• 제목/요약/키워드: simplifying

검색결과 535건 처리시간 0.012초

분산 저차 구조의 $H_{\infty}$ 제어기 설계를 위한 시스템의 간략화 방법 (Simplifying method for the design of decentralized reduced order $H_{\infty}$ controllers)

  • 조철형;서진헌
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 B
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    • pp.933-935
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    • 1996
  • The simplifying method for the design of decentralized reduced order $H_{\infty}$ controller is considered in this paper. When the controller is reconstructed for the original system, the decentralized condition of the controller for the transformed system is generally destroyed with older simplifying method. In designing the decentralized controller, direct output feedthrough terms give some difficulties by using other station's input information. We proposed a new solution for this problem.

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SIMPLIFYING COEFFICIENTS IN A FAMILY OF ORDINARY DIFFERENTIAL EQUATIONS RELATED TO THE GENERATING FUNCTION OF THE MITTAG-LEFFLER POLYNOMIALS

  • Qi, Feng
    • Korean Journal of Mathematics
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    • 제27권2호
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    • pp.417-423
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    • 2019
  • In the paper, by virtue of the $Fa{\grave{a}}$ di Bruno formula, properties of the Bell polynomials of the second kind, and the Lah inversion formula, the author simplifies coefficients in a family of ordinary differential equations related to the generating function of the Mittag-Leffler polynomials.

단순화 조건법을 이용한 지질 연대 분야의 학습 자료 개발과 그 효과 (Development and Effect of Learning Materials of Earth Science Using Simplifying Condition Method)

  • 김종희;정희경;김상달
    • 한국지구과학회지
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    • 제24권6호
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    • pp.495-507
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    • 2003
  • 본 연구는 정교화이론을 기초로 개발된 단순화 조건법을 적용하여 지구과학 교과의 지질연대 단원에서 지질 단면도 해석에 대한 학습자료를 개발하고 개발된 자료의 수업에서의 효과를 알아보는 것이다. 이를 위하여 고등학교 1학년 학생들을 대상으로, 단순화 조건법을 적용한 수업과 체제적 과제분석 결과를 바탕으로 개발된 자료를 적용한 수업과의 비교 실험을 실시하고 학습자의 자기주도적 학습특성과 과학성취도에 미치는 영향을 분석하였다 연구의 결과를 바탕으로 얻어진 결론으로는, 단순화 조건법을 이용한 수업은 다른 자료를 활용한 수업에 비하여 학생의 자기주도적 학습특성과 학업성취도에서 모두 긍정적인 영향을 미친 것으로 나타났다 이러한 연구의 결과는 단순화 조건법에 따라 개발된 자료를 활용한 수업에서 핵심과제(epitome)의 제시는 학생들에게 새롭고 복잡한 학습과제를 간단하고 의미 있게 하며 이를 기존의 지식들과 연결시켜주는 역할을 한 결과로 생각된다.

고조파 전류 제거를 위한 새로운 전류 보상 기법 (Novel Current Compensation Technique for Harmonic Current Elimination)

  • 정강률
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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    • pp.587-591
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    • 2004
  • This paper proposes a novel current compensation technique that can eliminate the harmonic currents included in line currents without computation of harmonic current components. A current controller with fast dynamics for an active filter is described. Harmonic currents are directly controlled without the need for sensing and computing the harmonic current of the load current, thus simplifying the control system. Current compensation is done in the time domain, allowing a fast time response. The DC voltage control loop keeps the voltage across the DC capacitor constant. High power factor control by an active filter is described. All control functions are implemented in software using a single-chip microcontroller, thus simplifying the control circuit. Any current-controlled synchronous rectifier can be used as a shunt active filter through only the simple modification of the software and the addition of current sensors. It is shown through experimental results that the proposed controller gives good performance for the shunt active filter.

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The Effect of The Lunar and Planetary Phases Drawing Module on Students' Conceptual Change and Achievement

  • Kim, Sang-Dal;Kim, Jong-Hee
    • 한국지구과학회지
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    • 제25권3호
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    • pp.176-184
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    • 2004
  • The concept of 'the lunar and planetary phases' is very difficult to understand and students may have various misconceptions on this concept. A module drawing the lunar and planetary phases was developed with the application of the simplifying conditions method. The effects of instruction using the module drawing the lunar and planetary phases on the conceptual change and the achievement was investigated in the consideration of learners' characteristics (spatial perception ability, science inquiry ability, required pre-requested learning ability). Findings were as follows: 1) This module was effective for learners' conceptual change and achievement, 2) This module had a positive influence for development the learners' characteristics and conceptual change with the middle level of science inquiry ability, the middle and low level of required pre-requisite learning ability, and middle level of the spatial perception ability.

복식에 표현된 큐비즘(Cubism)에 관한 연구 (The Study on Cubism expressed in Current Fashion)

  • 정연자
    • 복식
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    • 제39권
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    • pp.99-111
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    • 1998
  • Cubism has played a great role to change traditional concept of art and visual of people as developed into one of new art stlyes. It has avoided three dimensional perspectives and reformed the concept of time and space. It expresses objects with geometric shape by simplifying and reconstructing the objects after taking them apart. This has the effect of simultaneous vision and transparency and brings in collage by combining geometric image and visual elements. The results of the study as follows: First, the geometric shape expresses straight lines, curves, faces, and cubics by simplifying the objects. In fashion, it expresses circles, triangles, squares with a cloth. This shows visual changes as three dimensional space moves. Second, simultaneity disassembles and recontructs the objects. It tries to understand the internal shape with method of disassembling and makes visions coexist. In so doing, cubists adopt simultaneity for expressing shapes. In fashion, it expresses new items through disassembling or combining with other items. Third, transparency simplifies cubics by duplicating with transparent flats and crosses contour lines for reconstructing the simplified objects. This implies broader spatial order. It allows people to perceive penetration of layed clothes. Fourth, collage expresses geometric shape by adding visual elements(concrete image and color). It uses concrete image with paper, letters, cloth, etcs, which is not related to painting, and introduces various colors. In fashion, it uses dolls, postcards, feathers, metals, plastics, for patchwork.

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볼륨 변형과 실시간 햅틱 시뮬레이션을 위한 하이브리드 탄성체 모델 (Hybrid Elastic Model for Volumetric Deformation and Real-time Haptic Simulation)

  • 조재환;김석;박진아
    • 한국HCI학회:학술대회논문집
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    • 한국HCI학회 2009년도 학술대회
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    • pp.68-73
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    • 2009
  • 최근 다양한 햅틱 알고리즘과 햅틱 장비가 개발되면서 햅틱을 이용한 컴퓨터 시뮬레이션이 증가하고 있다. 햅틱 시뮬레이션은 기본적으로 1000Hz 정도의 비교적 고속 리프레쉬를 요구한다. 기존 햅틱 시뮬레이션은 대상 모델을 간략화 해서 고속 리프레쉬 요구사항을 만족 시켰다. 하지만, 유연체 가변형 모델 시뮬레이션은 시각적 변형요소가 중요하기 때문에 모델을 간략화 할 경우에 시각적으로 좋지 않은 결과를 초래한다. 햅틱 렌더링만 담당하는 모델을 따로 분리하여 병렬처리를 통해 햅틱과 변형 시뮬레이션을 모두 하는 경우도 있지만 두 모델간의 관계가 명백하지 않아 문제가 발생하기도 한다. 이 논문에서는 유연체 시뮬레이션을 위한 볼륨 변형 모델과 햅틱 렌더링 모델을 정의하고 두 모델간의 관계를 정의한다. 또한, 충돌처리등 사용자 인터랙션에 필요한 알고리즘을 제안하고 수술시뮬레이션 등에 적용해보고자 한다.

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Thermal Stability of Nanostructured Synthetic Ferrimagnets under Applied Magnetic Fields in the 45˚ Direction

  • Han, C.W.;Han, J.K.;Lim, S.H.
    • Journal of Magnetics
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    • 제15권3호
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    • pp.116-122
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    • 2010
  • An accurate analytical equation for the total energy in the framework of the single domain model is used to study the thermal stability of nanostructured synthetic ferrimagnets. Elliptical cells are considered that have lateral dimensions of 160 nm (long axis)$\times$80 nm (short axis) and varying values of thickness asymmetry for the two magnetic layers. The direction of the applied magnetic field, which points to the $45^{\circ}$ direction, is in the opposite direction to the thicker layer magnetization. A significant difference is observed in the applied magnetic field dependencies of the equilibrium magnetic configuration and the magnetic energy barrier when using the simplifying assumption that the self-demagnetizing field is identical in magnitude to the dipole field. At a small thickness asymmetry of 0.2 nm, for example, the magnetic energy barrier is reduced from 68 kT (T=300 K) to 6 kT at the remanent state and a progressive switching behavior changes into a critical behavior, as the simplifying assumption is used. The present results clearly demonstrate the need for an accurate analytical equation for the total energy in predicting the thermal stability of nanostructured synthetic ferrimagnets.