Applications of real number theorem proving in PVS

This work is supported by funding from the EPSRC under grants EP/H500162, EP/F02309X and GR/S31242Real number theorem proving has many uses, particularly for verification of safety critical systems and systems for which design errors may be costly. We discuss a chain of developments building on real number theorem proving in PVS. This leads from the verification of aspects of an air traffic control system, through work on the integration of computer algebra and automated theorem proving to a new tool, NRV, first presented here that builds on the capabilities of Maple and PVS to provide a verified and automatic analysis of Nichols plots. This automates a standard technique used by control engineers and greatly improves assurance compared with the traditional method of visual inspection of the Nichols plots.Publisher PDFPeer reviewe

Tools and Algorithms for the Construction and Analysis of Systems

This open access two-volume set constitutes the proceedings of the 27th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2021, which was held during March 27 – April 1, 2021, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2021. The conference was planned to take place in Luxembourg and changed to an online format due to the COVID-19 pandemic. The total of 41 full papers presented in the proceedings was carefully reviewed and selected from 141 submissions. The volume also contains 7 tool papers; 6 Tool Demo papers, 9 SV-Comp Competition Papers. The papers are organized in topical sections as follows: Part I: Game Theory; SMT Verification; Probabilities; Timed Systems; Neural Networks; Analysis of Network Communication. Part II: Verification Techniques (not SMT); Case Studies; Proof Generation/Validation; Tool Papers; Tool Demo Papers; SV-Comp Tool Competition Papers

Aspects in the Design of Spaceborne and Terrestrial Gravitational Wave Detectors

The aim behind much of the work outlined in this thesis has been mainly towards the development of test mass pendulum suspension systems suitable for laser gravitational wave detectors. These suspension systems have a dual purpose, namely providing seismic isolation and thermal noise reduction at the test mass. The techniques utilised throughout this work are comprised of a passive seismic isolation unit constructed from alternate layers of heavy metal and rubber (or spring) units, followed by the suspension of the test mass as a pendulum hung by fused silica fibres from the top of the isolation stage. Reviews of the theoretical work underpinning these systems have also been given, where the importance of low resonant mode frequencies of the isolation system, and high quality factors of the pendulum suspension fibres are highlighted. In chapter 2, details of the design, testing and current performance of a passive test mass seismic isolation system, constructed from layers of heavy metal and RTV-615 silicone rubber, are presented. The results of an experimental study of the anomalous compression characteristics of RTV (which lead to vertical stack resonant modes which are higher in frequency than one would normally expect) are also reported. Further to this it is shown that the compression modulus is subject to considerable stiffening when such units are placed under load. The construction and testing of a suspension system for the measurement of high pendulum and material quality factors are described, focusing on reducing recoil damping of the test pendulum. Results to date are reported for both measurement of pendulum and material quality factor of fused silica fibres. A theoretical analysis of the level of cross-coupling of seismic noise expected in the GEO 600 suspension system is presented, where the main mechanisms considered are cross coupling due to the radius of curvature of the Earth, and stiffness inequality of the test mass suspension wires. A theoretical study of attitude stability and phase-front distortion is carried out for LISA, a space-borne laser interferometric system. By considering the Fraunhofer phase variation in the far field resulting from distortions on a wavefront transmitted between two craft, the tolerable limit to the level of distortion on transmission is established

Space Transportation System and associated payloads: Glossary, acronyms, and abbreviations

A collection of acronyms in everyday use concerning shuttle activities is presented. A glossary of terms pertaining to the Space Transportation System is included