of control information, and a rate-control algorithm that op-erates at each hop along a flow. Using several real network topologies, we show that Flush closely tracks or exceeds the maximum goodput achievable by a hand-tuned but fixed rate for each hop over a wide range of path lengths and varying network

neurons are tuned relatively selectively to highly specific feature conjunctions may permit a neuronal ensemble to distinguish among complex, similar members of a large class of stimuli, such as the faces of conspecifics. Current information-theoretical approaches are providing more detail on how

This paper presents and evaluates two principles for designing robust, reliable, and efficient collection protocols. These principles allow a protocol to benefit from accurate and agile link estimators by handling the dynamism such estimators introduce to routing tables. The first is datapath validation: a protocol can use data traffic as active topology probes, quickly discovering and fixing routing loops. The second is adaptive beaconing: by extending the Trickle code propagation algorithm to routing control traffic, a protocol sends fewer beacons while simultaneously reducing its route repair latency. We study these mechanisms in an implementation called Collection Tree Protocol (CTP) and evaluate their contributions to its performance. We evaluate CTP on 12 different testbeds ranging in size from 20–310 nodes and comprising 7 hardware platforms, on 6 different link layers, and on interference-free and interference-prone channels. In all cases, CTP delivers> 90 % of packets. Many experiments achieve 99.9%. Compared to standard beaconing, CTP sends 73 % fewer beacons while reducing topology repair latency by 99.8%. Finally, when using low-power link layers, CTP has duty cycles of 3 % while supporting aggregate loads of 30 packets/minute. 1

m]]l]]s¶D]]¿÷mB]iv]b]oD]m¶¨]iv]§]iv]r]j]t¿rv]]irj]]t]]m] / | ap]]r¿]ÎNy]s¶D]]mb¶r]ix} Û]Ix]]rd]mb]} p—N]t]o%ism] in]ty]m] / || Û]Is]¡uÎc]rN]]riv]nd]p]*N]m]st¶ I always bow to Śri ̄ Śāradāmbā, the limitless ocean of the nectar of compassion, who bears a rosary, a vessel of nectar, the symbol of knowledge and a book in Her lotus hands. Dedicated to the Lotus Feet of the revered Sadguru. This thesis presents a new active mask (AM) framework and an algorithm for segmenta-tion of digital images, particularly those of punctate patterns from fluorescence microscopy. Fluorescence microscopy has greatly facilitated the task of understanding complex sys-tems at cellular and molecular levels in recent years. Segmentation, an important yet dif-ficult problem, is often the first processing step following acquisition. Our team previously demonstrated that a stochastic active contour based algorithm together with the concept of

Ultracold atoms in optical lattices provide a highly control-lable environment for the clean experimental realization of various model Hamiltonians from condensed matter and statistical physics. For example, the two-component Bose-Hubbard model, which re-duces to an anisotropic spin-1/2 Heisenberg model in a certain limit and thus allows for the study of quantum magnetism, can be im-plemented by using bosons with two different internal states that couple differently to an optical lattice potential. In this thesis, I present our first experiments with two-component hyperfine-state mixtures of ultracold 87Rb atoms in a state-dependent optical lat-tice, both in the strongly correlated regime and in the context of nonlinear atom optics. For the production of 87Rb Bose-Einstein condensates we have developed a moving-coil transporter apparatus featuring a mag-netic TOP trap which serves as a “phase-space funnel ” to load a

2010 to my wife, Joyce, and my family...- Résumé-

, sending few beacons in stable topologies yet quickly adapting to changes. Finally, Magnet addresses transient loops by using data traffic as active topology probes, quickly discovering and fixing routing failures. Magnet runs on six different mote platforms and we have tested it on four testbeds. In most

In this thesis, two sets of experimental studies in bosonic and fermionic gases are described. In the first part of the thesis, itinerant ferromagnetism was studied in a strongly interacting Fermi gas of ultracold atoms. The observation of nonmonotonic behavior of lifetime, kinetic energy, and size for increasing repulsive interactions pro-vides strong evidence for a phase transition to a ferromagnetic state. Our observations imply that itinerant ferromagnetism of delocalized fermions is possible without lattice and band structure, and our data validate the most basic model for ferromagnetism introduced by Stoner. In the second part of the thesis, the coherence properties of a Bose-Einstein con-densate (BEC) was studied in a radio frequency induced double-well potential imple-mented on a microfabricated atom chip. We observed phase coherence between the separated condensates for times up to 200 ms after splitting, a factor of 10 longer than the phase diffusion time expected for a coherent state for our experimental con-ditions. The enhanced coherence time is attributed to number squeezing of the initial

Sujet de la thèse: Dynamique quantique hors-équilibre et systèmes désordonnés pour des atomes ultrafroids bosoniques présentée par Bruno Sciolla pour obtenir le grade de Docteur de l’Université Paris-sud 11 Directeur de thèse: Henri Orland Thèse préparée sous la direction de Giulio Biroli

I first thank my thesis advisors Thiemo Voigt and Adam Dunkels for being my excellent advisors, and also for being the great colleagues you still are. Thiemo and Adam have complemented each other superbly, giving me feedback, perspectives, insights, and having made every single new venture truly fun. My deepest thanks also go to my professor Per Gunningberg, Uppsala University. Per has in a seemingly easy way spotted erroneous assumptions, has valued my research contributions, and has connected my own work with another broader world of research. I want to thank all colleagues in the Networked Embedded Systems group: