gun Kim),이호일(Ho Il Lee) 한국예방수의학회 1999 예방수의학회지 Vol.23 No.3

갑상샘 호르몬은 동물의 신장에서 이온 변동과 세포의 증식에 관여하는 중요한 조절인자이다. 따라서 갑상샘 호르몬투여가 배양한 고양이 사구체 혈관사이세포의 수축, 증식 및 PGE₂분비에 미치는 효과를 관찰하기 위하여 본 연구를 실시하였다. 고양이 사구체 혈관사이세포를 이용하여 갑상샘 호르몬이 혈관사이세포의 증식, 수축 및 PGE₂분비를 측정한 결과 배양된 고양이 사구체 혈관사이세포의 수축은 T₃(10⁻⁸, 10⁻⁷ 및 10⁻⁶M)와 T₄(10⁻⁸,10⁻⁷ 및 10⁻⁶M) 투여에서 대조군에 비하여 농도 의존적인 억제를 관찰할 수 있었다(P<0.05). 배양된 고양이 사구체 혈관사이세포의 증식 효과에서는 대조군에 비하여 10⁻⁷와 10⁻⁶M T₃에서 증식 효과를 관찰할 수 있었으며(p<0.05), T₄에서는 증식 효과를 관찰할 수 없었다. 배양된 고양이 사구체 혈관사이세포의 PGE₂분비 증가효과를 관찰할 수 있었으며(P<0.05), T₄에서는 분비 증가효과는 대조군에 비하여 10⁻⁷M T₃에서 분비 증가효과를 관찰할 수 없었다. 따라서 배양한 고양이 사구체 혈관사이세포에 갑상샘 호르몬 투여가 사구체 여과량과 신혈류량을 조절할 수 있는 증식, 수축 및 PGE₂의 분비 효과에 관여하고 있음을 추측할 수 있었다. Tyroid hormone is an important regulator of changing ion and proliferation in kidney. The glomerular mesangial cells were isolated and cultured from cats to investigate the effects of triiodothyronine (T₃) and thyroxine (T₄) on proliferation, contraction, and prostaglandin E₂(PGE₂) secretion. After 7 days in subculture, proliferation, contraction, and prostaglandin E₂(PGE₂) secretion were determined. Relaxation of mesangial cells was increased by T₃(10⁻⁸, 10⁻⁷, and 10⁻⁶ M) and T₄(10⁻⁸, 10⁻⁷, and 10⁻⁶ M) in a dose-dependent manner compared to controls(p<0.05). The proliferation of mesangial cells was increased by T₃(10⁻⁷,10⁻⁵ M) compared to controls(p<0.05), but T₄ did not increase. The PGE₂ secretion of mesangial cells was increased by T₃ (10⁻⁷M) compared to controls(p<0.05), but T₄ did not increase. These results suggest that thyroid hormone may be involved in proliferation, contraction, and PGE₂ secretion of cultured mesangial cells.

계장용 볼 밸브 유량계수 Cv 측정에 관한 연구

강창원(Chang-Won Kang),이중섭(Chung-Seob Yi),장세민(Se-Min Jang),이치우(Chi-Woo Lee) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.3

The results of the measurement of the flow-rate coefficient (Cv-value) and the analysis of a small ball valve are summarized follows. The Cv-values of 1/2-, 3/4- and 1-inch ball valves were measured using a flow-rate measurement test. The manufacturer obtained the Cv-value using a theoretical calculation method. The new experimental measurement and analysis method yielded more reliable results. In addition, the Cv value obtained through numerical analysis was almost identical the value provided by the manufacturer, which was based on experimental results. A Study on Flow Analysis results are all similar appearances as the reliability of the results.