• 한국수자원학회논문집
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• 제48권10호
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• pp.793-806
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• 2015

미계측유역의 유출량 모의는 수문학 분야에서 필수적인 사항이다. 강우-유출 모형을 이용하여 신뢰성 있는 유출량을 모의하기 위한 핵심사항은 강우-유출 모형의 매개변수를 추정하는 것이다. 하지만 현재 우리나라는 불충분한 수문자료로 인해 매개변수 추정에 어려움이 존재한다. 본 연구의 목표는 불확실성 반영을 위한 Bayesian 통계기법 기반의 강우-유출 모형의 매개변수를 지역화 하는 것이다. 그 방법은 다음과 같다. 첫째, 본 연구는 세계적으로 널리 사용되고 있는 Sacramento 강우-유출 모형에 Bayesian Markov Chain Monte Carlo 기법을 연계한 Bayesian Sacramento 강우-유출 모형을 사용하여 계측유역을 대상으로 13개 매개변수를 최적화하고 각 매개변수의 사후분포를 도출하였다. 둘째, 매개변수와 유역특성인자 사이에 회귀특성을 얻기 위해 다중선형회귀분석을 적용하여 유역특성을 고려한 지역화 매개변수를 결정하였다. 다중회귀분석을 통하여 산정된 지역화 매개변수를 계측유역에 전이하여 유출량을 모의 후 통계적 효율기준인 N-S계수, 일치계수 및 상관계수를 사용하여 지역화 매개변수 검증을 수행하였다.

• 한국산학기술학회논문지
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• 제20권7호
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• pp.272-280
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• 2019

본 연구는 알코올사용장애 환자의 가족지지, 자아탄력성, 취업의지의 관계를 파악하고, 취업의지에 영향을 미치는 요인을 확인하기 위한 서술적 조사연구이다. 자료수집은 알코올사용장애로 진단받고 입원 및 외래 치료를 받은 경험이 있는 20세 이상의 남성 128명을 대상으로 구조화된 설문지를 이용하였다. 자료분석은 SPSS 22.0 program을 이용하여 기술통계, 일원분산분석, 피어슨 상관계수, 다중회귀분석을 이용하였다. 연구결과 가족지지는 5점 만점에 4.30점, 자아탄력성은 4점 만점에 2.37점, 취업의지는 5점 만점에 4.06점이었다. 가족지지는 주거형태에 따라 자가소유 주택 거주자가 임대형 주택 거주자보다 높고($x^2=4.747$, p=.01), 자아탄력성은 교육정도에 따라 초대졸 이상이 중졸이하보다 높았으며(F=4.389, p=.01), 취업의지는 연령에 따라 40대 이하가 50대 이상보다 높았다(F=4.778, p=.01). 취업의지는 자아탄력성과 유의한 양의 상관관계가 나타나 자아탄력성이 높을수록 취업의지도 높았다.(r=.309, p<.01). 취업의지에 영향을 미치는 요인은 자아탄력성(${\beta}=-.314$, p<.01)과 연령(${\beta}=-.253$, p<.01)이며 16.3%의 설명력을 나타냈다. 연구결과를 토대로 알코올사용장애 환자의 취업의지를 향상시키기 위해 연령수준에 따른 접근이 필요하며 자아탄력성을 증진시킬 수 있는 프로그램이 개발되어 활용되기를 기대한다.

• 대한교통학회지
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• 제28권3호
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• pp.61-74
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• 2010

지능형 교통체계는 실시간 교통자료를 수집하고 방대한 양의 이력자료를 축적한다. 그러나 방대한 이력자료는 효율적으로 관리/이용되지 않고 있는 실정이다. ADMS와 같은 자료관리시스템이 도입되면서, 이력자료의 잠재적 활용성은 급격히 증대되고 있다. 그러나 자료관리스템의 교통자료는 다량의 누락자료를 포함하고 있다. 누락자료는 장기간에 걸쳐 빈번하게 교통자료를 이용할 수 없게 하기 때문에, 이력자료를 활용하는데 있어 주된 장애요인 중 하나이다. 따라서 누락자료 추정기법은 자료관리시스템에서 주요한 역할을 수행하게 된다. 이러한 한계를 극복하기 위하여, 본 연구에서는 자료관리스템에 탑재가 용이하며 이력자료에 포함된 누락자료를 추정하기 위한 누락자료 추정모형을 개발하였다. 개발모형은 비모수회귀식(NPR)을 기반으로 개발되었으며, 이력자료의 다양한 교통자료 패턴을 이용하고 현실적인 요구사항(변수 최소화, 연산속도, 다양한 형태의 누락자료 보정, 다중대체)을 충족하도록 설계되었다. 모형의 평가는 다양한 누락자료 형태의 상태에서 수행되었으며, 자료관리시스템에 탑재되기 위해 요구되는 정확도, 연산 수행속도에서 기존에 보고된 모형보다 우수한 성능을 보였다.

• 대한환경공학회지
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• 제39권8호
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• pp.449-455
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• 2017

기준공정과 개선대상공정 간의 투입물(Input, Material and energy), 배출물(Output, Product, Co-product), 환경오염물(Environmental emission) 데이터를 수집하고 공정 성과를 분석하였다. 이를 통해 환경적으로 주요한 투입물과 환경오염물을 파악하였다. 제조공정의 투입물과 환경오염물 간의 상관관계 분석을 통해 각 환경오염물에 대한 기여도가 큰 투입물을 파악하였다. 주요 환경오염물 처리 시, 경제적 최적화를 통한 종말처리공정 조합을 선형 프로그래밍 기법을 사용하여 규명하였다. 사례 연구로는 동일한 형태의 시멘트를 생산하는 EU와 국내 시멘트 제조공정을 선정하였다. 국내 시멘트 제조공정에서는 석탄이 주요 투입물로, 먼지, $SO_x$가 주요 환경오염물로 파악되었다. 제조공정의 투입물과 환경오염물 간의 다중회귀분석결과 석탄>원자재>석고 순으로 $CO_2$발생량에 기여도가 큰 것으로 나타났다. $SO_x$발생량의 경우 석탄의 기여도가 가장 컸으며, Dust 발생량의 경우 석고>원자재 순으로 기여도가 큰 것으로 나타났다. Dust 종말처리공정 최적화에서 전기집진기술 100%, 섬유필터기술 2.4% 조합이 최적이었다. $SO_x$종말처리공정 최적화에서는 건식첨가공정기술 100% 습식세정기술 25.88% 조합이 최적이었다. 이 연구의 특징은 제조공정에서 문제가 되는 주요 투입물과 환경오염물을 파악하는 방법을 제시하였다는 점이다. 또한, 기술적 경제적으로 최적의 조합인 종말처리공정 선정 방법을 제시하였다는 점이다.

• 한방안이비인후피부과학회지
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• 제19권3호통권31호
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• pp.134-145
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• 2006

Objective : This study was carried out to investigate what type of assumption and conditions are needed for the application of various statistical techniques such as descriptive statistics, t-test, analysis of variance, correlation analysis, regression analysis and chi-square test and to evaluate that they are used correctly in the research process. Methods : One more methods of statistical analysis were used in 91 papers among 162 papers selected from the journal of Korean oriental medical Ophthalmology & Otolaryngology & Dermatology from April 2003 to December 2005. So we analysed the type of statistical analysis method in 91 papers(clinical and experimental study) and assessed the their validity of statistical techniques by the check list consisting of 34 items(3 items for validity assessment of descriptive statistics, 6 items for t-test, 7 items for analysis of variance, correlation analysis and regression analysis, respectively, 4 items for chi-square test) Results : 1. The type of 65(40%) cases is experimental trial, the type of 55(34%) cases is case report, the type of 26(16%) cases is clinical trial and the type of 16(10%) cases is review, in 91 papers using statistical techniques among 162 papers selected from the journal of Korean oriental medical Ophthalmology & Otolaryngology & Dermatol-ogy from April 2003 to December 2005. 2. One more methods of statistical analysis were used in the experimental and clinical study. When we classified 125 units using statistical analysis methods in 91 papers according to statistical techniques such as descriptive statistics, t-test, analysis of variance, correlation analysis, regression analysis and chi-square test, the number of independent sample t-test is 33(26%), the number of only descriptive statistics is 28(22%), the number of independent sample t-test is 33(26%), the number of only descriptive statistics is 28(22%), the number of one way ANOVA is 15(12%), the number of non-parametric test 10(8%). 3. After carrying out one way ANOVA, the number of using multiple comparison methods is 15(Scheffe:6(26%), Duncan:4(17%), Dunnett:3(13%), Tukey:2(9%)) out of 23 (total case carrying out one way ANOVA). 8(35%) out of 23 did not enforce multiple comparison methods after carrying out one way ANOVA. 4. From the assessment of validity about 63 cases using statistical techniques(except descriptive statistics), 5(8%) cases are proper, the other 58(92%) are improper, so we recognized a serious misuse of statistical application in our journal. 5. The number of case below 10 sample size in experimental and clinical study(except descriptive statistics) is 31(34%) and frequent. Also the number of case containing no mention of sample size is 41(45%, including culture study). 6. For example of statistical error, there are wrong choice of statistical technique, lack of check on standard assumption(such as standard distribution, equivariance, independence), and so on. Conclusions : We investigated the validity of statistical analysis methods in our journal by check list consisting of 34 items and suggested correct statistical analysis methods. We should practice the spread of education about statistical analysis methods and precis application, enhance objectivity and reliability of our thesis and further correspond with purpose of scientific study.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7785-7788
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• 2015

Utilization of high energy photons (>10MV) with an optimal weight using a mixed energy technique is a practical way to generate a homogenous dose distribution while maintaining adequate target coverage in intact breast radiotherapy. This study represents a model for estimation of this optimal weight for day to day clinical usage. For this purpose, treatment planning computed tomography scans of thirty-three consecutive early stage breast cancer patients following breast conservation surgery were analyzed. After delineation of the breast clinical target volume (CTV) and placing opposed wedge paired isocenteric tangential portals, dosimeteric calculations were conducted and dose volume histograms (DVHs) were generated, first with pure 6MV photons and then these calculations were repeated ten times with incorporating 18MV photons (ten percent increase in weight per step) in each individual patient. For each calculation two indexes including maximum dose in the breast CTV ($D_{max}$) and the volume of CTV which covered with 95% Isodose line ($V_{CTV,95%IDL}$) were measured according to the DVH data and then normalized values were plotted in a graph. The optimal weight of 18MV photons was defined as the intersection point of $D_{max}$ and $V_{CTV,95%IDL}$ graphs. For creating a model to predict this optimal weight multiple linear regression analysis was used based on some of the breast and tangential field parameters. The best fitting model for prediction of 18MV photons optimal weight in breast radiotherapy using mixed energy technique, incorporated chest wall separation plus central lung distance (Adjusted R2=0.776). In conclusion, this study represents a model for the estimation of optimal beam weighting in breast radiotherapy using mixed photon energy technique for routine day to day clinical usage.

• 가정과삶의질연구
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• 제23권2호
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• pp.137-148
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• 2005

This study compared one-child households' economic structures between those who determined not to have more children and those who have a birth plan. This study examined the demographic characteristics and economic variables such as income, consumption expenditures, assets. debt, and a subjective evaluation of future economic status. Especially, it compared the effects of socioeconomic variables on expenditures on a child between low-fertility and birth-planned households. From a questionnaire completed by a husband or wife of one-child households, 154 low-fertility households and 201 birth-planned households were obtained. A t-test, chi-square test, multiple regression analysis and a dummy variable interaction technique were used. The findings of this study are as follows: First, low-fertility households were older, had higher income, and had more educated, employed wives. Their marital duration was longer, and their child was older than those of birth-planned households. Second, low-fertility households had higher consumption expenditures than did birth-planned households. Especially, expenditures of apparel and shoes, health care, education, and entertainment were significantly higher for low-fertility households. Also, low-fertility households spent more than did birth-planned households on a child. However, low-fertility households had significantly more debt than did their counterparts, and their expectation level of future economic status were lower than that of birth-planned households. Third, the effects of socioeconomic variables on expenditures on a child were different between low-fertility and birth-planned households. Age, education level, husband's occupation, wife's employment status, income, net asset, and subjective evaluation of future economic status showed significant differences. Income elasticity of expenditure on a child was significantly higher for low-fertility households than their counterparts.

• 디지털콘텐츠학회 논문지
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• 제19권4호
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• pp.749-756
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• 2018

본 연구는 머신러닝 기법을 이용한 온실 제어를 위한 예측모델을 개발하는 것이 목적이다. 시설원예연구소의 실험온실에서 측정된 데이터(2016년)를 사용하여 예측모델을 개발하였다. 모델의 예측성능 향상과 데이터의 신뢰성 확보를 위해 상관관계분석을 통해 데이터의 축소를 수행하였다. 데이터는 계절별 특성을 고려하여 봄, 여름, 가을 및 겨울로 나누어 구축하였다. 머신러닝 기반의 예측모델로 인공신경망, 순환신경망 및 다중회귀모델을 구축하고 비교분석을 통해 타당성을 평가하였다. 분석 결과에서, Selected dataset에서는 인공신경망 모델이 Full dataset에서는 다중회귀모델이 좋은 예측성능을 보였다.

• 대한지역사회영양학회지
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• 제10권3호
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• pp.319-330
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• 2005

College foodservice (FS) demands highly-developed operation technique which can provide adequate nutrients to their students, as well as to guide better eating habits and to meet students' various desires. The purpose of this study was to provide basic data to improve college FS satisfaction with food items by comparing 2 contract-managed and 2 self-operated college FS in Daejeon and Chungnam area. According to the results, $\59.1%$ of students frequently (over 3 times per week) took meals at college cafeteria and the main reason for using college cafeteria was the low-price of meal, although the students' Satisfaction degree with price of meal was lower in contract-managed FS than in self-operated FS. There were no differences in the food satisfaction degrees with overall appraisal of food items between 2 operating systems of college FS, but the satisfaction degrees with all food items were high in male as compared with female. The higher the negative self-perceived clinical symptoms scores, the lower the satisfaction with foods, which suggests that the health state of students was one of the factors that influenced college FS satisfaction. According to stepwise multiple regression analysis,'taste of boiled rice', 'overall appraisal of boiled rice', 'overall appraisal of soup', and 'variety of side dish', in decreasing order, were the most relatively important attributes for overall customer satis-faction with food taste of college FS. Finally, there should be further studies on important management factors to improve college FS satisfaction according to 2 operating system.

• 한국조경학회지
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• 제31권2호
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• pp.94-101
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• 2003

The purpose of this paper is to analyze the correlation between Death Rate of Trees (DRT) and the Physiological Characteristics of Trees(PCT) in POSCO Gwangyang works, which is a reclaimed area. To analyze the DRT, 15 species of deciduous trees were selected, for example Ulmus davidiana var., Zelkova serrata, Melia azedarach var. etc. Though there were numerous factors to affect the growing of trees, 5 PCT were considered to be main factors, soil salt tolerance, wind salt tolerance, water needs, transplanting difficulty, and nutrient needs. According to two kinds of soil-base: mound and pot area, we tested the relationship between 5 PCT and DRT by use of t-test and multiple regression analysis. The results are as follows. 1. The DRT of Acer palmatum, Cornus kousa, Magnolia kobus, Liriodendron tulipifera, and Albizzia julibrissin were high by more than 20%. On the other hand, Chionanthus retusa, Ulmus davidiana var. japonica Celtis sinensis, and Lagerstroemia indica were low by less than 10% in the DRT and are considered to be species suitable for planting in reclaimed areas. 2. The DRT of trees in pot areas was meaningfully higher than in mound areas; for this reason the mound technique is desirable as a soil-base for planting in reclaimed areas. 3. In the pot area, the independent variables, in the order of soil salt tolerance, wind salt tolerance, transplanting difficulty, had an effect on the DRT more significantly than in mount area. On the other hand, wind salt tolerance and soil salt tolerance affected the DRT in mount areas. This means that soil salt tolerance, wind salt tolerance, and transplanting difficulty have to be considered as significant factors to the DRT. Although the researchers tried to interpret how the PCT affected the DRT in order to analyze the relationship between the two in reclaimed areas, it was neglected at an experimental level. Therefore, future research should work on this aspect in detail.