• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.7
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• pp.565-572
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• 2021

In this study, a study on the performance and aging of explosive bolts stored for a long time among pyrotechnic mechanical devices(PMD) used as separation devices in the defense field is conducted. For this, explosive bolts that had been installed in the weapon system for about 10 years are secured. Performance and life extension test procedures are established based on the AIAA Standard and MIL-STD. Before performance evaluation, non-functional tests are performed to check whether external changes or failures occurred. Next, circuit inspection and X-ray tests are conducted to check the failure in internal circuits and structures. After that, performance test is carried out to confirm the operation of the samples that passed the non-functional test. Through this test, separation of bolt and separation time are measured, and some samples are tested after a high temperature storage test to confirm the remaining life and the possibility of extension. Finally, the remaining life and reliability are predicted based on the results of the test and the Arrhenius model to identify remaining shelf life and reliability depend on time.

• Journal of Agricultural Extension & Community Development
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• v.7 no.1
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• pp.155-166
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• 2000

When the marcher visited Korea in fall 1994, he was shocked to see high rise apartment buildings around the capitol region including Seoul and Suwon, resulting from rising demand of housing because of urban migration followed by second and third industrial development. After 6 years in March 2000, the researcher witnessed more apartment buildings and vinyl house complexes, one of the evidences of continued economic progress in Korea. Korea had to receive the rescue finance from International Monetary Fund (IMF) because of financial crisis in 1997. However, the sign of recovery was seen in a year, and the growth rate of Gross Domestic Products (GDP) in 1999 recorded as high as 10.7 percent. During this period, the Korean government has been working on restructuring of banks, enterprises, labour and public sectors. The major directions of government were; localization, reducing administrative manpower, limiting agricultural budgets, privatization of public enterprises, integration of agricultural organization, and easing of various regulations. Thus, the power of central government shifted to local government resulting in a power increase for city mayors and county chiefs. Agricultural extension services was one of targets of government restructuring, transferred to local governments from central government. At the same time, the number of extension offices was reduced by 64 percent, extension personnel reduced by 24 percent, and extension budgets reduced. During the process of restructuring, the basic direction of extension services was set by central Rural Development Administration Personnel management, technology development and supports were transferred to provincial Rural Development Administrations, and operational responsibilities transferred to city/county governments. Agricultural extension services at the local levels changed the name to Agricultural Technology Extension Center, established under jurisdiction of city mayor or county chief. The function of technology development works were added, at the same time reducing the number of educators for agriculture and rural life. As a result of observations of rural areas and agricultural extension services at various levels, functional responsibilities of extension were not well recognized throughout the central, provincial, and local levels. Central agricultural extension services should be more concerned about effective rural development by monitoring provincial and local level extension activities more throughly. At county level extension services, it may be desirable to add a research function to reflect local agricultural technological needs. Sometimes, adding administrative tasks for extension educators may be helpful far farmers. However, tasks such as inspection and investigation should be avoided, since it may hinder the effectiveness of extension educational activities. It appeared that major contents of the agricultural extension service in Korea were focused on saving agricultural materials, developing new agricultural technology, enhancing agricultural export, increasing production and establishing market oriented farming. However these kinds of efforts may lead to non-sustainable agriculture. It would be better to put more emphasis on sustainable agriculture in the future. Agricultural extension methods in Korea may be better classified into two approaches or functions; consultation function for advanced farmers and technology transfer or educational function for small farmers. Advanced farmers were more interested in technology and management information, while small farmers were more concerned about information for farm management directions and timely diffusion of agricultural technology information. Agricultural extension service should put more emphasis on small farmer groups and active participation of farmers in these groups. Providing information and moderate advice in selecting alternatives should be the major activities for consultation for advanced farmers, while problem solving processes may be the major educational function for small farmers. Systems such as internet and e-mail should be utilized for functions of information exchange. These activities may not be an easy task for decreased numbers of extension educators along with increased administrative tasks. It may be difficult to practice a one-to-one approach However group guidance may improve the task to a certain degree.

• Journal of Family Resource Management and Policy Review
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• v.4 no.1
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• pp.59-68
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• 2000

Everyone lives in a home. We pursue happiness and the meaning of life through home life or family life. Home life, therefore, has an important meaning in the whole life, But home life can be sustained only through housework and wage labor. All human activities can be divided into two kinds of activities. The one has intrinsic value, the other has extrinsic value. Housework belongs to the activity with intrinsic value, but wage labor belongs to the activity with extrinsic value. In view of home life, housework has primary meaning, and wage labor has subsidiary meaning. In other words, wage labor is only means of home life. We mush not forget that important fact. But we cannot help thinking that nowadays people consider wage labor itself as an aim of life. It is said that we are achieving self-actualization through wage labor, but it is not ture. To tell the truth, most of us are experiencing self-alienation in job. We must recover the legitimate relation between housework and wage labor. Wage labor is means of home life, therefore it is on the extension line of housework. If we achieve happiness through home life, we must recognize that wage labor is only means of home life, not an end in itself.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.3
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• pp.516-522
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• 2009

The dimmable magnetic ballast which applies the variable inductor needs a switching process for the dimming process, and it consists of mechanical relays because of costs and reliabilities. However, it is hard to operate with correct timing in mechanical relay, so relays reduce their own life time in inductive applications. Moreover this creates a destructive problem at the switching process. The life time reduction of relays means the life time reduction of the ballast. Thus, in this paper, we described the problem at the witching process in the dimmable magnetic ballast with a variable inductor, which consists of relays and the soft AC switching method in order to solve the problems. As result, we achieved the improvement of the life time and reliability of the ballast.

• Proceedings of the Korean Society of Crop Science Conference
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• 2007.11a
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• pp.33.2-33.2
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• 2007

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.200-207
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• 2007

Single base propellant using a nitrate ester compound NC decomposes naturally during storage time. Therefore, the research for storage life extension is necessary to single base propellant. In this research, $CaCO_3$ inorganic stabilizer had been added into single base propellants up to 0.3%, and the accelerated aging test of the propellant was started. And then, with applying the Arrhenius equation, the storage life of the test of the propellant was contrasted with that of reference propellant. As a result, the storage life of the propellant containing $CaCO_3$ inorganic stabilizer was about twice longer than the reference propellant.

• 한국약용작물학회:학술대회논문집
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• 2009.05a
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• pp.369-370
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• 2009

• Research in Plant Disease
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• v.20 no.1
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• pp.8-14
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• 2014

The socio-network activities for regional governments, agricultural research institutes, developing agencies and policy makers of any countries are very crucial and important to take into account the root cause of current problems faced by farmers. The survey was conducted in South Korea during the period January, 2008 to August, 2012 in order to shed light on prevalence of different diseases on watermelon in different regions and to better understand farmers' knowledge and perceptions for following watemelon's growing procedures and practices. A total of 590 cases were reported on 573 watermelon growers with highest 87.1% in Jeonbuk, 4.7% in Jeonnam, and 8.2% in other regions such as Gyeongbuk, Gyeongnam, Chungnam, Gwangju, Gyeonggi, Daegu, Gangwon, Changwon and Seoul. The maximum percentages of cases recorded were related to diseases and insect pest (38.6%) followed by physiological disorder (29.7%), cultural practices (18.8%), soil and fertilizer (9.0%), herbicide (2.9%) and others (1.0%). It was observed that the manifestation aspects of the diseases were changed due to increasing in proportion of 'in-facility' cultivation to 12,995 ha compared to 'open-field' cultivation (2,722 ha). The present survey revealed the necessity to reduce the damages incurred at watermelon farms as soon as possible through the breeding program to develop resistant cultivar, use of pathogen-free propagating plants, and efficient prevention of pathogen by regular monitoring of watermelon plants at farms.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.368-368
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• 2017

Rice is the world's three major crops that is the staple food of Asian. Japonica type rice is consumed in Korea. Rice cultivation area decreases steadily. That is affected by decrease of the farm income with the inventory of 1.7 million tons, which is 2 to 3 times more than the optimal amount due to the decrease in the consumption of rice per person and cultivate high yield varieties. In recent years, as income level has improved, interest in health has been high and consumption for health food has been steadily increasing. For health food, rice is added by adding grains such as millet, sorghum, oats, beans and colored rice rather than white rice. In 1997, RDA(Rural Development Administration) developed black rice 'Heuknambyeo', and then 20 varieties were bred until 2017. In CBARES(Chungbuk Agricultural Research and Extension Services), we have developed new rice varieties 'Cheongpungheukchal' in 2010, 'Cheongpungheukhyangchal' in 2014, 'Cheongpungheukchal' is high in farming preference because of high yield. Black rice has high content of GABA and water-soluble phenol, DPPH radical scavenging activity, and consumers are interested in the function in the body. Therefore, functional and antioxidant activities(anthocyanin, total polyphenol, ${\alpha}-glucosidase$ inhibition) and antioxidant activities(ABTs, DPPH) were analyzed by comparing white and black rice. Testing varieties are 'Chucheongbyeo', best quality cultivars 'Daebo' and 'Samgwang' as white rice which are cultivated much in Chungbuk area, and black rice are 10 varieties including 'Cheongpungheukchal', 'Cheongpungheukhyangchal', 'Josaengheukchal' and so on. It has transplanted on 25th May, at CBARES research paddy by 100% fertilizer recommendation rate. Harvesting time was 50 days after heading by varieties, and has researched growth properties, yield and yield components, functional and antioxidant activities. Anthocyanin content was not measured because there was no pigmented in white rice, the highest value of anthocyanin content was 'Shintoheukmi' and in the range of 125.6~249.6mg/100g by black rice varieties. Total polyphenol content was high 'Cheongpungheukchal' and 'Shintoheukmi' and in the range of 96.68~244.34 mg/100g in black rice, white rice lower than blackish rice at 19.84~22.51mg/100g. ${\alpha}-glucosidase$ inhibition was high 'Cheongpungheukchal', 'Cheongpungheukhyangchal' and 'Shintoheukmi' in the rage of 75.87~98.85% by black rice varieties, especially 'Samgwang' was 80.75% and the other white rice was higher than 58~68%.

• Journal of the Korean Home Economics Association
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• v.20 no.3
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• pp.85-102
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• 1982

The current employment status among young home economists and perspectives in occupations for prospective Home Economics graduates were explored in this study which utilized information from 17 to 21 colleges in Korea and colleges in the United States during the five years of 1977∼1981. The Home Economics content areas covered in this study were Clothing and Textiles, Foods and Nutrition, Housing and Interior Design, and Child Development and Family Life. The highest percentage of Korean graduates in Clothing and Textiles was employed either as teachers at the junior high school level or as designers in the clothing and textile industries. Quite a number of the graduates were engaged in further studies at the graduate level. Korean graduates with a master's degree were teaching at the college level and some had furthered their studies at the doctorate level either here or abroad. Koreans with a bachelor's degree in Foods and Nutrition held jobs as teachers in junior high school, dieticians at mass feeding institutions and hospitals, food scientists in food industries, and researchers in institutions. Those with a master's degree were teaching at the college level. Americans with a bachelor's degree worked as dieticians, supervisors in restaurants and institutions, extension workers, researchers at various facilities, teachers and clerks. Americans with a master's or doctorate degree were engaged in teaching at colleges or supervising at research or working as extension specialists. In general, Korean graduates were found to hold positions in less varied areas than their American counter-parts. Among forty-nine graduates those working in their professional field reported less sex discrimination that those working in other fields. The major area of employment in Housing and Interior Design or Home Management graduates in Korea was teaching while in the United States it was extension work, business, governmental work and teaching. It was suggested that in the future, career development in Korea be further explored to include extension service, research, social welfare, financial planning, business, free-lancing, funeral home, home-call, and correctional education. Interviews with executives from 6 business enterprises indicated that most of them were aware of the potential contribution home economists could make for their companies but they expressed a negative attitude towards women in general due to their short stay on the job. Jobs held by Child Development and Family Life majors with a bachelor's degree in Korea were mostly teaching positions in public, junior and senior high school. However, jobs such as nursery school teaching, working in clinical setting, business, and teaching at public, junior and senior high school predominated in the United states. Most Korean graduates with a master's degree were teaching in professional colleges while in the United Stated the job variation among the graduates was rather evenly distributed among teaching at college level, public and high school, nursery school and administration areas. Reports from 7 child development majors on the job indicated that they were paid less that secretarial workers. Only half of them were working in their major area and these expressed satisfaction with their work. Two thirds of the respondents indicated no sex discrimination. It was suggested that in the future Child Development and Family Life majors pursue employment in counseling, guidance, recreation, mass media, administration and outreach work as well as education, research and parent education in services for children, teen-agers, adults and families.