摘要：
With the advancements in low-power and miniature electronics, various smart devices are deployed and interconnected as the Internet of Things (IoT), collecting a massive amount of data from surrounding environments. Despite the popularity of ZigBee for low-power communications in IoT, WiFi has recently been recommended for data collection in IoT for its high data rate, high reliability, native IP compatibility, and vastly-deployed infrastructures. However, it is well known that WiFi is energy-consuming. Although many schemes have been designed to reduce WiFi energy consumption, they usually suffer from the dilemma that a longer (shorter) sleep of WiFi gives a lower (higher) energy consumption but a larger (smaller) latency, hindering the use of WiFi in a wide range of IoT applications that require a certain level of quality of service (QoS). To this end, we propose a Heterogeneity-aware Dual-interface Scheduling (HDS) scheme to fully exploit the heterogeneity between ZigBee and WiFi to realize energy-efficient and delay-constrained data collection in a tree-based IoT network, where each device is equipped with a ZigBee and a WiFi interface. The low-power feature of ZigBee is utilized as much as possible for high energy efficiency, while the high-reliability advantage of WiFi is leveraged when the ZigBee link quality is low for delay guarantee. Under network dynamics, HDS jointly allocates ZigBee and WiFi schedules to strike a balance between energy and delay for optimized performance. A prototype system is built atop an IoT platform integrated with commercial off-the-shelf ZigBee and WiFi modules. Experiment results show that the energy consumption of HDS is 80.3% and 43.6% lower than the standard power saving protocol and a state-of-the-art dual-interface scheme, respectively, under a moderate delay constraint. Additionally, the percentage of data packets that satisfy the delay constraint is above 98.6%.
期刊：
EUROPEAN PHYSICAL JOURNAL C,2024年84(1):1-7 ISSN：1434-6044
通讯作者：
Chen, X
作者机构：
[Zhou, Jing] Hunan City Univ, Dept Phys, Yiyang 413000, Hunan, Peoples R China.;[Zhou, Jing] Hunan City Univ, All solid state Energy Storage Mat & Devices Key L, Yiyang 413000, Peoples R China.;[Zhou, Jing; Ping, Jialun] Nanjing Normal Univ, Dept Phys, Nanjing 210097, Jiangsu, Peoples R China.;[Chen, Jun] Hubei Minzu Univ, Dept Phys, Enshi 445000, Peoples R China.;[Zhang, Le] Hubei Normal Univ, Coll Phys & Elect Sci, Huangshi 435002, Peoples R China.
通讯机构：
[Chen, X ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
摘要：
According to gauge/gravity correspondence, we study the holographic Schwinger effect within an anisotropic background. Firstly, the separate length of the particle-antiparticle pairs is computed within the context of an anisotropic background which is parameterized by dynamical exponent nu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\nu $$\end{document}. It is found that the maximum separate length x increases with the increase of dynamical exponent nu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\nu $$\end{document}. By analyzing the potential energy, we find that the potential barrier increases with the dynamical exponent nu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\nu $$\end{document} at a small separate distance. This observation implies that the Schwinger effect within an anisotropic background is comparatively weaker when contrasted with its manifestation in an isotropic background. Finally, we also find that the Schwinger effect in the transverse direction is weakened compared to the parallel direction in the anisotropic background, which is consistent with the top-down model.
摘要：
Fatigue driving is a serious threat to road safety, which is why accurately identifying fatigue driving behavior and warning drivers in time are of great significance in improving traffic safety. However, accurately recognizing fatigue driving is still challenging due to large intra-class variations in facial expression, continuity of behaviors, and illumination conditions. A fatigue driving recognition method based on feature parameter images and a residual Swin Transformer is proposed in this paper. First, the face region is detected through spatial pyramid pooling and a multi-scale feature output module. Then, a multi-scale facial landmark detector is used to locate 23 key points on the face. The aspect ratios of the eyes and mouth are calculated based on the coordinates of these key points, and a feature parameter matrix for fatigue driving recognition is obtained. Finally, the feature parameter matrix is converted into an image, and the residual Swin Transformer network is presented to recognize fatigue driving. Experimental results on the HNUFD dataset show that the proposed method achieves an accuracy of 96.512%, thus outperforming state-of-the-art methods.
摘要：
Driver behavior is an essential factor affecting traffic safety, and driver behavior monitoring systems (DMSs) are widely exploited in intelligent transportation systems to reduce the risk of traffic accidents. However, understanding driver behavior is challenging because of the uncertainty of real driving scenarios. Most of the existing methods use deterministic models, which suffer from data uncertainty, for recognizing driver behaviors. In this paper, the fuzzy deep attention network (FDAN) method is proposed to improve driver behavior recognition. FDAN integrates fuzzy logic and an attention mechanism into deep neural networks, which enhances the representation ability of the model and reduces the uncertainty of the data. The attention mechanism with a lightweight squeeze -and -excitation block is embedded in the deep learning model for adaptively refining features. A DMS is designed, and the distracted driver dataset from the real scene is built. Experimental results confirm the proposed method performs better than the existing methods.
期刊：
Waves in Random and Complex Media,2023年 ISSN：1745-5030
通讯作者：
Hongjian Li
作者机构：
[Cuixiu Xiong] College of Information and Electronic Engineering, Hunan City University, Yiyang, People’s Republic of China;[Hongjian Li; Chao Liu; Banxian Ruan; Min Li; Enduo Gao] School of Physics and Electronics, Central South University, Changsha, People’s Republic of China
通讯机构：
[Hongjian Li] S;School of Physics and Electronics, Central South University, Changsha, People’s Republic of China
摘要：
We propose a hybrid structure composed of a silver mirror and two spaced graphene monolayers to enhance light absorption. A broad plasmon-induced reflection (PIR) window can be generated because of the destructive interference between the bright and dark modes, resulting in a dual-narrowband absorption switching effect. The dual-narrowband absorption switch is strongly dependent on the geometric structure parameters and dynamic tuning parameter of the hybrid structure, and each parameter has a wide tuning range for absorption state ‘on/on’. Especially, compared with the hybrid structure composed of a graphene monolayer and one-dimensional photonic crystal (1D PC), the proposed structure is simpler and easier to fabricate, and the dynamic tuning width of Fermi energy of graphene for light absorption state ‘on/on’ is significantly broadened (∼3 times). Compared with plasmon-induced transparency (PIT) systems, the absorption performance of graphene is greatly enhanced, and the absorption is increased from about 50% to higher than 97%. Moreover, by adjusting the widths of the graphene monolayers, NAND and NOR logic gates are realized, and the output contrast between logic states ‘1’ and ‘0’ is high up to 18.6 dB. This study may provide an approach to construct dual-narrowband absorption switches, perfect absorbers, and plasmon logic gates.
作者机构：
[Hu, Xiaojie; Dong, Fuxiao; Wang, Haiou; Zhao, Bojun; Huo, Dexuan; Wang, Yan] Hangzhou Dianzi Univ, Inst Mat Phys, Key Lab Novel Mat Sensor Zhejiang Prov, Hangzhou 310018, Peoples R China.;[Tan, Weishi] Hunan City Univ, Coll Informat & Elect Engn, All Solid State Energy Storage Mat & Devices Key L, Yiyang 413002, Peoples R China.;[Tan, Weishi] Nanjing Univ Sci & Technol, Dept Appl Phys, Key Lab Soft Chem & Funct Mat, Minist Educ, Nanjing 210094, Peoples R China.
通讯机构：
[Weishi Tan; Haiou Wang] A;Authors to whom correspondence should be addressed.<&wdkj&>All-Solid-State Energy Storage Materials and Devices Key Laboratory of Hunan Province, College of Information and Electronic Engineering, Hunan City University, Yiyang 413002, China<&wdkj&>Key Laboratory of Soft Chemistry and Functional Materials, Ministry of Education, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Institute of Material Physics, Hangzhou Dianzi University, Hangzhou 310018, China
关键词：
magnetic properties;magnetocaloric;manganite;film;Pr0.7Sr0.3MnO3
摘要：
The magnetic behaviors and magnetocaloric effect (MCE) of Pr0.7Sr0.3MnO3 (PSMO-7) film grown on a (001) SrTiO3 single-crystal substrate by a pulsed laser deposition (PLD) were studied in this paper. X-ray diffraction with a high resolution (HRXRD) measurement shows that PSMO-7 film is grown with a (001) single orientation. The magnetic properties and the MCE related to the ferromagnetic (FM) phase transition of the PSMO-7 film are investigated using the temperature dependence of magnetization M(T) and the magnetic field dependence of magnetization M(H). The M(T) data suggest that with decreasing temperatures, the PSMO-7 film goes through the transition from the paramagnetic (PM) state to the FM state at around the Curie temperature (T-C). The T-C (about 193 K) can be obtained by the linear fit of the Curie law. Magnetic hysteresis loop measurements show that the PSMO-7 film exhibits the FM feature at temperatures of 10, 100, and 150 K (low magnetic hysteresis can be found), while the film reveals the PM feature with the temperature increased up to 200 and/or 300 K. The research results of M(H) data are consistent with the M(T) data. Furthermore, the magnetic entropy change (-delta S-M) of the PSMO-7 film was studied. It was found that the maximum value of (-delta S-M) near T-C reaches about 4.7 J/kg & BULL;K under the applied field change of 20 kOe, which is comparable to that of metal Gd (-delta S-M of 2.8 J/kg K under 10 kOe), indicating the potential applications of PSMO-7 film in the field of magnetic refrigeration.
作者机构：
[Cao, Kesheng; Wang, Yabo] School of Chemistry and Environmental Engineering, Henan Key Laboratory of Germplasm Innovation and Utilization of Eco-Economic Woody Plant, Pingdingshan University, Weilai Road, Pingdingshan, 467000, China;[Tian, Zhengshan] School of Chemistry and Environmental Engineering, Henan Key Laboratory of Germplasm Innovation and Utilization of Eco-Economic Woody Plant, Pingdingshan University, Weilai Road, Pingdingshan, 467000, China. tianzhengshan@163.com;[Zhang, Xunyou] College of Mechanical and Electrical Engineering, Chizhou University, Chizhou, 247000, China. xyzhang@czu.edu.cn;[Zhu, Qiuxiang] College of Information and Electronic Engineering, Hunan City University, Yingbin East Road, Yiyang, 413000, China
通讯机构：
[Zhang, Xunyou] C;[Tian, Zhengshan] S;School of Chemistry and Environmental Engineering, Henan Key Laboratory of Germplasm Innovation and Utilization of Eco-Economic Woody Plant, Pingdingshan University, Weilai Road, Pingdingshan, 467000, China.;College of Mechanical and Electrical Engineering, Chizhou University, Chizhou, 247000, China.
摘要：
As a basic building block of graphene-based materials, graphene oxide (GO) plays an important role in scientific research and industrial applications. At present, numerous methods have been employed to synthesize GO, there are still some issues that need to be solved, thus it is of importance to develop a green, safe and low-cost GO preparation method. Herein, a green, safe and fast method was designed to prepare GO, namely, graphite powder was firstly oxidized in a dilute sulfuric acid solution (H(2)SO(4), 6mol/L) with hydrogen peroxide (H(2)O(2), 30 wt%) as oxidant, and then exfoliated to GO by ultrasonic treatment in water. In this process, H(2)O(2) was the only oxidant, and no other oxidants were used, thus the explosive nature of GO preparation reaction in the conventional methods could be completely eliminated. This method has other advantages such as green, fast, low-cost and no Mn-based residues. The experimental results confirm that obtained GO with oxygen-containing groups has better adsorption property compared to the graphite powder. As adsorbent, GO can remove methylene blue (50mg/L) and Cd(2+) (56.2mg/L) from water with removal capacity of 23.8mg/g and 24.7mg/g, respectively. It provides a green, fast andlow-cost method to prepare GO for some applications such as adsorbent.
关键词：
Semiconductors;Nanocomposites;Coaxial CdS@ZnO nanowire array;Photodegradation;Methylene blue
摘要：
Herein, a novel coaxial CdS@ZnO nanowire array catalyst was synthesized by magnetron sputtering and hy-drothermal method. The optimum photocatalytic composite was obtained by controlling the ratio of CdS and ZnO. Take methylene blue (MB) as the model, the CdS@ZnO nanowire array (CdS@ZnO-10) exhibited strong photocatalytic solid activity, and the highest adsorption and photodegradation rate of MB reached 90.38 % in 50 min and 99.13 % in 120 min under simulated sunlight illumination. The mechanism of the heterojunction interface affecting photocatalytic performance was studied. Therefore, the synthesis approach could offer new design and controllable construction of coaxial structure for organic dye pollutant degradation.
期刊：
Applied Mathematics and Nonlinear Sciences,2023年 ISSN：2444-8656
通讯作者：
Lu, Y.
作者机构：
[Lu Y.] School of Humanities, Hunan City University, Hunan, Yiyang, 413000, China;[Zhou X.] College of Information and Electronic Engineering, Hunan City University, Hunan, Yiyang, 413000, China
通讯机构：
[Lu, Y.] S;School of Humanities, Hunan, China
关键词：
ELT model;Index system;Multicluster structure;Structural equation;Teaching model
摘要：
In order to overcome the problems of low cleaning efficiency and serious memory consumption in traditional large data cleaning methods, this paper proposes a new cleaning method of repeated big data based on association rule mining algorithm. This method uses association rule mining algorithm to obtain the frequent itemsets of repeated big data after repeated cycle calculation. At the same time, the output mode of the algorithm is optimised in parallel, and the Hadoop interface is modified to change the reading mode of MapReduce. The first frequent itemset is used to clean the repeated big data. The experimental results show that the proposed method can effectively reduce the execution time and memory consumption, and the shortest cleaning time is only 1.28 min, indicating the feasibility of the proposed method.
摘要：
In recent years, the provision of applications based on conferencing services over Software-Defined Networking (SDN) is increasing. So far, extensive studies have been conducted on improving conferencing services and supporting high-quality communication in SDN, and the importance of the issue has been understood by the research society. One of the challenges of guaranteeing conferencing services in SDN is the routing of network traffic taking into account Quality of Service (QoS) requirements. Most routing techniques in SDN guarantee end-to-end delay and bandwidth constraints. However, resource loss also plays a role in network performance, where it is clearly neglected in existing works. This study presents a guaranteed Latency-Bandwidth-Loss Routing algorithm based on Fuzzy approach to improve the performance of conference services in SDN (LBLRF). The purpose of the fuzzy-based approach is to increase the number of routed requests and improve the performance of conference services in SDN. LBLRF uses a postponement mechanism to improve the conference service, where it gives higher priority to the requests with low resource demand for connection. In addition, LBLRF is equipped with a hold time mechanism to release the reserved resources after satisfying the request requirements. This mechanism can increase the processing capacity of future requests by conserving network resources. Evaluations have been done by defining several scenarios on a synthetic SDN environment. The results of the experiments show that LBLRF provides a better request acceptance rate between 7% and 16% compared to the best results of existing algorithms.
摘要：
BiCuSeO compound is a promising thermoelectric material, which has attracted many experimental stud-ies through trial-and-error approaches to improve its thermoelectric performance by element doping, such that a fast and efficient prediction of thermoelectric property for unexplored and rarely explored doped-BiCuSeO is highly desired. In this work, a machine learning (ML) model for predicting the ZT value of M element doped-BiCuSeO (Bi1-xMxCuSeO) has been established via the correlation analysis for descriptors and the comparison among different ML approaches. The results show that Gradient Boosting Regressor is the most appropriate approach for our ML model, which is well validated by com-paring the predicted and experimental ZT values for the cases in the dataset. The ML model is also used to predict the ZT values of Bi1-xMxCuSeO with unexplored and rarely explored doping element M, and the optimal doping elements as well as their doping contents are screened out. The results indicate that the ZT of Bi0.86Po0.14CuSeO (Po-doped) and Bi0.88Cs0.12CuSeO (Cs-doped) are higher than that of pure BiCuSeO, and are improved by 104 % and 98 % at the 923 K, respectively. The enhancement is well explained by the first-principles calculations. The findings offer a guideline for exploring superior ther-moelectric performance in BiCuSeO.(c) 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
关键词：
Viscoelastic fluid;Activation energy;Stagnation point flow;Heat generation/absorption;Generalized Fourier and Fick ' s law;Stretching sheet
摘要：
This analysis describes the stagnation point and mixed convection flow of a viscoelastic micropolar fluid into a porous medium towards a stretchable sheet and magnetic field. Concentration and thermal stratification boundary conditions and activation energy are studied. For the flow of heat and mass transportation, Fourier and Fick's law is also accommodated into account. Suitable similarity variables are utilized to attain the dimen-sionless form of the governed equations. These dimensionless equations have been resolved numerically with the help of BVP4C approach. The velocity profile is reduced with the stronger estimations of eand M. The coefficient of skin friction has an increasing effect by improving values of K, fi, M, and SMALL ELEMENT OF. The velocity sketch has the opposite behavior for SMALL ELEMENT OF and fit. Stronger estimations of fi and Se lead to the decay of the temperature profile. The angular velocity of the fluid upsurges due to the stronger values of K.
