A Topological-like Model for Gravity in 4D Space-time

In this paper we consider a model for gravity in 4-dimensional space-time originally proposed by Chamseddine, which may be derived by dimensional reduction and truncation from a 5-dimensional Chern-Simons theory. Its topological origin makes it an interesting candidate for an easier quantization, e.g., in the Loop Quantization framework. The present paper is dedicated to a classical analysis of the model's properties. Cosmological solutions as well as wave solutions are found and compared with the corresponding solutions of Einstein's General Relativity with cosmological constant.Comment: 24 pages, 2 figures, PDFLatex. Typos corrected. Subsection 2.2.1 is new and subsection 2.2.3 (old subsection 2.2.2) has been improve

Monitoring the Accuracy of Multiple Occupancy Forecasts

Corporate executives closely monitor the accuracy of their hotels\u27 occupancy fore- casts since important decisions are based upon these predictions. This study lists the criteria for selecting an appropriate error measure. It discusses several evaluation methods focusing on statistical significance tests and demonstrates the use of two adequate evaluation methods: Mincer- Zamowitz\u27s efficiency test and Wilcoxon\u27s Non-Parametric Matched-Pairs Signed- Ranks test

Chern-Simons Gravity in Four Dimensions

Five dimensional Chern-Simons theory with (anti-)de Sitter SO(1,5) or SO(2,4) gauge invariance presents an alternative to General Relativity with cosmological constant. We consider the zero-modes of its Kaluza-Klein compactification to four dimensions. Solutions with vanishing torsion are obtained in the cases of a spherically symmetric 3-space and of a homogeneous and isotropic 3-space, which reproduce the Schwarzshild-de Sitter and $\Lambda$CDM cosmological solutions of General Relativity. We also check that vanishing torsion is a stable feature of the solutions.Comment: 25 pages, Late

Behaviour of Charged Spinning Massless Particles

We revisit the classical theory of a relativistic massless charged point particle with spin and interacting with an external electromagnetic field. In particular, we give a proper definition of its kinetic energy and its total energy, the latter being conserved when the external field is stationary. We also write the conservation laws for the linear and angular momenta. Finally, we find that the particle's velocity may differ from $c$ as a result of the spin---electromagnetic field interaction, without jeopardizing Lorentz invariance.Comment: PDFtex file, 20 pages, 3 figures Revised version published in Symmetry (Basel

Tracking people in crowds by a part matching approach

The major difficulty in human tracking is the problem raised by challenging occlusions where the target person is repeatedly and extensively occluded by either the background or another moving object. These types of occlusions may cause significant changes in the person's shape, appearance or motion, thus making the data association problem extremely difficult to solve. Unlike most of the existing methods for human tracking that handle occlusions by data association of the complete human body, in this paper we propose a method that tracks people under challenging spatial occlusions based on body part tracking. The human model we propose consists of five body parts with six degrees of freedom and each part is represented by a rich set of features. The tracking is solved using a layered data association approach, direct comparison between features (feature layer) and subsequently matching between parts of the same bodies (part layer) lead to a final decision for the global match (global layer). Experimental results have confirmed the effectiveness of the proposed method. © 2008 IEEE

Pelaksanaan Dispensasi Nikah di Bawah Umur di Desa Kulim Jaya Kecamatan Lubuk Batu Jaya Kabupaten Indragiri Hulu Menurut Undang-undang Nomor 1 Tahun 1974 Tentang Perkawinan

Underage marriage is a marriage that is performed by someone who has not met the minimum age limit for marriage . Underage marriage actually be done with specific reasons and must be accompanied by a decree of the Court of Religion according to the contents of Article 7 paragraph ( 2 ) of Law No. 1 of 1974 About Marriage ( hereinafter called the Marriage Act ) . In fact, in the village of Kulim Jaya there are still underage marriage that is not accompanied by a decree granting a dispensation marriage of Islamic Court . The purpose of this thesis research is to determine how the implementation of the dispensation of marriage in the village Kulim Lubuk Batu Jaya Jaya District of Indragiri Hulu , and to know the reason KUA Lubuk Batu Jaya remained married couples under age without a dispensation giving marriage of Religious Court and to know the reasons actors marriage minors do not follow the trial court granting the dispensation of Religion .The method used is Observation Research with juridical sociological approach , sedangkat nature of this thesis research is descriptive . The way research is by way of surveys and structured interviews . Results of the study found is still the presence of underage marriage in Kulim Jaya village which is not accompanied by a decree granting marriage dispensassi of Religious Court . KUA Lubuk Batu Jaya remained married couples under age without a court order as a state religion pregnant outside marriage and economic circumstances are not allowed to attend the session in the Religious . Performers underage marriage did not follow the trial in court to obtain a dispensation Religious marriage by reason of distances , complicated procedures and a long time . Suggestions author , the first expected to KUA Lubuk Batu Jaya in order not to marry underage partner without marriage dispensation decree of Islamic Court . Both the KUA Lubuk Batu Jaya to be more prudent in giving the decision to marry couples under age , and the third to parents whose children will marry underage dispensassi it has obtained a marriage in the Religious

Thermodynamics of phantom black holes in Einstein-Maxwell-Dilaton theory

A thermodynamic analysis of the black hole solutions coming from the Einstein-Maxwell-Dilaton theory (EMD) in 4D is done. By consider the canonical and grand-canonical ensemble, we apply standard method as well as a recent method known as Geometrothermodynamics (GTD). We are particularly interested in the characteristics of the so called phantom black hole solutions. We will analyze the thermodynamics of these solutions, the points of phase transition and their extremal limit. Also the thermodynamic stability is analyzed. We obtain a mismatch of the between the results of the GTD method when compared with the ones obtained by the specific heat, revealing a weakness of the method, as well as possible limitations of its applicability to very pathological thermodynamic systems. We also found that normal and phantom solutions are locally and globally unstable, unless for certain values of the coupled constant of the EMD action. We also shown that the anti-Reissner-Nordstrom solution does not posses extremal limit nor phase transition points, contrary to the Reissner-Nordstrom case.Comment: 23 pages, version accepted for publication in Physical Review

Complete loop quantization of a dimension 1+2 Lorentzian gravity theory

De Sitter Chern-Simons gravity in D = 1 + 2 spacetime is known to possess an extension with a Barbero-Immirzi like parameter. We find a partial gauge fixing which leaves a compact residual gauge group, namely SU(2). The compacticity of the residual gauge group opens the way to the usual LQG quantization techniques. We recall the exemple of the LQG quantization of SU(2) CS theory with cylindrical space topology, which thus provides a complete LQG of a Lorentzian gravity model in 3-dimensional space-time.Comment: Loops11 - Madrid - 2011 (4 pages, Latex