5,564 research outputs found
Mathematical control of complex systems
Copyright © 2013 ZidongWang et al.This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Nanoscale Quantum Calorimetry with Electronic Temperature Fluctuations
Motivated by the recent development of fast and ultra-sensitive thermometry
in nanoscale systems, we investigate quantum calorimetric detection of
individual heat pulses in the sub-meV energy range. We propose a hybrid
superconducting injector-calorimeter set-up, with the energy of injected pulses
carried by tunneling electrons. Treating all heat transfer events
microscopically, we analyse the statistics of the calorimeter temperature
fluctuations and derive conditions for an accurate measurement of the heat
pulse energies. Our results pave the way for novel, fundamental quantum
thermodynamics experiments, including calorimetric detection of single
microwave photons.Comment: 6 pages, 3 figures plus supplemental material, 8 pages, 1 figur
Evaluating Engagement in Digital Narratives from Facial Data
Engagement researchers indicate that the engagement level of people in a narrative has an influence on people's subsequent story-related attitudes and beliefs, which helps psychologists understand people's social behaviours and personal experience. With the arrival of multimedia, the digital narrative combines multimedia features (e.g. varying images, music and voiceover) with traditional storytelling. Research on digital narratives has been widely used in helping students gain problem-solving and presentation skills as well as supporting child psychologists investigating children's social understanding such as family/peer relationships through completing their digital narratives. However, there is little study on the effect of multimedia features in digital narratives on the engagement level of people.
This research focuses on measuring the levels of engagement of people in digital narratives and specifically on understanding the media effect of digital narratives on people's engagement levels. Measurement tools are developed and validated through analyses of facial data from different age groups (children and young adults) in watching stories with different media features of digital narratives. Data sources used in this research include a questionnaire with Smileyometer scale and the observation of each participant's facial behaviours
Three-dimensional numerical simulations of free convection in a layered porous enclosure
Three-dimensional numerical simulations are carried out for the study of free
convection in a layered porous enclosure heated from below and cooled from the
top. The system is defined as a cubic porous enclosure comprising three layers,
of which the external ones share constant physical properties and the internal
layer is allowed to vary in both permeability and thermal conductivity. The
model is based on Darcy's law and the Boussinesq approximation. A parametric
study to evaluate the sensitivity of the Nusselt number to a decrease in the
permeability of the internal layer shows that strong permeability contrasts are
required to observe an appreciable drop in the Nusselt number. If additionally
the thickness of the internal layer is increased, a further decrease in the Nusselt
number is observed as long as the convective modes remain the same, if the
convective modes change the Nusselt number may increase. Decreasing the
thermal conductivity of the middle layer causes first an increment in the Nusselt
number and then a drop. On the other hand, the Nusselt number decreases in
an approximately linear trend when the thermal conductivity of the layer is
increased
Minimum Cost Homomorphisms to Locally Semicomplete and Quasi-Transitive Digraphs
For digraphs and , a homomorphism of to is a mapping $f:\
V(G)\dom V(H)uv\in A(G)f(u)f(v)\in A(H)u \in V(G)c_i(u), i \in V(H)f\sum_{u\in V(G)}c_{f(u)}(u)HHHGc_i(u)u\in V(G)i\in V(H)GH$ and, if one exists, to find one of minimum cost.
Minimum cost homomorphism problems encompass (or are related to) many well
studied optimization problems such as the minimum cost chromatic partition and
repair analysis problems. We focus on the minimum cost homomorphism problem for
locally semicomplete digraphs and quasi-transitive digraphs which are two
well-known generalizations of tournaments. Using graph-theoretic
characterization results for the two digraph classes, we obtain a full
dichotomy classification of the complexity of minimum cost homomorphism
problems for both classes
Mathematical control of complex systems 2013
Mathematical control of complex systems have already become an ideal research area for control engineers, mathematicians, computer scientists, and biologists to understand, manage, analyze, and interpret functional information/dynamical behaviours from real-world complex dynamical systems, such as communication systems, process control, environmental systems, intelligent manufacturing systems, transportation systems, and structural systems. This special issue aims to bring together the latest/innovative knowledge and advances in mathematics for handling complex systems. Topics include, but are not limited to the following: control systems theory (behavioural systems, networked control systems, delay systems, distributed systems, infinite-dimensional systems, and positive systems); networked control (channel capacity constraints, control over communication networks, distributed filtering and control, information theory and control, and sensor networks); and stochastic systems (nonlinear filtering, nonparametric methods, particle filtering, partial identification, stochastic control, stochastic realization, system identification)
Posterior sub-tenon's bevacizumab injection in diabetic macular edema; a pilot study
Purpose: To evaluate the short-term results of sub-tenon's injection of bevacizumab in patients with clinically significant macular edema (CSME). Methods: In this prospective non-comparative interventional case series, sub-tenon's injection of 2.5. mg/0.1. ml bevacizumab was performed for eyes with CSME. Macular thickness and best corrected visual acuity measurements were performed before and one month after injections. Results: Nineteen eyes of twelve patients with a mean age of 59.8. ±. 5.7. years were evaluated. Thirteen eyes (68.4) had center-involving macular edema. No significant difference was observed between pre- and post-injection central subfield retinal thickness measurements (P= 0.3). Central subfield thickness measurements improved or remained unchanged in 13 eyes (68.4). Baseline BCVA of 0.48. ±. 0.35 LogMAR improved to 0.36. ±. 0.26 LogMAR after injection (P= 0.01). Improvement of. > 2 lines in BCVA was found in 5 eyes (26.3), and no eye lost. > 2 lines of BCVA. No complication associated with sub-tenon's injection was observed. Conclusion: Sub-tenon's injection of bevacizumab resulted in significant short-term visual improvement in eyes with CSME. Retinal thickness changes were not significant. © 2015 The Authors
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