• Title/Summary/Keyword: Dynamic Process

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The Pre-Results Of Geomorphological Investigation In Tui River Basin

  • Narangerel, S.;Enkhtaivan, D.
    • The Korean Journal of Quaternary Research
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    • v.22 no.2
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    • pp.43-44
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    • 2008
  • In this brief present are about some advanced results from investigation geomorphology in basin of river Tui and distribution of relief their peculiarities, types morphogenetic, convert to ekzogen process of relief ( fluvial system, permafrost process, wind process, slope process etc) and dynamic process of sedimentation.

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Coherent Diffraction Imaging at PAL-XFEL

  • Kim, Sangsoo;Nam, Kihyun;Park, Jaehyun;Kim, Kwangoo;Kim, Bongsoo;Ko, Insoo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.85.2-85.2
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    • 2016
  • With the advent of ultra-short high-intense XFEL (X-ray Free Electron Laser), time-resolved dynamics has become of great importance in exploring femtosecond real-world phenomena of nanoscience and biology. These include studying the response of materials to femtosecond laser excitation and investigating the interaction of XFEL itself with condensed matter. A variety of dynamic phenomena have been investigated such as radiation damage, ultrafast melting process, non-equilibrium phase transitions caused by orbital-lattice-spin couplings. As far as bulk materials are concerned, the sample size has no effect on the following dynamic process. As a result, imaging information is not required by and large. If the sample size is of tens of nanometers, however, sample starts to experience quantum confinement effect which, in turn, affects the following dynamic process. Therefore, to understand the fundamental dynamic phenomena in nano-science, time-resolved imaging information is essential. In this talk, we will briefly introduce scientific highlights achieved in XFEL-based dynamics. In case of bio-imaging, recent scientific topics will be mentioned as well. Finally, we will aim to present feasible topics in ultrafast time-resolved imaging and to discuss the future plan of CXI beamline at PAL-XFEL.

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Study about material properties of Al particles and deformation of Al alloy substrate by cold gas dynamic spray (초음속 저온분사법에 의한 알루미늄 합금 모재의 변형과 적층된 알루미늄 층의 물성에 대한 연구)

  • Lee, J.C.;Ahn, S.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.145-148
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    • 2006
  • Cold gas dynamic spray is a relatively new coating process by which coatings can be produced without significant heating during the process. Cold gas dynamic spray is conducted by powder sprayed by supersonic gas jet, and generally called the kinetic spray or cold-spray. Cold-spray was developed in Russia in the early 1980s to overcome the defect of thermal spray method. Its low process temperature can minimize thermal stress and also reduce the deformation of the substrate. Most researches on cold-spray have focused on micro scale coating, but our research team tried to apply this method to macro scale deposition. The macro scale deposition causes deformation of a thin substrate which is usually convex to the deposited side. In this research, the main cause of the deformation was investigated using 6061-T6 aluminum alloy and properties of deposited aluminum layer such as coefficient of thermal expansion, Elastic modulus, hardness, electric conductivity were measured. From the result of the analysis, it was concluded that compressive residual stress was the main reason of substrate deformation while CTE had little effect.

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The study on the Analysis of Useful Daylight Illuminance in rural standard house model - By Dynamic Daylight Simulation Using Weather Data - (농어촌주택 표준설계의 유용조도 분석에 관한 연구 - 기상데이터 기반 동적 자연채광 시뮬레이션을 기반으로 -)

  • Yun, Young Il;Song, Jeong Suk;Lee, Hyo Won
    • KIEAE Journal
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    • v.11 no.1
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    • pp.47-55
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    • 2011
  • Daylight is highly beneficial for improving the indoor environmental quality and reducing building energy consumption, daylighting applications are scarcely considered, especially during the Rural standard house models design process, because of lack of previous studies on elderly-light environment and complex simulation process. Therefore, daylighting process were performed using ECOTECT, which has various advantage such as easy user interface and simple simulation processes. Moreover, dynamic daylight simulation were performed using whether data. Static simulation are performed to compute static metrics such as daylight factor, whereas dynamic simulation are performed for dynamic metrics such as daylight autonomy and useful daylight illuminance using annual weather data On the basis of daylight autonomy and useful daylight illuminance analysis result, variations in annual daylight performances. A parametric and regression analysis of the window-to-wall ratio and visible transmittance showed that daylight factor, daylight autonomy increased with window-to-wall ratio and visible transmittance. It can be concluded that this new daylight criteria. useful daylight illuminance, will enable architect to obtain better fenestration design.

The Study on the Analysis of Useful Daylight Illuminance in Care Facilities - By Dynamic Daylight Simulation Using Weather Data - (요양시설의 유용조도 분석에 관한 연구 -기상데이터 기반 동적 자연채광 시뮬레이션을 기반으로-)

  • Yun, Youngil;Cho, Juyoung;Lee, Hyowon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.17 no.1
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    • pp.33-40
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    • 2011
  • Daylight is highly beneficial for improving the indoor environmental quality and reducing building energy consumption, daylighting applications are scarcely considered, especially during the care facility design process, because of lack of previous studies on elderly- light environment and complex simulation process. Therefore, daylighting process were performed using ECOTECT, which has various advantage such as easy user interface and simple simulation processes. Moreover, dynamic daylight simulation were performed using whether data. Static simulation are performed to compute static metrics such as daylight factor, whereas dynamic simulation are performed for dynamic metrics such as daylight autonomy and useful daylight illuminance using annual weather data On the basis of daylight autonomy and useful daylight illuminance analysis result, variations in annual daylight performances. A parametric and regression analysis of the window-to-wall ratio and visible transmittance showed that daylight factor, daylight autonomy increased with window-to-wall ratio and visible transmittance. It can be concluded that this new daylight criteria. useful daylight illuminance, will enable architect to obtain better fenestration design.

Design and control of extractive distillation for the separation of methyl acetate-methanol-water

  • Wang, Honghai;Ji, Pengyu;Cao, Huibin;Su, Weiyi;Li, Chunli
    • Korean Journal of Chemical Engineering
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    • v.35 no.12
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    • pp.2336-2347
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    • 2018
  • The azeotrope of methyl acetate methanol and water was isolated using extractive distillation with water as entrainer. The pressure-swing extractive distillation (PSED) process and vapor side-stream distillation column (VSDC) with the rectifier process were designed to separate the methyl acetate, methanol and water mixture. It was revealed that the VSDC with the rectifier process had a reduction in energy consumption than the PSED process. Four control schemes of the two process were investigated: Double temperature control scheme (CS1), $Q_R/F$ feedforward control of reboiler duty scheme for PESD (CS2), $Q_R/F$ feedback control scheme for VSDC (CS3), the feedback control scheme of sensitive plate temperature of side-drawing distillation column to dominate the compressor shaft speed (CS4). Feed flow and composition disturbance were used to evaluate the dynamic performance. As a result, CS4 is a preferable choice for separation of methyl acetate-methanol-water mixture. A control scheme combining the operating parameters of dynamic equipment with the control indicators of static equipment was proposed in this paper. It means using the sensitive plate temperature of side-drawing column to control the compressor shaft speed. This is a new control scheme for extractive distillation.

Numerical and Experimental Investigations of Dynamic Stall

  • Geissler, Wolfgang;Raffel, Markus;Dietz, Guido;Mai, Holger
    • 한국전산유체공학회:학술대회논문집
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    • 2009.04a
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    • pp.19-19
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    • 2009
  • Dynamic Stall is a flow phenomenon which occurs on the retreating side of helicopter rotor blades during forward flight. It also occurs on blades of stall regulated wind turbines under yawing conditions as well as during gust loads. Time scales occurring during this process are comparable on both helicopter and wind turbine blades. Dynamic Stall limits the speed of the helicopter and its manoeuvrability and limits the amount of power production of wind turbines. Extensive numerical as well as experimental investigations have been carried out recently to get detailed insight into the very complex flow structures of the Dynamic Stall process. Numerical codes have to be based on the full equations, i.e. the Navier-Stokes equations to cover the scope of the problems involved: Time dependent flow, unsteady flow separation, vortex development and shedding, compressibility effects, turbulence, transition and 3D-effects, etc. have to be taken into account. In addition to the numerical treatment of the Dynamic Stall problem suitable wind tunnel experiments are inevitable. Comparisons of experimental data with calculated results show us the state of the art and validity of the CFD-codes and the necessity to further improve calculation procedures. In the present paper the phenomenon of Dynamic Stall will be discussed first. This discussion is followed by comparisons of some recently obtained experimental and numerical results for an oscillating helicopter airfoil under Dynamic Stall conditions. From the knowledge base of the Dynamic Stall Problems, the next step can be envisaged: to control Dynamic Stall. The present discussion will address two different Dynamic Stall control methodologies: the Nose-Droop concept and the application of Leading Edge Vortex Generators (LEVoG's) as examples of active and passive control devices. It will be shown that experimental results are available but CFD-data are only of limited comparison. A lot of future work has to be done in CFD-code development to fill this gap. Here mainly 3D-effects as well as improvements of both turbulence and transition modelling are of major concern.

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Dynamic Slicing using Dynamic System Dependence Graph (동적 시스템 종속 그래프를 사용한 동적 슬라이싱)

  • 박순형;박만곤
    • Journal of Korea Multimedia Society
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    • v.5 no.3
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    • pp.331-341
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    • 2002
  • Traditional slicing techniques make slices through dependence graph and improve the accuracy of slices. However, traditional slicing techniques require many vertices and edges in order to express a data communication link because they are based on static slicing techniques. Therefore the graph becomes very complicated. We propose the representation of a dynamic system dependence graph so as to process the slicing of a software system that is composed of related programs in order to process certain jobs. We also propose programs on efficient slicing algorithm using relations of relative tables in order to compute dynamic slices of a software system. Using a marking table from results of the proposed algorithm can make dynamic system dependence graph for dynamic slice generation. Tracing this graph can generate final slices. We have illustrated our example with C program environment. Consequently, the efficiency of the proposed dynamic system dependence graph technique is also compared with the dependence graph techniques discussed previously. As the results, this is certifying that the dynamic system dependence graph is more efficient in comparison with system dependence graph.

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An Experimental Study on the Dynamic Load Characteristics of Surface Mount Device(SMD) (칩마운트 (SMD) 장비의 동하중(動荷重) 발생특성에 관한 실험적 연구)

  • Baek, Jae-Ho;Lee, Hong-Ki;Kim, Kang-Boo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.1913-1917
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    • 2000
  • SMD Equipment convey an electronic parts at high speed, then assemble parts into a circuit board, and it develop a long time-duration dynamic force to be caused by moving mass. Vibration problem to be caused by SMD Equipment have an effect on micro-meter level's precision production process, directly, and dynamic stability of building. In the cause of quantitatively access about its vibration problem, input information(or data) of structure dynamic analysis need accuracy information of dynamic load. Determination of Dynamic load is various kinds of method using experimental and theory. In this paper, we got dynamic load using direct measurement method. We expect that an study on the dynamic load characteristic of SMD can be used to Equipment development of low level vibration and basis information of structure dynamic analysis.

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