61 research outputs found

    Nonuniform-spaced Critical Behavior of Dynamical Quantum Phase Transitions in Multi-band Bloch Hamiltonian

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    We investigate the dynamical quantum phase transition (DQPT) in the multi-band Bloch Hamiltonian of the one-dimensional periodic Kitaev model after a quench from a Bloch band. Our study goes beyond the limitations of previous works that primarily focused on two-band models and reveals significant differences in DQPT between the two-band and multi-band systems. Our results show that only the quench from the Bloch states, which causes the band gap to collapse at the critical point, induces the DQPT after crossing the quantum phase transition; otherwise, the DQPT will not occur. Additionally, the critical times of the DQPT are not evenly spaced due to the deviation in the critical momentum caused by the non-analytic singularities of the Pancharatnam geometric phase. Our findings provide a better understanding of the characteristics of non-equilibrium systems surrounding DQPTs.Comment: 9 pages, 10 figure

    A Threshold Based Handover Triggering Scheme in Heterogeneous Wireless Networks

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    The widespread popularity of Wireless Local Area Network (WLAN) is recognized as an effective approach to complementing cellular networks for the high data rate and cost effective connectivity delivered to mobile users. Efficient handover and offloading schemes for integrated WLAN and cellular networks, referred to as Heterogeneous Wireless Networks, have thus attracted lots of attentions from both academia and industry. This paper proposes a novel Multiple-Threshold based Triggering (MTT) scheme for Cellular-to-WLAN handover control. Aiming at minimizing the probability of handover failures and unnecessary handovers, three thresholds are calculated based on a variety of network parameters such as system performance requirements, radius of the WLAN coverage, user mobility and handover delays. The thresholds are then compared against the predicted user residence time and estimated channel holding time inside WLAN to make vertical handover decisions (VHDs). Simulations were carried out to evaluate the effectiveness of MTT and results show that MTT minimizes handover failures and avoids unnecessary handovers in integrated cellular and WLAN networks, thus providing satisfactory Quality of Service (QoS) to users and improving system resource utilization

    Adaptive enhancement design of non-significant regions of a Wushu action 3D image based on the symmetric difference algorithm

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    The recognition of martial arts movements with the aid of computers has become crucial because of the vigorous promotion of martial arts education in schools in China to support the national essence and the inclusion of martial arts as a physical education test item in the secondary school examination in Shanghai. In this paper, the fundamentals of background difference algorithms are examined and a systematic analysis of the benefits and drawbacks of various background difference algorithms is presented. Background difference algorithm solutions are proposed for a number of common, challenging problems. The empty background is then automatically extracted using a symmetric disparity approach that is proposed for the initialization of background disparity in three-dimensional (3D) photos of martial arts action. It is possible to swiftly remove and manipulate the background, even in intricate martial arts action recognition scenarios. According to the experimental findings, the algorithm's optimized model significantly enhances the foreground segmentation effect of the backdrop disparity in 3D photos of martial arts action. The use of features such as texture probability is coupled to considerably enhance the shadow elimination effect for the shadow problem of background differences

    A New Load Torque Identification Sliding Mode Observer for Permanent Magnet Synchronous Machine Drive System

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    Load Adaptive PMSM Drive System Based on an Improved ADRC for Manipulator Joint

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    An Improved Anisotropic Vector Preisach Hysteresis Model Taking Account of Rotating Magnetic Fields

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    The expression and role of protein kinase C (PKC) epsilon in clear cell renal cell carcinoma

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    Protein kinase C epsilon (PKCĪµ), an oncogene overexpressed in several human cancers, is involved in cell proliferation, migration, invasion, and survival. However, its roles in clear cell renal cell carcinoma (RCC) are unclear. This study aimed to investigate the functions of PKCĪµ in RCC, especially in clear cell RCC, to determine the possibility of using it as a therapeutic target. By immunohistochemistry, we found that the expression of PKCĪµ was up-regulated in RCCs and was associated with tumor Fuhrman grade and T stage in clear cell RCCs. Clone formation, wound healing, and Borden assays showed that down-regulating PKCĪµ by RNA interference resulted in inhibition of the growth, migration, and invasion of clear cell RCC cell line 769P and, more importantly, sensitized cells to chemotherapeutic drugs as indicated by enhanced activity of caspase-3 in PKCĪµ siRNA-transfected cells. These results indicate that the overexpression of PKCĪµ is associated with an aggressive phenotype of clear cell RCC and may be a potential therapeutic target for this disease

    A potential therapeutic drug for osteoporosis: prospect for osteogenic LncRNAs

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    Long non-coding RNAs (LncRNAs) play essential roles in multiple physiological processes including bone formation. Investigators have revealed that LncRNAs regulated bone formation through various signaling pathways and micro RNAs (miRNAs). However, several problems exist in current research studies on osteogenic LncRNAs, including sophisticated techniques, high cost for in vivo experiment, as well as low homology of LncRNAs between animal model and human, which hindered translational medicine research. Moreover, compared with gene editing, LncRNAs would only lead to inhibition of target genes rather than completely knocking them out. As the studies on osteogenic LncRNA gradually proceed, some of these problems have turned osteogenic LncRNA research studies into slump. This review described some new techniques and innovative ideas to address these problems. Although investigations on osteogenic LncRNAs still have obtacles to overcome, LncRNA will work as a promising therapeutic drug for osteoporosis in the near future
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