• Title/Summary/Keyword: Correlation Detection

Search Result 1,737, Processing Time 0.026 seconds

A New Formula to Predict the Exact Detection Probability of a Generalized Order Statistics CFAR Detector for a Correlated Rayleigh Target

  • Kim, Chang-Joo
    • ETRI Journal
    • /
    • v.16 no.2
    • /
    • pp.15-25
    • /
    • 1994
  • In this paper we present a new formula which can predict the exact detection probability of a generalized order statistics (GOS) constant false alarm rate (DFAR) detector for a partially correlated Rayleigh target model (0 < $ \rho$< 1) in a closed form, where $\rho$ is the correlation coefficient between returned pulses. By simply substituting a set of specific coefficient into the derived formula, one can obtain the detection probability of any kind of CFAR detector. Detectors may include the order statistics CFAR detector, the censored mean level detector, and the trimmed mean CFAR detector, but are not necessarily restricted to them. The numerical result for the first order Markov correlation model as applied to some of the detectors shows that as $\rho$ increases from zero to one, higher signal-to-noise ratio is required to achieve the same detection probability.

  • PDF

DWT-PCA Combination for Noise Detection in Wireless Sensor Networks (무선 센서 네트워크에서 노이즈 감지를 위한 DWT-PCA 조합)

  • Dang, Thien-Binh;Le, Duc-Tai;Kim, Moonseong;Choo, Hyunseung
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2020.11a
    • /
    • pp.144-146
    • /
    • 2020
  • Discrete Wavelet Transform (DWT) is an effective technique that is commonly used for detecting noise in collected data of an individual sensor. In addition, the detection accuracy can be significant improved by exploiting the correlation in the data of neighboring sensors of Wireless Sensor Networks (WSNs). Principal component analysis is the powerful technique to analyze the correlation in the multivariate data. In this paper, we propose a DWT-PCA combination scheme for noise detection (DWT-PCA-ND). Experimental results on a real dataset show a remarkably higher performance of DWT-PCA-ND comparing to conventional PCA scheme in detection of noise that is a popular anomaly in collected data of WSN.

Performance Characteristics of a Symbol Timing Detection by Superposed Difference Method for OFDM (중첩의 차분화방식에 의한 OFDM 심벌 타이밍검출 성능)

  • Joo, Chang-Bok;Park, Dong-Ho
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.44 no.2
    • /
    • pp.46-54
    • /
    • 2007
  • In this paper, we introduce the performance of improved symbol timing detection by the superposed difference type symbol timing detection method in the OFDM system. Also, we represent the maximum detection probability of symbol synchronization timing at each received delay signal in multipath channel delay profile in the correlation and difference type symbol timing detection methods. The computer simulation results show that the correlation symbol timing detection method have maximum detection probability at the lead of the nth received delay signal of highest amplitude, but the difference type symbol timing detection method always have maximum detection probability at the lead of the first received delay signal in the channel delay spread of $70nsec{\sim}217nsec$. The simulation results indicate the possibility of the perfect detection of OFDM symbol synchronization timing and it fit well with the results of improved S/N to the eb/n0 and the performance of symbol timing detection of the proposed method.

Image Path Searching using Auto and Cross Correlations

  • Kim, Young-Bin;Ryu, Kwang-Ryol
    • Journal of information and communication convergence engineering
    • /
    • v.9 no.6
    • /
    • pp.747-752
    • /
    • 2011
  • The position detection of overlapping area in the interframe for image stitching using auto and cross correlation function (ACCF) and compounding one image with the stitching algorithm is presented in this paper. ACCF is used by autocorrelation to the featured area to extract the filter mask in the reference (previous) image and the comparing (current) image is used by crosscorrelation. The stitching is detected by the position of high correlation, and aligns and stitches the image in shifting the current image based on the moving vector. The ACCF technique results in a few computations and simplicity because the filter mask is given by the featuring block, and the position is enabled to detect a bit movement. Input image captured from CMOS is used to be compared with the performance between the ACCF and the window correlation. The results of ACCF show that there is no seam and distortion at the joint parts in the stitched image, and the detection performance of the moving vector is improved to 12% in comparison with the window correlation method.

Efficient Key Detection Method in the Correlation Electromagnetic Analysis Using Peak Selection Algorithm

  • Kang, You-Sung;Choi, Doo-Ho;Chung, Byung-Ho;Cho, Hyun-Sook;Han, Dong-Guk
    • Journal of Communications and Networks
    • /
    • v.11 no.6
    • /
    • pp.556-563
    • /
    • 2009
  • A side channel analysis is a very efficient attack against small devices such as smart cards and wireless sensor nodes. In this paper, we propose an efficient key detection method using a peak selection algorithm in order to find the advanced encryption standard secret key from electromagnetic signals. The proposed method is applied to a correlation electromagnetic analysis (CEMA) attack against a wireless sensor node. Our approach results in increase in the correlation coefficient in comparison with the general CEMA. The experimental results show that the proposed method can efficiently and reliably uncover the entire 128-bit key with a small number of traces, whereas some extant methods can reveal only partial subkeys by using a large number of traces in the same conditions.

Highly Reliable Watermark Detection Algorithm using Statistical Decision Method in Wavelet Domain (웨이블릿 영역에서 통계적 판정법을 이용한 고신뢰 워터마크 검출 알고리즘)

  • 권성근;김병주;이석환;권기구;김영춘;권기룡;이건일
    • Journal of Korea Multimedia Society
    • /
    • v.6 no.1
    • /
    • pp.67-77
    • /
    • 2003
  • Watermark detection has a crucial role in copyright protection and authentication for multimedia Because be the correlation -based algorithm which has widely been used in the watermark detection doesn't utilize the distributional characteristics of cover image to be marked, its performance is not optimum. So a new detection algorithm is proposed which is optimum for multiplicative watermark embedding. By relying on statistical decision method, the proposed method is derived according to the Bayes decision theory. Neyman Pearson criterion, and distribution of wavelet coefficients, thus Permitting to minimize the missed detection probability subject to a given false detection probability The superiority of the proposed method has been tested from a robustness perspective. The results confirm the superiority of the proposed technique over classical correlation -based method.

  • PDF

Intrusion Detection System Using the Correlation of Intrusion Signature (침입신호 상관성을 이용한 침입 탐지 시스템)

  • Na Guen-Sik
    • Journal of Internet Computing and Services
    • /
    • v.5 no.2
    • /
    • pp.57-67
    • /
    • 2004
  • In this paper we present the architecture of intrusion detection system that enhances the performance of system and the correctness of intrusion detection. A network intrusion is usually composed of several steps of action taken by the attackers. Each action in the steps can be characterized by its signature. But normal and non-intrusive action can also include the same signature, It can result in incorrect detection. The presented system uses the correlation of series of signatures that consist of an intrusion. So Its decision on an intrusion is highly reliable. And variations of known intrusions can easily be detected without any knowledge of the variations.

  • PDF

Double-Talk Detection Based on Soft Decision for Acoustic Echo Suppression (음향학적 반향 제거를 위한 Soft Decision 기반의 동시통화 검출)

  • Park, Yun-Sik;Chang, Joon-Hyuk
    • The Journal of the Acoustical Society of Korea
    • /
    • v.28 no.3
    • /
    • pp.285-289
    • /
    • 2009
  • In this paper, we propose a novel double-talk detection (DTD) technique based on soft decision in the frequency domain. In the proposed method, global near-end speech presence probability (GNSPP) considering the statistical model assumption and voice activity detection (VAD) decision of the near-end and far-end signal are applied to the DTD algorithm in the frequency domain instead of the traditional hard decision scheme using cross-correlation coefficients. The performance of the proposed algorithm is evaluated by the objective test under various environments, and yields better results compared with the conventional scheme.

Damage detection of subway tunnel lining through statistical pattern recognition

  • Yu, Hong;Zhu, Hong P.;Weng, Shun;Gao, Fei;Luo, Hui;Ai, De M.
    • Structural Monitoring and Maintenance
    • /
    • v.5 no.2
    • /
    • pp.231-242
    • /
    • 2018
  • Subway tunnel structure has been rapidly developed in many cities for its strong transport capacity. The model-based damage detection of subway tunnel structure is usually difficult due to the complex modeling of soil-structure interaction, the indetermination of boundary and so on. This paper proposes a new data-based method for the damage detection of subway tunnel structure. The root mean square acceleration and cross correlation function are used to derive a statistical pattern recognition algorithm for damage detection. A damage sensitive feature is proposed based on the root mean square deviations of the cross correlation functions. X-bar control charts are utilized to monitor the variation of the damage sensitive features before and after damage. The proposed algorithm is validated by the experiment of a full-scale two-rings subway tunnel lining, and damages are simulated by loosening the connection bolts of the rings. The results verify that root mean square deviation is sensitive to bolt loosening in the tunnel lining and X-bar control charts are feasible to be used in damage detection. The proposed data-based damage detection method is applicable to the online structural health monitoring system of subway tunnel lining.