Scientific and Technical Aerospace Reports Volume 38 July 28, 2000

85 dB amplifier design evolved by our system, and another figure shows the performance of that circuit (gain and frequency
response). In all tasks, our system is able to generate circuits that achieve the target specifications.
Author
Genetic Algorithms; Computer Aided Design; Circuits; Control Systems Design
20000064583 NASA Ames Research Center, Moffett Field, CA USA
Automation of the CFD Process on Distributed Computing Systems
Tejnil, Ed, MCAT Inst., USA; Gee, Ken, MCAT Inst., USA; Rizk, Yehia M., NASA Ames Research Center, USA; Welcome to
the NASA High Performance Computing and Communications Computational Aerosciences (CAS) Workshop 2000; February
2000; In English; See also 20000064579; No Copyright; Abstract Only; Available from CASI only as part of the entire parent
document
A script system was developed to automate and streamline portions of the CFD process. The system was designed to facilitate
the use of CFD flow solvers on supercomputer and workstation platforms within a parametric design event. Integrating solver
pre- and postprocessing phases, the fully automated ADTT script system marshalled the required input data, submitted the jobs
to available computational resources, and processed the resulting output data. A number of codes were incorporated into the script
system, which itself was part of a larger integrated design environment software package. The IDE and scripts were used in a
design event involving a wind tunnel test. This experience highlighted the need for efficient data and resource management in
all parts of the CFD process. to facilitate the use of CFD methods to perform parametric design studies, the script system was
developed using UNIX shell and Perl languages. The goal of the work was to minimize the user interaction required to generate
the data necessary to fill a parametric design space. The scripts wrote out the required input files for the user-specified flow solver,
transferred all necessary input files to the computational resource, submitted and tracked the jobs using the resource queuing structure,
and retrieved and post-processed the resulting dataset. For computational resources that did not run queueing software, the
script system established its own simple first-in-first-out queueing structure to manage the workload. A variety of flow solvers
were incorporated in the script system, including INS2D, PMARC, TIGER and GASP. Adapting the script system to a new flow
solver was made easier through the use of object-oriented programming methods. The script system was incorporated into an
ADTT integrated design environment and evaluated as part of a wind tunnel experiment. The system successfully generated the
data required to fill the desired parametric design space. This stressed the computational resources required to compute and store
the information. The scripts were continually modified to improve the utilization of the computational resources and reduce the
likelihood of data loss due to failures. An ad-hoc file server was created to manage the large amount of data being generated as
part of the design event. Files were stored and retrieved as needed to create new jobs and analyze the results. Additional information
is contained in the original.
Author
Applications Programs (Computers); Computational Fluid Dynamics; Object-Oriented Programming; Distributed Processing
20000064586 NASA Glenn Research Center, Cleveland, OH USA
Developing CORBA-Based Distributed Scientific Applications from Legacy FORTRAN Programs
Sang, Janche, Cleveland State Univ., USA; Kim, Chan, NASA Ames Research Center, USA; Lopez, Isaac, NASA Ames Research
Center, USA; Welcome to the NASA High Performance Computing and Communications Computational Aerosciences (CAS)
Workshop 2000; February 2000; In English; See also 20000064579; No Copyright; Abstract Only; Available from CASI only as
part of the entire parent document
Recent progress in distributed object technology has enabled software applications to be developed and deployed easily such
that objects or components can work together across the boundaries of the network, different operating systems, and different
languages. A distributed object is not necessarily a complete application but rather a reusable, self-contained piece of software
that co-operates with other objects in a plug-and-play fashion via a well-defined interface. The Common Object Request Broker
Architecture (CORBA), a middleware standard defined by the Object Management Group (OMG), uses the Interface Definition
Language (IDL) to specify such an interface for transparent communication between distributed objects. Since IDL can be mapped
to any programming language, such as C++, Java, Smalltalk, etc., existing applications can be integrated into a new application
and hence the tasks of code re-writing and software maintenance can be reduced. Many scientific applications in aerodynamics
and solid mechanics are written in FORTRAN. Refitting these legacy FORTRAN codes with CORBA objects can increase the
codes reusability. For example, scientists could link their scientific applications to vintage FORTRAN programs such as Partial
Differential Equation(PDE) solvers in a plug-and-play fashion. Unfortunately, CORBA IDL to FORTRAN mapping has not been
proposed and there seems to be no direct method of generating CORBA objects from FORTRAN without having to resort to manually
writing C/C++ wrappers. In this paper, we present an efficient methodology to integrate FORTRAN legacy programs into
a distributed object framework. Issues and strategies regarding the conversion and decomposition of FORTRAN codes into
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