Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 8 de 8
Filter
1.
Sensors (Basel) ; 20(8)2020 Apr 17.
Article in English | MEDLINE | ID: mdl-32316473

ABSTRACT

Speech emotion recognition often encounters the problems of data imbalance and redundant features in different application scenarios. Researchers usually design different recognition models for different sample conditions. In this study, a speech emotion recognition model for a small sample environment is proposed. A data imbalance processing method based on selective interpolation synthetic minority over-sampling technique (SISMOTE) is proposed to reduce the impact of sample imbalance on emotion recognition results. In addition, feature selection method based on variance analysis and gradient boosting decision tree (GBDT) is introduced, which can exclude the redundant features that possess poor emotional representation. Results of experiments of speech emotion recognition on three databases (i.e., CASIA, Emo-DB, SAVEE) show that our method obtains average recognition accuracy of 90.28% (CASIA), 75.00% (SAVEE) and 85.82% (Emo-DB) for speaker-dependent speech emotion recognition which is superior to some state-of-the-arts works.


Subject(s)
Emotions/physiology , Pattern Recognition, Automated/methods , Speech/physiology , Algorithms , Databases, Factual , Humans
2.
IEEE Trans Cybern ; 53(4): 2051-2061, 2023 Apr.
Article in English | MEDLINE | ID: mdl-34478391

ABSTRACT

This article presents a method of suppressing packet losses and exogenous disturbances for a networked control system (NCS) subject to network-introduced delays. The NCS has two feedback loops: 1) a local one and 2) a main one. The local feedback loop contains a state observer, an equivalent-input-disturbance (EID) estimator, and state feedback. It is used to ensure prompt disturbance suppression. The controller in the main feedback loop contains an internal model to track a reference input. The system is divided into two subsystems for the design of controllers. The state-observer gain is designed for one subsystem using the concept of perfect regulation to ensure disturbance estimation performance. The state-feedback gains of the other subsystem are designed based on a stability condition in the form of a linear matrix inequality (LMI). A tracking specification is embedded in the LMI-based stability condition to ensure satisfactory tracking performance. A case study on a two-finger robot hand control system and a comparison with a Smith-EID and H∞ controller approach validate the effectiveness and superiority of the presented method.

3.
ISA Trans ; 108: 69-77, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32958295

ABSTRACT

Exogenous disturbances largely affect the control performance of systems with time delays. This study considers a control problem of rejecting a disturbance in a PI control system for a time-varying state-delay plant. The equivalent-input-disturbance (EID) approach is integrated in a PI control system. An EID estimator estimates the overall effects of a time-varying delay and a disturbance. An EID estimate is combined into a PI control law to improve control performance. A less-conservative stability condition of the control system is derived using a Lyapunov-Krasovskii functional together with the Jensen's integral inequality and the reciprocally convex combination lemma. Parameters of the controllers in the system are calculated using the condition. Engine idle speed control is used to verify the effectiveness of this approach. Compared with the generalized extended-state observer and the sliding-mode control methods, our method reduced the tracking error to about one third and one sixth, respectively. This demonstrates the validity and superiority of our method.

4.
J Healthc Eng ; 2021: 6674744, 2021.
Article in English | MEDLINE | ID: mdl-33953899

ABSTRACT

Background: Osteoarthritis (OA) is a chronic and degenerative joint disease, which causes stiffness, pain, and decreased function. At the early stage of OA, nonsteroidal anti-inflammatory drugs (NSAIDs) are considered the first-line treatment. However, the efficacy and utility of available drug therapies are limited. We aim to use bioinformatics to identify potential genes and drugs associated with OA. Methods: The genes related to OA and NSAIDs therapy were determined by text mining. Then, the common genes were performed for GO, KEGG pathway analysis, and protein-protein interaction (PPI) network analysis. Using the MCODE plugin-obtained hub genes, the expression levels of hub genes were verified using quantitative real-time polymerase chain reaction (qRT-PCR). The confirmed genes were queried in the Drug Gene Interaction Database to determine potential genes and drugs. Results: The qRT-PCR result showed that the expression level of 15 genes was significantly increased in OA samples. Finally, eight potential genes were targetable to a total of 53 drugs, twenty-one of which have been employed to treat OA and 32 drugs have not yet been used in OA. Conclusions: The 15 genes (including PTGS2, NLRP3, MMP9, IL1RN, CCL2, TNF, IL10, CD40, IL6, NGF, TP53, RELA, BCL2L1, VEGFA, and NOTCH1) and 32 drugs, which have not been used in OA but approved by the FDA for other diseases, could be potential genes and drugs, respectively, to improve OA treatment. Additionally, those methods provided tremendous opportunities to facilitate drug repositioning efforts and study novel target pharmacology in the pharmaceutical industry.


Subject(s)
Osteoarthritis , Computational Biology/methods , Data Mining , Drug Discovery , Gene Expression Profiling , Humans , Osteoarthritis/drug therapy , Osteoarthritis/genetics , Osteoarthritis/metabolism , Protein Interaction Maps/genetics
5.
Am J Transl Res ; 9(6): 2694-2711, 2017.
Article in English | MEDLINE | ID: mdl-28670362

ABSTRACT

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common and aggressive malignant tumors in the world. In China, traditional medicine is commonly used in the treatment of cancer. Among these medicines, Jianpi Huayu Decoction (JHD) is a typical clinical prescription against multiple tumors. However, the exact function and targets of JHD are currently unknown. The aim of this study is to assess the efficacy of JHD against HCC. METHODS AND RESULTS: Hepatic carcinoma SMMC7221 cells were treated with JHD drug-serum in a dose- and time-dependent manner. Real-time PCR (RT-PCR), western-blot (WB), and immunofluorescence microscopy revealed that JHD increased both the mRNA and protein levels of Smad7 and decreased the protein level of p-Smad3. It subsequently increased the E-cadherin expression level and decreased those of N-cadherin and Vimentin. Metastasis and invasion were eventually inhibited, as determined by the wound healing and transwell invasion assays. Treatment of Tanshinone IIA (Tan IIA) showed similar results as JHD, indicating that it is most likely the main functional drug monomer of JHD. The in vivo assay in nude mice also revealed the efficacy of JHD to inhibit epithelial mesenchymal transition (EMT). CONCLUSION: JHD was shown to be an effective therapeutic strategy against HCC.

6.
J Zhejiang Univ Sci ; 5(8): 960-5, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15473052

ABSTRACT

Great efforts have been made to resolve the serious environmental pollution and inevitable declining of energy resources. A review of Chinese fuel reserves and engine technology showed that compressed natural gas (CNG)/diesel dual fuel engine (DFE) was one of the best solutions for the above problems at present. In order to study and improve the emission performance of CNG/diesel DFE, an emission model for DFE based on radial basis function (RBF) neural network was developed which was a black-box input-output training data model not require priori knowledge. The RBF centers and the connected weights could be selected automatically according to the distribution of the training data in input-output space and the given approximating error. Studies showed that the predicted results accorded well with the experimental data over a large range of operating conditions from low load to high load. The developed emissions model based on the RBF neural network could be used to successfully predict and optimize the emissions performance of DFE. And the effect of the DFEmain performance parameters, such as rotation speed, load, pilot quantity and injection timing, were also predicted by means of this model. In resumé, an emission prediction model for CNG/diesel DFE based on RBF neural network was built for analyzing the effect of the main performance parameters on the CO, NOx, emissions of DFE. The predicted results agreed quite well with the traditional emissions model, which indicated that the model had certain application value, although it still has some limitations, because of its high dependence on the quantity of the experimental sample data.


Subject(s)
Fossil Fuels , Gasoline , Neural Networks, Computer , Vehicle Emissions , Energy-Generating Resources
7.
J Zhejiang Univ Sci ; 4(5): 591-4, 2003.
Article in English | MEDLINE | ID: mdl-12958720

ABSTRACT

The present work used a methane-air mixture chemical kinetics scheme consisting of 119 elementary reaction steps and 41 chemical species to develop a simplified combustion model for prediction of the knock in dual fuel engines. Calculated values by the model for natural gas operation showed good agreement with corresponding experimental values over a broad range of operating conditions.


Subject(s)
Fossil Fuels , Vehicle Emissions , Carbon Monoxide/chemistry , Kinetics , Models, Statistical , Physical Phenomena , Physics , Temperature
8.
J Zhejiang Univ Sci ; 4(2): 170-4, 2003.
Article in English | MEDLINE | ID: mdl-12659230

ABSTRACT

In order to predict and improve the performance of natural gas/diesel dual fuel engine (DFE), a combustion rate model based on forward neural network was built to study the combustion process of the DFE. The effect of the operating parameters on combustion rate was also studied by means of this model. The study showed that the predicted results were good agreement with the experimental data. It was proved that the developed combustion rate model could be used to successfully predict and optimize the combustion process of dual fuel engine.


Subject(s)
Fossil Fuels , Gasoline , Hot Temperature , Models, Theoretical , Neural Networks, Computer , Thermodynamics , Air Pollutants , Air Pollution/prevention & control , Computer Simulation , Electric Power Supplies , Energy Transfer , Energy-Generating Resources , Models, Chemical , Motor Vehicles , Oxidation-Reduction , Quality Control , Reproducibility of Results , Sensitivity and Specificity , Vehicle Emissions/analysis
SELECTION OF CITATIONS
SEARCH DETAIL