Research on Data Tampering Prevention Method for ATC Network Based on Zero Trust

The traditional air traffic control information sharing data has weak security characteristics of personal privacy data and poor effect,which is easy to leads to the problem that the data is usurped.Starting from the application of the ATC(automatic train control)network,this paper focuses on the zero trust and zero trust access strategy and the tamper-proof method of information-sharing network data.Through the improvement of ATC’s zero trust physical layer authentication and network data distributed feature differentiation calculation,this paper reconstructs the personal privacy scope authentication structure and designs a tamper-proof method of ATC’s information sharing on the Internet.From the single management authority to the unified management of data units,the systematic algorithm improvement of shared network data tamper prevention method is realized,and RDTP(Reliable Data Transfer Protocol)is selected in the network data of information sharing resources to realize the effectiveness of tamper prevention of air traffic control data during transmission.The results show that this method can reasonably avoid the tampering of information sharing on the Internet,maintain the security factors of air traffic control information sharing on the Internet,and the Central Processing Unit(CPU)utilization rate is only 4.64%,which effectively increases the performance of air traffic control data comprehensive security protection system.

Intelligent Spectrum Management Based on Radio Map for Cloud-Based Satellite and Terrestrial Spectrum Shared Networks

Cloud-based satellite and terrestrial spectrum shared networks(CB-STSSN)combines the triple advantages of efficient and flexible net-work management of heterogeneous cloud access(H-CRAN),vast coverage of satellite networks,and good communication quality of terrestrial networks.Thanks to the complementary coverage characteristics,any-time and anywhere high-speed communications can be achieved to meet the various needs of users.The scarcity of spectrum resources is a common prob-lem in both satellite and terrestrial networks.In or-der to improve resource utilization,the spectrum is shared not only within each component but also be-tween satellite beams and terrestrial cells,which intro-duces inter-component interferences.To this end,this paper first proposes an analytical framework which considers the inter-component interferences induced by spectrum sharing(SS).An intelligent SS scheme based on radio map(RM)consisting of LSTM-based beam prediction(BP),transfer learning-based spec-trum prediction(SP)and joint non-preemptive prior-ity and preemptive priority(J-NPAP)-based propor-tional fair spectrum allocation is than proposed.The simulation result shows that the spectrum utilization rate of CB-STSSN is improved and user blocking rate and waiting probability are decreased by the proposed scheme.

Core-based Shared Tree Multicast Routing Algorithms for LEO Satellite IP Networks

A new core-based shared tree algorithm, viz core-cluster combination-based shared tree （CCST） algorithm and the weighted version （i.e. w-CCST algorithm） are proposed in order to resolve the channel resources waste problem in typical source-based multicast routing algorithms in low earth orbit （LEO） satellite IP networks. The CCST algorithm includes the dynamic approximate center （DAC） core selection method and the core-cluster combination multicast route construction scheme. Without complicated onboard computation, the DAC method is uniquely developed for highly dynamic networks of periodical and regular movement. The core-cluster combination method takes core node as the initial core-cluster, and expands it stepwise to construct an entire multicast tree at the lowest tree cost by a shortest path scheme between the newly-generated core-cluster and surplus group members, which results in great bandwidth utilization. Moreover, the w-CCST algorithm is able to strike a balance between performance of tree cost and that of end-to-end propagation delay by adjusting the weighted factor to meet strict end-to-end delay requirements of some real-time multicast services at the expense of a slight increase in tree cost. Finally, performance comparison is conducted between the proposed algorithms and typical algorithms in LEO satellite IP networks. Simulation results show that the CCST algorithm significantly decreases the average tree cost against to the others, and also the average end-to-end propagation delay ofw-CCST algorithm is lower than that of the CCST algorithm.

A Shared Multi-buffer Banyan Network

A Shared Multi-buffer Banyan Network is presented in this letter. Its control algorithm and switching fabric are simple, and it fits the high speed ATM network well. The simulation results show that the throughput of the proposed model is high.

ZTE Holds 1/4 Global CDMA Network Market Share

ZTE Corporation,a leading global provider of telecommunications equipment and network solutions,announced on July 30,2009 that it has been ranked as the second largest global CDMA network supplier with 25%

Green Multicast Grooming Based on Cross-Shared Protection in Optical WDM Networks

Currently,multicast survivability in optical network obtains more attention.This paper focuses on the field of multicast grooming shared protection in green optical network and designs a novel auxiliary graph and a shared matrix to address the survivable multicast resource consumption.This paper also proposes a new heuristic called Green Multicast Grooming algorithm based on spanning path Cross-Shared protection(GMGCSP),in which network reliability,energy efficiency and resource utilization are jointly considered.Simulation results testify that,compared to other algorithms,the proposed GMG-CSP not only has lower blocking probability and higher bandwidth utilization ratio,but also saves more energy.

M/S Controller Area Network(CAN) System Using Shared-Clock Scheduler

The Controller Area Network (CAN) is a well established control network for automotive and automation control applications. Time-Triggered Controller Area Network (TTCAN) is a recent development which introduces a session layer,for message scheduling,to the existing CAN standard,which is a two layer standard comprising of a physical layer and a data link layer. TTCAN facilitates network communication in a time-triggered fashion,by introducing a Time Division Multiple Access style communication scheme. This allows deterministic network behavior,where maximum message latency times can be quantified and guaranteed. In order to solve the problem of determinate time latency and synchronization among several districted units in one auto panel CAN systems,this paper proposed a prototype design implementation for a shared-clock scheduler based on PIC18F458 MCU. This leads to improved CAN system performance and avoid the latency jitters and guarantee a deterministic communication pattern on the bus. The real runtime performance is satisfied.

共享单车与公共交通多元关系分类及阈值研究

为准确评估共享单车和公共交通之间的复杂时空关系,根据替代或补充关系的具体成因类型,结合共享单车出行起讫点的分布情况,定义共享单车与公共交通多元关系;其次,考虑公共汽电车与轨道交通的差异性,提出一种基于弱监督全连接神经网络的共享单车与公共交通多元关系的分类模型,并根据共享单车轨迹数据,计算不同关系分类和交通方式下的公共交通可达范围、共享单车骑行时长及步行接驳距离边界阈值。结果表明:共享单车与公共交通的多元关系可分为接驳补充、空白补充、替代关系1和替代关系2。其中,共享单车与公共汽电车多元关系的三参数划分阈值分别为329.75 m、5.07 min和182.93 m,与轨道交通多元关系的划分阈值分别为816.96 m、10.27 min和653.91 m。共享单车与公共汽电车以替代关系1为主,占总行程的54.98%;共享单车与轨道交通以空白补充关系为主,占总行程的48.90%。共享单车与公共汽电车关系主要为多元替代与接驳补充,与轨道交通主要为多元补充与替代关系2。共享单车与公共汽电车的关系相比于轨道交通会更为复杂。本文可为促进共享单车与公共交通在各自优势距离上的协同发展提供支撑。

ZTE Gains Second Largest Share of the Global Optical Networking Market in 2011

ZTE gained the second largest share of the global optical networking market of any company for the second year in a row. ZTE gained 1.8 share points on 2010. In two years, the company moved from world No. 5 to world No. 2 in the global optical network market, and its annual revenues now surpass $1.7 billion.

ZTE Gains Second Largest Share of the Global Optical Networking Market in 2011

22 August 2012 -- ZTE Corporation, a publicly listed global provider of telecommunications equipment and network solutions, announced its interim results for the six months ended 30 June 2012. Based on both HKFRS and PRC ASBE, ZTE recorded revenue of RMB 42.64 billion for the period, an increase of 15.2% year-on-year. Pre-tax profit in the period was RMB 656 million, a decrease of 48.5% year-on-year. Basic earnings per share for the period were RMB 0.07. During the reporting period,

手机直连卫星关键技术分析与发展展望

手机直连卫星技术的快速发展是卫星载荷技术突破、手机终端技术创新、体制标准制定并验证等多种因素叠加的结果,通过对手机直连卫星发展现状的介绍,总结了手机直连卫星的2条技术路线和3种实现方式。面对星地频率共用、星载天线、星载基站等技术瓶颈,结合实际系统和应用场景给出了重点研究内容。探讨了作为5G通信重要组成部分和6G通信基础支撑的手机直连卫星技术未来的发展方向。

基于区块链的用户自定义位置共享方案

针对移动社交网络位置共享服务存在的隐私泄漏问题,提出基于区块链的用户自定义位置共享(BUDLS)方案.基于区块链实现位置信息分布式管理,防止中央服务器收集大量用户隐私,增强用户位置信息的可控性.设计基于公钥数字签名和同态加密相结合的加密机制,防止位置信息被攻击者非法获取.定义灵活的访问控制策略,根据用户需要提供可靠的服务.安全分析验证结果显示,BUDLS方案满足隐私安全目标.仿真实验结果表明,相比传统方案,BUDLS方案降低了时间成本,提高了位置查询的准确性,有效保护了移动社交网络平台用户的位置隐私.

IRS辅助的感知增强认知无线电网络资源分配方案

在过去的几十年里,大部分可用频谱已被用于高速通信服务。这导致了无线通信系统中的频谱资源稀缺问题。另一方面,大量可用频谱的利用率并不高。为提升通信系统的频谱利用率,学界提出了基于共享的认知无线电技术。认知无线电允许次用户与主用户共享频谱资源,对于提升无线通信网络的频谱效率十分重要,然而目前基于认知无线电的通信网络存在着低信噪比情况下感知性能低下、严苛干扰条件下性能提升受限等缺点。最近,智能反射面(Intelligent Reflecting Surface,IRS)被广泛应用在无线通信的各个领域,可以智能调控无线传输环境以满足频谱和能效的高要求。为了进一步提升认知无线电感知性能与频谱效率,提出了一种新颖的IRS辅助的感知增强频谱共享认知无线电网络。针对此网络,建立了次用户和速率最大化优化问题,联合优化次基站波束赋形向量、智能反射面相移矩阵、感知时间。因存在变量耦合,所构建的优化问题是非凸的,提出一种基于块坐标下降(Block Coordinate Descent,BCD)的迭代算法以交替优化波束形成和智能反射面相位以及感知时间。以逐次凸逼近(Successive Convex Approximation,SCA)求解非凸目标和约束函数,并利用半正定松弛(Semidefinite Relaxation,SDR)解决秩一条件约束,采用一维搜索来寻找最佳感知时间。通过仿真结果证明提出的方法能够快速收敛且对认知无线电网络的感知性能以及频谱效率有较大提升作用。

Resource Allocation based on Shared Criterion in OFDMA Distributed Radio Access Network

Distributed radio access network (DRAN) is a novel wireless access architecture and can solve the problem of the available spectrum scarcity in wireless communications. In this paper, we investigate resource allocation for the downlink of OFDMA DRAN. Unlike previous exclusive criterion based algorithms that allocate each subcarrier to only one user in the system, the proposed algorithms are based on shared criterion that allow each subcarrier to be allocated to multiple users through different antennas and to only one user through same antenna. First, an adaptive resource allocation algorithm based on shared criterion is proposed to maximize total system rate under each user's minimal rate and each antenna's maximal power constraints. Then we improve the above algorithm by considering the influence of the resource allocation scheme on single user. The simulation results show that the shared criterion based algorithm provide much higher total system rate than that of the exclusive criterion based algorithm at the expense of the outage performance and the fairness, while the improved algorithm based on shared criterion can achieve a good tradeoff performance.

网络共享文档的雨洪灾害“求救”事件时空分析

城市雨洪灾害频发、急需快速掌握灾害过程中“求救”事件类型、位置,并开展制图。提出了基于“网络共享文档”的文本挖掘方法。为分析不同“求救”事件在时空上分布特征,提出了核密度估计、最近邻分析等方法。以河南雨洪灾害过程中传播较为广泛的网络共享文档为例,验证了方案的可行性。结果表明:城市雨洪灾害过程中不同类型的“求救”事件在的扩散规律有较大差异;大多数求救事件在时间和空间尺度上都呈现为聚集的模式;基于网络共享文档的灾害分析和应急制图,能够在时效性、时间粒度等方面弥补传统雨洪灾害监测手段的不足。

企业扶贫行为传递对乡村振兴的启示——来自股东扶贫网络的证据

现有研究侧重从企业个体维度探讨其参与帮扶的影响因素,忽略了企业个体行为在社会网络中的嵌入性。鉴于此,选取2016~2020年中国A股上市公司精准扶贫数据,从以往研究较少涉及的社会网络视角出发,探究股东扶贫网络对企业扶贫行为的影响及其机理。研究发现:股东在扶贫网络中越靠近中心位置,企业参与精准扶贫的意愿就越强、扶贫投入就越多、扶贫效果就越好;机制检验表明,企业扶贫行为可以在股东扶贫网络中进行传递,股东扶贫网络主要通过信息渠道与公司治理渠道来影响企业扶贫行为;进一步发现,企业的产权性质、融资约束及所在地区的市场化程度,会对股东扶贫网络与企业扶贫行为之间的关系产生异质性影响。研究结论为推动企业参与乡村振兴战略提供了来自社会网络的分析视角,也为政府部门引导股东的社会责任投资提供了经验启示。

协同创新理论下中国国家实验室建设路径探索——基于美国能源部国家实验室的经验启示

为推进中国国家实验室的开放和协同创新,运用协同创新理论,基于对美国能源部国家实验室协同创新的实践经验分析,结合中国当前面临被西方主要国家技术封锁的严峻形势,探讨协同创新促进中国国家实验室建设的路径。协同创新包含了多方创新主体、共同目标、优势互补和合理分工、复杂的相互作用和整体协同效应等五方面的核心要素,其结构从简单无序布局向高级有序组织变革转变为网络化创新结构,因此要确保协同创新成果实现,需要充分考虑不同主体之间的利益平衡和风险控制等因素。美国能源部国家实验室具有明确的战略目标与使命、充足的财政投入与多元化经费来源、高效的管理运行机制、人员组成多元化的强大科研团队,其发展总体呈现开放化、网络化的对外合作趋势,在协同创新方面形成了强化战略导向和目标聚焦、深化产学研合作、建立高效的协同机制、强化人才培养和团队建设,以及鼓励创新、营造宽容失败的文化氛围等经验举措。借鉴美国经验,深化国际合作和加强内部合作是应对挑战、促进国家实验室建设的两翼。因此,应对当前西方国家技术封锁,中国国家实验室建设须毫不动摇地坚持开放共享与合作交流的理念,强化顶层设计与政策引导,深化产学研用合作,建立高效协同机制,实现多领域协同创新、引领学科交叉创新,并积极融入创新联合体建设,弘扬科学家精神、营造鼓励创新探索的科研文化氛围。

自动语音识别模型压缩算法综述

随着深度学习技术的发展,自动语音识别任务模型的参数数量越来越庞大,使得模型的计算开销、存储需求和功耗花费逐渐增加,难以在资源受限设备上部署.因此对基于深度学习的自动语音识别模型进行压缩,在降低模型大小的同时尽量保持原有性能具有重要价值.针对上述问题,全面综述了近年来该领域的主要工作,将其归纳为知识蒸馏、模型量化、低秩分解、网络剪枝、参数共享以及组合模型几类方法,并进行了系统综述,为模型在资源受限设备的部署提供可选的解决方案.

基于输入均压与虚拟直流电机相结合的直流电能路由器控制策略

针对中压直流配电网接入下的直流电能路由器在新能源出力等工况下,使用传统控制策略对直流母线的控制效果一般、电压易越限等问题,基于模块化的输入串联输出并联(input-series output-parallel,ISOP)型拓扑结构,提出一种基于输入均压与虚拟直流电机相结合的直流电能路由器控制策略。首先,研究输入均压控制过程中模块间的功率均衡控制特性并与输出均流控制进行比较;接着,将虚拟直流电机控制应用到控制算法中,使变流器模拟出直流电机的惯性特性;然后,对虚拟直流电机建立小信号数学模型,分析其工作机理以及参数对系统的影响;最后,在MATLAB/Simulink中搭建仿真模型进行验证。结果表明:所提控制策略能够在实现直流电能路由器各模块间功率均衡的同时,具有类似直流电机的惯量特性与阻尼特性,可显著提高直流配电网直流母线电压稳定性。

网络社区用户知识分享行为的机理研究——基于网络规模效应的调节作用

网络社区已经成为知识传播的重要方式。用户数量规模以及知识分享活跃度对网络社区的发展尤为重要。基于社会交互关系、信任和共同语言3个维度,从网络规模效应调节作用的视角构建了用户知识分享行为的机理模型。通过问卷调查获取数据对理论模型进行实证分析,研究表明社会交互关系、信任和共同语言对用户的知识分享意愿有显著正向影响;同边网络效应在信任对用户知识分享意愿的影响中起负向调节作用;跨边网络效应在社会交互关系、共同语言对用户知识分享意愿的影响中起正向调节作用。最后,从构建良好的知识网络社区环境、加大知识网络社区的品牌宣传、建立科学的知识分享激励机制等方面提出了具体对策。