A special purpose silicon compiler for designing supercomputing VLSI systems

Design of general/special purpose supercomputing VLSI systems for numeric algorithm execution involves tackling two important aspects, namely their computational and communication complexities. Development of software tools for designing such systems itself becomes complex. Hence a novel design methodology has to be developed. For designing such complex systems a special purpose silicon compiler is needed in which: the computational and communicational structures of different numeric algorithms should be taken into account to simplify the silicon compiler design, the approach is macrocell based, and the software tools at different levels (algorithm down to the VLSI circuit layout) should get integrated. In this paper a special purpose silicon (SPS) compiler based on PACUBE macrocell VLSI arrays for designing supercomputing VLSI systems is presented. It is shown that turn-around time and silicon real estate get reduced over the silicon compilers based on PLA's, SLA's, and gate arrays. The first two silicon compiler characteristics mentioned above enable the SPS compiler to perform systolic mapping (at the macrocell level) of algorithms whose computational structures are of GIPOP (generalized inner product outer product) form. Direct systolic mapping on PLA's, SLA's, and gate arrays is very difficult as they are micro-cell based. A novel GIPOP processor is under development using this special purpose silicon compiler

Integrated Process Chain for Aerostructural Wing Optimization and Application to an NLF Forward Swept Composite Wing

This contribution introduces an integrated process chain for aerostructural wing optimization based on high fidelity simulationmethods. The architecture of this process chain enables two of the most promising future technologies in commercial aircraft design in the context of multidisciplinary design optimization (MDO). These technologies are natural laminar flow (NLF) and aeroelastic tailoring using carbon fiber reinforced plastics (CFRP). With this new approach the application of MDO to an NLF forward swept composite wing will be possible. The main feature of the process chain is the hierarchical decomposition of the optimization problem into two levels. On the highest level the wing planform including twist and airfoil thickness distributions as well as the orthotropy direction of the composite structure will be optimized. The lower optimization level includes the wing box sizing for essential load cases considering the static aeroelastic deformations. Additionally, the airfoil shapes are transferred from a given NLF wing design. The natural laminar flow is considered by prescribing laminar-turbulent transition locations. Results of wing design studies and a wing optimization using the process chain are presented for a forward swept wing aircraft configuration. The wing optimization with 12 design parameters shows a fuel burn reduction in the order of 9% for the design mission

RADX Modulates RAD51 Activity to Control Replication Fork Protection

Summary: RAD51 promotes homologous recombination repair (HR) of double-strand breaks and acts during DNA replication to facilitate fork reversal and protect nascent DNA strands from nuclease digestion. Several additional HR proteins regulate fork protection by promoting RAD51 filament formation. Here, we show that RADX modulates stalled fork protection by antagonizing RAD51. Consequently, silencing RADX restores fork protection in cells deficient for BRCA1, BRCA2, FANCA, FANCD2, or BOD1L. Inactivating RADX prevents both MRE11- and DNA2-dependent fork degradation. Furthermore, RADX overexpression causes fork degradation that is dependent on these nucleases and fork reversal. The amount of RAD51 determines the fate of stalled replication forks, with more RAD51 required for fork protection than fork reversal. Finally, we find that RADX effectively competes with RAD51 for binding to single-stranded DNA, supporting a model in which RADX buffers RAD51 to ensure the right amount of reversal and protection to maintain genome stability. : Bhat et al. discover that RADX competes with RAD51 for ssDNA and silencing RADX confers fork protection to cells with compromised RAD51 filament stability caused by loss of BRCA1, BOD1L, and the Fanconi anemia pathway. In addition, they find that more RAD51 is needed for fork stabilization than fork reversal. Keywords: fork reversal, fork protection, RAD51, RADX, replication stress, MRE11, BRCA1, Fanconi anemi

Multiphysics Simulation Environments for Shell and Spatial Structures

IASS-IACM 2008 Session: Multiphysics Simulation Environments for Shell and Spatial Structures -- Session Organizers: Fehmi CIRAK (University of Cambridge), Ekkehard RAMM (Stuttgart University) -- Keynote Lecture: "Advanced approaches for fluid-shell interaction" by Wolfgang A. WALL , Axel GERSTENBERGER, Ursula M. MAYER, Ulrich KUTTLER (TU Munich) -- "Numerical simulation of fluid-structure interaction for wind-induced dynamic response of the 3rd Jinan Yellow River cable-stayed bridge" by Qi-Lin ZHANG , Zhen-Hua LIU (Tongji University), Ying ZHOU (Shandong University) -- "A consistent finite element approximation for piezoelectric shell structures" by Dieter LEGNER , Sven KLINKEL, Werner WAGNER (University of Karlsruhe) -- "Vibration analysis of thin-walled - gas or fluid filled - structures including the effect of the inflation/filling process" by Karl SCHWEIZERHOF , Marc HABLER (University of Karlsruhe) -- "Thin-walled structures interacting with incompressible flows" by Ekkehard RAMM , Malte VON SCHEVEN (University of Stuttgart), Christiane FORSTER, Wolfgang A. WALL (TU Munich) -- "Full SPH modeling of the dynamic failure of shells filled with a fluid" by Alain COMBESCURE (LaMCoS) -- , Farid ABED MERAIM (LPMM), Bertrand MAUREL (LaMCoS) -- "Fluid-shell coupled simulation of supersonic disk-gap-band parachutes" by Konstantinos KARAGIOZIS, Ramji KAMAKOTI, Carlos PANTANO (University of Illinois at Urbana-Champaign), Fehmi CIRAK (University of Cambridge) -- "Strongly coupled approach for the treatment of the fluid-structure interaction problems involving highly deformable solids and shells" by Riccardo ROSSI , P. RYZHAKOV, Eugenio ONATE (CINME, UPC) -- "Numerical simulation of fluid-structure interaction for wind-induced dynamic response of cylindrical steel tanks with a dome roof" by Qi-Lin ZHANG , Zhen-Hua LIU (Tongji University), Ying ZHOU (Shandong University