• 제목/요약/키워드: Reflection

검색결과 5,928건 처리시간 0.03초

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

  • 안태준;이승협;조용식
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2005년도 학술발표회 논문집
    • /
    • pp.1078-1082
    • /
    • 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.

  • PDF

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

  • 김영환;박경조;강우석
    • 동력기계공학회지
    • /
    • 제15권3호
    • /
    • pp.18-24
    • /
    • 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.

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

  • 김용근;박동화
    • 한국안광학회지
    • /
    • 제3권1호
    • /
    • pp.201-207
    • /
    • 1998
  • 눈의 cornea, crystalline의 reflection pattern을 알기 위해 matrix를 이용하여 image의 위치, size를 이론적으로 계산하였고, 3개의 light source와 reflex camera를 이용하여 reflection pattern를 측정할 수 있는 system을 만들었다. 단일 광원을 이용하여 retina에서 반사 pattern으로부터 눈의 원시 및 근시 등을 측정하였고, 2개의 광원을 이용한 reflection pattern으로부터 cornea, crystalline의 curvature를 측정하였다.

  • PDF

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
    • /
    • 제9권1호
    • /
    • pp.71-79
    • /
    • 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.

WRF를 이용한 모르터의 응결 및 경화 예측 (Setting and Hardening of Portland Cement Mortar Investigated with Wave Reflection Factor)

  • 노병철
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
    • /
    • pp.834-839
    • /
    • 2003
  • Previous research has been conducted on an ultrasonic wave reflection method that utilizes a steel plate embedded in the concrete to measure the reflection loss of shear waves at the steel-concrete interface. The reflection loss has been shown to have a linear relationship to compressive strength at early ages. The presented investigations continue this research by examining the fundamental relationship between the reflection loss, measured with shear waves, and the hydration kinetics of Portland cement mortar, represented by dynamic elastic moduli, compressive strength and degree of hydration. Dynamic elastic moduli are measured by fundamental resonant frequency and degree of hydration is determined by thermogravimetric analysis. The water/cement ratio was varied for the tested mixture compositions. The results presented herein show that compressive strength, dynamic shear modulus and degree of hydration have a linear relationship to the reflection loss for the tested mortars at early ages.

  • PDF

과학 모의 수업에 대한 반성 저널 쓰기와 토론을 통한 초등 예비교사의 생산적 반성 증진 (Facilitating Productive Reflection of Pre-service Elementary Teachers through Reflective Journal Writing and Discussion about Science Peer Teaching Practice)

  • 윤혜경
    • 한국초등과학교육학회지:초등과학교육
    • /
    • 제32권2호
    • /
    • pp.113-126
    • /
    • 2013
  • In this study, the researcher aimed to increase productive reflection of pre-service elementary teachers through reflective journal writing and discussion after science peer teaching practice. 'Productive reflection' involves consideration and analysis of interrelationships among aspects of teaching including learners and learning, subject matter knowledge, assessment, and instruction. During 8 week efforts, productive reflection has increased gradually in both individual journal and class discussion. However half of individual journals didn't show productive reflection even in the final stage. This implicated that development of reflective thinking is an achievable but progressive change. By describing the progress in discussion and participants' responses on journal writing and discussion activity, this study shed light on practical ways of enhancing reflective teacher education.

High-resolution seismic reflection surveying at paved areas using an S-wave type land streamer

  • Inazaki Tomio
    • 지구물리와물리탐사
    • /
    • 제7권1호
    • /
    • pp.1-6
    • /
    • 2004
  • High-resolution S-wave reflection surveying has been successfully conducted on paved areas using a Land Streamer originally designed by the author. The main feature of the Land Streamer tool is the non-stretch woven belt on which geophone units are mounted to form a multichannel geophone array similar to a marine streamer. Because it is easily towed by a vehicle or by hand, the tool leads to high performance in field measurements and resultant cost-effectiveness of high-resolution reflection surveys. Although each geophone unit is coupled to the pavement through a metallic baseplate instead of being firmly planted in the ground, the Land Streamer tool provides comparatively clean data, unaffected by traffic noise even on the pavement. Thus, the tool is capable of expanding the opportunity for S-wave reflection surveys in urban areas where many surfaces are paved and traffic noise is severe. A series of high-resolution S-wave reflection surveys on paved areas delineated detailed structures of surface layers shallower than 60 m, and proved the wide applicability of the tool to engineering, environmental applications, and earthquake disaster prevention projects.

레이저 다이오드 Mirror면의 Anti-Reflection 코팅 박막 제작 및 특성 분석 (The Manufacture and Properties Analysis of Anti-Reflection Coating Thin Film of Laser Diode Mirror)

  • 기현철;김선훈;김상택;김효진;김회종;홍경진;민용기;조재철;구할본
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
    • /
    • pp.103-106
    • /
    • 2006
  • Semiconductor laser diode has a reflective facet in a both-ends side fundamentally. Laser performance for improving, Anti-Reflection and High-reflection coating on the facet of semiconductor laser diode. To prevent internal feedback from both facets for realizing superluminescent diode and reducing the reflection-induced intensity noise of laser diode, it's key techniques are AR/HR coatings. In the study AR coating film were manufactured by Ion-Assisted Deposition(IAD) system. Then manufactured coating film measurement electrical properties(L-I-V, Se, Resistor) and Optical properties (wavelength FFP)

  • PDF

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

  • 이유경;이용환
    • 반도체디스플레이기술학회지
    • /
    • 제20권1호
    • /
    • pp.108-112
    • /
    • 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.

Reflection of plane waves from the boundary of a thermo-magneto-electroelastic solid half space

  • Singh, Baljeet;Singh, Aarti
    • Coupled systems mechanics
    • /
    • 제10권2호
    • /
    • pp.143-159
    • /
    • 2021
  • The theory of generalized thermo-magneto-electroelasticity is employed to obtain the plane wave solutions in an unbounded, homogeneous and transversely isotropic medium. Reflection phenomena of plane waves is considered at a stress free and thermally insulated surface. For incidence of a plane wave, the expressions of reflection coefficients and energy ratios for reflected waves are derived. To explore the characteristics of reflection coefficients and energy ratios, a quantitative example is set up. The half-space of the thermo-magneto-electroelastic medium is assumed to be made out of lithium niobate. The dependence of reflection coefficients and energy ratios on the angle of incidence is illustrated graphically for different values of electric, magnetic and thermal parameters.