检索结果-南通市图书馆

Stability analysis and stabilization of semi-Markov jump linear systems with unavailable sojourn-time information

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第7期67卷 211-223页

作者： Xiaotai WU yang tang Shuai MAO Ying ZHAO School of Mathematics and Physics Anhui Polytechnic University Key Laboratory of Advanced Control and Optimization for Chemical Processes Ministry of EducationEast China University of Science and Technology

This study addresses the stability and stabilization problems of discrete-time semi-Markov jump linear systems(S-MJLSs) with unavailable sojourn-time information. The sojourn-time probability mass functions(S-TPMFs) of discrete-time semi-Markov chains are no longer confined to the geometric distribution, and it is difficult to obtain accurate and comprehensive information for S-TPMFs in practice. This is because S-TPMFs are usually deduced from the statistical characteristics according to the sampled-data, while adequate samples are often costly and time consuming. In this study, when the S-TPMFs for semi-Markov chains are assumed to be unavailable, the σ-error mean square stability is investigated for discrete-time S-MJLSs with some widely used assumptions; for semi-Markov chains, only the transition probability matrix of the embedded chain is used. In addition, the existence conditions of the effective controller are provided for closed-loop systems without using the information of S-TPMFs. Numerical examples are presented to illustrate the validity of the obtained theoretical results.

关键词： semi-Markov chain semi-Markov jump linear systems $\sigma$-error mean square stability unavailable sojourn-time information

Causal reasoning in typical computer vision tasks

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第1期67卷 105-120页

作者： ZHANG KeXuan SUN QiYu ZHAO ChaoQiang tang yang Key Laboratory of Advanced Control and Optimization for Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China National Key Laboratory of Air based Information Perception and Fusion Luoyang 471000China Luoyang Institute of Electro Optical Equipment of Avic Luoyang 471000China

Deep learning has revolutionized the field of artificial *** on the statistical correlations uncovered by deep learning-based methods,computer vision tasks,such as autonomous driving and robotics,are growing *** being the basis of deep learning,such correlation strongly depends on the distribution of the original data and is susceptible to uncontrolled *** the guidance of prior knowledge,statistical correlations alone cannot correctly reflect the essential causal relations and may even introduce spurious *** a result,researchers are now trying to enhance deep learningbased methods with causal *** theory can model the intrinsic causal structure unaffected by data bias and effectively avoids spurious *** paper aims to comprehensively review the existing causal methods in typical vision and visionlanguage tasks such as semantic segmentation,object detection,and image *** advantages of causality and the approaches for building causal paradigms will be *** roadmaps are also proposed,including facilitating the development of causal theory and its application in other complex scenarios and systems.

关键词： causal reasoning computer vision tasks vision-language tasks semantic segmentation object detection

Computer vision tasks for intelligent aerospace perception: An overview

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第9期67卷 2727-2748页

作者： CHEN HuiLin SUN QiYu LI FangFei tang yang School of Information Science and Engineering East China University of Science and TechnologyShanghai 200237China School of Mathematics East China University of Science and TechnologyShanghai 200237China

Computer vision tasks are crucial for aerospace missions as they help spacecraft to understand and interpret the space environment,such as estimating position and orientation, reconstructing 3D models, and recognizing objects, which have been extensively studied to successfully carry out the missions. However, traditional methods like Kalman filtering, structure from motion, and multi-view stereo are not robust enough to handle harsh conditions, leading to unreliable results. In recent years, deep learning(DL)-based perception technologies have shown great potential and outperformed traditional methods, especially in terms of their robustness to changing environments. To further advance DL-based aerospace perception, various frameworks, datasets,and strategies have been proposed, indicating significant potential for future applications. In this survey, we aim to explore the promising techniques used in perception tasks and emphasize the importance of DL-based aerospace perception. We begin by providing an overview of aerospace perception, including classical space programs developed in recent years, commonly used sensors, and traditional perception methods. Subsequently, we delve into three fundamental perception tasks in aerospace missions: pose estimation, 3D reconstruction, and recognition, as they are basic and crucial for subsequent decision-making and control. Finally, we discuss the limitations and possibilities in current research and provide an outlook on future developments,including the challenges of working with limited datasets, the need for improved algorithms, and the potential benefits of multisource information fusion.

关键词： deep learning perception aerospace missions pose estimation 3D reconstruction recognition

Visual Semantic Segmentation Based on Few/Zero-Shot Learning:An Overview

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1106-1126页

作者： Wenqi Ren yang tang Qiyu Sun Chaoqiang Zhao Qing-Long Han Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China National Key Laboratory of Air-Based Information Perception and Fusion Aviation Industry Corporation of ChinaLuoyang 471000China School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia

Visual semantic segmentation aims at separating a visual sample into diverse blocks with specific semantic attributes and identifying the category for each block,and it plays a crucial role in environmental *** learning-based visual semantic segmentation approaches count heavily on largescale training data with dense annotations and consistently fail to estimate accurate semantic labels for unseen *** obstruction spurs a craze for studying visual semantic segmentation with the assistance of few/zero-shot *** emergence and rapid progress of few/zero-shot visual semantic segmentation make it possible to learn unseen categories from a few labeled or even zero-labeled samples,which advances the extension to practical ***,this paper focuses on the recently published few/zero-shot visual semantic segmentation methods varying from 2D to 3D space and explores the commonalities and discrepancies of technical settlements under different segmentation ***,the preliminaries on few/zeroshot visual semantic segmentation,including the problem definitions,typical datasets,and technical remedies,are briefly reviewed and ***,three typical instantiations are involved to uncover the interactions of few/zero-shot learning with visual semantic segmentation,including image semantic segmentation,video object segmentation,and 3D ***,the future challenges of few/zero-shot visual semantic segmentation are discussed.

关键词： Visual segmentation separating

Artificial intelligence-assisted design of new chemical materials: a perspective

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第8期67卷 334-336页

作者： Feng QIAN Wenli DU Weimin ZHONG yang tang Jingyi LU Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and Technology

New chemical materials are a fresh category of substances created through chemical reactions or by refining existing materials through secondary processes. By using creative methods, advanced technologies, innovative techniques, and state-of-the-art equipment, these materials(e.g., high-end polyolefin, nano materials) [1] are carefully designed and developed to showcase outstanding performance and unique capabilities beyond what traditional chemical materials can offer [2].

关键词：

同方期刊数据库

Experimental study on the sandstone abrasiveness via mineral composition and microstructure analysis

在线全文

学校读者我要写书评

暂无评论

PETROLEUM 2024年第3期10卷 440-445页

作者： Shi, Xiangchao tang, yang Chen, Shuai Gao, Leiyu Wang, Yuming Southwest Petr Univ State Key Lab Oil & Gas Reservoir Geol & Exploitat Chengdu 610500 Peoples R China

Rock abrasiveness is an important factor affecting the tool's lifetime and efficiency in breaking a rock. Characterizing rock abrasiveness helps in the design, optimization, and mean-life prediction of tools. Xray diffraction, cast thin section analysis, and CERCHAR abrasiveness tests were performed on 18 different sandstones to characterize rock abrasiveness and explore new methods for characterization. The relationship between the mineral composition and microstructure of sandstone and abrasiveness was investigated. The results show that different structural maturities have varying effects on abrasiveness. In addition, the higher the structural maturity, the more the abrasiveness. Furthermore, in sandstones of the same structural maturity, the abrasiveness increases with equivalent quartz content (EQC). The texture coefficient (TC) and CERCHAR abrasiveness index (CAI) of sandstones with the same structural maturity showed a good linear relationship. Moreover, the correlation coefficients considering the combined parameters are above 0.85. Therefore, obtaining the microstructure and mineral composition of sandstone can effectively characterize rock abrasiveness. It also provides a new method for predicting the abrasiveness of the rock in the well. (c) 2023 Southwest Petroleum University. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http:// ***/licenses/by-nc-nd/4.0/).

关键词： Abrasiveness Microstructure Mineral compositions Structural maturity Equivalent quartz content Sandstone CERCHAR ABRASIVITY INDEX GEOMECHANICAL PROPERTIES ROCK STRENGTH CAI DRILLABILITY PREDICTION TEXTURE DRILL WEAR

Mice with type I interferon signaling deficiency are prone to epilepsy upon HSV-1 infection

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Virologica Sinica 2024年第2期39卷 251-263页

作者： Wei yang Chong-yang tang Dong-Ying Fan Yi-Song Wang Pei-Gang Wang Jing An Guo-Ming Luan Beijing Key Laboratory of Epilepsy Sanbo Brain HospitalCapital Medical UniversityBeijing100093China Beijing Institute for Brain Disorders Capital Medical UniversityBeijing100093China Department of Neurosurgery Epilepsy CenterSanbo Brain HospitalCapital Medical UniversityBeijing100093China Department of Microbiology School of Basic Medical SciencesCapital Medical UniversityBeijing100069China Chinese Institute for Brain Research Beijing102206China

Viral encephalitis continues to be a significant public health *** our previous study,we discovered a lower expression of antiviral factors,such as IFN-β,STING and IFI16,in the brain tissues of patients with Rasmussen's encephalitis(RE),a rare chronic neurological disorder often occurred in children,characterized by unihemispheric brain ***,a higher cumulative viral score of human herpes viruses(HHVs)was also found to have a significant positive correlation with the unihemispheric atrophy in *** I IFNs(IFN-I)signaling is essential for innate anti-infection response by binding to IFN-α/βreceptor(IFNAR).In this study,we infected WT mice and IFNAR-deficient A6 mice with herpes simplex virus 1(HSV-1)via periocular injection to investigate the relationship between IFN-I signaling and HHVs-induced brain *** all mice exhibited typical viral encephalitis lesions in their brains,HSV-induced epilepsy was only observed in A6 *** gene expression matrix,functional enrichment analysis and protein-protein interaction network revealed four gene models that were positively related with HSV-induced ***,ten key genes with the highest scores were *** together,these findings indicate that intact IFN-I signaling can effectively limit HHVs induced neural symptoms and brain lesions,thereby confirming the positive correlation between IFN-I signaling repression and brain atrophy in RE and other HHVs encephalitis.

关键词： IFN-I signaling Human herpes viruses(HHVs) Rasmussen's encephalitis(RE)

Microstructure Evolution and Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 855-871页

作者： Peng Chen Wenhao Chen Jiaxin Chen Zhiyu Chen yang tang Ge Liu Bensheng Huang Zhiqing Zhang School of New Energy and Materials Southwest Petroleum UniversityChengdu 610500China Sichuan Provincial Engineering Research Center of Advanced Materials Manufacturing Technology for Shale Gas High-Efficient Exploitation Southwest Petroleum UniversityChengdu 610500China College of Materials Science and Engineering Chongqing UniversityChongqing 400045China School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China School of Robot Engineering Yangtze Normal UniversityChongqing 408100China

The investigation concentrates on friction stir welded(FSW)Al-Cu-Li alloy concerning its local microstructural evolution and mechanical *** grain features were characterized by electron back scattered diffraction(EBSD)technology,while precipitate characterization was conducted by using transmission electron microscopy(TEM)aligned along[011]Al and[001]Al zone *** mechanical properties are evaluated through micro-hardness and tensile *** can be found that nugget zones exhibit finely equiaxed grains evolved through complete dynamic recrystallization(DRX),primarily occurring in continuous dynamic recrystallization(CDRX)and discontinuous dynamic recrystallization(DDRX).In the thermal-mechanically affected zone(TMAZ),numerous sub-structured grains,exhibiting an elongated morphology,were created due to partial DRX,signifying the dominance of CDRX,DDRX,and geometric dynamic recrystallization(GDRX)in this region.T_(1)completely dissolves in the nugget zone(NZ)leading to the formation of Guinier-Preston zones and increase ofδ′,β′and S′.Conversely,T_(1)partially solubilizes in TMAZ,the lowest hardness zone(LHZ)and heat affected zone(HAZ),and the residual T_(1)undergoes marked coarsening,revealing various T_(1)*** solubilization and coarsening of T_(1)are primary contributors to the degradation of hardness and strength.θ′primarily dissolves and coarsens in NZ and TMAZ,whilst this precipitate largely coarsens in HAZ and LHZ.σ,TB,grain boundary phases(GBPs)and precipitate-free zone(PFZ)are newly generated during FSW.σexists in the TMAZ,LHZ and HAZ,whereas TB nucleates in *** and PFZ mostly develop in LHZ and HAZ,which can cause strain localization during tensile deformation,potentially leading to LHZ joint fracture.

关键词： Al-Cu-Li alloy Friction stir welding Microstructure evolution Mechanical properties

Nano-Ni-Induced Electronic Modulation of MoS_(2) Nanosheets Enables Energy-Saving H_(2) Production and Sulfide Degradation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第3期7卷 228-235页

作者： Fan Liu Xinghong Cai yang tang Wenqian Liu Qianwei Chen Peixin Dong Maowen Xu yangyang Tan Shujuan Bao Institute for Clean Energy&Advanced Materials School of Materials and EnergySouthwest UniversityChongqing 400715China

Electrocatalytic hydrogen evolution and sulfion(S^(2-))recycling are promising strategies for boosting H_(2)production and removing environmental ***,a nano-Ni-functionalized molybdenum disulfide(MoS_(2))nanosheet was assembled on steel mesh(Ni-MoS_(2)/SM)for use in sulfide oxidation reaction-assisted,energy-saving H_(2)*** and theoretical calculation results revealed that anchoring nano-Ni on high-surface-area slack MoS_(2)nanosheets not only optimized catalyst adsorption of polysulfides but also played an important role in promoting hydrogen evolution reaction kinetics by absorbing OH_(ad),thereby greatly enhancing the catalytic performance toward sulfide oxidation reaction and hydrogen evolution ***,the Ni/MoS^(2-)based hydrogen evolution reaction+sulfide oxidation reaction system achieved nearly 100%hydrogen production efficiency and only consumed 61%less power per kWh than the oxygen evolution reaction+hydrogen evolution reaction system,which suggested our proposed Ni-MoS_(2)and novel hydrogen production system are promising for sustainable energy production.

关键词： hydrogen evolution reaction low energy consumption molybdenum disulfide sulfide oxidation reaction