• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.2
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• pp.34-41
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• 1999

Adsorption of cationic polyacrylamide dry strength resins onto the surface of papermaking fibers and fines is critical for their effective utilization. Since dry strength resins are frequently employed when recycled fibers containing a great deal of fines are used as a raw material, their adsorption characteristic onto the recycled fiber fines is of great importance. In this study, effects of recycling on adsorption characteristics of cationic polyacrylamide onto primary and secondary fines were examined. Never dried bleached hardwood kraft pulp was beaten and dried for recycling. In each recycling step the adsorption characteristic of a cationic PAM onto primary and secondary fines was evaluated by kjeldahl nitrogen analysis method. The influence of recycling on water retention value and carboxyl content along with the sheet density and tensile strength was examined. Secondary fines of never dried pulp adsorbed twice as much of C-PAM as the primary fines, however, the adsorption capacity of the secondary fines decreased rapidly during the course of recycling and showed lower adsorption capacily than primary fines.

• Journal of Communications and Networks
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• v.16 no.2
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• pp.110-120
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• 2014

This article proposes a spectrum sharing method which can avoid the mutual interference in both primary and secondary systems. The two systems make them a priority to use two single-dimension orthogonal signals, the real and imaginary pulse amplitude modulation signals, if the primary system is not in outage with this use. A secondary transmitter is selected to be the primary relay and the active secondary source to perform this. This allows a simultaneous spectrum access without any mutual interference. Otherwise, the primary system attempts to use a full two-dimensional signal, the quadrature amplitude modulation signal. If there is no outage with respect to this use, the secondary spectrum access is not allowed. When both of the previous attempts fail, the secondary system is allowed to freely use the spectrum two whole time slots. The analysis and simulation are provided to analyze the outage performance and they validate the considerable improvement of the proposed method as compared to the conventional one.

• Journal of Korean Home Economics Education Association
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• v.6 no.2
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• pp.1-12
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• 1994

The purpose of the study were to: (1) determine important home management concepts in the secondary home economics education curriculum,(2) identify the educational needs related to home management perceived by secondary school students, and the factors affecting it, (3) use the findings to make recommendations for developing home economics curriculum and teaching home economics in the secondary school. The questionnaires were distributed to the 1,029 secondary school students, lived in seoul, local cities, and rural area. The data were analyzed by using descriptive statistics, T-test one ay ANOVA with scheffe test, and multiple regression analysis. Forty home management concepts were selected based on the related literatures. Stress man-agement, leisure time activities, resource use, making money for adolescents, work simplication methods were the concepts which showed the highest level of educational needs perceived by the students. The educational needs were affected by sex, school level, residence area of the respondents, and other factors related to the perception about home economics such as preference, GPA, etc.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.105-105
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• 2022

Unripen mandarin in Jeju Island is known to contain functional ingredients including various flavonoids. This Study was carried out to identify the components of Unripen mandarin extracts and Secondary metabolism by enzyme treatment on Unripen mandarin. We extracted Unripen mandarin using optimal extraction method and selected the most optimal enzyme among commercial enzymes for a Secondary metabolism. As a result, flavonoid components such as Hesperidine and Narirutin, which are known to be contained a lot in unripen mandarin, could be analyzed. However In this extraction method there were no other flavonoid components such as Nobiletin, Tangeretin known to contain in unripen mandarin. However as a result of secondary metabolism a new functional component called Prunin which was not known to be contained in unripen mandarin, was detected as a secondary metabolic product due to enzyme treatment. Through this, it can be confirmed that it would be possible to develop high-value-added products by enzyme treatment on unripen mandarin.

• KDI Journal of Economic Policy
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• v.46 no.2
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• pp.1-20
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• 2024

This study analyzes the impact of secondary tax liability borne by stockholders, an exception to the principle of limited liability, on corporate investment. The paper constructs a model of a firm to examine the effect of this secondary tax liability, finding that the violation of limited liability increases firms' expected bankruptcy costs, thereby reducing investments. By means of an empirical analysis, the paper examines whether firms with the largest shareholder stake exceeding 50%, the condition under which secondary tax liability is incurred, decrease their investments. The results show that firm investment is highly concentrated in observations of cases in which the largest shareholder stake does not exceed 50%. Investments decrease sharply in cases where the largest shareholder stake exceeds 50%. The results here provide implications pertaining to how exceptions of the limited liability principle, existing only in Korea, affect corporate investments.

• Journal of Digital Convergence
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• v.6 no.2
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• pp.41-53
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• 2008

This research is to redefine the concept of Good School and to validate an effective Good Secondary School Scale in Kyung-gi Province and Seoul. As statistical methods, SPSS 13.0 and AMOS 5.0 were used. Item Analysis and Exploratory Factor Analysis(EFA) were conducted to test the reliability of items and the factor structure. And Confirmatory Factor Analysis(CFA) was conducted to test the validity and fitness of the Good School Scale. The outcomes are as follows: First, six factors(school environment, curriculum, teacher, school-based management system, director) will increase the good schooling effectiveness. Second, As a result of Confirmatory Factor Analysis(CFA), the goodness of fit indices(GFI AGFI, CFI, RMSEA) demonstrate statistically significance and fitness of the model. The final Good School Scale supports 6 Good School Factors obtained in main test. Therefore, we can say that this scale can be used as a valid instrument to measure a real Good Schooling Effectiveness at the secondary school situation in Korea.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.10a
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• pp.63-68
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• 1991

The frequency window method has been extended to include strong coupling and multiple connections between the primary structure and the secondary structures. The rational polynomial expansion of the eigenvalue problem and the analytical methods for its solution are novel and distinguish this work from other eigenvalue analysis methods. The key results are the identification of parameters which quantify the resonance and coupling characteristics; the derivation of analytical dosed-form expressions describing the fundamental modal properties of the frequency windows; and the development of an iterative procedure which yields accurate convergent results for strongly-coupled primary-secondary structures.

• Journal of Microbiology
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• v.45 no.1
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• pp.79-82
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• 2007

The 58 rRNA gene from Sphingobium chungbukense DJ77 was identified. The secondary structure of the 199-base-long RNA was proposed. The two-base-long D loop was the shortest among all of the known 5S rRNAs. The U19-U64 non-canonical pair in the helix II region was uniquely found in strain DJ77 among all of the sphingomonads.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.385-396
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• 2000

The secondary motion of piston occurs due to the transient forces and moments in the clearances between piston skirt and cylinder liner The motions are very related to the skirt profile and the magnitude of piston-pin offset. Above all, the elastic deformation is another major effect on the piston secondary motion that has not been considered in the previous researches. In this work, the effects of elastic deformation of the piston skirt on the secondary piston motion are studied for the frictional power loss by using commercial softares, PISDYN and ANSYS.

• The Journal of Korean Association of Computer Education
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• v.21 no.2
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• pp.31-40
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• 2018

The purpose of this study is to analyze the perception of elementary and secondary parents on 'Informatics' education to solve the various social problems that can occur due to the application of mandatory 'Informatics' subject and find the stable public education settlement plans. For this purpose, we conducted and analysis of questionnaire survey on 'Informatics' education for parents of elementary and secondary students who participating the SW education camp in K university. The major results of this study are as follows. Firstly, both of elementary and secondary parents show high interest in the SW education policy of the government, but they are showing distrust about the timeliness of the actual SW education policy and the support of elementary and secondary education. Secondly, both of the elementary and secondary parents showed high awareness of the necessity and importance of 'Informatics' education and they recognized that 'Informatics' education should be done in high school. Thirdly, parents of elementary and secondary school students perceive that there is not enough time for 'Informatics' education and both of elementary and secondary parents to secure teachers with professional competence as a leading factor for stable settlement of 'Informatics' education in public education field. In this study, we suggested the stable settlement plans in public education field based on the analysis results.