• Title/Summary/Keyword: reflection journal

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Evaluation of the characteristics of the reflection plate to measure defects in the invisible area using infrared thermography

  • Kim, Sang Chae;Park, Il Cheol;Kang, Chan Geun;Jung, Hyunchul;Chung, Woon Kwan;Kim, Kyeong Suk
    • Nuclear Engineering and Technology
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    • v.52 no.4
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    • pp.856-862
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    • 2020
  • Defect inspection system for industrial applications takes the important portion. Non-destructive inspection method has been significantly improved. Infrared thermography, as one of method for non-destructive inspection, can provide relatively precise data and quick inspection time. This study, it was performed to measure defect according to the measurement limit of the non-visible areas such as the back surface of the pipe using reflection plate using reflection plate based on Infrared thermography. The materials of the reflection plate were determined in consideration of the space limitation and the thermal characteristics, and defects were detected by the manufactured reflection plate. Detection of defect in non-visible area using the candidate materials for reflection plate was conducted.

Identification of Reflection Coefficients for Overground Pipes Using Finite Element Method (유한요소법을 이용한 지상 파이프 반사계수 규명)

  • Kim, Y.W.;Park, K.J.;Kang, W.S.
    • Journal of Power System Engineering
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    • v.15 no.3
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    • pp.18-24
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    • 2011
  • In this study, the reflection of the L(0,2), axially symmetric guided elastic wave from defects in pipes above ground is examined using finite element method. Phase and group velocity dispersion curves for the pipe were presented for the selection of the excitation mode. Some simple signal processing was applied to determine the amplitude of each of the reflected waves and to calculate the reflection coefficient. The results show the reflection coefficient of this mode is very close to a linear function of the circumferential extent of the defect. The motivation for the work was the development of a technique for inspecting chemical plant pipelines, but the study addresses the nature of the reflection function and its general applicability.

The Measurements of the Photoreflection Pattern for Cornea and Crystalline (각막과 수정체의 Photoreflection Pattern 측정기구 개발)

  • Kim, YongGeun;Park, Dong-Hwa
    • Journal of Korean Ophthalmic Optics Society
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    • v.3 no.1
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    • pp.201-207
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    • 1998
  • It was theoretically calculated the image position and size using matrix to obtain the reflection pattern for eye's cornea and crystalline, and made system to measure the reflection pattern by three light sources and a reflex camera. Hyperopia and myopia were measured by reflect pattern using single light source at retina, and cornea and curvature of crystalline were measured by the reflection pattern using double light sources.

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Exploring a Deeper Meaning in Service-Learning Pedagogy and Implementing it in Family and Consumer Sciences Education

  • Kwon, Yoo-Jin
    • International Journal of Human Ecology
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    • v.9 no.1
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    • pp.71-79
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    • 2008
  • Service-Learning pedagogy includes community service and reflection as main components. Students can learn integration and application of knowledge beyond specific fields through experiences and reflection. The purpose of family and Consumer Sciences Education is related to connect theory and practice to improve individual, family, and community life. The curriculum focuses not only on content mastery in subjects, but also application of that knowledge to the real lives of students. Considering the purpose of service-learning as integration and application of knowledge, service- learning pedagogy can contribute to rethink family and Consumer Sciences Education. Reflection as a key component is examined for service-learning pedagogy. Exploring a deeper meaning of reflection in aspects of community connection, critical thinking, and transformative learning would extend the value of it and provide implications for implementing reflection in service-learning pedagogy in Family and Consumer Sciences Education.

Implementation of Reflection Removal Algorithm on Mobile Device (모바일 장치에서 반사 잔상 제거 알고리즘 구현)

  • Lee, YuKyong;Lee, Yong-Hwan
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.1
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    • pp.108-112
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    • 2021
  • Undesired reflection removal from an image captured through glass window is widely needed with the prevalence of camera. In this paper, we present and implement a reflection removal algorithm, which is specially designed for smart devices. Our implementation requires smart phone application to take two input pictures of the same target, one with flash light on and another with flash light off. Then, we find a flash spot in the picture, match the features to align the input pictures, transform the color space, and finally combine the pictures. As the result, we get a resulting image with removed reflection, achieving the visually pleasant.

The Reflection Color Light with the Structure of an Antireflection Lenses (렌즈 무반사막 구조에 의한 반사색광의 특성 연구)

  • Kim, Yong-Geun
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.1
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    • pp.93-102
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    • 1996
  • The optical system of lens must be designed to tramsmit light over wide wavelength range and to have lower reflectivity in order to obtain higher spectral transmittance. However, the reflection color light appears due to the remain-reflection light in any optical system of lens. The wavelength of the reflection color light can be controlled by the structure of the number of layers, thickness of layer, reflective index, wavelength of incidence, and substrate etc. In the optical systems of the single layer and the double layers, the reflection color light appears in the condition of the anti-reflection of ${\lambda}s/{\lambda}$ = 1.0 by the color mixture of the remain-reflection lights in the ranges of the longer wavelength side and the shorter one of the ${\lambda}s/{\lambda}$ = 1.0, and of the double layers and triple layers, the reflection color light positioned at P1 < ${\lambda}s/{\lambda}$ < P2 appears in the condition of the antireflection of ${\lambda}s/{\lambda}$ = $PI{\ll}1$ and $P2{\gg}1$. In the optical system of the multi-layers, many antireflection points are existed at the various s/ values, and the reflection color light by the color mixture of the remain-reflection lights in the ranges except for the antireflection points.

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The Differences Between Attentional networks according to Sex and Reflection-Impulsivity In The Cognitive Style of Young Children (유아의 성별 및 사려성-충동성 인지양식에 따른 주의력의 차이)

  • Kim, Hyoung Jai;Youn, Jeong Jin
    • The Korean Journal of Community Living Science
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    • v.24 no.3
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    • pp.301-312
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    • 2013
  • The purpose of this study was to investigate the differences between attentional networks according to sex and reflection-impulsivity in the cognitive styles of young children. The subjects of the study were 78 5-year-old children from the kindergarten or daycare center in Busan(with 40 in the reflection group, and 38 in the impulsivity group). The tests were conducted by using the Mating Familiar Test and the Attentional Network Test for young children. The study has used two independent t-tests to find out the differences between attentional networks according to sex, and reflection-impulsivity in the cognitive styles of young children. The results of this study were as follows. First, the boys with reflection cognitive style were significantly slower than the girls with the same style(t=2.18, p<.05). Second, young children with reflection cognitive style were significantly faster in the case of alerting effects than those with impulsivity cognitive style(t=-2.53, p<.05). The young children with reflection cognitive style were slower than those with impulsivity cognitive style in the case of orienting effect(t=2.04, p<.05). Children with a combination of both conflict effect and reflection cognitive style were significantly faster than those with impulsivity cognitive style(t=-2.89, p<.01). The results of the study suggested that there was a difference between attentional networks according to sex and reflection-impulsivity cognitive styles of young children.

Reflection of Plane Shock Wave over Concave and Convex Walls (오목, 볼록면에서 평면충격파의 반사)

  • JEON, Heung-Kyun;KWON, Jin-Kyung;KWON, Soon-Bum
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.11
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    • pp.1473-1480
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    • 1999
  • In the case of Impingement of plane moving shock wave over concave or convex double wedges (pseudo-stationary flow) and cylindrical walls (truly non-stationary flow), it Is expected that there are transitions from regular reflection to Mach reflection or vice versa In shock wave reflections. In these connections, it is necessary to verify the various of reflection process and transition angle for the reflection problems In double wedges, and to verify the transition angle, effects of curvature radius and initial wall angle on it for the reflection problems In cylindrical walls. Especially, we focused our attention to confirm the existence of hysteresis phenomenon induced by the different transition processes, and Neumann paradox, which is a small discrepancy between theoretical and experimental transition angles. Experiments were carried out by using the shock tube of $6{\times}6cm^2$, and high speed photographic technique consisted of delay unit, triggering system, light source of Xe lamp and so on was used for flow visualization.

Calculation of Differential Reflection Coefficient for Isolated Microscopic Well Structure

  • Lee, Jong-Tai
    • ETRI Journal
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    • v.21 no.3
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    • pp.41-48
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    • 1999
  • We have calculated differential reflection coefficient for isolated well structure of micro-scale, etched on dielectric surface. The differential reflection coefficient is computed using Green's second integral theorem. The purpose of our computation is to find a class of well profiles which give maximal diffusive scattering. To have such a maximal effect, we have concluded that the waist radius of Gaussian beam and its wavelength should be comparable to the well width and that well depth has to be larger than a wavelength. Exact calculation of differential reflection coefficients of dielectric surface with isolated structure on it may be used for the examination of dielectric surfaces and also in making simple but efficient diffuser.

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REFLECTION PRINCIPLES FOR GENERAL WIENER FUNCTION SPACES

  • Pierce, Ian;Skoug, David
    • Journal of the Korean Mathematical Society
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    • v.50 no.3
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    • pp.607-625
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    • 2013
  • It is well-known that the ordinary single-parameter Wiener space exhibits a reflection principle. In this paper we establish a reflection principle for a generalized one-parameter Wiener space and apply it to the integration of a class of functionals on this space. We also discuss several notions of a reflection principle for the two-parameter Wiener space, and explore whether these actually hold.