Search results for "Operating system"

Dynamic scheduling of periodic skippable tasks in an overloaded real-time system

2008

International audience; The need for supporting dynamic real-time environments where changes in workloads may occur requires a scheduling framework that explicitly addresses overload conditions, allows the system to achieve graceful degradation and supports a mechanism capable of determining the load to be shed from the system to handle the overload. In applications ranging from video reception to air-craft control, tasks enter periodically and have response time constraints, but missing a deadline is acceptable, provided most deadlines are met. Such tasks are said to be occasionally skippable and have an assigned skip parameter. We look at the problem of uniprocessor scheduling of skippabl…

Human and Machine Perception 2 - Emergence, Attention, and Creativity

1999

Analysis of ground fault current distribution along nonuniform multi-section lines

2008

In case of a substation supplied by a combined overhead-cable line, most of the ground fault current flows through the cable sheaths and discharges into the soil surrounding the point of discontinuity, where cables are connected to the overhead line. In the paper a new method is presented for computing the ground fault current distribution in case of feeding line consisting of two or more different sections, i.e. part overhead and part underground cable. Besides the calculation of the earth current at the fault location, the leakage current at the transit/transition stations as well as at the overhead line towers can be evaluated, in order to ensure proper safety conditions. Based on the tw…

Experimental validation of a general model for three phase inverters operating in healthy and faulty modes

2012

The paper presents the experimental verification of a general mathematical model of Voltage Source Inverters (VSI) able to simulate fault conditions and which is also useful for the simulation of fault-tolerant systems for different applications. In general, in the past, the problem of faulty inverters modeling has been addressed specifically by considering faults on the different phases as separate cases. Furthermore, traditional models include only the faulty mode and not the healthy mode, so resulting then not able to predict transient phenomena. The model hereafter presented overcomes this drawback. It was formulated by introducing the concept of “healthy leg binary variables”. Such var…

Ground-Fault Current Transfer at the Transition Station of a Combined Overhead-Cable Line. A Parametric Analysis

2007

When a substation is fed by a combined overhead-cable transmission line, a significant part of the ground fault current flows through the grounded cable sheaths and discharges into the earth at the transition station, where cables are connected to the overhead line. If the transition station is a dead-end steel pole structure, the local ground electrode, small and of high resistance, could be inadequate to maintain the ground potential rise within safety limits in case of a fault to ground at the receiving end substation. Based on a circuit model approach, the paper presents a parametric analysis of the fault current distribution between the faulted substation and the transition station, ta…

Power Consumption Analysis of Operating Systems for Wireless Sensor Networks

2010

In this paper four wireless sensor network operating systems are compared in terms of power consumption. The analysis takes into account the most common operating systems-TinyOS v1.0, TinyOS v2.0, Mantis and Contiki-running on Tmote Sky and MICAz devices. With the objective of ensuring a fair evaluation, a benchmark composed of four applications has been developed, covering the most typical tasks that a Wireless Sensor Network performs. The results show the instant and average current consumption of the devices during the execution of these applications. The experimental measurements provide a good insight into the power mode in which the device components are running at every moment, and t…

Designing an open source maintenance-free Environmental Monitoring Application for Wireless Sensor Networks

2015

We discuss the analysis and design of an Environmental Monitoring Application.The application is reliable and maintenance-free, runs in multihop wireless network.We analyze the different alternatives and tradeoffs, using open source software.The application is validated in long-term outdoor deployments with good results.Related work does not analyze the software design with open source. We discuss the entire process for the analysis and design of an Environmental Monitoring Application for Wireless Sensor Networks, using existing open source components to create the application. We provide a thorough study of the different alternatives, from the selection of the embedded operating system to…

A CORBA based architecture for distributed embedded systems using the RTLinux-GPL platform

2004

This paper describes an architecture for distributed computing on the RTLinux-GPL(GPL version of RTLinux, hereafter RTLinux) platform. The proposed architecture implements the CORBA (common object request broker architecture) model of computation, more specifically the minimum CORBA specification for embedded systems, and also provide the extensions for real-time computing. Since RTLinux lacks networking capabilities, the architecture implements all the required functionality in a layered fashion: network drivers, TCP/IP stack and an ORB (object request broker). Most of this work consists on a set of partings of some widely known open source Linux projects to RTLinux: Linux Ethernet device …

FIRST

2018

Thanks to the collective action of participating smartphone users, mobile crowdsensing allows data collection at a scale and pace that was once impossible. The biggest challenge to overcome in mobile crowdsensing is that participants may exhibit malicious or unreliable behavior, thus compromising the accuracy of the data collection process. Therefore, it becomes imperative to design algorithms to accurately classify between reliable and unreliable sensing reports. To address this crucial issue, we propose a novel Framework for optimizing Information Reliability in Smartphone-based participaTory sensing (FIRST) that leverages mobile trusted participants (MTPs) to securely assess the reliabil…

Quantum algorithms for formula evaluation

2010

We survey the recent sequence of algorithms for evaluating Boolean formulas consisting of NAND gates.