• KDI Journal of Economic Policy
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• v.30 no.2
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• pp.225-270
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• 2008

We analyze macroeconomic consequences of pay-as-you-go (PAYGO) public pension system with a simple overlapping generations model. Contrary to large body of existing literatures offering quantitative results based on simulation study, we take another route by adopting a highly simplified framework in search of qualitatively tractable analytical results. The main contribution of our results lies in providing a sound theoretical foundation that can be utilized in interpreting various quantitative results offered by simulation studies of large scale general equilibrium models. We present a simple overlapping generations model with a defined benefit(DB) PAYGO public pension system as a benchmark case and derive an analytical equilibrium solution utilizing graphical illustration. We also discuss the modifications of the benchmark model required to encompass a defined contribution(DC) public pension system into the basic framework. Comparative statics analysis provides three important implications; First, introduction and expansion of the PAYGO public pension, DB or DC, result in lower level of capital accumulation and higher expected rate of return on the risky asset. Second, it is shown that the progress of population aging is accompanied by lower capital stock due to decrease in both demand and supply of risky asset. Moreover, risk premium for risky asset increases(decreases) as the speed of population aging accelerates(decelerates) so that the possibility of so-called "the great meltdown" of asset market cannot be excluded although the odds are not high. Third, it is most likely that the switch from DB PAYGO to DC PAYGO would result in lower capital stock and higher expected return on the risky asset mainly due to the fact that the young generation regards DC PAYGO pension as another risky asset competing against the risky asset traded in the market. This theoretical prediction coincides with one of the firmly established propositions in empirical literature that the currently dominant form of public pension system has the tendency to crowd out private capital accumulation.

• Journal of the Korean Chemical Society
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• v.48 no.6
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• pp.645-653
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• 2004

The purpose of this study was to compare and analyze the cognitive levels of 11th grade students and those required in high school chemistry I textbooks standardized by the 7th national education curriculum. For this study, the cognitive development stages of 456 11th grade students were surveyed using short-version GALT (group assessment of logical thinking). Furthermore, 15 basic concepts were extracted from the contents on water and air, 2 units in chemistry I order to analyze the cognitive levels necessary for understanding high school textbooks, using CAT (curriculum analysis taxonomy). The results showed that 52.5% of the surveyed 11th grade students reached the formal operational level, 28.3% transitional levels, and 19.5% concrete operational levels. 68.9% of the academic high school students and 6.6% of the technical high school students reached the formal operational levels, and the ratio of formation was very different in each logics. As a result of the analyzing the cognitive levels needed for understanding chemistry I textbook contents, in spite of a change in national education curriculum, there were no great change in cognitive levels required by scientific concept except some inquiry activities. The cognitive levels in high school chemistry I textbooks by the 7th national education curriculum appeared higher than the cognitive levels of 11th grade student, but cognitive levels of inquiry activities were similar to the cognitive levels of the students. Chemistry teachers thought of chemistry I textbooks by the 7th national education curriculum as desirable because scientific concepts were reduced and a lot of real life materials were adapted. However, they pointed out a problem of difference in contents levels compared with chemistry I textbooks because scientific concepts were greatly reduced in chemistry I textbooks. The cognitive levels required in chemistry I textbooks still appeared higher than those of the students. Consequently, various teaching and learning methods and materials will have to be developed to be suitable for the students' cognitive levels.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.123-127
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• 2015

Wood piles are rarely used in the construction of a greenhouse in Korea, but they are relatively more often used in other countries, such as the Netherlands. There are several advantages associated with wood piles: they are more cost-effective, less time-consuming, and more ecofriendly than the steel pipes (SPs) and pre-stressed highstrength (PHC) piles. However, one of the limiting conditions is that they have to be installed below the groundwater level to prevent decay. Since the groundwater levels are generally high in the reclaimed lands in Korea, wood piles are expected to be used often as reinforcements for foundations of greenhouses in these areas. In this study, we measured the uplift capacities of wood piles through in-situ uplift capacity tests with an aim to provide basic design data for wood pile foundations. In order to test their applicability, we then compared these experimentally measured ultimate uplift capacities with the ones calculated through some of the existing theoretical equations. The wood piles used in the loading tests were made of softwood (pine wood), and the tests were performed using piles with different diameters (∅25cm and ∅30cm) and embedded depths (1m, 3m, and 5m). The test results revealed that the uplift capacity of the wood piles showed a clear linearly increasing tendency in proportion to the embedded depth, with the ultimate uplift capacities for the diameters 25cm and 30cm being 9.38 and 10.56tf, respectively, at the embedded depth of 5m; thus demonstrating uplift capacities of ${\geq}9tf$. The comparison between the actually measured values of the uplift capacity and the ones calculated through equations revealed that the latter, which were obtained using the ${\alpha}$ method, were generally in an approximate agreement with the in-situ measured values.

• Progress in Medical Physics
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• v.24 no.4
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• pp.315-322
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• 2013

The aim of this work is to verify the self-quality assurances in medical institutions in Korea through the external audits by the group of experts and have a mutual discussion of the systematic problems. In order to validate the external audits 30 of 80 medical institutions across the nation were picked out considering the regional distribution and the final 25 institutions applied voluntarily to take part in this work. The basic rules were setup that any information of the participants be kept secrete and the measurements be performed with the dosimetry system already verified through intercomparision. The outputs for 2 or more photon beams, the accuracy of gantry rotation and collimator rotation and the poistional accuracy of MLC movement were measured. The findings for the output measurement showed the differences of -0.8%~4.5%, -0.79%~3.01%, and -0.7%~0.07% with respect to that of the verified dosimetry system for the 6MV, 10MV, and 15MV, respectively. For the reference absorbed dose 8 (16%) of 50 photon beams in 25 medical institutions differed 2.0% or greater from the reference value. The coincidences of Field size with x-ray beam and radiation isocenters of Gantry roration and collimator rotation gave the results of within ${\pm}2$ mm for every institute except 2 institutions. The positional accuracy of MLC movement agreed to within ${\pm}1$ mm for every institute. For the beam qualities of 6 MV photon beams kQ values showed the distribution within 0.4% between maximum and minimum. For the protocols 21 institutions (84%) used absorbed dose to water based protocol while 4 insitutions (16%) used air kerma based one. 22 institutions employed the SSD technique while 3 institutions did the SAD one. External audit plays an important role in discovering the systematic problems of self-performing Quality Assurances and having in depth discussion for mutual complementation. Training experts of international level as well as national support system are required so that both the group of experts of medical physicists and government laboratory could perform together periodical and constant external audits.

• Food Science and Preservation
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• v.21 no.4
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• pp.512-519
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• 2014

This study was carried to investigate the physicochemical and microbiological characteristics of seasonal salted-Kimchi cabbage order to provide basic data for optimal salting and storage condition of seasonal Kimchi cabbage. Generally, fall season samples had slightly higher pH and acidity value than the other seasonal salted Kimchi cabbage. The soluble solids content of spring, summer, fall and winter samples were 5.95%, 6.18%, 6.29% and 7.76%, respectively. The salt content of all the seasonal salted Kimchi cabbage samples were insignificant. The number of microbial bacteria in the summer samples were generally much more significant than spring and winter samples. There was no significant difference in the color of seasonal salted Kimchi cabbage. As for the texture properties, the firmest samples in the surface rupture test were the spring samples (force: 4.92 kg), and the hardest samples in the puncture test were the summer samples (force: 11.71 kg). In the correlation analysis of the quality characteristics of seasonal samples, the soluble solids content and hardness of the seasonal salted Kimchi cabbage was significantly correlated at 1% significance level. Also, in the principal component analysis, F1 and F2 were shown to explain 27.28% and 35.59% of the total variance (62.87%), respectively. The hierarchical cluster analysis of the quality characteristics of seasonal samples, the samples were divided into three groups: spring cabbage group, summer cabbage group and fall and winter cabbage group.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.311-318
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• 2014

The purpose of this study was to look into the perception, experience, treatment of early childhood caries (ECC) and influential factors of perception in order to provide basic data useful for preventing the ECC by examining the relationship between oral health of young children in infancy and mother. In this study, 277 mothers were surveyed who had children in children under 6 years old and visiting the pediatrics, day care center, and pediatric dental clinics located in Daegu and Gyeongsangbuk-do from July 10, 2013 to September 5 of the same year. The results obtained from the survey were analyzed through chi-square test, t-test, and binary logistic regression analysis by using the SPSS 18.0, a statistical program. The results of analysis showed that ECC in children under 6 years old was associated with mother's age, education background of mothers, number of children and monthly income and had a significant correlation with mother's oral health-related knowledge and oral health care of their children. Thus, it would be necessary to develop oral health education programs and implement such oral health education programs at a national level on a regular basis for the mothers of young children in infancy and would-be mothers in order to reduce the ECC in infancy and promote oral health.

• Food Science and Preservation
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• v.13 no.1
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• pp.43-49
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• 2006

The chemical components of Korean paprika according to cultivars were investigated and analyzed to provide basic data for food materialization and processing. Nitrogen free extract contents of President, Special and Fiesta were 6.64, 6.22 and $6.01\%$ respectively. The contents of crude lipid and crude fiber in the Special, President and Fiesta were similar. Mineral components of paprika were rich in $K(83.41\-152.98\;mg\%),\;Mg(28.66\~39.46\;mg\%)\;and\;Mn(10.34\~18.96mg\%)$. Among the cultivars of paprika, K content had a slightly higher level in the President than those of Special and Fiesta. The major free Sugars of paprika were glucose $(1.36\~1.45\%)$ and fructose$(0.06\~1.53\%)$, respectively. The contents of total amino acids in paprika were $1,168.08\;mg\%$ in the Special, $1,112.97\;mg\%$ in the President and $874.79\;mg\%$ in the Fiesta. The major amino acids in the paprika were lysine, aspartic acid and glutamic acid Abundant organic acids of paprika were tartaric $(2.34\~4.32\;mg\%)$, succinic $(2.01\~2.42\;mg\%)$ and malic acids $(0.67\~1.72\;mg\%)$. Eight fatty acids in paprika were identified and the major fatty acids were stearic $(15.11\~34.68\%)$ and linoleic acids $(32.12\~60.36\%)$. The contents of ascorbic acid in paprika were $263.45\;mg\%$ in the Special, $284.24\;mg\%$ in the President and $206.34\;mg\%$ in the Fiesta. Total phenolics and carotenoid contents were higher in President cultivar than any other cultivars.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.2
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• pp.111-116
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• 2020

This study was conducted to determine the maintenance energy requirements of growing goats in order to establish an appropriate energy benefit system, to reduce feed costs and improve livestock productivity of goat farmers, and to present basic data for detailed specifications afterwards. This experiment was conducted as a group specification test for a total of 3 months, with 32 goats of three months age and conducted by four treatments with different energy levels (T1: NRC+0%, T2: NRC+10%, T3: NRC+20%, and T4: NRC+30%). The average daily gain was the highest in the treated with NRC + 10% of the energy level of the experimental diet, and the feed conversion ratio was in the range of 6.3 g to 7.3 g in the group feeding experiment. Although there was no significant difference in digestibility between treatments, the digestibility of dry matter, crude protein, and crude fat was higher in T2 treated with NRC + 10% than the other treatments. Through the regression equation of the values of MEI and ADG obtained through the experiment (Y=0.5439X+111.51, R²=0.712), the maintenance energy requirement of the goat in the growing period was estimated to be 111.51 kcal/kgBW^0.75.

• Journal of Korean Home Economics Education Association
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• v.32 no.1
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• pp.15-34
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• 2020

The purpose of this study was to examine the secondary school technology and home economics teachers' perception of the school curriculum organization and high school credit system. For this purpose, the questionnaire data of 345 secondary technology and home economics teachers nationwide were analyzed through descriptive statistics, t-test, and F-test with SPSS 24. The research results were as follows. First, technology and home economics teachers recognized that current schools lacked the time to organize technology and home economics curriculum (61.1%) and the number of teachers (53%). Most of them have participated (62.0%) and were very willing to participate in the school curriculum organization (4.47, 89.9%). Second, technology and home economics teachers were aware of the high school credit system more than the average (3.34), and more negative (52.8%) than positive (37.7%). As a positive influence, students recognized career choices (3.88) and deepened professional content in their major fields (3.81). On the other hand, the negative impact was the decrease in choice due to non-entry subjects (3.90) and the difficulty in moving teachers to school (3.57). Third, in order to stably respond to the introduction of high school credit system, technology and home economics teachers recognized the importance of coordinating career elective courses (4.51), developing and disseminating teaching and learning materials for elective courses (4.46), separating technology and home economics (4.45), and providing training on evaluation methods and applications (4.44). This study would be useful to provide the basic information and data for the future development of technology and home economics curriculum at the national level based on high school credit system.

• Research in Community and Public Health Nursing
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• v.12 no.3
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• pp.680-695
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• 2001

The purpose of this study was to provide basic data for developing nursing intervention for middle-aged women. This study identified health status, family functionality and spousal relationship and analyzed relationship between individual characteristics and family functionality/ spousal relationship. The subjects, of this study were 1.723 women from 45 to 55 years of age, who lived in J city. Data were analyzed using percentages, means, t-tests, ANOVA and Pearson's correlation coefficients with the SPSS statistical program. The results of the study were as follow: 1. The rate of women who perceived themselves to be healthy was 36.6%, those who did not was 30.8%. The most frequent health problem was a disease of the skeletal system (13.2%). 2. The mean score of family functionality was $3.25{\pm}.60$, with cohesion score of $3.58{\pm}.66$ and adaptability score of $2.99{\pm}.63$. 3. The mean score of total spousal relationship was $3.22{\pm}.42$; the relationship with in-laws was 3.78; sexual relationship, 3.74; life style, 3.44; and recreational activity. 3.39. 4. The women who experienced menopause perceived themselves to be unhealthier than those who did not. 5. Healthy women had a high score at total spousal relationship. personality of spouse. life style, recreational activity, and children's influence. 6. The women from 40 to 50 years of age. and women who graduated from middle or high school and had medium economic status showed a high score in family functionality. There was no correlation between family functionality and experience of the menopause. 7. Lower aged women were not good in personality of spouse (p<.05), sexual relationship (p<.05), and relationship with relatives (p<.05), Inexperienced women's menopause was influenced by their children (p<.05), Women who graduated from middle or high school (p<.001) and had medium economic status (p<.05) showed a high score in spousal relationship. 8. The higher the family functionality score. the higher spousal relationship. score (p<.001): love and communication (p<.001), personality of husband (p<.05), and religion (p<.001). relationship with relatives (p<.05), but the lower the score of recreational activity (p<.05), and share of role (p<.001) in the spousal relationship. 9. In the family functionality, the higher the cohesion score. the higher was the adaptability score (p<.001). l) The higher the cohesion score, the higher were love and communication, personality of husband. life style. sexual relationship. and children's influence, but the lower were share of role in spousal relationship(p<.001). 2) The higher the adaptability score, the higher were love and communication, religion, but the lower were the personality of husband, life style. sexual relationship, recreational activity, relationship with relatives, share of role(p<.001), and children's influence in spousal relationship (p<.05). 10. Variables within the spousal relationship have relationships with other variables. 1) The higher the love and communication score. the higher personality of husband religion, life style, communication. relationship with relatives, and children s influence (p<.001). 2) The higher personality of husband life style sexual relationship. recreational activity, relationship with relatives, share of role, and children's influence (p<.001). 3) The higher the religion score, the lower the recreational activity score (p<.05). 4) The higher the life style, the higher were the sexual relationship, recreational activity. relationship with relatives. share of role, and children's influence (p<.001). 5) The higher the sexual relationship score. the higher were recreational activity. relationship with relatives, share of role. and children's influence (p<.001). 6) The higher the recreational activity, the relationship with relatives, share of role. and children's influence (p<.001). 7) The higher the relationship with relatives, the higher were the share of role. the higher children's influence (p<.001). In conclusion. the spousal relationship was not good in unhealthy women, and the family functionality was related with the age of women and educational level. Also the spousal relationship was related with the age of women, personality of husband, sexual relationship. relationship with relatives by marriage and influence of sons and daughters. Menopause was related with spousal relationship, not related with family functionality. And the family functionality not related with perceived health status. but was correlated with spousal relationship. Therefore, the health management program for middle-aged woman should take place before menopause and must be based on promoting the family functionality and spousal relationship as well as physical health.