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.

Evaluation of the water conservation function in the Ili River Delta of Central Asia based on the InVEST model

The Ili River Delta(IRD)is an ecological security barrier for the Lake Balkhash and an important water conservation area in Central Asia.In this study,we selected the IRD as a typical research area,and simulated the water yield and water conservation from 1975 to 2020 using the water yield module of the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model.We further analyzed the temporal and spatial variations in the water yield and water conservation in the IRD from 1975 to 2020,and investigated the main driving factors(precipitation,potential evapotranspiration,land use/land cover change,and inflow from the Ili River)of the water conservation variation based on the linear regression,piecewise linear regression,and Pearson's correlation coefficient analyses.The results indicated that from 1975 to 2020,the water yield and water conservation in the IRD showed a decreasing trend,and the spatial distribution pattern was"high in the east and low in the west";overall,the water conservation of all land use types decreased slightly.The water conservation volume of grassland was the most reduced,although the area of grassland increased owing to the increased inflow from the Ili River.At the same time,the increased inflow has led to the expansion of wetland areas,the improvement of vegetation growth,and the increase of regional evapotranspiration,thus resulting in an overall reduction in the water conservation.The water conservation depth and precipitation had similar spatial distribution patterns;the change in climate factors was the main reason for the decline in the water conservation function in the delta.The reservoir in the upper reaches of the IRD regulated runoff into the Lake Balkhash,promoted vegetation restoration,and had a positive effect on the water conservation;however,this positive effect cannot offset the negative effect of enhanced evapotranspiration.These results provide a reference for the rational allocation of water resources and ecosystem protection in the IRD.

Value Assessment of Ecosystem Service Function of Ecological Public Welfare Forests in Wenchang City

Based on the measurement parameters and index in the Specifications for Assessment of Forest Ecosystem Services in China(LY/T 1721-2008),the value of ecological service functions of ecological public welfare forest in Wenchang City was evaluated and analyzed.The results show that the total value of ecosystem service function of ecological public welfare forests in Wenchang City is about 4.020 billion yuan,of which storage capacity,water purification,soil fixation,fertilizer(N,P and K fertilizer) conservation,carbon sequestration,oxygen release,forest nutrient accumulation,providing anion,absorbing SO_2,absorbing fluoride,absorbing NxO,absorbing soil heavy metals,dust retention,noise reduction,sterilization,forest protection,forest biodiversity protection,and forest recreation(ecological tourism) are about 1.510 billion,582.256 million,3.769 million,268.220 million,116.360 million,2.747 million,22.682 million,42.817 million,1.722 million,74,600,131,900,187.918 million,77.409 million,28.721 million,43.090 million,180.696 million,571.036 million,and 108.677 million yuan

Research on the Integrated Development of Disability Services in the Greater Bay Area From the Perspective of Media Functions

As the main window for the public to understand the outside world,mass media has an undeniable influence on economic and social development.The way in which the media reports on issues related to people with disabilities not only affects the voice of the disabled community,which determines the public image of the“disappearing”disabled community,but also affects the public awareness and recognition of the disability cause.To further explore the current status of mainstream media’s coverage of the disability cause,this article combines relevant concepts from media function theory and analyzes reports related to the integrated development of the disability cause in the Guangdong-Hong Kong-Macao Greater Bay Area by using the examples of the Zhuhai Special Zone Daily,Southern Metropolis Daily,and Shenzhen Special Zone Daily since the release of the Development Plan Outline for the Guangdong-Hong Kong-Macao Greater Bay Area in 2019.The results show that the“Integrated Development of the Disability Cause in the Bay Area”presented in the reports has the characteristics of service-oriented and cooperation-based,which is in line with the overall trend of the development of China’s disability cause.However,due to factors such as a small overall quantity of related reports,a relatively single style of reporting and information sources,and a strong promotional tone,there still exists a certain difference between the“media reality”and objective reality constructed by these reports.Therefore,this article suggests that institutional media should fully strengthen their coverage of relevant topics,while enhancing the timeliness and readability of reports by enriching various reporting elements.By further enhancing the effectiveness of reporting and communication,the integrated development of the disability cause in the Bay Area can be effectively promoted.

An Adaptive Hybrid Optimization Strategy for Resource Allocation in Network Function Virtualization

With the rapid development of Network Function Virtualization(NFV),the problem of low resource utilizationin traditional data centers is gradually being addressed.However,existing research does not optimize both localand global allocation of resources in data centers.Hence,we propose an adaptive hybrid optimization strategy thatcombines dynamic programming and neural networks to improve resource utilization and service quality in datacenters.Our approach encompasses a service function chain simulation generator,a parallel architecture servicesystem,a dynamic programming strategy formaximizing the utilization of local server resources,a neural networkfor predicting the global utilization rate of resources and a global resource optimization strategy for bottleneck andredundant resources.With the implementation of our local and global resource allocation strategies,the systemperformance is significantly optimized through simulation.

Distributed Matching Theory-Based Task Re-Allocating for Heterogeneous Multi-UAV Edge Computing

Many efforts have been devoted to efficient task scheduling in Multi-Unmanned Aerial Vehicle(UAV)edge computing.However,the heterogeneity of UAV computation resource,and the task re-allocating between UAVs have not been fully considered yet.Moreover,most existing works neglect the fact that a task can only be executed on the UAV equipped with its desired service function(SF).In this backdrop,this paper formulates the task scheduling problem as a multi-objective task scheduling problem,which aims at maximizing the task execution success ratio while minimizing the average weighted sum of all tasks’completion time and energy consumption.Optimizing three coupled goals in a realtime manner with the dynamic arrival of tasks hinders us from adopting existing methods,like machine learning-based solutions that require a long training time and tremendous pre-knowledge about the task arrival process,or heuristic-based ones that usually incur a long decision-making time.To tackle this problem in a distributed manner,we establish a matching theory framework,in which three conflicting goals are treated as the preferences of tasks,SFs and UAVs.Then,a Distributed Matching Theory-based Re-allocating(DiMaToRe)algorithm is put forward.We formally proved that a stable matching can be achieved by our proposal.Extensive simulation results show that Di Ma To Re algorithm outperforms benchmark algorithms under diverse parameter settings and has good robustness.

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.

Change of Forest Ecosystem Service Function and Its Value in Kanas Nature Reserve

In order to clarify the service function and value of forest ecosystem in Kanas Nature Reserve, the ecological service function and its value of forest ecosystem in Kanas Nature Reserve in 2009 and 2014 were evaluated by using the method of Specifications for Assessment of Forest Ecosystem Services in China(LY/T 1721-2008). The results showed that in 2014, the total value of forest ecosystem service function in Kanas Nature Reserve increased by 7.34% compared with that in 2009, and the value of water conservation and biodiversity accounted for the largest proportion. The increasing rate of functional value of shrub forest land was obviously higher than that of coniferous forest land and broad-leaf forest land. The service function and value of different forest types were obviously different.

Evaluation of the Functionality of the Networking of Sexual and Reproductive Health Rights Services in the Event of Gender-Based Violence in the Commune of Kpomasse in 2022

Introduction: In developing countries, gender-based violence (GBV) is a real public health problem. In Benin, GBV affects the majority of women and girls (69%). Benin has implemented strategies and set up integrated centers for the management of violence in order to reduce cases of violence and ensure the holistic management of victims. The objective of our study was to assess the functionality of the network of sexual and reproductive health rights (SRHR) in case of GBV in the commune of Kpomasse in 2022. Method: This descriptive and evaluative study was conducted from March 21 to April 11, 2022. The sampling method used was non-probabilistic. Reasoned choice and convenience were the techniques used for the different targets of the study. The functionality of the SRHR service network was assessed first by calculating scores at the structure, process and outcome levels, and then by analysis using the human rights-based approach. Results: Out of the 34 GBV victims identified, only one had received a full response and 54% of the victims had no knowledge of SRHR. The lack of knowledge about health care facilities was 41% for victims and 80% for non-victims in the community who participated in the study. In the case of gender-based violence, the community preferred to settle out of court rather than report it. The functionality of the networking of sexual and reproductive health rights services in the event of the occurrence of gender-based violence in the commune of Kpomassè is insufficient. Lack of knowledge of the roles of rights holders (DD) and duty bearers (DO) explains the insufficient functionality of networking. Conclusion: Training of SRHR service agents and community sensitization are essential to improve the functionality of SRHR service networking in the commune of Kpomasse.

Research on Service Function Chain Orchestrating Algorithm Based on SDN and NFV

Software defined network(SDN)and network function virtualization(NFV)have become a new paradigm of a new generation of network architecture.SDN and NFV can effectively improve the flexibility of deploying and managing service function chains(SFCs).By combining SDN and NFV and applying them to the resource orchestration problem of SFC deployment,the three-tier architecture consisting of SDN controller,network function virtualization and physical underlying computing resource layer in the process of heterogeneous network resource mapping is considered.And an optimization algorithm for active control resources based on SDN and NFV is proposed.Firstly,the user’s utility is modeled by the multistandard aggregated multi-criteria utility algorithm,and the optimization goal is transformed into the problem of maximizing the user’s utility.Then the controller,based on the algorithm’s prediction of the future state and realtime monitoring of the network utilization,makes decisions and issues control commands for the arriving SFC requests,based on which it occupies the underlying resources held by the virtualized network function(VNF).The simulation results show that,compared with the static timing resource allocation algorithm,the active control resource deployment algorithm proposed in the article has better performance in terms of resource utilization,acceptance rate,and user creation utility.

A Preliminary Exploration of the Functional Value Assessment of Ecosystem Services in Aral City

Using the principles and methods of eco-economics as the research object,Aral City comprehensively expounds the ecological service functions such as ecosystem regulation of climate,carbon sequestration,soil conservation,water conservation and purification environment,and evaluates its economic value.The total value of the estimated 2021 is 1303.65 million yuan.At the same time,the importance of ecological service functions of urban ecosystems,from large to small,is to sequester carbon and release oxygen,purify the environment,maintain soil,conserd water sources,regulate the climate.The ecosystem service function which needs to be paid attention to in the concept of ecological construction and restoration of the next stage of ecological construction in Aral City.

Result-as-a-Service (RaaS): Persistent Helper Functions in a Serverless Offering

Serverless Computing or Functions-as-a-Service (FaaS) is an execution model for cloud computing environments where the cloud provider executes a piece of code (a function) by dynamically allocating resources. When a function has not been executed for a long time or is being executed for the first time, a new container has to be created, and the execution environment has to be initialized resulting in a cold start. Cold start can result in a higher latency. We propose a new computing and execution model for cloud environments called Result-as-a-Service (RaaS), which aims to reduce the computational cost and overhead while achieving high availability. In between successive calls to a function, a persistent function can help in successive calls by precomputing the functions for different possible arguments and then distributing the results when a matching function call is found.

Providing Customized Security Based on Network Function Composition and Reconfiguration

Real-time multimedia sharing in Consumer-centric Multimedia Network(CMN) requires usability anywhere, anytime and from any device. However, CMNs are usually located or implemented on application layer, which makes CMNs subjected to their fixed substrate security framework. A fundamental diversifying attribute for the customized security experiences of CMNs is pressing. This paper proposes a programmable network structure which is named Service Processing Chain(SPC) based on network function combination. The SPC is established by the ordinal combination of network functions in substrate switches dynamically, and therefore constructs a special channel for each CMN with required security. The construction and reconfiguration algorithms of SPC are also discussed in this paper. Evaluations and implementation show that above approaches are effective in providing multilevel security with flexibility and expansibility. It is believed that the SPC could provide customized security service and drive participative real-time multimedia sharing for CMNs.

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.

The Need and Its Influence Factors for Community-based Rehabilitation Services for Disabled Persons in One District in Beijing

Purpose To explore the needs for basic community-based rehabilitation services for disabled persons in Xuanwu District, Beijing, China, and to identify factors which influence disabled persons to accept rehabilitation services. Method One hundred and eight disabled persons were selected by systematic sampling and simple random sampling to assess their needs for community-based rehabilitation services. Results Of the interviewees, 57A% needed the community-based rehabilitation services, but only 13.9% took advantage of it. The main factors influencing the interviewees to accept these services were cost （P〈0.05）, knowledge about rehabilitation medicine （P〈0.05）; and the belief in the therapeutic benefit of the community-based rehabilitation service （P〈0.05）. Conclusion A considerable gap exists between the supply of community-based rehabilitation services in Beijing and the needs for these services by disabled residents underscoring the need for improved availability, and for additional research.

Fishery Web Service Composition Method Based on Ontology

Various fishery information systems have been developed in different times and on different platforms. Wet） service application composition is crucial in the sharing and integration of fishery data and information. In the present paper, a heuristic web service composition method based on fishery ontology is presented, and the proposed web services are described. Ontology reasoning capability was applied to generate a service composition graph. The heuristic function was introduced to reduce the searching space. The experimental results show that the algorithm used considers the services semantic similarity and adiusts web service composition plan by dynamically relying on the empirical data.

Assessment of Service Value of Ecosystem in Karst Ecological Control Areas

To investigate the characteristics of service value of the karst rocky desertification ecosystem,we take water conservation,soil conservation,carbon-fixation and oxygen-production,production of organic matter,and purification of atmospheric environment as function indicators,to conduct quantitative assessment and analysis of service function value of ecosystem in Bijie Yachi,Qingzhen Hongfenghu and Guanling-Zhenfeng Huajiang demonstration areas in Guizhou Province,using remote sensing and field monitoring data in 2006. The results show that the rate of contribution of water conservation,soil conservation,carbon-fixation and oxygen-production functions to regional service value is high ( 37. 05%,36. 68% and 23. 15%,respectively) ; the rate of contribution of production of organic matter and purification of atmospheric environment functions to regional service value is low ( 2. 80% and 0. 32%,respectively) . The ranking of landscape in terms of service value per unit area is as follows: forestland ( 23.353 9 million yuan) > shrub land ( 10.630 1 million yuan) > grassland ( 5.036 7 million yuan) > dry land ( 3.381 2 million yuan) > farmland ( 2.508 8 million yuan) . The ranking of demonstration areas in terms of service value per unit area is as follows: Yachi Demonstration Area ( 12.44 million yuan) > Hongfenghu Demonstration Area ( 5. 91 million yuan) > Huajiang Demonstration Area ( 4. 4 million yuan) . It is negatively correlated with rocky desertification incidence within the region. The results also indicate that in the process of restoring and reconstructing the ecological environment in rocky desertification areas,increasing the area of forest vegetation,promoting the conversion of dry land and farmland into forestland, shrub land and grassland,will contribute to enhancement in ecological service value.

A preliminary study of cryosphere service function and value evaluation

Cryosphere science research and development(R&D) has been strongly committed to public service, integrating natural sciences with socioeconomic impacts. Owing to the current shift from purely natural cryosphere scientific research to linking cryosphere science with socioeconomic and cultural science, cross-disciplinary research in this field is emerging, which advocates future cryosphere science research in this field. Utilizing the cryosphere service function(CSF), this study establishes CSF and its value evaluation system. Cryosphere service valuation can benefit the decisionmakers' and public's awareness of environmental protection. Implementing sustainable CSF utilization strategies and macroeconomic policymaking for global environmental protection will have profound and practical significance as well as avoid environmental degradation while pursuing short-term economic profits and achieving rapid economic development.

基于动态和静态分析的单体应用FaaS改造方法

作为Serverless架构的一种典型形态,函数即服务(function as a service,FaaS)架构将业务抽象为细粒度的函数,并且提供弹性的自动伸缩等自动化运维功能,能够大幅降低运维成本.当前,许多在线服务系统中的一些高并发、高可用、灵活多变的业务(如支付、红包等)都已经迁移到了FaaS平台上,但是大量传统单体应用还是难以利用FaaS架构的优势.针对这一问题,提出了一种基于动态和静态分析的单体应用FaaS改造方法.该方法针对指定的单体应用API,通过动态分析和静态分析相结合的方式识别并剥离其实现代码和依赖,然后按照函数模板完成代码重构.针对函数在高并发场景下的冷启动问题,该方法利用基于IO多路复用的主从多线程Reactor模型优化了函数模板,提高了单个函数实例的并发处理能力.基于该方法实现了针对Java语言的原型工具Codext,在开源Serverless平台OpenFaaS上,面向4个开源单体系统进行了实验验证.

Value Evaluation of Water Ecosystem Services——A Case Study of Changshu City

[ Objective] The study aimed to quantitatively assess the values of water ecosystem services. [ Method] Combining the market value, travel cost and restoration cost method, the ecological services and their economic values of the lake Taodangmian were assessed from aspects of water supply, recreation and tourism, water purification and biodiversity maintenance. [ Resultl For the lake Taodangmian, its freshwater supply and tourism played more positive roles in the society than the others, while the functions of water purification and biodiversity maintenance brought negative effects, which shows that the ecological environment of Taodangmian has become increasingly worse and needs to be controlled and and protected further. [ Conclusion] The research could provide scientific references for the reasonable exploitation and utilization of water resources.