Zhiguo Hong

CTMC-Based Availability Analysis of Cluster System with Multiple Nodes

The availability of cluster system with multiple nodes was investigated by taking common mode failure (CMF) into account. Firstly, the availability of system with one cluster node was analyzed. Then on the basis of analysis, contraposing to the cluster system with two nodes and three nodes, four continuous time markov chain (CTMC) models in the case of No CMF and in the case of CMF were constructed respectively. Moreover, numerical comparison of steady availability for these two cases was conducted by solving related linear equations and the conclusion on the priority and inferiority comparison of different cases is derived thereby, which offers theoretical foundation for establishing cluster systems.

SPN-Based Performance Evaluation for Data and Voice Traffic Hybrid System

On the basis of analyzing the characteristics of voice traffic, this paper constructed a Stochastic Petri Net (SPN) model for data and ON-OFF voice traffic hybrid system. Then, average time delay of the system was analyzed and model-based simulation was conducted with Stochastic Petri Net Package (SPNP) 6.0. Consequently, variation trends of burst time and idle time on average time delay are derived thereby. The methodology of modeling and simulation in this paper can be further used to analyze the performance of multimedia hybrid traffic system.

A SPN-Based Delay Analysis of LEO Satellite Networks

In this paper, we focus on the average time delay analysis of Low Earth Orbit (LEO) satellite networks. Firstly, a geometrical analysis of LEO satellite networks is given according to the characteristics of communication process. By taking the communication process of LEO satellite networks into account, average time delay is formulated by four parameters, i.e. average altitude of LEO satellite networks, uplink bandwidth, Inter-satellite links (ISLs) bandwidth and downlink bandwidth. Then, a Stochastic Petri Net (SPN) model is constructed. Accordingly, in order to represent the characteristics of average time delay, the arrival rate in the SPN model is mapped from the four above-mentioned parameters. Furthermore, the effects of these parameters on average time delay are also analyzed with Stochastic Petri Net Package (SPNP) 6.0. Because of its easiness and accuracy, the proposed approach has great benefit to the design and performance analysis of satellite networks.

Analysis of film data based on Neo4j

Film data analysis is important for website to find relationship between film data. Other than normal relational database, a novel and popular graph database, Neo4j uses graph related concepts to describe data models, the data can easily be nodes, edges and their associated attributes. By focusing on film data, Neo4j-based analysis is conducted in this paper. Firstly, Neo4j and Cypher Query Language are introduced. Then Neo4j is applied to analyze the associations among key objects in film data which are directors, actors etc. Neo4j database is good at dealing with complex and multi-connection data, using Neo4j database to store and manage film data makes it convenient for film data analysis.

CTMC-based numerical analysis of cluster system with middle states in the case of common mode failure

By taking both CMF (Common Mode Failure) and middle states into account, numerical analysis of availability of cluster system is analyzed. Firstly, a CTMC (Continuous Time Markov Chain) model of cluster system containing three cluster nodes is constructed with failure rate (λ), repair rate (μ), CMF rate (7), reconfiguration rate (β) and reset rate (á) etc. Then the steady state solution of the CMTC model is concerned by solving the equations with the combination of several parameters. Subsequently, the effect of probability of being in automatic recovery mode (k) on availability of cluster system is analyzed and discussed via numerical values-based chart thereby. This work offers quantitative analysis of cluster systems availability.

SPN model-based performance evaluation of job scheduling plans for distributed rendering environment

Based on the workflow of jobs under DRE (distributed rendering environment), mathematical modeling and performance evaluation were used to investigate different job scheduling plans. Firstly, a SPN (Stochastic Petri Nets) model for job scheduling with different priorities was constructed. Furthermore, using methodologies of SPN model and queuing one, effect of rendering rate, job priority on average completion time was conducted with exemplification, which offers key quantity foundations for designing and choosing appropriate job scheduling algorithms.

Performance analysis of call blocking probability in LEO satellite networks

In this paper, a geometrical analysis is proposed to analyse the performance of call blocking probability in low earth orbit (LEO) satellite networks. Call blocking probability is an important measure to analyse the performance of LEO satellite networks. Assuming shape of the corresponding cells in the footprint of a typical LEO satellite network is hexagonal, a theorem on calculating the maximum call blocking probability is proven. Furthermore, by applying the theorem, the impact of the peak traffic, half depression angle and the height of LEO satellite networks on call blocking probability is also analysed. The results we get can be used as a reference for the performance optimization of LEO satellite networks.