Gaussian density fluctuations, mode coupling theory, and all that

We consider a toy model for glassy dynamics of colloidal suspensions: a single Brownian particle diffusing among immobile obstacles. If Gaussian factorization of static density fluctuations is assumed, this model can be solved without factorization approximation for any dynamic correlation function. The solution differs from that obtained from the ideal mode coupling theory (MCT). The latter is equivalent to including only some, positive definite terms in an expression for the memory function. An approximate re-summation of the complete expression suggests that, under the assumption of Gaussian factorization of static fluctuations, mobile particle's motion is always diffusive. In contrast, MCT predicts that the mobile particle becomes localized at a high enough obstacle density. We discuss the implications of these results for models for glassy dynamics.Comment: to be published in Europhys. Let

Is a Positive Review Always Effective? Advertising Appeal Effect in the Persuasion of Online Customer Reviews

Despite the expected value of online customer reviews as an emerging advertising medium, the manner of enforcing its effectiveness on customers’ purchase behavior is still a question not well answered. To address the question, we propose a new central route cue called “advertising appeal” to examine attitude and intention to purchase a product or service based on the reasoning of the elaboration likelihood model. We also propose that consumers’ consumption goal and attitude certainty separately moderate the advertising appeal effect on purchase intention through a degree of favorable attitude. We test these hypotheses by conducting a laboratory experiment with 50 participants. In this experiment, we manipulate two kinds of advertising appeals and consumption goals. This study demonstrates that attribute-based appeal reviews are more influential than emotion-based appeal reviews in the persuasion process, regardless of the individuals’ consumption goals. However, the advertising appeal effect on purchase intention is more pronounced for hedonic consumers than for utilitarian consumers

Modelling the Impact of Perceived Connectivity on the Intention to Use Social Media: Discovering Mediating Effects and Unobserved Heterogeneity

Early research examined the direct effect of perceived connectivity (PC) on intention to adopt information systems. In this study, we extend that research stream by examining the mediating effects of perceived enjoyment (PE) and perceived playfulness (PP) on the relationship between PC and the intention to use social media within the workplace. To test our proposed model, we collected data from 2,556 social media users from Australia, Canada, India, the UK, and the US. We applied the REBUS-PLS algorithm, a response-based method for detecting unit segments in PLS path modelling and assessing the unobserved heterogeneity in the data sample. Based on the strength of effects, the algorithm automatically detected two groups of users sharing the same intentions to use social media. A post hoc analysis of each group was done using contextual and demographic variables including geographic location, country, age, education and gender. Implications for practice and research are discussed

Susceptibility functions for slow relaxation processes in supercooled liquids and the search for universal relaxation patterns

In order to describe the slow response of a glass former we discuss some distribution of correlation times, e.g., the generalized gamma distribution (GG) and an extension thereof (GGE), the latter allowing to reproduce a simple peak susceptibility such as of Cole-Davidson type as well as a susceptibility exhibiting an additional high frequency power law contribution (excess wing). Applying the GGE distribution to the dielectric spectra of glass formers exhibiting no beta-process peak (glycerol, propylene carbonate and picoline) we are able to reproduce the salient features of the slow response (1e-6 Hz - 1e9 Hz). A line shape analysis is carried out either in the time or frequency domain and in both cases an excess wing can be identified. The latter evolves in a universal way while cooling and shows up for correlation times tau_alpha > 1e-8 s. It appears that its first emergence marks the break down of the high temperature scenario of mode coupling theory. - In order to describe a glass former exhibiting a beta-process peak we have introduced a distribution function which is compatible with assuming a thermally activated process in contrast to some commonly used fit functions. Together with the GGE distribution this function allows in the frame of the Williams-Watts approach to completely interpolate the spectra, e.g. of fluoro aniline (1e-6 Hz - 1e9 Hz). The parameters obtained indicate an emergence of both the excess wing and the beta-process again at tau_alpha > 1e-8s.Comment: 22 pages, 12 figure

The potential of tag-based contextualization mechanisms to leverage the sale of regional products and promote the regions through products

In small and rural regions, where we can many times find top quality products, there is, many times, a greater difficulty in promoting their products. This difficulty begins in the nature of the companies that manufacture these products. These companies are typically family-owned or small-sized, not having large capacity to carry out very elaborate marketing strategies. They often depend of the tourist attractiveness of the regions themselves to leverage their sales. This paper discuss the challenges for the promotion of regional products and rural regions, review the role of smartphones and the main tag-based contextualization mechanisms and their potential for leverage the sale of rural regional products and, finally, presents a cooperationbased conceptual model, where are combined contextualization-tags and mobile devices to promote regional products, leverage sales and promote rural regions by attracting new visitants, making regional products a window-mechanism to the promotion of rural regions heritage and tourism-related services

More than one dynamic crossover in protein hydration water

Studies of liquid water in its supercooled region have led to many insights into the structure and behavior of water. While bulk water freezes at its homogeneous nucleation temperature of approximately 235 K, for protein hydration water, the binding of water molecules to the protein avoids crystallization. Here we study the dynamics of the hydrogen bond (HB) network of a percolating layer of water molecules, comparing measurements of a hydrated globular protein with the results of a coarse-grained model that has been shown to successfully reproduce the properties of hydration water. With dielectric spectroscopy we measure the temperature dependence of the relaxation time of protons charge fluctuations. These fluctuations are associated to the dynamics of the HB network of water molecules adsorbed on the protein surface. With Monte Carlo (MC) simulations and mean--field (MF) calculations we study the dynamics and thermodynamics of the model. In both experimental and model analyses we find two dynamic crossovers: (i) one at about 252 K, and (ii) one at about 181 K. The agreement of the experiments with the model allows us to relate the two crossovers to the presence of two specific heat maxima at ambient pressure. The first is due to fluctuations in the HB formation, and the second, at lower temperature, is due to the cooperative reordering of the HB network

Collaborative Project Across Three Hong Kong Universities: A Case Study in E-Commerce Education

This paper reports on the work undertaken by three tertiary institutions in Hong Kong to provide business students with the opportunity to experience a project-based teamwork game in learning e-commerce (EC). The teaching objective of this EC project is to develop the knowledge and skills of students, such as in the use of EC site-building tools, critical thinking, communication skills, teamwork, and entrepreneurship. This study examined student attitudes toward the learning in introductory e-commerce course via a project-based teamwork game in EC using a non-traditional teaching approach. The results ofan evaluation indicate that the project-based teamwork approach performed to expectations. Based on the feedback from students from the three tertiary institutions, the project was found to facilitate the teaching and learning of EC and to be interesting, exciting, innovative, and more worthwhile than traditional textbook-based learning

Intelligent Financial Fraud Detection Practices: An Investigation

Financial fraud is an issue with far reaching consequences in the finance industry, government, corporate sectors, and for ordinary consumers. Increasing dependence on new technologies such as cloud and mobile computing in recent years has compounded the problem. Traditional methods of detection involve extensive use of auditing, where a trained individual manually observes reports or transactions in an attempt to discover fraudulent behaviour. This method is not only time consuming, expensive and inaccurate, but in the age of big data it is also impractical. Not surprisingly, financial institutions have turned to automated processes using statistical and computational methods. This paper presents a comprehensive investigation on financial fraud detection practices using such data mining methods, with a particular focus on computational intelligence-based techniques. Classification of the practices based on key aspects such as detection algorithm used, fraud type investigated, and success rate have been covered. Issues and challenges associated with the current practices and potential future direction of research have also been identified.Comment: Proceedings of the 10th International Conference on Security and Privacy in Communication Networks (SecureComm 2014