• 한국치위생학회지
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• 제19권2호
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• pp.287-295
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• 2019

Objectives: The purpose of this study was to investigate the factors affecting subjective oral symptoms according to the gender of youth from multi-cultural families in Korea using data from the 14th (2018) Korean Youth Health Behavior Survey. Methods: The independent variables used in this study consisted of gender and sweet drink intake. The dependent variable was experience of subjective oral symptoms. Compensation variables consisted of general characteristics of school type, academic performance, economic status, drinking status, smoking status, and number of tooth brushings day before. The subjects of the study were 835 children of multi-cultural families whose parents were foreigners. All statistical analyses were performed by complex samples cross-tabulation analysis and complex samples logistic regression analysis. Statistical analysis was performed using the PASW statistical package 21.0 (Statistical Packages for Social Science Inc., Chicago, IL, USA). A significance level of 0.05 was used for statistical significance. Results: The composite sample logistic regression analysis showed that there was a statistically significant difference between gender and intake of sweet drinks in experience of subjective oral symptoms. Conclusions: These results suggest that factors influence subjective oral symptoms in Korean multi-cultural adolescents. Therefore, I hope that they will be used as basic data for the introduction and development of a customized oral health education program for improving oral health of multi-cultural adolescents.

• 한국환경보건학회지
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• 제35권3호
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• pp.191-200
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• 2009

We investigated a trait of odor and the relationship between odor unit and odorous compounds using multiple regression analysis based on data compiled from Sihwa (SIC), Banwol (BIC), Banwol plating (BPIC) and Poseung industrial complex (PIC). These areas are odor control areas in Gyeonggi province. It was revealed that $NH_3$ and styrene concentrations in SIC and BPIC were relatively higher and $H_2S$ concentration especially in mc was more than five times higher than other areas. As a result of regression analysis using SAS, intensity of odor unit was highly related to concentrations of $H_2S$, TMA, styrene and n-valeraldehyde in SIC, $H_2S$, acetaldehyde, and butyraldehyde in BPIC and $NH_3$ in BIC.

• 한국정밀공학회지
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• 제26권6호
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• pp.90-96
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• 2009

Ultrasonic method using SH(shear horizontal) wave has been developed to determine the surface damage in fatigued material. Fatigue damages based on propagation energy were analyzed by multi-regression analysis in interrupted fatigue test specimen including CrMoV and 12Cr alloy steel. From the test results, as the fatigue damage increased the propagation time of the launched waves increased and amplitude of wavelet decreased. Also, analysis for the waveform modulation showed a reliable estimation, with confidence limit of 97% for 12Cr steel and 95% for CrMoV steel, respectively. Therefore, It is thought that SH ultrasonic wave technique can be applied to determine fatigue damage of in-service component nondestructively.

• 보건행정학회지
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• 제30권3호
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• pp.399-408
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• 2020

Background: The purpose of this study was to examine the impact of the regional characteristics on the accessibility of emergency care and the impact of emergency medical accessibility on the patients' prognosis and the emergency medical expenditure. Methods: This study used the 13th beta version 1.6 annual data of Korea Health Panel and the statistics from the Korean Statistical Information Service. The sample included 8,119 patients who visited the emergency centers between year 2013 and 2017. The arrival time, which indicated medical access, was used as dependent variable for multi-level analysis. For ordinal logistic regression and multiple regression, the arrival time was used as independent variable while patients' prognosis and emergency medical expenditure were used as dependent variables. Results: The results for the multi-level analysis in both the individual and regional variables showed that as the number of emergency medical institutions per 100 km² area increased, the time required to reach emergency centers significantly decreased. Ordinal logistic regression and multiple regression results showed that as the arrival time increased, the patients' prognosis significantly worsened and the emergency medical expenses significantly increased. Conclusion: In conclusion, the access to emergency care was affected by regional characteristics and affected patient outcomes and emergency medical expenditure.

• 소성∙가공
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• 제26권6호
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• pp.341-347
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• 2017

Flexibly-reconfigurable roll forming (FRRF) is a novel sheet metal forming technology conducive to produce multi-curvature surfaces by controlling strain distribution along longitudinal direction. Reconfigurable rollers could be arranged to implement a kind of punch die set. By utilizing these reconfigurable rollers, desired curved surface can be formed. In FRRF process, three-dimensional surface is formed from two-dimensional curve. Thus, it is difficult to predict the forming result. In this study, a regression analysis was suggested to construct a predictive model for a longitudinal curvature of FRRF process. To facilitate investigation, input parameters affecting the longitudinal curvature of FRRF were determined as maximum compression value, curvature radius in the transverse direction, and initial blank width. Three-factor three-level full factorial experimental design was utilized and 27 experiments using FRRF apparatus were performed to obtain sample data of the regression model. Regression analysis was carried out using experimental results as sample data. The model used for regression analysis was a quadratic nonlinear regression model. Determination factor and root mean square root error were calculated to confirm the conformity of this model. Through goodness of fit test, this regression predictive model was verified.

• 한국항공우주학회지
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• 제43권7호
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• pp.601-608
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• 2015

유연날개의 공력 및 구조 설계값을 설계 변수로 하여 정적 상태에서의 정적 공탄성해석 및 최적화를 수행하였다. 정적 공탄성해석과 최적화를 위해 상용 해석소프트웨어들이 연계된 강건한 다분야 최적설계 시스템을 개발하였다. 최적화 설계변수로는 가로세로비, 테이퍼비, 후퇴각과 날개 위아래 스킨 두께를 설정하였다. 전역적 다목적 최적화를 위해 실수기반 적응영역 다목적 유전자 알고리즘을 적용하였으며 계산시간을 줄이기 위해 메타모델로 서포트벡터회귀 기법을 적용하였다. 유연날개에 대한 파레토 결과 분석을 통해 최대 항속시간과 최소 중량에 대한 최적 결과를 확인하였다.

• 한국터널지하공간학회 논문집
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• 제13권6호
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• pp.531-555
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• 2011

본 연구에서는 암반대응형 TBM의 소요 사양 산출과 커터헤드 설계를 위한 통계모델을 도출하고자 하였다. 이를 위하여 다양한 암반 조건에서 수집된 871개의 TBM 굴진자료와 51개의 암석 선형절삭시험 결과에 대해 다변량 회귀분석을 실시하여, 다양한 암석 특성과 절삭 조건을 고려한 최적 모델을 도출하였다. 회귀분석을 통해 도출된 설계모델들을 2개의 쉴드터널 현장에 적용한 결과, 커터 관입깊이, 커터 작용력 및 커터 간격과 같은 TBM 핵심 설계항목의 예측결과들이 실제 현장의 굴진결과와 잘 부합되는 것으로 나타났다.

• 한국항공운항학회지
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• 제15권4호
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• pp.38-44
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• 2007

This paper describes the structural safety of solid fuel in the Hybrid Rocket Motor (HRM). Hybrid rocket combustion has the distinct regression characteristics which include the process of thermal pyrolysis and fuel vaporization. Most of all, this regression characteristics would structurally affect the strength of the fuel having a multi-port configuration, and even may cause the breaking from the fuel grain. This problem would probably influence the performance and operating safety of HRM. Therefore, for the safe operation of HRM, the critical port radius which determines the structurally safe region was discussed from the heat analysis of the solid fuel.

• 마케팅과학연구
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• 제8권
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• pp.183-206
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• 2001

본 연구는 호텔기업의 고객 포트폴리오 전략에 있어서 시장의 절대적 규모와 경쟁상황을 고려할 때 신규고객을 확보보다는 기존고객들의 재구매 의도에 미치는 영향요인에 관한 연구의 필요성이 대두된다는 환경에서 시작된다. 특히 호텔 서비스 재구매 의도에 미치는 영향요인은 순기능 요인만 존재하는 것이 아니라 역기능 요인 역시 존재함에도 불구하고 이를 간과하는 경향이 있다. 본 연구에서는 호텔기업의 성과요인에 작용하는 부정적 매개역할 요인으로 지각된 위험을 제시하고 이에 대한 실증 분석을 하였다. 우리나라 서울 소재 특급호텔의 고객을 대상으로 실시한 연구의 결과를 통해 첫째, 지각 된 서비스 품질(인적 품질, 물적 품질)이 재구매 의도에 미치는 정의 영향을 미친다는 것과 둘째, 지각된 위험(성과적 위험, 사회심리적 위험, 신체적 위험)이 재구매 의도에 미치는 부의 영향을 미친다는 것과 셋째, 지각된 위험이 지각된 서비스 품질과 재구매 의도간 매개적 역할을 하고 있음이 밝혀졌다. 본 연구의 결과를 통해 재구매 의도에 미치는 영향요인 중 역기능 요인에 관한 통제를 마케팅 전략 수립에 있어서 적극 활용하여야 한다는 시사점을 얻을 수 있다.

• Journal of the Korean Data and Information Science Society
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• 제23권1호
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• pp.151-159
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• 2012

본 논문에서는 외환시장에서 주성분 분석과 로지스틱 회귀분석을 이용한 다국 통화 포트폴리오 전략을 개발하는 것을 제안한다. 과거 환율시장의 분석에 대한 많은 연구가 진행되어 왔으나 상대적으로 외환시장에서의 거래 전략을 개발하는 연구는 거의 없었다. 본 연구는 크게 두 가지 목적을 가지고 있다. 첫 번째 목적은 주성분 분석을 적용시켜 포트폴리오를 구성하는 다양한 나라의 환율에 가중치 할당 방법을 제안하는 것이다. 두 번째 목적은 로지스틱 회귀분석을 이용하여 구성된 포트폴리오의 적절한 매수시점과 매도시점을 정하는 것이다. 이 논문의 실험결과는 제안한 투자전략의 유용성을 증명할 수 있을 것이며, 또한 이를 통해 시장참여자들에게 투자 결정에 있어 도움을 줄 수 있을 것이다.