• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.4
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• pp.1-9
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• 2012

A method to estimate the 3-D shape of surface with specular reflection is proposed, where the difference between the images reflected from a flat surface and a curved surface is used. First, we analyzed the geometry of the spatial reflection at specular surface and the variation of reflected light due to curved surface, whose results are used to estimate 3-D shape. The proposed method is shown to be effective via experiments using the illumination with spatially distributed light source and the CCD camera to capture the light reflected from a surface. In experiments, the captured images from curved surface with specular reflection are processed to approximately estimate 3-D shape.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.6
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• pp.80-89
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• 2017

The classical approaches to detect cracks are performed by experienced inspection professionals by annotating the crack patterns manually. Because of each inspector's personal subjective experience, it is hard to guarantee objectiveness. To solve this issue, automated crack detection methods have been proposed however the methods are sensitive to image noise. Depending on the quality of image obtained, the image noise affect overall performance. In this paper, we propose crack detection method using a convolutional encoder-decoder network to overcome these weaknesses. Performance of which is significantly improved in terms of the recall, precision rate and F-measure than the previous methods.

• Journal of the Korean Solar Energy Society
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• v.37 no.3
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• pp.1-12
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• 2017

This paper deals with the effectiveness of a fiber optic solar lighting system that uses a Fresnel lens mounted on a two-axis solar tracker. A series of comparative analyses were made concerning its performance as compared to fluorescent lighting by using a simulation model based on ECOTECT and RADIANCE as well as referring to actual data. ECOTECT was used to model the test room (space) while RADIANCE was used for its indoor lighting conditions (environment). It was found that the average indoor light levels of fluorescent lighting fully satisfy the KS standard (KS A 3011, general office, class [G]: 300-400-600 lux) whereas those of the solar lighting with light diffusers depends on the occlusion factor of roller shades installed on the south window.

• Journal of the Semiconductor & Display Technology
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• v.13 no.4
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• pp.65-70
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• 2014

This paper is to improve the problem of the LED dimming control system using the conventional PWM and DAC method. The conventional PWM method controls the average current to switch dimming signal. This method generates the flicker when controlling at a low current. In order to solve the problem, this system prevents the flicker with the DAC method. The LED is lit at micro-current flowing in the LED. And offset voltage is generated in the output of the DAC when the DAC output is very low voltage as 0V. This was resolved by the voltage drop of the output voltage to construct a negative offset circuit. In addition, the LED current can't flow as set values because of overheating of FET. In order to solve the problem, the 16 bits ADC in the microprocessor is a more accurate current control receives the LED current in comparison with the set value. Therefore, the LED dimming control system proposed in this paper showed the accurate and reliable more than conventional systems.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.3
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• pp.261-268
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• 2014

Precision screws have a wide range of industrial applications such as electrical and automotive products. To produce screw threads with high precision, not only high precision manufacturing technology but also reliable measurement technology is required. Machine vision systems have been used in the automatic inspection of screw threads based on backlight illumination, which cannot detect defects on the thread surface. Recently, an omnidirectional inspection system for screw threads was developed to obtain $360^{\circ}$ images of screws, based on front light illumination. In this study, the illumination design for the omnidirectional inspection system was modified by adding a light shield to improve the image uniformity. Optical simulation for various shield designs was performed to analyze image uniformity of the obtained images. The simulation results were analyzed statistically using response surface method, from which optical performance of the omnidirectional inspection system could be optimized in terms of image quality and uniformity.

• The Inventors News
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• no.43
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• pp.1-16
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• 2006

2006년 발명특허가족 신년 교례회/한국여성발명협회 '2006정기총회' 개최/삼성전자와 대만 AUO, 특허 공유하다/현대카드, 가맹점 주인 전용 카드 출시/외국 기업, 국내 메모리 카드 커넥터 특허출원 선점/IBM,특허 품질개선 프로젝트 실시/알레르기와의 전쟁, 특허로 잡는다/서울시, 여성경제 6단체와 여성일자리 창출 협약/'100대 우수특허제품 대상' 시상식/공익변리사 특허상담 서비스 확대 운영/들고 다니는 '휴대용 화장실' 눈길 끌어/특허청, 특허정보 확충으로 심사품질 제고/'전국 학생 창의력 올림피아드'/특허청, 연구기관과 지식관리시스템 연계/한국, 경영 및 생활 인프라 측면 중국보다 앞서/발명가의 양심선언 화제/국내 연구진, 수소자동차용 연료탱크 개발/미국 특허등록 순위 삼성전자 '넘버 5'/주소불명으로 인한 국가 자원 낭비 막는다/전구소켓에 끼워 쓰는 LED 조명 나왔다/대전시, 중소기업에 1천6백60억 지원/한국발명진흥회 박상원 상근부회장 선임/일본 닛치아, 특허 공세 시장되다/국내 최초로 숨쉬는 김치파우치 개발/역사속의 발명품/발명아이디어/특허Q&A/한미영 한국여성발명협회 회장/경상북도 문경교육청 발명교실/아이디어 착상 및 발명 기법/발명을 향한 블루오션의 손짓/해리스의 퍼머기/월드 NEWS/민간인과 학생 대상, 지식재산 교육과정 열려/네이버, 특허통합정보 서비스 제공/'제가 만든 해금 심금 울리죠'/정부출연연구소 '우리기술 사세요'/리빙 아이디어/협회소식/

• KIEAE Journal
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• v.9 no.1
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• pp.23-30
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• 2009

A lightcourt design is typically used to address issues concerning aesthetics, feeling, and mood. From the view point of environmental aspect, as an ecological shaft space, it plays a key role in controlling inner quality. In particularly, the lightcourt concept allows the exploitation of daylighting by bring natural light into the center of the building, thus eliminating dark deep spaces. Additionally, the lightcourt shades the inner space in summer. The amount of light available at the base of the lightcourt depends on a number of factors; translucency of the top, reflectance and the geometry of the space. In this paper is to exemplify a lightcourt configuration with a sloped wall. It promises the maximized a sense of freedom and daylighting availability. It is a matter of course that the lightcourt with open-top plays a role as a light source for the adjacent space to the lightcourt. A series of lighting simulation provides performance data of daylighting with changing photometric factors. For the case that a skylight is not available, an electric lighting design with metal halide lamps has been established to create luminous ceiling. As expected, a sloped lightcourt with open-top exposes its superiority of daylighting source. Ancillary considerations to enhance of daylighting potential for the adjacent space have been issued with performance data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.240-245
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• 2015

This paper presents an impact of flicker for various binary modulations of visible light communication (VLC) under dimming requirement. While previous approaches consider the statistics of the signal that cannot capture contributions of dynamic impacts of flicker, the power spectral density is evaluated for various VLC transmission schemes of dimming support. This enables to compare transmission schemes with the contribution of low and intermediate frequency components to flicker. Numerical results show that analog dimming has advantages over other techniques in terms of flicker and signal processing with waveforms and symbol distribution allows to mitigate flicker effects.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.1123-1127
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• 2005

The Conventional methods of color separation in computer-based machine vision offer only weak performance because of environmental factors such as light source, camera sensitivity, and others. In this paper, we propose an improved color separation method using RGB, HLS, color coordination space, and fuzzy similarity measure. RGB consists of red, green and blue, the three primary colors of light. HLS includes hue, light and saturation, the human recognition elements of co]or. A fuzzy similarity measure was employed for evaluate the similarity among fuzzy colors with the six features of RGB and HLS.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1646-1652
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• 2015

In this paper, we propose a depth conversion method for orthoscopic real image reconstruction in integral imaging. Pseudoscopic image has been regarded a problem in conventional integral imaging. the depth of reconstructed image is depending on a coordinate of an elemental image. The conversion from pseudoscopic to orthoscopic may be possible by analysing the geometrical relation between pickup and reconstruction system of elemental image. The feasibility of the proposed method has been confirmed through preliminary experiments as well as ray optical analysis.