• Title/Summary/Keyword: Variable properties

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Dynamic Properties of Squeeze Type Mount Using MR Fluid (MR유체를 이용한 스퀴즈모드 타입 마운트의 동특성)

  • Ahn, Young-Kong;Yang, Bo-Suk;Ha, Jong-Yong;Kim, Dong-Jo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.349.1-349
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    • 2002
  • This paper presents investigation of damping characteristics of squeeze mode type MR mount experimently. The MR mount proposed in the study has variable damping characteristics according to the applied magnetic field strength. Impact and force excitation tests were performed. The dynamic property of the mount using MR fluid was compared with that of the mount using conventional oil. (omitted)

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Usage of auxiliary variable and neural network in doubly robust estimation

  • Park, Hyeonah;Park, Wonjun
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.3
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    • pp.659-667
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    • 2013
  • If the regression model or the propensity model is correct, the unbiasedness of the estimator using doubly robust imputation can be guaranteed. Using a neural network instead of a logistic regression model for the propensity model, the estimators using doubly robust imputation are approximately unbiased even though both assumed models fail. We also propose a doubly robust estimator of ratio form using population information of an auxiliary variable. We prove some properties of proposed theory by restricted simulations.

A RESEARCH ON A NEW APPROACH TO EULER POLYNOMIALS AND BERNSTEIN POLYNOMIALS WITH VARIABLE [x]q

  • JUNG, NAM SOON;RYOO, CHEON SEOUNG
    • Journal of applied mathematics & informatics
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    • v.35 no.1_2
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    • pp.205-215
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    • 2017
  • In this paper, we consider a modified Euler polynomials ${\tilde{E}}_{n,q}(x)$ with variable $[x]_q$ and investigate some interesting properties of the Euler polynomials. We also give some relationships between the modified Euler polynomials and their Hurwitz zeta function. Finally, we derive some identities associated with Bernstein polynomials.

ROC Curve for Multivariate Random Variables

  • Hong, Chong Sun
    • Communications for Statistical Applications and Methods
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    • v.20 no.3
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    • pp.169-174
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    • 2013
  • The ROC curve is drawn with two conditional cumulative distribution functions (or survival functions) of the univariate random variable. In this work, we consider joint cumulative distribution functions of k random variables, and suggest a ROC curve for multivariate random variables. With regard to the values on the line, which passes through two mean vectors of dichotomous states, a joint cumulative distribution function can be regarded as a function of the univariate variable. After this function is modified to satisfy the properties of the cumulative distribution function, a ROC curve might be derived; moreover, some illustrative examples are demonstrated.

Fatigue Life Predictions for Variable Load Histories - Part II : Computer Software for Predictions of Fatigue Crack Initiation Life - (變動荷重下의 疲勞壽命 豫測 第2報)

  • 이시중;송지호;하재선
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.6
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    • pp.1350-1357
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    • 1988
  • A computer software was developed for predictions of fatigue crack initiation life of notched members under variable loadings. The software was constructed based on a new fatigue life prediction method utilizing modified .epsilon.-N curves, which can account for the stress interaction effect. The effect of mean plastic strain on low-cycle fatigue life was also incorporated in the software. The software can be utilized for the first step approximation when fundamental data of material fatigue properties are not available.

The Time Correlation Function Near (and at) a Stable Steady State, When a Chemical System Relaxes from the Unstable Steady State$^*$

  • Lee, Dong-Jae;Ryu, Moon-Hee;Lee, Jong-Myung
    • Bulletin of the Korean Chemical Society
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    • v.6 no.2
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    • pp.91-95
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    • 1985
  • The dynamic properties near (and at) a stable steady state are discussed, when a chemical system relaxes from the unstable steady state. The time-dependent correlation length for the fluctuating variable near a stable steady state is explicitly obtained by introducing the probability average for the variable satisfying the rate equation. The study is carried out about the effect of nonlinearity on the correlation length near (and at) a stable steady state.

A Study on Performance Analysis of Cryogenic Hydrostatic Journal Bearings : the Effects of Turbulent Flow, Pressure Drop and Variable Liquid Properties (극저온 정압 저널베어링의 성능해석에 관한 연구 : 난류유동, 압력강하, 가변 밀도 및 점도의 영향)

  • 김성기;강지훈;김경웅
    • Tribology and Lubricants
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    • v.19 no.3
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    • pp.139-145
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    • 2003
  • In this paper, static characteristics of a cryogenic hydrostatic journal bearing which has 2-rows staggered recesses are numerically analyzed. The regime of operation of this bearing is fully turbulent with large fluid inertia effects. The turbulent lubrication equation is solved under the assumption that turbulence parameters are decided by the Reynolds numbers. Pressure drop caused by inertia effect at the recess edge is considered in this analysis. Also density and viscosity of working fluid are considered as function of only pressure. Numerical results for a cryogenic Hydrostatic journal bearing show pressure distribution, load capacity, flow rate, and recess pressure. The effects of turbulent flow, pressure drop and variable liquid properties are discussed.

Influence of Drying on the Atterberg Limit and Grain-Size Distribution of the Ulsan Marine Deposited Clay (울산 해성퇴적 점토의 건조에 따른 연경도와 입도분포의 변화)

  • 민덕기;황광모;이신희
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.663-668
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    • 2000
  • In this study, the Atterberg limit and grain-size analysis were carried for the purpose of investigating the influence on drying and organic matter of Ulsan marine deposited clay. The results revealed that Atterberg limit was decreased and grain-size distribution was variable on drying. The presence of organic matter also influenced on the physical properties of the soils. The physical properties of marine deposited clay were variable on drying, so that we recommended grain-size analysis and Atterberg limit test were performed under the wet condition of the soils after sampling.

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SOME PROPERTIES OF GENERALIZED q-POLY-EULER NUMBERS AND POLYNOMIALS WITH VARIABLE a

  • KIM, A HYUN
    • Journal of applied mathematics & informatics
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    • v.38 no.1_2
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    • pp.133-144
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    • 2020
  • In this paper, we discuss generalized q-poly-Euler numbers and polynomials. To do so, we define generalized q-poly-Euler polynomials with variable a and investigate its identities. We also represent generalized q-poly-Euler polynomials E(k)n,q(x; a) using Stirling numbers of the second kind. So we explore the relation between generalized q-poly-Euler polynomials and Stirling numbers of the second kind through it. At the end, we provide symmetric properties related to generalized q-poly-Euler polynomials using alternating power sum.