124 research outputs found
Automating defects simulation and fault modeling for SRAMs
The continues improvement in manufacturing process density for very deep sub micron technologies constantly leads to new classes of defects in memory devices. Exploring the effect of fabrication defects in future technologies, and identifying new classes of realistic functional fault models with their corresponding test sequences, is a time consuming task up to now mainly performed by hand. This paper proposes a new approach to automate this procedure. The proposed method exploits the capabilities of evolutionary algorithms to automatically identify faulty behaviors into defective memories and to define the corresponding fault models and relevant test sequences. Target defects are modeled at the electrical level in order to optimize the results to the specific technology and memory architecture
Efficient parameterised compilation for hybrid quantum programming
Near term quantum devices have the potential to outperform classical
computing through the use of hybrid classical-quantum algorithms such as
Variational Quantum Eigensolvers. These iterative algorithms use a classical
optimiser to update a parameterised quantum circuit. Each iteration, the
circuit is executed on a physical quantum processor or quantum computing
simulator, and the average measurement result is passed back to the classical
optimiser. When many iterations are required, the whole quantum program is also
recompiled many times. We have implemented explicit parameters that prevent
recompilation of the whole program in quantum programming framework OpenQL,
called OpenQL_PC, to improve the compilation and therefore total run-time of
hybrid algorithms. We compare the time required for compilation and simulation
of the MAXCUT algorithm in OpenQL to the same algorithm in both PyQuil and
Qiskit. With the new parameters, compilation time in OpenQL is reduced
considerably for the MAXCUT benchmark. When using OpenQL_PC, compilation of
hybrid algorithms is up to two times faster than when using PyQuil or Qiskit
Efficient decomposition of unitary matrices in quantum circuit compilers
Unitary decomposition is a widely used method to map quantum algorithms to an
arbitrary set of quantum gates. Efficient implementation of this decomposition
allows for translation of bigger unitary gates into elementary quantum
operations, which is key to executing these algorithms on existing quantum
computers. The decomposition can be used as an aggressive optimization method
for the whole circuit, as well as to test part of an algorithm on a quantum
accelerator. For selection and implementation of the decomposition algorithm,
perfect qubits are assumed. We base our decomposition technique on Quantum
Shannon Decomposition which generates O((3/4)*4^n) controlled-not gates for an
n-qubit input gate. The resulting circuits are up to 10 times shorter than
other methods in the field. When comparing our implementation to Qubiter, we
show that our implementation generates circuits with half the number of CNOT
gates and a third of the total circuit length. In addition to that, it is also
up to 10 times as fast. Further optimizations are proposed to take advantage of
potential underlying structure in the input or intermediate matrices, as well
as to minimize the execution time of the decomposition.Comment: 13 page
PPM Reduction on Embedded Memories in System on Chip
This paper summarizes advanced test patterns designed to target dynamic and time-related faults caused by new defect mechanisms in deep-submicron memory technologies. Such tests are industrially evaluated together with the traditional tests at "Design of Systems on Silicon (DS2)" in Spain in order to (a) validate the used fault models and (b) investigate the added value of the new tests and their impact on the PPM level. The preliminary silicon results are presented and analyzed. They validate some of the new dynamic fault models and show the importance of considering dynamic faults for high outgoing product quality.Electrical Engineering, Mathematics and Computer Scienc
Analysis of RNAseq datasets from a comparative infectious disease zebrafish model using GeneTiles bioinformatics.
Animal science
BrainFrame: A node-level heterogeneous accelerator platform for neuron simulations
Objective. The advent of high-performance computing (HPC) in recent years has led to its increasing use in brain studies through computational models. The scale and complexity of such models are constantly increasing, leading to challenging computational requirements. Even though modern HPC platforms can often deal with such challenges, the vast diversity of the modeling field does not permit for a homogeneous acceleration platform to effectively address the complete array of modeling requirements. Approach. In this paper we propose and build BrainFrame, a heterogeneous acceleration platform that incorporates three distinct acceleration technologies, an Intel Xeon-Phi CPU
WhiskEras: A New Algorithm for Accurate Whisker Tracking
Rodents engage in active touch using their facial whiskers: they explore their environment by making rapid back-and-forth movements. The fast nature of whisker movements, during which whiskers often cross each other, makes it notoriously difficult to track individual whiskers of the intact whisker field. We present here a novel algorithm, WhiskEras, for tracking of whisker movements in high-speed videos of untrimmed mice, without requiring labeled data. WhiskEras consists of a pipeline of image-processing steps: first, the points that form the whisker centerlines are detected with sub-pixel accuracy. Then, these points are clustered in order to distinguish individual whiskers. Subsequently, the whiskers are parameterized so that a single whisker can be described by four parameters. The last step consists of tracking individual whiskers over time. We describe that WhiskEras performs better than other whisker-tracking algorithms on several metrics. On our four video segments, WhiskEras detected more whiskers per frame than the Biotact Whisker Tracking Tool. The signal-to-noise ratio of the output of WhiskEras was higher than that of Janelia Whisk. As a result, the correlation between reflexive whisker movements and cerebellar Purkinje cell activity appeared to be stronger than previously found using other tracking algorithms. We conclude that WhiskEras facilitates the study of sensorimotor integration by markedly improving the accuracy of whisker tracking in untrimmed mice
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