Mathematical models are often used in system identification applications. The dynamics of most systems, however, change over time and the sources of these changes cannot always be directly determined or measured. To m...
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With the advance of network technology in recent years, the dissemination and exchange of massive documents has become commonplace. Accordingly, the importance of content analysis techniques is increasing. Topic analy...
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ISBN:
(纸本)9781581139648
With the advance of network technology in recent years, the dissemination and exchange of massive documents has become commonplace. Accordingly, the importance of content analysis techniques is increasing. Topic analysis in large-scale document streams such as E-mails and news articles is an important research issue. This paper addresses techniques for "topic activation analysis" for document streams. For example, when news articles with a strong relationship to a given topic arrive frequently in a news stream, we can regard the activation level of the topic as high. In [I], Kleinberg proposed a method for analyzing document streams. Although the main objective of his method was to detect bursts of topics, it can also be used for topic activation analysis. His method, however, has a serious limitation in that it only looks at the arrival rate of documents and ignores the degree of relevance for each document. Another limitation is that his method is "batch-oriented." This paper first proposes a novel topic activation analysis scheme that incorporates both document arrival rate and relevance to address the first problem. It then presents an incremental scheme more appropriate for a document streaming environment. The proposed schemes are validated by experiments using real CNN news articles. Copyright 2005 ACM.
作者：
Senyk, NatalieSiegel, DavidMarine Science Program
Institute for Computational Earth System Science University of California Santa Barbara Santa Barbara CA 93106-3060 United States Department of Geography
Institute for Computational Earth System Science University of California Santa Barbara Santa Barbara CA 93106-3060 United States
The role of time in giant kelp, Macrocystis pyrifera, to describe spatial and temporal habitat distributions was examined by developing a biophysical model that utilizes remotely sensed data, along with other variable...
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The role of time in giant kelp, Macrocystis pyrifera, to describe spatial and temporal habitat distributions was examined by developing a biophysical model that utilizes remotely sensed data, along with other variables. The model is based on habitat preferences of giant kelp and consists of a set of rules generated from observable environmental parameters. The model generates in a time-series of optimal giant kelp habitat composites on seasonal to interannual time scales, which will be used to quantify persistence of kelp habitat. The results indicate a seasonal cycle of optimal habitat area, marked by large fluctuations in area between summer and winter for most of the study area.
The method of fundamental solutions (MFS) is first proposed in 1964 by Kupradze and theoretical basis of this method is constructed at the end of 1980's. As a meshless method, no domain meshing is required for MFS...
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Motivation: The rapid accumulation of biological network data translates into an urgent need for computational methods for graph pattern mining. One important problem is to identify recurrent patterns across multiple ...
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A cyclocopter propelled by the cycloidal blade system, which can be described as a horizontal rotary wing, is a new concept of VTOL vehicle. In this paper, cyclocopter rotor system is optimized for design variables su...
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A cyclocopter propelled by the cycloidal blade system, which can be described as a horizontal rotary wing, is a new concept of VTOL vehicle. In this paper, cyclocopter rotor system is optimized for design variables such as radius of rotor, rotating speed, maximum pitch angle, chord and span of blade, number of blades and airfoil. To apply response surface methodology, datum acquired by STAR-CD for aerodynamic design variables and MSC/NASTRAN for structural ones. Genetic algorithm is used to find the optimal values from the constructed response surface while objective functions are thrust, required power and stress of blade.
Large linear systems of saddle point type arise in a wide variety of applications throughout computationalscience and engineering. Due to their indefiniteness and often poor spectral properties, such linear systems r...
The purpose of this paper is to demonstrate the design and implementation of GISolve - a Grid-based problem solving environment for computationally intensive geographic information analysis based on geo-middleware. Th...
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Through investigation of transient phase characteristics, a methodology is developed to optimize the phase resetting properties of robust nonlinear biological oscillators;in particular, those of the circadian rhythm. ...
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Incomplete LU factorization is a valuable preconditioning approach for sparse iterative solvers. An "ideal" but inefficient preconditioner for the iterative solution of Ax = b is A-1 itself. This paper descr...
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Incomplete LU factorization is a valuable preconditioning approach for sparse iterative solvers. An "ideal" but inefficient preconditioner for the iterative solution of Ax = b is A-1 itself. This paper describes a preconditioner based on sparse approximations to partitioned representations of A-1, in addition to the results of implementation of the proposed method in a shared memory parallel environment. The partitioned inverses are normally somewhat sparse. Their sparsity can be enhanced with suitable ordering and partitioning algorithms. Sparse approximations to these partitioned inverse representations can be obtained either by discarding selected nonzero entries of these inverses or by precluding the creation of some inversion fills. Experimental results indicate that the use of these partitioned incomplete inverses as preconditioners results in excellent highly parallel preconditioners.
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