Department of Computer Engineering and Computational Sciences

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  • 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, Habib
    A 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.
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    Dynamic energy based text-in-speech spectrum hiding using speech masking properties
    (Institute of Electrical and Electronics Engineers Inc., 2010) Djebbar, Fatiha ; Abed-Meraim, Karim ; Guerchi, Driss ; Hamam, Habib
    In this paper we present a new method for text-in-speech Fast Fourier Transform (FFT) based steganography. Our method exploits high energetic magnitude frequency components of speech spectrum to hide the secret text. The energy level of each magnitude component is evaluated, and considered only if it is high enough to embed secret data. A frequency maskmg threshold is then calculated for each energetic frequency magnitude component to decide where to embed the secret text. As a result, the initial energy of the cover speech spectrum is slightly modified and the dIstortion error is always kept under the mask. The objective and subjective evaluations show that introducing the energy-based frequency masking 0l?ens new frontiers in text-in-speech steganography since hIgher bit rate text embedding was achieved while obtaining a stego-speech with unnoticeable distortion. © 2010 IEEE.
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    Text hiding in high frequency components of speech spectrum
    (Institute of Electrical and Electronics Engineers Inc., 2010) Djebbar, Fatiha ; Guerchi, Driss ; Abed-Meraim, Karim ; Hamam, Habib
    Boosted by recent advances in the information technology field, methods applied to ensure privacy of digital data became very important in many real life applications. Efficient secrecy can be achieved at least in part, by implementing steganograhy techniques. In this paper, we propose a new technique to hide text in wideband speech in noise free environment. We opted to work in the Fourier transform domain and hide the digital information within high frequency components. More precisely, our method exploits selected locations from the high-frequencies part of the cover speech to hide the secret text. We better preserve with high fidelity the spectrum shape of the speech carrier by employing an embedding rather than a replacement operation on the secret text. Our simulation results show that this approach maintains the robustness of the cover signal and achieves a higher hiding capacity. © 2010 IEEE.
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    A hybrid cooperative service discovery scheme for mobile services in VANET
    (Institute of Electrical and Electronics Engineers Inc., 2011) Lakas, Abderrahmane ; Serhani, Mohamed Adel ; Boulmalf, Mohammed
    Discovering and accessing services while on the road is an important component in the architecture of future vehicular ad hoc networks, and for a successful deployment of services. Several studies have focused on the design and development of new routing and dissemination techniques that allow vehicles to communicate with each other and with road side units. However, detecting and reaching available services in a vehicular network remains problematic due to the amount of wireless traffic generated when service queries or advertisements are flooded across the network. In this paper, we propose a cooperative hybrid service discovery scheme for discovering services provided by mobile vehicles. This scheme is achieved through cooperating vehicles using store-and-forward approach and by sharing collected service information. We also propose to study the performance of the scheme by varying its degree of reactiveness and proactiveness. It is integrated with a caching mechanism which substantially improves the performance of the service discovery in terms of reduction of the traffic generated, and minimization of the response time while increasing the discovery success rate. © 2011 IEEE.
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    OMAC : a new access control architecture for overlay multicast communications
    (John Wiley & Sons, Inc., 2011) Mohamed, Emad Eldin ; Barka, Ezedin
    Multicast communications concern the transfer of data among multiple users. Multicast communications can be provided at the network layera-an example is IP multicasta-or at the application layer, also called overlay multicast. An important issue in multicast communications is to control how different usersa-senders, receivers, and delivery nodesa-access the transmitted data as well as the network resources. Many researchers have proposed solutions addressing access control in IP multicast. However, little attention has been paid to overlay multicast. In this paper, we investigate the access control issues in overlay multicast and present OMAC: a new solution to address these issues. OMAC provides access control for senders, receivers, and delivery nodes in overlay multicast. The proposed architecture, which is based on symmetric key cryptosystem, centralizes the authentication process in one server whereas it distributes the authorization process among the delivery nodes. Moreover, delivery nodes are utilized as a buffer zone between end systems and the authentication server, making it less exposed to malicious end systems. To evaluate our work, we have used simulation to compare the performance of OMAC against previous solutions. Results of the simulation show that OMAC outperforms previous multicast access control schemes. © 2010 John Wiley & Sons, Ltd.
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    Digital image steganography : an FFT Approach
    (Springer Nature Switzerland AG, 2012) Rabie, Tamer
    This work describes a framework for image hiding that exploits spatial domain color properties of natural images combined with spectral properties of the Fourier magnitude and phase of these images. The theory is that as long as the Fourier phase of an image is maintained intact, the overall appearance of an image remains specious if the Fourier magnitude of the image is slightly modified. This hypothesis leads to a data hiding technique that promises high fidelity, double the capacity of previous methods, higher security, and robustness to tampering. Experimental results are presented throughout the paper which demonstrate the effectiveness of this novel approach. © Springer-Verlag Berlin Heidelberg 2012.
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    Encoding spectral parameters using cache codebook
    (Springer Nature Switzerland AG, 2012) Guerchi, Driss ; Rekik, Siwar
    A new efficient approach to quantize the spectral line frequencies (LSF) in a coder is proposed. The use of the full search algorithm in the spectral parameters quantization causes high complexity and large hardware storage. Attempts to reduce the complexity have been performed by lowering the size of the LSF codebook. This option leads to a sub-optimal solution; the number of LSF vectors to be tested affects the performance of the speech coder. Cache codebook (CCB) technique enhances the search of the optimal quantized spectral information. In this technique the size of the main codebook is kept unchanged while the number of closest match searches is reduced. Unlike the classical quantizer design, the CCB method involves one main codebook embedding four disjoint sub-codebooks. The content of the CCB at any time is an exact reproduction of one of the four sub-codebooks. The search for the best match to an input vector is limited to the LSF vectors of the CCB. Some criteria are used to accept or reject this closest match. The CCB is updated whenever the decision is in favor of rejection. The cache codebook was successfully embedded in a CELP coder to enhance the quantization of the spectral information. The comparison simulation results show that the Codebook Caching approach yields to comparable objective and subjective performance to that of the optimal full-search technique when using the same training and testing database. © Springer-Verlag Berlin Heidelberg 2012.
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    Leaker identification in multicast communication
    (Springer Nature Switzerland AG, 2012) Mohamed, Emad Eldin ; Guerchi, Driss
    Multicast is a communication mode in which data is exchanged among multiple end systems. An important concern in multicast communications is the protection of copyrights. While preventing copyright violations seems very difficult, tracing copyright violators (leaker identification) is more feasible and can be used as a deterrence alternative. In order to identify leakers in a multicast environment, every receiver should obtain a uniquely marked copy of the data. However, delivering unique copies from the sender to the receivers is inefficient. This paper investigates multicast leaker identification and introduces an efficient solution that is based on binary search tree. We introduce the notion of suspicious set that includes suspected end systems. When a leak is detected, all receivers are inserted in the suspicious set. Using a binary search, the suspicious set is refined successively until it includes only the leakers. An analytical study is conducted to evaluate the proposed solution. © Springer-Verlag Berlin Heidelberg 2012.
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    LPC-based narrowband speech steganography
    (Springer Nature Switzerland AG, 2012) Guerchi, Driss ; Mohamed, Emad Eldin
    This paper proposes a new speech steganography system for secure sound massages sharing. This system exploits the advancements in speech processing to hide efficiently secret speech in narrowband cover speech. Linear predictive coding is used to represent the secret speech with reduced number of parameters. These parameters are embedded in selective perceptually-irrelevant frequency locations of the cover speech. Objective and subjective measures show that the resulting stego speech, which contains the secret message, is indistinguishable from the cover speech. © Springer-Verlag Berlin Heidelberg 2012.
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    A lightweight middleware for an e-health WSN based system using Android technology
    (Institute of Electrical and Electronics Engineers Inc., 2012) Boulmalf, Mohammed ; Belgana, Ahmed ; Sadiki, Tayeb ; Hussein, Sara ; Aouam, Tarik ; Harroud, Hamid
    With the rapid development of Wireless Sensors Network (WSN) technology, together with its growing market due to the variety of applications in which this technology can be used, sensors are now available at very cheap prices, and relatively high quality. The medical field among other fields is one of the most promising fields in which sensors technology is undergoing great improvements. With the constant and continuing advances on the wireless sensor networks and applications, lots of medical applications that use sensors are emerging. Varying from pre-hospital, in-hospital applications to post-hospital and rehabilitation applications, sensors are used in a wide range of applications such as patient's drug administration to elderly remote supervision. With the lake of standardization, a framework that would govern the interaction between the applications and the network is a must to be capable of sensing, processing, and communicating vital health signs. In this research we proposed layered approach architecture for a lightweight portable middleware with the Android technology. Our system takes into consideration the design principles and issues related to medical applications. A prototype of the lightweight middleware for an e-Health WSN based System was designed and tested and we showed that the results are very promising. © 2012 IEEE.
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    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, Habib
    Hiding 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.
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    Speech steganography using wavelet and Fourier transforms
    (Springer Nature Switzerland AG, 2012) Rekik, Siwar ; Guerchi, Driss ; Selouani, Sid-Ahmed ; Hamam, Habib
    A 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.
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    A comparative analysis of BLE and 6LoWPAN for U-HealthCare applications
    (Institute of Electrical and Electronics Engineers Inc., 2013) Tabish, Rohan ; Mnaouer, Adel Ben ; Touati, Farid ; Ghaleb, Abdulaziz M.
    For decades, there exist a variety of low-power wireless technologies deployed for healthcare applications such as Zigbee/IEEE802.15.4, Bluetooth, ANT, NFC, IrDA. However, the recently announced Bluetooth Low Energy (BLE) technology claims to offer many new compelling features and is expected to get wide adoption by many mobile manufacturers around the world and hence be included in daily life mobile devices. Therefore, it is important to provide future adopters with a thorough yet insightful evaluation of this technology as contrasted to competing ones in the market today. In this paper, we present such evaluation from an experimental point of view as well as referring to technical specifications from manufacturers. The discussion is geared toward assessing the extent to which theses technologies can meet the stringent requirements for u-healthcare applicability. BLE and 6LoWPAN showed greater potentials for such applicability in terms of power demand, bit rate and latency. Nevertheless, BLE was found to be most robust to obstacles and was operable using single coin cell. © 2013 IEEE.
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    Towards u-health : an indoor 6LoWPAN based platform for real-time healthcare monitoring
    (Institute of Electrical and Electronics Engineers Inc., 2013) Touati, Farid ; Tabish, Rohan ; Mnaouer, Adel Ben
    Ubiquitous healthcare is the key to handle the challenges of the growing population around the world. A variety of u-healthcare systems have been developed using various short-range technologies and proprietary protocols which include Zigbee and bluetooth. With all these protocols, interoperability of smart devices remains a challenge. 6LoWPAN as an open standard has recently evolved to provide one common platform on the top of IEEE802.15.4 for low power devices and to mitigate this interoperability problem. In this paper, we present a novel 6LoWPAN based communication platform for next-generation u-healthcare system. The system integrates three nodes forwarding data to an edge router in order to provide real-time monitoring of the patient's ECG, temperature, and acceleration. A PC connected to the edge router acts as a two-directional Gateway between 6LoWPAN and internet. A new gateway application, listening to UDP packets from the 6LoWPAN nodes via the edge router along with any TCP client request from the internet, is developed. Thereby, any remote PC can connect to the gateway using TCP/IP by just connecting to the IP address and dedicated port of the gateway, fostering then ubiquity as well as Internet of Things. Nevertheless, the user can send instructions to any node where the application running on the gateway translates the command to a particular node. In our case, we used a Labview program to provide this connectivity. The whole system was tested successfully for different ECG rates using an ECG simulator. The received waveforms were found identical to those shown by a high-resolution scope wired to the ECG signals. © 2013 IEEE.
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    Establishing private social media networking platform for socio-political organizations (facilitating communities portals at Internet II)
    (IEEE Computer Society, 2013) Satti, Muhammad Manshad ; Satti, Mubbashar Manshad
    A Private Social Media Networking can be the foundation for a Social Media campaign that also includes Facebook's posts, Twitter's posts and e-mail messages. This branded website provides the members states or social political organizations with the ability to engage their, members or citizens and neighboring countries in a deeper, more meaningful conversation that will fully develop its public level relationship with other peer country - turning them from an ordinary relationship to closer friends (fans) and their advocates. The suggested private social media platform will have all of the functionality of facebook with the ability to create groups, chat rooms, conversation sub-sites for member countries and anything else they need. The private Social Media Networking platform for member states of Community will create a new type of social corridor. It has been widely realized that people seeks new and more meaningful ways to connect and engage with each other. Private Social Media Platform fills a gap in the current social spectrum by empowering and sharing conversations that is effortless but not automatic. In our initial research work, we shall present the best-of-class designers, developers and visionaries who will work together to help define the next generation needs by provisioning this platform. © 2013 IEEE.
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    Embedded gateway services for Internet of Things applications in ubiquitous healthcare
    (Institute of Electrical and Electronics Engineers Inc., 2014) Rasid, Mohd Fakhrin Ab ; Musa, Wan Mardiana Wan ; Kadir, Nurul Ashikin Abdul ; Noor, A. S. M. ; Touati, Faisal ; Mehmood, Waiser ; Khriji, Lazhar ; Al-Busaidi, Asma ; Mnaouer, Adel Ben
    The continuous advancement in computer and communication technologies has made personalized healthcare monitoring a rapidly growing area of interest. New features and services are envisaged, raising users' expectations in healthcare services. The emergence of Internet of Things brings people closer to connect the physical world to the Internet. In this paper, we present embedded services that are part of a ubiquitous healthcare system that allows automated and intelligent monitoring. The system uses IP connectivity and the Internet for end-to-end communication, from each 6LoWPAN sensor nodes to the web user interface on the Internet. The proposed algorithm in the Gateway performs multithreaded processing on the gathered medical signals for conversion to real data, feature extraction and wireless display. The user interface at the server allows users to access and view the medical data from mobile and portable devices. The ubiquitous system is exploring possibilities in connecting Internet with things and people for health services. © 2014 IEEE.
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    Renewable energy-harvested sensor systems for air quality monitoring
    (Institute of Electrical and Electronics Engineers Inc., 2014) Touati, Farid ; Legena, Claudio ; Galli, Alessio ; Crescini, Damiano ; Crescini, Paolo ; Mnaouer, Adel Ben
    Wireless sensor networks (WSNs) devoted to environmental monitoring has preponderantly assumed the adoption of a portable and limited energy source, (e.g. lithium, alkaline, NiMH batteries), to support the sensor functionalities. The usage of environmental resources as energy booster is now rising up as a workable energy source dedicated to embedded and wireless computing systems where manual replacement of hundreds or even thousands of batteries on a regular basis is not practical. Consequently, substantial research efforts have been spent on designing energy-efficient smart sensor nodes and networks to maximize the lifetime of WSNs. However, in air quality monitoring systems sensors are required to operate for much longer durations (like years or even decades) after they are deployed. Following the above approach this paper presents SENNO (SENsor NOde), a renewable energy-harvested sensor node that intelligently manages energy transfer for continuous operation without human intervention during air quality monitoring. This paper discusses the challenges of designing an autonomous system powered by ambient energy harvesting. Preliminary results show that, the presented approach could effectively report and trace air quality levels. © 2014 IEEE.
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    A 3G/WiFi-enabled 6LoWPAN-based U-healthcare system for ubiquitous real-time monitoring and data logging
    (IEEE Computer Society, 2014) Tabish, Rohan ; Ghaleb, Abdulaziz M. ; Hussein, Rima ; Touati, Farid ; Mnaouer, Adel Ben ; Khriji, Lazhar ; Rasid, Mohd Fadlee A.
    Ubiquitous healthcare (U-healthcare) systems are expected to offer flexible and resilient high-end technological solutions enabling remote monitoring of patients health status in real-time and provisioning of feedback and remote actions by healthcare providers. In this paper, we present a 6LowPAN based U-healthcare platform that contributes to the realization of the above expectation. The proposed system comprises two sensor nodes sending temperature data and ECG signals to a remote processing unit. These sensors are being assigned an IPv6 address to enable the Internet-of-Things (IoT) functionality. A 6LowPAN-enabled edge router, connected to a PC, is serving as a base station through a serial interface, to collect data from the sensor nodes. Furthermore, a program interfacing through a Serial-Line-Internet-Protocol (SLIP) and running on the PC provides a network interface that receives IPv6 packets from the edge router. The above system is enhanced by having the application save readings from the sensors into a file that can be downloaded by a remote server using a free Cloud service such as UbuntuOne. This enhancement makes the system robust against data loss especially for outdoor healthcare services, where the 3G/4G connectivity may get lost because of signal quality fluctuations. The system provided a proof of concept of successful remote U-healthcare monitoring illustrating the IoT functionality and involving 3G/4G connectivity while being enhanced by a cloud-based backup. © 2014 IEEE.
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    Feasibility of air quality monitoring systems based on environmental energy harvesting
    (Institute of Electrical and Electronics Engineers Inc., 2015) Touati, Farid ; Galli, Alessio ; Crescini, Damiano ; Crescini, Paolo ; Mnaouer, Adel Ben
    Capillary wireless sensor networks dedicated to air quality monitoring have provided essential information on hazardous air condition, generating early warnings to prevent danger situation for human health. The arising problem connected to capillary networks is the adoption of environmental energy as primary and/or unique energy source instead of the replacement of hundreds or even thousands of batteries on a regular basis that leads to high costs and practical problems of devices management. Aim of this paper is to presents a multiparametric sensor node for air quality monitoring, able to work without battery and human intervention, harvesting energy from the surrounding environment for perpetual operation. A complete autonomy system has been designed, experimental results of the harvest energy section and the budget allocation of the power consumption of the system are presented. Moreover the paper shows the experimental results of the studies conducted on the sensors section. A tailored calibration process for the sensors and the energy recovery section could effectively lead the system to trace the air quality levels in indoor and outdoor application, in a sort of 'set and forget' scenario. approach could effectively report and trace air quality levels. © 2015 IEEE.
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    Real-time DWT-based compression for wearable Electrocardiogram monitoring system
    (Institute of Electrical and Electronics Engineers Inc., 2015) Al-Busaidi, Asiya M. ; Khriji, Lazhar ; Touati, Farid ; Rasid, Mohd Fadlee A. ; Mnaouer, Adel Ben
    Compression of Electrocardiogram signal is important for digital Holters recording, signal archiving, transmission over communication channels and Telemedicine. This paper introduces an effective real-time compression scheme to overcome the limitation of payload size of the transmission channel. This scheme utilizes the Discrete Wavelet Transform (DWT), Bit-Field Preserving (BFP) and Running Length Encoding (RLE) methods which showed efficient compression results. The scheme dynamically checks if the compressed packets fit into the available payload. If not, the original signal will be divided into blocks and each block will be re-compressed again. The dynamic scheme was tested on large and small number of samples. The results show that a small block of 64, 128 or 256 samples will not affect the compression performance and no distortion occurred on the reconstructed signal. © 2015 IEEE.