• Journal of Preventive Medicine and Public Health
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• 제36권1호
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• pp.85-91
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• 2003

Objectives : We investigated the effects of the economic growth and unemployment rates on the suicide rate in Korea, between 1983 and 2000, using a time-series regression model. The purpose of this study was to model and test the magnitude of the rate of suicide, with the Korean unemployment rate and GDP. Methods : Using suicide rate per 100,000 Koreans and the unemployment rates between 1983 and 2000, as published by the Korea National Statistical Office, and the rate of fluctuation of the Korean GDP (Gross Domestic Product), as provided by the Bank of Korea, as an index of the economic growth rate, a time-series regression analysis, with a first-order autoregressive regression model, was peformed. Results : An 81.5% of the variability in the suicide rate was explained by GDP, and 82.6% Of that was explained by the unemployment rate. It was also observed that the GDP negatively correlated with the suicide rate, while the unemployment and suicide rates were positively correlated. For subjects aged over 20, both the GDP and unemployment rate were found to be a significant factors in explaining suicide rates, with coefficients of determination of 86.5 and 87.9%, respectively. For subjects aged under 20, however, only the GDP was found to be a significant factor in explaning suicide rates (the coefficient of determination is 38.4%). Conclusion : It was found that the suicide rate was closely related to the National's economic status of Korea, which is similar to the results found in studies in other countries. We expected, therefore, that this study could be used as the basis for further suicide-related studies.

• 한국전자통신학회논문지
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• 제5권6호
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• pp.637-644
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• 2010

본 연구는 양식장의 수질 환경 인자의 특성을 과학적으로 분석 요약하여 데이터에 의미를 부여하고자 하는 의도와 주기적 교체가 필요한 용존산소 센서에 대한 비용 절감 차원에서 용존 산소 예측을 위한 다중 회귀 모형식을 개발하는데 목적을 두었다. 고흥 거금도에 위치한 두 양식장의 2008.11월~2009.1월 동절기 데이터의 상관성 분석에서 수온은 용존산소와 pH에서는 음의 상관성을 나타냈고 pH는 염도와 용존산소에서 양의 상관성을 나타냈다. 2009년 금호수산 양식장의 수질인자에 대한 월별 통계량 값과 계절별 수질인자 간 차이를 표로 제시하였고 용존산소 예측을 위한 다중회귀 모형식을 개발하여 실제 관측치와 추정치와의 결과를 그래프로 제시하였다. 개발 된 다중 회귀식은 수온이 용존산소에 음의 영향을 주고 pH는 용존산소에 양의 영향을 준다. 또한 수온이 pH에 비해 용존산소 예측에 월등하게 큰 영향을 미치는 걸로 나타났다.

• 한국IT서비스학회지
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• 제6권2호
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• pp.63-80
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• 2007

In this paper, the function factors contributing to ITA/EA functions in their organizations, are suggested. Also the reasons to the construction of IT governance system and their effects on the their organizations are discussed and the relationships are verified by empirical model. From the survey, the data of the 227 respondents were collected and regression analysis was performed for validating the research model. ITA/EA functions consist of the IT infrastructure systemization, ITA/EA business process support, IT investment efficiency factors. And the factors of IT resource and performance management, IT process management, IT service management are included to IT governance. The main analysis results described significantly are shows as follows. At first, IT resource and performance management factor is effected by the ITA/EA business process support factor and IT investment efficiency factor. In similarly, IT service management factor is also affected by the factors such as ITA/EA business process support, IT investment efficiency, and IT infrastructure systemization. In additional analysis, IT investment efficiency factor in official sectors, ITA/EA business process support factor in private sectors respectively are described as the significant factors on the IT governance.

• 대한조선학회지
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• 제26권4호
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• pp.14-26
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• 1989

선박의 추진성능 추정을 위한 통계해석 기법을 연구하고 전산 프로그램을 만들었다. 조파저항계수의 추정식은 조파저항이론을 이용하여 스테이션 별 횡단면적계수의 곱으로 표현되도록 도출해 내었고, 이에 대한 회귀계수는 모형시험 결과를 회귀분석하여 얻었다. 형상계수, 반류비 및 추력감소율의 추정식들은 선체 주요지수, 스테이션 별 횡단면적계수 및 모형시험 결과들을 순순하게 회귀분석하여 얻었다. 통계해석은 여러가지 기술통계와 단계별 회귀분석 기법을 적절하게 이용하여 수행하였다. 추진성능 추정 프로그램은 저항계수, 추진계수, 프로펠러 단독효율 및 각종 척도효과 등을 모두 쉽게 수용할 수 있도록 다양하면서도 간결하게 만들었다.

• 응용통계연구
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• 제24권5호
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• pp.847-859
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• 2011

cDNA microarray-based comparative genomic hybridization(CGH) data includes low-intensity spots and thus a statistical strategy is needed to detect subtle differences between different cancer classes. In this study, genes displaying a high frequency of alteration in one of the different classes were selected among the pre-selected genes that show relatively large variations between genes compared to total variations. Utilizing copy-number changes of the selected genes, this study suggests a statistical approach to predict patients' classes with increased performance by pre-classifying patients with similar genetic alteration scores. Two-stage logistic regression model(TLRM) was suggested to pre-classify homogeneous patients and predict patients' classes for cancer prediction; a decision tree(DT) was combined with logistic regression on the set of informative genes. TLRM was constructed in cDNA microarray-based CGH data from the Cancer Metastasis Research Center(CMRC) at Yonsei University; it predicted the patients' clinical diagnoses with perfect matches (except for one patient among the high-risk and low-risk classified patients where the performance of predictions is critical due to the high sensitivity and specificity requirements for clinical treatments. Accuracy validated by leave-one-out cross-validation(LOOCV) was 83.3% while other classification methods of CART and DT performed as comparisons showed worse performances than TLRM.

• Nuclear Engineering and Technology
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• 제42권2호
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• pp.163-174
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• 2010

As pointed out in the OECD BEMUSE Program, when a high computation time is taken to obtain the relevant output values of a complex physical model (or code), the number of statistical samples that must be evaluated through it is a critical factor for the sampling-based uncertainty analysis. Two alternative methods have been utilized to avoid the problem associated with the size of these statistical samples: one is based on Wilks' formula, which is based on simple random sampling, and the other is based on the conventional nonlinear regression approach. While both approaches provide a useful means for drawing conclusions on the resultant uncertainty with a limited number of code runs, there are also some unique corresponding limitations. For example, a conclusion based on the Wilks' formula can be highly affected by the sampled values themselves, while the conventional regression approach requires an a priori estimate on the functional forms of a regression model. The main objective of this paper is to assess the feasibility of the ACE-RSM approach as a complementary method to the Wilks' formula and the conventional regression-based uncertainty analysis. This feasibility was assessed through a practical application of the ACE-RSM approach to the LOFT L2-5 LBLOCA PCT uncertainty analysis, which was implemented as a part of the OECD BEMUSE Phase III program.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권2호
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• pp.98-103
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• 2016

Purpose: The purpose of this paper is to get a meaningful information for improving manufacturing quality of the products before they are produced in client's manufacturing process. Methods: A variety of data mining techniques have been being used for wide range of industries from process data in manufacturing factories for quality improvement. One application of those is to get meaningful information from process data in manufacturing factories for quality improvement. In this paper, the failure rate at client's manufacturing process is predicted by using the parameters of the characteristics of the product based on PCA (Principle Component Analysis) and regression analysis. Results: Through a case study, we proposed the predicting methodology and regression model. The proposed model is verified through comparing the failure rates of actual data and the estimated value. Conclusion: This study can provide the guidance for predicting the failure rate on the manufacturing process. And the manufacturers can prevent the defects by confirming the factor which affects the failure rate.

• 동력기계공학회지
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• 제13권5호
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• pp.76-81
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• 2009

The fatalities of pedestrian account for about 21.2% of all fatalities at 2007 year in Korea. To reconstruct exactly the accident, it is important to calculate the throw distance of pedestrian in car to pedestrian accident. The frontal shape of SUV vehicle is dissimilar to passenger car and bus, so the trajectory and throw distance of pedestrian by SUV vehicle is not the same of passenger car and bus. The influencing on it can be classified into the factors of vehicle and pedestrian, and road factor. It was analyzed by PC-CRASH for simulation, and SPSS s/w was used for regression analysis. From the simulation results, the maximum impact energy of multi-body of pedestrian was occurred to that of torso body at the same time. And the throw distance increased with the increasing of impact velocity, and decreased with the increasing of impact offset. Also it decreased with the increasing of velocity of pedestrian at accident, and the throw distance of wet road was longer than that of dry road. Finally, the regression analysis model of SUV(Nissan Pathfinder type)vehicle in car to pedestrian accident was as follows; $$disti_i=-0.87-0.11offseti_i+0.69speed_i-4.27height_i+0.004walk_i+0.63wet_i+{\epsilon}_i$$.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2002년도 학술발표회 논문집(II)
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• pp.1334-1339
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• 2002

본 연구는 국내의 중소하천유역의 설계홍수량 산정을 위해 사용되고 있는 Clark 모형의 저류상수륵 실무자들이 쉽게 이용할 수 있도록 하는 데 목적이 있다. 이를 위해 과거의 강우-유출자료와 단위도를 바탕으로 대표단위도를 유도하고, 수문곡선 감수분석 개넘을 이용하여 Clark 모형의 저류상수를 산정하였다. 저류상수(K)는 Clark 방법의 매개변수 중 계획홍수량에 가장 큰 영향을 주는 인자이다. 따라서 본 연구에서는 실측자료가 없는 유역에서의 K값의 산정을 위해 유역면적, 주유로연장, 유역경사를 이용한 다중 회귀방정식을 제시하였다. 회귀분석결과 저류상수(k)는 지형학적 동질성이 있는 유역에서 뛰어난 상관관계를 나타내었으며 이를 이용하여 한강, 낙동강, 영산강, 금강, 섬진강 유역의 K에 대한 회귀분석식을 도출하였다.

• Journal of Preventive Veterinary Medicine
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• 제41권3호
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• pp.129-132
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• 2017

The current study identified risk factors associated with porcine circovirus type 2 (PCV2) infection on pig farms in the Republic of Korea using a multinomial logistic regression model to evaluate the PCV2 infection status of pigs at different growth stages. Compulsory disinfection of visitors (odds ratio [OR]: 0.019, 95% confidence interval [CI]: <0.001-0.378, p=0.0095), compulsory registration of visitors (OR: 0.002, 95% CI: <0.001-0.184, p=0.0070), regular blood testing (OR: 0.012, 95% CI: <0.001-0.157, p=0.0007), and running on-farm biosecurity learning programs for workers (OR: 0.156, 95% CI: 0.040-0.604, p=0.0072 and OR: 0.201, 95% CI: 0.055-0.737, p=0.0155, respectively) were identified as factors which could reduce the risk of PCV2 infection. However, visitation by a regular veterinarian (OR: 32.733, 95% CI: 3.768-284.327, p=0.0016) was associated with PCV2 infection.