Browsing by Author "Selouani, Sid-Ahmed"
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Item An autoregressive time delay neural network for speech steganalysis(Institute of Electrical and Electronics Engineers Inc., 2012) Rekik, Siwar; Selouani, Sid-Ahmed; Guerchi, Driss; Hamam, HabibHiding a secret message in speech signal, called steganography, is used to provide secure communication. The detection of hidden information in the transmitted message called steganalysis. The purpose of steganalysis is to identify the presence of embedded information, and does not actually attempt to extract or decode the hidden data. An automated method is required for detecting the existence of hidden message, since the huge amount of channeled information. However, the development and evaluation of steganalysis algorithms is a challenging task. In this paper we advocate a new steganalysis technique to classify a speech as having hidden information or not, using a powerful and sophisticated classifier called Autoregressive Time Delay Neural Network (AR-TDNN). The originality of this AR-TDNN is its quite ability to detect secret messages hidden with different steganographic algorithms, although the variation of detection rate depends on the particular hiding techniques and amount of hidden information. © 2012 IEEE.Item A cooperative and conversational virtual agent for M-commerce applications(Institute of Electrical and Electronics Engineers Inc., 2009) Rekik, Siwar; Selouani, Sid-Ahmed; Hamam, HabibThe aim of this paper is to present a cooperative approach to improve the Human-System spoken dialogues. The main advantage of the proposed approach is its ability to reach both of the user and the system goals more efficiently. The strategy that underlines our system is well adapted to the mobile applications since it involves effective spoken exchanges to reach the users' and system mutual goals. The proposed fram ework is built in order to use the Hidden Markov Models (HMMs) based CMU-Sphinx speech recognition engine f or mobile communications. To evaluate our approach a case-study in the M-trading field is considered. The analysis of the case study shows the efficiency ofour strategy in comparison with the usual ones. ©2009 IEEE.Item A highly robust audio hashing system using auditory-based front-end processing(Institute of Electrical and Electronics Engineers Inc., 2009) Salem, Abderraouf Ben; Selouani, Sid-Ahmed; Hamam, Habib; Caelen, JeanIn this paper, a robust perceptual audio hashing system is presented. A model of the human auditory system is used to extract robust features from the outputs of a non-linear filter bank that mimics the human basilar membrane. Experiments on various audio excerpts show that this new ear-based frontend processing provides very effective hash values. The proposed audio hashing system performs very satisfactorily in identification and it turned out very resilient to a large variety of severe audio attacks. ©2009 IEEE.Item A modal logic for the CARE usability properties for multimodal user interfaces(2008) Kamel, Nadjet; Selouani, Sid-Ahmed; Hamam, HabibThis paper proposes the use of model- checking technique to validate Multimodal User Interfaces (MUIs). It introduces a modal logic to express the CARE (Complementarity, Assignation, Redundancy and Equivalent) usability properties for MUIs : the LCARE modal logic. The syntax, the semantics and an axiom system for LCARE are defined. LCARE allows for the specification of the CARE usability properties that a MUI must satisfy. The model-checking technique is used to check whether a CARE property, expressed in LCARE, is satisfied by a MUI. For this purpose the user multimodal interactions are modeled by a transition system and the CARE properties are expressed in LCARE formulae. A satisfiability relation is defined. It checks whether a LCARE formula is satisfied by the transition system modeling the multimodal interactions. LCARE allows for the specification of all the CARE usability properties. An illustration is given for the Matis application (Multimodal Airline Travel Information System) as a case study.Item A model-checking approach for the verification of CARE usability properties for multimodal user interfaces(Praise Worthy Prize S.r.l., 2009-01) Kamel, Nadjet; Selouani, Sid-Ahmed; Hamam, HabibA model-checking-based approach is proposed to verify the CARE (Complementarity, Assignement, Redundancy and Equivalence) usability properties for Multimodal User Interfaces (MUIs). This approach reduces the states explosion problem which is the main inconvenience of the model-checking technique. For this, we propose to decompose the transition system describing the behaviours of the MUI into a set of transition systems, and we decompose the temporal logic formula, that specifies the CARE property, into a set of reachability property formulas. The decomposition is based on disabling a set of modalities in the system. The model-checking process of the CARE property is done through a set of stages. At each stage a reachability formula is checked on a MUI component transition system. The process is aborted if a reachability formula is not satisfied. This approach reduces the complexity of the CARE model-checking process. We illustrate this approach, using the SMV (Symbolic Model Verifier) model-checker, on a MUI of a mobile cell phone case study. © 2009 Praise Worthy Prize S.r.l. - All rights reserved.Item MULTI-STREAM FRONT-END PROCESSING FOR ROBUST DISTRIBUTED SPEECH RECOGNITION(International Society for Computers and Their Applications (ISCA), 2008) Kifaya, Kaoukeb; Nourozian, Atta; Selouani, Sid-Ahmed; Hamam, Habib; Tolba, HeshamItem On performing speech steganalysis using speech recognition and perceptual criteria(2010) Rekik, Siwar; Guerchi, Driss; Selouani, Sid-Ahmed; Hamam, HabibItem Speech steganography using wavelet and Fourier transforms(Springer Nature Switzerland AG, 2012) Rekik, Siwar; Guerchi, Driss; Selouani, Sid-Ahmed; Hamam, HabibA new method to secure speech communication using the discrete wavelet transforms (DWT) and the fast Fourier transform is presented in this article. In the first phase of the hiding technique, we separate the speech high-frequency components from the low-frequency components using the DWT. In a second phase, we exploit the low-pass spectral proprieties of the speech spectrum to hide another secret speech signal in the low-amplitude high-frequency regions of the cover speech signal. The proposed method allows hiding a large amount of secret information while rendering the steganalysis more complex. Experimental results prove the efficiency of the proposed hiding technique since the stego signals are perceptually indistinguishable from the equivalent cover signal, while being able to recover the secret speech message with slight degradation in the quality. © 2012 Rekik et al.; licensee Springer.