• Title/Summary/Keyword: reflection property

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Wave Run-up and Reflection on Slopes of S-berm Breakwaters Armored with Tetrapods (테트라포드를 이용한 S-berm 경사식 방파제의 처오름과 반사)

  • Ahn, Tae-Jun;Lee, Seung-Hyeob;Cho, Yong-Sik
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.1078-1082
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    • 2005
  • In this study, the run-up height and reflection property on slopes of S-berm and smooth slopes breakwaters are investigated by laboratory experiment. The run-up height analyzed the effect of reflection coefficient, surf similarity parameter. Measured reflection coefficients of smooth slope breakwaters are compared with those of S-berm breakwater with variable widths. In general, measured coefficients of S-berm breakwaters are smaller than those of smooth slope breakwaters.

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A study on invention.intellectual property education content reflection status and needs analysis in secondary vocational education (중등단계 직업교육에서의 발명.지식재산 교육내용 반영 실태 및 요구 분석 연구)

  • Lee, Byung-Wook;Lee, Chan-Joo;Lee, Sang-Hyun
    • 대한공업교육학회지
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    • v.39 no.2
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    • pp.1-18
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    • 2014
  • This study took existing invention intellectual property related textbooks being utilized in secondary vocational education, analyzed the formation status of 'key learning elements' reflection ratio and drew optimum key learning elements formation ratio by invention intellectual property education content required in secondary vocational education in the future. For this, the study task was set up as 'what kind and how much of invention intellectual property key learning elements are in the invention intellectual property textbook education content now and what is the desirable ratio of each key learning elements in the future'. To resolve this task, 3 specialists analyzed the invention intellectual property education content reflection status and optimum reflection ratio by invention intellectual property education content required in the future is suggested by Delphi survey. The results of this study are as following. First, the result of analysis on invention intellectual property key learning elements included in the invention patent recognition books being utilized in secondary vocational education was that the books included all key learning elements; however, some textbooks have the trend of concentrating in D area (problem-solving activities). Second, the result of analysis on the reflection ratio by invention intellectual property education content area in the invention patent recognition books being utilized in secondary vocational education was that there was the trend in most textbooks that they concentrate in intellectual property creation area; while some textbooks deal with intellectual property protection area and intellectual property utilization area. Regarding by achievement type, knowledge area was main in all textbooks. Meanwhile, function area is dealt in invention patent basic, invention and problem-solving and design textbooks. Attitude area is not dealt or is dealt insufficiently in most textbooks. Third, the optimum reflection ratio of invention intellectual property education key learning elements required in secondary vocational education in the future as obtained by specialists' delphi survey was that it is necessary to decrease D (problem-solving activities) 17.7% area, E(invention fusion knowledge) 2.9% area, K(patent application) 6.9% and L(patent information investigation) area 9.6%. Regarding the optimum reflection ratio of invention intellectual property education content, it is suggested that the invention literacy area 3.1%, intellectual property creation area 4.5% and intellectual property protection area 10.6% would be decreased; while intellectual property utilization area 17.7% would be increased. Regarding optimum reflection ratio of achievement type, it is suggested that knowledge area 52% would be decreased; while function area 32.3% and attitude area 19.6% would be increased.

A Study on S-wave Reflection method for the assessment of physical property of dam body (댐체 물성 평가를 위한 S파 반사법에 관한 연구)

  • Kim, Hyoung-Soo;Kim, Jung-Yul;Ha, Ik-Soo;Kim, Yoo-Sung
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.392-399
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    • 2005
  • Shear modulus (or rigidity) of dam material is an important parameter which can be directly associated with the deformation of dam. Seepage or leakage of water can cause the defects or cracks of dam body. The existence of cracks and rigidity of dam body are decisive information for the estimation of dam safety. Rigidity of material is mainly determined from S-wave velocity and the defects of dam body can be detected by seismic reflection survey. Therefore, seismic reflection survey will be a desirable method which can give a solution about dam safety problem. Among various physical properties of dam body, S-wave velocity is the most important information but it is not easy to get the information. In this study, diverse measuring techniques of S-wave reflection survey were attempted to get the information about S-wave velocity of dam body. Ultimately, S-wave velocity could be estimated by the analysis of SH reflection events which can be easily observed in shot gather data obtained from SH measuring technique. Meanwhile, P-wave reflection survey was also performed at the same profile. P-beam radiation technique which can reduce the surface waves and reinforce the P-wave reflection events was applied for giving a help to analyse P-wave velocity. In the end, P-and S-wave velocity, Vs/Vp, Poisson's ratio distribution of the vertical section under the profile could be acquired.

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Design of a lighting system for PCB visual pattern inspection (인쇄회로기판의 패턴 검사용 조명장치 설계)

  • Na, Hyun-Chan;Rho, Byung-Ok;Ryu, Yung-Kee;Cho, Hyung-Suck
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.1
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    • pp.1-11
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    • 1997
  • Austomated visual inspection(AVI) capability has become an important key component in the automated manufacturing system. In such a visual inspection system an intensity(or color) image of a scene is quickly affected by optical property of objects, condition and roughness of surface, lens and filters, image sensor property and lighting system. In particular, the lighting system disign is the most important factor, since it affects overall performance of the visual system. For fast and cheap automated visual inspection system it is important to obtain the good image quality which results from careful attention to the design of the lighting system. In this paper, the lighting subsystem of AVI system is analysed for the inspection of printed circuit board(PCB) patterns. The spectral reflectance of materials, which are composed of PCB, is measured for choosing the light source. The reflection property is theoretically obtained by a reflection model and also obtained by experiments which measure intensity with varying the viewing direction of image sensor and the lighting direction of illuminator. The illumination uniformity of a ring-type illuminator. The lighting system is designed based upon the experimental results and theoretial analysis.

Holographic optical security system using a reflection photopolymer (반사형 포토폴리머를 이용한 홀로그래픽 광 보안 시스템)

  • Sin, Chang-Won;Kim, Nam;Kim, Min-Su;Jeon, Seok-Hui;Kim, Eun-Gyeong
    • Proceedings of the Optical Society of Korea Conference
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    • 2008.02a
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    • pp.199-200
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    • 2008
  • In this paper, we researched optical characteristics of a holographic optical security system using a reflection recording material and optical random phase mask. The system have the property of optical security key with the phase mask. Also, a reflection recording geometry can reduced a size of the reconstruction system because a input beam to reconstruct a holographic image and a diffraction beam are the same side on the material.

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Computation of Section Curves, Reflection Characteristic Lines, and Asymptotic Curves for Visualization (가시화를 위한 단면곡선, 반사성질선, 점근선 생성 기법)

  • 남종호
    • Korean Journal of Computational Design and Engineering
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    • v.8 no.4
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    • pp.262-269
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    • 2003
  • An approach to compute characteristic curves such as section curves, reflection characteristic lines, and asymptotic curves on a surface is introduced. Each problem is formulated as a surface-plane inter-section problem. A single-valued function that represents the characteristics of a problem constructs a property surface on parametric space. Using a contouring algorithm, the property surface is intersected with a horizontal plane. The solution of the intersection yields a series of points which are mapped into object space to become characteristic curves. The approach proposed in this paper eliminates the use of traditional searching methods or non-linear differential equation solvers. Since the contouring algorithm has been known to be very robust and rapid, most of the problems are solved efficiently in realtime for the purpose of visualization. This approach can be extended to any geometric problem, if used with an appropriate formulation.

A study on the color analysis of the pigment by UV-Visible spectroscopy (분광분석기를 이용한 안료의 색상분석에 관한 연구)

  • Jung, Choong-Ho;Kang, Tae-Hee
    • Journal of the Korean Applied Science and Technology
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    • v.27 no.4
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    • pp.515-521
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    • 2010
  • In this research, we were prepared the glazed ceramic samples by the change of the pigment content and investigated to reveal the standardized color. The chemical composition of the pigment was analyzed using a ICP-OES. XRF mapping and UV-Vis spectroscopy were used to evaluate the color property and surface homogeneity. The color development was observed as a result of analyzing the pigment content and change of the color. The pigment content and the spectral reflection showed the relation of the inverse proportion and the standardized color which could be revealed through analysis data.

Measurement of Reflection Coefficient of Sound Absorbent Material with Respect to Angle of Incidence and Its Associated Errors (입사각에 따른 흡음재의 반사 계수 측정 방법론 및 오차에 대한 고찰)

  • 이수열;김상렬;김양한
    • Journal of KSNVE
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    • v.4 no.3
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    • pp.295-305
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    • 1994
  • The reflection coefficient of a material at oblique incidence is measured in a free field. The sound pressure distributions are measured at discrete points on two measurement lines and then decomposed into plane wave components by using spatial Fourier transform. The inciedent and reflected plane wave components are obtained from a set of "decomposition equations" of which uses the plane wave propagation theory. Numerical simulations and experiments have been performed to see the effect of finite size of measurement area. To reduce this effect, a window fuction has been performed to see the effects of finite size of mesurement area. To reduce this effect, a window function has been proposed and its effect on the measurement of sound absorbing material property has been studied as well. The reflection coefficient obtained by this method is compared with those obtained from other methods; 2-microphone method in a duct and an expirical equation of which determines the characteristic impedance .rho.c and propagation constant k of a material from flow resistance information.formation.

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Development of the Program Road lighting Road Surface Property Measuring Apparatus (도로조명용 프로그램과 노면특성 장치의 개발)

  • ;金紀勳
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.13 no.2
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    • pp.133-133
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    • 1999
  • Average illuminance and luminance can be calculated by graphical methods to a certain extent but to calculate for a wide place a suitable software is needed. Softwares suitable for this purpose have been already developed in foreign nations, but the appropriate softwares for domestic use have not been developed. Therefore a program is developed which is executable in Hangul Windows. The softwares LAPRoad, is developed to calculate luminance and illuminance distribution of road surface, as well as average luminance and illuminance, overall uniformity, longitudinal uniformity, threshold increment veilling luminance and glare. And an apparatus that measures road surface reflection properties is developed. Because the road surface reflection properties is very important in luminance calculation, then concrete road surface reflection properties were measured.

Study of space charge of metal/copper(II)-phthalocyanine interface (금속/copper(II)-phthalocyanine interface에서의 space charge 연구)

  • Park, Mie-Hwa;Lim, Eun-Ju;Yoo, Hyun-Jun;Lee, Kie-Jin;Cha, Deok-Joon;Lee, Young-San
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.526-530
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    • 2004
  • We report the space charge and the surface potential of the interface between metal and CuPc according to isotropic property and different metal by measuring the microwave reflection coefficients $S_{11}$ of copper(II)-phthalocyanine(CuPc) thin films by using a near-field microwave microscope(NSMM) in order to understand. CuPc thin films were prepared on gold and aluminium substrates using a thermal evaporation method. Two kinds of CuPc thin films were prepared. One was deposited on preheated substrate at $150^{\circ}C$ and the other was annealed after deposition by using thermal evaporation methods. The microwave reflection coefficients $S_{11}$ of CuPc thin films were changed by the dependence on the heat treatment conditions. By comparing reflection coefficient $S_{11}$ we measured electrical conductivity of CuPc thin films and studied this results with respect to the surface potential and space charge of the interface between metal and CuPc thin films.

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