Participants in the Ptolemy Project

Historical Figures

The Ptolemy and Tycho projects take their names from these historical figures:
Claudius Ptolemaeus
Ptolemy II
Egyptian King
Tycho Brahe

Principal Investigator

Edward A. Lee (


Christopher Hylands (
Ptolemy manager, release management, Tcl/Tk, Java, Tycho, system administration
Jennifer Basler (
Grant administration
Mary P. Stewart (
System administration

Postdoctoral Researchers and Visiting Scholars

John Reekie(GSRC) (
Functional language theory and compilers, parallel implementations of signal processing algorithms, graphical user interfaces, Tycho
Bart Kienhuis(GSRC) (
System level design using abstract modeling of architectures and applications.

Full-Time Graduate Students

John Davis, II (
Mutable systems, higher order functions
Mudit Goel (
Adaptive Digital Signal Processing
Bilung Lee (
Image and video processing, telecommunications software
Jie Liu (
Mixed signal design, CT domain.
Lukito Muliadi (
Discrete-event modeling and simulation
Stephen Neuendorffer (
Real-time Signal Processing
Jeffrey C. Tsay (
Mathematical algorithms for signal processing, multimedia applications
Yuhong Xiong (
Type System

Undergraduate students

Michael Leung (
Synchronous Dataflow

Contributors Not Currently at Berkeley

Neal Becker (Comsat Laboratories) (
SDF stars, HP port, Complex class
Shuvra S. Bhattacharyya (Hitachi America, Ltd.) (
Uniprocessor and multiprocessor scheduling, optimization of generated assembly code, interprocessor communication, Tycho, Master's Student 1988-1989 and Ph.D. Student 1991-1994
Joseph T. Buck (Synopsys, Inc.) (
Boolean dataflow, Ptolemy kernel, Linux port, ptcl, ptlang, scheduling, Motorola DSP assembly code generation, Ph.D. Student 1989-1993
Wan-Teh Chang (Netscape Communications)
Hierarchical finite-state machine controllers, telecommunications software, graphical user interfaces, higher-order functions, Ptolemy kernel, Tycho
William Chen (Columbia University) (
Native signal processing on the UltraSparc
Stephen Edwards (Synopsys) (
Synchronous/Reactive domain, hierarchical finite state machines, Statecharts, Esterel, Esterel compilers
Brian L. Evans (The University of Texas at Austin) (
Algorithm design, multidimensional signal processing, educational software, graphical user interfaces, Ptolemy Matlab/Mathematica interfaces, Tycho, Post-Doctoral Researcher 1993-1996
Alain Girault (INRIA) (
Synchronous languages, formal models for concurrent computations, distributed computing, Visiting Post-Doctoral Researcher 1995-1996
Michael Goodwin (
Audio signal processing, time-frequency analysis and synthesis, computer music
Soonhoi Ha (Seoul National University) (
Scheduling, dynamic dataflow, discrete-event domain, code generation, Ph.D. Student 1988-1992
Asawaree Kalavade (Bell Labs) (
Hardware/software partitioning and codesign, design methodology management, Thor, Silage, and design methodology management domains, Ph.D. Student 1990-1995
Tom Lane (Structured Software Systems) (
HP Port, many improvements to pigi and the kernel.
Praveen K. Murthy (
Scheduling, code generation, multidimensional dataflow, semantical issues in dataflow
Thomas M. Parks (MIT Lincoln Labs) (
Real-time computing, process networks, higher-order functions, code generation in C domain, Ph.D. Student 1990-1995
Rajagopal Nagarajan (Department of Computing, Imperial College, London ) (
Logic, concurrency, programming language semantics, specification and verification.
Wolfgang Reimer (Technical University of Ilmenau, Germany) (
Linux Ports
Eric K. Pauer (Sanders, a Lockheed Martin Company) (
Adaptive Computing Systems (ACS) domain, Architecture Trade Application
José Luis Pino (Hewlett Packard, EEsof Division) (
Multiprocessor scheduling, code generation for heterogeneous DSP systems, hierarchical scheduling, Motorola DSP assembly code generation, cosimulation, user interfaces
Sunil Samel (IMEC) (
HP port
S. Sriram (Texas Instruments) (
Parallel architectures, interprocessor communication, scheduling theory, Motorola DSP assembly code generation, Ph.D. Student 1990-1995
Richard S. Stevens (Naval Research Laboratory) (
Models and multiprocessor scheduling of dynamic dataflow computation, Processing Graph Method Navy standard
Stefan De Troch (IMEC) (
HP port
Xavier Warzee (Thomson CSF) (
ArrayOL domain, IBM RS/6000 port, Ptolemy evaluation
Michael C. Williamson (
Generating timed circuits from dataflow graphs, VHDL modeling, VHDL domain

Other Contributors

Some of these made their contribution through the Gabriel Project.
Raza Ahmed (Tektronix Inc.) (
Heuristic search packages for Mathematica, implementation cost target, Undergraduate researcher 1996
Egbert Ammicht (AT&T) (
DSP3 code generation
Sunil Bhave (
Audio interfaces and formats in Ptolemy, Undergraduate Researcher 1996-1997
Anindo Banerjea (
Discrete-event scheduling
John Barry (Georgia Institute of Technology) (
Optical communications, Ph.D. Student 1986-1992
Neal Becker (Comsat Laboratories) (
HP and Linux port, incremental linking development, user contributed stars.
Jeff C. Bier (Berkeley Design Technology, Inc.) (
Motorola DSP assembly code generation, Gabriel, Master's Student 1988-1989
Philip Bitar
Discrete-event domain, graphical user interface
Michael Bosse (Boston University) (
Tcl/Tk visualization in the IPUS domain (Integrated Processing and Understanding of Signals)
Rachel Bowers
Ptolemy demonstrations
Bill Bush
Vem schematic interface
Andrea Casotto
Vem schematic interface
Michael J. Chen (Geoworks) (
Multidimensional dataflow and signal processing, Master's Student 1993-1994
Kang Ngee Chia (UCLA) (
Code generation in C, Undergraduate Researcher Summer 1995
Cliff Cordeiro (
Interactive documentation
Gyorgy Csertan (Technical University of Budapest)
Converted Ptolemy 0.5.1 documentation to on-line hypertext HTML format
Rolando Diesta (
Discrete-event applications, networks, Graduate Student 1991-1995
Peter Dufault (HD Associates, Inc.) (>)
FreeBSD port
Chandan Egbert
Beta testing
Dirk Forchel (Technical University Dresden, Fraunhofer Institute of Microelectronic Circuits and Systems) ( and
Code Generation for the Dynamic Dataflow Domain (CGDDF) and Linux port
Yair Enden (Motorola)
Fix-point blocks in the CGC domain
Martha Fratt
Speech processing, Gabriel, Master's student 1989-1990
Ron Galicia (
Embedded multicomputing, real-time computer vision and image processing, hardware/software codesign
Edwin E. Goei (Sun) (
Vem schematic interface
Mike Grimwood
Digital infrared communication links, Gabriel, Master's student 1989-1990
Steve X. Gu (Nortel, formerly Northern Telecom) (
Tcl/Tk interface to Mathematica, educational software, software for wireless communications systems, Undergraduate Researcher 1994-1995
Luis Gutierrez (
Motorola 56000 Code Generation Stars, Texas Instruments C50 Domain, real-time video processing in embedded systems, Undergraduate Researcher 1996-1997
Eric Guntvedt
Erick Hamilton
Ptolemy Demonstrations
Richard Han (
Discrete-event applications, encryption in high error-rate applications, The Infopad Project, Current Ph.D. Student
David Harrison
Vem schematic interface
Paul E. Haskell (Compression Labs)
Image processing, video processing, and networks
Fritz Heinrichmeyer (FernUniverstitat at Hagen) (
Code generation domain for the TMS320C50 DSP processor
Holly Heine
Graphical user interface in Gabriel
Roger Hillson (Naval Research Laboratory) (
Dataflow, VHDL domains
Wai-Hung Ho
Gabriel demonstrations
Sangjin Hong (
Heterogeneous architecture design and simulation, communicating process domain
Steve How
Code generation, multirate systems, Gabriel, Master's student 1989-1990
Chih-Tsung Huang
Motorola DSP assembly code generation
Michael Huang (Boston University) (
islang preprocessor for stars in IPUS domain (Integrated Processing and Understanding of Signals)
Wei-Jen Huang (Stanford University)
Graphical user interface, Undergraduate Researcher 1994
Farhad Jalilvand (Intel) (
Communications demonstrations and subsystems, Undergraduate Researcher 1995
Alan Kamas (Independent Consultant) (
User Interface Design, Software Development, Project Manager 1991-1995
Seehyun Kim (
Fixed-point computation
Karim Khiar (Thomson CSF) (
Radar and higher-order functions, Visiting Master's Student 1994
Alireza Khazeni
Implementing fixed-point arithmetic and stars
Joel King (
Spice domain, mixed-signal simulation and IC design, Tycho, Master's student 1995-1996
Ed Knightly (U.C. Berkeley) (
Discrete-event scheduling, networks, Ph.D. Student 1991-1996
Ichiro Kuroda (NEC) (
Kernel development (parameter and state specification and parsing), Visiting Industrial Fellow 1989-1990
Alexander Kurpiers (Technical University of Darmstadt, Germany)
AIX port
Allen Lao (Applied Signal Technology) (
Message queue domain, ATM network simulations (video)
Phil D. Lapsley (Berkeley Design Technology, Inc.) (
Dataflow modeling, Motorola DSP assembly code generation, workstation and DSP board interfaces, Gabriel, Master's student 1990-1991
Jonathan Lee
Seungjun Lee
Communicating processes domain, Thor domain
Steven P. Levitan (Department of Electrical Engineering, University of Pittsburgh) (
Computer Aided Design and Simulation of Free Space Optoelectronic Information Processing Systems
Yu Kee Lim (
Software quality (debugging and documentation), developing new CGC stars, matrix support for code generation domains, ptdsp library, Undergraduate student researcher 1996
John Loh
Message queue domain, ATM networks
James Lundblad (
Configurable hardware
Yoshio Miki (Hitachi, Ltd.) (
Control logic generation, performance estimation of pipelines, interface between the SDF and DE domains, Visiting Industrial Scholar 1995
Takashi Miyazaki (NEC) (
Real-time video signal processing, DSP architectures
Brian Mountford
Douglas Niehaus (University of Kansas)
xxx domain, Tcl/Tk interface, pigi/oct interface
Maureen O'Reilly
Motorola DSP assembly code generation in Gabriel, modem design, Master's student 1989-1990
Johnathan Reason (U.C. Berkeley) (
NetBSD port, video coding over wireless networks, asynchronous video coding, The Infopad Project
Christopher Scannell (Naval Research Laboratory)
Beta testing
Farhana Sheikh (
Visual design methodology for real-time systems, parallel and distributed processing, and video signal processing, Master's Student 1995-1996
Sun-Inn Shih
Real-time video signal processing, code generation, Master's student 1993-1994
Gilbert C. Sih
Parallel scheduling, interprocessor communication, Ph.D. student 1987-1991
Mario Jorge Silva (Enterprise Integration Technologies) (
User interfaces
Neil Smyth (
Redevelopment of Ptolemy kernel in Java
Rick L. Spickelmier
Vem schematic interface
Matthew Tavis (Sapient) (
Graphical user interfaces, Tycho, Undergraduate researcher 1995-1996
Juergen Teich (ETH-Zurich) (
Scheduling, optimization, mixed synchronous/asynchronous systems, Postdoctoral Researcher 1994
Warren W. Tsai
VHDL modeling, Undergraduate Researcher 1995
William Tsu (
VHDL simulators attached to VHDL domain, Undergraduate Researcher 1995
Jens Voigt ( (Dresden University of Technology Communications Laboratory)
Dynamic Higher Order Functions in the DE Domain, C++ Ptolemy/Java interface
Alberto Vignani
Linux port
Gregory S. Walter
ATM networks, speech coding, Master's student 1991-1992
Patrick J. Warner (
Parallel processing, interprocessor communication, network of workstations target
Anders Wass
Thor domain
Kennard D. White (Diva Communications) (
C and Motorola DSP assembly code generation, CM5 target, user interfaces: tkoct and Xpole, filter design, Master's Student 1989-1993
Joseph M. Winograd (Boston University) (
Knowledge-based signal processing, IPUS (Integrated Processing and Understanding of Signals) domain
William Li (
Collaborating instances of Ptolemy, The Infopad Project
Andria Wong
Anthony Wong
Assembly code generation in Gabriel, Master's student 1991-1992
Bicheng William Wu (
Design of interactive digital signal processing tool.
Mei Xiao (Tyecin Systems Inc.) (
Image processing, graphical user interfaces, Master's Student 1993-1995
Chris Yu (Naval Research Laboratory)
Matrix representations

Last updated 02/25/99. Send comments to