• Journal of Chest Surgery
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• v.26 no.2
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• pp.141-147
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• 1993

A total of 40 patients having a diagnosis of atherosclerotic coronary arterial disease were analysed on the operative outcomes according to variables as follows: 1) preoperative risk factors such as age, sex, CCS (Canadian Cardiovascular Society) functional class, type of angina, number of diseased vessel, presence of left main coronary artery stenosis, previous history of habitual smoking and presence of other medical diseases (diabetes mellitus, essential hypertension), 2) preoperative management such as intravenous infusion of nitroglycerine, preoperative IABP (intra-aortic balloon pump) support and whether the operation was scheduled as emergency or not, 3) intraoperative variables such as infusion method and composition of cardioplegic solutions, number of distal anastomosis, use of internal mammary artery, total cardiopulmonary bypass time and total cross clamp time. Complications included operative death in 12.5％, perioperative myocardial infarction in 25.0％ and perioperative arrhythmia in 17.5％. Nineteen perioperative variables were analyzed to identify risk factors for these end points. For operative death, presence of left main coronary artery stenosis (p = 0.056) and cardiopulmonary bypass time (p = 0.029) were significant in the univariate analysis, but presence of left main coronary artery lesion (p = 0.011, $\chi$$^2$= 6.45) and abscence of preoperative of IABP support (p = 0.069, $\chi$$^2$ = 3.30) were independent predictor in multivariate analysis (stepwise linear logistic regression).

• Clinical and Experimental Pediatrics
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• v.63 no.2
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• pp.48-51
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• 2020

Background: The etiopathogenesis of late preterm (LPT) birth is undetermined. Placental histopathology, which reflects an adverse intrauterine environment and is reportedly associated with preterm labor and neonatal morbidities, has not been studied in LPT infants. Purpose: We investigated placental pathological lesion as markers of an adverse intrauterine environment during LPT labor. Methods: This retrospective case-control study compared placental histopathological and clinical variables between LPT and term neonates. Placental variables included chorioamnionitis, funisitis, hemorrhage, abruption, infarction, calcification, and syncytial knots. Maternal variables included age, substance abuse, pregnancyassociated diabetes mellitus and hypertension, duration of rupture of membrane, antibiotic use, and magnesium sulfate, whereas, those of neonates included gestational age, birth weight, race, sex, and Apgar scores. Standard statistical proedures were applied to analyze the data. Results: Chorioamnionitis (50% vs. 17.8%, P<0.001) and funisitis (20% vs. 4.4%, P=0.002) were more common in term infants. Placental infarction rate was insignificantly higher in LPT infants (25.6% vs. 14.3%, P=0.08). The mothers in the LPT group were older (30.4 years vs. 28.1 years, P=0.05; odds ratio [OR], 1.06; 95% confidence interval [CI], 0.998-1.12, P=0.056) and more often suffered from hypertension (28.9 vs. 12.9 %, P=0.02), and received magnesium sulfate (48.9 vs. 20%, P< 0.001; OR, 2.86; 95% CI, 1.12-7.29, P<0.05). Duration of rupture of membrane was higher in term infants (13.6 hours vs. 9.1 hours, P<0.001). Chorioamnionitis (OR, 0.33; 95% CI, 0.13-0.79; P<0.05) was associated with a lower risk of LPT delivery. Conclusion: Placental infection is not a risk factor for LPT births. There is a nonsignificant predominance of vascular anomalies in LPT placentas. Higher maternal age, magnesium sulfate therapy, and maternal hypertension are clinical risk factors for LPT labor.

• Fire Science and Engineering
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• v.32 no.3
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• pp.76-87
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• 2018

This study describes the damage effects modeling for a quantitative prediction about the hazardous distances from pressurized chlorine saturated liquid tank, which has two-phase leakage. The heavy gas, chlorine is an accidental substance that is used as a raw material and intermediate in chemical plants. Based on the evaluation method for damage prediction and accident effects assessment models, the operating conditions were set as the standard conditions to reveal the optimal variables on an accident due to the leakage of a liquid chlorine storage vessel. A model of the atmospheric diffusion model, ALOHA (V5.4.4) developed by USEPA and NOAA, which is used for a risk assessment of Off-site Risk Assessment (ORA), was used. The Yeosu National Industrial Complex is designated as a model site, which manufactures and handles large quantities of chemical substances. Weather-related variables and process variables for each scenario need to be modelled to derive the characteristics of leakage accidents. The estimated levels of concern (LOC) were calculated based on the Gaussian diffusion model. As a result of ALOHA modeling, the hazardous distance due to chlorine diffusion increased with increasing air temperature and the wind speed decreased and the atmospheric stability was stabilized.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.5 s.142
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• pp.727-736
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• 2005

The purpose of this study was to identify the new fashion brand evaluation attributes influenced by risk perception and its relationship with information search. As for the method of the research, questionnaires were given to 311 consumers who just finished shopping at new fashion brand stores. The results of this study were as follows: 1) New fashion brand evaluation attributes consisted of five factors; product experience attributes, celebrity credence attributes, product search attributes, brand credence attributes, salesperson search attributes. 2) New fashion brand evaluation attributes were found to be significantly influenced by risk perception. 3) The amount of information seeking and the use of information sources were found to be significantly related to the new fashion brand evaluation attributes. 4) The variables influencing on the new fashion brand evaluation attributes were age and monthly clothing expenses.

• Environmental Engineering Research
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• v.13 no.2
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• pp.73-78
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• 2008

For a given soil-contaminated site, a level of soil contamination is characterized and decisions on risk may be made from the risk assessment. The study evaluated critical design factors for the determination of sample size in the sampling design plan and the assessment of soil contaminant- leaching to groundwater. Two variables, the minimum relative detectable difference (T) and coefficient of variation (CV) were evaluated for the sample size determination. The minimum number of samples can be appropriately determined by CV under a T value greater than or equal to 0.2. Soil-contaminant leaching to groundwater was evaluated by using the Soil Screening Level equation of U.S. Environmental Protection Agency and the Risk Based Screening Level equation of American Society for Testing and Materials, with the same input parameters. The groundwater concentrations estimated from soil contaminant concentrations were significantly affected by the Darcy velocity of groundwater and the organic content of soil.

• Korean Journal of Child Studies
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• v.30 no.1
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• pp.11-25
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• 2009

This study aimed to investigate protective factors and risk factors in elementary students' life satisfaction. Participants were 2844 (1524 boys, 1320 girls) children who grades were 4th, 5th, 6th in KYPS (Korea Youth Panel Survey). Data mining decision tree model was performed with sex, appearance, delinquency, family income, attachment to parents, parental monitoring, attachment to teachers, academic achievement, peer delinquency, and attachments to peer. The results revealed that : (1) For 4th graders, academic achievement, attachment to parents, and appearance were significant predictors for life satisfaction. (2) For 5th graders, attachment to parents, academic achievement, parental monitoring and appearance were significant predictors for life satisfaction. (3) For 6th graders, attachment to parents, appearance, parental monitoring and delinquency were significant predictors for life satisfaction. Protective factors and risk factors were changed according to interactions between significant independent variables. These results suggest that children's diverse conditions should be considered individually in programs for children's life satisfaction.

• Journal of Distribution Science
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• v.13 no.2
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• pp.15-24
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• 2015

Purpose - Foreign exchange risk control is in an important component in the international supply chain management. This study shows the importance of the reference period in forecasting future exchange rates with a specific illustration of KIKO currency option contracts, and suggests feasible preventive measures. Research design, data, and methodology - Using monthly Won-Dollar exchange rate data for January 1995~July 2007, I evaluate the statistical characteristics of the exchange rate for two sub-periods; 1) a shorter period after the East Asian financial crisis and 2) a longer period including the financial crisis. The key instrument of analysis is the basic normal distribution theory. Results - The difference in the reference period could lead to an unexpected development in contract implementation and a consequent financial loss. We may avoid foreign exchange loss by using derivatives such as forwards or currency options. Conclusions - We should consider not only level values but also the volatilities of financial variables in making a binding financial contract. Appropriate measures may differ depending on the specific supply chain pattern. We may extend the study with surveys on actual risk measures.

• Journal of Korea Technology Innovation Society
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• v.7 no.3
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• pp.479-505
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• 2004

The purpose of this study is to investigate between CEO's Entrepreneurship in Venture Business and Organizational Effectiveness. CEO's Entrepreneurship variable consist of Innovativeness, Risk-taking and Proactiveness. Organizational effectiveness concept composed of system approach and the contingency theory and it's variable consisted of job satisfaction and organizational commitment. Statistical methods are adapted Frequency, Factor Analysis and CFA(Confirmatory Factor Analysis) of LISREL.8 program. Refined Survey data are 412/Major findings are as follows; Only Proactiveness variable of CEO's entrepreneurship have significant relation to Organizational Effectiveness(job satisfaction and organizational involvement). Innovativeness and Risk taking variables are partially supported to influence to Organizational Effectiveness.

• Communications for Statistical Applications and Methods
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• v.30 no.1
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• pp.1-19
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• 2023

Observational data with missing or incomplete data are common in biomedical research. Multiple imputation is an effective approach to handle missing data with the ability to decrease bias while increasing statistical power and efficiency. In recent years propensity score (PS) matching has been increasingly used in observational studies to estimate treatment effect as it can reduce confounding due to measured baseline covariates. In this paper, we describe in detail approaches to competing risk analysis in the setting of incomplete observational data when using PS matching. First, we used multiple imputation to impute several missing variables simultaneously, then conducted propensity-score matching to match statin-exposed patients with those unexposed. Afterwards, we assessed the effect of statin exposure on the risk of heart failure-related hospitalizations or emergency visits by estimating both relative and absolute effects. Collectively, we provided a general methodological framework to assess treatment effect in incomplete observational data. In addition, we presented a practical approach to produce overall cumulative incidence function (CIF) based on estimates from multiple imputed and PS-matched samples.

• Management & Information Systems Review
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• v.30 no.2
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• pp.1-25
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• 2011

In this study, a survey of online coupon user in their 20's and 30's was undertaken to explore how e-coupon attribute, perceived risk affect the intention to continuously use online coupons through mediation of online coupon user satisfaction. Four variables were used as E-coupon attribute variables(economy, amusement, reliability, usefulness) with coupon type and gender being used as moderating variables. The analysis results of relationship between e-coupon attributes, perceived risk and online coupon user satisfaction indicated that amusement, usefulness significantly affected online coupon user satisfaction, and this, in turn, significantly affected the intention to continuously use online coupons. In addition, the test of difference between groups in coupon type and gender, two moderating variables used in this study, found that with respect to coupon type, a moderating effect existed in reliability, usefulness whereas for gender, a moderating effect existed in only reliability. It is considered that this study will provide a credible evidence basis for Internet shopping malls in establishing a coupon promotion strategy including a specific promotional mix best suited to their needs and resources, while implicating that offering highly reliable online coupons will contribute to enhancing satisfaction level among customers using online coupons.