• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.6
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• pp.23-29
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• 2003

Transonic two-phase flow of Saturated humid air, in which relative humidity is 100%, with various condensation processes around thin airfoils is investigated. The study uses an extended transonic small-disturbance(TSD) model of Rusak and Lee [11, 12] which includes effects of heat addition to the flow due to condensation. Two possible limit types of condensation processes are considered. In the nonequilibrium and homogeneous process, the condensate mass fraction is calculated according to classical nucleation and droplet growth rate models. In the equilibrium process, the condensate mass fraction is calculated by assuming an isentropic process. The flow and condensation equations are solved numerical1y by iterative computations. Results under same upstream conditions describe the flow structure, field of condensate, and pressure distribution on airfoil's surfaces. It is found that flow characteristics, such as position and strength of shock waves and airfoil’s pressure distribution, are different for the two condensation processes. Yet, in each case, heat addition as a result of condensation causes significant changes in flow behavior and affects the aerodynamic performance of airfoils.

• The Journal of the Korea Contents Association
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• v.17 no.11
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• pp.200-208
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• 2017

The purpose of this study was to investigate the effects of isometric exercise based MNIT treatment on body composition, blood lipids, leptin and CRP in middle-aged obese women. For this purpose, middle-aged obese women (age: 40-50) with more 30% of body fat percentage in U city were recruited. They were divided into MNIT group(MG, n=9) and control group(CG, n=9). MNIT group was performed hand therapy program with abdomen exercise equivalent to RPE (9-11) (week 1-4) and exercise equivalent to RPE (11-12) (Week 5-8) and exercise equivalent to RPE (12-13) (week 9-12) 60 minutes a day for 3 days a week in 12 weeks. The results of this study were as follows: Body weight, fat mass, and body mass index had a significant lower in MG group than CG. There are no significant changes in blood profiles, and leptin. In conclusion, isometric based on MNIT may lead to development of an alternative therapy for middle-aged obese women.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5647-5654
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• 2012

In this paper, we developed an electro impedance spectroscopy (EIS) device, which are primarily used for the analysis of fuel cells or batteries, to widen its coverage to the next generation super capacitor EDLC characterization. The developed system was composed of a signal generator that can generate various signal patterns, a potentiostatic generator, and a high speed digital filter for signal processing and measurement program. The developed system is portable, which is not only suitable laboratory use but also for mass production line. The special features of the system include a patterned output signal from 0.01 to 20 kHz, and a fast Fourier transform (FFT) analysis of current signals, both of which are acquired simultaneously. Our tests showed similar results after comparing the analysis from our newly-developed device showing the characteristics of EDLC complex impedance and the analysis from an equivalent impedance which was applied to an equivalent circuit. Now, we can expect a fast inspection time from the application of the present system to the super capacitor production line, based on time-varying changes in electrochemical impedance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3442-3447
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• 2014

A simple method to evaluate the hygroscopic characteristics of polymer of microelectronic plastic package is suggested. To evaluate the characteristics, specimens were prepared, and the internally absorbed moisture masses were measured as a function of the absorbing time and calculated numerically. The hygroscopic pressure ratio was calculated by heat transfer analysis supported by commercial FEM code because the hygroscopic diffusion equation has the same form as the heat transfer equation. The moisture masses were then summed by the self developed code. The nonconductive polymers had quite different characteristics for the different lots, even though they were the same products. The absorbed moisture mass variations were calculated for several different characteristics, and the optimal curve of the mass variation close to experimental data was selected, whose solubility and diffusivity were affected by the hygroscopic characteristics of the material. The method can be useful in the industrial fields to quickly characterize the polymer material of the semiconductor package because the fast correspondence is normally required in industry. The weight changes in the aluminum-nonconductive-polymer joint due to moisture absorption were measured. The deformed system was also measured using the Moire Interferometry system and compared with the results of finite element analysis.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.925-932
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• 2017

Changes in the metabolite profiles of Lactobacillus sakei and its growth media, based on different culture times (0, 6, 12, and 24 h), were investigated using gas chromatography-mass spectrometry (MS) and liquid chromatography-MS with partial least squares discriminant analysis, in order to understand the growth characteristics of this organism. Cell and media samples of L. sakei were significantly separated on PLS-DA score plots. Cell and media metabolites, including sugars, amino acids, and organic acids, were identified as major metabolites contributing to the difference among samples. The alteration of cell and media metabolites during cell growth was strongly associated with energy production. Glucose, fructose, carnitine, tryptophan, and malic acid in the growth media were used as primary energy sources during the initial growth stage, but after the exhaustion of these energy sources, L. sakei could utilize other sources such as trehalose, citric acid, and lysine in the cell. The change in the levels of these energy sources was inversely similar to the energy production, especially ATP. Based on these identified metabolites, the metabolomic pathway associated with energy production through lactic acid fermentation was proposed. Although further studies are required, these results suggest that MS-based metabolomic analysis might be a useful tool for understanding the growth characteristics of L. sakei, the most important bacterium associated with meat and vegetable fermentation, during growth.

• The Journal of Korean Society for School & Community Health Education
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• v.1 no.1
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• pp.95-106
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• 2000

The purpose of this study was to be of use for the preparation of more desirable sex education system at elementary school, by making content analysis of the current textbooks related to sex education and surveying what opinions the persons concerned had about it. The purpose of this study were as follows; Elementary school textbooks were analyzed to find out what kind of sex education was included in them. And questionnaires on how to improve school sex education content were prepared, by which 207 male and female teachers were surveyed in the city of Paju and Koyang, Kyonggi province. The conclusions were as follows; 1. Content Analysis of Textbook Sex Education The content related to sex education was relatively much included in textbooks of the right life, morality and physical education. Although morality was a subject to be instructed for the third-grade students or older, elementary school students virtually received sex education from the first grade, as the right life and the joyful life were a subject for the lower-grade students, and this met the goal of sex education or the need of the times. However, sex education content leaned heavily toward family, family life or parental love. There was no mutual complement among subjects, and no link among grades, either. 2. Teacher Opinion on Sex Education Content for Each Grade When the subjects were asked about if sex education content was appropriate for each grade, they answered 20 items should be more emphasized and 6 items might be left out. And there were 6 items regarded by them as one that should be rearranged in consideration of grade. 3. The Ideal Opinion of Sex Education Content The following model could be recommended for elementary school sex education, which was designed to meet the objectives of school sex education as much as possible and to offer a systematic link among grades, based on the findings by textbook analysis and Questionnaire survey, and on elementary school sex education materials recommended by the Ministry of Education: The content selected for the first grade of elementary school was my body, cleanness of genitals, male-female cooperation, and family cooperation. For the second grade, the selected content was male-female physical difference, male female psychological difference, parental and I(origin of a birth). For the third grade, the selected things were important a body(cleanness of genitals), birth of a life, and male-female comprehension and cooperation. For the fourth grade, the selected things were physical development, management of genitals, physiology and management of menstruation, propagation and growth of organism, concern for the other sex, comprehension of and cooperation with the other sex, and prevention of sexual violence. Four the fifth grade, the selected things were secondary sex characteristic, physiology and management of menstruation, operation for phimosis, understanding of seminal emission, structure and function of the genital organs, birth and growth of a baby, television/sex information, and mass communications/sex information. For the sixth grade, the selected things were secondary sex characteristic, understanding of seminal emission, male-female cooperation, male and female role, male-female manners, mass communications/sex information, family and family life. Finally, what should be taught in sex education must be studied constantly, as it should be revised or supplemented periodically, according to student's sexual maturity or social, cultural changes.

• Korean Journal of Plant Resources
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• v.33 no.1
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• pp.33-39
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• 2020

This study was carried out to provide basic information for mass breeding and cultivating the saplings of Camellia japonica. The germination rates did not show definite tendency according to the changes of seed weight at room temperature and 4℃ dry storage conditions. The germination rate of 4℃ wet sand storage was increased with seed weight, but showed very low germination rate for 120 days of storage. The germination rate was above 80% in 60 days, 90 days and 120 days, respectively, at 4℃ wet filter paper storage conditions. The average days taken for those germinations were about 30 days at room temperature and 4℃ dry storage conditions, but wet storage (sand, filter paper) condition took the shortly nearly 13 days for those germinations. Leaf number, leaf dry weight, stem diameter and root dry weight were higher than total average by more than 1.21 g for seed weight. Stem length was higher than the average by more than 1.01 g, plant dry weight was higher than the average by more than 0.81 g, and stem dry weight was higher than the average by more than 0.61 g. In the case of seed weight becoming heavier, seedling growth was good but T/R ratio tended to decrease. In order to increase the mass production of seedlings using Camellia japonica seeds, we need to specify the weight and size of those seeds. The 4℃ wet filter paper storage condition was evaluated as the most efficient method for the seed storage used for seeding.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.1
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• pp.115-124
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• 1994

The purpose of this study was to examine the differences in representation of a globular radiopaque mass on the pantomograms and Waters' views and to compare the efficacy of periapical radiograms, pantomograms and Waters' views in detection of defects on the internal walls of the maxillary sinus. This study was performed with dried human skull. For the study of difference of radiopaque mass shadow in the two views, rubber ball with a diameter of 10㎜ was used as the experimental lesion. It was placed successively on the internal wall of the anterior, posterior, medial, lateral walls and floor of the maxillary sinus. To examine the detectability of defects for radiographic techniques, defects were formed in the anterior, posterior, medial, lateral walls, and floor of the maxillary sinus. They were formed with 0.5㎜, 0.75㎜, 1.0㎜, 2.0㎜ and 3.0㎜ sized steel round burs with a slow speed dental handpiece. By subsequently plugging the holes with zinc oxide eugenol paste, radiopaque defects were produced. After that the periapical radiograms, the pantomograms and the Waters' views were taken each and every defect. The obtained results were as follows: 1. Rubber balls placed on each internal wall of the maxillary sinus were correctly depicted on the posterior wall and the floor in case of the pantomogram, and on the anterior wall and the medial wall in case of the Waters' view. 2. On the detectability of defects for each radiographic technique, radiolucent defects were detected in different places for each technique. Periapical radiogram could detect 1.0㎜ defect on the floor of the maxillary sinus, pantomogram could detect 2.0㎜ defect on every internal wall of the maxillary sinus, and Waters' view could detect 3.0㎜ defect on the anterior wall of the maxillary sinus. 3. On the detectability of defects for each radiographic technique, radiopaque defects were detected in different places for each technique. Periapical radiogram could clearly detect 0.5㎜ defect on the floor of the maxillary sinus, pantomogram could detect 0.5㎜ defect on every internal wall of the maxillary sinus, and finally Waters' view could detect 0.5㎜defect on the anterior wall of the maxillary sinus but 0.75㎜ defect on the anterior wall, lateral wall and floor of the maxillary sinus. As the result, the periapical radiogram is the most simple and satisfactory method for investigating in the maxillary sinus. The pantomogram is suitable method for screening of changes in the maxillary sinus. And the Waters' view is available for detect of lesion in the anterior wall of the maxillary sinus. For the purpose of accurate diagnosis and evaluation of lesion in the maxillary sinus, these techniques supplement each other.

• Korean Journal of Health Education and Promotion
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• v.5 no.2
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• pp.110-141
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• 1988

This study was conducted to find out the mental health state of high school students. First-year students and third-year students af liberal high schools is Seoul were subject to this study. Questionnaire of Symptom Checklist-90 and various factors was adopted for the survey. A total of 916 questionnaires was sellected for the analysis, and the results are obtained as follows; 1) The characteristics in responses to mental health scale showed that obsessive-compulsive scale score was the highest, followed by interpersonal-sensitivity, depression, hostility, and anxiety. The subject group of the students showed higher scores in nine symptom dimensions except somatization than other normal group. 2) Girl-students showed higher scores than boy-students in somatization, depression, and anxiety, whereas the opposite was true in hostility. 3) Third-year students got high scores, in somatization, anxiety and Depression. 4) Parental marriage state of the repondents showed significant differences in nine symptom dimensions of mental health. Scores of the students with parents was the lowest, followed by those of students with only mother, only father and the rest(no parents, divorced, sepaerated, step-parent) in increasing order. 5) Smoking students showed high score in obsessive-compulsive, depression, hostility, paranoid ideation, and psychoticism. Especially in hostility, they got much higher score. 6) Students with poor record at school got higher scores in every symptom dimension than those with good record at school, especially in obsessive-compulsive and depression scale. 7) Parents' attitude toward student showed significant effect on every scale. Students under over-expectation or indifference from parents were in bad mental health state. 8) Students who have advisor proved to be in better mental health state than those who never consult their personal problems with others. 9) He who has family history got higher scores in some scales. 10) Respondents who looked upon what they have learned in high school as being rather an obstacle to sound social life got high scores in all the symptom dimensions and next came those of the students who answered that there were a lot of unnecessary things in their learning. 11) Those for whom it would not quite necessary to enter college if there were little formal schooling discrimination in society got high scores in obsessive-compulsive, interpersonal sensitivity, depression, hostility, and in psychoticism, especially higher in obsessive-compulsive scale. 12) Mental health state of the students who are influenced by the social surroundings, mass media, and the home environments showed high score in 8 symptom dimensions. 13) Abnormal response frequency of this sample is as follows; 24.0％ of boys, 23.8％ of girls, 22.5％ of the first-year students, and 26.9％ of the third-year students. There were significant difference among the grades. 14) The factors of distinctive correlation between the dimensions of SCL-90 and 16 factors were the father's negative attitude and depression, negative responses on teaching contents and anxiety, and smoking and hostility. In conclusion, mental health state of liberal highschool students on the whole showed worse than other normal groups. It had close terms with relation with their parents, schoolwork, smoking, teaching contents, the social surrounding, mass media, and the home environments. Thus I believe there need not only mental health education of students, training of teachers, counceling of parents, but also changes in teaching contents, and the improvement of educational system and the social surroundings under the national support.

• Toxicological Research
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• v.30 no.2
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• pp.91-97
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• 2014

This study aimed to identify changes in the level of neuropeptides among current smokers, former smokers, and individuals who had never smoked, and how smoking habits affect obesity and metabolic syndrome (MetS). Neuropeptide levels, anthropometric parameters, and metabolic syndrome diagnostic indices were determined among male workers; 117 of these had never smoked, whereas 58 and 198 were former and current smokers, respectively. The total sample comprised 373 male workers. The results obtained from anthropometric measurements showed that current smokers attained significantly lower body weight, body mass index, waist circumference, and abdominal fat thickness values than former smokers and those who had never smoked. Current smokers' eating habits proved worse than those of non-smokers and individuals who had never smoked. The level of brain-derived neurotrophic factor (BDNF) in the neuropeptides in the case of former smokers was $23.6{\pm}9.2pg/ml$, higher than that of current smokers ($20.4{\pm}6.1$) and individuals who had never smoked ($22.4{\pm}5.8$) (F = 6.520, p = 0.002). The level of adiponectin among former smokers was somewhat lower than that of current smokers, whereas leptin levels were higher among former smokers than current smokers; these results were not statistically significant. A relationship was found between adiponectin and triglyceride among non-smokers (odds ratio = 0.660, ${\beta}$ value=-0.416, p < 0.01) and smokers (odds ratio = 0.827, ${\beta}$ value=-0.190, p < 0.05). Further, waist circumference among non-smokers (odds ratio = 1.622, ${\beta}$ value=0.483, p < 0.001) and smokers (odds ratio = 1.895, ${\beta}$ value=0.639, p < 0.001) was associated with leptin. It was concluded that cigarette smoking leads to an imbalance of energy expenditure and appetite by changing the concentration of neuropeptides such as adiponectin, BDNF, leptin, and hsCRP, and influences food intake, body weight, the body mass index, blood pressure, and abdominal fat, which are risk factors for MetS and cardiovascular disease.