Eigenfunctions of the Laplace-Beltrami Operator on Hyperboloids

Eigenfunctions of the Laplace-Beltrami operator on a hyperboloid are studied in the spirit of the treatment of the spherical harmonics by Stein and Weiss. As a special case, a simple self-contained proof of Laplace's integral for a Legendre function is obtained.Comment: 5 page

Shorted Operators Relative to a Partial Order in a Regular Ring

In this paper, the explicit form of maximal elements, known as shorted operators, in a subring of a von Neumann regular ring has been obtained. As an application of the main theorem, the unique shorted operator (of electrical circuits) which was introduced by Anderson-Trapp has been derived.Comment: There was a small mistake in the published version which has been corrected her

Flooding attacks to internet threat monitors (ITM): Modeling and counter measures using botnet and honeypots

The Internet Threat Monitoring (ITM),is a globally scoped Internet monitoring system whose goal is to measure, detect, characterize, and track threats such as distribute denial of service(DDoS) attacks and worms. To block the monitoring system in the internet the attackers are targeted the ITM system. In this paper we address flooding attack against ITM system in which the attacker attempt to exhaust the network and ITM's resources, such as network bandwidth, computing power, or operating system data structures by sending the malicious traffic. We propose an information-theoretic frame work that models the flooding attacks using Botnet on ITM. Based on this model we generalize the flooding attacks and propose an effective attack detection using Honeypots

Inductive Algebras for Finite Heisenberg Groups

A characterization of the maximal abelian sub-algebras of matrix algebras that are normalized by the canonical representation of a finite Heisenberg group is given. Examples are constructed using a classification result for finite Heisenberg groups.Comment: 5 page

Effect of Peripheral Layer on Peristaltic Transport of a Micropolar Fluid

Peristaltic transport of two fluid model with micropolar fluid in the core region and Newtonian fluid in the peripheral layer is studied under the assumptions of long wavelength and low Reynolds number. The linearised equations governing the flow are solved and closed form expressions for pressure rise, time averaged flux and frictional force have been obtained. The effects of various parameters on these flow variables have been studied. It is found that the pressure rise increases with micropolar parameter (m) and central mean radius (η), but decreases with coupling number (N) and viscosity ratio (µ¯). The frictional force (F¯) decreases with coupling number (N) and viscosity ratio (µ¯) but increases with micropolar parameter (m) and mean radius of central layer (η)

Income uncertainty and household savings in China

China's urban household saving rate has increased markedly since the mid-1990s and the age-savings profile has become U-shaped. To understand these patterns, we analyze a panel of urban Chinese households over the period 1989–2009. We document a sharp increase in income uncertainty, largely due to an increase in the variance in household income attributed to transitory idiosyncratic shocks. We then calibrate a buffer-stock savings model to obtain quantitative estimates of the impact of rising household-specific income uncertainty as well as another shock to household income—the pension reforms that were instituted in the late 1990s. Our calibrations suggest that rising income uncertainty and pension reforms lead younger and older households, respectively, to raise their saving rates significantly. These two factors account for two-thirds of the increase in China's urban household saving rate and the U-shaped age-savings profile.We are grateful to Loren Brandt, Robert Moffitt, two anonymous referees, as well as participants at the NBER Summer Institute, China Economics Summer Institute, IMF Research Seminar, and the Workshop on China's Macroeconomy at the University of Toronto for comments and suggestions. We thank Lei (Sandy) Ye for research assistance. The views expressed in this paper are those of the authors and do not necessarily reflect those of the institutions the authors are affiliated with.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.jdeveco.2013.07.01

What does a strongly excited 't Hooft-Polyakov magnetic monopole do?

The time evolution of strongly exited SU(2) Bogomolny-Prasad-Sommerfield (BPS) magnetic monopoles in Minkowski spacetime is investigated by means of numerical simulations based on the technique of conformal compactification and on the use of hyperboloidal initial value problem. It is found that an initially static monopole does not radiate the entire energy of the exciting pulse toward future null infinity. Rather, a long-lasting quasi-stable `breathing state' develops in the central region and certain expanding shell structures -- built up by very high frequency oscillations -- are formed in the far away region.Comment: 4 pages, 6 figure