Conceptual multidisciplinary design via a multi-objective multi-fidelity optimisation method.

Air travel demand and the associated fuel emissions are expected to keep increasing in the following decades, forcing the aerospace industry to find ways to revolutionise the design process to achieve step-like performance improvements and emission reduction goals. A promising approach towards that goal is multidisciplinary design. To maximise the benefits, interdisciplinary synergies have to be investigated early in the design process. Efficient multidisciplinary optimisation tools are required to reliably identify a set of promising design directions to support engineering decision making towards the new generation of aircraft. To support these needs, a novel optimisation methodology is proposed aiming in exploiting multidisciplinary trends in the conceptual stage, exploring the design space and providing a pareto set of optimum configurations in the minimum cost possible. This is achieved by a combination of the expected improvement surrogate based optimisation plan, a novel Kriging modification to allow the use of multi-fidelity tools and a multi-objective sub-optimisation process infill formulation implemented within an multidisciplinary design optimisation architecture. A series of analytical test cases were initially used to develop the methodology and examine its performance under a set of criteria like global optimality, computational efficiency and dimensionality scaling. These were followed by two industrially relevant aerodynamic design cases, the RAE2822 transonic airfoil and the GARTEUR high lift configuration, investigating the effect of the constraint handling methods and the low fidelity tool. The cost reductions and exploration characteristics achieved by the method were quantified in realistic unconstrained, constrained and multi-objective problems. Finally, an aerostructural optimisation study of the NASA Common Research Model was used as a representative of a complex multidisciplinary design problem. The results demonstrate the framework’s capabilities in industrial problems, showing improved results and design space exploration but with lower costs than similarly oriented methods. The effect of the multidisciplinary architecture was also examined

Dependable Embedded Systems

This Open Access book introduces readers to many new techniques for enhancing and optimizing reliability in embedded systems, which have emerged particularly within the last five years. This book introduces the most prominent reliability concerns from today’s points of view and roughly recapitulates the progress in the community so far. Unlike other books that focus on a single abstraction level such circuit level or system level alone, the focus of this book is to deal with the different reliability challenges across different levels starting from the physical level all the way to the system level (cross-layer approaches). The book aims at demonstrating how new hardware/software co-design solution can be proposed to ef-fectively mitigate reliability degradation such as transistor aging, processor variation, temperature effects, soft errors, etc. Provides readers with latest insights into novel, cross-layer methods and models with respect to dependability of embedded systems; Describes cross-layer approaches that can leverage reliability through techniques that are pro-actively designed with respect to techniques at other layers; Explains run-time adaptation and concepts/means of self-organization, in order to achieve error resiliency in complex, future many core systems

Synthesis of Clock Trees with Useful Skew based on Sparse-Graph Algorithms

Computer-aided design (CAD) for very large scale integration (VLSI) involve

Software for Exascale Computing - SPPEXA 2016-2019

This open access book summarizes the research done and results obtained in the second funding phase of the Priority Program 1648 "Software for Exascale Computing" (SPPEXA) of the German Research Foundation (DFG) presented at the SPPEXA Symposium in Dresden during October 21-23, 2019. In that respect, it both represents a continuation of Vol. 113 in Springer’s series Lecture Notes in Computational Science and Engineering, the corresponding report of SPPEXA’s first funding phase, and provides an overview of SPPEXA’s contributions towards exascale computing in today's sumpercomputer technology. The individual chapters address one or more of the research directions (1) computational algorithms, (2) system software, (3) application software, (4) data management and exploration, (5) programming, and (6) software tools. The book has an interdisciplinary appeal: scholars from computational sub-fields in computer science, mathematics, physics, or engineering will find it of particular interest