• Title/Summary/Keyword: 정역학특성

Search Result 13, Processing Time 0.034 seconds

Investigation of ultraprecision machining characteristics by molecular statics simulation method (분자정역학 기법을 이용한 초미세 절삭특성에 관한 고찰)

  • 정구현;이성창;김대은
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.14 no.3
    • /
    • pp.122-129
    • /
    • 1997
  • Machining technology has emerged to the point of performing atomic-scale fabrication. In tail paper atomic-scale machining characteristics are investigated by using Molecular Statics simulation method. The cutting model used in this work simulates machining with tools such as an AFM. It is shown that built-up edge formation and cutting forces depend on tool tip geometry. Also, the material flow during cutting is shown for various cutting conditions such as depth of cut, rake angle, and edge radius of tool.

  • PDF

Influence of Reinforced Fiber on Local Failure of the Concrete subjected to Impact of High-Velocity Projectile (고속 비상체 충돌에 의한 콘크리트의 국부파괴에 미치는 혼입 섬유의 영향)

  • Kim, Hong-Seop;Kim, Gyu-Yong;Choe, Gyeong-Cheol;Kim, Jung-Hyun;Lee, Young-Wook;Han, Sang-Hyu
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2014.11a
    • /
    • pp.139-140
    • /
    • 2014
  • The purpose of this study in to evaluate relationship between mechanical properties of materials and fiber type by reinforced fiber with high-velocity impact fracture behavior of fiber reinforced concrete. As a result, for fracture behavior by high-velocity impact, it is considered that impact fracture behavior is not affected by static mechanical properties directly but affected by fiber type and density of the number of fiber. It is necessary to consider type, shape, mechanical properties and the number of fiber with flexural and tensile performance for the evaluation on impact resistance performance of fiber reinforced concrete.

  • PDF

Investigation on the Applicability of Structures by Evaluating the Static Properties and the Impact Resistance Performance of Amorphous Metallic Fiber Reinforced Cement Composites (비정질 강섬유보강 시멘트복합체의 정역학특성 및 내충격성능 평가를 통한 구조물 적용 가능성 검토)

  • Kang, Il-Soo;Kim, Gyu-Yong;Lee, Bo-Kyeong;Lee, Sang-Kyu;Son, Min-Jae;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2017.11a
    • /
    • pp.79-80
    • /
    • 2017
  • This study examined the effect that the amorphous metallic fibers had on the static mechanical properties and the impact resistance of cement composites to those of hooked steel fibers. The hooked steel fiber exhibited pull-out from the matrix after the peak flexural stress was attained, while the amorphous metallic fiber was not pulled out from the matrix, but was instead cut off. In terms of impact resistance, the amorphous metallic fiber reinforced cement composite was found to be more effective at resisting cracking than the hooked steel fiber reinforced cement composite. Therefore, amorphous metallic fiber should be used in fiber reinforced cement composite materials, and for structural materials, and for protection panels.

  • PDF

A Face Recognition using the Hidden Markov Model and Karhuman Loevs Transform (Hidden Markov Model과 Karhuman Loevs Transform를 이용한 얼굴인식)

  • Kim, Do-Hyun;Hwang, Suen-Ki;Kang, Yong-Seok;Kim, Tae-Woo;Kim, Moon-Hwan;Bae, Cheol-Soo
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.4 no.1
    • /
    • pp.3-8
    • /
    • 2011
  • The work presented in this paper describes a Hidden Markov Model(HMM)-based framework for face recognition and face detection. The observation vectors used to characterize the statics of the HMM are obtained using the coefficients of the Karhuman-Loves Transform(KLT). The face recognition method presented in this paper reduces significantly the computational complexity of previous HMM-based face recognition systems, while slightly improving the recognition rate. In addition, the suggested method is more effective than the exiting ones in face extraction in terms of accuracy and others even under complex changes to the surroundings such as lighting.

Face Recognition Method Robust to Change in Lighting Condition (조명의 변화에 강건한 얼굴인식)

  • Nam, Kee-Hwan;Han, Jun-Hee;Park, Ho-Sik;Lee, Young-Sik;Jung, Yen-Gil;Ra, Sang-Dong;Bae, Cheol-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • v.9 no.1
    • /
    • pp.1137-1140
    • /
    • 2005
  • The work presented in this paper describes a Hidden Markov Model(HMM)-based framework for face recognition and face detection. The observation vectors used to characterize the statics of the HMM are obtained using the coefficients of the Karhuman-Loves Transform(KLT). The face recognition method presented in this paper reduces significantly the computational complexity of previous HMM-based face recognition systems, while slightly improving the recognition rate. In addition, the suggested method is more effective than the exiting ones in face extraction in terms of accuracy and others even under complex changes to the surroundings such as lighting.

  • PDF

Face Detection And Recognition using Hidden Markov Models (HMM 을 이용한 얼굴 검출과 인식)

  • 박호석;차영석;최현수;배철수;권오홍;최철재;나상동
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2000.05a
    • /
    • pp.336-341
    • /
    • 2000
  • Hidden Markov Model(HMM)을 기반으로 한 얼굴 검출과 얼굴 인식에 대한 프레임작업에 대한 것이다. 관찰 벡터는 Karhunen-Loves Transform(KLT)의 상관관계를 이용하여 얻은 HMM의 정역학 특성을 사용하였으며, 본 연구에서 보여준 얼굴인식 방법은 이전의 HMM 기반의 얼굴인식 방법에서 인식률을 약간 개선함으로써 컴퓨터 연산을 훨씬 간단히 할 수 있음을 보여준다

  • PDF

Effect for Electrowetting of Droplet according to Applied Voltage and Height of Electrode (전극의 전압과 위치변화가 액적의 Electrowetting에 미치는 영향)

  • Sung, Tan-Il;Cho, Young-Han;Kim, Young-Sun;Choi, Hong-Soon;Park, Il-Han
    • Proceedings of the KIEE Conference
    • /
    • 2008.07a
    • /
    • pp.800-801
    • /
    • 2008
  • 유체의 전자기력에 의한 거동특성 파악을 위해 전자기 체적력에 의한 접근법을 이용하였다. 수정된 Kelvin force을 유체정역학 방정식에 도입하고 유체표면에서의 압력이 일정해야한다는 원리를 이용하여 유체 표면의 형상을 얻어낸다. 액적에 인가하는 전압의 크기와 전극을 꽂는 높이의 변화에 따른 액적의 Electrowetting 영향을 수치해석한다.

  • PDF

A Study on the Transient Motion Analysis for the Liquid Balinced Washing Machine (액체밸런서를 고려한 세탁기의 과도응답 특성에 관한 연구)

  • 이동익;오재응
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.19 no.1
    • /
    • pp.1-13
    • /
    • 1995
  • In order to investigate the effect of liquid balancer in washing machine, we identify the vibration characteristics of suspension system of washing machine and formulate the 4 D. O. F. system dynamic equations. As the washing machine rotates higher speed, it is emphasized to reduce the ecentric force due to unbalanced mass. Nowadays, the most effective cancelling method of eccentric force is known as the usage of liquid balancer. To determine the liquid distribution in liquid balancer, the fluid statics is considered. The system dynamic equations are solved by Runge-Kutta method and represent the good characteristics of real washing machine in X-Y plane. The accuracy of the numerical solution was examined by experiments. The simulation results show that the unbalanced mass has so much influence on vibration magnitude and the rotating shape of spin-basket. But the effect of mass reduction due to the dehydration of the spin-basket has little influence on transient vibration.

Primitive Instancing for the Definition of Non-conventional Hull (비정규 선형정의를 위한 원형요소 인스턴싱의 이용)

  • Won-Don Kim;Jong-Ho Nam;Kwang-Wook Kim
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.30 no.1
    • /
    • pp.1-9
    • /
    • 1993
  • Various geometric modeling techniques for a hull have been developed with wide application of computer to the ship design. Up to now, they are used for the representation of the sculptured surface with the piecewise polynominal curves or surfaces for a conventional hull. In this paper, a convenient and accurate modeling technique that is instancing and blending of the geometry primitives is introduced for a non-conventional hull such as SWATH, trimaran, caisson etc. Geometric characteristics, hydrostatic particulars and stability of the definded hull are calculated.

  • PDF

Design of a Small High - Speed SWATH Passenger Ship (소형고속 SWATH 여객선의 선형설계에 대한 연구)

  • Min, K.S.;Lee, Y.W.
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.33 no.1
    • /
    • pp.189-205
    • /
    • 1996
  • The first - stage study of the three - stage SWATH ship development program of Hyundai Maritime Research Institute has been completed. Various computer programs have been prepared in advance to calculate and predict various properties and characteristics of SWATH ships. With these design tools, theoretical analyses for the systematic variation of design parameters were performed, and step - by - step model tests were carried out to derive the final configuration.

  • PDF