4,025 research outputs found

    Social Friend Recommendation Based on Multiple Network Correlation

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    © 2015 IEEE. Friend recommendation is an important recommender application in social media. Major social websites such as Twitter and Facebook are all capable of recommending friends to individuals. However, most of these websites use simple friend recommendation algorithms such as similarity, popularity, or 'friend's friends are friends,' which are intuitive but consider few of the characteristics of the social network. In this paper we investigate the structure of social networks and develop an algorithm for network correlation-based social friend recommendation (NC-based SFR). To accomplish this goal, we correlate different 'social role' networks, find their relationships and make friend recommendations. NC-based SFR is characterized by two key components: 1) related networks are aligned by selecting important features from each network, and 2) the network structure should be maximally preserved before and after network alignment. After important feature selection has been made, we recommend friends based on these features. We conduct experiments on the Flickr network, which contains more than ten thousand nodes and over 30 thousand tags covering half a million photos, to show that the proposed algorithm recommends friends more precisely than reference methods

    Magnetically tunable properties related with carriers density in self-doped La1−xMnO3/y wt %Nb-SrTiO3 heteroepitaxial junctions

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    The self-doped La1−xMnO3 (x=0.1 and 0.3) thin films deposited on Nb-doped (wt % y) SrTiO3 (y=0.05 and 0.8) crystals to form heteroepitaxial junctions have been prepared by the pulse laser deposition method. The current-voltage loops of junction were measured at several fixed magnetic fields for the temperature from 10 to 300 K. We have focused on the effects of doping level and annealing time on the magnetically tunable property of the junction. The results show that these junctions have a typical temperature-dependent rectifying characteristics and asymmetrical hysteresis. The magnetically tunable property of the junction was related with the annealing time for the self-doped La1−xMnO3−δ thin film and the doping level in the Nb-doped SrTiO3 (STON) crystal. In the self-doped La0.9MnO3/0.05-STON junction annealed at 900 °C for 5 h, the relative ratio of voltage [Vb(0)−Vb(H)] /Vb(0) is about 70% at H=6 T and T=70 K for I=0.1 mA, showing a large magnetically tunable property. These results reveal the great potential of the manganites in configuring artificial devices.published_or_final_versio

    Efficient mining of frequent item sets on large uncertain databases

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    The data handled in emerging applications like location-based services, sensor monitoring systems, and data integration, are often inexact in nature. In this paper, we study the important problem of extracting frequent item sets from a large uncertain database, interpreted under the Possible World Semantics (PWS). This issue is technically challenging, since an uncertain database contains an exponential number of possible worlds. By observing that the mining process can be modeled as a Poisson binomial distribution, we develop an approximate algorithm, which can efficiently and accurately discover frequent item sets in a large uncertain database. We also study the important issue of maintaining the mining result for a database that is evolving (e.g., by inserting a tuple). Specifically, we propose incremental mining algorithms, which enable Probabilistic Frequent Item set (PFI) results to be refreshed. This reduces the need of re-executing the whole mining algorithm on the new database, which is often more expensive and unnecessary. We examine how an existing algorithm that extracts exact item sets, as well as our approximate algorithm, can support incremental mining. All our approaches support both tuple and attribute uncertainty, which are two common uncertain database models. We also perform extensive evaluation on real and synthetic data sets to validate our approaches. © 1989-2012 IEEE.published_or_final_versio

    Two-Stage Friend Recommendation Based on Network Alignment and Series Expansion of Probabilistic Topic Model

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    © 2017 IEEE. Precise friend recommendation is an important problem in social media. Although most social websites provide some kinds of auto friend searching functions, their accuracies are not satisfactory. In this paper, we propose a more precise auto friend recommendation method with two stages. In the first stage, by utilizing the information of the relationship between texts and users, as well as the friendship information between users, we align different social networks and choose some "possible friends." In the second stage, with the relationship between image features and users, we build a topic model to further refine the recommendation results. Because some traditional methods, such as variational inference and Gibbs sampling, have their limitations in dealing with our problem, we develop a novel method to find out the solution of the topic model based on series expansion. We conduct experiments on the Flickr dataset to show that the proposed algorithm recommends friends more precisely and faster than traditional methods

    Effects of annealing temperature on the characteristics of Ga-doped ZnO film metal-semiconductor-metal ultraviolet photodetectors

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    The epidemic of sexually transmitted infections in China: implications for control and future perspectives

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    China has experienced an increasing epidemic of sexually transmitted infections (STIs), including HIV. High risk groups likely to be infected include female sex workers (FSWs) and their clients, men who have sex with men (MSM), drug users and migrant workers. Prevention can be achieved through education of the population, condom promotion, early detection of symptomatic and asymptomatic people, and effective diagnosis and treatment of these patients and their partners. This article aims to describe the profile of the epidemic in high-risk groups in China as well as to detail the contributing factors and the implications for control. Programmes for the control of STIs should be immediate priorities in China, and primary and secondary prevention strategies are vital to this process

    Microstructures and resistivity of cuprate/manganite bilayer deposited on SrTiO3 substrate

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    Thin Yba[SUB2]Cu[SUB3]O[SUB7-δ/La[SUB0.67]Ca[SUB0.33]MnO[SUB3] (YBCO/LCMO) films were grown on SrTiO[SUB3](STO)substrates by magnetron sputtering technique. The microstructures of the bilayers were characterized and a standard four-probe technique was applied to measure the resistivity of the samples. The interdiffusions at the YBCO/LCMO and LCMO/STO interfaces formed two transient layers with the thickness of about 3 and 2 nm, respectively. All the bilayers were well textured along the c axis. At low temperature, the superconductivity can only be observed when the thickness of YBCO is more than 25 nm. When the thickness of YBCO is less than 8 nm, the bilayers show only ferromagnetism. The superconductivity and ferromagnetism perhaps coexist in the bilayer with the YBCO thickness of 12.5 nm. These interesting properties are related to the interaction between spin polarized electrons in the manganites and the cooper pairs in the cuprates. © 2003 American Institute of Physics.published_or_final_versio

    Rapid Syphilis Testing Uptake for Female Sex Workers at Sex Venues in Southern China: Implications for Expanding Syphilis Screening

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    : Accessibility of syphilis testing services is critical in syphilis control programs for female sex workers (FSWs), but few FSWs attend public STI clinics or other testing sites. Introduction of free rapid syphilis testing (RST) into outreach programs for FSWs will help improve test uptake. : Commercial sex venues were identified in two cities in South China. In cooperation with health advocacy organizations, health outreach teams from local public health or medical facilities approached all types of sex venues in study areas to offer free RST. Acceptability and uptake of RST among FSWs were evaluated. : A total of 2812 FSWs were offered RST and 2670 (95.0%) accepted syphilis testing. 182 (6.8%) FSWs had a positive RST result among whom 136 (74.7%) were willing to attend an STD clinic for confirmatory testing and treatment. More than half (89, 66.4%) of those with syphilis were not willing to notify their sex partners. Multivariate logistic analysis showed that syphilis test uptake was associated with residing in Jiangmen (AOR, 1.78; 95% CI, 1.15-2.77), older age (AOR, 2.11, 95% CI, 1.17-3.79 for age of 31 years or above), and not working at a service venue (AOR, 1.60; 95% CI, 1.10-2.34). : RST at sex venues is well accepted by FSWs when it is integrated into ongoing outreach services. Such programs provide excellent opportunities for expanding syphilis screening efforts among specific subgroups of FSW who are difficult to reach through clinic-based programs.<br/

    Broadband gradient impedance matching using an acoustic metamaterial for ultrasonic transducers

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    2016-2017 > Academic research: refereed > Publication in refereed journal201804_a bcmaVersion of RecordPublishe
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