• Title/Summary/Keyword: Pattern density function

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LGP Pattern Design by Using a Pattern Density Function with Simple Exponential Function (간단한 지수함수를 패턴 밀도 함수로 이용한 LGP 패턴 설계)

  • Kim, Young-Chul;Kim, Dae-Wook;Oh, Tae-Sik;Lee, Yong-Min;Ahn, Seung-Joon;Kim, Ho-Seob
    • Korean Journal of Optics and Photonics
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    • v.21 no.3
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    • pp.97-102
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    • 2010
  • A pattern density function using simulation analysis for controlling LGP output distribution was proposed. The pattern density function was found as [Pexp(-y/70)+Qexp(+y/25)]R. We analyzed the LGP output distribution of a hemi-sphere pattern using the function and then found that its output distribution was clearly improved as compared with that of the equi-distance pattern. We found that the density function works well for the pyramid pattern case as well as.

The description of wigner function and density matrix by computer tomograph (전산 시늉에 의한 위그너 함수와 밀도 행렬이 기술)

  • 강장원;조기현;윤선현
    • Korean Journal of Optics and Photonics
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    • v.11 no.6
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    • pp.441-446
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    • 2000
  • Wigner functions and density matrices are computer simulated for various quantum mechanical states of light. Wigner function and density matrices are evaluated by filtered back projection which includes inverse Radon transform from the distribution function of the photocurrents, which are calculated in the balanced homodyne detection scheme. The density matrix is also directly obtained by using the pattern function from the simulated phase independent photocurrent distribution function. ction.

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Identification of Two-phase Flow Patterns in a Horizontal Tubular Condenser (수평 응축관내 2상유동양식의 판별에 관한 연구)

  • Lee, S.C.;Han, Y.O.;Shin, H.S.;Lee, H.D.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.5 no.1
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    • pp.65-72
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    • 1993
  • An experiment has been carried out to identify flow patterns in a horizontal condensing flow with R-113. Characteristics of flow patterns were determined based upon a statistical analysis of differential pressure fluctuations at an orifice. The probability density function and power spectral density function of instantaneous pressure drop curves for various flow conditions were obtained. In comparison to the results of air-water flows, the flow patterns in a condensing flow such as annular, wavy, slug and plug could be identified. The experimental data determined by this technique were compared with the flow pattern maps suggested by other investigators. The result indicates that the statistical characteristics of differential pressure fluctuations at an orifice may be a useful tool for identifying flow patterns both in condensing flows and in adiabatic two-phase flows.

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A Study on Chemical Mechanical Polishing using Pattern Density based Modeling (패턴 밀도를 고려한 Chemical Mechanical Polishing에 관한 연구)

  • 이재경;문원하;황호정
    • Proceedings of the IEEK Conference
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    • 2002.06b
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    • pp.221-224
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    • 2002
  • Recently, simulation of Chemical Mechanical Polis hing is becoming more important because Process parameters on the material removal rate are complicated. And pattern-depent effects are a key concern in CMP processes. In this paper, we have been studied the changes of pattern density vs. oxide thickness with Stine's simulation model. We also have estimated the effective density using optimal window size with density mask, and have made a study of the change of oxide thickness as a function of polishing time.

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Identification of Two-Phase Flow Patterns Based on Statistical Characteristics of Differential Pressure Fluctuations (차압교란치의 통계적 특성에 의한 2상유동양식의 판별)

  • 이상천;이정표;김중엽
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.5
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    • pp.1290-1299
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    • 1990
  • Characteristics of flow patterns in horizontal gas-liquid two-phase flow for two different sizes of pipe were investigated based upon a statistical analysis of differential pressure fluctuations at an orifice. The probability density function and the power spectral density function of the traces indicate peculiar shapes depending upon the two-phase flow regime. Mixed and separated flows also could be identified by the autocorrelation function. The transition region from separated flow to mixed flow also could be identified by these statistical properties. The experimental data determined by this method were compared with the flow pattern maps suggested by other investigators. The result indicates that the statistical characteristics of differential pressure fluctuations at orifices may be a useful tool for identifying flow patterns of horizontal gas-liquid two-phase flow.

Landscape Preferences for Greenspace Structures (녹지구조에 따른 경관 선호도)

  • Jo, Hyun-Kil;Ahn, Tae-Won
    • Journal of Forest and Environmental Science
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    • v.28 no.1
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    • pp.56-62
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    • 2012
  • There is little information about appropriate greenspace structures to satisfy aesthetic function in Korea. The purpose of this study was to analyze Korean's aesthetic preferences for greenspace structures concerned with urban tree plantings of an areal type to explore desirable greenspace landscapes. The study considered 5 structural variables of greenspace which were species composition, tree density, tree size, vertical and horizontal structure, and tree layout pattern. A photo-questionnaire was prepared through color simulations of different landscape types for each structural variable. Preference responses of an interval-scale rating from 214 respondents were statistically analyzed between landscape types and between respondent groups. Respondents preferred greenspace landscapes with diverse tree species to single species, higher tree density to lower density, larger trees to many smaller trees, multilayered and grouped plantings to single-layered and sparse plantings, and informal pattern to formal pattern. These preferences tended to be relatively higher for educated specialist and student groups than for other generalist group. Thus, multilayered and dense plantings in natural pattern including larger trees of diverse species, which are similar to ecological plantings, are recommended to increase aesthetic function of greenspace.

Image Recognition by Learning Multi-Valued Logic Neural Network

  • Kim, Doo-Ywan;Chung, Hwan-Mook
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.2 no.3
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    • pp.215-220
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    • 2002
  • This paper proposes a method to apply the Backpropagation(BP) algorithm of MVL(Multi-Valued Logic) Neural Network to pattern recognition. It extracts the property of an object density about an original pattern necessary for pattern processing and makes the property of the object density mapped to MVL. In addition, because it team the pattern by using multiple valued logic, it can reduce time f3r pattern and space fer memory to a minimum. There is, however, a demerit that existed MVL cannot adapt the change of circumstance. Through changing input into MVL function, not direct input of an existed Multiple pattern, and making it each variable loam by neural network after calculating each variable into liter function. Error has been reduced and convergence speed has become fast.

Development of a 9as-liquid two-phase flowmeter using double orifice plates (2중판 오리피스를 이용한 기액 2상유량계의 개발)

  • 이상천;이상무;남상철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.5
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    • pp.619-629
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    • 1998
  • An experimental work was conducted to investigate a feasibility of simultaneous measurement of gas-liquid two-phase flowrates with double orifice plates using air and water. The tests were carried out under the atmospheric pressure and at the ambient temperature using two different tube sizes. Qualities of an air-water flow in the present study have values less than 0.1 and thus the mixed flow showed bubbly, plug, slug flow regimes. The probability density function (PDF) and the power spectral density function (PSDF) of the instantaneous pressure drop traces for the flow regimes were obtained. It is found that some distinctive features exist in the distribution of these functions, depending upon the two-phase flow pattern. The time-averaged value of the instantaneous pressure drop increases with increasing gas and liquid flowrates, showing a single-valued function for the total mass flowrate and the quality. It is also found that the two-phase discharge coefficient exhibits a consistent trend for variation of dimensionless parameters such as the superficial velocity ratio and the gas Reynolds number. The results indicate that simultaneous measurement of two-phase flowrate may be possible based upon a statistical analysis of the instantaneous pressure drop curves monitored using double orifice plates.

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Flow pattern characteristics in vertical two phase flow by PDF and signals from conductance probe (確率密度函數와 電導 Prode信號에 의한 垂直二相流의 流動樣式特性)

  • Son, Byung-Jin;Kim, In-Suhk;Lee, Jin
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.6
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    • pp.814-822
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    • 1986
  • Flow patterns and its transitions in vertical two phase flow of air-water isothermal flow are identified objectively by void output signals and moments computed from the Probability Density Function which is associated with the statistical measurement for time average local void fractions using conductance probe. It has been shown that the probe output signals, PDF distributions and its moments are deterministic criteria of flow pattern and transition classification.

Microprocessor Control of a Prosthetic Arm by EMG Pattern Recognition (EMG 패턴인식을 이용한 인공팔의 마이크로프로세서 제어)

  • Hong, Suk-Kyo
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.33 no.10
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    • pp.381-386
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    • 1984
  • This paper deals with the microcomputer realization of EMG pattern recognition system which provides identification of motion commands from the EMG signals for the on-line control of a prosthetic arm. A probabilistic model of pattern is formulated in the feature space of integral absolute value(IAV) to describe the relation between a motion command and the location of corresponding pattern. This model enables the derivation of sample density function of a command in the feature space of IAV. Classification is caried out through the multiclass sequential decision process, where the decision rule and the stopping rule of the process are designed by using the simple mathematical formulas defined as the likelihood probability and the decision measure, respectively. Some floating point algorithms such as addition, multiplication, division, square root and exponential function are developed for calculating the probability density functions and the decision measure. Only six primitive motions and one no motion are incorporated in this paper.

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