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Improving Curing Rate and Physical Properties of Korean Dendropanax Lacquer with Thermal and Photo Initiator by Dual Curing (이중경화법을 이용한 열개시제 및 광개시제가 배합된 황칠도료의 경화속도 촉진 및 물성향상 연구)

  • Hwang, Hyeon-Deuk;Moon, Je-Ik;Park, Cho-Hee;Kim, Hyun-Joong;Hwang, Baik
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.4
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    • pp.333-340
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    • 2010
  • The Korean Dendropanax lacquer, made from a natural resinous sap from Dendropanax orbifera Lev., was used as a golden and transparent varnish for the traditional artifacts (armor uits, helmets, arrowheads, etc.) to make them be brilliant golden color. The cured film of the acquer has excellent protective properties such as weatherability, water resistance, and nticorrosive. But, one of disadvantages is that takes a long time and much energy to fulfill curing the lacquer. The chemical constituents of the lacquer contained conjugated diene compounds s the photopolymerizable monomers. These monomers easily polymerized in sunlight to form olden-colored, hard-coating films in a short time. Photooxidation may be one of the most mportant reactions in the chemistry of the lacquer. Although the Korean Dendropanax Lacquer hould be dried to a thoroughly dry stage to achieve optimal film properties, curing with elevated emperatures may be required for the protracted curing time at atmospheric temperature. So we ntended to accelerate the curing rate of the lacquer by dual curing of thermal and radiation uring. The effect of thermal initiator on the thermal curing reaction was evaluated by monitoring he changes in double bond peak with FT-IR. Then the curing rate of the lacquer blended with hermal initiator and photoinitiator together was measured during dual curing using a RPT with V spot curing machine. Thermal initiator not only accelerated the curing rate but also improved he physical property. And the curing rate of the Korean Dendropanax lacquer was improved by ual curing method of thermal and UV curing. According to these results, the application area of he Korean Dendropanax lacquer could be expanded to surface coatings for electronic devices uch as mobile phones or electronics.

Effect of Nitrogen Levels on Yield and Quality of 2nd Harvested Tea(Camellia sinensis var. sinensis) (질소 비료 시용량에 따른 두물차(Camellia sinensis var. sinensis)의 수량 및 품질)

  • Park, Jang-Hyun
    • Korean Journal of Soil Science and Fertilizer
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    • v.31 no.3
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    • pp.238-245
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    • 1998
  • The reasonable level of nitrogen fertilizer is a key factor to reduce environmental contamination as well as to increase crop yield and quality. The treatments are $N=42kg\;10a^{-1}$, $N=48kg\;10a^{-1}$, $N=54kg\;10a^{-1}$. $N=60kg\;10a^{-1}$. $N=72kg\;10a^{-1}$ and $N=150kg\;10a^{-1}$. Analytical results of yield and quality of tea leaves harvested the second time are summarized as follows: The soil of experimental field was higher in organic matter($49.9g\;kg^{-1}$) and available phosphate($937mg\;kg^{-1}$) compared to the general field but lower in pH(5.07) compared to the general field. When the amount of nitrogen fertilizer application was raised, the yield of tea leaves, the content of nitrogen, total free amino acids, caffeine and chlorophyll increased: however, the yield of tea leaves increased to excessive levels. On the other hand, the increased level of nitrogen fertilizer did not show any difference in the contents of vitamin C and tannin. Eleven kinds of amino acids were isolated from second harvested leaves of tea where the content of theanine occupied over 50%, and content of $665{\sim}763mg\;100g^{-1}$. The contents of fatty acids and catechin did not show correlation with application level of nitrogen fertilizer. The content of fatty acid was produced $1,742{\sim}2,643mg\;100g^{-1}$, and content of catechin was produced 12.47~13.54%. In scoring test, $N=60kg\;10a^{-1}$ treatment was 0.5~6.0 point higher compared to other treatments. Consequently, $N=60kg\;10a^{-1}$ is considered to be the best level of nitrogen fertilizer in terms of decreased environmental contamination as well as to increase crop yield and quality.

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Co-authorship patterns and networks of Korean radiation oncologists

  • Choi, Jin-Hyun;Kang, Jin-Oh;Park, Seo-Hyun;Kim, Sang-Ki
    • Radiation Oncology Journal
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    • v.29 no.3
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    • pp.164-173
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    • 2011
  • Purpose: This research aimed to analyze the patterns of co-authorship network among the Korean radiation oncologists and to identify attributing factors for the formation of networks. Materials and Methods: A total of 1,447 articles including contents of ‘Radiation Oncology' and 'Therapeutic Radiology' were searched from the KoreaMed database. The co-authorship was assorted by the author's full name, affiliation and specialties. UCINET 6.0 was used to fi gure out the author's network centrality and the cluster analysis, and KeyPlayer 1.44 program was used to get a result of key player index. Sociogram was analyzed with the Netdraw 2.090. The statistical comparison was performed by a t-test and ANOVA using SPSS 16.0 with p-value < 0.05 as the significant value. Results: The number of articles written by a radiation oncologist as the first author was 1,025 out of 1,447. The pattern of coauthorship was classified into five groups. For articles of which the first author was a radiation oncologist, the number of singleauthor articles (type-A) was 81; single-institution articles (type-B) was 687; and multiple-author articles (type-C) was 257. For the articles which radiation oncologists participated in as a co-author, the number of single-institution articles (type-D) was 280 while multiple-institution articles (type-E) were 142. There were 8,895 authors from 1,366 co-authored articles, thus the average number of authors per article was 6.51. It was 5.73 for type-B, 6.44 for type-C, 7.90 for type-D, and 7.67 for type-E (p = 0.000) in the average number of authors per article. The number of authors for articles from the hospitals published more than 100 articles was 7.23 while form others was 5.94 (p = 0.005). Its number was 5.94 and 7.16 for the articles published before and after 2001 (p = 0.000). The articles written by a radiation oncologist as the first author had 5.92 authors while others for 7.82 (p = 0.025). Its number was 5.57 and 7.71 for the Journal of the Korean Society for Therapeutic Radiology and Oncology and others (p = 0.000), respectively. Among the analysis, a significant difference in the average number of author per article was indicated. The out-degree centrality of network among authors was 4.26% (2.03-7.09%) while in-degree centrality was 1.31% (0.53-2.84%). The three significant nodes were classified and listed as following: Choi, Eun Kyung for 1991-1995, Kim, Dae Young for 1998-2001, Park, Won and Lee, Sang Wook for 2003-2010. Choi, Eun Kyung and Kim, Dae Young appeared in two cases, and ranked as the highest degree in centrality. In the key player analysis, Choi, Eun Kyung and Lee, Sang Wook appeared in two cases, and ranked as the highest. From the cluster analysis, Sungkyunkwan University, Seoul National University and Yonsei University revealed as the three large clusters when Ulsan University, Chonnam National University, and Korea Institute of Radiological & Medical Science as the medium clusters. Conclusion: The Korean radiation oncologist's society shows a closed network with numerous relationships among the particular clusters, and the result indicates it is different from other institutions in the pattern of co-authorship formation of the major hospitals.

Comparison of Cytotoxin and Immune Activities between Natural and Tissue Cultured Plant in Artemisia capillaris Thunb. (자연산 및 조직배양 사철쑥의 세포독성 및 면역활성 비교)

  • Kim, Jung-Hwa;Kim, Dae-Ho;You, Jin-Hyun;Kim, Cheol-Hee;Kwon, Min-Chul;Hwang, Baik;Lee, Hyeon-Yong
    • Korean Journal of Medicinal Crop Science
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    • v.13 no.4
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    • pp.154-160
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    • 2005
  • This study was performed to compare anticancer and immune activities between natural Artemisia capillaris Thunb. extract and tissue cultured plant extract (hairy root, in vitro culture, callus). The inhibitory effect of cancer cell growth, human B cell growth and productivity of cytokines were examined. Furthermore, HPLC analysis was performed to confirm the components. The anticancer activities increased by more than 55% with the cultured callus of Artemisia capillaris T. for four cancer cell lines(Lung carcunoma, Stomach adenocarcinoma, Hepatocillular carcinoma, Breast adenocarcinoma), showing higher effect than natural Artemisia capillaris T. The extracts from hairy root and in vitro culture of Artemisia capillaris T. significantly increased the immune B cell growth. The immune B cell growth effect of natural Artemisia capillaris T. was higher than that of the tissue culture plants such as hairy root, in vitro culture and callus. Both natural and tissue cultured plants showed similar effects on cytokine secretion. The similar peak size was observed between natural Artemisia capillaris T. and cultured callus in HPLC analysis. As a results, the biological activities were not observed the difference between natural Artemisia capillaris T. and cultured callus. Thus, the cultured callus will be altered natural Artemisia capillaris T. in the environmental side and the resources preservative side

Effects of Bisphosphonate on Alveolar Bone Resolution during Experimental Tooth Movement in Rats - Biochemical & Histological Observations - (백서에서 실험적 치아이동시 치조골 흡수에 미치는 Bisphosphonate의 영향 - 생화학적 및 조직학적 관찰 -)

  • Choi, Jin-Hugh;Kim, Jong-Chul
    • The korean journal of orthodontics
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    • v.29 no.1 s.72
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    • pp.95-106
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    • 1999
  • This study was performed to examine the effect of bisphosphonate, an inhibitor of bone resorption, on the formation of osteoclast and bone resorption during experimental tooth movement. Whether bisphosphonate has a cytotoxicity in high dose was also examined. Eighty-seven male Sprague-Dawley rats, weighing 260-350g, were classified into normal (no appliance + $0.9\%$ NaCl), control (appliance + $0.9\%$ NaCl) and four bisphosphonate-treated (appliance + 0.8, 4, 20 or 100mg/kg) groups. The maxillary left first molar was moved mesially with the tipping movement using 50-70g of force. Bisphosphonate(etidronate disodium) was injected intraperitoneally with a dose of 0.8, 4, 20, or 100 mg/kg simultaneously with the application or the orthodontic force. They were killed at day 1, 3, or 7 after the application or the orthodontic force. The activities of serum acid phosphatase and lactate dehydrogenase (LDH) were assayed, and osteoclasts and the degree of bone resorption were examined histologically. The results obtained were as follows: 1. Acid phosphatase activities were significantly higher in the appliance groups, both control and bisphosphonate-treated (4, 20, and 100 mg/kg) groups, at days 1 and 3 than these in normal. At day 1, bisphosphonate-treated(4, 20mg/kg) groups showed even higher acid phosphatase than control. However, at day 7, no significant difference was noted between the control and bisphosphonate-treated groups. 2. LDH activities in the 4, 20mg/kg bisphosphonate-treated groups were increased during the experimental Periods examined, but there were no significant differences in the 0.8, 100mg/kg bisphosphonate-treated groups. 3. There was no bone resolution at day 1, but severe bone resorption was observed at days 3 and 7 in the control. Bone resorption was reduced by bisphosphonate-treatment at day 3. Bone resolution observed at day 7 was similar between the control and bisphosphonate-treated groups. 4. Few osteoclasts were observed at the alveolar bone in the control and bisphosphonate-treated groups at day 1. At day 3, numerous osteoclasts were shown in the control, the degree of which was reduced in bisphosphonate-treated groups. These results suggest that the inhibition of the osteoclast formation was not the mechanism of bone resorption by the bisphosphonate-treatment during experimenal tooth movement. There was no distinct cytotoxicity with a high dose of bisphosphonate. And the drug should be administrated repeatedly to maintain the inhibitory effect of bone resolution.

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Effect of Exercise Program of a Public Health Subcenter for Middle and Old Aged Women in an Urban Area (장.노년기 여성의 운동 프로그램 시행 전.후의 신체계측치와 혈액검사치의 변화 비교- 일개 도시 보건지소를 중심으로 -)

  • Gueon, Jun-Gyeong;Lee, Kyeong-Soo;Hwang, Tae-Yoon;Sohn, Seok-Joon;Kim, Kyoung-Won;Jang, Eun-Jin
    • Journal of agricultural medicine and community health
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    • v.34 no.3
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    • pp.359-367
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    • 2009
  • Objectives: This study was to identify the changes of body fat, blood pressure, blood glucose and serum lipid of middle and old aged women after participation in exercise program which includes aerobic(dance sports) and anaerobic(dumbbell gymnastics) exercises. Methods: One hundred women aged from 55 to 72 were surveyed before and after an exercise program. The exercise program was provided to the subjects performed during 6 months from July, 2007 to December, 2007 at a public health subcenter in Gumi City. Questionnaire survey for general characteristics, anthropometric measurement and blood test were taken before starting the program and anthropometric measurement and blood test after completing the program. Results: Body Weight, body fat and blood pressure showed significant change after the exercise program(p<0.05). Additionally in total glucose, total cholesterol and triglyceride significant change was observed(p>0.05). Waite circumference decreased, however did not show statistically significant difference. Conclusions: It was effective to participate in dance sports and dumbbell gymnastics exercise regularly. All of the positive changes through the study showed that there should be the program for middle and old aged women to exercise actively and also the middle and old aged women need have a active exercise habits as regular as possible. Additional studies confirming the results of this study are needed to compare the effects of the dance sports and dumbbell gymnastics exercise on the other age groups.

The Morphological characteristics of four Korean Abalone species in Nordotis (국내연안에 분포하는 둥근전복속 4종의 형태적 특징 고찰)

  • Won, Seung-Hwan;Kim, Soo-Kang;Kim, Sun-Chan;Yang, Byung-Kyu;Lim, Bong-Soo;Lee, Je-Hee;Lim, Han Kyu;Lee, Jung-Sick;Lee, Jun-Sang
    • The Korean Journal of Malacology
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    • v.30 no.1
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    • pp.87-93
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    • 2014
  • The Morphological characteristics of four species of Korean Abalone species, Nordotis discus hannai, N. discus discus, N. gigantea, N. madaka were compared. then Phenotypic traits were characterized. we collected from coast of samchonpo, sacjon-si, Gyeongsangnam-do and jeju-do of korea 69 individual of Nordotis discus hannai from 2013 December to 2014 January, 180 individual of N. discus, 72 individual of N. gigantea and 54 individual of N. madaka respectively then morphological traits of theses species characteristics were compared. The relationship between Shell length (SL), shell breth (SB), shell height (SH) and total weigh (TW) was expressed by the following equation: SB = 0.6346SL + 3.9082 ($R^2$ = 0.8956), SH = 0.2399SL + 3.2609 ($R^2$ = 0.8024), $TW=0.0009SL^{2.5622}$ ($R^2$ = 0.8088) in the Haliotis discus hannai, SB = 0.7249SL + 1.8035 ($R^2$ = 0.9634), SH = 0.3115SL - 11.223 ($R^2$ = 0.8593), $TW=0.0001SL^{2.9696}$ ($R^2$ = 0.8956) in the H. discus discus, SB = 0.7730SL - 1.1931 ($R^2$ = 0.933), SH = 0.2082SL + 3.2627 ($R^2$ = 0.6927), $TW=0.0002SL^{2.8330}$ ($R^2$ = 0.8431) in the Haliotis gigantea, SB = 0.7513SL - 1.0951 ($R^2$ = 0.913), SH = 0.2618SL - 6.1538 ($R^2$ = 0.6927), $TW=0.0001SL^{2.9614}$ ($R^2$ = 0.9353) in the Haliotis madaka.

A Brief Report of the Short-Term Home Range Study of a Pair of Raccoon Dogs(Nyctereutes procyonoides koreensis) in a Rural Area of Gurye, Chonnam Province, South Korea Using Radiotracking Method (전라남도 구례 농촌지역에서의 단기원격무선추적을 이용한 너구리(Nyctereutes procyonoides koreensis) 한 쌍의 행동권에 관한 연구)

  • Kim, Baek-Jun;Choi, Tae-Young;Park, Chong-Hwa;Kim, Young-Jun;Lee, Hang
    • Korean Journal of Environment and Ecology
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    • v.22 no.3
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    • pp.230-240
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    • 2008
  • The primary aim of this study is to estimate the home range of a pair of raccoon dogs(Nyctereutes procyonoides koreensis) and to compare with the previous study of raccoon dogs in a rural area of Gurye, the southern part of South Korea. Radiotracking was regularly carried out on 2 raccoon dogs for 2 days every 2 months(in June, August, October and December, 2006). During the 2 days, radiotracking was usually conducted every $1{\sim}3$ hours through day and night. The analysis of tracking data with a total of $46{\sim}64$ bearings showed that the total home range size of the pair was $0.41km^2$, and mean home range size was $0.32km^2$ by 95% minimum convex polygons(MCP) estimate. The home ranges of the male and female were largely overlapping(about $70{\sim}95%$), and the sizes were not very much different from each other. However, there was a big difference between day $(0.01km^2)$ and night-time $(0.35km^2)$ home ranges, and it was largest in summer$(0.56km^2)$ and smallest in winter $(<0.01km^2)$. In addition, the home range of the pair included 1 core area and 4 different feeding areas. In conclusion, our raccoon dog home range data using the same individuals but with more frequent bearings per day and more extended tracking intervals still showed very similar results to the previous study with less frequent bearings per day and more extensive tracking days.

Effects of Vitamins and Nucleic acids on the mycelial growth and the sclerotial production of Sclerotium rolfsii (Vitamin과 핵산이 Sclerotium rolfsii의 균사생장 및 균핵형성에 미치는 영향)

  • KIM KI CHUNG
    • Korean journal of applied entomology
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    • v.12 no.2
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    • pp.71-78
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    • 1973
  • The study was performed to clear the effects of thiamine, biotin, nicotinic acid, pyridoxine, inositol, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) on the mycelial growth and the sclerotial production of Sclerotium rolfsii Sacc. isolated from Magnolia kobus. The results are abstracted as follows: 1. Tested fungus was thiamine- deficient and required thiamine 20r/l for maximum growth of mycelia. At higher concentrations than thiamine 20r/l, however, mycelial growth was decreased with increasing the concentrations and was inhibited little less than that of thiamine-free control at 150r/l. 2. The effecfivenesses of the nitrogen sources on the mycelial growth under the thiamine presence were recognized in order of $NH_4NO_3>(NH_4)_2SO_4 >asparagine> KNO_3$, and on the sclerotial production were $KNO_3>NH_4NO_3>asparagine>(NH_4)_2SO_4$. The optimum concentrations of thiamine were about 12r/1 in $KNO_3$, about 16r/1 in asparagine on the growth of mycelia, and were about 8r/l in $KNO_3\;and\; NH_4NO_3,\; 16r/1$ in asparagine on the production of sclerotia. 3. After the organism began to grow, the pH value of cultral filtrate was rapidly dropped down to about 3.5. Hereafter it was slowly fallen down as the growth amount was increased, but was not depreciated below pH 2.2. 4. Nicotinic acid was not effective individually on the mycelial growth and the sclerotial formation of tested fungus without thiamine, but slight effect of it was recognized with thiamine 10r/l, even though maximum growth was shown at 7-10mg/1. Beyond that concentration, however, mycelial growth was rather depressed. 5. When ammonium sulphate or asparagine as the nitrogen sources was used, pyridoxine, biotin and inositol had not any effectivenesses on the mycelial growth and the sclerotial production of examined fungus. 6. In the concentrations of thiamine, biotin, pyridoxine and inositol, as long as thiamine was not added in those, their correlating effects on the growth of the organism were not observed at all. Equivalent or more effects on the mycelial growth were recognized in combinations of thiamin + pyridoxine, thiamine + inositol, thiamine + biotin + pyridoxine, and thiamine + biotin + pyridoxine + inositol compared with thiamino alone, and in combinations of thiamine + biotin and thiamine + biotin + inositol, mycelial growth was inhibited rather than that of thiamine alone. Sclerotial production of those combinations was increased more than that of thiamine alone in dry weight. 7, The little effects of DNA and RNA on the mycelial growth of the organism were recognized compared with the control(DNA-and RNA-free), and RNA was more effective than DNA. Maximum growth of mycelia was observed at RNA 2-6mg/1 and DNA 6mg/l. No effectivenesses on the sclerotial production were recognized in the RNA and DNA. 8. Mycelial growth of the organism was increased with increasing the concentrations of the RNA and the thiamine, that is, the effectiveness of RNA was revealed apparently under presence of thiamine, but was not shown in the sclerotial formation.

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Effectiveness of parenting education program for adolescents (청소년 대상 예비부모교육 프로그램 효과성 연구)

  • Jun, Mikyung;Lee, Eun Joo;Yu, Nan Sook;Wang, Seok-Soon;Choi, Saeeun
    • Journal of Korean Home Economics Education Association
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    • v.29 no.4
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    • pp.31-47
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    • 2017
  • The purpose of this study was to evaluate the effectiveness of parenting education program for adolescents. Parenting education program for adolescents was developed and implemented at three secondary schools in Seoul, Chungcheong province, and Gwangju metropolitan city with focus on the following topics respectively 'parent-child communication', 'understanding fatherhood', and 'preparation for parenting based on self-understanding'. Data were collected from self-reported inventory and 97 data copies for pre- and post tests were used for analyses. Data were analyzed for frequency, percentage, paired t-test and One way ANOVA using SPSS/PC 21.0 program. The results from mean comparison of pre- and post tests were as follows. First, perception of necessity for parenting education and needs for including parenting program into regular secondary school curriculum increased statistically, which means that parenting program must be implemented regularly to meet the demands of adolescents for parenting program. Second, the main reason for not having children was 'burden for rearing children', which means that enough child-care skill and information need to be included. Third, the mean difference between pre- and post tests regarding perception of performing parents' roles was statistically significant, which means that the participants' perception of performing parents' roles became positive. Fourth, the 32 high school students participating in parenting education of 'understanding fatherhood' did not have significant difference in gender role. The 29 middle school students participating in parenting education of 'parent-child communication' had significant difference in perception of communication. The 36 high school students participating in parenting education of 'preparation for parenting based on self-understanding' had significant difference in self-esteem. This results identified the effectiveness of parenting education for adolescents. Therefore, Home Economics subject must be selected to give the opportunity of parenting education to high school students.