39157407
Automatic Identification of Diatoms Using Decision Forests
A feature based identification scheme for microscopic images of diatoms is presented in this paper. Diatoms are unicellular algae found in water and other places wherever there is humidity and enough light for photo synthesis. The proposed automatic identification scheme follows a decision tree based classification approach. In this paper two different ensemble learning methods are evaluated and results are compared with those of single decision trees. As test sets two different diatom image databases are used. For each image in the databases general features like symmetry, geometric properties, moment invariants, and Fourier descriptors as well as diatom specific features like striae density and direction are computed.
6828280
Automatic Identification of Diatoms Using Visual Human-Interpretable Features
In this paper we present an identification scheme for diatoms using visual human-interpretable features. Diatoms are unicellular algae found in water and other places wherever there is humidity and enough light for photosynthesis. The automatic identification of diatoms has applications in a number of areas, for example, environmental monitoring and climate research. The overall identification is performed by an ensemble of multiple decision trees following the bagging approach. The use of human-interpretable features in contrast to traditional features, such as Fourier descriptors or moment invariants, makes it possible for a human expert to verify the induced decision trees and opens up the possibility of integrating human expert knowledge into automatically derived decision trees.
46027337
Identification of Diatoms by Grid Graph Matching
Diatoms are unicellular algae found in water and other places wherever there is humidity and enough light for photo synthesis. In this paper a graph matching based identification approach for the retrieval of diatoms from an image database is presented. The retrieval is based on the matching of labeled grid graphs carrying texture information of the underlying diatom. A grid graph is a regular, rectangular arrangement of nodes overlaid on an image. Each node of the graph is labeled with texture features describing a rectangular sub-region of the object. Properties of gray level co-occurrence matrices as well as of Gabor wavelets are used as texture features. The method has been evaluated on a diatom database holding images of 188 different diatoms belonging to 38 classes. For the identification of these diatoms recognition rates of more than 90 percent were obtained.
11071092
Docking by Monte Carlo minimization with a solvation correction: Application to an FKBP - substrate complex
A Monte Carlo docking procedure that combines random displacements of the substrate and protein side chains with minimization of the enzyme]substrate complex is described and applied to finding the binding mode of the blocked tetrapeptide N-acetyl-Leu-Pro-Phe-methylamide to the FK506 binding protein Ž . FKBP . The tetrapeptide, an analog of the preferred FKBP substrate, and the FKBP binding site are flexible during the docking procedure. The twisted-imide transition-state form of the substrate is used during docking. The enzyme charges are scaled individually to account for solvent screening of specific binding site residues during the Monte Carlo sampling. To evaluate the relative binding free energies of the resulting structures, a rapid method for calculating polar and nonpolar solvation effects is introduced. Accurate electrostatic solute]solvent energies are calculated by solving the finite-difference linearized Poisson]Boltzmann equation; nonpolar contributions to the stability of the different conformers are estimated by the free energy of cavity formation, which is obtained from the molecular surface, and the solute]solvent van der Waals energy, which is calculated with a continuum approach. In the conformation of the enzyme]substrate complex with the lowest free energy, the tetrapeptide is bound as a type VIa proline turn with solvent accessible ends to permit longer polypeptide chains to act as substrates. Except for the imide carbonyl, which is involved in polar interactions with aromatic side chains of the FKBP binding *Present address: Pharmaceutical Research, F. Hoffmann]La Roche Ltd., CH-4070 Basel, Switzerland. Author to whom all correspondence should be addressed. ( ) Journal of Computational Chemistry, Vol. 18, No. 6, 723]743 1997 Q 1997 by John Wiley & Sons CCC 0192-8651 / 97 / 060723-21 CAFLISCH, FISCHER, AND KARPLUS site, all of the seven potential hydrogen bond donors or acceptors of the tetrapeptide are satisfied. The FKBP binding site has a similar conformation in the substrate complex as in the FKBP-FK506 cocrystal structure, except for the predicted reorientation of the Tyr 82 hydroxyl, which plays an important role in substrate binding. The present model for the FKBP]substrate complex is in agreement with the recently determined crystal structure of a cyclic peptide]FK506 hybrid bound to FKBP and supports the structure obtained previously by iterative model building. In addition, it is consistent with the observed effects of FKBP point mutations on the enzyme activity. The approach described here should be useful, in general, for the prediction of the structure of a molecule in solution or as part of a complex. It provides for the effective sampling of conformational space and for the inclusion of solvent effects. Q 1997 by John Wiley & Sons, Inc.
6834710
The COSIMA prototype for multi-objective bargaining
Multi-objective bargaining is a challenging business model for B2C or B2B Internet applications. Our visual bargaining agent COSIMA builds on cooperative database technology like Preference SQL or Preference XPATH, which can efficiently implement \linebreak[4] multi-dimensional search engines with a Pareto-optimality semantics to find best alternative offers. COSIMA is a smart avatar with dynamically generated speech output. We have implemented several well-known bargaining strategies for a sample e-shop, where the customer can bargain on more attributes than just the price. The life-like appearance of COSIMA is supported by randomizing her bargaining tactics and by expressing visual emotions during bargaining. She can also learn and adapt dynamically to various bargaining preferences of the customers. The COSIMA prototype is carefully engineered by means of component-ware and IT-standards including SQL, XML and Java. This makes it scalable even to very large e-shop databases. Measurements show that this advanced user interface of COSIMA requires only a small overhead of a few seconds, including the bidding process. Thus real-time performance using state-of-the art software components and hardware is feasible. A preliminary user feedback has been very encouraging. COSIMA gave her debut to a large professional audience at the computer fair CeBIT 2002.
16636819
Fusion of audio and video information for multi modal person authentication
Abstract We present an algorithm functioning as a supervisor module in a multi-expert decision making machine. It uses the Bayes theory in order to estimate the biases of individual expert opinions. The biases are used to calibrate and conciliate expert opinions to a single decision. This supervision technique is applied to the real case of a person authentication technique using two modalities, face and speech. The visual part involves the matching of a coarse grid containing Gabor phase information from face images. The acoustic part is performed by a text-dependent speaker verification system based on Hidden Markov Models. Experimental results show that the proposed fusion method improves the quality of individual expert decisions by reaching success rates of 99.5%.
20140082
COSIMA/sup B2B/ - sales automation for e-procurement
We present a fully automated electronic sales agent for e-procurement portals. The key technologies for this breakthrough are based on preferences modeled as strict partial orders, enabling a deep personalization of the B2B sales process. The interplay of several novel middleware components achieves to automate skills that so far could be executed only by a human vendor. As personalized search engine for XML based e-catalogs, we use Preference XPath; the Preference Presenter implements a sales psychology based presentation of search results, supporting various human sales strategies; the Preference Repository provides the management of situated long-term preferences; the flexible Personalized Price Offer and the multi-objective Preference Bargainer provide a personalized price fixing and the opportunity to bargain about the price of an entire product bundle, applying up/cross and down selling techniques. Our prototype COSIMA/sup B2B/, supported by industrial partners, has been successfully demonstrated at a large computer fair.
3727579
Face authentication with Gabor information on deformable graphs
Elastic graph matching has been proposed as a practical implementation of dynamic link matching, which is a neural network with dynamically evolving links between a reference model and an input image. Each node of the graph contains features that characterize the neighborhood of its location in the image. The elastic graph matching usually consists of two consecutive steps, namely a matching with a rigid grid, followed by a deformation of the grid, which is actually the elastic part. The deformation step is introduced in order to allow for some deformation, rotation, and scaling of the object to be matched. This method is applied here to the authentication of human faces where candidates claim an identity that is to be checked. The matching error as originally suggested is not powerful enough to provide satisfying results in this case. We introduce an automatic weighting of the nodes according to their significance. We also explore the significance of the elastic deformation for an application of face-based person authentication. We compare performance results obtained with and without the second matching step. Results show that the deformation step slightly increases the performance, but has lower influence than the weighting of the nodes. The best results are obtained with the combination of both aspects. The results provided by the proposed method compare favorably with two methods that require a prior geometric face normalization, namely the synergetic and eigenface approaches.