• Title/Summary/Keyword: Colliding

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The evolution of a late-type galaxy in a Coma-like cluster

  • Hwang, Jeong-Sun;Park, Changbom;Banerjee, Arunima
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.64.1-64.1
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    • 2016

  • We study the evolution of a late-type galaxy (LTG) in a rich cluster environment by using N-body/SPH simulations. To do that we perform a set of simulations of a LTG falling in a Coma-like cluster and also the LTG colliding with early-type galaxies (ETGs) multiple times in the cluster environment. We use a catalog of the Coma cluster in order to estimate the typical number of collisions and the closest approach distances that a LTG would experience in the cluster. We investigate the cold gas depletion and star formation quenching of our LTG model influenced by the hot cluster gas as well as the hot halo gas of the colliding ETGs.

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A Modeling of Impact Dynamics and its Application to Impact Force Prediction

  • Ahn Kil-Young;Ryu Bong-Jo
    • Journal of Mechanical Science and Technology
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    • v.19 no.spc1
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    • pp.422-428
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    • 2005

  • In this paper, the contact force between two colliding bodies is modeled by using Hertz's force-displacement law and nonlinear damping function. In order to verify the appropriateness of the proposed contact force model, the drop type impact test is carried out for different impact velocities and different materials of the impacting body, such as rubber, plastic and steel. In the drop type impact experiment, six photo interrupters in series close to the collision location are installed to measure the velocity before impact more accurately. The characteristics of contact force model are investigated through experiments. The parameters of the contact force model are estimated using the optimization technique. Finally the estimated parameters are used to predict the impact force between two colliding bodies in opening action of the magnetic contactor, a kind of switch mechanism for switching electric circuits.

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Simultaneous analysis, design and optimization of trusses via force method

  • Kaveh, A.;Bijari, Sh.
    • Structural Engineering and Mechanics
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    • v.65 no.3
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    • pp.233-241
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    • 2018

  • In this paper, the Colliding Bodies Optimization (CBO), Enhanced Colliding Bodies Optimization (ECBO) and Vibrating Particles System (VPS) algorithms and the force method are used for the simultaneous analysis and design of truss structures. The presented technique is applied to the design and analysis of some planer and spatial trusses. An efficient method is introduced using the CBO, ECBO and VPS to design trusses having members of prescribed stress ratios. Finally, the minimum weight design of truss structures is formulated using the CBO, ECBO and VPS algorithms and applied to some benchmark problems from literature. These problems have been designed by using displacement method as analyzer, and here these are solved for the first time using the force method. The accuracy and efficiency of the presented method is examined by comparing the resulting design parameters and structural weight with those of other existing methods.

  • https://doi.org/10.12989/sem.2018.65.3.233 인용 KSCI

Truss optimization with dynamic constraints using UECBO

  • Kaveh, A.;Ilchi Ghazaan, M.
    • Advances in Computational Design
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    • v.1 no.2
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    • pp.119-138
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    • 2016

  • In this article, hybridization of enhanced colliding bodies optimization (ECBO) with upper bound strategy (UBS) that is called UECBO is proposed for optimum design of truss structures with frequency constraints. The distinct feature of the proposed algorithm is that it requires less computational time while preserving the good accuracy of the ECBO. Four truss structures with frequency limitations selected from the literature are studied to verify the viability of the algorithm. This type of problems is highly non-linear and non-convex. The numerical results show the successful performance of the UECBO algorithm in comparison to the CBO, ECBO and some other metaheuristic optimization methods.

  • https://doi.org/10.12989/acd.2016.1.2.119 인용

Energy Transfer Between Diatomic Molecules

  • Kim, Yoo-Hang;Shin, Hyung-Kyu
    • Bulletin of the Korean Chemical Society
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    • v.8 no.2
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    • pp.88-96
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    • 1987

  • The effects of initial vibrational energy on VV energy transfer in the collinear collision of two diatomic molecules, either homonuclear or heteronuclear, has been studied over a range of collision energies in classical mechanics. When initial vibrational energy is very large, only a small fraction of vibrational energy in the excited molecule is transferred to the colliding partner. In this case, the VV step is found to be strongly coupled with VT during the collision. At low collision energies, energy transfer in the homonuclear case of $O_2$+ $O_2$ with small initial vibrational energy is found to be very inefficient. In the heteronuclear case of CH + HC with the initial energy equivalent to one vibrational quantum, VV energy exchange is found to be very efficient at such energies. Between 0.3 and 0.5 ev, nearly all of vibrational energy of the excited molecule with one to about three vibrational quanta in CH + HC is efficiently transferred to the colliding partner through pure VV process in a sequence of down steps during the collision. The occurrence of multiple impacts during the collision of two heteronuclear molecules and the collisional bond dissociation of homonuclear molecules are also discussed.

  • https://doi.org/10.5012/bkcs.1987.8.2.88 인용 PDF