목적 : 대구지역 중학교 2학년의 시력, 굴절상태 및 안경교정 상태를 분석하였다. 방법 : 2017년 대구지역 중학교 2학년 182명(364안)을 대상으로 시력검사, 타각적/자각적 굴절검사로 1.0까지 완전교정, 기초 양안시 검사 등 및 안경착용 상태를 검사하였으며, 등가구면굴절력을 기초로 굴절이상 및 굴절상 태를 비교 분석하였다. 결과 : 참여학생 182명(364안) 중 정시는 121안(33.24%), 비정시는 243안(66.76%)으로 평균은 –1.54±2.25 D로 나타났다. 비정시 243안 중 근시성은 241안 평균 -2.98±2.15 D로 나타났으며, 원시성은 2안 평균 +3.50± 0.35 D 를 보였다. 근시성은 241안 중 고도근시는 24안(9.96%), 중도근시는 79안(32.78%) 그리고 저도근시는 138안(57.26%) 을 보였다. 전체 대상자 중 86명(47.25%)이 기존에 안경을 착용하고 있었다. 153안(42.03%)이 0.8 이상의 시력 그 리고 211안(57.97%)이 0.7 이하의 시력을 보였다. 시력 검사 전과 후의 등가구면굴절력은 각각 –1.54± 2.25 D와 – 1.96±2.27 D로 약 -0.42 D 정도 교정이 더 필요한 상태를 보였다(p＜0.010, t=9.46). 안경착용자 86명(172안)의 교정 전과 후는 각각 -3.25±2.27 D과 -3.47±2.29 D로 나타나, 약 -0.23 D의 추가 교정이 필요한 것으로 나타났 다(p＜0.010, t=3.97). 결론 : 중학교 2학년의 비정시는 근시가 주된 원인이었으며, 근시 정도는 중도근시에 가까운 심각한 굴절이상도 를 보였다. 안경착용 중이거나 미착용학생 모두 정기적인 시력검사가 중요하며 추후 전반적인 학생들의 지속적인 관 찰과 연구가 필요할 것으로 보인다.

목적 : 경북 경산시 내외의 2학년 초등학생들의 굴절상태와 교정상태를 비교 분석하였다. 방법 : 2015년 경산교육지원청 주관 ‘밝고 투명한 아이(eye)만들기’사업의 2차 사업으로 경산지역 전체 초등학교 31개교 중 27개교가 참여한 2학년 초등학생 1,662명(3,324안)을 대상으로 굴절상태와 안경착용 상태를 검사하였다. 도시지역과 농촌지역으로 구분하여 등가구면굴절력을 기초로 굴절이상을 비교 분석하였다. 결과 : 검사에 참여한 전체 초등학생 1,662명 중 207안(6.23%)이 정시, 3,117안(93.77%)이 평균 –1.01±1.32 D의 비정시로 나타났으며, 비정시중 근시성이 2693안으로 평균 –1.27±1.19 D 그리고 원시성이 424안으로 평균 0.62±0.79 D이었고, 근시안과 원시안의 비율은 전체 대상자에서 각각 81.02%와 12.75%를 보였다. 이 비정시안 들 중 454명(27.31%)이 안경을 착용하고 있었으며, 655안(19.70%)이 시력 0.7 이하로 교정이 필요한 상태였다. 지역 간 비교에서 도시와 농촌지역 초등학생들의 굴절이상도는 각각 –1.01±1.35 D와 –0.87±1.23 D로 통계적으 로 유의한 차이(p<0.010, t=-3.06)를 보였다. 근시성 굴절이상의 비교에서는 도시지역은 -1.32±1.23 D, 농촌지 역은 –1.20±1.14 D로 도시지역 학생들이 더 많은 근시성 굴절이상을 갖고 있었지만(p<0.010, t=2.74), 원시성에 는 유의한 차이를 보이지 않았다(p>0.050, t=1.71). 안경착용은 도시지역 초등학생들이 농촌지역 학생들 비해 5.78% 정도 더 많은 안경을 착용하고 있었다(p=0.001). 결론 : 굴절이상의 변화에 있어 중요한 시기인 저학년만을 대상으로 한 본 연구 결과에서 도시와 농촌 지역에 관계없이 근시가 주된 굴절이상의 원인으로 나타났으며, 앞으로 급속히 증가하는 초등학생 근시의 변화 추적 및 예방을 위해 지속적인 연구와 대책이 필요할 것으로 보인다.

In recent years, the diminishing of operation and maintenance cost using advanced maintenance technology is attracting many companies’ attention. Especially, the heavy machinery industry regards it as a crucial problem since a failure of heavy machinery requires high cost and long downtime. To improve the current maintenance process, the heavy machinery industry tries to develop a methodology to predict failure in advance and to find its causes using usage data. A better analysis of failure causes requires more data so that various kinds of sensor are attached to machines and abundant amount of product usage data is collected through the sensor network. However, the systemic analysis of the collected product usage data is still in its infant stage. Many previous works have focused on failure occurrence as statistical data for reliability analysis. There have been less works to apply product usage data into root cause analysis of product failure. The product usage data collected while failures occur should be considered failure cause analysis. To do this, this study proposes a methodology to apply product usage data into failure cause analysis. The proposed methodology in this study is composed of several steps to transform product usage into failure causes. Various statistical analysis combined with product usage data such as multinomial logistic regression, T-test, and so on are used for the root cause analysis. The proposed methodology is applied to field data coming from operated locomotive and the analysis result shows its effectiveness.

The purpose of this study was to determine the health behaviors and nutritional status related to dyslipidemia in Korean middle-aged adults (between 50 and 64 years old) from the Korean National Health and Nutrition Examinations Survey data (2007~2010). A total of 4,721 subjects were analyzed in this study. The subjects were divided into three groups (normal, borderline, and dyslipidemia) according to serum lipid levels. Parameters included in this study were drinking and smoking, anthropometric parameters, blood and nutritional parameters. The latter parameter included food/nutrients intake. All data was adjusted by sex, region, education level, and age. General linear model and logistic regression model were used for statistical analysis. The dyslipidemia group was comprised of more men than women. By contrast, the borderline group was comprised of more women than men (p<0.001). No significant differences were observed for other general characteristics. There were more smokers and drinkers(drinking per time) in the dyslipidemia group (p<0.05). Anthropometric data showed significant difference, ie, height (p<0.05), weight, body mass index, waist circumference, percent body fat, and blood pressure were higher in the dyslipidemia group (p<0.001). Only blood urea nitrogen showed no significant difference among groups. The HbA1c (p<0.01), fasting blood glucose, GOT, GPT, creatinine levels were higher in the dyslipidemia group (p<0.001). So it is required for the management of obesity in dyslipidemia group. The dyslipidemia group ate less sea food (p<0.05). The nutrients intake of energy and protein, thiamin, riboflavin, niacin, calcium, phosphorus were lower in the dyslipidemia group (p<0.05). Therefore, to lower dyslipidemia prevalence rates, it is necessary to increase the intake of foods containing ω-3 fatty acids. We also suggest a meal management program and nutritional education to recognize the risk of dyslipidemia, especially for people such as the individual in the borderline and dyslipidemia study groups. Key words: dyslipidemia, Korean middle-aged adults, nutritional status, health behaviors

The purpose of this study was to evaluate dietary habit and nutritional status by household income in female adults, using data from the 4th Korea National Health and Nutrition Examination Survey (2007~2009). Subjects were 8,356 women over the age of 20 years. The subjects were classified into 4 groups by household income level. Dietary data from 24 hr recall methods were used to analyze nutritional status. The obesity rate of the low income group was significantly higher than the rates of other income groups. Additionally, the nutritional status of the low income group was worse than those of other groups. The percentage of carbohydrate in total energy intake was higher and food security status was lower in the low income group than in other groups. Awareness and adherence to dietary guidelines were also lower in the low income group. Adherence to a dietary guideline of ‘avoiding salty foods and trying to eat foods with bland taste’ and ‘eating a variety of foods from each food group’ were lower than those of other groups. However, the frequency of skipping breakfast among the low income group was lower than that of others. Therefore, this study suggested that low income women should decrease the percentage of carbohydrate in total energy intake and adhere to dietary guidelines, especially those of avoiding salty foods and eating a variety of food groups, in order to improve their nutritional status.

Structural dynamic properties such as natural frequency depend not only on damage but also environmental condition (i.e., Temperature). Without removing the variation of environmental condition in the damage detection, false-positive or negative damage diagnosis may occur so that structural health monitoring becomes unreliable. One of methods used to solve this problem is to construct regression model based on structural responses with the environmental factors. However, it is difficult to determine where and which environmental variables to measure. One alternative is to remove the variability due to environmental variation without measurement of environmental variables. However, the performance of this method is depending on how to define the reference data set. Generally, there is no prior information on reference condition (i.e., healthy condition) during data mining. Reference condition is determined based on subjective perspective with human-intervention. To overcome the drawback of current methods, this paper investigates adaptive PCA technique for the monitoring of structural damage detection under environmental change. This method is not required to determine the reference condition and measure the environmental variables. Proposed method is tested on numerically simulated data for a range of noise in measurement under environmental variation.