• Title/Summary/Keyword: spot detection

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Biosensors for On-the-spot Detection of Bacteria from Foods (식품 유래 박테리아 현장검출용 바이오센서)

  • Lee, Won-Il;Kim, Bo-Yeong;Son, Young-Min;Kim, Ari;Lee, Nae-Eung
    • Journal of Sensor Science and Technology
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    • v.25 no.5
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    • pp.354-364
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    • 2016
  • Recently there have been extensive research activities on the development of on-the-spot detection technologies for bacteria from foods due to growing high demand for food safety. In particular, on-the-spot detection devices using biosensors with rapid, highly sensitive and multiplexed sensing capability are promising for portable or mobile applications. Firstly, issues related to on-the-spot bacteria detection are discussed. Then, detection methods for bacteria, types of biosensors depending on transducing principle and receptors, and platforms for integration of biosensors and signal readers are reviewed. Finally, prospects for development of on-the-spot detection devices are summarized.

Detection Algorithm of Lenslet Array Spot Pattern for Acquisition of Laser Wavefront (레이저 파면 획득용 Lenslet Array 점 패턴 검출 알고리즘)

  • Lee, Jae-Il;Lee, Young-Cheol;Huh, Joon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.8 no.4 s.23
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    • pp.110-119
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    • 2005
  • In this paper, a new detection algorithm was proposed for finding the position of lenslet array spot pattern used to acquire laser wavefront. Based on the analysis of the required signal processing characteristics, we categorized into and designed four main signal processing functions. The proposed was designed in order to have robust feature against a variation of geometrical form of the spot and also implemented to have semi-automatic thresholding capability based on CCD noise analysis. For performance evaluation, we made qualitative and quantitative comparisons with Carvalho's algorithm which has been published in recent. In the given experimental spot images, the proposed could detect the spots which has 1/3 times lower than the least S/N of which Carvalho's can detect and could reach to a detection precision of 0.1 pixel at the S/N. In functional aspect, the proposed could separate all valid spots locally. From these results, the proposed could have a superior precision of location detection of spot pattern in wider S/N range.

Night-Time Blind Spot Vehicle Detection Using Visual Property of Head-Lamp (전조등의 시각적 특성을 이용한 야간 사각 지대 차량 검출 기법)

  • Joung, Jung-Eun;Kim, Hyun-Koo;Park, Ju-Hyun;Jung, Ho-Youl
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.5
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    • pp.311-317
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    • 2011
  • The blind spot is an area where drivers visibility does not reach. When drivers change a lane to adjacent lane, they need to give an attention because of the blind spot. If drivers try to change lane without notice of vehicle approaching in the blind spot, it causes a reason to have a car accident. This paper proposes a night-time blind spot vehicle detection using cameras. At nighttime, head-lights are used as characteristics to detect vehicles. Candidates of headlight are selected by high luminance feature and then shape filter and kalman filter are employed to remove other noisy blobs having similar luminance to head-lights. In addition, vehicle position is estimated from detected head-light, using virtual center line represented by approximated the first order linear equation. Experiments show that proposed method has relatively high detection porformance in clear weather independent to the road types, but has not sufficient performance in rainy weather because of various ground reflectors.

Detection of Landmark Spots for Spot Matching in 2DGE (2차원 전기영동 영상의 스팟 정합을 위한 Landmark 스팟쌍의 검출)

  • Han, Chan-Myeong;Suk, Soo-Young;Yoon, Young-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.14 no.3
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    • pp.105-111
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    • 2011
  • Landmark Spots in 2D gel electrophoresis are used in many methods of 2DEG spot matching. Landmark Spots are obtained manually and it is a bottle neck in the entire protein analysis process. Automated landmark spots detection is a very crucial topic in processing a massive amount of 2DGE data. In this paper, Automated landmark spot detection is proposed using point pattern matching and graph theory. Neighbor spots are defined by a graph theory to use and only a centered spot and its neighbor spots are considered for spot matching. Normalized Hausdorff distance is introduced as a criterion for measuring degree of similarity. In the conclusion, the method proposed in this paper can get about 50% of the total spot pairs and the accuracy rate is almost 100%, which the requirements of landmark spots are fully satisfied.

New Vehicle Verification Scheme for Blind Spot Area Based on Imaging Sensor System

  • Hong, Gwang-Soo;Lee, Jong-Hyeok;Lee, Young-Woon;Kim, Byung-Gyu
    • Journal of Multimedia Information System
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    • v.4 no.1
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    • pp.9-18
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    • 2017
  • Ubiquitous computing is a novel paradigm that is rapidly gaining in the scenario of wireless communications and telecommunications for realizing smart world. As rapid development of sensor technology, smart sensor system becomes more popular in automobile or vehicle. In this study, a new vehicle detection mechanism in real-time for blind spot area is proposed based on imaging sensors. To determine the position of other vehicles on the road is important for operation of driver assistance systems (DASs) to increase driving safety. As the result, blind spot detection of vehicles is addressed using an automobile detection algorithm for blind spots. The proposed vehicle verification utilizes the height and angle of a rear-looking vehicle mounted camera. Candidate vehicle information is extracted using adaptive shadow detection based on brightness values of an image of a vehicle area. The vehicle is verified using a training set with Haar-like features of candidate vehicles. Using these processes, moving vehicles can be detected in blind spots. The detection ratio of true vehicles was 91.1% in blind spots based on various experimental results.

Hot Spot Detection of Thermal Infrared Image of Photovoltaic Power Station Based on Multi-Task Fusion

  • Xu Han;Xianhao Wang;Chong Chen;Gong Li;Changhao Piao
    • Journal of Information Processing Systems
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    • v.19 no.6
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    • pp.791-802
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    • 2023
  • The manual inspection of photovoltaic (PV) panels to meet the requirements of inspection work for large-scale PV power plants is challenging. We present a hot spot detection and positioning method to detect hot spots in batches and locate their latitudes and longitudes. First, a network based on the YOLOv3 architecture was utilized to identify hot spots. The innovation is to modify the RU_1 unit in the YOLOv3 model for hot spot detection in the far field of view and add a neural network residual unit for fusion. In addition, because of the misidentification problem in the infrared images of the solar PV panels, the DeepLab v3+ model was adopted to segment the PV panels to filter out the misidentification caused by bright spots on the ground. Finally, the latitude and longitude of the hot spot are calculated according to the geometric positioning method utilizing known information such as the drone's yaw angle, shooting height, and lens field-of-view. The experimental results indicate that the hot spot recognition rate accuracy is above 98%. When keeping the drone 25 m off the ground, the hot spot positioning error is at the decimeter level.

Real-Time Side-Rear Vehicle Detection Algorithm for Blind Spot Warning Systems (사각지역경보시스템을 위한 실시간 측후방 차량검출 알고리즘)

  • Kang, Hyunwoo;Baek, Jang Woon;Han, Byung-Gil;Chung, Yoonsu
    • KIISE Transactions on Computing Practices
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    • v.23 no.7
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    • pp.408-416
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    • 2017
  • This paper proposes a real-time side-rear vehicle detection algorithm that detects vehicles quickly and accurately in blind spot areas when driving. The proposed algorithm uses a cascade classifier created by AdaBoost Learning using the MCT (modified census transformation) feature vector. Using this classifier, the smaller the detection window, the faster the processing speed of the MCT classifier, and the larger the detection window, the greater the accuracy of the MCT classifier. By considering these characteristics, the proposed algorithm uses two classifiers with different detection window sizes. The first classifier quickly generates candidates with a small detection window. The second classifier accurately verifies the generated candidates with a large detection window. Furthermore, the vehicle classifier and the wheel classifier are simultaneously used to effectively detect a vehicle entering the blind spot area, along with an adjacent vehicle in the blind spot area.

Effect of the Incident Optical Spot Size Upon the Quadrant Photodetector on the Optical Displacement Detection Sensitivity (4분할 광 검출기 상의 광점 크기가 변위 측정감도에 미치는 영향)

  • Lee, Eun-Joong;Lee, Jin-Woo;Kouh, Tae-Joon
    • Journal of the Korean Magnetics Society
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    • v.18 no.2
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    • pp.71-74
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    • 2008
  • In this paper, we have measured the effect of the optical spot size, incident upon the quadrant photodetector, on the optical displacement sensitivity of the optical beam deflection technique. We have built an optical displacement detection system based on the optical beam deflection method using 3 mW He-Ne laser and measured the displacement sensitivity with changing the optical spot size on the quadrant photodetector. We have also calculated the changes in the optical displacement sensitivity as a function of the incident laser spot size by modeling a circular optical spot with constant laser intensity. Our experimental and theoretical studies show that the optical displacement sensitivity increases with the decrease in the optical spot size. This suggests that in the design of the optical motion detection systems with sub-nanometer sensitivity, the displacement sensitivity can be optimized by reducing the size of the incident optical spot on the detector.

Laser Spot Detection Using Robust Dictionary Construction and Update

  • Wang, Zhihua;Piao, Yongri;Jin, Minglu
    • Journal of information and communication convergence engineering
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    • v.13 no.1
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    • pp.42-49
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    • 2015
  • In laser pointer interaction systems, laser spot detection is one of the most important technologies, and most of the challenges in this area are related to the varying backgrounds, and the real-time performance of the interaction system. In this paper, we present a robust dictionary construction and update algorithm based on a sparse model of background subtraction. In order to control dynamic backgrounds, first, we determine whether there is a change in the backgrounds; if this is true, the new background can be directly added to the dictionary configurations; otherwise, we run an online cumulative average on the backgrounds to update the dictionary. The proposed dictionary construction and update algorithm for laser spot detection, is robust to the varying backgrounds and noises, and can be implemented in real time. A large number of experimental results have confirmed the superior performance of the proposed method in terms of the detection error and real-time implementation.

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

  • Park, Sung-Ho;Kim, Dong Uk;Do, Yongtae
    • Journal of Sensor Science and Technology
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    • v.27 no.4
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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.