• Title/Summary/Keyword: reflection group

검색결과 339건 처리시간 0.026초

$Z_2$-VECTOR BUNDLES OVER $S^1$

  • Kim, Sung-Sook
    • 대한수학회논문집
    • /
    • 제9권4호
    • /
    • pp.927-931
    • /
    • 1994
  • Let G be a cyclic group of order 2 and let $S^1$ denote the unit circle in $R^2$ with the standard metric. We consider smooth G-vector bundles over $S^1$ when G acts on $S^1$ by reflection. Then the fixed point set of G on $S^1$ is two points ${z_0, z_1}$. Let $E$\mid$_{z_0} and E$\mid$_{z_1}$ be the fiber G-representation spaces at $z_0$ and $z_1$ respectively. We associate an orthogonal G-representation $\rho_i : G \to O(n)$ to $E$\mid$_{z_i}, i = 0, 1$. Let det $p\rho_i(g), g \neq 1$, be denoted by det $E$\mid$_{z_i}$ since det $\rho_i(g)$ is independent of choice of $\rho_i$.

  • PDF

사람과 사회 중심의 기본의학 학습성과 (Human and Society-Centered Learning Outcomes in Basic Medical Education)

  • 김대현
    • 의학교육논단
    • /
    • 제18권3호
    • /
    • pp.150-155
    • /
    • 2016
  • Learning objectives for human and society-centered basic medical education to improve physicians' ability to practice in a Korean context were developed by the Korean Association of Medical Colleges in 2015-2016. The task-force committee identified eight domains for medical practitioners: human illness, reflection and self-improvement, patient safety, communication and collaboration, medical ethics, legal issues, social accountability, and professionalism. A total of 172 enabling learning outcomes and 42 terminal learning outcomes were identified by the workshop. The workshop members were representatives from 41 medical schools, the Korean Medical Association, and a scientific group (medical ethics, legal issues, and medical communication). The curriculum for "medical humanity and social medicine" was first published in 2007. The human and society-centered learning objectives that were developed will be revised annually.

Perspectives on THz Time Domain Spectroscopy

  • Cheville, R.Alan
    • Journal of the Optical Society of Korea
    • /
    • 제8권1호
    • /
    • pp.34-52
    • /
    • 2004
  • Over the past decade the experimental technique of THz time domain spectroscopy (㎔- TDS) has proved to be a versatile method for investigating a wide range of phenomena in the ㎔ or far infrared spectral region from 100 ㎓ to 5 ㎔. This paper reviews some recent results of the Ultrafast ㎔ Research Group at Oklahoma State University using ㎔-TDS as a characterization tool. The experimental technique is described along with recent results on ㎔ beam propagation and how ㎔ beam profiles arise from propagation of pulse fronts along caustics. To illustrate how spatio-temporal electric field measurements can determine material properties over a wide spectral range, propagation of ㎔ pulses through systems exhibiting frustrated total internal reflection (FTIR) are reviewed. Finally two potential metrology applications of ㎔-TDS are discussed, thin film characterization and non-destructive evaluation of ceramics. Although ㎔-TDS has been confined to the research laboratory, the focus on application may stimulate the adoption of ㎔- TDS for industrial or metrology applications.

다중채널 탄성파 탐사자료의 전산처리(I) - 해양반사파 자료처리 - (Digital Processing for Multichannel Seismic Data(I) -Marine Reflection Data Processing-)

  • 김기영;홍종국;주형태
    • 지질공학
    • /
    • 제1권1호
    • /
    • pp.85-108
    • /
    • 1991
  • 해양 탄성파탐사 자료처리는 자료의 양이 많고, 처리과정이 여러 개의 전문적인 단계로 이루어져 있으며, 각 단계별로 많은 처리변수를 결정해야 하는 특성이 있다. 따라서 전체 자료를 대표할 만한 표본 자료를 대상으로 주요 처리변수를 결정하게 되고, 그 결과를 전체 자료에 적용시키는 것이 일반적이다. 본 연구에서는 국내 대륙붕 지역에 적합한 처리단계 및 단계별 최적 처리변수들을 결정하기 위하여 실제자료를 대상으로 시험처리를 실시하였다. 이 시험처리에서 구한 처리순서 및 처리변수들을 사용하여 양호한 탄성파 구조보정단면도를 작성하였다.

  • PDF

습식 표면개질 처리된 폴리이미드 필름 표면의 특성에 관한 연구 (A Study on Characteristics of Surface Modified Polyimide Film by Wet Process)

  • 구석본;이홍기
    • 한국표면공학회지
    • /
    • 제39권4호
    • /
    • pp.166-172
    • /
    • 2006
  • Metallized Polyimide films are extensively used as base materials in microelectronics, optical and automotive applications. However it is difficult to deposit metals on those because of their structural stabilities. In this work, polyimide films are modified by a wet process with alkalinemetalhydroxide and additives to introduce functional groups. The surface molecular structures of polyimide are investigated using X-ray photoelectron spectroscopy(XPS), fourier transform infrared reflection spectroscopy(FTIR-ATR), atomic force micro-scopic(AFM). XPS spectra and FTIR spectra show that the surface structure of polyimide is converted into potassium polyamate. AFM image and AFM cross-sectional analyses reveal the increased roughness on the modified surface of polyimide films. As a result, it is shown that the adhesion strength between polyimide surface and electroless nickel layer is increased by the nano-anchoring effect.

DETECTION OF FILLED RICE PADDY FIELDS IN SOUTHEAST ASIA

  • ISHITSUKA, Naoki;OHNO, Hiroyuki;SAKAMOTO, Toshihiro;OGAWA, Shigeo;SAITO, Genya;Magsud, Mehdiyev;Ugsang, Donald M.;YOKOYAMA, Ryuzo
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
    • /
    • pp.757-759
    • /
    • 2003
  • Understanding the area of the rice paddy fields is important, and suitable for it the remote sensing. SAR is effective to the monitor in Southeast Asia with the rainy season. The detection of the filled rice paddy fields by RADARSAT was tried in the north part of Bangkok Thailand, and in the Mekong river valley Cambodia, which ware the main rice production country in Southeast Asia. We get observation data by RADARSAT and fields all through a year around Bangkok. However, because the flood had occurred on the study area in 2002 observed, the detection only of the rice fields ware difficult.

  • PDF

Damage detection on two-dimensional structure based on active Lamb waves

  • Peng, Ge;Yuan, Shen Fang;Xu, Xin
    • Smart Structures and Systems
    • /
    • 제2권2호
    • /
    • pp.171-188
    • /
    • 2006
  • This paper deals with damage detection using active Lamb waves. The wavelet transform and empirical mode decomposition methods are discussed for measuring the Lamb wave's arrival time of the group velocity. An experimental system to diagnose the damage in the composite plate is developed. A method to optimize this system is also given for practical applications of active Lamb waves, which involve optimal arrangement of the piezoelectric elements to produce single mode Lamb waves. In the paper, the single mode Lamb wave means that there exists no overlapping among different Lamb wave modes and the original Lamb wave signal with the boundary reflection signals. Based on this optimized PZT arrangement method, five damage localizations on different plates are completed and the results using wavelet transform and empirical mode decomposition methods are compared.

백색광 간섭계를 이용한 광학소자의 군지연분산 측정 (Measurement of the group-delay dispersion of optical elements using white-light interferometry)

  • Tayyab Imran;Hong, Kyung-Han;Yu, Tae-Jun;Nam, Chang-Hee
    • 한국광학회:학술대회논문집
    • /
    • 한국광학회 2003년도 하계학술발표회
    • /
    • pp.248-249
    • /
    • 2003
  • The characterization of laser mirrors is important for obtaining proper performance of femtosecond lasers. Characteristics of laser mirrors are usually described in terms of their reflectivity at a certain wavelength. In femtosecond laser applications, however, the dispersion property of the mirror should be considered because the temporal shape of a femtosecond light pulse changes during the reflection at the mirrors. (omitted)

  • PDF

COMBINATORIAL AUSLANDER-REITEN QUIVERS AND REDUCED EXPRESSIONS

  • Oh, Se-jin;Suh, Uhi Rinn
    • 대한수학회지
    • /
    • 제56권2호
    • /
    • pp.353-385
    • /
    • 2019
  • In this paper, we introduce the notion of combinatorial Auslander-Reiten (AR) quivers for commutation classes [${\tilde{w}}]$ of w in a finite Weyl group. This combinatorial object is the Hasse diagram of the convex partial order ${\prec}_{[{\tilde{w}}]}$ on the subset ${\Phi}(w)$ of positive roots. By analyzing properties of the combinatorial AR-quivers with labelings and reflection functors, we can apply their properties to the representation theory of KLR algebras and dual PBW-basis associated to any commutation class [${\tilde{w}}_0$] of the longest element $w_0$ of any finite type.

Modulation of chromatic reversibility of polydiacetylene Langmuir Schafer (LS) films by cadmium ion Ad/desorption

  • Lee, Gil Sun;Kim, Tae Young;Ahn, Dong June
    • Journal of Industrial and Engineering Chemistry
    • /
    • 제67권
    • /
    • pp.312-315
    • /
    • 2018
  • Although the reversibility of 10,12-pentacosadiynoic amino meta-acid(PCDA-mBzA) against temperature and pH was reported, the modulation of reversibility by ion adsorption at terminal functional group has not been investigated. In this work, we developed a simple method for modulating the reversibility of PCDA-mBzA films upon a thermal stimulus by cadmium ion adsorption inducing the breakage of the outer hydrogen bonding of two hydrogen bonds, which are responsible for the reversible properties of PCDA-mBzA. External reflection-Fourier transform infrared (ER-FTIR) analyses revealed that the hydrogen bonding between the carboxylic acid groups was broken through ion adsorption and only a single hydrogen bond between the amide groups remained in the PCDA-mBzA polymer. In addition, PCDA-mBzA films could recover their original property through cadmium ion desorption. These results present that the transition between reversibility and irreversibility can be modulated artificially simply through the adsorption and desorption of metal ions.