• Title/Summary/Keyword: State-Space

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On the Analysis of Dynamic Characteristics of Pipe Supporting Hydraulic Snubber in Electric Power Plant with State-space Model and Impulse Testing (상태공간 모델과 임펄스 시험에 의한 발전소 배관지지용 유압완충기의 동특성 해석)

  • Lee, Jae-Cheon;Hwang, Tae-Yeong
    • 연구논문집
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    • s.31
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    • pp.89-99
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    • 2001
  • This paper presents the modeling and analysis of dynamic characteristics of hydraulic snubber in electric power plant. The nonlinear state-space model of 14th order to describe the dynamics of the snubber was established by Simulink. The simulation results show that the hydraulic snubber reacts as like the conventional shock absolvers against the high pulse shock load. The snubber also shows the peculiar characteristics to the small step load, which temporarily lock the control valves up, however maintain same steady-state pressures of all internal chambers in the long run. Two case studies for the analysis of the snubber are addressed. Practical pulse testing method was also proposed to identify the frequency response of the snubber.

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Conceptual Design of a Solid State Telescope for Small scale magNetospheric Ionospheric Plasma Experiments

  • Sohn, Jongdae;Lee, Jaejin;Jo, Gyeongbok;Lee, Jongkil;Hwang, Junga;Park, Jaeheung;Kwak, Young-Sil;Park, Won-Kee;Nam, Uk-Won;Dokgo, Kyunghwan
    • Journal of Astronomy and Space Sciences
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    • v.35 no.3
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    • pp.195-200
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    • 2018
  • The present paper describes the design of a Solid State Telescope (SST) on board the Korea Astronomy and Space Science Institute satellite-1 (KASISat-1) consisting of four [TBD] nanosatellites. The SST will measure these radiation belt electrons from a low-Earth polar orbit satellite to study mechanisms related to the spatial resolution of electron precipitation, such as electron microbursts, and those related to the measurement of energy dispersion with a high temporal resolution in the sub-auroral regions. We performed a simulation to determine the sensor design of the SST using GEometry ANd Tracking 4 (GEANT4) simulations and the Bethe formula. The simulation was performed in the range of 100 ~ 400 keV considering that the electron, which is to be detected in the space environment. The SST is based on a silicon barrier detector and consists of two telescopes mounted on a satellite to observe the electrons moving along the geomagnetic field (pitch angle $0^{\circ}$) and the quasi-trapped electrons (pitch angle $90^{\circ}$) during observations. We determined the telescope design of the SST in view of previous measurements and the geometrical factor in the cylindrical geometry of Sullivan (1971). With a high spectral resolution of 16 channels over the 100 keV ~ 400 keV energy range, together with the pitch angle information, the designed SST will answer questions regarding the occurrence of microbursts and the interaction with energetic particles. The KASISat-1 is expected to be launched in the latter half of 2020.

MEMS space Telescope for the observation of Extreme Lightening (MTEL)

  • Park, Jae-Hyoung;Garipov, Garik;Jeon, Jin-A;Jin, Joo-Young;Jung, Ae-Ra;Kim, Ji-Eun;Kim, Min-Soo;Kim, Yong-Kweon;Klimov, Pavel;Khrenov, Boris;Lee, Chang-Hwan;Lee, Jik;Na, Go-Woon;Nam, Ji-Woo;Nam, Shin-Woon;Park, Il-Heung;Park, Yong-Sun;Suh, Jung-Eun;Yoo, Byong-Wook
    • Bulletin of the Korean Space Science Society
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    • 2009.04a
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    • pp.54.3-55
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    • 2009
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fictive Noise Control of Enclosed Sound Field Using LQR Controller (LQR 제어기를 이용한 밀폐음장의 능동소음제어)

  • 유우열;김우영;황원걸;이유엽
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.1
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    • pp.12-20
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    • 2002
  • To control the noise of an enclosed sound field, we built a state space model using the acoustic modal parameter description. Using the state space model, we can investigate the controllability and observability, and find an appropriate position of control speaker and microphone to control sound field of the enclosed space. We implemented LQR(linear quadratic regulator) controller and reduced order observer to reduce the first acoustic mode. Experiments showed satisfactory results of 4∼10 dB reduction of magnitude of the first acoustic mode, and support the feasibility of the proposed scheme to lightly damped acoustic field.

Colour Linear Array Image Enhancement Method with Constant Colour

  • Ji, Jing;Fang, Suping;Cheng, Zhiqiang
    • Current Optics and Photonics
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    • v.6 no.3
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    • pp.304-312
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    • 2022
  • Digital images of cultural relics captured using line scan cameras present limitations due to uneven intensity and low contrast. To address this issue, this report proposes a colour linear array image enhancement method that can maintain a constant colour. First, the colour linear array image is converted from the red-green-blue (RGB) colour space into the hue-saturation-intensity colour space, and the three components of hue, saturation, and intensity are separated. Subsequently, the hue and saturation components are held constant while the intensity component is processed using the established intensity compensation model to eliminate the uneven intensity of the image. On this basis, the contrast of the intensity component is enhanced using an improved local contrast enhancement method. Finally, the processed image is converted into the RGB colour space. The experimental results indicate that the proposed method can significantly improve the visual effect of colour linear array images. Moreover, the objective quality evaluation parameters are improved compared to those determined using existing methods.

A hierarchical approach to state estimation of time-varying linear systems via block pulse function (블럭펄스함수를 이용한 시스템 상태추정의 계층별접근에 관한 연구)

  • 안두수;안비오;임윤식;이재춘
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.3
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    • pp.399-406
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    • 1996
  • This paper presents a method of hierarchical state estimation of the time-varying linear systems via Block-pulse function(BPF). When we estimate the state of the systems where noise is considered, it is very difficult to obtain the solutions because minimum error variance matrix having a form of matrix nonlinear differential equations is included in the filter gain calculation. Therefore, hierarchical approach is adapted to transpose matrix nonlinear differential equations to a sum of low order state space equation from and Block-pulse functions are used for solving each low order state space equation in the form of simple and recursive algebraic equation. We believe that presented methods are very attractive nd proper for state estimation of time-varying linear systems on account of its simplicity and computational convenience. (author). 13 refs., 10 figs.

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Ultra Fast Flash Observatory to observe the prompt photons from Gamma Ray Bursts

  • Nam, Ji-Woo;Boggs, Steven;Ripov, G.;Grossan, Bruce;Jeon, Jin-A;Jin, Joo-Young;Jung, Ae-Ra;Kim, Ji-Eun;Kim, Min-Soo;Kim, Yong-Kweon;Klimov, P.;Khrenov, B.;Lee, Chang-Hwan;Lee, Jik;Na, Go-Woon;Nam, Shin-Woo;Park, Il-Heung;Park, Jae-Hyoung;Smoot, G.F.;Suh, Jung-Eun;Yoo, Byoung-Wook
    • Bulletin of the Korean Space Science Society
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    • 2009.04a
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    • pp.64.3-64.3
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    • 2009
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ESTIMATION OF THE SINGULAR COEFFICIENT IN THE STEADY STATE DIFFUSION EQUATION

  • Cho, Chung-Ki
    • Journal of applied mathematics & informatics
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    • v.10 no.1_2
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    • pp.309-323
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    • 2002
  • This paper studies the parameter estimation problem for a steady state flow in an inhomogeneous medium. Our approximation scheme could be used when the diffusion coefficient is singular. The function space parameter estimation convergence(FSPEC) is considered and numerical simulations are performed.

ON THE INTERNATIONAL RADIO ASTRONOMY OBSERVATORY ON PLATEAU SUFFA

  • HOJAEV A. S.;SHANIN G. I.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.411-412
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    • 1996
  • We present the update information on the International Radio Astronomy Observatory Suffa project and describe the original design of new 70-m radiotelescope RT-70 for millimeter astronomy as well. Some oreographic, seeing and climatic features of Suffa are also given.

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The Liability for Space Activity of Launching State of Space Object and Improvement of Korea's Space Policy (우주물체 발사국의 우주활동에 대한 책임과 우리나라 우주정책의 개선방향)

  • Lee, Kang-Bin
    • The Korean Journal of Air & Space Law and Policy
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    • v.28 no.2
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    • pp.295-347
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    • 2013
  • Korea launched the science satellite by the first launch vehicle Naro-ho(KSLV-1) at the Naro Space Center located at Oinarodo, Cohenggun Jellanamdo in August, 2009 and October, 2010. However, the first and second launch failed. At last, on January 30, 2013 the third launch of the launch vehicle Naro-ho has successfully launched and the Naro science satellite penetrated into the space orbit. Owing to the succeed of the launch of Naro-ho, Korea joined the space club by the eleventh turn following the United States, Russia, Japan and China. The United Nations adopted the Outer Space Treaty of 1967, the Rescue Agreement of 1968, the Liability Convention of 1972, the Regislation Convention of 1976, and Moon Agreement of 1979. Korea ratified the above space-related treaties except the Moon Agreement. Such space-related treaties regulate the international liability for the space activity by the launching state of the space object. Especially the Outer Space Treaty regulates the principle concerning the state's liability for the space activity. Each State Party to the Treaty that launches or procures the launching of an object into outer space is internationally liable for damage to another State Party or to its natural or judicial persons by such object or its component parts on the earth, in air space or in outer space. Under the Liability Convention, a launching state shall be absolutely liable to pay compensation for damage caused by its space object on the surface of the earth or to aircraft in flight. The major nations of the world made national legislations to observe the above space-related treaties, and to promote the space development, and to regulate the space activity. In Korea, the United States, Russia and Japan, the national space-related legislation regulates the government's liability of the launching state of the space object. The national space-related legislations of the major nations are as follows : the Outer Space Development Promotion Act and Outer Space Damage Compensation Act of Korea, the National Aeronautic and Space Act and Commercial Space Launch Act of the United States, the Law on Space Activity of Russia, and the Law concerning Japan Aerospace Exploration Agency and Space Basic Act of Japan. In order to implement the government's liability of the launching state of space object under space-related treaties and national legislations, and to establish the standing as a strong space nation, Korea shall improve the space-related policy, laws and system as follows : Firstly, the legal system relating to the space development and the space activity shall be maintained. For this matter, the legal arrangement and maintenance shall be made to implement the government's policy and regulation relating to the space development and space activity. Also the legal system shall be maintained in accordance with the elements for consideration when enacting the national legislation relevant to the peaceful exploration and use of outer space adopted by UN COPUOS. Secondly, the liability system for the space damage shall be improved. For this matter, the articles relating to the liability for the damage and the right of claiming compensation for the expense already paid for the damage in case of the joint launch and consigned launch shall be regulated newly. Thirdly, the preservation policy for the space environment shall be established. For this matter, the consideration and preservation policy of the environment in the space development and use shall be established. Also the rule to mitigate the space debris shall be adopted. Fourthly, the international cooperation relating to the space activity shall be promoted. For this matter, the international cooperation obligation of the nation in the exploration and use of outer space shall be observed. Also through the international space-related cooperation, Korea shall secure the capacity of the space development and enter into the space advanced nation.

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