• Title/Summary/Keyword: boundary detection

Search Result 618, Processing Time 0.029 seconds

An Algorithm to Determine Aerosol Extinction Below Cirrus Cloud from Mie-LIDAR Signals

  • Wang, Zhenzhu;Wu, Decheng;Liu, Dong;Zhou, Jun
    • Journal of the Optical Society of Korea
    • /
    • v.14 no.4
    • /
    • pp.444-450
    • /
    • 2010
  • The traditional approach to inverting aerosol extinction makes use of the assumption of a constant LIDAR ratio in the entire Mie-LIDAR signal profile using the Fernald method. For the large uncertainty in the cloud optical depth caused by the assumed constant LIDAR ratio, an not negligible error of the retrieved aerosol extinction below the cloud will be caused in the backward integration of the Fernald method. A new algorithm to determine aerosol extinction below a cirrus cloud from Mie-LIDAR signals, based on a new cloud boundary detection method and a Mie-LIDAR signal modification method, combined with the backward integration of the Fernald method is developed. The result shows that the cloud boundary detection method is reliable, and the aerosol extinction below the cirrus cloud found by inverting from the modified signal is more efficacious than the one from the measured signal including the cloud-layer. The error due to modification is less than 10% taken in our present example.

Effective Separation Method for Single-Channel Time-Frequency Overlapped Signals Based on Improved Empirical Wavelet Transform

  • Liu, Zhipeng;Li, Lichun;Li, Huiqi;Liu, Chang
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.13 no.5
    • /
    • pp.2434-2453
    • /
    • 2019
  • To improve the separation performance of time-frequency overlapped radar and communication signals from a single channel, this paper proposes an effective separation method based on an improved empirical wavelet transform (EWT) that introduces a fast boundary detection mechanism. The fast boundary detection mechanism can be regarded as a process of searching, difference optimization, and continuity detection of the important local minima in the Fourier spectrum that enables determination of the sub-band boundary and thus allows multiple signal components to be distinguished. An orthogonal empirical wavelet filter bank that was designed for signal adaptive reconstruction is then used to separate the input time-frequency overlapped signals. The experimental results show that if two source components are completely overlapped within the time domain and the spectrum overlap ratio is less than 60%, the average separation performance is improved by approximately 32.3% when compared with the classic EWT; the proposed method also improves the suitability for multiple frequency shift keying (MFSK) and reduces the algorithm complexity.

Electrical Resistance Tomography: Mesh Grouping and Boundary Estimation Algorithms

  • Kim Sin;Cho Hyo-Sung;Lee Bong-Soo
    • International Journal of Contents
    • /
    • v.1 no.1
    • /
    • pp.1-5
    • /
    • 2005
  • This paper presents the development and application of electrical resistance imaging techniques for the visualization of two-phase flow fields. Two algorithms, the so-called the mesh grouping and the boundary estimation, are described for potential applications of electrical resistance tomography (ERT) and results from extensive numerical simulations are also presented. In the electrical resistance imaging for two-phase flows, numerical meshes fairly belonging to each phase can be grouped to improve the reconstruction performance. In many cases, the detection of phase boundary is a key subject and a mathematical model to estimate phase boundary can be formulated in a different manner. Our results indicated that the mesh grouping algorithm is effective to enhance computational performance and image quality, and boundary estimation algorithm to determine the phase boundary directly.

  • PDF

A Study on A Boundary Tracking Algorithm for Finger Crease Pattern Identification Algorithm (손가락 마디지문 패턴을 이용한 개인식별 알고리즘 구현을 위한 경계 추적 알고리즘에 관한 연구)

  • Jung, Hee-Cheol;Shin, Chango-Ho;Lee, Hyun-Youl;Choi, Hwan-Soo
    • Proceedings of the KIEE Conference
    • /
    • 1999.11c
    • /
    • pp.818-820
    • /
    • 1999
  • In this paper, a new boundary tracking algorithm for extracting finger area, which may be utilized by a finger crease pattern recognition algorithm, is proposed. Due to noise and irregular illumination, conventional algorithms for boundary tracking such as skeleton-based tracking methods were not suitable for typical boundary image of hand. So we propose a new finger boundary tracking algorithm utilizing a boundary-point-detection mask. We have observed that the proposed method provides stable and optimised boundary tracking.

  • PDF

An Improvement of AdaBoost using Boundary Classifier

  • Lee, Wonju;Cheon, Minkyu;Hyun, Chang-Ho;Park, Mignon
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.23 no.2
    • /
    • pp.166-171
    • /
    • 2013
  • The method proposed in this paper can improve the performance of the Boosting algorithm in machine learning. The proposed Boundary AdaBoost algorithm can make up for the weak points of Normal binary classifier using threshold boundary concepts. The new proposed boundary can be located near the threshold of the binary classifier. The proposed algorithm improves classification in areas where Normal binary classifier is weak. Thus, the optimal boundary final classifier can decrease error rates classified with more reasonable features. Finally, this paper derives the new algorithm's optimal solution, and it demonstrates how classifier accuracy can be improved using the proposed Boundary AdaBoost in a simulation experiment of pedestrian detection using 10-fold cross validation.

The Image Segmentation Method using Adaptive Watershed Algorithm for Region Boundary Preservation

  • Kwon, Dong-Jin
    • International Journal of Internet, Broadcasting and Communication
    • /
    • v.11 no.1
    • /
    • pp.39-46
    • /
    • 2019
  • This paper proposes an adaptive threshold watershed algorithm, which is the method used for image segmentation and boundary detection, which extends the region on the basis of regional minimum point. First, apply adaptive thresholds to determine regional minimum points. Second, it extends the region by applying adaptive thresholds based on determined regional minimum points. Traditional watershed algorithms create over-segmentation, resulting in the disadvantages of breaking boundaries between regions. These segmentation results mainly from the boundary of the object, creating an inaccurate region. To solve these problems, this paper applies an improved watershed algorithm applied with adaptive threshold in regional minimum point search and region expansion in order to reduce over-segmentation and breaking the boundary of region. This resulted in over-segmentation suppression and the result of having the boundary of precisely divided regions. The experimental results show that the proposed algorithm can apply adaptive thresholds to reduce the number of segmented regions and see that the segmented boundary parts are correct.

Mention Detection with Pointer Networks (포인터 네트워크를 이용한 멘션탐지)

  • Park, Cheoneum;Lee, Changki
    • Journal of KIISE
    • /
    • v.44 no.8
    • /
    • pp.774-781
    • /
    • 2017
  • Mention detection systems use nouns or noun phrases as a head and construct a chunk of text that defines any meaning, including a modifier. The term "mention detection" relates to the extraction of mentions in a document. In the mentions, a coreference resolution pertains to finding out if various mentions have the same meaning to each other. A pointer network is a model based on a recurrent neural network (RNN) encoder-decoder, and outputs a list of elements that correspond to input sequence. In this paper, we propose the use of mention detection using pointer networks. Our proposed model can solve the problem of overlapped mention detection, an issue that could not be solved by sequence labeling when applying the pointer network to the mention detection. As a result of this experiment, performance of the proposed mention detection model showed an F1 of 80.07%, a 7.65%p higher than rule-based mention detection; a co-reference resolution performance using this mention detection model showed a CoNLL F1 of 52.67% (mention boundary), and a CoNLL F1 of 60.11% (head boundary) that is high, 7.68%p, or 1.5%p more than coreference resolution using rule-based mention detection.

Enhanced Local Directional Pattern based video shot boundary detection and automatic synchronization for STB quality inspection (STB 품질검사를 위한 개선된 지역 방향 패턴 기반 비디오 샷 경계 검출 및 자동 동기화)

  • Cho, Youngtak;Chae, Oksam
    • Journal of Convergence for Information Technology
    • /
    • v.9 no.3
    • /
    • pp.8-15
    • /
    • 2019
  • Recently, the importance of pre-shipment quality inspection has been emphasized due to the increase of STB supply. In this paper, we propose a method to support automation of quality inspection through simultaneous multi-channel input of STB video signal. The proposed method extracts a fingerprint using the center scan line of the image after stable video shot boundary detection using CeLDP combining color information and LDP code and performs synchronization between input video channels. The proposed method shows stronger shot boundary detection performance than the conventional shot detection method. Through the experiments applied to the real environment, it is possible to secure reliability and real-time quality check for synchronization between multi-channel inputs required for STB quality inspection. Also, based on the proposed method, we intend to study a large-scale quality inspection method in the future and propose a more effective quality inspection system.

Novelty Detection using SOM-based Methods (자기구성지도 기반 방법을 이용한 이상 탐지)

  • Lee, Hyeong-Ju;Jo, Seong-Jun
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • 2005.05a
    • /
    • pp.599-606
    • /
    • 2005
  • Novelty detection involves identifying novel patterns. They are not usually available during training. Even if they are, the data quantity imbalance leads to a low classification accuracy when a supervised learning scheme is employed. Thus, an unsupervised learning scheme is often employed ignoring those few novel patterns. In this paper, we propose two ways to make use of the few available novel patterns. First, a scheme to determine local thresholds for the Self Organizing Map boundary is proposed. Second, a modification of the Learning Vector Quantization learning rule is proposed so that allows one to keep codebook vectors as far from novel patterns as possible. Experimental results are quite promising.

  • PDF

Double sheet detection system for feeder robots in automation line

  • Kim, Dae-Nyeon;Jo, Kang-Hyun;Shin, In-Seung;Kim, Ki-Su;Kim, Tae-Ho;Kang, Hyun-Duk;Yoon, Yeon-Hong;Kim, Se-Yoon;Lee, Seung-Choon
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.73.4-73
    • /
    • 2001
  • We suggest a system to detection whether material picked up is double or single when the robot feeds them in automation line. This system measures thickness of metal plate and alarms when they are double sheet measuring boundary lines of metal sheet. This system calculates the minimum distance of straight boundary lines by eliminating noise in the edge regions. In the experimental system, double or single is determined by calculating implemented the thickness in the image where the distance of pixels are retrieved by the hash table. In this paper, the algorithm of histogram is adapted to experiment in the implement, thus proved as double sheet detection system.

  • PDF