• Title/Summary/Keyword: A487

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A Recurrent Cellular Schwannoma

  • Kim, Eung Re;Choi, Eun Oh;Lee, Kyung Bun;Kang, Chang Hyun;Kim, Young Tae;Park, In Kyu
    • Journal of Chest Surgery
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    • v.47 no.5
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    • pp.487-490
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    • 2014
  • Cellular schwannoma is an uncommon variant of schwannomas that can occur in a peripheral nerve. Although cellular schwannomas typically do not differ in prognosis from regular schwannomas, they are known to cause local recurrence when not completely resected. Here, we report the case of a patient with cellular schwannoma of the posterior mediastinum, which recurred after 13 years.

A New Lighting System for the Inspection of Check Defect of CRT Panel (CRT 판넬의 첵 불량 검출을 위한 새로운 조명 시스템)

  • 차준혁;권인소;하종은
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.6
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    • pp.487-493
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    • 2004
  • In this Paper, we propose a lighting system for the stable detection of check defects of the CRT panel through the analysis of the lighting interaction between the lighting unit and the CRT panel. The check defect is very difficult to detect reliably because of its high sensitivity according to the direction of incident light. At first, we model the physical shape of check defects using SEM image. And then we apply physics based illumination model to investigate the optical characteristics of the check defect. Finally, we propose a lighting system for the stable detection of check defect. Experimental results show the feasibility of the proposed lighting system for check inspection.

CONTINUITY OF APPROXIMATE POINT SPECTRUM ON THE ALGEBRA B(X)

  • Sanchez-Perales, Salvador;Cruz-Barriguete, Victor A.
    • Communications of the Korean Mathematical Society
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    • v.28 no.3
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    • pp.487-500
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    • 2013
  • In this paper we provide a brief introduction to the continuity of approximate point spectrum on the algebra B(X), using basic properties of Fredholm operators and the SVEP condition. Also, we give an example showing that in general it not holds that if the spectrum is continuous an operator T, then for each ${\lambda}{\in}{\sigma}_{s-F}(T){\setminus}\overline{{\rho}^{\pm}_{s-F}(T)}$ and ${\in}$ > 0, the ball $B({\lambda},{\in})$ contains a component of ${\sigma}_{s-F}(T)$, contrary to what has been announced in [J. B. Conway and B. B. Morrel, Operators that are points of spectral continuity II, Integral Equations Operator Theory 4 (1981), 459-503] page 462.

Numerical calculation of the wind action on buildings using Eurocode 1 atmospheric boundary layer velocity profiles

  • Lopes, M.F.P.;Paixao Conde, J.M.;Gomes, M. Gloria;Ferreira, J.G.
    • Wind and Structures
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    • v.13 no.6
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    • pp.487-498
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    • 2010
  • When designing structures to the wind action, the variation of the mean wind velocity and turbulence parameters with the height above the ground must be taken into account. This paper presents the numerical simulation results of atmospheric boundary layer (ABL) airflows, in a numerical domain with no obstacles and with a cubic building. The results of the flow characterization, obtained with the FLUENT CFD code were performed using the ${\kappa}-{\varepsilon}$ turbulence model with the MMK modification. The mean velocity and turbulence intensity profiles in the inflow boundary were defined in accordance with the Eurocode 1.4, for different conditions of aerodynamic roughness. The maintenance of the velocity and turbulence characteristics along the domain were evaluated in an empty domain for uniform incident flow and the ABL Eurocode velocity profiles. The pressure coefficients on a cubic building were calculated using these inflow conditions.

Shock-Tube Study of the Oxidation of Acetaldehyde at High Temperature

  • Won, Seok Jae;Ryu, Ji Cheol;Bae, Jun Hyeon;Kim, Yun Do;Gang, Jun Gil
    • Bulletin of the Korean Chemical Society
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    • v.21 no.5
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    • pp.487-492
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    • 2000
  • The combustion characteristics of a mixture of acetaldehyde, oxygen and argon behind a reflected shock wave at temperatures ranging from 1320 to 1897 K at 100 torr were studied. The emission from the OH radical at 306.4 nm and the pressure profile behind the reflected shock were measured to monitor ignition delay time. The ignition delay times were computed from a proposed mechanism of 110 elementary reactions involving 34 species. The simulation and sensitivity analysis confirm that the main channel for oxidation of acetaldehyde at high temperature consists of the Rice-herzfeld mechanism, the decomposition and oxidation of HCO, and the reaction of H with $O_2$.

An Analysis on Efficiency for the Environmental Friendly Agricultural Product of Strawberry in GyeongBuk Province (경북지역 친환경딸기 농가의 인증유형에 따른 효율성 분석)

  • Lee, Sang-Ho;Song, Kyung-Hwan
    • Korean Journal of Organic Agriculture
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    • v.21 no.4
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    • pp.487-500
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    • 2013
  • The purpose of this study is to estimate efficiency of environmental-friendly agricultural product by using Data Envelopment Analysis. A proposed method employs a bootstrapping approach to generating efficiency estimates through Monte Carlo simulation resampling process. The technical efficiency, pure technical efficiency, and scale efficiency measure of strawberry by pesticide-free certification is 0.967, 0.995, 0.968 respectively. However those of bias-corrected estimates are 0.918, 0.983, 0.934. We know that the DEA estimator is an upward biased estimator. In technical efficiency, average lower and upper confidence bounds of 0.807 and 0.960. According to these results, the DEA bootstrapping model used here provides bias-corrected and confidence intervals for the point estimates, it is more preferable.

Hydrodynamic Behavior Analysis of Vertical-Cylindrical Liquid-Storge Tanks by Mathematically Analytic Method (수학적 해석 방법에 의한 액체저장탱크의 액동압 거동 해석)

  • Park, Jong-Ryul;O, Taek-Yeol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.3
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    • pp.487-496
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    • 2002
  • Hydrodynamic behavior and response of vertical-cylindrical liquid-storage tank is considered. The equation of the liquid motion is shown by Laplace's differential equation with the fluid velocity potential. The solution of the Laplace's differential equation of the liquid motion is expressed with the modified Bessel functions. Only rigid tank is studied. The equivalent masses and heights for the tank contents are presented for engineering design model.

Systematic Approaches for Blue Light-emitting Polymers by Introducing Various Naphthalene Linkages into Carbazole Containing PPV Derivatives

  • Ahn, Taek
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.5
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    • pp.258-262
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    • 2013
  • Poly(2,3-naphthalenevinylene-alt-N-ethylhexyl-3,6-carbazolevinylene), 2,3-PNCPV, poly(2,6-naphthalene vinylenealt- N-ethylhexyl-3,6-carbazolevinylene), 2,6-PNCPV, and poly(1,4-naphthalenevinylene-alt-N-ethylhexyl-3,6- carbazolevinylene), 1,4-PNCPV were synthesized through the Wittig polycondensation reaction. The conjugation lengths of the polymers were controlled by differently linked naphthalenes in the polymer main chain. The resulting polymers were completely soluble in common organic solvents, and exhibited good thermal stability at up to $400^{\circ}C$. The synthesized polymers showed UV-visible absorbance and photoluminescence (PL) in the ranges of 357-374 nm and 487-538 nm, respectively. The carbazole and 2,3-linked naphthalene containing 2,3-PNCPV showed a blue PL peak at 487 nm. A single-layer light-emitting diode was fabricated with an ITO/polymer/Al configuration. The electroluminescence (EL) emission of 2,3-PNCPV was shown at 483 nm.

ALGEBRAS WITH A NILPOTENT GENERATOR OVER ℤp2

  • Woo, Sung-Sik
    • Bulletin of the Korean Mathematical Society
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    • v.43 no.3
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    • pp.487-497
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    • 2006
  • The purpose of this paper is to describe the structure of the rings $\mathbb{Z}_{p^2}[X]/({\alpha}(X))$ with ${\alpha}(X)$ a monic polynomial and $\={X}^{\kappa}=0$ for some nonnegative integer ${\kappa}$. Especially we will see that any ideal of such rings can be generated by at most two elements of the special form and we will find the 'minimal' set of generators of the ideals. We indicate how to identify the isomorphism types of the ideals as $\mathbb{Z}_{p^2}-modules$ by finding the isomorphism types of the ideals of some particular ring. Also we will find the annihilators of the ideals by finding the most 'economical' way of annihilating the generators of the ideal.

Design of 77-GHz Automotive Radar Frontend Modules (77 GHz 대역 차량용 레이더의 프론트 엔드 모듈 설계)

  • Park, Sangwook;Kwon, Manseok;Kam, Dong Gun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.4
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    • pp.487-490
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    • 2014
  • This paper describes a design of an automotive radar frontend module with taking care of the routing of 77-GHz signals on a printed circuit board including wire-bond and waveguide transitions.