In this paper the concurrent semantics of double-pushout (DPO) graph rewriting, which is classically deened in terms of shift-equivalence classes of graph derivations, is axiomatised via the construction of a free monoidal bi-category. In contrast to a previous attempt based on 2-categories, the use of bi-categories allows to deene rewriting on concrete graphs. Thus, the problem of composition ...

The fuel combustion in diesel engines can be improved by adding nanomaterials to the which result an reduction pollutant emissions and enhance quality of combustion. engine performance soot nanoparticles characteristics were evaluated this study with copper oxide (CuO2) rapeseed methyl ester (RME) under variable speeds. addition CuO2 RME significantly improve brake thermal efficiency (BTE) decl...

Six-Sigma has some measures which measure performance characteristics related to a process. In most of the traditional methods, exact estimation is used to assess these measures and to utilize them in practice. In this paper, to estimate some of these measures, including Defects per Million Opportunities (DPMO), Defects per Opportunity (DPO), Defects per unit (DPU) and Yield, a new algorithm ba...

Switch equivalence for transformation systems has been successfully used in many domains for the analysis of concurrent behaviour. When using graph transformation as modelling framework for these systems, the concept of negative application conditions (NACs) is widely used – in particular for the specification of operational semantics. In this paper we show that switch equivalence can be improv...

Graph grammars have been introduced in the late 1970s [1], then they have been significantly improved up to the 2000s [2]. A lot of significant results are due to H. Ehrig and his colleagues who have conceived an algebraic approach to graph rewriting by the means of category theory [1]. It opened the way to computations with attributes. In this approach, when dealing with model transformations,...

Graph grammars (or graph transformation systems), originally introduced as a generalization of string grammars, can be seen as a powerful formalism for the specification of concurrent and distributed systems, which properly extends Petri nets. The idea is that the state of a distributed system can be naturally represented (at a suitable level of abstraction) as a graph and local state transform...