• 응용통계연구
• /
• 제18권2호
• /
• pp.435-443
• /
• 2005

로지스틱 회귀모형에서 결정계수는 선형 회귀모형보다 다양하게 정의되며 그 값들도 매우 작아 로지스틱 회귀모형 평가기준으로 사용되는 통계량이 라고 할 수 없다. Liao와 McGee(2003)는 부적절한 설명변수의 추가 또는 표본크기의 변화에 민감하지 않은 두 종류의 수정 결정계수를 제안하였다. 본 연구에서는 실제자료에 적용한 로지스틱 회귀모형에서 수정 결정계수를 포함한 네 종류의 결정계수들을 변수선택의 기준으로 사용하여 기존의 변수선택 방법인 전진선택, 후진제거, 단계적 선택방법, AIC 통계량 등을 사용한 방법들과 비교하여 그 적절함과 효율성을 토론한다.

• Journal of the Korean Data and Information Science Society
• /
• 제22권4호
• /
• pp.691-699
• /
• 2011

현재까지 우리나라뿐만 아니라 세계적으로 급경사지 붕괴는 대표적인 자연재해로 알려져 있다. 급경사지 붕괴 피해를 방지하기 위해 행해진 많은 선행 연구를 바탕으로 일부 국내기관에서는 급경사지 평가표를 만들어 붕괴 예측에 활용하고 있다. 하지만, 대부분의 기존 연구는 비통계전문가들에 의해 행해졌기 때문에 평가표 구성의 통계적 타당성을 제시하지 못했다. 본 연구는 전국 지역을 대상으로 급경사지 (암반사면, 토사사면) 붕괴에 영향을 미칠 것으로 예상되는 인자들의 자료를 수집하고 그 인자들의 가중치를 판정하기 위하여 로지스틱 회귀분석 방법을 사용하였다. 선행연구들 중에 로지스틱 회귀분석을 이용한 기존의 연구들이 있었지만 다중공선성을 전혀 고려하지 않았기 때문에 결과가 신뢰할 만하지 못하다. 본 연구에서는 다중공선성을 제거된 급경사지 붕괴 예측모형을 제시하였다.

• The Journal of Korean Physical Therapy
• /
• 제25권5호
• /
• pp.330-336
• /
• 2013

Purpose: Respiratory is an essential vital component for conservation of life in human, which is controlled by respiratory muscles and its related neuromuscular regulation. The purpose of this study is to assess lung capacity and respiratory pressure in healthy children, and to investigate relationship and predictability between respiratory pressure and other related respiratory functions. Methods: A total of 31 healthy children were recruited for this study. Demographic information and respiratory related factors were assessed in terms of body surface area (BSA), chest mobility, lung capacity, and respiratory pressure. Correlation between respiratory pressure and the rested variables was analyzed, and multiple regression using the stepwise method was performed for prediction of respiratory muscle strength, in terms of respiratory pressure as the dependent variable, and demographic and other respiratory variables as the independent variable. Results: According to the results of correlation analysis, respiratory pressure showed significant correlation with age (r=0.62, p<0.01), BSA (r=0.80, p<0.01), FVC (r=0.80, p<0.01), and FEV1 (r=0.70, p<0.01). In results of multiple regression analysis using the backward elimination method, BSA and FVC were included as significant factors of the predictable statistical model. The statistical model showed a significant explanation power of 71.8%. Conclusion: These findings suggest that respiratory pressure could be a valuable measurement tool for evaluation of respiratory function, because of significant relationship with physical characteristics and lung capacity, and that BSA and FVC could be possible predictable factors to explain the degree of respiratory pressure. These findings will provide useful information for clinical assessment and treatment in healthy children as well as those with pulmonary disease.

• 대한지역사회영양학회지
• /
• 제18권4호
• /
• pp.312-323
• /
• 2013

Variables affecting bone heath of growing children were analyzed among forty nine 10-12 year old elementary students in three rural regions of north west Chungnam area. Information on age of the parents, duration of breast feeding and birth weight were collected from the guardians of the participants and nutrient intake and diet quality were assessed by average of three-day food records of participants with the help of dietitians. Bone health status was measured by calceneal broadband ultrasound attenuation (BUA) using quantitative ultrasound (QUS). Results showed that anthropometic indexes and nutrient intake levels were not different between boys and girls. However, iron intake was significantly lower in girls than in boys. Girls after menarche showed lower intake levels for thiamin, riboflavin, pyridoxine and niacin than girls before menarche. z-scores of BMI were lower than -1 and higher than +1 showed shorter breast feeding period than others but the difference was statistically non-significant. Overall, the subjects did not consume enough s of calcium, vitamin C and folic acid. Zinc intake and BMI were the most significant factors affecting BUA by the results of backward elimination in multiple regression models. Phosphorous and beta-carotene intakes showed significant negative relation with BUA. This study showed that children living in the rural area of Chungnam need extra care to keep their health and nutrient intakes especially for the nutrients known to affect growth. Tailored nutrition education needs to be more focused on the improvement of bone health status of children.

• 사상체질의학회지
• /
• 제19권1호
• /
• pp.98-115
• /
• 2007

1. Objectives This study focuses on the Validity of the Questionnaire about Sasang Constitution Classification for Mongolians 2. Methods By using the way of backward elimination, certain variables are chosen from the 438 cases whose physical conditions are absolutely diagnosed. After that, discriminant analysis for the selected variables has been done to obtain the physical constitution equation and the accuracy ratio of diagnosis which are useful for physical constitution diagnosis. 3. Results and Conclusions (1) In tile Validity for the Questionnaire of Sasang Constitution Classification for Mongolians, the accuracy ratio of diagnosis of Taeyangin is 100%, Soyangin 62.5%, Taeumin 76.7%, and Soeumin 66.1% respectively as a result of the discriminant analysis employing Cronbach's alpha coefficient. On the whole, the accuracy ratio of diagnosis is 70.1%. (2). In the Validity for the Questionnaire of Sasang Constitution Classification for Mongolians, the accuracy ratio of diagnosis of 70.1% means that it beats the maximum chance criterion of 41.4% and the proportional chance criterion of 34.4% by 28.7% and 35.7% respectively. Conclusively, this questionnaire has discriminant power.

• 한국산학기술학회논문지
• /
• 제21권9호
• /
• pp.373-379
• /
• 2020

본 연구는 소고기 소비자를 대상으로 2012년과 2019년 조사결과를 비교함으로써 소비자 소비성향 변화와 숙성육에 대한 인식에 영향을 미치는 요인에 대해 알아보고자 수행하였다. 육색 및 지방색, 신선도, 등급표시, 브랜드 여부의 품질판단기준과 풍미, 다즙성, 연도, 숙성기간, 마블링의 맛 결정요인, 그리고 근내지방이 건강에 해롭다는 인식에 대한 중요도를 후진소거법을 통한 회귀분석을 이용하여 분석하였다. 분석결과 품질판단기준의 신선도와 맛 결정요인의 다즙성, 연도, 숙성기간, 근내지방이 건강에 해롭다는 인식의 중요도는 증가한 것으로 분석되었다. 한편, 숙성육 구입의향 분석 결과 숙성육 구입의향에는 숙성육 인지여부, 숙성육에 대한 호감도, 신선도, 연도, 숙성기간이 영향을 미치는 것으로 분석되었다. 본 연구는 이러한 소비자 선호 변화에 대응하기 위해 소비자의 소비성향이 어떻게 변화하였는지를 분석하여 소고기 소비성향 및 소비의향 연구의 기초자료를 수집하고, 숙성육 인식에 어떠한 요인이 영향을 미치는지 분석하였다. 이를 통해 향후 소비자 선호의 다변화에 대응하고, 합리적인 생산 및 소비활동에의 반영을 위해 숙성육에 대한 인식을 제고할 필요성이 있을 것으로 여겨진다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제44권4호
• /
• pp.174-181
• /
• 2018

Objectives: The number of patients with medication-related osteonecrosis of the jaw (MRONJ) is increasing, but treatment remains controversial. Published papers and systematic reviews have suggested that surgical treatment is effective in patients with MRONJ. The purpose of this study was to determine whether preoperative University of Connecticut Osteonecrosis Numerical Scale (UCONNS), other serologic biomarkers, and size of necrosis are prognostic factors for outcome of surgical treatment in MRONJ. Materials and Methods: From January 2008 to December 2016, 65 patients diagnosed with MRONJ at the Department of Oral and Maxillofacial Surgery in College of Dentistry, Dankook University who required hospitalization and surgical treatment were investigated. Patient information, systemic factors, and UCONNS were investigated. In addition, several serologic values were examined through blood tests one week before surgery. The size of osteolysis was measured by panoramic view and cone-beam computed tomography in all patients. With this information, multivariate logistic regression analysis with backward elimination was used to examine factors affecting postoperative outcome. Results: In multivariate logistic analysis, higher UCONNS, higher C-reactive protein (CRP), larger size of osteolysis, and lower serum alkaline phosphate were associated with higher incidence of incomplete recovery after operation. This shows that UCONNS, CRP, serum alkaline phosphate, and size of osteolysis were statistically significant as factors for predicting postoperative prognosis. Conclusion: This study demonstrated that CRP, UCONNS, serum alkaline phosphate, and size of osteolysis were statistically significant factors in predicting the prognosis of surgical outcome of MRONJ. Among these factors, UCONNS can predict the prognosis of MRONJ surgery as a scale that includes various influencing factors, and UCONNS should be used first as a predictor. More aggressive surgical treatment and more definite surgical margins are needed when the prognosis is poor.

• 한국수산경영학회:학술대회논문집
• /
• 한국수산경영학회 2007년도 추계학술발표회 및 심포지엄
• /
• pp.167-184
• /
• 2007

The objectives of this paper are to identify the causes of the corporate distress and to develop a distress prediction model with the financial information in fishery industry. In this study, the corporate distress is defined as economic failure and technical insolvency. Economic failure occurs by reduction, shut-down, or change of the business and technical insolvency results from failure to pay the financial debt of companies. The 33 distressed firms from 1991 to 2003 were composed by 14 economic failure companies, 15 technical insolvency companies. 4 companies applied to the both cases. The analysis of distress prediction of fishery companies were accomplished according to the distress definition. The analysis was carried out as two steps. The first step was the univariate analysis, which was used for checking the prediction power of individual financial variable. The t-test is used to identify the differences in financial variables between the distressed group and the non-distressed group. The second step was to develop distress prediction model with logistic regression. The variables showed the significant difference in univariate analysis were selected as the prediction variables. The financial ratios, used in the logistic regression model, were selected by backward elimination method. To test stability of the distress prediction model, the whole sample was divided as three sub-samples, period 1(1990$\sim$1993), period 2(1994$\sim$1997), period 3(1998$\sim$2002). The final model built from whole sample appled each three sub-samples. The results of the logistic analysis were as follows. the growth, profitability, stability ratios showed the significant effect on the distress. the some different result was found in the sub-sample (economic failure and technical insolvency). The growth and the profitability were important to predict the economic failure. The profitability and the activity were important to predict technical insolvency. It means that profitability is the really important factor to the fishery companies.

• 수산경영론집
• /
• 제39권2호
• /
• pp.61-79
• /
• 2008

The objectives of this paper are to identify the causes of the corporate distress and to develop a distress prediction model with the financial information in fishery industry. In this study, the corporate distress is defined as economic failure and technical insolvency. Economic failure occurs by reduction, shut - down, or change of the business and technical insolvency results from failure to pay the financial debt of companies. The 33 distressed firms from 1991 to 2003 were composed by 14 economic failure companies, 15 technical insolvency companies. 4 companies applied to the both cases. The analysis of distress prediction of fishery companies were accomplished according to the distress definition. The analysis was carried out as two steps. The first step was the univariate analysis, which was used for checking the prediction power of individual financial variable. The t - test is used to identify the differences in financial variables between the distressed group and the non - distressed group. The second step was to develop distress prediction model with logistic regression. The variables showed the significant difference in univariate analysis were selected as the prediction variables. The financial ratios, used in the logistic regression model, were selected by backward elimination method. To test stability of the distress prediction model, the whole sample was divided as three sub-samples, period 1(1990 - 1993), period 2(1994 - 1997), period 3(1998 - 2002). The final model built from whole sample appled each three sub - samples. The results of the logistic analysis were as follows. the growth, profitability, stability ratios showed the significant effect on the distress. the some different result was found in the sub - sample (economic failure and technical insolvency). The growth and the profitability were important to predict the economic failure. The profitability and the activity were important to predict technical insolvency. It means that profitability is the really important factor to the fishery companies.

• 한국학교ㆍ지역보건교육학회지
• /
• 제21권1호
• /
• pp.61-74
• /
• 2020

Objectives: This study aims to examine hypertension patients' quality of life by using the data of the 7^th Korea National Health and Nutrition Examination Survey (1^st year, 2016), identify the factors related to this, and utilize the results as basic data for intervention that can improve hypertension patients' quality of life. Methods: For the research subjects, this study extracted 1,531 patients who were diagnosed with hypertension by a doctor from the total sample of 8,150 participants of the 7^th Korea National Health and Nutrition Examination Survey, and selected 1,072 patients with no missing value in the variables to be analyzed as the final research subjects. The SPSS(version25.0) program was used for the analysis of the collected data. Then, this study used a backward elimination multiple regression analysis method that applied complex sample, to examine the factors related with the finally estimated quality of life. Results: The results of this study revealed that hypertension patients' quality of life was related with age, occupation, spouse, household income, weight gain, restriction of activity, subjected health status, perceived stress, and presence of comorbidity. The final model explained 37.0% of the variance (Wald F=30.012 p<.001). Conclusions: When an intervention program is implemented for the improvement of hypertension patients' quality of life in the future, it will be effective to construct the program according to age group, employment, marital status and household income. As for the program operation, patients should get help therefrom to control weight, facilitate activities and relieve their stress, and they should be also motivated to feel healthy. Furthermore, education should be offered so that they appropriately manage their underlying disease at an early stage.