• 한국환경과학회지
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• 제28권12호
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• pp.1101-1110
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• 2019

This study investigated Post-Occupancy Evaluation (POE) of cherry blossom trails 'Cherry Road' in Daegu Catholic Univ. campus, at Gyeonsan-city, Korea. The evaluation focused on image preference and satisfaction of users i.e., students, using questionnaire surveys. A total 201 questionnaire samples were analyzed and most of the respondents were in the age group of 20. Frequency analysis was conducted on demographics, use behavior, reliability, and means. Factor analysis and multiple regression analysis were conducted for user satisfaction and image preference. Over 80% of visitors came with companions during daytime. The most common motives for use were strolling and walking, event and meeting, passing. For user satisfaction the mean scores were highest for landscape beauty (4.22), image improvement (4.14), campus image (4.08). Night lighting facility received the lowest score (3.32). Factor analysis concerning user satisfaction was categorized into environment-human behavior and physical factors. Multiple regression analysis showed that the overall satisfaction of user was significantly influenced by five independent variables: 'harmonious' (β=.214), 'night lighting facility' (β=.173), 'landscape beauty' (β=.208), 'lawn care' (β=.154), and 'walking trails' (β=.123). The mean scores of image variables were highest for 'beautiful' (5.81), 'bright' (5.67), and 'open' (5.64). The lowest scores was for 'quiet' (4.47). Exploratory factor analysis led to three factors being categorized: aesthetics, comforts, and simplicity. Result of multiple regression analysis indicated that the preference of space image was significantly influenced by five variables: 'bright' (β=.397), 'refreshing' (β=.211), 'cool' (β=.219), 'clean' (β=.182), and 'natural' (β=.-142). Hence, Cherry Road has a high level of user satisfaction and image evaluation, which is interpreted as having various cultural events and value for students on campus. To improve the satisfaction of Cherry Road in the future, it is necessary to secure night lighting, to manage trash cans, and to secure rest space.

• 응용통계연구
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• 제32권6호
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• pp.889-898
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• 2019

항목 무응답(item missing)이 발생한 설문조사에서 결측이 포함된 변수에 이상치(outlier)의 존재와 다른 설문문항 항목과의 논리적 한계(boundary) 조건들이 유의미하다면 결측치 대체문제는 매우 복잡해진다. 한계가 있는 결측값들을 포함한 변수에 이상치가 존재하는 경우, 기존의 회귀분석에 근거한 결측치 대체방법은 편향된 대체값 그리고 한계를 만족하지 않은 대체값을 제시할 가능성이 있다. 이에 본 논문은 회귀모형에 기반을 두고 결측치들을 대체를 함에 있어 이상치와 논리적 한계조건이 자료에 존재하는 경우, 다양한 로버스트 회귀모형과 다중대체 방법의 조합을 통해 해결점을 모색하고자 한다. 이를 위해 이들 방법들의 최적의 조합을 다양한 시나리오별로 모의실험을 통하여 찾아보고 이에 대하여 논의하였다.

• 한국화재소방학회논문지
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• 제28권2호
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• pp.69-75
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• 2014

본 연구에서는 방화발생에 영향을 미치는 요인을 도출하기 위하여 발생건수를 종속변수로 하고 경제 인구 사회적 요인을 독립변수로 하는 다중회귀분석을 실시하였다. 다중회귀분석은 선형함수, 준로그함수, 역준로그함수, 이중로그함수 4가지 함수형태에 대해 적용하였으며, 각 단계별로 변수의 선택과 제외를 고려하는 단계적선택 방식을 적용하였다. 다중공선성 문제와 자기상관 문제를 해결하기 위하여 분산확대지수(VIF)와 Durbin-Watson 계수 이용하였으며, 4가지 함수모형에 대하여 수정된 R 제곱(설명력) 값이 0.935 (93.5%)로 가장 값이 높고 통계적으로 유의한 선형함수모형을 최적의 모형으로 결정하고 모형에 대한 해석을 진행하였다. 선형함수모형 결과 방화발생에 영향을 미치는 요인은 범죄발생건수(0.829), 일반이혼율(0.151), 재정자주도(0.149), 소비자물가상승률(0.099) 순으로 도출되었다.

• 한국지반공학회논문집
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• 제33권6호
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• pp.27-36
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• 2017

자갈다짐말뚝(Gravel Compaction Pile) 공법은 연약지반 개량공법 중의 하나로 육상 및 해상에서 연약 지반을 개량하기 위해 많이 사용되어 왔다. 자갈다짐말뚝으로 보강된 지반의 극한 지지력은 자갈다짐말뚝 및 지반의 강도, 치환율, 시공조건 등에 영향을 받으며 이를 예측하기 위한 다양한 예측식이 제안되었다. 하지만 기존 예측식을 활용한 극한지지력 예측은 오차율 및 변동성이 매우 크며, 실제 설계에 활용하기에는 부적합한 것으로 나타났다. 본 연구에서는 자갈다짐말뚝으로 보강된 지반의 극한 지지력을 예측하기 위하여 현장 재하시험결과를 활용한 다중회귀분석을 수행하였으며, 단일잔류 교차검증에 따른 예측오차평가를 통하여 가장 효율적인 입력변수를 선정하고 이에 대한 극한 지지력 예측식을 제안하였다. 또한 선정된 입력변수를 활용하여 인공신경망 적용에 따른 극한 지지력 예측오차를 평가하고 이를 기존 예측식에 따른 결과와 비교 분석하였다.

• 한국융합학회논문지
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• 제10권7호
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• pp.1-6
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• 2019

현대사회는 1인가구가 증가함에 따라 불규칙한 식습관으로 인해 영양이 불균형하게 포진되어있다. 이러한 식습관은 위장질환, 소화기 질환 등 만성질환의 발병률을 증가시켰다. 본 논문은 위장질환 예방을 위한 다중회귀분석을 이용한 식이지식 예측을 제안한다. 제안하는 방법은 식이지식 예측을 통해 사용자의 위장질환과 식이영양을 관리하는 방법이다. 헬스 플랫폼에서 스마트 기기를 통해 수집된 사용자의 PHR을 통합한다. 통합된 데이터로부터 다중회귀분석을 이용하여 사용자의 식이와 활동량 변화를 분석한다. 사용자의 식이 성분과 소모 칼로리, 기초대사와 같은 상황정보를 입력으로 적절한 식이성분, 위장질환 수치의 변화를 예측하고 필요할 것으로 나타나는 영양성분을 사용자에게 권장한다. 이를 통해 현대인들은 균형 잡힌 식사를 통해 위장질환을 관리할 수 있다.

• 한국수자원학회논문집
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• 제55권3호
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• pp.229-243
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• 2022

우리나라 11개 기상관측지역의 월별 기상자료가 증발접시계수에 미치는 영향을 분석하고, 증발접시계수 산정을 위한 4가지 형태의 다변량 선형회귀모형의 적용성을 검토하였다. 개발된 증발접시계수 산정모형의 적용성을 평가하기 위해서 기존에 다른 연구자들에 의해서 제안된 6가지의 모형과 비교 평가하였다. 우리나라 11개 기상관측지역에서 증발접시계수는 1, 2, 3, 7, 11, 12월은 기온에 가장 큰 영향을 받고, 다른 월들은 일사량에 가장 큰 영향을 받는 것으로 나타났다. 전반적으로 모든 월에서 풍속과 상대습도는 기온이나 일사량과 비교해서 증발접시계수에 큰 영향을 미치지 않는 것으로 나타났다. 모든 지역과 월에서 각 지역별로 5개의 독립변수(풍속, 상대습도, 기온, 일조시간과 가조시간의 비, 일사량)를 적용하여 유도된 모형이 가장 양호한 증발량 산정 결과를 보였다. 모형 검증결과에 의하면 다변량 선형회귀분석을 적용하여 증발접시계수를 산정하는 경우 일부 지역과 월에서 제한적으로 적용할 수 있을 것으로 판단된다.

• 대한한의학회지
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• 제44권2호
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• pp.1-9
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• 2023

Objectives: To study symptom differentiation for yang deficiency and blood heat based on 117 psoriasis patients. Methods: Obtained frequency analysis (%), mean (%), and OR, CL(P-value) with prospective pre-post intervention design and multiple regression analysis. Results: There were no statistically significant differences as to sex, BMI, smoking and marital status, but there were statistically significant differences in variables of average age, family history, and alcohol consumption (P<0.05). There were no statistically significant differences in psoriasis symptoms as to initial age of onset, morbidity span, area of the initial onset, and the progression of psoriasis during the last three months of each patient. However, the type of psoriasis showed a statistically significant difference (p=0.011). While there were no statistically significant differences as to common cold, condition of psoriasis after recovering from the cold, skin condition, exercise, and seasonality, irregular perspiration showed significant difference (p<0.00). When confounding factors have been controlled the blood heat patient group as the comparison group, multiple regression analysis showed OR, CI(95%) of 1.06(0.31-3.63) for men, 0.28(0.08-1.06) for aged 30 to 49,0 and 0.18(0.04-0.80) for aged 50 and older. it was 0.06(0.01-0.7) for family history, 1.06(0.29-3.88) for drink alcohol, 19.90(2.53-156.7) for seasonality, and 10.28 (3.19-33.11) for perspiration problems. In these variables, Sex, age, smoking, and alcohol consumption showed no statistically significant results, but family history(p=0.049), seasonality(p=0.005), and irregular perspiration (p=0.017) were statistically significant. Conclusion: Family history, seasonality and irregular perspiration are the determining factors for yang deficiency and blood heat in psoriasis.

• 대한조선학회논문집
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• 제51권6호
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• pp.530-538
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• 2014

The weight estimation of floating offshore structures such as FPSO, TLP, semi-Submersibles, Floating Offshore Wind Turbines etc. in the preliminary design, is one of important measures of both construction cost and basic performance. Through both literature investigation and internet search, the weight data of floating offshore structures such as FPSO and TLP was collected. In this study, the weight estimation model was suggested for FPSO. The weight estimation model using non-linear regression analysis was established by fixing independent variables based on this data and the multiple regression analysis was introduced into the weight estimation model. Its reliability was within 4% of error rate.

• Water Engineering Research
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• 제4권2호
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• pp.59-68
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• 2003

The applicabilities and validities of two methodologies fur the prediction of THM (trihalomethane) formation in a water pipeline system were proposed and discussed. One is the multiple regression technique and the other is an artificial neural network technique. There are many factors which influence water quality, especially THMs formations in water pipeline systems. In this study, the prediction models of THM formation in water pipeline systems are developed based on the independent variables proposed by American Water Works Association(AWWA). Multiple linear/nonlinear regression models are estimated and three layer feed-forward artificial neural networks have been used to predict the THM formation in a water pipeline system. Input parameters of the models consist of organic compounds measured in water pipeline systems such as TOC, DOC and UV254. Also, the reaction time to each measuring site along pipeline is used as input parameter calculated by a hydraulic analysis. Using these variables as model parameters, four models are developed. And the predicted results from the four developed models are compared statistically to the measured THMs data set. It is shown that the artificial neural network approaches are much superior to the conventional regression approaches and that the developed models by neural network can be used more efficiently and reproduce more accurately the THMs formation in water pipeline systems, than the conventional regression methods proposed by AWWA.

• Asian-Australasian Journal of Animal Sciences
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• 제21권6호
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• pp.769-775
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• 2008

This study was on the relative net income (RNI) for 18,286 Iranian Holstein cows from 799 herds, with first freshening between 1991 and 2000. Two kinds of production system, which differed mainly in milk pricing system and feed cost, were considered. Four different models adopted from the literature were examined to find the optimum model. They differed by the cost of rearing and growth after first calving and they needed different amounts of economic data at the farm level. Results showed that four measures of RNI were highly correlated (>0.96) and could be used equally to measure lifetime profitability of cows. Therefore, in herds without a regular system for recording economic and management data, use of the simplest model is recommended. Multiple regression analysis revealed that RNI was affected by age at first freshening, milk yield and days of productive life (DPL), regardless of production system, and a similar breeding goal could be defined for the two systems. Multiple regression analysis of RNI showed that in order to obtain an unbiased estimate of economic value for DPL, the per day milk yield, not total lifetime milk yield, should be included in the regression model along with DPL. Regression analysis suggested that it is possible to predict RNI using information on age at first freshening along with the length of first lactation and per day milk yield with a coefficient of determination ranging from 0.44 to 0.47.