期刊文献+
共找到280篇文章
< 1 2 14 >
每页显示 20 50 100
Exploring Motor Imagery EEG: Enhanced EEG Microstate Analysis with GMD-Driven Density Canopy Method
1
作者 Xin Xiong Jing Zhang +3 位作者 Sanli Yi Chunwu Wang Ruixiang Liu Jianfeng He 《Computers, Materials & Continua》 SCIE EI 2024年第6期4659-4681,共23页
The analysis of microstates in EEG signals is a crucial technique for understanding the spatiotemporal dynamics of brain electrical activity.Traditional methods such as Atomic Agglomerative Hierarchical Clustering(AAH... The analysis of microstates in EEG signals is a crucial technique for understanding the spatiotemporal dynamics of brain electrical activity.Traditional methods such as Atomic Agglomerative Hierarchical Clustering(AAHC),K-means clustering,Principal Component Analysis(PCA),and Independent Component Analysis(ICA)are limited by a fixed number of microstate maps and insufficient capability in cross-task feature extraction.Tackling these limitations,this study introduces a Global Map Dissimilarity(GMD)-driven density canopy K-means clustering algorithm.This innovative approach autonomously determines the optimal number of EEG microstate topographies and employs Gaussian kernel density estimation alongside the GMD index for dynamic modeling of EEG data.Utilizing this advanced algorithm,the study analyzes the Motor Imagery(MI)dataset from the GigaScience database,GigaDB.The findings reveal six distinct microstates during actual right-hand movement and five microstates across other task conditions,with microstate C showing superior performance in all task states.During imagined movement,microstate A was significantly enhanced.Comparison with existing algorithms indicates a significant improvement in clustering performance by the refined method,with an average Calinski-Harabasz Index(CHI)of 35517.29 and a Davis-Bouldin Index(DBI)average of 2.57.Furthermore,an information-theoretical analysis of the microstate sequences suggests that imagined movement exhibits higher complexity and disorder than actual movement.By utilizing the extracted microstate sequence parameters as features,the improved algorithm achieved a classification accuracy of 98.41%in EEG signal categorization for motor imagery.A performance of 78.183%accuracy was achieved in a four-class motor imagery task on the BCI-IV-2a dataset.These results demonstrate the potential of the advanced algorithm in microstate analysis,offering a more effective tool for a deeper understanding of the spatiotemporal features of EEG signals. 展开更多
关键词 EEG microstate motor imagery K-means clustering algorithm gaus sian kernel function shannon entropy Lempel-Ziv complexity
下载PDF
The Analysis of Wolf Imagery in The Company of Wolves
2
作者 WANG Wen-ke 《Journal of Literature and Art Studies》 2024年第7期607-611,共5页
Imagery analysis is a commonly used analytical method in literary analysis.In Angela Carter’s work,the image of wolves is particularly prominent.Her“Werewolf Tetralogy”rewrites traditional culture and subverts trad... Imagery analysis is a commonly used analytical method in literary analysis.In Angela Carter’s work,the image of wolves is particularly prominent.Her“Werewolf Tetralogy”rewrites traditional culture and subverts traditional consciousness,and is the research object of many scholars.Starting from the analysis of the wolf image in The Company of Wolves,this paper uses Deleuze’s Becoming-Animal Theory to explore the construction of harmony between nature,humans and gender relations in The Company of Wolves. 展开更多
关键词 The Company of Wolves Wolf imagery Becoming-Animal
下载PDF
Color Expression and Mood Creation in Imagery Oil Painting
3
作者 Yixuan Xu 《Journal of Contemporary Educational Research》 2024年第1期7-12,共6页
Oil painting is a traditional Western painting form.With the introduction of China and the influence of China’s traditional painting and aesthetics,the painting style became more distinctive,expanding a new developme... Oil painting is a traditional Western painting form.With the introduction of China and the influence of China’s traditional painting and aesthetics,the painting style became more distinctive,expanding a new development direction of oil painting,and thus imagery oil painting came into being.Color,as the most important element in imagery oil painting,mainly plays the role of mood creation and emotional expression.Many creators are good at injecting their thoughts and emotions into the paintings through color matching,so as to enhance the artistic expression of the paintings.This paper analyzes the color expression characteristics of imagery oil painting and explores the color expression techniques in imagery oil painting and mood creation of imagery oil painting from several aspects. 展开更多
关键词 imagery oil painting Color expression Mood creation
下载PDF
Application of a hospital–community–family trinity rehabilitation nursing model combined with motor imagery therapy in patients with cerebral infarction 被引量:6
4
作者 Wen-Wen Li Min Li +1 位作者 Xiao-Juan Guo Fu-De Liu 《World Journal of Clinical Cases》 SCIE 2023年第3期621-628,共8页
BACKGROUND Rehabilitation nursing is considered an indispensable part of the cerebral infarction treatment system.The hospital–community–family trinity rehabilitation nursing model can provide continuous nursing ser... BACKGROUND Rehabilitation nursing is considered an indispensable part of the cerebral infarction treatment system.The hospital–community–family trinity rehabilitation nursing model can provide continuous nursing services across hospitals,communities,and families for patients.AIM To explore the application of a hospital–community–family rehabilitation nursing model combined with motor imagery therapy in patients with cerebral infarction.METHODS From January 2021 to December 2021,88 patients with cerebral infarction were divided into a study(n=44)and a control(n=44)group using a simple random number table.The control group received routine nursing and motor imagery therapy.The study group was given hospital–community–family trinity rehabilitation nursing based on the control group.Motor function(FMA),balance ability(BBS),activities of daily living(BI),quality of life(SS-QOL),activation status of the contralateral primary sensorimotor cortical area to the affected side,and nursing satisfaction were evaluated before and after intervention in both groups.RESULTS Before intervention,FMA and BBS were similar(P>0.05).After 6 months’intervention,FMA and BBS were significantly higher in the study than in the control group(both P<0.05).Before intervention,BI and SS-QOL scores were not different between the study and control group(P>0.05).However,after 6months’intervention,BI and SS-QOL were higher in the study than in the control group(P<0.05).Before intervention,activation frequency and volume were similar between the study and the control group(P>0.05).After 6 months’intervention,the activation frequency and volume were higher in the study than in the control group(P<0.05).The reliability,empathy,reactivity,assurance,and tangibles scores for quality of nursing service were higher in the study than in the control group(P<0.05).CONCLUSION Combining a hospital–community–family trinity rehabilitation nursing model and motor imagery therapy enhances the motor function and balance ability of patients with cerebral infarction,improving their quality of life. 展开更多
关键词 Activities of daily living Cerebral infarction Hospital-community-family trinity rehabilitation nursing model Motor skills Motor imagery therapy Postural balance
下载PDF
YOLOv5-Based Seabed Sediment Recognition Method for Side-Scan Sonar Imagery 被引量:1
5
作者 WANG Ziwei HU Yi +1 位作者 DING Jianxiang SHI Peng 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第6期1529-1540,共12页
Seabed sediment recognition is vital for the exploitation of marine resources.Side-scan sonar(SSS)is an excellent tool for acquiring the imagery of seafloor topography.Combined with ocean surface sampling,it provides ... Seabed sediment recognition is vital for the exploitation of marine resources.Side-scan sonar(SSS)is an excellent tool for acquiring the imagery of seafloor topography.Combined with ocean surface sampling,it provides detailed and accurate images of marine substrate features.Most of the processing of SSS imagery works around limited sampling stations and requires manual interpretation to complete the classification of seabed sediment imagery.In complex sea areas,with manual interpretation,small targets are often lost due to a large amount of information.To date,studies related to the automatic recognition of seabed sediments are still few.This paper proposes a seabed sediment recognition method based on You Only Look Once version 5 and SSS imagery to perform real-time sedi-ment classification and localization for accuracy,particularly on small targets and faster speeds.We used methods such as changing the dataset size,epoch,and optimizer and adding multiscale training to overcome the challenges of having a small sample and a low accuracy.With these methods,we improved the results on mean average precision by 8.98%and F1 score by 11.12%compared with the original method.In addition,the detection speed was approximately 100 frames per second,which is faster than that of previous methods.This speed enabled us to achieve real-time seabed sediment recognition from SSS imagery. 展开更多
关键词 seabed sediment real-time target recognition YOLOv5 model side-scan sonar imagery transfer learning
下载PDF
A double-layer model for improving the estimation of wheat canopy nitrogen content from unmanned aerial vehicle multispectral imagery 被引量:1
6
作者 LIAO Zhen-qi DAI Yu-long +5 位作者 WANG Han Quirine M.KETTERINGS LU Jun-sheng ZHANG Fu-cang LI Zhi-jun FAN Jun-liang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第7期2248-2270,共23页
The accurate and rapid estimation of canopy nitrogen content(CNC)in crops is the key to optimizing in-season nitrogen fertilizer application in precision agriculture.However,the determination of CNC from field samplin... The accurate and rapid estimation of canopy nitrogen content(CNC)in crops is the key to optimizing in-season nitrogen fertilizer application in precision agriculture.However,the determination of CNC from field sampling data for leaf area index(LAI),canopy photosynthetic pigments(CPP;including chlorophyll a,chlorophyll b and carotenoids)and leaf nitrogen concentration(LNC)can be time-consuming and costly.Here we evaluated the use of high-precision unmanned aerial vehicle(UAV)multispectral imagery for estimating the LAI,CPP and CNC of winter wheat over the whole growth period.A total of 23 spectral features(SFs;five original spectrum bands,17 vegetation indices and the gray scale of the RGB image)and eight texture features(TFs;contrast,entropy,variance,mean,homogeneity,dissimilarity,second moment,and correlation)were selected as inputs for the models.Six machine learning methods,i.e.,multiple stepwise regression(MSR),support vector regression(SVR),gradient boosting decision tree(GBDT),Gaussian process regression(GPR),back propagation neural network(BPNN)and radial basis function neural network(RBFNN),were compared for the retrieval of winter wheat LAI,CPP and CNC values,and a double-layer model was proposed for estimating CNC based on LAI and CPP.The results showed that the inversion of winter wheat LAI,CPP and CNC by the combination of SFs+TFs greatly improved the estimation accuracy compared with that by using only the SFs.The RBFNN and BPNN models outperformed the other machine learning models in estimating winter wheat LAI,CPP and CNC.The proposed double-layer models(R^(2)=0.67-0.89,RMSE=13.63-23.71 mg g^(-1),MAE=10.75-17.59 mg g^(-1))performed better than the direct inversion models(R^(2)=0.61-0.80,RMSE=18.01-25.12 mg g^(-1),MAE=12.96-18.88 mg g^(-1))in estimating winter wheat CNC.The best winter wheat CNC accuracy was obtained by the double-layer RBFNN model with SFs+TFs as inputs(R^(2)=0.89,RMSE=13.63 mg g^(-1),MAE=10.75 mg g^(-1)).The results of this study can provide guidance for the accurate and rapid determination of winter wheat canopy nitrogen content in the field. 展开更多
关键词 UAV multispectral imagery spectral features texture features canopy photosynthetic pigment content canopy nitrogen content
下载PDF
Shallow water bathymetry based on a back propagation neural network and ensemble learning using multispectral satellite imagery
7
作者 Sensen Chu Liang Cheng +4 位作者 Jian Cheng Xuedong Zhang Jie Zhang Jiabing Chen Jinming Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第5期154-165,共12页
The back propagation(BP)neural network method is widely used in bathymetry based on multispectral satellite imagery.However,the classical BP neural network method faces a potential problem because it easily falls into... The back propagation(BP)neural network method is widely used in bathymetry based on multispectral satellite imagery.However,the classical BP neural network method faces a potential problem because it easily falls into a local minimum,leading to model training failure.This study confirmed that the local minimum problem of the BP neural network method exists in the bathymetry field and cannot be ignored.Furthermore,to solve the local minimum problem of the BP neural network method,a bathymetry method based on a BP neural network and ensemble learning(BPEL)is proposed.First,the remote sensing imagery and training sample were used as input datasets,and the BP method was used as the base learner to produce multiple water depth inversion results.Then,a new ensemble strategy,namely the minimum outlying degree method,was proposed and used to integrate the water depth inversion results.Finally,an ensemble bathymetric map was acquired.Anda Reef,northeastern Jiuzhang Atoll,and Pingtan coastal zone were selected as test cases to validate the proposed method.Compared with the BP neural network method,the root-mean-square error and the average relative error of the BPEL method can reduce by 0.65–2.84 m and 16%–46%in the three test cases at most.The results showed that the proposed BPEL method could solve the local minimum problem of the BP neural network method and obtain highly robust and accurate bathymetric maps. 展开更多
关键词 BATHYMETRY back propagation neural network ensemble learning local minimum problem multispectral satellite imagery
下载PDF
Analysis of the Application of Ink Art in Graphic Design Imagery
8
作者 Ye Wang 《Journal of Contemporary Educational Research》 2023年第1期40-45,共6页
The graphic design industry has been developing rapidly in recent years.People have begun to focus on steering the development of graphic design in the direction of localization,integrating more traditional Chinese el... The graphic design industry has been developing rapidly in recent years.People have begun to focus on steering the development of graphic design in the direction of localization,integrating more traditional Chinese elements,raising the level of acceptance toward graphic design content,and disseminating traditional culture on this basis.Ink art plays an important role in the historical and cultural development process.It uses simple color contrast to construct different situations and possesses unique artistic charm and cultural heritage.Incorporating ink elements into graphic design may enhance the graphic design style and provide inspiration.This article focuses on the reasons,advantages,and strategies of using ink art in graphic design imagery,hoping to provide references for graphic design activities. 展开更多
关键词 Ink art Graphic design imagery Application analysis
下载PDF
An Hour's Freedom, Timeless Feminism: On Irony and Imagery in Kate Chopin's The Story of an Hour 被引量:2
9
作者 侯银华 《海外英语》 2011年第3X期174-175,共2页
By the brief introduction of Kate Chopin and her achievement, this paper elaborates the awakening of consciousness of the feminism of the protagonist in Kate Chopin's The Story of an Hour. In the short story, the ... By the brief introduction of Kate Chopin and her achievement, this paper elaborates the awakening of consciousness of the feminism of the protagonist in Kate Chopin's The Story of an Hour. In the short story, the author uses many literary elements to describe the characters, especially the irony and imagery. This thesis uses those rhetorical devices to vividly describe the characters and to criticize the inequality between men and women in the late 19th century.[1] 展开更多
关键词 FEMINISM IRONY imagery
下载PDF
Corticospinal excitability during motor imagery is diminished by continuous repetition-induced fatigue
10
作者 Akira Nakashima Takefumi Moriuchi +7 位作者 Daiki Matsuda Takashi Hasegawa Jirou Nakamura Kimika Anan Katsuya Satoh Tomotaka Suzuki Toshio Higashi Kenichi Sugawara 《Neural Regeneration Research》 SCIE CAS CSCD 2021年第6期1031-1036,共6页
Application of continuous repetition of motor imagery can improve the performance of exercise tasks.However,there is a lack of more detailed neurophysiological evidence to support the formulation of clear standards fo... Application of continuous repetition of motor imagery can improve the performance of exercise tasks.However,there is a lack of more detailed neurophysiological evidence to support the formulation of clear standards for interventions using motor imagery.Moreover,identification of motor imagery intervention time is necessary because it exhibits possible central fatigue.Therefore,the purpose of this study was to elucidate the development of fatigue during continuous repetition of motor imagery through objective and subjective evaluation.The study involved two experiments.In experiment 1,14 healthy young volunteers were required to imagine grasping and lifting a 1.5-L plastic bottle using the whole hand.Each participant performed the motor imagery task 100 times under each condition with 48 hours interval between two conditions:500 mL or 1500 mL of water in the bottle during the demonstration phase.Mental fatigue and a decrease in pinch power appeared under the 1500-mL condition.There were changes in concentration ability or corticospinal excitability,as assessed by motor evoked potentials,between each set with continuous repetition of motor imagery also under the 1500-mL condition.Therefore,in experiment 2,12 healthy volunteers were required to perform the motor imagery task 200 times under the 1500-mL condition.Both concentration ability and corticospinal excitability decreased.This is the first study to show that continuous repetition of motor imagery can decrease corticospinal excitability in addition to producing mental fatigue.This study was approved by the Institutional Ethics Committee at the Nagasaki University Graduate School of Biomedical and Health Sciences(approval No.18121302)on January 30,2019. 展开更多
关键词 central nervous system CONCENTRATION continuous repetition of motor imagery corticospinal excitability mental fatigue motor evoked potential motor imagery muscle fatigue NEUROPHYSIOLOGY transcranial magnetic stimulation
下载PDF
Imagery Analysis on Wordsworth’s the Daffodils
11
作者 冯秀茹 崔会拥 《海外英语》 2020年第9期204-205,共2页
Wordsworth was famous as one of those"Lake Poets".His famous romantic poem the Daffodils has been read and analyzed by now.This paper elucidates on Wordsworth’s choice of words and also on the greater profo... Wordsworth was famous as one of those"Lake Poets".His famous romantic poem the Daffodils has been read and analyzed by now.This paper elucidates on Wordsworth’s choice of words and also on the greater profound concept that he is trying to depict to his readers,and explains the poem showing how Wordsworth eloquently uses figurative language,imagery,and personification to describe a scenic display of the daffodils and demonstrate his thought"emotion recollected in tranquility"in hope of helping reader understand Wordsworth’s poetry much better. 展开更多
关键词 imagery ANALYSIS Daffodils
下载PDF
The Imagery of Rose in The Thorn Birds and The Scarlet Letter
12
作者 陆梅华 《海外英语》 2014年第15期180-181,183,共3页
The Thorn Birds and Scarlet Letter both explore the theme of love and religion, and both show the skilful use of imagism and symbolism. This essay analyzes the common images of the two novels and compares their simila... The Thorn Birds and Scarlet Letter both explore the theme of love and religion, and both show the skilful use of imagism and symbolism. This essay analyzes the common images of the two novels and compares their similarities and differences. 展开更多
关键词 imagery The THORN BIRDS SCARLET LETTER ROSE
下载PDF
Imagery in Jean Toomer's Reapers
13
作者 刘洋 《海外英语》 2014年第20期209-210,共2页
Jean Toomer was an important figure in African-American literature. He was an American poet,novelist and an important figure of the Harlem Renaissance. His most famous work,Cane,was published in 1923 and considered by... Jean Toomer was an important figure in African-American literature. He was an American poet,novelist and an important figure of the Harlem Renaissance. His most famous work,Cane,was published in 1923 and considered by many as a masterpiece of the Harlem Renaissance. Reapers is the first poem in Cane which is related to the reapers in southern plantation and rich in imagery. Toomer conveys profound theme by using various images in Reapers. 展开更多
关键词 Jean Toomer imagery Reapers CANE
下载PDF
Motor imagery training induces changes in brain neural networks in stroke patients 被引量:15
14
作者 Fang Li Tong Zhang +3 位作者 Bing-Jie Li Wei Zhang Jun Zhao Lu-Ping Song 《Neural Regeneration Research》 SCIE CAS CSCD 2018年第10期1771-1781,共11页
Motor imagery is the mental representation of an action without overt movement or muscle activation. However, the effects of motor imagery on stroke-induced hand dysfunction and brain neural networks are still unknown... Motor imagery is the mental representation of an action without overt movement or muscle activation. However, the effects of motor imagery on stroke-induced hand dysfunction and brain neural networks are still unknown. We conducted a randomized controlled trial in the China Rehabilitation Research Center. Twenty stroke patients, including 13 males and 7 females, 32–51 years old, were recruited and randomly assigned to the traditional rehabilitation treatment group(PP group, n = 10) or the motor imagery training combined with traditional rehabilitation treatment group(MP group, n = 10). All patients received rehabilitation training once a day, 45 minutes per session, five times per week, for 4 consecutive weeks. In the MP group, motor imagery training was performed for 45 minutes after traditional rehabilitation training, daily. Action Research Arm Test and the Fugl-Meyer Assessment of the upper extremity were used to evaluate hand functions before and after treatment. Transcranial magnetic stimulation was used to analyze motor evoked potentials in the affected extremity. Diffusion tensor imaging was used to assess changes in brain neural networks. Compared with the PP group, the MP group showed better recovery of hand function, higher amplitude of the motor evoked potential in the abductor pollicis brevis, greater fractional anisotropy of the right dorsal pathway, and an increase in the fractional anisotropy of the bilateral dorsal pathway. Our findings indicate that 4 weeks of motor imagery training combined with traditional rehabilitation treatment improves hand function in stroke patients by enhancing the dorsal pathway. This trial has been registered with the Chinese Clinical Trial Registry(registration number: Chi CTR-OCH-12002238). 展开更多
关键词 nerve regeneration STROKE hand function motor imagery brain neural network motion evoked potential dorsal pathway ventral pathway diffusion tensor imaging neural regeneration
下载PDF
Ultrawide-band radar imagery from multiple incoherent frequency subband measurements 被引量:7
15
作者 Xiaojian Xu Jia Li 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第3期398-404,共7页
The problem of combined radar imagery from multiple sparse frequency subbands initially incoherent to each other is of practical importance for radar target discrimination.A new coherent processing technique based on ... The problem of combined radar imagery from multiple sparse frequency subbands initially incoherent to each other is of practical importance for radar target discrimination.A new coherent processing technique based on probability density analysis of the subband data is proposed,which is applicable for radar imaging from measurements of two or more initially incoherent radar subbands.The coherence parameters for both amplitude and phase are obtained by combining modern spectral analysis with probability density estimation.The major advantage of the proposed technique lies in that it enables much more robust cohering for the sparse subband data of real-world complex targets. 展开更多
关键词 radar imagery coherent processing SUBBAND spectral analysis.
下载PDF
Derivation of Cloud-Free-Region Atmospheric Motion Vectors from FY-2E Thermal Infrared Imagery 被引量:4
16
作者 Zhenhui WANG Xinxiu SUI +5 位作者 Qing ZHANG Lu YANG Hang ZHAO Min TANG Yizhe ZHAN Zhiguo ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第2期272-282,共11页
The operational cloud-motion tracking technique fails to retrieve atmospheric motion vectors (AMVs) in areas lacking cloud; and while water vapor shown in water vapor imagery can be used, the heights assigned to the... The operational cloud-motion tracking technique fails to retrieve atmospheric motion vectors (AMVs) in areas lacking cloud; and while water vapor shown in water vapor imagery can be used, the heights assigned to the retrieved AMVs are mostly in the upper troposphere. As the noise-equivalent temperature difference (NEdT) performance of FY-2E split win- dow (10.3-11.5 μm, 11.6-12.8 μm) channels has been improved, the weak signals representing the spatial texture of water vapor and aerosols in cloud-free areas can be strengthened with algorithms based on the difference principle, and applied in calculating AMVs in the lower troposphere. This paper is a preliminary summary for this purpose, in which the principles and algorithm schemes for the temporal difference, split window difference and second-order difference (SD) methods are introduced. Results from simulation and cases experiments are reported in order to verify and evaluate the methods, based on comparison among retrievals and the "truth". The results show that all three algorithms, though not perfect in some cases, generally work well. Moreover, the SD method appears to be the best in suppressing the surface temperature influence and clarifying the spatial texture of water vapor and aerosols. The accuracy with respect to NCEP 800 hPa reanalysis data was found to be acceptable, as compared with the accuracy of the cloud motion vectors. 展开更多
关键词 atmospheric motion vector cloud-free area FY-2E IR split window imagery difference method
下载PDF
Airport automatic detection in large space-borne SAR imagery 被引量:5
17
作者 Shaoming Zhang Yi Lin Xiaohu Zhang Yingying Chen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第3期390-396,共7页
A method to detect airports in large space-borne synthetic aperture radar(SAR) imagery is studied.First,the large SAR imagery is segmented according to amplitude characteristics using maximum a posteriori(MAP) est... A method to detect airports in large space-borne synthetic aperture radar(SAR) imagery is studied.First,the large SAR imagery is segmented according to amplitude characteristics using maximum a posteriori(MAP) estimator based on the heavytailed Rayleigh model.The attention is then paid on the object of interest(OOI) extracted from the large images.The minimumarea enclosing rectangle(MER) of OOI is created via a rotating calipers algorithm.The projection histogram(PH) of MER for OOI is then computed and the scale and rotation invariant feature for OOI are extracted from the statistical characteristics of PH.A support vector machine(SVM) classifier is trained using those feature parameters and the airport is detected by the SVM classifier and Hough transform.The application in space-borne SAR images demonstrates the effectiveness of the proposed method. 展开更多
关键词 synthetic aperture radar(SAR) imagery airport detection image segmentation minimum-area enclosing rectangle support vector machine(SVM).
下载PDF
Motor Imagery and Error Related Potential Induced Position Control of a Robotic Arm 被引量:5
18
作者 Saugat Bhattacharyya Amit Konar D.N.Tibarewala 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第4期639-650,共12页
The paper introduces an electroencephalography(EEG) driven online position control scheme for a robot arm by utilizing motor imagery to activate and error related potential(ErrP) to stop the movement of the individual... The paper introduces an electroencephalography(EEG) driven online position control scheme for a robot arm by utilizing motor imagery to activate and error related potential(ErrP) to stop the movement of the individual links, following a fixed(pre-defined) order of link selection. The right(left)hand motor imagery is used to turn a link clockwise(counterclockwise) and foot imagery is used to move a link forward. The occurrence of ErrP here indicates that the link under motion crosses the visually fixed target position, which usually is a plane/line/point depending on the desired transition of the link across 3D planes/around 2D lines/along 2D lines respectively. The imagined task about individual link's movement is decoded by a classifier into three possible class labels: clockwise, counterclockwise and no movement in case of rotational movements and forward, backward and no movement in case of translational movements. One additional classifier is required to detect the occurrence of the ErrP signal, elicited due to visually inspired positional link error with reference to a geometrically selected target position. Wavelet coefficients and adaptive autoregressive parameters are extracted as features for motor imagery and ErrP signals respectively. Support vector machine classifiers are used to decode motor imagination and ErrP with high classification accuracy above 80%. The average time taken by the proposed scheme to decode and execute control intentions for the complete movement of three links of a robot is approximately33 seconds. The steady-state error and peak overshoot of the proposed controller are experimentally obtained as 1.1% and4.6% respectively. 展开更多
关键词 Brain-computer interfacing(BCI) error related potential(Errp) motor imagery decoding position control of a robot arm
下载PDF
Comparison of cerebral activation between motor execution and motor imagery of self-feeding activity 被引量:3
19
作者 Moemi Matsuo Naoki Iso +5 位作者 Kengo Fujiwara Takefumi Moriuchi Daiki Matsuda Wataru Mitsunaga Akira Nakashima Toshio Higashi 《Neural Regeneration Research》 SCIE CAS CSCD 2021年第4期770-774,共5页
Motor imagery is defined as an act wherein an individual contemplates a mental action of motor execution without apparent action.Mental practice executed by repetitive motor imagery can improve motor performance witho... Motor imagery is defined as an act wherein an individual contemplates a mental action of motor execution without apparent action.Mental practice executed by repetitive motor imagery can improve motor performance without simultaneous sensory input or overt output.We aimed to investigate cerebral hemodynamics during motor imagery and motor execution of a self-feeding activity using chopsticks.This study included 21 healthy right-handed volunteers.The self-feeding activity task comprised either motor imagery or motor execution of eating sliced cucumber pickles with chopsticks to examine eight regions of interest:pre-supplementary motor area,supplementary motor area,bilateral prefrontal cortex,premotor area,and sensorimotor cortex.The mean oxyhemoglobin levels were detected using near-infrared spectroscopy to reflect cerebral activation.The mean oxyhemoglobin levels during motor execution were significantly higher in the left sensorimotor cortex than in the supplementary motor area and the left premotor area.Moreover,significantly higher oxyhemoglobin levels were detected in the supplementary motor area and the left premotor area during motor imagery,compared to motor execution.Supplementary motor area and premotor area had important roles in the motor imagery of self-feeding activity.Moreover,the activation levels of the supplementary motor area and the premotor area during motor execution and motor imagery are likely affected by intentional cognitive processes.Levels of cerebral activation differed in some areas during motor execution and motor imagery of a self-feeding activity.This study was approved by the Ethical Review Committee of Nagasaki University(approval No.18110801)on December 10,2018. 展开更多
关键词 Activities of Daily Living brain function HEMODYNAMICS imagery(psychotherapy) mental practice motor cortex near-infrared neuroimaging NEUROSCIENCE rehabilitation spectroscopy
下载PDF
Algorithmic Foundation and Software Tools for Extracting Shoreline Features from Remote Sensing Imagery and LiDAR Data 被引量:8
20
作者 Hongxing Liu Lei Wang +2 位作者 Douglas J. Sherman Qiusheng Wu Haibin Su 《Journal of Geographic Information System》 2011年第2期99-119,共21页
This paper presents algorithmic components and corresponding software routines for extracting shoreline features from remote sensing imagery and LiDAR data. Conceptually, shoreline features are treated as boundary lin... This paper presents algorithmic components and corresponding software routines for extracting shoreline features from remote sensing imagery and LiDAR data. Conceptually, shoreline features are treated as boundary lines between land objects and water objects. Numerical algorithms have been identified and de-vised to segment and classify remote sensing imagery and LiDAR data into land and water pixels, to form and enhance land and water objects, and to trace and vectorize the boundaries between land and water ob-jects as shoreline features. A contouring routine is developed as an alternative method for extracting shore-line features from LiDAR data. While most of numerical algorithms are implemented using C++ program-ming language, some algorithms use available functions of ArcObjects in ArcGIS. Based on VB .NET and ArcObjects programming, a graphical user’s interface has been developed to integrate and organize shoreline extraction routines into a software package. This product represents the first comprehensive software tool dedicated for extracting shorelines from remotely sensed data. Radarsat SAR image, QuickBird multispectral image, and airborne LiDAR data have been used to demonstrate how these software routines can be utilized and combined to extract shoreline features from different types of input data sources: panchromatic or single band imagery, color or multi-spectral image, and LiDAR elevation data. Our software package is freely available for the public through the internet. 展开更多
关键词 SHORELINE Extraction Remote Sensing imagery LiDAR Data ArcGIS ARCOBJECTS VB.NET
下载PDF
上一页 1 2 14 下一页 到第
使用帮助 返回顶部