• 한국가시화정보학회지
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• 제21권3호
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• pp.65-74
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• 2023

Compared to epifluorescence(EPI) microscopy which captures fluorescence from the entire depth of sample, total internal reflection fluorescence(TIRF) can selectively visualize only a single surface of it. TIRF uses a thin evanescent field generated by the total internal reflection of laser light on surface. However, conventional TIRF system are designed for total internal reflection to occur at the upper surface of sample, making them unsuitable for sessile droplet imaging. We designed a TIRF system suitable for a sessile droplet imaging by utilizing slide glass as a lightguide. We presented the details for constructing the TIRF system using a prism, slide glass, air slit, and optical trap. Then, we compared the TIRF with EPI by imaging the droplet with fluorescent particles during its drying process. As a result, TIRF allows us to distinctly visualize the drying pattern on the bottom surface of droplet.

• 한국광학회지
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• 제23권1호
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• pp.36-41
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• 2012

표면 플라즈몬-폴라리톤(surface plasmon-polaritons, SPP)의 외부-전반사(total external reflection, TER) 현상은 유전체 만으로 된 경계 면에서는 일어나지 않는 SPP 만의 독특한 특성이다. 금속 면 위에 놓인 낮은 굴절률 유전체 선이 도파로 코어 역할을 하여 파장 이하의 크기를 갖는 도파모드를 형성하는 SPP-TER 도파로 구조를 제안하였다. 코어 단면적 변화에 따른 SPP-TER 모드의 전파 특성을 기존의 높은 굴절률 유전체 도파로 및 금속 도파로 구조와 비교 분석하였다. 코어의 면적이 작아짐에 따라 SPP-TER 모드의 크기가 파장보다 수십 배 작아질 수 있으면서도, 주변에 이득물질을 갖는 경우에는 기존의 도파로 구조보다도 높은 이득을 가질 수 있음을 보였다. 따라서, 제안된 SPP-TER 구조는 나노 크기의 레이저 구현에 기여하리라 기대된다.

• 한국전기전자재료학회논문지
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• 제23권6호
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• pp.471-476
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• 2010

This paper has studied dissymmetrical light distribution design using the secondary optics in the simulation. fundamental Lambertian radiation distribution based on LED has been cut off by the secondary optics, and the first surface slope of lens and second surface slope of total reflection area have been calculated through formula. PMMA (the index of refraction: 1.49361) which is material of lens has been selected. critical angle($42.02993^{\circ}$) between Air and PMMA has been calulated by snell's law, and total reflection angle slope has been selected about $16.67^{\circ}$ to occur the total reflection. when the first surface slope and the second surface slope has been set up, Rays of all total reflection area have generated the total reflection. finally, designed LED Module has been estimated by Korean Industrial Standards for LED safety street lighting. dissymmetrical light distribution have been analyzed with reached effect of road illuminance, and average road illuminance which are each 70.6 lx, 40.35 lx, and 25.88 lx have been satisfied with Korean Industrial Standards for LED safety street lighting.

• 전기학회논문지
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• 제56권9호
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• pp.1694-1698
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• 2007

This study suggests a new fluorescence microscope to observe micro-samples within fluorophore in a variety of biomedical fields including the fluorescence analysis of a biochip, such as a DNA micro-array. A fluorescence microscope is a device for irradiating light onto a micro-object, executing an excitation and fluorescence emission process. In this study, it adopts a total internal reflection fluorescence(TIRF) method to excite a whole micro-sample substrate different from an existing way which uses an evanescent wave resulting from a total internal reflection on the micro-sample surface. Suggested TIRF microscope can reduce optical noise and obtain images with higher sensitivity thus obtain precise information about the density, quantity, location, etc. of a flurophore, and can simultaneously process separate images even when plurality of fluorophores having different excitation and fluorescent wavelength ranges is distributed, thus easily obtain information about the fluorophores.

• 한국광학회지
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• 제7권2호
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• pp.112-119
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• 1996

TM 편광된 광자가 frustrated total internal reflection(FTIR) 구조에서 2차원적 터널링을 할 때 터널링에 소요되는 시간과 터널링되어 나오는 위치를 계산하였다. 이는 TM 편광된 광자의 FTIR 터널링 문제를 효과질량이 다른 이종 포텐셜 장벽을 터널링하는 전자의 문제로 변환시킴으로써 가능하였다. 계산된 결과를 TE 편광된 광자에 대한 경우와 비교하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.497-498
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• 2013

• 의학교육논단
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• 제19권3호
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• pp.169-174
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• 2017

This study explores the phenomenon of learner reflection in writing. Sixty-nine reflection logs were submitted by students after medical interview role plays. Using thematic analysis methodology, the following three steps were carried out: (1) the entire contents of the logs were analyzed and coded, (2) the coded contents were reclassified and categorized into higher themes, and (3) all reflection logs were re-analyzed to derive the frequency according to their classifications. The learners' reflection contents were classified into 'preparation,' 'experience,' and 'future plan.' The levels of reflection were 'simple information and appreciation,' 'acquisition and application of knowledge,' and 'analysis and criticism.' The types of reflection were identified only at the level of 'analysis and criticism' and could be classified into 'relativization,' 'objectification,' and 'internalization.' Students' reflection levels were highest in the levels of 'acquisition and application of knowledge' (49.3%), and 'analysis and criticism' (37.7%). A total of 14.5% of the students showed 'internalization.' In order to enable internalized reflection at a critical level, instructional strategies to induce and promote reflection are needed.

• ETRI Journal
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• 제33권2호
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• pp.275-278
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• 2011

This letter presents a polymer $1{\times}2$ thermo-optic totalinternal-reflection digital optical switch (TIR-DOS) with an index contrast of 1.5%-${\delta}$ operating at low power consumption. The structure of our $1{\times}2$ TIR-DOS was created by adding a reflection port to that of a conventional multimode filtering variable optical attenuator. To improve the total-internalr-eflection efficiency, a heater offset was applied to the crossing region of multimode waveguides of the TIR-DOS. The fabricated $1{\times}2$ TIR-DOS shows a low electrical power consumption of 18 mW for an on-off ratio of 35 dB.

• 한국산학기술학회논문지
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• 제7권5호
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• pp.852-857
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• 2006

본 논문은 디지털 지도를 이용하여 산악지형의 전계강도를 정밀하게 분석하는 방법을 제시한다. 일반적으로 전파의 전계 강도는 직접파와 수평면 반사를 주로 고려하였으나, 산악지역에서는 직접파와 수평면 반사 외에도 산악지형의 수직면에 의한 반사도 고려해야 한다. 이러한 점을 고려하여 산악지형에서 전파를 송신할 때 일어나는 직접파와 수평면 반사파, 산악 지형에 의한 수직면 반사파의 합성 전계를 전파의 편파 특성과 위상 특성을 고려하여 계산한 결과를 제시하였다.

• 한국해양공학회지
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• 제1권1호
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• pp.138-143
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• 1987

Friction welding has emerged as a reliable process for high-production commercial applications with significant economic and technical advantages. But nondestructive test in friction weld was not clearly developed. Therefore the experimental verification is necessary in order to understand the characteristcs of the pulse echo effects according to various change in welding conditions. This paper presents an attempt to determine the relationship between the varios welding conditions and the coefficients of reflection using the ultrasonic pulse echo method in dissibilar metals friction weld. The new approach of calculating the coefficients of reflection based on measured amplitudes of the echoes is applied in this paper. These coefficients provides a single quantitative measurement which involves both acoustic energy reflected at the welded interface as well as transmitted across the interface. As a result, it was known that the quantitave relationship between welding conditions and the coefficients of reflection using the ultrasonic pulse echo exists in dissimilar metals friction weld.