• Journal of Magnetics
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• 제19권3호
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• pp.295-299
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• 2014

Recently, module-integrated converter (MIC) research has shown interest in small-scale photovoltaic (PV) generation. The converter is capable of efficient power generation. In this system, the high frequency transformer should be made compact, and demonstrate high efficiency characteristics. This paper presents a core structure optimization procedure to improve the efficiency of a high frequency transformer of compact size. The converter circuit is considered in the finite element analysis (FEA) model, in order to obtain an accurate FEA result. The results are verified by the testing of prototypes.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.727-728
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• 2005

• 소음진동
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• 제7권6호
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• pp.967-974
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• 1997

Distributed piezoeletric sensor and actuator have been designed for efficient vibration control of a cantilevered beam. Both PZT and PVDF have been used in this study, the former as an actuator and the latter as a sensor for the integrated structure. We have optimized the position and the size of the PZT actuator and the electrode shape of the PVDF sensor. Finite element method is used to model the structure and the optimized actuators, we have designed the active electrode width of the PVDF sensor along the span of the beam. Actuator design is based on the criterion of minimizing the system energy in the control modes under a given initial condition. Model control forces for the residual (uncontrolled) modes have been minimized during the sensor design to minimize the observation spill-over. Genetic algorithm and sequential quadratic programming technique have been utilized as an optimization scheme. Discrete LQG control law has been applied to the integrated structure for real time vibration control. Performance of the sensor, the actuator, and the integrated smart structure has been demonstrated by experiments.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2016년도 춘계 종합학술대회 논문집
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• pp.255-256
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• 2016

In this paper, we analyze the operations and/or status of our structure which builds the management structure measuring integrated monitoring system based on linked open data in a short term or long term bases. We have applied a novel analyzing method of linked open data to expect what movements can be occurred in the structure, and we improve the monitoring system using an integrated design to solve the drawbacks of conventional types of monitoring. And collecting data through cloud and their reliability can be proved by evaluation of soundness of data amount and their confidence.

• 반도체디스플레이기술학회지
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• 제17권1호
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• pp.21-26
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• 2018

In this paper, a multiple coupling inductor with expandable-integrated magnetic structure was proposed to enable miniaturization of external switched mode power supply (SMPS) for a large display. Inductance formula of the proposed inductor structure was derived through magnetic circuit analysis for a simple inductance designing process. The proposed inductor was applied into a 1kW class interleaved bridgeless power factor correction circuit which requires four inductors, and experimental steady state result of the circuit was compared. According to the experimental result, it was found that the proposed multiple coupling inductor shows the electrical characteristics that can replace the conventional separated inductors and is suitable for miniaturization of the SMPS since the circuit configuration is possible with one shared inductor.

• East Asian mathematical journal
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• 제39권2호
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• pp.167-181
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• 2023

The purpose of this study is to confirm the possibility of whether learning using a math learning platform can be used to expand students' conceptual structure and to consider how to use it. To this end, first-year middle school students studied using a math learning platform. Then, the concept map created was compared and analyzed with the concept map created before learning to examine the change in the concept structure. The results of analyzing the concept map are as follows. First, the change in the hierarchical structure of the concept appeared as the division of the upper concept was subdivided. However, it has also been changed to comprehensively integrate and simplify higher concepts. The term-centered concept structure has changed to content-centered superordinate and subordinate concepts. In the concept structure, subordinate concepts linked to one higher concept were expanded and differentiated. Second, changes in the integrated structure did not form a linkage structure. The expansion of the integrated structure of concepts through learning using the learning platform was influenced by the composition of the learning contents designed in the learning platform.

• Journal of Advanced Marine Engineering and Technology
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• 제33권1호
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• pp.159-165
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• 2009

In this study, using a periodical ground structure(PGS) on GaAs monolithic microwave integrated circuit(MMIC), transmission line with a high isolation characteristic was developed for application to compact signal/bias lines of highly integrated MMIC. And the origin of the high isolation characteristic was theoretically investigated. The high isolation characteristic was originated from a resonance between adjacent microstrip lines employing PGS. With only a spacing of $20{\mu}m$, the coupled microstrip line employing PGS showed an isolation value of -47 dB at 60 GHz. The frequency range for high isolation was easily controlled by changing the PGS structure. Above results indicate that microstrip lines employing PGS are very useful for application to compact signal/bias lines of highly integrated MMIC requiring a high isolation characteristics between lines. In addition, equivalent circuit employing closed-form equation for the coupled line with PGS was also extracted.

• 한국CDE학회논문집
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• 제17권5호
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• pp.312-323
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• 2012

Planetary gearing is a gear system consisting of one or more planet gears, revolving about a sun gear. While the planetary gear system has many advantages- for example, high power density, large reduction in a small volume, multiple kinematic combinations, pure torsional reactions, and coaxial shafting, it has not been widely used because of its high bearing loads, inaccessibility, and design complexity. It is also necessary to shift several pairs of gear profiles at a same time. Therefore, designing profile shifted planetary gear system is a difficult and know-how dependent job. This study provides a practical solution to design a profile shifted gear system by the procedural design scheme, and proposes a bearing integrated structure of the dual stage profile shifted gear system with a robust output end. A dual stage profile shifted gear system with the bearing integrated structure is manufactured by the proposed design scheme in this study. This gear system is verified that it is good enough to commercialize, because it has high performance with high gear ratio and robust output end against axial and radial directional runouts in a small space.

• 한국과학교육학회지
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• 제19권2호
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• pp.204-216
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• 1999

이 연구에서는 자연계에 폭넓게 적용되는 기본 개념들을 몇 가지로 단순화시키고, 이것을 통합주제라고 정의하였다. 이것은 자연계를 관통하는 포괄적 개념 혹은 통합적 시각이라 할 수 있다. 관련 문헌을 분석하여 계(系), 상호작용, 조화와 균형, 구조와 기능, 그리고 순환의 다섯 가지 개념을 통합주제로 설정하고, 각 통합주제의 성격을 규명하였다. 그리고 설정된 통합주제의 성격에 부합하는 내용을 구성하여 각 영역별로 학습 주제와 학습 목표를 진술하였다. 제시된 통합과학 내용 구성은 그 형태에 있어서 간학문적 통합, 혹은 다학문적 통합이라 할 수 있으며, 현행 중학과학보다 통합의 심도가 깊다. 그리고 통합주제의 성격에 우선적으로 초점을 맞춰 구성한 것으로 기존의 4영역 안배 원칙에서 벗어났다. 이와 같은 통합과학 교육과정의 내용 구성 방안은 현재 우리 나라의 과학 교육과정에 새로운 관점을 제시하는 의미가 있다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.348-348
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• 2006

In the present study, porcine pepsin in various pH conditions was investigated by small-angle X-ray scattering (SAXS) in order to detailed information on the structure and its variations with pH conditions. These analyses identified the structure of pepsin, and compared with that obtained by single crystallography. Moreover, this study found the structure' variations with changing pH conditions. All the results will be discussed with considering the conformational characteristics of pepsin in solution and further correlate to the biological and spectroscopic characteristics reported previously.