Recent years have seen an explosive growth in the amount of biological data available for analysis. The large volume of data collected makes it necessary to automatically classify and sort such data on a very large sc...
详细信息
Recent years have seen an explosive growth in the amount of biological data available for analysis. The large volume of data collected makes it necessary to automatically classify and sort such data on a very large scale. Typically, investigators use computational sequence analysis tools to assign functions to newly found gene products. The problem is to find the functions of a (unknown) gene product given its amino acid sequence. In this work we search for functional similarity between gene products by matching the functional domains that they contain. The domain-based approach addresses the main problem of sequence-based similarity, i.e., when the region of a gene product that is matched by a query sequence is not related to the function of that gene product. We use the hidden Markov representation of a gene product domain as described in the PFAM database, and then infer annotations that come from the Gene Ontology. To compute domain similarity between two gene products we introduce a fuzzy Jaccard similarity measure. We tested our domain-based similarity for the functional annotation of a set of 194 gene products extracted from the ENSEMBL Web site. We compared the domain similarity approach to the traditional way of performing functional annotation using a sequence-based similarity (BLAST and Smith-Waterman). The annotation was performed in all cases using a fuzzy K-nearest neighbor algorithm. We found that our domain-based annotation was better than the most common BLAST approach, but not as good as complex Smith-Waterman technique. The domain-based annotation has about 70% correct annotation rate at 17% false annotation rate
This paper presents an experimental technique that allows the determination of the equivalent circuit of an aluminium electrolytic capacitor. The impedance of these electrolytic capacitors changes with frequency, beco...
详细信息
This paper presents an experimental technique that allows the determination of the equivalent circuit of an aluminium electrolytic capacitor. The impedance of these electrolytic capacitors changes with frequency, becoming approximately equal to a resistance near their resonance frequency. This resistance, the equivalent series resistance (ESR), becomes one of the most critical problems of static converters, which operate near the resonant frequency of the capacitor. The ESR leads to a significant increase in the alternating (AC) component of the output voltage, requiring a constant action of the control system. To validate this technique some experimental and simulated results are presented
Most edge detection algorithms include three main stages: smoothing, differentiation, and labeling. In this paper, we evaluate the performance of algorithms in which competitive learning is applied first to enhance ed...
详细信息
Most edge detection algorithms include three main stages: smoothing, differentiation, and labeling. In this paper, we evaluate the performance of algorithms in which competitive learning is applied first to enhance edges, followed by an edge detector to locate the edges. In this way, more detailed and relatively more unbroken edges can be found as compared to the results when an edge detector is applied alone. The algorithms compared are K-Means, SOM and SOGR for clustering, and Canny and GED for edge detection. Perceptionally, best results were obtained with the GED-SOGR algorithm. The SOGR is also considerably simpler and faster than the SOM algorithm.
The objective of our research was to find the best approach to handle missing attribute values in data sets describing preterm birth provided by the Duke University. Five strategies were used for filling in missing at...
详细信息
Enterprise integration is significant for the enforcement of novel business models in an enterprise/industry. The great heterogeneity of systems/applications in the enterprise environment requires the introduction of ...
详细信息
Enterprise integration is significant for the enforcement of novel business models in an enterprise/industry. The great heterogeneity of systems/applications in the enterprise environment requires the introduction of interoperability aspects in order to resolve integration problems in a flexible and dynamic way. Our approach introduces an advanced enterprise semantic model representing both enterprise structure and available services, through the use of ontologies. The model is associated by a specific architecture that uses the above model in combination with state-of-the-art technologies such as Web services and workflows
The performance of a cellular phone commercial helical antenna at 900~MHz band, both in free space and in the presence of a human head phantom was studied. Numerical simulation of the phone model for the latter case h...
The performance of a cellular phone commercial helical antenna at 900~MHz band, both in free space and in the presence of a human head phantom was studied. Numerical simulation of the phone model for the latter case has been performed giving 3D radiation diagrams. The effect of the phantom head on radiation diagrams is presented. The relative amount of the EM power absorbed in the head was obtained for several distances of the phone. Measurements were carried out in a RF anechoic chamber using standard horn antennas and a calibrated measuring system. Absolute radiation patterns of the antenna gain were obtained in the three principal planes. Significant reduction of the absorbed power could be achieved just by moving the phone 1 cm away from the head.
This paper presents a laboratory method that can be used to determine the intrinsic value of the equivalent series resistance (ESR) of electrolytic capacitors. One of the most critical problems of switch mode DC-DC co...
详细信息
This paper presents an experimental technique that allows the determination of the equivalent circuit of an aluminium electrolytic capacitor. The impedance of these electrolytic capacitors changes with frequency, beco...
详细信息
Exploring the vast number of possible feature interactions in domains such as gene expression microarray data is an onerous task. We propose Backward-Chaining Rule Induction (BCRI) as a semi-supervised mechanism for b...
详细信息
暂无评论