• Title/Summary/Keyword: Stable Procedure

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Plant Minimum Stable Load (Pmin) Test for Ilijan CCPP

  • Kim, Si Moon;Yun, Wan No;Jang, Cheol Ho;Park, Se Ik
    • KEPCO Journal on Electric Power and Energy
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    • v.2 no.1
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    • pp.83-88
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    • 2016
  • This paper describes the test results of plant minimum stable load (Pmin) for Ilijan Power Plant. The test was conducted on May 13 through 14, 2015 to investigate the plant operating and equipment condition in accordance with "Ilijan Plant Performance Test Procedure on Plant Minimum Stable Load" [1]. This paper also contains the assessment of the impact of Pmin to plant operating parameters and possible technical operating issues when operating at lower loads and to recommend the safe minimum load operation of Ilijan per block. In addition, this paper describes the performance calculation results of efficiency and heat rate depending on the load level.

An Incompressible Flow Computation using a Hierarchical Iterative Method (계층적 반복법을 이용한 비압축성 유동계산)

  • Kim Jin Whan;Jeong Chang Ryul
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.216-221
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    • 2004
  • In two dimensional incompressible flaws, a preconditioning technique called Hierarchical Iterative Procedure(HIP) has been implemented on a SUPG finite element formulation. By using the SUPG formulation, one can escape from the LBB constraint and hence achieve an equal order formulation. In this paper, we increased the order of interpolation up to cubic. The conjugate gradient squared(CGS) method is used for the outer iteration, and the HIP for the preconditioning for the incompressible Navier-Stokes equation. The hierarchical elements has been used to achieve a higher order accuracy in fluid flaw analyses, but a proper efficient iterative procedure for higher order finite element formulation has not been available so far. The numerical results by the present HIP for the lid driven cavity flaw showed the present procedure to be stable, very efficient and useful in flaw analyses in conjunction with hierarchical elements.

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An Incompressible Flow Computation by a Hierarchical Iterative Preconditioning (계층적 반복의 예조건화에 의한 비압축성 유동 계산)

  • KIM JIN WHAN;JEONG CHANG-RYUL
    • Journal of Ocean Engineering and Technology
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    • v.17 no.5 s.54
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    • pp.11-18
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    • 2003
  • In two-dimensional incompressible flows, a preconditioning technique called Hierarchical Iterative Procedure (HIP) has been implemented on a SUPG finite element formulation. By using the SUPG formulation, one can escape from the LBB constraint hence, achieving an equal order formulation. In this paper, we increased the order of interpolation up to cubic. The conjugate gradient squared (CGS) method is used for the outer iteration, and the HIP for the preconditioning for the incompressible Navier-Stokes equation. The hierarchical elements have been used to achieve a higher order accuracy in fluid flow analyses, but a proper and efficient iterative procedure for higher order finite element formulation has not been available, thus far. The numerical results by the present HIP for the lid driven cavity flow showed the present procedure to be stable, very efficient, and useful in flow analyses, in conjunction with hierarchical elements.

An Incompressible Flow Computation by a Hierarchical Iterative Preconditioning (계층적 반복의 예조건화에 의한 비압축성 유동 계산)

  • Kim J. W.;Jeong C. R.
    • 한국전산유체공학회:학술대회논문집
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    • 2004.03a
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    • pp.91-98
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    • 2004
  • In two dimensional incompressible flows, a preconditioning technique called Hierarchical Iterative Procedure(HIP) has been implemented on a stabilized finite element formulation. The stabilization has been peformed by a modified residual method proposed by Illinca et. al.[3]. The stabilization which is necessary to escape from the LBB constraint renders an equal order formulation. In this paper, we increased the order of interpolation whithin an element up to cubic. The conjugate gradient squared(CGS) method is used for the outer iteration, and the HIP for the preconditioning for the incompressible Navier-Stokes equation. The hierarchical elements has been used to achieve a higher order accuracy in fluid flow analyses, but a proper efficient iterative procedure for higher order finite element formulation has not been available so far. The numerical results by the present HIP for the lid driven cavity flow showed the present procedure to be stable, very efficient and useful in flow analyses in conjunction with hierarchical elements.

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An Incompressible Flow Computation by a Hierarchical Iterative and a Modified Residual Method (계층적 반복과 수정 잔여치법에 의한 비압축성 유동 계산)

  • Kim J. W.
    • Journal of computational fluids engineering
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    • v.9 no.3
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    • pp.57-65
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    • 2004
  • The incompressible Navier-Stokes equations in two dimensions are stabilized by a modified residual method, and then discretized by hierarchical elements. The stabilization is necessary to escape from the Ladyzhenskaya-Babuska-Brezzi(LBB) constraint and hence to achieve an equal order formulation. To expedite a standard iterative method such as the conjugate gradient squared(CGS) method, a preconditioning technique called the Hierarchical Iterative Procedure(HIP) has been applied. In this paper, we increased the order of interpolation within an element up to cubic. The hierarchical elements have been used to achieve a higher order accuracy in fluid flow analyses, but a proper efficient iterative procedure for higher order finite element formulation has not been available so far The numerical results by the present HIP for the lid driven cavity flow and others showed the present procedure to be stable, very efficient and useful in flow analyses in conjunction with hierarchical elements.

The Development of a Wearable Prototype to Measure Clothing Pressure through Sensor Calibration Procedure

  • Jin, Heejae;Lee, Hyojeong
    • Journal of the Korean Society of Clothing and Textiles
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    • v.46 no.5
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    • pp.827-835
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    • 2022
  • Clothing pressure is considered the essential factor affecting the comfort of clothing, so it is crucial that it is measured precisely. The purpose of this study is to construct a prototype using the Adafruit Flora as the Arduino system, which can be used as a wearable framework for easy, low-cost, and precise clothing pressure measurement. The study also aims to determine how best to conduct the procedure of sensor calibration. To optimize the accuracy of the sensors, the calibration procedure was implemented using mathematical methods that combined polynomial and exponential regression in a hybrid approach. The prototype can easily measure clothing pressure even during active movements, as seen in the detection of stable signals. In addition, since the system was specifically proposed as a wearable patch that can be easily attached and removed as necessary, it can also be used to standardize the value of clothing pressure in each movement.

Reliability of Strain Estimation on Triangular Network and A Case Study; Deformation of Korea due to 2011 Tohoku Earthquake observed by GPS (삼각망에서 변형률산출의 신뢰도와 적용례; GPS로 관측된 2011 토호쿠지진에 의한 한반도 변형)

  • Na, Sung-Ho;Chung, Tae Woong;Choi, Byung-Kyu;Yoo, Sung-Moon
    • Geophysics and Geophysical Exploration
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    • v.16 no.4
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    • pp.284-292
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    • 2013
  • A stable procedure is presented to attain most probable and unbiased estimate of principal strain, rotation, and dilatation for 2-dimensional geodetic data on triangular network. The proper network size should be chosen carefully, because the errors of these estimates of strain tensor and other associated observables grow inversely proportional to the area of station triangle. As a case study, the deformation observables for the GPS-monitored co-seismic displacement in Korea due to the 2011 Tohoku-Oki earthquake were attained accordingly.

Pan/Tilt Camera System using Real-Time ELSAC and Stop/Go Procedure (실시간 ELSAC을 이용한 Stop/Go 방식의 Pan/Tilt 카메라 시스템)

  • Lee, Suk-Ho
    • Journal of Broadcast Engineering
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    • v.17 no.6
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    • pp.1106-1109
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    • 2012
  • The stability of object tracking in non-stationary camera environment, such as intelligent surveillance system using a pan/tilt camera, is less stable compared with stationary camera environment. This is due to the fact that it is difficult to model a background image in non-stationary environment. In this letter, we propose a non-stationay pan/tilt camera surveillance system which uses a stop/go procedure together with a real-time active contour. The proposed system can track the object stable even in an environment where only a few difference frames can be obtained.

Anchoring Cadmium Chalcogenide Quantum Dots (QDs) onto Stable Oxide Semiconductors for QD Sensitized Solar Cells

  • Lee, Hyo-Joong;Kim, Dae-Young;Yoo, Jung-Suk;Bang, Ji-Won;Kim, Sung-Jee;Park, Su-Moon
    • Bulletin of the Korean Chemical Society
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    • v.28 no.6
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    • pp.953-958
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    • 2007
  • Anchoring quantum dots (QDs) onto thermodynamically stable, large band gap oxide semiconductors is a very important strategy to enhance their quantum yields for solar energy conversion in both visible and near-IR regions. We describe a general procedure for anchoring a few chalcogenide QDs onto the titanium oxide layer. To anchor the colloidal QDs onto a mesoporous TiO2 layer, linker molecules containing both carboxylate and thiol functional groups were initially attached to TiO2 layers and subsequently used to capture dispersed QDs with the thiol group. Employing the procedure, we exploited cadmium selenide (CdSe) and cadmium telluride (CdTe) quantum dots (QDs) as inorganic sensitizers for a large band gap TiO2 layer of dye-sensitized solar cells (DSSCs). Their attachment was confirmed by naked eyes, absorption spectra, and photovoltaic effects. A few QD-TiO2 systems thus obtained have been characterized for photoelectrochemical solar energy conversion.

Application Of Probability Filter For Maintenance Of Air Objects

  • Piskunov, Stanislav;Iasechko, Maksym;Yukhno, leksandr;Polstiana, Nadiia;Gnusov, Yurii;Bashynskyi, Kyrylo;Kozyr, Anton
    • International Journal of Computer Science & Network Security
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    • v.21 no.5
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    • pp.31-34
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    • 2021
  • The article considers the possibilities of increasing the accuracy of estimates of the parameters of the trajectory of the target with the provision of a given probability of stable support of the air object, in particular, during its maneuver. The aim of the work is to develop a filtration algorithm that provides a given probability of stable tracking of the air object by determining the regular components of filtration errors, in particular, when maneuvering the air object, and their compensation with appropriate correction of filter parameters and estimates of air object trajectory parameters.