Neko

Abstract: Recent trends and advancement in including more diverse and heterogeneous hardware in High-Performance Computing is challenging software developers in their pursuit for good performance and numerical stability. The well-known maxim "software outlives hardware" may no longer necessarily hold true, and developers are today forced to re-factor their codebases to leverage these powerful new systems. CFD is one of the many application domains affected. In this paper, we present Neko, a portable framework for high-order spectral element flow simulations. Unlike prior works, Neko adopts a modern object-oriented approach, allowing multi-tier abstractions of the solver stack and facilitating hardware backends ranging from general-purpose processors down to exotic vector processors and FPGAs. We show that Neko's performance and accuracy are comparable to NekRS, and thus on-par with Nek5000's successor on modern CPU machines. Furthermore, we develop a performance model, which we use to discuss challenges and opportunities for high-order solvers on emerging hardware.

Abstract: Abstract:Few contemporary artists channel the utopian impulses of the nonhuman turn with more creative energy than Neko Case. In her work, the untraceable movements of poisonous gases, the uncanny desires of tornadoes, and the recalcitrant withdrawal of subatomic particles envision an array of transits, elusions, and exit strategies so often denied to the subjects whose bodies, trajectories, and affective lives are policed by the regulatory cultural and institutional forces endemic to heteronormative biocapitalism, particularly poor and marginalized women. Drawing on recent scholarship in feminist new materialism as well as its critics, this essay considers the implications of these imaginings. On the one hand, the modes of agency that Case's songs invoke frequently entail a circumvention or suppression of specific political interests, making them susceptible to antifeminist and settler-colonialist appropriations; on the other hand, her work potentially offers a vision of the political that refuses to take human action as the inevitable starting point for its theories of power and domination, an increasingly urgent task in an age of ecological catastrophe, when the lives of earth's most vulnerable gendered and racialized subjects are irreducibly enmeshed in precarious planetary networks of biodependencies that include the actions of microbes, tornadoes, and atoms alike. In Case's most original compositions, a reductionist materialism attendant to the agency of the nonhuman complements rather than forecloses an older materialist tradition insistent on antagonism between conflicting interest groups as the motor engine of history and the social.

Abstract: In this paper we present NekoStat, an extension of the Neko tool. Neko is a Java framework and a communication platform that permits rapid prototyping of distributed applications; it provides tools to organize the applications using a layered architecture, with the network(s) at the bottom of the architecture. Neko is also a communication platform that allows sending and receiving of generic Java objects. Distributed systems realized within the Neko framework can be exercised both on real networks and on simulated ones, without changes in the application code. We constructed an extension to plain Neko, called NekoStat; it permits attainment of quantitative evaluations of distributed systems. In the paper we describe this extension; we motivate the development of NekoStat, we describe the design and finally we illustrate its usage through a case study, which highlights the usefulness of NekoStat.