A methodology for in situ migration of a handcrafted Directed Acyclic Graph (DAG), to a formal and expressive OWL version is presented. Well-known untangling methodologies recommend wholesale re-coding. Unable to do this, we have tackled portions of the DAG, lexically dissecting term names to property-based descriptions in OWL. The different levels of expressivity are presented in a model calle...

We analyze a new property of directed acyclic graphs (DAGs), called layerwidth, arising from a class of DAGs proposed by Eiter and Lukasiewicz. This class of DAGs permits certain problems of structural model-based causality and explanation to be tractably solved. In this paper, we first address an open question raised by Eiter and Lukasiewicz – the computational complexity of deciding whether a...

In this paper we study the problem of representing probabilistic independence models, in particular those closed under graphoid properties. We focus on acyclic directed graph (DAG): a new algorithm to build a DAG, given an ordering among random variables, is described and peculiarities and advantages of this approach are discussed. Moreover, we provide a necessary and sufficient condition for t...

Rather than approach the parallelization of the harmonic balance simulation method numerically, a novel scheduling-oriented approach is described. The technique leverages circuit substructure to expose potential parallelism in the form of a directed, acyclic graph (dag) of computations. This dag is then allocated and scheduled using various linear clustering techniques. The result is a highly s...

A Directed Acyclic Graph (DAG) of tasks with small communication delays has to be scheduled on the identical parallel processors of clusters connected by a hierarchical network. The number or processors and of clusters is not limited. Message contention has to be avoided. Task duplication is allowed. In this paper, we present a new polynomial algorithm that computes the earliest start dates of ...

A precedence relation can be represented non-uniquely by an activity on arc (AoA) directed acyclic graph (dag). This paper deals with the NP-hard problem of constructing an AoA dag having the minimum number o f arcs among those that have the minimum number of nodes. We show how this problem can be reduced in polynomial time to the set-cover problem so that the known methods of solving the set-c...

Whenever Ajax applications on mobile devices have to retrieve large XML data fragments from a remote server, a reduction of the exchanged data volume may be crucial to manage limited bandwidth and limited energy of the mobile device. We propose to use an XML compression technique that compresses an XML document to a binary directed acyclic graph (DAG) and to use DAG-based DOM evaluation on the ...

Consider a network of processes that exchange messages via FIFO communication channels. Each process chooses a subset of its neighboring processes to be its successors. Furthermore, there is a distinguished process, called root, that may be reached from any other process by following the successor relation at each hop. Thus, under the successor relation, the processes are arranged as a directed...

Task scheduling in cloud environment is a key technical problem on how to allocate available cloud resources to cloud users. Usually, a task in cloud environment can be cut into a serials of subtasks, which have precedence and dependency relationships among themselves. We describe the problem by means of a DAG (Directed Acyclic Graph) model. Then, we propose a priority algorithm for DAG task sc...

We apply MCMC to approximately calculate (i) the ratio of directed acyclic graph (DAG) models to DAGs for up to 20 nodes, and (ii) the fraction of chain graph (CG) models that are neither undirected graph (UG) models nor DAG models for up to 13 nodes. Our results suggest that, for the numbers of nodes considered, (i) the ratio of DAG models to DAGs is not very low, (ii) the ratio of DAG models ...