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2-local unstable homotopy groups of indecomposable A^(2)_(3)-complexes

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Science China mathematics 2024年第3期67卷 607-626页

作者： Zhongjian Zhu Jianzhong Pan College of mathematics and Physics Wenzhou UniversityWenzhou 325035China Hua Loo-Keng Key Laboratory of mathematics Institute of MathematicsAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China school of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

In this paper,we calculate the 2-local unstable homotopy groups of indecomposable A^(2)_(3)-*** main technique used is analysing the homotopy property of J(A,X),defined by Gray(1973) for a CW-pair(X,A),which is homoto... 详细信息

关键词： homotopy groups A^(2)_(n)-complexes fibration sequence relative James construction

The Exchange Attack and the Mixture Differential Attack Revisited: From the Perspective of Automatic Evaluation

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Chinese Journal of Electronics 2024年第1期33卷 19-29页

作者： Kexin QIAO Zhiyu ZHANG Zhongfeng NIU Liehuang ZHU school of Cyberspace Science and Technology Beijing Institute of Technology State Key Laboratory of Cryptology institute of Information Engineering Chinese Academy of Sciences school of Cryptography University of Chinese Academy of Sciences

Recent results show that the differential properties within quadruples boom as a new inspiration in cryptanalysis of Advanced Encryption Standard(AES)-like constructions. These methods include the exchange attack proposed in Asiacrypt’19, the mixture differential attack proposed in To SC’18, etc., where the essential properties are obtained by manually scrutinizing the structures of the AES-like constructions. This paper presents a novel framework and an automatic tool based on mixed integer linear programming to search for mixture differential distinguishers for general constructions. This framework considers what equality patterns among quadruples can make a distinguisher and traces how the patterns propagate through cipher components with accurate probability *** this tool, a 5-round AES distinguishing attack with lower complexity and more 6-round distinguishing attacks in the chosen plaintext scenarios are deduced. We prove that no exchange-type or mixture differential distinguisher exists for 7 and above rounds AES if the details of the Sbox and Mix Columns matrix are not taken into account.

关键词： Ciphers Estimation Encryption Mixed integer linear programming Complexity theory Standards

Explainable-AI-based two-stage solution for WSN object localization using zero-touch mobile transceivers

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Science China(Information Sciences) 2024年第7期67卷 27-45页

作者： Kai FANG Junxin CHEN Han ZHU Thippa Reddy GADEKALLU Xiaoping WU Wei WANG school of mathematics and Computer Science Zhejiang A&F University school of Software Dalian University of Technology Faculty of Applied Sciences Macao Polytechnic University Department of Electrical and Computer Engineering Lebanese American University school of Information Engineering Huzhou University Guangdong-Hong Kong-Macao Joint Laboratory for Emotional Intelligence and Pervasive Computing Artificial Intelligence Research Institute Shenzhen MSU-BIT University

Artificial intelligence technology is widely used in the field of wireless sensor networks(WSN).Due to its inexplicability, the interference factors in the process of WSN object localization cannot be effectively eliminated. In this paper, an explainable-AI-based two-stage solution is proposed for WSN object localization. In this solution, mobile transceivers are used to enlarge the positioning range and eliminate the blind area for object localization. The motion parameters of transceivers are considered to be unavailable,and the localization problem is highly nonlinear with respect to the unknown parameters. To address this,an explainable AI model is proposed to solve the localization problem. Since the relationship among the variables is difficult to fully include in the first-stage traditional model, we develop a two-stage explainable AI solution for this localization problem. The two-stage solution is actually a comprehensive consideration of the relationship between variables. The solution can continue to use the constraints unused in the firststage during the second-stage, thereby improving the performance of the solution. Therefore, the two-stage solution has stronger robustness compared to the closed-form solution. Experimental results show that the performance of both the two-stage solution and the traditional solution will be affected by numerical changes in unknown parameters. However, the two-stage solution performs better than the traditional solution, especially with a small number of mobile transceivers and sensors or in the presence of high noise. Furthermore,we have also verified the feasibility of the proposed explainable-AI-based two-stage solution.

关键词： explainable AI object localization semidefinite relaxation mobile transceiver two-stage solution closed-form solution

Galerkin-based quasi-smooth manifold element(QSME)method for anisotropic heat conduction problems in composites with complex geometry

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Applied mathematics and Mechanics(English Edition) 2024年第1期45卷 137-154页

作者： Pan WANG Xiangcheng HAN Weibin WEN Baolin WANG Jun LIANG school of Civil Engineering Central South UniversityChangsha 410083China institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China school of Science Harbin Institute of TechnologyShenzhen 518055Guangdong ProvinceChina

The accurate and efficient analysis of anisotropic heat conduction problems in complex composites is crucial for structural design and performance evaluation. Traditional numerical methods, such as the finite element method(FEM), often face a trade-off between calculation accuracy and efficiency. In this paper, we propose a quasi-smooth manifold element(QSME) method to address this challenge, and provide the accurate and efficient analysis of two-dimensional(2D) anisotropic heat conduction problems in composites with complex geometry. The QSME approach achieves high calculation precision by a high-order local approximation that ensures the first-order derivative *** results demonstrate that the QSME method is robust and stable, offering both high accuracy and efficiency in the heat conduction analysis. With the same degrees of freedom(DOFs), the QSME method can achieve at least an order of magnitude higher calculation accuracy than the traditional FEM. Additionally, under the same level of calculation error, the QSME method requires 10 times fewer DOFs than the traditional FEM. The versatility of the proposed QSME method extends beyond anisotropic heat conduction problems in complex composites. The proposed QSME method can also be applied to other problems, including fluid flows, mechanical analyses, and other multi-field coupled problems, providing accurate and efficient numerical simulations.

关键词： anisotropic heat conduction quasi-smooth manifold element(QSME) composite with complex geometry numerical simulation finite element method(FEM)

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Performance of the Multilayer Film for Infrared Stealth based on VO_(2) Thermochromism

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Journal of Thermal Science 2024年第4期33卷 1312-1324页

作者： LI Yaru WANG Fuqiang ZHANG Aoyu FU Zhichang SU Ronghua GAO Tengfei WANG Zhen GUO Jicheng ORDOS institute of Technology Ordos017000China school of Energy Science and Engineering Harbin Institute of TechnologyHarbin150001China school of New Energy Harbin Institute of Technology at WeihaiWeihai264209China Defense Engineering institute AMSPLABeijing100850China

With the development of detection and identification technology,infrared stealth is of great value to realize anti-reconnaissance detection of military *** present,infrared stealth materials generally have deficiency,such as complex structure,inconvenient radiation regulation and cumbersome preparation steps,which greatly limit the practical application of infrared stealth *** view of the above deficiency of infrared stealth materials,we proposed a kind of multilayer film for infrared stealth using VO2thermochromism based on the temperature response mechanism of tuna to adjust its color,and through the intelligent reversible radiation regulation mechanism to meet the infrared stealth requirements of tanks in different actual *** results show that when the temperature increases from 300 K to 373 K,the peak emissivity of the film decreases from 94%to 20%in the 8-14μm band after structural optimization,which can realize the infrared stealth of the high temperature target in the 8-14μm *** average emissivity of the multilayer film for infrared stealth at3-5μm and 8-14μm band can be reduced to 34%and 27%at 373 K,and the peak emissivity at 5-8μm band can reach 65%,realizing dual-band infrared stealth in the 3-5μm and 8-14μm bands and heat dissipation in the 5-8μm *** multilayer film for infrared stealth based on VO2thermochromism designed by the authors can meet the characteristics of simple film structure,convenient radiation regulation and simple preparation.

关键词： vanadium dioxide multilayer film infrared stealth thermal management

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Hierarchically Distributed Optimization with a Flexible and Complexity-Reducing Algorithm

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Journal of Systems Science & Complexity 2024年

作者： LIANG Shu ZHANG Lei WEI Yiheng LIU Yemo Department of Control Science and Engineering Tongji University Shanghai Research institute for Intelligent Autonomous Systems school of mathematics Southeast University Beijing Aerospace Automatic Control institute

In this paper, the authors consider distributed convex optimization over hierarchical networks. The authors exploit the hierarchical architecture to design specialized distributed algorithms so that the complexity can be reduced compared with that of non-hierarchically distributed *** this end, the authors use local agents to process local functions in the same manner as other distributed algorithms that take advantage of multiple agents' computing resources. Moreover, the authors use pseudocenters to directly integrate lower-level agents' computation results in each iteration step and then share the outcomes through the higher-level network formed by pseudocenters. The authors prove that the complexity of the proposed algorithm exponentially decreases with respect to the total number of pseudocenters. To support the proposed decomposition-composition method for agents and pseudocenters, the authors develop a class of operators. These operators are generalizations of the widely-used subgradient based operator and the proximal operator and can be used in distributed convex optimization. Additionally, these operators are closed with respect to the addition and composition operations; thus, they are suitable to guide hierarchically distributed design and analysis. Furthermore,these operators make the algorithm flexible since agents with different local functions can adopt suitable operators to simplify their calculations. Finally, numerical examples also illustrate the effectiveness of the method.

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Impurity modes in two-dimensional strongly coupled complex plasma crystals

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Plasma Science and Technology 2024年第8期26卷 1-7页

作者：吴诗杰徐韵乔冼顺宇何向磊杨肖易 school of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001People’s Republic of China school of Physics Harbin Institute of TechnologyHarbin 150001People’s Republic of China school of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001People’s Republic of China

Complex plasma fluctuation processes have been extensively studied in many aspects,especially lattice waves in strongly coupled plasma crystals,which are of great significance for understanding fundamental physical phenomena.A challenge of experimental investigations in two-dimensional strongly coupled complex plasma crystals is to keep the main body and foreign particles of different masses on the same horizontal *** solve the problem,we have proposed a potential well formed by two negatively biased grids to bind the negatively charged particles in a two-dimensional(2D)plane,thus achieving a 2D plasma crystal in the microgravity *** study of such phenomena in complex plasma crystals under microgravity environment then becomes *** this paper,we focus on the continuum spectrum,including both phonon and optic branches of the impurity mode in a 2D system in microgravity *** results show the dispersion relation of the longitudinal and transverse impurity oscillation modes and their *** the macroscopic visibility of complex mesoscopic particle lattices,theoretical and experimental studies on this kind of complex plasma systems will help us further understand the physical nature of a wide range of condensed matters.

关键词： microgravity environment complex plasma lattice dispersion relation

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A novel fracture-cavity reservoir outcrop geological knowledge base construction method considering parameter collection and processing, mutual transformation of data-knowledge, application and update

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Petroleum Science 2024年第4期21卷 2184-2202页

作者： Qi-Qiang Ren Jin-Liang Gao Peng Zhu Meng-Ping Li Jian-Wei Feng Qiang Jin San Zhang institute of Sedimentary Geology Chengdu University of Technology PetroChina Research institute of Petroleum Exploration and Development school of Energy Chengdu University of Technology school of Resources and Geosciences China University of Mining and Technology school of Geosciences China University of Petroleum (East China) school of Geosciences Yangtze University

This study endeavors to formulate a comprehensive methodology for establishing a Geological Knowledge Base(GKB) tailored to fracture-cavity reservoir outcrops within the North Tarim Basin. The acquisition of quantitative geological parameters was accomplished through diverse means such as outcrop observations, thin section studies, unmanned aerial vehicle scanning, and high-resolution cameras. Subsequently, a three-dimensional digital outcrop model was generated, and the parameters were standardized. An assessment of traditional geological knowledge was conducted to delineate the knowledge framework, content, and system of the GKB. The basic parameter knowledge was extracted using multiscale fine characterization techniques, including core statistics, field observations, and microscopic thin section analysis. Key mechanism knowledge was identified by integrating trace elements from filling, isotope geochemical tests, and water-rock simulation experiments. Significant representational knowledge was then extracted by employing various methods such as multiple linear regression, neural network technology, and discriminant classification. Subsequently, an analogy study was performed on the karst fracture-cavity system(KFCS) in both outcrop and underground reservoir settings. The results underscored several key findings:(1) Utilization of a diverse range of techniques,including outcrop observations, core statistics, unmanned aerial vehicle scanning, high-resolution cameras, thin section analysis, and electron scanning imaging, enabled the acquisition and standardization of data. This facilitated effective management and integration of geological parameter data from multiple sources and scales.(2) The GKB for fracture-cavity reservoir outcrops, encompassing basic parameter knowledge, key mechanism knowledge, and significant representational knowledge, provides robust data support and systematic geological insights for the intricate and in-depth examination of the genetic

关键词： Geological knowledge base Karst fracture-cavity system Mutual transformation of data-knowledge Knowledge base content and application Tarim basin

TGAIN: Geospatial Data Recovery Algorithm Based on GAIN-LSTM

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Computers, Materials and Continua 2024年第1期81卷 1471-1489页

作者： Yang L. Li L. Ma S. school of Soft Engineering Jinling Institute of Technology Nanjing 211169 China school of Computer Jinling Institute of Technology Nanjing 211169 China school of Network Security Jinling Institute of Technology Nanjing 211169 China

Accurate geospatial data are essential for geographic information systems (GIS), environmental monitoring, and urban planning. The deep integration of the open Internet and geographic information technology has led to increasing challenges in the integrity and security of spatial data. In this paper, we consider abnormal spatial data as missing data and focus on abnormal spatial data recovery. Existing geospatial data recovery methods require complete datasets for training, resulting in time-consuming data recovery and lack of generalization. To address these issues, we propose a GAIN-LSTM-based geospatial data recovery method (TGAIN), which consists of two main works: (1) it uses a long-short-term recurrent neural network (LSTM) as a generator to analyze geospatial temporal data and capture its temporal correlation; (2) it constructs a complete TGAIN network using a cue-masked fusion matrix mechanism to obtain data that matches the original distribution of the input data. The experimental results on two publicly accessible datasets demonstrate that our proposed TGAIN approach surpasses four contemporary and traditional models in terms of mean absolute error (MAE), root mean square error (RMSE), mean square error (MSE), mean absolute percentage error (MAPE), coefficient of determination (R2) and average computational time across various data missing rates. Concurrently, TGAIN exhibits superior accuracy and robustness in data recovery compared to existing models, especially when dealing with a high rate of missing data. Our model is of great significance in improving the integrity of geospatial data and provides data support for practical applications such as urban traffic optimization prediction and personal mobility analysis. © 2024 The Authors. Published by Tech Science Press.

关键词： data recovery generative adversarial networks Geospatial data temporal correlation