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We demonstrate experimentally and theoretically a controllable way of shifting the frequency of an optical pulse by using a combination of spectral hole burning, slow light effect, and linear Stark effect in a rare-earth-ion-doped crystal. We claim that the solid angle of acceptance of a frequency shift structure can be close to 2π, which means that the frequency shifter could work not only for op
A well-balanced exploration-exploitation trade-off is crucial for successful acquisition functions in Bayesian optimization. However, there is a lack of quantitative measures for exploration, making it difficult to analyze and compare different acquisition functions. This work introduces two novel approaches - observation traveling salesman distance and observation entropy - to quantify the explor
Bayesian optimization (BO ) is an effective method for optimizing expensive-to-evaluate black-box functions. While high-dimensional problems can be particularly challenging, due to the multitude of parameter choices and the potentially high number of data points required to fit the model, this limitation can be addressed if the problem satisfies simplifying assumptions. Axis-aligned subspace appro
BACKGROUND: This aggregated population study investigated the impact of the seemingly quasi-randomly assigned school winter holiday in weeks 6-10 (February to early March) on excess mortality in 219 European regions (11 countries) during the COVID-19 pandemic in the spring 2020. A secondary aim was to evaluate the impact of government responses to the early inflow of infected cases. METHODS: Data
This is the second component of a two-part paper dealing with a unification of characteristic mode decomposition. This second part addresses modal tracking, interpolation, the role of ohmic losses, and presents several numerical examples for surface-based method-of-moment formulations. A new tracking algorithm based on algebraic properties of the transition matrix is developed, achieving excellent
Can simple systems be regulated by simple controllers? Engineering experience indicates that this is often the case. Certainly, the overwhelming majority of industrially deployed controllers are proportional-integral-derivative (PID) controllers, many of which are tuned without detailed models. This is often in disappointing contrast with the controllers produced using model-based approaches. This
Hybrid computational schemes combining the advantages of a method of moments formulation of a field integral equation and T-matrix method are developed in this article. The hybrid methods are particularly efficient when describing the interaction of electrically small complex objects and electrically large objects of canonical shapes such as spherical multilayered bodies where the T-matrix method
We demonstrate how the individual mirrors of a high-quality Kirkpatrick-Baez (KB) mirror system can be aligned to each other to create an optimally focused beam, through minimizing aberrations in the phase of the ptychographically reconstructed pupil function. Different sources of misalignment and the distinctive phase artifacts they create are presented via experimental results from the alignment
Background: Estimating excess mortality and years of life lost (YLL) attributed to coronavirus disease 19 (COVID-19) infection provides a comprehensive picture of the mortality burden on society. We aimed to estimate the impact of the COVID-19 pandemic on age- and sex-specific excess mortality and YLL in Sweden during the first 17 months of the pandemic. Methods: In this population-based observati
Background Additional to a child's genetic inheritance, environmental exposures are associated with schizophrenia. Many are broadly described as childhood adversity; modelling the combined impact of these is complex. We aimed to develop and validate a scale on childhood adversity, independent of genetic and other environmental liabilities, for use in schizophrenia risk analysis models, using data
In modern industrial settings with small batch sizes it should be easy to set up a robot system for a new task. Strategies exist, e.g. the use of skills, but when it comes to handling forces and torques, these systems often fall short. We introduce an approach that provides a combination of task-level planning with targeted learning of scenario-specific parameters for skill-based systems. We propo
Upper bounds on the focusing efficiency of aperture fields and lens systems are formulated using integral equation representations of Maxwell’s equations and Lagrangian duality. Two forms of focusing efficiency are considered based on lens exit plane fields and optimal polarization currents within lens design regions of prescribed shape and available materials. Bounds are compared against the perf
Characteristic modes are formulated using the scattering dyadic, which maps incident plane waves to scattered far fields generated by an object of arbitrary material composition. Numerical construction of the scattering dyadic using arbitrary full-wave electromagnetic solvers is demonstrated in examples involving a variety of dielectric and magnetic materials. Wrapper functions for computing chara
This paper studies the problem of coordinating a group of nth-order integrator systems. As for the well-studied conventional consensus problem, we consider linear and distributed control with only local and relative measurements. We propose a closed-loop dynamic that we call serial consensus and prove it achieves nth order consensus regardless of model order and underlying network graph. This alle
When we speak, we typically also gesture. Gestures are an integral part of language use in both production and comprehension. They are therefore also vital in second language (L2), foreign language (FL), and bilingualism studies since they can open new windows on cognitive processes, interaction practices, and learning. This entry discusses methods and tools for studying second language users' and
In this paper, we present a global solution to a nonlinear H-infinity optimal control problem for control-affine systems with an associated potential function. We also give a closed-form expression for an optimal controller and demonstrate its potential for sparsity. This paper thus advances a recent result which considers the same problem restricted to systems with symmetric state matrix and nonl
This paper presents the construction and evaluation of SERP-test, a taxonomy aimed to improve communication between researchers and practitioners in the area of software testing. SERP-test can be utilized for direct communication in industry academia collaborations. It may also facilitate indirect communication between practitioners adopting software engineering research and researchers who are st
A low-latency and area-efficient FFT/IFFT scheme is presented. The main idea is to utilize OFDM guard bands to reduce the operation counts and processing time, which results in 42% latency reduction compared to the reported pipelined schemes. To realize this idea, a modified pipelined architecture and an efficient data scheduling scheme are proposed. Furthermore, the proposed architecture is scala
