Search results for "Computer network"
showing 10 items of 1634 documents
Efficient information gathering from large wireless sensor networks
2018
Abstract Considering large WSNs and comparing data aggregation approaches in terms of scalability, robustness, completeness, and time/energy effectiveness, recent research has asserted the superiority of serial structure-free approaches over serial structure-based ones, and over both parallel structure-free and parallel structure-based techniques. But, in spite of the fact that serial structure-free approaches excel in large and medium-scale networks, their underlying path-construction algorithms are not optimal and can be improved by reducing the involved communications and further shortening the visiting path. To respond to this need, this paper presents Geometric Serial Search (GSS); a n…
Performance of frame transmissions and event-triggered sleeping in duty-cycled WSNs with error-prone wireless links
2018
Abstract Two types of packet transmission schemes are prevalent in duty-cycled wireless sensor networks, i.e., single packet transmission and aggregated packet transmission which integrates multiple packets in one frame. While most existing models are developed based on an error-free channel assumption, this paper evaluates the performance of both transmission schemes under error-prone channel conditions. We develop a four-dimensional discrete-time Markov chain model to investigate the impact of channel impairments on the performance of frame transmissions. Together with tracking the number of packets in the queue, number of retransmissions and number of active nodes, the fourth dimension o…
Enabling early sleeping and early data transmission in wake-up radio-enabled IoT networks
2019
Abstract Wireless sensor networks (WSNs) are one of the key enabling technologies for the Internet of things (IoT). In such networks, wake-up radio (WuR) is gaining its popularity thanks to its on-demand transmission feature and overwhelming energy consumption superiority. Despite this advantage, overhearing still occurs when a wake-up receiver decodes the address of a wake-up call (WuC) which is not intended to it, causing a certain amount of extra energy waste in the network. Moreover, long latency may occur due to WuC address decoding since WuCs are transmitted at a very low data rate. In this paper, we propose two schemes, i.e., early sleeping (ES) and early data transmission (EDT), to …
Channel-dependent load balancing in wireless packet networks
2004
This paper refers to a wireless cellular packet network scenario where fast retransmission of corrupted packets is used to improve the packet error ratio. Since the ‘gross’ packet transmission rate (including retransmission) depends on the channel quality perceived, admitted calls weight unevenly in terms of effective resource consumption. In this paper, we suggest using channel quality information to drive load balancing mechanisms. We propose two novel metrics to determine the best cell to attach to, during handover or new call origination. Extensive simulation results prove the superiority of our proposed schemes with respect to traditional load balancing, which base their operation on t…
A Predictive Approach for the Efficient Distribution of Agent-Based Systems on a Hybrid-Cloud
2018
International audience; Hybrid clouds are increasingly used to outsource non-critical applications to public clouds. However, the main challenge within such environments, is to ensure a cost-efficient distribution of the systems between the resources that are on/off premises. For Multi Agent Systems (MAS), this challenge is deepened due to irregular workload progress and intensive communication between the agents, which may result in high computing and data transfer costs. Thus, in this paper we propose a generic framework for adaptive cost-efficient deployment of MAS with a special focus on hybrid clouds. The framework is based mainly on the use of a performance evaluation process that con…
Detecting Emotions in Comments on Forums
2014
The paper presents one of the most important issues in Natural Language Processing (NLP), emotion identification and classification to implement a computational technology based on existing resources, open-source or freely available for research purposes. Furthermore, we are interested to use it for establishing Gold standards in sentiment analysis area, such as SentiWordNet. In this sense, we propose to recognize and classify the emotions (sentiments) of the public consumer from the written texts which appeared on the various Forums. We analyse the writing style which refers to how consumers construct sentences together when they write comments to indicate their passion about an entity (pe…
User behaviours after critical mobile application incidents: the relationship with situational context
2015
Users occasionally have critical incidents with information systems IS. A critical IS incident is an IS product or service experience that a user considers to be unusually positive or negative. Critical IS incidents are highly influential in terms of users' overall perceptions and customer relationships; thus, they are crucial for IS product and service providers. Therefore, it is important to study user behaviours after such incidents. Within IS, the relationships between the situational context and user behaviours after critical incidents have not been addressed at all. Prior studies on general mobile use as a related research area have recognized the influence of the situational context,…
The Mediatization of E-Campaigning: Evidence From German Party Websites in State, National, and European Parliamentary Elections 2002-2009
2012
The rise of e-campaigning is often associated with its ability to circumvent journalistic principles of news selection and presentation. By this, parties and candidates are said to free themselves from the discretionary power of the mass media and to reach voters in an unfiltered way. This conventional wisdom is tested through a comparative content analysis of German party websites in state, national, and European parliamentary elections between 2002 and 2009. The results show that e-campaigns in all elections adhere in their messages to the media logic. Specifically, they replicate those patterns of offline coverage that have been held accountable for rising political alienation and civic …
Refinements on IEEE 802.11 Distributed Coordination Function Modeling Approaches
2010
With the popularity of the IEEE 802.11 standards, many analytical saturation throughput studies for the distributed coordination function (DCF) have been reported. In this paper, we outline a number of issues and criticalities raised by previously proposed models. In particular, a careful look at backoff counter decrement rules allows us to conclude that, under saturation conditions, the slot immediately following a successful transmission can be accessed only by the station (STA) that has successfully transmitted in the previous channel access. Moreover, due to the specific acknowledgment (ACK) timeout setting adopted in the standard, the slot immediately following a collision cannot be ac…
An efficient distributed algorithm for generating and updating multicast trees
2006
As group applications are becoming widespread, efficient network utilization becomes a growing concern. Multicast transmission represents a necessary lower network service for the wide diffusion of new multimedia network applications. Multicast transmission may use network resources more efficiently than multiple point-to-point messages; however, creating optimal multicast trees (Steiner Tree Problem in networks) is prohibitively expensive. This paper proposes a distributed algorithm for the heuristic solution of the Steiner Tree Problem, allowing the construction of effective distribution trees using a coordination protocol among the network nodes. Furthermore, we propose a novel distribut…