260 research outputs found
Latency Analysis of Coded Computation Schemes over Wireless Networks
Large-scale distributed computing systems face two major bottlenecks that
limit their scalability: straggler delay caused by the variability of
computation times at different worker nodes and communication bottlenecks
caused by shuffling data across many nodes in the network. Recently, it has
been shown that codes can provide significant gains in overcoming these
bottlenecks. In particular, optimal coding schemes for minimizing latency in
distributed computation of linear functions and mitigating the effect of
stragglers was proposed for a wired network, where the workers can
simultaneously transmit messages to a master node without interference. In this
paper, we focus on the problem of coded computation over a wireless
master-worker setup with straggling workers, where only one worker can transmit
the result of its local computation back to the master at a time. We consider 3
asymptotic regimes (determined by how the communication and computation times
are scaled with the number of workers) and precisely characterize the total
run-time of the distributed algorithm and optimum coding strategy in each
regime. In particular, for the regime of practical interest where the
computation and communication times of the distributed computing algorithm are
comparable, we show that the total run-time approaches a simple lower bound
that decouples computation and communication, and demonstrate that coded
schemes are times faster than uncoded schemes
Physical and chemical sensing applications of polypyrrole-coated foams
We live in a world of information, and emerging technologies, which compel us to look for new ways to collect, process, and distribute information. Today we are faced with an information overload problem as users struggle to locate the right information in the right way at the right time. In my view this is an âoverloadâ of trivial information coupled with a gap in access to important information. Digitization of information and communications has seen the rise and rise of computers to a now ubiquitous position in our society. However, the problem remains as to how to merge the digital world with sensing, and respond to changes in the real world. Ubiquitous information systems are needed that will automatically sense and importantly, respond to changes in their environment and usage in order to deliver a more intelligent, proactive and personalized information service. These systems may be wearable, enabling them to disappear into our personal space, enhancing rather than burdening our daily activities. Conventional sensors are generally unsuitable for wearable body monitoring devices either due to their physical structure or their functional requirements. This thesis examines this area of wearable sensors, detailing the development and characterisation of novel sensing materials and outlines their performance in various on-body monitoring applications
Enchanted objects: agency in the magic act and contemporary art practice
The following is taken directly from the abstract: 'In my research project I examine some of the ways in which the objects,strategies, and concepts of conjuringâor what Simon During has called âsecularâmagicâmight be seen to converge with those of contemporary art practice.
The theoretical concepts that I employ derive principally from Alfred Gellâs (anthropological) theory of art and agency. In Gellâs theory, an index/artwork is a mediatory (or secondary) agent, but an agent nonetheless, through which the (primary) agency of a social other can be communicated. Gellâs concept of enchantment, but also his interpretation of the status of the artwork as provisional
and problematic, rather than aesthetically or semiotically determined, is deployed as a means of creating a productively meaningful relationship between art and magic, both of which can be said to occlude the âabductionâ of agency in distinctive ways. Finally, Gellâs concept of agency provides a robust yet fluid set of paradigms for exploring the mobile, tripartite relationship between artist,artwork, and spectator.
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