727 research outputs found
Self-Stabilizing Supervised Publish-Subscribe Systems
In this paper we present two major results: First, we introduce the first
self-stabilizing version of a supervised overlay network by presenting a
self-stabilizing supervised skip ring. Secondly, we show how to use the
self-stabilizing supervised skip ring to construct an efficient
self-stabilizing publish-subscribe system. That is, in addition to stabilizing
the overlay network, every subscriber of a topic will eventually know all of
the publications that have been issued so far for that topic. The communication
work needed to processes a subscribe or unsubscribe operation is just a
constant in a legitimate state, and the communication work of checking whether
the system is still in a legitimate state is just a constant on expectation for
the supervisor as well as any process in the system
Towards Quantifying Non-Local Information Transfer: Finite-Bit Non-Locality
The advent of Bell's inequalities provoked the possibility that entangled
quantum phenomena is non-local in nature. Since teleportation only requires a
finite amount of classical information, i.e. two bits, the author asks whether
or not it is possible to further characterize the nature of internal
correlation in terms of information. Towards this end, the issue of the amount
of information that is transferred internally and non-locally is addressed.
There are two possibilities: the amount is infinite or the amount is finite. A
partial answer to this problem is given: it is shown that models exist whereby
the amount is finite. The EPR-Bell cosine correlation can be reproduced exactly
using on average 1.48 bits. The issue of simultaneity and the problems it poses
are also examined in this context. Several extensions are suggested.Comment: New version: minor changes. Presented at the Physics of Quantum
Electronics Conference, Jan. 3-7, 199
Element content and daily intake from dietary supplements (nutraceuticals) based on algae, garlic, yeast fish and krill oilsâShould consumers be worried?
The authors would like to thank Agilent Technologies for the loan of the 8800 ICP-QQQ used in this study. Michael Stiboller thanks European Unionâs Lifelong Learning Programme âLeonardo da Vinciâ: âALUMNI UNI GRAZ MOBILITY PROGRAMME 2013-2015â for financial support of his placement.Peer reviewedPostprin
Discourse Communication in Individuals with and without Traumatic Brain Injury
Traumatic brain injury (TBI) is a global health epidemic that has detrimental consequences for individuals who sustain the brain injury, their families, and society. As a result of TBI, many individuals experience significant cognitive-communicative impairments, including difficulties with structuring and eliciting discourse. The purpose of this study was to gain a better understanding of these language difficulties and their possible clinical implications by comparing discourse communication samples from adults with TBI to those from adults without TBI. Audio recordings of 18 adults, consisting of narratives on different genres of discourse communication (e.g., conversational, procedural, personal narrative, and fictional narrative), were used for the purposes of this project. The discourse samples of 4 individuals with TBI were compared with the discourse samples of 14 individuals without TBI on the basis of several discourse communication measures including: (1) story length, (2) frequency of discourse errors, (3) elements, (4) story organization, (5) information content, and (6) information relevance. Overall, the differences observed between the TBI and non-TBI individuals on the discourse communication tasks reflect the typical communication impairments experienced by those living with TBI. Compared to the discourse samples of participants without TBI, the individuals with TBI produced more linguistic dysfluencies and discourse errors which indicated impairments related to pragmatic skill, information transfer and relevance, linking the events in a story, and effectively structuring discourse communication. The participants without TBI showed strengths in the quality and completeness of their spoken narratives. Ultimately, the differences observed among participants from each group provide important insight into what types of speech-language therapy might be appropriate and effective for these individuals
Fast Hybrid Network Algorithms for Shortest Paths in Sparse Graphs
We consider the problem of computing shortest paths in hybrid networks, in which nodes can make use of different communication modes. For example, mobile phones may use ad-hoc connections via Bluetooth or Wi-Fi in addition to the cellular network to solve tasks more efficiently. Like in this case, the different communication modes may differ considerably in range, bandwidth, and flexibility. We build upon the model of Augustine et al. [SODA \u2720], which captures these differences by a local and a global mode. Specifically, the local edges model a fixed communication network in which O(1) messages of size O(log n) can be sent over every edge in each synchronous round. The global edges form a clique, but nodes are only allowed to send and receive a total of at most O(log n) messages over global edges, which restricts the nodes to use these edges only very sparsely.
We demonstrate the power of hybrid networks by presenting algorithms to compute Single-Source Shortest Paths and the diameter very efficiently in sparse graphs. Specifically, we present exact O(log n) time algorithms for cactus graphs (i.e., graphs in which each edge is contained in at most one cycle), and 3-approximations for graphs that have at most n + O(n^{1/3}) edges and arboricity O(log n). For these graph classes, our algorithms provide exponentially faster solutions than the best known algorithms for general graphs in this model. Beyond shortest paths, we also provide a variety of useful tools and techniques for hybrid networks, which may be of independent interest
Aminomethanol water elimination: Theoretical examination
The mechanism for the formation of hexamethylenetetraamine predicts the formation of aminomethanol from the addition of ammonia to formaldehyde. This molecule subsequently undergoes unimolecular decomposition to form methanimine and water. Aminomethanol is the predicted precursor to interstellar glycine, and is therefore of great interest for laboratory spectroscopic study, which would serve as the basis for observational searches. The height of the water loss barrier is therefore useful in the determination of an appropriate experimental approach for spectroscopic characterization of aminomethanol. We have determined the height of this barrier to be 55 kcal/mol at ambient temperatures. In addition, we have determined the infinite-pressure Rice-Ramsperger-Kassel-Marcus unimolecular decomposition rate to be < 10^(-25) s^(-1) at 300 K, indicating gas-phase kinetic stability for typical laboratory and hot core temperatures. Therefore, spectroscopic characterization of and observational searches for this molecule should be straightforward provided an efficient formation mechanism can be found
The role of cohomology in quantum computation with magic states
A web of cohomological facts relates quantum error correction,
measurement-based quantum computation, symmetry protected topological order and
contextuality. Here we extend this web to quantum computation with magic
states. In this computational scheme, the negativity of certain
quasiprobability functions is an indicator for quantumness. However, when
constructing quasiprobability functions to which this statement applies, a
marked difference arises between the cases of even and odd local Hilbert space
dimension. At a technical level, establishing negativity as an indicator of
quantumness in quantum computation with magic states relies on two properties
of the Wigner function: their covariance with respect to the Clifford group and
positive representation of Pauli measurements. In odd dimension, Gross' Wigner
function -- an adaptation of the original Wigner function to
odd-finite-dimensional Hilbert spaces -- possesses these properties. In even
dimension, Gross' Wigner function doesn't exist. Here we discuss the broader
class of Wigner functions that, like Gross', are obtained from operator bases.
We find that such Clifford-covariant Wigner functions do not exist in any even
dimension, and furthermore, Pauli measurements cannot be positively represented
by them in any even dimension whenever the number of qudits is n>=2. We
establish that the obstructions to the existence of such Wigner functions are
cohomological.Comment: 33 page
IDEA ASSESSMENT VIA ENTERPRISE CROWDFUNDING: AN EMPIRICAL ANALYSIS OF DECISION-MAKING STYLES
Deciding which ideas to pursu is an essential step in innovation management. Organizations increasingly open up their decision-making processes internally and externally by harnessing the collective intelligence of crowds. One mechanism for doing so is enterprise crowdfunding, i.e. inviting employees to propose and support ideas on a crowdfunding platform inside the enterprise. In this paper, we empirically analyze such an enterprise crowdfunding endeavor where hundreds of employees endowed with the discretion to spend company budget proposed dozens of ideas and decided to fund 10 of them. Based on log files and information on the employeesÂŽ roles in their enterprise, we investigate the time course of individual decision-making â i.e., whether they decide rather quickly or more time-lagged which ideas to support Factors that influnce decision-making style include characteristics of proposers, supporters, ideas, supportersÂŽ activity level, and the progress of the trial. From this, we derive suggestions for future research into crowdfunding, and we propose relevant design parameters for using crowdfunding as a tool for internal openness and Enterprise 2.0
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