Dynamic Routing of Multiple QoS-Required Flows in Cloud-Edge Autonomous Multi-Domain Data Center Networks

The 6th generation mobile networks(6G)network is a kind of multi-network interconnection and multi-scenario coexistence network,where multiple network domains break the original fixed boundaries to form connections and convergence.In this paper,with the optimization objective of maximizing network utility while ensuring flows performance-centric weighted fairness,this paper designs a reinforcement learning-based cloud-edge autonomous multi-domain data center network architecture that achieves single-domain autonomy and multi-domain collaboration.Due to the conflict between the utility of different flows,the bandwidth fairness allocation problem for various types of flows is formulated by considering different defined reward functions.Regarding the tradeoff between fairness and utility,this paper deals with the corresponding reward functions for the cases where the flows undergo abrupt changes and smooth changes in the flows.In addition,to accommodate the Quality of Service(QoS)requirements for multiple types of flows,this paper proposes a multi-domain autonomous routing algorithm called LSTM+MADDPG.Introducing a Long Short-Term Memory(LSTM)layer in the actor and critic networks,more information about temporal continuity is added,further enhancing the adaptive ability changes in the dynamic network environment.The LSTM+MADDPG algorithm is compared with the latest reinforcement learning algorithm by conducting experiments on real network topology and traffic traces,and the experimental results show that LSTM+MADDPG improves the delay convergence speed by 14.6%and delays the start moment of packet loss by 18.2%compared with other algorithms.

成语结构“There+be+negative+-ing participle……”初探

一次,在与一位外籍英语教师谈话时,我用了这样一个句子:“There’s no describing it.”(“简直无法形容。”)听了这话后,外籍教师称赞说这是“idiomatic English”。受到外籍教师称赞后,当然很自信,第二次不假思索又用了一个同样结构的句子:

A Corpus-based Study on the Use of Past Participles in Maritime English and General English

Four sampled corpora have been used for a quantitative analysis on usage of past participles(PPs) in maritime English (ME) and general English(GE). Part-of-speech tagging software CLAWS5 and AntConc 3.2.0 are used for extraction of PPs and da-ta collection. Standardized frequency based on 100000 words is adopted to ensure the comparability of PPs found in different corpo-ra. This study covers analysis of overall frequency distribution and different grammatical functions of PPs. Results show that ME prefers using more PPs and these PPs are more likely to be used as predicative and postpositive attribute than does GE.Detailed comparison and contrast about the use of PPs between GE and ME are also made, thus providing helpful information for learners or teachers of maritime English.

Multi-domain equivalent method for prediction of elastic modulus of complex fractured rock mass

Reliable estimation of deformation and failure behaviors of fractured rock mass is important for practical engineering design.This study proposes a multi-domain equivalent method for fracture network to estimate the deformation properties of complex fractured rock mass.It comprehends both the advantages of the discrete fracture network model and the equivalent continuum model to capture the features of discontinuities explicitly while reducing computational intensity.The complex fracture network is stochastically split into a number of subfracture networks according to the domain,length or angle.An analytical solution is derived to infer theoretically the relationship between the elastic moduli of the original complex fractured rock mass and the split subfractured rock masses by introducing a correction term based on the deformation superposition principle.Numerical simulations are conducted to determine the elastic moduli of split subfractured rock masses using universal distinct element code(UDEC),while the elastic modulus of the original model is estimated based on the currently proposed analytical relationship.The results show that the estimation accuracy with the current domainbased splitting model is far superior compared to those with the other two splitting models.Thus,the estimation method of elastic modulus of complex fractured rock mass based on domain splitting mode of fracture network is identified as the multi-domain equivalent method proposed in this paper.The reliability of this method is evaluated,and its high computational efficiency is demonstrated through exemplification with regard to different geometric configurations for stochastically artificial discrete fracture network.The proposed multi-domain equivalent method constructs the theoretical framework except for the regression analysis hypothesis compared to the density-reduced model equivalent method.

Multi-Domain Malicious Behavior Knowledge Base Framework for Multi-Type DDoS Behavior Detection

Due to the many types of distributed denial-of-service attacks(DDoS)attacks and the large amount of data generated,it becomes a chal-lenge to manage and apply the malicious behavior knowledge generated by DDoS attacks.We propose a malicious behavior knowledge base framework for DDoS attacks,which completes the construction and application of a multi-domain malicious behavior knowledge base.First,we collected mali-cious behavior traffic generated by five mainstream DDoS attacks.At the same time,we completed the knowledge collection mechanism through data pre-processing and dataset design.Then,we designed a malicious behavior category graph and malicious behavior structure graph for the characteristic information and spatial structure of DDoS attacks and completed the knowl-edge learning mechanism using a graph neural network model.To protect the data privacy of multiple multi-domain malicious behavior knowledge bases,we implement the knowledge-sharing mechanism based on federated learning.Finally,we store the constructed knowledge graphs,graph neural network model,and Federated model into the malicious behavior knowledge base to complete the knowledge management mechanism.The experimental results show that our proposed system architecture can effectively construct and apply the malicious behavior knowledge base,and the detection capability of multiple DDoS attacks occurring in the network reaches above 0.95,while there exists a certain anti-interference capability for data poisoning cases.

Performance Evaluation of Topologies for Multi-Domain Software-Defined Networking

Software-defined networking(SDN)is widely used in multiple types of data center networks,and these distributed data center networks can be integrated into a multi-domain SDN by utilizing multiple controllers.However,the network topology of each control domain of SDN will affect the performance of the multidomain network,so performance evaluation is required before the deployment of the multi-domain SDN.Besides,there is a high cost to build real multi-domain SDN networks with different topologies,so it is necessary to use simulation testing methods to evaluate the topological performance of the multi-domain SDN network.As there is a lack of existing methods to construct a multi-domain SDN simulation network for the tool to evaluate the topological performance automatically,this paper proposes an automated multi-domain SDN topology performance evaluation framework,which supports multiple types of SDN network topologies in cooperating to construct a multi-domain SDN network.The framework integrates existing single-domain SDN simulation tools with network performance testing tools to realize automated performance evaluation of multidomain SDN network topologies.We designed and implemented a Mininet-based simulation tool that can connect multiple controllers and run user-specified topologies in multiple SDN control domains to build and test multi-domain SDN networks faster.Then,we used the tool to perform performance tests on various data center network topologies in single-domain and multi-domain SDN simulation environments.Test results show that Space Shuffle has the most stable performance in a single-domain environment,and Fat-tree has the best performance in a multi-domain environment.Also,this tool has the characteristics of simplicity and stability,which can meet the needs of multi-domain SDN topology performance evaluation.

电子病历中文字词及其分布规律研究——以妇幼保健院电子病历为例

目的:通过研究电子病历中文字词提取及字词分布规律,探讨妇幼病历中文字词分布规律及特征词库构建。方法:以不同城市的两所妇幼保健医院某年患者全量电子病历为例,按互联网通用词库、医疗术语库、医疗术语分词库、病历分词库、术语及病历分词联合分词库等不同字词库对电子病历样本进行字词对比统计分析,并以此分析提取出妇幼病历字词分布规律及其字词特征。结果:妇幼病历样本统计结果表明,妇幼病历中文字词相对集中、量级有限、分布有规律、字词特征明显。结论:妇幼电子病历中文字词及其分布规律研究表明,妇幼电子病历中文字集中在2 000个左右,中文词也是集中在2 000个以内,妇幼特征词共有3 178个,因此以妇幼电子病历为例进行中文字词研究具有重要意义,对后期电子病历智能应用与开发具有参考价值。

面向柳州市时空信息云平台的地名地址全生命周期更新运营管理建设实践

地名地址是柳州时空信息云平台的重要组成部分之一,但是各类政务数据里面的地址标准不一、地址表述多样、地址运营更新困难,严重制约着时空信息云平台公共服务效率的进一步提升。据此,本文探讨了一种基于地名地址模型的全生命周期更新运营管理方法,通过引入社会企业地名地址大数据运营管理的实践能力,结合时空信息云平台的定位,采用人工智能地名地址匹配、深度学习的地址分词、地址语义图谱和归一化地址关联匹配等技术,确保柳州市地名地址数据表述更加标准、语义更加丰富;最终为各部门提供更加准确、翔实的地名地址服务,以满足“智慧城市”多样化应用的需求。

英语动词前置构式的句法语义和认知理据

动词前置构式属于非典型话题结构,体现了概念参照点关系,以表述类事件的前置动词短语为参照点,以存在核为目标。该构式是对先前语篇中的基线进行一系列加工阐释后形成的交互小句,具有独特的句法语义特征和语篇功能,主要用于明确前置动词所述事件的发生状况或存在状态,有别于明确事件参与者的分词倒装,也有别于让步倒装。让步倒装强调主语与前置成分之间,或主语所参与事件的实际结果与该事件应该产生的结果之间构成的对立性和反预期性。前置的动词是存在核之外的剩余部分,仅充当语篇锚定,不占据存在核的默认锚定成分位置,因此,前置不会引起倒装。

以语用语法观为导向的分词做状语教学策略探究

在高中学段,分词做状语一直是英语语法教学的重点,也是学生学习的难点,学生普遍存在认知模糊和应用能力缺失的问题,该文结合课例阐释了语用视角下的教学策略:问题导入以修正形式规则;语境导入以理解意义功能;捕捉生活情境以体验语言动态生成;捕捉语篇情境,以提升整体语言运用能力。以上教学策略帮助学生打破对该语法结构的认知和应用瓶颈,知道了什么时候用、如何用分词做状语,最终能生成衔接连贯的语篇。

Stabilized Multi-domain Simulation Algorithms and Their Application in Simulation Platform for Forging Manipulator

Most researches focused on the analytical stabilized algorithm for the modular simulation of single domain, e.g., pure mechanical systems. Only little work has been performed on the problem of multi-domain simulation stability influenced by algebraic loops. In this paper, the algebraic loop problem is studied by a composite simulation method to reveal the internal relationship between simulation stability and system topologies and simulation unit models. A stability criterion of multi-domain composite simulation is established, and two algebraic loop compensation algorithms are proposed using numerical iteration and approximate function in multi-domain simulation. The numerical stabilized algorithm is the Newton method for the solution of the set of nonlinear equations, and it is used here in simulation of the system composed of mechanical system and hydraulic system. The approximate stabilized algorithm is the construction of response surface for inputs and outputs of unknown unit model, and it is utilized here in simulation of the system composed of forging system, mechanical and hydraulic system. The effectiveness of the algorithms is verified by a case study of multi-domain simulation for forging system composed of thermoplastic deformation of workpieces, mechanical system and hydraulic system of a manipulator. The system dynamics simulation results show that curves of motion and force are continuous and convergent. This paper presents two algorithms, which are applied to virtual reality simulation of forging process in a simulation platform for a manipulator, and play a key role in simulation efficiency and stability.

A PSO Based Multi-Domain Virtual Network Embedding Approach

This paper proposed a multi-domain virtual network embedding algorithm based on multi-controller SDN architecture. The local controller first selects candidate substrate nodes for each virtual node in the domain. Then the global controller abstracts substrate network topology based on the candidate nodes and boundary nodes of each domain, and applies Particle Swarm Optimization Algorithm on it to divide virtual network requests. Each local controller then embeds the virtual nodes of the divided single-domain virtual network requests in the domain, and cooperates with other local controllers to embed the inter-domain virtual links. Simulation experimental results show that the proposed algorithm has good performance in reducing embedding cost with good stability and scalability.

Virtual 5G Network Embedding in a Heterogeneous and Multi-Domain Network Infrastructure

The pursuit of the higher performance mobile communications forces the emergence of the fifth generation mobile communication(5G). 5G network, integrating wireless and wired domain, can be qualified for the complex virtual network work oriented to the cross-domain requirement. In this paper, we focus on the multi-domain virtual network embedding in a heterogeneous 5G network infrastructure, which facilitates the resource sharing for diverse-function demands from fixed/mobile end users. We proposed the mathematical ILP model for this problem.And based on the layered-substrate-resource auxiliary graph and an effective six-quadrant service-type-judgment method, 5G embedding demands can be classified accurately to match different user access densities. A collection of novel heuristic algorithms of virtual 5G network embedding are proposed. A great deal of numerical simulation results testified that our algorithm performed better in terms of average blocking rate, routing latency and wireless/wired resource utilization, compared with the benchmark.

Cost-Aware Multi-Domain Virtual Data Center Embedding

Virtual data center is a new form of cloud computing concept applied to data center. As one of the most important challenges, virtual data center embedding problem has attracted much attention from researchers. In data centers, energy issue is very important for the reality that data center energy consumption has increased by dozens of times in the last decade. In this paper, we are concerned about the cost-aware multi-domain virtual data center embedding problem. In order to solve this problem, this paper first addresses the energy consumption model. The model includes the energy consumption model of the virtual machine node and the virtual switch node, to quantify the energy consumption in the virtual data center embedding process. Based on the energy consumption model above, this paper presents a heuristic algorithm for cost-aware multi-domain virtual data center embedding. The algorithm consists of two steps: inter-domain embedding and intra-domain embedding. Inter-domain virtual data center embedding refers to dividing virtual data center requests into several slices to select the appropriate single data center. Intra-domain virtual data center refers to embedding virtual data center requests in each data center. We first propose an inter-domain virtual data center embedding algorithm based on label propagation to select the appropriate single data center. We then propose a cost-aware virtual data center embedding algorithm to perform the intra-domain data center embedding. Extensive simulation results show that our proposed algorithm in this paper can effectively reduce the energy consumption while ensuring the success ratio of embedding.

Resolution for Conflicts of Inter-Operation in Multi-Domain Environment

This paper proposes a method to formalize the interoperation in multi-domain environment. Through employing the algebra method, we conclude four types of the conflicts for the interoperation, and analyzes the cause of the policy conflicts. For each type of conflicts, we formalize it and proposes the method of detection and resolution. Finally, the method is illuminated be effective through comparing our work with others.

Centralized Role-Based Access Control for Federated Multi-Domain Environments

The secure interaction among multiple security domains is a major concern. In this paper, we highlight the issues of secure interoperability among multiple security domains operating under the widely accepted Role Based Access Control （RBAC） model. We propose a model called CRBAC that easily establishes a global policy for roles mapping among multiple security domains. Our model is based on an extension of the RBAC model. Also, multiple security domains were composed to one abstract security domain. Also roles in the multiple domains are translated to permissions of roles in the abstract security domain. These permissions keep theirs hierarchies. The roles in the abstract security domain implement roles mapping among the multiple security domains. Then, authorized users of any security domain can transparently access resources in the multiple domains.

Design of Multi-domain Collaborative Simulation System for Dual Clutch Transmission Based on CAN Bus

A multi-domain collaborative simulation(MDCS) system for dual clutch transmission(DCT) was presented based on controller area network(CAN) bus.An interface card of CAN bus was designed,in which MDCS subsystems were linked as the nodes according to the interface mode of MDCS.A DCT simulation model was established based on Matlab/Simdriveline,whose running process was accurately controlled by the designed control system.The playback system of vehicle state(VPS) was proposed whose input was the road-test data,with a real vehicle test environment for the development of transmission control unit(TCU) being provided.A DCT kinematic system model was set up,and the running status of DCT parts could be displayed in real time.The functions of MDCS were verified based on the extra-urban driving cycle(EUDC) and the vehicle road-test data respectively.The results show the functions of MDCS are accomplished,and the unified supporting platform for the development of TCU is achieved by MDCS.

Multi-Domain Decomposition Pseudospectral Method for Nonlinear Fokker-Planck Equations

Results on the composite generalized Laguerre-Legendre interpolation in unbounded domains are established. As an application,a composite Laguerre-Legendre pseudospectral scheme is presented for nonlinear Fokker-Planck equations on the whole line. The convergence and the stability of the proposed scheme are proved. Numerical results show the efficiency of the scheme and conform well to theoretical analysis.

3D seismic response of a 2D hill-valley staggered topography modeled by a 2.5D multi-domain IBEM

A two and a half dimensional(2.5D)multi-domain indirect boundary element method(IBEM)is developed to study the wave scattering of obliquely incident P-,SV-and SH-waves by a hill-valley staggered topography in a multi-layered half-space.The IBEM algorithm includes using 2.5D full-space and half-space Green’s functions to construct scattered fields in decomposed closed and opened half-space regions,respectively,and using the dynamic stiffness method to solve the free fields.All regions are finally integrated by introducing the compatibility conditions to obtain the total wave fields.The proposed 2.5D IBEM has the flexibility in dealing with complex boundaries by directly applying the fictitious loads on the regions’boundaries,with a less storage requirement compared to the full 3D models.Besides,by combining the specific advantages of the two kinds of Green’s functions,the method is well suitable for handling coupled topographies with high accuracy.The method is validated by comparison with published results for a single valley as well as a single hill topography.The effects of height-to-width ratio of hill and layering on dynamic responses are further parametrically investigated by numerical implementations in frequency domain.Results show that the interaction between valley and hills can lead to a more significant amplification within the valley region,and dynamic responses are deeply influenced by the height-to-width of hill,simultaneously depending on incident angle and frequency.Besides,the site effects become more complex when the stratification feature is taken into account.