Link Quality Estimation of Cross-Technology Communication: The Case with Physical-Level Emulation

Research on cross-technology communication ( CTC ) has made rapid progress in recent years. While the CTC links are complex and dynamic, how to estimate the quality of a CTC link remains an open and challenging problem. Through our observation and study, we find that none of the existing approaches can be applied to estimate the link quality of CTC. Built upon the physical-level emulation, transmission over a CTC link is jointly affected by two factors: the emulation error and the channel distortion. Furthermore, the channel distortion can be modeled and observed through the signal strength and the noise strength. We, in this article, propose a new link metric called C-LQI and a joint link model that simultaneously takes into account the emulation error and the channel distortion in the In-phase and Quadrature ( IQ ) domain. We accurately describe the superimposed impact on the received signal. We further design a lightweight link estimation approach including two different methods to estimate C-LQI and in turn the packet reception rate ( PRR ) over the CTC link. We implement C-LQI and compare it with two representative link estimation approaches. The results demonstrate that C-LQI reduces the relative estimation error by 49.8% and 51.5% compared with s-PRR and EWMA, respectively.

From quantum link models to D-theory: a resource efficient framework for the quantum simulation and computation of gauge theories

Quantum link models provide an extension of Wilson’s lattice gauge theory in which the link Hilbert space is finite-dimensional and corresponds to a representation of an embedding algebra. In contrast to Wilson’s parallel transporters, quantum links are intrinsically quantum degrees of freedom. In D-theory, these discrete variables undergo dimensional reduction, thus giving rise to asymptotically free theories. In this way ( 1 + 1 ) -d C P ( N − 1 ) models emerge by dimensional reduction from ( 2 + 1 ) -d S U ( N ) quantum spin ladders, the ( 2 + 1 ) -d confining U ( 1 ) gauge theory emerges from the Abelian Coulomb phase of a ( 3 + 1 ) -d quantum link model, and ( 3 + 1 ) -d QCD arises from a non-Abelian Coulomb phase of a ( 4 + 1 ) -d S U ( 3 ) quantum link model, with chiral quarks arising naturally as domain wall fermions. Thanks to their finite-dimensional Hilbert space and their economical mechanism of reaching the continuum limit by dimensional reduction, quantum link models provide a resource efficient framework for the quantum simulation and computation of gauge theories. This article is part of the theme issue ‘Quantum technologies in particle physics’.

Improving Hillslope Link Model Performance from Non-Linear Representation of Natural and Artificially Drained Subsurface Flows

This study evaluates the potential for a newly proposed non-linear subsurface flux equation to improve the performance of the hydrological Hillslope Link Model (HLM). The equation contains parameters that are functionally related to the hillslope steepness and the presence of tile drainage. As a result, the equation provides better representation of hydrograph recession curves, hydrograph timing, and total runoff volume. The authors explore the new parameterization’s potential by comparing a set of diagnostic and prognostic setups in HLM. In the diagnostic approach, they configure 12 different scenarios with spatially uniform parameters over the state of Iowa. In the prognostic case, they use information from topographical maps and known locations of tile drainage to distribute parameter values. To assess performance improvements, they compare simulation results to streamflow observations during a 17-year period (2002–2018) at 140 U.S. Geological Survey (USGS) gauging stations. The operational setup of the HLM model used at the Iowa Flood Center (IFC) serves as a benchmark to quantify the overall improvement of the model. In particular, the new equation provides better representation of recession curves and the total streamflow volumes. However, when comparing the diagnostic and prognostic setups, the authors found discrepancies in the spatial distribution of hillslope scale parameters. The results suggest that more work is required when using maps of physical attributes to parameterize hydrological models. The findings also demonstrate that the diagnostic approach is a useful strategy to evaluate models and assess changes in their formulations.

Elementary pre-service teachers’ conscious lack of knowledge about technical artefacts

This study aims at characterizing elementary pre-service teachers’ conscious lack of knowledge about familiar technical artefacts and its relation to their knowledge about these artefacts. The participants were asked to state what they knew and also what they did not know about a sample of familiartechnical artefacts such as a fan or a lock. The results showed a difference between the structure of the student teachers’ lack of knowledge of these artefacts and the structure of their actual knowledge. These differences were analyzed in relation to Kroes’ (Camb J Econ 34:51–62, 2010. https://doi.org/10.1093/cje/bep019) model of technical artefacts. Firstly, the student teachers’ conscious lack of knowledge was mainly focused on the artefacts’ behavior rather than on their components and materials. Secondly, the participants found the function features of the artefacts unproblematic. Thirdly, unknown features about the origin of the artefacts were more frequently cited than the corresponding knowledge features. Finally, non-perceptual properties of the artefacts and the causal relations in which they or their parts are involved were important components both of the students’ knowledge and of the students’ unknowns.

Of Rats and Men, a Translational Model to Understand Vancomycin Pharmacokinetic/Toxicodynamic relationships.

Vancomycin area under the concentration curve (AUC) is known to predict vancomycin induced acute kidney injury (AKI). Data were analyzed from a rat model (n=48) and two prospective clinical studies [PROVIDE (n=263) and CAMERA2 (n=291)]. A logit-link model was used to calculate the multiplicative factors between the probability of AKI from clinical studies and the rat. The rat was 2.7 to 4.2 times more sensitive to AKI between AUCs of 199.5 and 794.3 mg*h/L, respectively.

ON THE USE OF MODEL BASED SYSTEMS ENGINEERING AND CAD FOR THE DESIGN OF PHYSICAL PRODUCTS

Model based systems engineering is often used as an alternative to the document based design of software or other technical systems. Its focus lies on the modelling of procedural aspects of the products, rather than on physical aspects. In mechanical engineering, the geometry and the physical properties of the product like strength, stiffness, kinematic and kinetic behaviour are described by CAD-systems. This paper tries to link model based systems engineering tools with modern CAD tools to facilitate the digitization of the development processes of physical products as part of the digitization of new digital business models.

Revisiting Union: A New Perspective on an Old Outcome

Background: To present the inherent and unique challenges associated with utilizing fracture healing as an outcome measure in foot and ankle orthopedics, specifically the statistical methods used in assessing time to union. Methods: In a previously published manuscript assessing the effect of delayed weightbearing on time to union following intramedullary (IM) screw fixation of Jones (Zone 2 fifth metatarsal base) fractures, patients were divided into early weightbearing (EWB, n=20) and delayed weightbearing (DWB, n=21) cohorts (within or beyond 2 weeks, respectively). Time to union was determined and compared between the 2 cohorts using cumulative link model analysis, with delayed union (12.5 weeks) defined from established literature. Results: Cumulative link model analysis demonstrated no significant differences in time to union (EWB: 25% by 6th week, 55% by 12th week; DWB: 33% by 6th week, 43% by 12th week; P = .819) or delayed unions (EWB, 20% vs DWB, 24%; P > .999). Conclusion: Our analysis using cumulative link models, or ordinal regression, in the statistical analysis of time to union, determined that that early weightbearing following IM screw fixation in Jones fractures appeared to be safe without delaying fracture healing. This statistical approach can be considered when describing a continuous outcome captured by infrequent observations.