Dynamical evolution of clustering in complex network of earthquakes

The network approach plays a distinguished role in contemporary science of complex systems/phenomena. Such an approach has been introduced into seismology in a recent work [S. Abe and N. Suzuki, Europhys. Lett. 65, 581 (2004)]. Here, we discuss the dynamical property of the earthquake network constructed in California and report the discovery that the values of the clustering coefficient remain stationary before main shocks, suddenly jump up at the main shocks, and then slowly decay following a power law to become stationary again. Thus, the network approach is found to characterize main shocks in a peculiar manner.Comment: 10 pages, 3 figures, 1 tabl

Scale-invariant statistics of period in directed earthquake network

A new law regarding structure of the earthquake networks is found. The seismic data taken in California is mapped to a growing directed network. Then, statistics of period in the network, which implies that after how many earthquakes an earthquake returns to the initial location, is studied. It is found that the period distribution obeys a power law, showing the fundamental difficulty of statistical estimate of period.Comment: 11 pages including 3 figure

Signatures of Exotic Hadrons

Hadron spectroscopy represented in the past a major tool for understanding the fundamental symmetries of strong forces. More recently, the interest on this topic has been revitalized by the discovery of new quarkonium-like resonances, that do not fit in the standard picture and whose understanding could improve our mastery of quantum chromodynamics. I review here the experimental signatures of these exotic hadrons, at present and future e+e- and hadron collider experiments.Comment: 25 pages, 11 figures, submitted to International Journal of Modern Physics

Rapidity Gaps from Colour String Topologies

Diffractive deep inelastic scattering at HERA and diffractive W and jet production at the Tevatron are well described by soft colour exchange models. Their essence is the variation of colour string-field topologies giving both gap and no-gap events, with a smooth transition and thereby a unified description of all final states.Comment: 3 pages, 6 eps figures, contribution to the DIS 99 workshop proceedings, uses npb.st

Box Drawings for Learning with Imbalanced Data

The vast majority of real world classification problems are imbalanced, meaning there are far fewer data from the class of interest (the positive class) than from other classes. We propose two machine learning algorithms to handle highly imbalanced classification problems. The classifiers constructed by both methods are created as unions of parallel axis rectangles around the positive examples, and thus have the benefit of being interpretable. The first algorithm uses mixed integer programming to optimize a weighted balance between positive and negative class accuracies. Regularization is introduced to improve generalization performance. The second method uses an approximation in order to assist with scalability. Specifically, it follows a \textit{characterize then discriminate} approach, where the positive class is characterized first by boxes, and then each box boundary becomes a separate discriminative classifier. This method has the computational advantages that it can be easily parallelized, and considers only the relevant regions of feature space

Microcanonical Foundation for Systems with Power-Law Distributions

Starting from microcanonical basis with the principle of equal a priori probability, it is found that, besides ordinary Boltzmann-Gibbs theory with the exponential distribution, a theory describing systems with power-law distributions can also be derived.Comment: 9 page

Supersymmetry breaking in a warped slice with Majorana-type masses

We study the five-dimensional (5D) supergravity compactified on an orbifold S^1/Z_2, where the U(1)_R symmetry is gauged by the graviphoton with Z_2-even coupling. In contrast to the case of gauging with Z_2-odd coupling, this class of models has Majorana-type masses and allows the Scherk-Schwarz (SS) twist even in the warped spacetime. Starting from the off-shell formulation, we show that the supersymmetry is always broken in an orbifold slice of AdS_5, irrespective of the value of the SS twist parameter. We analyze the spectra of gaugino and gravitino in such background, and find the SS twist can provide sizable effects on them in the small warping region.Comment: 1+20 pages, 6 figure

Gauged U(1)RU(1)_R Symmetries and Fayet-Iliopoulos Terms in 5D Orbifold Supergravity

We discuss a gauged $U(1)_R$ supergravity on five-dimensional (5D) orbifold ($S^1/Z_2$) in which both a $Z_2$-even U(1) gauge field and the $Z_2$-odd graviphoton take part in the $U(1)_R$ gauging. Based on the off-shell formulation of 5D supergravity, we analyze the structure of Fayet-Iliopoulos (FI) terms allowed in such model. Introducing a $Z_2$-even $U(1)_R$ gauge field accompanies new bulk and boundary FI terms in addition to the known integrable boundary FI term which could be present in the absence of any gauged $U(1)_R$ symmetry. Some physical consequences of these new FI terms are examined.Comment: 1+17 pages, 9 figures, typeset in JHEP styl