Higher Institute of Applied Science and Technology

Damascus, United States

Higher Institute of Applied Science and Technology

Damascus, United States
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Hamrita M.E.,Higher Institute of Applied science and Technology | Mabrouk A.B.,University of Monastir
International Journal of Wavelets, Multiresolution and Information Processing | Year: 2011

Scaling laws and generally self-similar structures are now well known facts in financial time series. Furthermore, these signals are characterized by the presence of stochastic behavior allowing their analysis with pure functional methods being incomplete. In the present paper, some existing models are reviewed and modified, based on wavelet theory and self-similarity, to recover multi-scaling cases for approximating financial signals. The resulting models are then tested on some empirical examples and analyzed for error estimates. © 2011 World Scientific Publishing Company.


Baher Safa Hanbali S.,Higher Institute of Applied science and Technology | Kastantin R.,Higher Institute of Applied science and Technology
International Journal of Electronics and Telecommunications | Year: 2017

the well-known range-Doppler coupling property of the LFM (Linear Frequency Modulation) pulse compression radar makes it more vulnerable to repeater jammer that shifts radar signal in the frequency domain before retransmitting it back to the radar. The repeater jammer, in this case, benefits from the pulse compression processing gain of the radar receiver, and generates many false targets that appear before and after the true target. Therefore, the radar cannot distinguish between the true target and the false ones. In this paper, we present a new technique to counter frequency shifting repeater jammers. The proposed technique is based on introducing a small change in the sweep bandwidth of LFM waveform. The effectiveness of the proposed technique is justified by mathematical analysis and demonstrated by simulation. © by S. Baher Safa Hanbali 2017.


Sghaier A.,University of Monastir | Zeghid M.,Higher Institute of Applied science and Technology | Massoud C.,University of Monastir | MacHhout M.,University of Monastir
2016 7th International Conference on Sciences of Electronics, Technologies of Information and Telecommunications, SETIT 2016 | Year: 2017

Arithmetic in GF(2n) finite fields in asymmetric cryptography is the key of an efficient cryptosystems implementation. Thus, cryptosystems based on algebraic curves such as Hyper/Elliptic curves (ECC,HECC) and Pairings need a big number of arithmetic operations. They required several GF(2n) inversions and multiplications which are the most time and area consuming operations. This paper describes a hardware architecture for computing both modular multiplication and modular inversion in GF(2n) finite fields, based on a Modified Serial Multiplication/Inversion (MSMI) algorithm. The algorithm is suitable for both hardware implementations and software implementations. The proposed design performs 8-bits, 16-bits, 32-bits or 64-bits modular multiplication or inversion. Our design was modeled using VHDL and implemented in the Xilinx FPGAs Virtex6. Implementation results prove that our MSMI uses only 219 FPGA slices, it achieves a maximum frequency of 150 MHz and it computes 163-bits modular multiplication in 4.21 μ secs. © 2016 IEEE.


Hanbali S.B.S.,Higher Institute of Applied science and Technology | Kastantin R.,Higher Institute of Applied science and Technology
International Journal of Microwave and Wireless Technologies | Year: 2017

Self-protection deceptive jammers create at the radar receiver output multiple-false targets that are impossible to isolate in both time and frequency domains. In this paper, we introduce a novel technique based on fractional Fourier transform (FrFT) to discriminate between the true target echo and those false targets in the case of frequency-shifting jammers. In fact, we exploit the capability of the FrFT to resolve, in a matched manner, spectra that are overlapping in time and frequency. This is a property that cannot be achieved using a standard matched filter. The theoretical analysis of this technique is presented and its effectiveness is verified by simulation. Copyright © Cambridge University Press and the European Microwave Association 2017


Nejlaoui M.,University of Monastir | Houidi A.,Higher Institute of Applied science and Technology | Affi Z.,University of Monastir | Romdhane L.,American University of Sharjah
Comptes Rendus - Mecanique | Year: 2016

This paper deals with the robust safety design optimization of a rail vehicle system moving in short radius curved tracks. A combined multi-objective imperialist competitive algorithm and Monte Carlo method is developed and used for the robust multi-objective optimization of the rail vehicle system. This robust optimization of rail vehicle safety considers simultaneously the derailment angle and its standard deviation where the design parameters uncertainties are considered. The obtained results showed that the robust design reduces significantly the sensitivity of the rail vehicle safety to the design parameters uncertainties compared to the determinist one and to the literature results. © 2017 Académie des sciences.


Sghaier S.,University of Monastir | Souani C.,Higher Institute of Applied science and Technology | Faeidh H.,Higher Institute of Applied science and Technology | Besbes K.,University of Monastir
Proceedings - 2016 Global Summit on Computer and Information Technology, GSCIT 2016 | Year: 2017

In this paper we propose a new technique to detect and extract any part that we need from a 3D face. The regions of interest of our approach are the eyes and the nose. Moreover, we are interested in the extraction of the salient landmarks in 3D face. Therefore, in this paper a new method is proposed to detect the nose tip and eye corners from a three-dimensional face range image. Our original technique allows fully automated processing, treating incomplete and noisy input data, and automatically rejecting non-facial areas. Besides, it is robust against holes in 3D image and insensitive to facial expressions. Besides, it is stable against translation and rotation of the face, and it is suitable for different resolutions of images. All the experiments have been performed on the GAVAB and FRAV 3D databases. After applying the proposed method to the 3D face, experimental results show that it is comparable to state-of-the-art methods in terms of its accuracy and flexibility. © 2016 IEEE.


Hanbali S.B.S.,Higher Institute of Applied science and Technology | Kastantin R.,Higher Institute of Applied science and Technology
International Journal of Microwave and Wireless Technologies | Year: 2017

The well-known range-Doppler coupling property of the chirp radar makes it more vulnerable to different types of deceptive repeater jammers that benefit from the pulse compression processing gain of the radar-matched filter. These jammers generate many false targets that appear before and after the true target. Therefore, the radar cannot distinguish the true target from the false ones. This paper reviews different self-protection repeater jammers and presents their pros and cons, in order to provide a reference for the study of jamming/anti-jamming methods. Copyright © Cambridge University Press and the European Microwave Association 2017


Gabsi S.,University of Monastir | Sghaier A.,University of Monastir | Zeghid M.,Higher Institute of Applied science and Technology | Machhout M.,University of Monastir
IPAS 2016 - 2nd International Image Processing, Applications and Systems Conference | Year: 2017

Pairing-based cryptography has got a lot of attention the last years, since the proposition of the tripartite key exchange. The best type of pairing is optimal ate pairing over Barreto-Naehrig curves which are based on two steps: Miller Loop and final exponentiation. Most of the researches were done for the Miller Loop. In this paper, we present the different methods for computing the hard part of the final exponentiation of optimal ate pairings based on a hard mathematical study. Using a comparative study based on the temporary number and memory resources, we will choose the best method to be then implemented in Matlab Software. Thus, the best one is Devigili et al. method presenting a reduced complexity and required number of registers. © 2016 IEEE.


Massoud C.,University of Monastir | Sghaier A.,University of Monastir | Zeghid M.,Higher Institute of Applied science and Technology | Machhout M.,University of Monastir
IPAS 2016 - 2nd International Image Processing, Applications and Systems Conference | Year: 2017

Recently, a lot of progress has been made in the implementation of asymmetric cryptography such that RSA or ECC (Elliptic Curve Cryptography) in both hardware and software. The Residue Number Systems (RNS) offer, many features make it very useful in cryptographic applications. Since the modular multiplication is the main operation, in this paper, we describe a Montgomery modular multiplication algorithm based on RNS. Then we implemented our design in TM i3 CPU, it computed the modular multiplication in only 9 ms (latency) and achieving maximum throughput of 528. © 2016 IEEE.


Saadaoui F.,Higher Institute of Applied science and Technology | Rabbouch H.,National School in Computer Science
Expert Systems with Applications | Year: 2014

The paper proposes a parsimonious nonlinear framework for modeling bivariate stochastic processes. The method is a vector autoregressive-like approach equipped with a wavelet-based feedforward neural network, allowing practitioners dealing with extremely random two-dimensional information to make predictions and plan their future more and more precisely. Artificial Neural Networks (ANN) are recognized as powerful computing devices and universal approximators that proved valuable for a wide range of univariate time series problems. We expand their coverage to handle nonlinear bivariate data. Wavelet techniques are used to strengthen the procedure, since they allow to break up processes information into a finite number of sub-signals, and subsequently extract microscopic patterns in both time and frequency fields. The proposed model can be very valuable especially when modeling nonlinear econophysical systems with high extent of volatility. © 2014 Elsevier Ltd. All rights reserved.

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