• Title/Summary/Keyword: Multi-body interactions

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SPH models of the interactions in Stephan's Quintet

  • Hwang, Jeong-Sun
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.58.2-58.2
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    • 2011
  • We present smoothed particle hydrodynamic models of the interactions in the compact galaxy group, Stephan's Quintet. Adding thermohydrodynamic effects to the earlier collisionless N-body simulations of Renaud et al. (2010), we further investigate the dynamical interaction history and evolution of the intergalactic gas of Stephan's Quintet. Specifically, we model the formation of the hot X-ray gas, the group-wide shock, and emission line gas as the result of NGC 7318b colliding with the group as well as reproduce the tidal structures in the group. We compare our model results to multi-wavelength observations.

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A Study on Development of Out-door Wear Design to Respond to the Climate and Environment -Focus on the design in collections after the year 2000- (기후와 환경에 대응하기 위한 아웃도어 웨어 디자인에 관한 연구 -2000년 이후 컬렉션에서 발표된 디자인을 중심으로-)

  • Bae, Jung-Min
    • Journal of the Korean Society of Costume
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    • v.61 no.7
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    • pp.101-109
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    • 2011
  • The present research aims to suggest the design of a new direction that copes with the changing environment. For example, the design for outdoor wear can be made through various methods that allows it to be worn for anytime and anywhere. Also, the research aimed to seek a development direction of outdoor wear design with environment-friendly expanded function that handles unpredictable environmental changes. The analysis of this research is as follows. First, it can be said that the trend of the outdoor wear design according to climate and environment changes is a design that seeks an efficient and rational role in functional aspects such as complex multi-functionality and minimum decorations as well as enhancing economic efficiency. Second, the outdoor wear design provides the optimal climate for the human body even in a continuously changing artificial environment. Its easy and comfortable function also helps to keep defense from possible risk elements. Lastly, this research seeks interactions among design, the body and environment. It also tries shape change using buttons and zippers, etc. according to expansion of a structural form of clothes as multi-functionality and versatility tools, and seeks a design form that can be reconstructed. The research that geared toward environmental changes should be further progressed in order to produce apparel that have efficient adaptability of any climate situations.

Analytical Research of Topside Installation in Mating phase with Crane Vessel

  • Lee, Jong-Hyun
    • Journal of Ocean Engineering and Technology
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    • v.25 no.4
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    • pp.1-6
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    • 2011
  • The installation of a topside structure can be categorized into the following stages: start, pre-lifting, lifting, lifted, rotating, positioning, lowering, mating, and end of installation. The transfer of the module onto the floating spar hull occurs in the last three stages, from lowering to the end. The coupled multi-body motions are calculated in both calm water and in irregular waves with a significant wave height (1.52m). The effects of the hydrodynamic interactions between the heavy lifting vessel and the spar hull during the lowering and mating stages are considered. The internal forces caused by the load transfer and ballasting are derived for the mating phases. The results of the internal forces for the calm water condition are compared with those in the irregular sea condition. Although the effect of the pitch motion on the relative vertical motion between the deck of the floating structure and the topside module is significant in the mating phases, the internal force induced pitch motion is too small to have this influence. However, the effect of the internal force on the wave-induced heave responses in the mating phases is noticeable in the irregular sea condition because transfer mass-induced draught changes for the floating structure are observed to have higher amplitudes than the external force induced responses. The impacts of the module on the spar hull in the mating phase are investigated.

Hydrodynamic Interaction Analysis of Floating Multi-body System

  • Kim, Young-Bok;Kim, Moo-Hyun;Kim, Yong-Yook;Kim, Young-Hun
    • International Journal of Ocean System Engineering
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    • v.1 no.4
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    • pp.198-204
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    • 2011
  • Recently, several problems have occurred in the space, infra-structure, and facility of the contiguity of existing harbors due to the trend of enlarged container vessels. In this regard, the Mobile Harbor has been proposed conceptually in this study as an effective solution for these problems. The concept is that of a transfer loader that transfers containers from a large container ship to the harbor on land, and is a catamaran type floating barge. The catamaran-type vessel is well known for its advantage in maneuverability, resistance, and effectiveness for working on board. For the safe and effective operation of the two floating bodies (a container ship and the mobile harbor in the near sea detached from the quay), robot arms, novel crane systems, and pneumatic fenders are specially devised with an additional mooring facility or DP (dynamic positioning) system. In this study, this concept is to be verified through comparison and simulation studies under various environmental conditions. It is shown that the proposed concept is in general feasible but there are several areas for further investigation and improvement.

Numerical Simulation of 3D Free-Surface Flows by Using CIP-based and FV-based Methods

  • Yang, Kyung-Kyu;Nam, Bo-Woo;Kim, Yong-Hwan
    • International Journal of Ocean System Engineering
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    • v.1 no.3
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    • pp.136-143
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    • 2011
  • In this paper, three-dimensional free-surface flows are simulated by using two different numerical methods, the constrained interpolation profile (CIP)-based and finite volume (FV)-based methods. In the CIP-based method, the governing equations are solved on stationary staggered Cartesian grids by a finite difference method, and an immersed boundary technique is applied to deal with wave-body interactions. In the FV-based method, the governing equations are solved by applying collocated finite volume discretization, and body-fitted meshes are used. A free-surface boundary is considered as the interface of the multi-phase flow with air and water, and a volumeof-fluid (VOF) approach is applied to trace the free surface. Among many variations of the VOF-type method, the tangent of hyperbola for interface capturing (THINC) and the compressive interface capturing scheme for arbitrary meshes (CICSAM) techniques are used in the CIP-based method and FV-based method, respectively. Numerical simulations have been carried out for dam-breaking and wave-body interaction problems. The computational results of the two methods are compared with experimental data and their differences are observed.

A Full Body Gumdo Game with an Intelligent Cyber Fencer using Multi-modal(3D Vision and Speech) Interface (멀티모달 인터페이스(3차원 시각과 음성 )를 이용한 지능적 가상검객과의 전신 검도게임)

  • 윤정원;김세환;류제하;우운택
    • Journal of KIISE:Computing Practices and Letters
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    • v.9 no.4
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    • pp.420-430
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    • 2003
  • This paper presents an immersive multimodal Gumdo simulation game that allows a user to experience the whole body interaction with an intelligent cyber fencer. The proposed system consists of three modules: (i) a nondistracting multimodal interface with 3D vision and speech (ii) an intelligent cyber fencer and (iii) an immersive feedback by a big screen and sound. First, the multimodal Interface with 3D vision and speech allows a user to move around and to shout without distracting the user. Second, an intelligent cyber fencer provides the user with intelligent interactions by perception and reaction modules that are created by the analysis of real Gumdo game. Finally, an immersive audio-visual feedback by a big screen and sound effects helps a user experience an immersive interaction. The proposed system thus provides the user with an immersive Gumdo experience with the whole body movement. The suggested system can be applied to various applications such as education, exercise, art performance, etc.

The Function of Computer Utilization in Educating and Researching Ocean Engineering Problems

  • Koo, Weon-Cheol;Kim, Moo-Hyun;Ryu, Sam
    • Journal of Ship and Ocean Technology
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    • v.12 no.4
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    • pp.1-6
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    • 2008
  • Nowadays, the computational capability and graphical power based on PCs increase very rapidly every year. As a result, the complicated engineering or scientific problems that could have only been handled by supercomputers a couple of decades ago can now be routinely run on PCs. Besides, the PCs can be assembled in parallel to increase its computational capability theoretically without limitation. The Web-based interface and communication tools are also being enhanced very rapidly and the real-time distance learning (E-Learning) and project cooperation on web get increasing attention. Using the-state-of-the-art computational method, a number of complicated and computationally intensive problems are being solved by PCs. The results can be well demonstrated on screen by graphics and animation tools. Those examples include the simulations of fully nonlinear waves, their interactions with floating bodies, global-motion analysis of multi-unit floating production system including complicated mooring lines and risers. Several examples will be presented in this regard. Also, Web and java-applet based educational tools have been developed at Texas A&M University for better understanding of waves and wave-body interactions. The background and examples of such Web-based educational tools published in Kim et al. (2003) are briefly introduced here.

Deciphering the Core Metabolites of Fanconi Anemia by Using a Multi-Omics Composite Network

  • Xie, Xiaobin;Chen, Xiaowei
    • Journal of Microbiology and Biotechnology
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    • v.32 no.3
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    • pp.387-395
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    • 2022
  • Deciphering the metabolites of human diseases is an important objective of biomedical research. Here, we aimed to capture the core metabolites of Fanconi anemia (FA) using the bioinformatics method of a multi-omics composite network. Based on the assumption that metabolite levels can directly mirror the physiological state of the human body, we used a multi-omics composite network that integrates six types of interactions in humans (gene-gene, disease phenotype-phenotype, disease-related metabolite-metabolite, gene-phenotype, gene-metabolite, and metabolite-phenotype) to procure the core metabolites of FA. This method is applicable in predicting and prioritizing disease candidate metabolites and is effective in a network without known disease metabolites. In this report, we first singled out the differentially expressed genes upon different groups that were related with FA and then constructed the multi-omics composite network of FA by integrating the aforementioned six networks. Ultimately, we utilized random walk with restart (RWR) to screen the prioritized candidate metabolites of FA, and meanwhile the co-expression gene network of FA was also obtained. As a result, the top 5 metabolites of FA were tenormin (TN), guanosine 5'-triphosphate, guanosine 5'-diphosphate, triphosadenine (DCF) and adenosine 5'-diphosphate, all of which were reported to have a direct or indirect relationship with FA. Furthermore, the top 5 co-expressed genes were CASP3, BCL2, HSPD1, RAF1 and MMP9. By prioritizing the metabolites, the multi-omics composite network may provide us with additional indicators closely linked to FA.

An Improved Theoretical Model to Explain Electronic and Optical Properties of p-Type GaAs/AlGaAs Superlattices for Multi-Wavelength Normal Incidence Photodetectors

  • Kim, Byoung-Whi;Choi, Eun-Chang;Park, Kwon-Chul;Kang, Seok-Youl
    • ETRI Journal
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    • v.18 no.4
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    • pp.315-338
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    • 1997
  • We extend our previous theoretical analysis of electronic and optical properties of p-type quantum well structures based on the two heavy- and light-hole system to include all the three valence bands. These theories are then used to clarify the origin of the normal incidence absorption and photo current at photon wavelengths of 2 - 3 ${\mu}m$, which was observed in addition to the absorption around 8 ${\mu}m$ by a recent experimental investigation with heavily doped p-type GaAs/AlGaAs multi-quantum well (MQW) structures. In the theoretical analysis, the Hartree and exchange-correlation many-body interactions are taken into account within one-particle local density approximation, and it is shown that normal incidence absorption occurs in two wavelength regions over the transition energy range higher than barrier height for p-type GaAs/AlGaAs superlattices with well doping of $2{\times}10^{19}\;cm^{-3}$; one region has broad absorption peaks with coefficients of about 5000 $cm^{-1}$ around 8 ${\mu}m$, and the other has two rather sharp peaks at 2.7 ${\mu}m$ and 3.4 ${\mu}m$ with 1800 $cm^{-1}$ and 1300 $cm^{-1}$, respectively. The result indicates that the theory explains the experimental observation well, as the theoretical and experimental results are in close agreement in general absorption features.

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Estimation of Wave Energy Extraction Efficiency for a Compact Array System of Small Buoys (밀집 배열 부이시스템의 파랑에너지 추출 효율 추정)

  • Choi, Yoon-Rak
    • Journal of Ocean Engineering and Technology
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    • v.25 no.1
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    • pp.8-13
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    • 2011
  • A compact array system of small buoys is used for wave energy extraction. To evaluate the performance of this system, hydrodynamic analysis is carried out in regular waves using the higher order boundary element method. The motion response of each buoy is calculated considering hydrodynamic interactions caused by other buoys. The effect of energy extraction device is modeled as a linear damping load. The efficiencies of energy conversion are compared using the various sizes and arrangements of the array system and the damping coefficients for energy extraction. The increase in size or the packing ratio of the system gives better efficiency. However, the wave condition and the cost for the system should be considered to optimize performance from the perspective of engineering and economics. The proposed nondimensionalized damping coefficient for energy extraction is 0.1~0.5.