Search results for "Avoidance"
showing 10 items of 297 documents
Adaptive Collision Avoidance through Implicit Acknowledgments in WSNs
2008
The large number of nodes, typical of many sensor network deployments, and the well-known hidden terminal problem make collision avoidance an essential goal for the actual employment of WSN technology. Collision avoidance is traditionally dealt with at the MAC Layer and plenty of different solutions have been proposed, which however have encountered limited diffusion because of their incompatibility with commonly available devices.In this paper we propose an approach to collision avoidance which is designed to work over a standard MAC Layer, namely the IEEE 802.15.4 MAC, and is based on application-controlled delays of packet transmission times. The proposed scheme is simple, decentralized …
Cooperative RTS/CTS MAC with relay selection in distributed wireless networks
2009
This paper proposes a cooperative multiple access protocol based on the Distributed Coordination Function (DCF) Request-To-Send/Clear-To-Send (RTS/CTS) scheme for distributed wireless networks. It answers three key questions concerning cooperation from the network perspective, namely when to cooperate, whom to cooperate with and how to protect cooperative transmissions. According to our protocol, the cooperation is initiated only if the direct transmission fails. An optimal relay node is selected in a distributed manner according to instantaneous relay channel conditions without prior information or extra signaling among relay candidates in the network. An additional three-way handshake is …
Revisit of RTS/CTS Exchange in High-Speed IEEE 802.11 Networks
2005
IEEE 802.11 medium access control (MAC), called distributed coordination function (DCF), provides two different access modes, namely, 2-way (basic access) and 4-way (RTS/CTS) handshaking. The 4-way handshaking has been introduced in order to combat the hidden terminal phenomenon. It has been also proved that such a mechanism can be beneficial even in the absence of hidden terminals, because of the collision time reduction. We analyze the effectiveness of the RTS/CTS access mode, in current 802.11b and 802.11a networks. Since the rates employed for control frame transmissions can be much lower than the rate employed for data frames, the assumption on the basis of the 4-way handshaking introd…
Grouping facilitates avoidance of parasites by fish
2013
Background. Parasite distribution is often highly heterogeneous, and intensity of infection depends, among other things, on how well hosts can avoid areas with a high concentration of parasites. We studied the role of fish behaviour in avoiding microhabitats with a high infection risk using Oncorhynchus mykiss and cercariae of Diplostomum pseudospathaceum as a model. Spatial distribution of parasites in experimental tanks was highly heterogeneous. We hypothesized that fish in groups are better at recognizing a parasitized area and avoiding it than solitary fish. Methods. Number of fish, either solitary or in groups of 5, was recorded in different compartments of a shuttle tank where fish co…
How do individual attachment patterns of both members of couples affect their perceived infertility stress? An actor–partner interdependence analysis
2016
Abstract There exists a lack of dyadic research examining how the attachment characteristics of infertile individuals influence their experience of infertility-related distress. The actor partner interdependence model was used to test a theoretical model by examining whether both infertile wives and husbands, who display high levels of attachment avoidance and/or attachment anxiety, will experience infertility-related distress. Seven hundred and seventy individuals (385 couples) completed the experience in close relationships, the fertility problem inventory, and the state-trait anxiety inventory prior to infertility treatment. Wives' distress was predicted by their own and by their husband…
MAC Protocols for WuR Enabled WSNs : Design and Performance Evaluation
2017
Master's thesis Information- and communication technology IKT591 - University of Agder 2017 Increasing energy efficiency is a challenging task for protocol design in wireless sensor networks (WSNs) as well as in Internet of things (IoT). Traditionally, duty-cycled (DC) protocols have been widely adopted for data transmissions in WSNs for energy conservation by reducing idle listening and overhearing. Recently, wake-up radio (WuR) has merged as a promising technique to replace DC protocols thanks to its superior performance in both network lifetime and transmission latency. This thesis work focuses on the design and performance evaluation of WuR-enabled MAC protocols considering various traf…
National Reports, Italy
2022
This text analyses the impact that a proposal for European harmonized rules on transaction avoidance law can have on Italian law.
Report on Italian Transaction Avoidance Law
2022
This text contains a report on Italian transaction avoidance law. It was written in order to contribute to an international project that massively influenced the European Commission in drawing up its "“Proposal for a Directive of the European Parliament and of the Council Harmonising Certain Aspects of Insolvency Law” – COM(2022) 702 final"
<title>HAP: a hybrid system for reasoning about actions and plans in robotics</title>
1990
The paper describes the main ideas and principles of HAP (Hybrid representation of Actions and Plans), a system for hybrid representation and reasoning in advanced robotics. In this context, hybrid representation refers to the integration of both symbolic and analogic knowledge representation paradigms. In particular, the logic/symbolic component is based on a KL-ONE-like representation language. The system embeds "analogic experts", that are concurrent procedures operating in a direct and fast way on the world representation. These "experts" help the system in planning a correct temporal sequence of actions. As a reference scenario, assembly (and disassembly) problems are considered. The a…
Corporate tax cuts and business-friendly policies in the UK - A review of electoral arguments during the 2015 legislative campaign
2016
The stance toward big business was a heated topic during Britain’s 2015 legislative campaign that led to the triumphal, albeit slightly unexpected, reelection of David Cameron, as Prime Minister. More profoundly, it raises the issue of the economic impact of corporate tax cuts and the nature of business-friendly policies in the UK. Firstly, we investigate the electoral arguments on both sides of the political spectrum. These discussions are framed within the overarching approach known as supply-side economics, which has been prevalent in English-speaking countries since the neoliberal revolution in the late 1970s. Secondly, we put forward the idea that widening inequalities, as suggested re…