University Scholar Series: Alejandro Garcia

Collaborating with DreamWorks On April 25, 2012 Professor Alejandro Garcia spoke in the University Scholar Series hosted by Provost Ellen Junn at the Dr. Martin Luther King, Jr. Library. Professor Alejandro Garcia developed and teaches Physics of Animation, a science course for visual artists. During 2011, he took a professional leave and worked in DreamWorks Animation\u27s department of Artistic Development as a physics consultant on Madagascar 3: Europe\u27s Most Wanted. In this seminar, Alejandro Garcia describes the animation industry from both the scientific and artistic perspectiveshttps://scholarworks.sjsu.edu/uss/1013/thumbnail.jp

Can the cosmological constant undergo abrupt changes?

The existence of a simple spherically symmetric and static solution of the Einstein equations in the presence of a cosmological constant vanishing outside a definite value of the radial distance is investigated. A particular succession of field configurations, which are solutions of the Einstein equations in the presence of the considered cosmological term and auxiliary external sources, is constructed. Then, it is shown that the associated succession of external sources tend to zero in the sense of the generalized functions. The type of weak solution that is found becomes the deSitter homogeneous space-time for the interior region, and the Schwartzschild space in the outside zone.Comment: 10 pages, 1 figur

Housing Market in Malaga: An Application of the Hedonic Methodology

The analysis of the factors that determine the price of the second-hand house, by means of the use of the hedonic methodology, constitutes the central objective of this work. This study has been applied to the market of the house corresponding to the municipality of Malaga (Spain), of where a sample of 1996 transactions, made during 2003, has been selected.This information has been facilitated by a real estate agency. The obtained results have allowed to identify those characteristics of the houses that more affect their price and quantify this influence, valuing it in monetary terms. It has been stated that the contribution of some structural attributes (the floor area, the number of toilets, the presence of private garage or the luminosity of the house) and others of location (proximity to the sea or downtown, and location in a certain zone) affects the price of the house decisively.

Understanding Corporate Bond Spreads Using Credit Default Swaps

Corporate bond spreads worldwide have widened markedly since the beginning of the credit crisis in 2007. This article examines default and liquidity risk--the main components of the corporate bond spread--for Canadian firms that issue bonds in the U.S. market, focusing in particular on their evolution during the credit crisis. They find that, during this period, the liquidity component increased more for speculative-grade bonds than it did for investment-grade bonds, consistent with a "flight-to-quality" phenomenon. An important implication of their results for policy-makers seeking to address problems in credit markets is that the liquidity risk in corporate spreads for investment and speculative bonds behaves differently than the default risk, especially during crisis episodes.

Unifying approach for fluctuation theorems from joint probability distributions

Any decomposition of the total trajectory entropy production for Markovian systems has a joint probability distribution satisfying a generalized detailed fluctuation theorem, when all the contributing terms are odd with respect to time reversal. The expression of the result does not bring into play dual probability distributions, hence easing potential applications. We show that several fluctuation theorems for perturbed non-equilibrium steady states are unified and arise as particular cases of this general result. In particular, we show that the joint probability distribution of the system and reservoir trajectory entropies satisfy a detailed fluctuation theorem valid for all times although each contribution does not do it separately

Defeasible Logic Programming: An Argumentative Approach

The work reported here introduces Defeasible Logic Programming (DeLP), a formalism that combines results of Logic Programming and Defeasible Argumentation. DeLP provides the possibility of representing information in the form of weak rules in a declarative manner, and a defeasible argumentation inference mechanism for warranting the entailed conclusions. In DeLP an argumentation formalism will be used for deciding between contradictory goals. Queries will be supported by arguments that could be defeated by other arguments. A query q will succeed when there is an argument A for q that is warranted, ie, the argument A that supports q is found undefeated by a warrant procedure that implements a dialectical analysis. The defeasible argumentation basis of DeLP allows to build applications that deal with incomplete and contradictory information in dynamic domains. Thus, the resulting approach is suitable for representing agent's knowledge and for providing an argumentation based reasoning mechanism to agents.Comment: 43 pages, to appear in the journal "Theory and Practice of Logic Programming