• Journal of Korean Neurosurgical Society
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• 제56권4호
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• pp.334-337
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• 2014

Objective : The purpose of this study is to identify the risk factors associated with the development of germinal matrix-intraventricular hemorrhage (GM-IVH) and the relationship of the severity of disease and prematurity. Methods : A total of 168 premature neonates whose birth weight ${\leq}1500g$ or gestational age ${\leq}34$ weeks were examined by cranial ultrasound (CUS) for detection of GM-IVH among the babies admitted between January 2011 and December 2012 in our medical center neonatal intensive care unit. The babies were divided into two groups : GM-IVH and non-IVH. Clinical presentations, precipitating factors of the patients and maternal factors were analyzed. Results : In univariate analysis, gestational age, birth weight, delivery method, presence of premature rupture of membrane (PROM) and level of sodium and glucose were statistically meaningful factors (p<0.05). But only two factors, gestational age and presence of patent ductus arteriosus (PDA) were statistically meaningful in multivariate logistic regression (p<0.05). Delivery method [normal vaginal delivery (NVD) to Caeserean section] was borderline significant (p<0.10). Conclusion : Presence of PDA and gestational age were the important risk factors associated with development of GM-IVH.

• 산업경영시스템학회지
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• 제42권1호
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• pp.106-114
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• 2019

Recently, the manufacturing process system in the industrial field has become more and more complex and has been influenced by many and various factors. Moreover, these factors have the dependent correlation rather than independent of each other. Therefore, the statistical analysis has been extended from the univariate method to the multivariate method. The process capability indices have been widely used as statistical tools to assess the manufacturing process performance. Especially, the multivariate process indices need to be enhanced with more useful information and extensive application in the recent industrial fields. The various multivariate process capability indices have been studying by many researchers in recent years. Hence, the purpose of the study is to compare the useful and various multivariate process capability indices through the simulation. Among them, we compare the useful models of several multivariate process capability indices such as $MC_{pm}$, $MC^+_{pm}$ and $MC_{pl}$. These multivariate process capability indices are incorporates both the process variation and the process deviation from target or consider the expected loss caused by the process deviation from target. Through the computational examples, we compare these process capability indices and discuss their usefulness and effectiveness.

• 한국콘텐츠학회논문지
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• 제18권1호
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• pp.623-641
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• 2018

본 연구는 집합적 리더십(collective leadership)의 유효성을 검증하는데 그 목적이 있다. 구체적으로 집합적 리더십이 창의적 행동에 미치는 직접효과와 집합적 리더십과 창의적 행동간 조직기반 자긍심의 간접효과를 검증하고, 이러한 간접효과의 메커니즘이 심리적 안전감에 의해 조절되는 조건부 간접효과를 규명하고자 한다. 본 연구는 동일방법편의(common method bias) 문제점을 최소화하기 위해 직급과 함께 직무상황에서의 정서성(affectivity)을 통제변수로 사용하였다. 회수된 설문지 319부 중 부적절한 자료(univariate outliers) 10부를 제외한 309부가 분석에 사용되었다. 연구결과, 집합적 리더십은 구성원들의 창의적 행동에 정(+)의 영향을 미쳤고, 조직기반 자긍심은 집합적 리더십과 창의적 행동과의 관계에서 부분매개 역할을 하였다. 또한, 심리적 안전감의 조건부 간접효과는 '매우 낮음', '낮음', '중간'의 세 단계를 제외한 '높음', '매우 높음'의 두 단계에서 유의한 것으로 나타났다. 본 연구결과가 함의하는 바는, 조직의 리더들이 집합적 리더십을 통해 구성원의 조직기반 자긍심과 창의적 행동을 촉진하는데 있어 심리적 안전감이 높아야 그 효과성이 커진다는 것이다.

• Korean Journal of Radiology
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• 제22권4호
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• pp.652-662
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• 2021

Objective: To investigate the association between CT imaging features and survival outcomes in patients with primary invasive mucinous adenocarcinoma (IMA). Materials and Methods: Preoperative CT image findings were consecutively evaluated in 317 patients with resected IMA from January 2011 to December 2015. The association between CT features and long-term survival were assessed by univariate analysis. The independent prognostic factors were identified by the multivariate Cox regression analyses. The survival comparison of IMA patients was investigated using the Kaplan-Meier method and propensity scores. Furthermore, the prognostic impact of CT features was assessed based on different imaging subtypes, and the results were adjusted using the Bonferroni method. Results: The median follow-up time was 52.8 months; the 5-year disease-free survival (DFS) and overall survival rates of resected IMAs were 68.5% and 77.6%, respectively. The univariate analyses of all IMA patients demonstrated that 15 CT imaging features, in addition to the clinicopathologic characteristics, significantly correlated with the recurrence or death of IMA patients. The multivariable analysis revealed that five of them, including imaging subtype (p = 0.002), spiculation (p < 0.001), tumor density (p = 0.008), air bronchogram (p < 0.001), emphysema (p < 0.001), and location (p = 0.029) were independent prognostic factors. The subgroup analysis demonstrated that pneumonic-type IMA had a significantly worse prognosis than solitary-type IMA. Moreover, for solitary-type IMAs, the most independent CT imaging biomarkers were air bronchogram and emphysema with an adjusted p value less than 0.05; for pneumonic-type IMA, the tumors with mixed consolidation and ground-glass opacity were associated with a longer DFS (adjusted p = 0.012). Conclusion: CT imaging features characteristic of IMA may provide prognostic information and individual risk assessment in addition to the recognized clinical predictors.

• 유통과학연구
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• 제17권11호
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• pp.73-79
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• 2019

Purpose: The purpose of this study was evaluated to compare the predictive power of distress prediction models by using discriminant analysis method and logit analysis method for food service franchise industry in Korea. Research design, data and methodology: Forty-six food service franchise industry with high sales volume in the 2017 were selected as the sample food service franchise industry for analysis. The fourteen financial ratios for analysis were calculated from the data in the 2017 statement of financial position and income statement of forty-six food service franchise industry in Korea. The fourteen financial ratios were used as sample data and analyzed by t-test. As a result seven statistically significant independent variables were chosen. The analysis method of the distress prediction model was performed by logit analysis and multiple discriminant analysis. Results: The difference between the average value of fourteen financial ratios of forty-six food service franchise industry was tested through t-test in order to extract variables that are classified as top-leveled and failure food service franchise industry among the financial ratios. As a result of the univariate test appears that the variables which differentiate the top-leveled food service franchise industry to failure food service industry are income to stockholders' equity, operating income to sales, current ratio, net income to assets, cash flows from operating activities, growth rate of operating income, and total assets turnover. The statistical significances of the seven financial ratio independent variables were also confirmed by logit analysis and discriminant analysis. Conclusions: The analysis results of the prediction accuracy of each distress prediction model in this study showed that the forecast accuracy of the prediction model by the discriminant analysis method was 84.8% and 89.1% by the logit analysis method, indicating that the logit analysis method has higher distress predictability than the discriminant analysis method. Comparing the previous distress prediction capability, which ranges from 75% to 85% by discriminant analysis and logit analysis, this study's prediction capacity, which is 84.8% in the discriminant analysis, and 89.1% in logit analysis, is found to belong to the range of previous study's prediction capacity range and is considered high number.

• 대한원격탐사학회지
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• 제37권4호
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• pp.777-788
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• 2021

Since aerosol has a relatively short duration and significant spatial variation, satellite observations become more important for the spatially and temporally continuous quantification of aerosol. However, optical remote sensing has the disadvantage that it cannot detect AOD (Aerosol Optical Depth) for the regions covered by clouds or the regions with extremely high concentrations. Such missing values can increase the data uncertainty in the analyses of the Earth's environment. This paper presents a spatial gap-filling framework using a univariate statistical method such as DCT-PLS (Discrete Cosine Transform-based Penalized Least Square Regression) and FMM (Fast Matching Method) inpainting. We conducted a feasibility test for the hourly AOD product from AHI (Advanced Himawari Imager) between January 1 and December 31, 2019, and compared the accuracy statistics of the two spatial gap-filling methods. When the null-pixel area is not very large (null-pixel ratio < 0.6), the validation statistics of DCT-PLS and FMM techniques showed high accuracy of CC=0.988 (MAE=0.020) and CC=0.980 (MAE=0.028), respectively. Together with the AI-based gap-filling method using extra explanatory variables, the DCT-PLS and FMM techniques can be tested for the low-resolution images from the AMI (Advanced Meteorological Imager) of GK2A (Geostationary Korea Multi-purpose Satellite 2A), GEMS (Geostationary Environment Monitoring Spectrometer) and GOCI2 (Geostationary Ocean Color Imager) of GK2B (Geostationary Korea Multi-purpose Satellite 2B) and the high-resolution images from the CAS500 (Compact Advanced Satellite) series soon.

• 동서간호학연구지
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• 제29권2호
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• pp.129-140
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• 2023

Objectives: Suicide rate in South Korea is one of the major public health concerns. This study examined the factors influencing the suicide methods of people who committed suicide in Gyeonggi-do, which accounts for one-fourth of the population of South Korea. Methods: This study analyzed the data of a total of 13,945 suicide deaths in Gyeonggi-do over a five-year period (2016-2020) provided by the Statistics Korea and the influence of social and demographic characteristics on the analyzed suicide methods. The differences in suicide methods according to the social and demographic characteristics of suicide victims were compared and analyzed through chi-squared, and items with significant differences in univariate tests were analyzed by multiple logisitic regression analysis. Results: Among suicide deaths, the most common method of suicide was hanging (52.4%). In particular, women, were employed, and stayed at home were higher risk of being hanged. The second most common method of suicide was leaping (17.7%). Women under the age of 30, those with a college degree or higher, those who were not working, time of death (6-12), and those outside the home were more likely to choose to take the leap. The third most common method of suicide was gas poisoning (15.8%). Young people under the age of 65, college graduates or higher, without a spouse, were employed, and spring season were at increased risk of choosing gas poisoning. Conclusions: The results highlight the need for policies that consider risk factors such as gender, age, education, marital status, employments status, time of suicide, and place of suicide in order to block access to suicide methods for suicide victims in Gyeonggi-do.

• Journal of Trauma and Injury
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• 제24권2호
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• pp.89-94
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• 2011

Purpose: A few studies have assessed the factors affecting the prognoses for major trauma patients and those improving the circumstances when dealing with the trauma system. In that light, we analyzed factors, such as pre-hospital factors, the time to admission, the length of stay in the emergency department (ED) and emergency operation, influencing the outcomes for trauma patients. Methods: The patients who visited our emergency department from April 1, 2009, to February 29, 2011, due to major trauma were enrolled in the study. The inclusion criterion was a revised trauma score (RTS) < 7 or injury severity score (ISS) ${\geq}$ 16. We used reviews of medical records, to analyze each step of emergency medical care with respect to patients' sex, age, visit time and visit date. Continuous variables were described as a median with an interquartile range, and we compared the variables between the survival and the mortality groups by using the Mann-Whitney U test. Fisher's exact test was used for nominal variables. Using the variables that showed statistical significance in univariate comparisons, we performed a logistic regression analysis, and we tested the model's adequacy by the using the Hosmer-Lemeshow method. Results: A total of 261 patients with major trauma satisfied either the RTS score criterion or the ISS score criterion. Excluding 12 patients with missing data, 249 patients were included in this study. The overall mortality rate was 16.9%. Time to ED arrival, time to admission, time of ED stay, RTS, ISS, and visit date being a holiday showed statistically significant differences between the survival and the mortality groups in the univariate analysis. RTS, ISS, length of ED stay, and visit date being a holiday showed statistical significance in the multivariate analysis. Conclusion: The mortality rate did not show a significant relationship with the time to ED arrival, use of 119, on time to admission. Rather, it elicited a quite significant correlation with the trauma scoring system (RTS and ISS), the time of ED stay, and the visit date being a holiday.

• Journal of Hospice and Palliative Care
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• 제8권2호
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• pp.200-208
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• 2005

목적: 악성 위장관 폐색 환자에서 완화적 시술이나 수술은 폐색의 다양한 증상을 조절할 뿐만 아니라 삶의 질을 향상시킨다. 본 연구는 완화적인 시술을 받았던 악성 위장관 폐색 말기암 환자의 임상적 특징과 예후인자를 알아보고자 하였다. 방법: 2002년 5월부터 2005년 5월까지 본원에서 악성 위장관 폐색으로 진단받아 완화적인 시술을 받았던 48명의 말기암 환자를 대상으로 후향적으로 조사하였다. 완화적인 암절제 환자는 제외하였다. 임상적 특성과 시술내용을 조사하였고 예후인자는 log-rank test를 이용한 단변량 분석을 하고 통계적으로 의미 있는 인자는 Cox's proportional hazard model을 사용하여 다변량 분석을 하였다. 결과: 연령의 중앙값은 65세이고 남자가 25명(52%), 여자가 23명(48%)이었다. 가장 많은 암은 대장직장암으로 26명(55%)이고 다음으로 10명(21%)의 위암이었다. 치료를 전혀 받지 않았던 환자는 25명(58%)이었고 20명(42%)은 치료를 받았으며 이 중 18명은 항암 치료를 받은 과거력이 있었다. 가장 흔한 증상은 통증으로 15명(31%)이었다. 활동도 1점 혹은 2점이 23명(48%), 3점 혹은 4점이 25명(52%)이었다. 가장 많은 완화적인 시술은 대장루술로 19명이 받았다. 완화적 시술로 인한 사망은 없었다. 단변량과 다변량 분석에 의해서 전체 생존기간과 무증상 생존기간에 대하여 활동도 만이 의미있는 독립 예후인자였다. 전체 중간 생존기간은 150일이었으며 무증상 중간 생존기간은 90일이었다. 결론: 완화적 시술을 받은 악성 위장관 폐색 환자의 전체 중간 생존기간과 무증상 중간 생존기간에 대하여 활동도만이 유일한 독립 예후인자였다.

• 환경생물
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• 제34권4호
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• pp.365-373
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• 2016

환경생태 자료 분석에 사용된 많은 자료가 시간에 따라 얻어지고 있다. 조사된 시점의 수가 적은 경우에는 자료가 충분한 정보를 주지 않기 때문에 반복 측정하거나 여러 지점을 조사하여 종합적인 분석을 수행하게 된다. 이때 사용하는 방법이 경시적 자료 분석(longitudinal data analysis) 또는 혼합모형(mixed model) 분석이다. 그러나 시점의 수가 많아 정보의 양이 충분하다면 반복적인 자료가 필요하지 않으며 이러한 자료는 시계열 분석 기법을 이용하여 분석하게 된다. 특히 현재와 같이 다수의 시점에서 얻어진 자료의 수가 많아지고 있는 상항에서 각 변수 간에 서로 어떤 영향을 주는지 또는 향후 어떤 경향을 띠게 되는지 예측을 원한다면 시계열 분석 기법을 사용하여 자료를 분석해야 한다. 본 연구에서는 단변량 시계열 분석(univariate time series analysis), 개입 분석(intervention time series model), 전이함수 모형 분석(transfer function model), 다변량 시계열 분석(multivariate time series model) 기법을 소개하고 현재까지 진행된 국내외 연구 논문을 살펴보았다. 또한 향후 환경생태 자료 분석에서 중요하게 사용될 수 있는 오차수정 모형(error correction model)을 소개하였다.