실험적 방법에 의한 ICT 파이어 댐퍼의 내화성능연구

허남수(Nam-Soo Hur),김인환(In-Whan Kim),장성철(Sung Cheol Jang),김재웅(Jae-Woong Kim) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.5

In this paper, fire resistance test was carried out to obtain class H-120 thermal insulation of fire dampers according to a hydrocarbon fire conditions. Specimens were fabricated three different types according to the change of the insulation system applied to damper blade and coaming which were measured surface temperature by performing the fire resistance test. As a test result, specimen-1, 2 of an uninsulated damper blade were exceeded thermal insulation acceptance criteria at 21 minutes, 46 minutes respectively, but specimen-3 of an insulated damper blade was satisfied thermal insulation acceptance criteria during 120 minutes. The test results showed that the insulation of the damper blade was an important factor in the fireproof performance of fire dampers concerning the coaming length minimum 500 mm on the unexposed side as specified test standard.

선박용 강제통풍 팬의 기어식 베인댐퍼 성능평가

허남수(Hur Nam-Soo),장성철(Jang Sung-Cheol),이경준(Lee Kyung-Jun) 한국산업융합학회 2016 한국산업융합학회 논문집 Vol.19 No.4

Thus, this study aimed to develop a gear-type vane damper in order to replace the link-type vane damper. To achieve this goal, the torque generated in a gear-type vane damper was analyzed, and a structural analysis was conducted. In addition, the fluid flow was analyzed according to the changes in the vane’s angle, and experimental tests such as a dry-heat test and cold test were conducted considering the operating conditions of the vessels. Moreover, an appropriate actuator was selected for the developed gear-type vane damper, and studies on the reduction in the backlash due to the facing-pressure adjustment length and flow rate and leakage test due to the vane’s angle were conducted.

기업(企業)의 자본비용(資本費用)에 관한 연구(硏究) ―우리 나라 제조업(製造業)의 상장회사(上場會社)를 중심(中心)으로―

허남수 ( Hur Nam Soo ) 경남대학교 산업경영연구소 1984 지역산업연구 Vol.7 No.1

First, the major purpose of this thesis is to examine the financial structure, capital structure and business performance of listed companies, to analyze the overall change flow of the cost of capital by the industry and by the year and to know whether the optimal capital structure exists or no. Second, as a sample for this empirical test, the repre sentative manufacturing corporations settled in December were selected. However, after analyzing three year’s data-from 1979 to 1981,the corporations that can’t calculate the equity- capital due to loss and the industris that have small number of tsampling units are excluded from test, because they are not the proper sample for the test. Consequently, 72 corporations among 133 of 6 industries could survive as a sample for computing the cost capital. Third, in the calulation of the cost of capital, the settled hypotheses have some limitations; calculated not by market price but by book priced only homogeneity of industry and fiscal period are considered, existence of homogeneous risk class is not considered. As disscussed in capital structure pattern, the debt dependence rates of listed firms have been steadily rising since regression of 1970. As a consequence, some firms have faced taced troubles such as heavy interest payable, decrease in sales, poor return rate. Others have excessive investment of fixed assets, the preference tendency of debt due to inflation and so on. The following financial policies should be carried out to resolve these problems. First, the capital structure of company should be optimized. After considering the size of firm, time, and financial situation for the optimization of capital structure, basically firms should raise funds withn the range of not harming liquidity, utilize it effectively and improve productivity. Second, the equity capital should be expanded. In comparison with foreign companies, the equity capital compont ratio of Korean listed companies is so far below that of foreign companies. It is needed to enrich the equity capital through the increase of issue of foreign securities, stocks of market price, convertible bonds. As circumstances require, the system that can give sanction to companies not keeping a required level of the equity capital in taxation or finance should be established. Third, the policy that can maintain financial stability and increase profitability should be established. Chapter Three reveals that the stability of listed firms goes bad to worse. In some cases, excessive investments in vestments in fixed assets or real estate for non-business use have harmed the stability of company. Stability rather than growth should be sought in these companies. The following alternatives for stability are required; the reduction of facilities investment; the saving of working capital through shortening the turnover rate of invertories and receivables; the activation of production technology development; the rising of stock price. Marketing strategy of sales promotion and rational management policy should be established in order to raise raturn rate and capital turnover rate. In addition, companies should cut down interests payable through the reduction of debt financing and establish strategy to increase non-operating income, for example, royalty of patents as advanced countries. Fourth, new tax system and dividend policy should be sought. The high debt ratio of our firms is considered to be caused by the insufficiency of national capital, the immaturity of capital market, the supply of funds low interest rate from financial institions, tax-effect from debt financing and the influence of inflation. The support of tax system and dividend policy is required to resolve these problems. To begin with, the interest income of individuals like dividend income must be taxed as a composite income. For the efficient performance, the system recognizing only real-name trade of all deposits, national, public and company bonds would be desirade. Despite of interest rate decline, the financial structure of listed companies is in a state the worse for par dividend. Dividend must be paid to stockholders in proportion to. the rates of return, not by par dividend. Hence companies with weak financial structure can get out of the trouble of stock price. Fifth, the finacial policy should be rationalized. As a matter of fact, the deterioration of capital structure has its origin in lack of internal management. But government also must back up firms with proper financial policy. Thanks to recent decline of interest rate, the financial structure of firms has been rapidly improved. Government should make efforts to keep the present level of interest rate stable for a long- time. However, in principle, the system of interest rate should be elastically controlled through the market mechanism of our listed firms, higher paid-in Capital ratio than foreign firms gives firms a severe dividend pressure. Therefore, surplus funds should be restrained from moving in capital in order to reinforce internal retained earnings. The moving in capital of reserve for revaluation of assets should be restricted, too. It is necessary for country to complement or abolish the assets revaluation system that had been already abolished in advanced countries, As a result, our companies can escape from heavy pressure of dividend and improve capital structure. Our companies, as above mentioned, have the abnormal pattern of the capital structure. For the normalization of capital structure, mangers of company should have right management ideas, above all, avoid excessive dependence of external financing and seek the enrichment strategy of the equity capital. And government also should establish the policy to adapt to changes of business environments with right understanding of financial situation.

우리나라 벤처캐피탈의 변동추이와 발전방향

허남수(Hur Nam Soo) 한국중소기업학회 1998 中小企業硏究 Vol.20 No.2

N/A

벤처기업공개와 벤처캐피탈리스트의 역할 분석

허남수(Nam Soo Hur),윤병섭(Byung Seop Yoon),이기환(Ki Hwan Lee) 한국재무관리학회 2002 財務管理硏究 Vol.19 No.1

본 논문은 1999년 1월부터 2000년 12월까지 코스닥증권시장에 등록한 벤처기업의 IPO를 대상으로 발행시장에서 벤처캐피탈리스트의 역할을 살펴보고 있다. 특히 미국의 발행시장에서는 벤처캐피탈리스트가 투자한 기업이 조기에 공개되는 현상이 나타나는 것으로 보고되고 있는 바, 우리 나라에서도 이러한 현상이 존재하는지를 실증적으로 조사하고 있다. 코스닥증권시장에 등록한 벤처기업의 IPO를 대상으로 발행시장에서 벤처캐피탈리스트의 역할에 관한 우리의 연구 결과는 다음과 같다. 첫째, 벤처기업과 비벤처기업의 초기 초과수익률의 차이분석에서, 벤처기업은 AR_1에서 할인발행의 정도가 적어 Megginson-Weiss(1991)의 결과와 유사한 것으로 나타났지만, AR_2에서 발행가격 결정시 고려하지 못하는 비계수적 환경요인 등 미래기대수익에 대한 일반투자자의 평가가 호의적으로 나타나 발행회사의 입장에서는 할인발행의 정도가 큰 것으로 나타났다. 이는 이기환·임병균 ·최해술(1998), 장상수·길재욱(2000) 등의 연구와 유사한 결과를 보이고 있다. 둘째, 벤처캐피탈리스트의 명성에 따라 초기 초과수익률에 차이가 있었다. 즉, KTB지원기업의 초기 초과수익률이 낮았다. 셋째, 벤처캐피탈리스트의 보유지분을 변동에 대한 차이는 IPO전 평균보유지분율은 비KTB가 높았으나 공개 후 평균보유지분율은 KTB가 높았다. 이때 보유지분을 변동이 적은 KTB지원기업의 초기 초과수익률이 낮았다. 특히 업력과 총자산의 규모가 할인발행을 줄이는 역할을 하는 것으로 나타났다. 업력은 Muscarella-Vetsuypens(1989)의 연구와 일치하고 있다. 넷째, 2개 이상의 벤처캐피탈리스트로부터 공동으로 투자받은 벤처기업의 초기 초과수익률이 하나의 벤처캐피탈로부터 단독으로 투자받은 벤처기업의 초기 초과수익률보다 낮았다. 그러나 통계적 유의성은 없었다. 다섯째, IPO까지 소요기간의 차이가 있는지에 대한 분석에서 비KTB지원기업이 보다 빨리 공개되고 있어 조기업적과시현상(grandstsanding)을 보였다. 이는 Gompers(1996)의 연구와 일치한다. 여섯째, 등록주선인의 시장점유율에 차이가 있는지를 분석한 결과, KTB가 투자한 벤처기업 등록주선인의 평균시장점유율이 낮았다. 그러나 통계적 유의성은 없었다.

터보공기압축기 코어 동특성 연구

허남수(Nam-Soo Hur),이형우(Hyoung-Woo Lee) 한국마린엔지니어링학회 2006 한국마린엔지니어링학회지 Vol.30 No.8

해양플랜트용 H-120 Class 파이어 댐퍼의 성능 실험

장성철(Sung Cheol Jang),허남수(Nam-Soo Hur),김인환(In-Whan Kim) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.2

In this paper, a fire resistance test was carried out in accordance with the change of the insulation conditions on the exposed side and unexposed side of a coaming to obtain the optimal insulation conditions for class H-120 insulation in connection with specimen1 of the preceding paper for an evaluation of the fireproof performance of fire dampers according to hydrocarbon fire conditions. In the test results, specimen2(88 mm, 171 ℃) met the class H-120 insulation conditions, but specimen3(76mm, 181℃) exceeded the thermal insulation acceptance criteria at 110 minutes. Therefore, specimen2(88 mm) represents the optimal insulation conditions as a possible lightweight materialas compared to specimen1. From a comparison of the test results, we concluded that the temperature increase of the coaming insulation surface was influenced by conductive heat from the bulkhead and that the coaming surface was influenced by radiant heat from the blade and coaming.

LQG/LTR 방법을 이용한 터렛 서보시스템의 강인한 제어기 설계

김종화(Jong Hwa Kim),허남수(Nam Soo Hur),이만형(Mam Hyung Lee) Korean Society for Precision Engineering 1989 한국정밀공학회지 Vol.6 No.2

SCM420H 유성기어의 연삭효과에 관한 연구

안인효(In-Hyo An),허남수(Nam-Soo Hur),이인범(In-Bum Lee),류성기(Sung-Ki Lyu) 한국기계가공학회 2012 한국기계가공학회지 Vol.11 No.5

This study dealt with effect of the grinding in SCM420H planetary gears. The hardness, tooth profile, lead and roughness of the gear surface can be improved by grinding process. Therein, the grinding techniques are widely used especially as one of the physical surface improvement methods. As the results, the gear grinding process reduced vibration and noise, and increased the life of the gear. And the gear grinding improved the surface of gear tooth in a short time and low cost, thus, it is a very important process in manufacturing industry. But nowadays, it is hard to find the detail information of gear grinding process. The test piece is a planetary gear which is used in the industrial machine. The manufacture process of the test piece contains hobbing, shaving, carburizing and grinding. This study investigated the effect of the grinding process to the physiognomy and the fatigue strength of test piece which was made by SCM420H.

저진동 슬래그 분쇄장치용 감속기 개발

이형우(Hyoung Woo Lee),허남수(Nam Soo Hur),김인환(?In Hwan KIM) 한국마린엔지니어링학회 2012 한국마린엔지니어링학회지 Vol.36 No.8