Friction may be a major obstacle for stability and control performance. Based on a nominal control law, which stabilizes a nonlinear dynamical system to an equilibrium or to a desired limit cycle motion and which is derived without taking the friction disturbance into account, a method for compensating the impact of the friction is presented and stability analysis for the closed loop system is pre

In this paper two simplified transform based estimators for MIMO OFDM systems using the DFT and an SVD based transform are compared over a tapped delay line channel model. In the resulting symbol error rate plots, it is seen that the DFT based estimator experiences an error floor caused by the mismatch between the discrete time model and a continuous time reality. This error floor becomes a proble

Abstract not available

2015 markerar 100-årsminnet av armeniska folkmordet i Osmanska imperiet under första världskriget. Denna publikation är ett led i programmet för ihågkommandet av folkmordets 100-årsminne och innehåller de hundra mest förekommande frågorna. Boken innehåller korta sammanfattade svar till dessa frågor med källhänvisningar och referenser till andra litteratur som läsaren kan sedan använda för vidare f

This paper treats modelling of power systems with converters in alinear time-periodic framework.A power converter is a nonlinear switching device connecting an ACsystem to a DC system. The converter generates harmonics that mightcause instabilities in systems of this kind. About a nominal periodictrajectory the power converter is well described by a periodic gainmatrix, whereas the power grids oft

Today the Sun is in a relatively uncrowded place. The distance between it and the nearest other star is relatively large (about 200 000 times the Earth-Sun distance!). This is beneficial to life on Earth; a close encounter with another star is extremely unlikely. Such encounters would either remove the Earth from its orbit around the Sun or leave it on an eccentric orbit similar to a comet's. But

To predict the effects of environmental change and nature management on the distribution of plant species, it is crucial to understand the mechanisms of plant niche differentiation and habitat specialization. The importance to habitat specialization of particular plant traits and requirement of the regenerative phase of the plants life has received scanty interest. Our experiments on seed germinat

A uniplanar-compact electromagnetic band-gap (UC-EBG) structure is implemented at 60 GHz on a conventional PTFE (polytetrafluoroethylene) substrate. The structure surrounds a stacked microstrip antenna with gridded parasitic patch. The UC-EBG implementation results in about 5 dB decrease in the antenna E-plane normalized radiation pattern for angles along the substrate. The measured antenna gain i

Abstract not available

Product alternatives suggested by a generative design system often need to be evaluated on qualitative criteria. This evaluation necessitates that several feasible solutions which fulfill all technical constraints can be proposed to the user of the system. Also, as concept development is an iterative process, it is important that these solutions are generated quickly; i.e., the system must have a