Acceleration of hardware code coverage closure using machine learning

Abstract. With the ever-increasing system-on-chip (SoC) design complexity, the verification of such systems is becoming more and more challenging and extremely time consuming. Hence, the human efforts put in this task seem neither to be sufficient, nor efficient enough anymore to maintain a good pace with the escalating market demands. In this work, we will present a descent way of utilizing machine learning (ML) for reducing the overhead of hardware design verification in terms of resources consumption. Our focus in this thesis is especially about the time spent on coverage closure that usually occupies a great deal of the whole verification time. Both deep learning (DL) and reinforcement learning (RL) are deployed for this purpose, in two different experiments, in order to come out with the most coherent way to accomplish the coverage closure task. On one hand, neural networks (NNs) were used to help visualize whether a stimulus is worth to run the simulation with, by predicting the coverage number that it would generate. On the other hand, Q-learning was used to predict the minimal set of tests needed to reach some code coverage goal, by optimizing and reducing the set of tests while still achieving the same coverage levels. The results of these experiments show captivating findings. First, the root mean square error (RMSE) of the neural network models was about 3 and 5 in predicting two different coverage values, respectively, which is quite good for a training run on a small dataset. Second, our Q-agent was able to do better than the coverage ranking utility of the simulation tool by almost 43%, where it reduced the number of tests from 63, as suggested by the simulator, to 36. This should remarkably reduce the required number of simulations in weekly regressions, hence result in a huge gain in time and resources. Both of these approaches aim at reducing the engineers’ efforts through accelerating the verification process and automating it, which frees some of the engineers’ time and allow them to focus on more important matters

A General 3D Non-Stationary 5G Wireless Channel Model

A novel unified framework of geometry-based stochastic models (GBSMs) for the fifth generation (5G) wireless communication systems is proposed in this paper. The proposed general 5G channel model aims at capturing small-scale fading channel characteristics of key 5G communication scenarios, such as massive multiple-input multiple-output (MIMO), high-speed train (HST), vehicle-to-vehicle (V2V), and millimeter wave (mmWave) communication scenarios. It is a three-dimensional (3D) non-stationary channel model based on the WINNER II and Saleh-Valenzuela (SV) channel models considering array-time cluster evolution. Moreover, it can easily be reduced to various simplified channel models by properly adjusting model parameters. Statistical properties of the proposed general 5G small-scale fading channel model are investigated to demonstrate its capability of capturing channel characteristics of various scenarios, with excellent fitting to some corresponding channel measurements

Effects of the Velocity and the Nature of the Inert Gas on the Stainless Steel Laser Cut Quality

Abstract: The effects of inert assisting gas nature and velocity on laser cut quality are investigated. A pure fusion cutting process just above melting point is considered, where the molten steel velocity is given as a function of the two acting forces represented by the pressure gradient and the frictional forces applied by the laminar gas flow. In the case of nitrogen assisting gas, the stainless steel melt film exhibits a visible separation point. The point where the melt flow is separated out from the solid wall depends strongly on the gas velocity. It is pushed down the cut surface when the gas velocity is increased. Furthermore, we have investgated the use of different inert gases (nitrogen, argon and helium) to blow the molten material out of the kerf, and it was noted that the argon and the nitrogen gases evacuate more easily the molten metallic film, compared to the helium gas from their cooling rates point of view. It is concluded that the two first gases are more efficient in laser cutting process of metals. We have studied a 4 mm stainless steel plate thickness without taking into account the transverse movement of the treated workpiece, the numerical solution is obtained by the volume of fluid (VOF) and solidification/melting models, implemented by Fluent CFD software

A Novel SAGE Algorithm for Estimating Parameters of Wideband Spatial Nonstationary Wireless Channels with Antenna Polarization

In this article, a novel space-alternating generalized expectation-maximization (SAGE) algorithm is proposed for parameter estimations of wideband spatial nonstationary wireless channels with antenna polarization (SAGE-WSNSAP). Compared with the traditional SAGE algorithm, the proposed SAGE-WSNSAP algorithm adds spatial nonstationarity by introducing birth-death coefficients at both transmitter (Tx) and receiver (Rx) sides into the parametric model. To reduce the complexity of the SAGE-WSNSAP algorithm, a coarse-to-fine search method is adopted in the initialization step. In addition, multiple-input multiple-output (MIMO) channel measurements are conducted to validate the proposed algorithm. The measurement results of the angle-delay power spectral density (PSD) and average delay PSD are compared with those estimated by the far-field SAGE algorithm, the near-field SAGE algorithm, and the proposed algorithm. It is found that the estimation results using the proposed SAGE-WSNSAP algorithm show higher similarity to measurement results than using the other two SAGE algorithms. In comparison to the far-field and near-field SAGE algorithms, the SAGE-WSNSAP algorithm can extract more effective multipath components (MPCs) and improve the power extraction ratios.</p

Multifrequency Wireless Channel Measurements and Characterization in Large Indoor Office Environments

This article performs extensive channel measurements and characteristics analysis to investigate large-scale fading (LSF) and small-scale fading (SSF) of wireless local area network (WLAN) channels in large indoor office environments. Multifrequency single-input-single-output (SISO) channel measurements are conducted at 3, 5.5, and 6.5 GHz under the same conditions to explore the frequency dependence of LSF, delay spread (DS), and $K$ -factor (KF). Then, SISO channel measurements with different half-power beamwidths (HPBWs) of antennas are performed at 5.5 GHz in access point (AP) to user equipment (UE) and AP-to-AP scenarios. The effects of antenna HPBW on LSF, DS, and KF are investigated, thereby inspiring the AP deployment in high-density (HD) scenarios. Finally, $32 \times 64$ multiple-input-multiple-output (MIMO) channel measurements at 5.5 GHz are conducted to study the SSF of the time nonstationarity and multilink correlation. The time nonstationarity, including the parameters' drifting and cluster evolution caused by the movement of the UE, is verified by the measurement results. Multilink correlations are illustrated from the perspectives of the angular power spectral density (APSD) and correlation matrix collinearity (CMC). The results show that the distance between users and separation angle can affect the multilink correlation.</p

The vascular bone marrow niche influences outcome in chronic myeloid leukemia via the E-selectin - SCL/TAL1-CD44 axis.

The endosteal bone marrow niche and vascular endothelial cells provide sanctuaries for leukemic cells. In murine chronic myeloid leukemia (CML) CD44 on leukemia cells and E-selectin on bone marrow endothelium are essential mediators for the engraftment of leukemic stem cells. We hypothesized that non-adhesion of CML-initiating cells to E-selectin on the bone marrow endothelium may lead to superior eradication of leukemic stem cells in CML after treatment with imatinib than imatinib alone. Indeed, here we show that treatment with the E-selectin inhibitor GMI-1271 in combination with imatinib prolongs survival of mice with CML via decreased contact time of leukemia cells with bone marrow endothelium. Non-adhesion of BCR-ABL1(+) cells leads to an increase of cell cycle progression and an increase of expression of the hematopoietic transcription factor and proto-oncogene Scl/Tal1 in leukemia-initiating cells. We implicate SCL/TAL1 as an indirect phosphorylation target of BCR-ABL1 and as a negative transcriptional regulator of CD44 expression. We show that increased SCL/TAL1 expression is associated with improved outcome in human CML. These data demonstrate the BCR-ABL1-specific, cell-intrinsic pathways leading to altered interactions with the vascular niche via the modulation of adhesion molecules - which could be exploited therapeutically in the future

Performance Investigation of Spatial Modulation Systems Under Non-Stationary Wideband High-Speed Train Channel Models

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.In this paper, the bit error rate (BER) performance of a new multiple-input-multiple-output technique, named spatial modulation (SM), is studied under a novel non-stationary wideband high-speed train (HST) channel model in different scenarios. Time-varying parameters obtained from measurement results are used to configure the channel model to make all results more realistic. A novel statistic property called the stationary interval in terms of the space-time correlation function is proposed to describe the channel model's time-varying behavior. The accurate theoretical BER expression of SM systems is derived under the time-varying wideband HST channel model with the non-ideal channel estimation assumption. The simulation results demonstrate that the BER performance of SM systems shows a time-varying behavior due to the non-stationary property of the employed HST channel model. The system performance can maintain a relative stationary status within the specified stationary interval. It can also be observed that the BER performance of SM systems under the HST channel model is mainly affected by the correlation between sub-channels, inter-symbol-interference, Doppler shift, and channel estimation errors

by M Sprenger Rapid communications HIV and AIDS in the European Union, 2009 4

D Tubin-Delic, on behalf of the outbreak control team Surveillance and outbreak reports Control of a multi-hospital outbreak of KPC-producing Klebsiella pneumonia

Curbing methicillin-resistant Staphylococcus aureus in 38 French hospitals through a 15-year institutional control program

BACKGROUND: The Assistance Publique-Hôpitaux de Paris (AP-HP) institution administers 38 teaching hospitals (23 acute care and 15 rehabilitation and long-term care hospitals; total, 23 000 beds) scattered across Paris and surrounding suburbs in France. In the late 1980s, the proportion of methicillin resistance among clinical strains of Staphylococcus aureus (MRSA) reached approximately 40% at AP-HP.METHODS: A program aimed at curbing the MRSA burden was launched in 1993, based on passive and active surveillance, barrier precautions, training, and feedback. This program, supported by the strong commitment of the institution, was reinforced in 2001 by a campaign promoting the use of alcohol-based hand-rub solutions. An observational study on MRSA rate was prospectively carried out from 1993 onwards. RESULTS: There was a significant progressive decrease in MRSA burden (-35%) from 1993 to 2007, whether recorded as the proportion (expressed as percentage) of MRSA among S aureus strains (41.0% down to 26.6% overall; 45.3% to 24.2% in blood cultures) or incidence of MRSA cases (0.86 down to 0.56 per 1000 hospital days). The MRSA burden decreased more markedly in intensive care units (-59%) than in surgical (-44%) and medical (-32%) wards. The use of ABHR solutions (in liters per 1000 hospital days) increased steadily from 2 L to 21 L (to 26 L in acute care hospitals and to 10 L in rehabilitation and long-term care hospitals) following the campaign. CONCLUSION: A sustained reduction of MRSA burden can be obtained at the scale of a large hospital institution with high endemic MRSA rates, providing that an intensive program is maintained for a long period