Risk-Balanced Routing Strategy for Service Function Chains of Cyber-Physical Power System Considering Cross-Space Cascading Failure

Cyber-physical power system(CPPS)has significantly improved the operational efficiency of power systems.However,cross-space cascading failures may occur due to the coupling characteristics,which poses a great threat to the safety and reliability of CPPS,and there is an acute need to reduce the probability of these failures.Towards this end,this paper first proposes a cascading failure index to identify and quantify the importance of different information in the same class of communication services.On this basis,a joint improved risk-balanced service function chain routing strategy(SFC-RS)is proposed,which is modeled as a robust optimization problem and solved by column-and-constraint generation(C-CG)algorithm.Compared with the traditional shortest-path routing algorithm,the superiority of SFC-RS is verified in the IEEE 30-bus system.The results demonstrate that SFC-RS effectively mitigates the risk associated with information transmission in the network,enhances information transmission accessibility,and effectively limits communication disruption from becoming the cause of cross-space cascading failures.

Service Function Chain Deployment Algorithm Based on Multi-Agent Deep Reinforcement Learning

Aiming at the rapid growth of network services,which leads to the problems of long service request processing time and high deployment cost in the deployment of network function virtualization service function chain(SFC)under 5G networks,this paper proposes a multi-agent deep deterministic policy gradient optimization algorithm for SFC deployment(MADDPG-SD).Initially,an optimization model is devised to enhance the request acceptance rate,minimizing the latency and deploying the cost SFC is constructed for the network resource-constrained case.Subsequently,we model the dynamic problem as a Markov decision process(MDP),facilitating adaptation to the evolving states of network resources.Finally,by allocating SFCs to different agents and adopting a collaborative deployment strategy,each agent aims to maximize the request acceptance rate or minimize latency and costs.These agents learn strategies from historical data of virtual network functions in SFCs to guide server node selection,and achieve approximately optimal SFC deployment strategies through a cooperative framework of centralized training and distributed execution.Experimental simulation results indicate that the proposed method,while simultaneously meeting performance requirements and resource capacity constraints,has effectively increased the acceptance rate of requests compared to the comparative algorithms,reducing the end-to-end latency by 4.942%and the deployment cost by 8.045%.

Service Function Chain Migration in LEO Satellite Networks

With the advancements of software defined network(SDN)and network function virtualization(NFV),service function chain(SFC)placement becomes a crucial enabler for flexible resource scheduling in low earth orbit(LEO)satellite networks.While due to the scarcity of bandwidth resources and dynamic topology of LEO satellites,the static SFC placement schemes may cause performance degradation,resource waste and even service failure.In this paper,we consider migration and establish an online migration model,especially considering the dynamic topology.Given the scarcity of bandwidth resources,the model aims to maximize the total number of accepted SFCs while incurring as little bandwidth cost of SFC transmission and migration as possible.Due to its NP-hardness,we propose a heuristic minimized dynamic SFC migration(MDSM)algorithm that only triggers the migration procedure when new SFCs are rejected.Simulation results demonstrate that MDSM achieves a performance close to the upper bound with lower complexity.

AdaptNF: Adaptive service chain scheduling with stateless migration and NF consolidation

The combination of network function virtualization and software-defined networking allows various network functions to process flows according to their characteristics and requirements.Due to the highly dynamic nature of the workload,the network infrastructure needs to properly schedule the underlying resources in order to respond to workload changes in a timely manner.However,the existing NFV platform lacks a comprehensive solution for how to scale under workload variation,which may seriously hurt the overall system performance.To improve the scalability of the NFV platform and ensure consistent high performance under dynamic workloads,we propose AdaptNF,a novel NFV platform designed to support a combination of course-grained and fine-grained resource scheduling strategies.To deal with resource imbalance,which is the essential scheduling problem that leads to insufficient NFV performance,AdaptNF adopts a novel algorithm that can efficiently balance the workload among multiple network function instances through stateless flow migration.Our controlled experiments show that the AdaptNF scheme can optimize resource allocation and ensure outstanding performance after scaling.In terms of network throughput and latency,AdaptNF significantly improves the performance of the underlying NFV platform.

Dynamic Backup Sharing Scheme of Service Function Chains in NFV

Service function chains(SFC)mapping takes the responsibility for managing virtual network functions(VNFs).In SFC mapping,existing solutions duplicate VNFs with redundant instances to provide high availability in response to failures.However,as a compromise,these solutions result in high resource consumption due to device maintenance.In this paper,we propose a novel method named dynamic backup sharing(DBS)that allows SFCs to dynamically share backups to reduce resource consumption.DBS formulates the problem of sharing backups among different VNFs as an integer linear programming(ILP).Thereafter,we design a novel online algorithm based on dynamic programming to solve the problem.The experimental results indicate that DBS outperforms state-ofthe-art works by reducing resource consumption and improving the number of accepted requests.

Connected Advantage Interlinked supply chains are good for both China and the rest of the world

As both a beneficiary of global supply chain integration and a contributor to the creation of a new supply chain ecosystem,China is of immense importance to the growth of international supply chains.For example,it’s manufacturing industry is indispensable across every stage of the global supply chain from raw material to intermediate goods production and the assembly of finished products.And with a large consumer base,China has been the place where global goods and services are consumed.

Research on telecommunication resale service supply chain coordination with revenue-sharing contract

The competition and cooperation between traditional telecom operators and resale operators in the supply chain are discussed, when the telecom industry developed telecommunication resale service. Supply chain contract is an effective way to coordinate the supply chain. This paper analyzes the revenue-sharing contract between telecom operators and resale operators. The study shows that by setting up a rational revenue-sharing ratio and wholesale price, a revenue-sharing contract can coordinate this supply chain, and telecom operators and resale operators can achieve a 'win-win' solution.

基于SDN/NFV的Service Chaining关键技术研究

随着数据时代的到来,运营商如何开展数据业务尤其重要。分析了基于SDN的动态Service Chaining的需求、标准进展、应用场景,介绍了当前动态Service Chaining的总体架构、控制面逻辑Service Chaining生成及数据面Service Chaining的转发方案,并对转发方案做了比较和分析。

LSSC内物流服务集成商管理策略对提供商安全生产行为的影响研究

考虑由“功能型物流服务提供商—物流服务集成商—客户”构成的物流服务供应链(Logistics Service Supply Chain, LSSC),针对链内提供商安全生产问题的动态性与复杂性,探究集成商不同管理策略对提供商安全生产行为的影响。采用计算实验方法,抽象模拟出二者在选择与合作阶段的交互活动,分别进行集成商订单配置决策中安全因素权重、安全生产考评标准、安全风险抵押金对提供商安全生产行为的影响实验。研究结果表明:在客户具有安全偏好情况下,集成商通过合理的订单配置决策可实现提供商安全生产水平与自身收益的协同提升;当安全生产考评标准超过提供商可接受阈值时,其安全生产水平反而将会降低;收取安全风险抵押金可使提供商安全生产水平有所提高,但效果有限。

Coordination of Multi-leaders and Multi-followers in Supply Chain of Value-Added Telecom Services

In order to study supply chain of the telecom value-added service,a multi-leaders and multi-followers Stackelberg game model with multiple telecom operators and multiple service providers whose income is composed of information fee division and advertisement was constructed.Then a demonstration was simulated,and the results were compared with the situation of service providers' income only from information fee division.The simulated and compared results indicate that,the enterprises in the supply chain have the nature of pursuing the maximum profits in capital markets;meanwhile,first-mover advantages and some enterprise can get more profits with the information asymmetry.

Re-Evaluation of China＇s Service Trade Competitiveness： A Global Value Chain Perspective

Based on the Worm Input-Output Database （WIOD）, this paper conducts a forward-linkage decomposition of value-added in trade to estimate China＇s service value-added exports and its service sector＇s international competitiveness during 2000- 2014. Result indicates that during the sample period, China＇s service exports measured by forward-linkage decomposition method accounted for around 35% in its total export. While the value of services exported directly through the service sector accounted for a falling share, the value of services exported through other sectors represented an increasing share. China ranks second in the world in terms of market share of service exports. However, the revealed comparative advantage （RCA） of China＇s service exports and export sophistication remains limited.

Service Function Chain in Small Satellite-Based Software Defined Satellite Networks

Software Defined Satellite Networks(SDSN) are proposed to solve the problems in traditional satellite networks, such as time-consuming configuration and inflexible traffic scheduling. The emerging application of small satellite and research of SDSN make it possible for satellite networks to provide flexible network services. Service Function Chain(SFC) can satisfy this need. In this paper, we are motivated to investigate applying SFC in the small satellite-based SDSN for service delivery. We introduce the structure of the multi-layer constellation-based SDSN. Then, we describe two deployment patterns of SFC in SDSN, the Multi-Domain(MD) pattern and the Satellite Formation(SF) pattern. We propose two algorithms, SFP-MD, and SFP-SF, to calculate the Service Function Path(SFP). We implement the algorithms and conduct contrast experiments in our prototype. Finally, we summarize the applicable conditions of two deployment patterns according to the experimental results in terms of hops, delay, and packet loss rate.

Multi-Path Service Function Chaining for Mobile Surveillance of Animal Husbandry

Animal husbandry is the pillar industry in some ethnic areas of China.However,the communication/networking infrastructure in these areas is often underdeveloped,thus the difficulty in centralized management,and challenges for the effective monitoring.Considering the dynamics of the field monitoring environment,as well as the diversity and mobility of monitoring targets,traditional WSN(Wireless Sensor Networks)or IoT(Internet of Things)is difficult to meet the surveillance needs.Mobile surveillance that features the collaboration of various functions(camera,sensing,image recognition,etc.)deployed on mobile devices is desirable in a volatile wireless environment.This paper proposes the service function chaining for mobile surveillance of animal husbandry,which orchestrates multi-path multifunction(MPMF)chains to help mobile devices to collaborate in complex surveillance tasks,provide backup chains in case the primary service function chain fails due to mobility,signal strength,obstacle,etc.,and make up for the defects of difficult deployment of monitoring facilities in ethnic areas.MPMF algorithmmodels both mobile devices and various functions deployed on them as abstract graph nodes,so that chains that are required to traverse various functions and hosting mobile devices can be orchestrated in a single graphbased query through modified and adapted Dijkstra-like algorithms,with their cost ordered automatically.Experiment results show that the proposed MPMF algorithm finds multiple least-costly chains that traverse demanded functions in a timely fashion on Raspberry Pi-equipped mobile devices.

Service Function Chain Orchestration across Multiple Clouds

Network function virtualization is a new network concept that moves network functions from dedicated hardware to software-defined applications running on standard high volume severs. In order to accomplish network services, traffic flows are usually processed by a list of network functions in sequence which is defined by service function chain. By incorporating network function virtualization in inter-data center(DC) network, we can use the network resources intelligently and deploy network services faster. However, orchestrating service function chains across multiple data centers will incur high deployment cost, including the inter-data center bandwidth cost, virtual network function cost and the intra-data center bandwidth cost. In this paper, we orchestrate SFCs across multiple data centers, with a goal to minimize the overall cost. An integer linear programming(ILP) model is formulated and we provide a meta-heuristic algorithm named GBAO which contains three modules to solve it. We implemented our algorithm in Python and performed side-by-side comparison with prior algorithms. Simulation results show that our proposed algorithm reduces the overall cost by at least 21.4% over the existing algorithms for accommodating the same service function chain requests.

Based on the service supply chain to explore urban community endowment service problems and solutions——Based on the survey of Wuhan

This article introduces the connotation and operation mode of ‘Service Supply Chain’ into the research of community endowment service, based on the present situation investigation in different types of community endowment service in Hongshan and Wuchang district of Wuhan, combines with the operation concept of service supply chain to analysis the present bottleneck factors existing in the urban community of endowment service supply chain, and concludes the solving measures. This paper aims to improve the service level of the community endowment in all aspects, and concludes effective means and countermeasures in improving community endowment service quality.

Security Policies for Web Service Invocation of Automotive Industry Chain Collaboration Platform

To meet the actual requirements of an automotive industry chain collaboration platform （AICCP）, this paper offers several simple but effective security policies based upon the traditional security mechanism of data transfer, including user ID verification with SOAP （simple object access protocol）, header, SOAP message encryption with SOAP extension and XML （extensible markup language） file encryption and decryption. Application of these policies to the AICCP for more than one year proves the effectiveness of the data exchange practice between the AICCP and enterprise Intranet.

Simulation of Service Supply Chainly Formation Based on Mobile Agent

In E-Commerce, consumers and service suppliers can find the services through the searching of Mobile Agents (MA). The suppliers disassemble the service requests of consumers into the sub-requests. Then suppliers respond the sub-requests cooperatively. Thus the Service Supply Chain (SSC) can be formed. But the existing bottom-up and up-bottom supply chain formation fashions cannot be adapted to the SSC in distributed environment of E-Commerce. Task Dependency Network is exploited to illustrate the service relationship among consumers and suppliers. The formation of SSC with some simulations is elaborated. Then the influence on the formation of SSC caused by the type of service suppliers, the quantities of MA and its variety in number is elucidated.

Evaluation of Different Electronic Product Code Discovery Service Models

Electronic Product Code Discovery Service (EPCDS) is an important concept in supply chain processes and in Internet of Things (IOT). It allows supply chain participants to search for their partners, communicate with them and share product information using standardized interfaces securely. Many researchers have been proposing different EPCDS models, considering different requirements. In this paper, we describe existing architecture designs of EPCDS systems, namely Directory Service Model, Query Relay Model and Aggregating Discovery Service Model (ADS). We also briefly mention Secure Discovery Service (SecDS) Model, which is an improved version of Directory Service Model with a secure attribute-based access control mechanism. Then, we analyze the strengths and limitations of these models, by comparing based on non-functional features such as data ownership, confidentiality, business relationship independence, availability, reliability, implementation complexity, visibility, and scalability. From the analysis results, we have a better understanding of which model is more suitable in what kinds of situations or scenarios. Moreover, we suggest possible improvements and identify possible future add-on applications to SecDS model in the paper.

The Low-Carbon Operations in Ecotourism Service Supply Chain Management

The ecotourism has quickly developed as the fastest growing industry in recent years. Ecotourism is one kind of tourism industry that also consists of complex service providers like travel agents, hotels, transportations （such as airplane, bus, and ship） restaurants, and destinations, connecting with operational diversity; therefore, those of supported services are linked with a supply chain together, and its management is called ecotourism service supply chain management （ESSCM）. Moreover, a low-carbon operation management has also become an important challenge to ecotourism nowadays. Based on the problems of service and low-carbon operation management made together above, exploring an effective solution into ecotourism is worthy. Using ESSCM as a strategy for solving industrial problems of service and low-carbon operations management in ecotourism is explored in this paper. The contributions here include clearly explanations of what ESSCM is and how ESSCM is used with low-carbon operations as a sustainability strategy, and finally a practical case study is also examined in the end.

A Web Service Framework for Environmental and Carbon Footprint Monitoring in Construction Supply Chains

With the growing environmental concerns, green supply chain management （GSCM） is gaining significant attention in the construction industry. Tracking and monitoring the environmental effects brought forth by the participating members along a supply chain is important to GSCM. The GreenSCOR model developed by the Supply Chain Council provides a generic framework for measuring the total carbon footprint and environmental footprint in a supply chain. The model is based on the Supply Chain Operations Reference （SCOR） model, which represents a supply chain network in a hierarchically structured manner. This paper describes the GreenSCOR framework and its potential application to the construction industry. This paper also presents a web services approach to incorporate the GreenSCOR model to the implementation of collaborative information systems. Each process element in the SCOR model is represented and delivered as individual web service units, which can be reused and integrated using standard web services technologies. The service units are combined and managed in a prototype web service collaborative framework, called SC Collaborator, which is designed and developed for supporting construction supply chain management. An illustrative example is presented to demonstrate the implementation of the GreenSCOR-based SC Collaborator framework.