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A feedback-based scheme for cooperative content distribu- tion for mobile systems aimed at reducing energy and li- censed spectrum usage is presented. The paper is motivated by the problems in implementing peer-to-peer based content distribution in mobile networks due to the risks of unfair en- ergy expenditure. A technique for incentivizing cooperation and for enforcing agreements between peers i
Dynamical flow networks with heterogeneous routing are analyzed in terms of stability and resilience to perturbations. Particles flow through the network and, at each junction, decide which downstream link to take on the basis of the local state of the network. Differently from single-commodity scenarios, particles belong to different classes, or commodities, with different origins and destination
With larger penetrations of wind power, the uncertainty increases in power systems operations. The wind power forecast errors must be accounted for by adapting existing operating tools or designing new ones. A switch from the deterministic framework used today to a probabilistic one has been advocated. This two-part paper presents a framework for risk-based operations of power systems. This framew
The position and orientation estimation problem for mobile robots is approached by fusing measurements from inertial sensors, wheel encoders, and a camera. The sensor fusion approach is based on the standard extended Kalman filter, which is modified to handle measurements from the camera with unknown prior delay. A real-time implementation is done on a four-wheeled omni-directional mobile robot, u
The development of a predictive control algorithm for glycaemia regulation in diabetic subjects requires patient-specific models of the glucose metabolism which are physiologically relevant, parsimonious, yet able to accurately forecast blood glucose. Given the measured data: total plasma insulin [mIU/L]; plasma glucose [mg/dL]; plasma glucose rate of appearance after intestinal absorption [mg/kg
We propose here a new procedure for output feedback design for systems with nonlinearities satisfying quadratic constraints. It provides an alternative for the classical observer-based design and relies on transformation of the closed-loop system with a dynamic controller of particular structure into a special block form. We present two sets of sufficient conditions for stability of the transforme
Insulin therapy for tight glycemia regulation in T1DM strongly depends on patients ́ daily decisions about insulin delivery adaptations in relation to: health status, current BG, target BG, insulin sensitivity, diet and foreseen activities. A personalized predictor providing near future BG predictions would support the users in the decision-making tasks while letting them maintaining control over
We consider the problem of stabilizing and minimizing the disturbance response of a SISO LTI plant, subject to a stochastic disturbance, over an analog communication channel with additive white noise and a signal-to-noise ratio (SNR) constraint. The controller is linear, based on output feedback and has a structure with two degrees of freedom: One part represents sensing and encoding operations an
A previous paper introduced an online gradient method to iteratively update local controllers for improved performance. In this paper we modify that method to get an offline method for distributed control synthesis. The complexity of the method is linear in the number of neighbors to each agent. Since the controllers are constructed to be distributed and the method is an iterative scheme, the con
This paper introduces a new Open Source Java library suited for the simulation of embedded control systems. The library is based on the ideas and architecture of TrueTime, a toolbox of Matlab devoted to this topic, and allows Java programmers to simulate the performance of control processes which run in a real time environment. Such simulations can improve considerably the learning and design of m
Wind turbines operating in wind farms are coupled by the wind flow. This coupling results in increased turbulence levels for downwind turbines, and consequently higher maintenance costs. In this paper, we consider a scenario where a wind farm is asked to produce less than maximum power. The objective is to minimize fatigue loads on the turbines, while maintaining the desired power production. We s
Cloud applications are often subject to unexpected events like flashcrowds and hardware failures. Users that expect a predictable behavior may abandon an unresponsive application when these events occur. Researchers and engineers addressed this problem on two separate fronts: first, they introduced replicas - copies of the application with the same functionality - for redundancy and scalability; s
Numerous auto-scaling strategies have been proposed in the past few years for improving various Quality of Service (QoS) indicators of cloud applications, for example, response time and throughput, by adapting the amount of resources assigned to the application to meet the workload demand. However, the evaluation of a proposed auto-scaler is usually achieved through experiments under specific cond
This work concerns efficient and reliable numerical simulations of the dynamic behaviour of a moving-boundary model for tubulin-driven axonal growth. The model is nonlinear and consists of a coupled set of a partial differential equation (PDE) and two ordinary differential equations. The PDE is defined on a computational domain with a moving boundary, which is part of the solution. Numerical simul
Popular Abstract in Swedish I Sverige har andelen förtidspensionärer ökat under lång tid och uppgick år 1998 till 7.6% av befolkningen i arbetsför ålder (16-64 år). Den vanligaste orsaken till att en individ förtidspensioneras är reducerad arbetsförmåga till följd av problem i rörelseorganen. Kunskaperna om förtidspensionärers livskvalitet är bristfälliga. Syftet med denna studie var att studera lThe starting-point of this thesis was the high rate of disability pensioners in Sweden and the lack of knowledge about what a disability pension entails for quality of life (QL). The aim of the study was to gain knowledge about QL among disability retirees with musculoskeletal disorders (ERPs). A questionnaire was sent in 1992 to 450 ERPs in Kristianstad Municipality, Sweden, granted their disabil
Abstract in German A complete documentation of the castles in SE Denmark
Entrained flow gasification is a promising technique where biomass is converted to a synthesis gas (syngas) under fuel-rich conditions. In contrast to combustion, where the fuel is converted to heat, CO2, and H2O, the syngas from gasification is rich in energetic gases such as CO and H-2. These compounds (CO and H-2) represent the building blocks for further catalytic synthesis to chemicals or bio
For several reinforcement learning models in strategic-form games, convergence to action profiles that are not Nash equilibria may occur with positive probability under certain conditions on the payoff function. In this paper, we explore how an alternative reinforcement learning model, where the strategy of each agent is perturbed by a strategy-dependent perturbation (or mutations) function, may e
