• Title/Summary/Keyword: Dimensional change

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The change of pupil size after viewing three dimensional TV (2안식 입체TV 주시전후의 동공면적의 변화)

  • Cho, Am
    • Proceedings of the ESK Conference
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    • 1995.04a
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    • pp.187-198
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    • 1995
  • The physiological change of eyes while viewing 3D TV was investigated. The change of pupil size was used as the measure of evaluation. The results are as follows: (1) The pupil size decreases after viewing 3D images. (2) The indoor illumination has a significant effect on the pupil size in both 2D and 3D cases. (3) Less change of pupil size were observed under the indoor illumination. Thus, if we only focus on the visual load on the eye, for viewing 3D images, it will be better to use indoor illumination.

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Dimensional Change of Acetylated Softwood (아세틸화 침엽수재의 치수변화 특성)

  • Han, Gyu-Seong;Cho, Nam-Seok
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.4
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    • pp.40-46
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    • 1996
  • It is well-known fact that dimensional stability of wood is greatly enhanced by acetylation of wood. This dimensional stability results from bulking of the reacted acetate within the cell wall, which reduces further swelling when the modified woods corne into contact with water or water vapor. The purpose of this research was to determine the water absorption and dimensional stability of the acetylated solid wood in liquid water and in humidity tests. Radiata pine, Siberian larch, and Japanese larch were acetylated. Antiswelling efficiency(ASE) and equilibrium moisture content(EMC) of acetylated wood, at 95% RH and $20^{\circ}C$ after 4weeks, was quite dependent on WPG, but was not dependent on species.

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An Efficient 2-dimensional Addressing Mode for Image Processor (영상처리용 프로세서를 위한 이차원 어드레스 지정 기법)

  • 고윤호;조경석;김성대
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.1105-1108
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    • 1999
  • In this paper, we propose a new addressing mode, which can be used for programmable image processor to perform image- processing algorithms effectively. Conventional addressing modes are suitable for one-dimensional data processing such as voice, but the proposed addressing mode consider two-dimensional characteristics of image data. The proposed instruction for two-dimensional addressing requires two operands to specify a pixel and doesn't require any change of memory architecture. Combining several instructions to load a pixel-data from an external memory to a register, the proposed instruction reduces code size so that satisfy hish performance and low power requirements of image processor. In addition, it uses inherent two-dimensional characteristics of image data and offers user-friendly instruction to assembler programmer.

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A numerical Analysis on Three-Dimensional Inviscid Transonic Cascade Flow (3차원 비점성 천음속 익렬 유동에 관한 수치해석적 연구)

  • 이훈구;유정열
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.2
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    • pp.336-347
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    • 1992
  • The three dimensional inviscid transonic cascade flow was investigated numerically, incorporation a four stage Runge-Kutta integration method proposed by Jameson. Time marching to the steady state was accelerated by using optimum time step and enthalpy damping. In describing the boundary conditions at inlet and outlet, Riemann invariants are considered. By adding a second and a fourth order artificial viscocities, the numerical instability due to the propagation of undamped disturbance or the rapid change of state near the shock has been prevented. The numerical results for are bump cascade, cambered two dimensional turbine cascade and three dimensional stator cascade agreed reasonably well with previous results. It has been known that the accuracy of the solution depended a lot on the modeling of the leading or trailing edge.

Fabrication of Fibrous A12O3-(m-ZrO2)/t-ZrO2 Composites Having 2, 3-Dimensional Array (2,3차원배열을 갖는 섬유상 A12O3-(m-ZrO2)/t-ZrO2 복합재료의 제조)

  • Kim Ki-Hyun;Lee Byong-Taek
    • Korean Journal of Materials Research
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    • v.15 no.9
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    • pp.608-612
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    • 2005
  • Microstructure and mechanical properties of fibrous $A1_2O_3-(m-ZrO_2)/t-ZrO_2$ composite were investigated depending on the dimensional array. By the change of stacking arrangement of fibrous filaments, 2 and 3-dimensional fibrous composites were successfully obtained without bulk defects such as shrinkage cavity and cracks. The maximum mechanical properties were achieved In the 3-dimensional array composite, due to the fine fibrous and dense microstructure control, in which the values of vickers hardness, fracture toughness and bending strength were about 1507 Hv, $7.2MPa{\cdot}m^{1/2}$ and 650 MPa, respectively.

A Study on Dimensional Accuracy in Circular Pocket Machining of SCM415 Steel (SCM415강의 원형포켓 가공시 치수정밀도에 관한 연구)

  • Shin, Mi-Jung;Choi, Chul-Woong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.9
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    • pp.58-63
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    • 2019
  • In this research, we examine the change of dimensional accuracy in the cutting process while changing cutting conditions such as feed rate and spindle rotational speed with chromium molybdenum steel (SCM415) material and TiCN- and TiAlN-coated end mill tools. According to dimensional accuracy measurement, TiCN-coated tool displays the most accurate dimensional tolerance at ${\varnothing}20mm$ at feed rates of 200 mm/min and 250 mm/min at a spindle rotation speed of 4,000 rpm. The largest dimension of the coating tool was able to make the TiAlN-coated tool suitable when comparing the smallest dimension.

Change of electroencephalograph during 3-dimensional image load (입체 TV 영상(3D) 주시시의 유발전위)

  • Cho, Am
    • Journal of the Ergonomics Society of Korea
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    • v.9 no.2
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    • pp.29-35
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    • 1990
  • To investigate and analyze of the human brain-wave changes during 3-dimenslonal image load were expected to take not only an important basic information of 3-dimensional TV usage but also 3-dimensional image design. In this experiment, to analyze the difference of visual analyze handing system for which we present the 2- dimensional image having no parallex and 3-dimensional image by visual evoked potentials(VEP). 2-dimensional image and 3-dimensional image displayed on the screen through video. In the test, the time interval was one sec for presentation of stimulus considering united time of visual information of right eye and left eye during watching the 3-dimensional image also display time interval was 200 mesc for each stimulus image. Results are as follow, (1) N190 appears faster 16msec-20msec in the point of Fz, Cz, Pz, Oz when loaded 3D4 angle than 2D3 angle. (2) About of the P300, 3D4 angle(Otherwise, Oz point was reverse) and in the case of no equipment of liquid crystal shutter, there appeared PEAK near the P250. (3) There were 5% significant difference when the liquid crystal shutter was equiped and didn't, Therefore, this phenomenon show the possibility that Liquid crystal shutter influences on Visual Evoked Potentials.

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