550 research outputs found

    Crystallization kinetics and role of stress in Al induced layer exchange crystallization process of amorphous SiGe thin film on glass

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    The present study reports Al induced crystallization (AIC) of amorphous (a)-SiGe in Al-Ge-Si ternary system at low temperature ~ 350 degree C. In addition to crystallization, the isothermal annealing of a-SiGe/AlOx/Al/corning-glass (CG) structure was found to be accompanied by an Al induced layer exchange (ALILE) phenomenon. The evolution of residual stress in the Al layer during isothermal annealing is evaluated using X-ray diffraction based technique to ascertain the role of stress in the ALILE process. A corroboration of the stress with the growth kinetics, analyzed using Avrami theory of phase transformation gives a comprehensive understanding of the ALILE crystallization process in this system. The grown polycrystalline SiGe thin film is a potential candidate for novel technological applications in semiconductor devices.Comment: 24 pages, 11 figure

    An algorithmic approach to handle circular trading in commercial taxing system

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    Tax manipulation comes in a variety of forms with different motivations and of varying complexities. In this paper, we deal with a specific technique used by tax-evaders known as circular trading. In particular, we define algorithms for the detection and analysis of circular trade. To achieve this, we have modelled the whole system as a directed graph with the actors being vertices and the transactions among them as directed edges. We illustrate the results obtained after running the proposed algorithm on the commercial tax dataset of the government of Telangana, India, which contains the transaction details of a set of participants involved in a known circular trade

    Near-field examination of perovskite-based superlenses and superlens-enhanced probe-object coupling

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    A planar slab of negative index material works as a superlens with sub-diffraction-limited imaging resolution, since propagating waves are focused and, moreover, evanescent waves are reconstructed in the image plane. Here, we demonstrate a superlens for electric evanescent fields with low losses using perovskites in the mid-infrared regime. The combination of near-field microscopy with a tunable free-electron laser allows us to address precisely the polariton modes, which are critical for super-resolution imaging. We spectrally study the lateral and vertical distributions of evanescent waves around the image plane of such a lens, and achieve imaging resolution of wavelength/14 at the superlensing wavelength. Interestingly, at certain distances between the probe and sample surface, we observe a maximum of these evanescent fields. Comparisons with numerical simulations indicate that this maximum originates from an enhanced coupling between probe and object, which might be applicable for multifunctional circuits, infrared spectroscopy, and thermal sensors.Comment: 20 pages, 6 figures, published as open access article in Nature Communications (see http://www.nature.com/ncomms/

    Ambipolar gate effect and low temperature magnetoresistance of ultrathin La0.8Ca0.2MnO3 Films

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    Ultrathin La0.8Ca0.2MnO3 films have been measured in a field-effect geometry. The electric field due to the gate produces a large ambipolar decrease in resistance at low temperatures. This is attributed to the development of a pseudogap in the density of states and the couple of localized charge to strain. The gate effect and mangetoresistance are interpreted in a consistent framework. The implications for the low temperature behavior of a manganite film in the two dimensional limit are discussed.Comment: 4 pages, 3 figure

    Internationalisation speed and MNE performance: A study of the market-seeking expansion of retail MNEs

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    Existing research is divided on whether firms that rapidly expand their overseas operations perform better than firms that internationalize slowly. Drawing on Penrose’s theory of the growth of the firm we argue that the positive effects of rapid internationalization give way to negative effects with increasing internationalization speed, leading to an inverted U-shaped association between internationalization speed and firm performance. We analyse the market-seeking expansion of 110 retailers over a 10-year period (2003–2012) and find support for a curvilinear relationship between internationalization speed and firm performance that is moderated by the geographic scope of firms’ internationalization path and firms’ international experience. Our study contributes to resolving conflicting views on the link between internationalization speed and firm performance

    A Novel Example-Dependent Cost-Sensitive Stacking Classifier to Identify Tax Return Defaulters

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    Tax evasion refers to an entity indulging in illegal activities to avoid paying their actual tax liability. A tax return statement is a periodic report comprising information about income, expenditure, etc. One of the most basic tax evasion methods is failing to file tax returns or delay filing tax return statements. The taxpayers who do not file their returns, or fail to do so within the stipulated period are called tax return defaulters. As a result, the Government has to bear the financial losses due to a taxpayer defaulting, which varies for each taxpayer. Therefore, while designing any statistical model to predict potential return defaulters, we have to consider the real financial loss associated with the misclassification of each individual. This paper proposes a framework for an example-dependent cost-sensitive stacking classifier that uses cost-insensitive classifiers as base generalizers to make predictions on the input space. These predictions are used to train an example-dependent cost-sensitive meta generalizer. Based on the meta-generalizer choice, we propose four variant models used to predict potential return defaulters for the upcoming tax-filing period. These models have been developed for the Commercial Taxes Department, Government of Telangana, India. Applying our proposed variant models to GST data, we observe a significant increase in savings compared to conventional classifiers. Additionally, we develop an empirical study showing that our approach is more adept at identifying potential tax return defaulters than existing example-dependent cost-sensitive classification algorithms. &nbsp

    Structure of the St. Louis encephalitis virus postfusion envelope trimer

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    St. Louis encephalitis virus (SLEV) is a mosquito-borne flavivirus responsible for several human encephalitis outbreaks over the last 80 years. Mature flavivirus virions are coated with dimeric envelope (E) proteins that mediate attachment and fusion with host cells. E is a class II fusion protein, the hallmark of which is a distinct dimer-to-trimer rearrangement that occurs upon endosomal acidification and insertion of hydrophobic fusion peptides into the endosomal membrane. Herein, we report the crystal structure of SLEV E in the posfusion trimer conformation. The structure revealed specific features that differentiate SLEV E from trimers of related flavi- and alphaviruses. SLEV E fusion loops have distinct intermediate spacing such that they are positioned further apart than previously observed in flaviviruses but closer together than Semliki Forest virus, an alphavirus. Domains II and III (DII and DIII) of SLEV E also adopt different angles relative to DI, which suggests that the DI-DII joint may accommodate spheroidal motions. However, trimer interfaces are well conserved among flaviviruses, so it is likely the differences observed represent structural features specific to SLEV function. Analysis of surface potentials revealed a basic platform underneath flavivirus fusion loops that may interact with the anionic lipid head groups found in membranes. Taken together, these results highlight variations in E structure and assembly that may direct virus-specific interactions with host determinants to influence pathogenesis

    Entrepreneurial-intention constraint model: A comparative analysis among post-graduate management students in India, Singapore and Malaysia

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    YesAlthough literature on entrepreneurship has increasingly focused on intention-based models, not much emphasis has been laid on understanding the combined effect of contextual and situational factors along with support of university environment on the formation of entrepreneurial intention among students. In an effort to make up for this shortfall, by taking Theory of Planned Behavior as basic framework, the present study seeks to understand the influence of three of the most important factors, viz. (a) endogenous barriers, (b) exogenous environment, and (c) university environment and support on the entrepreneurial intention among management students. The study sample consisted of 1,097 students, wherein 526 students were from India, 252 from Singapore, and 319 were from Malaysia. The results indicates that along with positive attitude and perceived behavioral control that directly influences entrepreneurial intention, university environment and support and exogenous environment also have an indirect but significant impact on shaping of entrepreneurial intention among students. With this, it was found that exogenous environment was found to have a negative relationship with both attitude towards behavior and perceived behavioral control for all three countries.The full-text of this article will be released for public view at the end of the publisher embargo on 2 Jun 2018

    Sympatric woodland Myotis bats form tight-knit social groups with exclusive roost home ranges

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    Background: The structuring of wild animal populations can influence population dynamics, disease spread, and information transfer. Social network analysis potentially offers insights into these processes but is rarely, if ever, used to investigate more than one species in a community. We therefore compared the social, temporal and spatial networks of sympatric Myotis bats (M. nattereri (Natterer's bats) and M. daubentonii (Daubenton's bats)), and asked: (1) are there long-lasting social associations within species? (2) do the ranges occupied by roosting social groups overlap within or between species? (3) are M. daubentonii bachelor colonies excluded from roosting in areas used by maternity groups? Results: Using data on 490 ringed M. nattereri and 978 M. daubentonii from 379 colonies, we found that both species formed stable social groups encompassing multiple colonies. M. nattereri formed 11 mixed-sex social groups with few (4.3%) inter-group associations. Approximately half of all M. nattereri were associated with the same individuals when recaptured, with many associations being long-term (>100 days). In contrast, M. daubentonii were sexually segregated; only a quarter of pairs were associated at recapture after a few days, and inter-sex associations were not long-lasting. Social groups of M. nattereri and female M. daubentonii had small roost home ranges (mean 0.2 km2 in each case). Intra-specific overlap was low, but inter-specific overlap was high, suggesting territoriality within but not between species. M. daubentonii bachelor colonies did not appear to be excluded from roosting areas used by females. Conclusions: Our data suggest marked species- and sex-specific patterns of disease and information transmission are likely between bats of the same genus despite sharing a common habitat. The clear partitioning of the woodland amongst social groups, and their apparent reliance on small patches of habitat for roosting, means that localised woodland management may be more important to bat conservation than previously recognised
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