• 제목/요약/키워드: Extinction Point

검색결과 78건 처리시간 0.025초

필지경계점 중심의 경계점등록부 작성 방안 (A Study on the Framing Plan of Boundary Point Record Book Based on Parcel Boundary Point)

  • 김준현;권기욱
    • 한국측량학회지
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    • 제32권spc4_2호
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    • pp.375-386
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    • 2014
  • 본 연구에서는 지적재조사사업의 완료에 따라 작성할 경계점등록부의 구성방안에 대해 기존의 경계점좌표등록부, 경계점표지등록부, 지상경계점등록부에서 나타난 문제점을 검토하고 이를 바탕으로 경계점의 등록과 관리를 위한 필지경계점 중심의 경계점등록부 작성방안을 제시하였다. 도출된 결과를 요약하면 다음과 같다. 첫째, 3개의 경계점 관련 등록부를 통합하여 관리함으로써 경계점 위치 설명도가 없는 지역에서도 기준점 현황을 바로 확인할 수 있어 신속한 측량이 이루어질 수 있다. 둘째, 일필지 단위의 필지중심이 아닌 필지경계점 중심의 경계점등록부를 작성함으로써 경계점의 연혁관리가 용이하고 경계점의 생성, 이기, 소멸 등에 있어 경계점의 지속적인 관리가 가능하다. 셋째, 경계점 위치 설명도는 토지분할 시점에 작성을 하게 되지만 토지분할의 목적이 주로 건물 신축이므로 건물 준공시점에 경계점 표시변경 신청으로 지형지물과 일치하는 경계점 위치 설명도를 유지할 수 있다.

On the Stability of Critical Point for Positive Systems and Its Applications to Biological Systems

  • Lee, Joo-Won;Jo, Nam Hoon;Shim, Hyungbo;Son, Young Ik
    • Journal of Electrical Engineering and Technology
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    • 제8권6호
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    • pp.1530-1541
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    • 2013
  • The coexistence and extinction of species are important concepts for biological systems and can be distinguished by an investigation of stability. When determining local stability of nonlinear systems, Lyapunov indirect method based on the Jacobian linearization has been widely employed due to its simplicity. Despite such popularity, it is not applicable to singular systems whose Jacobian has at least one eigenvalue that is equal to zero. In such singular cases, an appropriate Lyapunov function should be sought to determine the stability of systems, which is rather difficult and quite involved. In this paper, we seek for a simple criterion to determine stability of the equilibrium that is located at the boundary of the positive orthant, when one of eigenvalues of the Jacobian is zero. The goal of the paper is to present a generalized condition for the equilibrium to attract all trajectories that starting from initial condition in the positive orthant and near the equilibrium. Unlike the Lyapunov direct method, the proposed method requires just a simple algebraic computation for checking the stability of the critical point. Our approach is applied to various biological systems to show the effectiveness of the proposed method.

연속 레이저 흡수에 의한 증발제거 과정의 관련 인자 영향 고찰 (Effect of Parameters in Evaporative Removal Process by Absorption of a CW Laser)

  • 김진윤;송태호
    • 대한의용생체공학회:의공학회지
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    • 제16권1호
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    • pp.67-76
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    • 1995
  • Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd: YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as BrJ, and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased. To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained.

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Pool 화재에서의 표면 냉각에 의한 소화 (Extingushiment by the Colling Effect of the Fuel Surface with Pool Fires)

  • 한용식;김명배;신현동
    • 한국화재소방학회논문지
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    • 제11권4호
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    • pp.15-23
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    • 1997
  • A series of measurements and visualization to investigate the extingushiment of water sprays with pool fires is presented. Fire source is a small-scale pool burner with methanol, ethanol and gasoline. Measurements of temperature, O2, CO2, and CO concentrations along the plume centerline are carried out to observe pool structures without water sprays. Visualization by the Ar-ion laser sheet flow pattern of droplets of the sprays above the pool fires. It is observed than in the case of methanol and ethanol, water sprays continuously penetrate into the center of fuel surfaces. The gasoline pool fire allows intermittent penetration of water sprays because of pulsating characteristics of the gasoline flame. To evaluate the cooling effect of the fuel surface by the sprays, the temperature was measured at the fuel surface. As soon as the mists reach the fuel surface of methanol and ethanol, the temperatures of the fuel surface decrease rapidly below the boiling point, and then the fires are extinguished. Due to the application of mist upon the gasoline fire, though the fuel temperature decrease abruptly at the time of the injection, such a repid decrease do not continue till the extinction point.

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EXPERIMENTS ON THE INTERACTION OF WATER SPRAYS WITH POOL FIRES

  • Han, Yong-Shik;Kim, Myung-Bae;Shin, Hyun-Dong
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.518-525
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    • 1997
  • A series of measurements and visualization to investigate the interaction of water sprays with pool fires is presented. Fire source is a small-scale pool burner with methanol, ethanol and gasoline. Measurements of temperatures, $O_2$, $CO_2$, and CO concentrations along the plume centerline are carried out to observe pool fire structures without water sprays. Visualization by the Ar-ion laser sheet shows flow pattern of droplets of the sprays above the pool fires. It is observed that in the case of methanol and ethanol, water sprays continuously penetrate into the center of fuel surfaces. The gasoline pool fire allows intermittent penetration of water sprays because of pulsating characteristics of the gasoline flame. To evaluate the cooling effect of the fuel surface by the sprays, the temperature was measured at the fuel surface. As soon as the mists reach the fuel surface of methanol and ethanol, the temperatures of the fuel surface decrease rapidly below the boiling point, and then the fires are extinguished. Due to the application of mist upon the gasoline fire, though the fuel temperature decrease abruptly at the time of the injection, such a rapid decrease do not continue till the extinction point.

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디젤 엔진 운전 조건에서 분무 연소 과정과 난류 화염 구조 특성에 대한 해석 (Characteristization of Spray Combustion and Turbulent Flame Structures in a Typical Diesel Engine Condition)

  • 이영재;허강열
    • 한국연소학회지
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    • 제14권3호
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    • pp.29-36
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    • 2009
  • Simulation is performed to analyze the characteristics of turbulent spray combustion in a diesel engine condition. An extended Conditional Moment Closure (CMC) model is employed to resolve coupling between chemistry and turbulence. Relevant time and length scales and dimensionless numbers are estimated at the tip and the mid spray region during spray development and combustion. The liquid volume fractions are small enough to support validity of droplets assumed as point sources in two-phase flow. The mean scalar dissipation rates (SDR) are lower than the extinction limit to show flame stability throughout the combustion period. The Kolmogorov scales remain relatively constant, while the integral scales increase with decay of turbulence. The chemical time scale decreases abruptly to a small value as ignition occurs with subsequent heat release. The Da and Ka show opposite trends due to variation in the chemical time scale. More work is in progress to identify the spray combustion regimes.

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러프 셋 이론을 사용한 HVDC 시스템을 위한 적응 Granule 제어 (Adaptive Granule Control with the Aid of Rough Set Theory for a HVDC system)

  • 왕중선;양정제;안태천
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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    • pp.144-147
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    • 2006
  • A proportional intergral (PI) control strategy is commonly used for constant current and extinction angle control in a HVDC (High Voltage Direct Current) system. A PI control strategy is based on a stactic design where the gains of a PI controller are fixed. Since the response of a HVDC plant dynamically changes with variations in the operation point a PI controller performance is far from optimum. The contribution of this paper is the presentation of the design of a rough set based, fuzzy adaptive control scheme. Experimental results that compare the performance of the adaptive control and PI control schemes are also given.

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A CATALOG OF AGB STARS IN IRAS PSC

  • Suh, Kyung-Won;Kwon, Young-Joo
    • 천문학회지
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    • 제42권4호
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    • pp.81-91
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    • 2009
  • We make a new catalog of AGB stars in our Galaxy from the sources listed in the Infrared Astronomical Satellite (IRAS) point source catalog (PSC) compiling the lists of previous works with verifying processes. We verify the class identification of AGB stars into oxygen-rich and carbon-rich stars using the information from recent investigations. For the large sample of AGB stars, we present infrared two-color diagrams from the observations at near infrared bands and IRAS PSC. On the two-color diagrams, we plot the tracks of theoretical radiative transfer model results with increasing dust shell optical depths. Comparing the observations with the theoretical tracks, we discuss the meaning of the infrared two-color diagrams.

Flexure hinge mechanism having amplified rectilinear motion for confocal scanning microscopy using optical section

  • Kwon, Oh-Kyu;Park, Poo-Gyeon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.162.6-162
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    • 2001
  • Confocal scanning microscopy (CSM) is an important instrument in a wide variety of imaging applications because of its ability to provide three-dimensional images of thick, volume specimens. The mechanism for two-dimensional beam scanning and optical sectioning has an important roe in CSM as the three-dimensional profiler. This optical sectioning property arises from the use of a point detector, which serves to attenuate the signals from out-of-focus. The intensity profile for the open loop scanning should be matched with its response for the standard. The non-linearity can be minimized with the optical sectioning or the optical probe of the closed loop control. This paper shows the mathematical expression of the light such as the extinction curve in the optical fields of system using AO deflector, the axial/lateral response experimentally when the error sources change, and the methods of optical sectioning. Thorough design of optical sectioner is crucial to the success of CSM in the field ...

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디지털 이미지 법을 이용한 가솔린 분무의 유동 특성에 관한 연구 (A Study on the Flow Characteristics of Gasoline Spray using Digital Image Processing)

  • 이창식;이기형;전문수;김영호
    • 한국자동차공학회논문집
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    • 제6권4호
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    • pp.219-227
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    • 1998
  • This paper describes the fuel spray characteristics of gasoline port injectors such as the breakup procedures of liquid fuel, breakup and extinction behaviors of fuel spray at nozzle tip, time history of SMD and velocity distribution of fuel spray in the direction of fuel stream. Pintle-type gasoline fuel injector was used to analyze mentioned spray characteristics. In order to visualize the fuel spray behaviors and to measure the droplet mean diameter and velocities of spray droplets, the Schlieren method, digital image processing and auto-correlation PIV were applied in this study. In addition, the spray characteristics according to the variation of time were considered. The results of fuel spray show that the liquid sheet breakup starts at 10mm downstream actively. The flying time is approximately 4msec between 50mm and 80mm down the nozzle tip. Also, SMD of fuel spray, the number of droplets and fuel velocity distribution at each point of downstream are discussed.

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