• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.834-839
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• 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.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.215-218
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• 2003

We have developed a reflective 3.5" QVGA color TFT-LCD with high reflection within viewing angle. For this, We have introduced new pixel design and asymmetric reflector. Based on these technical concepts, we get a high aperture ratio of 93.5% and much higher reflection up to 64% with a 3.5" prototype panel.

• 대한전자공학회논문지
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• 제6권3호
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• pp.8-11
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• 1969

In the precision measurement of the voltage standing wave ratio (VSWR) or reflection coefficient by means of the slotted line technique, one of the important factors is the maximum error due to the discontinuities and multi-reflection in the slotted line. Particularly, this error becomes a critical factor when the VSWR or the reflection coefficient to be measured is very small. In this paper, the exact expression of this error is obtained by means of the Signal flow graph method.

• 제어로봇시스템학회논문지
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• 제6권10호
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• pp.894-902
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• 2000

This paper proposes a force reflection control method with a speed saturation compensation scheme for the slave manipulators having a speed saturation due to the high reduction ratio joints. When speed saturation is generated, the proposed force reflection control method not only shows an anti-windup feature in controlling the slave manipulator but also makes the master manipulator move slowly using the force reflection caused by saturation. In this way, the position of the slave manipulator tracks the reference position regardless of speed saturation. The experimental results show that the proposed control method provides excellent performance.

• Fibers and Polymers
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• 제6권2호
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• pp.127-130
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• 2005

Intrinsic UV reflection and fluorescence behaviors of polycarbonate, polyurethane and poly(ethylene terephthalate) films were investigated in order to characterize the interaction of water in these films. During water sorption process, UV reflection spectra of polycarbonate and polyurethane films showed little peak position changes. Fluorescence emission spectra of polycarbonate films showed red spectral shifts from 332 nm with water immersion time. This red-shifted peak could be due to phenyl-2-phenoxybenzoate, which is one of the major thermal degradation products in polycarbonate. Fluorescence peaks of polyurethane films appeared at two different positions and the ratio of these peak intensities increased with increasing immersion time. In the case of PET films, the UV reflection spectrum showed the peak intensity around 340 nm to change in response to water sorption. The fluorescence near 388 nm probably due to ground state dimer exhibited sensitivity with water sorption, when excited at 340 nm.

• 대한공업교육학회지
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• 제39권2호
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• pp.1-18
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• 2014

본 연구에서는 중등단계 직업교육에서 활용되고 있는 기존 발명 지식재산 관련 교과서를 대상으로 '발명 지식재산 핵심 학습 요소'의 반영 비율에 대한 편성 실태를 분석하고, 앞으로 중등단계 직업교육에서 요구되는 적정한 발명 지식재산 교육내용별 편성 비율을 제안하고자 하였다. 이를 위해서 현재 특성화고 및 마이스터고에서 사용되고 있는 발명 지식재산 교과서의 교육내용에 '어떤 종류의 발명 지식재산 핵심 학습 요소가, 얼마나 있는지와, 향후 어떤 학습 요소를 얼마나 편성하는 것이 바람직한가'를 연구 문제로 설정하였다. 이를 해결하기 위해서 내용분석 방법을 활용하여 발명 지식재산 교육내용의 반영 실태를 분석하고, 델파이 조사로 앞으로 요구되는 발명 지식재산 교육내용별 반영 비율을 제시하였다. 본 연구를 통해서 얻어진 결과를 제시하면 다음과 같다. 첫째, 중등단계 직업교육에서 활용되고 있는 기존 발명특허 인정도서에 포함된 발명 지식재산 핵심 학습 요소를 분석한 결과 모든 핵심 학습 요소가 교과서에 분포하고 있었으나 일부 교과서에서는 D(문제 해결과 활동)영역이 집중되어 있는 경향이 있었다. 둘째, 중등단계 직업교육에서 활용되고 있는 발명특허 인정도서에 제시되어 있는 발명 지식재산 교육내용의 영역별 반영 비율을 분석한 결과 대부분의 교과서가 창출영역에 치중되어 있는 경향이 있었으며, 일부 교과서에서는 보호영역과 활용영역을 다루고 있었다. 그러나 대체적으로 활용영역에 대한 반영 비율이 미흡한 실정이었다. 성취유형별로는 모든 교과서에서 지식영역이 주를 이루고 있었다. 또한 발명특허기초, 발명과 문제해결, 발명과 디자인 교과서에서만 기능영역을 일부 다루고 있었으며, 태도영역은 대부분의 교과서에서 없거나 미흡하게 다루고 있었다. 셋째, 전문가 델파이 조사를 통해 얻어진 중등단계 직업교육에서 요구 되는 발명 지식재산 교육 핵심 학습 요소 영역 중에서 D(문제 해결과 활동) 17.7%, E(발명 융합 지식) 2.9%, K(특허출원) 6.9%, L(특허정보 조사) 9.6%를 줄여야 하는 것으로 나타났다. 발명 지식재산 교육내용 중에서 발명 소양영역 3.1%, 지식재산 창출영역 4.5%, 지식재산 보호영역 10.6%를 줄여야 하고, 지식재산 활용영역은 17.7%를 늘려야 하는 것으로 나타났다. 또한 성취유형의 적정 반영 비율은 지식영역은 52%를 줄여야 하고, 기능영역 32.3%, 태도영역 19.6%를 늘려야 하는 것으로 나타났다.

• 제어로봇시스템학회논문지
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• 제2권4호
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• pp.324-329
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• 1996

In this paper, we present a vision algorithm to extract the tire information markings on the sidewall of tires. Since the appearance of tire marks is the same as its background, a primary feature to distinguish tire marks from their background is the roughness. Generally, the roughness of tire marks is different from that of its bakground: the surface of tire marks is smoother than the backgrounds. Light incident on the tire surface is reflected differently according to the roughness. For smoother surfaces, the surface irradiance is much stronger than that of rough surfaces. Based on these phenomena and observation, we propose an optimal illumination condition based on Torrance-Sparrow reflection model. We also develop an efficient reflectance-ratio based operator to extract the boundary of tire marks. Even with a very simple masking operation, we were able to obtain remarkable boundary extraction results from real experiments using many tires. By explicitly using the surface reflection model to explain the intensity variation on the black tire surface, we demonstrate that a physics-based vision method is powerful and feasible in extracting surface markings on tires.

• Journal of Advanced Research in Ocean Engineering
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• 제1권1호
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• pp.44-54
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• 2015

Breakwaters are the coastal structures constructed either perpendicular (shore connected) or parallel (detached) to the coast. The main function of breakwater is to create a tranquil medium on its leeside by reflecting the waves and also dissipating the wave energy arriving from seaside, resulting in ease of manoeuvrability to boats or ships to their berthing places. Different types of breakwaters are being used at present, such as rubble mound breakwater, vertical wall type breakwater and composite breakwater. The objective of this paper is to investigate reflection coefficients (Kr) and dissipation (loss) coefficients (Kl) for physical models of Quarter circle caisson breakwater of three different radii of 0.550 m, 0.575 m and 0.600 m with S/D ratio of 2.5 (S=spacing between perforations, D=diameter of perforations). The models were tested in the monochromatic wave flume of the department, for different incident wave heights (Hi), Wave periods (T) and water depths (d). It was observed that reflection coefficient increased with increase in the wave steepness (Hi/gT2) and decreased with increase in depth parameter (d/gT2) and hs/d (Height of structure including rubble base/depth of water). The loss coefficient decreased with increase in the wave steepness and increased with increase in depth parameter and hs/d.

• 지질공학
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• 제24권2호
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• pp.171-178
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• 2014

In seismic reflection data processing, the crossdip correction effectively focuses the stacking energy near the sharp bends of a crooked survey line. Additionally, approximate 3-D information on the reflector (e.g., true crossdip angle and lateral continuity) are locally investigated as a by-product of the crossdip correction procedure. Improvement of the signal-to-noise ratio and estimation of reflector crossdip attitude are tested, in terms of both common midpoint bin direction and processing-line type, using synthetic seismic reflection data. To effectively image the reflection energy near bends in seismic survey lines, straight-line binning is preferred to slalom-line binning.

• Journal of Magnetics
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• 제13권2호
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• pp.70-75
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• 2008

In this study, a MOKE (Magneto-optical Kerr effect) measurement method for magnetic nanostructures is proposed. Theoretically, the MOKE signal enhancement can be predicted and confirmed when an anti-reflection coated substrate is used. Since MOKE is a ratio of reflectivity and the difference between the reflectivities for two magnetic states, when the reflectivity of the substrate part is reduced by employing an anti-reflection coated substrate, MOKE signal enhancement can be achieved. The enhancement is confirmed by simple numerical MOKE calculations. When the reflectivity of an anti-reflection coated substrate is 0.7%, the calculated MOKE signal is about 79% of its bulk values for the 100-nm wide Fe nanowire with a 1500-nm radius laser beam. It was found that, for various numerical calculations, a larger MOKE signal is obtained relative to a smaller substrate reflectivity.