Sökresultat

This paper presents a directional analysis of the on-body propagation channels using the high resolution space alternating generalized expectation (SAGE) maximization algorithm. The analysis has been done on data obtained through FDTD simulations, on a male and a female numerical phantom. For estimating the angle of arrival (AoA) at a four element square array located at the chest, two different p

Parallel robots are generally said to be more accurate but to have a smaller workspace compared to serial robots. With the Gantry-Tau robot, a parallel robot with a large, reconfigurable workspace was presented. This article tries to identify the maximum achievable end-effector positioning accuracy of the Gantry-Tau robot. To this end, a couple of new kinematic error models are presented and evalu

We introduce the problem of reoptimizing the network after a link failure has been repaired as an effective way for reducing capacity usage and improving network performance. Numerical results show gains higher than 42%.

Max-min fairness (MMF) is a general objective of multi-criteria optimization with important and natural applications in communication network design. The notion of MMF and optimization models involving MMF seem not to be commonly known to network designers and therefore they are not used to an extent they deserve. Moreover, the MMF approaches are sometimes “reinvented”, in some cases not correctly

A resource management framework for media applications modelled as dataflow streams is described. The framework is aimed at multi-core applications and the main resource managed is the CPU time. The management is implemented using reservation-based scheduling in combination with optimization and feedback. Experiences of applying the framework to media applications are reported. A simulation model

During the recent years, researchers in control engineering have proposed more resource-efficient control strategies than the traditional periodic control paradigm, resulting in two main control approaches: event-based and self-triggered control. Such nonperiodic, state-based control methods, although subject to many open research problems, can provide similar control performance as periodic contr

Using a simulated model of a house consisting of two adjacent rooms, the temperature of the two rooms is controlled with a PI controller and a decoupled PI controller. This is compared to MPC control. In the simulation example here, both the MPC controller and the decoupled PI controller decreased the interaction between the temperature dynamics of the two rooms, as compared to an independent PI c

The use of industrial robots in the aircraft industry has been hampered by a combination of poor accuracy of the robots and poor calibration of the workcell, and also manufacturing variability in composite parts. A way to handle these difficulties is using force control. An experimental case where a semi-compliant rib is aligned to multiple surfaces is used as an example to show this. The constrai

A new version of the stream cipher Grain-128 is proposed. The new version, Grain-128a, is strengthened against all known attacks and observations on the original Grain-128, and has built-in support for authentication. The changes are modest, keeping the basic structure of Grain-128. This gives a high confidence in Grain-128a and allows for easy updating of existing implementations.

In this paper we consider time-division-duplex (TDD) reciprocity calibration of a massive MIMO system. The calibration of a massive MIMO system can be done entirely at the base station (BS) side by sounding the BS antennas one-by-one while receiving with the other BS antennas. With an M antenna BS, this generates M(M - 1) signals that can be used for calibration purposes. In this paper we study se

Theory for Adaptive Nonlinear Model Predictive Control is developed based on the relaxed dynamic programming inequality. The adaptivity in the controller lies in the choice of control horizon. The control horizon is chosen such that a variation of the relaxed dynamic programming inequality holds for all time steps along the closed loop trajectory. This provides guarantees for asymptotic stability

Composition is a practice of key importance in software engineering. When real-time applications are composed it is necessary that their timing properties (such as meeting the deadlines) are guaranteed. The composition is performed by establishing an interface between the application and the physical platform. Such an interface does typically contain information about the amount of computing capac