We consider the Ptolemy cluster algebras, which are cluster algebras of finite type A (with non-trivial coefficients) that have been described by Fomin and Zelevinsky using triangulations of a regular polygon. Given any seed Σ in a Ptolemy cluster algebra, we present a formula for the expansion of an arbitrary cluster variable in terms of the cluster variables of the seed Σ. Our formula is give...

The problem addressed by this paper is that real-time embedded software today is commonly built using programming abstractions with little or no temporal semantics. The paper discusses the use of an extension to the Ptolemy II framework as a coordination language for the design of distributed real-time embedded systems. Specifically, the paper shows how to use modal models in the context of the...

tics. For example, the co-design finite state machines We implement a finite state machine (FSM) domain for specifying and simulating control functionality of a system within the Ptolemy software environment. The FSM domain is successfully integrated with synchronous dataflow (SDF) and discrete-event (DE) concurrency domains in Ptolemy. In this heterogeneous combination, the semantics of FSM, c...

A model of computation (MoC) is a formal abstraction of execution in a computer. There is a need for composing diverse MoCs in e-science. Kepler, which is based on Ptolemy II, is a scientific workflow environment that allows for MoC composition. This paper explains how MoCs are combined in Kepler and Ptolemy II and analyzes which combinations of MoCs are currently possible and useful. It demons...

Modeling and simulation of digital hardware at the behavioral level enable designers to experiment with a system without specifying implementation details. Verilog is a language that supports modeling and simulation at di erent levels of abstraction. However, all components in the same design must conform to a certain timing model, which may not be natural for all components. Ptolemy is a simul...

The Ptolemy project studies modeling, simulation, and design of concurrent, real-time, embedded systems. The focus is on assembly of concurrent components. The key underlying principle in the project is the use of well-defined models of computation that govern the interaction between components. The software system Ptolemy II has been in public release for about nine months now, and includes a ...

A model of computation (MoC) is a formal abstraction of execution in a computer. There is a need for composing MoCs in e-science. Kepler, which is based on Ptolemy II, is a scientific workflow environment that allows for MoC composition. This paper explains how MoCs are combined in Kepler and Ptolemy II and analyzes which combinations of MoCs are currently possible and useful. It demonstrates t...

It is becoming increasingly popular to describe real time signal proessing systems targetted for FPGA or ASIC implementation using structural signal flow graphs. We have implemented support for generation of synthesizeable as well as testbench VHDL code from Ptolemy II models. A helper based approach borrowing heavily from the existing Ptolemy II C code generation framework is used. This work d...

TinyOS is a component-based operating system designed for wireless embedded sensor networks. TOSSIM provides discrete event simulation of homogeneous TinyOS programs at the interrupt level. This paper presents PtinyOS, an integrated development environment built in Ptolemy II for developing and simulating heterogeneous TinyOS programs. PtinyOS will allow application developers to easily transit...