The kinetic fragility of liquids as manifestation of the elastic softening

We show that the fragility $m$, the steepness of the viscosity and relaxation time close to the vitrification, increases with the degree of elastic softening, i.e. the decrease of the elastic modulus with increasing temperature, in universal way. This provides a novel connection between the thermodynamics, via the modulus, and the kinetics. The finding is evidenced by numerical simulations and comparison with the experimental data of glassformers with widely different fragilities ($33 \le m \le 115$), leading to a fragility-independent elastic master curve extending over eighteen decades in viscosity and relaxation time. The master curve is accounted for by a cavity model pointing out the roles of both the available free volume and the cage softness. A major implication of our findings is that ultraslow relaxations, hardly characterised experimentally, become predictable by linear elasticity. As an example, the viscosity of supercooled silica is derived over about fifteen decades with no adjustable parameters.Comment: 7 pages, 6 figures; Added new results, improved the theoretical sectio

An Intelligent Group Decision Support System for Urban Tourists: Development and evaluation of a well-structured group decisionmaking process

When a group decides to plan and organize a vacation, many researchers mention that group decision making within the travel planning problem often leads to suboptimal decisions. This can be explained by the fact that the process of travel group decision making is typically ineffective. To overcome some of the problems, we propose an intelligent Group Decision Support System named Trip.Easy that creates synergy between human and machine intelligence in order to improve group decision making. The objective of this study is to develop a prototype of the Trip.Easy GDSS that combines a well-structured decision process with domain knowledge and an intelligent recommendation mechanism that facilitates reaching a consensus for the group trip planning problem. As a result, a well-designed group decision process is provided that (i) facilitates users and makes them aware of all interesting outcomes by providing intelligent recommendations, (ii) supports collaboration at a distance, (iii) minimizes irrational acts due to various influences and (iv) facilitates effective communication by means of a clear and fair process that converges to an outcome that satisfies all group members. Subsequently, a structured experiment has been designed and conducted to empirically acquire measurements of users’ satisfaction for the designed group decision process. A total of 120 participants, divided into 30 groups, were invited for the experiment. Each group was instructed to organize a city trip while using the Trip.Easy GDSS. After each session, the participants were asked to fill in a questionnaire. Analysis of the data showed that users were satisfied with the decision process of Trip.Easy GDSS. Users perceived the interaction through the graphical user interface with the Trip.Easy GDSS during the decision process as user-friendly. Furthermore, users valued the process as fair. Based upon these findings, we may conclude that the proposed group decision process that is integrated in the Trip.Easy GDSS prototype is able to facilitate users to converge towards a satisfying travel destination.MKEMan-Machine Interaction groupElectrical Engineering, Mathematics and Computer Scienc

Virtual Distribution Systems: an integrated model with research initiatives

In this article, we attempt to give a comprehensive review of how classical supply chain models have evolved with advances in information technology and its related branches of knowledge. To illustrate a possible solution to meet the challenges of the present day, we propose a model of a Virtual Distribution System for a supplier (or a group of suppliers) to use in planning and operating the distribution of goods and merchandise to customers over the entire region. These customers often demand that the products they have ordered be delivered to their preferred destinations in a highly efficient way. The modular structure of this system enables it to be more flexible and responsive to dynamic changes in the market. Illustrative example of the solution obtained by the main distribution model is given in the paper.Department of Management and Marketin

Seasonal Influenza A Virus in Feces of Hospitalized Adults

In a cohort of hospitalized adults with seasonal influenza A in Hong Kong, viral RNA was frequently (47%) detected in stool specimens. Viable virus was rarely isolated. Viral RNA positivity had little correlation with gastrointestinal symptoms and outcomes. In vitro studies suggested low potential for seasonal influenza viruses to cause direct intestinal infections

Possible role of aerosol transmission in a hospital outbreak of influenza

Background. We examined the role of aerosol transmission of influenza in an acute ward setting. Methods. We investigated a seasonal influenza A outbreak that occurred in our general medical ward (with open bay ward layout) in 2008. Clinical and epidemiological information was collected in real time during the outbreak. Spatiotemporal analysis was performed to estimate the infection risk among patients. Airflow measurements were conducted, and concentrations of hypothetical virus-laden aerosols at different ward locations were estimated using computational fluid dynamics modeling. Results. Nine inpatients were infected with an identical strain of influenza A/H3N2 virus. With reference to the index patient's location, the attack rate was 20.0% and 22.2% in the “same” and “adjacent” bays, respectively, but 0% in the “distant” bay (P=.04). Temporally, the risk of being infected was highest on the day when noninvasive ventilation was used in the index patient; multivariate logistic regression revealed an odds ratio of 14.9 (95% confidence interval, 1.7–131.3; P=.015). A simultaneous, directional indoor airflow blown from the “same” bay toward the “adjacent” bay was found; it was inadvertently created by an unopposed air jet from a separate air purifier placed next to the index patient's bed. Computational fluid dynamics modeling revealed that the dispersal pattern of aerosols originated from the index patient coincided with the bed locations of affected patients. Conclusions. Our findings suggest a possible role of aerosol transmission of influenza in an acute ward setting. Source and engineering controls, such as avoiding aerosol generation and improving ventilation design, may warrant consideration to prevent nosocomial outbreaks