• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.2
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• pp.65-72
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• 2019

In long freight trains, there is a brake time delay in neighboring freight cars, which causes damage and fractures in the couplers, especially at their knuckle. A problem in the couplers of the cars can cause derailment and damages of human life and property. In this study, maximum forces on the couplers are studied when a long freight car brakes with the brake delay time and coupler gap. We make a dynamic model of 50 freight cars and couplers, applying contact between the couplers and a characteristic curve to express the force and displacement of the buffers using SIMPACK, which is a multi-body dynamics program. We use EN 14531-2, which is a standard of freight car brakes, to verify the dynamic model. Then, we compare the analyzed impact force with the coupler knuckle standard after applying the two carriages of a locomotive in the model based on the dispersed double head control system. The result shows that all coupler gap conditions satisfy the infinite lifetime of the material when the brake delay time is 0.1 second.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2184-2194
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• 2021

The Free-Piston Stirling engine (FPSE) is of interest for many research in aerospace due to its advantages of long operating life, higher efficiency, and zero maintenance. In this study, a 1-kW FPSE was proposed by analyzing the requirements of Space Reactor Power Systems (SRPS), of which performance was evaluated by developing a code through the Simple Analysis Method. The results of SAM showed that the critical parameters of FPSE could satisfy the designed requirements. The heater of the FPSE was designed with the copper rectangular fins to enhance heat transfer, and the parametric study of the heater was performed with Computational Fluid Dynamics (CFD) software STAR-CCM⁺. The Performance Evaluation Criteria (PEC) was used to evaluate the heat transfer enhancement of the fins in the heater. The numerical results of the CFD program showed that pressure drop and Nusselt number ratio had a linear growth with the height of fins, and PEC number decreased as the height of fins increased, and the optimum height of the fin was set as 4 mm according to the minimum heat exchange surface area. This paper can provide theoretical supports for the design and numerical analysis of an FPSE for SRPSs.

• Korean Journal of Poultry Science
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• v.51 no.1
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• pp.21-26
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• 2024

This study was conducted to investigate the composition of the fatty acids in the breast meat of Red-brown Korean native chickens (KNC-R). This study used a total sample of three hundred eighty-two KNC-R (males: 190, females: 192). We used the fatty acid methyl ester (FAME) method to extract the fatty acids. A 2-way ANOVA of the R program was used to assess the effects of batch and sex on each fatty acid trait. Analysis of the fatty acid in the sampled population showed that the predominant fatty acid was oleic acid (C18:1; 28.252%) which is monounsaturated fatty acid (MUFA), followed by palmitic acid (C16:0; 20.895%), saturated fatty acid (SFA), and two omega-6 polyunsaturated fatty acid (PUFAs): linoleic (C18:2; 15.975%), and arachidonic (C20:4; 10.541%). Indices used to evaluate the nutritional quality of fat in the diet: ratio between PUFAs and SFAs (P/S), thrombogenicity index (TI), and atherogenicity index (AI) were calculated and were 0.959, 0.814, and 0.355, respectively. Currently, meat consumers need healthier fatty acids. Therefore, information on the content of fatty acid in chicken meat is very important for meat consumers in choosing the type of the meat to be consumed.

• Korean Journal of Cognitive Science
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• v.26 no.2
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• pp.209-239
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• 2015

Previous studies on the effect of incidental semantic priming on judgment, have focused mainly on mutually exclusive hypotheses. However, the present study explored whether incidental semantic activation affects diagnostic inference depending on the type of the hypothesis: mutually exclusive hypotheses vs compatible hypotheses. In Experiment 1, in case of mutually exclusive hypotheses, the final hypothesis was selected according to the incidental semantic priming, but there was no difference in the number of generated hypothesis in comparison with the control. However, for compatible hypotheses (i.e., both hypotheses can be true), the semantic priming affected the number of generated hypotheses, but not the selection of the final hypothesis. The same pattern of results was observed even when the cognitive load was increased. In Experiment 2, we found a boundary condition of incidental semantic activation on diagnostic inference. When cues related to each of the hypotheses were presented simultaneously, the incidental semantic effect disappeared. These results suggest that people consider all possible cues when making diagnostic inference in daily life. In light of these findings, further research on hypothesis generation/evaluation should take the type of hypothesis into account.

• Korean Journal of Health Education and Promotion
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• v.3 no.1
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• pp.43-55
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• 1985

The recent problems of adolescents are leading us to amphasize school mental health program. Therefore, for the first step of that program, this study was attempted to find out the students' daily life stress, their adaptation beharior to resolve that stress, and their self-concept which has an effect on that beharior, to analyze the relationship among those three variables, and to provide basic data which help maintain and promote students' adaptability and mental health. The subjects were 4 classes each grade, 743 students who were chosen as a sample subject among the total of 3,250 students of a junior girls' school in Seoul by stratified sampling method. The Oquestionnair surrey was done from April 1, 1985 to April 6, 1985. The instruments were (1) a part of Junghoon chois' perceptual Orientation Scale for measuring self-perception of students, (2) Rosenberg's Questionnair for measuring students' evaluation of self-esteem, (3) modified Bell's Adoptive Behavior Questionnair, and (4) the Measuring scale for stress developed by the investigator. The collected data were analyzed by using descriptive statistics, x²-test, t-test, ANOVA, and Pearsons' Correlation. The results are summarized as follows: 1. The range of mean score of self-concept, stress, and adaptation beharior is 1-5 respectively. The mean score of self concept was 3.45. The mean score of stress was 2.53, and the degree of stress was in order of the problem of study and grade marks, girl friend, appearance, and relaxation. The subjects preferred effective long-term adaptation method (Mean=2.81) to ineffective short-term adaptation method. (Mean=2.47) 2. The self-concept had the highest degree when students were 1st grade, in good health condition, taking high grade marks, both parents existing, fathers' educational level being above college, and being in high economic status. The degree of stress was significantly high when students were 3rd grade, in poor health condition, having low grade marks, being in poor economic status, and fathers' educational level being under elimentary school. In relation with adaptation method, 1st grade students used more sbort-term and long-term method, and when students had high grade marks, being in high economic status. they used more long-term adaptation behavior. 3. Two Hypotheses of this research were tested: Hypothesis 1. "The higher the students' self-concept is, the more they use long-term adaptation method." was accepted. (r=.2482, p<.01) (t=-4.99, p<.001) Hypothesis 2. "The higher the students' stress is, the more they use short-term adaptation method." was accepted. (r=.2897, p<.01) (t= -7.51, p<.001) In conclusion, a person in charge of school health can help students to adapt effectively by planning and implementing methods which highten their self-concept and lower their stress. But because the correlation among self-concept, stress and adaptation behavior was at a low level, I think that the study, which confirm the relationship of those three variables, is needed.

• Journal of Agricultural Extension & Community Development
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• v.8 no.1
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• pp.25-40
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• 2001

The purposes of the study were to identify satisfaction and achievement of learning by female learner's characteristics, and to suggest measures to improve quality of education in internet education programs. In order to determine the educational effectiveness associated with the characteristics of learners, this study attempted to employ two way approaches by observing the degree of achievement for learning, which represents an instructor-oriented approach, and the degree of satisfaction for education, which represents a learner-oriented approach to enhance the quality of internet education for female learners. As an approach to evaluate the educational effectiveness, the degree of achievement in learning(Tyler's classical approach), and the degree of satisfaction for education (Scriven's consumer-oriented evaluation model) were utilized. A survey form was developed by the researcher after reviewing the various tools originated from Boshier, Cross, Gagne and Choi, and distributed to a panel of judges that examined the content validity of the instrument. The sample for the study consisted of 160 female learners from three universities in Seoul and capital area, and the survey form was used to collect data for this study. The SPSS WIN program was used in analyzing the data and a series of statistical tests were conducted including frequency, percentile, t-test, ANOVA, correlation, multiple regression, and factor analysis. The statistical significance level was 0.05. The following conclusion were drawn from this study of female internet education. First, it was evident that female internet learners tend to utilize information from internet, and this can be interpreted as participants' positive attitude, and voluntary participation. Second, educational facilities and services should be improved in the future, because the level of satisfaction was low in these areas compared to curriculum and educational methodology. Third, the participating factors influenced by the level of satisfaction for education of learner characteristics were the 'formation of inter-personal relationship and willingness to change' and the 'needs for education on internet', thus appeared that both social and educational needs influenced the level of satisfaction for education. Fourth, the degree of achievement in learning was higher in the order of 1) attitude 2) function 3) knowledge, thus, attitude change was the most important in achievement of learning. Fifth, the individual background that influenced the level of achievement in learning were age and educational experience. As for the individual level of achievement for learning, the younger and more educated group were more satisfied.

• Journal of the Korean Chemical Society
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• v.62 no.2
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• pp.137-147
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• 2018

The purpose of this study was to analysis total number of 123 SSI programs by SSI criteria. The criteria was consisted of subject, school level, starting point, scientific evidence, social content, use of scientific knowledge, level of conflict of interest, and evaluation and reflection. The results of the analysis are as follows. First, elementary school programs were the most and middle school programs were relatively few. Second, starting point was mainly in the actual situation, the fiction and nonfiction situation, and the situation including the controversy and conflict was less than 10%. Third, it was based on scientific evidence but mainly influenced by individual values and perceptions. Fourth, social contents were developed mainly in ethics/morality/value, political/social life/economy, environment contents. Fifth, the use of scientific knowledge mainly consisted of scientific decision making, scientific critical thinking, and information search. However, science inquiry, risk assessment, and cost effectiveness were less than 10%. Scientific inquiry is the essential factor of science education, and one of core competencies of national science curriculum. SSI program should be able to experience various kinds of conflicts, and to evaluate and reflect through reflection.

• Korean Journal of Community Nutrition
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• v.14 no.6
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• pp.767-776
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• 2009

This study evaluated the effect of nutritional improvement of 0~5 year children of financially poor families after nutrition supplement of children and nutrition education in parents/guardians. The subject selected among applicants for low-income family financing of the government included 198 children (0~12 months:92, 1~5 years:106), and the average ages were 5.3 months and 2.4 years respectively. Food that includes each nutrient factor was provided to the subject for six months. Nutrition education was performed in two ways, through class and private education, once a month for both. Nutritional improvement was evaluated by body measurement and anemia prevalence rate. As to the survey on breast-feeding, complete breast-feeding accounted for 58.7%, weaning food 27.3%, and combined feeding 14.1% respectively, which shows that breast-feeding accounted for the largest percentage. The education program improved knowledge and attitude of the parents/guardians, which brings in positive effects on growth of children as well. The nutrition knowledge score was improved after nutrition education in 0~12 month children $(8.5\pm1.75\;to\;8.9\pm1.69)$ and 1~5 year children $(7.3\pm1.39\;to\;7.8\pm1.30)$. The nutrition attitude score was significantly improved in 0~12month children $(52.0\pm6.99$ to $53.5\pm5.21$, p < 0.001) and 1~5year children ($45.1\pm7.30$ to $49.0\pm5.96$, p < 0.001). In evaluation on nutritional improvement based on body measurements, it turned out that the wasting was reduced as for children in consideration of the height and weight according to the subject's age. The concentration of hemoglobin after the nutrient treatment for six months was significantly improved, and the anemia prevalence rate as well was reduced from 40.6% to 13.5%, which indicates the significant improvement. Based on the findings above, it turned out that providing quality food to children and nutrition education to the parents/guardians poorly fed in low-income families improved knowledge and attitude of the guardians and prevents anemia and improves growth, which brings in positive effects on growth of children. In the results regarding attitude and knowledge on nutrient/dietary life; however, the improvement level was relatively low when the extent before the education was too small, which indicates the need to revise and complement the contents and methods. In addition, as shown in the result of body measurement, long-term and consistent investigation is necessary since it is difficult to judge the effect on growth only based on short-term nutrient supplement.

• Phonetics and Speech Sciences
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• v.16 no.1
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• pp.41-48
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• 2024

The significance of self-reported voice assessments concerning patients' chief complaints and quality of life has increased. Therefore, readability assessments of questionnaire items are essential. In this study, readability analyses were performed based on text grade and complexity, vocabulary frequency and grade, and lexical diversity of the 11 Korean versions of self-reported voice disorder questionnaires (KVHI, KAVI, KVQOL, K-SVHI, K-VAPP, K-VPPC, TVSQ, K-VDCQ, K-VFI, K-VTDS, and K-VoiSS). Additionally, a comparative readability assessment was conducted on the original versions of these questionnaires to discern the differences between their Korean counterparts and the questionnaires for children. Consequently, it was determined that voice disorder questionnaires could be used without difficulty for populations with lower literacy levels. Evaluators should consider subjects' reading levels when conducting assessments, and future developments and revisions should consider their reading difficulties.

• Women's Health Nursing
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• v.2 no.1
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• pp.53-67
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• 1996

A total health state evaluation of Korean female elderlies was made by using the questionary scheme measuring the physical, mental and social functions of the elderlies, in order to investigate the critical factors for the health maintenance of female elderlies and to develop their preventive nursing program. A total of 280 subjects over 65 years old living in Seoul and the suburban area were selected and interviewed during the period of September and October in 1995. The materials collected were analyzed statistically by using SAS data processing program, and the results and recommendations are summarized as follows. 1. The physical health state of Korean elderly women was evaluated to be satisfactory by showing an average score of 3.722 in 5.0 full-score scale. But this score was lower than those evaluated for the elderlies combined both sexes(4.054). The mental health state of the subjects was also evaluated as high scoring 3.484, possibly due to the fact that 78% of the subjects lived together with their children's family. On the other hand, the social health state of the subjects was relatively low scoring 2.585, mainly due to that 80% of them was widows which was resulted by the 6-7 years longer life-expectancy of Korean women. 2. A significant differences in the physical health state scores between different age groups was observed, indicating the rapid ageing process occurring in this age group. The family structure was appeared to be an important factor influencing the physical health state of the female elderlies ; the physical health score of the women with her husband only was higher than that of those living with children's families, and the lowest score was obtained from those living alone. 3. The age was the most important factor determining the mental health state of the subjects, while the religion, educational status, marriage state and family structure did not significantly influenced the mental health state of the aged women. 4. The social health state of the subject was deeply influenced by the marriage state and family structure, showing significantly lower scores with widowers compared to the married couples. Those living with their married spouse only obtained the highest social health score, while those living along showed the lowest score. The parent and grandparentship of those living with their children and the religion, especially Catholic and Protestant, had positive influence on the social health state of the aged women. 5. The mental health state of aged women showed significant correlation with the factors determining the physical health, except for digestive system related ability and sexual ability and the highest extra home ability. 6. The mental health state of aged women showed significant correlation with the factors determining social health, especially with the parent and grandparentship and the family relative's role. From these results, the following recommendations are made. 1. Since the physical, mental and social health states of aged people are deeply influenced by the sex and the average values of the both sex can create misleading figures, the health evaluation of the elderlies should be made separately by sex. 2. Since the health state of aged women is highly influenced by their family structure, the spouse's role and living with married couple only should be emphasized in respect of preventive health care. 3. The social activity programs and grandparentship teaching programs should be prepared in the nursing care program for aged people.