• Title/Summary/Keyword: 비선형 다중회귀분석

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Prediction and analysis of acute fish toxicity of pesticides to the rainbow trout using 2D-QSAR (2D-QSAR방법을 이용한 농약류의 무지개 송어 급성 어독성 분석 및 예측)

  • Song, In-Sik;Cha, Ji-Young;Lee, Sung-Kwang
    • Analytical Science and Technology
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    • v.24 no.6
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    • pp.544-555
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    • 2011
  • The acute toxicity in the rainbow trout (Oncorhynchus mykiss) was analyzed and predicted using quantitative structure-activity relationships (QSAR). The aquatic toxicity, 96h $LC_{50}$ (median lethal concentration) of 275 organic pesticides, was obtained from EU-funded project DEMETRA. Prediction models were derived from 558 2D molecular descriptors, calculated in PreADMET. The linear (multiple linear regression) and nonlinear (support vector machine and artificial neural network) learning methods were optimized by taking into account the statistical parameters between the experimental and predicted p$LC_{50}$. After preprocessing, population based forward selection were used to select the best subsets of descriptors in the learning methods including 5-fold cross-validation procedure. The support vector machine model was used as the best model ($R^2_{CV}$=0.677, RMSECV=0.887, MSECV=0.674) and also correctly classified 87% for the training set according to EU regulation criteria. The MLR model could describe the structural characteristics of toxic chemicals and interaction with lipid membrane of fish. All the developed models were validated by 5 fold cross-validation and Y-scrambling test.

Influence Factors of Typical Real Estate Development Projects (부동산 개발사업의 유형별 투자결정요인 분석)

  • Lee, Taek-Soo;Lee, Joo-Hyung
    • The Journal of the Korea Contents Association
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    • v.13 no.1
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    • pp.456-466
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    • 2013
  • The most important thing to develop real estate asset would be a feasibility study. To secure feasibility of development projects, reducing and minimizing the cost of land and construction also would be the important thing. To analyze optimal land-value for real estate development projects, I have collected 204 balance sheets of development projects in South Korea. With the help of statistical technology, I could have selected useful data from those balance sheets. After detailed analysis of statistical data, I could have reached conclusion that the most important factor to earning rate would be land cost per unit ground area under the constraint of given sale price. So far the main pattern of feasibility study of development projects was land cost and construction cost. However, by this study, I have found a new fact that construction cost has little effect to earning rate and land cost per unit ground area is the most effect to earning rate especially in residential facilities rather than commercial ones.

The Effects of the Dietary Lifestyle and Demographic Characteristics on the Brand Image of Restaurants with Nutritional Labeling (식생활라이프스타일과 인구통계적 특성이 외식영양표시 외식업체의 브랜드 이미지에 미치는 영향)

  • Kim, Na-Hyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.6
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    • pp.548-556
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    • 2019
  • The purpose of this study is to analyze the impact of dietary lifestyles and demographic characteristics on the Brand image of restaurants with Nutritional labeling to provide basic marketing data for establishing differentiated Brand image strategies for restaurant businesses. To that end, the SPSS21.0 (ver.) program, frequency analysis, descriptive statistics, factor analysis, reliability analysis, correlation analysis, and multiple linear regression analysis were conducted to verify the hypothesis. As a result, the Brand image of restaurants with Nutritional labeling improved as the metropolitan area sought safety, non-capital area sought taste, males sought health, and females sought safety. In terms of age, it was analyzed that as more people in their 20s sought taste, those their 30s and 40s sought safety, and both married and unmarried people sought safety, the Brand image of restaurants with Nutritional labeling improved. In other words, it could be seen that people with Dietary lifestyles who pursued health and safety had positive images of restaurants with Nutritional labeling regardless of residential area, age, gender, marital status, or whether they had children.

Distribution Behavior of Ni between CaO-SiO2-Al2O3-MgO Slag and Cu-Ni Alloy (CaO-SiO2-Al2O3-MgO 슬래그와 Cu-Ni합금 사이의 Ni 분배거동)

  • Han, Bo-Ram;Sohn, Ho-Sang
    • Resources Recycling
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    • v.24 no.1
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    • pp.35-42
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    • 2015
  • To obtain the fundamental information on the dissolution of nickel into the slag in the pyrometallurgical processes for treatment of wasted PCB, the distribution ratios of nickel between CaO-$SiO_2-Al_2O_3$-MgO slag and copper-5 wt%Ni alloy were measured at 1623 K to 1823 K under a controlled $CO_2$-CO atmosphere. The distribution ratio of Ni increased linearly with increasing oxygen partial pressure. Therefore, the dissolution reaction of nickel into the slags could be described by the following equation; $$Ni(l)_{metal}+\frac{1}{2}O_2(g)NiO(l)_{slag}$$ The distribution ratio of Ni increased linearly with increasing content of basic oxides(CaO and MgO) in slag. However, the distribution ratio of Ni decreased linearly with increasing temperature. From these results, the empirical equation of distribution ratio of Ni was obtained by the following equation from the analysis of experimental conditions by multiple regression. $${\log}L_{Ni}=0.4000{\log}P_{O2}-5.1{\times}10^{-4}T+0.3375\(\frac{X_{CaO}+X_{MgO}}{X_{SiO2}}\)$$

Cost Prediction Models in the Early Stage of the Roadway Planning and Designbased on Limited Available Information (가용정보를 활용한 기획 및 설계초기 단계의 도로 공사비 예측모델)

  • Kwak, Soo-Nam;Kim, Du-Yon;Kim, Byoung-Il;Choi, Seok-Jin;Han, Seung-Heon
    • Korean Journal of Construction Engineering and Management
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    • v.10 no.4
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    • pp.87-100
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    • 2009
  • The quality of early cost estimates is critical to the feasibility analysis and budget allocation decisions for public capital projects. Various researches have been attempted to develop cost prediction models in the early stage of a construction project. However, existing studies are limited on its applicability to actual projects because they focus primarily on a specific phase as well as utilize restricted information while the amount of information collectable differs from one another along with the project stages. This research aims to develop two-staged cost estimation model for the schematic planning and preliminary design process of a construction projects, considering the available information of each phase. In the schematic planning stage where outlined information of a project is only available, the Case-Based Reasoning model is used for easy and rapid elicitation of a project cost based on the extensive database of more than 90 actual highway construction projects. Then, the representing quantity-based model is proposed for the preliminary design stage where more information on the quantities and unit costs are collectable based on the alternative routes and cross-sections of a highway project. Real case studies are used to demonstrate and validate the benefits of the proposed approach. Through the two-stage cost estimation system, users are able to hold a timely prospect to presume the final cost within the budge such that feasibility study as well as budget allocation decisions are made on effectively and competitively.

The Interaction of High Sensitivity C-Reactive Protein and Uric Acid on Obesity in Koreans: Based on the Seventh Korea National Health and Nutrition Examination Survey (KNHANES VII, 2016~2018) (대한민국에서 비만에 대한 고감도 C-반응성 단백과 요산의 상호작용: 제7기 국민건강영양조사를 이용해서(KNHANES VII, 2016~2018))

  • Pyo, Sang Shin
    • Korean Journal of Clinical Laboratory Science
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    • v.53 no.4
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    • pp.342-352
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    • 2021
  • We used data from the 7th Korea National Health and Nutrition Examination Survey (KNHANES) (2016~2018) to investigate an association between high sensitivity C-reactive protein (hsCRP) and uric acid in the obese. Obesity was defined as a body mass index (BMI) of 25 kg/m2 or more, severe obesity as a BMI of 30 kg/m2 or more, and morbid obesity as a BMI of 35 kg/m2 or more. In the complex samples multiple logistic regression, despite adjustment by adding major risk factors, the odds ratio (OR) for obesity was higher in the group with high levels of both, hsCRP and uric acid than the reference group at all stages (obesity, OR 1.89, P<0.001 vs. severe obesity, OR 5.04, P<0.001 vs. morbid obesity, OR 8.20, P<0.001). The association between hsCRP and uric acid in obese patients increased from 1.89 to 8.20 as the obesity level increased, suggesting that participants with increased BMI were significantly affected by hsCRP and uric acid. Moreover, the interaction between hsCRP and uric acid was statistically significant even in the model corrected for major confounding factors (P for interaction=0.009).

Study Health Promoting Lifestyle on Depression, Stress and Self-esteem of North Korean Adolescents Refugees (북한이탈청소년의 우울, 스트레스 및 자아존중감에 따른 건강증진생활 연구)

  • Lee, Ju Hyun;Kim, Min Ji;Park, Hyunchun;Yu, Shi-Eun;Noh, Jin-Won
    • The Journal of the Korea Contents Association
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    • v.15 no.3
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    • pp.160-167
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    • 2015
  • This study is to investigate the relationship between health promoting lifestyles around the psychosocial aspects such as depression, stress and self-esteem of young North Korean defectors. In particular, the purpose is mentally still less of a mature compared to adults, adolescents need greater understanding. For this purpose, North Korean Youth 150 people were surveyed, questionnaires 85 parts were used in the final analysis excluded from the additional 65. To analyze the factors affecting the health of life was performed multiple linear regression. Analysis result, general self, school self, stress had significant influence on health promoting lifestyles. The conclusion of this study is social psychology factors such as stress self-esteem of North Korean Adolescents refugees is addressed health promoting lifestyles and causal relationship, and promote health of adolescents shows wonderful self-esteem. It suggests that the necessary establishment. This effort is called for to reliably establish the North Korean youth to be part of a future South Korean society.

Corporate Default Prediction Model Using Deep Learning Time Series Algorithm, RNN and LSTM (딥러닝 시계열 알고리즘 적용한 기업부도예측모형 유용성 검증)

  • Cha, Sungjae;Kang, Jungseok
    • Journal of Intelligence and Information Systems
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    • v.24 no.4
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    • pp.1-32
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    • 2018
  • In addition to stakeholders including managers, employees, creditors, and investors of bankrupt companies, corporate defaults have a ripple effect on the local and national economy. Before the Asian financial crisis, the Korean government only analyzed SMEs and tried to improve the forecasting power of a default prediction model, rather than developing various corporate default models. As a result, even large corporations called 'chaebol enterprises' become bankrupt. Even after that, the analysis of past corporate defaults has been focused on specific variables, and when the government restructured immediately after the global financial crisis, they only focused on certain main variables such as 'debt ratio'. A multifaceted study of corporate default prediction models is essential to ensure diverse interests, to avoid situations like the 'Lehman Brothers Case' of the global financial crisis, to avoid total collapse in a single moment. The key variables used in corporate defaults vary over time. This is confirmed by Beaver (1967, 1968) and Altman's (1968) analysis that Deakins'(1972) study shows that the major factors affecting corporate failure have changed. In Grice's (2001) study, the importance of predictive variables was also found through Zmijewski's (1984) and Ohlson's (1980) models. However, the studies that have been carried out in the past use static models. Most of them do not consider the changes that occur in the course of time. Therefore, in order to construct consistent prediction models, it is necessary to compensate the time-dependent bias by means of a time series analysis algorithm reflecting dynamic change. Based on the global financial crisis, which has had a significant impact on Korea, this study is conducted using 10 years of annual corporate data from 2000 to 2009. Data are divided into training data, validation data, and test data respectively, and are divided into 7, 2, and 1 years respectively. In order to construct a consistent bankruptcy model in the flow of time change, we first train a time series deep learning algorithm model using the data before the financial crisis (2000~2006). The parameter tuning of the existing model and the deep learning time series algorithm is conducted with validation data including the financial crisis period (2007~2008). As a result, we construct a model that shows similar pattern to the results of the learning data and shows excellent prediction power. After that, each bankruptcy prediction model is restructured by integrating the learning data and validation data again (2000 ~ 2008), applying the optimal parameters as in the previous validation. Finally, each corporate default prediction model is evaluated and compared using test data (2009) based on the trained models over nine years. Then, the usefulness of the corporate default prediction model based on the deep learning time series algorithm is proved. In addition, by adding the Lasso regression analysis to the existing methods (multiple discriminant analysis, logit model) which select the variables, it is proved that the deep learning time series algorithm model based on the three bundles of variables is useful for robust corporate default prediction. The definition of bankruptcy used is the same as that of Lee (2015). Independent variables include financial information such as financial ratios used in previous studies. Multivariate discriminant analysis, logit model, and Lasso regression model are used to select the optimal variable group. The influence of the Multivariate discriminant analysis model proposed by Altman (1968), the Logit model proposed by Ohlson (1980), the non-time series machine learning algorithms, and the deep learning time series algorithms are compared. In the case of corporate data, there are limitations of 'nonlinear variables', 'multi-collinearity' of variables, and 'lack of data'. While the logit model is nonlinear, the Lasso regression model solves the multi-collinearity problem, and the deep learning time series algorithm using the variable data generation method complements the lack of data. Big Data Technology, a leading technology in the future, is moving from simple human analysis, to automated AI analysis, and finally towards future intertwined AI applications. Although the study of the corporate default prediction model using the time series algorithm is still in its early stages, deep learning algorithm is much faster than regression analysis at corporate default prediction modeling. Also, it is more effective on prediction power. Through the Fourth Industrial Revolution, the current government and other overseas governments are working hard to integrate the system in everyday life of their nation and society. Yet the field of deep learning time series research for the financial industry is still insufficient. This is an initial study on deep learning time series algorithm analysis of corporate defaults. Therefore it is hoped that it will be used as a comparative analysis data for non-specialists who start a study combining financial data and deep learning time series algorithm.

Usefulness of $^{201}Tl$ Myocardial Perfusion SPECT in Prediction of Left Ventricular Remodeling following an Acute Myocardial Infarction (급성심근경색 후 발생하는 좌심실 재구도 예측에 대한 $^{201}Tl$ 심근관류 SPECT의 운용성)

  • Yoon, Seok-Nam;Park, C.H.;Hwang, Kyung-Hoon
    • The Korean Journal of Nuclear Medicine
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    • v.34 no.1
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    • pp.30-38
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    • 2000
  • Purpose: We investigated the role of myocardial perfusion SPECT in prediction of ventricular dilatation and the role of revascularization including thrombolytic therapy and PTCA in prevention of ventricular dilatation after an acute myocardial infarction (AMI). Materials and Methods: We performed dipyridamole stress, 4 hour redistribution, and 24 hour reinjection Tl-201 SPECT in 16 patients with AMI two to nine days after attack. Perfusion and wall motion abnormalities were quantified by perfusion index (PI) and wall motion index (WMI). Left ventricular ejection fraction (LVEF), WMI and ventricular volume were measured within 1 week of AMI and after average of 6 months. According to serial changes of left ventricular end-diastolic volume (LVEDV), patients were divided into two groups. We compared WMI, PI and LVEF between the two groups. Relationships among degree of volume, stress-rest PI, WMI, CKMB, Q wave, LVEF and revascularization were analysed using multivariate analysis. Results: Only initial rest perfusion index was significantly different between the two groups (p<0.05). While initial LVEF, stress PI, CKMB, trial of revascularization procedure, presence of Q wave and WMI were not significantly different between the two groups. Eight of 16 patients (50%) showed LV dilatation on follow-up echocardiography. Three of 3 patients (100%) who did not undergo revascualrization procedure documented LV dilatation. And only 5 (38%) of the remaining 13 patients who underwent revascularization revealed LV dilatation. There was no difference in infarct location between the two groups. By multivariate linear regression analysis in patients only undergoing revascularization, rest perfusion index was the only significant factor. Conclusion: Myocardial perfusion SPECT performed prior to revascularization was useful in prediction of LV dilatation after an AMI. Rest perfusion index on myocardial perfusion plays as a significant predictor of left ventricular dilatation after AMI. And revascularization appears to be a valuable procedure in alleviating LV dilatation after AMI with or without viable myocardium in a limited number of patients studied retrospectively.

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The Relationship between Physical Characteristics and Walking Ability in Elderly: A Cross-Sectional Study (노인들의 보행 능력과 신체적인 특성 간의 상관관계: 단면 연구)

  • Park, Mi-Hee;Park, Hyun-Ju;Oh, Duck-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.6
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    • pp.2664-2671
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    • 2012
  • This study aimed to investigate the relationship between physical characteristics and walking ability in the elderly population. Subjects were 77 elderly (38 men and 39 women) who are capable of walking independently with and without walking aids. Correlation and stepwise multiple linear regression analyses were used to analyze the relationship between physical characteristics (age, gender, height, weight, body mass index, muscle mass, waist/hip ratio, heart rate, vital capacity, flexibility, maximum oxygen consumption, one-leg standing time, and strength of knee flexor and extensor) and walking velocity of subjects. Age, height, vital capacity, one-leg standing time, and strength of knee flexor and extensor showed significant correlations with walking velocity of subjects (p<.05). Further, the strength of knee flexor explained 27% of the variance, and up to 32% of the walking velocity could be explained when the strength of knee extensor were added to the model. The findings suggest that walking velocity of elderly depends on the strength of lower limb's strength and a variety of physical characteristics.