Direct data-driven forecast of local turbulent heat flux in Rayleigh-Bénard convection

A combined convolutional autoencoder-recurrent neural network machine learning model is presented to directly analyze and forecast the dynamics and low-order statistics of the local convective heat flux field in a two-dimensional turbulent Rayleigh-Bénard convection flow at Prandtl number Pr=7 and Rayleigh number Ra=10^7. Two recurrent neural networks are applied for the temporal advancement of turbulent heat transfer data in the reduced latent data space, an echo state network, and a recurrent gated unit. Thereby, our work exploits the modular combination of three different machine learning algorithms to build a fully data-driven and reduced model for the dynamics of the turbulent heat transfer in a complex thermally driven flow. The convolutional autoencoder with 12 hidden layers is able to reduce the dimensionality of the turbulence data to about 0.2% of their original size. Our results indicate a fairly good accuracy in the first- and second-order statistics of the convective heat flux. The algorithm is also able to reproduce the intermittent plume-mixing dynamics at the upper edges of the thermal boundary layers with some deviations. The same holds for the probability density function of the local convective heat flux with differences in the far tails. Furthermore, we demonstrate the noise resilience of the framework. This suggests that the present model might be applicable as a reduced dynamical model that delivers transport fluxes and their variations to coarse grids of larger-scale computational models, such as global circulation models for atmosphere and ocean

Searching for Faint Planetary Nebulae Using the Digital Sky Survey

Recent Halpha surveys such as SHS and IPHAS have improved the completeness of the Galactic planetary nebula (PN) census. We now know of ~3,000 PNe in the Galaxy, but this is far short of most estimates, typically ~25,000 or more for the total population. The size of the Galactic PN population is required to derive an accurate estimate of the chemical enrichment rates of nitrogen, carbon, and helium. In addition, a high PN count (~20,000) is strong evidence that most 1-8 Msun main sequence stars will go through a PN phase, while a low count (<10,000) argues that special conditions (e.g., a close binary interaction) are required to form a PN. We describe a technique for finding hundreds more PNe using the existing data collections of the digital sky surveys, thereby improving the census of Galactic PNe.Comment: 11 pages, 7 figures, accepted for publication in the Publications of the Astronomical Society of Australia (PASA), full resolution paper available at http://www.wiyn.org/jacoby_pasa.pd

A theoretical framework to describe communication processes during medical disability assessment interviews

BACKGROUND: Research in different fields of medicine suggests that communication is important in physician-patient encounters and influences satisfaction with these encounters. It is argued that this also applies to the non-curative tasks that physicians perform, such as sickness certification and medical disability assessments. However, there is no conceptualised theoretical framework that can be used to describe intentions with regard to communication behaviour, communication behaviour itself, and satisfaction with communication behaviour in a medical disability assessment context. OBJECTIVE: The objective of this paper is to describe the conceptualization of a model for the communication behaviour of physicians performing medical disability assessments in a social insurance context and of their claimants, in face-to-face encounters during medical disability assessment interviews and the preparation thereof. CONCEPTUALIzATION: The behavioural model, based on the Theory of Planned Behaviour (TPB), is conceptualised for the communication behaviour of social insurance physicians and claimants separately, but also combined during the assessment interview. Other important concepts in the model are the evaluation of communication behaviour (satisfaction), intentions, attitudes, skills, and barriers for communication. CONCLUSION: The conceptualization of the TPB-based behavioural model will help to provide insight into the communication behaviour of social insurance physicians and claimants during disability assessment interviews. After empirical testing of the relationships in the model, it can be used in other studies to obtain more insight into communication behaviour in non-curative medicine, and it could help social insurance physicians to adapt their communication behaviour to their task when performing disability assessment

Privacy in Mediated and Nonmediated Interpersonal Communication: How Subjective Concepts and Situational Perceptions Influence Behaviors

New communication media such as social networking sites (SNSs) and instant messengers (IMs) challenge users’ privacy perceptions. Technical infrastructures and the flow of digital information lead to novel privacy risks that individuals are often not acquainted with. Users’ subjective perceptions of privacy may thus be flawed and lead to irrational behavior. In this work, we investigated a concept that has been addressed only implicitly in academic research on privacy: the user’s subjective perception of a given level of privacy. We examined the literature on how privacy perceptions have been conceptualized in traditional theories of privacy and how these conceptualizations are challenged in social media communication. We first qualitatively explored laypeople’s privacy concepts and investigated their subjective perceptions of privacy levels and subsequent private disclosures in different mediated and nonmediated communication settings. Interviews with N  = 33 Germans revealed that, similar to academic privacy theories, they tend to conceptualize privacy as control over social, physical, and psychological boundaries. However, trust and other-dependent privacy emerged as important novel aspects for understanding privacy regulation in online communication. We further found that individuals consistently perceived a high level of privacy in face-to-face situations and a low level of privacy in public communication on SNSs. With regard to IMs, however, their answers were mixed: Uncertainty regarding digital communication properties and audiences as well as limited control over the communication setting prevented a reliable and shared perception of the privacy level. With regard to privacy behavior and private disclosures, we found that people tend to adapt their sharing of private information to the perceived level of privacy

Privacy_in_Mediated_and_Nonmediated_Communication_Sample_Description – Supplemental material for Privacy in Mediated and Nonmediated Interpersonal Communication: How Subjective Concepts and Situational Perceptions Influence Behaviors

<p>Supplemental material, Privacy_in_Mediated_and_Nonmediated_Communication_Sample_Description for Privacy in Mediated and Nonmediated Interpersonal Communication: How Subjective Concepts and Situational Perceptions Influence Behaviors by Doris Teutsch, Philipp K. Masur and Sabine Trepte in Social Media + Society</p