Previous attempts at disturbing the galactic disk by the Magellanic Clouds relied on direct tidal forcing. However, by allowing the halo to actively respond rather than remain a rigid contributor to the rotation curve, the Clouds may produce a wake in the halo which then distorts the disk. Recent work reported here suggests that the Magellanic Clouds use this mechanism to produce disk distortio...

Existing SPARQL-to-SQL translation techniques have limitations that reduce their robustness, efficiency and dependability. These limitations include the generation of inefficient or even incorrect SQL queries, lack of formal background, and poor implementations. Moreover, some of these techniques cannot be used over arbitrary DB schemas due to the lack of support for RDB to RDF mapping language...

We present a RDB2OWL mapping specification language that is aimed at presenting RDB-to-RDF/OWL mappings possibly involving advanced correspondences between the database and ontology in a human comprehensible way. The RDB2OWL mappings can be regarded as documentation of the database-to-ontology relation. The RDB2OWL language reuses the OWL ontology structure as a backbone for mapping specificati...

A new Chemo–Dynamical Smoothed Particle Hydrodynamic (CD-SPH) code is presented. The disk galaxy is described as a multi–fragmented gas and star system, embedded in a cold dark matter halo with a rigid potential field. The star formation (SF) process, SNII, SNIa and PN events, and the chemical enrichment of gas, have all been considered within the framework of the standard SPH model, which we u...

BACKGROUND Interbody fusion by open discectomy is the usual treatment for degenerative disk disease but requires a relatively long recovery period. The transforaminal posterolateral approach is a well-known standard in endoscopic spine surgery that allows direct access to the disk with progressive tissue dilation. The aim of this study was to assess the feasibility of percutaneous transforamina...

Many applications or algorithms in sensor networks require positional information of the sensors. Most approaches for this problem rely either on distances between communicating node pairs or on local angular information. Although distance-based methods are widespread, we here present a technique for direction-based localization in general networks. Whereas Bruck et al. proved that the correspo...

We apply two theoretical and two numerical methods to the problem of a disk placed in a groove and subjected to gravity and a torque. Methods assuming rigid particles are indeterminate – certain combinations of forces cannot be calculated, but only constrained by inequalities. In methods assuming deformable particles, these combinations of forces are determined by the history of the packing. Th...