• Title/Summary/Keyword: Illumination System

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Correction of Radiometric Distortion Caused by Geometric Property in SAR image using SAR Simulation (SAR영상의 모의제작에 의한 기하학적 복사왜곡의 보정)

  • Jeong, Soo;Yeu, Bock-Mo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.16 no.1
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    • pp.1-7
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    • 1998
  • SAR data can be achieved independently of weather conditions or sun illumination which is main limitation of electro-optical sensor to get image. The information from imagery can be more enlarged using Shh data be-cause SAR data offers different information from electro-optical sensor. SAR data contains various distortions caused by the radar specification and geometric properties of data acquisition. These distortions should be removed to get the information with acceptable accuracy. In this study, we aimed to correct the radiometric distortion in Shh image caused by the geometric property of the object. For this purpose, we simulated the SAR image by modelling of the power of return beam which is variable according to the geometric configuration between SAR antenna and ground object. Dividing the SAR image by the simulation image, then, we can get the radiometrically corrected image. As a result of this study, we could minimize the effect of radiometric distortion in achieving some qualitative information from SAR image for the related field, such as Geospatial Information System.

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A Study on School Health Promotion Services (학교보건사업을 통한 건강증진 사업에 대한 연구)

  • Nam, Chul Hyun
    • Journal of the Korean Society of School Health
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    • v.10 no.2
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    • pp.193-211
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    • 1997
  • The study was designed to gain necessary basic data in order to grasp the health knowledge, attitude, and practice level of students and teachers of elementary, middle and high schools. This study was conducted through interviews of 3,400 students and 1,022 teachers attending 14 different schools large, middle and small cities and rural towns during a period of nine months (from Oct. 2 1995 to Jun. 30 1996). By the results of this study, the recommendations can be summarized as follows: 1. A school health development committee should be established of 10 members: school health related teachers (physical trainers, nurses, and teachers in charge of health), parents, persons related to health administration, local medical doctors, and student reprensentatives in order to support and immplement school health development plans. 2. Like advanced countries, a health class of 2~4 hours should beplaced in middle and high schools. A nurse majoring in health from a university should be the teacher. 3. A curriculum of health should contain the following: education on health, sex, alcohol, tabacco, the misuse of the drugs, the structure and function of human body, the growth of the body, mental health, safety and emergency care, the prevention of disease, proper eating habits and nutrition, daily health life, family health education, society health, community health, environmental pollution and individual responsibility. 4. Create a school health promotion center, with a nurse's office, and a sports center which has health machines (bars, aerobics, training, twist machine, belt massage, running machine, bench press, chest waist, hack hip extension machine) as well as a physical strength measuring machine (muscular strength, alertness, flexibility, endurance, lung functions and so on), so that the teaching staff and students can use them and train their bodies. 5. Through a refresher education program, urge teachers to understand school health promotion services. 6. Regulate a standard and establish a system of monitoring the physical enviroment of the school (the height of desks and chairs, illumination facilities, ventilation facilities, safe drinking water). 7. Create a check list of health to evaluate improvement.

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Study on the $N_2$ Plasma Treatment of Nanostructured $TiO_2$ Film to Improve the Performance of Dye-sensitized Solar Cell

  • Jo, Seul-Ki;Roh, Ji-Hyung;Lee, Kyung-Joo;Song, Sang-Woo;Park, Jae-Ho;Shin, Ju-Hong;Yer, In-Hyung;Park, On-Jeon;Moon, Byung-Moo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.337-337
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    • 2012
  • Dye sensitized solar cell (DSSC) having high efficiency with low cost was first reported by Gr$\ddot{a}$tzel et al. Many DSSC research groups attempt to enhance energy conversion efficiency by modifying the dye, electrolyte, Pt-coated electrode, and $TiO_2$ films. However, there are still some problems against realization of high-sensitivity DSSC such as the recombination of injected electrons in conduction band and the limited adsorption of dye on $TiO_2$ surface. The surface of $TiO_2$ is very important for improving hydrophilic property and dye adsorption on its surface. In this paper, we report a very efficient method to improve the efficiency and stability of DSSC with nano-structured $TiO_2$. Atmospheric plasma system was utilized for nitrogen plasma treatment on nano-structured $TiO_2$ film. We confirmed that the efficiency of DSSC was significantly dependent on plasma power. Relative in the $TiO_2$ surface change and characteristics after plasma was investigated by various analysis methods. The structure of $TiO_2$ films was examined by X-ray diffraction (XRD). The morphology of $TiO_2$ films was observed using a field emission scanning electron microscope (FE-SEM). The surface elemental composition was determined using X-ray photoelectron spectroscopy (XPS). Each of plasma power differently affected conversion efficiency of DSSC with plasma-treated $TiO_2$ compared to untreated DSSC under AM 1.5 G spectral illumination of $100mWcm^{-2}$.

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Planetary Long-Range Deep 2D Global Localization Using Generative Adversarial Network (생성적 적대 신경망을 이용한 행성의 장거리 2차원 깊이 광역 위치 추정 방법)

  • Ahmed, M.Naguib;Nguyen, Tuan Anh;Islam, Naeem Ul;Kim, Jaewoong;Lee, Sukhan
    • The Journal of Korea Robotics Society
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    • v.13 no.1
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    • pp.26-30
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    • 2018
  • Planetary global localization is necessary for long-range rover missions in which communication with command center operator is throttled due to the long distance. There has been number of researches that address this problem by exploiting and matching rover surroundings with global digital elevation maps (DEM). Using conventional methods for matching, however, is challenging due to artifacts in both DEM rendered images, and/or rover 2D images caused by DEM low resolution, rover image illumination variations and small terrain features. In this work, we use train CNN discriminator to match rover 2D image with DEM rendered images using conditional Generative Adversarial Network architecture (cGAN). We then use this discriminator to search an uncertainty bound given by visual odometry (VO) error bound to estimate rover optimal location and orientation. We demonstrate our network capability to learn to translate rover image into DEM simulated image and match them using Devon Island dataset. The experimental results show that our proposed approach achieves ~74% mean average precision.

New BLU Sheet with Linear Arrays of Deformed Bar Prism for Direct Back Light Unit (직하형 Back Light Unit에 사용하는 변형 막대프리즘의 1차원 배열로 구성한 새로운 BLU 필름)

  • Jang, Sun-Young;Jo, Jae-Heung;Baek, Seung-Sun
    • Korean Journal of Optics and Photonics
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    • v.18 no.6
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    • pp.401-409
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    • 2007
  • A new sheet of back light unit(BLU) to reduce the number of sheets and enhance the optical performances of direct back light unit(BLU) in a liquid crystal display is proposed and designed. In order to improve the straightness and spatial uniformity of brightness of the BLU, we design the new sheet with linear arrays of complicated bar prism by using the fusion of cylindrical lens and bar prism. Then, we investigate and analyze various optical performances of a BLU including the new sheet through an illumination optical system design program. From these results, we determine the optimum geometrical structure of the sheet. Under the optimum condition, the luminance efficiency and spatial uniformity of luminance of the BLU are 53.5% and 83.5% respectively. And the vertical and horizontal widths of the angular luminance distribution are $90^{\circ}$ and $112.5^{\circ}$ respectively. Finally we have fabricated a new BLU sheet according to this design shape by using an ordinary resins.

Design and Fabrication of a Light-Guiding Plate for a Photobioreactor Utilizing a Hybrid LED Plus Sunlight Source (LED와 태양광 하이브리드 광원을 이용한 광생물 반응기용 도광판 설계 및 제작)

  • Lim, Hyon-Chol;Yang, Seung-Jin;Baek, Jun-Hyeok;Kim, Jae-Young;Jang, Kyungmin;Kim, Jongtye;Jeong, Sanghwa;Park, Jong-Rak
    • Korean Journal of Optics and Photonics
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    • v.27 no.2
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    • pp.73-80
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    • 2016
  • In this paper, we report the results of a study on the design and fabrication of a light-guiding plate (LGP) using a hybrid light-emitting diode (LED) and sunlight source that can be applied to a photobioreactor. LGP patterns for the LED source were designed and engraved on an LGP, together with previously reported patterns for a sunlight source. A control system for the hybrid LGP was designed to maintain the output photon flux density (PFD) from the LGP at a constant value. When the target value of the output PFD was set to $70{\mu}E/(m^2{\cdot}s)$, the error range of the output PFD was found to be within ${\pm}2%$.

Physical Measurement of Color Changes in Foods (식품(食品)의 색도변화(色度變化) 측정법(測定法))

  • Cho, Sung-Hwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.13 no.1
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    • pp.1-8
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    • 1984
  • The tools and techniques for measuring the spectral distribution of light emitted by, transmitted by, or reflected from food surfaces are described for determining the extent to which original natural color is preserved in processing and subsequent storage of foods. Color differences may be evaluated indirectly in terms of some physical characteristic of the sample or extracted fraction thereof that is largely responsible for the color characteristics. For evaluation more directly in terms of what the observer actually seen, color differences are measured by reflectance spectrophotometry and photoelectric colorimetry and expressed as differences in psychophysical indexes such as luminous reflectance and chromaticity. The standard system, against which other systems could be compared, is the one recommended by the International Committee on illumination and which is based on the 'standard observer', which is a simulated standard eye, consisting of three primary color filters Z, with X being essentially amber in color, Y, green and Z, blue. Any spectrophotometric curve of reflectance obtained from the surface of an object can be integrated in terms of X, Y and Z. Psychophysical notation may be converted by standard methods to the colorimetrically more descriptive terms of Munsell hue, value and chroma.

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A Lane-Departure Identification Based on Linear Regression and Symmetry of Lane-Related Parameters (차선관련 파라미터의 대칭성과 선형회귀에 기반한 차선이탈 인식)

  • Yi Un-Kun;Lee Joon-Woong
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.5
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    • pp.435-444
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    • 2005
  • This paper presents a lane-departure identification (LDI) algorithm for a traveling vehicle on a structured road. The algorithm makes up for the weak points of the former method based on EDF[1] by introducing a Lane Boundary Pixel Extractor (LBPE), the well known Hough transform, and liner regression. As a filter to extract pixels expected to be on lane boundaries, the LBPE plays an important role in enhancing the robustness of LDI. Utilizing the pixels from the LBPE the Hough transform provides the lane-related parameters composed of orientation and distance, which are used in the LDI. The proposed LDI is based on the fact the lane-related parameters of left and right lane boundaries are symmetrical as for as the optical axis of a camera mounted on a vehicle is coincident with the center of lane; as the axis deviates from the center of lane, the symmetrical property is correspondingly lessened. In addition, the LDI exploits a linear regression of the lane-related parameters of a series of successive images. It plays the key role of determining the trend of a vehicle's traveling direction and minimizing the noise effect. Except for the two lane-related parameters, the proposed algorithm does not use other information such as lane width, a curvature, time to lane crossing, and of feet between the center of a lane and the optical axis of a camera. The system performed successfully under various degrees of illumination and on various road types.

A Defect Inspection Method in TFT-LCD Panel Using LS-SVM (LS-SVM을 이용한 TFT-LCD 패널 내의 결함 검사 방법)

  • Choi, Ho-Hyung;Lee, Gun-Hee;Kim, Ja-Geun;Joo, Young-Bok;Choi, Byung-Jae;Park, Kil-Houm;Yun, Byoung-Ju
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.6
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    • pp.852-859
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    • 2009
  • Normally, to extract the defect in TFT-LCD inspection system, the image is obtained by using line scan camera or area scan camera which is achieved by CCD or CMOS sensor. Because of the limited dynamic range of CCD or CMOS sensor as well as the effect of the illumination, these images are frequently degraded and the important features are hard to decern by a human viewer. In order to overcome this problem, the feature vectors in the image are obtained by using the average intensity difference between defect and background based on the weber's law and the standard deviation of the background region. The defect detection method uses non-linear SVM (Supports Vector Machine) method using the extracted feature vectors. The experiment results show that the proposed method yields better performance of defect classification methods over conveniently method.

Forward Error Correction based Adaptive data frame format for Optical camera communication

  • Nguyen, Quoc Huy;Kim, Hyung-O;Lee, Minwoo;Cho, Juphil;Lee, Seonhee
    • International journal of advanced smart convergence
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    • v.4 no.2
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    • pp.94-102
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    • 2015
  • Optical camera communication (OCC) is an extension of Visible Light Communication. Different from traditional visible light communication, optical camera communications is an almost no additional cost technology by taking the advantage of build-in camera in devices. It was became a candidate for communication protocol for IoT. Camera module can be easy attached to IoT device, because it is small and flexible. Furthermore almost smartphone equip one or two camera for both back and font side with high quality and resolution. It can be utilized for receiving the data from LED or positioning. Actually, OCC combines illumination and communication. It can supply communication for special areas or environment where do not allow Radio frequency such as hospital, airplane etc. There are many concept and experiment be proposed. In this paper we proposed utilizing Android smart-phone camera for receiver and introduce new approach in modulation scheme for LED at transmitter. It also show how Manchester coding can be used encode bits while at the same time being successfully decoded by Android smart-phone camera. We introduce new data frame format for easy decoded and can be achieve high bit rate. This format can be easy to adapt to performance limit of Android operator or embedded system.