A mis padres, que valen más que cien maestros. ABSTRACT I ABSTRACT Despite the well known advantages of distributed processing for intensive computations like simulation, frameworks often fail to exploit them. A distributed simulation is harder to develop than a sequential one, because it is necessary to interface and map activities to processors and handle the ensuing communication and synchro...

In the domain of heterogeneous model composition, semantic adaptation is the “glue” that is necessary to assemble heterogeneous models so that the resulting composed model has well-defined semantics. In this paper, we present an execution model for a semantic adaptation interface between heterogeneous models. We introduce a Domain-Specific Language (DSL) for specifying such an interface explici...

Complex systems demand diversity in the modeling mechanisms. One way to deal with a diversity of requirements is to create flexible modeling frameworks that can be adapted to cover the field of interest. The downside of this approach is a weakening of the semantics of the modeling frameworks that compromises interoperability, understandability, and analyzability of the models. An alternative ap...

A perennial problem in the process of developing signal processing systems is identifying an architecture which meets the computational and memory needs of the algorithm yet is still affordable in terms of cost, size, and complexity. To aid in making this decision, an architecture trade tool, using the Ptolemy kernel, has been developed. The purpose of this tool is to provide the user with an e...

Many of today’s signal processing applications are becoming more and more computationally intensive, requiring an increasing number of processors to satisfy their needs. Along with the larger number of processors, the bandwidth needed to pass data among the processors has also increased dramatically. In many classes of applications, designing an architecture to satisfy the data passing requirem...

In the past few decades, the importance of video signal processing in the communication industry has expanded drastically. Simple broadcasting can no longer satisfy the demands of the public. As a result, multi-media has became one of the fastest growing business in the industry. Because of the large data processing involved, software implementation of video algorithms for real-time purpose is ...

Wideband code division multiple access (WCDMA), a widely accepted 3G interface, is based on direct sequence (DS) CDMA technology. In this paper, a simulator implemented in Ptolemy software according to the physical layer specification of the WCDMA system is described. This paper is concerned with providing an analysis and simulation scheme to calculate the error probabilities of WCDMA system in...

SUMMARY Longest path problem is a problem for finding a longest path in a given graph. While the graph classes in which the Hamiltonian path problem can be solved efficiently are widely investigated, there are few known graph classes such that the longest path problem can be solved efficiently. Polynomial time algorithms for finding a longest cycle and a longest path in a Ptolemaic graph are pr...

We have developed piecewise linear models to provide accurate (waveform) simulations of large signal (rail-to-rail) behavior of CMOS circuits, used in logic gates, the driver electronics [1] and in the transimpedance amplifiers of optoelectronic systems . These models have successfully been implemented in Chatoyant ; a design framework and simulation tool that uses system-level models of optoel...

PeaCE(Ptolemy extension as a Codesign Environment) was developed for the hardware and software codesign framework which allows us to express both data flow and control flow. The fFSM is a model for describing the control flow aspects in PeaCE, but it has difficulties in verifying their specifications due to lack of their formality. Thus we propose the formal semantics of the model based on its ...