• Title/Summary/Keyword: projections

Search Result 631, Processing Time 0.024 seconds

Injective JW-algebras

  • Jamjoom, Fatmah Backer
    • Kyungpook Mathematical Journal
    • /
    • v.47 no.2
    • /
    • pp.267-276
    • /
    • 2007
  • Injective JW-algebras are defined and are characterized by the existence of projections of norm 1 onto them. The relationship between the injectivity of a JW-algebra and the injectivity of its universal enveloping von Neumann algebra is established. The Jordan analgue of Theorem 3 of [3] is proved, that is, a JC-algebra A is nuclear if and only if its second dual $A^{**}$ is injective.

  • PDF

Construction of 3 Dimensional Object from Orthographic Views (2차원 평면투영도로부터 3차원 물체의 구성)

  • Kim, Eung-Kon
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.27 no.12
    • /
    • pp.1825-1833
    • /
    • 1990
  • This paper proposes an efficient algorithm that constructs 3-dimensional solid object from 3 orthogonal views. This algorithm inputs vertex and edge information of 3 orthogonal views and generates 2 dimensional surfaces, 3 dimensional vertices, edges and surfaces and then compares 2 dimensional projections of 3 dimensional surfaces with surfaces from othorgonal views. This algorithm is useful for CAD system, 3 dimensional scene analysis system and object modeling for real-time animation and has been implemented in C language on IRIS workstation. The effectiveness of this algorithm is shown by examples of aircrafts' models.

  • PDF

A Method of Structure Analysis for Crystals Containing Semi-heavy Atom (準重原子를 포함하는 結晶의 새로운 構造解析法)

  • Kim, Jik-Tae;Shin, Hyun-So;Koo, Chung-Hoe
    • Journal of the Korean Chemical Society
    • /
    • v.16 no.1
    • /
    • pp.13-17
    • /
    • 1972
  • A method is described to obtain the refined atomic coordinates from two dimensional electron density projections containing partially or completely overlapped semiheavy atoms. Benzidine perchlorate and hydrazonium diphosphate were used in this work as examples. The results show that the suggested method gives an excellent guide.

  • PDF

OBLIQUE PROJECTIONS AND SHIFT-INVARIANT SPACES

  • Park, Sang-Don;Kang, Chul
    • Journal of applied mathematics & informatics
    • /
    • v.26 no.5_6
    • /
    • pp.1207-1214
    • /
    • 2008
  • We give an elementary proof of one of the main results in [H.O. Kim, R.Y. Kim, J.K. Lim, The infimum cosine angle between two finitely generated shift-invariant spaces and its applications, Appl. Comput. Har-mon. Anal. 19 (2005) 253-281] concerning the existence of an oblique projection onto a finitely generated shift-invariant space along the orthogonal complement of another finitely generated shift-invariant space under the assumption that the generators generate Riesz bases.

  • PDF

Energy Absorption Mechanism of Glass/Epoxy 3-D braided structure in Low Velocity Impact Test (유리/에폭시 3차원 브레이드 복합재료의 저속 충격 에너지 흡수기구)

  • Joo Ki Ho;Sul In Hwan;Kim Soo Chang;Kang Tae Jin
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2004.10a
    • /
    • pp.167-170
    • /
    • 2004
  • In order to investigate the impact behaviors of 3-D braided glass/epoxy composites, the energy profiles and damage area were compared to the laminates of similar volume fraction and composition. The energy profiles showed different characteristics from each other which indicates they have distict energy absorption mechanisms. The image analysis on the damage projections visualized the crack propagation paths along the fiber direction.

  • PDF

Innovative Technologies for Tactical Combat Aircraft Powerplants (전술전투기용 추진기관의 혁신 기술)

  • Lee, Gi-Yeong;Gang, Su-Jun
    • The Journal of Aerospace Industry
    • /
    • s.45
    • /
    • pp.67-81
    • /
    • 1998
  • With projections into the future advanced Korea fighter development, the trend of tactical combat aircraft powerplants technique development over the past decade is presented. Ti was particularly focused on current innovative powerplants technologies such as lower density stronger materials and turbomachniery aerodynamics. With reviewing the status of aircraft powerplants which are currently underdeveloped next generation combat aircraft, it shows some core techniques that are needed for developing Korean type combat aircraft.

  • PDF

Determination of Two- Dimensional Distribution of Fission Products in the Irradiated Fuel Rod by Image Reconstruction Methods (비파괴적인 영상재구성 방법에 의한 조사 핵연료봉 단면내 핵분열 생성물의 이차원분포 결정)

  • Park, K.J.;Ro, S.G.
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.9 no.2
    • /
    • pp.8-17
    • /
    • 1989
  • Reconstruction of the radial two-dimensional of fission products using projections obtained by nondestructive transversal direction gamma scanning was evaluated, and then compared with the destructive sectional gamma scanning results. Although the nondestructive method has a little drawback compared to the destructive method in the accuracy, the former seemed to be sufficiently applicable.

  • PDF

Design and FEM Analysis of Ultrasonic Linear Motor (초음파 리니어 모터의 설계와 유한요소 해석)

  • 김태열
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 1999.10a
    • /
    • pp.210-215
    • /
    • 1999
  • The standing waves of the fourth bending ode of vibration and the first longitudinal mode of vibration were utilized to construct a ultrasonic linear motor. The geometrical dimensions of the vibrator were determined by Euler-Bernoulli theory. FEM(finite element method) employed to calculate the vibration mode of the metal-piezoceramic composite thin plate vibrator. ANSYS was used to design positions of the projections and calculate displacement of vibrator.

  • PDF

A Mathematical Definition of Cognitive Science

  • Hyun, Woo-Sik
    • Proceedings of the Korean Society for Cognitive Science Conference
    • /
    • 2010.05a
    • /
    • pp.2-7
    • /
    • 2010
  • Formally, we may define cognitive science as the convergent study between symbolic and connectionist approaches at macro and micro levels. Since what we refer to as the human mind is regarded as a mathematical product of the human brain and the computing machine, we can obtain two mathematical dynamical projections: one from the set of human brains to the set of mind, the other from the set of computing machines to the set of mind. Then, we are having a new projection from the classical models to the quantum mind.

  • PDF

ON THE SPECTRAL MAXIMAL SPACES OF A MULTIPLICATION OPERATOR

  • Park, Jae-Chul;Yoo, Jong-Kwang
    • Journal of the Korean Mathematical Society
    • /
    • v.33 no.1
    • /
    • pp.205-216
    • /
    • 1996
  • In [13], Ptak and Vrbova proved that if T is a bounded normal operator T on a complex Hilbert space H, then the ranges of the spectral projections can be represented in the form $$ \varepsilon(F)H = \bigcap_{\lambda\notinF} (T - \lambda I) H for all closed subsets F of C, $$ where $\varepsilon$ denotes the spectral measure associated with T.

  • PDF