Papers by Author: Long Long Song

Abstract: Information management systems become more common and more important in all walks of life. Many serious problems such as multi-source information heterogeneity, mass redundant data, and data security occur in the systems as the explosive increment of data. A novel redundant data deleting algorithm based on the cloud storage platform was proposed in this paper to deal with the problem of mess data storing. Storage space division algorithm and different users were divided in an appropriate way to improve the efficiency of reading and writing. A typical information management system was used to verify the feasibility and effectiveness of the algorithms proposed in this paper.

Abstract: Complex mass faults diagnosis of the pantograph type current collector was difficult. Based on the analysis of the structure, working principle and failure mode of the pantograph type current collector, fault tree of the pantograph was established. A lot of expert knowledge has been collected to support this diagnose process. Some serious problems such as ambiguity, uncertainty and inconsistency exist in the knowledge. Focused on the deficiencies, ontology modeling was proposed in this paper. StrOnto, FaultOnto and FTOnto were established to standardize the knowledge and to improve the efficiency of fault diagnosing. Finally, combined with the example of the pantograph type current collector of CRH2 EMU-train, the proposed algorithms proposed in this paper were proved reasonable and effective.

Abstract: Frequency-smear phenomenon caused by fierce rotating speed variation made it difficult to extract the fault features of the rolling bearing. An approach based on time-frequency order tracking and SPWVD was proposed in this paper. The influence of speed variation was reduced by resampling the time-domain non-stationary signal at constant angle increments with order tracking analysis. The precision of instantaneous frequency estimation (IFE) in time-frequency order tracking was improved by the use of Smoothed Pseudo Wigner-Ville Distribution (SPWVD). The simulation signal and experiment on test-rig revealed that the proposed method was more effective than the traditional order tracking in clarifying incipient fault.