• Title/Summary/Keyword: energy space

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A Geometrical Structural Model of 2:1 Trioctahedral Clay Minerals (2:1 삼팔면체 점토광물의 기하학적 구조모델)

  • 유재영
    • Journal of the Mineralogical Society of Korea
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    • v.4 no.2
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    • pp.90-98
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    • 1991
  • This study introduces a new structural model of 1M 2:1 trioctahedral clay minerals or, more generally, 2:1 trioctahedral phyllosilicates. The structural model requires only the chemical formulae of the clay minerals as an input and uses the regression relation (Radoslovich, 1962) to calculate the a- and b-dimensions of the phyllosilicates with the given chemical formulae. The atomic coordinates of the constituent atoms are geometrically calculated for C2/m space group under the assumption that the interatomic distances are constant. To determine the c-dimension, this study calculates the binding energies of 1M 2:1 trioctahedral phyllosilicates as a function of d(001) and find the minimum energy producing d(001). The structural model generates the cell dimensions, interaxial angles, interatomic distances, octahedral, tetrahedral and interlayer thickness, polyhedron deformation angles and atomic coordinates in the unit cell. The simulated structural parameters of phlogopite and annite are very close to the reported data by Hazen and Burnham (1973), suggesting that the structure simulation using only the chemical formule is successful, and thus, that the structural model of this study overcomes the difficulties in the previous models by other investigators.

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Herschel-PACS Observations of YSOs

  • Lee, Jin-Hui;Lee, Jeong-Eun;DIGIT team, DIGIT team
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.84.1-84.1
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    • 2011
  • We observed several young stellar objects (YSOs) using the Photodetector Array Camera and Spectrometer (PACS) aboard the Herschel Space Observatory. CO, OH, $H_2O$, [O I], and [C II] lines were detected. CO rotational diagrams show two distinct gas components of ~400 K and ~1000 K with a break around 1500 K of the CO excitation energy, indicative of two different heating mechanisms: PDR and outflow shocks. OH and $H_2O$ line fluxes can be fitted with temperatures different from what are derived from the CO rotational diagrams. In order to understand the physical environment of line formation, the sources were modeled with the 3-D radiative transfer code, LIME. We present the results of observations, simple analysis, and modeling of Herschel-PACS spectra of the YSOs.

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AUTOMATIC TUNING OF FUZZY OPTIMAL CONTROL SYSTEM

  • Hoon-Kang;Lee, Hong-Gi-;Kim, Yong-Ho-;Jeon, Hong-Tae
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1195-1198
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    • 1993
  • We investigate a systematic design procedure of automated rule generation of fuzzy logic based controller for uncertain dynamic systems such as an engine dynamic model.“Automated Tuning”means autonomous clustering or collection of such meaningful transitional relations in the state-space. Optimal control strategies are included in the design procedures, such as minimum squared error, minimum time, minimum energy or combined performance criteria. Fuzzy feedback control systems designed by the cell-state transition method have the properties of closed-loop stability, robustness under parameter variabtions, and a certain degree of optimality. Most of all, the main advantage of the proposed approach is that reliability can be potentially increased even if a large grain of uncertainty is involved within the control system under consideration. A numerical example is shown in which we apply our strategic fuzzy controller design to a highly nonlinear model of engine idle speed contr l.

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Control Lyapunov Function Design by Cancelling Input Singularity

  • Yeom, Dong-Hae;Joo, Young-Hoon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.12 no.2
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    • pp.131-136
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    • 2012
  • If one can find a control Lyapunov function (CLF) for a given nonlinear system, the control input stabilizing the system can be easily obtained. To find a CLF, the time derivative of an energy function should be negative definite. This procedure frequently requires a control input which is a rational function or includes an inverse function. The control input is not defined on the specific state-space where the denominator of the rational function is equal to 0 or the inverse function does not exist. In this region with singularities, the trajectory of the control system cannot be generated, which is one of the most important reasons why it is hard to make the origin of a nonlinear system be globally asymptotically stable. In this paper, we propose a smooth control law ensuring the globally asymptotic stability by means of cancelling the singularity in the control input.

Natural Ventilation in High-Rise Building with Double Facades, saving or waste of Energy

  • Lee, Eung-Jik;Pasquay, Till
    • KIEAE Journal
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    • v.2 no.3
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    • pp.39-45
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    • 2002
  • Double facades are built to allow natural ventilation in high rise buildings and buildings with high outside noise level. In high rise Buildings the gains in summer can be reduced by sufficient sun protection devices placed outside the rooms in the ventilated space between the inner and outer facade. To evaluate the energetic performance, three buildings with double facade were monitored for at least one year (Siemens Building in Dortmund/Germany, Victoria Insurance Company in Duesseldorf/Germany and RWE Tower in Essen/Germany). The results document the indoor climate, the boundary conditions for further planning and the possibilities for high rise buildings without or with little cooling facilities.

A study on the analysis of Korean eco-housing in Bang chon village (방촌마을의 생태주거단지 계획 분석에 관한 연구)

  • Choi, Yool
    • KIEAE Journal
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    • v.2 no.1
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    • pp.33-40
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    • 2002
  • The objective of this study is to interpret a typical Korean traditional settlement for searching for planning criteria of ecological friendly housing estates. The interpreting framework is five environmental ecological ideas as the adaptation to the exterior of village, the eco-space in village, the interior of house, the cycling of material and the reasonable energy system, prevention of environment pollution and reduction of wastes. Through the interpretation, it has been found out that Bang chon village has been developed to an environmental ecological rational setting and has the meaningful elements for environmental friendly housing estates. Particularly, the spatial components of Bang-chon are characterized by the concept of multi-function, and diversity, which are worth of being considered as important planning of ecological friendly housing estates.

Development of an Impulse Electromagnetic Wave Generator having Rise time of Pico Second (Pico second 기립시간의 충격 전자기파 발생기의 개발)

  • Kim, Young-Bae;Lee, Hong-Sik;Jung, Sun-Shin
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.12
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    • pp.597-600
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    • 2006
  • When the energy of the nanoseconds high voltage pulse with hundreds picoseconds of the pulse rise time is emitted into the free space via an antenna, an ultra wide band electromagnetic wave is generated. This electromagnetic wave is expected to be used in transmitting vast amount of informations to far distance, high performance radars, post-packaging pasteurization of food, the detection of underground buried objects, searching of underground water veins or caves, the treatment of waste water or polluted gases and so forth. Additionally, this technology can be used in EMI(electromagnetic interference) evaluation of measuring instruments or printed circuit boards.

Study on Wind Power Prediction model based on Spatial Modeling (공간모델링 기반의 풍력발전출력 예측 모델에 관한 연구)

  • Jung, Solyoung;Hur, Jin;Choy, Young-do
    • KEPCO Journal on Electric Power and Energy
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    • v.1 no.1
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    • pp.163-168
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    • 2015
  • In order to integrate high wind generation resources into power grid, it is an essential to predict power outputs of wind generating resources. As wind farm outputs depend on natural wind resources that vary over space and time, spatial modeling based on geographic information such as latitude and longitude is needed to estimate power outputs of wind generation resources. In this paper, we introduce the basic concept of spatial modeling and present the spatial prediction model based on Kriging techniques. The empirical data, wind farm power output in Texas, is considered to verify the proposed prediction model.

Very Short-term Electric Load Forecasting for Real-time Power System Operation

  • Jung, Hyun-Woo;Song, Kyung-Bin;Park, Jeong-Do;Park, Rae-Jun
    • Journal of Electrical Engineering and Technology
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    • v.13 no.4
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    • pp.1419-1424
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    • 2018
  • Very short-term electric load forecasting is essential for real-time power system operation. In this paper, a very short-term electric load forecasting technique applying the Kalman filter algorithm is proposed. In order to apply the Kalman filter algorithm to electric load forecasting, an electrical load forecasting algorithm is defined as an observation model and a state space model in a time domain. In addition, in order to precisely reflect the noise characteristics of the Kalman filter algorithm, the optimal error covariance matrixes Q and R are selected from several experiments. The proposed algorithm is expected to contribute to stable real-time power system operation by providing a precise electric load forecasting result in the next six hours.

A Study on Selection of a Control Slope for Daylight Responsive Dimming Systems (광센서 조광제어시스템의 제어기울기 선정방법에 관한 연구)

  • Joo, Keun-Tak;Choi, An-Seop
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.11a
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    • pp.179-184
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    • 2005
  • The daylight responsive dimming systems, which use daylight and automatically controls the brightness of electric lighting, according to the amount of daylight coming into the indoor, as well as always maintains target illuminance, is an energy saving type system. The control slope that decide the dimming percent for dimming ballast to run this system efficiently should be decided exactly. This research ran performance assessment applying daylight responsive dimming systems to actual space, and supplemented control slope in the sky condition for the elevation of system. Also we revaluated a system by modified control slope and compiled valid propriety and alternative for the elevation system.

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