A Fibrational Approach to Automata Theory

For predual categories C and D we establish isomorphisms between opfibrations representing local varieties of languages in C, local pseudovarieties of D-monoids, and finitely generated profinite D-monoids. The global sections of these opfibrations are shown to correspond to varieties of languages in C, pseudovarieties of D-monoids, and profinite equational theories of D-monoids, respectively. As an application, we obtain a new proof of Eilenberg's variety theorem along with several related results, covering varieties of languages and their coalgebraic modifications, Straubing's C-varieties, fully invariant local varieties, etc., within a single framework

Eilenberg Theorems for Free

Eilenberg-type correspondences, relating varieties of languages (e.g. of finite words, infinite words, or trees) to pseudovarieties of finite algebras, form the backbone of algebraic language theory. Numerous such correspondences are known in the literature. We demonstrate that they all arise from the same recipe: one models languages and the algebras recognizing them by monads on an algebraic category, and applies a Stone-type duality. Our main contribution is a variety theorem that covers e.g. Wilke's and Pin's work on $\infty$-languages, the variety theorem for cost functions of Daviaud, Kuperberg, and Pin, and unifies the two previous categorical approaches of Boja\'nczyk and of Ad\'amek et al. In addition we derive a number of new results, including an extension of the local variety theorem of Gehrke, Grigorieff, and Pin from finite to infinite words

Design and Analysis of a Novel 25 GHz Interleaver for DWDM Applications with Two Ring Configurations

We present a novel scheme of an excellent flat-top 25 GHz optical interleaver based on two ring configurations. And the Advanced Systems Analysis Program (ASAP) optical modeling software has been utilized for the interleaver design. The optical path difference for interference and the phase shift are provided by the interferometer with two birefringent crystals and dual-ring arrangement. The proposed structure exhibits the passband utilization of more than 90% and the channel isolation greater than 95 dB within the C-band. Furthermore, we improve the dispersion performance by employing λ/6 wave plates as birefringent compensators for interleavers. The research results illustrate that our proposed scheme with compensator can improve the dispersion of more than 85.8%. Comparing the performance with the previous studies of optical interleavers with birefringent crystal and ring structure, the proposed system can achieve an excellent 25 GHz multichannel filter for dense wavelength division multiplexing (DWDM) transmission systems

How Website Design Quality Affects Flow Experience and User Satisfaction: A Comparison of Behavioral and Neuroscience Studies

The quality of website design is a main factor that affects user experience and satisfaction with an e-commerce site. This has been confirmed by many existing literature. However, most of these studies are based on user response through questionnaire surveys. It is well-known that user responses are potentially inaccurate and are subjective to the common method bias. Recently, neuroscience method that takes advantage of neuro-scientific equipment to collect psychophysiological evidence has gained much attention in social sciences and information systems. Therefore, it is interesting to compare our findings from behavioral and neuroscience studies to see whether this new method may provide insights into our understanding of website design effect. With the above purpose in mind, this study designed a field experiment on existing e-tailing websites in Taiwan and China. Both behavioral and neuroscience methods were applied to collect data about their flow experience and user satisfaction. The particular instrument for collecting brain wave data was a one-point electro-encephalogram (EEG), which is useful for measuring attention and relaxation. Our research model includes five main website design factors (convenience, aesthetics, content, interactivity and customization) as independent variables, flow experience as a mediator, and user satisfaction as the dependent variable. Our results indicate that all five design factors had significant impact on the flow experience and the flow experience had significant positive effect on user satisfaction in our behavior study. Our neuroscience study, however, shows different findings: only convenience, content, and customization had positive impact on the flow experience. Although the effect of flow experience (measured by attention and relaxation) on user satisfaction still exist, but the R-square value is much lower (reduced from 0.56 to 0.10). We argue that there are two possible interpretations: one is that the measurement we used may not be able to capture the full flow experience as a questionnaire could do. Another alerting explanation is that previous research on flow experience and user satisfaction may have overlooked the potential common method bias issue in analyzing their data

A Comparative Study for 2D and 3D Computer-aided Diagnosis Methods for Solitary Pulmonary Nodules

Many computer-aided diagnosis (CAD) methods, including 2D and 3D approaches, have been proposed for solitary pulmonary nodules (SPNs). However, the detection and diagnosis of SPNs remain challenging in many clinical circumstances. One goal of this work is to investigate the relative diagnostic accuracy of 2D and 3D methods. An additional goal is to develop a two-stage approach that combines the simplicity of 2D and the accuracy of 3D methods. The experimental results show statistically significant differences between the diagnostic accuracy of 2D and 3D methods. The results also show that with a very minor drop in diagnostic performance the two-stage approach can significantly reduce the number of nodules needed to be processed by the 3D method, streamlining the computational demand

Knowledge Creation and Firm Performance: Mediating Processes from an Organizational Agility Perspective

Knowledge creation has emerged as a critical area in information systems research in the past decade (Nonaka 1994). However, the mechanism through which knowledge creation enhances firm performance remains unclear. This paper examines the role of organization agility as a mediator between knowledge creation processes and firm performance. Our survey study of 134 firms indicates that two forms of organizational agility – customer agility and operational agility, significantly and fully mediate the effect of knowledge creation on firm performance. Our findings extend prior research by providing insights into the role of organizational agility in facilitating the effect of knowledge creation processes on firm performance. Implications for researchers and managers are discussed