We saw the definition of base, circuit, rank, span and flat of matroids last lecture. We begin this lecture by studying some more basic properties of a matroid. Exercise 1 Show that a set I ⊆ S is independent in a matroid M iff ∀y ∈ I, there exists a flat F such that I − y ⊆ F and y ∈ F. Exercise 3 Verify that (S, I *) is indeed a matroid. Remark 4 Having an independence or rank oracle for M im...

Detecting foreground pixels is the rst step to detect objects of interestin videos. The objective of this thesis is to propose a new background estimationmethod to detect foreground pixels. The proposed method can adapt the estimatedbackground to various changes of environment (e.g. changes of illumination or ofcontextual objects).The proposed background estimation method co...

The motivation for the work reported in this thesis has been to lessen the gap between theory and practice within the eld of parallel computing When looking for new and faster parallel algorithms for use in massively parallel systems it is tempting to investigate promising alternatives from the large body of research done on parallel algorithms within the eld of theoretical computer science The...

The authors describe Bayesian estimation for the parameters of the bivariate gamma distribution due to Kibble (1941). The density of this distribution can be written as a mixture, which allows for a sim ple data augmentation scheme. The authors propose a Markov chain Monte Carlo algorithm to facilitate estimation. They show that the resulting chain is geometrically ergodic, and thus a regenerat...

This article is a theoretical basis for the software implementation of the Physical space Statistical Analysis System PSAS that is used for atmospheric data analysis at the NASA Data Assimilation O ce DAO The PSAS implements a statistical algo rithm that combines irregularly spaced observations with a gridded forecast to produce an optimal estimate of the state of the atmosphere Starting frommo...

The bin packing optimization problem packs a set of objects into a set of bins so that the amount of wasted space is minimized The bin packing problem has many important applications These include multiprocessor scheduling resource allocation and real world planning packing routing and scheduling optimization problems The bin packing problem is NP complete Since there is therefore little hope i...

Groupware systems are computer based systems which supports two or more users working in a tightly coupled fashion on a common task. This paper briefly introduc ess a family of concurrency control algorithms for groupware systems. These algo rithms maintain consistency without locking, and without rollback, within a dynam ic non-serializable environment. A consistency theorem for this family of...

Editors Frances Rosamond (Univ Bergen) [email protected] and Valia Mitsou (Univ Paris Diderot) [email protected]. Congratulations to all for many awards and prizes, graduates, new jobs, and wonderful research. ALGO 2017 showcased ten awards and 8 of them were related to parameterized complexity! This newsletter includes articles by the IPEC Best Paper and Excellent Student Paper Award...

Known results: • Generalizes Set Cover, (Non-Metric / Multi-level) Facility Location, Group Steiner Tree • Ω(log2− n)-hard (Halperin, Krauthgamer ’03) • |X| -apx in poly by sophisticated greedy algo (Zelikovsky ’97) • O(log |X|)-apx in nO(log |X|) time by more sophisticated greedy algo (Charikar, Chekuri, Cheung, Goel, Guha and Li ’99) • LP’s have integrality gap Ω( √ k) already for 5 layers; e...