• 한국산학기술학회논문지
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• 제13권8호
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• pp.3417-3426
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• 2012

본 연구는 기본적으로 소유구조(내부 외국인 지분율)가 대리인 비용(자산효율성 비중 영업외비용 비중)에 어떠한 영향을 미치는 가에 대한 실증연구이다. 그러나 소유구조와 대리인 비용의 상관성에 대한 기존연구들이 단순히 Pooled OLS Model을 사용하고 있기에 본 연구에서는 단순 Pooled OLS Model이 방대한 양의 패널형 자료의 검증에는 통계적 신뢰성이 부족하다는 전제하에, Pooled-OLS Model의 적합성 검증 결과를 토대로, 자료형성의 시점 및 기업의 효과를 반영하는 Fixed Effect Model과 Random Effect Model을 추가적인 연구모형으로 형성하고 이를 비교분석함으로써 실증분석 결과의 신뢰성 및 통계적 타당성을 높이고자 하였다. 연구 자료는 IMF 경제 위기 이후인 1998~2007년까지 10년간이며 금융업을 제외한 331개 기업을 대상으로 하였다. 주요 결과로는 모델의 적합성 검증결과 대리인 비용 항목 중 자산효율성 비중은 Random Effect Model을 사용하는 것이 적절하였으나 이에 반하여 영업외비용 비중은 Fixed Effect Model의 사용이 적합하였다. 이에 따른 실증분석결과는 Pooled OLS Model에서 채택되었던 가설이 대부분 기각되는 결과가 나왔다. 이는 실증분석에 있어서 사용하는 모형에 따라 다른 분석결과의 도출이 가능하다는 점을 보여주어 연구 자료에 따른 적합한 연구모형의 형성이 통계적으로 유의한 실증결과의 도출을 위해 무엇보다 중요하다는 점을 시사하고 있다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권4호
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• pp.189-195
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• 2006

In this paper, the inductance characteristics of interior permanent magnet synchronous motor (IPMSM) considering cross-coupling effect is analyzed. It is known that the IPMSM has it's operating point at the saturated region. So the cross-coupling effect exists, therefore cross-coupling inductance exists. With the application of Fixed Permeability Method (FPM), we can obtain more exact inductance characteristics of IPMSM. In this paper, a novel method based on the FPM is proposed, which can consider the cross-coupling effect. And the cross-coupling inductance which is the analysis result is shown. Finally, the validity of proposed method is verified by the comparison with the experimental result.

• 한국ITS학회 논문지
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• 제14권1호
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• pp.85-93
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• 2015

기존의 교통사고모형은 수집된 데이터에 대한 추정된 모수가 고정되어있다고 가정하여 교통량이나 기하구조의 길이와 폭 등은 설치형태와 관계없이 동일한 값을 적용하는 고정효과모형을 이용하여 개발하였다. 하지만 고정효과를 이용한 모형은 모형을 통해 추정된 계수의 표준오차 값이 과소 추정되거나 각 계수의 t-값이 과도하게 산정되어 모형의 설명력이 낮아지게 된다. 이를 극복하기 위하여 교통량, 기하구조, 그리고 관측되지 않은 다른 요인 등에 대한 이질성을 고려한 임의효과모형을 활용하여 모형을 개발할 수 있다. 본 연구에서는 임의효과모형의 효용성을 파악하고자 대전광역시 주요 89개 교차로를 대상으로 데이터를 수집하여 임의효과와 고정효과를 이용한 음이항 회귀모형을 개발하고 이를 비교 분석하였다. 모형개발 결과 년평균일교통량, 제한속도, 차로수, 우회전 전용차로 설치유무, 전방신호등 설치유무 등이 유효한 설명변수로 나타났으며 모형의 설명력을 비교해보면 로그-우도함수값이 임의효과에서 -1537.802로 고정효과의 로그-우도함수값 -1691.327보다 모형 설명력이 좋은 것으로 나타났으며 우도비의 경우 임의효과에서 0.279로 고정효과의 0.207보다 개선된 것으로 나타나 임의효과를 이용한 모형이 고정효과를 이용한 모형보다 우수한 것으로 나타났다.

• 수산경영론집
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• 제47권2호
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• pp.15-32
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• 2016

The Association of Southeast Asian Nations(ASEAN) has been the most essential organization in Asia. In spite of the world economic crisis, Southeast Asian countries have shown fast economic growth since 2000, and they have been actively expanding investments and trades especially with major countries. Research on competitiveness in ASEAN market has spawned an increasingly large literature, but empirical research on the determinants of Korea's export to ASEAN is limited. The purpose of this study is to draw out the determinant of Korean fisheries export to ASEAN by carrying out a panel analysis. For achieving such a purpose, pooled OLS, Hausman Test, Fixed Effect, Random Effect are performed. The last 20 years' data over the period of 1995 to 2014 concentrated on the ASEAN 6 countries such as Indonesia, Malaysia, Philippine, Singapore, Thailand, Vietnam is used in this study. Amount of aquatic products export to ASEAN is used as the dependent variable; real exchange rate, real GDP, relative price level and GDP per capita are used as the explanatory variables and FTA as dummy variable. Empirical results show that fixed-effect analysis is the best model among all the models. As the fixed effect model shows, real exchange rate, real GDP, GDP per capita and dummy variable(FTA) play positive and statistically significant roles in fisheries export to ASEAN, while price variable plays a negative and statistically significant role to the dependent variable.

• 한국병원경영학회지
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• 제23권2호
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• pp.42-53
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• 2018

Purpose: this study investigates the effect of private health insurance on healthcare utilization. Methodology: For the analysis, we employed the three level nested two part model. Findings: the private health insurance adoption was associated with higher health care utilization. In particular, indemnity and fixed insurances adoption was associated with higher probability of outpatient visit, the number of outpatient visit and outpatient cost. While indemnity insurance adoption was associated with higher inpatient admission probability and inpatient days, fixed insurance adoption was associated only with higher inpatient admission probability. Practical Implications: indemnity and fixed insurance adoption were related with the adverse selection as well as moral hazard.

• 한국유기농업학회지
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• 제19권4호
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• pp.565-575
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• 2011

Recently, the use of antibiotics to improve animal productivity in livestock industry was strictly restricted. For these reason, probiotics have been regarded as one of promising materials for an antibiotic alternative. In this study, we investigated how the probiotics influences on the performance of broiler chicken via meta-analysis. Eighteen researches from 1997 to 2010 were used for meta-analysis. The standard summary effects were calculated via fixed effect model and random effect model (Borenstein et al., 2009). Heterogeneity was calculated by using the Cochran's Q statistics (Kook et al., 2009) and publication bias was calculated via Egger's regression (Lee et al., 2011). In fixed model average daily gain, body weight serum protein content and cecal LAB showed positive effect significantly. Feed intake, feed/gain and serum cholesterol showed significant negative effect. In serum triglyceride, negative effect was found but significance was not shown. In random model, average daily gain body weight and cecal LAB showed positive effects with significance and feed/gain and serum cholesterol represented significant negative effects. Publication bias was found only in feed/gain.

• 노동경제논집
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• 제40권1호
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• pp.69-97
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• 2017

본 논문은 한국노동패널 자료를 이용하여 2000년부터 2014년까지 공무원과 민간부문의 임금격차 추세를 고정효과 방법으로 추정한다. 관측되지 않은 이질성(unobserved heterogeneity)을 제거하고 시간에 따른 임금격차 변화를 추정하기 위해 로그 임금 차분을 이용한 고정효과 방법을 사용한다. 고정효과 추정 결과, 2000년부터 2014년까지 공무원과 민간부문의 임금격차는 통계적으로 유의하지 않은 것으로 나타난다. 뿐만 아니라, OLS 추정에서 나타나는 역 V자 형태(2007년을 기점으로 공무원 임금 프리미엄이 감소)의 추세도 고정효과 분석에서는 나타나지 않는다.

• 통상정보연구
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• 제11권2호
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• pp.111-126
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• 2009

This study analysed determinants of Foreign Direct Investment to ASEAN+ 3 member nations using panel data for which cross-sectional data are combined with time series data. The data for the analysis included the amount of FDI, GDP, and indexes of economic independence. This study collected data from six nations(Indonesia, Malaysia, Philippines, Singapore, Thailand, Vietnam) whose data were easily available, China and Japan from 2003 to 2007 and analysed them. The results are summarized as follows: Using the pooled OLS method, we found Model 2 had the highest explanatory power whose adjusted R-squared was 89.4%, which accounted for about 89% of foreign investment. Using the fixed effect model, Model 2 had the highest explanatory power whose adjusted R-squared was 96.8%, which accounted for about 97% of foreign investment. Using the probability effect model, Model 5 had the highest explanatory power, but in respect to its statistical significance, only GDP was 1% significant and the rest variables had no significance.

• 보건의료산업학회지
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• 제10권3호
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• pp.13-25
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• 2016

Objectives : The purposes of this study was to analyze business performance of university hospitals for the past 10 years. Methods : Management and finance data from 2005 to 2014 were collected from balance sheets, income statements and annual reports from 27 university hospitals. The dependant variable used was profitability which included return on assets, operating margin and net profit to gross revenues 1. The independent variables were general characteristics, liquidity, stability, activity and financial ratios. Results : University hospitals over the last 10 years had achieved good management performance. Using financial leverage, patient revenues, operating profit, nonpatient revenues, total assets and total debt, the total amount had increased by more than double. The ratio of fixed liability and fixed assets turnover was found to have a significant positive (+) effect on management performance in the years 2012-2014. Conclusions : Based on these results, this study suggests a more in-depth analysis using fixed liabilities and fixed assets.

• The Journal of Asian Finance, Economics and Business
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• 제8권10호
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• pp.219-228
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• 2021

The study examines the behavior of stock prices after large price changes. It further examines the effect of firm size on stock returns, and the presence of the disposition effect. The study employs the event study methodology using daily price data from Pakistan Stock Exchange (PSX) for the period January 2001 to July 2012. Furthermore, to examine the factors that explain stock price behavior after large price movements, the study employs a two-way fixed-effect model that allows for the analysis of unobservable company and time fixed effects that explain market reversals or continuation. The findings suggest that winners perform better than losers after experiencing large price shocks thus showing a momentum behavior. In addition, the winners remain the winner, while the losers continue to lose more. This suggests that most of the investors in PSX behave rationally. Further, the study finds no evidence of disposition effect in PSX. The investors underreact to new information and the prices continue to move in the direction of initial change. The pooled regression estimates show that firm size is positively related to post-event abnormal returns while the fixed-effect model reveals the presence of unobservable firm-specific and time-specific effects that account for price continuation.