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Multi-Dimensional QoS Evaluation and Optimization of Mobile Edge Computing for IoT:A Survey

Chinese Journal of Electronics 2024年第4期33卷 859-874页

作者： Jiwei HUANG Fangzheng LIU Jianbing ZHANG Beijing Key Laboratory of Petroleum data Mining China University of Petroleum Department of Computer science and technology China University of Petroleum

With the evolvement of the Internet of things(IoT), mobile edge computing(MEC) has emerged as a promising computing paradigm to support IoT data analysis and processing. In MEC for IoT, the differentiated requirements on quality of service(QoS) have been growing rapidly, making QoS a multi-dimensional concept including several attributes, such as performance, dependability, energy efficiency, and economic factors. To guarantee the QoS of IoT applications, theories and techniques of multi-dimensional QoS evaluation and optimization have become important theoretical foundations and supporting technologies for the research and application of MEC for IoT,which have attracted significant attention from both academia and industry. This paper aims to survey the existing studies on multi-dimensional QoS evaluation and optimization of MEC for IoT, and provide insights and guidance for future research in this field. This paper summarizes the multi-dimensional and multi-attribute QoS metrics in Io T scenarios, and then several QoS evaluation methods are presented. For QoS optimization, the main research problems in this field are summarized, and optimization models as well as their corresponding solutions are elaborated. We take notice of the booming of edge intelligence in artificial intelligence-empowered Io T scenarios, and illustrate the new research topics and the state-of-the-art approaches related to QoS evaluation and optimization. We discuss the challenges and future research directions.

关键词： Internet of things Mobile edge computing Quality of service Quality of service evaluation Quality of service optimization PERFORMANCE EVALUATION RESOURCE-ALLOCATION SERVICE MIGRATION DELAY CLOUD DEPENDABILITY MECHANISM INTERNET SYSTEM THINGS

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AP assembled on ultrafine aluminum particle and its application to NEPE propellant

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Defence technology（防务技术） 2024年第6期36卷 20-29页

作者： Huixin Wang Qiang Li Hui Ren Liangjun Xie Tingting Liu Zhihong Chen State Key Laboratory of Explosion science and technology Beijing Institute of TechnologyBeijing 100081China Inner Mongolia institute of Synthetic Chemicals Hohhot 010010China

Coating modification is an important way to enhance the reactivity of aluminum *** this paper,ammonium perchlorate and aluminum powder were assembled into energetic microunits by liquid deposition *** particles with AP as shell and ultrafine aluminum powder as the core(Al@AP)were *** micromorphology results show that the coated particles are about 5μm,and the coating layer is evenly distributed on the outer surface of aluminum powder,indicating a complete *** energetic microunits were implanted into the nitrate ester plasticizing adhesive system(NEPE)as solid phase *** effect of filler on the rheological properties,safety,mechanical properties,thermal reaction and energy properties of the system was analyzed by comparing with the raw aluminum *** test results show that the rheological properties,mechanical properties and pressure index of NEPE containing system Al@AP meets the requirements of solid propellant *** with Al based propellant,the mechanical sensitivity and thermal sensitivity are decreased,the safety is better,and the explosion heat of the propellant is increased by 7.8%.The engine test shows that the specific impulse is increased by 1.2 ***@AP can improve the energy output and safety of NEPE propellant,and has potential application prospects in high-energy propellants.

关键词： Aluminum powder Coating NEPE propellant Energy output Applied research

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ZrB_(2)-SiC ceramics toughened with oriented paper-derived graphite for a sustainable approach

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Journal of Advanced Ceramics 2024年第2期13卷 207-219页

作者： Luca Zoli Francesca Servadei Simone Failla Matteo Mor Antonio Vinci Pietro Galizia Diletta Sciti CNR-ISSMC Institute of ScienceTechnology and Sustainability for CeramicsFaenza I-48018Italy

Carbon fibre-reinforced ultra-high temperature ceramics(UHTCs)are considered a class of promising materials for several applications,the most appealing ones being in the aerospace *** is necessary to overcome the brittleness and low thermal shock resistance of ceramics and is often provided through the addition of carbon fibres or other carbon-based phases,such as nanotubes,graphene,and *** present work is focused on the toughening of UHTCs through incorporation of 30-50 vol% thin,ordered graphite layers from conventional filter paper followed by hot pressing *** filter paper was selected because it undergoes thermolysis with no melting stage forming a strong carbonaceous residue that can be used as *** and mechanical properties of toughened composites were compared to those of other materials reinforced with short carbon fibres and the effect of different distribution of graphite was *** of graphite allowed toughness to be increased from 3−4 MPa·m^(1/2)(for unreinforced materials)to 5.1−5.5 MPa·m^(1/2),similar to results obtained with short fibre *** high-temperature properties,such as strength and toughness as well as oxidation resistance at 1500℃,were also examined.

关键词： borides paper-derived graphite microstructure toughness sustainability

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Facial Expression Recognition with High Response-Based Local Directional Pattern (HR-LDP) Network

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Computers, Materials & Continua 2024年第2期78卷 2067-2086页

作者： Sherly Alphonse Harshit Verma School of Computer science and Engineering Vellore Institute of TechnologyChennaiIndia

Although lots of research has been done in recognizing facial expressions,there is still a need to increase the accuracy of facial expression recognition,particularly under uncontrolled *** use of Local Directional Patterns(LDP),which has good characteristics for emotion detection has yielded encouraging *** innova-tive end-to-end learnable High Response-based Local Directional Pattern(HR-LDP)network for facial emotion recognition is implemented by employing fixed convolutional filters in the proposed *** combining learnable convolutional layers with fixed-parameter HR-LDP layers made up of eight Kirsch filters and derivable simulated gate functions,this network considerably minimizes the number of network *** cost of the parameters in our fully linked layers is up to 64 times lesser than those in currently used deep learning-based detection *** seven well-known databases,including JAFFE,CK+,MMI,SFEW,OULU-CASIA and MUG,the recognition rates for seven-class facial expression recognition are 99.36%,99.2%,97.8%,60.4%,91.1%and 90.1%,*** results demonstrate the advantage of the proposed work over cutting-edge techniques.

关键词： Emotion classification CNN network HR-LDP

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A deep learning model enabled multi-event recognition for distributed optical fiber sensing

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science China(Information sciences) 2024年第3期67卷 291-307页

作者： Yujiao LI Xiaomin CAO Wenhao NI Kuanglu YU institute of Information science School of Computer and Information TechnologyBeijing Jiaotong University Beijing Key Laboratory of Advanced Information science and Network technology Beijing Jiaotong University

Fiber optic sensors that utilize backscattered light offer distributed real-time measurements and have been seen tremendous improvements in sensing distance and spatial resolution over the last ***, these improvements in sensor capabilities lead to a significant increase in the amount of data that needs to be processed. Traditional processing schemes are no longer adequate, so the development of novel signal processing methods is critical. Phase-sensitive optical time domain reflectometry(Φ-OTDR) is now applied in various applications for multi-event recognition, and it would usually be difficult, sometimes even unrealistic to label all the acquired samples due to its real-time and seamless monitoring nature. To fully take advantage of the information contained within the large number of unlabeled samples, which were formerly not utilized and hence wasted, we propose a semi-supervised model to boost the event classification performance of Φ-OTDR. The model extracts respectively the temporal features and the spatial bidirectional features together with a dual attention mechanism. Its classification accuracy has been improved up to 96.9%with only 1230 labeled samples. In addition, our model shows significant advantages when the number of labeled samples is reduced. Importantly, our method improves the accuracy of multi-event classification without any modification to the optical setup.

关键词： $\Phi$-OTDR event recognition semi-supervised learning mean teacher MT-ACNN-SA-BiLSTM

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Joint Sample Position Based Noise Filtering and Mean Shift Clustering for Imbalanced Classification Learning

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Tsinghua science and technology 2024年第1期29卷 216-231页

作者： Lilong Duan Wei Xue Jun Huang Xiao Zheng School of Computer science and technology Anhui University of TechnologyMaanshan 243032China institute of Artificial Intelligence Hefei Comprehensive National Science CenterHefei 230088China

The problem of imbalanced data classification learning has received much *** classification algorithms are susceptible to data skew to favor majority samples and ignore minority *** weighted minority oversampling technique(MWMOTE)is an effective approach to solve this problem,however,it may suffer from the shortcomings of inadequate noise filtering and synthesizing the same samples as the original minority *** this end,we propose an improved MWMOTE method named joint sample position based noise filtering and mean shift clustering(SPMSC)to solve these ***,in order to effectively eliminate the effect of noisy samples,SPMsC uses a new noise filtering mechanism to determine whether a minority sample is noisy or not based on its position and distribution relative to the majority *** that MWMOTE may generate duplicate samples,we then employ the mean shift algorithm to cluster minority samples to reduce synthetic replicate ***,data cleaning is performed on the processed data to further eliminate class *** on extensive benchmark datasets demonstrate the effectiveness of SPMsC compared with other sampling methods.

关键词： imbalanced data classification oversampling noise filtering clustering

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Effects of projectile parameters on the momentum transfer and projectile melting during hypervelocity impact

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Defence technology（防务技术） 2024年第2期32卷 89-103页

作者： Wenjin Liu Qingming Zhang Renrong Long Zizheng Gong Ren Jiankang Xin Hu Siyuan Ren Qiang Wu Guangming Song State Key Laboratory of Explosion science and technology Beijing Institute of TechnologyBeijing100081China Beijing institute of Spacecraft Environment Engineering China Academy of Space TechnologyBeijing100094China

The effects of projectile/target impedance matching and projectile shape on energy,momentum transfer and projectile melting during collisions are investigated by numerical *** comparing the computation results with the experimental results,the correctness of the calculation and the statistical method of momentum transfer coefficient is *** shapes of aluminum,copper and heavy tungsten alloy projectiles striking aluminum,basalt,and pumice target for impacts up to 10 km/s are *** influence mechanism of the shape of the projectile and projectile/target density on the momentum transfer was *** an increase in projectile density and length-diameter ratio,the energy transfer time between the projectile and targets is *** projectile decelerates slowly,resulting in a larger cratering *** energy consumed by the projectile in the excavation stage increased,resulting in lower mass-velocity of ejecta and momentum transfer *** numerical simulation results demonstrated that for different projectile/target combinations,the higher the wave impedance of the projectile,the higher the initial phase transition velocity and the smaller the mass of phase *** results can provide theoretical guidance for kinetic impactor design and material selection.

关键词： Hypervelocity impact Energy partitioning Impact melting Momentum transfer

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From 0D to 3D:Hierarchical structured high-performance free-standing silicon anodes based on binder-induced topological network architecture

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Journal of Energy Chemistry 2024年第6期93卷 16-23,I0002页

作者： Yihong Tong Ruicheng Cao Guanghui Xu Yifeng Xia Hongyuan Xu Hong Jin Hui Xu Xi’an Jiaotong University Suzhou Academy Suzhou 215123JiangsuChina Nano science and technology institute University of Science and Technology of ChinaSuzhou 215123JiangsuChina

Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely ***,to resolve the appeal issues,a free-standing anode with a"corrugated paper"shape on micro-scale and a topological crosslinking network on the submicron and nano-scale is ***,an integrated three-dimensional electrode structure is constructed based on robust carbon nanotubes network with firmly anchored SiNPs via forming interlocking *** which,the hierarchical interlocking structure is achieved by directional induction of the binder,which ensures well integration during cycling so that significantly enhances mechanical stability as well as electronic and ionic conductivity of *** from it,this anode exhibits outsta nding performance under harsh service conditions including high Si loading,ultrahigh areal capacity(33.2 mA h cm^(-2)),and high/low temperatures(-15-60℃),which significantly extends its practical ***,the optimization mechanism of this electrode is explored to verify the crack-healing and structure-integration maintaining along cycling via a unique self-stabilization ***,from both the fundamental and engineering views,this strategy offers a promising path to produce high-performance free-standing electrodes for flexible device applications especially facing volume effect challenges.

关键词： Topological network Self-stabilization Flexibility Free-standing Silicon anode

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Advances in large viewing angle and achromatic 3D holography

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Light(science & Applications) 2024年第7期13卷 1224-1225页

作者： Jiaming Huang Yu Chen Guixin Li Department of Materials science and Engineering Southern University of Science and TechnologyShenzhen 518055China institute for Applied Optics and Precision Engineering Southern University of Science and TechnologyShenzhen 518055China

Optical holography is a promising technique to achieve a naked-eye 3D ***,the narrow viewing angle and chromatic aberration are the two key issues that usually limit the holographic display performance.A recent work proposes a novel way to circumvent these constraints by introducing a color liquid crystal grating into a timesequenced holography system.

关键词： angle chromatic holographic

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Synergy enhancement of Co single atoms and asymmetric subnanoclusters for Fenton-like activation

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Nano Research 2024年第9期17卷 7935-7944页

作者： Ming Ma Zhiyi Sun Ziwei Deng Xiang Li Fang Zhang Wenxing Chen School of Materials Key Laboratory of Cluster Science Ministry of EducationBeijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsAdvanced Technologies Research Institute(Jinan)Advanced Research Institute of Multidisciplinary ScienceSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China Energy and Catalysis Center School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Analysis and Testing Center Beijing Institute of TechnologyBeijing Institute of TechnologyBeijing 100081China

As a new water treatment technology,Fenton-like reaction has great *** this study,we successfully prepared an excellent Fenton-like catalyst,which is composed of cobalt monoatoms and asymmetric subnanoclusters(labeled CoSA/Clu-C_(2)N),and exhibits excellent peroxymonosulfate(PMS)activation *** directly comparing the catalytic properties of CoSA-C_(2)N and CoSA/Clu-C_(2)N,the synergistic effects of coasymmetric Co subclusters and Co atoms on the activation of PMS and degradation of organic micropollutants were *** results showed that CoSA/Clu-C_(2)N had higher degradation rates of carbamazepine(CBZ),antipyrine(AT)and chlorobenzoic acid(CA)when combined with active oxidant *** cyclic frequency of CBZ was 5.4 min^(-1),which was twice as high as the catalytic constant of CoSA-C_(2)N(2.4 min^(-1)).The results show that CoSA/Clu-C_(2)N cobalt subnanoclusters and cobalt single atom can synergistically improve the catalytic performance of activated PMS oxidation of micropollutants in *** addition,electron paramagnetic resonance(EPR)technology has proved that the introduction of Co subnano clusters in CoSA/Clu-C_(2)N is conducive to the production of singlet oxygen(1O2),thereby improving the efficiency of pollutant *** work lays a solid foundation for the future design of advanced multifunctional catalysts by carefully regulating and combining monmetallic atoms and metal subnanoclusters.

关键词： carbamazepine Fenton-like reaction Co single atoms asymmetrical sub-nanoclusters peroxymonosulfate synergy enhancement

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