关键词：
UAV-LiDAR;individual tree segmentation;forest stand volume estimation;Gaussian mixture model
摘要：
The main problems of forest parameter extraction and forest stand volume estimation using unmanned aerial vehicle light detection and ranging (UAV-LiDAR) technology are the lack of precision in individual tree segmentation and the inability to directly obtain the diameter at breast height (DBH) parameter. To address such limitations, the study proposed an improved individual tree segmentation method combined with a DBH prediction model to obtain the tree height (H) and DBH for calculating the volume of trees, thus realizing the accurate estimation of forest stand volume from individual tree segmentation aspect. The method involves the following key steps: (1) The local maximum method with variable window combined with the Gaussian mixture model were used to detect the treetop position using the canopy height model for removing pits. (2) The measured tree DBH and H parameters of the sample trees were used to construct an optimal DBH-H prediction model. (3) The duality standing tree volume model was used to calculate the forest stand volume at the individual tree scale. The results showed that: (1) Individual tree segmentation based on the improved Gaussian mixture model with optimal accuracy, detection rate r, accuracy rate p, and composite score F were 89.10%, 95.21%, and 0.921, respectively. The coefficient of determination R2 of the accuracy of the extracted tree height parameter was 0.88, and the root mean square error RMSE was 0.84 m. (2) The Weibull model had the optimal model fit for DBH-H with predicted DBH parameter accuracy, the R2 and RMSE were 0.84 and 2.28 cm, respectively. (3) Using the correctly detected trees from the individual tree segmentation results combined with the duality standing tree volume model estimated the forest stand volume with an accuracy AE of 90.86%. In conclusion, using UAV-LiDAR technology, based on the individual tree segmentation method and the DBH-H model, it is possible to realize the estimation of forest stand volume at the individual tree scale, which helps to improve the estimation accuracy.
作者机构：
[Zhou, Shuang-shuang] Hunan City Univ, Sch Informat Sci & Engn, Yiyang 413000, Hunan, Peoples R China.;[Khan, Muhammad Ijaz; Khan, Sami Ullah] Prince Mohammad Bin Fahd Univ, Dept Mech Engn, POB,1664, Al Khobar 31952, Saudi Arabia.;[Khan, Sami Ullah] Namal Univ, Dept Math, Mianwali 42250, Pakistan.;[Qayyum, Sumaira] Quaid I Azam Univ, Dept Math, Islamabad 44000, Pakistan.
通讯机构：
[Khan, MI ] P;Prince Mohammad Bin Fahd Univ, Dept Mech Engn, POB,1664, Al Khobar 31952, Saudi Arabia.
关键词：
heat generation;surface reaction;CNTs based nanofluid;stretching/shrinking sheet;thermal radiation;76Wxx
摘要：
The investigation endorsed the convective flow of Carreau nanofluid over a stretched surface in presence of entropy generation optimization. The novel dynamic of viscous dissipation is utilized to analyze the thermal mechanism of magnetized flow. The convective boundary assumptions are directed in order to examine the heat and mass transportation of nanofluid. The thermal concept of thermophoresis and Brownian movements has been re-called with the help of Buongiorno model. The problem formulated in dimensionless form is solved by NDSolve MATHEMATICA. The graphical analysis for parameters governed by the problem is performed with physical applications. The affiliation of entropy generation and Bejan number for different parameters is inspected in detail. The numerical data for illustrating skin friction, heat and mass transfer rate is also reported. The motion of the fluid is highest for the viscosity ratio parameter. The temperature of the fluid rises via thermal Biot number. Entropy generation rises for greater Brinkman number and diffusion parameter.
期刊：
IEEE Transactions on Fuzzy Systems,2024年:1-13 ISSN：1063-6706
作者机构：
[Khin-Wee Lai] School of Engineering, Universiti Malaya, Kuala Lumpur, Malaysia;[Xiang Wu; Yong-Ting Zhang; Ming-Zhao Yang; Huan-Huan Wang] Institute of Medical Information Security, Xuzhou Medical University, Xuzhou, China;[Ge-Lan Yang] Department of Information Science and Engineering, Hunan City University, Yiyang, China
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：
Journal of Materials Science: Materials in Electronics,2024年35(16):1-9 ISSN：0957-4522
通讯作者：
Wang, HO;Tan, WS
作者机构：
[Lu, Gefei; Su, Kunpeng; Wang, Haiou; Wang, Haochen; Yang, Lin; Huang, Shuai] Hangzhou Dianzi Univ, Coll Mat & Environm Engn, 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, Key Lab Soft Chem & Funct Mat, Minist Educ, Dept Appl Phys, Nanjing 210094, Peoples R China.
通讯机构：
[Wang, HO ; Tan, WS ] H;Hangzhou Dianzi Univ, Coll Mat & Environm Engn, Key Lab Novel Mat Sensor Zhejiang Prov, Hangzhou 310018, Peoples R China.;Hunan City Univ, Coll Informat & Elect Engn, All Solid State Energy Storage Mat & Devices Key L, Yiyang 413002, Peoples R China.;Nanjing Univ Sci & Technol, Key Lab Soft Chem & Funct Mat, Minist Educ, Dept Appl Phys, Nanjing 210094, Peoples R China.
摘要：
Magnetoresistance and temperature coefficient of resistance (TCR) of manganites with ferromagnetism have been reported extensively, but the magnetoresistance and TCR of antiferromagnetic manganites are scarce. The transport properties, TCR, and magnetoresistance effect of antiferromagnetic NdMnO3 have been studied in this work. NdMnO3 samples exhibit semiconductor conductivity, and with the different applied magnetic fields, they still maintain semiconductor characteristics and have considerable stability. Under an applied magnetic field of 6 T, a small negative magnetoresistance of 8% appears near 150 K. Moreover, the conduction mechanism and TCR of NdMnO3 are studied. Three models, thermal activation (TA) model, small polaron (SP) model, and variable range jump (VRH) model, are used to analyze the electrical transport of NdMnO3 samples. The results show that the transport behavior of NdMnO3 samples is more consistent with the TA model. The maximum TCR is 9.4% K-1 within the low temperature region (above liquid nitrogen temperature). The TCR decreases with increasing temperature and it remains 2.5% K-1 near room temperature. Antiferromagnetic NdMnO3 has good TCR performance, which can be applied to temperature sensing field and has good application prospect in antiferromagnetic insulating electronic devices.
作者机构：
[Ni, Li] Hunan City Univ, Coll Informat & Elect Engn, Yiyang 413000, Peoples R China.;[Qiang, Wu; Manman, Peng] Hunan Univ, Coll Informat & Engineer, Changsha 410008, Peoples R China.
通讯机构：
[Ni, L ] H;Hunan City Univ, Coll Informat & Elect Engn, Yiyang 413000, Peoples R China.
关键词：
information networks;spectral clustering;deep embedding
摘要：
With the development of network technology, information networks have become one of the most important means for people to understand society. As the scale of information networks expands, the construction of network graphs and high-dimensional feature representation will become major factors affecting the performance of spectral clustering algorithms. To address this issue, in this paper, we propose a spectral clustering algorithm based on similarity graphs and non-linear deep embedding, named SEG_SC. This algorithm introduces a new spectral clustering model that explores the underlying structure of graphs through sparse similarity graphs and deep graph representation learning, thereby enhancing graph clustering performance. Experimental analysis with multiple types of real datasets shows that the performance of this model surpasses several advanced benchmark algorithms and performs well in clustering on medium- to large-scale information networks.
作者机构：
[Zhou, Xinshao; Wang, Yonghong] Hunan City Univ, Coll Informat & Elect Engn, Yiyang 413000, Peoples R China.;[Zhou, Xinshao; Wang, Yonghong] Hunan City Univ, Hunan Engn Res Ctr Intelligent Monitoring & Disast, Yiyang 413000, Peoples R China.;[Shao, Chunchen; Yang, Susu; Shao, Shuyao; Ge, Weiting; Zuo, Yangyan; Yang, G; Yang, Gang; Sun, Weiwei] Ningbo Univ, Dept Geog & Spatial Informat Tech, Ningbo 315211, Peoples R China.;[Zheng, Ke] Ningbo Vehicle Emiss Control Ctr, Task Dept, Ningbo 315100, Peoples R China.
通讯机构：
[Yang, G ] N;Ningbo Univ, Dept Geog & Spatial Informat Tech, Ningbo 315211, Peoples R China.
关键词：
Spartina alterniflora;phenological characteristics;Landsat time series images;Yangtze River Delta
摘要：
Spartina alterniflora (S. alterniflora) has grown rapidly in China since its introduction in 1979, showing the trend of alien species invasion, which has seriously affected the ecosystem balance of coastal wetlands. The temporal and spatial expansion law of S. alterniflora can be obtained through remote sensing monitoring, which can provide a reference and basis for S. alterniflora management. This paper presents a method for extracting and mapping S. alterniflora based on phenological characteristics. The coastal areas of the Yangtze River Delta Urban Agglomeration are selected as the research area, and the Landsat time series data from 1990 to 2022 on the Google Earth Engine (GEE) platform are used to support the experiment in this paper. Firstly, the possible growing area of S. alterniflora was extracted using the normalized differential moisture index (NDMI), normalized differential vegetation index (NDVI), and normalized differential water index (NDWI); Then, the time series curve characterizing the phenological characteristics of vegetation was constructed using the vegetation index to determine the difference phase of phenological characteristics between S. alterniflora and other vegetation. Finally, a decision tree was constructed based on the phenological feature difference phase data to extract S. alterniflora, and it is applied to the analysis of temporal and spatial changes of S. alterniflora in the study area from 1990 to 2022. The results show that the area of S. alterniflora increased from similar to 1426 ha in 1990 to similar to 44,508 ha in 2022. However, the area of S. alterniflora began to show negative growth in 2015 due to the construction of nature reserves and ecological management. The results of correlation analysis showed that the growth of C. japonicum was significantly affected by temperature stress and weakly affected by precipitation. This study verified that Landsat time series images can effectively extract vegetation phenological information, which has strong feasibility for extraction and dynamic monitoring of S. alterniflora and provides technical support for the management and monitoring of invasive plants in coastal wetlands.
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：
Driven by emerging wireless applications, numerous smart objects will be deployed, forming things networks interconnected by the Internet of Things (IoT). Many of these networks follow the low-power multihop wireless network (LPMWN) paradigm due to the good scalability of the distributed schemes adopted by LPMWNs. Although distributed schemes may operate satisfactorily most of the time, they are often complex and costly to manage. To simplify network management, the LoRa (long range) wireless technology has been introduced into LPMWNs for centralized network control. Unfortunately, due to LoRa's inherent limitation that a downlink packet must be in response to a precedent uplink packet, the existing protocols typically require every node to periodically send an uplink packet to the gateway for downlink network command dissemination. This causes intensive uplink collisions and quickly depletes LoRa bandwidth, especially when the network is large. In light of these pitfalls, we propose a (cross-interface downlink relay (CDR)) scheme, which leverages the ZigBee communications that are already available in LPMWNs to relay LoRa downlink data traffic for bandwidth-efficient and delay-guaranteed data dissemination. CDR determines the optimal network topology for bandwidth-minimized data relay while adjusting system parameters to ensure each node's delay requirement under network dynamics. A prototype system is implemented by integrating LoRa and ZigBee into an IoT platform. Extensive outdoor experiments show that the bandwidth consumption of CDR is 39.3% lower than a state-of-the-art LoRa data dissemination protocol for ZigBee-based LPMWNs under a moderate data traffic and delay requirement. Besides, CDR improves energy efficiency and network lifetime significantly.
期刊：
Computers in Biology and Medicine,2024年176:108543 ISSN：0010-4825
通讯作者：
Rui Li
作者机构：
[Liu, Yan; Li, Rui; Li, Renfa; Fu, Xiangzheng; Gong, Yinyin] College of Computer Science and Electronic Engineering, Hunan University, Changsha, 410082, China;[Liu, Yan; Li, Renfa; Gong, Yinyin] Hunan Engineering Research Center of Advanced Embedded Computing and Intelligent Medical Systems, Hunan University, Changsha, 410082, China;[Li, Rui] Hunan Engineering Research Center of Advanced Embedded Computing and Intelligent Medical Systems, Hunan University, Changsha, 410082, China. Electronic address: rui@hnu.edu.cn;[Wang, Jilong] Peng Cheng Laboratory, Shenzhen, 518066, China;[Cao, Buwen] College of Information and Electronic Engineering, Hunan City University, Yiyang, 413002, China
通讯机构：
[Rui Li] C;College of Computer Science and Electronic Engineering, Hunan University, Changsha, 410082, China<&wdkj&>Hunan Engineering Research Center of Advanced Embedded Computing and Intelligent Medical Systems, Hunan University, Changsha, 410082, China
摘要：
Proteins play a vital role in various biological processes and achieve their functions through protein-protein interactions (PPIs). Thus, accurate identification of PPI sites is essential. Traditional biological methods for identifying PPIs are costly, labor-intensive, and time-consuming. The development of computational prediction methods for PPI sites offers promising alternatives. Most known deep learning (DL) methods employ layer-wise multi-scale CNNs to extract features from protein sequences. But, these methods usually neglect the spatial positions and hierarchical information embedded within protein sequences, which are actually crucial for PPI site prediction. In this paper, we propose MR2CPPIS, a novel sequence-based DL model that utilizes the multi-scale Res2Net with coordinate attention mechanism to exploit multi-scale features and enhance PPI site prediction capability. We leverage the multi-scale Res2Net to expand the receptive field for each network layer, thus capturing multi-scale information of protein sequences at a granular level. To further explore the local contextual features of each target residue, we employ a coordinate attention block to characterize the precise spatial position information, enabling the network to effectively extract long-range dependencies. We evaluate our MR2CPPIS on three public benchmark datasets (Dset 72, Dset 186, and PDBset 164), achieving state-of-the-art performance. The source codes are available at https://github.com/YyinGong/MR2CPPIS.
期刊：
Frontiers in Marine Science,2024年11:1336783 ISSN：2296-7745
通讯作者：
Wang, YH
作者机构：
[Zhang, Shuai; Wang, Yanhui; Zhao, Peng; Wu, Sheng; Jiang, Nian; Zhang, Pingping] Harbin Engn Univ, Yantai Grad Sch, Yantai, Peoples R China.;[Liu, Yang] Hunan City Univ, Coll Informat Sci & Engn, Yiyang, Peoples R China.
通讯机构：
[Wang, YH ] H;Harbin Engn Univ, Yantai Grad Sch, Yantai, Peoples R China.
关键词：
Floating photovoltaic;offshore;Marine environment protection;Technological feasibility;life cycle of photovoltaic;potential impacts
摘要：
The development of solar energy is one of the most effective means to deal with the environmental and energy crisis. The floating photovoltaic (PV) system is an attractive type because of its multiple advantages and has been well developed based on fresh water areas on land. This paper focuses on the expansion of this sector towards the ocean, offshore floating PV plants, which is the new growth point with huge potential for the future PV sector. For this new field, the technology readiness level is really low and research to understand the interaction between offshore floating PV plants and marine environment are proceeding. In this paper, we aim to discuss the technological feasibility of offshore floating PV plants as well as analyze potential impacts on the marine environment during the life cycle of PV from manufacturing until disposal.
摘要：
Peer tutoring is beneficial as a method of education because it allows students with different learning styles to work together in comfortable settings to complete academic assignments that will improve their grades. Peer tutoring gives students of all skill levels the chance to collaborate, democratically, and amicably work on academic assignments in pairs. With this method, students with different levels of intelligence rely on one another to understand academic material, especially while completing challenging assignments. Hence, the current investigation aims to explore the effectiveness of online peer tutoring programs in college education. The findings of the analysis indicate that the impact of online peer tutoring on academic performance is consistent across diverse academic disciplines. By examining the full range of advantages of online tutoring programs in higher education, examining their effects on students' learning engagement, concentrating on China as a special context, and providing helpful recommendations for their implementation in higher education, the study makes a novel contribution to the field of online tutoring programs. The results demonstrate that college students who regularly engage in online peer tutoring are more likely to have higher retention rates. As per the findings, the analysis proves that online peer tutoring significantly enhances the sense of community among college students, leading to increased engagement in their coursework. The results reveal that online peer tutoring significantly enhances collaborative learning skills among college students.
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：
<jats:title>Abstract</jats:title><jats:p>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 <jats:inline-formula><jats:alternatives><jats:tex-math>$$\nu $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mi>ν</mml:mi>
</mml:math></jats:alternatives></jats:inline-formula>. It is found that the maximum separate length <jats:italic>x</jats:italic> increases with the increase of dynamical exponent <jats:inline-formula><jats:alternatives><jats:tex-math>$$\nu $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mi>ν</mml:mi>
</mml:math></jats:alternatives></jats:inline-formula>. By analyzing the potential energy, we find that the potential barrier increases with the dynamical exponent <jats:inline-formula><jats:alternatives><jats:tex-math>$$\nu $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mi>ν</mml:mi>
</mml:math></jats:alternatives></jats:inline-formula> 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.</jats:p>
期刊：
EUROPEAN PHYSICAL JOURNAL C,2024年84(7):1-10 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, Key Lab Hunan Prov, All Solid State Energy Storage Mat & Devices, Yiyang 413000, Peoples R China.;[Fadafan, Kazem Bitaghsir] Shahrood Univ Technol, Fac Phys, POB 3619995161, Shahrood, Iran.;[Chen, Xun; Chen, X] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
通讯机构：
[Chen, X ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
摘要：
In this work, we use the AdS/CFT correspondence to study the behavior of a triply heavy baryon within anisotropic backgrounds. Beginning with the total action of the three quarks, we derive the balance equation for the three-quark system and compute the separation distance and potential energy. Our results reveal a consistent decrease in both the separation distance and potential energy for the A configuration and the B configuration as the anisotropy coefficient a increases. This suggests that the presence of an anisotropic background promotes the dissolution of the three-quark system. Additionally, we compare the potential energies of the A and B configurations and observe that the A configuration has a slightly smaller potential energy, suggesting greater stability compared to the B configuration.
摘要：
The use of the shaft-rate electromagnetic fields generated by moving ships for detection and sensing purposes has several advantages, including effective target recognition and excellent concealment. It offers a solution to the challenges faced in detecting underwater targets. In this study, we propose a method to identify and analyze the shaft-rate electromagnetic field signals using an improved deep learning algorithm and a spectral-direction analysis technique. Initially, we apply variational mode decomposition (VMD) to identify the multifrequency characteristics of both synthesized and real extremely low-frequency (ELF) electromagnetic signals, creating a reliable sample library for deep learning. Next, we develop an improved deep learning model that combines the residual network (ResNet) with the aforementioned sample library to accurately detect the weak narrowband electromagnetic field signals hidden within the noise. Additionally, we use the spectral-direction analysis method to estimate the direction of the ship's movement. Finally, we validate our proposed method through a synthetic model and a field experiment. The results demonstrate the effectiveness of our approach in identifying the shaft-rate electromagnetic field signals and accurately estimating the direction of moving ships. The developed method shows the potential for accurate sensing and localization of moving ships.
