92,162 research outputs found
Bipartite graph partitioning and data clustering
Many data types arising from data mining applications can be modeled as
bipartite graphs, examples include terms and documents in a text corpus,
customers and purchasing items in market basket analysis and reviewers and
movies in a movie recommender system. In this paper, we propose a new data
clustering method based on partitioning the underlying bipartite graph. The
partition is constructed by minimizing a normalized sum of edge weights between
unmatched pairs of vertices of the bipartite graph. We show that an approximate
solution to the minimization problem can be obtained by computing a partial
singular value decomposition (SVD) of the associated edge weight matrix of the
bipartite graph. We point out the connection of our clustering algorithm to
correspondence analysis used in multivariate analysis. We also briefly discuss
the issue of assigning data objects to multiple clusters. In the experimental
results, we apply our clustering algorithm to the problem of document
clustering to illustrate its effectiveness and efficiency.Comment: Proceedings of ACM CIKM 2001, the Tenth International Conference on
Information and Knowledge Management, 200
Tuning electronic structure of graphene via tailoring structure: theoretical study
Electronic structures of graphene sheet with different defective patterns are
investigated, based on the first principles calculations. We find that
defective patterns can tune the electronic structures of the graphene
significantly. Triangle patterns give rise to strongly localized states near
the Fermi level, and hexagonal patterns open up band gaps in the systems. In
addition, rectangular patterns, which feature networks of graphene nanoribbons
with either zigzag or armchair edges, exhibit semiconducting behaviors, where
the band gap has an evident dependence on the width of the nanoribbons. For the
networks of the graphene nanoribbons, some special channels for electronic
transport are predicted.Comment: 5 figures, 6 page
Effects of Australian Economic Activities on Waste Generation and Treatment
Understanding the relationships between the Australian economic system and waste generation from intermediate sectors and households is a prerequisite for planning and implementing waste management strategies at a national scale. Data of waste generation accounts link to those of national economic accounts. However, in Australia, some years’ data are absent and so these links cannot be made. To rectify this data gap, this paper interpolates and extrapolates the Australian input-output table (IOT) of 2010–2011. Waste input-output (WIO) analysis is then used to assess the effects of the Australian economy on waste generation and treatment between 2009–2010 and 2010–2011. Analysis indicated that the result of interpolation was more reasonable than that of extrapolation, and the interpolation of the Australian IOT of 2010–2011 can be applicable. This comparative analysis of the time series data in WIO model has identified that: (1) per million $AUD of output of the Construction sector generated the most amount of direct and total waste during the period; (2) the relationships between the development of Australian economy and waste generation illustrate that the Australian economy is currently a traditional linear economy; (3) the effectiveness of waste-related policies are shown by the growth of the sums of direct and total effects of intermediate sectors on the Recovery sector; and (4) the amount of waste generated by households increased sharply over the two years. The physical flows of waste footprint show details of waste generation and treatment in the Australian economic system. The information provided in this paper is beneficial to formulate tailor-made policies for waste management in Australia
Ti-rich and Cu-poor grain-boundary layers of CaCuTiO detected by x-ray photoelectron spectroscopy
Cleaved and polished surfaces of CaCuTiO ceramics have been
investigated by x-ray photoelectron spectroscopy (XPS) and energy dispersive
x-ray spectroscopy (EDX), respectively. While EDX technique shows the identical
CaCuTiO stoichiometry for the two surfaces, XPS indicates that
the cleaved surface with grain-boundary layers is remarkably Ti-rich and
Cu-poor. The core-level spectrum of Cu 2 unambiguously shows the existence
of monovalent copper only for the cleaved surface. Possible grain-boundary
structure and its formation are discussed.Comment: 8 pages, 3 figure
Probing Electroweak Symmetry Breaking Mechanism at the LHC: A Guideline from Power Counting Analysis
We formulate the equivalence theorem as a theoretical criterion for
sensitively probing the electroweak symmetry breaking mechanism, and develop a
precise power counting method for the chiral Lagrangian formulated electroweak
theories. Armed with these, we perform a systematic analysis on the
sensitivities of the scattering processes
and for testing all possible effective bosonic
operators in the chiral Lagrangian formulated electroweak theories at the CERN
Large Hadron Collider (LHC). The analysis shows that these two kinds of
processes are "complementary" in probing the electroweak symmetry breaking
sector.Comment: Extended version, 11-page-Latex-file and 3 separate PS-Figs. To be
Published in Mod.Phys.Lett.
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