scholarly journals Selective Feature Generation Method Based on Time Domain Parameters and Correlation Coefficients for Filter-Bank-CSP BCI Systems

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3769 ◽  
Author(s):  
Yongkoo Park ◽  
Wonzoo Chung
Keyword(s):  
Time Domain ◽  
Filter Bank ◽  
Correlation Coefficients ◽  
Channel Selection ◽  
Classification Performance ◽  
Selection Methods ◽  
Common Spatial Pattern ◽  
Correlated Channels ◽  
Fisher Ratio ◽  
Highly Correlated

This paper presents a novel motor imagery (MI) classification algorithm using filter-bank common spatial pattern (FBCSP) features based on MI-relevant channel selection. In contrast to existing channel selection methods based on global CSP features, the proposed algorithm utilizes the Fisher ratio of time domain parameters (TDPs) and correlation coefficients: the channel with the highest Fisher ratio of TDPs, named principle channel, is selected and a supporting channel set for the principle channel that consists of highly correlated channels to the principle channel is generated. The proposed algorithm using the FBCSP features generated from the supporting channel set for the principle channel significantly improved the classification performance. The performance of the proposed method was evaluated using BCI Competition III Dataset IVa (18 channels) and BCI Competition IV Dataset I (59 channels).

scholarly journals An Optimized Channel Selection Method Based on Multifrequency CSP-Rank for Motor Imagery-Based BCI System

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Jian Kui Feng ◽  
Jing Jin ◽  
Ian Daly ◽  
Jiale Zhou ◽  
Yugang Niu ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Classification Accuracy ◽  
Channel Selection ◽  
Selection Method ◽  
Selection Methods ◽  
Eeg Signals ◽  
Common Spatial Pattern ◽  
Linear Discriminant ◽  
Novel Method ◽  
Electroencephalogram Eeg

Background. Due to the redundant information contained in multichannel electroencephalogram (EEG) signals, the classification accuracy of brain-computer interface (BCI) systems may deteriorate to a large extent. Channel selection methods can help to remove task-independent electroencephalogram (EEG) signals and hence improve the performance of BCI systems. However, in different frequency bands, brain areas associated with motor imagery are not exactly the same, which will result in the inability of traditional channel selection methods to extract effective EEG features. New Method. To address the above problem, this paper proposes a novel method based on common spatial pattern- (CSP-) rank channel selection for multifrequency band EEG (CSP-R-MF). It combines the multiband signal decomposition filtering and the CSP-rank channel selection methods to select significant channels, and then linear discriminant analysis (LDA) was used to calculate the classification accuracy. Results. The results showed that our proposed CSP-R-MF method could significantly improve the average classification accuracy compared with the CSP-rank channel selection method.

Classification of EEG Signals Based on Filter Bank and Sparse Representation in Motor Imagery Brain-Computer Interfaces

2019 ◽  
Vol 29 (03) ◽  
pp. 2050034 ◽  
Author(s):  
Jin Wang ◽  
Qingguo Wei
Keyword(s):  
Sparse Representation ◽  
Motor Imagery ◽  
Filter Bank ◽  
Classification Performance ◽  
Brain Computer Interfaces ◽  
Eeg Signals ◽  
Fisher Score ◽  
Common Spatial Pattern ◽  
Signal Processing Algorithm ◽  
Computer Interfaces

To improve the classification performance of motor imagery (MI) based brain-computer interfaces (BCIs), a new signal processing algorithm for classifying electroencephalogram (EEG) signals by combining filter bank and sparse representation is proposed. The broadband EEG signals of 8–30[Formula: see text]Hz are segmented into 10 sub-band signals using a filter bank. EEG signals in each sub-band are spatially filtered by common spatial pattern (CSP). Fisher score combined with grid search is used for selecting the optimal sub-band, the band power of which is employed for designing a dictionary matrix. A testing signal can be sparsely represented as a linear combination of some columns of the dictionary. The sparse coefficients are estimated by [Formula: see text] norm optimization, and the residuals of sparse coefficients are exploited for classification. The proposed classification algorithm was applied to two BCI datasets and compared with two traditional broadband CSP-based algorithms. The results showed that the proposed algorithm provided superior classification accuracies, which were better than those yielded by traditional algorithms, verifying the efficacy of the present algorithm.

Classification of EEG Signals Using Filter Bank Common Spatial Pattern Based on Fisher and Laplacian Criteria

2012 ◽  
Vol 239-240 ◽  
pp. 1033-1038
Author(s):  
Qing Guo Wei ◽  
Bin Wan ◽  
Zong Wu Lu
Keyword(s):  
Feature Selection ◽  
Spatial Pattern ◽  
Filter Bank ◽  
Selection Criterion ◽  
Classification Performance ◽  
Fisher Score ◽  
Common Spatial Pattern ◽  
Frequency Bands ◽  
Operational Frequency ◽  
Laplacian Score

Common spatial pattern (CSP) is a highly successful algorithm in motor imagery based brain-computer interfaces (BCIs). The performance of the algorithm, however, depends largely on the operational frequency bands. To address the problem, a filter bank was applied to find optimal frequency bands. In filter bank, CSP was applied in all sub-band signals for feature extraction. The feature selection is the key of filter bank method for increasing classification performance. In this study, coefficient decimation (CD) technique was used to devise filter bank, while Fisher score and Laplacian score were proposed as feature selection criterion. In off-line analysis, the proposed method yielded relatively better cross-validation classification accuracies.

Relationship between Coffee Prices in Spot and Futures Markets-An Empirical Analysis

2020 ◽  
pp. 180-188
Keyword(s):  
New York ◽  
Correlation Coefficients ◽  
Strong Relationship ◽  
Futures Market ◽  
Regression Coefficients ◽  
Futures Prices ◽  
Market Prices ◽  
Spot Prices ◽  
Correlation And Regression Analysis ◽  
Highly Correlated

The present study explored the relationship between spot and futures coffee prices. The Correlation and Regression analysis were carried out based on monthly observations of International Coffee Organization (ICO) indicator prices of the four groups (Colombian Milds, Other Milds, Brazilian Naturals, and Robustas) representing Spot markets and the averages of 2nd and 3rd positions of the Intercontinental Exchange (ICE) New York for Arabica and ICE Europe for Robusta representing the Futures market for the period 1990 to 2019. The study also used the monthly average prices paid to coffee growers in India from 1990 to 2019. The estimated correlation coefficients indicated both the Futures prices and Spot prices of coffee are highly correlated. Further, estimated regression coefficients revealed a very strong relationship between Futures prices and Spot prices for all four ICO group indicator prices. Hence, the ICE New York (Arabica) and ICE Europe (Robusta) coffee futures prices are very closely related to Spot prices. The estimated regression coefficients between Futures prices and the price paid to coffee growers in India confirmed the positive relationship, but the dispersion of more prices over the trend line indicates a lesser degree of correlation between the price paid to growers at India and Futures market prices during the study period.

scholarly journals Striatal Dopamine Transporter Spect Quantification: Head-To-Head Comparison Between Two Three-Dimensional Automatic Tools

2020 ◽  
Author(s):  
Silvia Morbelli ◽  
Dario Arnaldi ◽  
Eugenia Cella ◽  
Stefano Raffa ◽  
Isabella Donegani ◽  
...  
Keyword(s):  
Dopamine Transporter ◽  
Gold Standard ◽  
Rating Scale ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Striatal Dopamine ◽  
Dat Spect ◽  
Disease Rating ◽  
Highly Correlated ◽  
Visual Reading

Abstract Purpose. Our aim was the head-to-head comparison between two automatic tools for semi-quantification of striatal dopamine transporter (DAT) specific-to-non displaceable (SBR) ratio brain SPECT values in a naturalistic cohort of patients. Procedures. We analyzed consecutive scans from one-hundred and fifty-one outpatients submitted to brain DAT SPECT for a suspected parkinsonism. Images were post-processed using a commercial (Datquant®) and a free (BasGanV2) software. Reading by expert was the gold-standard. A subset of patients with pathological or borderline scan was evaluated with the clinical Unified Parkinson’s disease rating scale, motor part (MDS-UPDRS-III). Results. SBR, putamen-to-caudate (P/C) ratio, and both P and C asymmetries were highly correlated between the two software with Pearson’s ‘r’ correlation coefficients ranging from .706 to .887. Correlation coefficients with the MDS-UPDRS III score were higher with caudate than with putamen SBR values with both software, and in general higher with BasGanV2 than with Datquant® . Datquant® correspondence with expert reading was 84.1% (94.0% by additionally considering the P/C ratio as a further index). BasGanV2 correspondence with expert reading was 80.8% (86.1% by additionally considering the P/C ratio). Conclusions. Both Datquant® and BasGanV2 work reasonably well and similarly one another in semi-quantification of DAT SPECT. Both tools have their own strength and pitfalls that must be known in detail by users in order to obtain the best help in visual reading and reporting of DAT SPECT.

scholarly journals The Arabic Version of the Mobile App Rating Scale: Development and Validation Study (Preprint)

2019 ◽  
Author(s):  
Marco Bardus ◽  
Nathalie Awada ◽  
Lilian A Ghandour ◽  
Elie-Jacques Fares ◽  
Tarek Gherbal ◽  
...  
Keyword(s):  
Weight Management ◽  
Information Quality ◽  
Rating Scale ◽  
Arab World ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Mobile App ◽  
Health Apps ◽  
Highly Correlated

BACKGROUND With thousands of health apps in app stores globally, it is crucial to systemically and thoroughly evaluate the quality of these apps due to their potential influence on health decisions and outcomes. The Mobile App Rating Scale (MARS) is the only currently available tool that provides a comprehensive, multidimensional evaluation of app quality, which has been used to compare medical apps from American and European app stores in various areas, available in English, Italian, Spanish, and German. However, this tool is not available in Arabic. OBJECTIVE This study aimed to translate and adapt MARS to Arabic and validate the tool with a sample of health apps aimed at managing or preventing obesity and associated disorders. METHODS We followed a well-established and defined “universalist” process of cross-cultural adaptation using a mixed methods approach. Early translations of the tool, accompanied by confirmation of the contents by two rounds of separate discussions, were included and culminated in a final version, which was then back-translated into English. Two trained researchers piloted the MARS in Arabic (MARS-Ar) with a sample of 10 weight management apps obtained from Google Play and the App Store. Interrater reliability was established using intraclass correlation coefficients (ICCs). After reliability was ascertained, the two researchers independently evaluated a set of additional 56 apps. RESULTS MARS-Ar was highly aligned with the original English version. The ICCs for MARS-Ar (0.836, 95% CI 0.817-0.853) and MARS English (0.838, 95% CI 0.819-0.855) were good. The MARS-Ar subscales were highly correlated with the original counterparts (<i>P</i>&lt;.001). The lowest correlation was observed in the area of usability (<i>r</i>=0.685), followed by aesthetics (<i>r</i>=0.827), information quality (<i>r</i>=0.854), engagement (<i>r</i>=0.894), and total app quality (<i>r</i>=0.897). Subjective quality was also highly correlated (<i>r</i>=0.820). CONCLUSIONS MARS-Ar is a valid instrument to assess app quality among trained Arabic-speaking users of health and fitness apps. Researchers and public health professionals in the Arab world can use the overall MARS score and its subscales to reliably evaluate the quality of weight management apps. Further research is necessary to test the MARS-Ar on apps addressing various health issues, such as attention or anxiety prevention, or sexual and reproductive health.

GROWTH AND DEVELOPMENT OF PERUVIAN CHILDREN

PEDIATRICS ◽  
1956 ◽  
Vol 17 (4) ◽  
pp. 510-523
Author(s):  
M. F. Trulson ◽  
C. Collazos ◽  
D. M. Hegsted
Keyword(s):  
Rural Areas ◽  
Growth And Development ◽  
Partial Correlation ◽  
Correlation Coefficients ◽  
Significant Degree ◽  
Skeletal Age ◽  
Developmental Patterns ◽  
Specific Effects ◽  
Developmental Age ◽  
Highly Correlated

One hundred nine school children from 2 rural areas in the coastal area of Peru were measured and weighed and roentgenograms of the hand and wrist were obtained. Three-fourths of the children were below Stuart's tenth percentile in height. Roughly, a third of the children were below the tenth percentile in weight. Fifteen per cent of the girls and 30 per cent of the boys were above the fiftieth percentile in weight. Forty to forty-five per cent of the children were in the stocky to obese channels of the Wetzel grid; 5 to 10 per cent would be classified as fair to poor, and roughly half would be considered average. Developmental age (Wetzel) was 7.5 ± 15.6 months less than chronological age for boys, 10.5 ± 11.3 months less for girls. A third of the boys and 15 per cent of the girls were advanced in Wetzel developmental age. It was apparent that the heavier children were generally advanced in Wetzel developmental age. Roentgenograms of the hand and wrist were assessed by comparing the films to the Greulich-Pyle Standards. Skeletal age was -11.3 ± 12.7 months for boys and -7.1 ± 9.8 for girls. Eighteen per cent of the population were advanced in skeletal age. Boys were more retarded than girls in skeletal age. The correlation and partial correlation coefficients for all combinations of the 4 measurements (retardation in weight, retardation in height, retardation in skeletal age and retardation in developmental age) were calculated. The various pairs were all rather highly correlated, this being particularly true of weight and Wetzel developmental age. The partial correlation coefficients show, however, that skeletal age was not closely correlated with any of the other 3 measurements. Height and developmental age were negatively correlated to a significant degree, and developmental age and weight were so closely related that they appear to be measures of the same characteristic in this population. Individual dietary histories are not available from these children, but it is known that the diets in the area are considerably below recommended levels in certain nutriients. Whether dietary deficiencies are factors in the apparently abnormal developmental patterns, or if the patterns are truly abnormal for the Peruvian child or indicate an adverse effect on health, remain to be shown. It is pointed out that there are probably advantages in studies upon growth and development in different areas of the world where a variety of dietary or environmental factors may have specific effects.

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