• Title/Summary/Keyword: simplifying

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

  • Jo, Cheol-H.;Seo, Jin-H.
    • Proceedings of the KIEE Conference
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    • 1996.07b
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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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    • v.27 no.2
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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.

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

  • Kim, Jong-Hee;Jeong, Hui-Gyeong;Kim, Sang-Dal
    • Journal of the Korean earth science society
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    • v.24 no.6
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    • pp.495-507
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    • 2003
  • The purpose of this study was three-folded to suggest the Simplifying Conditions Method (SCM) as a means of task analysis and sequencing of instructional content, to develop teaching-learning materials by analyzing part of the geological time scale of the earth science and finally to analyze the effectiveness of this method. SCM began by simplifying a complex task into the basic components by eliminating various complexities, which produced a simple representative of the entire task. The next step was to relax conditions on the basic version one by one, thereby gradually introducing progressively more complex tasks to the students. This sequential strategy enabled students to understand the task holistically and to acquire authentic skills from very onset of the course. Moreover, Early mastery of skills enhances the effectiveness and efficiency of instruction. The result of this study revealed that instruction through SCM was more effective in developing students' self-directed learning characteristics and academic achievement than instruction through sequential task analysis methodology.

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

  • Jeong Gang-Youl
    • Proceedings of the KIPE Conference
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    • 2004.07b
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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
    • Journal of the Korean earth science society
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    • v.25 no.3
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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.

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

  • 정연자
    • Journal of the Korean Society of Costume
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    • v.39
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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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Hybrid Elastic Model for Volumetric Deformation and Real-time Haptic Simulation (볼륨 변형과 실시간 햅틱 시뮬레이션을 위한 하이브리드 탄성체 모델)

  • Cho, Jae-Hwan;Kim, Seok;Park, Jin-Ah
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.68-73
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    • 2009
  • As various haptic algorithms and haptic equipments have developed, the computer simulation includes the haptic simulation. Basically, the haptic simulation requires very fast refresh rate approximately 1000 Hz. The traditional haptic simulations have satisfied that requirement by simplifying the target model. In soft body simulation, simplifying the deformation is not good because the visual feedback is important. Separating haptic model from deformable model can be solution of that problem. However, the user may feel a subtle distiction because the relationship between two models are not clear. In this paper, we propose the hybrid model to manipulate haptic rendering and deformation and define the relationship between two models.

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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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    • v.15 no.3
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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.