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Lingyun Zhang Taorong Qiu Zhiqiang Lin Shuli Zou Xiaoming Bai 《Entropy (Basel, Switzerland)》2020,22(11)
Functional brain network (FBN) is an intuitive expression of the dynamic neural activity interaction between different neurons, neuron clusters, or cerebral cortex regions. It can characterize the brain network topology and dynamic properties. The method of building an FBN to characterize the features of the brain network accurately and effectively is a challenging subject. Entropy can effectively describe the complexity, non-linearity, and uncertainty of electroencephalogram (EEG) signals. As a relatively new research direction, the research of the FBN construction method based on EEG data of fatigue driving has broad prospects. Therefore, it is of great significance to study the entropy-based FBN construction. We focus on selecting appropriate entropy features to characterize EEG signals and construct an FBN. On the real data set of fatigue driving, FBN models based on different entropies are constructed to identify the state of fatigue driving. Through analyzing network measurement indicators, the experiment shows that the FBN model based on fuzzy entropy can achieve excellent classification recognition rate and good classification stability. In addition, when compared with the other model based on the same data set, our model could obtain a higher accuracy and more stable classification results even if the length of the intercepted EEG signal is different. 相似文献
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In actual driving scenes, recognizing and preventing drivers’ non-standard driving behavior is helpful in reducing traffic accidents. To resolve the problems of various driving behaviors, a large range of action, and the low recognition accuracy of traditional detection methods, in this paper, a driving behavior recognition algorithm was proposed that combines an attention mechanism and lightweight network. The attention module was integrated into the YOLOV4 model after improving the feature extraction network, and the structure of the attention module was also improved. According to the 20,000 images of the Kaggle dataset, 10 typical driving behaviors were analyzed, processed, and recognized. The comparison and ablation experimental results showed that the fusion of an improved attention mechanism and lightweight network model had good performance in accuracy, model size, and FLOPs. 相似文献
126.
《Electroanalysis》2006,18(18):1833-1837
Proof‐of‐concept is shown for the indirect electrochemical detection of model amphetamines, D ‐amphetamine sulfate and pseudoephedrine, based on the labeling of the amphetamine models with sodium 1,2‐naphthoquinone‐4‐sulfonate (NQS). The presence of the amphetamine models is monitored via either the reduction in the magnitude of the voltammetric peak corresponding to the electrochemical reduction of the quinone functionality of the sodium 1,2‐naphthoquinone‐4‐sulfonate or via growth of a new voltammetric peak related to reaction between the amphetamine model and NQS, both of which are well resolved from one another. The protocol is shown to be successful in artificial saliva and authentic human oral (saliva) fluid. Such a protocol may be particularly attractive for roadside testing of amphetamines in drug drivers. 相似文献
127.
It is very difficult to display greyscale for an optically driving liquid crystal display (ODLCD) because the driving unit and display unit are separate, and there are no electronics in the display part of ODLCD. In this paper, two greyscale generation methods are proposed to achieve this goal. Six and nine grey levels are separately achieved through the two methods. 相似文献
128.
A quick and simple dispersive liquid-liquid microextraction (DLLME) metiiod was established to extract the diphenhydramine (DPH) in saliva followed by poZable high-resolution ion mobility spectrometry (IMS) detection. 2 mL saliva was collected and the protein was firstly precipitated by 10% ZnS04, then DPH in saliva was extracted by 2 mL dichloromethane. The extraction time was 5 min. Ater centZfugation at 3500 r/min for 20 min, the dichloromethane layer was taken and dred in vacuum at 45°C. Then the residue was disolved in methanol for IMS analysis. The results showed that the separation and analysis of DPH was aciiieved in a shor time. The DPH had a good linear relationship in the range of 39. 4 ~ 1080 ng mL, the standard curve equation was 7=3. 62 X 103 C-0.754 (#2 = 0.978), the limit of detection and limit of quantitation were 11.8 and 39. 4 ng/mL, respectively. The average recovery was 89%-112% with RSD & 1. 5%. This metiiod can be used for rapidly determination of DPH in human saliva. © 2021, Youke Publishing Co.,Ltd. All rights reserved.
129.
Low-density polyethylene (LDPE)/p, p-oxybis (benzenesulfonylhydrazide) (OBSH) system was carried out to investigate the cell growth during foaming process with a visualization apparatus at a constant temperature. The results showed that the cells growth of LDPE foams follows the Logistic function with a higher correlation coefficient of 0.96738. Here, a method was adopted to establish the relationships between cell growth and foaming process with first and second derivatives of cell mean diameter vs. time, which reflected the cells growth rate and driving force during cell growth, respectively. Moreover, we elucidated the interactions of cells growth at less-foamed, better-foamed and over-foamed stages were asymmetric during foaming process, which resulted from the greater cells deformation. This revealed the method in describing cells growth provided a visual comprehension of the mechanisms for foaming process. 相似文献
130.
The paper reports and compares the results of the electromechanical, acoustical and thermodynamical characterization of a low-frequency sonotrode-type ultrasonic device inside a small sonoreactor, immersed in three different loading media, namely, water, juice and milk, excited at different excitation levels, both below and above the cavitation threshold. The electroacoustic efficiency factor determined at system resonance through electromechanical characterization in degassed water as the reference medium is 88.7% for the device in question. This efficiency can be reduced up to three times due to the existence of a complex sound field in the reactor in linear driving conditions below the cavitation threshold. The behaviour of the system is more stable at higher excitation levels than in linear operating conditions.During acoustical characterization, acoustic pressure is spatially averaged, both below and above the cavitation threshold. The standing wave patterns inside the sonoreactor have a stronger influence on the variation of the spatially distributed RMS pressure in linear operating conditions. For these conditions, the variation of ±1.7 dB was obtained, compared to ±1.4 dB obtained in highly nonlinear regime. The acoustic power in the sonoreactor was estimated from the magnitude of the averaged RMS pressure, and from the reverberation time of the sonoreactor as the representation of the losses. The electroacoustic efficiency factors obtained through acoustical and electromechanical characterization are in a very good agreement at low excitation levels. The irradiated acoustic power estimated in nonlinear conditions differs from the dissipated acoustic power determined with the calorimetric method by several orders of magnitude.The number of negative pressure peaks that represent transient cavitation decreases over time during longer treatments of a medium with high-power ultrasound. The number of negative peaks decreases faster when the medium and the vessel are allowed to heat up. 相似文献