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19 pages, 12179 KiB  
Article
MRT-YOLO: A Fine-Grained Feature-Based Method for Object Detection
by Haoran Yan, Feng Gao, Jiajia Zhao and Xing Zhang
Electronics 2024, 13(23), 4687; https://doi.org/10.3390/electronics13234687 - 27 Nov 2024
Abstract
Object detection is an essential component of autonomous driving, unmanned aerial vehicle (UAV) reconnaissance, and other domains. It equips drones and vehicles with the capability to perceive and comprehend their surrounding environment, making it a crucial technology for achieving safe and reliable autonomous [...] Read more.
Object detection is an essential component of autonomous driving, unmanned aerial vehicle (UAV) reconnaissance, and other domains. It equips drones and vehicles with the capability to perceive and comprehend their surrounding environment, making it a crucial technology for achieving safe and reliable autonomous driving as well as UAV spot reconnaissance. This paper proposes an end-to-end, high-precision, multi-scale real-time detection algorithm called MRT-YOLO based on YOLOv8. Firstly, in the feature downsampling process of the backbone network, we extend the channel depth to enhance the model’s learning capability for fine-grained features and thereby improve its performance in retaining feature information. Secondly, we enhance the cross-stage partial layer version 2 (C2f) module in YOLOv8 by incorporating a channel self-attention mechanism within it, which optimizes performance through effective feature interaction and integration. Simultaneously, we also employ an improved bidirectional feature pyramid network (BiFPN) and introduce the proposed multi-scale feature learning (MFL) module to further enhance the model’s feature extraction ability. In this study, we fuse the feature maps (C2, C3, C4, and C5) from the backbone network to generate a new feature map C6, thus increasing cross-connections between low-level and high-level features. Lastly, a multi-scale small object detection structure is designed to enhance recognition sensitivity toward densely distributed small objects. The proposed algorithm’s effectiveness and superiority are demonstrated through experiments conducted on two datasets: VisDrone (UAV vision dataset) and BDD100K (automatic driving dataset). Full article
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<p>SPD-Conv module structure diagram.</p>
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<p>Structure diagram of channel attention module.</p>
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<p>Backbone network comparison.</p>
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<p>Neck structure of the MRT-YOLO algorithm.</p>
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<p>MRT-YOLO network architecture.</p>
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<p>The number of individual classes in the VisDrone dataset.</p>
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<p>The number of individual classes in the BDD100K dataset.</p>
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<p>Sample images of the VisDrone dataset.</p>
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<p>Sample images of the BDD100K dataset.</p>
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<p>Comparison of PR curves.</p>
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<p>Confusion matrix for YOLOv8s network model.</p>
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<p>Confusion matrix of the MRT-YOLO network model.</p>
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<p>Comparison of actual test results.</p>
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26 pages, 20446 KiB  
Article
Gas Content and Geological Control of Deep Jurassic Coalbed Methane in Baijiahai Uplift, Junggar Basin
by Bing Luo, Haichao Wang, Bin Sun, Zheyuan Ouyang, Mengmeng Yang, Yan Wang and Xiang Zhou
Processes 2024, 12(12), 2671; https://doi.org/10.3390/pr12122671 - 27 Nov 2024
Viewed by 294
Abstract
Deep coalbed methane (CBM) resources are abundant in China, and in the last few years, the country’s search for and extraction of CBM have intensified, progressively moving from shallow to deep strata and from high-rank coal to medium- and low-rank coal. On the [...] Read more.
Deep coalbed methane (CBM) resources are abundant in China, and in the last few years, the country’s search for and extraction of CBM have intensified, progressively moving from shallow to deep strata and from high-rank coal to medium- and low-rank coal. On the other hand, little is known about the gas content features of deep coal reservoirs in the eastern Junggar Basin, especially with regard to the gas content and the factors that affect it. Based on data from CBM drilling, logging, and seismic surveys, this study focuses on the gas content of Baijiahai Uplift’s primary Jurassic coal seams through experiments on the microscopic components of coal, industrial analysis, isothermal adsorption, low-temperature CO2, low-temperature N2, and high-pressure mercury injection. A systematic investigation of the controlling factors, including the depth, thickness, and quality of the coal seam and pore structure; tectonics; and lithology and thickness of the roof, was conducted. The results indicate that the Xishanyao Formation in the Baijiahai Uplift usually has a larger gas content than that in the Badaowan Formation, with the Xishanyao Formation showing that free gas and adsorbed gas coexist, while the Badaowan Formation primarily consists of adsorbed gas. The coal seams in the Baijiahai Uplift are generally deep and thick, and the coal samples from the Xishanyao and Badawan formations have a high vitrinite content, which contributes to their strong gas generation capacity. Additionally, low moisture and ash contents enhance the adsorption capacity of the coal seams, facilitating the storage of CBM. The pore-specific surface area of the coal samples is primarily provided by micropores, which is beneficial for CBM adsorption. Furthermore, a fault connecting the Carboniferous and Permian systems (C-P) developed in the northeastern part of the Baijiahai Uplift allows gas to migrate into the Xishanyao and Badaowan formations, resulting in a higher gas content in the coal seams. The roof lithology is predominantly mudstone with significant thickness, effectively reducing the dissipation of coalbed methane and promoting its accumulation. Full article
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<p>Geological background map and comprehensive histogram of coal-bearing strata [<a href="#B21-processes-12-02671" class="html-bibr">21</a>].</p>
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<p>Isothermal adsorption curve. Note: (<b>a</b>) is the isothermal adsorption curve of Xishanyao Formation and (<b>b</b>) is the isothermal adsorption curve of Badaowan Formation.</p>
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<p>Measured and anticipated gas contents in the Baijiahai Uplift. (<b>a</b>) Xishanyao Formation and (<b>b</b>) Badaowan Formation.</p>
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<p>Neural network model calculation process.</p>
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<p>Comparison of adsorption gas content between adsorption model and neural network model. (<b>a</b>) Xishanyao Formation and (<b>b</b>) Badaowan Formation.</p>
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<p>Distribution of adsorbed gas content in Baijiahai Uplift. (<b>a</b>) Xishanyao Formation and (<b>b</b>) Badaowan Formation.</p>
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<p>Distribution of free gas content in Baijiahai Uplift.</p>
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<p>Gas content distribution in Baijiahai Uplift.</p>
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<p>Contour map of buried depth of Baijiahai Uplift. (<b>a</b>) Xishanyao Formation and (<b>b</b>) Badaowan Formation.</p>
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<p>Variation diagram of gas content with buried depth of coal seam.</p>
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<p>Contour map of Baijiahai Uplift thickness. (<b>a</b>) Xishanyao Formation and (<b>b</b>) Badaowan Formation.</p>
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<p>Variation diagram of gas content with coal seam thickness.</p>
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<p>(<b>a</b>) Relationship between VL and vitrinite content; (<b>b</b>) relationship between VL and moisture content; (<b>c</b>) relationship between VL and ash yield of Xishanyao Formation; (<b>d</b>) relationship between VL and ash yield of Badaowan Formation.</p>
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<p>Characterization of pore volume’s full pore size of DN141 well. (<b>a</b>) Xishanyao Formation and (<b>b</b>) Badaowan Formation.</p>
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<p>Characterization of pore-specific surface area and full pore size of DN141 well. (<b>a</b>) Xishanyao Formation and (<b>b</b>) Badaowan Formation.</p>
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<p>(<b>a</b>) The relationship between adsorption gas content and pore-specific surface area and (<b>b</b>) the relationship between free gas content and pore volume.</p>
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<p>Distribution map of the Baijiahai Uplift traps.</p>
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<p>Seismic geological interpretation section (Reference: PetroChina). (<b>a</b>) The seismic profiles of wells DN11, DN18, C49, C504, C17, BJ3, and C32 are shown. (<b>b</b>) Well location distribution map.</p>
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<p>Relationship diagram of roof lithology and gas content. (<b>a</b>) Xishanyao Formation and (<b>b</b>) Badaowan Formation.</p>
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<p>Lithology and thickness of main coal seam roof in Baijiahai Uplift. (<b>a</b>) Jurassic roof lithology frequency distribution histogram and (<b>b</b>) Jurassic roof thickness box diagram.</p>
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17 pages, 4611 KiB  
Article
Characteristics of Damage to Rural Houses in the High-Intensity Area of the Jishishan Mw 6.2 Earthquake
by Xiumei Zhong, Qian Wang, Yan Wang, Ping Wang, Chen Li and Xuefeng Hu
Buildings 2024, 14(12), 3762; https://doi.org/10.3390/buildings14123762 - 26 Nov 2024
Viewed by 169
Abstract
On 18 December 2023, a 6.2-magnitude earthquake struck Jishishan, affecting multiple counties and cities in Gansu and Qinghai Provinces. The seismic intensity of the meizoseismal area was VIII, resulting in extensive structural damage and building collapses. A damage assessment was conducted of the [...] Read more.
On 18 December 2023, a 6.2-magnitude earthquake struck Jishishan, affecting multiple counties and cities in Gansu and Qinghai Provinces. The seismic intensity of the meizoseismal area was VIII, resulting in extensive structural damage and building collapses. A damage assessment was conducted of the epicenter and surrounding high-intensity zones. To understand the typical structures and characteristics of the buildings that were damaged in these high-intensity zones, this study summarizes the characteristics of the damage to typical rural houses, compares the damage of the rural houses across different sites, and analyzes the causes behind these variations. The findings of the study indicate the following: (1) Timber and some brick–timber structures, due to their age, insufficient material strength, and lack of adequate connections between parts of the building, primarily experienced severe damage or total collapse, characterized by through-wall cracks, partial collapses, or complete collapses. (2) Brick–concrete structures predominantly suffered moderate to severe damage due to factors such as improper layout, uneven façades, and inadequate or incomplete seismic measures. The observed damage included significant wall cracks and extensive damage to two-story buildings. (3) Frame structures, mainly used for public facilities like schools, hospitals, and health centers, exhibited strong integrity and excellent seismic performance, resulting in minimal to no damage, with damage largely confined to non-load-bearing components. (4) The amplification effects of seismic waves in thick loess basin areas, slope sites, and the hanging wall effect of faults exacerbated structural damage to rural houses located in certain villages within the high-intensity areas. The results of this study can serve as a reference for post-disaster reconstruction and seismic retrofitting of buildings and contribute positively to enhancing the disaster resilience of rural housing. Full article
(This article belongs to the Section Building Structures)
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<p>Distribution of the survey sites of the rural buildings in the high-seismic-intensity zone of the Jishishan M6.2 earthquake.</p>
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<p>Typical earthquake damage photos of adobe civil structure. (<b>a</b>) Front wall collapsed. (<b>b</b>) Wall cracks and partially collapsed. (<b>c</b>) Pediment collapsed. (<b>d</b>) Total collapse.</p>
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<p>Typical earthquake damage photos of civil rammed earth wall structure. (<b>a</b>) Wall cracks. (<b>b</b>) Vertical and horizontal wall flash cracks. (<b>c</b>) Roof collapse. (<b>d</b>) Partial collapse.</p>
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<p>Typical earthquake damage photos of brick–wood structure. (<b>a</b>) Eaves damage. (<b>b</b>) wall cracks. (<b>c</b>) Partial collapse. (<b>d</b>) Total collapse.</p>
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<p>Photos of typical earthquake damage of brick–concrete structure. (<b>a</b>) Wall cracks. (<b>b</b>) Story two destruction. (<b>c</b>) Partial collapse. (<b>d</b>) Total collapse.</p>
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<p>Photographs of typical earthquake damage to frame structures. (<b>a</b>) Wall cracks between windows. (<b>b</b>) Door frame extrusion deformation. (<b>c</b>) Wall bulging deformation. (<b>d</b>) Door frame deformation. (<b>e</b>) Longitudinal and transverse wall penetration cracks. (<b>f</b>) Cracks under the beam.</p>
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<p>Photographs of typical earthquake damage to frame structures. (<b>a</b>) Wall cracks between windows. (<b>b</b>) Door frame extrusion deformation. (<b>c</b>) Wall bulging deformation. (<b>d</b>) Door frame deformation. (<b>e</b>) Longitudinal and transverse wall penetration cracks. (<b>f</b>) Cracks under the beam.</p>
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<p>Photographs of typical earthquake damage to dwellings using anti-seismic construction measures. (<b>a</b>) Experimental middle school building. (<b>b</b>) Frame dwellings in Kexinmin Village.</p>
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<p>Photographs of earthquake damage to brick structures at different sites. (<b>a</b>) Gaoli Village. (<b>b</b>) Shenjiaping Village.</p>
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<p>Photographs of vertical and horizontal wall damage. (<b>a</b>) Mirror direction: north east. (<b>b</b>) Mirror direction: northwest.</p>
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32 pages, 13406 KiB  
Article
Enhancing Data Security Through VLSM Subnetting and TCP/IP Model in an ENT
by Caxton Okoh, Waba Nasali Theophilus, Paul Dawkins and Sebamalai Paheerathan
Appl. Sci. 2024, 14(23), 10968; https://doi.org/10.3390/app142310968 - 26 Nov 2024
Viewed by 180
Abstract
Data in-transit from an at-rest state can be securely transmitted and managed within a network. Background: This work covers the design and simulation of an Enhanced Network Topology (ENT) with multiple components that connects multiple locations of an imaginary organisation structure. The components [...] Read more.
Data in-transit from an at-rest state can be securely transmitted and managed within a network. Background: This work covers the design and simulation of an Enhanced Network Topology (ENT) with multiple components that connects multiple locations of an imaginary organisation structure. The components of the network locations are mix-vendor components. The focus is on how classless IP address allocation, routing protocols, hierarchical network topology, and the updated Transmission Control Protocol/Internet Protocol (TCP/IP) model are put together to enhance performance and security. The simulation is performed using Cisco Packet Tracer where the packet transfer and connections within the network are examined. Methods: The Variable Length Subnet Mask (VLSM) approach is applied to a network design to secure data and information. We provided and detailed the implementation of subnetting, routing protocols, the updated TCP/IP model, and simulation within Cisco Packet Tracer. Our paper demonstrates the applicability of a single IP address range (0-255) where only the fourth octet changes to serve to secure information across networks through creating subnets. Results: The results of the simulation are further analysed; the security protocols are summarised. Conclusions: Our work has potential to be applied to Supervisory Control and Data Acquisition (SCADA) networks, Internet of Things (IoT) and Cloud networks; a useful resource for academia and industry professionals. Full article
(This article belongs to the Special Issue Advanced Technologies in Data and Information Security III)
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<p>The updated TCP/IP model layers with protocols.</p>
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<p>CIDR with VLSM subnetting chart. The two downward arrows indicate increases in the number of Subnets and number of bits allocated to the Network portion of the IP address respectively. The upward arrow depicts an increase in the number of hosts per subnet. The highlighted number means for a network with 8 subnets, there are 32 hosts in each subnet and network boundaries is aligned to the CIDR of 27.</p>
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<p>An example ENT relates to Hierarchical Network Topology.</p>
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<p>Topology of the network created with Cisco Packet Tracer.</p>
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<p>(<b>a</b>) DHCP Configuration on Location A Boundary Router (Router0). (<b>b</b>) Static Configuration of IP on Server in Location A. (<b>c</b>) Configuration of DNS on Server in Location A. (<b>d</b>) Configuration of HTTP on Server in Location A. (<b>e</b>) Configuration of HTTP index page on Server in Location A.</p>
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<p>(<b>a</b>) DHCP Configuration on Location A Boundary Router (Router0). (<b>b</b>) Static Configuration of IP on Server in Location A. (<b>c</b>) Configuration of DNS on Server in Location A. (<b>d</b>) Configuration of HTTP on Server in Location A. (<b>e</b>) Configuration of HTTP index page on Server in Location A.</p>
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<p>(<b>a</b>) DHCP Configuration on Location A Boundary Router (Router0). (<b>b</b>) Static Configuration of IP on Server in Location A. (<b>c</b>) Configuration of DNS on Server in Location A. (<b>d</b>) Configuration of HTTP on Server in Location A. (<b>e</b>) Configuration of HTTP index page on Server in Location A.</p>
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<p>(<b>a</b>) DHCP Configuration on Location C Boundary Router (Router2). (<b>b</b>) DHCP Configuration on Location B Boundary Router (Router2).</p>
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<p>(<b>a</b>) Wireless Router Configuration LAN interface. (<b>b</b>) Wireless Router DHCP Configuration.</p>
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<p>EIGRP configuration for Router0.</p>
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<p>EIGRP configuration for Router1.</p>
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<p>EIGRP configuration for Router2.</p>
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<p>(<b>a</b>) Password configuration on Router. (<b>b</b>) Password configuration on Switch.</p>
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<p>(<b>a</b>) Password configuration on Router. (<b>b</b>) Password configuration on Switch.</p>
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<p>(<b>a</b>) Location A pool DHCP successful configuration. (<b>b</b>) Location C pool DHCP successful configuration.</p>
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<p>(<b>a</b>) Successful configuration of EIGRP on Router0. (<b>b</b>) Successful configuration of EIGRP on Router1. (<b>c</b>) Successful configuration of EIGRP on Router2.</p>
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<p>(<b>a</b>) Successful configuration of EIGRP on Router0. (<b>b</b>) Successful configuration of EIGRP on Router1. (<b>c</b>) Successful configuration of EIGRP on Router2.</p>
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<p>(<b>a</b>) Successful configuration of EIGRP on Router0. (<b>b</b>) Successful configuration of EIGRP on Router1. (<b>c</b>) Successful configuration of EIGRP on Router2.</p>
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<p>(<b>a</b>) Accessing the Server from within Location A using PC2. (<b>b</b>) Accessing the Server from within Location B using PC1.</p>
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<p>(<b>a</b>) PC2 in Location A pings another PC in Location C. (<b>b</b>) PC0 in Location B pings Laptop0 in Location C. (<b>c</b>) PC2 in Location B pings another PC in Location A.</p>
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<p>(<b>a</b>) Ping and Tracert from Location A to Location C. (<b>b</b>) Ping and Tracert from Location B computer to Location C computer.</p>
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<p>EIGRP, RIPv2, and OSPF performance protocols connecting devices in the network.</p>
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<p>Routing protocols performance comparison.</p>
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<p>Connecting via SSH to a Router.</p>
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25 pages, 1533 KiB  
Article
A Network Analysis of Emotional Intelligence in Chinese Preschool Teachers
by Sha Xie, Beiyi Su, Siman Yang, Jing Li and Hui Li
Behav. Sci. 2024, 14(12), 1132; https://doi.org/10.3390/bs14121132 - 25 Nov 2024
Viewed by 213
Abstract
Emotional intelligence significantly influences various aspects of teachers’ professional and personal lives, notably affecting preschoolers’ social skills and emotional development during formative years. This study utilizes a network analysis approach to explore the complex relationships among four components of emotional intelligence: emotional labor, [...] Read more.
Emotional intelligence significantly influences various aspects of teachers’ professional and personal lives, notably affecting preschoolers’ social skills and emotional development during formative years. This study utilizes a network analysis approach to explore the complex relationships among four components of emotional intelligence: emotional labor, emotional regulation, professional well-being, and professional identity. Participants included 2069 frontline Chinese teachers (34 males, 2035 females; M = 28.64, SD = 5.98; M years of teaching = 6.88, SD = 5.29) with no leadership roles, categorized into three stages of their careers based on years of teaching experience: novice (0–3 years; n = 612), advanced beginners (4–6 years; n = 537), and competent (7–40 years; n = 920). Findings revealed that joy of teaching, role value, and professional value were identified as the most critical elements within the emotional state network of early childhood education teachers. The strongest connections in teachers’ emotional networks were found between school connectedness and joy of teaching (r = 0.474), surface acting behavior and natural acting behavior (r = 0.419), and professional value and professional behavior (r = 0.372). Furthermore, teachers across different career stages exhibited similar characteristics and intrinsic connections among emotional state components. These findings deepen our understanding of the emotional state networks of ECE teachers, highlighting shared features and interconnected mechanisms, and suggest that enhancing teachers’ emotional intelligence through targeted professional development can improve both teacher well-being and preschoolers’ social–emotional outcomes. Policies that foster strong school connectedness and reduce emotional labor are key to promoting sustained joy in teaching, particularly for novice and advanced beginner teachers. Full article
19 pages, 780 KiB  
Article
Transformer Dil-DenseUnet: An Advanced Architecture for Stroke Segmentation
by Nesrine Jazzar, Besma Mabrouk and Ali Douik
J. Imaging 2024, 10(12), 304; https://doi.org/10.3390/jimaging10120304 - 25 Nov 2024
Viewed by 286
Abstract
We propose a novel architecture, Transformer Dil-DenseUNet, designed to address the challenges of accurately segmenting stroke lesions in MRI images. Precise segmentation is essential for diagnosing and treating stroke patients, as it provides critical spatial insights into the affected brain regions and the [...] Read more.
We propose a novel architecture, Transformer Dil-DenseUNet, designed to address the challenges of accurately segmenting stroke lesions in MRI images. Precise segmentation is essential for diagnosing and treating stroke patients, as it provides critical spatial insights into the affected brain regions and the extent of damage. Traditional manual segmentation is labor-intensive and error-prone, highlighting the need for automated solutions. Our Transformer Dil-DenseUNet combines DenseNet, dilated convolutions, and Transformer blocks, each contributing unique strengths to enhance segmentation accuracy. The DenseNet component captures fine-grained details and global features by leveraging dense connections, improving both precision and feature reuse. The dilated convolutional blocks, placed before each DenseNet module, expand the receptive field, capturing broader contextual information essential for accurate segmentation. Additionally, the Transformer blocks within our architecture address CNN limitations in capturing long-range dependencies by modeling complex spatial relationships through multi-head self-attention mechanisms. We assess our model’s performance on the Ischemic Stroke Lesion Segmentation Challenge 2015 (SISS 2015) and ISLES 2022 datasets. In the testing phase, the model achieves a Dice coefficient of 0.80 ± 0.30 on SISS 2015 and 0.81 ± 0.33 on ISLES 2022, surpassing the current state-of-the-art results on these datasets. Full article
(This article belongs to the Special Issue Advances in Medical Imaging and Machine Learning)
20 pages, 3184 KiB  
Article
GATv2EPI: Predicting Enhancer–Promoter Interactions with a Dynamic Graph Attention Network
by Tianjiao Zhang, Xingjie Zhao, Hao Sun, Bo Gao and Xiaoqi Liu
Genes 2024, 15(12), 1511; https://doi.org/10.3390/genes15121511 - 25 Nov 2024
Viewed by 242
Abstract
Background: The enhancer–promoter interaction (EPI) is a critical component of gene regulatory networks, playing a significant role in understanding the complexity of gene expression. Traditional EPI prediction methods focus on one-to-one interactions, neglecting more complex one-to-many and many-to-many patterns. To address this gap, [...] Read more.
Background: The enhancer–promoter interaction (EPI) is a critical component of gene regulatory networks, playing a significant role in understanding the complexity of gene expression. Traditional EPI prediction methods focus on one-to-one interactions, neglecting more complex one-to-many and many-to-many patterns. To address this gap, we utilize graph neural networks to comprehensively explore all interaction patterns between enhancers and promoters, capturing complex regulatory relationships for more accurate predictions. Methods: In this study, we introduce a novel EPI prediction framework, GATv2EPI, based on dynamic graph attention neural networks. GATv2EPI leverages epigenetic information from enhancers, promoters, and their surrounding regions and organizes interactions into a network to comprehensively explore complex EPI regulatory patterns, including one-to-one, one-to-many, and many-to-many relationships. To avoid overfitting and ensure diverse data representation, we implemented a connectivity-based sampling method for dataset partitioning, which constructs graphs for each chromosome and assigns entire connected subgraphs to training or test sets, thereby preventing information leakage and ensuring comprehensive chromosomal representation. Results: In experiments conducted on four cell lines—NHEK, IMR90, HMEC, and K562—GATv2EPI demonstrated superior EPI recognition accuracy compared to existing similar methods, with a training time improvement of 95.29% over TransEPI. Conclusions: GATv2EPI enhances EPI prediction accuracy by capturing complex topological structure information from gene regulatory networks through graph neural networks. Additionally, our results emphasize the importance of epigenetic features surrounding enhancers and promoters in EPI prediction. Full article
(This article belongs to the Special Issue Advances and Applications of Machine Learning in Biomedical Genomics)
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Graphical abstract

Graphical abstract
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<p>GATv2EPI model framework. (<b>A</b>) EPI feature region selection model diagram. Red and yellow represent enhancers and promoters, respectively, while the green section indicates the flanking regions of the enhancer–promoter pairs. (<b>B</b>) Feature extraction. Features are extracted from the enhancers, promoters, and their surrounding areas. The resultant feature vectors are used to construct the node features within the graph. (<b>C</b>) Construction of the EPI graph structure. The extracted features of enhancers and promoters are represented as nodes, with edges representing their spatial association relationships. (<b>D</b>) EPI prediction based on GATv2. GATv2 dynamically calculates attention coefficients and incorporates a multi-head attention mechanism to update node expressions. The features of the edges and adjacent nodes are then utilized to classify the enhancer–promoter (EP) pairs.</p>
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<p>Comparative performance of TransEPI and GATv2 EPI across different cell lines. If there are multiple panels, they should be listed as follows: (<b>A</b>) the bar chart displays AUC scores for the TransEPI and GATv2 EPI methods across four cell lines: NHEK, IMR90, HMEC, and K562; (<b>B</b>) this panel shows AUPR scores for the same methods and cell lines.</p>
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<p>Comparative performance of TransEPI and GATv2EPI models in normal and cancer cells. The left panel shows the AUC scores, while the right panel displays the AUPR scores.</p>
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<p>Heatmaps of feature importance for enhancers and promoters in gene regulatory networks. This figure illustrates the feature importance across various genomic positions relative to enhancers and promoters for four different cell types. Panels (<b>A</b>–<b>D</b>) represent the heatmaps for different cell types: (<b>A</b>) NHEK, (<b>B</b>) IMR90, (<b>C</b>) HMEC, and (<b>D</b>) K562. The heatmaps display the relative importance of specific genomic features, such as transcription factors and histone modifications, within a window ranging from −10 to +10 around the enhancer or promoter regions. The x-axis indicates the relative genomic position, while the y-axis shows different feature types. The color scale represents the magnitude of feature importance, where warmer colors indicate higher importance.</p>
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<p>Intersection analysis of enhancer–promoter interactions across different cell lines. This Venn diagram displays the overlaps and distinctions in enhancer–promoter interactions among four cell lines: K562, HMEC, IMR90, and NHEK. The intersections highlight shared and unique regulatory connections.</p>
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<p>Distribution of node degrees for enhancers and promoters across different cell lines. This figure illustrates the distribution of node degrees within EPI networks for various cell lines, where the node degree represents the number of connections to other regulatory elements. Panel (<b>A</b>) shows the distribution of the number of promoters regulated by each enhancer, while panel (<b>B</b>) illustrates the distribution of the number of enhancers regulating each promoter. Violin plots are used to effectively convey the range and density of the data, revealing the complexity of regulatory interactions and highlighting the potential roles of enhancers and promoters in regulating gene expression within EPI networks.</p>
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<p>Distribution of bipartite clustering coefficients for enhancers and promoters across different cell lines. This figure illustrates the distribution of bipartite clustering coefficients (BCCs) within the EPI network across various cell lines, using a bubble chart to visually represent the data. The size and color of each bubble vary to indicate the BCC values for enhancer and promoter nodes, reflecting their tendency to form dense regulatory clusters or isolated interaction pairs. Higher BCC values suggest that enhancers and promoters are part of highly interconnected clusters, facilitating complex gene regulation. In contrast, lower BCC values indicate more isolated interactions, where nodes typically regulate fewer genes. This distribution highlights the complexity of regulatory networks and the role of spatial clustering in gene expression regulation.</p>
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<p>Structural distributions of connected subgraphs across different cell lines. This figure displays the structural characteristics of connected subgraphs within the enhancer–promoter interaction (EPI) networks for four distinct cell lines: (<b>A</b>) NHEK, (<b>B</b>) IMR90, (<b>C</b>) HMEC, and (<b>D</b>) K562. Panels from left to right represent the distributions of node counts, edge counts, and average node degrees within each subgraph. The node count distribution predominantly shows smaller values, indicating that most subgraphs consist of few nodes, thus implying limited connectivity. The edge count and average degree distributions further support this observation, reflecting sparse connections between regulatory elements. Interestingly, the K562 and NHEK cell lines exhibit some larger and denser subgraphs, suggesting more intricate regulatory clusters that might play significant roles in gene expression regulation. This variation suggests a diverse architectural landscape of enhancer–promoter interactions, which could underlie cell-type-specific regulatory complexities.</p>
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19 pages, 4339 KiB  
Article
VDMNet: A Deep Learning Framework with Vessel Dynamic Convolution and Multi-Scale Fusion for Retinal Vessel Segmentation
by Guiwen Xu, Tao Hu and Qinghua Zhang
Bioengineering 2024, 11(12), 1190; https://doi.org/10.3390/bioengineering11121190 - 25 Nov 2024
Viewed by 297
Abstract
Retinal vessel segmentation is crucial for diagnosing and monitoring ophthalmic and systemic diseases. Optical Coherence Tomography Angiography (OCTA) enables detailed imaging of the retinal microvasculature, but existing methods for OCTA segmentation face significant limitations, such as susceptibility to noise, difficulty in handling class [...] Read more.
Retinal vessel segmentation is crucial for diagnosing and monitoring ophthalmic and systemic diseases. Optical Coherence Tomography Angiography (OCTA) enables detailed imaging of the retinal microvasculature, but existing methods for OCTA segmentation face significant limitations, such as susceptibility to noise, difficulty in handling class imbalance, and challenges in accurately segmenting complex vascular morphologies. In this study, we propose VDMNet, a novel segmentation network designed to overcome these challenges by integrating several advanced components. Firstly, we introduce the Fast Multi-Head Self-Attention (FastMHSA) module to effectively capture both global and local features, enhancing the network’s robustness against complex backgrounds and pathological interference. Secondly, the Vessel Dynamic Convolution (VDConv) module is designed to dynamically adapt to curved and crossing vessels, thereby improving the segmentation of complex morphologies. Furthermore, we employ the Multi-Scale Fusion (MSF) mechanism to aggregate features across multiple scales, enhancing the detection of fine vessels while maintaining vascular continuity. Finally, we propose Weighted Asymmetric Focal Tversky Loss (WAFT Loss) to address class imbalance issues, focusing on the accurate segmentation of small and difficult-to-detect vessels. The proposed framework was evaluated on the publicly available ROSE-1 and OCTA-3M datasets. Experimental results demonstrated that our model effectively preserved the edge information of tiny vessels and achieved state-of-the-art performance in retinal vessel segmentation across several evaluation metrics. These improvements highlight VDMNet’s superior ability to capture both fine vascular details and overall vessel connectivity, making it a robust solution for retinal vessel segmentation. Full article
(This article belongs to the Section Biosignal Processing)
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<p>The architecture of VDMNet, which is composed of encoder, decoder, and skip connections.</p>
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<p>The proposed Fast Multi-Head Self-Attention Mechanism. (<b>a</b>) Fast Multi-Head Self-Attention Mechanism encoder. (<b>b</b>) Fast Multi-Head Self-Attention Mechanism decoder. They share similar concepts, but (<b>b</b>) takes two inputs: the high-resolution features from skip connections in the encoder and the low-resolution features from the decoder.</p>
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<p>Multi-Scale Fusion Module.</p>
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<p>Retinal vessel segmentation results of the proposed VDMNet and other segmentation networks. From top to bottom, the OCTA images of rows 1 and 3 come from ROSE-1, and rows 5 and 7 come from OCTA-3M, respectively. Rows 2, 4, 6, and 8 show the corresponding locally zoomed-in OCTA images, as well as the ground truth and segmentation results.</p>
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25 pages, 1578 KiB  
Review
Optimizing Power Flow and Stability in Hybrid AC/DC Microgrids: AC, DC, and Combined Analysis
by Ghanshyam Meena, Veerpratap Meena, Akhilesh Mathur, Vinay Pratap Singh, Ahmad Taher Azar and Ibrahim A. Hameed
Math. Comput. Appl. 2024, 29(6), 108; https://doi.org/10.3390/mca29060108 - 24 Nov 2024
Viewed by 273
Abstract
A microgrid (MG) is a unique area of a power distribution network that combines distributed generators (conventional as well as renewable power sources) and energy storage systems. Due to the integration of renewable generation sources, microgrids have become more unpredictable. MGs can operate [...] Read more.
A microgrid (MG) is a unique area of a power distribution network that combines distributed generators (conventional as well as renewable power sources) and energy storage systems. Due to the integration of renewable generation sources, microgrids have become more unpredictable. MGs can operate in two different modes, namely, grid-connected and islanded modes. MGs face various challenges of voltage variations, frequency deviations, harmonics, unbalances, etc., due to the uncertain behavior of renewable sources. To study the impact of these issues, it is necessary to analyze the behavior of the MG system under normal and abnormal operating conditions. Two different tools are used for the analysis of microgrids under normal and abnormal conditions, namely, power flow and short-circuit analysis, respectively. Power flow analysis is used to determine the voltages, currents, and real and reactive power flow in the MG system under normal operating conditions. Short-circuit analysis is carried out to analyze the behavior of MGs under faulty conditions. In this paper, a review of power flow and short-circuit analysis algorithms for MG systems under two different modes of operation, grid-connected and islanded, is presented. This paper also presents a comparison of various power flow as well as short-circuit analysis techniques for MGs in tabular form. The modeling of different components of MGs is also discussed in this paper. Full article
(This article belongs to the Special Issue Applied Optimization in Automatic Control and Systems Engineering)
16 pages, 9898 KiB  
Article
Lithium Iron Phosphate Battery Failure Under Vibration
by Jianying Li, Zhanhong Chen, Yinghong Xie, Hao Wen, Chaoming Cai and Hai Wang
World Electr. Veh. J. 2024, 15(12), 548; https://doi.org/10.3390/wevj15120548 - 24 Nov 2024
Viewed by 216
Abstract
The failure mechanism of square lithium iron phosphate battery cells under vibration conditions was investigated in this study, elucidating the impact of vibration on their internal structure and safety performance using high-resolution industrial CT scanning technology. Various vibration states, including sinusoidal, random, and [...] Read more.
The failure mechanism of square lithium iron phosphate battery cells under vibration conditions was investigated in this study, elucidating the impact of vibration on their internal structure and safety performance using high-resolution industrial CT scanning technology. Various vibration states, including sinusoidal, random, and classical impact modes, were tested to simulate real-world usage scenarios. The findings demonstrate that different vibration conditions exert varying degrees of influence on the battery cells. Despite experiencing slight deformation and displacement after exposure to vibrations, their overall performance remains stable, with no significant safety hazards detected. Moreover, it was observed that while the side gap increases due to the partial absorption of impact load by both the battery cells and connection components, the bottom gap remains unchanged. This study holds immense significance in enhancing electric vehicle safety and reliability, while providing a scientific foundation for future optimization designs of lithium iron phosphate batteries. Full article
(This article belongs to the Special Issue Research Progress in Power-Oriented Solid-State Lithium-Ion Batteries)
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<p>Test equipment. (<b>a</b>) Xin Wei CE-6006n charging and discharging motor; (<b>b</b>) YPA -ZD composite constant-temperature and humidity vibration table; (<b>c</b>) YXLON industrial CT.</p>
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<p>Sinusoidal vibration test data diagrams.</p>
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<p>Sinusoidal vibration test data diagrams.</p>
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<p>Random vibration test data diagrams.</p>
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<p>Random vibration test data diagrams.</p>
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<p>Classical impact test data diagrams.</p>
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<p>Classical impact test data diagrams.</p>
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<p>Cross-section of CT scanning before (<b>a</b>) and after (<b>b</b>) sinusoidal vibration test. The text "场景坐标系" in the figure represents the scene coordinate system, the text “距离”in the figure represents the distance, the same as below.</p>
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<p>Vertical section of CT scan of left pole before (<b>a</b>) and after (<b>b</b>) sinusoidal vibration test.</p>
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<p>Vertical section of CT scan of right pole before (<b>a</b>) and after (<b>b</b>) sinusoidal vibration test.</p>
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<p>Vertical section of CT scan of pressure relief port before (<b>a</b>) and after (<b>b</b>) sinusoidal vibration test.</p>
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<p>Cross-section of CT scan before (<b>a</b>) and after (<b>b</b>) random vibration test.</p>
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<p>Vertical section of CT scan of left pole before (<b>a</b>) and after (<b>b</b>) after random vibration test.</p>
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<p>Vertical section of CT scan of right pole before (<b>a</b>) and after (<b>b</b>) random vibration test.</p>
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<p>Vertical section of CT scan of pressure relief port before (<b>a</b>) and after (<b>b</b>) random vibration test.</p>
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<p>Cross-section of CT scan before (<b>a</b>) and after (<b>b</b>) classical impact test.</p>
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<p>Vertical section of CT scan of left pole before (<b>a</b>) and after (<b>b</b>) classical impact test.</p>
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<p>Vertical section of CT scan of right pole before (<b>a</b>) and after (<b>b</b>) classical impact test.</p>
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<p>Vertical section of CT scan of pressure relief port before (<b>a</b>) and after (<b>b</b>) classical impact test.</p>
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22 pages, 4744 KiB  
Article
The RedFish API and vSphere Hypervisor API: A Unified Framework for Policy-Based Server Monitoring
by Vedran Dakić, Karlo Bertina, Jasmin Redžepagić and Damir Regvart
Electronics 2024, 13(23), 4624; https://doi.org/10.3390/electronics13234624 - 23 Nov 2024
Viewed by 244
Abstract
Integrating remote monitoring systems is crucial in the ever-changing field of data center management to enhance performance and guarantee reliability. This paper outlines a comprehensive strategy for monitoring remote servers by utilizing agents that establish connections to the RedFish API (Application Programming Interface) [...] Read more.
Integrating remote monitoring systems is crucial in the ever-changing field of data center management to enhance performance and guarantee reliability. This paper outlines a comprehensive strategy for monitoring remote servers by utilizing agents that establish connections to the RedFish API (Application Programming Interface) and vSphere hypervisor API. Our solution uses the RedFish standard to provide secure and standardized management of hardware components in diverse server environments. This improves interoperability and scalability. Simultaneously, the vSphere agent enables monitoring and hardware administration in vSphere-based virtualized environments, offering crucial insights into the state of the underlying hardware. This system, which employs two agents, simplifies the management of servers and seamlessly integrates with current data center infrastructures, enhancing efficiency. The policy-based alerting system built on top of these agents offers many capabilities based on both agents leveraging their alerting systems. This, in turn, can improve the capabilities of next-generation data centers. Full article
(This article belongs to the Section Computer Science & Engineering)
20 pages, 4950 KiB  
Article
A Dual-Branch Residual Network with Attention Mechanisms for Enhanced Classification of Vaginal Lesions in Colposcopic Images
by Haima Yang, Yeye Song, Yuling Li, Zubei Hong, Jin Liu, Jun Li, Dawei Zhang, Le Fu, Jinyu Lu and Lihua Qiu
Bioengineering 2024, 11(12), 1182; https://doi.org/10.3390/bioengineering11121182 - 22 Nov 2024
Viewed by 267
Abstract
Vaginal intraepithelial neoplasia (VAIN), linked to HPV infection, is a condition that is often overlooked during colposcopy, especially in the vaginal vault area, as clinicians tend to focus more on cervical lesions. This oversight can lead to missed or delayed diagnosis and treatment [...] Read more.
Vaginal intraepithelial neoplasia (VAIN), linked to HPV infection, is a condition that is often overlooked during colposcopy, especially in the vaginal vault area, as clinicians tend to focus more on cervical lesions. This oversight can lead to missed or delayed diagnosis and treatment for patients with VAIN. Timely and accurate classification of VAIN plays a crucial role in the evaluation of vaginal lesions and the formulation of effective diagnostic approaches. The challenge is the high similarity between different classes and the low variability in the same class in colposcopic images, which can affect the accuracy, precision, and recall rates, depending on the image quality and the clinician’s experience. In this study, a dual-branch lesion-aware residual network (DLRNet), designed for small medical sample sizes, is introduced, which classifies vaginal lesions by examining the relationship between cervical and vaginal lesions. The DLRNet model includes four main components: a lesion localization module, a dual-branch classification module, an attention-guidance module, and a pretrained network module. The dual-branch classification module combines the original images with segmentation maps obtained from the lesion localization module using a pretrained ResNet network to fine-tune parameters at different levels, explore lesion-specific features from both global and local perspectives, and facilitate layered interactions. The feature guidance module focuses the local branch network on vaginal-specific features by using spatial and channel attention mechanisms. The final integration involves a shared feature extraction module and independent fully connected layers, which represent and merge the dual-branch inputs. The weighted fusion method effectively integrates multiple inputs, enhancing the discriminative and generalization capabilities of the model. Classification experiments on 1142 collected colposcopic images demonstrate that this method raises the existing classification levels, achieving the classification of VAIN into three lesion grades, thus providing a valuable tool for the early screening of vaginal diseases. Full article
(This article belongs to the Section Biosignal Processing)
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<p>Three states of vaginal epithelium under iodine staining.</p>
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<p>(<b>Left</b>): Variability in characteristics in the same type of vaginal epithelial lesion. (<b>Right</b>): Similar characteristics across different lesion types.</p>
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<p>DLRNet is comprised of four main modules: the lesion localization and segmentation module, the dual-branch classification module, the attention-guidance module, and the weighted fusion module.</p>
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<p>Localized colposcopic image: The red contours indicate the key area of interest in the vagina. The images above show the original with a red boundary, and the images below show the segmented results.</p>
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<p>Network architecture of attention-guided blocks.</p>
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<p>Confusion matrix of colposcopic predictions by physicians.</p>
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<p>t-SNE visualization of ablation experimental results on the test set. (<b>a</b>) Single (global), (<b>b</b>) Single (local), (<b>c</b>) Dual (No pretrained), (<b>d</b>) Dual + Attention, (<b>e</b>) Dual* (Pretrained), (<b>f</b>) Dual* + Attention.</p>
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<p>ROC curves for each disease, comparing classic models and the proposed method. (<b>a</b>) 0: Normal, (<b>b</b>) 1: LSIL, (<b>c</b>) 2: HSIL +, (<b>d</b>) Mean.</p>
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<p>Grad-CAM visualizations comparing the proposed method with other classical methods: (<b>a</b>) Endoscopic images; (<b>b</b>) CNN; (<b>c</b>) VGG Net-D &amp; Net-E; (<b>d</b>) Mobilenets; (<b>e</b>) ResNet (ILSVRC’15); (<b>f</b>) DenseNet-BC; (<b>g</b>) GoogLeNet; (<b>h</b>) EfficientNet; (<b>i</b>) DLRNet.</p>
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14 pages, 6106 KiB  
Article
Analysis and Validation of Lightweight Carriage Structures Using Basalt Fiber Composites
by Xianglin Wang, Shaoqing Yuan, Wei Sun, Wenfeng Hao, Xufeng Zhang and Zhongjia Yang
Materials 2024, 17(23), 5723; https://doi.org/10.3390/ma17235723 - 22 Nov 2024
Viewed by 325
Abstract
With the growth in road transport volume and increasingly stringent environmental regulations, the use of lightweight dump trucks not only reduces fuel consumption but also enhances transport efficiency, aligning with the principles of green development. It has now become a key focus in [...] Read more.
With the growth in road transport volume and increasingly stringent environmental regulations, the use of lightweight dump trucks not only reduces fuel consumption but also enhances transport efficiency, aligning with the principles of green development. It has now become a key focus in the field of heavy-duty vehicle research. The carriage is located at the rear of the dump truck, connected to the chassis, and serves as the box for carrying cargo, making its strength and durability crucial. As one of the important components of heavy-duty vehicles, the carriage accounts for 15% to 25% of the total vehicle weight, and its weight reduction efficiency is significantly higher than that of other vehicle systems. This paper presents a prefabricated carriage structure based on basalt fiber composite panels combined with a metal frame, achieving the lightweight design of the carriage while meeting the stringent requirements for high load-bearing capacity and strength in heavy-duty vehicles, and significantly improving assembly and production efficiency. Given the complex working environment and diverse loading demands of heavy vehicles, this study incorporates real operating conditions of dump trucks, utilizing theoretical calculations and design analyses to construct finite element models for various scenarios, followed by detailed numerical simulations in ABAQUS (2023). Additionally, a bending–shear test of the side panel was designed and conducted to validate the accuracy of the finite element model, with comparative analysis performed between simulation results and experimental data, effectively assessing the safety and reliability of this lightweight composite carriage structure. The results indicate that the designed carriage not only meets the strength, stiffness, and impact resistance requirements of current heavy-duty carriages but also significantly reduces the carriage weight. This research provides scientific reference and engineering value for the application of composite materials in the lightweight design and structural optimization of dump trucks. Full article
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<p>Research content flowchart.</p>
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<p>(<b>a</b>) 3D model of basalt fiber composite dump truck carriage; (<b>b</b>) Production image of dump truck carriage.</p>
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<p>Three standard tensile specimens.</p>
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<p>Standard specimen tensile test.</p>
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<p>(<b>a</b>) Finite element model mesh diagram of the carriage; (<b>b</b>) Boundary condition settings.</p>
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<p>Test site diagrams; (<b>a</b>) Bending Resistance Mechanical Performance Testing of the side panel; (<b>b</b>) Strain gauge data collection diagram.</p>
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<p>Stress–Strain nephogram of the carriage under different conditions; (<b>a</b>) Static condition; (<b>b</b>) Full-load start-up acceleration condition; (<b>c</b>) Full-load braking condition; (<b>d</b>) Full-load turning condition; (<b>e</b>) Full-load turning braking condition.</p>
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<p>Maximum stress and strain values under different conditions. Note: (1) Static condition; (2) Full-load start-up acceleration condition; (3) Full-load braking condition; (4) Full-load turning condition; (5) Full-load turning braking condition.</p>
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<p>Impact of different loads:(<b>a</b>) 0.05 t; (<b>b</b>) 0.1 t; (<b>c</b>) 0.15 t; (<b>d</b>) 0.2 t.</p>
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<p>(<b>a</b>) Experimental compression load-displacement curve diagram; (<b>b</b>) Stocking film layout point.</p>
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<p>Stress values at different points in the finite element nephogram.</p>
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23 pages, 5837 KiB  
Article
Mechanical Design, Analysis, and Dynamics Simulation of a Cable-Driven Wearable Flexible Exoskeleton System
by Xuetong Jin, Wenqian Ding, Mathias Baumert, Yan Wei, Qinglin Li, Wei Yang and Yuqiao Yan
Technologies 2024, 12(12), 238; https://doi.org/10.3390/technologies12120238 - 21 Nov 2024
Viewed by 554
Abstract
As a new development direction in exoskeleton research, wearable flexible exoskeleton systems are highly favored for their freedom of movement, flexibility, lightweight design, and comfortable wearability. These systems are gradually becoming the preferred choice for rehabilitation therapy, and enhancing physical performance. In this [...] Read more.
As a new development direction in exoskeleton research, wearable flexible exoskeleton systems are highly favored for their freedom of movement, flexibility, lightweight design, and comfortable wearability. These systems are gradually becoming the preferred choice for rehabilitation therapy, and enhancing physical performance. In this thesis, based on existing research in wearable flexible exoskeletons, we aim to design a lightweight wearable upper limb rehabilitation exoskeleton that meets the needs of stroke patients with a high likelihood of upper limb impairment. The system should provide sufficient flexibility for comfortable and convenient use while minimizing the weight to reduce the user’s burden during wear. Our proposed lightweight wearable flexible exoskeleton assists users in achieving rehabilitation exercises for both the shoulder (external/internal rotation) and forearm (flexion/extension) movements. The system consists of a flexible fabric section connecting the torso–shoulder–upper arm, a flexible fabric section for the forearm, and a back-mounted actuation device. The fabric sections primarily consist of elastic textile materials with a few rigid components. Emphasizing lightweight design, we strive to minimize the exoskeleton’s weight, ensuring optimal user comfort. The actuation device connects to the fabric sections via tensioned wires, driven by a motor to induce arm movement during rehabilitation exercises. To enhance safety and prevent secondary upper limb injuries due to exoskeleton malfunction, we incorporate a physical limiter retricting the exoskeleton’s range of motion. Additionally, we include tension-adjustment mechanisms and cushioning springs to improve the feasibility of this wearable flexible exoskeleton. After completing the structural design, this paper conducted a basic static and kinematic analysis of the exoskeleton system to provide theoretical support. Additionally, the feasibility and effectiveness of the exoskeleton system design were verified through dynamic simulations. Full article
(This article belongs to the Section Assistive Technologies)
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<p>Conceptual design of lightweight upper limb wearable rehabilitation exoskeleton.</p>
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<p>U-shaped bearing for adjusting wire tension.</p>
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<p>Conceptual design of lightweight upper limb wearable rehabilitation exoskeleton: three views and tension-adjustable structure with ropes.</p>
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<p>Design of limiter structure.</p>
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<p>Schematic diagram of the driving system.</p>
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<p>The kinematic analysis diagram 1 of the upper arm’s external/internal rotation concerning the shoulder joint.</p>
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<p>The kinematic analysis diagram 2 of the upper arm’s angle of external/internal rotation concerning the shoulder joint.</p>
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<p>The kinematic analysis diagram 1 of the forearm’s flexion/extension movements concerning the elbow joint.</p>
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<p>The kinematic analysis diagram 2 of the forearm’s flexion/extension movements concerning the elbow joint.</p>
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<p>The force analysis diagram of the upper arm’s external/internal rotation movements concerning the shoulder joint.</p>
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<p>The force analysis diagram of the forearm’s flexion/extension movements concerning the elbow joint.</p>
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<p>Positioning diagram for limiter.</p>
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<p>The relationship curves of angular velocity/angular acceleration of the shoulder joint with respect to time in the simulation of shoulder joint internal/external rotation.</p>
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<p>The relationship curves of angular velocity/angular acceleration of the elbow joint with respect to time in the simulation of elbow joint flexion/extension.</p>
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<p>(<b>a</b>): The relationship curves of angular velocity/angular acceleration of the shoulder joint with respect to time in compound movements. (<b>b</b>): The relationship curves of angular velocity/angular acceleration of the elbow joint with respect to time in compound movements.</p>
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<p>Modeling and visualization of lightweight wearable rehabilitation exoskeleton.</p>
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19 pages, 4133 KiB  
Article
Abnormal-Sound Diagnosis for Kaplan Hydroelectric Generating Units Based on Continuous Wavelet Transform and Transfer Learning
by Yu Liu, Zhuofei Xu, Pengcheng Guo and Longgang Sun
Sensors 2024, 24(23), 7441; https://doi.org/10.3390/s24237441 - 21 Nov 2024
Viewed by 359
Abstract
To realize abnormal-sound diagnosis in hydroelectric generating units, this study proposes a method based on continuous wavelet transform (CWT) and Transfer Learning (TL). A denoising algorithm utilizing spectral noise-gate technology is proposed to enhance fault characteristics in hydroelectric units. Subsequently, Continuous Wavelet Transform [...] Read more.
To realize abnormal-sound diagnosis in hydroelectric generating units, this study proposes a method based on continuous wavelet transform (CWT) and Transfer Learning (TL). A denoising algorithm utilizing spectral noise-gate technology is proposed to enhance fault characteristics in hydroelectric units. Subsequently, Continuous Wavelet Transform is applied to obtain frequency components, and the results are converted into a series of pseudo-color images to highlight information differences. A transfer model is subsequently developed for feature extraction, utilizing simplified fully connected layers to reduce modeling costs. The study optimizes key parameters during the signal-processing stage and achieves an improved parameter-setting scheme. Acoustic signals corresponding to four different fault states and a normal state are collected from a Kaplan hydroelectric generating unit in a hydropower station. The signal diagnosis accuracy rates before filtering are 84.83% and 95.14%. These rates significantly improved to 98.88% and 98.06%, respectively, demonstrating the effectiveness of the noise-reduction process. To demonstrate the superiority of the improved model in this work, a series of classic deep-learning models, including AlexNet, Resnet18, and MobileNetV3, are used for comparative analysis. The proposed method can effectively diagnose faults in Kaplan hydroelectric generating units with a high accuracy, which is crucial for the daily monitoring and maintenance of these units. Full article
(This article belongs to the Section Fault Diagnosis & Sensors)
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<p>Acoustic signal denoising algorithm for hydroelectric units.</p>
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<p>Images obtained from CWT.</p>
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<p>CWT images with different window lengths: (<b>a</b>) Normal running sound in the hydroelectric unit; (<b>b</b>) Metal collision in the hydroelectric unit.</p>
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<p>CWT images with scale factors: (<b>a</b>) Normal running sound in the hydroelectric unit; (<b>b</b>) Metal collision in the hydroelectric unit.</p>
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<p>The network structure of VGG16.</p>
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<p>Improved VGG16 model.</p>
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<p>High-frequency microphone array.</p>
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<p>Time-frequency images of original acoustic signals: (<b>a</b>) Waterwheel room; (<b>b</b>) Gallery near the access manhole.</p>
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<p>Time-frequency images of original acoustic signals: (<b>a</b>) Waterwheel room; (<b>b</b>) Gallery near the access manhole.</p>
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<p>Time-frequency images of denoising acoustic signals: (<b>a</b>) Waterwheel room; (<b>b</b>) Gallery near the access manhole.</p>
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<p>Time-frequency images of denoising acoustic signals: (<b>a</b>) Waterwheel room; (<b>b</b>) Gallery near the access manhole.</p>
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<p>Training curves in waterwheel room: (<b>a</b>) Loss value; (<b>b</b>) Training accuracy.</p>
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<p>Time-frequency images of original acoustic signals: (<b>a</b>) Waterwheel room (<b>b</b>) Gallery near the access manhole.</p>
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<p>Time-frequency images of denoising acoustic signals: (<b>a</b>) Waterwheel room (<b>b</b>) Gallery near the access manhole.</p>
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