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SYMMETRIC SIGN PATTERN MATRICES THAT REQUIRE UNIQUE INERTIA
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作者 Hall Frank J. 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2000年第S1期12-14,共3页
In qualitative and combinatorial matrix theory,we study properties of a matrix basedon qualitative information,such as the signs of entries in the matrix.A matrix whose en-tries are from the set{+,-,0}is called a sign... In qualitative and combinatorial matrix theory,we study properties of a matrix basedon qualitative information,such as the signs of entries in the matrix.A matrix whose en-tries are from the set{+,-,0}is called a sign pattern matrix (or sign pattern).For a re-al matrix B,by sgn (B) we mean the sign pattern matrix in which each positive (respec-tively,negative,zero) entry of B is replaced by+(respectively,-,0).If A is an 展开更多
关键词 CYCLE In length SYMMETRIC SIGN pattern MATRICES THAT REQUIRE UNIQUE INERTIA SMR
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Centre symmetric quadruple pattern-based illumination invariant measure
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作者 Hu Changhui Zhang Yang +1 位作者 Lu Xiaobo Liu Pan 《Journal of Southeast University(English Edition)》 EI CAS 2020年第4期407-413,共7页
A centre symmetric quadruple pattern-based illumination invariant measure(CSQPIM)is proposed to tackle severe illumination variation face recognition.First,the subtraction of the pixel pairs of the centre symmetric qu... A centre symmetric quadruple pattern-based illumination invariant measure(CSQPIM)is proposed to tackle severe illumination variation face recognition.First,the subtraction of the pixel pairs of the centre symmetric quadruple pattern(CSQP)is defined as the CSQPIM unit in the logarithm face local region,which may be positive or negative.The CSQPIM model is obtained by combining the positive and negative CSQPIM units.Then,the CSQPIM model can be used to generate several CSQPIM images by controlling the proportions of positive and negative CSQPIM units.The single CSQPIM image with the saturation function can be used to develop the CSQPIM-face.Multi CSQPIM images employ the extended sparse representation classification(ESRC)as the classifier,which can create the CSQPIM image-based classification(CSQPIMC).Furthermore,the CSQPIM model is integrated with the pre-trained deep learning(PDL)model to construct the CSQPIM-PDL model.Finally,the experimental results on the Extended Yale B,CMU PIE and Driver face databases indicate that the proposed methods are efficient for tackling severe illumination variations. 展开更多
关键词 centre symmetric quadruple pattern illumination invariant measure severe illumination variations single sample face recognition
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Inertia Set of a Nonnegative Symmetric Sign Pattern
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作者 刘颖 马红平 苗正科 《Northeastern Mathematical Journal》 CSCD 2008年第4期311-318,共8页
For a symmetric sign pattern S1 the inertia set of S is defined to be the set of all ordered triples si(S) = {i(A) : A = A^T ∈ Q(S)} Consider the n × n sign pattern Sn, where Sn is the pattern with zero e... For a symmetric sign pattern S1 the inertia set of S is defined to be the set of all ordered triples si(S) = {i(A) : A = A^T ∈ Q(S)} Consider the n × n sign pattern Sn, where Sn is the pattern with zero entry (i,j) for 1 ≤ i = j ≤ n or|i -j|=n- 1 and positive entry otherwise. In this paper, it is proved that si(Sn) = {(n1, n2, n - n1 - n2)|n1≥ 1 and n2 ≥ 2} for n ≥ 4. 展开更多
关键词 sign pattern symmetric sign pattern INERTIA inertia set
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Enhancing SDP-CNN for Gear Fault Detection Under Variable Working Conditions via Multi-Order Tracking Filtering
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作者 Mario Spirto Armando Nicolella +4 位作者 Francesco Melluso Pierangelo Malfi Chiara Cosenza Sergio Savino Vincenzo Niola 《Journal of Dynamics, Monitoring and Diagnostics》 2025年第4期226-238,共13页
In the field of gear fault detection,the symmetrized dot pattern(SDP)technique,combined with a convolutional neural network(CNN),is widely used to classify various types of defects.The SDP-CNN combination is used to t... In the field of gear fault detection,the symmetrized dot pattern(SDP)technique,combined with a convolutional neural network(CNN),is widely used to classify various types of defects.The SDP-CNN combination is used to transform vibration signals and simplify the defect classification process under stationary operating conditions.This work aims to enhance the SDP-CNN combination for detecting incipient defects in gear under variable working conditions.The vibration signals are filtered by Vold-Kalman Filter Multi-Order Tracking to highlight fault characteristics under variable working conditions.Subsequently,the signals are SDP-transformed and are then classified by optimized CNN.The new pipeline has been validated on an experimental dataset and compared with the classical one by developing both two-and multi-class CNNs.The results showed the applicability of the new pipeline in terms of percentage accuracy and ROC curve compared to the classical approach.Finally,the proposed pipeline was compared with other ML literature techniques using the same dataset. 展开更多
关键词 convolutional neural network fault detection order tracking symmetrized dot pattern vibrational signal processing
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EWMA control chart based on its first hitting time and coronavirus alert levels for monitoring symmetric COVID-19 cases
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作者 Areepong Yupaporn Sunthornwat Rapin 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2021年第8期364-374,共11页
Objective:To define the alert levels for the total number of COVID-19 cases derived by using quantile functions to monitor COVID-19 outbreaks via an exponentially weighted moving-average(EWMA)control chart based on th... Objective:To define the alert levels for the total number of COVID-19 cases derived by using quantile functions to monitor COVID-19 outbreaks via an exponentially weighted moving-average(EWMA)control chart based on the first hitting time of the total number of COVID-19 cases following a symmetric logistic growth curve.Methods:The cumulative distribution function of the time for the total number of COVID-19 cases was used to construct a quantile function for classifying COVID-19 alert levels.The EWMA control chart control limits for monitoring a COVID-19 outbreak were formulated by applying the delta method and the sample mean and variance method.Samples were selected from countries and region including Thailand,Singapore,Vietnam,and Hong Kong to generate the total number of COVID-19 cases from February 15,2020 to December 16,2020,all of which followed symmetric patterns.A comparison of the two methods was made by applying them to a EWMA control chart based on the first hitting time for monitoring the COVID-19 outbreak in the sampled countries and region.Results:The optimal first hitting times for the EWMA control chart for monitoring COVID-19 outbreaks in Thailand,Singapore,Vietnam,and Hong Kong were approximately 280,208,286,and 298 days,respectively.Conclusions:The findings show that the sample mean and variance method can detect the first hitting time better than the delta method.Moreover,the COVID-19 alert levels can be defined into four stages for monitoring COVID-19 situation,which help the authorities to enact policies that monitor,control,and protect the population from a COVID-19 outbreak. 展开更多
关键词 COVID-19 alert levels Symmetric pattern of the total number of COVID-19 cases Monitoring COVID-19 situation EWMA control chart
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