Shared buffer switches have many advantages such as relatively low cell loss rate and good buffer utilization, and they are increasingly favoured in recent VLSI switch designs for ATM. However, their performance degrades dramatically under nonuniform traffic due to the monopolization of the buffer by some favoured cells. To overcome this, restricted types of sharing and Hot-Spot-PushOut (HSPO) ...

The single-pushout approach to graph transformation is extended to the algebraic transformation of partial many-sorted unary algebras. The main result presented in this article is an algebraic characterization of the single-pushout transformation in the categories of all conformisms, all closed quomorphisms, and all closed-domain closed quomorphisms of unary partial algebras over a given signat...

Graph rewriting has numerous applications, such as software engineering and biology techniques. This technique is theoretically based on pushouts and pullbacks, which are involved with given categories. This paper deals with the definition of pushout and pullback, and their properties.

We demonstrate how category theory provides specifications that can efficiently be implemented via imperative algorithms and apply this to the field of graph transformation. By examples, we show paradigm software development makes it easy quickly write correct performant code. provide a modern implementation rewriting techniques at level abstraction finitely-presented $$\mathcal C$$ -sets clari...

In the framework of the double-pushout approach to graph grammars, we propose a new notion of parallel composition, called synchronized composition, of production applications. Our aim is to allow (pairs of) productions which are possibly not parallel independent, to be applied in parallel, provided that they are not mutually exclusive.The notion of synchronized composition we propose is not co...

Synchronous and asynchronous graph transformations are discussed on the basis of distributed graph transformations. All types of graph transformations presented are formulated in the single-pushout approach to graph transformations and compared with each other. Some criteria are given to preserve or reestablish synchrony according to the deenition proposed in this paper.

In the double-pushout approach to graph transformations, most authors assume the left-hand side to be injective, since the noninjective case leads to ambiguous results. Taking into consideration productions that change labels, however, may add ambiguity even in the case of injective graph productions. A well-known solution to this problem is restricting the categorical treatment to the underlyi...

It is proved that in any pointed category with pullbacks, coequalizers and regular epi-mono factorizations, the class of regular epimorphisms is stable under pullback along the so-called balanced effective descent morphisms. Here “balanced” can be omitted if the category is additive. A balanced effective descent morphism is defined as an effective descent morphism p : E → B such that any subobj...

Asynchronous Transfer Mode (ATM) shared buffer switches have numerous advantages such as relatively high throughput and good buffer utilization, and they are increasingly favoured in recent VLSI switch designs. But under nonuniform traffic, the performance degrades dramatically due to the monopolization of the buffer by some favoured cells. To overcome this, restricted types of sharing and Hot-...