1,618 research outputs found
Decoherence of Einstein-Podolsky-Rosen steering
We consider two systems A and B that share Einstein-Podolsky-Rosen (EPR)
steering correlations and study how these correlations will decay, when each of
the systems are independently coupled to a reservoir. EPR steering is a
directional form of entanglement, and the measure of steering can change
depending on whether the system A is steered by B, or vice versa. First, we
examine the decay of the steering correlations of the two-mode squeezed state.
We find that if the system B is coupled to a reservoir, then the decoherence of
the steering of A by B is particularly marked, to the extent that there is a
sudden death of steering after a finite time. We find a different directional
effect, if the reservoirs are thermally excited. Second, we study the
decoherence of the steering of a Schr\"odinger cat state, modeled as the
entangled state of a spin and harmonic oscillator, when the macroscopic system
(the cat) is coupled to a reservoir
Quantifying wind and pressure effects on trace gas fluxes across the soil–atmosphere interface
Acknowledgements. We would like to acknowledge the manufacturers of the inner toroid: Mark Bentley and Steve Howarth from the University of York, Dept. of Biology, mechanical and electronics workshops respectively. Furthermore, we would like to acknowledge the Forestry Commission for access and aid at Wheldrake Forest, Mike Bailey and Natural Resources Wales for access and assistance at Cors Fochno, and Norrie Russell and the Royal Society for the Protection of Birds for access and aid at Forsinard. We would also like to thank Graham Hambley, James Robinson, and Elizabeth Donkin for equipment preparation and sampling. Phil Ineson is thanked for the loan of essential equipment, site suggestions, and accessible power supply. Funding was provided by the University of York, Dept. of Biology, and by a grant to YAT by the UK Natural Environment Research Council (NE/H01182X/1).Peer reviewedPublisher PD
Real-time information processing of environmental sensor network data using Bayesian Gaussian processes
In this article, we consider the problem faced by a sensor network operator who must infer, in real time, the value of some environmental parameter that is being monitored at discrete points in space and time by a sensor network. We describe a powerful and generic approach built upon an efficient multi-output Gaussian process that facilitates this information acquisition and processing. Our algorithm allows effective inference even with minimal domain knowledge, and we further introduce a formulation of Bayesian Monte Carlo to permit the principled management of the hyperparameters introduced by our flexible models. We demonstrate how our methods can be applied in cases where the data is delayed, intermittently missing, censored, and/or correlated. We validate our approach using data collected from three networks of weather sensors and show that it yields better inference performance than both conventional independent Gaussian processes and the Kalman filter. Finally, we show that our formalism efficiently reuses previous computations by following an online update procedure as new data sequentially arrives, and that this results in a four-fold increase in computational speed in the largest cases considered
Overcoming data scarcity of Twitter: using tweets as bootstrap with application to autism-related topic content analysis
Notwithstanding recent work which has demonstrated the potential of using
Twitter messages for content-specific data mining and analysis, the depth of
such analysis is inherently limited by the scarcity of data imposed by the 140
character tweet limit. In this paper we describe a novel approach for targeted
knowledge exploration which uses tweet content analysis as a preliminary step.
This step is used to bootstrap more sophisticated data collection from directly
related but much richer content sources. In particular we demonstrate that
valuable information can be collected by following URLs included in tweets. We
automatically extract content from the corresponding web pages and treating
each web page as a document linked to the original tweet show how a temporal
topic model based on a hierarchical Dirichlet process can be used to track the
evolution of a complex topic structure of a Twitter community. Using
autism-related tweets we demonstrate that our method is capable of capturing a
much more meaningful picture of information exchange than user-chosen hashtags.Comment: IEEE/ACM International Conference on Advances in Social Networks
Analysis and Mining, 201
Comparison between controlled and uncontrolled spray-DIC modeling for dehydration process
The work reported here focuses on the controllability expressions in the mathematical modeling of dehydration process of food concentrates in producing powder using spray-DIC (spray-Détente Instantaneé Controlee or spray-instant controlled pressure drop). This paper presents the second-order partial differential equations for mathematical modeling of moisture and heat transfer in spray-DIC process. This paper proposes the enhancement in the simple model of DIC technique with controllability expression to be used in the spray-DIC. The controllability expression in the drying process models gives better results when compared to the models without the controllability expression. The results were computed and shown by MATLAB 2013 with Windows 8 operating systems. The controllability expression in dehydration process model using the spray-DIC drier manage to succesfully control the dehydration process
The 2011 Retrovirology Prize winner Masao Matsuoka: forward looking and antisense
Masao Matsuoka wins the 2011 Retrovirology Prize
Assessing forest carbon accumulation potential across different treatments using field inventory data
Parallel computing of numerical schemes and big data analytic for solving real life applications
This paper proposed the several real life applications for big data analytic using parallel computing software. Some parallel computing software under consideration are Parallel Virtual Machine, MATLAB Distributed Computing Server and Compute Unified Device Architecture to simulate the big data problems. The parallel computing is able to overcome the poor performance at the runtime, speedup and efficiency of programming in sequential computing. The mathematical models for the big data analytic are based on partial differential equations and obtained the large sparse matrices from discretization and development of the linear equation system. Iterative numerical schemes are used to solve the problems. Thus, the process of computational problems are summarized in parallel algorithm. Therefore, the parallel algorithm development is based on domain decomposition of problems and the architecture of difference parallel computing software. The parallel performance evaluations for distributed and shared memory architecture are investigated in terms of speedup, efficiency, effectiveness and temporal performance
Sentiment analysis tools should take account of the number of exclamation marks!!!
There are various factors that affect the sentiment level expressed in textual comments. Capitalization of letters tends to mark something for attention and repeating of letters tends to strengthen the emotion. Emoticons are used to help visualize facial expressions which can affect understanding of text. In this paper, we show the effect of the number of exclamation marks used, via testing with twelve online sentiment tools. We present opinions gathered from 500 respondents towards “like” and “dislike” values, with a varying number of exclamation marks. Results show that only 20% of the online sentiment tools tested considered the number of exclamation marks in their returned scores. However, results from our human raters show that the more exclamation marks used for positive comments, the more they have higher “like” values than the same comments with fewer exclamations marks. Similarly, adding more exclamation marks for negative comments, results in a higher “dislike”
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