• 한국보건간호학회지
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• 제29권2호
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• pp.165-176
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• 2015

Purpose: This study was conducted to examine the relationships of depression symptom, self-esteem, and stress with health-related quality of life(HRQOL) in patients with hypertension registered to a community health center. Methods: This study was a correlational survey using a convenience sampling. A total of 110 patients diagnosed with hypertension were recruited from a health center in Gyeonggi-do. The questionnaires used were the Cardiovascular Disease Specific-HRQOL questionnaire, Center for Epidemiologic Studies Depression, Rosenberg Self-Esteem Scale, and Perceived Stress Scale. The acquired data were analyzed using IBM SPSS version 22.0. Multiple linear regression analysis was performed. Results: Moderate depression symptom(${\beta}=-.368$, p<.001), severe depression symptom (${\beta}=-.450$, p<.001), stress(${\beta}=-.339$, p=.001), and gender(${\beta}=-.148$, p=.049) were significant predictors for the HRQOL. Multiple linear regression showed that 51.8% ($R^2=.518$) of the variance in the HRQOL was explained. Conclusion: Based on these results, development of an intervention or education program, to decrease depression symptoms and stress is recommended. This may improve the HRQOL in patients with hypertension registered to a community health center.

• Near Infrared Analysis
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• 제1권2호
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• pp.35-39
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• 2000

The purpose of this research was to find out suitable soil sample preparation and sample holding tools for NIR reflection radiation for estimating soil components. NIR reflectance was scanned at 2nm intervals from 1,100 to 2,500nm with an InfraAlyzer 500(Bran+Luebbe Co.). Coarse(2.0mm) and fine(0.5mm) soil sample and various sample holding tools were used to obtain mean diffuse reflection of the soil for the calibration and validation of the calibration set in estimating moisture, organic matter and total nitrogen of the soils. Multiple linear regression was used to obtain the best correlation of NIR spectroscopy method. Correlation of NIR spectroscopy method. Correlation of NIR spectra for finely and coarsely sized soil did not show much difference. The standard errors of prediction(SE) using different types of sample holding tools for organic matter, total nitrogen and soil moisture were better than 0.765, 0.041 and 0.63% respectively. From the results it can be concluded that NIR spectroscopy with flow type cell could be used as a fast routine testing method in quantitative determination of organic matter, total nitrogen and soil moisture.

• 한국도로학회논문집
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• 제15권2호
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• pp.121-129
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• 2013

PURPOSES : This study deals with the traffic accidents of rotary in Korea. The objective of this study is to develop the accident models by age group based on the various data of rotaries. METHODS : In pursuing the above, this study gives particular attentions to classifying the accident data of 17 rotaries by age, collecting the data of geometric structure, traffic volume and others, and developing the models using SPSS 17.0 and EXCEL. RESULTS : First, 3 multiple linear regression models which were all statistically significant were developed. The value of model of under 30-49 age group were, however, evaluated to be 0.688 and be less than those of other models. Second, the most powerful variables were analyzed to be traffic volume in the model of under 30 age group, circulatory roadway width in the model of 30-49 age group, and the number of approach lane in the model of above 50 age group. Finally, the test results of accident models using RMSE were all evaluated to be fitted to the given data. CONCLUSIONS : This study propose install streetlights, speed humps and widen Circulatory as effective improvements for reduction of accident in rotary.

• International Journal of Automotive Technology
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• 제4권2호
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• pp.101-108
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• 2003

There are a lot of factors that influence automotive fuel economy such as average trip time per kilometer, average trip speed, the number of times of vehicle stationary, and so forth. These factors depend on road conditions and traffic environment. In this study, various driving data were measured and recorded during road tests in Seoul. The accumulated road test mileage is around 1,300 kilometers. The objective of the study is to identify the driving patterns of the Seoul metropolitan area and to analyze the fuel economy based on these driving patterns. The driving data which was acquired through road tests was analysed statistically in order to obtain the driving characteristics via modal analysis, speed analysis, and speed-acceleration analysis. Moreover, the driving data was analyzed by multivariate statistical techniques including correlation analysis, principal component analysis, and multiple linear regression analysis in order to obtain the relationships between influencing factors on fuel economy. The analyzed results show that the average speed is around 29.2 km/h, and the average fuel economy is 10.23 km/L. The vehicle speed of the Seoul metropolitan area is slower, and the stop-and-go operation is more frequent than FTP-75 test mode which is used for emission and fuel economy tests. The average trip time per kilometer is one of the most important factors in fuel consumption, and the increase of the average speed is desirable for reducing emissions and fuel consumption.

• 한국산학기술학회논문지
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• 제16권4호
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• pp.2828-2836
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• 2015

2종 시설물에 해당하는 국도 내 암반비탈면의 평가체계를 보완, 수정하기 위해 문헌자료를 바탕으로 평가항목 후보를 도출하고, 전문가를 대상으로 델파이 설문을 실시하여 암반비탈면의 최종 평가항목을 선정하였다. 단계별 다중회귀분석을 통해 평가 항목의 유의성을 검토한 결과 도출된 항목은 모두 유의확률 0.05이하로 유의미한 것으로 나타났고, 비교적 유사한 수준의 가중치를 나타내어 평가항목이 타당하게 선정되었다는 것을 확인하였다. 제안된 평가항목과 기존 평가항목에 대하여 내용타당도(CVR)와 신뢰도를 검토를 통해 기존 평가체계에서 제외될 수 있는 항목을 선정하고 기존 평가체계를 보완할 수 있는 항목을 추가하여 최종적으로 18개의 암반비탈면 평가항목을 도출하였다.

• 한국분무공학회지
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• 제20권4호
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• pp.247-253
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• 2015

Recently, the engine calibration technique has been much more complicated than that of the past engine case in order to satisfy the strict emission regulations. The current calibration method for the diesel engine which has an increasing market is both costly and time-consuming. New engine calibration method is required to develop for high-quality diesel engines with low cost and release it at the appropriate time. This study provides the optimal calibrating technique for complex engine systems using statistical modeling and numerical optimization. Firstly, it design a test plan based on Design of Experiments, a V-optimality methodology which is suitable looking for set-points, and determine the shape of test engine response. Secondly, it uses functions to make linear regression model for data analysis and optimization to fit the models of engines behavior. Finally, it generates the optimal calibrations obtained directly from empirical engine models using Grey Relational Analysis and compares the calibrations with data. This method can develop a process for systematically identifying the optimal balance of engine emissions.

• 한국보건간호학회지
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• 제20권2호
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• pp.141-150
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• 2006

Purpose: This study was conducted to investigate the levels of ego-identity and related factors in middle-aged women who lived in G city. Methods: The participants in this descriptive study were 437 middle-aged (40-60 year old) women. Data were collected from January to February, 2006. Personal interviews with a structured questionnaire (9 items of general characteristics, 30 items of subjects' characteristics related to health and 56 items of ego-identity) were conducted used. The data were analyzed using descriptive statistics, t-test, ANOVA, and multiple linear regression analysis. Results: Ego-identity was significantly associated with the variables of age, educational level, monthly income, living with the parents of the subject's husband, number of children, smoking. exercise, depression, perceived health status, and satisfaction of marital status (p<0.05). In multiple linear regression analysis of the subjects' characteristics which were significantly associated with ego-identity, monthly income, living with the parents of the subject's husband, and depression were significant variables (p<0.05). Conclusion: It is necessary to study the depression of middle-aged women in Geoje city and develop programs with consideration for the significant factors which can improve their ego-identity.

• 한국안전학회지
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• 제24권1호
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• pp.1-6
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• 2009

In machining of ceramic materials, they are very difficult-to cut materials because of there high strength and hardness. Machining of ceramics are characterized by cracking and brittle fracture. Generally, ceramics are machined using conventional method such as grinding and polishing. However these processes are generally costly and have low MRR(material removal rate). This paper focuses on machinability evaluation of machinable ceramics for products with CNC machining center. Thus, in this paper, experiment applying cutting parameters is performed based on experimental design method. A design and analysis of experiments is conducted to study the effects of these parameters on the surface roughness by using the S/N ratio, analysis of ANOVA, and F-test. And multiple linear regression analysis is applied to compare experimental with predicted data in consideration of surface roughness. Cutting parameters, namely, feed, cutting speed and depth of cut are used to accomplish purpose of this paper. Required experiments are performed, and the results are investigated.

• 한국보건간호학회지
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• 제35권1호
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• pp.47-59
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• 2021

Purpose: To assess levels of mental health among community health practitioners during the COVID-19 outbreak in Korea and associations between practitioner mental health and personal and psychosocial factors. Methods: Data were collected from a convenient sample of 275 community health practitioners using an online questionnaire, which included items on mental health (K-WEMWBS), psychosocial factors (COVID-19 sensitivity, COVID-19 self-confidence, social support, perceived stress), and personal characteristics. Collected data were analyzed using the t-test, one-way ANOVA, Scheffe's test, Pearson's correlation coefficients, and multiple linear regression in SPSS 25.0. Results: Mean mental health score was 51.27±8.47. Multiple linear regression revealed that time spent as a community health practitioner, COVID-19 self-confidence, social support, and perceived stress were significantly associated with mental health. Conclusion: The findings of this study suggest that comprehensive intervention with emphases on improving COVID-19 self-confidence, social support, and reducing stress is required to improve community health practitioner mental health. The results also indicate a need for educational programs aimed at improving the mental health of young community health practitioners.

• Journal of Information Processing Systems
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• 제14권6호
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• pp.1508-1520
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• 2018

In this paper, we propose an improved model to provide users with a better long-term prediction of waterworks operation data. The existing prediction models have been studied in various types of models such as multiple linear regression model while considering time, days and seasonal characteristics. But the existing model shows the rate of prediction for demand fluctuation and long-term prediction is insufficient. Particularly in the deep running model, the long-short-term memory (LSTM) model has been applied to predict data of water purification plant because its time series prediction is highly reliable. However, it is necessary to reflect the correlation among various related factors, and a supplementary model is needed to improve the long-term predictability. In this paper, convolutional neural network (CNN) model is introduced to select various input variables that have a necessary correlation and to improve long term prediction rate, thus increasing the prediction rate through the LSTM predictive value and the combined structure. In addition, a multiple linear regression model is applied to compile the predicted data of CNN and LSTM, which then confirms the data as the final predicted outcome.