• Title/Summary/Keyword: Distance Function

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CONVEXITY OF DISTANCE FUNCTION BETWEEN GEODESICS

  • Kim, In-Su;Kim, Yong-Il;Lee, Doo-Hann
    • Honam Mathematical Journal
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    • v.30 no.2
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    • pp.335-341
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    • 2008
  • In this paper, we use the convexity of distance function between geodesics in a singular Hadamard space to generalize Hadamard-Cartan theorem for 2-dimensional metric spaces. We also determine a neighborhood of a closed geodesic where no other closed geodesic exists in a complete space of nonpositive curvature.

Multiresponse Optimization in the Presence of the Goal Regions for the Respective Responses: A Method by Minimization of the Sum of Squares of Relative Changes (각 반응의 목표 영역 존재시의 다반응 최적화: 상대변화 제곱합의 최소화에 의한 방법)

  • 홍승만;임성수;이민우
    • Journal of Applied Reliability
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    • v.1 no.2
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    • pp.165-173
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    • 2001
  • The desirability function approach by Derringer and Suich (1980) and the generalized distance approach by Khuri and Conlon (1981) are two major approaches to multiresponse optimization for improvement of quality of a product or process. So far, the desirability function method has been the only tool for multiresponse optimization in the situations where there are the goal regions for the respective responses. For such situations, we propose a multiresponse optimization method based on the generalized distance approach.

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Analysis of Inter-Particle Distance Distribution in a Diamond Sawing Blade

  • Lee, Hyun-Woo;Kim, Yong-Seog
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2003.10a
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    • pp.62-63
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    • 2003
  • The inter-particle distance between diamonds on the segment surface of sawing blade predicted theoretically and measured experimentally followed a Gamma or Weibull function, rather than a normal distribution function. These results suggest that random dispersion of diamond particles in the segment may not be an efficient way of improving cutting efficiency of the blade.

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ANGULAR DIAMETER DISTANCE IN PERTURBED FRIEDMANN SPACETIME: EFFECTS OF GRAVITATIONAL WAVES (건드림된 프리이드만 시공간 속의 각지름 거리: 중력파의 효과)

  • SONG D. J.
    • Publications of The Korean Astronomical Society
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    • v.19 no.1
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    • pp.1-10
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    • 2004
  • On the framework of a linearly perturbed Friedmann-Robertson-Walker spacetime, we derive an expression for the cosmological angular diameter distance affected by scalar and tensor perturbations. Our expression is applicable in linear order to distances in general FRW models. We study the effect of a stocastic gravitaional wave background on the two-point correlation function of the angular diameter distance fluctuations and, on the basis of this we also derive an expression for the power spectrum of the angular diameter distance fluctuations.

OES Analysis for Diamond Film Growth by Vapor Activation Method Using CH3OH/H2O Gas (CH3OH/H2O 가스의 기상활성법을 이용한 다이아몬드 박막성장 과정에서의 OES분석)

  • Lee, Kwon-Jai;Koh, Jae-Gui;Shin, Jae-Soo
    • Korean Journal of Materials Research
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    • v.13 no.1
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    • pp.31-35
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    • 2003
  • The intensity is measured as functions of both distance from filament to substrate and $CH_3$OH/($CH_3$OH+$H_2$O) ratio by OES(Optical Emission Spectroscopy) to investigate the effects of activation species such as $H_{\alpha}$, $H_{\beta}$, H$\Upsilon\;C_3$, CH on diamond film growth.$ H_{\alpha}$ increases as $CH_3$OH composition decreases, while CH increases as $CH_3$OH composition increases. The intensity of $H_{\alpha}$ decreases as the distance increases and that of CH increases as the distance increases. The intensities of other activation species of $H_{\beta}$, H$\Upsilon\;C_3$, do not vary as a function of measured position distance. It varies randomly. It means that various parameters for depositing diamond thin film can be explained by the intensity(density) change of activation species, as a function of the distance of the filament.

Classification of algae in watersheds using elastic shape

  • Tae-Young Heo;Jaehoon Kim;Min Ho Cho
    • Communications for Statistical Applications and Methods
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    • v.31 no.3
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    • pp.309-322
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    • 2024
  • Identifying algae in water is important for managing algal blooms which have great impact on drinking water supply systems. There have been various microscopic approaches developed for algae classification. Many of them are based on the morphological features of algae. However, there have seldom been mathematical frameworks for comparing the shape of algae, represented as a planar continuous curve obtained from an image. In this work, we describe a recent framework for computing shape distance between two different algae based on the elastic metric and a novel functional representation called the square root velocity function (SRVF). We further introduce statistical procedures for multiple shapes of algae including computing the sample mean, the sample covariance, and performing the principal component analysis (PCA). Based on the shape distance, we classify six algal species in watersheds experiencing algal blooms, including three cyanobacteria (Microcystis, Oscillatoria, and Anabaena), two diatoms (Fragilaria and Synedra), and one green algae (Pediastrum). We provide and compare the classification performance of various distance-based and model-based methods. We additionally compare elastic shape distance to non-elastic distance using the nearest neighbor classifiers.

Low Noise Characteristics of the Comformal Sensor Array's Support Structure (곡면배열 센서의 저소음화를 위한 지지구조 설계 구조)

  • Lee, Jong-Kil;Lee, Sang-Won;Seo, Hee-Sun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2010.10a
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    • pp.340-341
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    • 2010
  • Noise reduction is an important factor to design low noise sensor array. In this paper three layers of the de-coupler in the conformal sensor array were used to investigate noise reduction. Conformal sensor array is positioned in the layers and the distance from the layer is 0.25cm~1.5cm. Transfer function in the frequency density function is investigated according to the three different positions. When increasing the embedded distance the flow noise decreased in the region of the kx>10.

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UBVI CCD PHOTOMETRY OF THE OPEN CLUSTER NGC559

  • ANN HONG BAE;LEE SANG HYUN
    • Journal of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.29-34
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    • 2002
  • We have conducted UBVI CCD photometry of an intermediate-age open cluster NGC 559 to investigate the effect of dynamical evolution on the stellar distributions in NGC 559. Our photometry allows better estimates of distance and age of the cluster owing to much deeper photometry (V $\le$ 21) than previous ones. It is found that the luminosity function and mass function as well as the spatial stellar distributions are affected by the dynamical evolution. Mass segregation leads to the central concentration of the high mass stars, which results in the flattened mass function inside the half mass radius.

Real-time obstacle avoidance for redundant manipulator (여유 자유도 로봇의 실시간 충돌 회피)

  • 조웅장;권동수
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1140-1143
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    • 1996
  • A new approach based on artificial potential function is proposed for the obstacle avoidance of redundant manipulators. Unlike the so-called "global" path planning method, which requires expensive computation for the path search before the manipulator starts to move, this new approach, "local" path planning, researches the path in real-time using the local distance information. Previous use of artificial potential function has exhibited local minima in some complex environments. This thesis proposes a potential function that has no local minima even for a cluttered environment. This potential function has been implemented for the collision avoidance of a redundant robot in Simulation. The simulation also employ an algorithm that eliminates collisions with obstacles by calculating the repulsive potential exerted on links, based on the shortest distance to object.

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