• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.19-22
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• 2012

본 연구에서는 폭발사고가 반복되고 있는 마그네슘합금(Mg-Al alloy) 분진의 예방대책을 위한 안전자료로 활용하기 위하여 폭발특성평가 실험과 화염전파속도를 추정하였다. 화염전파속도는 폭발과압 강도에 영향을 주지만 분진폭발에서는 화염의 확산에 따른 피해예측에도 중요한 자료로 활용될 수 있다. 밀폐공간의 분진폭발에서 화염전파속도를 계산하기 위하여 분진의 연소시간과 화염면의 도달시간을 고려하여 폭발압력으로부터 추정하는 방법을 제시하고 마그네슘합금의 성분비율에 따라 폭발에 따른 화염전파속도를 계산하였다. 그 결과, Mg-Al(60:40 wt%), Mg-Al(50:50 wt%), Mg-Al(40:60 wt%)의 최대화염전파속도는 각각 15.5, 18, 15.2 m/s로 추정되었으며 성분비율에 따라 최대화염속도는 변화하는 경향을 나타냈다.

• 프린팅코리아
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• s.14
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• pp.36-43
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• 2003

한국은행이 최근에 발표한 1990년 이후 인쇄업체의 기업경영 분석에 따르면 인쇄산업의 성장세는 주춤하거나 하락세를 보인 반면, 각 기업의 재무구조는 건실해 진 것으로 조사됐다. 외형보다는 내실화에 집중하는 경향은 97-98년을 전후로 뚜렷하게 나타났는데, 구제금융의 한파 이후 환율상승과 이자율 급등에 어려움을 겪었던 업체들이 기업의 내실 경영에 치중했기 때문이다. 기업 경영의 안정성이 점차 확보되는 가운데 몇가지 우려되는 점은 과다경쟁으로 인한 부가가치 하락과 99년 이후 양호해 지던 각종 지표들이 2002년 들어 주춤하는 양상을 보이고 있다는 점이다. 한국은행 발표자료를 업계의 성장성, 생산성, 손익의 관계비율, 매출액과 관련된 기업경영, 자산 및 부채 관계비율로 나누어 분석해 보았다.

• Journal of Korean Society of Transportation
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• v.8 no.1
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• pp.119-128
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• 1990

교통자산과 같은 내구재는 일정 기간 동안의 수명을 가지게 된다. 이 기간 동안에 내구재는 어떠한 형태로 소비되어 지고 이에 따라 내구재는 효율성을 잃어 간다. 내구재를 효율적으로 사용하기 위해서는 적절한 관리를 필요로 한다. 본 연구는 내구재를 효율적으로 사용하기 위해 필요한 관리비용의 동적형태를 이론적으로 고찰한 다음, 미국에서의 업무용 비행기의 관리비용자료를 사용하여 경험적인 결과를 제시한다. 본 연구의 결과는 다음과 같다. (1) 관리비용은 시간이 감에 따라 줄어든다. 그러나 관리비용의 잠재가격(Shadow Price)에 대한 비율은 여러 가지 외적변수들에 결정된다. (2) 미국에서의 업무용 비행기의 시장가격에 대한 관리비용의 비율은 시간이 감에 따라 늘어난다.

• Proceedings of the Korean Society of Grassland Science Conference
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• 1999.06a
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• pp.83-84
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• 1999

애기수영의 생태적 방제를 위한 초종간 경쟁을 통하여 애기수영의 생육을 억압하여, 기초적인 자료를 얻고자 하였다. 공시초종은 reed canarygrass, kentucky bluegrass, tall fescue, orchardgrass의 4초종으로 애기수영과 종자비율을 10:0, 8:2, 6:4, 4:6, 2:8: 0:10의 6수준으로 6월 중순에 파종한 후 9월초 3엽기의 개체를 혼파비율에 맞추어 1/2000a 크기의 pot에 각각 5개체씩 이식하고 이듬해 6월말에 조사를 실시하였다.(중략)

• The Korean Journal of Financial Management
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• v.24 no.4
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• pp.201-232
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• 2007

In this study, we investigated public announcements of stock splits using the Korean Stock Market data from 2000 through 2007. The purposes of this study are to examine whether stock splits have the information contents in the Korean capital markets, and to investigate the possible cause of the market reactions. We measured the market reactions with abnormal returns, cumulative abnormal returns and cumulative average abnormal returns. For the purpose, two specific hypotheses were tested. One is 'Signalling Effects' where stock splits function as a signal through which managers transmit a favorable information for investors. The other is 'Liquidity Effects' where stock splits increase the trading convenience. We have th following results. Firstly, positive market effects were found when stock splits were announced. Secondly, there was difference in trading convenience between the high and the low split ratios. Finally, the long term performance through stock splits in the Korean capital markets was not significant.

• The Korean Journal of Financial Management
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• v.21 no.1
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• pp.231-253
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• 2004

We examine hedge strategies that use Won-dollar futures to hedge the price risk of the Won-dollar exchange rate. We employ the naive hedge model, minimum variance hedge model and bivariate ECT-ARCH(1) model as hedge instruments, and analyze their hedge performances. The sample period covers from January 2, 2001 to December 31, 2002 with sub-samples such as daily, weekly, bi-weekly prices of the Won-dollar futures and cash. The important findings may be summarized as follows. First, there is no significant difference in hedge ratio between the risk minimum variance model and bivariate ECT-ARCH(1) model that controls for the cointegration relationship of the Won-dollar futures and cash. Second, hedge performance of the naive model and minimum variance model with constant hedge ratios is not far behind that of bivariate ECT-ARCH(1) model with time-varying hedge ratios. This results imply that investors are encouraged to use the minimum variance hedge model to hedge Won-dollar exchange rate with Won-dollar futures. Third, hedge performance and effectiveness of each model is also analyzed with respect to hedge period appear to be greater over long than over the short period. This evidence supports the hypothesis that futures prices would have more time to respond to the greater cash price changes over the longer holding period, leading to an improved hedge performance.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.342-349
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• 2006

The survey guideline of forest products statistics suggests a certain type of standard to aggregate production amount of each item such as dry bracken, raw dates, cracked nuts, It does not, however, give any information about transition ratios, which would apply to convert weights of fresh bracken into dry one, or cracked nuts into the non-cracked. This has been one of the main factors which would make the statistics unreliable. The purpose of this study is to examine the aggregation realities and to put forward some proposals to improve forest products statistics with transition ratios. Targets of this study are 10 forest products that are strongly related to the mentioned problems. With the calculated transition ratios and some assumptions the changing rate of the official statistics of 2004 production amounts ranged from -41% to 474% for the 10 subjects. The suggested figures for transitions are based only on one-year analysis results. Therefore more periods are required to improve the accuracy and the reliability, and this study would be a good starting point.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.340-352
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• 2018

This study presents a method to find the extant central halls with the plan most similar to the remains and to find out and compare the architectural style of extant buildings for the restoration. In the Joseon dynasty, there existed both remains and the extant hall. In particular, the $3{\times}2Kan$ hall is the minimum size that functions as the hall, so the number of comparison articles is small. The subjects are three remains and 29 Extant Halls. The absolute size of the comparison articles are the Area, Ratio of front/side, and the relative sizes are the Ratio of front Eokan/Hyeopkan and Ratio of the front Eokan/the side row. The Daeungjeon remain in Bugjijangsa is similar in absolute size and relative sizes to Oeosa daeungjeon. The Bubdang remain in Seonchalsaji is similar to Sangwonsa daeungjeon in the Area and Ratio of front/side, and similar to Daejeogsa geungnakjeon in the Ratio of front/side and Ratio of front Eokan/Hyeopkan. The Bubdang remain in Seungseonsaji is similar to Seodongsa daeungjeon in the Area, Ratio of front Eokan/Hyeopkan and Ratio of the front Eokan /the side row. Consequently, this method has high value as a way to expand by other comparison articles.

• Management & Information Systems Review
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• v.38 no.4
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• pp.25-39
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• 2019

The purpose of this study is to analyze the management performance of hospitals by analyzing the ratio of stability, profitability ratio, and growth rate through the financial ratios of medical institutions using accounting information disclosure data of medical institutions, financial status table and profit and loss statement. The main goal is to analyze and analyze financial statements of medical institutions' accounting information in 2016 and 2017, analyze the difference and analyze the general characteristics and financial ratios by type, type and size of medical institutions, The financial characteristics of medical institutions were identified. The ratio of stability, profitability, and growth rate through financial ratios were compared and analyzed. In addition, we analyzed the correlation between the medical profit margin, the total asset profit margin, the medical profit margin rate, and the net profit margin of the medical institutions through the financial ratios of accounting information disclosure data of medical institutions. The main results are as follows: First, the size of the hospital and the size of the debt through the change of assets, liabilities and capital of the financial statement are increasing, the size of own capital is relatively decreased, and the management performance is getting worse It is showing. Second, the increase in average medical revenues in the income statement is small, and the average increase in net profit is small. Thus, medical institutions were able to confirm the difficulty in creating profits through medical activities. In addition, there was a large difference in the debt ratio, the stability ratio, and the profitability ratio of the general hospitals and the general hospitals according to the types of medical institutions, and the difference in the average financial ratios of national and public hospitals, school corporation hospitals, I could confirm. The correlation between independent variables in the correlation was -0.904 between the capital ratio and the total assets turnover ratio, -0.800 between the labor cost ratio and the hospital income ratio, and -0.631 between the labor cost ratio and the foreign profit ratio. In order to improve the management deterioration of hospitals by using accounting information disclosure data of medical institutions, it is necessary to have a large effect on the net profit margin of the medical care and the net profit margin of the total assets.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.366-372
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• 2020

The Army's rocket missile is a one-shot weapon system, which is produced and used for only one mission, and requires high reliability. While reliability analysis with failure data can result in underestimation of the life distribution, reliability analysis with all the non-failure data can result in overestimation of the life distribution. Under or overestimation of the life distribution can lead to cost increase by early disposal or complete observation of all rocket missiles. In order to overcome this problem, the Army suggests the guideline of the number of samples from non-failure data for reliability analysis with failure data. However, the currently used sampling method can generate errors for predicting the failure rate. To solve this problem, this study proposes a new sampling procedure for predicting a future failure rate using non-failure data. The comparison test between the currently used sampling method and the proposed sampling method is conducted and the result shows that the proposed sampling method can predict the future failure rate more accurately.