Quantum bounds for gravitational de Sitter entropy and the Cardy-Verlinde formula

We analyze different types of quantum corrections to the Cardy-Verlinde entropy formula in a Friedmann-Robertson-Walker universe and in an (anti)-de Sitter space. In all cases we show that quantum corrections can be represented by an effective cosmological constant which is then used to redefine the parameters entering the Cardy-Verlinde formula so that it becomes valid also with quantum corrections, a fact that we interpret as a further indication of its universality. A proposed relation between Cardy-Verlinde formula and the ADM Hamiltonian constraint is given.Comment: LaTeX file, 15 pages, reference is adde

Inflated 3D ConvNet context analysis for violence detection

According to the Wall Street Journal, one billion surveillance cameras will be deployed around the world by 2021. This amount of information can be hardly managed by humans. Using a Inflated 3D ConvNet as backbone, this paper introduces a novel automatic violence detection approach that outperforms state-of-the-art existing proposals. Most of those proposals consider a pre-processing step to only focus on some regions of interest in the scene, i.e., those actually containing a human subject. In this regard, this paper also reports the results of an extensive analysis on whether and how the context can affect or not the adopted classifier performance. The experiments show that context-free footage yields substantial deterioration of the classifier performance (2% to 5%) on publicly available datasets. However, they also demonstrate that performance stabilizes in context-free settings, no matter the level of context restriction applied. Finally, a cross-dataset experiment investigates the generalizability of results obtained in a single-collection experiment (same dataset used for training and testing) to cross-collection settings (different datasets used for training and testing)

Gotcha-I: A Multiview Human Videos Dataset

The growing need of security in large open spaces led to the need to use video capture of people in different context and illumination and with multiple biometric traits as head pose, body gait, eyes, nose, mouth, and further more. All these traits are useful for a multibiometric identification or a person re-identification in a video surveillance context. Body Worn Cameras (BWCs) are used by the police of different countries all around the word and their use is growing significantly. This raises the need to develop new recognition methods that consider multibiometric traits on person re-identification. The purpose of this work is to present a new video dataset called Gotcha-I. This dataset has been obtained using more mobile cameras to adhere to the data of BWCs. The dataset includes videos from 62 subjects in indoor and outdoor environments to address both security and surveillance problem. During these videos, subjects may have a different behavior in videos such as freely, path, upstairs, avoid the camera. The dataset is composed by 493 videos including a set of 180° videos for each face of the subjects in the dataset. Furthermore, there are already processed data, such as: the 3D model of the face of each subject with all the poses of the head in pitch, yaw and roll; and the body keypoint coordinates of the gait for each video frame. It’s also shown an application of gender recognition performed on Gotcha-I, confirming the usefulness and innovativeness of the proposed dataset

Gait Analysis for Gender Classification in Forensics

Gender Classification (GC) is a natural ability that belongs to the human beings. Recent improvements in computer vision provide the possibility to extract information for different classification/recognition purposes. Gender is a soft biometrics useful in video surveillance, especially in uncontrolled contexts such as low-light environments, with arbitrary poses, facial expressions, occlusions and motion blur. In this work we present a methodology for the construction of a gait analyzer. The methodology is divided into three major steps: (1) data extraction, where body keypoints are extracted from video sequences; (2) feature creation, where body features are constructed using body keypoints; and (3) classifier selection when such data are used to train four different classifiers in order to determine the one that best performs. The results are analyzed on the dataset Gotcha, characterized by user and camera either in motion

MTT-30

Abstract -Only approximate relations are so far available for the pufling figure of an oscillator. An exact derivation of the pnlling figure is presented here, tafdng fufly into account the nonlinearity of the oscillator admittance. Effect of the oscillator nonlinearity on the asymmetry of the pulling range is presented

(Non) singular Kantowski-Sachs Universe from quantum spherically reduced matter

Using s-wave and large N approximation the one-loop effective action for 2d dilaton coupled scalars and spinors which are obtained by spherical reduction of 4d minimal matter is found. Quantum effective equations for reduced Einstein gravity are written. Their analytical solutions corresponding to 4d Kantowski-Sachs (KS) Universe are presented. For quantum-corrected Einstein gravity we get non-singular KS cosmology which represents 1) quantum-corrected KS cosmology which existed on classical level or 2)purely quantum solution which had no classical limit. The analogy with Nariai BH is briefly mentioned. For purely induced gravity (no Einstein term) we found general analytical solution but all KS cosmologies under discussion are singular. The corresponding equations of motion are reformulated as classical mechanics problem of motion of unit mass particle in some potential V.Comment: LaTeX file, 16 pages, a few misprints are correcte

Generating Gowdy cosmological models

Using the analogy with stationary axisymmetric solutions, we present a method to generate new analytic cosmological solutions of Einstein's equation belonging to the class of $T^3$ Gowdy cosmological models. We show that the solutions can be generated from their data at the initial singularity and present the formal general solution for arbitrary initial data. We exemplify the method by constructing the Kantowski-Sachs cosmological model and a generalization of it that corresponds to an unpolarized $T^3$ Gowdy model.Comment: Latex, 15 pages, no figure

Minisuperspace Examples of Quantization Using Canonical Variables of the Ashtekar Type: Structure and Solutions

The Ashtekar variables have been use to find a number of exact solutions in quantum gravity and quantum cosmology. We investigate the origin of these solutions in the context of a number of canonical transformations (both complex and real) of the basic Hamiltonian variables of general relativity. We are able to present several new solutions in the minisuperspace (quantum cosmology) sector. The meaning of these solutions is then discussed.Comment: 23 pages, latex, 3 figures (uuencoded, separate file