In a Krein space various norms can be defined by choosing different underlying fundamental decompositions. In this note we consider this dependence explicitly and draw the conclusion that - even in a Pontryagin space - there does not exist a natural choice motivated by minimizing properties.

I många forskares värld utgör seminarierummet en förtätad plats. Själva idén om det akademiska textseminariet är omhuldad, särskilt inom de humanistiska och samhällsvetenskapliga ämnesområdena. Seminariet är en väl förankrad arbetsform inom universitetet. Det är där de höga tankarna tänks och ventileras, det är där lärande och forskning går hand i hand, och det är där kollegialiteten praktiseras i

We study a version of the functional Hodrick–Prescott filter in the case when the associated operator is not necessarily compact but merely closed and densely de ned with closed range. We show that the associated optimal smoothing operator preserves the structure obtained in the compact case when the underlying distribution of the data is Gaussian.

We consider a large class of operator means and prove that a number of ergodic theorems, as well as growth estimates known for particular cases, continue to hold in the general context under fairly mild regularity conditions. The methods developed in the paper not only yield a new approach based on a general point of view, but also lead to results that are new, even in the context of the classical

Making decisions between alternatives are challenging when there is weak or unreliable knowledge about the risks and benefits of the alternatives. This requires a trade-off between risks (and benefits). Here, we comment on a recent paper on risk–risk trade-offs and highlight the difficulties of making such trade-offs when the available evidence is of different strength. One current example of a ri

The combination of complementary measurement techniques has become a frequent approach to improve scientific knowledge. Pairing of the high lateral resolution scanning force microscopy (SFM) with the spectroscopic information accessible through scanning transmission soft x-ray microscopy (STXM) permits assessing physical and chemical material properties with high spatial resolution. We present pro

Given the current energy crises, recent efforts have been directed at bringing energy efficiency and environmental awareness across the board into architectural education in Egypt. Although interest in sustainable design teaching and learning started more than 20 years ago at both post graduate and undergraduate level in Egypt, ecological illiteracy persists in architecture education. There is a l

With regards to research animal models related to immune thrombocytopenia (ITP), there is an extensive literature of over 300 publications published since 1959. It appears that many of these models either confirm what has been found in human ITP or, in some instances, are the first to describe a phenomenon related to ITP that is still of relevance today in human medicine. These models will undoubt

Immune thrombocytopenia (ITP) is a bleeding disorder characterized by antibody-opsonized platelets being prematurely destroyed in the spleen, although some patients with ITP may have a cell-mediated form of thrombocytopenia. Although several animal models of ITP have been developed, few mimic primary chronic ITP nor have any shown cell-mediated platelet destruction. To create this type of model, s

Companies are constantly being pressured to innovate in order to stay competitive in the short run and have new offerings in the long run. One way of boosting innovation is to develop idea support systems that go beyond the traditional methods and tools. Through a qualitative study, this paper explores the lessons learned from developing an online platform for idea generation, and discusses it in

In this paper the linearized equations of motion in multibody dynamics are derived. Explicit expressions for the coefficient matrices are presented and given their physical interpretations. The equations of motion are presented in terms of the mechanical stiffness, its adjoint and the associated differential operators. It is demonstrated how the adjoint matrix may be used to find solutions to the

We propose a functional version of the Hodrick–Prescott filter for functional data which take values in an in nite-dimensional separable Hilbert space. We further characterize the associated optimal smooth- ing operator when the associated linear operator is compact and the underlying distribution of the data is Gaussian.

A helicopter flying through an atmosphere containing particulates may accumulate high electrostatic charges which can challenge its operational safety. In this paper we elaborate and validate a triboelectric charging model to predict the electrification experienced by a helicopter while hovering in dusty air. We employed Large Eddy simulations to describe the turbulent structures inherent in the f

We derive process limit distribution results for the Nelson–Aalen estimator of a hazard function and for the Kaplan–Meier estimator of a distribution function, under different dependence assumptions. The data are assumed to be right censored observations of a stationary time series. We treat weakly dependent as well as long range dependent data, and allow for qualitative differences in the depende