This document discusses using the Service-ORiented Computing EnviRonment (SORCER) platform for deterministic and stochastic optimization problems. It describes how global optimization algorithms VTDIRECT95 and QNSTOP were modified to run as optimization services on SORCER. As a case study, the EBF3PanelOpt framework for structural optimization of curvilinear aircraft panels was integrated with SORCER. This allowed the optimization problem to be solved in a distributed manner across computational resources for significantly faster objective function evaluations.

1. Service-ORiented Computing
EnviRonment (SORCER) for
Deterministic Global and
Stochastic Optimization
Chaitra Raghunath
Advisor: Dr. Layne T. Watson

2. Why optimize?

3. Why optimize?

4. Multidisciplinary Design Optimization
Multidisciplinary design optimization (MDO) – a field of
engineering that uses optimization methods to solve
design problems incorporating a number of disciplines.
[1]

5. Optimization Algorithms
 Optimization algorithm – a procedure which is executed
iteratively by comparing various solutions till an
optimum or a satisfactory solution is found.
 VTDIRECT95 and QNSTOP:
 Global optimization algorithms well suited for
multidisciplinary design optimization (MDO).
 Exhibit parallelism.
 Able to accommodate problems of higher dimensions.

6. Objective Function
 An equation to be optimized given certain constraints
and with variables that need to be minimized of
maximized using nonlinear programming techniques.
Point co-
ordinates (X)
Objective
Function
F(X)

7. Why is optimization costly?

8. Motivation
 Requirements of conceptual design of complex
systems – extensive exploration of design space and
analyses of a large number of potential design
configurations.
 Traditional conceptual design – low fidelity models,
poor accuracy.
 Physics based modeling – better accuracy,
computationally intensive.
 Need for a platform to cope with computational
complexity, high design time and high cost of
production.

9. SOC and SORCER
 Addresses the challenges faced by HPC in terms of
scalability, availability, reliability, and flexibility.
 Service-oriented computing (SOC) – utilizes platform-
agnostic services that effectively communicate with one
another to perform user-requested tasks in a distributed
computing environment.
Service
Registry
Find
Service
Requestor
Publish
Bind
Service
Requestor
Service
Provider

10. SOC and SORCER (cont.)
SORCER – derived from the SOA (service-oriented architecture)
model; Java-based, network-centric computing platform that
enables execution of service-oriented programs.
Advantages:
 Large scale, distributed, decentralized
 Leveraging the power of HPC
 Reusability
 Cost effective
 Better utilization of computational resources
 Load balancing across computational resources

11. Modifying VTDIRECT95 and
QNSTOP for SORCER
 Use of JNI (Java Native Interface) to allow Java
applications to invoke native code and vice versa.
 Use of JNI’s invocation interface – allows a regular
non-Java program running on the native operating
system to invoke a JVM to gain access to Java classes
and features.
 JNI wrapper – layer of abstraction between the
optimization algorithm and the Java block that
evaluates the objective for a given design point.

12. Modifying VTDIRECT95 and
QNSTOPP for SORCER (cont.)

13. VTdirect and QNSTOPS as
SORCER services
 Leveraging the power of Exertion-oriented Programming
(EOP) to make a number of services available to users in
a distributed computing environment.
SORCER terminology:
 Service provider: A remote object accepting exertions
from service requestors and performs calculations.
 Service requestor: An object that creates exertions and
submits them to the grid.
 Exertion: Defines collaboration – service-oriented
programs.

14. VTdirect and QNSTOPS as
SORCER services (cont.)
Steps involved in creating a provider that allows use of
VTdirect as a service:
 Wrap the Fortran 95 subroutine with JNI.
 Set up infrastructure for a SORCER provider.
//Code to execute the corresponding executable
./vtdirect
 Set up infrastructure for a SORCER requestor.
//Exert collaboration
Exertion result = vtdirectTask.exert();

15. Engineering Application: Optimization of
Curvilinear Blade-stiffened panels
 EBF3PanelOpt Framework – structural optimization of
curvilinearly stiffened panels to facilitate building of
optimal light-weight structures.
 Deployed as a provider within SORCER.

16. Engineering Application: Optimization of
Curvilinear Blade-stiffened panels

17. Engineering Application: Optimization of
Curvilinear Blade-stiffened panels

18. Numerical Results
Conventional aircraft wing panel geometry along with the
loads.

19. Numerical Results

20. Numerical Results

21. Numerical Results

22. Numerical Results

23. Numerical Results

24. Conclusion
 The algorithms packages VTDIRECT95 and QNSTOP were
successfully implemented as SORCER services.
 The EBF3PanelOpt framework was successfully integrated with
SORCER, facilitating the optimization of curvilinearly stiffened
panel in a truly distributed manner.
 With the use of SORCER’s JavaSpaces technology, computers
could be added on the fly, hence providing flexibility.
 Distributed parallelism and load balancing across
computational resources with SORCER helped in significantly
speeding up objective function evaluations in a dynamically
scalable environment.

25. Questions?

26. References
[1]. Deshpande S., Watson L. T., Love N. J., Canfield R. A.,
and Kolonay R. M., “Aircraft Design Markup Language for
Multidisciplinary Aircraft Design and Analysis”, AIAA –
Journal of Information Sciences, Vol. 12, No. 2, Feb. 2015.