Efficient tool path computation using multi-core GPUs

Tool path generation is one of the most complex problems in Computer Aided Manufacturing. Although some efficient strategies have been developed, most of them are only useful for standard machining. However, the algorithms used for tool path computation demand a higher computation performance, which makes the implementation on many existing systems very slow or even impractical. Hardware acceleration is an incremental solution that can be cleanly added to these systems while keeping everything else intact. It is completely transparent to the user. The cost is much lower and the development time is much shorter than replacing the computers by faster ones. This paper presents an optimisation that uses a specific graphic hardware approach using the power of multi-core Graphic Processing Units (GPUs) in order to improve the tool path computation. This improvement is applied on a highly accurate and robust tool path generation algorithm. The paper presents, as a case of study, a fully implemented algorithm used for turning lathe machining of shoe lasts. A comparative study will show the gain achieved in terms of total computing time. The execution time is almost two orders of magnitude faster than modern PCs.

An introduction to alysidal algebra (IV)

Purpose – Deontical impure systems are systems whose object set is formed by an s-impure set, whose elements are perceptuales significances (relative beings) of material and/or energetic objects (absolute beings) and whose relational set is freeways of relations, formed by sheaves of relations going in two-way directions and at least one of its relations has deontical properties such as permission, prohibition, obligation and faculty. The paper aims to discuss these issues. Design/methodology/approach – Mathematical and logical development of human society ethical and normative structure. Findings – Existence of relations with positive imperative modality (obligation) would constitute the skeleton of the system. Negative imperative modality (prohibition) would be the immunological system of protection of the system. Modality permission the muscular system, that gives the necessary flexibility. Four theorems have been formulated based on Gödel's theorem demonstrating the inconsistency or incompleteness of DISs. For each constructed systemic conception can happen to it one of the two following things: either some allowed responses are not produced or else some forbidden responses are produced. Responses prohibited by the system are defined as nonwished effects. Originality/value – This paper is a continuation of the four previous papers and is developed the theory of deontical impure systems.

Rafael Tasis, els fonaments d’un gènere

Rafael Tasis fou un escriptor català pioner de la novel·la policíaca o detectivesca. Va ser també un destacat crític literari, llibreter, periodista i activista polític. És autor d’una trilogia formada per les obres La bíblia valenciana, Es hora de plegar i Un crim al Paralelo. Les seves aportacions teòriques a la novel·la i, especialment, a la de gènere, van ser de molta envergadura, demostració de la seva enorme capacitat de treball. Tasis va teoritzar sobre el gènere policíac i s’adonà, abans que ningú a Catalunya, de la importància que agafaria la novel·la negra americana. També va apostar per un escriptor inèdit, Manuel de Pedrolo, de qui va considerar que seria el novel·lista català més considerable del segle XX. Com a novel·lista i crític literari va donar testimoni de la vida i els ambients barcelonins i de l’atractiu de la utilització del material urbà de Barcelona com a argument de novel·les. La figura de Tasis respon a la de l'intel·lectual preocupat pels afers públics i, de manera més concreta, a la de l'escriptor en acte de servei permanent.