Improved diagnosis using enhanced fault dominance

Defect diagnosis can benefit from fault dominance relations to reduce the set of defect candidate sites. This paper presents new fault dominance collapsing operators that further reduce the set of candidates considered during the initial phase of diagnosis. In contrast to existing dominance-based methods which operate on pairs of faults, the proposed method operates on sets of faults. Fault-related entities are generated to guide the diagnosis process. The proposed collapsing operators can be used to accelerate effect-cause diagnosis. Experimental results demonstrate that the proposed method achieves a higher collapsing ratio than existing methods.     

Acoustic emission for detecting deterioration of capacitors under aging

There is continuous pressure on production cost reduction of foil-based capacitors, widely used in domestic appliance. Therefore, investigation of the deterioration mechanisms within capacitors is important to reduce their production costs at maintained reliability. These mechanisms were observed in two capacitors batches of classes Y2 (27 nF) and X2 (470 nF). An acoustic emission signal was observed when the capacitors were polarized by excessive voltage. This signal is induced by partial discharges that can lead to capacitor destruction. Next, the capacitors were aged at elevated temperature and also in presence of excessive polarization. We conclude that the acoustic emission signal can predict deterioration of dielectric insulation resistance in capacitors of class Y2. The observed destruction of capacitor of class X2 is caused mainly by detachment of the sprayed metalized contacts that is induced by overheating during partial discharges sparking.     

A modification to the Peng–Robinson-fitted equation of state for pure substances

In this work we present two modifications to the Peng–Robinson-Fitted equation of state where pure component parameters are regressed to vapor pressure and saturated liquid density data. The first modification (PR-f-mod) is a method that enhances the equation of state pure component property predictions through simple temperature dependent pure component parameters. In the second modification (PR-f-prop) we propose a temperature dependency for co-volume b in the repulsive parameter of the EoS, and revise the temperature function in the attractive term. The agreement with experimental data for 72 pure substances, including highly polar compounds, is remarkably good. We obtain average absolute deviations in saturated liquid density of less than 1% for all substances studied.     

Multi-cabinet implementation for Load-Balanced Optical Switch

Load-Balanced Optical Switch (LBOS) [20] ensures close-to-100% throughout and all-optical transmission between linecards. In this paper, we extend LBOS for multi-cabinet implementation. The challenges lie in the fact that the practical implementation requirements in single-cabinet LBOS become un-scalable for multi-cabinet scenario. First of all, we remove the restriction on LBOS that propagation delay (t_p) between adjacent linecards must equal to the transmission time (t_pkt) for sending one packet. The delay t_p is relaxed to be any value, which can accommodate the long and unequal distances fibers among cabinets. Secondly, we outstrip the upper bound of switch size N = 160 in LBOS. The basic idea is that the adjacent linecards share an identical channel/wavelength. Then LBOS can be scaled to support the large switch size of multi-cabinet. Last but not least, a more feasible fair scheduler is devised to replace the original one in LBOS. The simulation results show that multi-cabinet LBOS yields a much better delay/throughput performance than other multi-cabinet optical switches (e.g. Fasnet [8]).