• 제목/요약/키워드: brightness control

검색결과 420건 처리시간 0.031초

AUTOMATIC ORTHORECTIFICATION OF AIRBORNE IMAGERY USING GPS/INS DATA

  • Jang, Jae-Dong;Kim, Young-Seup;Yoon, Hong-Joo
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.684-687
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    • 2006
  • Airborne imagery must be precisely orthorectified to be used as geographical information data. GPS/INS (Global Positioning System/Inertial Navigation System) and LIDAR (LIght Detection And Ranging) data were employed to automatically orthorectify airborne images. In this study, 154 frame airborne images and LIDAR vector data were acquired. LIDAR vector data were converted to raster image for employing as reference data. To derive images with constant brightness, flat field correction was applied to the whole images. The airborne images were geometrically corrected by calculating internal orientation and external orientation using GPS/INS data and then orthorectified using LIDAR digital elevation model image. The precision of orthorectified images was validated using 50 ground control points collected in arbitrary selected five images and LIDAR intensity image. In validation results, RMSE (Root Mean Square Error) was 0.365 smaller then two times of pixel spatial resolution at the surface. It is possible that the derived mosaicked airborne image by this automatic orthorectification method is employed as geographical information data.

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Study on the Characteristic of Eye Movement for Visual Improvement of the Elderly

  • Yu, Mi;Piao, Yong-Jun;Kim, Yong-Yook;Kwon, Tae-Kyu;Hong, Chul-Un;Kim, Nam-Gyun
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.202-205
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    • 2005
  • The purpose of this work is to identify the characteristic of eye movement for visual training of the elderly. This investigation is to examine the relationship between the head and the eye motor system for the localization of visual target direction in three-dimensional space. All experiments were performed in a soundproof chamber. Twenty-one red LEDs (Light-Emitting Diode, Brightness: 20cd/$m^2$) arrayed in three lines on a half circle-surrounding panel are used. LEDs are horizontally 30 degree apart and vertically 20 degree apart from each other. The condition of stimulation is random and anti-saccade. Physiological parameter such as EOG (Electro-Oculography) was measured by BIOPAC system. We measure the mean latency time, which is the time from the start of visual stimulation to the response of the human body. The result shows that the mean latency time is short in the case of the condition of anti-saccade, the fixed head and a quarter visual stimulation. This finding can be used in developing programs for various visual improvements for the elderly by analyzing the characteristic of eye movement.

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LED Backlight Driving Circuits and Dimming Method

  • Kwon, Oh-Kyong;Jung, Young-Ho;Lee, Yong-Hak;Cho, Hyun-Suk;Nam, Ki-Soo;In, Hai-Jung
    • Journal of Information Display
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    • 제11권4호
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    • pp.173-181
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    • 2010
  • In this paper, light-emitting-diode (LED) backlight driving circuits and dimming method for medium-sized and large liquid crystal displays (LCDs) are proposed. The double loop control method, the intelligent-phase-shifted PWM dimming method, the fast-switching current regulator, and the current matching techniques are proposed to improve not only the current regulation characteristics and the power efficiency but also the current matching characteristics and the transient response of the LED current. The brightness of the backlight using the proposed local dimming method was determined from the histogram of the local block to reduce the power consumption of the backlight without image distortion. The measured maximum power efficiency of the LED backlight driving circuit for medium-sized LCDs was 90%, and the simulation results showed an 88% maximum power efficiency of the LED backlight driving circuit for large LCDs. The maximum backlight power-saving ratio of the proposed dimming method was 41.7% in the simulation with a high-contrast image. The experiment and simulation results showed that the performance of LEDs as LCD backlight units (BLUs) improved with the proposed circuits and method.

PHEV용 Charge Indicator 시험기 개발 (Development of Charge Indicator Inspection System for Plug-in Hybrid Electric Vehicle)

  • 김진영;강준희
    • 센서학회지
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    • 제25권2호
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    • pp.155-159
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    • 2016
  • In this work, we have developed a test system to examine whether the charge indicator of the plug-in hybrid electric vehicle (PHEV) works properly or not. In PHEV, the driver should charge the necessary electricity by plugging in manually and be able to know the charging status through the charge indicator conveniently located for the charging individual. Our system used the CAN bus to transmit the same commands from ECU to the indicator to test the proper operation of the indicator lights. It measured the electric current values during operation and analyzed to determine the quality of the indicators. The inspection items included the proper packaging, the electrical shorts, the LED lighting during charging, the LED lighting for charging failure, and the LED lighting when errors occur. We developed the system for the operators in the factory allowing them to approve the test results at the site. We developed the hardware, the control software, and the software to store the test results and the history of the products in the database. Serial numbers were given to the good quality products and the bar code labels were printed to trace the products afterwards. Through this work, we developed a system to inspect the electric parts in real time upon fabrication. We are planning to further improve our system to inspect the brightness of the indicator by adding the vision inspection in future.

Visual Sensing of the Light Spot of a Laser Pointer for Robotic Applications

  • Park, Sung-Ho;Kim, Dong Uk;Do, Yongtae
    • 센서학회지
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    • 제27권4호
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    • pp.216-220
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    • 2018
  • In this paper, we present visual sensing techniques that can be used to teach a robot using a laser pointer. The light spot of an off-the-shelf laser pointer is detected and its movement is tracked on consecutive images of a camera. The three-dimensional position of the spot is calculated using stereo cameras. The light spot on the image is detected based on its color, brightness, and shape. The detection results in a binary image, and morphological processing steps are performed on the image to refine the detection. The movement of the laser spot is measured using two methods. The first is a simple method of specifying the region of interest (ROI) centered at the current location of the light spot and finding the spot within the ROI on the next image. It is assumed that the movement of the spot is not large on two consecutive images. The second method is using a Kalman filter, which has been widely employed in trajectory estimation problems. In our simulation study of various cases, Kalman filtering shows better results mostly. However, there is a problem of fitting the system model of the filter to the pattern of the spot movement.

GENERATION OF AN IMPERVIOUS MAP BY APPLYING TASSELED-CAP ENHANCEMENT USING KOMPSAT-2 IMAGE

  • Koh, Chang-Hwan;Ha, Sung-Ryong
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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    • pp.378-381
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    • 2008
  • The regulating and relaxing targets in the Land Use Regulation and Total Maximum Daily Loads are influenced by Land cover information. For the providing more accurate land information, this study attempted to generate an impervious surface map using KOMPSAT-2 image which a Korea manufactured high resolution satellite image. The classification progress of this study carried out by tasseled-cap spectral enhancement through each class extraction technique neither existing classification method. KOMPSAT-2 image of this study is enhanced by Soil Brightness Index(SBI), Green vegetation Index(GVI), None-Such wetness Index(NWI). Then ranges of extracted each index in enhanced image are determined. And then, Confidence Interval of classes was determined through the calculating Non-exceedance Probability. Spectral distributions of each class are changed according to changing of Control coefficient(${\alpha}$) at the calculated Non-exceedance Probability. Previously, Land cover classification map was generated based on established ranges of classes, and then, pervious and impervious surface was reclassified. Finally, impervious ratio of reclassified impervious surface map was calculated with blocks in the study area.

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아로니아 분말 첨가량에 따른 아로니아 앙금의 항산화 활성 및 품질 특성 (Quality Characteristics and Antioxidant Effects of White Bean Paste added Aronia Powder)

  • 이정애
    • 한국조리학회지
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    • 제23권3호
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    • pp.29-37
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    • 2017
  • This study investigated the physicochemical and sensory characteristics of white bean paste prepared with various amounts of aronia powder (as ratios of 0%, 2%, 4%, 6%, 8%, 10%). The result shows that the pH of white bean paste decreased significantly with the addition of aronia powder. From chromatography, the brightness, L-value was decreased by increasing the adding rate of aronia powder. The a-value of sample group adding 2% of aronia powder was the highest and that of sample group adding 8% was the lowest (p<0.01). Sample group adding 8% of aronia powder achieved the highest appraisal from many factors, such as springiness, cohesiveness, chewiness, brittleness, and adhesiveness. The total polyphenols and anthocyanin contents were proportionally increased with increasing the level of aronia powder added in white bean paste. The antioxidant activity measured by DPPH and NSA radical scavenging activities was significantly higher than control and increased proportionally to the aronia powder concentration. The result of sensory test shows that sample group adding 6% of aronia powder achieved the highest. Based on the above results, this study suggests that the addition of 6% aronia powder may be the best substitution ratio for white bean paste of the improvement of sensory preference and antioxidant.

위성 적외영상 자료를 이용한 현업용 기상레이더 반사도 합성자료의 채프에코 제거 (Elimination of Chaff Echoes in Reflectivity Composite from an Operational Weather Radar Network using Infrared Satellite Data)

  • 한혜영;허복행;정성화;이규원;유철환;이종호
    • 대기
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    • 제21권3호
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    • pp.285-300
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    • 2011
  • To discriminate and eliminate chaff echoes in radar measurements, a new removal algorithm in two-dimensional reflectivity composite at the height of 1.5 km has been developed by using the brightness temperature($T_B$) obtained from MTSAT-1R. This algorithm utilizes the fact that chaffs are not appeared in infrared satellite data of MTSAT-1R, but detected in radar measurements due to their significant backscattering in the given radar wavelength. The algorithm is evaluated for three different situations: chaff only, chaff mixed with convective storms, and chaff covered with clouds. The algorithm shows excellent performance for the cases of chaff only and chaff mixed with convective storms. However, the performance of the algorithm significantly depends on the presence of clouds. Thus, the statistical analysis of $T_B$ is performed in order to optimize the monthly threshold.

Effect of PFI mill and Valley beater refining on cellulose degree of polymerization, alpha cellulose contents, and crystallinity of wood and cotton fibers

  • Hai, Le Van;Park, Hee Jung;Seo, Yung Bum
    • 펄프종이기술
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    • 제45권4호
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    • pp.27-33
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    • 2013
  • Manufacturing fabrics from dissolving cellulosic pulp is increasing in these days. For making high quality of cellulose-based fabrics, control of cellulose DP (degree of polymerization), its alpha cellulose content, its brightness, and its crystallinity are important. To process the cellulosic raw material, refining of cellulosic fibers is essential, and it is important to know if refining affects those important cellulose properties. The effects of PFI mill and Valley beater refining on the alpha-cellulose content, cellulose DP, crystallinity, and paper mechanical properties of wood and two different cotton fibers were studied. The results showed that PFI mill refining rarely affected those properties. Fibers refined by a Valley beater displayed a small reduction in fiber length in comparison with those refined by a PFI mill. However, the Valley beater refining method produced almost no changes in cellulose properties, either. The refining process seemed to have very little effect on the cellulose DP, crystallinity index, or alpha-cellulose content until the freeness decreased to around 300 mL CSF for wood and 100 mL CSF for cotton fibers, respectively. There were also no differences in tensile strength development in two refining methods.

Characteristics of electric field in the liquid metal ion source with a suppressor

  • Min, Boo-Ki;Cho, Byeong-Seong;Oh, Hyun-Joo;Kang, Seung-Oun;Choi, Eun-Ha
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.283-283
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    • 2010
  • The liquid metal ion sources(LMIS) in FIB system have many advantages of high current density, high brightness and low ion energy spread. Most FIB systems use LMIS because the ion beam spot size of LMIS is smaller than other ion sources. LMIS is basically emitted by an extractor but the new electrode called the suppressor is able to control the emission current. We investigated characteristics LMIS with a suppressor, the function of the suppressor in LMIS, the change of the electric field by the suppressor and the advantages of using the suppressor. The characteristics of the threshold voltage and current-voltage (I-V) were observed under the varying extracting voltage with floated suppressor voltage, and under the varying suppressor voltages with fixed extractor voltage. We also simulated LMIS with the suppressor through CST(Computer Simulation Technology). The emission current increases as the suppressor voltage decreases because the suppressor voltage which restrains the electric field goes down, The threshold voltage increases as the suppressor voltage increases. We can explain characteristics and functions of LMIS with a suppressor using the electric field.

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