Mechanical Systems: Symmetry and Reduction

Reduction theory is concerned with mechanical systems with symmetries. It constructs a lower dimensional reduced space in which associated conservation laws are taken out and symmetries are \factored out" and studies the relation between the dynamics of the given system with the dynamics on the reduced space. This subject is important in many areas, such as stability of relative equilibria, geometric phases and integrable systems

Real-Time Estimation of Earthquake Magnitude for Seismic Early Warning

A prototype system for earthquake early warning and rapid shake map evaluation is being developed and tested in southern Italy based on a dense, wide-dynamic seismic network (accelerometers + seismometers) under installation in the Apenninic belt region (Irpinia Seismic Network). It can be classi\u85ed as a regional Earthquake Early Warning Systems con-sisting of a wide seismic sensor network covering a portion or the entire area which is threatened by quakes strike. The real time magnitude estimate will take advantage from the high spatial density of the network in the source region and the wide dynamic range of installed instruments. Based on the o ine analysis of high quality strong-motion data bases recorded in Italy, several methods envisaged, using di¤erent observed quantities (peak amplitude, dominant frequency, square velocity integral,...) to be measured on seismograms, as a func-tion of time, either on on P and early-S wave signals. Results from the analysis of the italian strong motion data-base, point out the possibility of using low-pass \u85ltered displacement and velocity peak amplitudes measured in time windows lasting less than 3-4 sec after the rst P or S wave arrivals. These parameters show to be robustly correlated with moment magnitude

Isofocusing and immunological investigations on cephalopod lens proteins

Soluble lens proteins from Octopus vulgaris, Sepia officinalis, and Loligo vulgaris were analyzed by thin-layer isoelectric focusing and compared by various immunochemical methods using antibodies directed against total soluble lens protein antigens from the said three species. The results show close similarity between Sepia and Loligo lens proteins. Antibodies made against Sepia and Loligo lens proteins did not react against Octopus total lens soluble protein antigens. Our results suggest a common ancestry for Sepia and Loligo which is different from that of Octopus

4 Real-time Estimation of Earthquake Magnitude for Seismic Early Warning

A prototype system for earthquake early warning and rapid shake map evaluation is being developed and tested in southern Italy based on a dense, dynamic seismic network (accelerometers + seismometers) under installation in the Apenninic belt region (Irpinia Seismic Network). It can be classified as a regional Earthquake Early Warning System consisting of a broad-based seismic sensor network covering a portion or the entire area which is threatened by the quake's strike. The real time magnitude estimate will take advantage from the high spatial density of the network in the source region and the broad dynamic range of installed instruments. Based on the offline analysis of high quality strong-motion data bases recorded in Italy, several methods are envisaged, using different observed quantities (peak amplitude, dominant frequency, square velocity integral, …) to be measured on seismograms, as a function of time, both on P and early-S wave signals. Results from the analysis of the Italian strong motion database point out the possibility of using low-pass filtered displacement and velocity peak amplitudes measured in time windows lasting less than 3-4 sec after the first P- or S-wave arrivals. These parameters show they are robustly correlated with moment magnitude. The correlation found of 3Hz low-pass filtered PGV and PGD with magnitude is discussed and interpreted in terms of plausible dynamic models of the earthquake rupture process during its initial stage

Reply to comment by P. Rydelek et al. on ‘‘Earthquake magnitude estimation from peak amplitudes of very early seismic signals on strong motion records’’

Based on the analysis of Mediterranean, near-source, strong motion records Zollo et al. [2006] (hereinafter referred to as ZLN) showed that peak displacement amplitudes of initial P- and S-wave seismic signals scales with the earthquake size in the moment magnitude range 4 < Mw < 7.4. Similar evidence have been also reported for southern California [Wu and Zhao, 2006] and Taiwan [Wu et al., 2006] using only P-wave arrivals up to 100 km distance on mostly short period and broadband waveform data.PublishedL203033.1. Fisica dei terremotiJCR Journalreserve