Pre-exascale accelerated application development:The ORNL Summit experience

High-performance computing (HPC) increasingly relies on heterogeneous architectures to achieve higher performance. In the Oak Ridge Leadership Facility (OLCF), Oak Ridge, TN, USA, this trend continues as its latest supercomputer, Summit, entered production in early 2019. The combination of IBM POWER9 CPU and NVIDIA V100 GPU, along with a fast NVLink2 interconnect and other latest technologies, pushes system performance to a new height and breaks the exascale barrier by certain measures. Due to Summit's powerful GPUs and much higher GPU-CPU ratio, offloading to accelerators becomes a requirement for any application, which intends to effectively use the system. To facilitate navigating a complex landscape of competing heterogeneous architectures, a collection of applications from a wide spectrum of scientific domains is selected for early adoption on Summit. In this article, the experience and lessons learned are summarized, in the hope of providing useful guidance to address new programming challenges, such as scalability, performance portability, and software maintainability, for future application development efforts on heterogeneous HPC systems

Edge insertion for optimal triangulations

10.1007/BF02573962Discrete & Computational Geometry10147-6

Ensino à distância na engenharia: contornos e perspectivas Distance education in engineering: an outline and perspectives

Os programas de pós -graduação em engenharia têm formado, no país, quantidade apreciável de mestrês nos últimos anos. Parcela muito pequena desses, no entanto, tem sido constituída por empregados de empresas que efetivamente os tenham enviado à Universidade para a obtenção de títulos pós-graduados. Por outro lado, em razão da recessão por que passamos, muitos dos candidatos a programas de mestrado em engenharia são jovens que não conseguiram emprego na indústria. Muitos desses jovens continuarão rondando as universidades e os órgãos de fomento, tentando prosseguir seus estudos (doutorado), pleiteando uma bolsa no exterior, etc. Na América do Norte e na Europa tem-se lançado mão, em larga escala, do ensino à distância de nível superior, visando suprir as necessidades do sistema produtivo e da sociedade. Neste artigo discutem-se os aspectos conceituais e técnicos ligados ao ensino à distância na Europa e na América do Norte, apresentando-se uma bibliografia atualizada sobre a questão. Em seguida é feita uma análise das perspectivas e condições para sua implantação no Brasil.<br>The post-graduate Engineering programmes in Brazil have produced quite a number of new masters during the past few years. Only a small part of them, however, are employees specifically sent by their employers to obtain an advanced degree at the University. On the other hand, due to the economic recession, a good part of the master's candidates are young people that were not able to get a position in the job market. Most of them will be still wandering around the university after getting their master's diploma. Some will try a further doctor's programme. Others will seek a scholarship to study abroad, etc. This means that the impact of the Brazilian post-graduation programmes on the country’s developing process has been not too significant. In North America and in Europe distance education has been used extensively, even at the post-graduate level, with the clear objective of responding to the needs of the industry and society, and improving the skills of the labor force. This paper brings out, to the Brazilian audience, some conceptual and technical aspects related to distance education in Europe and North America. An updated bibliography will help the reader to further investigate the subject in more detail. An analysis of the perpectives and conditions to successfully introduce distance education in Brazil is presented

Whole-volume integrated gyrokinetic simulation of plasma turbulence in realistic diverted-tokamak geometry

Performance prediction for ITER is based upon the ubiquitous experimental observation that the plasma energy confinement in the device core is strongly coupled to the edge confinement for an unknown reason. The coupling time-scale is much shorter than the plasma transport time-scale. In order to understand this critical observation, a multi-scale turbulence-neoclassical simulation of integrated edge-core plasma in a realistic diverted geometry is a necessity, but has been a formidable task. Thanks to the recent development in high performance computing, we have succeeded in the integrated multiscale gyrokinetic simulation of the ion-temperature-gradient driven turbulence in realistic diverted tokamak geometry for the first time. It is found that modification of the self-organized criticality in the core plasma by nonlocal core-edge coupling of ITG turbulence can be responsible for the core-edge confinement coupling. &amp;copy; 2009 IOP Publishing Lt