University of California, Irvine

About: University of California, Irvine is a education organization based out in Irvine, California, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 47031 authors who have published 113602 publications receiving 5521832 citations. The organization is also known as: UC Irvine & UCI.

The adaptive web: methods and strategies of web personalization

Abstract: I. Modeling Technologies.- User Models for Adaptive Hypermedia and Adaptive Educational Systems.- User Profiles for Personalized Information Access.- Data Mining for Web Personalization.- Generic User Modeling Systems.- Web Document Modeling.- II. Adaptation Technologies.- Personalized Search on the World Wide Web.- Adaptive Focused Crawling.- Adaptive Navigation Support.- Collaborative Filtering Recommender Systems.- Content-Based Recommendation Systems.- Case-Based Recommendation.- Hybrid Web Recommender Systems.- Adaptive Content Presentation for the Web.- Adaptive 3D Web Sites.- III. Applications.- Adaptive Information for Consumers of Healthcare.- Personalization in E-Commerce Applications.- Adaptive Mobile Guides.- Adaptive News Access.- IV. Challenges.- Adaptive Support for Distributed Collaboration.- Recommendation to Groups.- Privacy-Enhanced Web Personalization.- Open Corpus Adaptive Educational Hypermedia.- Semantic Web Technologies for the Adaptive Web.- Usability Engineering for the Adaptive Web.

A Framework for Collaborative, Content-Based and Demographic Filtering

Abstract: We discuss learning a profile of user interests for recommending information sources such as Web pages or news articles. We describe the types of information available to determine whether to recommend a particular page to a particular user. This information includes the content of the page, the ratings of the user on other pages and the contents of these pages, the ratings given to that page by other users and the ratings of these other users on other pages and demographic information about users. We describe how each type of information may be used individually and then discuss an approach to combining recommendations from multiple sources. We illustrate each approach and the combined approach in the context of recommending restaurants.

Processes and patterns of oceanic nutrient limitation

Abstract: Microbial activity is a fundamental component of oceanic nutrient cycles. Photosynthetic microbes, collectively termed phytoplankton, are responsible for the vast majority of primary production in marine waters. The availability of nutrients in the upper ocean frequently limits the activity and abundance of these organisms. Experimental data have revealed two broad regimes of phytoplankton nutrient limitation in the modern upper ocean. Nitrogen availability tends to limit productivity throughout much of the surface low-latitude ocean, where the supply of nutrients from the subsurface is relatively slow. In contrast, iron often limits productivity where subsurface nutrient supply is enhanced, including within the main oceanic upwelling regions of the Southern Ocean and the eastern equatorial Pacific. Phosphorus, vitamins and micronutrients other than iron may also (co-)limit marine phytoplankton. The spatial patterns and importance of co-limitation, however, remain unclear. Variability in the stoichiometries of nutrient supply and biological demand are key determinants of oceanic nutrient limitation. Deciphering the mechanisms that underpin this variability, and the consequences for marine microbes, will be a challenge. But such knowledge will be crucial for accurately predicting the consequences of ongoing anthropogenic perturbations to oceanic nutrient biogeochemistry.

New directions in the pursuit of Majorana fermions in solid state systems

Abstract: The 1937 theoretical discovery of Majorana fermions--whose defining property is that they are their own anti-particles--has since impacted diverse problems ranging from neutrino physics and dark matter searches to the fractional quantum Hall effect and superconductivity. Despite this long history the unambiguous observation of Majorana fermions nevertheless remains an outstanding goal. This review article highlights recent advances in the condensed matter search for Majorana that have led many in the field to believe that this quest may soon bear fruit. We begin by introducing in some detail exotic `topological' one- and two-dimensional superconductors that support Majorana fermions at their boundaries and at vortices. We then turn to one of the key insights that arose during the past few years; namely, that it is possible to `engineer' such exotic superconductors in the laboratory by forming appropriate heterostructures with ordinary s-wave superconductors. Numerous proposals of this type are discussed, based on diverse materials such as topological insulators, conventional semiconductors, ferromagnetic metals, and many others. The all-important question of how one experimentally detects Majorana fermions in these setups is then addressed. We focus on three classes of measurements that provide smoking-gun Majorana signatures: tunneling, Josephson effects, and interferometry. Finally, we discuss the most remarkable properties of condensed matter Majorana fermions--the non-Abelian exchange statistics that they generate and their associated potential for quantum computation.

Measurement of the rate of ve + d → p + p + e- interactions produced by 8B solar neutrinos at the sudbury neutrino observatory

Abstract: Solar neutrinos from the decay of 8B have been detected at the Sudbury Neutrino Observatory (SNO) via the charged current (CC) reaction on deuterium and by the elastic scattering (ES) of electrons. The CC reaction is sensitive exclusively to νe, while the ES reaction also has a small sensitivity to νμ and ντ. The flux of νe from 8B decay measured by the CC reaction rate is φCC(ν e )=[1.75±0.07(stat.) −0.11 +0.12 (syst.)×0.05(theor.)]×106cm−2s−1. Assuming no flavor transformation, the flux inferred from the ES reaction rate is φES(ν x )=[2.39±0.34(stat.) −0.14 +0.16 (syst.)]×106cm−2s−1. Comparison of φCC(νe) to the Super-Kamiokande collaboration’s precision value of φES(νx) yields a 3.3σ difference, assuming the systematic uncertainties are normally distributed, providing evidence that there is a nonelectron flavor active neutrino component in the solar flux. The total flux of active 8B neutrinos is thus determined to be (5.44±0.99)×106 cm−2 s−1, in close agreement with the predictions of solar models.