• Title/Summary/Keyword: Light sensing

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Design & Test of Stereo Camera Ground Model for Lunar Exploration

  • Heo, Haeng-Pal;Park, Jong-Euk;Shin, Sang-Youn;Yong, Sang-Soon
    • Korean Journal of Remote Sensing
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    • v.28 no.6
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    • pp.693-704
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    • 2012
  • Space-born remote sensing camera systems tend to be developed to have very high performances. They are developed to provide extremely small ground sample distance, wide swath width, and good MTF (Modulation Transfer Function) at the expense of big volume, massive weight, and big power consumption. Therefore, the camera system occupies relatively big portion of the satellite bus from the point of mass and volume. However, the camera systems for lunar exploration don't need to have such high performances. Instead, it should be versatile for various usages under various operating environments. It should be light and small and should consume small power. In order to be used for national program of lunar exploration, electro-optical versatile camera system, called MAEPLE (Multi-Application Electro-Optical Payload for Lunar Exploration), has been designed after the derivation of camera system requirements. A ground model of the camera system has been manufactured to identify and secure relevant key technologies. The ground model was mounted on an aircraft and checked if the basic design concept would be valid and versatile functions implemented on the camera system would worked properly. In this paper, results of design and functional test performed with the field campaigns and air-born imaging are introduced.

Applications of Ground-Based Remote Sensing for Precision Agriculture

  • Hong Soon-Dal;Schepers James S.
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2005.08a
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    • pp.100-113
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    • 2005
  • Leaf color and plant vigor are key indicators of crop health. These visual plant attributes are frequently used by greenhouse managers, producers, and consultants to make water, nutrient, and disease management decisions. Remote sensing techniques can quickly quantify soil and plant attributes, but it requires humans to translate such data into meaningful information. Over time, scientists have used reflectance data from individual wavebands to develop a series of indices that attempt to quantify things like soil organic matter content, leaf chlorophyll concentration, leaf area index, vegetative cover, amount of living biomass, and grain yield. The recent introduction of active sensors that function independent of natural light has greatly expanded the capabilities of scientists and managers to obtain useful information. Characteristics and limitations of active sensors need to be understood to optimize their use for making improved management decisions. Pot experiments involving sand culture were conducted in 2003 and 2004 in a green house to evaluate corn and red pepper biomass. The rNDVI, gNDVI and aNDVI by ground-based remote sensors were used for evaluation of corn and red pepper biomass. The result obtained from the case study was shown that ground remote sensing as a non-destructive real-time assessment of plant nitrogen status was thought to be a useful tool for in season crop nitrogen management providing both spatial and temporal information.

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LCD Embedded Hybrid Touch Screen Panel Based on a-Si:H TFT

  • You, Bong-Hyun;Lee, Byoung-Jun;Lee, Jae-Hoon;Koh, Jai-Hyun;Takahashi, Seiki;Shin, Sung-Tae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.964-967
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    • 2009
  • A new hybrid-type touch screen panel (TSP) has been developed based on a-Si:H TFT which can detect the change of both $C_{LC}$ and photo-current. This TSP can detect the difference of $C_{LC}$ between touch and no-touch states in unfavorable conditions such as dark ambient light and shadows. The hybrid TSP sensor consists of a detection area which includes one TFT for photo sensing and two TFTs for amplification. Compared to a single internal capacitive TSP or an optical sensing TSP, this new proposed hybrid-type TSP enables larger sensing margin due to embedding of both optical and capacitive sensors.

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Automatic Model Helicopter for using in the Remote Sensing (리모트 계측을 위한 소형 헬리콥터 개발)

  • Kim, Hee-Chul;Kang, Chul-Ung;Lim, Jong-Hwan;Kim, Seong-Gun
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.168-171
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    • 2003
  • We introduced a small-sized automatic model helicopter for using in the remote sensing. The feature of our helicopter system is that the helicopter system is realized using commercialized radio-controlled model helicopter, whose payload is 1.5 kg. Therefore, our system has may benefits when apply our system to practical tasks. The compactness and light-weight of our system is realized by the introduction of our original technique to suppress the vibration noise using a slimy material as well as the introduction of latest sensors and semiconductor products. Submerging the acceleration sensor into a slimy material, moise ratio is highly improved. In this paper, we show an experimental results for the effect of our orignal technique to remove the vibration noise of helicopter. The result of hovering flying test shows the effectiveness of our system.

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Satellite Monitoring and Prediction for the Occurrence of the Red Tide in the Middle Coastal Area in the South Sea of Korea

  • Yoon, Hong-Joo;Kim, Young-Seup
    • Korean Journal of Remote Sensing
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    • v.19 no.1
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    • pp.21-30
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    • 2003
  • It was studied the relationship between the red tide occurrence and the meteorological and oceanographic factors, the choice of potential area for red tide occurrence, and the satellite monitoring for red tide. From 1990 through 2001, the red tide continuously appeared and the number of red tide occurrence increased every year. Then, the red tide bloomed during the periods of July and August. An important meteorological factor governing the mechanisms of the increasing in number of red tide occurrence was heavy precipitation. Oceanographic factors of favorable marine environmental conditions for the red tide formation included warm water temperature, low salinity, high suspended solid, low phosphorus, low nitrogen. A common condition for the red tide occurrence was heavy precipitation 2∼4 days earlier, and the favorable conditions for the red tide formation were high air temperature, proper sunshine and light winds for the day in red tide occurrence. From satellite images, it was possible to monitor the spatial distributions and concentrations of red tide. It was founded the potential areas for red tide occurrence in August 2000 by CIS conception: Yeosu∼Dolsan coast, Gamak bay, Namhae coast, Marado coast, Goheung coast, Deukryang bay, respectively.

Surface Deformation Measurement of the 2020 Mw 6.4 Petrinja, Croatia Earthquake Using Sentinel-1 SAR Data

  • Achmad, Arief Rizqiyanto;Lee, Chang-Wook
    • Korean Journal of Remote Sensing
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    • v.37 no.1
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    • pp.139-151
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    • 2021
  • By the end of December 2020, an earthquake with Mw about 6.4 hit Sisak-Moslavina County, Croatia. The town of Petrinja was the most affected region with major power outage and many buildings collapsed. The damage also affected neighbor countries such as Bosnia and Herzegovina and Slovenia. As a light of this devastating event, a deformation map due to this earthquake could be generated by using remote sensing imagery from Sentinel-1 SAR data. InSAR could be used as deformation map but still affected with noise factor that could problematize the exact deformation value for further research. Thus in this study, 17 SAR data from Sentinel-1 satellite is used in order to generate the multi-temporal interferometry utilize Stanford Method for Persistent Scatterers (StaMPS). Mean deformation map that has been compensated from error factors such as atmospheric, topographic, temporal, and baseline errors are generated. Okada model then applied to the mean deformation result to generate the modeled earthquake, resulting the deformation is mostly dominated by strike-slip with 3 meter deformation as right lateral strike-slip. The Okada sources are having 11.63 km in length, 2.45 km in width, and 5.46 km in depth with the dip angle are about 84.47° and strike angle are about 142.88° from the north direction. The results from this modeling can be used as learning material to understand the seismic activity in the latest 2020 Petrinja, Croatia Earthquake.

A Study on Oil's Contamination Detection System using Optical Fiber Sensor (광섬유 센서를 이용한 오일 오염도 검사시스템 연구)

  • Song, Doo-Sang;Hong, Jun-Hee;Ryu, Sang-Hyun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.4
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    • pp.541-546
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    • 2012
  • This study investigates the detection system of oil pollution level using single optical fiber sensor. This study focus on sensing of oil pollution by moisture and iron powder which are representatives of oil pollution factor. In addition, It is placed that the water and iron powder as an oil pollution factor in the oil tank which is the oil circulation in. The oil pollution detection system was measured by the changing of intensity of light and sensing gap. The result of this experimentation not only confirmed the contamination by moisture volume in the oil tank from the section 190ppm to 540ppm, but also monitored the contamination by iron volume from the section 1200ppm to 3500ppm. This study confirmed effectiveness of this detection system using optical fiber sensor. There is expectations of measuring another section by various optical fiber sensor.

The Fabrication and Characteristics of the Pyroelectric IR Sensor using P(VDF/TrFE) Thin Films Fabricated by the Spin Coating Technique

  • Kwon, Sung-Yeol
    • KIEE International Transactions on Electrophysics and Applications
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    • v.12C no.4
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    • pp.225-228
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    • 2002
  • The pyroelectric sensor of P(VDF/TrFE) film as sensing materials has been fabricated and evaluated with another commercial pyroelectric sensor using ceramic materials for sensing, The device was mounted in TO-5 housing to detect infrared light of a 5.5~14 ${\mu}{\textrm}{m}$ wavelength. The NEP(noise equivalent power) and specific detectivity D* of the device were 2.13$\times$10$^{-8}$ W and 9.37 10$^{6}$ cm/W under emission energy of 13 ㎼/$\textrm{cm}^2$, respectively.

A Study on Automatic Seam Tracking using Vision Sensor (비전센서를 이용한 자동추적장치에 관한 연구)

  • 전진환;조택동;양상민
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.1105-1109
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    • 1995
  • A CCD-camera, which is structured with vision system, was used to realize automatic seam-tracking system and 3-D information which is needed to generate torch path, was obtained by using laser-slip beam. To extract laser strip and obtain welding-specific point, Adaptive Hough-transformation was used. Although the basic Hough transformation takes too much time to process image on line, it has a tendency to be robust to the noises as like spatter. For that reson, it was complemented with Adaptive Hough transformation to have an on-line processing ability for scanning a welding-specific point. the dead zone,where the sensing of weld line is impossible, is eliminated by rotating the camera with its rotating axis centered at welding torch. The camera angle is controlled so as to get the minimum image data for the sensing of weld line, hence the image processing time is reduced. The fuzzy controller is adapted to control the camera angle.

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High Efficiency Multi-Channel LED Driver IC with Low Current-Balance Error Using Current-Mode Current Regulator

  • Yoon, Seong-Jin;Cho, Je-Kwang;Hwang, In-Chul
    • Journal of Electrical Engineering and Technology
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    • v.12 no.4
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    • pp.1593-1599
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    • 2017
  • This paper presents a multi-channel light-emitting diode (LED) driver IC with a current-mode current regulator. The proposed current regulator replaces resistors for current sensing with a sequentially controlled single current sensor and a single regulation loop for sensing and regulating all LED channel currents. This minimizes the current mismatch among the LED channels and increases voltage headroom or, equivalently, power efficiency. The proposed LED driver IC was fabricated in a $0.35-{\mu}m$ BCD 60-V high voltage process, and the chip area is $1.06mm^2$. The measured maximum power efficiency is 93.4 % from a 12-V input, and the inter-channel current error is smaller than as low as ${\pm}1.3%$ in overall operating region.