9,330 research outputs found

    Surface and Edge States in Topological Semi-metals

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    We study the topologically non-trivial semi-metals by means of the 6-band Kane model. Existence of surface states is explicitly demonstrated by calculating the LDOS on the material surface. In the strain free condition, surface states are divided into two parts in the energy spectrum, one part is in the direct gap, the other part including the crossing point of surface state Dirac cone is submerged in the valence band. We also show how uni-axial strain induces an insulating band gap and raises the crossing point from the valence band into the band gap, making the system a true topological insulator. We predict existence of helical edge states and spin Hall effect in the thin film topological semi-metals, which could be tested with future experiment. Disorder is found to significantly enhance the spin Hall effect in the valence band of the thin films

    Order-Preserving Abstractive Summarization for Spoken Content Based on Connectionist Temporal Classification

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    Connectionist temporal classification (CTC) is a powerful approach for sequence-to-sequence learning, and has been popularly used in speech recognition. The central ideas of CTC include adding a label "blank" during training. With this mechanism, CTC eliminates the need of segment alignment, and hence has been applied to various sequence-to-sequence learning problems. In this work, we applied CTC to abstractive summarization for spoken content. The "blank" in this case implies the corresponding input data are less important or noisy; thus it can be ignored. This approach was shown to outperform the existing methods in term of ROUGE scores over Chinese Gigaword and MATBN corpora. This approach also has the nice property that the ordering of words or characters in the input documents can be better preserved in the generated summaries.Comment: Accepted by Interspeech 201

    An Evaluation of Container Development Strategies in the Port of Taichung

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    AbstractThe objective of this study is to examine the container development strategies in the port of Taichung from the viewpoints of carriers, port authorities and shipping academics. The six most important strategic attributes from the all respondents perceptions are Enhancing the services of direct shipping with Mainland China, simplified customs procedures, simplified administrative procedures, developing service routes with Hong Kong and Mainland China, improving port information systems, and flexible rate to response market change. Based on a factor analysis, the findings reflect that price and incentive strategic dimension was the most import strategic dimension, followed by marketing and direct shipping with Mainland China as well as reorganization and information service strategic dimensions. In addition, the perceived implemented period for container development strategic attributes for the Taichung Port was also investigated in this study. Results indicated that four development strategies stood out as being short-term need to perform to all respondents were providing one-stop shopping services for carriers, flexible rate to response market change, enhancing employee training and knowledge, and strengthening port marketing and promotion. Theoretical and managerial implications of the research findings are discussed

    Dark Aberrant Crypt Foci with activated Wnt pathway are related to tumorigenesis in the colon of AOM-treated rat

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    © 2008 Lu et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

    Trajectory tracking control of a hydraulic-tendon actuator with an application to the exoskeleton

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    This paper presents a hydraulic actuator and tendon drive system that was specifically designed for a lower-limb exoskeleton to provide high power and low inertia. The dynamics of the actuator-tendon system were analyzed based on the exoskeleton system and an adaptive sliding-mode trajectory tracking controller was designed for the drive system. The stability proof indicates that the controller is globally stable. The experimental results demonstrated that the controller provides high tracking accuracy and is robust to external disturbances and unmodeled nonlinearities. Moreover, the controller has less errors than the conventional PID controller. Further tests that included the joints of the exoskeleton were conducted to verify the performance of the controller

    Effect of intravitreal injection of anti-VEGF on choroidal thickness and blood flow in posterior ciliary artery in patients with wet ARMD

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    AIM:To investigate the effect of intravitreal injection of anti-vascular endothelial growth factor(VEGF)on choroidal thickness and posterior ciliary artery blood flow in patients with wet age-related macular degeneration(ARMD). METHODS:A total of 93 wet ARMD patients enrolled into the ophthalmology department in our hospital from September 2014 to December 2016 were selected into our study. The patients were treated with anti-VEGF vitreous injection for 3mo. The central retinal thickness(CRT), subfoveal choroidal thickness(SFCT), best corrected visual acuity(BCVA, LogMAR), choroidal neovascularization(CNV)and parameters of ciliary arterial blood flow \〖systolic peak flow velocity(PSV), end-diastolic blood flow velocity(EDV)and mean blood velocity(mV), resistance index(RI)/pulse index(PI)\〗 before treatment(T0), 1mo after treated(T1), 2mo after treated(T2), 3mo after treated(T3)were recorded and compared. All patients had been followed for 18mo, and side-effect were recorded. RESULTS: All wet ARMD patients had successfully completed intravitreal anti-VEGF injection. Compared with before treatment, BCVA, CRT, SFCT, and CNV had gradually decreased(F=72.738, 32.333, 7.305 and 957.450, PPF=2.619, 1.942, 0.820, P>0.05). Compared with before treatment, RI index had gradually decreased(F=25.451, PF=8.660, PT2≈T1>T0; RI: T3≈T2CONCLUSION: Intravitreal injection of anti-VEGF can effectively reduce choroidal thickness and increase ciliary posterior arterial perfusion, with a good long-term effect and less risk

    A New Recursive Dynamic Lot-Sizing Model with Multi-Level Discount

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    The optimal solution of dynamic lot-sizing problem with multi-level discount is solved by integer programming model in the past papers. However, a complex computation and a large computer memory are generated. Due to the complexity and the big computer memory, the heuristic approaches and the variable neighborhood algorithm are usually adopted in the large-scale multi-level lot-sizing problem. This paper develops a model with a recursive relation between the adjacent periods, and to obtain an optimal solution when multi-level discount is considered. Four types of the feasible policies in the Dynamic Lot-Sizing model with multi-level discount are classified to develop the recursive relations. A few properties, theorems and algorithms are developed to show the recursion between the adjacent periods. The number of addition items will significantly be reduced. The recursive algorithm can significantly decrease the computational entries, comparison entries and computer memory and improve the computation efficiency
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