• Title/Summary/Keyword: photo-detection

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A DLRF(Diode Laser Range Finder) Using the Cumulative Binary Detection Algorithm (레이저 다이오드를 이용한 이진 신호누적 방식의 거리측정기 기술)

  • Yang, Dong-Won
    • Journal of the Korea Institute of Military Science and Technology
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    • v.10 no.4
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    • pp.152-159
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    • 2007
  • In this paper, a new design technique on the LRF which is useful for low power laser and a CBDA(Cummulative Binary Detection Algorithm) is proposed. The LD(Laser Diode) and Si-APD(Silicon Avalanche Photo Diode) are used for saving a power. In order to prove the detection range, the Si-APD binary data are accumulated before the range computation and the range finding algorithm. A prototype of the proposed DLRF(Diode Laser Range Finder) system was made and tested. An experimental result shows that the DLRF system have the same detection range using a less power(almost 1/32) than an usual military LRF. The proposed DLRF can be applied to the Unmanned Vehicles, Robot and Future Combat System of a tiny size and a low power LRF.

Vision chip for edge detection with a function of pixel FPN reduction (픽셀의 고정 패턴 잡음을 감소시킨 윤곽 검출용 시각칩)

  • Suh, Sung-Ho;Kim, Jung-Hwan;Kong, Jae-Sung;Shin, Jang-Kyoo
    • Journal of Sensor Science and Technology
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    • v.14 no.3
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    • pp.191-197
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    • 2005
  • When fabricating a vision chip, we should consider the noise problem, such as the fixed pattern noise(FPN) due to the process variation. In this paper, we propose an edge-detection circuit based on biological retina using the offset-free column readout circuit to reduce the FPN occurring in the photo-detector. The offset-free column readout circuit consists of one source follower, one capacitor and five transmission gates. As a result, it is simpler and smaller than a general correlated double sampling(CDS) circuit. A vision chip for edge detection has been designed and fabricated using $0.35\;{\mu}m$ 2-poly 4-metal CMOS technology, and its output characteristics have been investigated.

Fast Detection of Forgery Image using Discrete Cosine Transform Four Step Search Algorithm

  • Shin, Yong-Dal;Cho, Yong-Suk
    • Journal of Korea Multimedia Society
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    • v.22 no.5
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    • pp.527-534
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    • 2019
  • Recently, Photo editing softwares such as digital cameras, Paintshop Pro, and Photoshop digital can create counterfeit images easily. Various techniques for detection of tamper images or forgery images have been proposed in the literature. A form of digital forgery is copy-move image forgery. Copy-move is one of the forgeries and is used wherever you need to cover a part of the image to add or remove information. Copy-move image forgery refers to copying a specific area of an image itself and pasting it into another area of the same image. The purpose of copy-move image forgery detection is to detect the same or very similar region image within the original image. In this paper, we proposed fast detection of forgery image using four step search based on discrete cosine transform and a four step search algorithm using discrete cosine transform (FSSDCT). The computational complexity of our algorithm reduced 34.23 % than conventional DCT three step search algorithm (DCTTSS).

Quinine Assay with Home-Built UV-LED Fluorometer: Quantitative Analysis, Photo-Bleaching, Fluorescence Quenching, and Urine Analysis

  • Cheon, Tae-Min;Cheong, Byeong-Seo;Cho, Han-Gook;Kim, Jin-Hee;Kim, Kyoug-Soo
    • Journal of the Korean Chemical Society
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    • v.56 no.5
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    • pp.577-582
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    • 2012
  • Quinine quantitative analysis, photo-bleaching, fluorescence quenching, and urine analysis have been performed by means of a UV-LED fluorometer, which can be easily built and used in a high-school laboratory. The quinine detection range is estimated to be 0.05-80 ppm, enough for many classroom luminescence experiments. The quinine content in commercial tonic water is determined from the calibration curve, and UV photo-bleaching of this anti-malarial drug is demonstrated with clear wavelength dependence. Halide quenching of quinine fluorescence is also observed and the increase in quenching efficiency in the order of $Cl^-$, $Br^-$, and $I^-$ is evident. Urine analyses for the student volunteers have been carried out and the results clearly reveal excretion of the ingested quinine. The student participants are exuberant throughout the course of this study and sense the practices resourceful.

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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Influence of the Thin-Film Ag Electrode Deposition Thickness on the Current Characteristics of a CVD Diamond Radiation Detector

  • Ban, Chae-Min;Lee, Chul-Yong;Jun, Byung-Hyuk
    • Journal of Radiation Protection and Research
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    • v.43 no.4
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    • pp.131-136
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    • 2018
  • Background: We investigated the current characteristics of a thin-film Ag electrode on a chemical vapor deposition (CVD) diamond. The CVD diamond is widely recognized as a radiation detection material because of its high tolerance against high radiation, stable response to various dose rates, and good sensitivity. Additionally, thin-film Ag has been widely used as an electrode with high electrical conductivity. Materials and Methods: Considering these properties, the thin-film Ag electrode was deposited onto CVD diamonds with varied deposition thicknesses (${\fallingdotseq}50/98/152/257nm$); subsequently, the surface thickness, surface roughness, leakage current, and photo-current were characterized. Results and Discussion: The leakage current was found to be very low, and the photo-current output signal was observed as stable for a deposited film thickness of 98 nm; at this thickness, a uniform and constant surface roughness of the deposited thin-film Ag electrode were obtained. Conclusion: We found that a CVD diamond radiation detector with a thin-film Ag electrode deposition thickness close to 100 nm exhibited minimal leakage current and yielded a highly stable output signal.

Aerial Dataset Integration For Vehicle Detection Based on YOLOv4

  • Omar, Wael;Oh, Youngon;Chung, Jinwoo;Lee, Impyeong
    • Korean Journal of Remote Sensing
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    • v.37 no.4
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    • pp.747-761
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    • 2021
  • With the increasing application of UAVs in intelligent transportation systems, vehicle detection for aerial images has become an essential engineering technology and has academic research significance. In this paper, a vehicle detection method for aerial images based on the YOLOv4 deep learning algorithm is presented. At present, the most known datasets are VOC (The PASCAL Visual Object Classes Challenge), ImageNet, and COCO (Microsoft Common Objects in Context), which comply with the vehicle detection from UAV. An integrated dataset not only reflects its quantity and photo quality but also its diversity which affects the detection accuracy. The method integrates three public aerial image datasets VAID, UAVD, DOTA suitable for YOLOv4. The training model presents good test results especially for small objects, rotating objects, as well as compact and dense objects, and meets the real-time detection requirements. For future work, we will integrate one more aerial image dataset acquired by our lab to increase the number and diversity of training samples, at the same time, while meeting the real-time requirements.

Fine Gap Control Using Pneumatic Servo System (공압서보시스템에 의한 미세 간극제어 시스템 설계)

  • 김동환;김영진;정대화
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.12
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    • pp.45-56
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    • 2002
  • A pneumatic servo system requiring a fine gap control in a photo-electric sensor which is used for a LCD array detection device is introduced. The gap controlled by the pneumatic servo system remains within around 50~80 ${\mu}{\textrm}{m}$, and the system possesses an effect to eliminate undesirable particles on the LCD plate by blowing air out. The air flow rate is initially controlled by a servo valve and expanded by a booster valve, thus the controlled air pressure contributes to maintaining an appropriate gap between the LCD plate and photo-electric sensor An air floating plate of two degrees of freedom is designed and fabricated, and a fine tilting motion control is also implemented by assigning different gap commands. The pressure control and direct gap control are proposed, and each performance is verified experimentally.

Implementation of 4 Channel Photo-Plethysmogram System(I) (4 채널의 Photo-plethysmogram 시스템 구현에 관한 연구(I))

  • Kim, Hyoung-Tae;Han, Soon-Chen;Kim, Jung-Kuk;Huh, Woong;Park, Young-Bae
    • Proceedings of the IEEK Conference
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    • 2002.06e
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    • pp.253-256
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    • 2002
  • In this paper, we implement the volume pulse detection system which can quantitatively represent an artery elasticity. The system consists of transducer which has IRLED-photodiode detecter, temperature sensor, filters, preprocessing circuits, A/D converter, serial communication part and computer system. In order to presume the artery elasticity information we measure the volume pulse at four points and then evaluate the transition time, distance and the correlation coefficient of the pulse wave between the points. We test the system with 10 subjects during the week for basic experiment and obtain the data at four points. As the result of experiment, we can detect normalized volume pulse wave and evaluated parameter with effectively.

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Intelligent Immigration Control System by Using Passport Recognition and Face Verification

  • Kim, Kwang-Beak
    • Journal of the Korean Institute of Intelligent Systems
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    • v.16 no.2
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    • pp.240-246
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    • 2006
  • This paper proposes the intelligent immigration control system that authorizes the traveler through immigration and detects forged passports by using automatic recognition of passport codes, the passport photo and face verification. The proposed system extracts and deskewes the areas of passport codes from the passport image. This paper proposes the novel ART algorithm creating the adaptive clusters to the variations of input patterns and it is applied to the extracted code areas for the code recognition. After compensating heuristically the recognition result, the detection of forged passports is achieved by using the picture and face verification between the passport photo extracted from the passport image and the picture retrieved from the database based on the recognized codes. Due to the proposed ART algorithm and the heuristic refinement, the proposed system relatively shows better performance.