Manufacturing enterprise collaboration network:An empirical research and evolutionary model

With the increasingly fierce market competition,manufacturing enterprises have to continuously improve their competitiveness through their collaboration and labor division with each other,i.e.forming manufacturing enterprise collaborative network(MECN)through their collaboration and labor division is an effective guarantee for obtaining competitive advantages.To explore the topology and evolutionary process of MECN,in this paper we investigate an empirical MECN from the viewpoint of complex network theory,and construct an evolutionary model to reproduce the topological properties found in the empirical network.Firstly,large-size empirical data related to the automotive industry are collected to construct an MECN.Topological analysis indicates that the MECN is not a scale-free network,but a small-world network with disassortativity.Small-world property indicates that the enterprises can respond quickly to the market,but disassortativity shows the risk spreading is fast and the coordinated operation is difficult.Then,an evolutionary model based on fitness preferential attachment and entropy-TOPSIS is proposed to capture the features of MECN.Besides,the evolutionary model is compared with a degree-based model in which only node degree is taken into consideration.The simulation results show the proposed evolutionary model can reproduce a number of critical topological properties of empirical MECN,while the degree-based model does not,which validates the effectiveness of the proposed evolutionary model.

A Genetic Algorithm and Analysis of Designing Large Enterprise Network Topology

The design of enterprise network topology is in fact a multi-object nonlinear programming problem. In this paper, distance, traffic distribution and transmission delay are chosen as the important factors to be considered in the subnetwork partition of the network topology design. A mathematical model is presented and The Genetic Algorithm is used to solve the optimization object function. The application results demonstrate that the method can well solve the problem of subnetwork partition.

An Aided Tool for Enterprise Network Design

With the rapid development of network technologies, it is necessary to make use of an aided tool (AT) to help enterprise network design (END). The AT must process many requirements qualitatively and quantitatively and then give out the logical network guidance and preferred solution. The AT also needs to carry out a simulation program, and gives the feasibility report. This paper will introduce the authors research work on above aspects.

Network Systems in CIM Environment

This paper discusses the architecture. protocol standards, and the design strategy of network systemsin the CIM environment. The first part describes problems in standardizing communication protocols, analyses communication attributes in the CIM environment. and explains our strategies. The second part presents the design ofthe CIMS/ERC network system and its traffic statistics.

Pre-scan based fast handoff scheme for enterprise IEEE 802.11 networks

In IEEE 802.11 networks, many access points（APs） are required to cover a large area due to the limited coverage range of APs, and frequent handoffs may occur while a station（STA） is moving in an area covered by several APs. However, traditional handoff mechanisms employed at STAs introduce a few hundred milliseconds delay, which is far longer than what can be tolerated by some multimedia streams such as voice over Internet protocol（Vo IP）, it is a challenging issue for supporting seamless handoff service in IEEE 802.11 networks. In this paper, we propose a pre-scan based fast handoff scheme within an IEEE 802.11 enterprise wireless local area network（EWLAN） environment. The proposed scheme can help STA obtain the best alternative AP in advance after the pre-scan process, and when the handoff is actually triggered, STA can perform the authentication and reassociation process toward the alternative AP directly. Furthermore, we adopt Kalman filter to minimize the fluctuation of received signal strength（RSS）, thus reducing the unnecessary pre-scan process and handoffs. We performed simulations to evaluate performance, and the simulation results show that the proposed scheme can effectively reduce the handoff delay.