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Structural and Physical Properties of Sealant Paste Prepared by Silica/Polymer Composites (실리카/고분자 복합체를 이용한 실란트 페이스트의 구조 및 물리적 특성)

  • Yoon, Jong-Kuk;Park, Jung-Il;Koo, Kyung-Wan;Jang, Young-Sil
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.6
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    • pp.916-921
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    • 2012
  • Sealant paste with silica immersed in cross-linked epoxy-acrylate polymer resin was prepared by thermal and UV curing process. The curing mechanism of polymer resin resulted from 2 functional groups of epoxy and acrylic structure. The properties of microstructure, thermal conductivity and mechanical strength were investigated for its various applications. The adhesion strength is increased by increasing the thermal curing time until 15 minutes, and curing efficiency is saturated over 20 minutes. The increase rate per day of pot life and viscosity is 4.8%, indicating it has excellent storage stability. It is found that the formulation of silica pastes can be applied to heavy industries, building materials, display and various industries.

Globally Optimal Solutions for Cross-Layer Design in Fast-Fading Lossy Delay-Constrained MANETs

  • Pham, Quoc-Viet;Kim, Hoon;Hwang, Won-Joo
    • Journal of Korea Multimedia Society
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    • v.18 no.2
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    • pp.168-177
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    • 2015
  • To increase the overall utility and decrease the link delay and power consumption, a joint optimal cross-layer design of congestion control at the transport layer, link delay at the data link layer and power allocation at the physical layer for mobile ad hoc networks is considered in this paper. As opposed to previous work, the rate outage probability in this work is based on exactly closed-form; therefore, the proposed method can guarantee the globally optimal solutions to the underlying problem. The non-convex formulated problem is transformed into a convex one, which is solved by exploiting the duality technique. Finally, simulation results verify that our proposal achieves considerable benefits over the existing method.

A Study on Design of the Cross Type Ultrasonic Rotary Motor (Cross형 초음파 회전모터의 설계에 관한 연구)

  • Chong, Hyon-Ho;Park, Tae-Gone
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.191-192
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    • 2005
  • In this study, the ultrasonic motor which has hollowed cross type stator was designed, and the elastic body of ultrasonic motor was optimized by using a finite element analysis program(ANSYS 9.0). When the length of leg(L) of the elastic body was increased and the width of piezoceramics was decreased, the resonant frequency was increased and the displacement of contact point between the rotor and the stator was increased. However, when the length of the leg was over the 1/3 point of the width of ceramics, the displacement of the contact point was decreased, because the elastic buckle was generated in the leg.

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The Evolution of Community Nutrition in the U.S.

  • Gillespie, Ardyth M.H.
    • Journal of Community Nutrition
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    • v.5 no.4
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    • pp.195-208
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    • 2003
  • Drawing from journal articles, community nutrition textbooks, government documents, national conference reports, the author's own work in community programming, and discussions with practicing Community Nutritionists, this article illuminates the scope and character of community nutrition in the United States. It traces the roots of community nutrition in home economics, nutrition, education, communication, social and behavioral sciences, and describes the evolution of theory. And finally it suggests issues to be addressed by community nutrition researchers and practitioners through collaborations that integrate perspectives within community nutrition and strategically cross disciplinary boundaries. These include: 1) theory development and application in research and practice within philosophically consistent perspectives; 2) methodological development (qualitative and quantitative) drawing from the social and behavioral sciences that apply to community nutrition; 3) taking a long view of community nutrition and recognizing that change requires integrated efforts over long periods of time; 4) engaging community stakeholders in research as well as program planning and 5) engaging with community nutritionists from other countries for cross-cultural research and conceptualization. This journal and the Korean Society for Community Nutrition, as the only journal and society expressly devoted to community nutrition, would be the best context for such collaborations.

Discharge Characteristics of Surface Discharge AC PDP : Cross-talk and other geometric effect (AC-PDP의 제작결함과 전기적 특성의 상관관계에 관한 연구)

  • Kim, Suk-Ki;Lee, Sung-Hyon;Park, Jung-Tae;Park, Chung-Hoo;Cho, Jung-Soo
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2019-2021
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    • 1999
  • In this paper, the AC-PDP's structural defects with a gap between front and rear glass are investigated. Breakdown voltage, sustain voltage, current and brightness have been measured for various gaps between two plates under various gas pressures. The experimental results show that the firing voltage, sustain voltage and brightness were decreased whereas the discharge current was increased as the gap increased. When the gap is over $40{\mu}m$, it was impossible to drive cells separately.

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Consonantal and Vocalic Effects in Korean Stop Identification

  • Kim, Mi-Ryoung
    • Speech Sciences
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    • v.8 no.1
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    • pp.93-111
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    • 2001
  • This study investigates the contribution of vocalic information following the release of an initial stop to the identification of the three-way stop contrast (aspirated, lax, and tense) in Korean. Recent studies showed that there is a strong interaction between consonant types and tone. The findings raise questions concerning Korean listeners' use of tonal (or vocalic F0) variation in differentiation initial tense, lax, and aspirated stops. The above issues are addressed in the present study using a cross-splicing methodology. The overall results show that low vocalic F0 provided the most salient information for lax stops; tense and aspirated stop identification depended on a combination of VOT, F0, and H1-H2 characteristics. The perceptual dominance of F0 over VOT for lax stops is consistent with the size of the F0 difference in utterance-initial position, as well as their prominent role in Korean intonational phonology.

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Coriolis Coupling Influence on the H+LiH Reaction

  • Zhai, Hongsheng;Li, Wenliang;Liu, Yufang
    • Bulletin of the Korean Chemical Society
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    • v.35 no.1
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    • pp.151-157
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    • 2014
  • We have reported the reaction probability, integral reaction cross section, and rate constant for the title system calculated with the aid of a time-dependent wave packet approach. The ab initio potential energy surface (PES) of Prudente et al. (Chem. Phys. Lett. 2009, 474, 18) is employed for the purpose. The calculations are carried out over the collision energy range of 0.05-1.4 eV for the two reaction channels of H + LiH ${\rightarrow}$ Li + $H_2$ and $H_b$ + $LiH_a$ ${\rightarrow}$ $LiH_b$ + $H_a$. The Coriolis coupling (CC) effect are taken into account. The importance of including the Coriolis coupling quantum scattering calculations are revealed by the comparison between the Coriolis coupling and the centrifugal sudden (CS) approximation calculations.

Drift Velocities and Distribution Function for Electrons $SF_6$-Ar Mixtures Gas ($SF_6$-Ar 혼합기체의 전자이동속도와 전자분포함수)

  • Kim, Sang-Nam
    • Proceedings of the KIEE Conference
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    • 2008.11b
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    • pp.85-88
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    • 2008
  • Drift velocities and Distribution Function for electrons in $SF_6$-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range $30{\sim}300[Td]$ by a two term Boltzmann equation and by a Monte Carlo simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6$-Ar mixtures were measured by time-of-flight method, The results show that the deduced electron drift velocities agree reasonably well with theoretical for a rang of E/N values The results simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

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The analysis on the electron swarm parameter in $SiH_4$+Ar mixtures ($SiH_4$+Ar혼합기체의 전자군 파라미터 해석)

  • Seong, Nak-Jin;Kim, Sang-Nam
    • Proceedings of the KIEE Conference
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    • 2002.06a
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    • pp.106-109
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    • 2002
  • This paper calculates and gives the analysis of electron swarm transport coefficients as described electric conductive characteristics of pure Ar, pure $SiH_4$, Ar + $SiH_4$ mixture gases ($SiH_4$--0.5%, 2.5%, 5%) over the range of E/N =0.01${\sim}$300[Td]. P=0.1, 1, 5.0[Torr] by Monte Carlo the Backward prolongation method of the Boltzmann equation using computer simulation without using expensive equipment. The results have been obtained by using the electron collision cross sections by TOF. PT.SST sampling, compared with the experimental data determined by the other author. It also proved the reliability of the electron collision cross sections and shows the practical values of computer simulation.

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Optical Disk Drive Servo System using Modified Disturbance Observer (수정된 외란관측기를 이용한 광디스크 드라이브 서보 시스템)

  • Jeong, Jong-Il;Chung, Chung-Choo;Pyo, Hyeon-Bong;Park, Yong-Woo
    • Proceedings of the KIEE Conference
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    • 2003.11c
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    • pp.372-375
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    • 2003
  • Using disturbance observer is effective to enhance tracking performance of system in the presence of disturbances. Various types of disturbance observers have been proposed to improve sensitivity of systems, but they tend to bring poor transient response due to cross coupling of inter-loops. In this paper, we propose dual disturbance observer(Dual DOB) which is designed to reduce the cross coupling. Dual DOB is consist of an internal DOB and an external DOB, that are designed for different object. The Dual DOB is applied to Optical Disk Drive tracking system. It is shown that the Dual DOB has improved performance over conventional DOB via experimental result. There is good agreement between simulation and experimental results.

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