Application of variable zero-moment point in walking control of the biped robot

Using the predictive control based on zero-moment point (ZMP), the biped robot can walk comparatively stably. However, the problems such as lack of self-adaptivity are also highlighted mainly on account of modeling errors and environmental perturbations; specifically, the tracking errors of ZMP are generated, leading to a reduced walking stability. To address this problem, in the present work, the expected ZMP was decomposed into the reference ZMP which is pre-planned offline, and the variable ZMP which can be varied in real time. With the addition of the variable ZMP, the outside interferences can be eliminated. By combining the predictive control system and the inverse system of variable ZMP, the walking pattern of the robot with favorable self-adaptivity can be achieved. Finally, the simulation results indicate that the self-adaptivity of the robot can be effectively improved using the proposed control system

The Left-Side Bias Is Reduced to Other-Race Faces in Caucasian Individuals

One stable marker of face perception appears to be left-side bias, the tendency to rely more on information conveyed by the left side of the face than the right. Previous studies have shown that left-side bias is influenced by familiarity and prior experience with face stimuli. Since other-race facial recognition is characterized by reduced familiarity, in contrast to own-race facial recognition, the phenomenon of left-side bias is expected to be weaker for other-race faces. Among Chinese participants, face inversion has been found to eliminate the left-side bias associated with own-race faces. Therefore, it is of interest to know whether face inversion influences left-side bias for non-Chinese research participants and can be generalized across own- and other-race faces. This study assessed 65 Caucasian participants using upright and inverted chimeric Caucasian and Asian faces in an identity similarity-judgment task. Although a significant left-side bias was observed for upright own-race faces, this bias was eliminated by facial inversion, indicating that such a bias depends on the applicability of configural processing strategies. For other-race faces, there was no left-side bias in the upright condition. Interestingly, the inverted presentation yielded a right-side bias. These results show that while left-side bias is affected by familiarity differences between own- and other-race faces, it is a universal phenomenon for upright faces. Inverted presentation strongly reduces left-side bias and may even cause it to revert to right-side bias, suggesting that left-side bias depends on configural face processing.Peer Reviewe

Atomically dispersed quintuple nitrogen and oxygen co-coordinated zirconium on graphene-type substrate for highly efficient oxygen reduction reaction.

A cost-effective and long stability catalyst with decent electrochemical activity would play a crucial role in accelerating applications of metal-air batteries. Here, we report quintuple nitrogen and oxygen co-coordinated Zr sites on graphene (Zr-N/O-C) by using a ball-milling, solid-solution-assisted pyrolysis method. The as-prepared Zr-N/O-C catalyst with 2.93 wt % Zr shows a half-wave potential of 0.910 V, an onset potential of 1.000 V in 0.1 M KOH, impressive durability (95.1% remains after 16,000 s), and long-term stability (5 mV loss over 10,000 cycles). Zn-air batteries with the Zr-N/O-C electrode exhibit a maximum power density of 217.9 mW cm−2 and a high cycling life of over 1,000 h, exceeding the counterpart equipped with a Pt/C benchmark. Theoretical simulations demonstrate that nitrogen and oxygen dual-ligand confinement effectively tunes the d-band center and balances key intermediates binding energy of intrinsic quintuple coordination Zr sites

Effects of S. cerevisiae strains on the sensory characteristics and flavor profile of kiwi wine based on E-tongue, GC-IMS and 1H-NMR

The fermentation of kiwifruit into kiwi wine (KW) can represent a strategy to reduce the economic losses linked to fruits imperfections, spoilage, over production and seasonality. In the study, Pujiang kiwifruit, a China National Geographical Indication Product, was used as raw material to produce KW fermented by four commercial S. cerevisiae strains, namely Drop Acid Yeast, DV10, SY and RW. The sensory characteristics and flavor profile of KW were assessed by means of sensory evaluation, E-tongue, GC-IMS and 1H-NMR. KW fermented by RW strain obtained the higher sensory evaluation score. E-tongue could clearly distinguish the taste differences of KW fermented by distinct S. cerevisiae strains. A total of 128 molecules were characterized by GC-IMS and 1H-NMR, indicating that the combinations of multiple technologies could provide a comprehensive flavor profile of KW. The main flavor compounds in KW pertained to the classes of esters and alcohols. Several pathways were found to be differently altered by the fermentation with the different yeast strains, namely butanoate metabolism, glycerolipid metabolism, alanine, aspartate and glutamate metabolism, arginine biosynthesis, arginine and proline metabolism. The present study will facilitate screening suitable S. cerevisiae strains for KW production and provide a theoretical basis for large-scale production of KW

A Mott insulator continuously connected to iron pnictide superconductors

Iron-based superconductivity develops near an antiferromagnetic order and out of a bad metal normal state, which has been interpreted as originating from a proximate Mott transition. Whether an actual Mott insulator can be realized in the phase diagram of the iron pnictides remains an open question. Here we use transport, transmission electron microscopy, X-ray absorption spectroscopy, and neutron scattering to demonstrate that NaFe$_{1-x}$Cu$_x$As near $x\approx 0.5$ exhibits real space Fe and Cu ordering, and are antiferromagnetic insulators with the insulating behavior persisting above the N\'eel temperature, indicative of a Mott insulator. Upon decreasing $x$ from $0.5$, the antiferromagnetic ordered moment continuously decreases, yielding to superconductivity around $x=0.05$. Our discovery of a Mott insulating state in NaFe$_{1-x}$Cu$_x$As thus makes it the only known Fe-based material in which superconductivity can be smoothly connected to the Mott insulating state, highlighting the important role of electron correlations in the high-$T_{\rm c}$ superconductivity.Comment: in press, Nat. Commun., 4 figures, supplementary information available upon reques

Sonoelectrochemical synthesis of highly photoelectrochemically active TiO2 nanotubes by incorporating CdS nanoparticles

Self-organized anodic TiO2 nanotube arrays (TiO2NTs) are functionalized with CdS nanoparticle based perfusion and deposition through a single-step sonoelectrodeposition method. Even controlled at 50 degrees C, CdS nanoparticles with smaller size and more homogeneous distribution are successfully synthesized in dimethyl sulfoxide (DMSO) under ultrasonic irradiation. Moreover, TiO2 nanotubes can be filled with nanoparticles because of the ultrasonic effect. The CdS incorporated TiO2NTs (CdS-TiO2NTs) effectively harvest solar light in the UV as well as the visible light (up to 480 nm) region. Compared with pure TiO2NTs, a more than ninefold enhancement in photocurrent response is observed using the CdS-TiO2NTs. Maximum incident photon to charge carrier efficiency (IPCE) values of 99.95% and 9.85% are observed respectively for CdS-TiO2 nanotubes and pure TiO2NTs. The high value of IPCE observed with the CdS-TiO2NTs is attributed to the increased efficiency of charge separation and transport of electrons. A schematic diagram is proposed to illustrate the possible process of CdS formation in nanotubes under sonochemical and electrochemical conditions.Natural Science Foundation of China and Fujian Province [20773100, U0750015]; Technical Program of Fujian Province and Xiamen City, China [2007H0031, 3502Z20073004

Weighing in on the Off-Label Use: Initial Experience of Neuroform EZ Stenting for Intracranial Arterial Stenosis in 45 Patients

Background: The role of stenting for intracranial arterial stenosis (ICAS) has been increasingly debated due to negative results of randomized trials. Thus, exploration of more appropriate devices may hopefully shed light on the endovascular approach, especially for patients with recalcitrant ICAS related to a high risk of stroke. We sought to present and analyze the data of Neuroform EZ stenting for medically refractory ICAS in a single-center series.Materials and methods: Between November 2016 and January 2018, 45 consecutive patients treated with the Neuroform EZ stent were included in our retrospective study. Outcomes evaluation included successful procedure rate, vascular event within 30 days and recurrent stenosis for at least 6 months after the procedure.Results: The technical success rate was 100% for all 46 stenotic lesions. Mean pre-stent stenosis was 86.5 ± 8.7%, improving to 23.7 ± 18.1% after stenting. Combined procedure related vascular event rate was 2.2% (n = 1) within 30 days after the procedure. No in-stent restenosis was observed during an average follow-up period of 7.3 months.Conclusion: The Neuroform EZ stent system could serve as an off-label but promising optional device for ICAS stenting in a carefully selected subgroup of patients. Further longer-term clinical follow-up is mandatory to validate our initial results

I4U Submission to NIST SRE 2018: Leveraging from a Decade of Shared Experiences

The I4U consortium was established to facilitate a joint entry to NIST speaker recognition evaluations (SRE). The latest edition of such joint submission was in SRE 2018, in which the I4U submission was among the best-performing systems. SRE'18 also marks the 10-year anniversary of I4U consortium into NIST SRE series of evaluation. The primary objective of the current paper is to summarize the results and lessons learned based on the twelve sub-systems and their fusion submitted to SRE'18. It is also our intention to present a shared view on the advancements, progresses, and major paradigm shifts that we have witnessed as an SRE participant in the past decade from SRE'08 to SRE'18. In this regard, we have seen, among others, a paradigm shift from supervector representation to deep speaker embedding, and a switch of research challenge from channel compensation to domain adaptation.Comment: 5 page