• 제목/요약/키워드: field extension

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AN ACTION OF A GALOIS GROUP ON A TENSOR PRODUCT

  • Hwang, Yoon-Sung
    • 대한수학회논문집
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    • 제20권4호
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    • pp.645-648
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    • 2005
  • Let K be a Galois extension of a field F with G = Gal(K/F). Let L be an extension of F such that $K\;{\otimes}_F\;L\;=\; N_1\;{\oplus}N_2\;{\oplus}{\cdots}{\oplus}N_k$ with corresponding primitive idempotents $e_1,\;e_2,{\cdots},e_k$, where Ni's are fields. Then G acts on $\{e_1,\;e_2,{\cdots},e_k\}$ transitively and $Gal(N_1/K)\;{\cong}\;\{\sigma\;{\in}\;G\;/\;{\sigma}(e_1)\;=\;e_1\}$. And, let R be a commutative F-algebra, and let P be a prime ideal of R. Let T = $K\;{\otimes}_F\;R$, and suppose there are only finitely many prime ideals $Q_1,\;Q_2,{\cdots},Q_k$ of T with $Q_i\;{\cap}\;R\;=\;P$. Then G acts transitively on $\{Q_1,\;Q_2,{\cdots},Q_k\},\;and\;Gal(qf(T/Q_1)/qf(R/P))\;{\cong}\;\{\sigma{\in}\;G/\;{\sigma}-(Q_1)\;=\;Q_1\}$ where qf($T/Q_1$) is the quotient field of $T/Q_1$.

Cyclic Vector Multiplication Algorithm Based on a Special Class of Gauss Period Normal Basis

  • Kato, Hidehiro;Nogami, Yasuyuki;Yoshida, Tomoki;Morikawa, Yoshitaka
    • ETRI Journal
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    • 제29권6호
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    • pp.769-778
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    • 2007
  • This paper proposes a multiplication algorithm for $F_{p^m}$, which can be efficiently applied to many pairs of characteristic p and extension degree m except for the case that 8p divides m(p-1). It uses a special class of type- Gauss period normal bases. This algorithm has several advantages: it is easily parallelized; Frobenius mapping is easily carried out since its basis is a normal basis; its calculation cost is clearly given; and it is sufficiently practical and useful when parameters k and m are small.

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Comparison between Isokinetic Peak Torque and Isotonic 1RM on the Knee Joint

  • Jaehyun Yoo
    • Physical Therapy Rehabilitation Science
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    • 제12권2호
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    • pp.201-205
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    • 2023
  • Objective: Resistance exercise is a necessary element to improve quality of life, and measurement and evaluation of muscle strength provide important information for prescription and management of rehabilitation and exercise programs. This study analyzed the correlation between direct and indirect 1RM for isokinetic maximum torque of the knee joint in order to provide useful information in the field of exercise programs. In addition, the flexion-extension ratio and the difference in left-right deviation were verified. Design: A cross-sectional study Methods: The subjects of this study were 33 healthy adult men and women without medical problems who participated in the health exercise class program at S University in Seoul. The correlation between isokinetic maximum torque and direct and indirect 1RM was analyzed, and a dependent t-test was performed to analyze the flexion-extension ratio and left-right deviation. Results: There was a high correlation between the isokinetic maximum torque and direct and indirect 1RM, and no statistically significant difference was shown between the test methods in the analysis of the flexion-extension ratio and left-right deviation. Conclusions: Isokinetic muscle function measuring equipment is expensive, so it is difficult to use it in local exercise rehabilitation and training sites. Through this study, it was found that direct and indirect 1RM isokinetic maximum torque showed a high correlation, and there was no difference in evaluating muscle function such as flexion-extension ratio and left-right deviation. Therefore, it is considered that the muscle function evaluation using 1RM in general field can be usefully utilized.

경북지역 양파, 마늘, 감자, 보리밭의 잡초 분포 및 우점 특성 (Dominance and Distribution of Weed Occurrence on Onion, Garlic, Potato, and Barley Fields of Gyeongbuk Province)

  • 김상국;신종희;박상구;김세종
    • Weed & Turfgrass Science
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    • 제4권2호
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    • pp.77-84
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    • 2015
  • 본 연구는 2014년 4월부터 9월까지 경북지역 13개 시 군의 식량작물(양파, 보리, 마늘, 감자) 재배포장에 발생되는 잡초의 분포와 우점도를 알아보기 위하여 수행되었다. 양파밭은 30과 125종, 마늘밭은 29과 101종, 감자밭은 30과 88종, 보리밭은 27과 108종으로 조사되었다. 잡초종 수에 따른 주요 과(family)는 Table 2와 같다. 양파밭에서는 국화과(Compositae) 33종으로 전체 잡초종에서 26.4%, 마디풀과(Polygonaceae)와 십자화과(Cruciferae) 11종으로 8.8%를 차지하였다. 동계작물 재배지의 주요 5개 과에 대한 초종수와 점유율은 양파밭 73종 58.4%, 마늘밭 58종 57.5%, 감자밭 51종 58.0% 및 보리밭 66종 61.1%로 양파밭, 보리밭, 마늘밭, 감자밭 순으로 초종이 많았고 초종별 점유율은 보리밭에서 61.1%로 가장 높았다. PCA (Principal Community Analysis) 분석에서 보리밭의 벼룩나물, 뚝새풀 및 쇠별꽃은 마늘, 양파 및 감자밭에서 발생되는 초종과 뚜렷한 구별성을 보였다.

Long-term Assessment of Chemical Properties from Paddy Soils in Gyeongnam Province

  • Son, Daniel;Sonn, Yeon-Kyu;Kang, Seong-Soo;Heo, Jae-Young;Kim, Dae-Ho;Choi, Yong-Jo;Lee, Sang-Dae;Ok, Yong Sik;Lee, Young Han
    • 한국토양비료학회지
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    • 제49권2호
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    • pp.132-137
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    • 2016
  • Field monitoring was performed to evaluate the chemical properties of 260 paddy soils every 4 years from 1999 to 2015 in Gyeongnam province. Soil chemical properties, including soil pH, electrical conductivity, amount of organic matter (OM), available phosphate ($P_2O_5$), exchangeable potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na), and available silicate ($SiO_2$) were analyzed. In 2015, the average values of pH, OM, available $P_2O_5$, exchangeable K, Ca, and Mg, and available $SiO_2$ was 5.8, $30g\;kg^{-1}$, $222mg\;kg^{-1}$, $0.37cmol_c\;kg^{-1}$, $6.5cmol_c\;kg^{-1}$, and $1.4cmol_c\;kg^{-1}$, $252mg\;kg^{-1}$, respectively. The frequency distribution within optimum range of paddy soils was 49.2%, 20.8%, 18.5%, and 5.8% for soil pH, OM, available $P_2O_5$, and available $SiO_2$, respectively. The available $P_2O_5$ concentrations in 2015 was excess level with portion of 58% and did not alter significantly during the experimental period. Although the average of available $SiO_2$ concentration has tended to increase with every year, the insufficient proportion of available $SiO_2$ concentration in 2015 was 48%. These results indicated that a balanced management of soil chemical properties can properly control the amount of fertilizer applied for sustainable agriculture in paddy field.

Effect of Biodegradable Mulch Film on Soil Microbial Community

  • Moon, Jin-Young;Song, Jae-Ki;Shin, Jung-Ho;Cho, Yong-Cho;Bae, Jin-Woo;Heo, Jae-Young;Kang, Hang-Won;Lee, Young-Han
    • 한국토양비료학회지
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    • 제49권2호
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    • pp.125-131
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    • 2016
  • The biodegradable film application can escape from plastic environmental pollution. This experiments studied the effect of biodegradable mulch film on the soil microbial community using fatty acid methyl ester method in soybean production field. The soil $NO_3$-N content in polyethylene mulch film (PE) soil was significantly higher than biodegradable mulch film soil (p < 0.05). The soil microbial community of Gram negative bacteria showed significantly higher in biodegradable mulch film soil than PE mulch film soil (p < 0.05). In addition, biodegradable mulch film soil had significantly low ratio of cy17:0 to $16:1{\omega}7c$ and cy19:0 to $18:1{\omega}7c$ compared with those of PE mulch film soil (p < 0.05), indicating that microbial stress decreased. The ratio of cy17:0 to $16:1{\omega}7c$ and cy19:0 to $18:1{\omega}7c$ should be considered as a potential responsible factor for the obvious differentiation that was observed between the biodegradable mulch film soil and PE mulch film soil in a upland field. The results of this experimentation show the potential of using biodegradable mulch film in place of PE.

트랩식물로서 해바라기의 미국선녀벌레 유인효과 (Attraction Effect of Sunflowers to Metcalfa pruinosa (Say) (Hemiptera: Flatidae) as Trap Plants)

  • 최용석;황인수;이경주;김민중;백성훈;서화영
    • 한국응용곤충학회지
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    • 제59권4호
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    • pp.427-432
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    • 2020
  • 해바라기, 콩, 들깨, 참깨를 트랩식물로 이용하여 미국선녀벌레 약충에 대한 유인효과를 조사한 결과, 실내실험의 경우, 어린단계와 성숙단계 모두에서 해바라기가 각각 평균 47.6%와 66.5%로 가장 높은 유인력을 보였고, 야외실험의 경우에도 어린단계와 성숙단계 모두에서 해바라기가 각각 평균 52.3%, 53.2%로 가장 높았다. 실내실험과 야외실험에서 어린단계의 콩은 시간이 지나면서 해바라기 다음으로 유인력이 높았으나 성숙단계의 콩은 들깨 보다도 낮은 유인력을 보였으며 실내실험과 야외실험간 비교에서 동일 트랩식물간 유의성은 없는 것으로 보아 미국선녀벌레 약충에 대하여 가장 유인력이 높은 식물은 해바라기였다.

웹담당 농촌지도요원의 직무수행능력과 문제점 인식에 대한 연구 (Differential Skills and Competencies Required of Agricultural Extension Educators on Web-based Services)

  • 유병민
    • 농촌지도와개발
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    • 제8권1호
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    • pp.15-23
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    • 2001
  • As Internet and World Wide Web become more popular in our society, the interests in effective application to the field of rural development and agricultural extension service are increasing. The potential in Web-based agricultural extension service is expressed in many areas, such as agriculture information, Web-based training and education, and virtual rural community for rural development and agricultural extension service. The research on the Web and its related issues has been conducted in many ways, but the interests in the competencies and skills of staff who are in charge of Web developing and managing have not been exposed yet. The purpose of this study was to investigate the important competencies and skills for Web developing and managing for enhancing the effectiveness of rural development and agricultural extension service. Twelve extension service staff and on staff in the extension service support center were interviewed. The results of study showed that there were eight essential competencies; competencies to understand rural community and agricultural extension service, to understand the farmers as Web users, to design and develop effective Web sites, to understand the nature of hypertext, to utilize instruction theories, to absorb new technology, to manage projects, and to utilize external sources. The results of study also showed that there was lack of support systems for Web development and information. Overall, the findings of this study suggest that establishing long-term education and training system for technology, electronic performance support systems, and cooperation with universities and colleges for technology are of particular importance for promoting Web-based extension services.

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