1,496 research outputs found

    Switchable in-plane anomalous Hall effect by magnetization orientation in monolayer Mn3Si2Te6\mathrm{Mn}_{3}\mathrm{Si}_{2}\mathrm{Te}_{6}

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    In-plane anomalous Hall effect (IPAHE) is an unconventional anomalous Hall effect (AHE) with the Hall current flows in the plane spanned by the magnetization or magnetic field and the electric field. Here,we predict a stable two-dimensional ferromagnetic monolayer Mn3Si2Te6\mathrm{Mn}_{3}\mathrm{Si}_{2}\mathrm{Te}_{6} with collinear ordering of Mn moments in the basal plane. Moreover, we reveal that the monolayer Mn3Si2Te6\mathrm{Mn}_{3}\mathrm{Si}_{2}\mathrm{Te}_{6} possesses a substantial periodic IPAHE due to the threefold rotational symmetry, which can be switched by changing the magnetization orientation by external magnetic fields. In addition, we briefly discuss the impacts of moderate strains on the electronic states and AHE, which lead to a near quantized Hall conductivity. Our work provides a potential platform for realizing a sizable and controllable IPAHE that greatly facilatates the application of energy-efficient spintronic devices.Comment: 7 pages, 8 figure

    Empirical study of Android test generation tools on an industrial app

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    Given the ever increasing number of research tools to automatically generate inputs to test Android applications (or simply apps), researchers recently asked the question “Are we there yet?” (in terms of the practicality of the tools). In particular, researchers conduct an empirical study on existing testing techniques and tools on open-source Android apps. In this thesis, we present two significant extensions of that study. First, we conduct the first industrial case study of applying existing available testing tools against WeChat, a popular messenger app with over 800 million monthly active users. Second, we study the characteristics of covered activities achieved by testing tools to show which tools can be used in combination with other tools to achieve an optimal activity coverage. We also study the reasons why some activities are covered by only a particular testing tool to help app or tool developers improve their testing tools. Furthermore, we manually categorize not-covered activities to provide insightful information about the not-covered code entities. Such categorization will motivate app developers to spend additional resources during their testing efforts to cover such activities

    Ancillary Service Capacity Optimization for Both Electric Power Suppliers and Independent System Operator

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    Ancillary Services (AS) in electric power industry are critical to support the transmission of energy from generators to load demands while maintaining reliable operation of transmission systems in accordance with good utility practice. The ancillary services are procured by the independent system operator (ISO) through a process called the market clearing process which can be modeled by the partial equilibrium from the ends of ISO. There are two capacity optimization problems for both Market participants (MP) and Independent System Operator (ISO). For a market participant, the firm needs to determine the capacity allocation plan for various AS to pursue operating revenue under various uncertainties which can never be accurately estimated. We thereby employ a heuristic named “resource reservation” to suggest two types of bids, the regular and the must-win for a market participant to pursue higher expected revenue and satisfactory performance in terms of revenue under the worst case scenario. Meanwhile, the ISO, needs to determine the total amount of capacity required to guarantee the overall reliability of the transmission system. Our numerical experiment is based on our industrial partner’s operational data and the simulation result suggests that our proposed methods would greatly outperform the deterministic methods in terms of the profitability for a market participant and the ISO’s entire system’s reliability

    Minimizing Kinetic Inductance in Tantalum-Based Superconducting Coplanar Waveguide Resonators for Alleviating Frequency Fluctuation Issues

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    Advancements in the fabrication of superconducting quantum devices have highlighted tantalum as a promising material, owing to its low surface oxidation microwave loss at low temperatures. However, tantalum films exhibit significantly larger kinetic inductances compared to materials such as aluminum or niobium. Given the inevitable variations in film thickness, this increased kinetic inductance leads to considerable, uncontrolled frequency variances and shifts in components like superconducting coplanar waveguide (SCPW) resonators. Achieving high precision in resonator frequencies is crucial, particularly when multiple resonators share a common Purcell filter with limited bandwidth in superconducting quantum information processors. Here, we tackle this challenge from both fabrication and design perspectives, achieving a reduction in resonator frequency fluctuation by a factor of more than 100. Concurrently, the internal quality factor of the SCPW resonator remains at high level. Our findings open up new avenues for the enhanced utilization of tantalum in large-scale superconducting chips

    An Approximate Dynamic Programming Approach to Vehicle Platooning Coordination in Networks

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    Platooning connected and autonomous vehicles (CAVs) provide significant benefits in terms of traffic efficiency and fuel economy. However, most existing platooning systems assume the availability of pre-determined plans, which is not feasible in real-time scenarios. In this paper, we address this issue in time-dependent networks by formulating a Markov decision process at each junction, aiming to minimize travel time and fuel consumption. Initially, we analyze coordinated platooning without routing to explore the cooperation among controllers on an identical path. We propose two novel approaches based on approximate dynamic programming, offering suboptimal control in the context of a stochastic finite horizon problem. The results demonstrate the superiority of the approximation in the policy space. Furthermore, we investigate platooning in a network setting, where speed profiles and routes are determined simultaneously. To simplify the problem, we decouple the action space by prioritizing routing decisions based on travel time estimation. We subsequently employ the aforementioned policy approximation to determine speed profiles, considering essential parameters such as travel times. Our simulation results in SUMO indicate that our method yields better performance than conventional approaches, leading to potential travel cost savings of up to 40%. Additionally, we evaluate the resilience of our approach in dynamically changing networks, affirming its ability to maintain efficient platooning operations

    Forsythiaside A inhibits hydrogen peroxide-induced inflammation, oxidative stress, and apoptosis of cardiomyocytes

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    Purpose: To investigate the effect of forsythiaside A on heart failure.Methods: An in vitro cell model of myocardial injury was established by incubating H9c2 primary cardiomyocytes with hydrogen peroxide (H2O2). Apoptosis was measured by flow cytometry. Expression of inflammatory factors, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and enzymelinkedimmunosorbent assay (ELISA). Oxidative stress was evaluated by measuring malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) levels by ELISA.Results: Incubation with H2O2 increased H9c2 cell apoptosis (p < 0.001). Treatment with forsythiaside A reduced Bax expression and enhanced Bcl-2 expression which suppressed apoptosis of H2O2- induced H9c2 cells. Forsythiaside A also attenuated the H2O2-induced increase in TNF-α and IL-6expressions in H9c2 cells (p < 0.001). The H2O2-induced increase in MDA and decrease in SOD and GSH-Px in H9c2 cells were reversed by treatment with forsythiaside A. IκBα protein expression was downregulated, whereas p65 phosphorylation (p-p65), p-IκBα, nuclear factor erythropoietin-2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1) were upregulated in H2O2-induced H9c2 cells. Forsythiaside A increased IκBα, Nrf2, and HO-1 expression and decreased p-p65 and p-IκBα expression in H2O2-induced H9c2 cells.Conclusion: Forsythiaside A exerts anti-inflammatory, anti-oxidant, and anti-apoptotic effects against H2O2-induced H9c2 cells through inactivation of NF-κB pathway and activation of Nrf2/HO-1 pathway. These results support the potential clinical application of forsythiaside A for the treatment of heart failure
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