1,311 research outputs found
An Extended Network Coding Opportunity Discovery Scheme in Wireless Networks
Network coding is known as a promising approach to improve wireless network
performance. How to discover the coding opportunity in relay nodes is really
important for it. There are more coding chances, there are more times it can
improve network throughput by network coding operation. In this paper, an
extended network coding opportunity discovery scheme (ExCODE) is proposed,
which is realized by appending the current node ID and all its 1-hop neighbors'
IDs to the packet. ExCODE enables the next hop relay node to know which nodes
else have already overheard the packet, so it can discover the potential coding
opportunities as much as possible. ExCODE expands the region of discovering
coding chance to n-hops, and have more opportunities to execute network coding
operation in each relay node. At last, we implement ExCODE over the AODV
protocol, and efficiency of the proposed mechanism is demonstrated with NS2
simulations, compared to the existing coding opportunity discovery scheme.Comment: 15 pages and 7 figure
Range-Free Localization with the Radical Line
Due to hardware and computational constraints, wireless sensor networks
(WSNs) normally do not take measurements of time-of-arrival or
time-difference-of-arrival for rangebased localization. Instead, WSNs in some
applications use rangefree localization for simple but less accurate
determination of sensor positions. A well-known algorithm for this purpose is
the centroid algorithm. This paper presents a range-free localization technique
based on the radical line of intersecting circles. This technique provides
greater accuracy than the centroid algorithm, at the expense of a slight
increase in computational load. Simulation results show that for the scenarios
studied, the radical line method can give an approximately 2 to 30% increase in
accuracy over the centroid algorithm, depending on whether or not the anchors
have identical ranges, and on the value of DOI.Comment: Proc. IEEE ICC'10, Cape Town, South Africa, May, 201
Internode Distance-Based Redundancy Reliable Transport in Underwater Sensor Networks
Underwater communication is a very challenging topic. Protocols used in terrestrial sensor networks cannot be directly applied in the underwater world. High-bit error rate and large propagation delay make the design of transport protocols especially awkward. ARQ-based reliable transport schemes are not appropriate in underwater environments due to large propagation delay, low communication bandwidth, and high error probability. Thus, we focus on redundancy-based transport schemes in this paper. We first investigate three schemes that employ redundancy mechanisms at the bit and/or packet level to increase the reliability in a direct link scenario. Then, we show that the broadcast property of the underwater channel allows us to extend those schemes to a case with node cooperative communication. Based on our analysis, an adaptive redundancy transport protocol (ARRTP) for underwater sensor networks is proposed. We suggest an architecture for implementation. For two kinds of topologies, namely, regular and random, we show that ARRTP presents a better transmission success probability and energy efficiency tradeoff for single- and multihop transmissions. We also offer an integrated case study to show that ARRTP is not only supplying reliability but also has some positive effect in guiding the deployment of underwater sensor nodes
Convergence Visualizer of Decentralized Federated Distillation with Reduced Communication Costs
Federated learning (FL) achieves collaborative learning without the need for
data sharing, thus preventing privacy leakage. To extend FL into a fully
decentralized algorithm, researchers have applied distributed optimization
algorithms to FL by considering machine learning (ML) tasks as parameter
optimization problems. Conversely, the consensus-based multi-hop federated
distillation (CMFD) proposed in the authors' previous work makes neural network
(NN) models get close with others in a function space rather than in a
parameter space. Hence, this study solves two unresolved challenges of CMFD:
(1) communication cost reduction and (2) visualization of model convergence.
Based on a proposed dynamic communication cost reduction method (DCCR), the
amount of data transferred in a network is reduced; however, with a slight
degradation in the prediction accuracy. In addition, a technique for
visualizing the distance between the NN models in a function space is also
proposed. The technique applies a dimensionality reduction technique by
approximating infinite-dimensional functions as numerical vectors to visualize
the trajectory of how the models change by the distributed learning algorithm.Comment: (c) 2023 IEEE. Personal use of this material is permitted. Permission
from IEEE must be obtained for all other uses, in any current or future
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this work in other work
流行研究会と塚原渋柿園 : 〈江戸趣味〉の中の身ぶり
本稿は国立歴史民俗博物館の共同研究「歴史表象の形成と消費文化」(平成22-24年度)における報告「流行研究会の文人たち : 塚原渋柿園の位置」(平成23年7月9日 於国立歴史民俗博物館)を論文化したものである
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