期刊文献+
共找到8篇文章
< 1 >
每页显示 20 50 100
Detecting Malicious Uniform Resource Locators Using an Applied Intelligence Framework
1
作者 Simona-Vasilica Oprea Adela Bara 《Computers, Materials & Continua》 SCIE EI 2024年第6期3827-3853,共27页
The potential of text analytics is revealed by Machine Learning(ML)and Natural Language Processing(NLP)techniques.In this paper,we propose an NLP framework that is applied to multiple datasets to detect malicious Unif... The potential of text analytics is revealed by Machine Learning(ML)and Natural Language Processing(NLP)techniques.In this paper,we propose an NLP framework that is applied to multiple datasets to detect malicious Uniform Resource Locators(URLs).Three categories of features,both ML and Deep Learning(DL)algorithms and a ranking schema are included in the proposed framework.We apply frequency and prediction-based embeddings,such as hash vectorizer,Term Frequency-Inverse Dense Frequency(TF-IDF)and predictors,word to vector-word2vec(continuous bag of words,skip-gram)from Google,to extract features from text.Further,we apply more state-of-the-art methods to create vectorized features,such as GloVe.Additionally,feature engineering that is specific to URL structure is deployed to detect scams and other threats.For framework assessment,four ranking indicators are weighted:computational time and performance as accuracy,F1 score and type error II.For the computational time,we propose a new metric-Feature Building Time(FBT)as the cutting-edge feature builders(like doc2vec or GloVe)require more time.By applying the proposed assessment step,the skip-gram algorithm of word2vec surpasses other feature builders in performance.Additionally,eXtreme Gradient Boost(XGB)outperforms other classifiers.With this setup,we attain an accuracy of 99.5%and an F1 score of 0.99. 展开更多
关键词 Detecting malicious URL CLASSIFIERS text to feature deep learning ranking algorithms feature building time
下载PDF
AUTO-EXTRACTING TECHNIQUE OF DYNAMIC CHAOS FEATURES FOR NONLINEAR TIME SERIES 被引量:6
2
作者 CHEN Guo 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第4期524-529,共6页
The main purpose of nonlinear time series analysis is based on the rebuilding theory of phase space, and to study how to transform the response signal to rebuilt phase space in order to extract dynamic feature informa... The main purpose of nonlinear time series analysis is based on the rebuilding theory of phase space, and to study how to transform the response signal to rebuilt phase space in order to extract dynamic feature information, and to provide effective approach for nonlinear signal analysis and fault diagnosis of nonlinear dynamic system. Now, it has already formed an important offset of nonlinear science. But, traditional method cannot extract chaos features automatically, and it needs man's participation in the whole process. A new method is put forward, which can implement auto-extracting of chaos features for nonlinear time series. Firstly, to confirm time delay r by autocorrelation method; Secondly, to compute embedded dimension m and correlation dimension D; Thirdly, to compute the maximum Lyapunov index λmax; Finally, to calculate the chaos degree Dch of Poincare map, and the non-circle degree Dnc and non-order degree Dno of quasi-phase orbit. Chaos features extracting has important meaning to fault diagnosis of nonlinear system based on nonlinear chaos features. Examples show validity of the proposed method. 展开更多
关键词 Nonlinear time series analysis Chaos Feature extracting Fault diagnosis
下载PDF
Deep learning for predictive mechanical properties of hot-rolled strip in complex manufacturing systems
3
作者 Feifei Li Anrui He +5 位作者 Yong Song Zheng Wang Xiaoqing Xu Shiwei Zhang Yi Qiang Chao Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第6期1093-1103,共11页
Higher requirements for the accuracy of relevant models are put throughout the transformation and upgrade of the iron and steel sector to intelligent production.It has been difficult to meet the needs of the field wit... Higher requirements for the accuracy of relevant models are put throughout the transformation and upgrade of the iron and steel sector to intelligent production.It has been difficult to meet the needs of the field with the usual prediction model of mechanical properties of hotrolled strip.Insufficient data and difficult parameter adjustment limit deep learning models based on multi-layer networks in practical applications;besides,the limited discrete process parameters used make it impossible to effectively depict the actual strip processing process.In order to solve these problems,this research proposed a new sampling approach for mechanical characteristics input data of hot-rolled strip based on the multi-grained cascade forest(gcForest)framework.According to the characteristics of complex process flow and abnormal sensitivity of process path and parameters to product quality in the hot-rolled strip production,a three-dimensional continuous time series process data sampling method based on time-temperature-deformation was designed.The basic information of strip steel(chemical composition and typical process parameters)is fused with the local process information collected by multi-grained scanning,so that the next link’s input has both local and global features.Furthermore,in the multi-grained scanning structure,a sub sampling scheme with a variable window was designed,so that input data with different dimensions can get output characteristics of the same dimension after passing through the multi-grained scanning structure,allowing the cascade forest structure to be trained normally.Finally,actual production data of three steel grades was used to conduct the experimental evaluation.The results revealed that the gcForest-based mechanical property prediction model outperforms the competition in terms of comprehensive performance,ease of parameter adjustment,and ability to sustain high prediction accuracy with fewer samples. 展开更多
关键词 hot-rolled strip prediction of mechanical properties deep learning multi-grained cascade forest time series feature extraction variable window subsampling
下载PDF
Experimental validation of a signal-based approach for structural earthquake damage detection using fractal dimension of time frequency feature 被引量:2
4
作者 Tao Dongwang Mao Chenxi +1 位作者 Zhang Dongyu Li Hui 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2014年第4期671-680,共10页
This article extends a signal-based approach formerly proposed by the authors, which utilizes the fractal dimension of time frequency feature (FDTFF) of displacements, for earthquake damage detection of moment resis... This article extends a signal-based approach formerly proposed by the authors, which utilizes the fractal dimension of time frequency feature (FDTFF) of displacements, for earthquake damage detection of moment resist frame (MRF), and validates the approach with shaking table tests. The time frequency feature (TFF) of the relative displacement at measured story is defined as the real part of the coefficients of the analytical wavelet transform. The fractal dimension (FD) is to quantify the TFF within the fundamental frequency band using box counting method. It is verified that the FDTFFs at all stories of the linear MRF are identical with the help of static condensation method and modal superposition principle, while the FDTFFs at the stories with localized nonlinearities due to damage will be different from those at the stories without nonlinearities using the reverse-path methodology. By comparing the FDTFFs of displacements at measured stories in a structure, the damage-induced nonlinearity of the structure under strong ground motion can be detected and localized. Finally shaking table experiments on a 1:8 scale sixteen-story three-bay steel MRF with added frictional dampers, which generate local nonlinearities, are conducted to validate the approach. 展开更多
关键词 earthquake damage detection time frequency feature fractal dimension signal-based shaking table test frictional damper
下载PDF
TCL: a taxi trajectory prediction model combining time and space features 被引量:2
5
作者 Jiao Jichao Chen Xinping +1 位作者 Guan Meng Zhao Yaxin 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2021年第3期63-75,共13页
Vehicle trajectory modeling is an important foundation for urban intelligent services. Trajectory prediction of cars is a hot topic. A model including convolutional neural network(CNN) and long short-term memory(LSTM)... Vehicle trajectory modeling is an important foundation for urban intelligent services. Trajectory prediction of cars is a hot topic. A model including convolutional neural network(CNN) and long short-term memory(LSTM) was proposed, which is named trajectory-CNN-LSTM(TCL). CNN can extract the spatial features of the trajectory in the input image. Besides, LSTM can extract the time-series features of the input trajectory. After that, the model uses fully connected layers to merge the two features for the final predicting. The experiments on the Porto dataset of The European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases(ECML-PKDD) show that the average prediction error of TCL is reduced by 0.15 km, 0.42 km, and 0.39 km compared to the trajectory-convolution(T-CONV), multi-layer perceptron(MLP), and recurrent neural network(RNN) model, respectively. 展开更多
关键词 global navigation satellite system(GNSS) trajectory data trajectory prediction spatilal features time features
原文传递
Multiple-Channel Weight-Based CNN Fault Diagnosis Method
6
作者 Peng Xu Xinyu Liu +3 位作者 Junyu Lin Zhongyu Lu Fengming Li Husheng Gou 《国际计算机前沿大会会议论文集》 EI 2023年第1期89-105,共17页
It is difficult to comprehensively extract device status information for CNNs under a single source high-frequency timing signal,and CNNs cannot effec-tively achieve precise identification and classification based on the... It is difficult to comprehensively extract device status information for CNNs under a single source high-frequency timing signal,and CNNs cannot effec-tively achieve precise identification and classification based on the importance of multichannel features.This article proposes a CNN fault diagnosis method based on multi-channel weight adaptation.This methodfirst normalizes different data sources as input as different channels of CNN,and uses the characteristics of convolutional networks to achieve the characteristics of different data sources.Fusion and extraction.Then,the SNET module is embedded into the CNN net-work,adapted to the weight of each channel,and the accuracy of classification is improved.Finally,through comparative experiments,this method can further improve the accuracy of fault recognition. 展开更多
关键词 Convolutional Neural Network timing features Weight Adaptation
原文传递
Adaptive Ultra-short-term Wind Power Prediction Based on Risk Assessment 被引量:3
7
作者 Yusheng Xue Chen Yu +4 位作者 Kang Li Fushuan Wen Yi Ding Qiuwei Wu Guangya Yang 《CSEE Journal of Power and Energy Systems》 SCIE 2016年第3期59-64,共6页
A risk assessment based adaptive ultra-short-term wind power prediction(USTWPP)method is proposed in this paper.In this method,features are first extracted from the historical data,and then each wind power time series... A risk assessment based adaptive ultra-short-term wind power prediction(USTWPP)method is proposed in this paper.In this method,features are first extracted from the historical data,and then each wind power time series(WPTS)is split into several subsets defined by their stationary patterns.A WPTS that does not match any of the stationary patterns is then included in a subset of non-stationary patterns.Each WPTS subset is then related to a USTWPP model that is specially selected and optimized offline based on the proposed risk assessment index.For online applications,the pattern of the last short WPTS is first recognized,and the relevant prediction model is then applied for USTWPP.Experimental results confirm the efficacy of the proposed method. 展开更多
关键词 Error evaluation offline optimization online matching positive error vs negative error risk index time series features wind power prediction
原文传递
Space moving target detection using time domain feature
8
作者 王敏 陈金勇 +1 位作者 高峰 赵金宇 《Optoelectronics Letters》 EI 2018年第1期67-70,共4页
The traditional space target detection methods mainly use the spatial characteristics of the star map to detect the targets, which can not make full use of the time domain information. This paper presents a new space ... The traditional space target detection methods mainly use the spatial characteristics of the star map to detect the targets, which can not make full use of the time domain information. This paper presents a new space moving target detection method based on time domain features. We firstly construct the time spectral data of star map, then analyze the time domain features of the main objects(target, stars and the background) in star maps, finally detect the moving targets using single pulse feature of the time domain signal. The real star map target detection experimental results show that the proposed method can effectively detect the trajectory of moving targets in the star map sequence, and the detection probability achieves 99% when the false alarm rate is about 8×10^(-5), which outperforms those of compared algorithms. 展开更多
关键词 AS Space moving target detection using time domain feature
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部