• Title/Summary/Keyword: Life Extension

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Breeding and characterization of a long shelf-life cultivar 'DanBi 7Ho' by mono-mono crossing in Pleurotus eryngii

  • Kim, Min Keun;Sim, Soon Ae;Park, Ji Hye;Ryu, Jae San;Choi, Si Lim;Hong, Kwang Pyo
    • Journal of Mushroom
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    • v.16 no.3
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    • pp.140-146
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    • 2018
  • Pleurotus eryngii is one of the most commercially important mushrooms cultivated in Korea. However, the shelf-life of the fruiting body is short, limiting its export. A new hybrid strain H17 of P. eryngii was developed to extend the shelf-life by mono-mono crossing between monokaryotic strains derived from DanBi and KNR2774. Although the cultivation period of H17 was slightly longer than that of the reference cultivar Kenneutari No.2, the quality did not change and remained normal after a period of 65.0 days at $4^{\circ}C$. This result was significantly different from that of the reference cultivar Kenneutari No.2. Analysis of the genetic characteristics of the new hybrid strain H17 revealed a different profile from that of the parental and reference cultivars when random amplification of polymorphic DNA (RAPD) primers was used. These results demonstrate that H17 is a new cultivar with improved storability after harvesting.

Returns to Investment on Extension Service in Korea;Implications for the Structural Change (농촌지도사업(農村指導事業)의 투자효과(投資效果) 변화(變化)의 추이(推移);지도사업(指導事業)의 구조변화(構造變化)에 대응(對應)하여)

  • Choi, Min-Ho;Choe, Young-Chan
    • Journal of Agricultural Extension & Community Development
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    • v.2 no.1
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    • pp.1-21
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    • 1995
  • This study examines the socioeconomic returns to agricultural research and extension services in Korea, using multivariate time series technique and Akino-Hyami formula. Results find that the socioeconomic returns are quite competitive in case of agricultural research with 44.82% internal rate of return and very high in case of extension services with 207.82% internal rate of return. Agricultural production responds to the agricultural research shock about four years after the shock. The magnitudes of the impacts increase until a peak is reached nine years after the initial expenditures and the impacts declines to a zero level after about twenty years. This lag lengths are consistent to the usual literature on research, which finds lags of seven to thirty years. Agricultural production responds to an agricultural extension shock immediately and declines to a zero level after about four years. Thus, the lag lengths are much shorter than those by research shock.

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Agricultural Extension, Rural Adult Education and Community Development (농촌지도, 농촌사회교육과 지역사회개발)

  • Cheong, Ji-Woong
    • Journal of Agricultural Extension & Community Development
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    • v.4 no.2
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    • pp.385-392
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    • 1997
  • This paper attempted to describe the relationships among agricultural extension, rural adult education and community development, which has developed as a disciplinary major (ag. extension in 1971, rural adult education in 1990 and community development in 1997) at the College of Agriculture and Life Science, Seoul National University. Reviewing the related literatures and observing the practical rural development in the Republic of Korea, conclusion was made in such a way that agricultural extension - rural adult education - community development be natural series of disciplinary development process as well as practical development in industrializing and urbanizing country like the Republic of Korea.

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Problems in Localization of Extension Educators in Korea (농촌지도직 공무원 지방직 전환의 문제)

  • Kim, Sung-Soo
    • Journal of Agricultural Extension & Community Development
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    • v.7 no.1
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    • pp.247-254
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    • 2000
  • Since 1997, Korean government changed the status of extension educators from central government staff to county/city government staff for the sake of democratization and localization, regardless of opposition of academic society of extension professionals. Localization of extension educators followed by government restructuring in Korea, resulted various problems, such as 1) Decreased morale and number of extension educators, thus weakening the extension educational function, 2) Weakened linkages between national and local extension offices, 3) Less opportunity for in-service edition of extension educators, 4) Weakened linkages between agricultural research and extension, etc. During the last 30 years, extension services have helped Korean farmers in achieving self sufficiency of rice and year around supply of green vegetables by diffusion of vinyl house technology. Various problems after three years of localization of extension educators were discussed between announcer of radio KBS and a professor of extension in an interview format, and it was concluded that national efforts should be needed to restore morale of extension educators to continually achieve the national goals of food production, balanced national development and preservation of environment, at the same time to meet increasing needs of farmers.

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Achievement and New Directions of the Korea Agricultural Extension Specialist Association (전문지도 연구회 활동성과의 발전방향)

  • Choi, Hyo-Yeol;Park, Kyung-Chul
    • Journal of Agricultural Extension & Community Development
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    • v.7 no.2
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    • pp.327-331
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    • 2000
  • The purposes of this study were to analyze achievement of the Korea Agricultural Extension Specialist Association and suggest new directions for further development. The Korea Agricultural Extension Specialist Association was organized to develop competencies in specialized field for extension educators in 1996. About 47% of extension educators joined academy during the 5 year period, even though there were many difficulty in organizing extension educators, the Korea Agricultural Extension Specialist Association has achieved to increase independent learning activity, to share new information and improve agent’s competency. New directions for the future development of the Korea Agricultural Extension Specialist Association activities should include the following measures; 1) Academy manages to help member’s competency, 2) Every member of the Association tries to make a concrete goal of activity, 3) The Association members should find ways to enable farmers to remain informed on agricultural extension services to people.

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Localization Process of Agricultural Extension Personnel and the Tasks for the Future (농촌지도직 공무원의 지방직 전환 과정과 앞으로의 과제)

  • Kim, Sung-Soo
    • Journal of Agricultural Extension & Community Development
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    • v.3 no.2
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    • pp.167-176
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    • 1996
  • Localization process of agricultural extension personnel in Korea were in progress with insufficient debates for effective personnel management. Although the members of the Korean Agricultural Extension Society were strongly opposed to the plan to decentralize agricultural extension personnel from central to local government status, the administrative action took place to localize as of January 1997. The Korean Agricultural Extension Society filed the petition against to the plan pinpointing lowered morale of extension personnel, the financial burden of local governments, jeopardizing stability, undermining efficiency, and people`s attitude towards central and local government. The dangers of decentralization of agricultural extension services may cause serious problems in varied areas. More extensive debates would be needed in deciding the future directions of agricultural extension services analyzing the basic characteristics of agricultural extension, linkages of research and extension, financial burden of local government, specialization of extension personnel, and unnecessary duplication of investment among local governments.

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Parametric inference on step-stress accelerated life testing for the extension of exponential distribution under progressive type-II censoring

  • El-Dina, M.M. Mohie;Abu-Youssef, S.E.;Ali, Nahed S.A.;Abd El-Raheem, A.M.
    • Communications for Statistical Applications and Methods
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    • v.23 no.4
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    • pp.269-285
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    • 2016
  • In this paper, a simple step-stress accelerated life test (ALT) under progressive type-II censoring is considered. Progressive type-II censoring and accelerated life testing are provided to decrease the lifetime of testing and lower test expenses. The cumulative exposure model is assumed when the lifetime of test units follows an extension of the exponential distribution. Maximum likelihood estimates (MLEs) and Bayes estimates (BEs) of the model parameters are also obtained. In addition, a real dataset is analyzed to illustrate the proposed procedures. Approximate, bootstrap and credible confidence intervals (CIs) of the estimators are then derived. Finally, the accuracy of the MLEs and BEs for the model parameters is investigated through simulation studies.