1. LIGHTWEIGHT STRUCTURES in CIVIL ENGINEERING INTERNATIONAL SEMINAR of IASS POLISH CHAPTER Organized by Polish Chapter of International Association for Shell and Spatial Structures Warsaw-Częstochowa, 3 December, 2004 OVERLOADING OF OPERATORS IN FEMA SYSTEM W. PRZYBYŁO 1 and M. MAŹNIEWSKI 2 1 Professor, Częstochowa University of Technology, ul. Akademicka 3, 42-200 Częstochowa, POLAND 2 PhD. student, Częstochowa University of Technology, ul. Akademicka 3, 42-200 Częstochowa, POLAND

2. FEM (Finite Elements Method) ● Constructions are divided into many elements ● Elements are described with matrices ● Hypermatrix - matrix of matrices ● Problems associated with matrices: – high requirements of disk and memory space – high requirements of computational power – costly and time-consuming calculations

3. Characteristics of matrix operations ● Problems' solutions are constructed as a set of subtasks ● Subtasks are executed one by another ● Some subtasks are repeated many times with different data-sets ● Some subtasks are independent one of another ● Subtasks can be executed simultaneously

4. Parallelization of multiplying matrices

5. Comparison of computer systems ● Single computer – one CPU ● Symetric Multiprocessor(SMP) ● Parallel computer – many processors in one box – one processor – one task ● Clusters – set of computers jointed with network – Saving money by using owned hardware – Big computational power with low cost – Easy enlarging – Reliable calculations – Fail-safe system

6. Speeding-up calculations ● Simultaneous subtasks' execution ● Computer programs' parallelization ● Building clustered systems ● Requirements: – Synchronization of data – Interprocess communication – Network communication

7. Modelling algorithms into computer programs ● Algorithm – description of problem solution ● Algorithms are constructed with cooperation of specialists ● Computer program – representation of algorithm – different syntax of programming languages – Only programmers understand source code – Mathematic operations replaced with programming operations

8. Overloading of operators ● Arithmetic operators – works only with basic data- types(char, integer value, real value...) ● Defining own data-types – Objective Programming ● Matrix operations – Definition of object: MATRIX ● Overloading operators – allowing them work with user-defined data-types ● Problems with matrices operations – Large matrices need large disk and memory spaces – Assignment of matrices – copying one matrix to another

9. Overloading of operators cont. ● Classic mode – a:=1, b:= 2 – integer values – c := a + b, c = 3 – integer value ● Overloading operators – A – matrix, dimension: n x n – B – matrix, dimension: n x n – C : = A + B - matrix, dimension n x n – D : = A * B – matrix, dimension n x n

10. FEMA System ● Designed for matrices and hypermatrices operations ● Modular system for modular operations(parallelization enabled) ● Maximum dimension of data sets, minimum time of processing

11. Proposed approach ● Overloading matrix operations ● Replacing copying of matrices – with commands from FEMA system ● Dividing task into subtasks ● Writing steering files for every subtask ● Sending steering files to nodes of clusters ● Processing calculations in professional system(FEMA) ● Aggregation of calculations' results

12. Example ● Adding matrices: – in source code: C = A + B – in result : PHAH A B C ● Multiplying matrices: – in source code: C = A * B – in result :PHMH A B C

13. Appendix: Parallel example ● Steering file is read by master-program ● Worker-program is invoked ● Master-program sends steering file to worker ● Worker-program writes steering file to hard-disk ● Worker-program invokes FEMA system ● FEMA system read task-definition and input data ● FEMA system executes operations and writes results to hard-disk

15. Steering file example (fema.CIN) ● DDEX ● DEX-BAT ● DDEX7 ● 2 ● 3 ● Y ● N ● END

16. Console output ● [1:t40005] Master process..262149..[ bind and ready to distribute tasks ].. ● [1:t40005] Master [262149]..Checking steering-file [/tmp/fema.CIN] structure...OK ● [1:t40005] Worker-process..ID...262150: [ ready to execute tasks ] ● [1:t40005] Process: [262149] ready to send steering file.. ● [1:t40006] Process: [262150] ready to get steering file.. ● [1:t40005] [262149]..We've read: ● [1:t40005] DDEX ● [1:t40005] DEX-BAT ● [1:t40005] DDEX7 ● [1:t40005] 2 ● [1:t40005] 3 ● [1:t40005] Y ● [1:t40005] N ● [1:t40005] END ● [1:t40005] Process [262149]..sending steering file to worker(s).. ● [1:t40006] Process: [262150] retrieved cmd: ● [1:t40006]..DDEX ● [1:t40006] DEX-BAT ● [1:t40006] DDEX7 ● [1:t40006] 2 ● [1:t40006] 3 ● [1:t40006] Y ● [1:t40006] N

17. ● [1:t40006] END ● [1:t40005] Process: [262149] - retrieved confirmation.. ● [1:t40005] Process: [262149] exiting.. ● [1:t40005] EOF ● [1:t40006]....confirmation sent to master.. ● [1:t40006] Process: [262150]..Attempting to write steering file [/home/pvm3/bin/LINUX/FEMA/task/fema.CIN].. ● [1:t40006] Process: [262150] - [ OK ] file has been written ● [1:t40006] Process: [262150]..Attempting to run FEMA system.. ● [1:t40006] Process: [262150]..checking for task-definition file.. ● [1:t40006] Process: [262150] - [ OK ] task-definition file is proper.. ● [1:t40006] Process: [262150]..running FEMA system.. ● [1:t40006] sh: CLS: command not found ● [1:t40006] sh: PAUSE: command not found ● [1:t40006] sh: CLS: command not found ● [1:t40006] [34;1m************************************************************************ ******** ● [1:t40006] WELCOME TO FEMA DATABASE MADE BY FEMA ENGINEERING LTD ● [1:t40006] YOU HAVE SELECTED /home/pvm3/bin/LINUX/f88.exe, ● [1:t40006] WITH /home/pvm3/bin/LINUX/FEMA/task/fema.INP AS ARGUMENT ● [1:t40006] ****************************************************************************** ** ● [1:t40006] [0m*************************************************************************** * ● [1:t40006] EOF