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A Novel Approach to Prediction of the 3-Dimensional Structures of Protein Backbones by Neural Networks

Neural Information Processing Systems

One current aim of molecular biology is determination of the (3D) tertiary structures ofproteins in their folded native state from their sequences of amino acid 523 524 Fredholm, Bohr, Bohr, Brunak, Cotterill, Lautrup, and Thtersen residues. Since Kendrew & Perutz solved the first protein structures, myoglobin and hemoglobin, and explained from the discovered structures how these proteins perform their function, it has been widely recognized that protein function is intimately linkedwith protein structure[l]. Within the last two decades X-ray crystallographers have solved the 3-dimensional (3D) structures of a steadily increasing number of proteins in the crystalline state, and recently 2D-NMR spectroscopy has emerged as an alternative method for small proteins in solution. Today approximately three hundred 3D structures have been solved by these methods, although only about half of them can be considered as truly different, and only around a hundred of them are solved at high resolution (that is, less than 2A). The number of protein sequences known today is well over 20,000, and this number seems to be growing at least one order of magnitude faster than the number of known 3D protein structures. Obviously, it is of great importance to develop tools that can predict structural aspects of proteins on the basis of knowledge acquired from known 3D structures.


On the Circuit Complexity of Neural Networks

Neural Information Processing Systems

Viewing n-variable boolean functions as vectors in'R'2", we invoke tools from linear algebra and linear programming to derive new results on the realizability of boolean functions using threshold gat.es. Using this approach, one can obtain: (1) upper-bounds on the number of spurious memories in HopfielJ networks, and on the number of functions implementable by a depth-d threshold circuit; (2) a lower bound on the number of ort.hogonal input.


ART2/BP architecture for adaptive estimation of dynamic processes

Neural Information Processing Systems

The goal has been to construct a supervised artificial neural network that learns incrementally an unknown mapping. As a result a network consisting ofa combination of ART2 and backpropagation is proposed and is called an "ART2/BP" network. The ART2 network is used to build and focus a supervised backpropagation network. The ART2/BP network has the advantage of being able to dynamically expand itself in response to input patterns containing new information. Simulation results show that the ART2/BP network outperforms a classical maximum likelihood method for the estimation of a discrete dynamic and nonlinear transfer function.


Speech Recognition Using Demi-Syllable Neural Prediction Model

Neural Information Processing Systems

The Neural Prediction Model is the speech recognition model based on pattern prediction by multilayer perceptrons. Its effectiveness was confirmed bythe speaker-independent digit recognition experiments. This paper presents an improvement in the model and its application to large vocabulary speech recognition, based on subword units. The improvement involves an introduction of "backward prediction," which further improves the prediction accuracy of the original model with only "forward prediction". Inapplication of the model to speaker-dependent large vocabulary speech recognition, the demi-syllable unit is used as a subword recognition unit.


Lg Depth Estimation and Ripple Fire Characterization Using Artificial Neural Networks

Neural Information Processing Systems

This srudy has demonstrated how artificial neural networks (ANNs) can be used to characterize seismic sources using high-frequency regional seismic data. We have taken the novel approach of using ANNs as a research tool for obtaining seismic source information, specifically depth of focus for earthquakes and ripple-fire characteristics for economic blasts, rather than as just a feature classifier between earthquake and explosion populations. Overall, we have found that ANNs have potential applications to seismic event characterization and identification, beyond just as a feature classifier. In future studies, these techniques should be applied to actual data of regional seismic events recorded at the new regional seismic arrays. The results of this study indicates that an ANN should be evaluated as part of an operational seismic event identification system. 1 INTRODUCTION ANNs have usually been used as pattern matching algorithms, and recent studies have applied ANNs to standard classification between classes of earthquakes and explosions using wavefonn features (Dowla, et al, 1989), (Dysart and Pulli, 1990).



Mobile Robot Competition and Exhibition

AI Magazine

Announcement of the new Mobile Robot Competition and Exhibition, to be held annually at the AAAI National Conference on Artificial Intelligence. Announcement of the new Mobile Robot Competition and Exhibition, to be held annually at the AAAI National Conference on Artificial Intelligence.


Decision Analysis and Expert Systems

AI Magazine

Decision analysis and expert systems are technologies intended to support human reasoning and decision making by formalizing expert knowledge so that it is amenable to mechanized reasoning methods. Despite some common goals, these two paradigms have evolved divergently, with fundamental differences in principle and practice. We present the key ideas of decision analysis and review recent research and applications that aim toward a marriage of these two paradigms. This work combines decision-analytic methods for structuring and encoding uncertain knowledge and preferences with computational techniques from AI for knowledge representation, inference, and explanation.


Letters to the Editor

AI Magazine

Second, I was one of the few academic AI AAAI can encourage practitioners to Corporate functions. Applications researchers who attended some sessions make their data available to researchers. In addition to helping researchers in used in successful applications. AI research is relevant to the prob-in this regard. University of California Second, my research has recently at Irvine focused on learning methods that If you have a track record of successfully revise the knowledge base of an expert developing and deploying system when the expert system conflicts knowledge based systems to solve with an expert's decision on a real-world problems, and you wish set of examples.


The Cognitive Structure of Emotions: A Review

AI Magazine

Each of the The second volume promises to inherent to the task of specifying objections is then analyzed from a draw on a characterization of AI's the deterministic or nondeterministic formal standpoint because the relevant essential methodology as continuous machine, and complexity of electric elements of formal theory are attempts to overcome the formal or logical circuits), physical limits of introduced in subsequent chapters. I hope to see my (that is, finite, discrete concepts can Lovelace's objection. Despite the criticisms dissipate after reading the never form a perfect model of a continuous introductory character of the chapter, second volume. Let's get a feeling of what this first and possible-world semantics. With volume is really about.