• Title/Summary/Keyword: field extension

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An Improved Scalar Multiplication on Elliptic Curves over Optimal Extension Fields (최적확장체에서 정의되는 타원곡선 상에서 효율적인 스칼라 곱셈 알고리즘)

  • 정병천;이재원;홍성민;김환준;김영수;황인호;윤현수
    • Proceedings of the Korean Information Science Society Conference
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    • 2000.10a
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    • pp.593-595
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    • 2000
  • 본 논문에서는 최적확장체(Optimal Extension Field; OEF)에서 정의되는 타원곡선 상에서 효율적인 스칼라 곱셈 알고리즘을 제안한다. 이 스칼라 곱셈 알고리즘은 프로비니어스 사상(Frobenius map)을 이용하여 스칼라 값을 Horner의 방법으로 Base-Ф 전개하고, 이 전개된 수식을 일괄처리 기법(batch-processing technique)을 사용하여 연산한다. 이 알고리즘을 적용할 경우, Kobayashi 등이 제안한 스칼라 곱셈 알고리즘보다 40% 정도의 성능향상을 보인다.

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Estimation of Transition Curves Extension Method for Railway Curved Zone Improvements (철도곡선부 개량을 위한 완화곡선 연장방법의 적용성 평가)

  • 정의환
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.11a
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    • pp.73-80
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    • 2004
  • The speed up of conventional lines feel strongly the necessity of it, for fully realizing a role of transportation system, for human life style is high, and increasing of time value. Especially curved lines zone have crucial effects on the speed of train. In this study, the extension method of transition curve is evaluated, based on the alignment of Jang-Hang line, investigated field conditions of the sections where the curves exist. The result of this research is very applicable to the condition where it is difficult to over-all alignment improvements.

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Ehtiopiam Agricultural Extension System -The Past Experience, Present Status and Future Direction- (에티오피아 농촌지도사업의 현재와 미래)

  • Besha, Dagnachew Bekele;Park, Duk-Byeong
    • Journal of Agricultural Extension & Community Development
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    • v.21 no.1
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    • pp.219-244
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    • 2014
  • Agricultural extension service in Ethiopia was started in early 1950s with mandate of transferring local research outputs and technologies to farmers, and importing technologies and improved practices from abroad. Extension service provided in this early time was limited to areas surrounding the experiment stations. Since then, Ethiopian Agricultural extension service has passed through at least five stages: the land grant extension system, the Comprehensive Package Programs, the Minimum Package Projects, the Peasant Agricultural Development Program, and the Participatory Demonstration and Training Extension System (PADETS). The comprehensive package extension program was initially implemented in selected pilot areas and eventually to be scaled up to cover about 90% of the farming community within 15-20 years time. The program used demonstration plots managed by development agents and used to train farmers organized through various field days. However, since all of these programs were operational in only small areas, the vast majority of the country was out of their reach. Through Participatory Demonstration and Training Extension System, the extension service in Ethiopia has come under the spotlight and government debates and external reviews are putting additional scrutiny on the system. Despite this long history, the system is still in its infancy in terms of coverage, communication and institutional pluralism. Currently in Ethiopia the Agricultural extension is provided primarily by the public sector, operating in a decentralized manner through which extension is implemented at the district level. Therefore, the main focus of this paper is to scrutinize the past, the present and the future Agricultural extension system in Ethiopia.

Screening and Identification of an Antifungal Pseudomonas sp. That Suppresses Balloon Flower Root Rot Caused by Rhizoctonia solani

  • Ryu, Jae-San;Lee, Sang-Dae;Lee, Young-Han;Lee, Seong-Tae;Kim, Dong-Kil;Cho, Soo-Jeong;Park, Sang-Ryeol;Bae, Dong-Won;Park, Ki-Hun;Yun, Han-Dae
    • Journal of Microbiology and Biotechnology
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    • v.10 no.4
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    • pp.435-440
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    • 2000
  • A pathogenic fungus causing balloon flower root rot (Platycodon grandiflorum) was isolated from naturally infected roots. The microbial characteristics of the isolated microorganism were similar to those of Rhizoctonia solani. About 500 bacterial species from field soils were screened for a biological agent against the above-mentioned putative pathogen, and several bacteria with the antifungal activity were isolated. Among them, the isolated JS2 was identified as Pseudomonas aeruginosa. This strain showed a broad spectrum of antifungal activity potentially. When the antifungal substance was purified from a broth culture of JS2, it was identified as 2,4-diacetylphloroglucinol (Phl).

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Study on rice double cropping in Southern Korea paddy field

  • Seong, Deok-Gyeong;Kim, Young-Gwang;Nam, Jin-Woo;Choi, Yong-Jo;Hong, Kwang-Pyo
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.320-320
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    • 2017
  • Recently, the rice growing time was extended by the global warming. This study was conducted to investigate the possibility of rice double cropping system in southern Korea. The first transplanting was with six cultivars ('Kilala397', 'Baekilmi', 'Joun', 'Hanseol' and 'Jungmo1031') on April 15. All cultivars could be harvested at the end of July. Adaptable cultivars for the first cultivation were 'Kilala397', Baekilmi' and 'Joun'. The rice yields at the first cultivation was about 95% of local average yield. Although the yield was slightly less, the first cultivation was considered to have economic benefits, because of the high market price of rice. In the second transplanting was with five cultivars ('Manjong', 'Joun', 'Deabo', 'Jinok' and 'Kilala397') on April 15. All cultivars could be harvested in early November. Adaptable cultivars for the second cultivation were 'Jinok' and 'Kilala397'. The rice yields at the second cultivation was about below the 60% of local average yield, because there was the less growth than normal season cultivation. Consequently, southern Korea' annual rice double cropping system is considered to have no economic value yet. However, the research should be continued considering the temperature rise of global warming.

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Occurrence of Stem Rot of Valeriana fauriei Caused by Sclerotium rolfsii (Sclerotium rolfsii에 의한 쥐오줌풀 흰비단병 발생)

  • Kwon, Jin-Hyeuk;Jeong, Seon-Gi;Jin, Young-Min;Song, Won-Doo
    • The Korean Journal of Mycology
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    • v.38 no.2
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    • pp.205-207
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    • 2010
  • Stem and petiole rot symptoms of Valeriana fauriei occurred sporadically in the herb exhibition field in Gyeongsangnam-do Agricultural Research and Extension Services, Hamyang-gun, Gyeongnam Province in Korea. The typical symptom is water-soaking on the stem, rotting, wilting, blighting and the infected plants eventually died. White mycelial mats spreaded over lesions, and then sclerotia were formed on the infected plant parts and near soil surface line. On the basis of mycological characteristics and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii. This is the first report of stem rot on Valeriana fauriei caused by Sclerotium rolfsii in Korea.

Feasibility of a simple determination of soil organic matter content using spectrophotometric method in Korean soils (분광법을 이용한 토양 유기물의 간이 측정 방법의 국내 적용 가능성)

  • Seo, Young-Ho;Mo, Young-Moon;Cho, Byoung-Ouk;Kang, An-Seok;Jeong, Byeong-Chan;Jung, Yeong-Sang
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.1008-1011
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    • 2010
  • A method currently used to determine soil organic matter (SOM), Tyurin method, is time consuming and expensive while accurate. Recently, a spectrophotometric determination was reported to be rapid, accurate, stable, easy to execute, and amendable to field use for soil samples obtained from Texas, USA. The objective of this study was to test if the spectrophotometric method is applicable to soils in Korea. Soil organic matter was extracted by 1 M HCl followed by a 0.25 M NaOH-0.1 M sodium pyrophosphate solution at a ratio of 1:250 soil:extractant. Soil organic matter determined by Tyurin method was linearly related to the value based on absorbance at 300 nm of the soil extracts with a coefficient of determination ($r^2$) of 0.81. Therefore, the result imply that this spectrophotometric method can be used to determine the soil organic matter of agricultural soils in Korea.

Soil Physico-chemical Properties of Organic Grapes Farms with Different Culture Facilities and Soil Management Practices

  • Kim, Sun-Kook;Kim, Byeong-Sam;Kang, Beom-Ryong;Yang, Seung-Koo;Kim, Byeong-Ho;Kim, Hee-Kwon;Kim, Hyun-Woo;Choi, Kyeong-Ju
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.5
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    • pp.399-407
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    • 2013
  • Organic grape was generally produced in rainshield or plastic greenhouse culture while most of fruits were produced in open field. But little attention has been given to soil properties with different culture facilities in organic grape cultivation. This study was conducted to investigate soil physico-chemical properties of organic grapes farms with different culture facilities and soil management practices. Organic fertilizer was main resource to manage soil at organic grapes farms. Organic grapes farms were applied with total amount of organic fertilizer at one time, either at basal or additional fertilization, whereas conventional grapes farms applied with split fertilization. Bulk density and penetration resistance of soil were lower at both rainshield and green manure-applied plastic greenhouse cultures than those at clean plastic greenhouse culture. Especially, in plastic greenhouse, sod culture with natural weed after green manure application was more effective than general sod culture in improving physical properties of the rhizosphere. The contents of organic matter, available phosphate and exchangeable potassium tended to increase in the soils applied with green manure, and the difference of soil chemical properties were significant between rainshield and plastic greenhouse cultures. The optimum soil management was required in plastic greenhouse because pH, available phosphate and exchangeable cations reached over optimum range. Consequently, the ground cover management is the key factor to affect the chemical properties as well as soil physical properties extensively in plastic greenhouse. It is found that sod culture with natural weed after green manure application resulted in enhancement of utilization efficiency of nitrogen, phosphoric acid and potassium in soil in comparison with general sod culture.

Influence of Perceived Similarity on Fashion Brand Extension -Exploring the Moderating Effect of Brand Relationship Quality- (지각된 유사성이 패션 브랜드 확장효과에 미치는 영향력에 있어서 소비자-브랜드 관계 질의 조절효과)

  • Kim, Joo-Hyun;Lee, Yu-Ri
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.7
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    • pp.721-735
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    • 2011
  • This study: 1) identifies differences in consumers' perceived similarity of extended products to their parent product in terms of brand attributes, 2) identifies the influence of the perceived similarity on consumer's attitude toward and purchase intention of extended products (i.e., brand extension effect), and 3) examines the moderating effect of Brand Relationship Quality (BRQ) on brand extension effects. A survey questionnaire was distributed to a convenience sample of individuals aged 20-39. A total of 576 valid responses were used for the final analysis. The results showed that: 1) the consumers perceived more similarity in the extended products when the extended products maintain more consistent attributes with their parent product, 2) the higher the perceived similarity was then the higher the brand extension effect, and 3) brand relationship quality moderated the influence of perceived similarity on attitude and purchase intention. When consumers build a high relationship quality with a brand, then the brand extension effect is likely to be high regardless of the perceived similarity of the extended products. This study consequently has its own contribution in that it empirically examined the brand extension effect in the fashion field and evidenced the role of BRQ in brand extension.