Francisco Marcos Assis

Dr. Francisco Marcos Assis

Federal University of Campina Grande, Campina Grande, Paraíba, Brazil
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Research Focus & Metrics

Academic Career Length

31Years (1996-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2005 in International Journal of Quantum Information
Verified
Journal Article
Closed access
RMRex A. C. Medeiros
Rex A. C. Medeiros
FAFrancisco Marcos Assis
Francisco Marcos Assis

16 September 2021 in IEEE Transactions on Information Theory
Verified
Journal Article
Closed access
FPFrancisco Revson Fernandes Pereira
Francisco Revson Fernandes Pereira
RPRuud Pellikaan
Ruud Pellikaan
GGGiuliano Gadioli La Guardia
Giuliano Gadioli La Guardia
FAFrancisco Marcos Assis
Francisco Marcos Assis
Quantum error-correcting codes play the role of suppressing noise and decoherence in quantum systems by introducing redundancy. Some strategies can be used to improve the parameters of these codes. For example, entanglement can provide a way for quantum error-correcting codes to achieve higher rates than the one obtained by means of the traditional stabilizer formalism. Such codes are called entanglement-assisted quantum error-correcting (EAQEC) codes. In this paper, we utilize algebraic geometry codes to construct several families of EAQEC codes derived from the Euclidean and the Hermitian construction. Three families constructed here consist of codes whose quantum Singleton defect is equal to zero, one, or two. We also construct families of EAQEC codes with an encoding rate exceeding the quantum Gilbert-Varshamov bound. Additionally, asymptotically good towers of linear complementary dual codes are used to obtain asymptotically good families of EAQEC codes consuming maximal entanglement. Furthermore, a simple comparison with the quantum Gilbert-Varshamov bound demonstrates that, by utilizing the proposed construction, it is possible to generate an asymptotically family of EAQEC codes that exceeds this bound.

7 September 2020 in IET Signal Processing
Verified
Journal Article
Open access
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VVVinícius Vieira
Vinícius Vieira
RCRosângela Coelho
Rosângela Coelho
FAFrancisco Marcos Assis
Francisco Marcos Assis
This study presents a widespread analysis of affective vocal expression classification systems. In this study, the Hilbert–Huang–Hurst coefficient (HHHC) vector is proposed as a non‐linear vocal source feature to represent the emotional states according to their effects on the speech production mechanism. Affective states are highlighted by the empirical mode decomposition‐based method, which exploits the non‐stationarity of the acoustic variations. Hurst coefficients are then estimated from the decomposition modes to form the feature vector. Additionally, a vector of the index of non‐stationarity (INS) is introduced as dynamic information to the HHHC. The proposed feature vector is evaluated in speech emotion classification experiments with three databases in German and English languages. Three state‐of‐the‐art acoustic feature vectors are adopted as a baseline. The ‐integrated Gaussian mixture model ( ‐GMM) is also introduced for the emotion representation and classification. Its performance is compared to competing for stochastic and machine learning classifiers. Results demonstrate that the HHHC leads to significant classification improvement when compared to the baseline acoustic feature vectors. Moreover, results also show that the ‐GMM outperforms the competing classification methods. Finally, the complementarity aspects of HHHC and INS are also evaluated for the GeMAPS and eGeMAPS feature sets.

1 September 2009 in Computerized Medical Imaging and Graphics
Verified
Journal Article
Closed access
Wellington Pinheiro dos SantosWellington Pinheiro dos Santos
Wellington Pinheiro dos Santos
FAFrancisco Marcos Assis
Francisco Marcos Assis
RSR.E. Souza
R.E. Souza
PFP.B. Santos Filho
P.B. Santos Filho
Fernando BuarqueFernando Buarque
Fernando Buarque

1 August 2018 in Chaos: An Interdisciplinary Journal of Nonlinear Science
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Journal Article
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VVVinícius J. D. Vieira
Vinícius J. D. Vieira
SCSilvana C. Costa
Silvana C. Costa
SCSuzete L. N. Correia
Suzete L. N. Correia
LLLeonardo W. Lopes
Leonardo W. Lopes
WCWashington C. de A. Costa
Washington C. de A. Costa
FAFrancisco Marcos Assis
Francisco Marcos Assis
This work summarizes the research related to digital speech signal processing with recurrence quantification analysis (RQA) applied to voice disorder assessment. The main motivation for these studies is the fact that RQA is able to exploit the nonlinear dynamical nature of the speech production system. Due to the use of recurrence quantification measures to represent the behavior of speech signals, promising results were obtained in the characterization and classification of laryngeal pathologies and voice disorders. These contributions may help one to evaluate the usability and efficiency of RQA in vocal disorder assessment.

1 October 2011
Verified
Conference Paper
Closed access
CLChristiane Ferreira Lemos Lima
Christiane Ferreira Lemos Lima
FAFrancisco Marcos Assis
Francisco Marcos Assis
Cleonilson Protasio SouzaCleonilson Protasio Souza
Cleonilson Protasio Souza
The selection of optimal attributes from the set of all possible attributes of a network traffic is the first step to detect network intrusions. However, in order to optimize the effectiveness of intrusion detection procedure and decrease its complexity, it is still a challenge to select an optimal attribute subset. In this context, the primary problem of attribute selection is the criterion to evaluate a given attribute subset. In this work, it is presented an evaluation of Rényi and Tsallis entropy performances compared with Shannon entropy in order to obtain an optimal attribute subset that increase the capability of the Intrusion Detection System to classify the traffic as normal or as suspicious. In the experimental results, the detection accuracy and the false alarm rate almost remains the same or even becomes better depending on the attack category (e.g. in the DoS and Probing attack) when small attribute subsets are used compared when all attributes are used.