Displays are one of the most mature technologies in the field of printed electronics. Their ability to be manufactured in large quantities and at low cost has led to their recent uptake into the consumer market. Within this article this technology is extended to electrochromic display stickers. This is achieved using a recent reverse display architecture screen printed on textile and paper sticker substrates. The electrochromic stickers are comparable to plastic control substrates and show little performance difference even when adhered to curved surfaces. The electrochromic display technology is extended to sticker labels for authentication applications by patterning either the dielectric or the graphical layer. A proof-of-concept prototype emulating a wax seal on an envelope is presented to show that other colors can be implemented in this technology. © 2023 The Authors.

It has been known for over 70 years that there is an asymptotic transition of Charlier polynomials to Hermite polynomials. This transition, which is still presented in its classical form in modern reference works, is valid if and only if a certain parameter is integer. In this light, it is surprising that a much more powerful transition exists from Charlier polynomials to the Hermite function, valid for any real value of the parameter. This greatly strengthens the asymptotic connections between Charlier polynomials and special functions, with applications in queueing theory, where this transition is crucial for solving first-passage problems with moving boundaries. It is shown in this paper that the convergence is locally uniform, and a sharp rate bound is proved. In addition, it is shown that there is a transition of derivatives of Charlier polynomials to the derivative of the Hermite function, again with a sharp rate bound. Finally, it is proved that zeros of Charlier polynomials converge to zeros of the Hermite function. © 2021, The Author(s).

Hodgkin and Huxley's seminal neuron model describes the propagation of voltage spikes in axons, but it cannot explain certain full-neuron features crucial for understanding the neural code. We consider channel current fluctuations in a trisection of the Hodgkin-Huxley model, allowing an analytic-mechanistic explanation of these features and yielding consistently excellent matches with in vivo recordings of cerebellar Purkinje neurons, which we use as model systems. This shows that the neuronal encoding is described conclusively by a soft-thresholding function having just three parameters. © 2021 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Grunden för alla hjärnans funktioner utgörs av hur nervcellerna fungerar. Eftersom nervceller i huvudsak bara skickar information mellan varandra blir en kritisk aspekt att för stå hur den informationsöverföringen går till. En opålitlighet i informationsöverföringen kan till exempel skapa en variation som gör att vårt beteende blir mindre stereotypt, mindre dator- eller maskinlikt, och mer ”biologiskt”. Denna variation kan vara till fördel genom att sänka risken att våra tankar hela tiden hamnar i samma hjulspår, vilket kan driva kreativitet och på så sätt ge bättre problemlösningsför måga. Martin Nilsson, RISE Research Institute of Sweden, och Henrik Jörntell, Lunds universitet, har nyligen utfört en grundlig analys och rekonstruktion av hur signalerna som skickas mellan nervcellerna skapas och har på så sätt kunnat ge en helomfattande bild av hur signal överföringen fungerar.

Biology-inspired computing is often based on spiking networks, but can we improve efficiency by going to higher levels of abstraction? To do this, we need to explain the precise meaning of the spike trains that biological neurons use for mutual communication. In a cooperation between RISE and Lund University, we found a spectacular match between a mechanistic, theoretical model having only three parameters on the one hand, and in vivo neuron recordings on the other, providing a clear picture of exactly what biological neurons “do”, i.e., communicate to each other.

We present simple solutions of first-passage and first-exit time problems for general moving boundaries and general Itô processes in one dimension, including diffusion processes with convection. The approach uses eigenfunction expansion, despite the boundary time-variability that, until now, has been an obstacle for spectral methods. The eigenfunction expansion enables the analytical reduction of the problem to a set of equivalent ordinary differential equations, which can be input directly to readily available solvers. The method is thus suitable as a basis for efficient numerical computation. We illustrate the technique by application to Wiener and Ornstein–Uhlenbeck processes for a variety of moving boundaries, including cases for which exact results are known.

This report presents the results of the SafePos pre-study, in which different technologies for safety positioning to be used by first responders were identified, and techniques for ad hoc positioning were evaluated. The aim of the project, was to test various systems for localisation and communication and narrow- and wide-band radio transmission techniques, and to further investigate how the presence of such a system could support fire and rescue operations in complex underground environments. Tests have been carried out in real, pre-existing mining environments, and complex office corridors with similar conditions to those of a mine as regards curves and obstructions have been used for introductory tests. A computer application for digital simulation has been developed and adapted to the system, although this only operates on a relatively basic level, so as to support the testing of the positioning and communication systems; thus, more can be done to improve performance for real-life applications. The analysis was conducted by studying the results of the experiments and linking them to expected usage during a fire and rescue operation. Tests have also been carried out in cooperation with the fire and rescue services in order to identify equipment and wearable technologies that could support and make fire and rescue operations in mines and other complex underground constructions safer and more efficient. In order to transfer information to and from these wearable technologies and to improve the likelihood of a safe and efficient fire and rescue operation, positioning and connectivity are requirements.Keywords: Underground constructions, mine, fire safety, positioning, connectivity

When the boundary—the total number of servers—in an Erlang loss system is a function of time, customers may also be lost due to boundary variations. On condition that these customers are selected independently of their history, we solve for the hitting-time distribution and transient distribution of busy servers. We derive concise asymptotic expressions in the time domain for normal loads in the heavy-traffic limit, i.e., when the offered load ρ is high, and the number of servers scales as ρ+O(√ρ). The solutions are computationally efficient, and simulations confirm the theoretical results.

Directional antennas provide angle-of-arrival information, which can be used for localization and routing algorithms in wireless sensor networks. We briefly describe three classical, major types of antennas: 1) the Adcock-pair antenna, 2) the pseudo-Doppler antenna, and 3) the electronically switched parasitic element antenna. We have found the last type to be the most suitable for wireless sensor networks, and we present here the early design details and beam pattern measurements of a prototype antenna for the 2.4-GHz ISM band, the SPIDA: SICS Parasitic Interference Directional Antenna.