• 소성∙가공
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• 제29권5호
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• pp.241-250
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• 2020

In this study, the methodology of the springback prediction of automotive parts applied 3rd generation AHSS was investigated using the response surface model analysis based on a regression model, and the meta model analysis based on a Kriging model. To design the learning data set for constructing the springback prediction models, and the experimental design was conducted at three levels for each processing variable using the definitive screening designs method. The hat-shaped member, which is the basic shape of the member parts, was selected and the springback values were measured for each processing type and processing variable using the finite element analysis. When the nonlinearity of the variables is small during the hat-shaped member forming, the response surface model and the meta model can provide the same processing parameter. However, the accuracy of the springback prediction of the meta model is better than the response surface model. Even in the case of the simple shape parts forming, the springback prediction accuracy of the meta model is better than that of the response surface model, when more variables are considered and the nonlinearity effect of the variables is large. The efficient global optimization algorithm-based Kriging is appropriate in resolving the high computational complexity optimization problems such as developing automotive parts.

• 대한통합의학회지
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• 제7권3호
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• pp.71-83
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• 2019

Purpose: This meta-analysis aimed to analyze to the effects of aquatic exercise programs in children with cerebral palsy and identify directions for future research. Methods: A systematic search based on the PRISMA guidelines was undertaken for studies conducted between 2006 and 2018 on aquatic exercise programs in children with cerebral palsy. A total of 10 studies were selected according to the inclusion criteria. The methodological quality was assessed using the Risk of Bias Tool for Randomized Controlled Trials (RoB) and Risk-of-Bias Assessment Tool for Non-randomized Studies (RoBANS). A meta-analysis software (CMA 3.0) was used to calculate the mean effect size, effect size by intervention (Halliwick and Watsu Aquatic methods), and effect size by outcome. Results: The mean effect size was 0.457. The effect size by intervention was largest for the Halliwick method, followed by the Watsu method. The effect size by outcome was largest for range of motion, followed by the gross motor function measure, the Pediatric Berg Balance Scale, and the Modified Ashworth Scale. Meta-regression analysis showed effect size increased when sample size, number of sessions, and length of sessions increased. Conclusion: The results show that aquatic exercise programs have a positive effect on children with cerebral palsy. Therefore, it is necessary to develop a guideline that recommends the appropriate intervention and the identifies the direction of future studies on aquatic exercise programs.

• Journal of the Korean Data and Information Science Society
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• 제21권4호
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• pp.651-667
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• 2010

항-고지혈 효과에 대한 연관 측도로 효과 인자를 고려한 헤지의 표준화된 평균차를 이용하였다. 고정효과모형을 적용하여 메타분석을 시행하였다. 그 결과 변의 콜레스테롤 농도와 총 콜레스테롤 농도 그리고 트리글리세리드 농도에서 통계적으로 유의한 감소를 보였으며, 고농도지단백 콜레스테롤 농도에서 통계적으로 유의한 증가를 보였다. 다음으로 연구 간 분산을 고려하지 않고 고정효과모형을 가정하여 분석한 모든 변수들에 대해 동질성 검정을 실행하여 연구 간의 이질성의 존재를 확인하였다. 그 결과 신장의 무게, 간의 무게, 고농도지단백 콜레스테롤, 저농도지단백 콜레스테롤, 총 콜레스테롤, 트리글리세리드 농도에서 동질성을 만족하지 않았다.

• Journal of Veterinary Science
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• 제23권1호
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• pp.13.1-13.12
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• 2022

Background: Toxoplasma gondii can infect humans and most animals and has a very high infection rate worldwide, including in China. The number of people infected with T. gondii in China increases with the number of cats. Objectives: We investigated the seropositive rate of T. gondii in cats over the last five years and analyzed the risk factors via meta-analysis. Methods: We retrieved 20 studies, with a total of 5,158 cats, published between 2016 and 2020, used the DerSimonian-Laird model and calculated seroprevalence estimates with the variance stabilizing double arcsine transformation. Results: The overall seroprevalence rate after sinusoidal conversion was 19.9% (95% confidence interval [CI], 15.9-23.9; 966/5,158), lower than the domestic report from 1995 to 2015 (24.5%, 95% CI, 20.1-29.0). There was substantial heterogeneity among studies (χ² = 262.32; p < 0.001; I² = 64.6%). Regression analysis of possible heterogeneous causes and subgroup analysis showed that age and whether cats were stray or not have a significant effect on the seropositive rate. Conclusions: Articles published in recent five years suggest that the seroprevalence estimates of Toxoplasma gondii in cats has decreased. Cats, as the final host of T. gondii, are an important cause of the spread of the parasite, and this is an important concern for public health.

• Journal of the Korean Data and Information Science Society
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• 제26권2호
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• pp.355-365
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• 2015

지난 수 십년간 전 지구적인 기후가 극적으로 변화함에 따라 가장 중요한 문제 중 하나로 인식되고 있는 식량 안보에 대하여 기후 변화의 영향을 평가하는 연구가 활발하게 진행되어 왔다. 본 연구에서는 메타분석을 이용하여 기후변화가 국내 농업에 미치는 영향을 분석하였다. 특히, 국내 농업에서 큰 비중을 차지하는 쌀에 대하여 이산화탄소 농도와 두 적응방안(파종시기 변경과 품종 변경)에 대한 효과를 추정하였다. 관심있는 효과에 대한 요약통계량을 이용하는 기존의 일반적인 메타분석 방법과는 달리, 다양한 온실가스 배출 시나리오와 대순환 모형을 사용하여 쌀 생산량을 예측한 6개의 개별 연구로부터 자료를 통합하여 메타분석을 수행하였다. 모델링 접근법으로써 쌀 생산량의 변화율을 종속변수로 설정하고, 이산화탄소 농도와 적응방안의 주 효과와 상호 작용 효과를 독립변수로 설정하여 회귀분석 실시하였다. 결과적으로 적응방안이 고려되지 않을 경우 이산화탄소 농도의 증가는 쌀 생산량을 감소시키나, 적응방안이 고려된다면 이산화탄소 농도의 증가는 쌀 생산량을 증가시키는 것으로 나타났다. 추가로 파종시기 변경 방안보다 품종 변경 방안이 쌀 생산량을 더 증가시키는 것을 알 수 있었다. 본 연구 결과는 향후 기후변화 대응책을 수립하는데 정량적 자료로 활용될 것으로 기대된다.

• 중환자간호학회지
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• 제9권1호
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• pp.51-65
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• 2016

Purpose: This study aimed to estimate the pooled prevalence of workplace bullying among nurses and examine the effect of moderate factors. Methods: Studies that assessed nursing workplace bullying using the negative act questionnaire developed by Einarsen et al. were searched for in 8 databases. The pooled prevalence was calculated with overall event rate and meta-ANOVA was performed for subgroup analysis. A funnel plot and Egger's linear regression asymmetry test were performed to confirm the publication bias of meta-analyzed studies. Results: A total of 23 studies (N=11,748) were included in the systematic review, and 14 studies (N=4,585) that reported prevalence using operational criteria of victim were selected for meta-analysis. The pooled prevalence of workplace bullying was 22.2% (95% CI: 19.0~25.7). Domestic studies reported lower prevalence than international studies (18.6% vs. 27.0%, Q=8.75, p=.003). The prevalences were different according to publication year (30.6% in 2008~2010, 19.5% in 2011~2014, 21.8% in 2015, Q=11.89, p=.003). Studies that recruited only new nurses reported higher prevalence than others (28.4% vs. 20.6%, Q=3.92, p=.048). Publication bias was not found. Conclusions: Workplace bullying is prevalent in the nursing profession, and is more serious for new graduate nurses. Individual and organizational measures for preventing workplace bullying among nurses need to be sought.

• Journal of Preventive Medicine and Public Health
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• 제49권6호
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• pp.367-375
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• 2016

Objectives: The established theory that breast density is an independent predictor of breast cancer risk is based on studies targeting white women in the West. More Asian women than Western women have dense breasts, but the incidence of breast cancer is lower among Asian women. This meta-analysis investigated the association between breast density in mammography and breast cancer risk in Asian women. Methods: PubMed and Scopus were searched, and the final date of publication was set as December 31, 2015. The effect size in each article was calculated using the interval-collapse method. Summary effect sizes (sESs) and 95% confidence intervals (CIs) were calculated by conducting a meta-analysis applying a random effect model. To investigate the dose-response relationship, random effect dose-response meta-regression (RE-DRMR) was conducted. Results: Six analytical epidemiology studies in total were selected, including one cohort study and five case-control studies. A total of 17 datasets were constructed by type of breast density index and menopausal status. In analyzing the subgroups of premenopausal vs. postmenopausal women, the percent density (PD) index was confirmed to be associated with a significantly elevated risk for breast cancer (sES, 2.21; 95% CI, 1.52 to 3.21; $I^2=50.0%$). The RE-DRMR results showed that the risk of breast cancer increased 1.73 times for each 25% increase in PD in postmenopausal women (95% CI, 1.20 to 2.47). Conclusions: In Asian women, breast cancer risk increased with breast density measured using the PD index, regardless of menopausal status. We propose the further development of a breast cancer risk prediction model based on the application of PD in Asian women.

• 디지털산업정보학회논문지
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• 제13권4호
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• pp.125-139
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• 2017

In this paper, we developed a framework to detect and predict insider information leakage by collecting and restoring network traffic. For automated behavior analysis, many meta information and behavior information obtained using network traffic collection are used as machine learning features. By these features, we created and learned behavior model, network model and protocol-specific models. In addition, the ensemble model was developed by digitizing and summing the results of various models. We developed a function to present information leakage candidates and view meta information and behavior information from various perspectives using the visual analysis. This supports to rule-based threat detection and machine learning based threat detection. In the future, we plan to make an ensemble model that applies a regression model to the results of the models, and plan to develop a model with deep learning technology.

• 한국산학기술학회논문지
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• 제21권2호
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• pp.94-102
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• 2020

본 연구는 골관절염 환자의 우울과 불안 감소를 위한 자가관리중재의 효과를 메타분석한 연구로 자가관리중재의 객관적인 근거를 제시하기 위해 수행되었다. 연구방법으로는 PubMed, EMBASE, CINAHL, Ovid-MEDLINE과 Korean database에서 2019년 9월 30일까지 발표된 국내·외 문헌을 검색하였고, 자가관리중재의 효과 크기를 분석하기 위해 R version 3.5.1 프로그램을 이용하였다. 연구결과로는 총 1,877편의 문헌 중 11편의 연구가 최종 분석되었고, 참가자는 총 2,751명이었다. 자가관리중재 분석결과 골관절염 환자의 우울과 불안 감소를 위한 전체 효과크기는 -0.44(95% CI: -0.66, -0.22)로 작은 정도의 유효한 차이를 보였다(p<.001). 하위분석으로 우울은 -0.37(95% CI: -0.66, -0.08)로 작은 효과크기, 불안은 -0.56(95% CI: -0.92, -0.20)으로 중간정도의 효과크기를 나타냈다. 이질성을 설명하기 위해 중재 장소, 중재 기간, 중재 제공자에 대한 meta-ANOVA를 실시하였다. 출판오류 분석은 funnel plot으로 분석하였고, 시각적으로 비교적 대칭이었으며, egger's regression test로 비대칭이 아님을 확인하였다(bias=0.19, p=.928). 본 연구의 결과는 골관절염 환자의 우울과 불안 감소를 위한 자가관리중재의 효과를 확인하여 임상적 근거를 마련하였다.

• 한국융합학회논문지
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• 제9권7호
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• pp.301-308
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• 2018

본 연구는 장애노인 신체활동 프로그램의 구성 유형을 분석하고 효과에 대한 메타분석을 실시하였다. 검색된 전체 177편의 연구 중 본 연구를 위해 선별과정과 필수적인 요소를 갖춘 총 14편의 연구가 선정되었지만, 한 연구 안에 신체활동 효과의 범주가 중복된 경우 개별 연구로 가정하여 총 28개의 효과 크기를 계산하였다. 메타분석을 위해 선행연구들의 효과 크기와 출간오류 등을 분석하였으며, Hedges'g, funnel plot, forest plot, Egger's regression test, trim-and-fill, fail-safe N 등을 수행하였다. 그 결과 첫째, 장애노인에게 신체활동은 효과적이고 심동적, 인지적, 정의적 영역에 좋은 효과가 나타났다. 둘째, 기본운동기술, 게임 및 스포츠, 체력운동의 신체활동 프로그램은 장애노인의 심동적, 인지적, 정의적 영역에 좋은 효과가 나타났다. 셋째, 장애노인의 심동적 영역은 기본운동기술 프로그램이 가장 효과가 높았으며, 인지적 영역은 게임 및 스포츠, 정의적 영역은 체력운동 프로그램이 가장 효과가 높은 것으로 나타났다.