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This study demonstrates the effects of technologies applied for the development of gasoline direct injection (GDI) engine for improving the brake thermal efficiency (BTE). The test engine has a relatively high stroke to bore ratio of 1.4 with a displacement of 2156 cm3. All experiments have been conducted for stoichiometric operation at 2000 RPM. First, since compression ratio (CR) is directly related to the thermal efficiency, four CR were explored for operation without exhaust gas recirculation (EGR). Then, for the same four CR, EGR was used to suppress the knock occurrence at high loads, and its effect on initial and main combustion duration was compared. Second, the shape of intake port was revised to increase tumble flow for reducing combustion duration, and extending EGR-stability limit further. Then, as an effective method to ensure stable combustion for EGR-diluted stoichiometric operation, the use of twin spark ignition (SI) system is examined by modifying both valve diameters of intake and exhaust, and its effect is compared against that of single spark ignition. In addition, the layout of twin spark ignition was also examined for the location of front-rear and intake-exhaust. To get the maximum BTE at high load, 12 V electronic super charger (eSC) was applied. Under the condition of using 12 V eSC, the effect of intake cam duration was identified by increasing from 260 deg to 280 deg. Finally, 48 V eSC was applied with the longer intake camshaft duration of 280 deg. As a result, the maximum BTE of 44% can be achieved for stoichiometric operation with EGR.

This study demonstrates the effects of technologies applied for the development of a gasoline direct injection (GDI) engine for improving the brake thermal efficiency (BTE) over 44%. The GDI engine for the current study is an in-line four-cylinder engine with a displacement of 2156cm3, which has relatively high stroke to bore ratio of 1.4 (110mm stroke and 79mm bore). All experiments have been conducted using a gasoline having RON 92 for stoichiometric operation at 2000RPM. First, since compression ratio is directly related to the thermal efficiency, four compression ratios (14.3, 15.2, 15.8 and 17.2) were explored for operation without exhaust gas recirculation (EGR). Then, for the same four compression ratios, EGR was used to suppress the knock occurrence at high loads with high compression ratio (CR), and its effect on initial and main combustion duration was compared. Second, the shape of intake port was revised to increase tumble flow of in-cylinder charge for reducing combustion duration at low and high load, and extending EGR-stability limit further eventually. Then, as an effective method to ensure stable, complete and fast combustion for EGR-diluted stoichiometric operation, the use of twin spark ignition system is examined by modifying both valve diameter of intake and exhaust, and its effect is compared against that of single spark ignition. In addition, the layout of twin spark ignition was also examined for the location of Front-Rear and Intake-Exhaust. To get the maximum BTE at high load, 12V electronic super charger (eSC) was applied. Under the condition of using 12V eSC, the effect of intake cam duration was identified by increasing from 260deg to 280deg. Finally, 48V eSC was applied with the longer intake camshaft duration of 280deg. As a result, the maximum BTE of 44% can be achieved for stoichiometric operation with EGR.

The purpose of the study is to assess the relationship between the prevalence of metabolic syndrome–related risk factors and work tenure among office workers. A 10-year cohort analysis was conducted using employees’ health examinations given to new employees within 1 or 2 years of joining the firm and every 5 years thereafter. Age-adjusted odds ratios (95% confidence interval [CI], p < .05) were calculated based on a contrast test with general estimating equations. Specifically, the age-adjusted odds ratios and CIs of those with 20 ± 1 years of work, compared with those with 1 to 2 years of work, were as follows: triglycerides (≥150 mg/dl) 3.01 (2.11, 4.28), waist circumference (male ≥90 cm) 2.70 (1.63, 4.45), and fasting glucose (≥100 mg/dl) 2.67 (1.78, 4.01). The findings of the relationship between metabolic syndrome risk and work tenure as well as the baseline health data of new employees provide a foundation for developing a workplace health management system.

Background: The purpose of this study is to assume appropriate outpatient consultation time for each clinical department on the ba-sis of measured outpatient consultation time and satisfaction of outpatient.Methods: We surveyed the feeling and satisfactory outpatient consultation time, satisfaction, revisiting intention and recommenda-tion to others to 1,105 patients of single general hospital in Gyeonggi-do and measured their real outpatient consultation time from October 28 to November 27 in 2013. On the basis of satisfaction, we estimated appropriate outpatient consultation time through area under the receiver operating characteristic curve in logistic regression model.Results: Feeling outpatient consultation time was 5.1 minutess, satisfactory outpatient consultation time which was suggested by patient was 6.3 minutes, and real outpatient consultation time was 4.2 minutes. Department which had longest real outpatient con-sultation time was infection (7 minutes) and department which had longest satisfactory outpatient consultation time was neurology (9.4 minutes). From the univariate and the multiple linear regression analysis, real outpatient consultation time was longer in pulmon-ology patient, new patient and afternoon patient, satisfactory outpatient consultation time was longer in infection, neurology, neuro -psychiatry, neurosurgery, and rehabilitation patient. Appropriate real outpatient consultation time was suggested as 5.6 minutes which differentiated high and low satisfied patient group. However, we could not assume appropriate outpatient consultation time for each clinical department because the number of patient who had bad satisfaction was too low.Conclusion: To improve patient’s satisfaction, we hope outpatient reservation system is operated as each patient’s outpatient consul-tation time is at least 5.6 minutes.Keywords: Outpatient; Consultation time; Departments; Appropriate

In this paper, the main cause on excitation of the combustion instability which may occur in the hybrid rocket motor with a diaphragm was studied. Hybrid rocket motor propulsion tests considering various experimental conditions such as with a diaphragm or not, a diameter of diaphragm, oxidizer mass flow rate, fuel length, etc were performed, and the combustion visualization for the inside of a hybrid rocket motor with a diaphragm was performed. With these experimental results, it was confirmed that the main cause of a large excitation was the hole-tone, and it was shown that the hole-tone model can be predicted experimental primary pressure oscillation frequency quite well.

The purpose of this study was to provide informations on what middle school students know and think about food additives, and their purchase behavior of processed foods containing food additives. The data were gathered by questionaries from 360 students attending in the 3 randomly selected middle schools around Gyeonggi Province. The valid 340 out of 360 questionaries were analysed by SPSS/WIN 12.0. As a result, the middle school students showed low interest in 4 kinds of representative food additives such as synthetic seasoning, artificial sweetener, artificial dye, and synthetic preservative. They thought that the food additives is necessary but not improve the quality of food, and may have harmful effects on health. The students who has mother of university graduate, and taught by text book A showed the highest interest. Most students rarely checked the indication of food additives on the processed food package, and they hardly put any effort to avoid the processed foods containing food additives. According to the results of this study, the students were not aware and did not know about the food additives enough, and needs to be educated more and in detail in home economics class.

Artificial superlattice of the ferroelectric BaTiO 3 /SrTiO 3 multilayer thin film has been fabricated by pulsed laser deposition. In this hetero epitaxial BTO/STO layers, each layers have been continuously grown on (La 0.5 ,Sr 0.5 )TiO 3 /MgO(100) with a periodicity ranging from (BTO 1 unit cell /STO 1 unit cell ) 125 to (BTO 125 unit cell /STO 125 unit cell ) 1 . The total thickness of BaTiO 3 /SrTiO 3 superlattice was 100 nm. X-ray diffraction results clearly showed that epitaxial BTO/STO superlattice was formed with a various periodicity. The depth profile in the superlattice showed that there was no serious interdiffusion between BaTiO 3 and SrTiO 3 layer by Auger electron spectroscope(AES).

Objectives: Recommended Menu (RM) prepared according to the Target Pattern expected to meet the dietary reference intake (DRI) of nutrients. Nutritional adequacy of RM in 'DRI for Koreans 2015' were analyzed to verify whether such expectation was fulfilled. Methods: Dishes in RM are categorized by 5...

Objectives: Maintaining a balanced diet is very crucial for adolescents. However, adolescents, who may have a short notion about the amount of food, find it difficult to plan daily meals by applying the target pattern proposed by the Korean Nutrition Society. This study was carried out to revise the target pattern based on cooked dishes instead of raw material food groups as an easier way for Korean adolescents to plan their meals.

Objectives: Vegetables are the most left over side dishes in school lunch programs. This study intended to analyze the differences in preference for vegetables among the students of different age groups in order to determine potential ways of increasing vegetable consumption in this study group.

Objectives: The purpose of this study was to provide the preliminary data for dietary education to increase students' vegetables intake. Methods: The attitude of vegetables consumption (5-Likert scale), preference score (7Likert scale) and eating frequency (5-Likert scale) of 9 fragrance vegetables were investigated by survey questionnaire. A total of 370 students enrolled in primary, middle, high schools, and university participated in the study and data were analyzed by the SPSS WIN (ver 12.0). Results: About 40% of those surveyed answered that they do not eat some kinds of foods and 16% of students do not eat vegetables, the most unfavorable foods. The students in all groups (primary 2 and 5 , middle and high school, university students) answered that they liked vegetables with the highest score in university students, and they did not often eat fragrance vegetables. Lower age student group, especially primary school 2 showed more positive attitudes of eating challenge toward no experience, bad taste, and dislike but nutritious vegetable foods. The most important factor of vegetable preference was taste, the biggest reason of both like and dislike. Only 4 students designated nutrition as for vegetable dislike reason, means that all students knew about the nutritional importance of vegetables. It was shown that the color and flavor of the vegetables act as dislikable reason rather than likable reason. The significant correlations between preference score and intake frequency of fragrance vegetables were confirmed, and the younger the students the greater the correlation coefficient. Conclusions: Thus providing more chance to experience vegetables, such as fragrance vegetables and education about the importance of balanced diet will be an effective way of increasing vegetables intake, and the younger the students the greater the education effect. Korean J Community Nutr 19(3): 223~230, 2014

The purpose of this study was to provide information on obesity assessment for Koreans. Among total of 1012 research papers enlisted in the Korean J Community Nutrition form 1996 to 2011, 248 articles were examined in which subjects were divided into more than 2 groups by obesity rate. About the method of anthropometric data collection, more than half of the research papers examined 52.5% and 28.7% of studies utilized the directly measured data and self-described data, respectively. About the utilization of obesity assessment methods, indirect methods of weight-height index (BMI, BMI percentile, and Rohrer index) and PIBW (WLR, Broca index, and KDA) were 62.4% and 23.2%, respectably, and the direct method of percent body fat assessment was only 9.3%. The most frequently utilized methods were WLR in under primary and primary school children, and BMI in the middle and high school students and in adults. For primary school students, WLR was the most frequently utilized method up to 2007, but it changed to BMI percentile afterward. Broca Index was no longer utilized since 2008. There were no articles utilizing BMI percentile and Rohrer index for obesity assessment in adults. Criteria for obesity assessment were not consistent among research papers: for example, % body fat, 19~40%; BMI, 20~30; BMI percentile, 85th or 95th. In the case of PIBW, 120% of ideal weight was the most frequently utilized criterion for obesity. Based on these findings, we suggest that proper methods and criteria of obesity assessment for each age group should be determined and proclaimed. (Korean J Community Nutr 18(5) : 525~538, 2013)

This study was conducted to investigate the time spent, activity coefficient and energy expenditure on 7 different types of activity. Total of 386 5th and 6th grade primary school boys and girls in Seoul participated in this study. The participants spent 8 hrs for rest, 4 hrs for out of school study, 3 hrs for leisure, 1 hr 45 mins. for hygiene, 1 hr for commute, and 15 mins. for house choir activity in the day of 6 class hours. The average activity coefficient of 1 day for boys and girls were 1.69 and 1.64, respectively. The TEEs were 2,382 kcal and 2,050 kcal for boys and girls, respectively. The energy cost for study related activity (in school and study activities) was 40% of the TEE, and for rest 20%, for commute 9%, and for hygiene 10% of the TEE. The energy cost for house choir was only about 2% of TEE. The 91.2% participant's EER was higher than the EER shown in the table of 2010 DRI for Koreans. When the participant's EER was compared with the energy allowance calculated by the method in 2000 RDA for Korean, 81.6% was in the range of ± 5%, and the correlation coefficients between the 2 values were 0.981 for boys and 0.978 for girls, which means high agreements. (Korean J Community Nutr 16(2) : 195~205, 2011)