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Demand-Responsive Transportation Vehicle Routing Optimization Based on Two-Stage Method

Computers, materials and Continua 2024年第1期81卷 443-469页

作者： ma j. Liu H. Chen L. School of Railway Transportation Shanghai Institute of Technology Shanghai 201418 China

Demand-responsive transportation (DRT) is a flexible passenger service designed to enhance road efficiency, reduce peak-hour traffic, and boost passenger satisfaction. However, existing optimization methods for initial passenger requests fall short in addressing real-time passenger needs. Consequently, there is a need to develop real-time DRT route optimization methods that integrate both initial and real-time requests. This paper presents a two-stage, multi-obj.ctive optimization model for DRT vehicle scheduling. The first stage involves an initial scheduling model aimed at minimizing vehicle configuration, and operational, and CO2 emission costs while ensuring passenger satisfaction. The second stage develops a real-time scheduling model to minimize additional operational costs, penalties for time window violations, and costs due to rej.cted passengers, thereby addressing real-time demands. Additionally, an enhanced genetic algorithm based on Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is designed, incorporating multiple crossover points to accelerate convergence and improve solution efficiency. The proposed scheduling model is validated using a real network in Shanghai. Results indicate that real-time scheduling can serve more passengers, and improve vehicle utilization and occupancy rates, with only a minor increase in total operational costs. Compared to the traditional NSGA-II algorithm, the improved version enhances convergence speed by 31.7% and solution speed by 4.8%. The proposed model and algorithm offer both theoretical and practical guidance for real-world DRT scheduling. © 2024 The Authors.

关键词： artificial intelligence applications Demand responsive transit genetic algorithm muti-obj.ctive optimization

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A Facial Expression Recognition Method Integrating Uncertainty Estimation and Active Learning

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Computers, materials and Continua 2024年第1期81卷 533-548页

作者： Wang y. Zhang j. Sun R. School of Computer Science and Engineering Chongqing University of Technology Chongqing 400054 China Data Space Research Institute of Hefei Comprehensive National Science Center Hefei 230088 China

The effectiveness of facial expression recognition (FER) algorithms hinges on the model’s quality and the availability of a substantial amount of labeled expression data. However, labeling large datasets demands significant human, time, and financial resources. Although active learning methods have mitigated the dependency on extensive labeled data, a cold-start problem persists in small to medium-sized expression recognition datasets. This issue arises because the initial labeled data often fails to represent the full spectrum of facial expression characteristics. This paper introduces an active learning approach that integrates uncertainty estimation, aiming to improve the precision of facial expression recognition regardless of dataset scale variations. The method is divided into two prima.y phases. First, the model undergoes self-supervised pre-training using contrastive learning and uncertainty estimation to bolster its feature extraction capabilities. Second, the model is fine-tuned using the prior knowledge obtained from the pre-training phase to significantly improve recognition accuracy. In the pre-training phase, the model employs contrastive learning to extract fundamental feature representations from the complete unlabeled dataset. These features are then weighted through a self-attention mechanism with rank regularization. Subsequently, data from the low-weighted set is relabeled to further refine the model’s feature extraction ability. The pre-trained model is then utilized in active learning to select and label information-rich samples more efficiently. Experimental results demonstrate that the proposed method significantly outperforms existing approaches, achieving an improvement in recognition accuracy of 5.09% and 3.82% over the best existing active learning methods, margin, and Least Confidence methods, respectively, and a 1.61% improvement compared to the conventional segmented active learning method. © 2024 The Authors.

关键词： active learning Expression recognition self-supervised learning uncertainty estimation

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Message Verification Protocol Based on Bilinear Pairings and Elliptic Curves for Enhanced Security in Vehicular Ad Hoc Networks

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Computers, materials and Continua 2024年第1期81卷 1029-1057页

作者： Nyangaresi V.O. Ghaib A.A. j.sim H.M. Abdulj.bbar Z.A. ma j. Al Sibahee M.A. Aldarwish A.j.y. Ali A.H. Neamah H.A. Department of Computer Science and Software Engineering Jaramogi Oginga Odinga University of Science and Technology Bondo 40601 Kenya Department of Applied Electronics Saveetha School of Engineering SIMATS Tamilnadu Chennai 602105 India Information Technology Department Management Technical College Southern Technical University Basrah 61004 Iraq Department of Computer Science College of Education for Pure Sciences University of Basrah Basrah 61004 Iraq College of Big Data and Internet Shenzhen Technology University Shenzhen 518118 China Huazhong University of Science and Technology Shenzhen Institute Shenzhen 518000 China National Engineering Laboratory for Big Data System Computing Technology Shenzhen University Shenzhen 518060 China Computer Technology Engineering Department Iraq University College Basrah 61004 Iraq Department of mathematics College of Education for Pure Sciences University of Basrah Basrah 61004 Iraq Institute of mathematics University of Debrecen Debrecen H-4002 Hungary Department of Electrical Engineering and Mechatronics Faculty of Engineering University of Debrecen Debrecen 4028 Hungary

Vehicular ad hoc networks (VANETs) provide intelligent navigation and efficient route management, resulting in time savings and cost reductions in the transportation sector. However, the exchange of beacons and messages over public channels among vehicles and roadside units renders these networks vulnerable to numerous attacks and privacy violations. To address these challenges, several privacy and security preservation protocols based on blockchain and public key cryptography have been proposed recently. However, most of these schemes are limited by a long execution time and massive communication costs, which make them inefficient for on-board units (OBUs).Additionally, some of them are still susceptible toma.y *** such, this study presents a novel protocol based on the fusion of elliptic curve cryptography (ECC) and bilinear pairing (BP) operations. The formal security analysis is accomplished using the Burrows-Abadi-Needham(BAN) logic, demonstrating that our scheme is verifiably secure. The proposed scheme's informal security assessment also shows that it provides salient security features, such as non-repudiation, anonymity, and unlinkability. Moreover, the scheme is shown to be resilient against attacks, such as packet replays, forgeries,message falsifications, and impersonations. Fromthe performance perspective, this protocol yields a 37.88% reduction in communication overheads and a 44.44% improvement in the supported security features. Therefore, the proposed scheme can be deployed in VANETs to provide robust security at low overheads. © 2024 The Authors. Published by Tech Science Press.

关键词： Attacks bilinear elliptic curve cryptography (ECC) privacy security vehicular ad hoc network (VANET)

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Paraelectric Doping Simultaneously Improves the Field Frequency Adaptability and Dielectric Properties of Ferroelectric materials: A Phase-Field Study

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Computers, materials and Continua 2024年第1期81卷 213-228页

作者： Wang Z. Cao j. Liu Z. Zhao y. School of materials Science and Engineering Collaborative Innovation Center of Ministry of Education and Shanxi Province for High-Performance Al/Mg Alloy Materials North University of China Taiyuan 030051 China Beij.ng Advanced Innovation Center for materials Genome Engineering University of Science and Technology Beijing Beijing 100083 China Institute of materials Intelligent Technology Liaoning Academy of Materials Shenyang 110004 China

Recent years, the polarization response of ferroelectrics has been entirely studied. However, it is found that the polarization may disappear gradually with the continually applied of electric field. In this paper, taking K0.48Na0.52NbO3(KNN) as an example, it was demonstrated that the residual polarization began to decrease when the electric field frequency increased to a certain extent using a phase-field methods. The results showed that the content of out-of-plane domains increased first and then decreased with the increase of applied electric field frequency, the maximum polarization disappeared at high frequencies, and the hysteresis loop became elliptical. In order to further study the abnormal changes of hysteresis loops of ferroelectrics under high electric field frequency, we analyzed the hysteresis loop and dielectric response of solid solution 0.1SrTiO3-0.9K0.48Na0.52NbO3. It was found that the doped hysteresis loop maintained its shape at higher frequency and the dielectric constant increased. This kind of doping has a higher field frequency adaptability, which has a key guiding role in improving the dielectric properties of ferroelectric thin films and expanding the frequency application range of ferroelectric nano memory. © 2024 The Authors. Published by Tech Science Press.

关键词： dielectric properties doping electric field frequency Ferroelectric ceramics phase field method

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Improved Harris Hawks Algorithm and Its Application in Feature Selection

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Computers, materials and Continua 2024年第1期81卷 1251-1273页

作者： Zhang Q. Li y. Zhan j. Chen S. School of Computer Science and Information Engineering Harbin Normal University Harbin 150025 China College of Systems Engineering National University of Defense Technology Changsha 410073 China

This research focuses on improving the Harris' Hawks Optimization algorithm (HHO) by tackling several of its shortcomings, including insufficient population diversity, an imbalance in exploration vs. exploitation, and a lack of thorough exploitation depth. To tackle these shortcomings, it proposes enhancements from three distinct perspectives: an initialization technique for populations grounded in opposition-based learning, a strategy for updating escape energy factors to improve the equilibrium between exploitation and exploration, and a comprehensive exploitation approach that utilizes variable neighborhood search along with mutation operators. The effectiveness of the Improved Harris Hawks Optimization algorithm (IHHO) is assessed by comparing it to five leading algorithms across 23 benchmark test functions. Experimental findings indicate that the IHHO surpasses several contemporary algorithms its problem-solving capabilities. Additionally, this paper introduces a feature selection method leveraging the IHHOalgorithm(IHHO-FS) to address challenges such as lowefficiency in feature selection and high computational costs (time to find the optimal feature combination and model response time) associated with high-dimensional datasets. Comparative analyses between IHHO-FS and six other advanced feature selection methods are conducted across eight datasets. The results demonstrate that IHHO-FS significantly reduces the computational costs associated with classification models by lowering data dimensionality, while also enhancing the efficiency of feature selection. Furthermore, IHHO-FS shows strong competitiveness relative to numerous algorithms. © 2024 The Authors. Published by Tech Science Press.

关键词： deep exploitation strategy energy factor update strategy feature selection HHO IHHO population diversity

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Effect of Al_(2)O_(3)on the Mechanical Properties of(B_(4)C+Al_(2)O_(3))/Al Neutron Absorbing materials

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1411-1420页

作者： j.X.Cai B.M.Shi N.Li y.Liu Z.G.Zhang y.N.Zan Q.Z.Wang B.L.Xiao Z.y.ma Shi‑Changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of Nuclear materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nuclear Equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing 100840China Department of materials Science School of Mechanical EngineeringShenyang UniversityShenyang 110044China

B_(4)C/Al composites are widely utilized as neutron absorbing materials for the storage and transportation of spent nuclear *** order to improve the high-temperature mechanical properties of B_(4)C/Al composites,in-situ nano-Al_(2)O_(3)was introduced utilizing oxide on Al powder *** this study,the Al_(2)O_(3)content was adj.sted by utilizing spheroid Al powder with varying diameters,thereby investigating the impact of Al_(2)O_(3)content on the tensile properties of(B_(4)C+Al_(2)O_(3))/Al *** was found that the pinning effect of Al_(2)O_(3)on the grain boundaries could hinder the recovery of dislocations and lead to dislocation accumulation at high *** the result,with the increase in Al_(2)O_(3)content and the decrease in grain size,the high-temperature strength of the composites increased *** finest Al powder used in this investigation had a diameter of 1.4μm,whereas the resultant composite exhibited a maximum strength of 251 MPa at room temperature and 133 MPa at 350℃,surpassing that of traditional B_(4)C/Al composites.

关键词： Al matrix composites Neutron absorbing materials (B_(4)C+Al_(2)O_(3))/Al composites High-temperature strength

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Graph Attention Residual Network Based Routing and Fault-Tolerant SchedulingMechanism for Data Flow in Power Communication Network

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Computers, materials and Continua 2024年第1期81卷 1641-1665页

作者： Lin Z. Zeng Z. yu y. Ren y. Qiu X. Chen j. State Key Laboratory ofNetworking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China State Grid j.angsu Electric Power Co. Ltd Nanjing 210008 China

For permanent faults (PF) in the power communication network (PCN), such as link interruptions, the timesensitive networking (TSN) relied on by PCN, typically employs spatial redundancy fault-tolerance methods to keep service stability and reliability, which often limits TSN scheduling performance in fault-free ideal states. So this paper proposes a graph attention residual network-based routing and fault-tolerant scheduling mechanism (GRFS) for data flow in PCN, which specifically includes a communication system architecture for integrated terminals based on a cyclic queuing and forwarding (CQF) model and fault recovery method, which reduces the impact of faults by simplified scheduling configurations of CQF and fault-tolerance of prioritizing the rerouting of faulty time-sensitive (TS) flows; considering that PF leading to changes in network topology is more appropriately solved by doing routing and time slot inj.ction decisions hop-by-hop, and that reasonable network load can reduce the damage caused by PF and reserve resources for the rerouting of faulty TS flows, an optimization model for j.int routing and scheduling is constructed with scheduling success rate as the obj.ctive, and with traffic latency and network load as constraints; to catch changes in TSN topology and traffic load, a D3QN algorithm based on a multi-head graph attention residual network (MGAR) is designed to solve the problem model, where the MGAR based encoder reconstructs theTSNstatus into feature embedding vectors, and a dueling network decoder performs decoding tasks on the reconstructed feature embedding vectors. Simulation results show that GRFS outperforms heuristic fault-tolerance algorithms and other benchmark schemes by approximately 10%in routing and scheduling success rate in ideal states and 5% in rerouting and rescheduling success rate in fault states. © 2024 The Authors. Published by Tech Science Press.

关键词： deep reinforcement learning fault tolerance graph attention network Time-sensitive network

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Helicobacter pylori infection may result in poor gastric cleanliness in magnetically controlled capsule gastroscopy examination: A single-center retrospective study

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Laparoscopic, Endoscopic, and Robotic Surgery 2024年第4期7卷 147-154页

作者： Xia j. Fang j. Chen L. Meng y. Su L. Department of General Practice Sir Run Run Shaw Hospital Zhejiang University School of Medicine Hangzhou 310016 China

Obj.ctive: magnetically controlled capsule gastroscopy (MCCG) is an effective method for screening gastric diseases; however, its performance may be affected by gastric cleanliness. We aimed to explore the correlation between Helicobacter pylori infection and the degree of gastric cleanliness in the MCCG. Methods: This retrospective study enrolled 297 participants from October 2020 to April 2024 at Sir Run Run Shaw Hospital, Zhej.ang University School of Medicine. Participant characteristics, MCCG examination results, and (13) C-urea breath test (C13-UBT) results were collected. The gastric cleanliness in MCCG examinations was assessed using a gastric cleanliness score. Binary logistic regression was used to analyze the relationships among participant characteristics, H. pylori infection, and gastric cleanliness. Chi-square tests and Fisher's exact tests were used to analyze the relationships among gastric lesions, H. pylori infection, and gastric cleanliness. Results: Among the participants, 24.2% had H. pylori infection, and 17.5% had poor gastric cleanliness. Hypertension (odds ratio [OR]: 2.63; 95% confidence interval [CI]: 1.36–5.09; p = 0.004) was associated with a greater likelihood of H. pylori infection. H. pylori infection (OR: 3.76; 95% CI: 1.99–7.09; p y was noted in the prevalence of focal erosions (p ylori infection. The proportion of positive gastric lesions was not significantly different between the good gastric cleanliness group and the poor gastric cleanliness group (25.7% vs. 21.2%; p = 0.490). Conclusion: The findings of this study revealed that H. pylori infection was associated with hypertension. H. pylori infection may lead to poor gastric cleanliness. Institutions are advised to perform C13-UBT before MCCG, and participa

关键词： C-urea breath test Gastric cleanliness Helicobacter pylori Hypertension magnetically controlled capsule gastroscopy

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Construction of 2D/2D Ti_(3)C_(2)T_(x)MXene/CdS heteroj.nction with photothermal effect for efficient photocatalytic hydrogen production

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j.urnal of materials Science & Technology 2024年第4期171卷 1-9页

作者： T.y.Huang Z.yang S.y.yang Z.H.Dai y.j.Liu j.H.Liao G.y.Zhong Z.j.Xie y.P.Fang S.S.Zhang Key Laboratory for Biobased materials and Energy of Ministry of Education Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China School of Chemical Engineering and Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utilization of light energy in photocatalytic *** photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor ***,a novel stable Ti_(3)C_(2)T_(x)MXene/CdS heteroj.nction catalyst is obtained by in-situ epitaxial growth of two-dimensional(2D)CdS nanosheets on 2D MXene interface via a solvothermal *** exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocat-alytic hydrogen evolution capability upon the heterogeneous *** unique 2D/2D structure effectively mitigated the recombination of photogenerated carriers,enhancing the photocatalytic performance of the ***,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃under visible light irradiation at an intensity of 0.1 W/cm^(2),which is 1.84 times higher than that of *** irradiation of visible and near infrared light,the composite catalyst with photothermal ef-fect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of CdS *** study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.

关键词： Two-dimensional structure Heterostructure Photothermal effect Photocatalyst Hydrogen evolution

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Universal insertion of molecules in ionic compounds under pressure

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National Science Review 2024年第1期11卷 120-128页

作者： Feng Peng yanming ma Chris j.Pickard Hanyu Liu maosheng Miao College of Physics and Electronic Information Luoyang Normal University Department of Chemistry and Biochemistry California State University Northridge State Key Laboratory of Superhard materials & Key Laboratory of material Simulation Methods and Software of Ministry of Education College of Physics Jilin University International Center of Future Science Jilin University Department of materials Science & Metallurgy University of Cambridge Advanced Institute for materials Research Tohoku University Department of Earth Science University of California Santa Barbara

Using first-principles calculations and crystal structure search methods, we found that ma.y covalently bonded molecules such as H2, N2, CO2, NH3, H2O and CH4may react with NaC l, a prototype ionic solid,and form stable compounds under pressure while retaining their molecular structure. These molecules,despite whether they are homonuclear or heteronuclear, polar or non-polar, small or large, do not show strong chemical interactions with surrounding Na and Cl ions. In contrast, the most stable molecule among all examples, N2, is found to transform into cyclo-N5-anions while reacting with NaC l under high pressures. It provides a new route to synthesize pentazolates, which are promising green energy materials with high energy density. Our work demonstrates a unique and universal hybridization propensity of covalently bonded molecules and solid compounds under pressure. This surprising miscibility suggests possible mixing regions between the molecular and rock layers in the interiors of large planets.

关键词： molecule-solid hybrid materials high-pressure crystal structure prediction density functional theory planet interior

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