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Search Results: 1 - 10 of 185 matches for " Fethi Tlili "
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ASIP Solution for Implementation of H.264 Multi Resolution Motion Estimation  [PDF]
Fethi Tlili, Akram Ghorbel
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2010, DOI: 10.4236/ijcns.2010.35060
Abstract: Motion estimation is the most important module in H.264 video encoding algorithm since it offer the best compression ratio compared to intra prediction and entropy encoding. However, using the allowed features for inter prediction such as variable block size matching, multi-reference frames and fractional pel search needs a lot of computation cycles. For this purpose, we propose in this paper an Application Specific Instruction-set Processor (ASIP) solution for implementing inter prediction. An exhaustive full and fractional pel combined with variable block size matching search are used. The solution, implemented in FPGA, offers both performance and flexibility to the user to reconfigure the search algorithm.
Performance Evaluation and Analysis of Switching Algorithms in MIMO-OFDM System with Ideal and Non-Ideal CSI  [PDF]
Yosra Mlayeh, Fethi Tlili, Fatma Rouissi, Ilham Ouachani, Adel Ghazel
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2010, DOI: 10.4236/ijcns.2010.312129
Abstract: In this paper we analyzed the bit error rate performance of a switching algorithm between spatial multiplex-ing and diversity for an OFDM MIMO system with ideal channel state information. The effect of channel estimation error was studied and we verified by simulations that the spatial multiplexing outperforms the switching algorithm. Given that the switching algorithm is based on the comparison of the channel matrix Demmel condition number to a threshold, its accuracy is compromised when channel estimation error in-creases. As a first intuitive solution, we proceeded to the adaptation of the threshold, but this didn’t lead to a pertinent improvement for the main reason that channel estimation errors did affect the MIMO techniques which use different constellation. Based on that, we proposed a new estimation technique that improved the bit error rate performance significantly.
Complexity Results for Wireless Sensor Network Scheduling  [PDF]
Fethi Jarray
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.24045
Abstract: We study the problem of scheduling multi sensors to visit and observe a group of sites at discrete time points over a planning horizon of given length. We show that scheduling under a given number of visits for each site and in each period is an NP-complete problem by providing equivalence with a problem in discrete tomography. We also give a polynomial time algorithm to schedule the sensors under a given number of visits in each period.
Multiplication and Translation Operators on the Fock Spaces for the q-Modified Bessel Function  [PDF]
Fethi Soltani
Advances in Pure Mathematics (APM) , 2011, DOI: 10.4236/apm.2011.14039
Abstract: We study the multiplication operator M by z2 and the q-Bessel operator Δq,αon a Hilbert spaces Fq,α of entire functions on the disk D( o, ) , 0<q<1 ; and we prove that these operators are adjoint-operators and continuous from Fq,α into itself. Next, we study a generalized translation operators on Fq,α .
Effect of Annealing on the Structural and Optical Properties of CuIn1–xAlxS2 thin Films  [PDF]
Fethi Smaili
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.29164
Abstract: The effects of annealing of CuIn1–xAlxS2thin films for different temperature, which were grown by thermal evaporation, were investigated through X-ray diffraction (XRD), energy dispersive X-ray analysis (EDS) and optical absorption measurements. Post growth was used to modify the structural and optical properties of the CIAS thin films. Then it realized in three different temperatures 250, 300 and 400℃. It is found that significant difference of the transparent films in function of annealing temperature. The FWHM in the X-ray diffraction pattern is found to decrease with an increase in annealing temperature indicating that the crystalline nature of the CIAS improves with increase in annealing temperature. The position of the (112) peak and other peaks in the X-ray diffraction pattern has been observed to shift to higher values of 2θ with the increase of gallium concentration. We demonstrate a significant enhancement of the interdiffusion in the dot thin film.
Toeplitz and Translation Operators on the q-Fock Spaces  [PDF]
Fethi Soltani
Advances in Pure Mathematics (APM) , 2011, DOI: 10.4236/apm.2011.16059
Abstract: In this work, we introduce a class of Hilbert spaces Fq of entire functions on the disk , , with reproducing kernel given by the q-exponential function eq(z); and we prove some properties concerning Toeplitz operators on this space. The definition and properties of the space extend naturally those of the well-known classical Fock space. Next, we study the multiplication operator Dq by and the q-Derivative operator on the Fock space Fq ; and we prove that these operators are adjoint-operators and continuous from this space into itself. Lastly, we study a generalized translation operators and a Weyl commutation relations on Fq .
Fock Spaces for the q-Dunkl Kernel  [PDF]
Fethi Soltani
Advances in Pure Mathematics (APM) , 2012, DOI: 10.4236/apm.2012.23023
Abstract: In this work, we introduce a class of Hilbert spaces of entire functions on the disk , 0<q<1 , with reproducing kernel given by the q-Dunkl kernel . The definition and properties of the space extend naturally those of the well-known classical Fock space. Next, we study the multiplication operator Q by z and the q-Dunkl operator on the Fock space ; and we prove that these operators are adjoint-operators and continuous from this space into itself.
Discourse and Intercultural Academic Rhetoric  [PDF]
Fethi Helal
Open Journal of Modern Linguistics (OJML) , 2013, DOI: 10.4236/ojml.2013.32020
Abstract: This paper is critically concerned with the recent attempts in contrastive rhetoric (CR) to interpret the linguistic and rhetorical differences found in the academic discourses produced by Anglophone and nonAnglophone academic and research writers. Framing this critique within a discourse view of language, culture and communication, this paper points to the need to go beyond such a priori, static, and too often vague concepts as language and culture as explanatory variables in intercultural (academic) rhetoric. Moreover, using data that examined the use of English in lingua franca contexts, the paper urges researchers in CR to consider the differences and misunderstandings arising from a history of socialization of academics to different discourse communities, varying assumptions of what constitutes appropriate academic genres, as well as the identities and meanings that are co-constructed in concrete and situated rhetorical action. It is believed that such a perspective on intercultural academic communication will not only help move the CR agenda forward, but will also lead to a better understanding of communicative and intercultural competence, and dialogue with the cultural academic “other”.
The Commutants of the Dunkl Operators on ε(Rd)  [PDF]
Mohamed Sifi, Fethi Soltani
Advances in Pure Mathematics (APM) , 2012, DOI: 10.4236/apm.2012.24035
Abstract: We consider the harmonic analysis associated with the Dunkl operators on Rd. We study the Dunkl mean-periodic functions on the space ε(Rd) (the space of C-functions). We characterize also the continuous linear mappings from ε(Rd) into itself which commute with the Dunkl operators.
Quantitative Analysis and Paleoasociations of the Aptian Urgonian Complex in the Ouenza Area (NE Algeria)
Mohamed Tlili,Abderahmane Toubal
Online Journal of Earth Sciences , 2012,
Abstract: The Aptian deposits of the easternmost part of the saharian Atlas, are represented by shallow carbonate platform limestones and the outer platform marly sediments. The application of statistical methods to the analysis of the microfacies by the factorial analysis of correspondances and the classification by the dynamic cluster method allows us to visualize the ecosequential evolution and the various biological associations.
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