We give an algebraic presentation of directed acyclic graph structure, introducing a symmetric monoidal equational theory whose free PROP we characterise as that of finite abstract dags with input/output interfaces. Our development provides an initial-algebra semantics for dag structure.

Several rule discovery algorithms have the disadvantage to discover too much patterns sometimes obvious, useless or not very interesting to the user. In this paper we propose a new approach for patterns ranking according to their unexpectedness using semantic distance calculated based on a prior background knowledge represented by domain ontology organized as DAG (Directed Acyclic Graph) hierar...

Two prominent genetic programming approaches are the graph-based Cartesian Genetic Programming (CGP) and Linear Genetic Programming (LGP). Recently, a formal algorithm for constructing a directed acyclic graph (DAG) from a classical LGP instruction sequence has been established. Given graphbased LGP and traditional CGP, this paper investigates the similarities and differences between the two im...

A hybrid blockchain structure (hybrid directed acyclic graph, or H-DAG) is proposed in this article to solve the existing problem of architectures using symmetric key encryption technology by combining characteristics single-chain blockchains and DAG distributed ledgers. By improving block transaction structures optimizing consensus mechanism, H-DAG confirmed orders while maintaining high-throu...

In computer science a directed acyclic graph, also called DAG, is a directed graph with no directed cycles. Utility of DAG‘s is widely known and appreciated. Some algorithms for example, search algorithms become simpler when applied to DAGs. DAGs considered as a generalization of trees have a lot of applications in computer science, bioinformatics, physics and many natural activities of humanit...

Introduction In the last decade, there has been considerable progress in understanding a certain class of statistical models, known as directed acyclic graph (DAG) models, which encode independence, and conditional independence constraints. (See Pearl, 1988). This research has had fruitful results in many areas: there is now a relatively clear causal interpretation of these models, there are ef...

This paper proposes a novel method of representing syntactic and semantic attributes of multimedia content. The methods are based on a new data structure, which includes a directed acyclic graph (DAG) representation. It is well-known that DAG's occupy a middle ground between tree-based and graph-based representations. In the proposed scheme, we exploit the advantages of both representations, as...

Recently, a new compact representation for suboptimal alignments was proposed by Naor and Brutlag (1993). The kernel of that representation is a minimal directed acyclic graph (DAG) containing all suboptimal alignments. In this paper, we propose a method that computes such a DAG in space linear to the graph size. Let F be the area of the region of the dynamic-programming matrix bounded by the s...

Directed Acyclic Graphs are often used to model circuits and networks. The path length in such Directed Acyclic Graphs represents circuit or network delays. In the vertex splitting problem, the objective is to determine a minimum number of vertices from the graph to split such that the resulting graph has no path of length greater than a given δ. The problem has been proven to be NP-hard. A Gen...

Directed acyclic graph (DAG) models are widely used to represent casual relationships among random variables in many application domains. This article studies a special class of non-Gaussian DAG models, where the conditional variance each node given its parents is quadratic function mean. Such fairly flexible and admit popular distributions as cases, including Poisson, Binomial, Geometric, Expo...