Optimal Modeled Six-Phase Space Vector Pulse Width Modulation Method for Stator Voltage Harmonic Suppression

Dual Y shift 30 six-phase motors are expected to be extensively applied in high-power yet energy-effective fields, and a harmonic-suppressing control strategy plays a vital role in extending their prominent features of low losses and ultra-quiet operation. Aiming at the suppression of harmonic voltages, this paper proposes a six-phase space vector pulse width modulation method based on an optimization model, namely OM-SVPWM. First, four adjacent large vectors are employed in each of 12 sectors on a fundamental sub-plane. Second, the optimization model is constructed to intelligently determine activation durations of the four vectors, where its objective function aims to minimize the synthesis result on a harmonic sub-plane, and its constraint condition is that the synthesis result on the fundamental sub-plane satisfies a reference vector. Finally, to meet the real-time requirement, optimum solutions are obtained by using general central path following algorithm (GCPFA). Simulation and experiment results prove that, the OM-SVPWM performs around 37% better than a state-of-the-art competitive SVPWM in terms of harmonics suppression, which promise the proposed OM-SVPWM conforms to the energy-effective direction in actual engineering applications.Peer reviewe

Sn(II)-containing phosphates as optoelectronic materials

We theoretically investigate Sn(II) phosphates as optoelectronic materials using first principles calculations. We focus on known prototype materials Sn$_n$P$_2$O$_{5+n}$ (n=2, 3, 4, 5) and a previously unreported compound, SnP$_2$O$_6$ (n=1), which we find using global optimization structure prediction. The electronic structure calculations indicate that these compounds all have large band gaps above 3.2 eV, meaning their transparency to visible light. Several of these compounds show relatively low hole effective masses ($\sim$2-3 m$_0$), comparable the electron masses. This suggests potential bipolar conductivity depending on doping. The dispersive valence band-edges underlying the low hole masses, originate from the anti-bonding hybridization between the Sn 5s orbitals and the phosphate groups. Analysis of structure-property relationships for the metastable structures generated during structure search shows considerable variation in combinations of band gap and carrier effective masses, implying chemical tunability of these properties. The unusual combinations of relatively high band gap, low carrier masses and high chemical stability suggests possible optoelectronic applications of these Sn(II) phosphates, including p-type transparent conductors. Related to this, calculations for doped material indicate low visible light absorption, combined with high plasma frequencies.Comment: 10 pages, 10 figures, Supplementary informatio

Research on the Realization Path of Intelligent Logistics in the “New Retail” Era

New retail is the product of innovation and transformation of e-commerce, physical retail and modern logistics. New retail relies on omni-channel logistics based on supply chain integration, order-driven precise logistics service and high intensity urban distribution carrying capacity, which has brought huge impacts and development opportunities to the logistics industry. At present, there are limitations in China\u27s intelligent logistics, both in terms of logistics infrastructure construction, logistics information services, and regulatory guarantee systems, which restrict the development of new retail . In order to realize the high-quality support of new retail by intelligent logistics, a trinity of intelligent logistics construction path of government guidance, market leadership, and social co-governance is proposed. We should accelerate the construction of intelligent logistics infrastructure under the guidance of the government, give full play to the leading role of the market to build an intelligent logistics information platform, and build a multi-security logistics security system through joint governance of all sectors of society to meet the overall objective of the high-quality support of logistics for new retail

Identity-adaptive Facial Expression Recognition Through Expression Regeneration Using Conditional Generative Adversarial Networks

Subject variation is a challenging issue for facial expression recognition, especially when handling unseen subjects with small-scale labeled facial expression databases. Although transfer learning has been widely used to tackle the problem, the performance degrades on new data. In this paper, we present a novel approach (so-called IA-gen) to alleviate the issue of subject variations by regenerating expressions from any input facial images. First of all, we train conditional generative models to generate six prototypic facial expressions from any given query face image while keeping the identity related information unchanged. Generative Adversarial Networks are employed to train the conditional generative models, and each of them is designed to generate one of the prototypic facial expression images. Second, a regular CNN (FER-Net) is fine- tuned for expression classification. After the corresponding prototypic facial expressions are regenerated from each facial image, we output the last FC layer of FER-Net as features for both the input image and the generated images. Based on the minimum distance between the input image and the generated expression images in the feature space, the input image is classified as one of the prototypic expressions consequently. Our proposed method can not only alleviate the influence of inter-subject variations but will also be flexible enough to integrate with any other FER CNNs for person-independent facial expression recognition. Our method has been evaluated on CK+, Oulu-CASIA, BU-3DFE and BU-4DFE databases, and the results demonstrate the effectiveness of our proposed method

Thérèse Desqueyroux, victime de la parole

François Mauriac, écrivain illustre français, est renommé surtout par ses romans poétiques, dont l’ouvrage le plus représentatif s’intitule Thérèse Desqueyroux. L’article présent traite l’origine de la tragédie de l’héroïne Thérèse de ce roman. L’analyse se déroule sous les angles de l’environnement, de la communication entre les gens, du processus du crime et de la fonction du langage. A travers ces études, on tire la conclusion que la tragédie de Thérèse réside dans l’incommunication des êtres et l’impuissance langagière

Effectiveness of folic acid fortified flour for prevention of neural tube defects in a high risk region

Despite efforts to tackle folate deficiency and Neural Tube Defects (NTDs) through folic acid fortification, its implementation is still lacking where it is needed most, highlighting the need for studies that evaluate the effectiveness of folic acid fortified wheat flour in a poor, rural, high-risk, NTD region of China. One of the most affected regions, Shanxi Province, was selected as a case study. A community intervention was carried out in which 16,648 women of child-bearing age received fortified flour (eight villages) and a control group received ordinary flour (three villages). NTD birth prevalence and biological indicators were measured two years after program initiation at endline only. The effect on the NTD burden was calculated using the disability-adjusted life years (DALYs) method. In the intervention group, serum folate level was higher than in the control group. NTDs in the intervention group were 68.2% lower than in the control group (OR = 0.313, 95% CI = 0.207-0473, p < 0.001). In terms of DALYs, burden in intervention group was approximately 58.5% lower than in the control group. Flour fortification was associated with lower birth prevalence and burden of NTDs in economically developing regions with a high risk of NTDs. The positive findings confirm the potential of fortification when selecting an appropriate food vehicle and target region. As such, this study provides support for decision makers aiming for the implementation of (mandatory) folic acid fortification in China

The Role of Psychological Ownership in Privacy Risk Compensation: A Moderated Mediation Model

Social media users tend to disclose a large amount of private information despite their high privacy concerns, which is termed as the privacy paradox in existing literature. Recent studies have found that privacy paradox can be explained by a privacy risk compensation process: users engage in privacy protection behaviors to cope with privacy threats, which in turn increase their privacy disclosure. However, it remains unclear under what condition the privacy risk compensation process can take place. In this study, we integrate the psychological ownership theory with risk compensation theory, and find that psychological ownership plays a moderation role in strengthening the privacy risk compensation. An online survey was conducted with 300 Facebook users, and our hypotheses were greatly supported. Our findings encourage social media platforms to provide more functional design elements to support users’ privacy protection behaviors and satisfy their motivational needs of psychological ownership of privacy