• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 추계학술대회 논문집
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• pp.79-81
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• 2007

본 논문에서는 소나용 고출력 전력증폭기의 효율을 향상시키기 위하여 Class E 설계 기법을 분석하고 소나 시스템의 송신기에 적용하였다. Class E 기법에 기반하여 전력소자를 스위칭 모드로 동작시켜서 Zero Voltage Switching(ZVS)이 발생하도록 회로를 설계함으로써 전력 소자의 전력 손실을 최소화하고 전력 증폭기의 효율을 최대화하여 주었다. 설계된 Class E 기법의 전력 증폭기의 동작 및 타당성을 시뮬레이션을 통하여 검증하였다.

• 한국의류학회지
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• 제20권4호
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• pp.620-630
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• 1996

This study identified overlap of male innovativeness and of opinion leadership across product class. Product class include clothing, hairstyle and cosmetics, small electronic appliances, large electronic appliances, interior supplies, sports and leisure supplies, and cars. 423 male adults working in Seoul area was surveyed using questionnaire. Results of statistical analysis supported that innovativeness and opinion leadership are not monomorphic but polymorphic across product class. Higher degree of overlap and higher degree of correlationship of innovativness and of opinion leadership exist across product class which share similar characteristics such as clothing-cosmetics, small electronic appliances-large electronic appliances. Innovative communicator ranged from 5.0% to 11.4% in which percentage of innovative communicator was highest in the case of clothing purchase.

• 가정과삶의질연구
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• 제17권4호
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• pp.159-172
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• 1999

Relationships between socio-demographic variables and parents' education invest-ment motivation variables and extra-class private education expenditures were examined using a sample of 602 households in Inchon Korea. Tobit analysis was used. Singal-cognitive motivation parents' duty motivation household income housing asset father's occupation class and number of children had significant effects on extra-class private education expenditures on general high school students. To alleviate overspending in extra-class private education diploma pursuing society has to be changed and formal school education need to be properly functioning. Finally parents seek new child education paradigm for the creative labor demand in the next millenium.

• 대한가정학회지
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• 제38권12호
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• pp.1-14
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• 2000

The purpose of this study is to identify the change according to income bracket and the trade-off between expenditure items by analyzing expenditure patterns of the urban households as a reset of the IMF. The results of this study are as follows; The composition percentage and the amount of consumption expenditure of urban households after IMF decrease in all classes. But the change of composition percentage by the decrease of consumption expenditure is different in every class. The percentage of decrease of the upper class is higher than that of the lower class in an essential expenditure of household, which is food. And the percentage of decrease of the lower class is higher than that of the higher class in the discretionary expenditures such as clothes and education.

• 한국실내디자인학회논문집
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• 제39호
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• pp.92-99
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• 2003

Big 3 Korean department stores - Lotte, Hyundai, and Shinsegae have pursued a differentiation strategy in order to survive the era of big-bang. This study has proposed to present a frame work with which we can recognize the character of design, which is pertinent to a differentiation strategy. The results of study are as follow ; 1) Lotte department store reveals the 3 strategies - location, composition and specialization strategy and the character of design has traditional, high class and neutral disposition. 2) Hyundai department store reveals high class strategy and the character of design has high class and modern disposition. 3) Shinsegae department store reveals high class and specialization strategies and the character of design has high class, tradition and modem disposition.

• 대한산업공학회지
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• 제29권3호
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• pp.222-229
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• 2003

In this paper, we address a layout design problem, PTN[2], for determining an appropriate 2-class-based dedicated storage layout in a class of unit load storage systems. Our strong conjecture is that PTNI2] is NP-hard. Restricting PTN[2], we provide three solvable cases of PTN[2] in which an optimal solution to the solvable cases is one of the partitions based on the PAI(product activity index)-nonincreasing ordering. However, we show with a counterexample that a solution based on the PAI-non increasing ordering does not always give an optimal solution to PTN[2]. Utilizing the derived properties, we construct an effective heuristic algorithm for solving PTN[2] based on a PAI-non increasing ordering with performance ratio bound. Our algorithm with O($n^2$) is effective in the sense that it guarantees a better class-based storage layout than a randomized storage layout in terms of the expected single command travel time.

• Nonlinear Functional Analysis and Applications
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• 제26권5호
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• pp.887-902
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• 2021

In this paper, we have introduced a generalized class Sⁱ_H (m, n, 𝛾, 𝜙, 𝜓; 𝛼), i ∈ {0, 1} of harmonic univalent functions in unit disc 𝕌, a sufficient coefficient condition for the normalized harmonic function in this class is obtained. It is also shown that this coefficient condition is necessary for its subclass 𝒯 Sⁱ_H (m, n, 𝛾, 𝜙, 𝜓; 𝛼). We further obtained extreme points, bounds and a covering result for the class 𝒯 Sⁱ_H (m, n, 𝛾, 𝜙, 𝜓; 𝛼). Also, show that this class is closed under convolution and convex combination. While proving our results, certain conditions related to the coefficients of 𝜙 and 𝜓 are considered, which lead to various well-known results.

• Perspectives in Nursing Science
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• 제11권2호
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• pp.132-143
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• 2014

Purpose: This study was designed to explore adolescents' experience with yoga class in South Korea. Methods: Qualitative data were collected by focus group interviews from February to March 2014. Eleven adolescents who experienced yoga class were recruited from two different schools. The interview questions investigated adolescents' experience with yoga regarding expectations before yoga class, positive changes after yoga, and advice for future yoga classes. Results: Three primary themes from the qualitative content analysis include 1) motivation to join a yoga class, 2) perceived benefits after class and 3) suggestions for school-based yoga. We found that high school students had intrinsic and extrinsic motivations to join yoga classes, and the perceived benefits included physical, psychological, cognitive and social aspects. The students also indicated the need for support by person, yoga with fun and information, yoga tailored by individual goal, simple and easy class. Conclusion: These results suggest that yoga could be an appropriate intervention for holistic health care, and school-based yoga should be applied by focusing on the various situational needs of adolescents'. Furthermore, when yoga leads to healthy habits compared to just simple exercise, a balanced development of adolescents can be achieved.

• Journal of Forest and Environmental Science
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• 제28권1호
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• pp.24-29
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• 2012

This paper assesses the stmpage value of Korean white pine (Pinus koraiensis) stands in the Research Forest of Kangwon National University. Assessment was done by means of the cost value method (Faustmann formula) for age class I, Glaser method for age class II-V, and inversion market method for age class over VI. Generally the value of stumpage is calculated by the inversion market method in the market. However, immature trees and middle age class trees are not assessed in market, and the Korean forest is not old enough to harvest. So, when forests are damaged by attacks from forest fire, blight and harmful insects, the forest cannot be compensated for the loss from the government or insurance company. For this reason, the value of all-age class trees are calculated by using appropriate methods. As a result, the value of age I class stands (0.3 ha) is calculated as 1,786,305 (won), age II-Vclass stands (22.1 ha) 206,677,975 (won) and age VI class and over stands (24.8 ha) 523,789,603 (won).

• 한국초등과학교육학회지:초등과학교육
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• 제37권3호
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• pp.296-308
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• 2018

The purpose of this study is to analyze the characteristics and differences of gesture between career teachers and novice teachers in elementary science class. In order to analyze the gesture of elementary science teachers, gesture analysis framework was developed. The teachers who participated in the experiment were 2 beginner teachers and 2 career teachers. We analyzed 'bones and muscles', 'digestion', 'breathing', and 'excretion' of 'body' section in the second semester of 5th grade. The video recording of the class scene with the camcorder was recorded and analyzed by Observer XT. The results of this study are summarized as follows. First, the career teacher lessens unnecessary gestures than the novice teacher. During the class, the career teachers lessened the gestures not related to the context of the class. These differences were more prominent in the activities of the group with many unexpected situations than those of the teachers who prepared the class contents. Second, career teachers have more communication control act than novice teachers. Career teachers have often made adjustments to induce learner presentations or control unnecessary utterances. Third, career teachers efficiently interacted with learners using gestures that can enhance communication.