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It has been shown that a partially reflective surface (PRS) antenna with a larger reflection magnitude has a higher antenna gain, based on practical design examples. In this paper, PRS antennas with different reflection magnitudes are analyzed using an intuitive ray-tracing model. It is derived that the larger reflection magnitude enables a smaller phase delay and a more uniform magnitude distribu
A novel synthesizing procedure is introduced and employed to extract locally-optimal cloaking devices. Their performance is compared with fundamental bounds found using a convex optimization approach. The optimization method is based on a method-of-moments paradigm utilizing rank-1 updates of the structure iteratively performed based on a greedy algorithm. This approach produces locally optimal sh
This abstract presents the versatility and computational effectiveness of characteristic mode decomposition based on the transition matrix. The described treatment is valid for all lossless and linear material distributions and is independent of the numerical method used to resolve a particular scattering scenario.
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
As the number of antennas scales up, research efforts have been directed towards finding decentralized receiver solutions for multi-antenna architectures. In a recent paper, a novel matrix decomposition - the WAX decomposition - was proposed, which has direct bearing on characterizing the level of decentralization that is possible if the complexity of the decentralized processing is limited. Howev
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
Software corpora are crucial for evaluating research artifacts and ensuring repeatability of outcomes. Corpora such as DaCapo and Defects4J provide a collection of real-world open-source projects for evaluating the robustness and performance of software tools like static analysers. However, what do we know about these corpora? What do we know about their composition? Are they really suited for our
The design of an adaptive controller with bounded L2-gain from disturbances to errors for linear time-invariant systems with uncertain parameters restricted to a finite set is investigated. The synthesis of the controller requires finding matrices satisfying non-convex matrix inequalities. We propose an approach for finding these matrices based on repeatedly linearizing the terms that cause the no
The manuscript is devoted to optimal control for a class of linear positive systems with linear objective function and linear constraints. The solution to the corresponding Bellman equation is a linear value function, which can be found by linear programming.
In addition to a rise in mean air and water temperatures, more frequent and intense extreme climate events (such as heat waves) have been recorded around the globe during the past decades. These environmental changes are projected to intensify further in the future, and we still know little about how they will affect ecological processes driving harmful cyanobacterial bloom formation. Therefore, w
A key challenge in X-ray crystallography is to find a good point on the crystal on which to center the beam because the crystal takes radiation damage after a number of shots which significantly distort the measurements. Therefore, the beam needs to be aimed manually by an operator, which results in significant additional effort and time.This paper presents an approach toward automating the beam a
Agricultural landscapes have changed fast in Europe, which has led to steep declines in farmland biodiversity. While this has differentially impacted “farmland species”, some of these seem to be able to use alternative man-made open habitats in forests, such as forest clear-cuts and powerline rights-of-way. We investigated the use of clear-cuts by two historically declining farmland birds, the Yel
In massive multiple-input multiple-output (MIMO) systems, the large size of channel state information (CSI) matrix significantly increases the computational complexity of uplink detection and size of required memory to store the channel data. To address these challenges, we propose to perform detection in the angular domain, where the channel information can be presented in a more condensed way. T
Purpose: Radiographic abnormalities in the pubic bone and symphysis are often seen in athletes with groin pain. The aim was to create a grading scale of such radiologic changes. Material and Methods: Plain radiography of the pelvic ring including the pubic bone and the symphysis was performed in 20 male athletes, age 19-35, with long-standing uni- or bilateral groin pain. We used two control grou
Context. Extremely metal-poor (EMP) stars preserve a fossil record of the composition of the ISM when the Galaxy formed. It is crucial, however, to verify whether internal mixing has modified their surface composition, especially in the giants where most elements can be studied. Aims. We aim to understand the CNO abundance variations found in some, but not all EMP field giants analysed earlier. Mi
Public preferences for sustainable land use policy instruments and the motivations behind such preferences are important to make appropriate policies. Based on survey data (n = 309) from northeastern Somalia, we examined preferences for a set of land use policy instruments relative to no policy (i.e. the current status quo) and how cultural worldviews predict such preferences. We used a multinomia
This paper presents a stabilized scheme that solves the wave propagation problem in a general bianisotropic, stratified medium. The method utilizes the concept of propagators, i.e., the wave propagation operators that map the total tangential electric and magnetic fields from one plane in the slab to another. The scheme transforms the propagator approach into a scattering matrix form, where a spec
The aim of this thesis is to investigate whether tort liability claims against public authorities for breaches of the ECHR can be defined as a constitutional right in Swedish law. The theoretical definition of what constitutes a constitutional right is constructed through elements of Robert Alexy’s A Theory of Constitutional Rights. The theory is applied on the current applicable law regarding the
