Adaptive poleplacement: the division by zero problem

We re-examine the division by zero problem which occurs in certainty equivalence based indirect adaptive control algorithms applied to linear systems. By exploiting a parametrization for linear systems induced by the continued fraction description of its transfer function, the division by zero problem obtains a very simple geometric representation that can be used to virtually eliminate the problem in the adaptive algorith

Limitations of robust adaptive pole placement control for first order systems

The limitations of pole placement control when there is an adaptive disturbance whose size depends on the previous input and output signals are investigated. It is shown that the control objective of robust stabilization restricts the set of systems that can be dealt with. An adaptive algorithm applicable to systems in this set is proposed and analyzed

The pole zero cancellation problem in adaptive pole-placement revisited

We revisit the pole-zero cancellation problem in adaptive pole-placement. It is well known that an on-line identified model in an adaptive pole-placement algorithm need not be controllable. Since the controller design usually requires that the model is controllable, this results in an ill defined control step. By exploiting the properties of the closed loop unfalsified models set, we derive an algorithm which does not suffer this difficulty The analysis is presented in the case that the system belongs to the model class

Autonomic Management of Large Clusters and Their Integration into the Grid

We present a framework for the co-ordinated, autonomic management of multiple clusters in a compute center and their integration into a Grid environment. Site autonomy and the automation of administrative tasks are prime aspects in this framework. The system behavior is continuously monitored in a steering cycle and appropriate actions are taken to resolve any problems. All presented components have been implemented in the course of the EU project DataGrid: The Lemon monitoring components, the FT fault-tolerance mechanism, the quattor system for software installation and configuration, the RMS job and resource management system, and the Gridification scheme that integrates clusters into the Grid

A Roadmap for HEP Software and Computing R&D for the 2020s

Particle physics has an ambitious and broad experimental programme for the coming decades. This programme requires large investments in detector hardware, either to build new facilities and experiments, or to upgrade existing ones. Similarly, it requires commensurate investment in the R&D of software to acquire, manage, process, and analyse the shear amounts of data to be recorded. In planning for the HL-LHC in particular, it is critical that all of the collaborating stakeholders agree on the software goals and priorities, and that the efforts complement each other. In this spirit, this white paper describes the R&D activities required to prepare for this software upgrade.Peer reviewe

EOS workshop

A brief overview how EOS FUSEX (and client in general) are rolled out and configured at CERN. 5mi