Manticore: Hardware-Accelerated RTL Simulation with Static Bulk-Synchronous Parallelism

The demise of Moore's Law and Dennard Scaling has revived interest in specialized computer architectures and accelerators. Verification and testing of this hardware heavily uses cycle-accurate simulation of register-transfer-level (RTL) designs. The best software RTL simulators can simulate designs at 1--1000~kHz, i.e., more than three orders of magnitude slower than hardware. Faster simulation can increase productivity by speeding design iterations and permitting more exhaustive exploration. One possibility is to use parallelism as RTL exposes considerable fine-grain concurrency. However, state-of-the-art RTL simulators generally perform best when single-threaded since modern processors cannot effectively exploit fine-grain parallelism. This work presents Manticore: a parallel computer designed to accelerate RTL simulation. Manticore uses a static bulk-synchronous parallel (BSP) execution model to eliminate runtime synchronization barriers among many simple processors. Manticore relies entirely on its compiler to schedule resources and communication. Because RTL code is practically free of long divergent execution paths, static scheduling is feasible. Communication and synchronization no longer incur runtime overhead, enabling efficient fine-grain parallelism. Moreover, static scheduling dramatically simplifies the physical implementation, significantly increasing the potential parallelism on a chip. Our 225-core FPGA prototype running at 475 MHz outperforms a state-of-the-art RTL simulator on an Intel Xeon processor running at $\approx$ 3.3 GHz by up to 27.9$\times$ (geomean 5.3$\times$) in nine Verilog benchmarks

Portable Electrochemical Gas Sensing System with a Paper-Based Enzyme Electrode

An unconventional portable electrochemical gas sensor composed of a smartphone, a finger-sized sensing chip and a single use paper-based enzyme electrode was proposed to detect a particular target gaseous inclusion for self-breath-analysis with ease. This attempt allowed us to monitor our physical status immediately and continuously regardless of a time, place or person due to the improved convenience, immediacy, and affordability. The custom CMOS chip with the capability of performing an amperometric determination when the power voltage supplied from the earphone jack of a smartphone was designed as an analytical device. A disposable enzyme electrode was prepared simply from a chromatography paper and a commercial carbon pencil instead of the conventional indisposable material and complex manufacturing process. The quantification of ethanol in gaseous samples was demonstrated in range from 50 to 500ppm (V/V) in accord with concentrations in exhaled breath. The response current increased linearly with increasing vapor ethanol concentration

Portable Electrochemical Sensing System Attached to Smartphones and Its Incorporation with Paper-based Electrochemical Glucose Sensor

This paper described the development of a small and low cost biosensor consisting of a smartphone-based electrochemical biosensor device and a paper-based biosensor. The device harvested power from the smartphone and transferred data through audio jack. We designed CMOS circuits including a power supply circuit, a potentiostat, and a ΔΣ modulator. The fabrication of a paper-based biosensor was simple: the three electrodes were directly drawn on chromatography paper using a carbon pencil. The paper-based biosensor was low cost, disposable, portable and friendly to the environment. The sensing system was designed to perform the chronoamperometry measurement, and the glucose concentration in a liquid specimen was detected. Results showed that the sensing system was capable of measuring the glucose concentration as precisely as expensive equipments

Atmospheric Reanalyses-Recent Progress and Prospects for the Future. A Report from a Technical Workshop, April 2010

In April 2010, developers representing each of the major reanalysis centers met at Goddard Space Flight Center to discuss technical issues - system advances and lessons learned - associated with recent and ongoing atmospheric reanalyses and plans for the future. The meeting included overviews of each center s development efforts, a discussion of the issues in observations, models and data assimilation, and, finally, identification of priorities for future directions and potential areas of collaboration. This report summarizes the deliberations and recommendations from the meeting as well as some advances since the workshop

Toward the Understanding of the Metabolism of Levodopa I. DFT Investigation of the Equilibrium Geometries, Acid-Base Properties and Levodopa-Water Complexes

Levodopa (LD) is used to increase dopamine level for treating Parkinson’s disease. The major metabolism of LD to produce dopamine is decarboxylation. In order to understand the metabolism of LD; the electronic structure of levodopa was investigated at the Density Functional DFT/B3LYP level of theory using the 6-311+G** basis set, in the gas phase and in solution. LD is not planar, with the amino acid side chain acting as a free rotator around several single bonds. The potential energy surface is broad and flat. Full geometry optimization enabled locating and identifying the global minimum on this Potential energy surface (PES). All possible protonation/deprotonation forms of LD were examined and analyzed. Protonation/deprotonation is local in nature, i.e., is not transmitted through the molecular framework. The isogyric protonation/deprotonation reactions seem to involve two subsequent steps: First, deprotonation, then rearrangement to form H-bonded structures, which is the origin of the extra stability of the deprotonated forms. Natural bond orbital (NBO) analysis of LD and its deprotonated forms reveals detailed information of bonding characteristics and interactions across the molecular framework. The effect of deprotonation on the donor-acceptor interaction across the molecular framework and within the two subsystems has also been examined. Attempts to mimic the complex formation of LD with water have been performed

A mesoscale model intercomparison: A case of explosive development of a tropical cyclone (COMPARE III)

The performance of current mesoscale numerical models is evaluated in a case of model intercomparison project (COMPARE III). Explosive development of Typhoon Flo (9019) occurred in the case in September 1990 during the cooperative three field experiments, ESCAP/WMO-led SPECTRUM, US-led TCM-90, and former USSR-led TYPHOON-90 in the western North Pacific. Sensitivity to initial fields as well as impact of enhanced horizontal resolution are examined in the model intercomparison. Both track and intensity predictions are very sensitive to the choice of initial fields prepared with different data assimilation systems and the use of a particular synthetic tropical cyclone vortex. Horizontal resolution enhanced from 50km through 20km down to a 10km grid has a large impact on intensity prediction. This is presumably due to a better presentation of inner structure with higher resolution. There is little impact on track prediction in this target period when the typhoon was in its before-recurvature stage. While most models show large biases in underestimating central pressure deepening, some of the participating models with a particular initial field succeed in reproducing qualitatively the time evolution of central pressure, including slow deepening in the first half and rapid deepening in the second half of the simulation period of 72 hours. However, differences leading to different intensity predictions among models have yet to be identified. Intercomparison of the simulation results shows that wind field has a close relationship with precipitation distribution. This suggests that better prediction of precipitation distribution is crucial for better prediction of wind field, and vice versa. Through the COMPARE III experiments, it has become clear that precise simulation of tropical cyclone structure, especially in the inner-core region, is very important for accurate intensity prediction. Consideration, therefore, should be given to this point, when improvements in resolution, initialization, and physics of numerical models for tropical cyclone intensity prediction are reviewed

AMY coordinated observations, reanalysis and data management

Proceedings of GRENE 3rd Workshop (17-19 March, 2014, Bali, Indonesia