The Hopper XE6 system, NERSC’s first peta-flop system with over 153,000 cores has increased the computing hours available to the Department of Energy’s Office of Science users by more than a factor of 4. As NERSC users transition from the Franklin XT4 system with 4 cores per node to the Hopper XE6 system with 24 cores per node, they have had to adapt to a lower amount of memory per core and onn...

As clusters continue to grow in size and complexity, providing scalable and predictable performance is an increasingly important challenge. A crucial roadblock to achieving predictable performance is stragglers, i.e., tasks that take significantly longer than expected to run. At this point, speculative execution has been widely adopted to mitigate the impact of stragglers. However, speculation ...

hopper groups can be explained by a single underlying mechanism, that is, the development of a set to respond (industriousness) or of a set to not respond (laziness). Presumably the treadle group learned that reinforcement is contingent on some response and they entered the autoshaping situation with a set or expectation that a similar contingency still applied. The hopper birds responded less ...

The Kalman filter and its nonlinear variants have been widely used for filtering and state estimation. However, models with severe nonlinearities are not handled well by Kalman filters. Such an application is presented in this paper: the estimation of the overflow losses in a hopper-dredger. The overflow mixture density and flow-rate have to be estimated based on noisy measurements of the total...

The benefits of legged locomotion shown in nature overcome challenges such as obstacles or terrain smoothness typically encountered with wheeled vehicles. This paper evaluates the benefits of using optimal control on a single leg hopper during the entire hopping motion. Basic control without considering physical constraints is implemented through handtuned PD controllers following the Raibert c...

Humans have an innate ability to extract important information from data sets or images, but also to solve particular problems on which computers may struggle. Serious gaming, and the related crowdsourcing term, are new computational paradigms attempting to process enormous amounts of scientific data exploiting these innate humans capabilities. In this paper we present Space Hopper, a “serious ...

Problems related to brown plant hopper outbreaks management in the Mekong Delta-Vietnam are complex and need aggregating information across administrative scales. Brown plant hoppers density and environmental indicators are main factors that support stakeholders have suitable decision making. Due to detail levels of information are different from field scale to region scale, upscaling informati...