33,054 research outputs found
Reliable and timely event notification for publish/subscribe services over the internet
The publish/subscribe paradigm is gaining attention for the development of several applications in wide area networks (WANs) due to its intrinsic time, space, and synchronization decoupling properties that meet the scalability and asynchrony requirements of those applications. However, while the communication in a WAN may be affected by the unpredictable behavior of the network, with messages that can be dropped or delayed, existing publish/subscribe solutions pay just a little attention to addressing these issues. On the contrary, applications such as business intelligence, critical infrastructures, and financial services require delivery guarantees with strict temporal deadlines. In this paper, we propose a framework that enforces both reliability and timeliness for publish/subscribe services over WAN. Specifically, we combine two different approaches: gossiping, to retrieve missing packets in case of incomplete information, and network coding, to reduce the number of retransmissions and, consequently, the latency. We provide an analytical model that describes the information recovery capabilities of our algorithm and a simulation-based study, taking into account a real workload from the Air Traffic Control domain, which evidences how the proposed solution is able to ensure reliable event notification over a WAN within a reasonable bounded time window. © 2013 IEEE
Electric Vehicles Charging Control based on Future Internet Generic Enablers
In this paper a rationale for the deployment of Future Internet based
applications in the field of Electric Vehicles (EVs) smart charging is
presented. The focus is on the Connected Device Interface (CDI) Generic Enabler
(GE) and the Network Information and Controller (NetIC) GE, which are
recognized to have a potential impact on the charging control problem and the
configuration of communications networks within reconfigurable clusters of
charging points. The CDI GE can be used for capturing the driver feedback in
terms of Quality of Experience (QoE) in those situations where the charging
power is abruptly limited as a consequence of short term grid needs, like the
shedding action asked by the Transmission System Operator to the Distribution
System Operator aimed at clearing networks contingencies due to the loss of a
transmission line or large wind power fluctuations. The NetIC GE can be used
when a master Electric Vehicle Supply Equipment (EVSE) hosts the Load Area
Controller, responsible for managing simultaneous charging sessions within a
given Load Area (LA); the reconfiguration of distribution grid topology results
in shift of EVSEs among LAs, then reallocation of slave EVSEs is needed.
Involved actors, equipment, communications and processes are identified through
the standardized framework provided by the Smart Grid Architecture Model
(SGAM).Comment: To appear in IEEE International Electric Vehicle Conference (IEEE
IEVC 2014
Supporting Change-Aware Semantic Web Services
The Semantic Web is not only evolving into a provider of structured meaningful content and knowledge representation, but also into a provider of services. While most of these services support external users of the SW, we focus on a vital service within the SW â change management and adaptation. Change is a ubiquitous feature of the SW. In this paper, we propose a service architecture that embraces and utilises change to provide higher quality services. We introduce pilot implementations of two supporting services within this architecture
Fine Grained Component Engineering of Adaptive Overlays: Experiences and Perspectives
Recent years have seen significant research being carried out into peer-to-peer (P2P) systems. This work has focused on the styles and applications of P2P computing, from grid computation to content distribution; however, little investigation has been performed into how these systems are built. Component based engineering is an approach that has seen successful deployment in the field of middleware development; functionality is encapsulated in âbuilding blocksâ that can be dynamically plugged together to form complete systems. This allows efficient, flexible and adaptable systems to be built with lower overhead and development complexity. This paper presents an investigation into the potential of using component based engineering in the design and construction of peer-to-peer overlays. It is highlighted that the quality of these properties is dictated by the component architecture used to implement the system. Three reusable decomposition architectures are designed and evaluated using Chord and Pastry case studies. These demonstrate that significant improvements can be made over traditional design approaches resulting in much more reusable, (re)configurable and extensible systems
Power Systems Monitoring and Control using Telecom Network Management Standards
Historically, different solutions have been developed for power systems control and telecommunications network management environments. The former was characterized by proprietary solutions, while the latter has been involved for years in a strong standardization process guided by criteria of openness. Today, power systems control standardization is in progress, but it is at an early stage compared to the telecommunications management area, especially in terms of information modeling. Today, control equipment tends to exhibit more computational power, and communication lines have increased their performance. These trends hint at some conceptual convergence between power systems and telecommunications networks from a management perspective. This convergence leads us to suggest the application of well-established telecommunications management standards for power systems control. This paper shows that this is a real medium-to-long term possibility
Wearable learning tools
In life people must learn whenever and wherever they experience something new. Until recently computing technology could not support such a notion, the constraints of size, power and cost kept computers under the classroom table, in the office or in the home. Recent advances in miniaturization have led to a growing field of research in âwearableâ computing. This paper looks at how such technologies can enhance computerâmediated communications, with a focus upon collaborative working for learning. An experimental system, MetaPark, is discussed, which explores communications, data retrieval and recording, and navigation techniques within and across real and virtual environments. In order to realize the MetaPark concept, an underlying network architecture is described that supports the required communication model between static and mobile users. This infrastructure, the MUON framework, is offered as a solution to provide a seamless service that tracks user location, interfaces to contextual awareness agents, and provides transparent network service switching
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