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Optimization of Gas-Flooding Fracturing Development in Ultra-Low Permeability Reservoirs

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Fluid Dynamics & Materials Processing 2024年第3期20卷 595-607页

作者： Lifeng Liu Menghe Shi Jianhui wang wendong wang Yuliang Su Xinyu Zhuang Tight Oil Research Institute PetroChina Research Institute of Petroleum Exploration&DevelopmentBeijing100083China Key Laboratory of Unconventional Oil&Gas Development China University of Petroleum(East China)Qingdao266580China Oil&Gas Technology Research Institute Changqing Oilfield CompanyXi’an710018China

Ultra-low permeability reservoirs are characterized by small pore throats and poor physical properties, which areat the root of well-known problems related to injection and production. In this study, a gas injection floodingapproach is analyzed in the framework of numerical simulations. In particular, the sequence and timing of fracturechanneling and the related impact on production are considered for horizontal wells with different fracturemorphologies. Useful data and information are provided about the regulation of gas channeling and possible strategiesto delay gas channeling and optimize the gas injection volume and fracture parameters. It is shown that inorder to mitigate gas channeling and ensure high production, fracture length on the sides can be controlled andlonger fractures can be created in the middle by which full gas flooding is obtained at the fracture location in themiddle of the horizontal well. A Differential Evolution (DE) algorithm is provided by which the gas injectionvolume and the fracture parameters of gas injection flooding can be optimized. It is shown that an improvedoil recovery factor as high as 6% can be obtained.

关键词： Ultra-low permeability reservoir gas injection flooding component simulation fracture parameters intelligent optimization differential evolution

Blow-up of critical norms for the 3-D Navier-Stokes equations

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Science China Mathematics 2017年第4期60卷 637-650页

作者： wang wendong ZHANG ZhiFei School of Mathematical Sciences Dalian University of Technology School of Mathematical Sciences Peking University

Let u =(uh, u3) be a smooth solution of the 3-D Navier-Stokes equations in R3× [0, T). It was proved that if u3 ∈ L∞(0, T;˙B-1+3/p p,q(R3)) for 3 < p, q < ∞ and uh∈ L∞(0, T; BMO-1(R3)) with uh(T) ∈ VMO-1(R3), then u can be extended beyond T. This result generalizes the recent result proved by Gallagher et al.(2016), which requires u ∈ L∞(0, T;˙B-1+3/pp,q(R3)). Our proof is based on a new interior regularity criterion in terms of one velocity component, which is independent of interest.

关键词： Stokes方程三维爆破临界速度分量光滑解证明 BP

The C~α regularity of a class of non-homogeneous ultraparabolic equations

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Science China Mathematics 2009年第8期52卷 1589-1606页

作者： wang wendong ZHANG LiQun Institute of Mathematics Academy of Mathematics and Systems ScienceHua Loo-Keng Key Laboratory of MathematicsChinese Academy of SciencesBeijing 100190China

We obtain the Cα regularity for weak solutions of a class of non-homogeneous ultra- parabolic equation, with measurable coefficients. The result generalizes our recent Cα regularity results of homogeneous ultraparab... 详细信息

关键词： non-homogeneous ultraparabolic equations Cα regularity Kruzhkov’s approaches

Studying on equilibriums between price and QoS in multi-provider overlay access networks

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High Technology Letters 2006年第2期12卷 129-135页

作者：王玉峰 wang wendong College of Telecommunications and Information Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 P.R. China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 P.R. China

From the viewpoint of game theory, this paper proposes a model that combines QoS index with price factor in overlay access networks, and uses the multinomial logic (MNL) to model the choice behaviour of users. Each service class is considered an independent and competitive entity offered by each provider, which aims at maximizing its own utility. Based on noncooperative game, we prove the existence and uniqueness of equilibriums between QoS levels and prices among various service classes, and demonstrate the properties of equilibriums. Finally, these results are verified via numerical analysis.

关键词：重迭存取网络非合作对策多项式分对数模型纳什均衡

On the feasibility and efficacy of control traffic protection in software-defined networks

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Science China(Information Sciences) 2015年第12期58卷 44-62页

作者： HU YanNan wang wendong GONG XiangYang QUE XiRong CHENG ShiDuan State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications

Software Defined Networking(SDN) is an emerging networking paradigm that assumes a logically centralized control plane separated from the data plane. Despite all its advantages, separating the control and data planes introduces new challenges regarding resilient communications between the two. That is, disconnections between switches and their controllers could result in substantial packet loss and performance degradation.This paper addresses this challenge by studying the issue of control traffic protection in SDNs with arbitrary numbers of controllers. Specifically, we propose a control traffic protection scheme that combines both local rerouting and constrained reverse path forwarding protections, through which switches can locally react to failures and redirect the control traffic using standby backup forwarding options. Our goal is then to find a set of primary routes for control traffic, called protected control network, where as many switches as possible can benefit from the proposed protection scheme. We formulate the protected control network problem, prove its NP-hardness, and develop an algorithm that reconciles protectability and performance(e.g., switch-to-control latency). Through extensive simulations based on real topologies, we show that our approach significantly improves protectability of control traffic. The results should help further the process of deploying SDN in real-world networks.

关键词： software-defined network protection control traffic resilience optimization

The effect of solvent in evaporation-induced self-assembly:A case study of benzene periodic mesoporous organosilica

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Science China Chemistry 2011年第12期54卷 1920-1925页

作者： wang wendong FAULKNER Daniel MOIR Jonathon OZIN Geoffrey A Materials Chemistry Research Group Department of Chemistry University of Toronto 80 St. George Street Toronto M5S 3H6 Canada Department of Materials Science ＆ Engineering University of Toronto 184 College St Toronto M5S 3E4 Canada

Volatile organic solvents were considered to have little influence on the synthesis of mesostructured materials through evaporation-induced self-assembly(EISA),because upon evaporation they leave the sol and hence do not interfere with the self-assembly process.We show here that the choice of solvent is crucial in the synthesis of thin films of phenylene-bridged periodic mesoporous organosilica(benzene PMO).Methanol is found to be a better solvent for the synthesis of thin films,whereas ethanol favors the formation of(HO)3Si-C6H4-Si(OH)3 crystals,the identity and structure of which is established by X-ray diffraction.A ternary reactant composition diagram is designed to visualize the relationship among multiple synthesis experiments and to guide the interpretation of experimental results and optimization of the quality of the periodic mesoporous organosilica film.Our study highlights the importance of solvent choice,a factor often neglected in EISA.We expect it to inspire researchers to explore the effect of solvent in designing the synthesis of mesoporous materials.

关键词：溶剂蒸发介孔材料周期性自组装诱导挥发性有机溶剂苯案例

Coverage Area Based Opportunistic Forwarding Algorithm in VANETs

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China Communications 2012年第12期9卷 56-67页

作者： Ding Yu wang wendong Gong Xiangyang Cui Yong wang Bai State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 P. R. China Department of Computer Science and Technology Tsinghua University Beijing 100084 P. R. China School of Computer Science Beijing University of Posts and Telecommunications Beijing 100876 P. R. China

The highly mobility of vehicles,intermittent communication between the vehicles and the requirements of real time applications are some of the main challenges of multi-hop message delivery in Vehicular Ad Hoc Networks(VANETs).There are also additional challenges,especially when the destination for the message delivery is a moving vehicle.In this paper,we propose a novel multi-hop message delivery method,called the Coverage Area-based oPportunistic message forwarding algorithm(CAP).The main idea of CAP is to cover the potential area of a moving target vehicle as much as possible with the reachable area of the required delivery messages,so that the message can be delivered successfully.Because the success ratio and overhead of the multi-hop message delivery are two important but incompatible parameters in CAP,two tunings are discussed in the algorithm in order to maintain the balance of the two parameters.The simulation results show that compared with other reference approaches,CAP provides an efficient message delivery with a higher success ratio and a shorter message delay.

关键词：覆盖区域算法转发消息传递网路无线车用 CAP

Virtual network embedding in software-defined hybrid networks

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The Journal of China Universities of Posts and Telecommunications 2018年第4期25卷 75-85页

作者： Xu Ran wang wendong Gong Xiangyang Que Xirong State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunication

Network virtualization provides a powerful way of sharing substrate networks. Efficient allocation of network resources for multiple virtual networks( VNs) has always been a challenging task. Especially under the everincreasing demand of customized VN requests,many problems arise as network conditions change constantly.Particularly with the emergance of resource conflict alongside the development of VNs,service provider( SP) needs to provide a faster and more effective solution. Recently,software defined network( SDN) has emerged as a new networking paradigm,SDN’s centralized control and customizable routing features present new opportunities for convenient and flexible embedding VNs in the network. However,due to the limitations of SDN,replacing all legacy devices in current operational networks by SDN-enabled switches in a short span of time is impractical.Thus,in our study,we focus on the scenario of VN embedding( VNE) in software-defined hybrid networks. In this work,first of all,we propose partially deploying SDN nodes; and then,we use the characteristics of SDN to allocate resources for VN requests,and redirect the path for requests conflict in hybrid SDN network. We formulate the problems and provide simple algorithms to solve them. Simulation results show that our scheme has high ratio in responsiveness and acceptance.

关键词： SDN hybrid network VNE

Efficient Security Multimedia System on Embedded Platform

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China Communications 2010年第4期7卷 120-125页

作者： wang Lifeng MENG Qinglei XIAO Chen MA Jian DU Yaogang wang wendong Beijing Electronic Science and Technology Institute Beijing 100070 China Institute of Network Technology Beijing University of Posts and Telecommunications Beijing 100876 China 706 Institute Second Academy of CASIC Beijing 100854 China School of Computer Science and Technology Bei Hang University Beijing 100083 China

Security video communication is a challenging task,especially for wireless video applications.An efficient security multimedia system on embedded platform is designed.By analyzing the hardware architecture and resource,the efficient DSP-based H.264/AVC coding is studied by efficient video coding techniques and system optimizing implementation.To protect the confidentiality and integrity of media information,a novel security mechanism is presented,which includes user identify authentication and a perceptual video encryption algorithm based on exploiting the special feature of entropy coding in H.264.Experimental results show that the proposed hardware framework has high performance and achieves a better balance between security and efficiency.The proposed security mechanism can achieve high security and low complexity cost,and has a little effect on the compression ratio and transmission bandwidth.What’s more,encoding and encryption at the same time,the performance of data process can meet real-time application.

关键词：安全视频通信通信技术用户识别身份验证