• 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.

• 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.

• 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.

• 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.

• 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.

• 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.

• 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)

• 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.

• 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.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2009년도 춘계학술대회 논문집
• /
• pp.221-222
• /
• 2009