Search results for "Distributed computing"
showing 10 items of 622 documents
Effects and Benefits of Node Sharing Strategies in HPC Batch Systems
2019
Processor manufacturers today scale performance by increasing the number of cores on each CPU. Unfortunately, not all HPC applications can efficiently saturate all cores of a single node, even if they successfully scale to thousands of nodes. For these applications, sharing nodes with other applications can help to stress different resources on the nodes to more efficiently use them. Previous work has shown that the performance impact of node sharing is very application dependent but very little work has studied its effects within batch systems and for complex parallel application mixes. Administrators therefore typically fear the complexity of running a batch system supporting node sharing…
A task scheduling algorithm for HPC applications using colored stochastic Petri Net models
2017
The increase in demand for High Performance Computing (HPC) scientific applications motivates the efforts to reduce costs of running these applications. The problem to solve is that of dynamical multi-criterial optimal scheduling of an application on a HPC platform with a high number of heterogeneous nodes. The solution proposed by the authors is a HPC hardware-software architecture that includes the infrastructure for two level (node and inter-node level) adaptive load balancing. The article presents the development of an Coloured Petri Net(CPN) for such an architecture. The model was used for the development of a dynamic distributed algorithm for the scheduling problem. The CPN allowed a …
A FAST Method to Achieve Flexible Production Programming Systems
2008
One of the main critical problems in manufacturing system domains is the production scheduling process, because an agile and reactive production planning and scheduling system is essential in manufacturing. The production scheduling process is a complex problem in which finding a suitable production scheduling can greatly increase the effectiveness of highly flexible production processes. Nevertheless, this high flexibility makes the production scheduling and acquisition of relevant data quite complicated. Therefore, there is a strong demand for a universal and flexible tool for production scheduling capable of increasing the utilization of resources and that supports a decision-making proc…
An Efficient, Robust, and Scalable Trust Management Scheme for Unattended Wireless Sensor Networks
2012
Unattended Wireless Sensor Networks (UWSNs) are characterized by long periods of disconnected operation and fixed or irregular intervals between visits by the sink. The absence of an online trusted third party, i.e., an on-site sink, makes existing trust management schemes used in legacy wireless sensor networks not applicable to UWSNs directly. In this paper, we propose a trust management scheme for UWSNs to provide efficient, robust and scalable trust data storage. For trust data storage, we employ geographic hash table to efficiently identify data storage nodes and to significantly reduce storage cost. We demonstrate, through detailed analyses and extensive simulations, that the proposed…
Towards a layer-less network architecture — A case from Wireless Sensor Networks
2011
Ad hoc and Wireless Sensor Networks (WSNs) form a challenging domain for existing network protocols and paradigms to fit into. The traditional models conceived for wired networking and adapted for wireless and mobile environments provide an inefficient and ungraceful outcome when exercised against highly dynamic and highly mobile nature of ad hoc wireless sensor networks. Efforts are being made to tweak existing (and sometimes create from scratch) principles and models that can provide a concrete framework for such newer paradigms. The momentum of the traditional layered architecture carried over from the wired networks to infrastructure based wireless networks pushes the same approaches as…
XML Enabled Metamodeling and Tools for Cooperative Information Systems
2001
The development of tools to support semantic resolution is a key issue in the design of heterogeneous interoperable information systems. This paper presents a methodology and a data model translator toolkit, called X-TIME, for the design and management of interoperable information systems. X-TIME combines a metamodelling approach and XML features to provide support for automated design of wrappers or semantic reconciliators. It is a flexible semantics oriented approach that takes into account several important characteristics of interoperable information systems, including extensibility and composability. Extensibility requires a translation scheme that can easily integrate new data models.…
Dynamic Ordering of Firewall Rules Using a Novel Swapping Window-based Paradigm
2016
Designing and implementing efficient firewall strategies in the age of the Internet of Things (IoT) is far from trivial. This is because, as time proceeds, an increasing number of devices will be connected, accessed and controlled on the Internet. Additionally, an ever-increasingly amount of sensitive information will be stored on various networks. A good and effi- cient firewall strategy will attempt to secure this information, and to also manage the large amount of inevitable network traffic that these devices create. The goal of this paper is to propose a framework for designing optimized firewalls for the IoT. This paper deals with two fundamental challenges/problems encountered in such…
Scheduling Domestic Shiftable Loads in Smart Grids: A Learning Automata-Based Scheme
2017
In this paper, we consider the problem of scheduling shiftable loads, over multiple users, in smart grids. We approach the problem, which is becoming increasingly pertinent in our present energy-thirsty society, using a novel distributed game-theoretic framework. From a modeling perspective, the distributed scheduling problem is formulated as a game, and in particular, a so-called “Potential” game. This game has at least one pure strategy Nash Equilibrium (NE), and we demonstrate that the NE point is a global optimal point. The solution that we propose, which is the pioneering solution that incorporates the theory of Learning Automata (LA), permits the total supplied loads to approach the p…
A nested virtualization tool for information technology practical education
2016
Background A common problem of some information technology courses is the difficulty of providing practical exercises. Although different approaches have been followed to solve this problem, it is still an open issue, specially in security and computer network courses. Results This paper proposes NETinVM, a tool based on nested virtualization that includes a fully functional lab, comprising several computers and networks, in a single virtual machine. It also analyzes and evaluates how it has been used in different teaching environments. Conclusions The results show that this tool makes it possible to perform demos, labs and practical exercises, greatly appreciated by the students, that woul…
Development of a low-cost IoT system to detect and locate lightning strikes
2020
Lightnings are violent natural phenomena and can generate many expenditures, specially when they strike in urban areas. The identification of the concrete geographic area where they strike is of critical importance for emergency services in order to enhance their effectiveness by doing an intensive coverage of the affected area. To achieve this aim, this paper proposes a design, prototype and validation of a distributed network of Internet of Things (IoT) devices to enable detection and location of lightning strikes. The IoT devices are empowered with lightning detection capabilities and are synchronized with the other devices in the sensor network. All of them cooperate within a network th…