These are notes from introductory lectures given at the Ecole Normale in Paris and at the Strasbourg meeting dedicated to the memory of Claude Itzykson. I review in considerable detail and in a hopefully pedagogical way the work of Seiberg and Witten on N = 2 supersymmetric SU(2) gauge theory without extra matter. This presentation basically follows their original work, except in the last secti...

One of the ultimate targets of lean manufacturing paradigm is to balance production and produce at takt time in production cells. This paper investigates the performance of a lean cell that implements the previous lean goals under uncertainty. The investigation is based on a system dynamics approach to model a dynamic lean cell. Backlog is used as a performance metric that reflects the cell’s r...

In Hilbert space L2(Rn), we prove the equivalence between the mod-ulus of smoothness and the K-functionals constructed by the Sobolev space cor-responding to the Fourier transform. For this purpose, Using a spherical meanoperator.

In this paper, we present new multi-year and 72-day mean seasonal-latitudinal tidal structures in exospheric temperature derived from joint analysis of CHAMP and GRACE accelerometer measurements. These results include diurnal tides DE3, DE2, D0, and DW2 and semidiurnal tides S0, SE1, SE2, SE3, SW4, and SW6. We also employ Hough mode extensions (HMEs) and the Climatological Model of Thermosphere...

In this paper, we consider the problem of modeling machine availability in enterprise-area and wide-area distributed computing settings. Using availability data gathered from three different environments, we detail the suitability of four potential statistical distributions for each data set: exponential, Pareto, Weibull, and hyperexponential. In each case, we use software we have developed to ...

This paper presents our analysis of the failure behavior of large scale systems using the failure logs collected by Los Alamos National Laboratory on 22 of their computing clusters.We note that not all nodes show similar failure behavior in the systems. Our objective, therefore, was to arrive at an ordering of nodes to be incrementally (one by one) selected for duplication so as to achieve a ta...

This paper turns the concept of input distributions on its head to exploit inverse input distributions Al though such distributions are not always true math ematical inverses they do capture an intuitive prop erty inputs that have high frequencies in the original distribution will have low frequencies in the inverse distribution and vice versa We can use the inverse distribution in several di e...

We present a topological characterization for fuzzy regular languages: we show that there is a bijective correspondence between fuzzy regular languages and the set of all clopen fuzzy subsets with finite image in the induced fuzzy topological space of Stone space (Profinite space), and then we give a representation of closed fuzzy subsets in the induced fuzzy topological space via fuzzy regular...

Some theoretical evaluation methods of mean time to failure (MTTF) in 2-component standby redundant system with priority have been suggested under the prerequisite that the probability distributions of failure and repair times in each component are respectively specified by the explicit functions. However, this prerequisite might be considerably strict in practical scenes. If we cannot identify...