Data-dependent cycle-accurate power modeling of RTL-level IPs using machine learning

In a chip design project, early design planning has a strong impact on the schedule and the cost of design. Power estimation is part of early design planning, and it greatly affects design decisions. Power modeling performed at a high level of abstraction is fast but inaccurate due to lack of circuit switching activity information. By contrast, power modeling performed at a low level of abstraction is more accurate as the synthesized circuit synthesis is known, but this simulation is typically slow. This report explores a power modeling approach performed at register transfer level (RTL). It exploits machine learning models in order to have a fast yet relatively accurate cycle-by-cycle power estimation. The approach is data-dependent, where cycle-specific models are trained based on the switching activity of signals obtained from RTL simulation and cycle-by-cycle power values obtained from a reference gate-level simulation of an existing RTL design. Therefore, if any changes are applied to the RTL design, re-training of models is required. The approach aims at obtaining fast yet accurate power predictions for new invocations of a given trained model using signal activity information collected during simulation of the unmodified RTL. At a low level, the complete visibility of signals in a design unintuitively might cause overtraining the model leading to inaccurate estimation. The suggested model employs automatic feature selection in each cycle. Based on the invocations used to train the cycle-by-cycle models, only signals that may switch during a given cycle will be selected as the features for their respective cycle-specific model. The method was tested on an 8-by-8 DCT design and the power estimates were within 6.5% of those from a commercial power analysis tool. This report also simulates and compares the approach of cycle-specific models to the approach of a single global model for all cycles and show that the cycle-specific approach is twice as accurate.Electrical and Computer Engineerin

Development of a GEM based TPC Readout for ILD

For the International Large Detector (ILD), foreseen to be built at the International Linear Collider (ILC), a Time Projection Chamber (TPC) is intended to be used as the main tracking detector. The amplification will be provided by Micro Pattern Gaseous Detectors (MPGDs). One option is the use of Gas Electron Multipliers (GEM) in combination with a segmented pad readout plane. The TPC group at DESY developed a modular system implementing a triple GEM stack mounted on thin ceramic grids. This material choice allows for high mechanical rigidity of the support structure at a reduced amount of material and dead area compared to commonly used GRP frames. This contribution gives an overview of the current status of this system. This includes a discussion of points we wanted to improve over the last generation of modules and what was implemented in the newest version. Also improvements in the production process of the modules, which ensure a consistent quality and present a step towards possible batch production.Comment: Talk presented at the International Workshop on Future Linear Colliders (LCWS2016), Morioka, Japan, 5-9 December 2016. C16-12-05.

Low-x QCD at the LHC with the ALICE detector

We give a brief review of the physics of gluon saturation and non-linear QCD evolution at small values of the Bjorken-$x$ variable. We discuss the ALICE capability for low-$x$ studies at the LHC. In particular, we concentrate on the heavy quark production in the CGC framework and its observation with the ALICE Muon Spectrometer.Comment: 7 pages, 2 figures, Talk given at Excited QCD 2009, winter meeting on QCD, 8-14 February 09, Zakopane, Polan

Quarkonia measurements with ALICE at the LHC

In this paper, we summarize the perspectives on quarkonia detection in the ALICE experiment at the CERN LHC, both in the dielectron and dimuon decay channels.Comment: 4 pages, 1 figure, Talk given at Quark Matter 2009: The 21st International Conference on UltraRelativistic Nucleus- Nucleus Collisions (QM 2009), March 30-April 4, Knoxville, TN, US

Who speaks for the Middle East : a new generation of journalists is challenging how their region is covered

This article is an investigation of the changes in fcoverage of the Middle East by the English-speaking press. It looks at how the traditional foreign-correspondent model has shifted since the American invasion of Iraq in 2003, and asks whether hiring reporters who come from the countries they cover will produce more accurate coverage.JournalismMiddle Eastern Studie

Vortex sheet dynamics and turbulence

The nonlinear evolution of a vortex sheet driven by the Kelvin--Helmholtz instability is characterized by the formation of a spiral possessing complex stretching and intensity patterns. We show that the power energy spectrum of a single two-dimensional vortex sheet tends to the usual fluid turbulent spectrum, with an exponent of -3. Using numerical simulations and asymptotic methods, we demonstrate the relation between this power law and the singularities in the geometry and vorticity distribution of the sheet.Comment: Submitted to Phys. Rev. Letters, the Dynamique des vortex Collaboratio