76,715 research outputs found
A novel object tracking algorithm based on compressed sensing and entropy of information
Acknowledgments This research is supported by (1) the Ph.D. Programs Foundation of Ministry of Education of China under Grant no. 20120061110045, (2) the Science and Technology Development Projects of Jilin Province of China under Grant no. 20150204007G X, and (3) the Key Laboratory for Symbol Computation and Knowledge Engineering of the National Education Ministry of China.Peer reviewedPublisher PD
Greedy Strategy Works for k-Center Clustering with Outliers and Coreset Construction
We study the problem of k-center clustering with outliers in arbitrary metrics and Euclidean space. Though a number of methods have been developed in the past decades, it is still quite challenging to design quality guaranteed algorithm with low complexity for this problem. Our idea is inspired by the greedy method, Gonzalez\u27s algorithm, for solving the problem of ordinary k-center clustering. Based on some novel observations, we show that this greedy strategy actually can handle k-center clustering with outliers efficiently, in terms of clustering quality and time complexity. We further show that the greedy approach yields small coreset for the problem in doubling metrics, so as to reduce the time complexity significantly. Our algorithms are easy to implement in practice. We test our method on both synthetic and real datasets. The experimental results suggest that our algorithms can achieve near optimal solutions and yield lower running times comparing with existing methods
Scalable and Accurate Online Feature Selection for Big Data
Feature selection is important in many big data applications. Two critical
challenges closely associate with big data. Firstly, in many big data
applications, the dimensionality is extremely high, in millions, and keeps
growing. Secondly, big data applications call for highly scalable feature
selection algorithms in an online manner such that each feature can be
processed in a sequential scan. We present SAOLA, a Scalable and Accurate
OnLine Approach for feature selection in this paper. With a theoretical
analysis on bounds of the pairwise correlations between features, SAOLA employs
novel pairwise comparison techniques and maintain a parsimonious model over
time in an online manner. Furthermore, to deal with upcoming features that
arrive by groups, we extend the SAOLA algorithm, and then propose a new
group-SAOLA algorithm for online group feature selection. The group-SAOLA
algorithm can online maintain a set of feature groups that is sparse at the
levels of both groups and individual features simultaneously. An empirical
study using a series of benchmark real data sets shows that our two algorithms,
SAOLA and group-SAOLA, are scalable on data sets of extremely high
dimensionality, and have superior performance over the state-of-the-art feature
selection methods.Comment: This paper has been accepted by the journal of ACM Transactions on
Knowledge Discovery from Data (TKDD) and will be available soo
An Effective Field Theory for Jet Processes
Processes involving narrow jets receive perturbative corrections enhanced by
logarithms of the jet opening angle and the ratio of the energies inside and
outside the jets. Analyzing cone-jet processes in effective field theory, we
find that in addition to soft and collinear fields their description requires
degrees of freedom which are simultaneously soft and collinear to the jets.
These collinear-soft particles can resolve individual collinear partons,
leading to a complicated multi-Wilson-line structure of the associated
operators at higher orders. Our effective field theory provides, for the first
time, a factorization formula for a cone-jet process, which fully separates the
physics at different energy scales. Its renormalization-group equations control
all logarithmically enhanced higher-order terms, in particular also the
non-global logarithms.Comment: 9 pages, 1 figure. v2: PRL versio
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