Miracle-dz/UniFAR-FTUs huggingface dataset:
SCIENTIFIC PRINCIPLES OF GROUP TECHNOLOGY

Novel hydroxyhalogenated elastomers are produced by first partially epoxidizing a high molecular diene elastomer in a solvent medium and then reacting the partially epoxidized product with a hydrohalogen acid in a solvent medium. Diene elastomers such as polymer and copolymers of butadiene, isoprene, dimethyl-2,3-butadiene, chloroprene, cyanobutadienes and piperylene are first epoxidized and then reacted with hydrohalogenated acids such as hydrochloric, hydrobromic, hydriodic and mixtures thereof. The hydroxyhalogenated elastomers thus produced can be vulcanized by an extremely broad range of vulcanization agents and covulcanized with many other elastomers. The vulcanizates of these elastomers are characterized by such properties as very good resistance to aromatic and aliphatic solvents and oils, excellent stability at high or low temperatures and low moisture absorption.
Comparison of state-of-the-art estimators for electrical parameter identification of PMSM

In this paper, four state-of-the-art online estimation approaches, i.e. recursive least square (RLS) approach, model reference adaptive system (MRAS), extended Kalman filter (EKF) and unscented Kalman filter (UKF) for parameter identification of permanent magnet synchronous machines (PMSM) are implemented and compared. Moreover, a promising estimation method, the moving horizon estimator (MHE), is also investigated. The performance comparison is conducted with simulations and experiments under various scenarios on a permanent magnet synchronous motor among these five techniques.
Anomaly Detection and Classification using Distributed Tracing and Deep Learning

Artificial Intelligence for IT Operations (AIOps) combines big data and machine learning to replace a broad range of IT Operations tasks including availability, performance, and monitoring of services. By exploiting log, tracing, metric, and network data, AIOps enable detection of faults and issues of services. The focus of this work is on detecting anomalies based on distributed tracing records that contain detailed information for the availability and the response time of the services. In large-scale distributed systems, where a service is deployed on heterogeneous hardware and has multiple scenarios of normal operation, it becomes challenging to detect such anomalous cases. We address the problem by proposing unsupervised, response time anomaly detection based on deep learning data modeling techniques; unsupervised dynamic error threshold approach; tolerance module for false positive reduction; and descriptive classification of the anomalies. The evaluation shows that the approach achieves high accuracy and solid performance in both, experimental testbed and large-scale production cloud.
Deep Reinforcement Learning based Load Balancing Policy for balancing network traffic in datacenter environment

Load balancer plays important role in handling a huge amount of network traffic by routing the request/traffic in such a way that clients get immediate response to their requests. But traffic management in this era of bigdata is becoming a challenging task and to maintain them with human support is becoming more expensive. We can address this challenge by applying Deep reinforcement learning for a network load balancer which will be both time and cost effective. Deep reinforcement learning understands and adjusts continuously with dynamic environment. Which can be used to optimize the performance of load balancer.
Predictive Current Control Based on Variable Amplitude Virtual Vectors for Six-Phase Permanent Magnet Synchronous Machines

This paper proposes a new predictive current control (PCC) strategy based on variable amplitude virtual voltage vectors for six-phase asymmetrical permanent magnet synchronous machines (PMSMs) with isolated neutrals. The proposed strategy combines the optimal virtual vector with a zero vector during a sampling period in order to regulate its effective amplitude. The analytical expression for the duty cycle of the optimal virtual vector is derived and the switching patterns used to synthesize the virtual vectors are presented. Several simulation results are presented to assess the very good performance of the drive under the proposed control strategy, in comparison with standard PCC and with PCC based on virtual vectors with fixed amplitude.
Wideband Pyramidal Ridged Horn Design by SIW Technology

A wideband ridged horn using printed circuit and substrate integrated waveguide (SIW) technologies has been explored in this letter. A stepped flaring has been introduced in E-plane by adding multiple substrate layers, which is further loaded by a pair of E-plane flared balanced ridges to increase its operating bandwidth. The proposed technique is free from the requirement of any chemical glue or adhesive. A conventional SIW-based H-plane flaring is used. This horn is found to operate over 70% impedance bandwidth showing a consistent three-dimensional symmetric broadside radiation with an 8.7–19 dBi peak gain.
Read-Decoupled Radiation Hardened RD-DICE SRAM Cell for Low-Power Space Applications

Conventional 6T Static Random Access Memory(SRAM) cell suffers from data flip (Single event upset) due to continuous bombardment of radiation particles in the space environment. To mitigate single-event upset (SEU) which arises due to radiation, radiation-hardened SRAM cell such as dual interlocked storage cell (DICE) is proposed in the literature. However, DICE SRAM uses 4 bit-lines for the read and write operations, and which consume significantly high power when compared with the conventional 6T SRAM cell with 2 bit-lines. To resolve this issue, we propose a read-decoupled DICE SRAM cell, which uses only single bit-line for a read operation. Simulations results obtained from Spice for 1 KB SRAM array implemented in UMC 65nm and SCL 180nm technology node show that by simply decoupling read and write operation in DICE SRAM, read energy(write energy) and read delay(write delay) reduce by at least 72 %(17%) and 67%(37%) respectively. SEU results obtained from Cogenda tool show that the read-decoupled DICE is immune to radiations as is DICE.
Million-Core-Scalable Simulation of the Elastic Migration Algorithm on Sunway TaihuLight Supercomputer

Migration algorithm is one of the most essential methods in seismic application to image the underground geology, and to help scientists and researchers in geophysics exploration better understand the earth system. However, due to the desire in migration algorithm for covering lager region and acquiring better resolution, many tough challenges have to be tackled for current state-of-the-art computing systems. This work optimized and scaled the elastic migration algorithm onto the Sunway TaihuLight supercomputer, one of the most powerful systems of the world. Targeting at the major process, the reverse time migration (RTM) algorithm, a set of algorithmic, process-level, and thread-level optimizations is proposed, to significantly improve the performance (up to 163× speedup in time-to-solution) on Sunway CPU. Our design is successfully scaled to over two million cores (2,662,400 cores in total) on the Sunway TaihuLight supercomputer, with nearly ideal weak-scaling efficiency. The largest run is able to achieve a sustainable performance of processing over 859 billion cells per second.
Efficiency Improvement of Motor Drive System by using a GaN Three Phase Inverter

This paper shows the effectiveness for employing the GaN-FET inverter for operating the traction motor of a compact Electric Vehicle. Utilizing GaN-FET inverter can not only reduce the conduction loss, but also reduce the switching loss. Therefore GaN-FET inverter can operate motors in higher switching frequency compared with Si-IGBT inverters. It is effective to increase the switching frequency of the inverter to improve the motor efficiency because harmonic iron losses can be reduced dramatically by increasing the switching frequency, but the inverter loss becomes relatively large when the switching frequency is set too high. Therefore, optimized switching frequency should be obtained to maximize the total efficiency of the motor drive system. Experiments are carried out to compare efficiencies of motor drive system with Si-IGBT/GaN-FET inverter in several switching frequencies. Optimization of the switching frequency for maximizing the total efficiency is demonstrated to make effective use of the GaN-FET inverter in the motor drive system.
Adaptive sliding mode block control of induction motors

The authors design the two sliding mode control algorithms for the (/spl alpha/, /spl beta/) model of induction motors using block control linearization technique. Adaptive observers are designed to estimate the state variables (the rotor flux), the disturbance (the load torque), and the plant parameters (the rotor resistance and the moment of inertia) assuming that the rotor speed and the stator current are measurable.
Reaxff Molecular Dynamics Simulation of Material Removal Mechanisms During CMP Process of Silica Glass in Aqueous H2O2

Molecular dynamics simulations using Reactive Force Field (ReaxFF) are employed to study the silica glass chemical mechanical polishing (CMP) process in aqueous H2O2. The material removal mechanisms in CMP process are studied by analyzing the tribochemical process of silica glass. Results shows that the surface of silica glass is hydroxylated after the reaction with H2O2 solution. Through dehydrogenation and dehydroxylation, the Si-O-Si bridge bonds are formed between abrasive layer and silica glass surface. The chemical bonds between surface atoms and substrate atoms are broken due to the stretch of bridge bonds. The relationship between the sliding speed and the removal of atoms is also studied.
Design, fabrication and characterization of a buckled beam actuator for micro-displacement applications

Buckled beam-based bistable actuators are the key for contactless digital actuation. In this paper, the design, fabrication and characterization of bistable buckled beams is presented. A series of structures based on pre-shaped buckled beams of lengths ranging from 2 to 4 mm, a constant width of 5 um and an actuation stroke ranging from 20 to 100 um was fabricated. Experimental data show a significant difference with classical model predictions, mainly because the actuation method results in a displacement which is a combination of several buckling modes. Thus the model commonly used for buckled beams design has then been modified in order to take into account the beam shape effectively fabricated and experimental results. An accurate model was obtained, enabling good prediction of the experimental switching behavior of microfabricated buckled beams.
Control Scheme for Stand-alone DFIG Feeding an Isolated Load

This study addresses the control scheme of a standalone doubly fed induction generator (DFIG) feeding an isolated load. In order to control the voltage and frequency of the terminal bus, A direct voltage control is adopted. An instantaneous active and reactive component method is adopted in the proposed control strategy. Both the rotor and load side converter commands are built with the hysteresis controller according to the error between actual and reference currents. The simulation of stability performances analysis of 2 MW DFIG system is carried under Matlab/Simulink.
Improvement of Position Sensorless Control Performance for High Speed PMSM with All-pass Filters

This paper proposes a stable position sensorless control method from extremely low speed region to high speed region in high speed permanent magnet synchronous motor. One of the authors have already developed highly accurate position sensorless control in the low speed range by using an All-pass filter (APF) and a Band-pass filter (BPF). There exists a drawback, however, such that the discretization error in the high speed region deteriorates the position estimation performance since the flux estimator is constructed in the stationary frame. To solve this issue, this flux estimator using APF is constructed in the estimated rotating coordinate in this paper, realizing stable and highly accurate position sensorless drives in whole speed region except of standstill. Also, this paper experimentally shows the effectiveness of the proposed method.
On a switching control problem with càdlàg costs

This work addresses a switching control problem under which the cost associated with the changes of regimes is allowed to have discontinuities in time. Our main contribution is to show several characterizations of the optimal cost function as well as the existence of ε-optimal control policies. As a by-product, we also study the existence and uniqueness of solutions of a system of backward stochastic differential equations whose barriers (or obstacles) are discontinuous (in fact of càdlàg type) and depend itself on the unknown solution. In the last part of the paper, we study the case when an underlying diffusion is part of the dynamic of the system. In this special case, the optimal payoff becomes a weak solution of the HJB system of PDEs with discontinuous obstacles which is of quasi-variational type. This paper is somehow a continuation of the papers [B. Djehiche, S. Hamadène, and A. Popier, A finite horizon optimal multiple switching problem, SIAM J. Control Optim. 48 (2009), pp. 2751–2770; S. Hamadène and M.A. Morlais, Viscosity solutions of systems of PDEs with interconnected Obstacle and switching problem, Appl. Math. Optim. 67 (2013), pp. 163–196. ] that consider continuous costs.
COded Taking And Giving (COTAG): Enhancing Transport Layer Performance over Millimeter Wave Access Networks.

Millimeter wave (mmWave) access networks have the potential to meet the high-throughput and low-latency needs of immersive applications. However, due to the highly directional nature of the mmWave beams and due to their susceptibility to human-induced blockage, the associated wireless communication links are vulnerable to large fluctuations in channel quality. These large fluctuations result in disproportionately adverse effects on performance of transport layer protocols such as Transmission Control Protocol (TCP). Furthermore, we show in this paper, that TCP continues to significantly under perform even when dual-connectivity is used to combat the effects of channel quality fluctuations. To overcome this challenge, we propose a network layer solution, Coded Taking and Giving (COTAG) scheme to sustain low-latency and high-throughput end-to-end TCP performance. In particular, COTAG creates network encoded packets at the network gateway and each mmWave access point (AP) aiming to adaptively take the spare bandwidth on each link in the network for packet transmission. Further, if one link does not have enough bandwidth, COTAG actively gives up the transmission opportunity via conditionally dropping packets. Consequently, the proposed COTAG actively adapts to changes in mmWave link quality and enhances the TCP performance without jeopardizing the latency of immersive connect delivery. To evaluate the effectiveness of the proposed COTAG, we conduct experiments and simulations using off-the-shelf APs and NS-2. The evaluation results show the proposed COTAG significantly improves end-to-end TCP performance.
Shaping the Internet: 10 Years of IXP Growth

Over the past decade, IXPs have been playing a key role in enabling interdomain connectivity. Their traffic volumes have grown dramatically and their physical presence has spread throughout the world. While the relevance of IXPs is undeniable, their long-term contribution to the shaping of the current Internet is not fully understood yet. In this paper, we look into the impact on Internet routes of the intense IXP growth over the last decade. We observe that while in general IXPs only have a small effect in path shortening, very large networks do enjoy a clear IXP-enabled path reduction. We also observe a diversion of the routes, away from the central Tier-1 ASes supported by IXPs. Interestingly, we also find that whereas IXP membership has grown, large and central ASes have steadily moved away from public IXP peerings, whereas smaller ones have embraced them. Despite all this changes, we find though that a clear hierarchy remains, with a small group of highly central networks
Properties of extragalactic thick discs recovered from ultra-deep Stripe82 imaging

Context. Thick discs can give invaluable information on the formation and evolution history of galaxies as most, if not all, disc galaxies have a thin (classical) disc and a thick disc. Aims. We study the structure of thick discs in extraordinary depth by reaching a surface brightness limit of μrdeep ∼ 28.5−29 mag arcsec−2 with combined g, r, i band images from the IAC Stripe 82 Legacy Project. Methods. We present the characterisation of the thick discs in a sample of five edge-on galaxies. A study of the radial and vertical surface brightness profiles is presented by comparing our data with point spread function (PSF) deconvolved models. Our method begins with an analysis of the background and masking processes. Then we consider the effects of the PSF through galaxy modelling. The galaxy disc components are fitted considering that the thin and thick discs are two stellar fluids that are gravitationally coupled in hydrostatic equilibrium. Results. We find that effects due to the PSF are significant when low surface brightness is reached, especially in the vertical profiles, but it can be accounted for by careful modelling. The galaxy outskirts are strongly affected by the faint wings of the PSF, mainly by PSF-redistributed light from the thin disc. This is a central problem for ultra-deep imaging. The thick-disc component is required to reach satisfactory fit results in the more complex galaxies in our sample, although it is not required for all galaxies. When the PSF is ignored, the brightness of these structures may be overestimated by up to a factor of ∼4. Conclusions. In general, our results are in good agreement with those of previous works, although we reach deeper surface brightness levels, so that the PSF effects are stronger. We obtain scale heights and mass ratios of thin and thick discs (zt, zT, and MT/Mt), which provide excellent agreement with previous studies. Our small initial sample provides evidence for aspects of a wide variety of formation theories for the thick discs in disc galaxies.
Capacity and Algorithms for a Cognitive Network with Primary-Secondary User Cooperation

In this work, we examine cognitive radio networks, where secondary users may act as relays for messages sent by the primary user, hence offering performance improvement of primary transmissions, while at the same time obtaining more transmission opportunities for their own data. In particular, assuming the broadcast packet erasure model with feedback, we investigate the capacity of the fundamental cooperative cognitive radio network which consists of one primary and one secondary transmitter-receiver pairs. The primary transmitter is the owner of the channel and as such, we intend to keep its operations simple and to avoid increasing its storage requirements. Specifically, the primary transmitter does not receive data sent by the secondary transmitter and does not perform any coding operations. On the other hand, the secondary transmitter can overhear primary transmissions and is allowed to perform any coding operations. We develop an outer bound to the capacity of the fundamental cooperative cognitive radio network under consideration. Then, we propose a coding-scheduling algorithm suitable for this type of networks, which involves only XOR network coding operations. The complexity of the scheduling decisions of the proposed algorithm depends on the channel statistical parameters and three cases, depending on the relations between channel erasure probabilities, are distinguished. For the first two cases the rate region of the proposed algorithm coincides with the developed capacity outer bound, hence the algorithm is capacity achieving. For the third case, the rate region of the proposed algorithm is not identical to the outer bound; however, numerical results show that it is fairly close to the derived outer bound for a wide range of the statistical parameters of the system.
The local properties of supernova explosions and their host galaxies

We aim to understand the properties at the locations of supernova (SN) explosions in their host galaxies and compare with the global properties of these host galaxies. We use the integral field spectrograph (IFS) of Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) to generate 2D maps of the parameter properties for 11 SN host galaxies. The sample galaxies are analyzed one by one in detail in terms of their properties of velocity field, star formation rate, oxygen abundance, stellar mass, etc. This sample of SN host galaxies has redshifts around z ∼ 0.03 , which is higher than those of previous related works. The higher redshift distribution allows us to obtain the properties of more distant SN host galaxies. Metallicity (gas-phase oxygen abundance) estimated from integrated spectra can represent the local metallicity at SN explosion sites with small bias. All the host galaxies in our sample are metal-rich galaxies (12+ log (O/H) > 8.5 ) except for NGC 6387, which means SNe may be more inclined to explode in metallicity-rich galaxies. There is a positive relation between global gas-phase oxygen abundance and the stellar mass of host galaxies. We also try to compare the differences of the host galaxies between SNe Ia and SNe II. In our sample, both SNe Ia and SNe II can explode in normal galaxies, but SNe II can also explode in an interacting or a merging system, in which star formation is occurring in the galaxy.
Manipulating Nonclassicality via Quantum State Engineering Processes: Vacuum Filtration and Single Photon Addition

The effect of two quantum state engineering processes that can be used to burn a hole at vacuum in the photon number distribution of quantum states of radiation field is compared using various witnesses of lower‐ and higher‐order nonclassicality as well as a measure of nonclassicality. Specifically, the modification in nonclassical properties due to vacuum state filtration and a single photon addition on an even coherent state, binomial state, and Kerr state are investigated using the criteria of lower‐ and higher‐order antibunching, squeezing, and sub‐Poissonian photon statistics. Further, the amount of nonclassicality present in these engineered quantum states having enormous applications in continuous variable quantum communication is quantified and analyzed by using an linear entropy‐based entanglement potential. It is observed that all the quantum states studied here are highly nonclassical, and the hole‐burning processes can introduce/enhance nonclassical features. However, it is not true in general. A hole at vacuum implies a maximally nonclassical state (as far as Lee's nonclassical depth is concerned), but a particular process of hole burning at vacuum does not ensure the existence of any particular nonclassical feature. Specifically, lower‐ and higher‐order squeezing are not observed for photon‐added and vacuum filtered even coherent states.
The Euler characteristic of $\operatorname{Out}(F_n)$

We prove that the rational Euler characteristic of $\operatorname{Out}(F_n)$ is always negative and its asymptotic growth rate is $\Gamma(n- \frac32)/\sqrt{2\pi} \log^2 n$. This settles a 1987 conjecture of J. Smillie and the second author. We establish connections with the Lambert $W$-function and the zeta function.