Filetype
Managing the resources of a virtualized data-center is a key issue in cloud computing. Existing research mostly assumes that applications are either allocated the required resources or fail. Combined with the fact that most cloud applications have dynamic resource requirements, this imposes a fundamental limitation to cloud computing: To guarantee on-demand resource allocations, the data-center ne
The purpose of the risk management process, RiskUse is to provide practitioners, mainly risk managers with a software risk management process that has a well-defined user perspective. The aim is to present a risk management process that allows the development organisation to perform adequate risk management activities that can ensure that the developed software is safe from a user perspective.
Traditionally, control loops are closed using periodic sensing and actuation. When communication resources are scarce, however, much may be gained from transmitting only when something important has happened in the loop. This paper presents a simple model of the interference between event-based control loops caused by sharing a common medium, based on the coupled dynamics of a Markov chain represe
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
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
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
Use of feedforward can alleviate feedback and adaptive actions. Feedforward signals can be generated from reference models and the same models can also be used as reference models in adaptive control. A method for designing the reference models is presented in the paper. By exploiting the structure of the equations describing air vehicles it is possible to find reference models that scale to the p
Abstract in UndeterminedThe scalability of intelligent transport systems (ITS) applications is difficult to test in a field operational test (FOT) due to the high number of ITS equipped vehicles required. Therefore, computer simulations for evaluating different wireless communication technologies for ITS different applications can serve as a complement. In this paper we present results from lab me
Augmented Reality (AR) has emerged as a technology able to greatly support the interaction between people and digital information by merging virtual objects with the real environment. So far, research in this field has been mainly focused on single-user scenarios with pre-stored digital data whose visualization needs to be appropriately and promptly aligned with physical objects. Instead, latest d
Given a set of commodities and a network where some arcs can fail while others are reliable, we first consider the problem of computing a minimum-cost pair of paths not sharing failing links. If a reliable link belongs to both paths then its cost is counted only once. We show that this problem can be solved in strongly polynomial time. Second, we consider a routing problem where each commodity can
Traditionally, hypervisors, operating systems, and runtime systems have been providing an abstraction layer over the bare-metal hardware. Traditional abstractions, however, do not consider for non-functional requirements such as system-level constraints or users' objectives. As these requirements are gaining increasing importance, researchers are looking into making user-specified and system-level
In this technical report, we consider ultra light-weight constructions of message authentication in hardware applications. We examine several known constructions and evaluate details around their hardware implementations. These constructions are all based on the framework of universal hash functions.
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
