Search results for "Pattern"

Dissimilarity Measures for the Identification of Earthquake Focal Mechanisms

2013

This work presents a study about dissimilarity measures for seismic signals, and their relation to clustering in the particular problem of the identification of earthquake focal mechanisms, i.e. the physical phenomena which have generated an earthquake. Starting from the assumption that waveform similarity implies similarity in the focal parameters, important details about them can be determined by studying waveforms related to the wave field produced by earthquakes and recorded by a seismic network. Focal mechanisms identification is currently investigated by clustering of seismic events, using mainly cross-correlation dissimilarity in conjunction with hierarchical clustering algorithm. By…

Indexed Two-Dimensional String Matching

2016

Improving Harris corner selection strategy

2011

This study describes a corner selection strategy based on the Harris approach. Corners are usually defined as interest points for which intensity variation in the principal directions is locally maximised, as response from a filter given by the linear combination of the determinant and the trace of the autocorrelation matrix. The Harris corner detector, in its original definition, is only rotationally invariant, but scale-invariant and affine-covariant extensions have been developed. As one of the main drawbacks, corner detector performances are influenced by two user-given parameters: the linear combination coefficient and the response filter threshold. The main idea of the authors' approa…

Face Expression Recognition through Broken Symmetries

2008

Security systems, criminology, physical access control and man-machine interactions are examples of applications where recognition of human faces may be crucial. In the present paper a new signature, based on a measure of axial symmetry called DST, is proposed as a significant feature to analyze facial expressions. The measure of symmetry is an elaborate difference between the internal and external symmetry kernels of an object. The idea here is to use the evolution of the symmetry measure of a face over an ordered set of its sub-images. We claim that different evolutionary trends will represent different face expressions. The proposed signature has been tested on several face databases (ps…

Speeding up the Consensus Clustering methodology for microarray data analysis

2010

Abstract Background The inference of the number of clusters in a dataset, a fundamental problem in Statistics, Data Analysis and Classification, is usually addressed via internal validation measures. The stated problem is quite difficult, in particular for microarrays, since the inferred prediction must be sensible enough to capture the inherent biological structure in a dataset, e.g., functionally related genes. Despite the rich literature present in that area, the identification of an internal validation measure that is both fast and precise has proved to be elusive. In order to partially fill this gap, we propose a speed-up of Consensus (Consensus Clustering), a methodology whose purpose…

Reliability and Fabrication of Molds for Nanoimprinting

2010

During the last decade there has been a growing attention to nanoscaled materials and to the related technologies to produce them. The problems to overcome in the manufacturing of these kinds of items increase dramatically on decreasing the dimension of the devices. In this sense, the scientific research has been strongly stimulated to try to improve and optimize all the critical issues. One of the most attractive fields in nanomanufacturing is related to nanoimprinting, i.e. to the possibility to transfer a nanoscaled pattern from a mold to another substrate. In this technology, among the others, there are two main critical steps: the preparation of a good mold and the use of a correct rel…

Control of a nonlinear continuous bioreactor with bifurcation by a type-2 fuzzy logic controller

2008

The object of this paper is the application of a type-2 fuzzy logic controller to a nonlinear system that presents bifurcations. A bifurcation can cause instability in the system or can create new working conditions which, although stable, are unacceptable. The only practical solution for an efficient control is the use of high performance controllers that take into account the uncertainties of the process. A type-2 fuzzy logic controller is tested by simulation on a nonlinear bioreactor system that is characterized by a transcritical bifurcation. Simulation results show the validity of the proposed controllers in preventing the system from reaching bifurcation and instable or undesirable s…

Coexistence between IEEE802.15.4 and IEEE802.11 through cross-technology signaling

2017

When different technologies use the same frequency bands in close proximity, the resulting interference typically results in performance degradation. Coexistence methods exist, but these are often technology specific and requiring technology specific interference detection methods. To remove the root cause of the performance degradation, devices should be able to negotiate medium access even when using different technologies. To this end, this paper proposes an architecture that allows crosstechnology medium access by means of a Time Division Multiple Access (TDMA) scheme. In order to achieve cross-technology synchronization, which is required for the TDMA solution, an energy pattern beacon…

Cross-Technology WiFi/ZigBee Communications: Dealing With Channel Insertions and Deletions

2016

In this letter, we show how cross-technology interference can be exploited to set up a low-rate bidirectional communication channel between heterogeneous WiFi and ZigBee networks. Because of the environment noise and receivers' implementation, the cross-technology channel can be severely affected by insertions and deletions of symbols, whose effects need to be taken into account by the coding scheme and communication protocol.

A New Preclinical Decision Support System Based on PET Radiomics: A Preliminary Study on the Evaluation of an Innovative 64Cu-Labeled Chelator in Mou…

2022

The 64Cu-labeled chelator was analyzed in vivo by positron emission tomography (PET) imaging to evaluate its biodistribution in a murine model at different acquisition times. For this purpose, nine 6-week-old female Balb/C nude strain mice underwent micro-PET imaging at three different time points after 64Cu-labeled chelator injection. Specifically, the mice were divided into group 1 (acquisition 1 h after [64Cu] chelator administration, n = 3 mice), group 2 (acquisition 4 h after [64Cu]chelator administration, n = 3 mice), and group 3 (acquisition 24 h after [64Cu] chelator administration, n = 3 mice). Successively, all PET studies were segmented by means of registration with a standard te…