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Examples of Boundary Layers Associated with the Incompressible Navier-Stokes Equations

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Chinese Annals of Mathematics,Series B 2010年第5期31卷 781-792页

作者： xiaoming wang Department of Mathematics Florida State University Tallahassee FL 32306 USA.

The author surveys a few examples of boundary layers for which the Prandtl boundary layer theory can be rigorously *** of them are associated with the incompressible Navier-Stokes equations for Newtonian fluids equipped with various Dirichlet boundary conditions(specified velocity).These examples include a family of(nonlinear 3D) plane parallel flows,a family of(nonlinear) parallel pipe flows,as well as flows with uniform injection and suction at the *** also identify a key ingredient in establishing the validity of the Prandtl type theory,i.e.,a spectral constraint on the approximate solution to the Navier-Stokes system constructed by combining the inviscid solution and the solution to the Prandtl type *** is an additional difficulty besides the wellknown issue related to the well-posedness of the Prandtl type *** seems that the main obstruction to the verification of the spectral constraint condition is the possible separation of boundary layers.A common theme of these examples is the inhibition of separation of boundary layers either via suppressing the velocity normal to the boundary or by injection and suction at the boundary so that the spectral constraint can be verified.A meta theorem is then presented which covers all the cases considered here.

关键词： Boundary layer Navier-Stokes system Prandtl theory Corrector Inviscid limit Spectral constraint Nonlinear plane parallel channel flow Nonlinear pipe flow Injection and suction

Access control scheme with tracing for outsourced databases

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Frontiers of Computer Science 2012年第6期6卷 677-685页

作者： xiaoming wang Guoxiang YAO Department of Computer Science Jinan UniversityGuangzhou 510632China

To manage dynamic access control and deter pi- rate attacks on outsourced databases, a dynamic access control scheme with tracing is proposed. In our scheme, we introduce the traitor tracing idea into outsource databases, and employ a polynomial function and filter function as the basic means of constructing encryption and decryption procedures to reduce computation, communication, and storage overheads. Compared to previous access control schemes for outsourced databases, our scheme can not only protect sensitive data from leaking and perform scalable encryption at the server side without shipping the outsourced data back to the data owner when group membership is changed, but also provide trace-and-revoke features. When malicious users clone and sell their decryption keys for profit, our scheme can trace the decryption keys to the malicious users and revoke them. Furthermore, our scheme avoids massive message exchanges for establishing the decryption key between the data owner and the user. Compared to previously proposed publickey traitor tracing schemes, our scheme can simultaneously achieve full collusion resistance, full recoverability, full revocation, and black-box traceability. The proof of security and analysis of performance show that our scheme is secure and efficient.

关键词： outsourced databases access control malicious user tracing adding and revoking users

SEOT: Secure dynamic searchable encryption with outsourced ownership transfer

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Frontiers of Computer Science 2023年第5期17卷 165-177页

作者： Jianwei LI xiaoming wang Qingqing GAN Department of Information Science and Technology Jinan UniversityGuangzhou 510632China Department of Cyber Security Guangdong University of Foreign StudiesGuangzhou 510006China

When one enterprise acquires another,the electronic data of the acquired enterprise will be transferred to the acquiring *** particular,if the data system of acquired enterprise contains a searchable encryption mechanism,the corresponding searchability will also be *** this paper,we introduce the concept of Searchable Encryption with Ownership Transfer(SEOT),and propose a secure SEOT *** on the new structure of polling pool,our proposed searchable encryption scheme not only achieves efficient transfer of outsourced data,but also implements secure transfer of data ***,we optimize the storage cost for user to a desirable *** prove our scheme can achieve the secure characteristics,then carry out the performance evaluation and *** results demonstrate that our scheme is superior in efficiency and practicability.

关键词： cloud computing ownership transfer searchable encryption forward secure outsourced computation

Al/Hf ratio-dependent mechanisms of microstructure and mechanical property of nearly fully dense Al—Hf reactive material

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Defence Technology（防务技术） 2024年第1期31卷 230-241页

作者： Junbao Li Weibing Li xiaoming wang ZNDY of Ministerial Key Laboratory Nanjing University of Science and TechnologyNanjing 210094China

This study proposed three types of Al—Hf reactive materials with particle size ratios(a),which were almost completely dense(porosity of<5.40%)owing to their preparation using hot-pressing *** characteristics and phase composition were analyzed,and the influence of particle size ratios on dynamic mechanical behavior and damage mechanism were *** prepared sample with a=0.1 exhibited continuous wrapping of the Hf phase by the Al ***—Hf contact(continuous Hf phase)within the sample gradually increased with increasing a,and a small amount of fine Hf appeared for the sample with a=*** reactive materials exhibited clear strain-rate sensitivity,with flow stressσ0.05and failure strainεfincreasing approximately linearly with increasing strain rate.ε.It is found that the plastic deformation of the material increased with increasing strain *** a increased from 0.1 to 1,the flow stress gradually *** failure of the material was dominated by ductile fracture with a large Al phase plastic deformation band for lower a,while brittle fracture with crushed Hf particles occurred at higher ***,a constitutive model based on BP neural network was proposed to describe the stress-strain relationships of the materials,with an average relative error of 2.22%.

关键词： Reactive material Particle size Split Hopkinson pressure bar test Stressestrain relationship Impact failure BP neural network

Dynamics modeling and optimal control for multi-information diffusion in Social Internet of Things

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Digital Communications and Networks 2024年第3期10卷 655-665页

作者： Yaguang Lin xiaoming wang Liang wang Pengfei Wan School of Computer Science Shaanxi Normal UniversityXi'an710119China

As an ingenious convergence between the Internet of Things and social networks,the Social Internet of Things(SIoT)can provide effective and intelligent information services and has become one of the main platforms for people to spread and share ***,SIoT is characterized by high openness and autonomy,multiple kinds of information can spread rapidly,freely and cooperatively in SIoT,which makes it challenging to accurately reveal the characteristics of the information diffusion process and effectively control its *** this end,with the aim of exploring multi-information cooperative diffusion processes in SIoT,we first develop a dynamics model for multi-information cooperative diffusion based on the system dynamics theory in this ***,the characteristics and laws of the dynamical evolution process of multi-information cooperative diffusion are theoretically investigated,and the diffusion trend is *** this basis,to further control the multi-information cooperative diffusion process efficiently,we propose two control strategies for information diffusion with control objectives,develop an optimal control system for the multi-information cooperative diffusion process,and propose the corresponding optimal control *** optimal solution distribution of the control strategy satisfying the control system constraints and the control budget constraints is solved using the optimal control ***,extensive simulation experiments based on real dataset from Twitter validate the correctness and effectiveness of the proposed model,strategy and method.

关键词： Social Internet of Things Information diffusion Dynamics modeling Trend prediction Optimal control

Thinopyrum ponticum and Th. intermedium: the promising source of resistance to fungal and viral diseases of wheat

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Journal of Genetics and Genomics 2009年第9期36卷 557-565页

作者： Hongjie Li xiaoming wang The National Key Facility for Crop Gene Resources and Genetic Improvement (NFCR1) Institute of Crop Sciences Chinese Academy of Agricultural Sciences Beijing 100081 China

Thinopyrum ponticum and Th. intermedium provide superior resistance against various diseases in wheat （Ttricum aestivum）. Because of their readily crossing with wheat, many genes for disease resistance have been introduced from the wheatgrasses into wheat. Genes for resistance to leaf rust, stem rust, powdery mildew, Barley yellow dwarf virus, Wheat streak mosaic virus, and its vector, the wheat curl mite, have been transferred into wheat by producing chromosome translocations. These genes offer an opportunity to improve resistance of wheat to the diseases; some of them have been extensively used in protecting wheat from damage of the diseases. Moreover, new resistance to diseases is continuously detected in the progenies of wheat-Thinopyrum derivatives. The present article summaries characterization and application of the genes for fungal and viral disease-resistance derived from Th. ponticum and Th. intermedium.

关键词： wheat disease resistance gene Thinopyrum pontieum Th. intermedium wheatgrass

A guidance and control design with reduced information for a dual-spin stabilized projectile

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Defence Technology（防务技术） 2024年第3期33卷 494-505页

作者： Yu wang Jiyan Yu xiaoming wang Jia Fangxiu Intelligent Ammunition Technology National Defense Key Discipline Laboratory Nanjing University of Science and TechnologyNanjingJiangsu210094China

In this paper,an integrated guidance and control method based on an adaptive path-following controller is proposed to control a spin-stabilized projectile with only translational motion information under the constraint of an actuator,uncertainties in aerodynamic parameters and measurements,and control system *** to the fairly high rotation speed,the dynamic model of this missile is strongly nonlinear,uncertain and coupled in pitch,yaw and roll channels.A theoretical equivalent resultant force and uncertainty compensation method are comprehensively used to realize decoupling of pitch and *** response to the strong nonlinear and time-varying characteristics of the dynamic system,the quasi-linear model whose parameters are obtained by interpolation of points selected as the segmentation points in the trajectory envelope,is used for calculation in each *** cope with the system uncertainty caused by model approximation,parameter uncertainty and ballistic interference,an extended state estimator is used to compensate the output feedback according to the test ballistic *** order to improve the tracking efficiency and ensure the tracking error convergence with only translational motion information,the virtual guide point,whose derivative is deduced according to the Lyapunov principle,is calculated in real time according to the projection relationship between the real-time position and the reference trajectory,and a virtual line-of-sight angle and the backstepping method are used for the design of the guidance and control *** order to avoid the influence of control input saturation on the guidance and control performance due to the actuator limitation and improve the robustness of the system,an anti-saturation compensator is designed according to the two-step *** feasibility and effectiveness of the path-following controller is verified through closed-loop flight simulations with measurement,control,and condition *** result

关键词： Spin-stabilized projectile Reduced information Path-following control Extended state observer Coupled nonlinear system Input saturation

台风灾害影响的产业链跨部门传导机制——以台风“天鸽”为例

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灾害学 2025年第1期40卷 213-219页

作者：林舒婷夏琳琳王晓明梁赛广东工业大学生态环境与资源学院湾区生态安全与绿色发展基础研究卓越中心大湾区城市环境安全与绿色发展教育部重点实验室广东广州510006 中国科学院西北生态环境资源研究院冰冻圈科学国家重点实验室甘肃兰州730000

极端天气事件会通过产业链对经济系统产生级联影响,现有研究聚焦极端天气事件影响评估,但仍未明晰极端天气事件影响在经济系统产业链的跨部门传导机制。该文通过整合自适应区域投入产出模型、结构路径分析和介数中心性分析方法,以台风... 详细信息

极端天气事件会通过产业链对经济系统产生级联影响,现有研究聚焦极端天气事件影响评估,但仍未明晰极端天气事件影响在经济系统产业链的跨部门传导机制。该文通过整合自适应区域投入产出模型、结构路径分析和介数中心性分析方法,以台风“天鸽”为例,揭示了台风灾害影响对广东省产业链的跨部门传导机制。研究发现,台风“天鸽”造成广东省经济损失共310亿元,其中间接损失占13%。在台风灾害发生阶段,造成经济损失的关键传导路径与建筑业紧密相关,如非金属矿物制品业→建筑业;关键传输部门包括通信设备、计算机和其他电子设备制造业,金属冶炼和压延加工业等;典型的关键部门间关联包括金属冶炼和压延加工业→建筑业等。在重建阶段,金属矿采选业、金融业、房地产业等部门从重建需求中获得较多经济收益。研究为提高产业链适应能力和灾后资金分配提供决策支持。

关键词：极端天气事件台风经济影响投入产出分析产业链

Efficient and secure auditing scheme for outsourced big data with dynamicity in cloud

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Science China(Information Sciences) 2018年第12期61卷 97-111页

作者： Qingqing GAN xiaoming wang Xuefeng FANG Department of Computer Science Jinan University

Big data offers significant benefits; however, security and privacy problems must be considered,especially with regard to outsourced big data. Auditing outsourced big data is an important factor in security and privacy. However, most of the existing auditing techniques are not suitable for outsourced big data due to their high computational and communication costs at the auditor and the data owner (DO) side. In this paper, we propose an efficient auditing scheme for outsourced big data based on algebraic signatures and an XOR-homomorphic function, that can achieve numerous advantages, such as fewer challenges and proofs,non-block verification, data privacy preservation, and lower computational and communication costs. The proposed scheme enables a trusted third-party auditor, on behalf of DOs, to audit the outsourced data in a cloud. Thus, reducing the computational burden on the DOs. Subsequently, we construct a new data structure called a Record Table(RTable) and extend the basic auditing scheme to support the data dynamic operations. As our extended scheme does not use public key encryption, the entire process of updating the data incurs only a small computational and communication overhead with regard to the auditor, the DOs,and the cloud server. Finally, the proposed basic scheme is proved secure under the security model against various attacks. Analysis of the performance shows that both our basic scheme and extended scheme are highly efficient.

关键词： dynamic auditing algebraic signature XOR-homomorphic function provable security cloud storage