What we need: Project managers` evaluation of top management actions required for software development projects

Web 2.0 is now an important internet application because of the integration of social interaction and web technologies. Previous information system studies usually specified their research context as a utilitarian system or hedonic system and the results were concluded within one specific system type. Web 2.0 application provides a flexible environment for different kinds of user motivations that can be used for utilitarian or hedonic purpose. This study extended the Technology Acceptance Model (TAM) by introducing a moderating factor into the model, in order to study users’ behavioral intentions in a Web 2.0 environment. We designed two task types of user motivation and conducted our experiment on two Web 2.0 websites. According to the PLS (Partial Least Squares) analysis, this study demonstrated that utilitarian and hedonic purposes had a moderating effect on the relationship between perceived belief and user attitude as well as the relationship between perceived information quality and perceived belief in the Web 2.0 application. The relationship between perceived usefulness and attitude was stronger in the utilitarian user motivation; whereas the relationship between perceived ease of use and attitude was stronger when the user had hedonic motivation to use the Web 2.0 application. We also found that perceived information quality had significant impact on the perceived usefulness and perceived ease of use

Using Peer-to-Peer Technology for Knowledge Sharing in Communities of Practices

Communities of Practices (CoPs) are informal structures within organizations that bind people together through informal relationships and the sharing of expertise and experience. As such, they are effective tools for the creation and sharing of organizational knowledge, and, increasingly, organizations are adopting them as part of their knowledge management strategies. In this paper, we examine the knowledge sharing characteristics and roles of CoPs and develop a peer-to-peer knowledge sharing architecture that matches the behavioral characteristics of the members of the CoPs. We also propose a peer-to-peer knowledge sharing tool called KTella that enables members of CoPs to voluntarily share and retrieve knowledge more effectively

Exploring An Individual’s Intention to Use Blogs: The Roles of Social, Motivational and Individual Factors

Blogs are a new type of media for social interaction; they have become very popular, and have shown their influence throughout our society. However, little is known about what motivates an individual to participate in blogging activities. This study aims to explore how an individual\u27s intention is influenced by social, motivational and individual factors. A survey, involving 283 subjects, was conducted to examine the proposed model. The results revealed that personal innovativeness in the domain of information technology (PIIT), perceived usefulness and perceived enjoyment have direct impacts on a persons\u27 intent to use blogs. On the other hand, factors such as subjective norms and blog self-efficacy influence an individual\u27s motivational factors; these factors, in turn, influence an individual\u27s behavioral intention in regard to blog usage. The findings of this study not only contribute to a theoretical building of those factors that effect blog usage, but also provide implications to practitioners for understanding and promoting blog usage

Interfacial effects on the polarization of BiFeO3BiFeO_{3} films

By considering an interfacial layer between the electrode and the $BiFeO_{3}$($BFO$) layer, the polarization and the hysteresis behavior of $BFO$ film are simulated. It is found that the non-ferroelectric interface will increase the coercive field, and remarkably suppress the polarization of the ultrathin film under low applied fields. Due to the competition between the interfacial effect and the internal compressive stress, the maximum polarization on the P-E loop of a $BFO$ film can be independent on the film thickness under an adequate applied field.Comment: 3 pages, 2 figure

Nanoscale modification of porous gelatin scaffolds with chondroitin sulfate for corneal stromal tissue engineering

Recent studies reflect the importance of using naturally occurring biopolymers as three-dimensional corneal keratocyte scaffolds and suggest that the porous structure of gelatin materials may play an important role in controlling nutrient uptake. In the current study, the authors further consider the application of carbodiimide cross-linked porous gelatin as an alternative to collagen for corneal stromal tissue engineering. The authors developed corneal keratocyte scaffolds by nanoscale modification of porous gelatin materials with chondroitin sulfate (CS) using carbodiimide chemistry. Scanning electron microscopy/energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy showed that the amount of covalently incorporated polysaccharide was significantly increased when the CS concentration was increased from 0% to 1.25% (w/v). In addition, as demonstrated by dimethylmethylene blue assays, the CS content in these samples was in the range of 0.078–0.149 nmol per 10 mg scaffold. When compared with their counterparts without CS treatment, various CS-modified porous gelatin membranes exhibited higher levels of water content, light transmittance, and amount of permeated nutrients but possessed lower Young’s modulus and resistance against protease digestion. The hydrophilic and mechanical properties of scaffolds modified with 0.25% CS were comparable with those of native corneas. The samples from this group were biocompatible with the rabbit corneal keratocytes and showed enhanced proliferative and biosynthetic capacity of cultured cells. In summary, the authors found that the nanoscale-level modification has influence on the characteristics and cell-material interactions of CS-containing gelatin hydrogels. Porous membranes with a CS content of 0.112 ± 0.003 nmol per 10 mg scaffold may hold potential for use in corneal stromal tissue engineering

Microscopic theory of quantum dot interactions with quantum light: local field effect

A theory of both linear and nonlinear electromagnetic response of a single QD exposed to quantum light, accounting the depolarization induced local--field has been developed. Based on the microscopic Hamiltonian accounting for the electron--hole exchange interaction, an effective two--body Hamiltonian has been derived and expressed in terms of the incident electric field, with a separate term describing the QD depolarization. The quantum equations of motion have been formulated and solved with the Hamiltonian for various types of the QD excitation, such as Fock qubit, coherent fields, vacuum state of electromagnetic field and light with arbitrary photonic state distribution. For a QD exposed to coherent light, we predict the appearance of two oscillatory regimes in the Rabi effect separated by the bifurcation. In the first regime, the standard collapse--revivals phenomenon do not reveal itself and the QD population inversion is found to be negative, while in the second one, the collapse--revivals picture is found to be strongly distorted as compared with that predicted by the standard Jaynes-Cummings model. %The model developed can easily be extended to %%electromagnetic excitation. For the case of QD interaction with arbitrary quantum light state in the linear regime, it has been shown that the local field induce a fine structure of the absorbtion spectrum. Instead of a single line with frequency corresponding to which the exciton transition frequency, a duplet is appeared with one component shifted by the amount of the local field coupling parameter. It has been demonstrated the strong light--mater coupling regime arises in the weak-field limit. A physical interpretation of the predicted effects has been proposed.Comment: 14 pages, 7 figure

An Efficient Alternating Riemannian/Projected Gradient Descent Ascent Algorithm for Fair Principal Component Analysis

Fair principal component analysis (FPCA), a ubiquitous dimensionality reduction technique in signal processing and machine learning, aims to find a low-dimensional representation for a high-dimensional dataset in view of fairness. The FPCA problem involves optimizing a non-convex and non-smooth function over the Stiefel manifold. The state-of-the-art methods for solving the problem are subgradient methods and semidefinite relaxation-based methods. However, these two types of methods have their obvious limitations and thus are only suitable for efficiently solving the FPCA problem in special scenarios. This paper aims at developing efficient algorithms for solving the FPCA problem in general, especially large-scale, settings. In this paper, we first transform FPCA into a smooth non-convex linear minimax optimization problem over the Stiefel manifold. To solve the above general problem, we propose an efficient alternating Riemannian/projected gradient descent ascent (ARPGDA) algorithm, which performs a Riemannian gradient descent step and an ordinary projected gradient ascent step at each iteration. We prove that ARPGDA can find an $\varepsilon$-stationary point of the above problem within $\mathcal{O}(\varepsilon^{-3})$ iterations. Simulation results show that, compared with the state-of-the-art methods, our proposed ARPGDA algorithm can achieve a better performance in terms of solution quality and speed for solving the FPCA problems.Comment: 5 pages, 8 figures, submitted for possible publicatio

Control-Data Separation and Logical Condition Propagation for Efficient Inference on Probabilistic Programs

We introduce a novel sampling algorithm for Bayesian inference on imperative probabilistic programs. It features a hierarchical architecture that separates control flows from data: the top-level samples a control flow, and the bottom level samples data values along the control flow picked by the top level. This separation allows us to plug various language-based analysis techniques in probabilistic program sampling; specifically, we use logical backward propagation of observations for sampling efficiency. We implemented our algorithm on top of Anglican. The experimental results demonstrate our algorithm's efficiency, especially for programs with while loops and rare observations.Comment: 11 pages with appendice

Crosstalk between transcription factors and microRNAs in human protein interaction network

<p>Abstract</p> <p>Background</p> <p>Gene regulatory networks control the global gene expression and the dynamics of protein output in living cells. In multicellular organisms, transcription factors and microRNAs are the major families of gene regulators. Recent studies have suggested that these two kinds of regulators share similar regulatory logics and participate in cooperative activities in the gene regulatory network; however, their combinational regulatory effects and preferences on the protein interaction network remain unclear.</p> <p>Methods</p> <p>In this study, we constructed a global human gene regulatory network comprising both transcriptional and post-transcriptional regulatory relationships, and integrated the protein interactome into this network. We then screened the integrated network for four types of regulatory motifs: single-regulation, co-regulation, crosstalk, and independent, and investigated their topological properties in the protein interaction network.</p> <p>Results</p> <p>Among the four types of network motifs, the crosstalk was found to have the most enriched protein-protein interactions in their downstream regulatory targets. The topological properties of these motifs also revealed that they target crucial proteins in the protein interaction network and may serve important roles of biological functions.</p> <p>Conclusions</p> <p>Altogether, these results reveal the combinatorial regulatory patterns of transcription factors and microRNAs on the protein interactome, and provide further evidence to suggest the connection between gene regulatory network and protein interaction network.</p