Predicting regression test failures using genetic algorithm-selected dynamic performance analysis metrics

A novel framework for predicting regression test failures is proposed. The basic principle embodied in the framework is to use performance analysis tools to capture the runtime behaviour of a program as it executes each test in a regression suite. The performance information is then used to build a dynamically predictive model of test outcomes. Our framework is evaluated using a genetic algorithm for dynamic metric selection in combination with state-of-the-art machine learning classifiers. We show that if a program is modified and some tests subsequently fail, then it is possible to predict with considerable accuracy which of the remaining tests will also fail which can be used to help prioritise tests in time constrained testing environments

Utilization of space resources in the space transportation system

Utilization of space resources (i.e., raw materials obtained from nonterrestrial sources) has often been cited as a prerequisite for large-scale industrialization and habitation of space. While transportation of extremely large quantities of material from Earth would be costly and potentially destructive to our environment, vast quantities of usable resources might be derived from the Moon, the asteroids, and other celestial objects in a cost-effective and environmentally benign manner. The primary purpose of the parametric cost model developed as part of this study is to identify the factors that have the greatest influence on the economics of space resource utilization. In the near term, this information can be used to devise strategies for technology development so that capabilities developed will produce cost-effective results

Entanglement entropy of Wilson loops: Holography and matrix models

A half-BPS circular Wilson loop in $\mathcal{N}=4$ $SU(N)$ supersymmetric Yang-Mills theory in an arbitrary representation is described by a Gaussian matrix model with a particular insertion. The additional entanglement entropy of a spherical region in the presence of such a loop was recently computed by Lewkowycz and Maldacena using exact matrix model results. In this note we utilize the supergravity solutions that are dual to such Wilson loops in a representation with order $N^2$ boxes to calculate this entropy holographically. Employing the matrix model results of Gomis, Matsuura, Okuda and Trancanelli we express this holographic entanglement entropy in a form that can be compared with the calculation of Lewkowycz and Maldacena. We find complete agreement between the matrix model and holographic calculations.Comment: 17 pages, 1 figur

Information and Barometric Prices: An Explanation for Price Stickiness

Price stickiness plays a decisive role in many macroeconomic models, yet why prices are sticky remains a puzzle. We develop a microeconomic model in which two competing firms are free to set prices, but face uncertainty about the state of demand. With some probability, there is a positive demand shock, which is observed but by one firm. In equilibrium, only the informed firm adjusts its price after the shock, while the uninformed firm raises its price only with a delay, after observing the price of its competitor. Hence, prices are sticky in the sense that one firm's price does not adjust immediately. Further, if getting information is costly, the model implies that the larger firm tends to be better informed and to adjust its price first.Price Setting; Sticky Prices; Asymmetric Information; Barometic Price Leadership

International print and digital repositories initiatives in the United States: CRL, Portico, LOCKSS, Internet Archive : 6th scientific symposium Frankfurt - 6. wissenschaftliches Symposium Frankfurt ; October 5 - 7, 2006

This panel will explore the broad horizon of print and digital repository efforts underway in the United States