• Title/Summary/Keyword: Variations

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SL/SST variations and their correlations in the North East Asian Sens by remote sensing (Topex/Poseidon, NOAA)

  • Yoon, Hong-Joo
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.04a
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    • pp.297-299
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    • 2003
  • Altimeter(Topex/Poseidon) and AVHRR(NOAA) data were used to study the variations and correlations of Sea Level(SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate as the border of the East Sea(Japan Sea). SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

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Investigation of Cyclic Variations of IMEP Under Idling Operation in Spark Ignition Engines

  • Han, Sung-Bin
    • Journal of Mechanical Science and Technology
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    • v.15 no.1
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    • pp.81-87
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    • 2001
  • Cyclic variability limits the range of operating conditions of spark ignition engines, especially under lean and highly diluted operation conditions. The cyclic combustion variations can be characterized by pressure parameters, combustion related parameters, and flame-front related parameters. The coefficient of variation (COV) in indicated mean effective pressure (IMEP) defines the cyclic variability in indicated work per cycle.

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DCF Formulae for the Case of Simultaneous Random Variations of the Rates of Inflation and Return (할인율과 인플레율이 동시에 확율분포를 취할 경우의 DCF공식)

  • 최진영;정동길
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.6 no.9
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    • pp.27-33
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    • 1983
  • This Paper represents time-dependent stochastic variations of common discounted cash flow formulae with explicit consideration given to inflation. The cash flow, the ratio of discounting or compounding, and the rate of inflation are allowed to vary with time in a random fashion in equations for the compound amount of a single payment, present worth of a single payment, amount of an annuity, periodic deposits to accumulate a future amounts, present worth of an annuity and capital recovery And all formulae are derived for the case of discrete random variations.

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A Quantitative analysis about Wheel Load Variations (실 주행열차의 윤중변동에 대한 정량적 분석)

  • Kim Hyun-Min;Oh Ji-Tack
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.728-732
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    • 2004
  • The purpose of this study is to examine wheel load variations on the bridge. It had been reported that wheel load variations involved un-sprung mass, sprung mass and train running speed, but there are no examples that measured in the running speed actuality track. In this experiment, Attach measurement sensor to equal distance on the track and measured wheel loads by using a dynamic shear strain technique.

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SL/SST variations and their Correlations in the North East Asian Seas by Remote Sensing

  • Yoon, Hong-Joo
    • Journal of information and communication convergence engineering
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    • v.1 no.1
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    • pp.58-60
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    • 2003
  • Altimeter(Topex/Poseidon) and AVHRR(NOAA) data were used to study the variations and correlations of Sea Level(SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate. SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

Web based ARC welding monitoring system (웹기반 아크용접 모니터링 감시 기술)

  • Kim T.J.;JE J.H.;Park S.U.;Kim C.U.
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.1278-1280
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    • 2004
  • In this paper, we propose a new diagnosis method of DC/DC converter aging. The method is based on the variations of parasitic resistor for the aging process. We apply an on-line diagnosis of DC/DC converter because the observation is not a device, but a system. This study proposes a method of DC/DC converter diagnosis by analyzing the variations of model on the variations of parasitic resistor.

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An Adaptive Fuzzy Based Control applied to a Permanent Magnet Synchronous Motor under Parameter and Load Variations (ICCAS 2004)

  • Kwon, Chung-Jin;Kim, Sung-Joong;Won, Kyoung-Min
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1168-1172
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    • 2004
  • This paper presents a speed controller based on an adaptive fuzzy algorithm for high performance permanent magnet synchronous motor (PMSM) drives under parameter and load variations. In many speed tracking control systems PI controller has been used due to its simple structure and easy of design. PI controller, however, suffers from the electrical machine parameter variations and disturbances. In order to improve the tracking control performance under load variations, the PI controller parameters are modified during operation by adaptive fuzzy method. This method based on optimal fuzzy logic system has simple structure and computational simplicity. It needs only sample data which is obtained by optimal controller off-line. As the sample data implemented in the adaptive fuzzy system can be modified or extended, a flexible control system can be obtained. Simulation results show the usefulness of the proposed controller.

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Kinematic Tolerance Synthesis Using Generalized Configuration Spaces (컨피규레이션 공간을 이용한 기구학적 공차 설계)

  • Kyung M.-H.
    • Korean Journal of Computational Design and Engineering
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    • v.10 no.4
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    • pp.284-292
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    • 2005
  • This paper presents a new framework of kinematic tolerance synthesis and describes the implemented algorithm for planar mechanical systems comprised of higher kinematic pairs. Input to the synthesis algorithm is a parametric model of the mechanical system with allowed parameter ranges (tolerance ranges). The model is specified as the part profiles consisting of line and arc segments and the motion axes along which each part moves. The algorithm analyzes tolerance in generalized configuration space, called contact zones bounding the worst-case variations, and identifies bad system variations. The bad system variations then are removed out of the parameter ranges by adjusting the nominal parameter values if possible and then shrinking the ranges otherwise. This cycle is repeated until no more bad variations we found. I show the effectiveness of the algorithm by case studies on several mechanisms.

Small Area Variation (소규모 지역간 의료이용의 차이에 관한 문헌고찰)

  • 조우현;김한중
    • Health Policy and Management
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    • v.1 no.1
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    • pp.42-53
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    • 1991
  • Analysis of health care utilization is very important for health care policy development. Traditional studies of health care utilization were focused on measuring the level of health care utilization and on analyzing the determinants of health care utilization in the defined areas and populations. But there were some limitations in comparing the health care utilizations rates in traditional studies because so many factors were to be considered. Small area analysis is a method used to demonstrate substantial variations in health care utilization with popualtion-base use rates among similar geographic areas. This review discusses the methods, magnitude and trend of geographic variations, factors influencing small area variations, and makes suggestions for further study. Finally, the article discusses the necessity and feasibility of small area analysis in Korea.

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One-Dimensional Model for Simulations of Atmospheric Mixed Layer : Application to Dukyang Bay Area (대기혼합층 모사를 위한 1차원 수치모형 : 득량만에서의 적용)

  • Kim, Yoo-Keun;Moon, Sung-Euii;Ahn, Joong-Bae
    • Journal of Environmental Science International
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    • v.6 no.5
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    • pp.425-435
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    • 1997
  • One-dimensional thermodynamic mixed layer model to stimulate variations of meteorological variables wish the planetary boundary layer has been developed In this study. This model consists of 2 prognostic equations, which can predict the variations of potential temperature and mixing ratio and several diagnostic equations. Physics within the surface and mixed layers has been considered seperately in the model. For the variations of the model, Its result has been analysed and compared with observated data over Ole Dukyang Bay for one day, July 23, 1992. The simulated height of mixed layer is comparable to the observation and the variations of temperature and mixing ratio in the mixed layer are also reasonably simulated. Those Imply that the model responds appropriately with given boundary conditions In sprite of Its simplilfied assumptions applied to the model and insufficient boundary and Initial conditions.

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