A complex system is a system composed of many components which may interact with each other. Examples of complex systems are Earth’s global climate, organisms, diseases, the human brain, infrastructure such as power grid, transportation or communication systems, social and economic organizations (like cities), an ecosystem, a living cell, and ultimately the entire universe.
The study of complex systems calls for an interdisciplinary approach combining disciplines such as Biology, Computer Science, Data Science, Economics, Mathematics, Physics and Sociology.
Start of applications: October 7th Deadline for applications: October 20th Notification of acceptance: November 10th
Many researchers may face this problem developing numerical applications. We prototype using a high-level language appealing for its eye to program, readability, nice plotting, very talkative debugger. When it comes to productions runs, we like to translate the prototypes in lower-level compiler languages to benefit from runtime performance, parallelisation possibilities but loosing many interesting features from high-level languages.
Our contribution presented at JuliaCon 2019 (Baltimore MA, USA) is an illustration of Julia solving “the two language problem”. We replace our Matlab prototype and the CUDA C + MPI production code by a single Julia code that serves both prototyping and production tasks. We showcase the port to Julia of a massively parallel Multi-GPU hydro-mechanical stencil-based solver in 3-D. The iterative solver can be applied to a wide range of coupled differential equations.
We report a close to optimal weak scaling on 1024 NVIDIA Tesla P100 GPUs on the hybrid Cray XC-50 “Piz Daint” supercomputer at the Swiss National Supercomputing Centre, CSCS (Figure 1). We compare these results obtained with our Julia prototype to a reference scaling realised using the Multi-GPU production code solver written in CUDA C + MPI that achieved a high performance and a nearly ideal parallel efficiency on up to 5120 NVIDIA Tesla P100 GPUs “Piz Daint”. Soon in press.
This year’s Nvidia GPU Technology Conference to take place in San Jose, Silicon Valley, CA. Besides the opening keynote by CEO Jensen Huang, a former researcher from the Swiss Geocomputing Centre, Ludovic Räss, gave a talk on geo-supercomputing. Recording is accessible hereafter or on GTC on-demand:
Common thoughts suggests that environmental respective “green” computing is tightly linked to rapid execution of a given computer program or routine. This post reports some interesting relations between computer languages, their relative execution time and their energy consumption
You can now access here majority of the speakers contribution to the Swiss Geocomputing Centre kick-off workshop. Thank you again very much to all the participants for their presence, and to all the speakers and poster presenters for their contributions.
Thibault Duretz, Ludovic Räss, Yury Podladchikov and Stefan Schmalholz recently published a new study about multi-physics couplings with focus on thermomechanical interactions.
Their contribution (accessible here) assesses the ability of an iterative technique to resolve nonlinear interactions between thermal and mechanical processes. This new approach to solution is particularly well suited for parallel devices, such GPUs. The authors benchmark their proposed solver against a direct-iterative type of more classical approach (TM2Di).
Jose Fernando Mendes Professor at the University of Aveiro
Structural Properties of Multiplex Networks
Many complex systems, both natural, and man-made, can be represented as multiplex or interdependent networks. Multiple dependencies make a system more fragile: damage to one element can lead to avalanches of failures throughout the system. In this talk I will present recent developments about the structural properties of multiplex networks. The transition founded is asymmetric. It is hybrid in nature, having a discontinuity like a first-order transition, but exhibiting critical behavior, only above the transition, like a second-order transition. A complete understanding of the transition cannot therefore be had without first understanding this critical behavior. I will discuss and describe the nature of such hybrid phase transitions and the appearance of avalanches at criticality. José Fernando F. Mendes is a theoretical physicist working on Statistical Physics. His research focuses mainly in the study of complex systems and the structure and the evolution of complex networks like the World Wide Web, the Internet, biological networks, etc. Other interests are related with: granular media, self-organized criticality, non-equilibrium phase transitions, deposition models,etc. He is co-author of over 130 scientific papers receiving about 18,000 citations, with his most cited works more than 3,000 citations.