Image processing using cellular neural networks based on multi-valued and universal binary neurons

Multi-valued and universal binary neurons (MVN and UBN) are the neural processing elements with the complex-valued weights and high functionality. It is possible to implement an arbitrary mapping described by partially defined multiple-valued function on the single MVN. An arbitrary mapping described by partially defined or fully defined Boolean function, which can be non-threshold, may be implemented on the single UBN. The quickly converging learning algorithms exist for both types of neurons. Such features of the MVN and UBN may be used for solving the different problems. One of the most successful applications of the MVN and UBN is their usage as basic neurons in the Cellular Neural Networks (CNN). It opens the new effective opportunities in nonlinear image filtering and its applications to noise reduction, edge detection and solving of the super resolution problem. A number of experimental results are presented to illustrate the performance of the proposed algorithms.An erratum to this article can be found at     

Information-Based Evaluation Criterion for Classifier's Performance

In the past few years many systems for learning decision rules from examples were developed. As different systems allow different types of answers when classifying new instances, it is difficult to appropriately evaluate the systems' classification power in comparison with other classification systems or in comparison with human experts. Classification accuracy is usually used as a measure of classification performance. This measure is, however, known to have several defects. A fair evaluation criterion should exclude the influence of the class probabilities which may enable a completely uninformed classifier to trivially achieve high classification accuracy. In this paper a method for evaluating the information score of a classifier's answers is proposed. It excludes the influence of prior probabilities, deals with various types of imperfect or probabilistic answers and can be used also for comparing the performance in different domains.     

Current operational amplifiers: Basic architecture,properties, exploitation and future

This review paper describes all major considerations of the design of current operational amplifiers (COAs). It is demonstrated, that the single-input, differential-output COA as the adjoint element to the differentialinput, single-output voltage operational amplifier (VOA) is employable in current processing circuits alike the VOAs in voltage processing circuits. On an example of a basic one-high-gain-stage current-operational-amplifier architecture the procedure and the strategy of the design is explained and the main first and second order properties of this device are described. The paper is concluded showing elementary approaches of the derivation of the exploitation of the COAs in current processing circuits interreciprocal to voltage processing circuits and discussing the considerations of the exploitation of the COAs in VLSI designs.     

Chromosome comparison between populations of the collared peccary, Tayassu tajacu, raised in captivity

The collared peccary (Tayassu tajacu) is widely distributed over the American continent, being found from the south of the USA to the north of Argentina. In Brazil, it is spread all over the country, being one of the potential species to be raised in captivity. Therefore, the cytogenetic techniques could be a potential tool for reproductive monitoring of animals raised in captivity, mainly when destined for commercial purposes. This study had the objective of determining the chromosome number of two populations raised in captivity and characterizing them by GTG banding. For this purpose, an analysis was made of mitotic metaphases obtained from lymphocyte cultures made from blood samples of 11 animals, six of which from the Northeast and five from the North of Brazil. The results of this analysis showed the same karyotype pattern for the species (2n=30 chromosomes and NF=48), besides corresponding to the South American pattern of the species, i.e., without a translocation between autosomes 1 and 8, chromosome X acrocentric, and no differences were found between the two populations studied. However, chromosomal polymorphisms were observed compared to data from the literature on populations from North and South America.     

Design of thermophoretic probe for precise particle sampling

We proposed a design methodology for improved thermophoretic probes that can sample particles with high spatial resolution. A bending vibration analysis for the instantaneous motion of a probe has been done together with direct observation of the probe motion and flow disturbance for systematic study of the effect of different designs on particle sampling. Direct observation of the motion of thermophoretic sampling probes revealed that the probe with a low stiffness would result in inaccurate particle sampling. Based on these, the thermophoretic sampling probe was modified to minimize probe vibration and flow disturbance and this modified design was confirmed to sample particles with higher spatial resolution than the original one by examining transmission electron microscope (TEM) images of particles collected in a flame.     

Response surface methodology applied for Orange II photocatalytic degradation in TiO2 aqueous suspensions

BACKGROUND: Heterogeneous photocatalysis is influenced by a number of parameters involving synergistic effects; hence, an experimental strategy design that considers interactions between the main variables is needed. The response surface methodology was applied for the investigation of photodegradation of 20 mg L^?1 Orange II in aqueous solutions and for optimization of color removal efficiency. Preliminary studies were performed to identify the parameters to be selected for optimization. RESULTS: The input variables considered for experimental design were: solution initial pH, oxidizing agent (H₂O₂) initial concentration and UV‐A irradiation time. The multivariate experimental design allowed the development of a quadratic response surface model to be used for the prediction of color removal efficiency over the full range of the experimental region. Under the optimum conditions established in the region of experimentation (pH = 6.9, [H₂O₂]₀ = 183 mg L^?1 and t = 32 min), a 100% color removal efficiency was obtained in experiments. CONCLUSIONS: It was found that the variables considered have important effects on color removal efficiency. The results demonstrate that the use of experimental design strategy is indispensable for successful investigation and adequate modeling of the process because the interdependence of the reaction parameters cannot be neglected. Copyright © 2008 Society of Chemical Industry     

FE3 EPR investigation of PLZT 1/65/35 and 8/65/35

X-band EPR spectra of PLZT 1/65/35 and PLZT 8/65/35 doped with 1% FE³⁺ were recorded at temperature range -175°C to 200°C. Three types of paramagnetic centers were found. Two of them are in strong axial and rhombic crystal field due to neighboring oxygen and lead vacancies. The other center has symmetry determined by polarization and oxygen octahedra tilt. EPR spectra of PLZT 8/65/35 are in agreement with its glassy behavior.     

Optimal control of nonlinear systems to given orbits

Using optimal control techniques we derive and demonstrate the use of an explicit single-step control method for directing a nonlinear system to a target orbit and keeping it there. We require that control values remain near the uncontrolled settings. The full nonlinearity of the problem in state space variables is retained. The “one-step” of the control is typically a composition of known or learned maps over (a) the time required to learn the state, (b) the time to compute the control and (c) the time to apply the control. No special targeting is required, yet the time to control is quite rapid. Working with the dynamics of a well-studied nonlinear electrical circuit, we show how this method works efficiently and accurately in two situations: when the known circuit equations are used, and when control is performed only on a Poincaré section of the reconstructed phase space. In each case, because the control rule is known analytically, the control strategy is computationally efficient while retaining high accuracy. The target locations on the selected target trajectory at each control stage are determined dynamically by the initial conditions and the system dynamics, and the target trajectory is an approximation to an unstable periodic orbit of the uncontrolled system. A linear stability analysis shows that dissipation in the dynamical system is essential for reaching a controllable state.     

Word sense disambiguation for spam filtering

Spam has become a major issue in computer security because it is a channel for threats such as computer viruses, worms, and phishing. More than 86% of received e-mails are spam. Historical approaches to combating these messages, including simple techniques such as sender blacklisting or the use of e-mail signatures, are no longer completely reliable. Many current solutions feature machine-learning algorithms trained using statistical representations of the terms that most commonly appear in such e-mails. However, these methods are merely syntactic and are unable to account for the underlying semantics of terms within messages. In this paper, we explore the use of semantics in spam filtering by introducing a pre-processing step of Word Sense Disambiguation (WSD). Based upon this disambiguated representation, we apply several well-known machine-learning models and show that the proposed method can detect the internal semantics of spam messages.     

Verification of randomized consensus algorithms under round-rigid adversaries

International Journal on Software Tools for Technology Transfer - Randomized fault-tolerant distributed algorithms pose a number of challenges for automated verification: (i) parameterization in...