• 제목/요약/키워드: dynamic transformation

검색결과 520건 처리시간 0.028초

반복형태식을 이용한 多物體系의 動力學的 해석 (Dynamic analysis of a multibody system using recursive-formula)

  • 신상훈;유완석
    • 대한기계학회논문집
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    • 제12권6호
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    • pp.1265-1272
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    • 1988
  • 본 연구에서는 속도변환을 이용하여 기본체(base body)가 움직이는 경우에 대 한 일반적인 운동방정식을 유도하고, 이를 적절히 변형시킴으로써 로봇분야에서 이미 유도된 식과 비슷한 반복형태의 식을 얻을 수 있음을 보임으로써, 기계의 동력학 분야 에서 사용하고 있는 속도변환의 방법이 기본체가 고정되어 있는 경우가 대부분인 로봇 분야에서도 적용될 수 있음을 보이고자 한다. 또한 유도된 반복형태식을 이용하여 개방연쇄계(open-loop system)로 이루어진 기계시스템의 동력학 시뮬레이션에 적합한 알고리즘을 만들고 자동차를 예제로 택하여 유도된 방법의 타당성과 효율성을 검토하 였다.

재해석 기법을 이용한 동적 구조시스템의 System Identification (System Identification of Dynamic Systems Using Structural Reanalysis Method)

  • 한경봉;박선규;김형열
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.421-424
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    • 2004
  • Model updating is a very active research field, in which significant efforts has been invested in recent years. Model updating methodologies are invariably successful when used on noise-free simulated data, but tend to be unpredictable when presented with real experimental data that are-unavoidably-corrupted with uncorrelated noise content. In this paper, Reanalysis using frequency response functions for correlating and updating dynamic systems is presented. A transformation matrix is obtained from the relationship between the complex and the normal frequency response functions of a structure. The transformation matrix is employed to calculate the modified damping matrix of the system. The modified mass and stiffness matrices are identified from the normal frequency response functions by using the least squares method. Full scale pseudo dynamic pier test is employed to illustrate the applicability of the proposed method. The result indicate that the damping matrix of correlated finite element model can be identified accurately by the proposed method. In addition, the robustness of the new approach uniformly distributed measurement noise is also addressed.

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SCM 440 강재의 동적 재결정 조직 변화에 관한 연구 (The Evolution of Dynamically Recrystallized Microstructure for SCM 440)

  • 한형기;유연철
    • 소성∙가공
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    • 제10권1호
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    • pp.35-41
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    • 2001
  • The high temperature deformation behavior of SCM 440 can be characterized by the hot torsion test in the temperature ranges of $900^{\circ}C$~$1100^{\circ}C$ and strain rate ranges of 0.05/sec~5/sec. The aim of this paper is to establish the quantitative equation of the volume fraction of dynamic recrystallization (DRX) as a function of processing variables, such as strain rate ($\varepsilon$), temperature (T), and strain ('$\varepsilon$). During hot deformation, the evolution of microstructure could be analyzed from work hardening rate ($\theta$). For the exact prediction of dynamic softening mechanism the critical strain ($\varepsilon_c$), the strain for maximum softening rate ($\varepsilon^*$ and Avrami' exponent (m') were quantitatively expressed by dimensionless parameter, Z/A, respectively. The transformation-effective strain-temperature curve for DRX could be composed. It was found that the calculated results were agreed with the experimental data for the steel at any deformation conditions.

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GAN 및 키포인트와 로컬 아핀 변환을 이용한 스타일 변환 동적인 이미지 애니메이션 네트워크 구축 (Construction of Dynamic Image Animation Network for Style Transformation Using GAN, Keypoint and Local Affine)

  • 장준보
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2022년도 춘계학술발표대회
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    • pp.497-500
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    • 2022
  • High-quality images and videos are being generated as technologies for deep learning-based image style translation and conversion of static images into dynamic images have developed. However, it takes a lot of time and resources to manually transform images, as well as professional knowledge due to the difficulty of natural image transformation. Therefore, in this paper, we study natural style mixing through a style conversion network using GAN and natural dynamic image generation using the First Order Motion Model network (FOMM).

TRANSFORMATION OF DIMENSIONLESS HEAT DIFFUSION EQUATION FOR THE SOLUTION OF DYNAMIC DOMAIN IN PHASE CHANGE PROBLEMS

  • Ashraf, Muhammad;Avila, R.;Raza, S. S.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제13권1호
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    • pp.31-40
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    • 2009
  • In the present work transformation of dimensionless heat diffusion equation for the solution of moving boundary problems have been formulated. The formulation is based on 1-D, 2-D and 3-D, unsteady heat diffusion equations. These equations are rst turned int dimensionless form by using dimensionless quantities and their transformation was formulated in liquid and solid phases. The salient feature of this work is that during the transformation of dimensionless heat diffusion equation there arises a convective term $\tilde{v}$ which is responsible for the motion of interface in liquid as well as solid phase. In the transformed heat equation, a correction factor $\beta$ also arises naturally which gives the correct transformed flux at interface.

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NITINOL 형상기억합금의 열적/기계적 특성 평가 (Evaluation of Thermomechanical Characteristics of NITINOL Shape Memory Alloy)

  • 윤성호
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.683-686
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    • 2001
  • The thermomechanical characteristics of NITINOL shape memory alloy were evaluated using DSC with small samples and DMA with three-point bending specimens. The shape memory alloy of 54.4Ni/45.5Ti wt.% was used so that the austenite finish temperature was in the range of $50~100^{\circ}C$. Two types of sample were tested in the experiments corresponding to as-received and annealed conditions. Simple beam bending theory was used to calculate the dynamic moduli of the shape memory alloy. According to the results, a large discrepancy in transformation temperatures was found between DSC and DMA techniques. Annealing treatment was found to suppress the R-phase transformation during cooling and the secondary plateau in the austenite transformation. Such a heat treatment was also significantly influenced to raise the transformation temperatures and the moduli of the shape memory alloy.

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사각관의 수치 모델링 및 동적 붕괴 해석 (The Numerical Modelling and Dynamic Collapse Analysis of the Rectangular Tube)

  • 강신유;한동철
    • 한국자동차공학회논문집
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    • 제1권2호
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    • pp.42-48
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    • 1993
  • In this paper, dynamic collapse behavior of the rectangular tube under impact loading is anlayzed using nonlinear finite element method of shell element. In case of shell element formulation using corotational element coordinates system, dynamic collapse behavior is analyzed without initial imperfection, and with initial imperfection. This paper reveals that the collapse of a rectangular tue without initial imperfection is caused by an error of transformation of the corotational coordinates system.

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The Dramatization of Habitus: A Bourdieun Reading of Pygmalion

  • Hwang, Hoon-Sung
    • 영어영문학
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    • 제55권3호
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    • pp.383-398
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    • 2009
  • Based on the Greek myth of Pygmalion and the fairy tale of Cinderella, Shaw's Pygmalion demonstrates a masterful coalescence of these two narrative motifs into a coherent plot scheme. Even more significant is his keen insight into the conflicts created at the tripartite intersection of human activity concerning language/class/culture, which, as the leitmotif, revolves around lessons in language learning. This play basically deals with human transformation and by its very nature, Higgins's experimentation with transforming Eliza cannot stop at language alone. Her cultural transformation ripples over into the realms of gesture and even a unique way of living (modus vivendi) intimately associated with taste and manners, which Bourdieu terms as habitus. By acquiring a new fashion and language, Eliza is reborn as a new lady aspiring to be filled with a newly acquired habitus. While separating her from her old Cockney style, Higgins inculcates Queen's English in Eliza, in which process her changed speech styles gradually transforms and restructures her deportment and manners, finally generating new practices, perceptions and attitudes. The gist of Pygmalion is however less Eliza's ascent into the middle class than her battle for symbolic capital waged at the level of language. By problematizing his contemporary practice of habitus conventionalized and warped by class distinctions based on economic, social and cultural capitals, Shaw creates a new humanist model of man founded on spiritual and rational virtues. In conclusion, Eliza is not a frigid Galatea but a dynamic character that goes through a brilliant transformation of three stages: 1) linguistic; 2) cultural, and 3) humanist. Finally she is built into a "consort battleship" on an equal standing with her sculptor. The process of her character-building cannot be illuminated without resorting to the dynamic notion of habitus, which highlights the process of inculcation, structuring, generation and transposing. Given the overwhelming weight of the heroine's role and the dynamic process of her transformation as the major plot scheme, this play should be christened Galatea in lieu of Pygmalion.

로보트 팔의 최소시간 위치제어에 관한 연구 (A study on time optimal positioning control of robotic manipulator)

  • 김종찬;배준경;박종국
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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    • pp.45-48
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    • 1986
  • In this paper, time optimal positioning control of the robotic manipulator is discussed. The equations for dynamic model of the robotic manipulator are nonolinear, and each link is highly coupled. A feedback linearizing and decoupling transformation makes the dynamic model linearized and decoupled, and optimal control input for the linear and decoupled system is derived.

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중탄소강의 동적 재결정에 관한 연구 (Dynamic Recrystallization of Medium Carbon Steels)

  • 김성일;한창훈;유연철;이덕락;주웅용
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2000년도 추계학술대회 논문집
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    • pp.33-36
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    • 2000
  • The dynamic recrystallization (DRX) of medium carbon steels (SCM 440 and POSMA45) was studied with torsion test in the temperature range of $900-1100^{\circ}C$ and the strain rate range of $5.0x10^{-2}\;-\;5.0x10^0/sec$. To establish the quantitative equations for DRX, the evolution of flow stress curve with strain was analyzed. The critical strain (${\varepsilon}_c$) and strain for maximum softening rate ( ${\varepsilon}^{*}$) could be confirmed by the analysis of work hardening rate ($d{\sigma}/d{\varepsilon}\;=\; \theta$). The volume fraction of dynamic recrystallization ($X_{DRX}$) as a function of processing variables, such as strain rate ( $\dot{\varepsilon}$ ), temperature (T), and strain ( $\varepsilon$ ) were established using the ${\varepsilon}_c$ and ${\varepsilon}^{*}$. For the exact prediction, the ${\varepsilon}_c$, ${\varepsilon}^{*}$ and Avrami' exponent (m') were quantitatively expressed by dimensionless parameter, Z/A respectively. The transformation-effective strain-temperature curve for DRX could be composed. It was found that the calculated results were agreed with the experimental data for the steels at any deformation conditions.

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