Natural deduction system in paraconsistent setting: proof search for PCont

This paper continues a systematic approach to build natural deduction calculi and corresponding proof procedures for non-classical logics. Our attention is now paid to the framework of paraconsistent logics. These logics are used, in particular, for reasoning about systems where paradoxes do not lead to the `deductive explosion', i.e., where formulae of the type `A follows from false', for any A, are not valid. We formulate the natural deduction system for the logic PCont, explain its main concepts, define a proof searching technique and illustrate it by examples. The presentation is accompanied by demonstrating the correctness of these developments.

Digital evidence as a means of proof before the International Court of Justice

This article discusses the use of digital evidence as a means of proof before the International Court of Justice (ICJ). The absence of specific Court rules and procedures for digital evidence (with the exception of Practice Direction IX bis) is not necessarily an obstacle to its production and evaluation before the ICJ, as the general evidentiary rules can also be applied to digital evidence. The article first looks at the rules on the production of documentary evidence and then examines the specific issues related to audiovisual evidence. Finally, it examines the admissibility of digital evidence unlawfully obtained by a litigant through unilateral transborder access to data. The article concludes that, even if specific regulation may be needed as to the specific way in which authenticity and accuracy of digital evidence are to be established, the particular facts of the case and the grounds of challenge can vary widely, and it is doubtful that any regulation could be sufficiently flexible to deal with this in advance.

Corrections

Summary form only given, as follows. In Vol. 12, no. 3 (Summer 2007), page 9, bottom of the left column, in 'Computer Architecture and Amdahl??s Law' by Gene Amdahl, the claim about invalidating Amdahl??s Law in 1988 came from a team at Sandia National Laboratories, and not Los Alamos. The correct text should read: "Several years later I was informed of a proof that Amdahl's Law was invalidated by someone at Sandia National Laboratories, where a number of computers interconnected as an Ncube by communication lines, but with each computer also connected to I/O devices for loading the operating system, initial data, and results." On page 20 of the same issue, in the second sentence of the diagram explanation note by Justin Rattner, the percentage figures for the sequential and the system coordination parts of the workload were interchanged. The correct version of this sentence should read: "assuming a fixed sized problem, Amdahl speculated that most programs would require at least 10% of the computation to be sequential (only one instruction executing at a time), with overhead due to interprocessor coordination averaging 25%."

Residential heat pump installations: the role of vocational education and training

Meeting European emissions targets is reliant on innovative renewable technologies, particularly ‘renewable heat’ from heat pumps. Heat pump performance is driven by Carnot efficiency and optimum performance requires the lowest possible space heating flow temperatures leading to greater sensitivity to poor design, installation and operation. Does sufficient training and installer capacity exist for this technology? This paper situates the results of heat pump field trial performance in a socio-technical context, identifying how far installer competence requirements are met within the current vocational education and training (VET) system and considers possible futures. Few UK installers have formal heat pump qualifications at National Vocational Qualification (NVQ) level 3 and heat pump VET is generally through short-course provision where the structure of training is largely unregulated with no strict adherence to a common syllabus or a detailed training centre specification. Prerequisites for short-course trainees, specifically the demand for heating system knowledge based on metric design criteria, is limited and proof of ‘experience’ is an accepted alternative to formal educational qualifications. The lack of broader educational content and deficiencies in engineering knowledge will have profound negative impacts on both the performance and market acceptance of heat pumps. Possible futures to address this problem are identified.