For 3D medical data visualization, typically Transfer Functions (TFs) are employed to classify the data and to assign visual attributes to each material class. However, it is generally difficult to obtain a good trans...
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In the standard formulation of supervised learning the input is represented as a vector of features. However, in most real-life problems, we also have additional information about each of the features. This informatio...
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In the standard formulation of supervised learning the input is represented as a vector of features. However, in most real-life problems, we also have additional information about each of the features. This information can be represented as a set of properties, referred to as meta-features. For instance, in an image recognition task, where the features are pixels, the meta-features can be the (x, y) position of each pixel. We propose a new learning framework that incorporates meta-features. In this framework we assume that a weight is assigned to each feature, as in linear discrimination, and we use the meta-features to define a prior on the weights. This prior is based on a Gaussian process and the weights are assumed to be a smooth function of the meta-features. Using this framework we derive a practical algorithm that improves generalization by using meta-features and discuss the theoretical advantages of incorporating them into the learning. We apply our framework to design a new kernel for handwritten digit recognition. We obtain higher accuracy with lower computational complexity in the primal representation. Finally, we discuss the applicability of this framework to biological neural networks.
This paper suggests a method for multiclass learning with many classes by simultaneously learning shared characteristics common to the classes, and predictors for the classes in terms of these characteristics. We cast...
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ISBN:
(纸本)9781595937933
This paper suggests a method for multiclass learning with many classes by simultaneously learning shared characteristics common to the classes, and predictors for the classes in terms of these characteristics. We cast this as a convex optimization problem, using trace-norm regularization and study gradient-based optimization both for the linear case and the kernelized setting.
This paper announces a new software side-channel attack — enabled by the branch prediction capability common to all modern high-performance CPUs. The penalty paid (extra clock cycles) for a mispredicted branch can be...
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In this paper,we present a novel approach of hardware-accelerated pointcloud-based isosurface extraction on tetrahedral cells. In contrast to previous methods, our method takes advantage of programmable capability on ...
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In this paper,we present a novel approach of hardware-accelerated pointcloud-based isosurface extraction on tetrahedral cells. In contrast to previous methods, our method takes advantage of programmable capability on the modern graphics hardware to render the isosurface silhouette and reduces the video memory consumption per tetrahedron. We achieve this by using a GPU-based geometry-generating method called fat-point *** classify tetrahedra into three isosurface cases and compute corresponding parameters in vertex processors,and then generate implicit isosurface silhouette in fragment processors. Utilizing the high performance OpenGL vertex buffer objects, our algorithm can achieve a rendering rate of three million tetrahedra per second.
Protein structural class is the most basic and important classification of protein structures. The prediction technique of protein structural class has been developing for decades. Two popular methods, the amino acid ...
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We present a general model-independent approach to the analysis of data in cases when these data do not appear in the form of co-occurrence of two variables X, Y, but rather as a sample of values of an unknown (stocha...
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ISBN:
(纸本)9780262195683
We present a general model-independent approach to the analysis of data in cases when these data do not appear in the form of co-occurrence of two variables X, Y, but rather as a sample of values of an unknown (stochastic) function Z(X, Y ). For example, in gene expression data, the expression level Z is a function of gene X and condition Y;or in movie ratings data the rating Z is a function of viewer X and movie Y. The approach represents a consistent extension of the Information Bottleneck method that has previously relied on the availability of co-occurrence statistics. By altering the relevance variable we eliminate the need in the sample of joint distribution of all input variables. This new formulation also enables simple MDL-like model complexity control and prediction of missing values of Z. The approach is analyzed and shown to be on a par with the best known clustering algorithms for a wide range of domains. For the prediction of missing values (collaborative filtering) it improves the currently best known results.
The paper is devoted to the approximation of a control element for an abstract parabolic equation. The presentation is given for general approximation schemes, which includes finite element methods, finite difference ...
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For 3D medical data visualization, typically Transfer Functions (TFs) are employed to classify the data and to assign visual attributes to each material class. However, it is generally difficult to obtain a good trans...
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For 3D medical data visualization, typically Transfer Functions (TFs) are employed to classify the data and to assign visual attributes to each material class. However, it is generally difficult to obtain a good transfer function. This paper presents a novel approach for exploring appropriate transfer functions by utilizing Artificial Intelligent (AI) techniques: the search for a transfer function is reformulated as a global optimization problem, which is subsequently solved by using the Particle Swarm Optimizers (PSO). The initial population of transfer functions is pre-defined by users or selected randomly. The fitness value of each transfer function is defined by user on associated final rendering images or by user-defined objective functions. This approach bridges transfer functions and rendering images, and offers users an image that focuses on the part they interested in the medical datasets.
Over the past few years, the notion of stability in data clustering has received growing attention as a cluster validation criterion in a sample-based framework. However, recent work has shown that as the sample size ...
ISBN:
(纸本)9781605603520
Over the past few years, the notion of stability in data clustering has received growing attention as a cluster validation criterion in a sample-based framework. However, recent work has shown that as the sample size increases, any clustering model will usually become asymptotically stable. This led to the conclusion that stability is lacking as a theoretical and practical tool. The discrepancy between this conclusion and the success of stability in practice has remained an open question, which we attempt to address. Our theoretical approach is that stability, as used by cluster validation algorithms, is similar in certain respects to measures of generalization in a model-selection framework. In such cases, the model chosen governs the convergence rate of generalization bounds. By arguing that these rates are more important than the sample size, we are led to the prediction that stability-based cluster validation algorithms should not degrade with increasing sample size, despite the asymptotic universal stability. This prediction is substantiated by a theoretical analysis as well as some empirical results. We conclude that stability remains a meaningful cluster validation criterion over finite samples.
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