Enhancement of superconductivity by frustrating the charge order

We study strong electron-phonon interacting systems where the geometry of the crystalline lattice frustrates the formation of charge order. Our results show that under such condition, high-Tc superconductivity can occur in a wide range of electron-phonon coupling strengths. This result is obtained by studying the Holstein model on triangular lattice using sign-problem-free quantum Monte Carlo method

Orbital fluctuations and strong correlations in quantum dots

In this lecture note we focus our attention to quantum dot systems where exotic strongly correlated behavior develops due to the presence of orbital or charge degrees of freedom. After giving a concise overview of the theory of transport and Kondo effect through a single electron transistor, we discuss how SU(4) Kondo effect develops in dots having orbitally degenerate states and in double dot systems, and then study the singlet-triplet transition in lateral quantum dots. Charge fluctuations and Matveev's mapping to the two-channel Kondo model in the vicinity of charge degeneracy point are also discussed.Comment: Lecture note to appear in Philosophical Magazin

Efficient notification of meeting points for moving groups via independent safe regions

In applications like social networking services and online games, multiple moving users form a group and wish to be continuously notified with the best meeting point from their locations. To reduce the communication frequency of the application server, a promising technique is to apply safe regions, which capture the validity of query results with respect to the users' locations. Unfortunately, the safe regions in our problem exhibit characteristics such as irregular shapes and dependency among multiple safe regions. These unique characteristics render existing safe region methods that focus on a single safe region inapplicable to our problem. To tackle these challenges, we first examine the shapes of safe regions in our problem context and propose feasible approximations for them. We design efficient algorithms for computing these safe regions, as well as develop compression techniques for representing safe regions in a compact manner. Experiments with both real and synthetic data demonstrate the efficiency of our proposal in terms of computation and communication costs. © 2013 IEEE.published_or_final_versio

An integrated visual framework for the human-Web interface

© 2002 IEEE. The design of Web sites has been largely ad hoc, with little concern about the effectiveness of navigation and maintenance. This paper presents a general framework with a human-Web interface that supports Web design through visual programming and reverse Web engineering through visualization. The paper describes the framework in the context of a Web tool, known as HWIT which has been developed for a pilot study

Knowledge and experiences of needle prick injuries (NPI) among nursing students at a

Background: Healthcare workers and students on training who are directly involved in treating and nursing patients face a great risk of acquiring blood-borne infections from the workplace. Needle prick injuries (NPI) are the commonest route by which such infections are transmitted from patients to healthcare providers. Nursing students on training are no exception, as they get exposed to acciden- tal needle pricks and contamination during their hospital activities. Lack of appropriate resources, knowledge and skills, coupled with the unavailability of the universal standard precautionary procedures and compliance thereof, constitute high risks for needle prick injuries. Adequate knowledge and adherence to safety practices could prevent the occurrence of NPI and the related consequences. A survey was conducted among nursing students at a specific university in Gauteng to assess their knowledge of NPI, to identify and describe factors that contribute to the occurrence of NPI, and to discover the circumstances of needle prick accidents among the targeted group of students. Methods: A cross-sectional quantitative survey was conducted among nursing students from the second to the fourth year of study registered at the specific university for the 2007 academic year. Questionnaires were hand delivered to a convenient sample of nursing students attending mandatory nursing classes. Those who consented signed a consent form. Participants completed and handed back the questionnaires to the researchers on the same day that they were delivered. Data collected included factors contributing to NPI and high-risk procedures leading to NPI, as perceived by these students. A knowledge assessment of NPI guidelines, policies and protocols and prevalence of NPI among these students was also done. Results: A response rate of 96 (74%) was achieved. The average age of the respondents was 23 years, with a minimum age of 18 and a maximum age of 35. The sample consisted of more females than males. The majority of respondents were in the second year of study. The majority (56%) rated needle recapping, disposing used needles (28.1%) and cleaning sharp instruments (56.3%) as extremely high-risk procedures. Furthermore, 30.2% of the respondents thought suturing and blood taking (33.3%) were high-risk procedures for NPI, while 25% rated administering injections, 35.5% rated blood transfusion and 74.8% rated the lack of adequate containers for sharps disposal to be highly associated with the risk of NPI. A significant proportion of the respondents rated the lack of knowledge about NPI (policies and protocols) at institutions of clinical training as an extremely high risk, followed by the lack of accompaniment and in-service training. Only 16.0% of the respondents had suffered NPI and only 8.3% had reported the incident. Conclusion: Procedures rated as high risk were considered to be most likely associated with the occurrence of NPI. Appropriate guide- lines, adequate knowledge and the enforcement of compliance with standard precautionary measures could reduce the incidence of NPI among nursing students. South African Family Practice Vol. 50 (5) 2008: pp. 48-48

Efficient Notification of Meeting Points for Moving Groups via Independent Safe Regions

published_or_final_versio

Efficient Dynamic Approximate Distance Oracles for Vertex-Labeled Planar Graphs

Let $G$ be a graph where each vertex is associated with a label. A Vertex-Labeled Approximate Distance Oracle is a data structure that, given a vertex $v$ and a label $\lambda$, returns a $(1+\varepsilon)$-approximation of the distance from $v$ to the closest vertex with label $\lambda$ in $G$. Such an oracle is dynamic if it also supports label changes. In this paper we present three different dynamic approximate vertex-labeled distance oracles for planar graphs, all with polylogarithmic query and update times, and nearly linear space requirements

Modeling the optical constants of AlxGa1-xAs alloys

Extension of Adachi's model with a Gaussian-like broadening function instead of a Lorentzian one is used to model the optical dielectric function of the alloy AlxGa1-xAs. Gaussian-like broadening is accomplished by replacing the damping constant in the Lorentzian line shape with a frequency dependent expression. In such a manner, the comparative simplicity of analytic formulae of the model is preserved, while the accuracy becomes comparable to more intricate models, and/or models with a significantly greater number of parameters. The employed model describes accurately the optical dielectric function in the spectral range from 1.5 to 6.0 eV in the entire alloy composition range. Relative rms error obtained for the refractive index is below 2.2% for all compositionspublished_or_final_versio

Regulation of cell proliferation by large-conductance calcium-activated potassium and volume-sensitive chloride channels in human cardiac fibroblasts

Oral presentationpublished_or_final_versionThe 15th Annual Research Conference of the Department of Medicine, The University of Hong Kong, Hong Kong, 16 January 2010. In Hong Kong Medical Journal, 2010, v. 16, suppl. 1, p. 23, abstract no. 2

An Evolutionary Algorithm to Generate Real Urban Traffic Flows

In this article we present a strategy based on an evolutionary algorithm to calculate the real vehicle ows in cities according to data from sensors placed in the streets. We have worked with a map imported from OpenStreetMap into the SUMO traffic simulator so that the resulting scenarios can be used to perform different optimizations with the confidence of being able to work with a traffic distribution close to reality. We have compared the results of our algorithm to other competitors and achieved results that replicate the real traffic distribution with a precision higher than 90%.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This research has been partially funded by project number 8.06/5.47.4142 in collaboration with the VSB-Technical University of Ostrava and Universidad de Málaga UMA/FEDER FC14-TIC36, programa de fortalecimiento de las capacidades de I+D+i en las universidades 2014-2015, de la Consejería de Economía, Innovación, Ciencia y Empleo, cofinanciado por el fondo europeo de desarrollo regional (FEDER). Also, partially funded by the Spanish MINECO project TIN2014-57341-R (http://moveon.lcc.uma.es). The authors would like to thank the FEDER of European Union for financial support via project Movilidad Inteligente: Wi-Fi, Rutas y Contaminación (maxCT) of the "Programa Operativo FEDER de Andalucía 2014-2020. We also thank all Agency of Public Works of Andalusia Regional Government staff and researchers for their dedication and professionalism. Daniel H. Stolfi is supported by a FPU grant (FPU13/00954) from the Spanish Ministry of Education, Culture and Sports