185 research outputs found
A Semisupervised Support Vector Machines Algorithm for BCI Systems
As an emerging technology, brain-computer interfaces (BCIs) bring us new communication interfaces which translate brain activities into control signals for devices like computers, robots, and so forth. In this study, we propose a semisupervised support vector machine (SVM) algorithm for brain-computer interface (BCI) systems, aiming at reducing the time-consuming training process. In this algorithm, we apply a semisupervised SVM for translating the features extracted from the electrical recordings of brain into control signals. This SVM classifier is built from a small labeled data set and a large unlabeled data set. Meanwhile, to reduce the time for training semisupervised SVM, we propose a batch-mode incremental learning method, which can also be easily applied to the online BCI systems. Additionally, it is suggested in many studies that common spatial pattern (CSP) is very effective in discriminating two different brain states. However, CSP needs a sufficient labeled data set. In order to overcome the drawback of CSP, we suggest a two-stage feature extraction method for the semisupervised learning algorithm. We apply our
algorithm to two BCI experimental data sets. The offline data analysis results demonstrate the effectiveness of our algorithm
Hop-Reservation Multiple Access with Variable Slots
AbstractHop-reservation multiple access control protocols in Ad Hoc networks are widely researched for its virtue in anti-jamming. Several typical such protocols are introduced and compared. Based on the analysis about their performance on anti-jamming and ability to serve upper protocols, a hop-reservation multiple access protocol with variable slot (HMAVS) is proposed. By the adaptation of variable length slots, the hop speed of control channel can be supported to the largest extent while diverse applications can be served without additional cost. Simulation results demonstrate the preference of HMAVS to other existing protocols
Studies on the active SISFCL and its impact on the distance protection of the EHV transmission line
Abstract
The active saturated iron-core superconductive fault current limiter (SISFCL) is a good choice to decrease fault current. This paper introduced the principles and impedance characteristic of the active SISFCL. Then, it shows the current-limiting effects of the SISFCL. Besides, the impact of the active SISFCL on the distance protection of the EHV transmission line is evaluated. Based on that, the coordination scheme of the distance protections is proposed. A 500 kV double-circuit transmission system with SISFCLs is simulated by Electro-Magnetic Transients Program including DC (EMTDC). Simulation tests demonstrate the correctness and validity of theoretical analyses
Research on Target Detection Algorithm of Radar and Visible Image Fusion Based on Wavelet Transform
The target detection rate of unmanned surface vehicle is low because of waves, fog, background clutter and other environmental factors on the interference. Therefore, the paper studies the target detection algorithm of radar and visible image fusion based on wavelet transform. The visible image is preprocessed to ensure the detection effect. The multi-scale fractal model is used to extract the target features, and the difference between the fractal features of the target and the background is used to detect the target. The radar image is denoised by a combination of median filtering and wavelet transform. The processed visible light and radar image are fused with wavelet transform strategy. The coefficients of the low frequency sub-band are processed by the average fusion strategy. The coefficients of the high frequency sub-band are processed using a strategy with a higher absolute value. The standard deviation, the spatial frequency and the contrast resolution of the image fusion result are compared. The simulation results show that the processed image is better than the unprocessed image after the fusion
Detection of Solar-like Oscillations in Subgiant and Red Giant Stars Using 2 minute Cadence TESS Data
Based on all 2 minute cadence TESS light curves from Sector 1 to 60, we provide a catalog of 8651 solar-like oscillators, including frequency at maximum power (νmax , with its median precision σ = 5.39%), large frequency separation (Δν, σ = 6.22%), and seismically derived masses, radii, and surface gravity values. In this sample, we have detected 2173 new oscillators and added 4373 new Δν measurements. Our seismic parameters are consistent with those from Kepler, K2, and previous TESS data. The median fractional residual in νmax is 1.63%, with a scatter of 14.75%, and in Δν it is 0.11%, with a scatter of 10.76%. We have detected 476 solar-like oscillators with νmax exceeding the Nyquist frequency of Kepler long-cadence data during the evolutionary phases of subgiants and the base of the red giant branch, which provide a valuable resource for understanding angular momentum transport
Correlation of caecal microbiome endotoxins genes and intestinal immune cells in Eimeria tenella infection based on bioinformatics
IntroductionThe infection with Eimeria tenella (ET) can elicit expression of various intestinal immune cells, incite inflammation, disrupt intestinal homeostasis, and facilitate co-infection with diverse bacteria. However, the reciprocal interaction between intestinal immune cells and intestinal flora in the progression of ET-infection remains unclear.ObjectiveThe aim of this study was to investigate the correlation between cecal microbial endotoxin (CME)-related genes and intestinal immunity in ET-infection, with subsequent identification of hub potential biomarker and immunotherapy target.MethodsDifferential expression genes (DEGs) within ET-infection and hub genes related to CME were identified through GSE39602 dataset based on bioinformatic methods and Protein-protein interaction (PPI) network analysis. Moreover, immune infiltration was analyzed by CIBERSORT method. Subsequently, comprehensive functional enrichment analyses employing Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis along with Gene Ontology (GO), gene set enrichment analysis (GSEA), and gene set variation analysis (GSVA) were performed.ResultsA total of 1089 DEGs and 25 hub genes were identified and CXCR4 was ultimately identified as a essential CME related potential biomarker and immunotherapy target in the ET-infection. Furthermore, activated natural killer cells, M0 macrophages, M2 macrophages, and T regulatory cells were identified as expressed intestinal immune cells. The functional enrichment analysis revealed that both DEGs and hub genes were significantly enriched in immune-related signaling pathways.ConclusionCXCR4 was identified as a pivotal CME-related potential biomarker and immunotherapy target for expression of intestinal immune cells during ET-infection. These findings have significant implications in elucidating the intricate interplay among ET-infection, CME, and intestinal immunity
Facile and Scalable Preparation of Graphene Oxide-Based Magnetic Hybrids for Fast and Highly Efficient Removal of Organic Dyes
This study reports the facile preparation and the dye removal efficiency of nanohybrids composed of graphene oxide (GO) and Fe[subscript 3]O[subscript 4] nanoparticles with various geometrical structures. In comparison to previously reported GO/Fe[subscript 3]O[subscript 4] composites prepared through the one-pot, in situ deposition of Fe[subscript 3]O[subscript 4] nanoparticles, the GO/Fe[subscript 3]O[subscript 4] nanohybrids reported here were obtained by taking advantage of the physical affinities between sulfonated GO and Fe[subscript 3]O[subscript 4] nanoparticles, which allows tuning the dimensions and geometries of Fe3O4 nanoparticles in order to decrease their contact area with GO, while still maintaining the magnetic properties of the nanohybrids for easy separation and adsorbent recycling. Both the as-prepared and regenerated nanohybrids demonstrate a nearly 100% removal rate for methylene blue and an impressively high removal rate for Rhodamine B. This study provides new insights into the facile and controllable industrial scale fabrication of safe and highly efficient GO-based adsorbents for dye or other organic pollutants in a wide range of environmental-related applications
Response of miR156-SPL Module during the Red Peel Coloration of Bagging-Treated Chinese Sand Pear (Pyrus pyrifolia Nakai)
MicroRNA156 is an evolutionarily highly conserved plant micro-RNA (miRNA) that controls an age-dependent flowering pathway. miR156 and its target SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes regulate anthocyanin accumulation in plants, but it is unknown whether this process is affected by light. Red Chinese sand pear (Pyrus pyrifolia) fruits exhibit a unique coloration pattern in response to bagging treatments, which makes them appropriate for studying the molecular mechanism underlying light-induced anthocyanin accumulation in fruit. Based on high-throughput miRNA and degradome sequencing data, we determined that miR156 was expressed in pear fruit peels, and targeted four SPL genes. Light-responsive elements were detected in the promoter regions of the miR156a and miR156ba precursors. We identified 19 SPL genes using the “Suli” pear (Pyrus pyrifolia Chinese White Pear Group) genome database, of which seven members were putative miR156 targets. The upregulated expression of anthocyanin biosynthetic and regulatory genes and downregulated expression of PpSPL2, PpSPL5, PpSPL7, PpSPL9, PpSPL10, PpSPL13, PpSPL16, PpSPL17, and PpSPL18 were observed in pear fruits after bags were removed from plants during the anthocyanin accumulation period. Additionally, miR156a/ba/g/s/sa abundance increased after bags were removed. Yeast two-hybrid results suggested that PpMYB10, PpbHLH, and PpWD40 could form a protein complex, probably involved in anthocyanin biosynthesis. Additionally, PpSPL10 and PpSPL13 interacted with PpMYB10. The results obtained in this study are helpful in understanding the possible role of miR156 and its target PpSPL genes in regulating light-induced red peel coloration and anthocyanin accumulation in pear
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