Viewer's Affective Feedback for Video Summarization

Dammak, Majdi,Wali, Ali,Alimi, Adel M. Korea Information Processing Society 2015 Journal of information processing systems Vol.11 No.1

For different reasons, many viewers like to watch a summary of films without having to waste their time. Traditionally, video film was analyzed manually to provide a summary of it, but this costs an important amount of work time. Therefore, it has become urgent to propose a tool for the automatic video summarization job. The automatic video summarization aims at extracting all of the important moments in which viewers might be interested. All summarization criteria can differ from one video to another. This paper presents how the emotional dimensions issued from real viewers can be used as an important input for computing which part is the most interesting in the total time of a film. Our results, which are based on lab experiments that were carried out, are significant and promising.

Viewer`s Affective Feedback for Video Summarization

( Majdi Dammak ),( Ali Wali ),( Adel M Alimi ) 한국정보처리학회 2015 Journal of information processing systems Vol.11 No.1

For different reasons, many viewers like to watch a summary of films without having to waste their time. Traditionally, video film was analyzed manually to provide a summary of it, but this costs an important amount of work time. Therefore, it has become urgent to propose a tool for the automatic video summarization job. The automatic video summarization aims at extracting all of the important moments in which viewers might be interested. All summarization criteria can differ from one video to another. This paper presents how the emotional dimensions issued from real viewers can be used as an important input for computing which part is the most interesting in the total time of a film. Our results, which are based on lab experiments that were carried out, are significant and promising.

Threshold Effects on the Relationship Between Inflation Rate and Economic Growth in Tunisia

Thouraya Boujelbène Dammak,Kamel Helali 한국국제경제학회 2017 International Economic Journal Vol.31 No.2

Using an econometric technique suggested by Hansen [(2001). The new econometrics of structural change: Dating breaks in U.S. Labor productivity. Journal of Economic Perspectives, 15, 117–128], this paper studies the inflation–economic growth nexus in the case of Tunisia for the 1993-01–2012-11 period. The results show that there is one inflation threshold value that does exist for Tunisia. This evidence strongly sustains the view that the relationship between inflation rate and economic growth is non-linear. The estimated threshold regression model suggests that a threshold value of inflation rate below 3.48% fosters economic growth. In addition, above this threshold level, there is a statistically significant negative relationship between inflation rate and economic growth. These results have important implications to policy-makers who should pay attention to the inflation phenomena. Therefore, a new policy that takes into account such a threshold should be set up.

An extended finite element method for modeling elastoplastic FGM plate-shell type structures

Hanen Jrad,Jamel Mars,Mondher Wali,Fakhreddine Dammak 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.3

In this paper, an extended finite element method is proposed to analyze both geometric and material non-linear behavior of general Functionally Graded Material (FGM) plate-shell type structures. A user defined subroutine (UMAT) is developed and implemented in Abaqus/Standard to study the elastoplastic behavior of the ceramic particle-reinforced metal-matrix FGM plates-shells. The standard quadrilateral 4-nodes shell element with three rotational and three translational degrees of freedom per node, S4, is extended in the present study, to deal with elasto-plastic analysis of geometrically non-linear FGM plate-shell structures. The elastoplastic material properties are assumed to vary smoothly through the thickness of the plate-shell type structures. The nonlinear approach is based on Mori-Tanaka model to underline micromechanics and locally determine the effective FGM properties and self-consistent method of Suquet for the homogenization of the stress-field. The elasto-plastic behavior of the ceramic/metal FGM is assumed to follow Ludwik hardening law. An incremental formulation of the elasto-plastic constitutive relation is developed to predict the tangent operator. In order to to highlight the effectiveness and the accuracy of the present finite element procedure, numerical examples of geometrically non-linear elastoplastic functionally graded plates and shells are presented. The effects of the geometrical parameters and the volume fraction index on nonlinear responses are performed.

Geometrically nonlinear meshfree analysis of 3D-shell structures based on the double directors shell theory with finite rotations

Hana Mellouli,Hanen Jrad,Monther Wali,Fakhreddine Dammak 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.31 No.4

In this paper, a geometrically nonlinear meshfree analysis of 3D various forms of shell structures using the double director shell theory with finite rotations is proposed. This theory is introduced in the present method to remove the shear correction factor and to improve the accuracy of transverse shear stresses with the consideration of rotational degrees of freedom.The present meshfree method is based on the radial point interpolation method (RPIM) which is employed for the construction of shape functions for a set of nodes distributed in a problem domain. Discrete system of geometrically nonlinear equilibrium equations solved with the Newton-Raphson method is obtained by incorporating these interpolations into the weak form. The accuracy of the proposed method is examined by comparing the present results with the accurate ones available in the literature and good agreements are found.

Optimum shape design of incompressible hyperelastic structures with analytical sensitivity analysis

A. Jarraya,M. Wali,F. Dammak 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.8

This paper is focused on the structural shape optimization of incompressible hyperelastic structures. An analytical sensitivity is developedfor the rubber like materials. The whole shape optimization process is carried out by coupling a closed geometric shape in R2 withboundaries, defined by B-splines curves, exact sensitivity analysis and mathematical programming method (S.Q.P: sequential quadraticprogramming). Design variables are the control points coordinate. The objective function is to minimize Von-Mises stress, constrained tothe total material volume of the structure remains constant. In order to validate the exact Jacobian method, the sensitivity calculation isperformed: numerically by an efficient finite difference scheme and by the exact Jacobian method. Numerical optimization examples arepresented for elastic and hyperelastic materials using the proposed method.

An extended finite element method for modeling elastoplastic FGM plate-shell type structures

Jrad, Hanen,Mars, Jamel,Wali, Mondher,Dammak, Fakhreddine Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.3

In this paper, an extended finite element method is proposed to analyze both geometric and material non-linear behavior of general Functionally Graded Material (FGM) plate-shell type structures. A user defined subroutine (UMAT) is developed and implemented in Abaqus/Standard to study the elastoplastic behavior of the ceramic particle-reinforced metal-matrix FGM plates-shells. The standard quadrilateral 4-nodes shell element with three rotational and three translational degrees of freedom per node, S4, is extended in the present study, to deal with elasto-plastic analysis of geometrically non-linear FGM plate-shell structures. The elastoplastic material properties are assumed to vary smoothly through the thickness of the plate-shell type structures. The nonlinear approach is based on Mori-Tanaka model to underline micromechanics and locally determine the effective FGM properties and self-consistent method of Suquet for the homogenization of the stress-field. The elasto-plastic behavior of the ceramic/metal FGM is assumed to follow Ludwik hardening law. An incremental formulation of the elasto-plastic constitutive relation is developed to predict the tangent operator. In order to to highlight the effectiveness and the accuracy of the present finite element procedure, numerical examples of geometrically non-linear elastoplastic functionally graded plates and shells are presented. The effects of the geometrical parameters and the volume fraction index on nonlinear responses are performed.

Trade-threshold Effect on Inflation in Tunisia: New Evidence Resulting from a Nonlinear Approach

Khoutem Ben Jedidia,Thouraya Boujelbene Dammak,Helali Kamel 한국국제경제학회 2019 International Economic Journal Vol.33 No.1

Trade openness is an important determinant of the inflation process. The effect of trade openness on inflation, however, is still an issue of debate at both theoretical and empirical levels. This study tried to provide a contribution to the literature by examining the relationship between inflation and trade openness in Tunisia over the period 1975Q1-2015Q4 using a nonlinear model. The originality of this study stems from the fact that it is the first investigation considering both the Residual-Based Tests for Cointegration in Models with the Regime Shifts and Threshold Regression model. The linear model confirms the existence of a positive relationship between inflation and trade in Tunisia. Yet, considering the nonlinear model, trade openness growth and Consumer Price Index (CPI) inflation growth show a statistically significant negative link as long as the trade openness evolution does not exceed the threshold. Nevertheless, if the trade openness growth is higher than the threshold, integrating the trade positively affects CPI inflation. Furthermore, a positive influence of Money supply growth on this type of inflation was noticed in Tunisia in all the considered regimes proving the effect of monetary factors on inflation level. Consequently, trade openness could be used to control inflation in Tunisia.

Buckling analysis of a laminated composite plate with delaminations using the enhanced assumed strain solid shell element

Abdessalem Hajlaoui,Abdessalem Jarraya,Imen Kallel-Kamoun,Fakhreddine Dammak 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.10

The paper deals with the validation of a recently proposed hexahedral solid-shell finite element in the buckling analysis of a laminated composite plate with delaminations. The object is to study the buckling behavior of structures with delaminations using the enhanced assumed strain (EAS) solid shell element with 5, 7 and 9 parameters. The EAS three-dimensional finite element formulation presented in this paper is free from shear locking and leads to accurate results for distorted element shapes. The developed FE model is used to study the effects of some parameters in the buckling load, such as the stacking sequences, delamination size, aspect ratio, width-to-thickness ratio. The feasibility of the proposed method is confirmed by numerical examples. Results show that using hexahedral solid-shell finite element in the buckling analysis is more efficient than using the enhanced solid finite element.