Pattern Recognition
Controlling the Complexity of HMM Systems by Regularization
Neukirchen, Christoph, Rigoll, Gerhard
This paper introduces a method for regularization ofHMM systems that avoids parameter overfitting caused by insufficient training data. Regularization isdone by augmenting the EM training method by a penalty term that favors simple and smooth HMM systems. The penalty term is constructed as a mixture model of negative exponential distributions that is assumed to generate the state dependent emission probabilities of the HMMs. This new method is the successful transfer of a well known regularization approach in neural networks to the HMM domain and can be interpreted as a generalization of traditional state-tying for HMM systems. Theeffect of regularization is demonstrated for continuous speech recognition tasks by improving overfitted triphone models and by speaker adaptation with limited training data. 1 Introduction One general problem when constructing statistical pattern recognition systems is to ensure the capability to generalize well, i.e. the system must be able to classify data that is not contained in the training data set.
The NASD Regulation Advanced-Detection System (ADS)
Kirkland, J. Dale, Senator, Ted E., Hayden, James J., Dybala, Tomasz, Goldberg, Henry G., Shyr, Ping
The National Association of Securities Dealers, Inc., regulation advanced-detection system (ADS) monitors trades and quotations in The Nasdaq Stock Market to identify patterns and practices of behavior of potential regulatory interest. ADS has been in operational use at NASD Regulation since the summer of 1997 by several groups of analysts, processing approximately 2 million transactions a day, generating over 10,000 breaks. More important, it has greatly expanded surveillance coverage to new areas of the market and to many new types of behavior of regulatory concern. ADS combines detection and discovery components in a single system that supports multiple regulatory domains and shares the same market data. ADS makes use of a variety of AI techniques, including visualization, pattern recognition, and data mining, in support of the activities of regulatory analysis, alert and pattern detection, and knowledge discovery.
Multiresolution Tangent Distance for Affine-invariant Classification
Vasconcelos, Nuno, Lippman, Andrew
The ability to rely on similarity metrics invariant to image transformations is an important issue for image classification tasks such as face or character recognition. We analyze an invariant metric that has performed well for the latter - the tangent distance - and study its limitations when applied to regular images, showing that the most significant among these (convergence to local minima) can be drastically reduced by computing the distance in a multiresolution setting. This leads to the multi resolution tangent distance, which exhibits significantly higher invariance to image transformations, and can be easily combined with robust estimation procedures.
Multiresolution Tangent Distance for Affine-invariant Classification
Vasconcelos, Nuno, Lippman, Andrew
The ability to rely on similarity metrics invariant to image transformations is an important issue for image classification tasks such as face or character recognition. We analyze an invariant metric that has performed well for the latter - the tangent distance - and study its limitations when applied to regular images, showing that the most significant among these (convergence to local minima) can be drastically reduced by computing the distance in a multiresolution setting. This leads to the multi resolution tangent distance, which exhibits significantly higher invariance to image transformations, and can be easily combined with robust estimation procedures.
Multiresolution Tangent Distance for Affine-invariant Classification
Vasconcelos, Nuno, Lippman, Andrew
The ability to rely on similarity metrics invariant to image transformations isan important issue for image classification tasks such as face or character recognition. We analyze an invariant metric that has performed well for the latter - the tangent distance - and study its limitations when applied to regular images, showing that the most significant among these (convergence to local minima) can be drastically reduced by computing the distance in a multiresolution setting. This leads to the multiresolution tangent distance, which exhibits significantly higher invariance to image transformations,and can be easily combined with robust estimation procedures.
Applied AI News
Buzzeo (Phoenix, Ariz.), a software engineering firm, has developed a highly adaptable self-service application that automates various administrative Bell Helicopter Textron (Fort Worth, rapid transit (BART) system. The lab functions for the higher-education Tex.), a manufacturer of helicopters, will develop a system to better train marketplace. This rule-based has implemented an intelligent system both new BART operators and those system has helped Buzzeo cut its to automate the procurement needing periodic retraining. ATS enables customers traffic problems at commercial airports. Technical Library at the to track packages through a The $9.3 million, two-story Phillips site on Kirtland Air Force Base, nationwide 800 number by simply building, called the Surface Development New Mexico, is using advanced pattern-recognition stating a tracking number to learn and Test Facility, is being built at technology to design the status of a package.
A Constructive RBF Network for Writer Adaptation
This paper discusses a fairly general adaptation algorithm which augments a standard neural network to increase its recognition accuracy for a specific user. The basis for the algorithm is that the output of a neural network is characteristic of the input, even when the output is incorrect. We exploit this characteristic output by using an Output Adaptation Module (OAM) which maps this output into the correct user-dependent confidence vector. The OAM is a simplified Resource Allocating Network which constructs radial basis functions online. We applied the OAM to construct a writer-adaptive character recognition system for online handprinted characters.