Cram\'{e}r-type moderate deviations for Studentized two-sample UU-statistics with applications

Two-sample $U$-statistics are widely used in a broad range of applications, including those in the fields of biostatistics and econometrics. In this paper, we establish sharp Cram\'{e}r-type moderate deviation theorems for Studentized two-sample $U$-statistics in a general framework, including the two-sample $t$-statistic and Studentized Mann-Whitney test statistic as prototypical examples. In particular, a refined moderate deviation theorem with second-order accuracy is established for the two-sample $t$-statistic. These results extend the applicability of the existing statistical methodologies from the one-sample $t$-statistic to more general nonlinear statistics. Applications to two-sample large-scale multiple testing problems with false discovery rate control and the regularized bootstrap method are also discussed.Comment: Published at http://dx.doi.org/10.1214/15-AOS1375 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Fostering Knowledge Exchange in Online Communities: A Social Capital Building Approach

Prior studies on knowledge contribution started with the motivating role of social capital to predict knowledge contribution but did not specifically examine how they can be built in the first place. Our research addresses this gap by highlighting the role technology plays in supporting the development of social capital and eventual knowledge sharing intention. Herein, we propose four technology-based social capital builders – identity profiling, sub-community building, feedback mechanism, and regulatory practice – and theorize that individuals’ use of these IT artifacts determine the formation of social capital, which in turn, motivate knowledge contribution in online communities. Data collected from 253 online community users provide support for the proposed structural model. The results show that use of IT artifacts facilitates the formation of social capital (network ties, shared language, identification, trust in online community, and norms of cooperation) and their effects on knowledge contribution operate indirectly through social capital

Corporate E-banking: A Study based on DeLone and McLean’s IS Success Model

Although there are ample of studies dealing with retail internet banking, very few studies have investigated corporate internet banking. The objective of the current research is to study the determinants of the intention to continue use online banking of the existing corporate customers. This study collected data from 154 customers of an international bank to test a model developed from the DeLone and McLean’s IS success model. The results show that system quality contributes most to the perception of overall quality of the corporate e-banking service as well as the impact on the future use intention. Other factors that are found to be important are human service quality, information quality, and accuracy and security of the system

System Development Service Quality: A Comparison of the In-House Development and the Application Outsourcing Environment

Very few studies have investigated the service quality of the system development process. In this study, an instrument based on SERVPERF\u27s service quality dimensions, i.e., tangibles, reliability, empathy, responsiveness, and assurance, was developed to study the service quality for in-house and outsourced system development process. Analysis of the data collected from 152 system users who had also involved in the development of those systems supported the validity and reliability of the newly developed measures. The relative contribution of the individual service quality dimensions to the overall system development service quality was found to vary between the outsourcing and in-house group, so as the impact of the overall system development service quality on the perceived usefulness and perceived ease of use. These results suggest that users may evaluate the services provided by outsourcing vendors and in-house IT personnel differently

Building Trust in Online Shopping: The Moderating Effect of Individualism and Collectivism

As online shopping becoming more global, consumers with different culture had different consideration when shopping online. Thus, this study attempts to investigate how one specific dimension of culture, individualism-collectivism, moderates the relationship between online trust and its determinants The determinant factors under investigation include perceived risk, privacy, security, social exchange and information content. Data collected from customers of online shops from Hong Kong and Switzerland were used to test the research model. The result indicated that perceived risk had a negative relationship with Trust. Perceived risk had a stronger effect on trust for collectivists than individualists. Also, Security had a positive relationship with trust. The study showed that information content was positively related to trust of online vendors. Information content had a stronger effect on trust for individualists then collectivists

Temperature-dependent evolutions of excitonic superfluid plasma frequency in a srong excitonic insulator candidate, Ta2_2NiSe5_5

We investigate an interesting anisotropic van der Waals material, Ta$_{2}$NiSe$_{5}$, using optical spectroscopy. Ta$_{2}$NiSe$_{5}$ has been known as one of the few excitonic insulators proposed over 50 years ago. Ta$_{2}$NiSe$_{5}$ has quasi-one dimensional chains along the $a$-axis. We have obtained anisotropic optical properties of a single crystal Ta$_{2}$NiSe$_{5}$ along the $a$- and $c$-axes. The measured $a$- and $c$-axis optical conductivities exhibit large anisotropic electronic and phononic properties. With regard to the $a$-axis optical conductivity, a sharp peak near 3050 cm$^{-1}$ at 9 K, with a well-defined optical gap ($\Delta^{EI} \simeq$ 1800 cm$^{-1}$) and a strong temperature-dependence, is observed. With an increase in temperature, this peak broadens and the optical energy gap closes around $\sim$325 K($T_c^{EI}$). The spectral weight redistribution with respect to the frequency and temperature indicates that the normalized optical energy gap ($\Delta^{EI}(T)/\Delta^{EI}(0)$) is $1-(T/T_c^{EI})^2$. The temperature-dependent superfluid plasma frequency of the excitonic condensation in Ta$_{2}$NiSe$_{5}$ has been determined from measured optical data. Our findings may be useful for future research on excitonic insulators.Comment: 17 pages, 5 figure

Inherent Mach-Zehnder interference with "which-way" detection for single particle scattering in one dimension

We study the coherent transport of single photon in a one-dimensional coupled-resonator-array, "non-locally" coupled to a two-level system. Since its inherent structure is a Mach-Zehnder interferometer, we explain the destructive interference phenomenon of the transmission spectrums according to the effect of which-way detection. The quantum realization of the present model is a nano-electromechanical resonator arrays with two nearest resonators coupled to a single spin via their attached magnetic tips. Its classical simulation is a waveguide of coupled defected cavity array with double couplings to a side defected cavity.Comment: 5 papges, 4 figure