Outline of a Theory of Strongly Semantic Information

Peer reviewe

Automated specification-based testing of graphical user interfaces

Tese de doutoramento. Engenharia Electrónica e de Computadores. 2006. Faculdade de Engenharia. Universidade do Porto, Departamento de Informática, Escola de Engenharia. Universidade do Minh

Fourth NASA Langley Formal Methods Workshop

This publication consists of papers presented at NASA Langley Research Center's fourth workshop on the application of formal methods to the design and verification of life-critical systems. Topic considered include: Proving properties of accident; modeling and validating SAFER in VDM-SL; requirement analysis of real-time control systems using PVS; a tabular language for system design; automated deductive verification of parallel systems. Also included is a fundamental hardware design in PVS

Monitoring impacts from Council Regulation (EU) No 333/2011: End-of-waste criteria for Al/Fe scrap

On 9 October 2011, Council Regulation 333/2011 came into force establishing criteria by which scrap from iron and steel, aluminium and aluminium alloys could cease to be regulated as waste. This study examines the impacts of the Regulation on scrap availability, trade flows, prices, administrative requirements and environment or human health incidents. Because no data currently distinguishes between waste and end-of-waste compliant scrap, information was collected from the EU Competent Authorities and industry using detailed surveys. Across Europe, approximately 250 companies provided responses to the industry survey (representing approximately one quarter of the membership of the scrap industry associations), with a further 15 submissions from industry associations and 25 from Competent Authorities, although the survey responses were notably skewed towards Italy. The results of the study show that more than 1,100 scrap industry companies are already using the end-of-waste criteria across Europe. Uptake is most pronounced in Italy, where over 1,000 scrap companies generate end-of-waste compliant scrap. This rapid uptake in Italy is due in part to a specific legal framework on secondary raw materials already in place before the introduction of the end-of-waste criteria. In the rest of Europe there are a further 100 scrap companies active in end-of-waste scrap. In terms of the quantity of end-of-waste compliant scrap available on the market, this study estimates that, as a lower bound, at least 15% of EU scrap steel and 10% of EU scrap aluminium is compliant. Importantly, this study has found almost no evidence that end-of-waste has caused any negative impacts on the market, whether that be to scrap quality, availability/trade or on the environment. On the contrary, quite a number of the survey participants, both from industry and Competent Authorities highlighted the perceived benefits of the introduction of end-of-waste for metal scrap. These perceived benefits include: creating a simplified regulatory framework and offering companies greater flexibility and legal certainty. Some companies identified improved scrap quality and increased sales prices. At the expert workshop participants debated several ideas for a future monitoring system. One key conclusion was that there is no urgent need to revisit monitoring in the near future, due to the relatively modest rate of uptake outside Italy and the very few, if any, negative impacts observed so far. A repeat of the industry and authorities’ surveys in 2-3 years times was deemed to be the most appropriate way to monitor end-of-waste for scrap metal, and copper scrap could be added to the scope of that exercise.JRC.J.5-Sustainable Production and Consumptio

Formal methods and digital systems validation for airborne systems

This report has been prepared to supplement a forthcoming chapter on formal methods in the FAA Digital Systems Validation Handbook. Its purpose is as follows: to outline the technical basis for formal methods in computer science; to explain the use of formal methods in the specification and verification of software and hardware requirements, designs, and implementations; to identify the benefits, weaknesses, and difficulties in applying these methods to digital systems used on board aircraft; and to suggest factors for consideration when formal methods are offered in support of certification. These latter factors assume the context for software development and assurance described in RTCA document DO-178B, 'Software Considerations in Airborne Systems and Equipment Certification,' Dec. 1992

A Formal Verification Environment for Use in the Certification of Safety-Related C Programs

In this thesis the design of an environment for the formal verification of functional properties of safety-related software written in the programming language C is described. The focus lies on the verification of (primarily) geometric computations. We give an overview of the applicable regulations for safety-related software systems. We define a combination of higher-order logic as formalised in the theorem prover Isabelle and a specification language syntactically based on C expressions. The language retains the mathematical character of higher-level specifications in code specifications. A memory model for C is formalised which is appropriate to model low-level memory operations while keeping the entailed verification overhead in tolerable bounds. Finally, a Hoare style proof calculus is devised so that correctness proofs can be performed in one integrated framework. The applicability of the approach is demonstrated by describing its use in an industrial project

The Important Reform of Significant Clauses Within the Essential Standard Forms of the Time Charterparty

The time charter plays a very significant role in the practical shipping field. However, the time charterparty itself has attracted little consideration by researchers working in the field. In addition, there are still many legal issues that require resolution as it is possible to easily confuse merchants, leading to further practical disputes. This thesis explores the core characteristics of the time charter. It discusses crucial legal issues and aims to resolve potential legal disputes. It also considers key improvements to the relevant significant clauses in the current essential standard forms of the time charterparty by way of recommending revisions to clauses within various charterparties such as the BALTIME form, the NYPE 46 form, the NYPE 93 form and the GENTIME form. The original contribution of this thesis is not only the modification of vital clauses in these essential forms for merchants, but also the provision of constructive ways of reforming the remaining clauses in these forms thereby providing a potential guiding framework for the revision of other standard charterparty forms in the future

Automated Validation of State-Based Client-Centric Isolation with TLA ⁺

Clear consistency guarantees on data are paramount for the design and implementation of distributed systems. When implementing distributed applications, developers require approaches to verify the data consistency guarantees of an implementation choice. Crooks et al. define a state-based and client-centric model of database isolation. This paper formalizes this state-based model in, reproduces their examples and shows how to model check runtime traces and algorithms with this formalization. The formalized model in enables semi-automatic model checking for different implementation alternatives for transactional operations and allows checking of conformance to isolation levels. We reproduce examples of the original paper and confirm the isolation guarantees of the combination of the well-known 2-phase locking and 2-phase commit algorithms. Using model checking this formalization can also help finding bugs in incorrect specifications. This improves feasibility of automated checking of isolation guarantees in synthesized synchronization implementations and it provides an environment for experimenting with new designs.</p