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Search Results: 1 - 10 of 138901 matches for " K Belhaj "
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A Markov Model for Human Resources Supply Forecast Dividing the HR System into Subgroups  [PDF]
Rachid Belhaj, Mohamed Tkiouat
Journal of Service Science and Management (JSSM) , 2013, DOI: 10.4236/jssm.2013.63023

Modeling the manpower management mainly concerns the prediction of future behavior of employees. The paper presents a predictive model of numbers of employees in a hierarchical dependent-time system of human resources, incorporating subsystems that each contains grades of the same family. The proposed model is motivated by the reality of staff development which confirms that the path evolution of each employee is usually in his family of grades. That is the reason of dividing the system into subgroups and the choice of the superdiagonal transition matrix.

Enhancement of Characteristics of Antenna Arrays Employing S-Shaped Resonators  [PDF]
Belgacem Aouadi, Jamel Belhaj Tahar
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2012, DOI: 10.4236/jemaa.2012.48045
Abstract: This paper illustrates a simple kind of tri-band printed G-shaped monopole antenna for Multiple-Input-Multiple-Output (MIMO) systems. The proposed antenna is used to achieve three operating frequencies, 2.45 GHz, 5.2 GHz and 8.2 GHz for wireless communications. To improve the isolation between the two radiating elements, we use left-handed materials composed of only S-shaped resonators to get negative refractive index at the three operating frequencies. When one layer of S-shaped resonators is employed, the antenna correlation, the diversity gain and the bandwidth are also enhanced. The simulated results are presented and evaluated with and without left-handed materials.
Evaluation of Solar Energy Potential for the Red Sea Project, Kingdom of Saudi Arabia  [PDF]
Ahmad Siouti, Atef Belhaj Ali
Natural Resources (NR) , 2019, DOI: 10.4236/nr.2019.104007
Abstract: There has been extreme utilization of petroleum derivatives in recent decades for the generation of electrical vitality, which is contaminating nature in a regularly expanding approach to respond to the exponential demand for electrical power. In light of the essential vision of Saudi Arabia’s government towards the fractional change of reliance on oil as a national wellspring of economy, there is consideration for dependence on resources available inside the country, especially the potentials of renewable sources as alternatives. Saudi Arabia appreciates its geographical advantage inside the sun-belt zone, which has the most impressive sun-situated radiation total on earth. It is a correlative ideal position to consider interest in this valuable asset, through which it can achieve its vision by virtue of its promising whole deal prospects. This study highlights an approach for creating sunlight-based maps that examines the intensity of sun-radiation and its viability to deliver power. The system is to record the measures of sunlight radiation from several allocated data acquisition sites over the study area and balance them with the standard count, and later, make a sun-map in light of the yield. Likewise, the study will register the rate of energy from sun-situated radiation for the area and make preliminary proposals for the achievement of this test.
L’usage politique de l’islam : l’universel au service d’un état. Le cas du Maroc The Political Use of Islam. The Universal in the Service of a State. The Moroccan Case
Abdessamad Belhaj
Recherches Sociologiques et Anthropologiques , 2011, DOI: 10.4000/rsa.575
Abstract: Lorsqu’il s’agit d’étudier les rapports des pays arabes à la mondialisation, il est nécessaire d’évoquer l’islam. En tant que facteur local, la symbolique islamique offre des ressources de légitimation au pouvoir. Le cas marocain illustre bien la manière dont les rapports existant entre le Makhzen et le répertoire religieux (Amīr al-Mu’minīne, la bayca , la chérifibilité… ) font de l’introduction de la modernité un simple espace virtuel et fonctionnel. L’émergence de la contestation islamiste participe à la consécration du répertoire traditionnel. D’autre part, depuis les trois dernières décennies, l’essor de l’islam mondialisé offre au Maroc des opportunités politiques à l’échelle mondiale. Ceci est observable au niveau du r le joué par le pays dans le cadre de la diplomatie islamique (OCI, ISESCO… ) ou au niveau de son positionnement dans l’islam européen. La gestion de l’interaction entre l’islam local et l’islam global, adaptée à la conjoncture internationale, assure le maintien au pouvoir du régime. One cannot study the relationships between Arab countries and globalization without taking Islam into account for it offers symbolic support to legitimizing local power. Morocco is a good example : the relations between the royal court (Makhzen) and Islamic features such as being the Commander of the Faithful or Sheriffhood make of modernity a mere virtual or functional sphere. Even the emergence of Islamic contestation contributes to the consecration of the traditional repertory. On the other hand, the rise of world Islam during the last thirty years has opened up political opportunities for Morocco on the international stage – for instance the agencies of Islamic diplomacy (OCI, ISESCO) or the quest for a new role in European Islam. By managing the interaction between the local and the global, the regime is able to keep itself in power.
Symétrie en Physique: Algèbres de Lie, Théorie des groupes et Représentations
Adil Belhaj
Physics , 2012,
Abstract: These notes form an introduction to Lie algebras and group theory. Most of the material can be found in many works by various authors given in the list of references. The reader is referred to such works for more detail.
On Geometric Engineering of Supersymmetric Gauge Theories
Adil Belhaj
Physics , 2000,
Abstract: We present the basic ideas of geometric engineering of the supersymmetric quantum field theories viewed as a low energy limit of type II strings and F-theory on singular Calabi Yau manifolds. We first give the main lines of toric geometry as it is a powerful technique to deal compact complex manifolds. Then we introduce mirror symmetry which plays a crucial role in the study of superstring dualities and finally we give elements on Calabi Yau singularities. After that we study the geometric engineering of N=2 supersymmetric gauge theories in six and four dimensions. Finally we make comments regarding $ N=1$ SYM in four dimensions.
Manifolds of G_2 Holonomy from N=4 Sigma Model
Adil Belhaj
Physics , 2002, DOI: 10.1088/0305-4470/35/42/302
Abstract: Using two dimensional (2D) N=4 sigma model, with $U(1)^r$ gauge symmetry, and introducing the ADE Cartan matrices as gauge matrix charges, we build " toric" hyper-Kahler eight real dimensional manifolds X_8. Dividing by one toric geometry circle action of X_8 manifolds, we present examples describing quotients $X_7={X_8\over U(1)}$ of G_2 holonomy. In particular, for the A_r Cartan matrix, the quotient space is a cone on a $ {S^2}$ bundle over r intersecting $\bf WCP^2_{(1,2,1)}$ projective spaces according to the A_r Dynkin diagram.
F-theory Duals of M-theory on G2 Manifolds from Mirror Symmetry
Adil Belhaj
Physics , 2002, DOI: 10.1088/0305-4470/36/14/319
Abstract: Using mirror pairs (M_3, W_3) in type II superstring compactifications on Calabi-Yau threefolds, we study, geometrically, F-theory duals of M-theory on seven manifolds with G_2 holonomy. We first develop a way for getting Landau Ginzburg (LG) Calabi-Yau threefols W_3, embedded in four complex dimensional toric varieties, mirror to sigma model on toric Calabi-Yau threefolds M_3. This method gives directly the right dimension without introducing non dynamical variables. Then, using toric geometry tools, we discuss the duality between M-theory on (S^1 x M_3)/Z_2 with G_2 holonomy and F-theory on elliptically fibered Calabi-Yau fourfolds with SU(4) holonomy, containing W_3 mirror manifolds. Illustrating examples are presented.
M-theory on G_2 manifolds and the method of (p,q) brane webs
Adil Belhaj
Physics , 2003, DOI: 10.1088/0305-4470/37/18/011
Abstract: Using a reformulation of the method of (p,q) webs, we study the four-dimensional N=1 quiver theories from M-theory on seven-dimensional manifolds with G_2 holonomy. We first construct such manifolds as U(1) quotients of eight-dimensional toric hyper-K\"ahler manifolds, using N=4 supersymmetric sigma models. We show that these geometries, in general, are given by real cones on \bf S^2 bundles over complex two-dimensional toric varieties, \cal \bf V^2= {{\bf C}^{r+2}/ {{\bf C}^*}^r}. Then we discuss the connection between the physics content of M-theory on such G_2 manifolds and the method of (p,q) webs. Motivated by a result of Acharya and Witten [hep-th/0109152], we reformulate the method of $(p,q)$ webs and reconsider the derivation of the gauge theories using toric geometry Mori vectors of \cal \bf V^2 and brane charge constraints. For {\bf WP^2}_{w_1,w_2, w_3}, we find that the gauge group is given by G=U(w_1n)\times U(w_2n)\times U(w_3n). This is required by the anomaly cancellation condition.
Mirror Symmetry and Landau Ginzburg Calabi-Yau Superpotentials in F-theory Compactifications
Adil Belhaj
Physics , 2001, DOI: 10.1088/0305-4470/35/4/309
Abstract: We study Landau Ginzburg (LG) theories mirror to 2D N=2 gauged linear sigma models on toric Calabi-Yau manifolds. We derive and solve new constraint equations for Landau Ginzburg elliptic Calabi-Yau superpotentials, depending on the physical data of dual linear sigma models. In Calabi-Yau threefolds case, we consider two examples. First, we give the mirror symmetry of the canonical line bundle over the Hirzebruch surfaces $\bf F_n$. Second, we find a special geometry with the affine so(8) Lie algebra toric data extending the geometry of elliptically fibered K3. This geometry leads to a pure N=1 six dimensional SO(8) gauge model from the F-theory compactification. For Calabi-Yau fourfolds, we give a new algebraic realization for ADE hypersurfaces.
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