Efficient Lossless Compression Based Reversible Data Hiding Using Multilayered n-Bit Localization

We proposed an innovative reversible data hiding technique that is formulated on histogram shifting by using multilayer localized n-bit truncation image (LBPTI), namely, generated form 8-bit plane by means of efficient lossless compression. After selecting the reference point from the block, the neighbor topmost points are used to attain the data embedding without modifying the peak point; in addition, the key information regarding peak point is not mandatory in extraction end to extract the secret information. In order to make the embedded cover-image similar to the histogram of original cover-image, we exploited the localization with efficient lossless compression on lower block level to increase the embedding capacity while controlling extra bit to expand additional embedding capacity on optimum level besides sustaining the quality of cover-image.

A Priority-Based Defragmentation Scheme in Flexible Bandwidth Optical Networks

Flexible Bandwidth Optical Networks(FBON) can improve spectrum usage rates comparing to traditional WDM networks, leaving one critical problem of spectrum fragments. This paper proposes a novel defragmentation scheme that determines the sequence of connections going through defragmentation processes. In sequencing connections, priority zones are divided and priority levels are set accordingly. Bandwidths or path lengths are what make a difference in a connection’s priority. As simulation results show, priority-based defragmentation scheme can achieve lower block rates as well as lower interruption rates. The simulation results also prove the preference of local defragmentation to global defragmentation and the preference of narrow-band defragmentation to broad-band defragmentation.

Seismology and Tectonics

The earthquake of April 22, 1991 was located in the eastern foothills of the Cordillera de Talamanca in Valle de la Estrella with epicentral coordinates of 9°38.62′N and 84°5.92″W and a focal depth of 21.5 km (Figure 2-1). An analysis of the seismograms recorded at teleseismic distances indicates that the causative fault was a shallow-angle thrust fault striking in a southeast-northwest direction and dipping at less that 30° gently towards the southwest. The lower block moved in a westerly direction while uplifting the upper-block east coast of Costa Rica by 1 to 1.5 meters. The plane of this fault rupture may either have reached the surface some distance offshore, or, possibly, failed to reach the surface. Aftershock data are consistent with this interpretation.