Multicomponent solution in modified theory of gravity in the early universe

We study the modified theory of gravity in Friedmann Robertson Walker universe composed of several perfect fluids. We consider the power law inflation and determine the equation of state parameters in terms of the parameters of modified gravity's Lagrangian in the early universe. We also discuss briefly the gravitational baryogenesis in this model.Comment: 9 pages, accepted for publication in Physical Review

A Note on Gravitational Baryogenesis

The coupling between Ricci scalar curvature and the baryon number current dynamically breaks CPT in an expanding universe and leads to baryon asymmetry. We study the effect of time dependence of equation of state parameter of the FRW universe on this asymmetry.Comment: 10 pages, accepted for publication in Physical Review

Cancer registry in Iran: A brief overview

Cancer registry is an important tool for any successful cancer control program. The first formal cancer related data from Iran were published in 1956. In 1969, observations documenting a high incidence of esophageal cancer in the Caspian Littoral, urged researchers to set up the first population-based cancer registry in this region. This cancer registry was established jointly by University of Tehran and the International Agency for Research on Cancer (IARC). In 1976, another cancer registry started its activities in Fars Province. In 1984, the Parliament passed a bill mandating the report of all tissues "diagnosed or suspected as cancer tissue" to the Ministry of Health. While only 18% of all estimated cancer cases were reported in first reports, this rate increased to 81% in 2005 In 1998, Tehran Population-Based Cancer Registry started to collect data from cases of cancer referred to the treatment and diagnostic facilities throughout the Tehran metropolis. Digestive Disease Research Center, Tehran University of Medical Sciences, established four new population-based cancer registries in Northern Iran and another in Kerman Province in the south. These five provinces have a total population of about 9.5 million, and constitute about 16% of the total population of Iran. While the pathology-based cancer registration is in place, we hope that the addition of the population-based cancer registries, and establishment of new registries in poorly-covered areas, will improve cancer reporting in the country

Cancer incidence in Golestan province: Report of an ongoing population-based cancer registry in Iran between 2004 and 2008

Background: Golestan Province, at the western end of the Asian esophageal cancer (EC) belt in northeastern Iran, was reported to have one of the highest worldwide rates of EC in the 1970s. We have previously shown a declining incidence of EC in Golestan during the last decades. This study reports additional new results from the Golestan Population-based Cancer Registry (GPCR). Methods: The GPCR collected data from newly diagnosed (incident) cancer cases from all 68 public and private diagnostic and therapeutic centers in Golestan Province. CanReg-4 software was used for data entry and analysis based on the guidelines of the International Agency for Research on Cancer (IARC). Age-standardized incidence rates (ASR) of cancers were calculated using the 2000 world standard population. Results: From 2004 through 2008, 9007 new cancer cases were reported to the GPCR. The mean (SD) age was 55.5 (18.6) years, and 54 were diagnosed in men. The ASRs of all cancers were 175.3 and 141.1 per 100,000 person-years for males and females, respectively. Cancers of the stomach (ASR:30.7), esophagus (24.3), and lung (15.4) were the most common cancers in males. In females, breast cancer (ASR:26.9) was followed by malignancies of the esophagus (19.1) and stomach (12.4). The diagnosis of cancer was based on histopatho- logical reports in 71 and on death certificate only in 9 ofcases. Conclusions: The EC incidence rate continues to decline in Golestan, while the incidence rates of stomach, colorectal, and breast cancers continue to increase

Detection and classification of buried dielectric anomalies using neural networks–further results

Includes bibliographical references.The development of a neural network-based detection and classification system for use with buried dielectric anomalies is the main focus of this paper. Several methods of data representation are developed to study their effects on the trainability and generalization capabilities of the neural networks. The method of Karhonen-Loeve (KL) transform is used to extract energy dependent features and to reduce the dimensionality of the weight space of the original data set. To extract the shape-dependent features of the data, another data preprocessing method known as Zernike moments is also studied for its use in the detector/classifier system. The effects of different neural network paradigms, architectural variations, and selection of proper training data on detection and classification rates are studied. Simulation results for nylon and wood targets indicate superior performance when compared to conventional schemes.This work was supported by the U.S. Army Belvoir RDandE Center under contract No. DAAL03-86-D-0001

Two-dimensional block processors - structures and implementations

Includes bibliographical references.Two-dimensional (2-D) block processing technique for linear filtering of digital images is introduced. New 2-D block structures are derived for 2-D recursive digital filters realized by difference equations and state-space formulations. Several special cases have also been considered and the relevant 2-D block structures are given. The computational costs of different implementation techniques employing high-speed convolution algorithms such as fast Fourier transform, number theoretic transform and polynomial transform have been studied. A comparison among the relative efficiencies of these implementation schemes is made and a suitable method is then proposed using short convolution algorithm which results in a minimized computational time

Two-dimensional block transforms and their properties

Includes bibliographical references.For two-dimensional (2-D) digital filters implemented by a block recursive equation, explicit relations between their frequency characteristics and those of scalar filter are obtained. Specifically, these include the relation between the discrete-time Fourier transform (DTFT) of the block recursive equation and that of the scalar 2-D difference equation, and the relation between the block matrix transfer function of the block processor and the scalar transfer function. These relations that are independent of the type of realization of the block processor have been obtained using the eigenvalue properties of a special type of circulant matrix introduced in this correspondence

Cosmological entropy and generalized second law of thermodynamics in F(R,G)F(R,G) theory of gravity

We consider a spatially flat Friedmann-Lemaitre-Robertson-Walker space time and investigate the second law and the generalized second law of thermodynamics for apparent horizon in generalized modified Gauss Bonnet theory of gravity (whose action contains a general function of Gauss Bonnet invariant and the Ricci scalar: $F(R,G)$). By assuming that the apparent horizon is in thermal equilibrium with the matter inside it, conditions which must be satisfied by $F(R,G)$ are derived and elucidated through two examples: a quasi-de Sitter space-time and a universe with power law expansion.Comment: 10 pages, minor changes, typos corrected, accepted for publication in Europhysics Letter

Rational invariant subspace approximations with applications

Includes bibliographical references.Subspace methods such as MUSIC, Minimum Norm, and ESPRIT have gained considerable attention due to their superior performance in sinusoidal and direction-of-arrival (DOA) estimation, but they are also known to be of high computational cost. In this paper, new fast algorithms for approximating signal and noise subspaces and that do not require exact eigendecomposition are presented. These algorithms approximate the required subspace using rational and power-like methods applied to the direct data or the sample covariance matrix. Several ESPRIT- as well as MUSIC-type methods are developed based on these approximations. A substantial computational saving can be gained comparing with those associated with the eigendecomposition-based methods. These methods are demonstrated to have performance comparable to that of MUSIC yet will require fewer computation to obtain the signal subspace matrix