Moving forward with combinatorial interaction testing

Combinatorial interaction testing (CIT) is an efficient and effective method of detecting failures that are caused by the interactions of various system input parameters. In this paper, we discuss CIT, point out some of the difficulties of applying it in practice, and highlight some recent advances that have improved CIT’s applicability to modern systems. We also provide a roadmap for future research and directions; one that we hope will lead to new CIT research and to higher quality testing of industrial systems

Le Cam spacings theorem in dimension two

The definition of spacings associated to a sequence of random variables is extended to the case of random vectors in [0,1]^2. Beirlant & al. (1991) give an alternative proof of the Le Cam (1958) theorem concerning asymptotic normality of additive functions of uniform spacings in [0,1]. I adapt their technique to the two-dimensional case, leading the way to new directions in the domain of Complete Spatial Randomness (CSR) testing

Recent Advances in the Economics of Individual Subjective Well-Being

Over the last decades, empirical research on subjective well-being in the social sciences has provided a major new stimulus to the discourse on individual happiness. Recently this research has also been linked to economics where reported subjective wellbeing is often taken as a proxy measure for individual welfare. In our review, we intend to provide an evaluation of where the economic research on happiness stands and of three directions it might develop. First, it offers new ways for testing the basic assumptions of the economic approach and for going about a new understanding of utility. Second, it provides a new possibility for the complementary testing of theories across fields in economics. Third, we inquire how the insights gained from the study of individual happiness in economics affect public policy. Keywords: Economics, happiness, life satisfaction, survey data, income, public goods, unemployment JEL Classifications: A10, D60, H41, I31

ShapeFit and ShapeKick for Robust, Scalable Structure from Motion

We introduce a new method for location recovery from pair-wise directions that leverages an efficient convex program that comes with exact recovery guarantees, even in the presence of adversarial outliers. When pairwise directions represent scaled relative positions between pairs of views (estimated for instance with epipolar geometry) our method can be used for location recovery, that is the determination of relative pose up to a single unknown scale. For this task, our method yields performance comparable to the state-of-the-art with an order of magnitude speed-up. Our proposed numerical framework is flexible in that it accommodates other approaches to location recovery and can be used to speed up other methods. These properties are demonstrated by extensively testing against state-of-the-art methods for location recovery on 13 large, irregular collections of images of real scenes in addition to simulated data with ground truth

Dynamics of trade-by-trade price movements: decomposition and models

In this paper we introduce a decomposition of the joint distribution of price changes of assets recorded trade--by--trade. Our decomposition means that we can model the dynamics of price changes using quite simple and interpretable models which are easily extended in a great number of directions, including using durations and volume as explanatory variables. Thus we provide an econometric basis for empirical work on market microstructure using time series of transactions data. We use maximum likelihood estimation and testing methods to assess the fit of the model to a year of IBM stock price data taken from the New York Stock Exchange.Activity, autologistic, conditional independence, decomposition, directions, durations, forecasting, GLARMA, logarithmic distribution, prediction decomposition, size, transactions data.

High efficiency magnetic bearings

Research activities concerning high efficiency permanent magnet plus electromagnet (PM/EM) pancake magnetic bearings at the University of Maryland are reported. A description of the construction and working of the magnetic bearing is provided. Next, parameters needed to describe the bearing are explained. Then, methods developed for the design and testing of magnetic bearings are summarized. Finally, a new magnetic bearing which allows active torque control in the off axes directions is discussed