Accelerating Numerical Simulation of Multiple Scattering for Radiation Transport

master's thesis

• Title (croatian): Ubrzavanje numeričke simulacije višestrukog raspršenja za prijenos zračenja
• Author: Stjepan Požgaj
• Mentor: Zlatko Drmač (mentor)
• Committee member: Zlatko Drmač (predsjednik povjerenstva)
• Committee member: Nela Bosner (član povjerenstva)
• Committee member: Zvonimir Bujanović (član povjerenstva)
• Committee member: Ozren Perše (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Mathematics); Zagreb
• Defense date and country: 2022-07-21, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Mathematics

Abstract

The Juelich Rapid Spectral Simulation Code (JURASSIC) is a fast radiative transfer model for the analysis of atmospheric remote sensing measurements in the mid-infrared spectral region. It is used to derive the state of the atmosphere from the measurements. It was written in C and features an MPI/OpenMP hybrid parallelization for use on supercomputers. JURASSIC-GPU was developed by porting JURASSIC to GPUs using the CUDA programming language. To incorporate particles into the model, scattering of the infrared radiation on the particles was accounted for in the JURASSIC-scatter model, but this model so far did not benefit from tuning and acceleration of the reference model. The goal of the work in this thesis was to accelerate the JURASSIC-scatter forward model. It was done by combining it with JURASSIC-GPU. The implementation that uses both models was benchmarked on JUWELS – one of the world’s top supercomputers, and the achieved speedup was around 10×. After that, to remove code duplicates and to make the code easier to understand and maintain, JURASSIC-scatter and JURASSIC-GPU were merged into the new unified code project named JURASSIC-unified. This unified implementation has even better performance – it is around 24× faster then the initial JURASSICscatter implementation. In addition to a new feature, the JURASSIC-unified project was adapted so that even the JURASSIC reference project can use it as a library.

Abstract (croatian)

Juelich Rapid Spectral Simulation Code (JURASSIC) je model radijacijskog transporta koji se koristi u analizi atmosferskih daljinskih mjerenja zračenja iz srednje infracrvenog područja. Služi za otkrivanje stanja atmosfere na temelju zadanih mjerenja. Napisan je u programskom jeziku C i pomoću MPI/OpenMP hibridne paralelizacije prilagoden za izvođenje na superračunalima. JURASSIC-GPU je verzija JURASSIC-a kojoj je uz pomoć programskog jezika CUDA omogućeno efikasnije izvršavanje na grafičkim procesorima. Kako bi se u model uključile čestice, raspršenje infracrvenog zračenja je dodano u JURASSIC-scatter modelu, no taj model još nije imao koristi od ubrzavanja JURASSIC modela koji zanemaruje čestice. Glavni cilj ovog diplomskog rada bio je ubrzati JURASSIC-scatter model. To je napravljeno njegovim kombiniranjem s JURASSIC-GPU modelom. Performanse implementacije koja koristi oba modela izmjerene su na JUWELS-u – jednom on najboljih svjetskih superra čunala, i postignuto je ubrzanje od oko 10 puta. Nakon toga, kako bi se maknuli duplikati iz ta dva projekta i napravio razumljiviji kod koji će biti jednostavniji za održavanje, odlučeno je da se JURASSIC-scatter i JURASSIC-GPU spoje u novi projekt – JURASSICunified. Takva jedinstvena implementacija ima još bolje performanse – ubrzanje u odnosu na JURASSIC-scatter je oko 24 puta. Uz dodavanje jedne nove funkcionalnosti, JURASSICunified projekt je prilagođen tako da ga i model koji zanemaruje čestice može koristiti kao biblioteku.

• Keywords: Juelich Rapid Spectral Simulation Code; JURASSIC; radiative transfer model; atmospheric radiation; mid-infrared spectral region; C programming language; CUDA programming language; JURASSIC-scatter; JURASSIC-GPU; JURASSIC-unified project
• Keywords (croatian): Juelich Rapid Spectral Simulation Code; JURASSIC; model radijacijskog transporta; atmosferska zračenja; infracrveno područje; programski jezik C; programski jezik CUDA; JUWELS; JURASSIC-scatter; JURASSIC-GPU; JURASSICunified
• Language: english
• URN:NBN: urn:nbn:hr:217:654904
• Study programme: Title: Computer Science and Mathematics; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra računarstva i matematike (magistar/magistra računarstva i matematike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-09-14 11:48:22