• 품질경영학회지
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• 제18권1호
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• pp.84-95
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• 1990

The objective of this study is to understand the effect of measurement-related investment. That is, this study aims at verifying the correlation between the measurement-related investment and inferiority rate of products by statistical analysis. The samples of this study are 376 industrial companies in Korea, and the research data was analysed on inferiority state of industrial companies with a measurement standard laboratory. The analysis was made by the elementary statistics, the correlation analysis and the regression analysis. The results are summarized as follows : First, the inferioriy rate of the industrial companies with a measurement standard laboratory was relatively lower than that of the other companies without the laboratory by statistical significance. Second, the increment on measurement-related investment had a negative correlation with the increment of inferiority rate, and the increase of measurement-related investment showed decrease of the inferiority rate by regression analysis.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 가을 학술발표회 논문집
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• pp.297-298
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• 2003

Linear density regularity is one of the important characteristics of fiber bundle and yarns, influencing the process performance and the product quality. Analysis on the variation of bundle thickness for various draft ratios and frequencies is therefore of great significance, because an optimum drafting condition can be obtained by establishing the effect of major process factors on the output. (omitted)

• 대한산업공학회지
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• 제40권4호
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• pp.375-381
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• 2014

Data mining is a process of discovering useful patterns or information from large amount of data. Decision tree is one of the data mining algorithms that can be used for both classification and prediction and has been widely used for various applications because of its flexibility and interpretability. Decision trees for classification generally generate a number of rules that belong to one of the predefined category and some rules may belong to the same category. In this case, it is necessary to determine the significance of each rule so as to provide the priority of the rule with users. The purpose of this paper is to propose a rule selection method in classification tree models that accommodate the umber of observation, accuracy, and effectiveness in each rule. Our experiments demonstrate that the proposed method produce better performance compared to other existing rule selection methods.

• 한국산학기술학회논문지
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• 제13권4호
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• pp.1640-1647
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• 2012

본 연구는 2007년 1월부터 2009년 12월까지 3년간 코스닥기업의 유상증자 형태 중 제3자 배정을 통해 대금을 납입한 81개 기업 197건에 대하여 사건연구를 통해 납입 전, 후의 주가반응을 비교분석하였고, 더 나아가 누적초과수익률에 영향을 미치는 요인이 무엇인지를 다중회귀분석을 통해 파악하였다 본 연구의 결과를 요약하면 다음과 같다. 첫째, (-5, +5) 초과수익률은 납입일 5일전부터 1일전까지 1% 수준에서 유의적인 정(+)의 초과수익률을 보이는 것으로 나타났고, 사건일인 납입 일에는 유의적인 초과수익률이 존재하지 않는 것으로 나타났다. 납입일 이후 5일 동안은 1% 유의수준에서 부(-)의 초과수익률을 보였다. 둘째, 납입일 전, 후 40일간(-40, +40)의 초과수익률은 납입일 전 40일 동안 1% 수준에서 유의적인 정(+)의 초과수익률을 나타냈으며, 납입일 이후 40일 동안 1% 수준에서 유의적인 부(-)의 초과수익률을 보였다. 셋째, 납입일 이후 1년간(0, 1년)의 초과수익률은 1% 수준에서 유의적인 부(-)의 초과수익률을 보였다. 넷째, (-5, +5)까지의 누적초과수익률에 영향을 미치는 요인은 기업규모로 정(+)의 영향을 미쳤으며, 10% 유의수준에서 유의적이었다. 유보율과 부채비율은 (-40, +40)의 누적초과수익률에 10% 유의수준에서 유의적으로 각각 정(+)과 부(-)의 영향을 미치는 것으로 나타났다. (0, 1년)의 누적초과수익률에 영향을 미치는 요인은 기업규모, 부채비율, 대주주지분율은 각각 1%, 5%, 10% 유의수준에서 유의적인 부(-)의 영향을, 유보율은 1% 유의수준에서 유의적으로 정(+)의 영향을 미치는 것으로 나타났다.

• 한국산업보건학회지
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• 제16권4호
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• pp.346-355
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• 2006

The purpose of this study was conducted to ascertain the difference between impinger and passive sampling methods in the process of sampling and analyzing on airborne formaldehyde. Formaldehyde generating workplaces included in this study comprised four types of manufacturing industry such as two workplaces of products of wood, cork, straw and plaiting materials manufacturing industries, one casting metal manufacturing industry, and one parts and accessories for motor vehicles and it′s engines manufacturing industry. Workplaces contained in this study were located in some manufacturing area of Busan industrial complex and this study was carried out during a period from January 2003 to December 2004. Analytical accuracy, precision and detection limit of two methods was compared. Exposure level of its airborne concentration was evaluated in formaldehyde generating workplaces those were classified by types of industry, working process, and time. The results were as follows ; 1. A rate of recovery was 107.1% in impinger method and 101.8% in passive method, and precision was 7.79% in impinger method and 4.40% in passive method. There was no statistical significance in analytical accuracy and precision between two methods. A limitation of detection was 0.011 ppm in passive method which was lower than that of impinger method (0.020 ppm) by 1.8 times. 2. Airborne formaldehyde concentration of impinger method was different from passive method. It′s concentration by passive method was higher by 5.1 times than that by impinger method in the parts and accessories for motor vehicles and it′s engines manufacturing industry (P<0.05). Only in molding process among several types of processes, formaldehyde concentration in passive method was higher by 5.1 times than that in impinger method (P<0.05). Furthermore, formaldehyde concentration in passive method was higher by 1.7 times than that in impinger method (P<0.05) in the first half of year 2003. 3. The geometric mean of formaldehyde concentration in impinger method was lower than that in passive method, but there was no statistical significance of formaldehyde concentration by the difference of sampling method. In conclusion, it is difficult to conclude which is better between the two sampling methods because of no statistical significance for the difference of concentration. Because of lacks of certified passive sampling and analytical method, at present situation, studies on verification of accuracy and precision, obstructive reaction against validity on its exposure assessment, and research to develop domestically manufactured passive sampler in terms of cost-effectiveness should be continuously carried out.

• 재무관리연구
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• 제25권1호
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• pp.23-49
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• 2008

본 논문의 목적은 과거의 산업 포트폴리오 수익률이 확률추세로부터 어떻게 전체 주식시장과 두 가지 거시경제 변수인 경기동행지수와 산업생산 등을 예측할 수 있는 지를 알아보는 데에 있다. 이를 위하여 본 연구에서는 연구모형을 설정한 후 세 가지 검정절차를 제시하고 이를 실증적으로 분석하였다. 당월의 전체 주식시장 수익률은 과거의 시차를 지닌 특정 산업부문 포트폴리오 수익률에 대하여 양(+)의 상관관계를 유지하고 있다는 '예측 1'과 전체 주식시장의 수익률은 특정산업부문의 수익률에 대하여 선행성을 지닐 수 없다는 '예측 2'에 대한 검정 결과는 '예측 1'과 '예측 2'가 지지되고 있음을 파악할 수 있었다. 그리고 산업별 포트폴리오 수익률과 거시경제변수 간의 높은 상관관계를 토대로 하여 전체 주식시장 수익률 예측을 가능하게 하는 업종 정보의 점진적 확산 현상이 발생하게 되는가를 검토하기 위하여 각 산업들의 포트폴리오 수익률과 전체 주식시장 수익률이 VAR 모형을 토대로 볼 경우 Granger 인과관계를 갖고 있는 지를 분석하였다. 분석결과 21개 업종은 각 산업별 포트폴리오 수익률이 전체 주식시장 수익률을 5% 수준에서 통계적으로 유의한 영향을 주고 있음을 알 수 있었다. 이들 21개의 산업별 포트폴리오 수익률은 경제적으로도 중요한 의미를 지니고 있어 산업제품의 가격 상승과 하락이 경제에 미치는 영향을 파악할 수 있다. 특히 음료 업종에서 전체 주식시장 수익률과 상호간의 인과성을 나타내었으며, 인터넷과 화장품 업종에서는 전체 주식시장 수익률이 이들 업종에 대하여 일방적인 영향을 보이고 있음을 알 수 있었다.

• The Journal of Asian Finance, Economics and Business
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• 제7권9호
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• pp.315-328
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• 2020

In this study, we examined various aspects of discretionary accruals. We compared the power of Jones Model (JM), Modified Jones Model (MJM) and Performance Matched Model (PMM). Furthermore, we tested whether accruals derived from cash flow approach or balance sheet approach provide better results and we investigated the significance of country and industry control variables in models. In order to perform these tests, we constructed thirty equations. The data consists of 319 non-financial companies over five years in the GCC region. We used panel data regression models, and testing suggests us to use random effect model as the most suitable one. The results show that PMM has the highest explanatory power among models and it is followed by JM and MJM, consecutively. Secondly, results reveal that accruals derived from cash flow approach provide more accurate results. Moreover, country dummies are significant in models with cash flow approach and they lose significance in balance sheet approach. We differentiated industries due to two different classifications: the first group with higher number of industries is more precise compared to the second group with a narrower scope and lower number of industries. The model including both industrial and country-wise dummies scores highest in significance.

• 대한인간공학회지
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• 제20권2호
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• pp.47-57
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• 2001

To simulate an actual slip to measure floor slipperiness, slip resistance testers simulate slip in only forward direction because forward slip in the landing phase was found to be the most important factor for loss of balance. Backward slip in the take off phase was possible but was excluded in the friction test protocol because it was not dangerous. However, backward slip was tested in the friction test protocol without any theoretical background of the significance in generating dangerous slips and falls and was proven to be as good as forward slip in measuring floor slipperiness. Therefore, this study was designed to investigate the significance of backward slip in generating dangerous slips and falls with different combinations of floor and shoe sole. The results showed different tendency of backward slip in take off phase being significant in generating dangerous slips and falls because backward slip in the takeoff phase affected gait pattern disturbances seriously. resulted in dangerous falls. Fast toe velocity increased the severity of backward slip and confirmed the significance of backward slip in generating dangerous slips and falls. As a result, this study recommends the utilization of backward slip in the measurement of floor slipperiness.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.1231-1236
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• 2005

Global construction projects manifest more risks than do other industries. Often, firms doing business in construction markets find these risks intimidating. To secure corresponding profits, many global contractors attempt to forecast the effects of risks and establish risk management strategies. However, one key problem with present-day risk management methods is that they are basically analytical or mathematical-oriented approaches which are not easy to adopt in real business. Based on preliminary investigations and evaluations of current tools, this research elicits more practical algorithms for risk checklist by constructing risk scenarios over the whole period of project execution. For the application of the algorithms, a "SE/RF" (Source-Event/Regular-Floating) checklist is suggested, which sorts out risk sources and their subsequent events, as well as dividing various risk factors into either regular or floating categories. In addition, the "PIS" (Probability-Impact-Significance) method is introduced, in place of traditional "PI" (Probability-Impact) methods, by adding the additional criterion of "risk significance" to determine the degree of risk exposure in a more realistic way. As a result, we draw the significant finding that the "PIS" method presents a closer evaluation regarding degree of risk exposure as compared to the level of expert judgments than those from traditional methods. Finally, we provide an integrated procedure for international project risk management with all of the research achievements being incorporated.

• 한국컴퓨터정보학회논문지
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• 제28권5호
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• pp.179-187
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• 2023

본 논문은 크론바흐 알파 신뢰계수의 유의성 검정에서 이상치가 검정력에 미치는 영향을 연구한 것이다. 표본 크기, 문항들의 수, 이상치의 수, 모집단의 크론바흐 알파 레벨의 네 개의 변수들에 변화를 주었다. 데이터 시물에이션을 위해 다변량 정규분포를 사용했고 균일분포로부터 이상치를 추출하여 사용했다. 크론바흐 알파 신뢰도의 유의성 검정을 위해 모수적 검정(F 검정)과 퍼뮤테이션 검정을 사용하였다. 결과적으로 퍼뮤테이션 검정의 검정력은 F검정의 검정력 보다 크거나 같았고, 두 검정의 검정력은 모두 이상치의 수가 많아질수록 감소하였으며 이러한 이상치의 영향은 모집단의 알파 레벨이 증가할수록 크게 나타났다.