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Optical Property and Surface Morphology Control by Randomly Patterned Etching (불규칙 패턴 에칭에 의한 표면 형상 제어와 광학적 특성)

  • Kim, Sung Soo;Lee, Jeong Woo;Jeon, Bup Ju
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.12
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    • pp.800-805
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    • 2017
  • Randomly patterned and wet chemical etching processes were used to treat anti-glare of display cover glasses. The surface and optical properties of grain size and surface morphology controlled by randomly patterned etching and wet chemical solution etching were investigated. The surface morphology and roughness of the etched samples were examined using a spectrophotometer and a portable surface roughness (Ra) measuring instrument, respectively. The gloss caused by reflection from the glass surface was measured at $60^{\circ}$ using a gloss meter. The surface of the sample etched by the doctor-blade process was more uniform than that obtained from a screen pattern etching process at gel state etching process of the first step. The surface roughness obtained from the randomly patterned etching process depended greatly on the mesh size, which in turn affected the grain size and pattern formation. The surface morphology and gloss obtained by the etching process in the second step depended primarily on the mesh size of the gel state etching process of the first step. In our experimental range, the gloss increased on decreasing the grain size at a lower mesh size for the first step process and for longer reaction times for the second step process.

Experimental behavior assessment of short, randomly-oriented glass-fiber composite pipes

  • Salar Rasti;Hossein Showkati;Borhan Madroumi Aghbashi;Soheil Nejati Ozani;Tadeh Zirakian
    • Steel and Composite Structures
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    • v.47 no.6
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    • pp.679-691
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    • 2023
  • The application of short, fiber-reinforced polymer composite pipes has been increasing rapidly. A comprehensive review of the prior research reveals that the majority of the previously-reported studies have been conducted on the filament-wound composite pipes, and fewer studies have been reported on the mechanical behavior of short, randomly-oriented fiber composite pipes. On this basis, the main objective of this research endeavor is to investigate the mechanical behavior and failure modes of short, randomly-oriented glass-fiber composite pipes under three-point bending tests. To this end, an experimental study is performed in order to explore the load-bearing capacity, failure mechanism, and deformation performance of such pipes. Fourteen properly-instrumented composite pipe specimens with different diameters, thicknesses, lengths, and nominal pressures have been tested and also simulated using the finite element approach for verification purposes. This study demonstrates the effectiveness of the diameter-to-thickness ratio, length-to-diameter ratio, and nominal pressure on the mechanical behavior and deformation performance of short, randomly-oriented glass-fiber composite pipes.

Kernel Ridge Regression with Randomly Right Censored Data

  • Shim, Joo-Yong;Seok, Kyung-Ha
    • Communications for Statistical Applications and Methods
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    • v.15 no.2
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    • pp.205-211
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    • 2008
  • This paper deals with the estimations of kernel ridge regression when the responses are subject to randomly right censoring. The iterative reweighted least squares(IRWLS) procedure is employed to treat censored observations. The hyperparameters of model which affect the performance of the proposed procedure are selected by a generalized cross validation(GCV) function. Experimental results are then presented which indicate the performance of the proposed procedure.

Comparison of the Numerical, Theoretical, and Empirical Scattering Models for Randomly Rough Surfaces

  • Hong Jin-Young;Oh Yisok
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.725-728
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    • 2005
  • The scattering problem of the randomly rough surface is examined by the method of moments(MoM), small perturbation method (SPM), integral equation method (IEM) and the semi-empirical polarimetic model. To apply the numerical technique of the MoM to microwave scattering from a rough surface, at first, many independent randomly rough surfaces with a rms height and a correlation length are generated with Gaussian random deviate. Then, an efficient Monte Carlo simulation technique is applied to estimate the scattering coefficients of the surfaces.

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Generalized Exponential Regression Model with Randomly Censored Data (임의중도절단자료를 갖는 일반화된 지수회귀모형)

  • 하일도
    • Journal of Korea Society of Industrial Information Systems
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    • v.4 no.2
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    • pp.39-43
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    • 1999
  • We consider generalized exponential regression model with randomly censored data and propose a modified Fisher scoring method which estimates the model parameters. For this, the likelihood equations are derived and then the estimating algorithm is developed. We illustrate the proposed method using a real data.

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ON THE WEAK LAW FOR RANDOMLY INDEXED PARTIAL SUMS FOR ARRAYS

  • Hong, Dug-Hun;Sung, Soo-Hak;Andrei I.Volodin
    • Communications of the Korean Mathematical Society
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    • v.16 no.2
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    • pp.291-296
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    • 2001
  • For randomly indexed sums of the form (Equation. See Full-text), where {X(sub)ni, i$\geq$1, n$\geq$1} are random variables, {N(sub)n, n$\geq$1} are suitable conditional expectations and {b(sub)n, n$\geq$1} are positive constants, we establish a general weak law of large numbers. Our result improves that of Hong [3].

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Development of Real-time Simultaneous Discharge Algorithm for Randomly Feeding Object (무작위 이송 개체용 실시간 동시 배출 알고리즘 개발)

  • Kim, S. C.;Hwang, H.
    • Journal of Biosystems Engineering
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    • v.24 no.2
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    • pp.145-152
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    • 1999
  • Methods of discharging each graded agricultural product are divided into two according to the type of feeding. One is based on feeding objects using a series of specially designed holders mounted with an equal interval. The other is randomly feeding objects while being isolated without a specific interval. In this paper, a real time simultaneous discharge algorithm, which is good for objects randomly fed individually and for multi-objects located along a series of discharge buckets, was developed. And the developed algorithm was implemented to the controller and the performance was verified using the system developed for dried mushrooms. The discharge system used for the experiment was composed of a variable speed conveyor, a series of double channel bucket mounted along both sides of the conveyor, and a series of air nozzles and optic sensors. Developed algorithm worked perfectly and could be directly used for automatic discharge system for randomly feeding agricultural products.

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Two-step LS-SVR for censored regression

  • Bae, Jong-Sig;Hwang, Chang-Ha;Shim, Joo-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.2
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    • pp.393-401
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    • 2012
  • This paper deals with the estimations of the least squares support vector regression when the responses are subject to randomly right censoring. The estimation is performed via two steps - the ordinary least squares support vector regression and the least squares support vector regression with censored data. We use the empirical fact that the estimated regression functions subject to randomly right censoring are close to the true regression functions than the observed failure times subject to randomly right censoring. The hyper-parameters of model which affect the performance of the proposed procedure are selected by a generalized cross validation function. Experimental results are then presented which indicate the performance of the proposed procedure.

An effective proposal for strength evaluation of steel plates randomly corroded on both sides under uniaxial compression

  • Khedmati, Mohammad Reza;Nouri, Zorareh Hadj Mohammad Esmaeil;Roshanali, Mohammad Mahdi
    • Steel and Composite Structures
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    • v.11 no.3
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    • pp.183-205
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    • 2011
  • This paper presents the results of an investigation into the post-buckling behaviour and ultimate strength of imperfect corroded steel plates used in ship and other marine-related structures. A series of elastic-plastic large deflection finite element analyses is performed on randomly corroded steel plates. The effects of general corrosion on both sides of the plates are introduced into the finite element models using a random thickness surface model. The effects on plate compressive strength as a result of parametric variation of the corroded surface geometry are evaluated. A proposal on the effective thickness is concluded in order to estimate the ultimate strength and explore the post-buckling behaviour of randomly corroded steel plates under uniaxial compression.