9,865 research outputs found

    Nonlocal Flow of Convex Plane Curves and Isoperimetric Inequalities

    Full text link
    In the first part of the paper we survey some nonlocal flows of convex plane curves ever studied so far and discuss properties of the flows related to enclosed area and length, especially the isoperimetric ratio and the isoperimetric difference. We also study a new nonlocal flow of convex plane curves and discuss its evolution behavior. In the second part of the paper we discuss necessary and sufficient conditions (in terms of the (mixed) isoperimetric ratio or (mixed) isoperimetric difference) for two convex closed curves to be homothetic or parallel.Comment: 23 page

    A parametrized three-dimensional model for MEMS thermal shear-stress sensors

    Get PDF
    This paper presents an accurate and efficient model of MEMS thermal shear-stress sensors featuring a thin-film hotwire on a vacuum-isolated dielectric diaphragm. We consider three-dimensional (3-D) heat transfer in sensors operating in constant-temperature mode, and describe sensor response with a functional relationship between dimensionless forms of hotwire power and shear stress. This relationship is parametrized by the diaphragm aspect ratio and two additional dimensionless parameters that represent heat conduction in the hotwire and diaphragm. Closed-form correlations are obtained to represent this relationship, yielding a MEMS sensor model that is highly efficient while retaining the accuracy of three-dimensional heat transfer analysis. The model is compared with experimental data, and the agreement in the total and net hotwire power, the latter being a small second-order quantity induced by the applied shear stress, is respectively within 0.5% and 11% when uncertainties in sensor geometry and material properties are taken into account. The model is then used to elucidate thermal boundary layer characteristics for MEMS sensors, and in particular, quantitatively show that the relatively thick thermal boundary layer renders classical shear-stress sensor theory invalid for MEMS sensors operating in air. The model is also used to systematically study the effects of geometry and material properties on MEMS sensor behavior, yielding insights useful as practical design guidelines

    The Antecedents and Consequences of RFID Technology Adoption for China’s Logistics Companies

    Get PDF
    With the fast growth in China’s economy, the logistics industry in China is set to take off, and more and more logistics companies begin to adopt innovative logistics technologies. RFID technology has been regarded as an important innovative application in logistics operations and supply chain management. This paper aims to study the antecedents and consequences of RFID technology adoption from the perspective of technological innovation by conducting a questionnaire survey on China’s logistics companies. The factors influencing RFID technology adoption consist of organizational and environmental dimensions. Research findings reveal that organizational encouragement for innovation, quality of human capital, organizational accumulation of related knowledge, perceived environmental uncertainty, and governmental support exhibit significant influences on the willingness to adopt RFID technology. Logistics companies with higher levels of willingness to adopt RFID technology will be associated with better supply chain performance

    Technological Innovation for China’s Logistics Industry

    Get PDF
    China’s logistics industry has started to pay attention to adopt more efficient logistics technologies to provide better services for their customers. This paper employes the questionnaire survey to study the factors influencing the adoption of technological innovations by logistics service providers in China as well as the influences of technological innovation on supply chain performance. Technological innovations are categorized into data acquisition technologies, information technologies, warehousing technologies, and transportation technologies. The results show that the adoption of technological innovations is significantly influenced by technological, organizational and environmental factors, and adopting innovative technologies will increase supply chain performance for the logistics industry in China.China’s logistics industry has started to pay attention to adopt more efficient logistics technologies to provide better services for their customers. This paper employes the questionnaire survey to study the factors influencing the adoption of technological innovations by logistics service providers in China as well as the influences of technological innovation on supply chain performance. Technological innovations are categorized into data acquisition technologies, information technologies, warehousing technologies, and transportation technologies. The results show that the adoption of technological innovations is significantly influenced by technological, organizational and environmental factors, and adopting innovative technologies will increase supply chain performance for the logistics industry in China.China’s logistics industry has started to pay attention to adopt more efficient logistics technologies to provide better services for their customers. This paper employes the questionnaire survey to study the factors influencing the adoption of technological innovations by logistics service providers in China as well as the influences of technological innovation on supply chain performance. Technological innovations are categorized into data acquisition technologies, information technologies, warehousing technologies, and transportation technologies. The results show that the adoption of technological innovations is significantly influenced by technological, organizational and environmental factors, and adopting innovative technologies will increase supply chain performance for the logistics industry in China

    An Empirical Study on Logistics Service Providers’ Intention to Adopt Green Innovations

    Get PDF
    This study examines six factors that will influence the intention to adopt green innovations for logistics service providers. The determinant factors include technological, organizational and environmental dimensions. The data came from the questionnaire survey on logistics companies in Taiwan, and 162 samples were analyzed. According to the survey results, all the factors have positive influences on the intention to adopt green practices. Explicitness and accumulation of green practices, organizational encouragement, quality of human resources, environmental uncertainty and governmental supports exhibit significant influences on the willingness to adopt green practices.This study examines six factors that will influence the intention to adopt green innovations for logistics service providers. The determinant factors include technological, organizational and environmental dimensions. The data came from the questionnaire survey on logistics companies in Taiwan, and 162 samples were analyzed. According to the survey results, all the factors have positive influences on the intention to adopt green practices. Explicitness and accumulation of green practices, organizational encouragement, quality of human resources, environmental uncertainty and governmental supports exhibit significant influences on the willingness to adopt green practices.This study examines six factors that will influence the intention to adopt green innovations for logistics service providers. The determinant factors include technological, organizational and environmental dimensions. The data came from the questionnaire survey on logistics companies in Taiwan, and 162 samples were analyzed. According to the survey results, all the factors have positive influences on the intention to adopt green practices. Explicitness and accumulation of green practices, organizational encouragement, quality of human resources, environmental uncertainty and governmental supports exhibit significant influences on the willingness to adopt green practices

    Determinants and Impacts of the Relative Use of Depository Receipts and Euro Convertible Bonds by High-tech Corporations: An Empirical Study

    Get PDF
    This paper adopts Taiwan's high-tech companies as the sample to address and examine four new determinants of various foreign financing instruments and test their impacts on the issuing firms. Our empirical findings are consistent with the following notions. First, the firms with higher foreign holding and foreign investment will be likely to adopt foreign financing policy. Moreover, the firms with higher stock dividend payment in Taiwan will adopt both of ECB (Euro convertible bond) and DR (depository receipt). Firm managers with better education background will prefer DR. Second, the use of DR can effectively decrease the volatility of stock returns but also pronounce a negative influence on the mean of stock returns. In contrast, the use of ECB can effectively increase the mean but can not significantly decrease the volatility.

    Optical transitions between Landau levels: AA-stacked bilayer graphene

    Full text link
    The low-frequency optical excitations of AA-stacked bilayer graphene are investigated by the tight-binding model. Two groups of asymmetric LLs lead to two kinds of absorption peaks resulting from only intragroup excitations. Each absorption peak obeys a single selection rule similar to that of monolayer graphene. The excitation channel of each peak is changed as the field strength approaches a critical strength. This alteration of the excitation channel is strongly related to the setting of the Fermi level. The peculiar optical properties can be attributed to the characteristics of the LL wave functions of the two LL groups. A detailed comparison of optical properties between AA-stacked and AB-stacked bilayer graphenes is also offered. The compared results demonstrate that the optical properties are strongly dominated by the stacking symmetry. Furthermore, the presented results may be used to discriminate AABG from MG, which can be hardly done by STM
    • …
    corecore