SFC Design and VNF Placement Based on Traffic Volume Scaling and VNF Dependency in 5G Networks

The development of Fifth-Generation(5G)mobile communication technology has remarkably promoted the spread of the Internet of Things(IoT)applications.As a promising paradigm for IoT,edge computing can process the amount of data generated by mobile intelligent devices in less time response.Network Function Virtualization(NFV)that decouples network functions from dedicated hardware is an important architecture to implement edge computing,deploying heterogeneous Virtual Network Functions(VNF)(such as computer vision,natural language processing,intelligent control,etc.)on the edge service nodes.With the NFV MANO(Management and Orchestration)framework,a Service Function Chain(SFC)that contains a set of ordered VNFs can be constructed and placed in the network to offer a customized network service.However,the procedure of NFV orchestration faces a technical challenge in minimizing the network cost of VNF placement due to the complexity of the changing effect of traffic volume and the dependency on theVNFrelationship.To this end,we jointly optimize SFC design and VNF placement to minimize resource cost while taking account of VNF dependency and traffic volume scaling.First,the problem is formulated as an Integer Linear Programming(ILP)model and proved NPhard by reduction from Hamiltonian Cycle problem.Then we proposed an efficient heuristic algorithm called Traffic Aware and Interdependent VNF Placement(TAIVP)to solve the problem.Compared with the benchmark algorithms,emulation results show that our algorithm can reduce network cost by 10.2%and increase service request acceptance rate by 7.6%on average.

An Empirical Analysis on the Stable Return of Resident Funds

This paper mainly studies how investors invest in funds to obtain high returns while avoiding risks.Firstly,from the perspective of portfolio investment,this paper introduces the traditional Markowitz mean-variance model and capital asset pricing model(CAPM),then selects four funds from different industries by MATLAB program in Sina Finance and Economics Network for application analysis from which the optimal portfolio point can be obtained under the combination of efficient frontier and capital allocation line.Subsequently,by analyzing the returns of long-term holdings and short-term operations of Noan Growth Hybrid Fund,it is confirmed that long-term holding funds can better cope with the changing market so as to obtain more stable returns.Finally,this paper discusses the dynamic adjustments of asset portfolio.Resident investors are supposed to take into account the market situation and the changes of the fund itself to adjust the holding fund portfolio.Based on the research in this paper,resident investors ought to combine investment funds to diversify risk allocation and make long-term holding plans according to their risk tolerance.At the same time,they should also make appropriate dynamic adjustments when the external environment changes to ensure long-term benefits.