• Title/Summary/Keyword: Escape Analysis

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A Study on the Trapping Phenomenon and Relief Port Position of Oil Hydraulic Gear Pump (유압 기어펌프의 폐입현상과 릴리프 홈의 위치에 관한 연구)

  • 김철호;노춘경;정재연
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.06a
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    • pp.133-140
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    • 1999
  • It is possible for a volume of fluid to become trapped in the space between two adjoining teeth ad the tips of the teeth engage in Gear Pump with involute teeth. This trapped fluid leads to several harmful results, for example fluctuating pressure and aeration of pump. In this study, hence, theoretical and experimental analyses on this 'Trapping' were accomplished as using relief port(or escape port), one of the means for avoid it. Also, the grasp and analysis on variational type of the internal pressure in parallel with above experiments are achieved so that hydrodynamic behaviors in pump were contemplated.

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Population Ageing Crisis and Causal loop Analysis on the It's Dynamics in Rural County Regions (우리나라 군지역의 고령화 위기와 동태성의 인과순환적 구조분석)

  • Choi, Nam Hee;Lee, Jong Kun;Kim, Keun Sei;Lee, Myung Suk
    • Korean System Dynamics Review
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    • v.15 no.1
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    • pp.75-96
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    • 2014
  • This research primarily aims at analyzing major crises originating from marginalizing population, especially in counties. In addition, based on the system dynamics approaches, it pays attention to divulging causal loop structure which has been rather strengthened by diverse interactions among key variables. Judging from simulation works, even though Korea is exposed to unprecedented aging trends over decades, its counter response seems inadequate and insufficient, mostly dismissing a series of impact embedded in the aging dynamics. This research statistically confirms that demographic marginalization trends have already begun in the villages within Eup and Myon counties. Furthermore, this research pinpoints out the fact that it would be almost impossible for majority of villages within Eup and Myon counties to escape from going out of existence in the course of time, as they tend to be entrapped vicious cycle of marginalization or extinction.

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Practical Bifurcation Criteria considering Inductive Power Pad Losses in Wireless Power Transfer Systems

  • Kim, Minkook;Lee, Jae-Woo;Lee, Byoung Kuk
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.173-181
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    • 2017
  • In this paper, the bifurcation criteria for inductive power transfer (IPT) systems is suggested considering the inductive power pad losses. The bifurcation criteria for series-series (SS) and series-parallel (SP) topologies are derived in terms of the main parameters of the IPT system. For deriving precise criteria, power pad resistance is obtained by copper loss calculation and core loss analysis. Utilizing the suggested criteria, possibility of bifurcation occurrence can be predicted in the design process. In order to verify the proposed criteria, 50 W IPT laboratory prototype is fabricated and the feasibilities of the switching frequency and AC load resistance shift to escape from bifurcation are identified.

MONTE CARLO SIMULATION OF COMPTONIZATION IN A SPHERICAL SHELL GEOMETRY

  • SEON KWANG IL;MIN KYOUNG WOOK;CHOI CHUL SUNG;NAM UK WON
    • Journal of The Korean Astronomical Society
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    • v.27 no.1
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    • pp.45-53
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    • 1994
  • We present the calculation of X -ray spectra produced through Compton scattering of soft X-rays by hot electrons in the spherical shell geometry, using fully relativistic Monte Carlo simulation. With this model, we show that the power-law component, which has been observed in the low luminosity state of low-mass X-ray binaries (LMXBs), is explained physically. From a spectral. analysis, we find that spectral hardness is mainly due to the relative contribution of scattered component. In addition, we see that Wi en spectral features appear when the plasma is optically thick, especially in the high energy range, $E{\gtrsim}100keV$. We suggest that after a number of scattering the escape probability approaches an asymptotic form depending on the geometry of the scattering medium rather than on the initial photon spectrum.

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The Analysis of TSC Equation by Asymptotic Estimation (점근해법에 의한 열자격 전류식의 분석)

  • Oh, Yong-Cheul;Hong, Jin-Woong;Kim, Ki-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05d
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    • pp.96-99
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    • 2003
  • In this paper, it presents a method to calculate the escape frequency factor$(\nu)$ and its verification from TSC(Thermally Stimulated Current) equation and their simulation curves. To apply calculation method of $\nu$ using asymptotic estimation, it utilized TSC data with 1K interval. This method enables one to get the exact value of $\nu$ and activation energy at the same time by using computer programming. So, it regards their calculation method as a useful process to obtain the value of physical behavior.

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Flow Analysis of Building Pressurization System for Smoke Control (건물의 가압방연시스템 설계를 위한 유동해석에 관한 연구)

  • 김명배;한용식
    • Fire Science and Engineering
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    • v.14 no.2
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    • pp.14-20
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    • 2000
  • Many pressurization systems are designed and built with the goal of providing a smoke-free escape route in the event of a building fire. A secondary objective is to provide a smoke-free staging area for fire fighters. In the present study, a computer program is developed to calculate pressure loss and flow rate at several building elements such as a room, a ]tabby a staircase and an air supply shaft. By the program as the dosing tool for the pressurization system, the capacity of the injection fan is calculated, and the design method is proposed for the optimization of the fan capacity.

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A Study on the Relief Port Position of Oil Hydraulic Gear Pump with Involute Teeth (Involute 치형을 가진 유압 기어펌프의 릴리프 홈의 위치에 관한 연구)

  • 김철호;정재연
    • Tribology and Lubricants
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    • v.16 no.2
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    • pp.126-132
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    • 2000
  • It is possible for a volume of fluid to become trapped in the space between two adjoining teeth as the tips of the teeth engage in Gear Pump with involute teeth. This trapped fluid leads to several harmful results, for example fluctuating pressure and aeration of pump. In this study, hence, theoretical and experimental analyses on this'Trapping'were accomplished as using relief port(or escape port), one of the means for avoid it. Also, the grasp and analysis on variational type of the internal pressure in parallel with above experiments are achieved so that hydrodynamic behaviors in pump were contemplated.

Survival of Miamiensis avidus (Ciliophora: Scuticociliatia) from antibody-dependent complement killing

  • Lee, Eun Hye;Kang, Yue Jai;Kim, Ki Hong
    • Journal of fish pathology
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    • v.28 no.3
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    • pp.171-174
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    • 2015
  • Previously, we had reported that some Miamiensis avidus, a major pathogen of scuticociliatosis in cultured olive flounder, strongly agglutinated by flounder immune sera could escape from the agglutinated mass within a few hours. In the present study, we observed that M. avidus not only escaped from the agglutinated mass but also conducted division(s) before shedding its old covering. Furthermore, ciliates that survived the antibody-dependent complement killing (ADCK) assay were not killed even when re-exposed to a freshly prepared ADCK assay. This result suggests that the liberated ciliates from the ADCK assay might change not only their i-antigen types but also the epitopes of major surface antigens, which debilitate antibody-mediated complement killing ability.

Potential Swimming Motility Variation by AcrR in Escherichia coliS

  • Kim, Ye Jin;Im, So Young;Lee, Jae Ok;Kim, Ok Bin
    • Journal of Microbiology and Biotechnology
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    • v.26 no.10
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    • pp.1824-1828
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    • 2016
  • AcrR, the toxic-compounds-response regulator, regulates motility in microorganisms, presumably to escape from toxic environments. In this study, the genome-wide target genes of AcrR were investigated in a ΔacrR mutant strain by microarray analysis. In the absence of AcrR, the transcription of most flagella/motility genes was highly increased. In addition, flagella formation was increased in this mutant strain. Motility assays revealed that AcrR modulates swimming motility, but not swarming.

Basis Mode of Turbulent Flame in a Swirl-Stabilized Gas Turbine using LES and POD

  • Sung, Hong-Gye;Yang, Vigor
    • Journal of the Korean Society of Combustion
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    • v.6 no.2
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    • pp.29-35
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    • 2001
  • Unsteady numerical study has been conducted on combustion dynamics of a lean-premixed swirl-stabilized gas turbine swirl injector. A three-dimensional computation method utilizing the message passing interface (MPI) parallel architecture, large eddy simulation(LES), and proper orthogonal decomposition (POD) technique was applied. The unsteady turbulent flame dynamics are simulated so that the turbulent flame structure can be characterized in detail. It was observed that some fuel lumps escape from the primary combustion zone, and move downstream and consequently produce hot spots. Those flame dynamics coincides with experimental data. In addition, basis modes of the unsteady turbulent flame are characterized using proper orthogonal decomposition (POD) analysis. The flame structure based on odd basis modes is apparently larger than that of even ones. The flame structure can be extracted from the summation of the basis modes and eigenvectors at any moment.

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