293 research outputs found
Automation and Control
Advances in automation and control today cover many areas of technology where human input is minimized. This book discusses numerous types and applications of automation and control. Chapters address topics such as building information modeling (BIM)ābased automated code compliance checking (ACCC), control algorithms useful for military operations and video games, rescue competitions using unmanned aerial-ground robots, and stochastic control systems
A Socio-inspired CALM Approach to Channel Assignment Performance Prediction and WMN Capacity Estimation
A significant amount of research literature is dedicated to interference
mitigation in Wireless Mesh Networks (WMNs), with a special emphasis on
designing channel allocation (CA) schemes which alleviate the impact of
interference on WMN performance. But having countless CA schemes at one's
disposal makes the task of choosing a suitable CA for a given WMN extremely
tedious and time consuming. In this work, we propose a new interference
estimation and CA performance prediction algorithm called CALM, which is
inspired by social theory. We borrow the sociological idea of a "sui generis"
social reality, and apply it to WMNs with significant success. To achieve this,
we devise a novel Sociological Idea Borrowing Mechanism that facilitates easy
operationalization of sociological concepts in other domains. Further, we
formulate a heuristic Mixed Integer Programming (MIP) model called NETCAP which
makes use of link quality estimates generated by CALM to offer a reliable
framework for network capacity prediction. We demonstrate the efficacy of CALM
by evaluating its theoretical estimates against experimental data obtained
through exhaustive simulations on ns-3 802.11g environment, for a comprehensive
CA test-set of forty CA schemes. We compare CALM with three existing
interference estimation metrics, and demonstrate that it is consistently more
reliable. CALM boasts of accuracy of over 90% in performance testing, and in
stress testing too it achieves an accuracy of 88%, while the accuracy of other
metrics drops to under 75%. It reduces errors in CA performance prediction by
as much as 75% when compared to other metrics. Finally, we validate the
expected network capacity estimates generated by NETCAP, and show that they are
quite accurate, deviating by as low as 6.4% on an average when compared to
experimentally recorded results in performance testing
Efficient and flexible geocasting for opportunistic networks
With the proliferation of smartphones and their advanced connectivity capabilities, opportunistic networks have gained a lot of traction during the past years; they are suitable for increasing network capacity and sharing ephemeral, localised content. They can also offload traffic from cellular networks to device-to-device ones, when cellular networks are heavily stressed. Opportunistic networks can play a crucial role in communication scenarios where the network infrastructure is inaccessible due to natural disasters, large scale terrorist attacks or government censorship. Geocasting, where messages are destined to specific locations (casts) instead of explicitly identified devices, has a large potential in real world opportunistic networks, however it has attracted little attention in the context of opportunistic networking. In this thesis, we propose Geocasting Spray And Flood (GSAF), a simple but efficient and flexible geocasting protocol for opportunistic, delay tolerant networks. GSAF follows a simple but elegant and flexible approach where messages take random walks towards the destination cast. Messages that follow directions away from the cast are extinct when the device buffer gets full, freeing space for new messages to be delivered. In GSAF, casts do not have to be pre-defined; instead users can route messages to arbitrarily defined casts. Also, the addressed cast is flexible in comparison to other approaches and can take complex shapes in the network. DA-GSAF as the direction aware version of the GSAF is proposed as well which use location information to aid routing decisions in the GSAF. Extensive evaluation shows that GSAF and DA-GSAF are significantly more efficient than existing solutions, in terms of message delivery ratio and latency as well as network overhead
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