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Search Results: 1 - 10 of 139494 matches for " Abdelaziz. K. Hamada "
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Behavior Analysis in a learning Environment to Identify the Suitable Learning Style
Abdelaziz . K. Hamada,Magdy .Z. Rashad,Mohamed.G. Darwesh
International Journal of Computer Science & Information Technology , 2011,
Abstract: Personalized adaptive systems rely heavily on the learning style and the learner's behavior.Due to traditional teaching methods and high learner/teacher ratios, a teacher faces great obstacles inthe classroom. In these methods, teachers deliver the content and learners just receive it. Moreover,teachers can’t cope with the individual differences among learners. This weakness may be attributed tovarious reasons such as the high number of learners accommodated in each classroom and the lowteaching skills of the teacher himself/herself, Therefore, identifying learning styles is a critical step inunderstanding how to improve the learning process.This paper presented an automatic tool for identifying learning styles based on the Felder-Silvermanlearning style model in a learning environment using a social book marking website such aswww.tagme1.com .The proposed tool used the learners’ behaviour while they are browsing / exploring their favorite webpages in order to gather hints about their learning styles. Then the learning styles were calculated basedon the gathered indications from the learners' database.The results showed that the proposed tool recognition accuracy was 72% when we applied it on 25learners with low number of links per learner. Recognition accuracy increased to 86.66% when weapplied it on 15 learners with high number of links per learner.
From Learning Style of Webpage Content to Learner’s Learning Style
Mohamed.G. Darwesh,Magdy .Z. Rashad,Abdelaziz. K. Hamada
International Journal of Computer Science & Information Technology , 2012,
Abstract: Technology plays an important role in the development of students who can search for the conceptswhich they learn in the books on the Internet and find out more information on them. This will increasethe depth of their knowledge.According to some researches, students tend to be more active and more participative when technologyis being integrated in their lesson resulting to better comprehension and good performance.Using technology in the learning process can facilities automatic detection of the learner’s learningstyles which can help the learner to develop his coping strategies to compensate for his/her weaknesses,capitalize on his/her strengths, improve the quality of the learning process and make it more effective.This research presents an automatic tool for detecting learning styles in a learning environment byanalyzing the content of the learner’s favorite WebPages using social bookmarkingservices(www.tagme1.com) and shows that how actual behavior of the learners during the learningprocess can be used as an effective source for detecting their learning styles based on Felder-Silvermanlearning style model (FSLSM) .
Field Study on the Mycotoxin Binding Effects of Clay in Oreochromis niloticus Feeds and Their Impacts on the Health Status throughout the Culture Season
Mohamed Abdelaziz,Wael Anwar,Abeer Hamada abdelrazek
Interdisciplinary Bio Central , 2010,
Abstract: Total aflatoxin and ochratoxin were detected in 3 naturally contaminated fish feed samples using immune-affinity method. The results revealed that the average levels of aflatoxins in the 3 examined samples were (15, 22 and 12 μg / kg) respectively while the average levels of ochratoxins were (15, 6 and 6μg / kg).The levels of aflatoxins and ochratoxins after adding different doses of clay as a mycotoxin binder, revealed that the levels of aflatoxin in the treated samples after using clay at dose 2kg / ton detected as (2,1 and zero) respectively and levels of ochratoxins were 12, 2 and 2 respectively. The levels of aflatoxins in the treated samples after using clay at a dose 4kg / ton was (1, zero and zero) respectively, while the levels of ochratoxins were 1, zero and zero respectively. The results of determination of the effects of clay on the health status and performance of Oreochromis niloticus in comparing with a control group revealed that the survival rate in control group was 81% after the end of the culture season. The results also revealed that the survival rate in group 2 which received clay treated feed was 86%. The results of regular parasitological examination revealed the identification of trichodina as external protozoa in Oreochromis niloticus from both ponds but without manifestation of disease signs. The results of bacteriological examination revealed the identification of pseudomonas flouresence from some moribund Oreochromis niloticus.
Recursion Relations in Liouville Gravity coupled to Ising Model satisfying Fusion Rules
K. Hamada
Physics , 1994, DOI: 10.1103/PhysRevD.51.6959
Abstract: The recursion relations of 2D quantum gravity coupled to the Ising model discussed by the author previously are reexamined. We study the case in which the matter sector satisfies the fusion rules and only the primary operators inside the Kac table contribute. The theory involves unregularized divergences in some of correlators. We obtain the recursion relations which form a closed set among well-defined correlators on sphere, but they do not have a beautiful structure that the bosonized theory has and also give an inconsistent result when they include an ill-defined correlator with the divergence. We solve them and compute the several normalization independent ratios of the well-defined correlators, which agree with the matrix model results.
Vertex Operators for Super Yang-Mills and Multi D-Branes in Green-Schwarz Superstring
K. Hamada
Physics , 1996, DOI: 10.1016/S0550-3213(97)00221-6
Abstract: We study vertex operators for super Yang-Mills and multi D-branes in covariant form using Green-Schwarz formalism. We introduce the contact terms naturally and prove space-time supersymmetry and gauge invariance. The nonlinear realization of broken supersymmetry in the presence of D-branes is also discussed. The shift of fermionic coordinate \delta^{(-)}\Psi =\eta becomes exact symmetry of D-brane in the static gauge, where $\eta$ is a constant spinor in U(1) direction.
Quantum Theory of Dilaton Gravity in 1+1 Dimensions
K. Hamada
Physics , 1992, DOI: 10.1016/0370-2693(93)91340-S
Abstract: We discuss the quantum theory of 1+1 dimensional dilaton gravity, which is an interesting model with analogous features to the spherically symmetric gravitational systems in 3+1 dimensions. The functional measures over the metrics and the dilaton field are explicitly evaluated and the diffeomorphism invariance is completely fixed in conformal gauge by using the technique developed in the two dimensional quantum gravity. We argue the relations to the ADM formalism. The physical state conditions reduce to the usual Wheeler-DeWitt equations when the dilaton $\df^2 ~ (=\e^{-2\phi}) $ is large enough compared with $\kappa =(N-51/2)/12$, where $N $ is the number of matter fields. This corresponds to the large mass limit in the black hole geometry. A singularity appears at $\df^2 =\kappa (>0) $. The final stage of the black hole evaporation corresponds to the region $\df^2 \sim \kappa $, where the Liouville term becomes important, which just comes from the measure of the metrics. If $\kappa < 0 $, the singularity disappears.
Gravitational Collapse in 1+1 Dimensions and Quantum Gravity
K. Hamada
Physics , 1992,
Abstract: We investigate the quantum theory of 1+1 dimensional dilaton gravity, which is an interesting toy model of the black hole dynamics. The functional measures of gravity part are explicitly evaluated and derive the Wheeler-DeWitt like equations as physical state conditions. In ADM formalism the measures are very ambiguous, but in our formalism they are explicitly defined. Then the new features which are not seen in ADM formalism come out. A singularity appears at $\df^2 =\kappa (>0) $, where $\kappa =(N-51/2)/12 $ and $ N$ is the number of matter fields. At the final stage of the black hole evaporation, the Liouville term becomes important, which just comes from the measures of the fields. Behind the singularity the quantum mechanical region $\kappa > \df^2 >0 $ extends, where the sign of the kinetic term in the Wheeler-DeWitt like equation changes. If $\kappa <0 $, the singularity disappears. We briefly discuss the possibility of gravitational tunneling and the issue of the information loss. (Talk given at "YITP Workshop on Theories of Quantum Fields -Beyond Perturbation-", Kyoto, Japan, 14-17 July 1992. Some misleading arguments in the preprint UT-Komaba 92-7 entitled "Quamtum Theory of Dilaton Gravity in 1+1 Dimensions" are corrected. The several remarks on the quantization are included. The difference from the other quantum theory is clarified.
Extended Finite Element Modeling: Basic Review and Programming  [PDF]
Yazid Abdelaziz, K. Bendahane, A. Baraka
Engineering (ENG) , 2011, DOI: 10.4236/eng.2011.37085
Abstract: In this work, we have exposed a recent method for modeling crack growth without re-meshing. The main advantage of this method is its capability in modeling discontinuities independently, so the mesh is prepared without any considering the existence of discontinuities. The paper covers the formulation and implementation of XFEM, and discusses various aspects of the approach (enrichments functions, level set representation, numerical integration…). Numerical experiments show the effectiveness and robustness of the XFEM implementation.
Phytic Acid Exposure Alters AflatoxinB1-Induced Reproductive and Oxidative Toxicity in Albino Rats (Rattus norvegicus)
Abdelaziz S. Abu El-Saad,Hamada M. Mahmoud
Evidence-Based Complementary and Alternative Medicine , 2009, DOI: 10.1093/ecam/nem137
Abstract: The increased use of feed in Egypt's aquaculture and animal industries raises concerns about the possible presence of mycotoxins in feedstuffs. The use of alternative medicine, such as botanicals and nutritional supplements, has become popular with inflammatory cases. The present study aimed to testify the role played by phytic acid (IP6) in enhancing the reproductive and oxidative toxicity induced in aflatoxinB1 (AFB1) treated white male albino rats (Rattus norvegicus) throughout treatment and withdrawal periods. One hundred and twenty white male albino rats were grouped into four groups. Group 1, was injected with 300 μg kg−1 body wt of AFB1 once every 3 days for 15 days and left uninjected for another 15 days to study the withdrawal effect. Group 2, was injected with 300 μg kg−1 body wt of AFB1 once every 3 days for 15 days and treated simultaneously with IP6 daily for another 15 days. Group 3, was treated daily with IP6 (40 mg kg−1 body wt) for 15 days and with no treatment for other 15 days. Group 4, injected with equivalent volume of sterile phosphate buffer saline solution as a control group. Sera were taken at the experimental intervals and assayed for testosterone hormone, follicular-stimulating hormone (FSH) and luteinizing hormone (LH) to determine the toxicological impact of AFB1 and the possibility of amelioration by phytic acid on the reproductive performance of the studied animal. The effects of AFB1 treatment on the absolute and relative weight of testis as well as its histopathologic effect on the testis and the possibility of amelioration by IP6 treatment were evaluated. The activities of enzymatic and non-enzymatic anti-oxidants, in addition to lipid peroxidation were measured in the testis’ homogenate of AFB1-treated rats. A decrease in sex hormone levels, an increase in testicular lipid peroxidation product levels and a significant decrease in testicular glutathione content, catalase and total peroxidase and superoxide dismutase activities were recorded. The histopathologic alterations revealed a degeneration and highly mitotic division within the spermatogenic nuclei, in addition to some karyomegaly and nuclear pyknosis. It is concluded that the reduction in the toxicity of free radicals by phytic acid might be responsible for the protective influence observed.
Quantum Gravity and Black Hole Dynamics in 1+1 Dimensions
K. Hamada,A. Tsuchiya
Physics , 1992, DOI: 10.1142/S0217751X93001922
Abstract: We study the quantum theory of 1+1 dimensional dilaton gravity, which is an interesting toy model of the black hole dynamics. The functional measures are explicitly evaluated and the physical state conditions corresponding to the Hamiltonian and the momentum constraints are derived. It is pointed out that the constraints form the Virasoro algebra without central charge. In ADM formalism the measures are very ambiguous, but in our formalism they are explicitly defined. Then the new features which are not seen in ADM formalism come out. A singularity appears at $\df^2 =\kappa (>0) $, where $\kappa =(N-51/2)/12 $ and $ N$ is the number of matter fields. Behind the singularity the quantum mechanical region $\kappa > \df^2 >0 $ extends, where the sign of the kinetic term in the Hamiltonian constraint changes. If $\kappa <0 $, the singularity disappears. We discuss the quantum dynamics of black hole and then give a suggestion for the resolution of the information loss paradox. We also argue the quantization of the spherically symmetric gravitational system in 3+1 dimensions. In appendix the differences between the other quantum dilaton gravities and ours are clarified and our status is stressed.
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