Passive fault-tolerant control for vehicle active suspension system based on H2/H∞ approach

In this paper, a robust passive fault-tolerant control (RPFTC) strategy based on H2/H∞ approach and an integral sliding mode passive fault tolerant control (ISMPFTC) strategy based on H2/H∞ approach for vehicle active suspension are presented with considering model uncertainties, loss of actuator effectiveness and time-domain hard constraints of the suspension system. H∞ performance index less than γ and H2 performance index is minimized as the design objective, avoid choosing weighting coefficient. The half-car model is taken as an example, the robust passive fault-tolerant controller and the integral sliding mode passive fault tolerant control law is designed respectively. Three different fault modes are selected. And then compare and analyze the control effect of vertical acceleration of the vehicle body and pitch angular acceleration of passive suspension control, robust passive fault tolerant control and integral sliding mode passive fault tolerant control to verify the feasibility and effectiveness of passive fault tolerant control algorithm of active suspension. The studies we have performed indicated that the passive fault tolerant control strategy of the active suspension can improve the ride comfort of the suspension system

Effect of butylphthalide combined with ozagrel sodium on cerebral perfusion and oxidative stress indexes in patients with transient ischemic attack

This study has been undertaken to evaluate the effect of butylphthalide combined with ozagrel sodium on cerebral perfusion and oxidative stress indexes in patients with transient ischemic attack. In this study, a total of 116 patients diagnosed as transient ischemic attack in our hospital (February 2018-February 2020) have been selected and divided into two groups according to the treatment methods.58 cases in the control group have been treated with ozagrel sodium, 58 cases in the observation group have been treated with butylphthalide combined with ozagrelsodium. The CT perfusion imaging parameters, oxidative stress indexes, plaque area, and the levels of platelet activating factor (PAF), α-granule membrane protein-140 (GMP-140), fibrinogen (FIB), platelet aggregation rate (PAgT), neuron-specific enolase (NSE), oxygen-inducible factor-1α ( HIF-1α ), and matrix metalloproteinases-9 ( MMP-9) in the two groups have been recorded, and the total effective rate and adverse reaction rate have been counted. The results shown that the total effective rate of the observation group is higher than that of the control group, and the difference is statistically significant (χ2 = 4.640, P = 0.031). The average time (MTT) required for the two groups of contrast agents to pass through the local brain tissue and the time (TTP) required starting the injection of contrast agents to reach the peak concentration decreased compared to that with before treatment. After treatment, the MTT and TTP of the observation group are shorter than those of the control group (P < 0.05). Compared with before treatment, superoxide dismutase (SOD) in the two groups has higher than that in the control group, PAF, GMP-140, FIB, PAgT, NSE, HIF-1α, MMP-9, malondialdehyde (MDA) and plaque area has decreased. After treatment, the levels of related factors in the observation group are better than those in the control group, and the plaque area is less than that in the control group (P < 0.05).There has been no significant difference in the adverse reaction rate between the observation group and the control group (χ2 = 0.438, P = 0.508)

Neural differentiation of adipose-derived stem cells by indirect co-culture with Schwann cells

To investigate whether adipose-derived stem cells (ADSCs) could be subject to neural differentiation induced only by Schwann cell (SC) factors, we co-cultured ADSCs and SCs in transwell culture dishes. Immunoassaying, Western blot analysis, and RT-PCR were performed (1, 3, 7, 14 d) and the co-cultured ADSCs showed gene and protein expression of S-100, Nestin, and GFAP. Further, qRT-PCR disclosed relative quantitative differences in the above three gene expressions. We think ADSCs can undergo induced neural differentiation by being co-cultured with SCs, and such differentia­tions begin 1 day after co-culture, become apparent after 7 days, and thereafter remain stable till the 14th day

Topological Dirac states beyond π\pi orbitals for silicene on SiC(0001) surface

The discovery of intriguing properties related to the Dirac states in graphene has spurred huge interest in exploring its two-dimensional group-IV counterparts, such as silicene, germanene, and stanene. However, these materials have to be obtained via synthesizing on substrates with strong interfacial interactions, which usually destroy their intrinsic $\pi$($p_z$)-orbital Dirac states. Here we report a theoretical study on the existence of Dirac states arising from the $p_{x,y}$ orbitals instead of $p_z$ orbitals in silicene on 4H-SiC(0001), which survive in spite of the strong interfacial interactions. We also show that the exchange field together with the spin-orbital coupling give rise to a detectable band gap of 1.3 meV. Berry curvature calculations demonstrate the nontrivial topological nature of such Dirac states with a Chern number $C = 2$, presenting the potential of realizing quantum anomalous Hall effect for silicene on SiC(0001). Finally, we construct a minimal effective model to capture the low-energy physics of this system. This finding is expected to be also applicable to germanene and stanene, and imply great application potentials in nanoelectronics.Comment: 6 Figures , Accepted by Nano Letter

Utilization of H-reversal Trajectory of Solar Sail for Asteroid Deflection

Near Earth Asteroids have a possibility of impacting with the Earth and always have a thread on the Earth. This paper proposes a way of changing the trajectory of the asteroid to avoid the impaction. Solar sail evolving in a H-reversal trajectory is utilized for asteroid deflection. Firstly, the dynamics of solar sail and the characteristics of the H-reversal trajectory are analyzed. Then, the attitude of the solar sail is optimized to guide the sail to impact with the object asteroid along a H-reversal trajectory. The impact velocity depends on two important parameters: the minimum solar distance along the trajectory and lightness number. A larger lightness number and a smaller solar distance lead to a higher impact velocity. Finally, the deflection capability of a solar sail impacting with the asteroid along the H-reversal is discussed. The results show that a 10 kg solar sail with a lead-time of one year can move Apophis out of a 600-m keyhole area in 2029 to eliminate the possibility of its resonant return in 2036

N-Phenyl-N-{4-[5-(4-pyrid­yl)-1,3,4-oxadiazol-2-yl]phen­yl}aniline

The title compound, C25H18N4O, is a non-planar bipolar ligand containing triphenyl­amine and 1,3,4-oxadiazole units. In the mol­ecule, the benzene ring, the 1,3,4-oxadiazole ring, and the pyridine ring are twisted slightly with respect to each other [dihedral angle between the benzene and 1,3,4-oxadiazole rings = 9.4 (4) and between the 1,3,4-oxadiazole and pyridine rings = 3.0 (4)°]. Moreover, the dihedral angles between the two phenyl rings and the benzene ring are 88.2 (4) and 113.3 (4)°, and that between the two phenyl rings is 67.9 (4)°. The closest distances between the pyridine ring and the 1,3,4-oxadiazole and benzene rings in adjacent mol­ecules are 3.316 and 3.363 Å, respectively, indicating the existence of π–π inter­actions

Understand Data Preprocessing for Effective End-to-End Training of Deep Neural Networks

In this paper, we primarily focus on understanding the data preprocessing pipeline for DNN Training in the public cloud. First, we run experiments to test the performance implications of the two major data preprocessing methods using either raw data or record files. The preliminary results show that data preprocessing is a clear bottleneck, even with the most efficient software and hardware configuration enabled by NVIDIA DALI, a high-optimized data preprocessing library. Second, we identify the potential causes, exercise a variety of optimization methods, and present their pros and cons. We hope this work will shed light on the new co-design of ``data storage, loading pipeline'' and ``training framework'' and flexible resource configurations between them so that the resources can be fully exploited and performance can be maximized