Inter-Data Commonality Detection for Spectrum Monitoring in Wireless Sensor Networks

Cooperative spectrum monitoring with multiple sensors has been deemed as an efficient mechanism for improving the monitoring accuracy and enlarging the monitoring area in wireless sensor networks.However,there exists redundancy among the spectrum data collected by a sensor node within a data collection period,which may reduce the data uploading efficiency.In this paper,we investigate the inter-data commonality detection which describes how much two data have in common.We define common segment set and divide it into six categories firstly,then a method to measure a common segment set is conducted by extracting commonality between two files.Moreover,the existing algorithms fail in finding a good common segment set,so Common Data Measurement(CDM)algorithm that can identify a good common segment set based on inter-data commonality detection is proposed.Theoretical analysis proves that CDM algorithm achieves a good measurement for the commonality between two strings.In addition,we conduct an synthetic dataset which are produced randomly.Numerical results shows that CDM algorithm can get better performance in measuring commonality between two binary files compared with Greedy-String-Tiling(GST)algorithm and simple greedy algorithm.

Effect of Microstructure of Composite Powders on Microstructure and Properties of Microwave Sintered Alumina Matrix Ceramics

Two kinds of different structured alumina-titania composite powders were used to prepare alumina matrix ceramics by microwave sintering. One was powder mixture of alumina and titania at a micron-submicron level, in which fused-and-crushed alumina particles （micrometers） was clad with submicron-sized titania. The other was powder mixture of alumina and titania at nanometer-nanometer level, in which nano-sized alumina and nano-sized titania particles were homogeneously mixed by ball-milling and spray dried to prepare spherical alumina-titania composite powders. The effect of the microstructure of composite powders on microstructure and properties of microwave sintered alumina matrix ceramics were investigated. Nano-sized composite （NC） powder showed enhanced sintering behavior compared with micro-sized composite （MC） powders. The as- prepared NC ceramic had much denser, finer and more homogenous microstructure than MC ceramic. The mechanical properties of NC ceramic were significantly higher than that of MC ceramic, e.g. the flexural strength, Vickers hardness and fracture toughness of NC ceramic were 85.3%, 130.3% and 25.7% higher than that of MC ceramic, respectively. The improved mechanical properties of NC ceramic compared with that of MC ceramic were attributed to the enhanced densification and the finer and more homogeneous microstructure through the use of the nanostructured composite powders.

Short-form OPA1 is a molecular chaperone in mitochondrial intermembrane space

Mitochondria,double-membrane organelles,are known to participate in a variety of metabolic and signal transduction pathways.The intermembrane space(IMS)of mitochondria is proposed to subject to multiple damages emanating from the respiratory chain.The optic atrophy 1(OPA1),an important protein for mitochondrial fusion,is cleaved into soluble short-form(S-OPA1)under stresses.Here we report that S-OPA1 could function as a molecular chaperone in IMS.We purified the S-OPA1(amino acid sequence after OPA1 isoform 5 S1 site)protein and showed it protected substrate proteins from thermally and chemically induced aggregation and strengthened the thermotolerance of Escherichia coli(E.coli).We also showed that S-OPA1 conferred thermotolerance on IMS proteins,e.g.,neurolysin.The chaperone activity of S-OPA1 may be required for maintaining IMS homeostasis in mitochondria.