• Communications of the Korean Mathematical Society
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• v.20 no.4
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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 $T/Q_1$.

• ETRI Journal
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• v.29 no.6
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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.

• Journal for History of Mathematics
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• v.13 no.2
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• pp.151-160
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• 2000

In this paper we prove that for all irreducible complex characters of a finite group, there exist F-representations and a finite degree field extension F ⊇ Q, where Q is the rational number field.

• Physical Therapy Rehabilitation Science
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• v.12 no.2
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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.

• Korean Journal of Mathematics
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• v.26 no.2
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• pp.293-297
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• 2018

In the paper [4], we constructed 3-part of the Hilbert class field of imaginary quadratic fields whose class number is divisible exactly by 3. In this paper, we extend the result for any odd prime p.

• Weed & Turfgrass Science
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• v.4 no.2
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• pp.77-84
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• 2015

We surveyed the distribution pattern of weeds in onion, garlic, potato, and barley fields including 304 sites of Gyeongsangbuk-do. The weeds were summarized as 30 family and 125 species in onion crop field, 29 family and 101 species in garlic field, 30 family 88 species in potato field, finally 27 family and 108 species. Compositae was dominant family (26.4%, 33 species), followed by Polygonaceae (8.8%, 11 species), Cruciferae (8.8%, 11 species) in onion field. Compositae was also dominant family (24.8%, 25 species) in garlic field, it was 22.7% (20 species) in potato field, and it was also 24.1% (26 species) in barley field, respectively. Among these winter crops, major five families were occupied 61.1, 58.4, 58.0 and 57.5% in turn at barley, onion, potato and garlic fields. The PCA-covariance plot analysis for investigation of occurrence pattern of weeds by four winter crop fields revealed that the occurrence pattern of weed species in barley field was distinguished by Alopecurus aequalis var. amurensis, Stellaria alsine var. undulate and Stellaria aquatica.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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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.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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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.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.427-432
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• 2020

The ability of sunflower, bean, green perilla, and sesame to attract Metcalfa pruinosa was tested in both laboratory and field conditions. In the laboratory experiment, sunflowers showed the highest attractiveness to M. pruinosa nymphs and adults. These results were the same as those in the field experiment. Sunflowers showed the highest attractiveness among the four candidates as a trap plant for M. pruinosa, with comparable average attractiveness values for nymphs and adults to those in the laboratory. Young beans also showed high attractiveness to M. pruinosa, albeit lower than those of sunflowers. However, the attractiveness of mature beans was low. Sunflowers consistently (P < 0.05) showed significantly higher attractiveness than that of the other three plants, regardless of plant age. Thus, sunflowers would serve as a good trap plant for both the nymphs and adults of M. pruinosa.

• Journal of Agricultural Extension & Community Development
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• v.8 no.1
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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.