Gauge Field Strength Tensor from the Overlap Dirac Operator

We derive the classical continuum limit of the operator tr$_s \sigma_{\mu\nu} D^{ov}(x,x)$ with $D^{ov}$ being the overlap Dirac operator and show that it corresponds to the gauge field strength tensor $F_{\mu\nu}(x)$.Comment: 17 page

Ratio tests for change point detection

We propose new tests to detect a change in the mean of a time series. Like many existing tests, the new ones are based on the CUSUM process. Existing CUSUM tests require an estimator of a scale parameter to make them asymptotically distribution free under the no change null hypothesis. Even if the observations are independent, the estimation of the scale parameter is not simple since the estimator for the scale parameter should be at least consistent under the null as well as under the alternative. The situation is much more complicated in case of dependent data, where the empirical spectral density at 0 is used to scale the CUSUM process. To circumvent these difficulties, new tests are proposed which are ratios of CUSUM functionals. We demonstrate the applicability of our method to detect a change in the mean when the errors are AR(1) and GARCH(1,1) sequences.Comment: Published in at http://dx.doi.org/10.1214/193940307000000220 the IMS Collections (http://www.imstat.org/publications/imscollections.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

Migration as a Political and Public Phenomenon: The Case of Hungary

Publication within the project “The V4 towards migration challenges in Europe. An analysis and recommendations” is financed by Visegrad Fun

Cryopreservation of Pike Perch Sperm in Hatchery Conditions

Experiments were carried out on pike perch (Sander lucioperca L.) to find a method for stripping sperm without contamination by urine, to determine sperm concentration, and to fertilize large batches of eggs with cryopreserved sperm. Induced spawning technology for pike perch, an important predator fish species in Hungarian and central-eastern European pond aquaculture, has been developed only recently. Sperm cryopreservation can be an important tool for several reasons including the simplification of hatchery work and long-term preservation of genomes of males with high genetic value. In the present study, sperm was stripped without urine contamination, improving sperm quality, and large amounts of eggs were fertilized using 0.25 ml sperm, resulting in hatching percentages of 55±3% for 30-g batches of eggs and 87% for a 50-g batch

The Analysis of Space-Time Structure in QCD Vacuum II: Dynamics of Polarization and Absolute X-Distribution

We propose a framework for quantitative evaluation of dynamical tendency for polarization in arbitrary random variable that can be decomposed into a pair of orthogonal subspaces. The method uses measures based on comparisons of given dynamics to its counterpart with statistically independent components. The formalism of previously considered X-distributions is used to express the aforementioned comparisons, in effect putting the former approach on solid footing. Our analysis leads to definition of a suitable correlation coefficient with clear statistical meaning. We apply the method to the dynamics induced by pure-glue lattice QCD in local left-right components of overlap Dirac eigenmodes. It is found that, in finite physical volume, there exists a non-zero physical scale in the spectrum of eigenvalues such that eigenmodes at smaller (fixed) eigenvalues exhibit convex X-distribution (positive correlation), while at larger eigenvalues the distribution is concave (negative correlation). This chiral polarization scale thus separates a regime where dynamics enhances chirality relative to statistical independence from a regime where it suppresses it, and gives an objective definition to the notion of "low" and "high" Dirac eigenmode. We propose to investigate whether the polarization scale remains non-zero in the infinite volume limit, in which case it would represent a new kind of low energy scale in QCD.Comment: v2: 38 pages, 12 figures, author-preferred version; v3: journal-preferred versio

Real-Time Time-Varying Equilibrium Interest Rates: Evidence on the Czech Republic

This paper examines (real-time) equilibrium interest rates in the Czech Republic in 2001:1- 2005:12 estimating various specifications of simple Taylor-type monetary policy rules. First, we estimate it using GMM. Second, we apply structural time-varying coefficient model with endogenous regressors to evaluate fluctuations of equilibrium interest rate over time. The results suggest that there is substantial interest rate smoothing and central bank primarily responds to inflation (forecast) developments. The estimated parameters seem to sustain the equilibrium determinacy. We find that the equilibrium interest rates gradually decreased over sample period to the levels comparable to those of in the euro area reflecting capital accumulation, smaller risk premium and successful disinflation in the Czech economy.http://deepblue.lib.umich.edu/bitstream/2027.42/57228/1/wp848 .pd

Financial Accelerator Effects in the Balance Sheets of Czech Firms

The paper examines a financial accelerator mechanism in analyzing determinants of corporate interest rates. Using a panel of the financial statements of 448 Czech firms from 1996-2002, we find that balance sheet indicators matter for the interest rates paid by firms. Market access is particularly important in this regard. The strength of corporate balance sheets seem to vary with firm size. There is also evidence that monetary policy has a stronger effect on smaller than on larger firms. On the other hand, we find no asymmetry in the monetary policy effects over the business cycle.http://deepblue.lib.umich.edu/bitstream/2027.42/57227/1/wp847 .pd

Triple Play Services in XG-PON Network.

This paper focuses on Triple Play services in XG-PON networks and their implementation and analysis in NS-3. Nowadays, Triple Play services dominate copper/optical networks. The network simulator allowed simulation of Passive Optical Networks (PON), especially XG-PON. Each service in the XG-PON simulation is represented OnOff application with different parameters. This article describes implementation and analysis of these services in basic topology of the XG-PON network