期刊文献+
共找到172篇文章
< 1 2 9 >
每页显示 20 50 100
Dimensionality reduction model based on integer planning for the analysis of key indicators affecting life expectancy
1
作者 Wei Cui Zhiqiang Xu Ren Mu 《Journal of Data and Information Science》 CSCD 2023年第4期102-124,共23页
Purpose:Exploring a dimensionality reduction model that can adeptly eliminate outliers and select the appropriate number of clusters is of profound theoretical and practical importance.Additionally,the interpretabilit... Purpose:Exploring a dimensionality reduction model that can adeptly eliminate outliers and select the appropriate number of clusters is of profound theoretical and practical importance.Additionally,the interpretability of these models presents a persistent challenge.Design/methodology/approach:This paper proposes two innovative dimensionality reduction models based on integer programming(DRMBIP).These models assess compactness through the correlation of each indicator with its class center,while separation is evaluated by the correlation between different class centers.In contrast to DRMBIP-p,the DRMBIP-v considers the threshold parameter as a variable aiming to optimally balances both compactness and separation.Findings:This study,getting data from the Global Health Observatory(GHO),investigates 141 indicators that influence life expectancy.The findings reveal that DRMBIP-p effectively reduces the dimensionality of data,ensuring compactness.It also maintains compatibility with other models.Additionally,DRMBIP-v finds the optimal result,showing exceptional separation.Visualization of the results reveals that all classes have a high compactness.Research limitations:The DRMBIP-p requires the input of the correlation threshold parameter,which plays a pivotal role in the effectiveness of the final dimensionality reduction results.In the DRMBIP-v,modifying the threshold parameter to variable potentially emphasizes either separation or compactness.This necessitates an artificial adjustment to the overflow component within the objective function.Practical implications:The DRMBIP presented in this paper is adept at uncovering the primary geometric structures within high-dimensional indicators.Validated by life expectancy data,this paper demonstrates potential to assist data miners with the reduction of data dimensions.Originality/value:To our knowledge,this is the first time that integer programming has been used to build a dimensionality reduction model with indicator filtering.It not only has applications in life expectancy,but also has obvious advantages in data mining work that requires precise class centers. 展开更多
关键词 Integer programming Multidimensional data dimensionality reduction Life expectancy
下载PDF
Dimensionality Reduction Using Optimized Self-Organized Map Technique for Hyperspectral Image Classification
2
作者 S.Srinivasan K.Rajakumar 《Computer Systems Science & Engineering》 SCIE EI 2023年第11期2481-2496,共16页
The high dimensionalhyperspectral image classification is a challenging task due to the spectral feature vectors.The high correlation between these features and the noises greatly affects the classification performanc... The high dimensionalhyperspectral image classification is a challenging task due to the spectral feature vectors.The high correlation between these features and the noises greatly affects the classification performances.To overcome this,dimensionality reduction techniques are widely used.Traditional image processing applications recently propose numerous deep learning models.However,in hyperspectral image classification,the features of deep learning models are less explored.Thus,for efficient hyperspectral image classification,a depth-wise convolutional neural network is presented in this research work.To handle the dimensionality issue in the classification process,an optimized self-organized map model is employed using a water strider optimization algorithm.The network parameters of the self-organized map are optimized by the water strider optimization which reduces the dimensionality issues and enhances the classification performances.Standard datasets such as Indian Pines and the University of Pavia(UP)are considered for experimental analysis.Existing dimensionality reduction methods like Enhanced Hybrid-Graph Discriminant Learning(EHGDL),local geometric structure Fisher analysis(LGSFA),Discriminant Hyper-Laplacian projection(DHLP),Group-based tensor model(GBTM),and Lower rank tensor approximation(LRTA)methods are compared with proposed optimized SOM model.Results confirm the superior performance of the proposed model of 98.22%accuracy for the Indian pines dataset and 98.21%accuracy for the University of Pavia dataset over the existing maximum likelihood classifier,and Support vector machine(SVM). 展开更多
关键词 Hyperspectral image dimensionality reduction depth-wise separable model water strider optimization self-organized map
下载PDF
Principal Manifolds and Nonlinear Dimensionality Reduction via Tangent Space Alignment 被引量:68
3
作者 张振跃 查宏远 《Journal of Shanghai University(English Edition)》 CAS 2004年第4期406-424,共19页
We present a new algorithm for manifold learning and nonlinear dimensionality reduction. Based on a set of unorganized data points sampled with noise from a parameterized manifold, the local geometry of the manifold i... We present a new algorithm for manifold learning and nonlinear dimensionality reduction. Based on a set of unorganized data points sampled with noise from a parameterized manifold, the local geometry of the manifold is learned by constructing an approximation for the tangent space at each point, and those tangent spaces are then aligned to give the global coordinates of the data points with respect to the underlying manifold. We also present an error analysis of our algorithm showing that reconstruction errors can be quite small in some cases. We illustrate our algorithm using curves and surfaces both in 2D/3D Euclidean spaces and higher dimensional Euclidean spaces. We also address several theoretical and algorithmic issues for further research and improvements. 展开更多
关键词 nonlinear dimensionality reduction principal manifold tangent space subspace alignment singular value decomposition.
下载PDF
Multi-label dimensionality reduction and classification with extreme learning machines 被引量:9
4
作者 Lin Feng Jing Wang +1 位作者 Shenglan Liu Yao Xiao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第3期502-513,共12页
In the need of some real applications, such as text categorization and image classification, the multi-label learning gradually becomes a hot research point in recent years. Much attention has been paid to the researc... In the need of some real applications, such as text categorization and image classification, the multi-label learning gradually becomes a hot research point in recent years. Much attention has been paid to the research of multi-label classification algorithms. Considering the fact that the high dimensionality of the multi-label datasets may cause the curse of dimensionality and wil hamper the classification process, a dimensionality reduction algorithm, named multi-label kernel discriminant analysis (MLKDA), is proposed to reduce the dimensionality of multi-label datasets. MLKDA, with the kernel trick, processes the multi-label integrally and realizes the nonlinear dimensionality reduction with the idea similar with linear discriminant analysis (LDA). In the classification process of multi-label data, the extreme learning machine (ELM) is an efficient algorithm in the premise of good accuracy. MLKDA, combined with ELM, shows a good performance in multi-label learning experiments with several datasets. The experiments on both static data and data stream show that MLKDA outperforms multi-label dimensionality reduction via dependence maximization (MDDM) and multi-label linear discriminant analysis (MLDA) in cases of balanced datasets and stronger correlation between tags, and ELM is also a good choice for multi-label classification. 展开更多
关键词 MULTI-LABEL dimensionality reduction kernel trick classification.
下载PDF
Nonlinear Dimensionality Reduction and Data Visualization:A Review 被引量:4
5
作者 Hujun Yin 《International Journal of Automation and computing》 EI 2007年第3期294-303,共10页
Dimensionality reduction and data visualization are useful and important processes in pattern recognition. Many techniques have been developed in the recent years. The self-organizing map (SOM) can be an efficient m... Dimensionality reduction and data visualization are useful and important processes in pattern recognition. Many techniques have been developed in the recent years. The self-organizing map (SOM) can be an efficient method for this purpose. This paper reviews recent advances in this area and related approaches such as multidimensional scaling (MDS), nonlinear PC A, principal manifolds, as well as the connections of the SOM and its recent variant, the visualization induced SOM (ViSOM), with these approaches. The SOM is shown to produce a quantized, qualitative scaling and while the ViSOM a quantitative or metric scaling and approximates principal curve/surface. The SOM can also be regarded as a generalized MDS to relate two metric spaces by forming a topological mapping between them. The relationships among various recently proposed techniques such as ViSOM, Isomap, LLE, and eigenmap are discussed and compared. 展开更多
关键词 dimensionality reduction nonlinear data projection multidimensional scaling self-organizing maps nonlinear PCA principal manifold
下载PDF
Feature Extraction and Dimensionality Reduction of Arc Sound under Typical Penetration Status in Metal Inert Gas Welding 被引量:2
6
作者 LIU Lijun LAN Hu +1 位作者 ZHENG Hongyan JIAN Xiaoxia 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第2期293-298,共6页
Arc sound is well known as the potential and available resource for monitoring and controlling of the weld penetration status,which is very important to the welding process quality control,so any attentions have been ... Arc sound is well known as the potential and available resource for monitoring and controlling of the weld penetration status,which is very important to the welding process quality control,so any attentions have been paid to the relationships between the arc sound and welding parameters.Some non-linear mapping models correlating the arc sound to welding parameters have been established with the help of neural networks.However,the research of utilizing arc sound to monitor and diagnose welding process is still in its infancy.A self-made real-time sensing system is applied to make a study of arc sound under typical penetration status,including partial penetration,unstable penetration,full penetration and excessive penetration,in metal inert-gas(MIG) flat tailored welding with spray transfer.Arc sound is pretreated by using wavelet de-noising and short-time windowing technologies,and its characteristics,characterizing weld penetration status,of time-domain,frequency-domain,cepstrum-domain and geometric-domain are extracted.Subsequently,high-dimensional eigenvector is constructed and feature-level parameters are successfully fused utilizing the concept of primary principal component analysis(PCA).Ultimately,60-demensional eigenvector is replaced by the synthesis of 8-demensional vector,which achieves compression for feature space and provides technical supports for pattern classification of typical penetration status with the help of arc sound in MIG welding in the future. 展开更多
关键词 metal inert gas welding PENETRATION arc sound feature extraction dimensionality reduction
下载PDF
Dimensionality Reduction by Mutual Information for Text Classification 被引量:2
7
作者 刘丽珍 宋瀚涛 陆玉昌 《Journal of Beijing Institute of Technology》 EI CAS 2005年第1期32-36,共5页
The frame of text classification system was presented. The high dimensionality in feature space for text classification was studied. The mutual information is a widely used information theoretic measure, in a descript... The frame of text classification system was presented. The high dimensionality in feature space for text classification was studied. The mutual information is a widely used information theoretic measure, in a descriptive way, to measure the stochastic dependency of discrete random variables. The measure method was used as a criterion to reduce high dimensionality of feature vectors in text classification on Web. Feature selections or conversions were performed by using maximum mutual information including linear and non-linear feature conversions. Entropy was used and extended to find right features commendably in pattern recognition systems. Favorable foundation would be established for text classification mining. 展开更多
关键词 text classification mutual information dimensionality reduction
下载PDF
Graph-Based Dimensionality Reduction for Hyperspectral Imagery: A Review 被引量:1
8
作者 Zhen Ye Shihao Shi +4 位作者 Zhan Cao Lin Bai Cuiling Li Tao Sun Yongqiang Xi 《Journal of Beijing Institute of Technology》 EI CAS 2021年第2期91-112,共22页
Hyperspectral image(HSI)contains a wealth of spectral information,which makes fine classification of ground objects possible.In the meanwhile,overly redundant information in HSI brings many challenges.Specifically,the... Hyperspectral image(HSI)contains a wealth of spectral information,which makes fine classification of ground objects possible.In the meanwhile,overly redundant information in HSI brings many challenges.Specifically,the lack of training samples and the high computational cost are the inevitable obstacles in the design of classifier.In order to solve these problems,dimensionality reduction is usually adopted.Recently,graph-based dimensionality reduction has become a hot topic.In this paper,the graph-based methods for HSI dimensionality reduction are summarized from the following aspects.1)The traditional graph-based methods employ Euclidean distance to explore the local information of samples in spectral feature space.2)The dimensionality-reduction methods based on sparse or collaborative representation regard the sparse or collaborative coefficients as graph weights to effectively reduce reconstruction errors and represent most important information of HSI in the dictionary.3)Improved methods based on sparse or collaborative graph have made great progress by considering global low-rank information,local intra-class information and spatial information.In order to compare typical techniques,three real HSI datasets were used to carry out relevant experiments,and then the experimental results were analysed and discussed.Finally,the future development of this research field is prospected. 展开更多
关键词 hyperspectral image dimensionality reduction graph embedding sparse representation collaborative representation
下载PDF
Spatial weight matrix in dimensionality reduction reconstruction for microelectromechanical system-based photoacoustic microscopy 被引量:1
9
作者 Yuanzheng Ma Chang Lu +2 位作者 Kedi Xiong Wuyu Zhang Sihua Yang 《Visual Computing for Industry,Biomedicine,and Art》 2020年第1期247-256,共10页
A micro-electromechanical system(MEMS)scanning mirror accelerates the raster scanning of optical-resolution photoacoustic microscopy(OR-PAM).However,the nonlinear tilt angular-voltage characteristic of a MEMS mirror i... A micro-electromechanical system(MEMS)scanning mirror accelerates the raster scanning of optical-resolution photoacoustic microscopy(OR-PAM).However,the nonlinear tilt angular-voltage characteristic of a MEMS mirror introduces distortion into the maximum back-projection image.Moreover,the size of the airy disk,ultrasonic sensor properties,and thermal effects decrease the resolution.Thus,in this study,we proposed a spatial weight matrix(SWM)with a dimensionality reduction for image reconstruction.The three-layer SWM contains the invariable information of the system,which includes a spatial dependent distortion correction and 3D deconvolution.We employed an ordinal-valued Markov random field and the Harris Stephen algorithm,as well as a modified delay-and-sum method during a time reversal.The results from the experiments and a quantitative analysis demonstrate that images can be effectively reconstructed using an SWM;this is also true for severely distorted images.The index of the mutual information between the reference images and registered images was 70.33 times higher than the initial index,on average.Moreover,the peak signal-to-noise ratio was increased by 17.08%after 3D deconvolution.This accomplishment offers a practical approach to image reconstruction and a promising method to achieve a real-time distortion correction for MEMS-based OR-PAM. 展开更多
关键词 Photoacoustic microscopy Spatial weight matrix dimensionality reduction Distortion correction Mutual information
下载PDF
Rough Sets Hybridization with Mayfly Optimization for Dimensionality Reduction
10
作者 Ahmad Taher Azar Mustafa Samy Elgendy +1 位作者 Mustafa Abdul Salam Khaled M.Fouad 《Computers, Materials & Continua》 SCIE EI 2022年第10期1087-1108,共22页
Big data is a vast amount of structured and unstructured data that must be dealt with on a regular basis.Dimensionality reduction is the process of converting a huge set of data into data with tiny dimensions so that ... Big data is a vast amount of structured and unstructured data that must be dealt with on a regular basis.Dimensionality reduction is the process of converting a huge set of data into data with tiny dimensions so that equal information may be expressed easily.These tactics are frequently utilized to improve classification or regression challenges while dealing with machine learning issues.To achieve dimensionality reduction for huge data sets,this paper offers a hybrid particle swarm optimization-rough set PSO-RS and Mayfly algorithm-rough set MA-RS.A novel hybrid strategy based on the Mayfly algorithm(MA)and the rough set(RS)is proposed in particular.The performance of the novel hybrid algorithm MA-RS is evaluated by solving six different data sets from the literature.The simulation results and comparison with common reduction methods demonstrate the proposed MARS algorithm’s capacity to handle a wide range of data sets.Finally,the rough set approach,as well as the hybrid optimization techniques PSO-RS and MARS,were applied to deal with the massive data problem.MA-hybrid RS’s method beats other classic dimensionality reduction techniques,according to the experimental results and statistical testing studies. 展开更多
关键词 dimensionality reduction metaheuristics optimization algorithm MAYFLY particle swarm optimizer feature selection
下载PDF
Local Preserving Graphs Using Intra-Class Competitive Representation for Dimensionality Reduction of Hyperspectral Image
11
作者 Zhen Ye Shihao Shi +1 位作者 Tao Sun Lin Bai 《Journal of Beijing Institute of Technology》 EI CAS 2021年第2期139-158,共20页
As a key technique in hyperspectral image pre-processing,dimensionality reduction has received a lot of attention.However,most of the graph-based dimensionality reduction methods only consider a single structure in th... As a key technique in hyperspectral image pre-processing,dimensionality reduction has received a lot of attention.However,most of the graph-based dimensionality reduction methods only consider a single structure in the data and ignore the interfusion of multiple structures.In this paper,we propose two methods for combining intra-class competition for locally preserved graphs by constructing a new dictionary containing neighbourhood information.These two methods explore local information into the collaborative graph through competing constraints,thus effectively improving the overcrowded distribution of intra-class coefficients in the collaborative graph and enhancing the discriminative power of the algorithm.By classifying four benchmark hyperspectral data,the proposed methods are proved to be superior to several advanced algorithms,even under small-sample-size conditions. 展开更多
关键词 intra-class competition graph construction hyperspectral image dimensionality reduction
下载PDF
An Improved Parameter Dimensionality Reduction Approach Based on a Fast Marching Method for Automatic History Matching
12
作者 Hairong Zhang Yongde Gao +4 位作者 Wei Li Deng Liu Jing Cao Luoyi Huang Xun Zhong 《Fluid Dynamics & Materials Processing》 EI 2022年第3期609-628,共20页
History matching is a critical step in reservoir numerical simulation algorithms.It is typically hindered by difficulties associated with the high-dimensionality of the problem and the gradient calculation approach.He... History matching is a critical step in reservoir numerical simulation algorithms.It is typically hindered by difficulties associated with the high-dimensionality of the problem and the gradient calculation approach.Here,a multi-step solving method is proposed by which,first,a Fast marching method(FMM)is used to calculate the pressure propagation time and determine the single-well sensitive area.Second,a mathematical model for history matching is implemented using a Bayesian framework.Third,an effective decomposition strategy is adopted for parameter dimensionality reduction.Finally,a localization matrix is constructed based on the single-well sensitive area data to modify the gradient of the objective function.This method has been verified through a water drive conceptual example and a real field case.The results have shown that the proposed method can generate more accurate gradient information and predictions compared to the traditional analytical gradient methods and other gradient-free algorithms. 展开更多
关键词 History matching parameter dimensionality reduction sensitive area gradient correction
下载PDF
Comparison of Kernel Entropy Component Analysis with Several Dimensionality Reduction Methods
13
作者 马西沛 张蕾 孙以泽 《Journal of Donghua University(English Edition)》 EI CAS 2017年第4期577-582,共6页
Dimensionality reduction techniques play an important role in data mining. Kernel entropy component analysis( KECA) is a newly developed method for data transformation and dimensionality reduction. This paper conducte... Dimensionality reduction techniques play an important role in data mining. Kernel entropy component analysis( KECA) is a newly developed method for data transformation and dimensionality reduction. This paper conducted a comparative study of KECA with other five dimensionality reduction methods,principal component analysis( PCA),kernel PCA( KPCA),locally linear embedding( LLE),laplacian eigenmaps( LAE) and diffusion maps( DM). Three quality assessment criteria, local continuity meta-criterion( LCMC),trustworthiness and continuity measure(T&C),and mean relative rank error( MRRE) are applied as direct performance indexes to assess those dimensionality reduction methods. Moreover,the clustering accuracy is used as an indirect performance index to evaluate the quality of the representative data gotten by those methods. The comparisons are performed on six datasets and the results are analyzed by Friedman test with the corresponding post-hoc tests. The results indicate that KECA shows an excellent performance in both quality assessment criteria and clustering accuracy assessing. 展开更多
关键词 dimensionality reduction kernel entropy component analysis(KECA) kernel principal component analysis(KPCA) CLUSTERING
下载PDF
Multifactor dimensionality reduction analysis of syndrome characteristics of chronic persistent asthma
14
作者 Yanyan Meng Aiping Chen +4 位作者 Qi Shi Yue Yan Chaolumen Han Huiyuan Sun Youlin Li 《Journal of Traditional Chinese Medical Sciences》 2015年第3期159-165,共7页
Objective:To analyze the syndrome characteristics in patients with chronic persistent asthma.Methods:365 patients(121 males,244 females,60.829.1 years old)with chronic persistent asthma were enrolled in this cross-sec... Objective:To analyze the syndrome characteristics in patients with chronic persistent asthma.Methods:365 patients(121 males,244 females,60.829.1 years old)with chronic persistent asthma were enrolled in this cross-sectional study.The information of syndrome,symptoms,signs,tongue coating and pulse were collected from all patients.The syndrome characteristics of chronic persistent asthma were examined through the multifactor dimensionality reduction(MDR)analysis and the results were verified by the Chi-square test.Results:The results of the MDR analysis and the Chi-square test showed the following positive correlation of the interaction among:the deficiency syndrome of the lung and spleen and deep pulse,disinclination to talk due to lack of qi,fatigue,lassitude and thick tongue coating;the deficiency syndrome of the lung and kidney and dizziness and disinclination to talk due to lack of qi,fatigue,lassitude and pallid complexion;the syndrome of phlegm-heat obstructing the lung and rapid pulse,abdominal distension,disinclination to talk due to lack of qi,frequent urination and lassitude;the syndrome of phlegm-dampness obstructing the lung and disinclination to talk due to lack of qi,greasy coating,fatigue and lassitude.(P<.05 for all).Conclusion:The syndrome of chronic persistent asthma is characterized by fatigue and lassitude due to dysfunction of the lung,spleen and kidney. 展开更多
关键词 Bronchial asthma Chronic persistent period Traditional Chinese medicine Syndrome characteristics Multifactor dimensionality reduction
下载PDF
Cryptographic Lightweight Encryption Algorithm with Dimensionality Reduction in Edge Computing
15
作者 D.Jerusha T.Jaya 《Computer Systems Science & Engineering》 SCIE EI 2022年第9期1121-1132,共12页
Edge Computing is one of the radically evolving systems through generations as it is able to effectively meet the data saving standards of consumers,providers and the workers. Requisition for Edge Computing based ite... Edge Computing is one of the radically evolving systems through generations as it is able to effectively meet the data saving standards of consumers,providers and the workers. Requisition for Edge Computing based items havebeen increasing tremendously. Apart from the advantages it holds, there remainlots of objections and restrictions, which hinders it from accomplishing the needof consumers all around the world. Some of the limitations are constraints oncomputing and hardware, functions and accessibility, remote administration andconnectivity. There is also a backlog in security due to its inability to create a trustbetween devices involved in encryption and decryption. This is because securityof data greatly depends upon faster encryption and decryption in order to transferit. In addition, its devices are considerably exposed to side channel attacks,including Power Analysis attacks that are capable of overturning the process.Constrained space and the ability of it is one of the most challenging tasks. Toprevail over from this issue we are proposing a Cryptographic LightweightEncryption Algorithm with Dimensionality Reduction in Edge Computing. Thet-Distributed Stochastic Neighbor Embedding is one of the efficient dimensionality reduction technique that greatly decreases the size of the non-linear data. Thethree dimensional image data obtained from the system, which are connected withit, are dimensionally reduced, and then lightweight encryption algorithm isemployed. Hence, the security backlog can be solved effectively using thismethod. 展开更多
关键词 Edge computing(e.g) dimensionality reduction(dr) t-distributed stochastic neighbor embedding(t-sne) principle component analysis(pca)
下载PDF
SAR Image Compression Using Integer to Integer Transformations, Dimensionality Reduction, and High Correlation Modeling
16
作者 Sergey Voronin 《Journal of Computer and Communications》 2022年第2期19-32,共14页
In this document, we present new techniques for near-lossless and lossy compression of SAR imagery saved in PNG and binary formats of magnitude and phase data based on the application of transforms, dimensionality red... In this document, we present new techniques for near-lossless and lossy compression of SAR imagery saved in PNG and binary formats of magnitude and phase data based on the application of transforms, dimensionality reduction methods, and lossless compression. In particular, we discuss the use of blockwise integer to integer transforms, subsequent application of a dimensionality reduction method, and Burrows-Wheeler based lossless compression for the PNG data and the use of high correlation based modeling of sorted transform coefficients for the raw floating point magnitude and phase data. The gains exhibited are substantial over the application of different lossless methods directly on the data and competitive with existing lossy approaches. The methods presented are effective for large scale processing of similar data formats as they are heavily based on techniques which scale well on parallel architectures. 展开更多
关键词 SAR Imagery Integer-to-Integer Transforms dimensionality reduction High Correlation Modeling Lossy and Lossless Compression
下载PDF
Critical Evaluation of Linear Dimensionality Reduction Techniques for Cardiac Arrhythmia Classification
17
作者 Rekha Rajagopal Vidhyapriya Ranganathan 《Circuits and Systems》 2016年第9期2603-2612,共10页
Embedding the original high dimensional data in a low dimensional space helps to overcome the curse of dimensionality and removes noise. The aim of this work is to evaluate the performance of three different linear di... Embedding the original high dimensional data in a low dimensional space helps to overcome the curse of dimensionality and removes noise. The aim of this work is to evaluate the performance of three different linear dimensionality reduction techniques (DR) techniques namely principal component analysis (PCA), multi dimensional scaling (MDS) and linear discriminant analysis (LDA) on classification of cardiac arrhythmias using probabilistic neural network classifier (PNN). The design phase of classification model comprises of the following stages: preprocessing of the cardiac signal by eliminating detail coefficients that contain noise, feature extraction through daubechies wavelet transform, dimensionality reduction through linear DR techniques specified, and arrhythmia classification using PNN. Linear dimensionality reduction techniques have simple geometric representations and simple computational properties. Entire MIT-BIH arrhythmia database is used for experimentation. The experimental results demonstrates that combination of PNN classifier (spread parameter, σ = 0.08) and PCA DR technique exhibits highest sensitivity and F score of 78.84% and 78.82% respectively with a minimum of 8 dimensions. 展开更多
关键词 Data Preprocessing Decision Support Systems Feature Extraction dimensionality reduction
下载PDF
Adaptive Metric Learning for Dimensionality Reduction
18
作者 Lihua Chen Peiwen Wei +1 位作者 Zhongzhen Long Yufeng Yu 《Journal of Computer and Communications》 2022年第12期95-112,共18页
Finding a suitable space is one of the most critical problems for dimensionality reduction. Each space corresponds to a distance metric defined on the sample attributes, and thus finding a suitable space can be conver... Finding a suitable space is one of the most critical problems for dimensionality reduction. Each space corresponds to a distance metric defined on the sample attributes, and thus finding a suitable space can be converted to develop an effective distance metric. Most existing dimensionality reduction methods use a fixed pre-specified distance metric. However, this easy treatment has some limitations in practice due to the fact the pre-specified metric is not going to warranty that the closest samples are the truly similar ones. In this paper, we present an adaptive metric learning method for dimensionality reduction, called AML. The adaptive metric learning model is developed by maximizing the difference of the distances between the data pairs in cannot-links and those in must-links. Different from many existing papers that use the traditional Euclidean distance, we use the more generalized l<sub>2,p</sub>-norm distance to reduce sensitivity to noise and outliers, which incorporates additional flexibility and adaptability due to the selection of appropriate p-values for different data sets. Moreover, considering traditional metric learning methods usually project samples into a linear subspace, which is overstrict. We extend the basic linear method to a more powerful nonlinear kernel case so that well capturing complex nonlinear relationship between data. To solve our objective, we have derived an efficient iterative algorithm. Extensive experiments for dimensionality reduction are provided to demonstrate the superiority of our method over state-of-the-art approaches. 展开更多
关键词 Adaptive Learning Kernel Learning Dimension reduction Pairwise Constraints
下载PDF
AE-TPGG:a novel autoencoder-based approach for single-cell RNA-seq data imputation and dimensionality reduction
19
作者 Shuchang ZHAO Li ZHANG Xuejun LIU 《Frontiers of Computer Science》 SCIE EI CSCD 2023年第3期217-234,共18页
Single-cell RNA sequencing(scRNA-seq)technology has become an effective tool for high-throughout transcriptomic study,which circumvents the averaging artifacts corresponding to bulk RNA-seq technology,yielding new per... Single-cell RNA sequencing(scRNA-seq)technology has become an effective tool for high-throughout transcriptomic study,which circumvents the averaging artifacts corresponding to bulk RNA-seq technology,yielding new perspectives on the cellular diversity of potential superficially homogeneous populations.Although various sequencing techniques have decreased the amplification bias and improved capture efficiency caused by the low amount of starting material,the technical noise and biological variation are inevitably introduced into experimental process,resulting in high dropout events,which greatly hinder the downstream analysis.Considering the bimodal expression pattern and the right-skewed characteristic existed in normalized scRNA-seq data,we propose a customized autoencoder based on a twopart-generalized-gamma distribution(AE-TPGG)for scRNAseq data analysis,which takes mixed discrete-continuous random variables of scRNA-seq data into account using a twopart model and utilizes the generalized gamma(GG)distribution,for fitting the positive and right-skewed continuous data.The adopted autoencoder enables AE-TPGG to captures the inherent relationship between genes.In addition to the ability of achieving low-dimensional representation,the AETPGG model also provides a denoised imputation according to statistical characteristic of gene expression.Results on real datasets demonstrate that our proposed model is competitive to current imputation methods and ameliorates a diverse set of typical scRNA-seq data analyses. 展开更多
关键词 scRNA-seq autoencoder TPGG data imputation dimensionality reduction
原文传递
A VAE-Bayesian deep learning scheme for solar power generation forecasting based on dimensionality reduction
20
作者 Devinder Kaur Shama Naz Islam +2 位作者 MdApel Mahmud Md.Enamul Haque Adnan Anwar 《Energy and AI》 2023年第4期319-328,共10页
The advancements in distributed generation(DG)technologies such as solar panels have led to a widespread integration of renewable power generation in modern power systems.However,the intermittent nature of renewable e... The advancements in distributed generation(DG)technologies such as solar panels have led to a widespread integration of renewable power generation in modern power systems.However,the intermittent nature of renewable energy poses new challenges to the network operational planning with underlying uncertainties.This paper proposes a novel probabilistic scheme for renewable solar power generation forecasting by addressing data and model parameter uncertainties using Bayesian bidirectional long short-term memory(BiLSTM)neural networks,while handling the high dimensionality in weight parameters using variational auto-encoders(VAE).The forecasting performance of the proposed method is evaluated using various deterministic and probabilistic evaluation metrics such as root-mean square error(RMSE),Pinball loss,etc.Furthermore,reconstruction error and computational time are also monitored to evaluate the dimensionality reduction using the VAE component.When compared with benchmark methods,the proposed method leads to significant improvements in weight reduction,i.e.,from 76,4224 to 2,022 number of weight parameters,quantifying to 97.35%improvement in weight parameters reduction and 37.93%improvement in computational time for 6 months of solar power generation data. 展开更多
关键词 Bayesian deep learning Bidirectional long-short term memory dimensionality reduction Generation forecasting Renewable power generation Variational auto-encoders
原文传递
上一页 1 2 9 下一页 到第
使用帮助 返回顶部