• 제목/요약/키워드: continuum

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Box-Beam 형상 날개의 동적 등가연속체 모델링에 관한 연구 (Dynamic Equivalent Continuum Modeling of a Box-Beam Typed Wing)

  • 이우식;김영수
    • 대한기계학회논문집
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    • 제17권11호
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    • pp.2704-2710
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    • 1993
  • A simple and straightforward method is introduced for developing continuum beam-rod model of a box-beam typed aircraft wing with composite layered skin based on "energy equivalence." The equivalent continuum structral properties are obtained from the direct comparison of the reduced stiffness and mass matrices for box-beam typed wing with those for continuum beam-rod model. The stiffness and mass matrices are all represented in terms of the continuum degrees-of freedom defined in this paper. The finite-element method. The advantage of the present continuum method is to give every continuum structural properties including all possible coupling terms which represent the couplings between different deformations. To evaluate the continuum method developed in this paper, free vibration analyses for both continuum beam-rod and box-beam are conducted. Numerical tests show that the present continuum method gives very reliable structural and dynamic properties compared to the results by the conventional finite-element analysis. analysis.

평판형 트러스구조물의 연속체 모델링 및 동적해석 (Continuum Modeling and dynamic Analysis of Platelike Truss Structures)

  • 이우식;김종윤
    • 대한기계학회논문집
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    • 제16권6호
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    • pp.1021-1029
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    • 1992
  • 본 연구에서는 거대한 평판형 격자구조물에 대한 등가 연속체모델을 유도하기 위한 보다 간편하고 합리적인 방법을 개발하고, 예제해석을 통해 새로이 개발된 방법 의 타당성을 보이는데 있다.

정보 컨티뉴엄 모델에 관한 연구: 기록과 정보 간의 관계 정립을 위한 예비적 분석 (A Study on the Information Continuum Model: Preliminary Analysis to Establish the Relationship Between Records and Information)

  • 김명훈
    • 한국기록관리학회지
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    • 제22권3호
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    • pp.21-36
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    • 2022
  • 최근 기록이 지닌 정보로서의 속성에 주목해야 한다는 논의가 활발히 제기되고 있다. 이는 전자기록 환경을 맞아 행위에 대한 증거로서의 속성에만 초점을 맞추어 온 동향에 대한 반향이다. 하지만 아직까지 기록이 지닌 정보로서의 속성에 대한 명확한 개념은 정립되지 않은 상태이다. 이에 본고에서는 기록과 정보 간의 관계 정립을 위한 일환으로 정보 컨티뉴엄 모델을 분석하고자 한다. 정보 컨티뉴엄은 레코드 컨티뉴엄을 기반으로 레코드키핑 관점에서의 새로운 정보 개념을 정립하기 위해 고안된 이론 체계로, 레코드키핑 내에 존재하는 정보관리를 위한 요소들을 파악할 수 있는 하나의 개념적 틀을 제공해준다. 이에 2장에서는 레코드 컨티뉴엄 개발 이후 정보 컨티뉴엄이 개발된 배경 및 과정을 살펴본 다음, 구조주의 이론 등 정보학 이론을 차용해 정립한 정보의 개념을 레코드 컨티뉴엄과 연계하여 고찰하였다. 이어 3장에서는 정보 컨티뉴엄의 개념적 구조와 함께 정보의 활용 목적 및 방식을 고찰한 후, 레코드키핑 내에 존재하는 정보관리를 위한 요소들을 구조적으로 도식화한 정보 컨티뉴엄 모델상의 4개 차원 및 속성을 분석하였다. 이러한 분석을 기반으로 4장에서는 정보 컨티뉴엄이 지닌 의의 및 한계를 제시하고자 하였다.

등가연속체 Beam-Rod 모델을 이용한 항공기 날개의 공력탄성 해석 (Aeroelastic Analyses of Aircraft Wing by Using Equivalent Continuum BeamalRod Model)

  • 이우식;이항
    • 대한기계학회논문집
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    • 제19권3호
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    • pp.615-622
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    • 1995
  • It may be inefficient to conduct the aeroelastic analysis by using full-scale conventional finite-element analyses or experiments, from the initial design phase, for an aircraft wing which can be considered as the discontinuum complex structure with composite laminated skins. In this paper, therefore more efficient aeroelastic analysis has been conducted for a box-beam typed aircraft wing by using the equivalent continuum beam-rod model which is derived from the concept of energy equivalence. Equivalent structural properties of the continuum beam-rod model are obtained from the direct comparison of the finite-element matrices of continuum beam-rod model with those of box-beam typed aircraft wing. Numerical results by the continuum beam-rod model approach are compared with those by the conventional finite-element analysis approach to show that the continuum beam-rod model proposed herein is quite satisfactory as a simplified model of aircraft wing structure for aeroelastic analyses.

스프링 구조를 이용한 4자유도 연속체 로봇의 개발 (Development of a 4-DOF Continuum Robot Using a Spring Backbone)

  • 윤현수;이병주
    • 로봇학회논문지
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    • 제3권4호
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    • pp.323-330
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    • 2008
  • This work deals with a 4-DOF flexible continuum robot that employs a spring as its backbone. The mechanism consists of two modules and each module has 2 DOF. The special features of the proposed mechanism are the flexibility and the backdrivability of the whole body by using a spring backbone. Thus, even in the case of collision with human body, this device can ensure safety. The design and the kinematics for this continuum mechanism are introduced. The performance of this continuum mechanism was shown through simulation and experiment.

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CONTINUUM-WISE EXPANSIVENESS FOR C1 GENERIC VECTOR FIELDS

  • Manseob Lee
    • 대한수학회지
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    • 제60권5호
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    • pp.987-998
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    • 2023
  • It is shown that every continuum-wise expansive C1 generic vector field X on a compact connected smooth manifold M satisfies Axiom A and has no cycles, and every continuum-wise expansive homoclinic class of a C1 generic vector field X on a compact connected smooth manifold M is hyperbolic. Moreover, every continuum-wise expansive C1 generic divergence-free vector field X on a compact connected smooth manifold M is Anosov.

Characterization of Natvig Type Continuum Structure functions

  • Lee, Seung-Min
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2002년도 정기학술대회
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    • pp.305-305
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    • 2002
  • A continuum structure function is a non-decreasing mapping from the unit hypercube to the unit interval. Within the class of continuum structure functions, new axiomatic characterizations of the Natvig and the Barlow-Wu subclass are obtained.

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Multiscale simulation based on kriging based finite element method

  • Sommanawat, Wichain;Kanok-Nukulchai, Worsak
    • Interaction and multiscale mechanics
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    • 제2권4호
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    • pp.353-374
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    • 2009
  • A new seamless multiscale simulation was developed for coupling the continuum model with its molecular dynamics. Kriging-based Finite Element Method (K-FEM) is employed to model the continuum base of the entire domain, while the molecular dynamics (MD) is confined in a localized domain of interest. In the coupling zone, where the MD domain overlaps the continuum model, the overall Hamiltonian is postulated by contributions from the continuum and the molecular overlays, based on a quartic spline scaling parameter. The displacement compatibility in this coupling zone is then enforced by the Lagrange multiplier technique. A multiple-time-step velocity Verlet algorithm is adopted for its time integration. The validation of the present method is reported through numerical tests of one dimensional atomic lattice. The results reveal that at the continuum/MD interface, the commonly reported spurious waves in the literature are effectively eliminated in this study. In addition, the smoothness of the transition from MD to the continuum can be significantly improved by either increasing the size of the coupling zone or expanding the nodal domain of influence associated with K-FEM.

우주전파 관측용 연속파 수신시스템 제작에 관한 연구 (A Study on the Manufacture of the Continuum Receiver System for Observing Cosmic Radio Waves)

  • 서정빈;이창훈;임인성;한석태
    • 전자공학회논문지B
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    • 제31B권9호
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    • pp.67-75
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    • 1994
  • In this paper, we manufactured the continuum receiver system for observing the continuum waves emitted from the continuum sources with using the 14m radio-telescope. The receiving system measures the total power of the continuum sources and consists of DC-amplifier, beam-chopper system. Phase-Locked Loop(PLL) circuit, blanking circuit and its period selection circuit, V/F converter, and counter part which are capable of interfacing with the computer which is used for a data acquisition and making the radio-telescope track the source. We compared the obsevation results which use the existing DVM method with the observation results which use the continuum receiver to measure the total power of the sources. Moreover, by method of beam switching observation which uses newly installed beam chopper system. We can significantly improve the observational efficiency more than the existing position switching observation method.

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연속체모델에 의한 수치해석결과에 대한 재평가 (Reassessment on numerical results by the continuum model)

  • 정재동;유호선;노승탁;이준식
    • 대한기계학회논문집B
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    • 제20권12호
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    • pp.3926-3937
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    • 1996
  • In recent years there has been increased interest in the continuum model associated with the solidification of binary mixtures. A review of the literature, however, shows that the model verification was not sufficient or only qualitative. Present work is conducted for the reassessment of continuum model on the solidification problems of binary mixtures widely used for model validation. In spite of using the same continuum model, the results do not agree well with those of Incropera and co-workers which are benchmark problems typically used for validation of binary mixture solidification. Inferring from the agreement of present results with the analytic, experimental and other model's numerical results, this discrepancy seems to be caused by numerical errors in applying continuum model developed by Incropera and co-workers, not by the model itself. Careful examination should be preceded before selecting validation problems.