• Journal of information and communication convergence engineering
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• 제9권4호
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• pp.475-482
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• 2011

In this research, we have attempted to estimate the water quality of fish farms in terms of parameters such as water temperature, dissolved oxygen, pH, and salinity by employing observational data obtained from a coastal ocean observatory of a national institution located close to the fish farm. We requested and received marine data comprising nine factors including water temperature from Korea Hydrographic and Oceanographic Administration. For verifying our results, we also established an experimental fish farm in which we directly placed the sensor module of an optical mode, YSI-6920V2, used for self-cleaning inside fish tanks and used the data measured and recorded by a environment monitoring system that was communicating serially with the sensor module. We investigated the differences in water temperature and salinity among three areas - Goheung Balpo, Yeosu Odongdo, and the experimental fish farm, Keumho. Water temperature did not exhibit significant differences but there was a difference in salinity (significance <5%). Further, multiple regression analysis was performed to estimate the water quality of the fish farm at Keumho based on the data of Goheung Balpo. The water temperature and dissolved-oxygen estimations had multiple regression linear relationships with coefficients of determination of 98% and 89%, respectively. However, in the case of the pH and salinity estimated using the oceanic environment with nine factors, the adjusted coefficient of determination was very low at less than 10%, and it was therefore difficult to predict the values. We plotted the predicted and measured values by employing the estimated regression equation and found them to fit very well; the values were close to the regression line. We have demonstrated that if statistical model equations that fit well are used, the expense of fish-farm sensor and system installations, maintenances, and repairs, which is a major issue with existing environmental information monitoring systems of marine farming areas, can be reduced, thereby making it easier for fish farmers to monitor aquaculture and mariculture environments.

• 한국과학교육학회지
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• 제22권5호
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• pp.1010-1029
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• 2002

The purpose of this research was to survey middle school students' preference for science and its causal factors, so as to analyze the causal relationships between them. Preference for science and its causal factors were defined theoretically, and a theoretical model was constructed to measure them and analyze the causal relationship by structural equation modeling. According to the theoretical model and a pilot test, a questionnaire was developed with three parts; the background information of a respondent, the preference for science, and the causal factors of preference. The questionnaire was administered to one class per grade of randomly selected 8 middle schools from 4 areas across the country, and 819 students' data were collected. Preference for science was defined as a state of mind. It revealed to what extent, and how, one likes science. It consisted of 3 categories - 'emotional response', 'behavioral volition', 'valuational comprehension', and each category was divided into two subcategories. Causal factors affecting the preference for science consisted of three categories - personal, educational and social factors, and each was divided into 2 or 3 subcategories. Middle school students' preference for science was middling as a total. Curiosity about contents of science and valuation of science were high, comparatively, but behavioral volition about science was especially low. Students' responses to the causal factors were relatively high in every educational factor and sociocultural valuation of social factors, but relatively low in socioeconomic rewards of social factors, and especially low in personal factors. The causal relationship about the preference for science was investigated by multiple regression analysis and path analysis, using the structural equation model. Multiple regression analysis about the preference for science and its causal factors revealed important factors. The important factors were personal ability, the personal traits, rewards in school science, and contents of school science in order of magnitude of standardized regression coefficient ${\beta}$. Stepwise regression analysis with each of the subcategories of the preference for science as dependent variables showed what factors were important in each subcategory. According to the result of structural equation modeling, personal factors affected 'emotional response' and 'behavioral volition' directly, and social factors affected 'valuational comprehension' directly. Educational factors affected all categories of the preference for science by influencing not only 'emotional response' and 'valuational comprehension' directly, but also 'behavioral volition' indirectly. The way to promote middle school students' preference for science was suggested, based on the analysis result.

• 대한소아치과학회지
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• 제34권3호
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• pp.430-437
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• 2007

현재 혼합치열 분석 방법으로 가장 널리 사용되고 있는 Moyers의 예측표나 Tanaka와 Johnston의 예측방정식은 북유럽 인종의 백인 자료를 바탕으로 만들어졌기 때문에 한국인에게 적용하기에는 무리가 있다. 또한 최근에는 이들이 제시한 하악 전치에 기초한 방법이 미맹출 견치와 소구치 폭경의 합을 예측하기 위한 최적의 예측인자인지에 대해서도 의문이 제기되고 있다. 본 연구의 목적은 한국인 집단을 대상으로 미맹출 견치와 소구치의 근원심 폭경을 예측하기 위한 최적의 예측인자가 어떤 치아의 조합인지 밝히고, 그 조합을 이용한 예측 방정식을 제시하며, 새로운 예측 방정식의 임상 적용을 위해 그 타당성을 검증하는 것이다. 완전한 영구치열을 가진 성인 178명(남자 108명, 여자 70명, 평균 나이 21.63세)의 자료를 기초로 예측방정식을 도출하였으며, 53명의 청소년(남자 25명, 여자 28명, 평균 나이 14.22세)으로 검증집단을 구성하여 그 타당성을 검증하였다. 그 결과 다음과 같은 결론을 얻었다. 1. 한국인 혼합치열기 청소년에서 미맹출 견치와 소구치 폭경의 합을 예측하기 위한 최적의 치아 조합은 상악 중절치, 하악 측절치, 상악 제1대구치 폭경의 합이었다($r=0.65{\sim}0.80$). 2. 상악 중절치, 하악 측절치, 상악 제1대구치 폭경의 합을 기초로 하고 부가적인 설명 변수로 성별과 악궁을 포함시켜 계산한 예측 방정식은 다음과 같이 계산되었다. 남자, 상악: $Y\;=\;0.332{\times}X_0\;+\;6.195$ 남자, 하악: $Y\;=\;0.332{\times}X_0\;+\;5.269$ 여자, 상악: $Y\;=\;0.332{\times}X_0\;+\;5.929$ 여자, 하악: $Y\;=\;0.332{\times}X_0\;+\;5.003$ 예측 방정식의 설명력은 64%였으며 표준오차(SEE)는 0.71mm였다. 3. 새로운 예측 방정식을 검증 집단에 적용하여 검증한 결과, 약 97%에서 실제 측정한 견치와 소구치 폭경의 합과 예측치와의 차이가 1mm 이하였다.

• 한국환경보건학회지
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• 제7권1호
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• pp.1-7
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• 1981

During 20 days from November 4 to 28, 1980, the quantities of grease and oil, BOD (biological oxygen demand), COD (chemical oxygen demand), SS (suspended solid) were measured at Grit Chamber, Primary Sedimentation Tank, Secondary Sedimentation Tank in Chung Gye Chun sewage treatment plant. The results were as follows. 1. The average of grease and oil quantities were 251mg/l at Grit Chamber, 185mg/l at Primary Sedimentation Tank, 47mg/l at Secondary Sedimentation Tank. 2. In the secondary treatment for the removal of grease and oil, the removed quantities of grease and oil were increased according to increasing the quantities of influent grease and oil. The regression equation were as follows G.O.removed=0.731 G.O. influent+3.235 (r=0.887) 3. The average of grease and oil removal rate was 76.4% and the standard deviation of grease and oil removal rate daily was 10.6%. 4. G.O. (grease and oil) and BOD, COD, SS showed significant correlationship at Grit Chamber, Primary Sedimentation Tank, Secondary Sedimentation Tank. (P<0.05). 5. In the secondary treatment, effluent grease & oil and other parameters were analyzed by means of Stepwise multiple regression. Multple regression equation for estimates of effluent grease and oil were as follows. $GO_E=-9.1637+2.0380 SS_E+0.068 SS_I$ (r=0.778) 6. The correlative parameters for the effluent grease and oil seem to be the influent SS and the effluent SS. 7. It was estimated that the removal of grease and oil would be improved by means of improvement of suspended solids removal efficiency but it is necessary to inquire further into the study.

• 간호행정학회지
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• 제17권2호
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• pp.189-197
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• 2011

Purpose: This study was an analysis of the relationship between perception for appraisal of staff nurses in operating rooms and performance and organizational commitment. Method: The survey was conducted with 176 staff nurses in operating rooms in 2 hospitals in Seoul. Data were analyzed using frequency, one-way ANOVA, Pearson correlation analysis, and stepwise multiple regression. Result: 1. Perception for appraisal including accuracy and justice was significantly related to organizational commitment (r=.496, P=.000). Perception for appraisal including accuracy and justice was slightly related to performance (r=.220, P=.003). 2. In order to determine the percentage of the variance of performance and organizational commitment that could be predicted by perception for appraisal, perception for appraisal was entered in the regression equation. Accuracy accounted for 25% of the variance in the organizational commitment. To determine the percentage of the variance of performance that could be predicted by perception for appraisal and organizational commitment, the perception for appraisal and organizational commitment were entered in the regression equation. Organizational commitment accounted for 21% of the variance in the performance. Consequently accuracy predicted organizational commitment. Organizational commitment predicted performance. Conclusions: Findings indicate the need to increase accuracy of performance appraisal to promote organizational commitment and performance in perioperative nurses.

• 한국전문물리치료학회지
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• 제18권4호
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• pp.11-18
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• 2011

The aim of this study was to analyze the relationship between physical impairments and daily activities on the basis of the outcome measurements in stroke patients. Seventy-six stroke patients participated in this study. Two physical therapists evaluated 3 clinical common measurements, i.e., the Fugl-Meyer Assessment (FMA), the Berg Balance Scale (BBS), and the Functional Independence Measure (FIM). Multiple regression analysis was used, as the dependent variables were the BBS and FIM; the independent variables were post-stroke duration, FMA of Upper Extremity (FMU), and FMA of Lower Extremity (FML). In the regression equation of the BBS, the coefficient of determination ($R^2$) was .383, and the FML was found to be the most important variable for determining the BBS score. In the regression equation of the FIM, $R^2$ was .531, and the FML was found to be the most important variable for determining the FIM. These results suggest that there is a need to determine the function of activities on the basis of the physical impairments of stroke patients. More variable measurement tools on the levels of body function and structure, as well as activity limitations are required.

• 한국농공학회논문집
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• 제61권1호
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• pp.9-20
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• 2019

The primary objective of this study was to analyze the delivery ratio using Hydrological Simulation Program - Fortran (HSPF) in Okdong-cheon watershed. Model parameters related to hydrology and water quality were calibrated and validated by comparing model predictions with the 8-day interval filed data collected for ten years from the Korea Ministry of Environment. The results indicated that hydrology and water quality parameters appeared to be reasonably comparable to the field data. The pollutant delivery loads of the watershed in 2015 were simulated using the HSPF model. The delivery ratios of each subwatershed were also estimated by the simple ratio calculation of pollutant discharge load and pollutant delivery load. Coefficients of the regression equation between the delivery ratio and specific discharge were also computed using the delivery ratio. Based on the results, multiple regression analysis was performed using the discharge and the physical characteristics of the subwatershed such as the area. The equation of delivery ratio derived in this study is only for the Okdong-cheon watershed, so the larger studies are needed to apply the findings to other watersheds.

• Journal of Forest and Environmental Science
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• 제24권3호
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• pp.155-158
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• 2008

Site index is the essential tool for forest management to estimate the productivity of forest land Generally, site index equation is developed and used by relationship between stand age and dominant tree heights. However, there is a limit to use the site index equation in the application of variable ages, environmental influence, and estimation of site index for unstocked land. Therefore, it was attempted to develop a new site index equations based on various environmental factors including site and topographical variables. This study was conducted to develop regional site index equations based on the relationship between site index and soil factors for Pinus densiflora. Environmental factors that obtained from GIS application, were selected by stepwise-regression. Site index Equation was estimated by multiple regression from selected factors. Four environmental factors were selected in the final site index equations by stepwise regression. It was observed that coefficients of determination for site index equations were ranged from 0.34 which seem to be relatively low but good enough for estimation of forest stand productivity. The site index equations developed in this study were also verified to be useful by three evaluation statistics such as model's estimation bias, model's precision and mean square error type of measure.

• 한국산림과학회지
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• 제89권3호
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• pp.297-305
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• 2000

이 연구는 북한산국립공원(北漢山國立公圓) 북동사면(北東斜面) 일대(一帶) 계류수질(溪流水質) 오염(汚染)에 영향(影響)하는 인자(因子)를 파악함으로써 국립공원내 계류수질 보전을 위한 과학적 기초 자료를 제공하기 위하여 1998년 7월부터 1999년 11월까지 수행하였다. 계류수질오염(溪流水質汚染)을 판단하는 지표(指標)인 전기전도도(電氣傳導度)의 설명에 유의한 영향을 미치는 인자는 탐방객수와 $Cl^-$ 점유비 등 2개 인자로 5% 수준에서 유의하여 북한산국립공원을 이용하는 탐방객수(探訪客數)의 증가(增加)는 계류수의 전기전도도(電氣傳導度)를 상승시켜 계류수질(溪流水質) 오염(汚染)에 영향(影響)을 미치는 것으로 분석(分析)되었다. 다중회귀분석결과 용존산소포화도의 설명에 유의한 영향을 미치는 인자는 용존산소량과 수온 등 2개 인자로 1% 수준에서 유의하였다. $Cl^-$의 설명에 유의한 영향을 미치는 인자는 전기전도도, $K^+$, $Na^+$, $SO_4{^{2-}}$, 이온총량, $Cl^-$점유비, $SO_4{^{2-}}$점유비 등 7개 인자로 5%, 1% 수준에서 유의하였다. 또한, $NO_3{^-}$의 설명에 유의한 영향을 미치는 인자는 $Na^+$, $Ca^{2+}$, $SO_4{^{2-}}$, $Cl^-$점유비, $NO_3{^-}$점유비 등 5개 인자로 5%, 1% 수준에서 유의하였으며, $SO_4{^{2-}}$의 설명에 유의한 영향을 미치는 인자는 $NO_3{^-}$, 이온총량 등 2개 인자로 5% 수준에서 유의하였다.

• 한국의류학회지
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• 제9권1호
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• pp.17-27
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• 1985

In order to investigate the warmth retaining properties of fabrics some characteristics such as thickness. porosity, packing density, thermal conductivity, moisture regain and air permeability were measured and experimental results were analysed statistically to relate the warmth retaining properties with those characteristics. From the analysis, the following results were obtained. 1. When the warmth retaining properties of fabrics (Y) are dependent variable and thickness ($x_1$), porosity ($x_2$), packing density ($x_3$), thermal conductivity ($x_4$), moisture regain ($x_5$) and air permeability ($x_6$) are independent variables, the regression equation of warmth retaining properties can be represented as follows. 1) Y= 1.6005+46.817$x_1$, (R=0.9487) 2)Y=-1.4187+26.5072$x_1$+0.2055$x_2$(R=0.9704) 3) Y= -3.6908+17.4482$x_1$+0.1782$x_2$+28.3243$x_3$ (R=0.9756) 4) Y=0.9202+16.9553$x_1$+0. 1167$x_2$+30.3577$x_3$+1.8884$x_4$ (R=0.9792) 5) Y=0.9353+17.2266$x_1$+0.1177$x_2$+28.9821$x_3$-1.8302$x_4$+0.0151$x_5$ (R=0.9792) 6) Y=0.7583+17.2343$x_1$+0.1196$x_2$+28.8830$x_3$-1.8336$x_4$+0.0187$x_5$0.0004$x_5$ (R=0.9792) 2. The warmth retaining properties of fabrics are merely affected by adding thermal conductivity, moisture regain and multiple regression equation which contains thickness, porosity and packing density as variables. Therefore the multiple regression which contains thickness, porosity and packing density as variables Y=-3.6908+17.4482$x_1$+0.1782$x_2$+28.3243$x_3$ is highly practical.