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Search Results: 1 - 10 of 166 matches for " Alima Damak Masmoudi "
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Pulse Mode Neural Network Implementation for Handwritten Digit Recognition
Alima Damak Masmoudi,Mohamed Krid,Dorra Sellami Masmoudi
Asian Journal of Information Technology , 2012,
Abstract: This study describes a new pulse mode artificial neural network (PNN) implementation based on floating point number format. For on-chip learning operations, the back-propagation algorithm is modified to have pulse mode operations for effective hardware implementation. By using floating point number system for synapse weight value representation, any function can be approximated by the network. The convergence rate of the learning and generalization capability is improved. The proposed network is applied for digit recognition application. The recognition approach is based on a series of features, which are at most independent of orientation and position. The most important featurea are based on Zernike moments. However, an exclusive use of Zernike moments in digit recognition increases tremendously the neural network size, since higher orders are needed to ensure best recognition rates. Moreover, given their geometrical invariance, Zernike moments give the same description to some different digits such as 6 and 9. Thus, we make use of other features based on structural descriptors witch are the terminating point number and the terminating location number which is orientation dependent. This features based presentation of the digits reduces the required Zernike order and the number of hidden layers and adds a great simplicity to the design, making possible the on-chip learning implementation for online operations. The proposed PNN is implemented on a Virtex II FPGA platform. Various experiments are carried on for design evaluation.
Prevalence and Impact of Anxiety and Depression on Type 2 Diabetes in Tunisian Patients over Sixty Years Old
Jawaher Masmoudi,Rahma Damak,Hela Zouari,Uta Ouali,Anouar Mechri,Nouri Zouari,Abdelaziz Jaoua
Depression Research and Treatment , 2013, DOI: 10.1155/2013/341782
Abstract: Objectives. To estimate the prevalence of anxiety and depression using the Hospital Anxiety and Depression Scale (HADS) in a population aged over sixty years with type 2 diabetes and to study the impact of anxiety and depression on glycemic balance and disease outcome. Results. The prevalence of anxiety and depression in the 62 subjects included in the study was, respectively, 40.3% and 22.6%. We found a relationship between these disorders and complicated diabetes. The subjects having an imperfectly balanced diabetes had a higher average anxiety score than those having a good glycemic control ( versus ; ). No relationship was found between diabetes balance and depression. Conclusion. Association between anxiety and depressive disorders and diabetes is frequent and worsens patients’ outcome, in terms of diabetes imbalance as well as in terms of diabetic complications. Our study shows that there is need for physicians to detect, confirm, and treat anxiety and depressive disorders in elderly diabetic patients. 1. Introduction In Tunisia, the proportion of individuals over 60 years is increasing, and it reached 9% in 2004 [1]. Diabetes is a major public health problem in Tunisia. Its prevalence has increased steadily and is currently about 9.9% [2]. Prevalence increases with age (11.9% for 60 years or older) [3, 4]. In addition, depression and anxiety, at the top of mental disorders list, mainly remain undiagnosed [5, 6], in particular in the elderly [7, 8] and consequently untreated [9]. Studying the link between diabetes and depressive as well as anxiety disorders in elderly subjects is useful for several reasons. First, diabetes as well as depression constitutes a major source of functional incapacity, and thus of loss of autonomy, in the elderly population [10]. Second, the association of these two pathologies in the same person worsens total health outcome [11] and quality of life [6, 12]. Finally, this association increases health care expenditures [11] and mortality [13]. The aim of this study is to estimate the prevalence of anxiety and depression in a population of elderly subjects aged over sixty suffering from type 2 diabetes and to study the impact of anxiety and depression on glycemic control and the evolution of the disease. 2. Methods We undertook a descriptive and analytical cross-sectional study on 62 patients who have consulted during September and October 2010 at the Department of Functional Explorations and Metabolic Diseases of Habib Bourguba University Hospital, Sfax, Tunisia. Recruitment was carried out on an ad hoc basis. The
Some Applications of the Non Propagation Theorem  [PDF]
Nassim Athmouni, Mondher Damak
Advances in Pure Mathematics (APM) , 2012, DOI: 10.4236/apm.2012.21006
Abstract: We use C*-algebras to determine non-propagation estimates for a certain class of generalized Schr?dinger operators acting on L2(x) , where X is a locally compact group. In particular, the Schr?dinger operators on trees are included.
Analysis of Teacher Perception’s of Students’ Participation in Physical Education Session in Sfax  [PDF]
Mouna Khecharem Damak, Mourad Bahloul
Creative Education (CE) , 2015, DOI: 10.4236/ce.2015.610107
Abstract: The concept of social representations is a polymorphous concept and is not always stable due to its interdisciplinary nature. In this paper, we will try to identify, on the one hand, the semantic universe of social representations of teachers and then identify the socio-cognitive and pedagogical processes which are at their origin, and on the other hand, tackle the problematic of the effects of social representations of students’ participation in physical education sessions as seen by Tunisian teachers. Actually, this study is part of a central question: “What does talking about social representations mean?”. As part of a convenience sampling, 200 novice and experienced physical education teachers voluntarily participated in this study. All the teachers work in secondary schools in the region of Sfax. The results of the study show that externals influence the relation-ship with the teacher, the relationship with others and pupils’ motivation plays a key role in students’ participation or non-participation during physical education.
High-Performance CMOS Current Mirrors: Application to Linear Voltage-to-Current Converter Used for Two-Stage Operational Amplifier  [PDF]
Radwene Laajimi, Mohamed Masmoudi
Circuits and Systems (CS) , 2012, DOI: 10.4236/cs.2012.34044
Abstract: This paper presents two schemes of high performance CMOS current mirror, one of them is used for operational tran-sconductance amplifier (OTA) in analog VLSI systems. The linearity, output impedance, bandwidth and accuracy are the most parameters to determine the performance of the current mirror. Here a comparison of two architectures based on same architecture of the amplifier is presented. This comparison includes: linearity, output impedance, bandwidth and accuracy. These two circuits are validated with simulation in technology AMS 0.35 μm. An operational amplifier based on the adapted current mirror is proposed. Its frequency analysis with large bandwidth is validated with the same technology.
Growth of Young Olive Trees: Water Requirements in Relation to Canopy and Root Development  [PDF]
Masmoudi-Charfi Chiraz
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.47163

The study was carried out in northTunisia(36.5?N, 10.2?E) in order to get a comprehensive view of the growth dynamic of young olive orchards (Olea europaea L.,). The experiment involved irrigated trees of cultivars Chétoui, Manzanille, Meski and Picholine, planted at 6 ×6 m2spacing. Tree height, shoot length and canopy, fruit and trunk diameters were monitored regularly after plantation on 12 trees per variety. Root development was analyzed on Chétoui trees, only. Growth patterns were established annually for each variety before proposing an average model for each growth parameter. Results showed that tree height, shoot length and trunk diameter grew following an S-shaped curve with maximum annual increases occurring on the 4th year for tree height and a year later for canopy. The minimum gain coincided with the highest fruit load year, indicating that competition for assimilates concerns also young trees. Average growth patterns for tree height and shoots showed sustained rates all over the growing season with seven distinct periods of growth. Rapid growth occurred in April, July, and September, with similar growth trends observed for productive and less productive cultivars. However, the studied varieties behaved differently. Picholine cv., provided the most important increases and was the best water user. Results also showed that most roots were confined to the top soil layers and developed nearby the trunks. High root densities and important water depletion were observed in this area and thus, water and fertilizers should be supplied for young trees at these depths and distances from trunks. Root and canopy development were highly correlated (r = 0.94) and interfered with fruit growth. When trees set their first productions, the root-canopy ratio approximated the unit. An optimum ratio between root length and leaf area was found (2.3 km·m?2) for the 6-year-old tree, indicating good equilibrium

The Effectiveness of the ECB Announcement Channel  [PDF]
Ahmed Hachicha, Afif Masmoudi
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.56097

Empirical study on the factors that induce jumps in interest rates in the euro area is still missing. In this paper, maximum likelihood estimates of I-distribution parameters are extracted using as a first step, an original linear model. According to the contribution of ([1] [2]) in the case of developing a class of Poisson-Gaussian model, we try to enhance the predictive power of this model by distinguishing between a pure Gaussian and Poisson-Gaussian distributions. Such an empirical tool permits to optimizing results through a comparative analysis dealing with the fluctuation of the Euro-interbank offered rate and its statistical descriptive behaviour. The analytical and empirical methods try to evaluate the behavioural success of the ECB intervention in setting interest rates for different maturities. Jumps in euribor interest rate can mainly be linked to surprise decisions of the European Central Bank, and the too frequent meetings of the ECB before November 2001. Despite this special event that leads to a certain lack of predictability, other few day-of-week effects are modelled to prove eventual evidence of bond market overreaction. Empirical results prove that Mondays and Wednesdays are the preponderant days. Regarding monetary policy, negative surprises induce larger jumps than positive ones.

Margin Parameter Variation for an Adaptive Observer to a Class of Systems
Elleuch Dorsaf, Damak Tarak
International Journal of Engineering , 2011,
Abstract: In this paper, adaptive observer robustness is studies. The adaptive observer is proposed to anonlinear system linearized by output injected for variable structure systems. Despites, theadaptive observer is suggesting to supply the parameter variation but it isn't usually verified.Unfortunately, the parameter uncertainty impact state convergence. For that a margin parametervariation is determined which the convergence of the state is guaranty. Simulation results showthat the adaptive observer is robust only in the definite parameter margin variation.
On the essential spectra of matrix operators and applications
Mondher Damak,Aref Jeribi
Electronic Journal of Differential Equations , 2007,
Abstract: In this paper, we investigate the essential spectra of some matrix operators on Banach spaces. The results obtained are used for describing the essential spectra of differential operators.
C-cross products and a generalized mechanical N-body problem
Mondher Damak,Vladimir Georgescu
Electronic Journal of Differential Equations , 2000,
Abstract: For each finite dimensional real vector space X we construct a C*-algebra A graded by the lattice of all subspaces of X and we compute its quotient with respect to the algebra of compact operators. This allows one to describe the essential spectrum and to prove the Mourre estimate for the self-adjoint operators affiliated to A.
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