Our goal was to model the ability of dermatologists to build consistent clusters of pigmented skin lesions in patients. A consensus clustering allows modeling the diversity of skin lesions in each patient as a result ...
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ISBN:
(纸本)9781467364553
Our goal was to model the ability of dermatologists to build consistent clusters of pigmented skin lesions in patients. A consensus clustering allows modeling the diversity of skin lesions in each patient as a result of the partitions proposed by nine dermatologists. To learn the dermatologists' consensus clustering, we used two supervised clustering methods, namely the structural approach and the pairwise approach. These methods learnt similarity measures between individuals' skin lesions to cluster future individuals' sets of skin lesions in the same fashion as the dermatologists do. The agreement between partitions obtained from the sequential fusion of both methods and the consensus clustering matches dermatologists agreement.
We present a neural system that recognizes faces under strong variations in pose and illumination. The generalization is learnt completely on the basis of examples Of a subset of persons (the model database) in fronta...
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ISBN:
(纸本)9783642042768
We present a neural system that recognizes faces under strong variations in pose and illumination. The generalization is learnt completely on the basis of examples Of a subset of persons (the model database) in frontal and rotated view and under different Similarities in identical pose/illumination are calculated by bunch graph matching, identity is coded by similarity rank lists. A neural network based on spike timing decodes these rank lists. We show that identity decisions can be made on the basis of few spikes. Recognition results on a large database of Chinese faces show that;the transformations were successfully learnt.
We propose a system that employs low-level image segmentation followed by color and two-dimensional (2-D) shape matching to automatically group those low-level segments into objects based on their similarity to a set ...
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We propose a system that employs low-level image segmentation followed by color and two-dimensional (2-D) shape matching to automatically group those low-level segments into objects based on their similarity to a set of example object templates presented by the user. A hierarchical content tree data structure is used for each database image to store matching combinations of low-level regions as objects. The system automatically initializes the content tree with only "elementary nodes" representing homogeneous low-level regions. The "learning" phase refers to labeling of combinations of low-level regions that have resulted in successful color and/or 2-D shape matches with the example template(s). These combinations are labeled as "object nodes" in the hierarchical content tree. Once learning is performed, the speed of second-time retrieval of learned objects in the database increases significantly. The learning step can be performed off-line provided that example objects are given in the form of user interest profiles. Experimental results are presented to demonstrate the effectiveness of the proposed system with hierarchical content tree representation and learning by color and 2-D shape matching on collections of car and face images.
In this paper, we study a learning model for designing heuristics automatically under resource constraints. We focus on improving performance related heuristic methods (HM's) in knowledge lean application domains....
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In this paper, we study a learning model for designing heuristics automatically under resource constraints. We focus on improving performance related heuristic methods (HM's) in knowledge lean application domains. We assume that learning is episodic, that the performance measures of an episode are dependent only on the final state reached in evaluating the corresponding test case and are independent of the intermediate decisions and internal states, and that the aggregate performance measures of the HM's involved are independent of the order of evaluation of test cases. The learning model is based on testing a population of competing HM's for an application problem, and switches from one to another dynamically, depending on the outcome of previous tests. Its goal is to find a good HM within the resource constraints, with proper trade-off between cost and quality. It complements existing point-based machine learning models that maintain only one incumbent HM, and that test the HM extensively before switching to alternative ones. It extends existing work on classifier systems by addressing issues related to delays in feedback, scheduling of tests of HM's under limited resources, anomalies in performance evaluation, and scalability of HM's. Finally, we describe our experience in applying the learning method on five application problems.
This article describes LAIR, a constructive induction system that acquires conjunctive concepts by applying a domain theory to introduce new features into the evolving concept description. Each acquired concept is add...
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This article describes LAIR, a constructive induction system that acquires conjunctive concepts by applying a domain theory to introduce new features into the evolving concept description. Each acquired concept is added to the domain theory, making LAIR a closed-loop learning system that weakens the inductive bias with each iteration of the learning loop. LAIR's novel feature is the use of an incremental deductive strategy for constructive induction, reducing the amount of inference required for learning. A series of experiments manipulated features of learning tasks to assess this incremental method of constructive induction relative to an uncontrolled constructive induction process that extends each example description with all derivable features. These learning tasks differed in global characteristics of the domain theory, the training sequence, and the percentage of irrelevant features in the example descriptions. The results show that LAIR's constructive induction approach saves considerable inferencing effort, with little or no cost in the number of examples needed to reach a learning criterion. The experimental results also underscored the importance of viewing a domain theory as a search space, identifying several factors that impact the deductive and inductive aspects of constructive induction, such as concept definition overlap, density of features, and fan-in and fan-out of inference chains. The paper also discusses LAIR's operation as a pac-learner and its relation to other constructive induction techniques.
A common finding is that information order influences belief revision (e.g., Hogarth & Einhorn,1992Hogarth,R. ***,H. *** effects in belief updating: The belief-adjustment *** Psychology, 24:1–55.[Crossref],[Web o...
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A common finding is that information order influences belief revision (e.g., Hogarth & Einhorn,1992Hogarth,R. ***,H. *** effects in belief updating: The belief-adjustment *** Psychology, 24:1–55.[Crossref],[Web of Science ®],[Google Scholar]). We tested personal experience as a possible mitigator. In three experiments participants experienced the probabilistic relationship between pieces of information and object category through a series of trials where they assigned objects (planes) into one of two possible categories (hostile or commercial), given two sequentially presented pieces of probabilistic information (route and ID), and then they had to indicate their belief about the object category before feedback. The results generally confirm the predictions from the Hogarth and Einhorn model. Participants showed a recency effect in their belief revision. Extending previous model evaluations the results indicate that the model predictions also hold for classification decisions, and for pieces of information that vary in their diagnostic values. Personal experience does not appear to prevent order effects in classification decisions based on sequentially presented pieces of information and in belief revision.
We first put forward the idea of a positive extension matrix (PEM) on paper. Then, an algorithm, AE_ 11, was built with the aid of the PEM. Finally, we made the comparisons of our experimental results and the final re...
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We first put forward the idea of a positive extension matrix (PEM) on paper. Then, an algorithm, AE_ 11, was built with the aid of the PEM. Finally, we made the comparisons of our experimental results and the final result was fairly satisfying.
Gold (1967) discovered a fundamental enumeration technique, the so-called identification-by-enumeration, a simple but powerful class of algorithms for learning from examples (inductive inference). We introduce a varie...
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Gold (1967) discovered a fundamental enumeration technique, the so-called identification-by-enumeration, a simple but powerful class of algorithms for learning from examples (inductive inference). We introduce a variety of more sophisticated (and more powerful) enumeration techniques and characterize their power. We conclude with the thesis that enumeration techniques are even universal in that each solvable learning problem in inductive inference can be solved by an adequate enumeration technique. This thesis is technically motivated and discussed.
learningfrom cluster examples (LCE) is a hybrid task combining features of two common grouping tasks: learning from examples and clustering. In LCE, each training example is a partition of objects. The task is then t...
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learningfrom cluster examples (LCE) is a hybrid task combining features of two common grouping tasks: learning from examples and clustering. In LCE, each training example is a partition of objects. The task is then to learn from a training set, a rule for partitioning unseen object sets. A general method for learning such partitioning rules is useful in any situation where explicit algorithms for deriving partitions are hard to formalize, while individual examples of correct partitions are easy to specify. In the past, clustering techniques have been applied to such problems, despite being essentially unsuited to the task. We present a technique that has qualitative advantages over standard clustering approaches. We demonstrate these advantages by applying our method to problems in two domains;one with dot patterns and one with more realistic vector-data images.
This paper is devoted to the use of genetic programming for the search of hypothesis space in visual learning tasks. The long-term goal of our research is to synthesize human-competitive procedures for pattern discrim...
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ISBN:
(纸本)3540423591
This paper is devoted to the use of genetic programming for the search of hypothesis space in visual learning tasks. The long-term goal of our research is to synthesize human-competitive procedures for pattern discrimination by means of learning process based directly on the training set of images. In particular, we introduce a novel concept of evolutionary learning employing, instead of scalar evaluation function, pairwise comparison of hypotheses, which allows the solutions to remain incomparable in some cases. That extension increases the diversification of the population and improves the exploration of the hypothesis space search in comparison with 'plain' evolutionary computation using scalar evaluation. This supposition is verified experimentally in this study in an extensive comparative experiment of visual learning concerning the recognition of handwritten characters.
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