Measuring Maximum Latewood Density By Image Analysis At The Cellular Level

A study was conducted to compare the precision of X-ray densitometry (XRD) and video image analysis (VIA) in measuring wood density of the last-formed latewood. The precision was determined by examining the convergence of the replicated measurements of maximum latewood density (MAXD). by XRD, and maximum percentage of cell-wall area (MAX%), by VIA. VIA was a more precise method for determining density of the last-formed tracheids than XRD. The linear relationship between MAXD and MAX% was significant at P < 0.01. The results indicate that MAX% can be used as an alternative to X-ray measurements of MAXD

Entropic measure of directional emissions in microcavity lasers

We propose a noble notion of the directional emission in microcavity lasers. First, Shannon entropy of the far-field profiles in the polar coordinate can quantify the degree of unidirectionality of the emission, while previous notions about the unidirectionality can not efficiently measure in the robust range against a variation of the deformation parameter. Second, a divergence angle of the directional emission is defined phenomenologically in terms of full width at half maximum, and it is barely applicable to a complicated peak structure. However, Shannon entropy of semi-marginal probability of the far-field profiles in the cartesian coordinate can present equivalent results, and moreover it is applicable to even the cases with a complicated peak structure of the emission

Interactive media server with media synchronized raid storage system

We propose an efficient placement algorithm and per-disk prefetching method to effectively support interactive operations in the media server. Our placement policy is incorporated with an encoder having a special bitcount control scheme that repeatedly tunes quantization parameters to adjust the bitcounts of video frames. This encoder can generate coded frames whose sizes are synchronized with the RAID stripe size, so that when various fast-forward levels are accessed we can reduce the seek and rotational latency and enhance the disk throughput of each disk in the RAID system. In the experimental results, the proposed placement policy and bitrate control scheme can significantly improve the average service time, which can enlarge the capacity of the interactive media server