Generating optimized Fourier interpolation routines for density function theory using SPIRAL

© 2015 IEEE.Upsampling of a multi-dimensional data-set is an operation with wide application in image processing and quantum mechanical calculations using density functional theory. For small up sampling factors as seen in the quantum chemistry code ONETEP, a time-shift based implementation that shifts samples by a fraction of the original grid spacing to fill in the intermediate values using a frequency domain Fourier property can be a good choice. Readily available highly optimized multidimensional FFT implementations are leveraged at the expense of extra passes through the entire working set. In this paper we present an optimized variant of the time-shift based up sampling. Since ONETEP handles threading, we address the memory hierarchy and SIMD vectorization, and focus on problem dimensions relevant for ONETEP. We present a formalization of this operation within the SPIRAL framework and demonstrate auto-generated and auto-tuned interpolation libraries. We compare the performance of our generated code against the previous best implementations using highly optimized FFT libraries (FFTW and MKL). We demonstrate speed-ups in isolation averaging 3x and within ONETEP of up to 15%

Goal-based self-contextualization

Abstract. System self-contextualizability is the system ability to autonomously adapt its behavior to the uncontrollable relevant context to keep its objectives satisfied. Self-contextualizable system must have alternative behaviors each fitting to a set of contexts. We propose to start considering context at the level of requirements engineering, adopting Tropos goal model to express requirements and complementing it with our proposed context analysis. We define variation points on goal model where a context-based decision might need to be taken, and propose constructs to analyze context. While goal analysis provides constructs to hierarchically analyze goals and discover alternative sets of tasks to be executed to satisfy a goal, our proposed context analysis provides constructs to hierarchically analyze context and discover alternative sets of facts to be monitored to verify a context.

Technic and Collaboration Breakdown Structures: Drivers of collaborative problem solving approaches in a supply chain context

Problem Solving Methodologies have been par excellence a cornerstone element of the firms’ strategy on achieving effective continuous improvement. But the enterprise evolution towards an extended environment characterized by network-based organization has radically changed the problem solving paradigms. This paper aims to propose a generic and collaborative methodology addressing more complex and distributed problems, dealing with Supply Chain issues and having a key role as a driver for building global competitive advantages and create superior performances at a Supply Chain level

Modeling and analyzing variability for mobile information systems

Abstract. Advances in size, power, and ubiquity of computing, sensors, and communication technology made possible the development of mobile or nomadic information systems. Variability of location and system behavior is a central issue in mobile information systems, where behavior of software has to change and re-adapt to the different location settings. This paper concerns modeling and analysis of the complementary relation between software and location variability. We use graphical and formal location modeling techniques, show how to elicit and use location model in conjunction with Tropos goal-oriented framework, and introduce automated analysis on the location-based models.

Reverse Engineering Quantum Field Theory

An approach to the foundations of quantum theory is advertised that proceeds by "reverse engineering" quantum field theory. As a concrete instance of this approach, the general boundary formulation of quantum theory is outlined.Comment: 5 pages, LaTeX + aipproc (included), contribution to the proceedings of the conference "Quantum Theory: Reconsideration of Foundations - 6" (V\"axj\"o, 2012