• 제목/요약/키워드: system theory

검색결과 7,723건 처리시간 0.048초

MODEL BASED DIAGNOSTICS FOR A GEARBOX USING INFORMATION THEORY

  • Choi, J.;Bryant, M.D.
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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    • pp.459-460
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    • 2002
  • This article discusses a diagnostics method based on models, and information theory. From an extensive system dynamics bond graph model of a gearbox [1], simulated were various cases germane to this diagnostics approach, including the response of an ideal gearbox, which functions perfectly to designer's specifications, and degraded gearboxes with tooth root cracking. By comparing these cases and constructing a signal flow analogy between the gearbox and a communication channel, Shannon' s information theory [2], including theorems, was applied to the gearbox to assess system health, in terms of ability to function.

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3상 불평형 전압 시스템에서의 전압원 active power filter (The VSI active power filter in 3-phase unsymmetrical voltage system)

  • 김갑동;이완수;김민태;오성업;주형준;이진;성세진
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1999년도 전력전자학술대회 논문집
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    • pp.667-670
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    • 1999
  • An active power filter is used to eliminate harmonic currents. This paper applied the extension pq theory to harmonic currents compensation. An active power filter based on extension pq theory is more effective than pq theory in 3-phase unsymmetrical voltage system. When extension pq theory is used, the result of simulation present source current is not distorted. Pulse-width modulation method is CRPWM(Current-Regulated PWM).

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The Fundamental Understanding Of The Real Options Value Through Several Different Methods

  • Kim Gyutai;Choi Sungho
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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    • pp.620-627
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    • 2003
  • The real option pricing theory has emerged as the new investment decision-making techniques superceding the traditional discounted cash flow techniques and thus has greatly received muck attention from academics and practitioners in these days the theory has been widely applied to a variety of corporate strategic projects such as a new drug R&D, an internet start-up. an advanced manufacturing system. and so on A lot of people who are interested in the real option pricing theory complain that it is difficult to understand the true meaning of the real option value. though. One of the most conspicuous reasons for the complaint may be due to the fact that there exit many different ways to calculate the real options value in this paper, we will present a replicating portfolio method. a risk-neutral probability method. a risk-adjusted discount rate method (quasi capital asset pricing method). and an opportunity cost concept-based method under the conditions of a binomial lattice option pricing theory.

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Design of Unsharp Mask Filter based on Retinex Theory for Image Enhancement

  • Kim, Ju-young;Kim, Jin-heon
    • Journal of Multimedia Information System
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    • 제4권2호
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    • pp.65-73
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    • 2017
  • This paper proposes a method to improve the image quality by designing Unsharp Mask Filter (UMF) based on Retinex theory which controls the frequency pass characteristics adaptively. Conventional unsharp masking technique uses blurring image to emphasize sharpness of image. Unsharp Masking(UM) adjusts the original image and sigma to obtain a high frequency component to be emphasized by the difference between the blurred image and the high frequency component to the original image, thereby improving the contrast ratio of the image. In this paper, we design a Unsharp Mask Filter(UMF) that can process the contrast ratio improvement method of Unsharp Masking(UM) technique with one filtering. We adaptively process the contrast ratio improvement using Unsharp Mask Filter(UMF). We propose a method based on Retinex theory for adaptive processing. For adaptive filtering, we control the weights of Unsharp Mask Filter(UMF) based on the human visual system and output more effective results.

6자유도 진동 흡진기의 기하적 설계 이론 (Geometrical Design Theory of a 6 DOF Vibration Absorber)

  • 장선준;최용제
    • 한국정밀공학회지
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    • 제22권7호
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    • pp.191-199
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    • 2005
  • Many researchers have been investigating the design of multi-mode absorption vibration absorber for multi degree-of-freedom (DOF) system. The approach taken to this problem has been to find the optimized constants of stiffness and damping for the given set of single-DOF absorbers or single multi-DOF absorber attached to a multi degree-of-freedom system. This paper presents a novel geometrical and direct design theory of a 6 DOF vibration absorber via screw theory. Theoretical development is demonstrated by a practical example in which the diagonal stiffness matrix is synthesized using rectangular configuration of springs. The performance of this absorber is simulated by modal analysis.

Finite Element Analysis of Functionally Graded Plates using Inverse Hyperbolic Shear Deformation Theory

  • Kulkarni, Kamlesh;Singh, Bhrigu Nath;Maiti, Dipak Kumar
    • International Journal of Aerospace System Engineering
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    • 제3권1호
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    • pp.1-4
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    • 2016
  • Functionally graded materials (FGMs) are becoming very popular in various industries due to their effectiveness of the utilization of their constituent elements. However, the modelling of these materials is difficult due to the complex nature of variation of material properties across the thickness. Many shear deformation theories have been developed and employed for the analysis of such functionally graded plates (FGPs). A recently developed inverse hyperbolic shear deformation theory has been successfully employed by Grover et al. [1] for the analysis of laminated composites and sandwich plates. The objective of the study is to obtain finite element solution for the structural analysis of functionally graded plates using inverse hyperbolic shear deformation theory. Finite element analysis facilitates the analysis of complex problems such as functionally graded plates with different boundary conditions and different loadings.

SPIRAL BALANCE THERAPY에 대한 연구 (A Study on the Tanaka's Spiral Balance Theory)

  • 안경모;오민석
    • 혜화의학회지
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    • 제9권1호
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    • pp.647-660
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    • 2000
  • As above, it described Dr.Tanaka's Spiral Balance Theory and studied the theoretical background and the special meridian circulation system, diagnostics and treatments. Though the considered the rule of the tenseness of the body as muscle movement theory, it corresponds with tradtional meridians theory in oriental medicine. If we study and develop the traditional meridians circulaition system more, we can expect clinical development applying to any theories in the field of oriential medicine such as acupuncture therapy, moxa therapy and chiropractc therapy. etc, as well as tapaing therapy, electronic stimulation therapy and exercising therapy.

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Duality in an Optimal Harvesting Problem by a Nonlinear Age-Spatial Structured Population Dynamic System

  • Kim, Yong-Kuk;Lee, Mi-Jin;Jung, Il-Hyo
    • Kyungpook Mathematical Journal
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    • 제51권4호
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    • pp.353-364
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    • 2011
  • Duality in the optimal harvesting for a nonlinear age-spatial structured population dynamic model is studied in the framework of optimal control problem. In this paper the duality theory that displays the conjugacy of the primal problem is established and an application is given. Duality theory plays an important role in both optimization theory and methodology and the results may be applied to a realistic biological system on the point of optimal harvesting.

d-q이론을 이용한 개통 연계형 단상 인버터 제어기 설계기법 (Controller Design of Utility-connected Single-phase Inverter using d-q Theory)

  • 박창주;김창현;김명철;최재영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 B
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    • pp.1247-1249
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    • 2003
  • Despite many advantages, d-q theory was available only for three phase system. But recently, some papers proposed the application methods of d-a theory or similar theories for single phase systems. This paper presents the control method of the utility-connected single-phase inverter using d-q theory. The suggested method gives single-phase system instantaneous controllability and also makes the realization of APF(Active Power Filter) without DFT operation and PFC(Power Factor Controller) possible. This paper deals with utility-connected single phase inverter with PFC function. The controller was verified by simulation tool.

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다중 속성 협상과 상호 이익을 위한 중개 에이전트 시스템 (Mediator Agent System for Reciprocity and Negotiation using Multi-attributes)

  • 박상현;양성봉
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제31권3호
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    • pp.308-316
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    • 2004
  • 본 논문에서는 일반적인 상거래에서와는 다른 전자상거래 환경의 특성을 바탕으로 구매자와 판매자의 상거래에서 양자간 최대이익을 제공해 줄 수 있는 중개 에이전트 시스템을 제안하였다. 판매자와 구매자의 상거래를 통하여 얻을 수 있는 최적의 타협안은 어느 한쪽으로 이익이 치우치지 않고 양자간 이익의 합이 최대가 되는 제안으로 정의하였다. 중개 에이전트는 상품의 다중 속성을 고려하여 협상을 수행하며, 구매자와 판매자의 이익은 Multi Attribute Utility Theory(MAUT)를 이용하여 표현하였다. 중개 에이전트를 이용한 협상 과정은 협상에 참여한 구매자와 판매자의 협상 정보를 이용하여 정수계획법으로 모형화 하였다. 중개 에이전트 시스템과의 비교를 위하여 상호이익의 보장이라는 동일한 조건 하에서, 구매자와 판매자에이전트 사이의 상호작용을 이용한 협상 알고리즘의 하나인 trade-off mechanism을 적용하여 협상 시스템을 구현하였다. Trade-off mechanism에 의한 타협안의 경우 최적간을 보장하지 못하는 반면 중개 에이전트 시스템에 의한 타협안은 상대적으로 빠른 시간 내에 양자간 최대 이익을 제공하는 최적의 타협안을 보장해 주었다.