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Area and Timing Estimation in Register Files Using Neural Networks  [PDF]
Assim Sagahyroon, Jamal Abdalla
Circuits and Systems (CS) , 2012, DOI: 10.4236/cs.2012.33037
Abstract: The increase in issue width and instructions window size in modern processors demand an increase in the size of the register files, as well as an increase in the number of ports. Bigger register files implies an increase in power consumed by these units as well as longer access delays. Models that assist in estimating the size of the register file, and its timing early in the design cycle are critical to the time-budget allocated to a processor design and to its performance. In this work, we discuss a Radial Base Function (RBF) Artificial Neural Network (ANN) model for the prediction of time and area for standard cell register files designed using optimized Synopsys Design Ware components and an UMC130 nm library. The ANN model predictions were compared against experimental results (obtained using detailed simulation) and a nonlinear regression-based model, and it is observed that the ANN model is very accurate and outperformed the non-linear model in several statistical parameters. Using the trained ANN model, a parametric study was carried out to study the effect of the number of words in the file (D), the number of bit in one word (W) and the total number of Read and Write ports (P) on the latency and area of standard cell register files.
Universal Current-Mode Biquad Employing Dual Output Current Conveyors and MO-CCCA with Grounded Passive Elements  [PDF]
Kasim Karam Abdalla
Circuits and Systems (CS) , 2013, DOI: 10.4236/cs.2013.41013
Abstract:

A new universal multiple input multiple output (MIMO) type current-mode biquad employing two dual output current conveyors (DOCCII), one multiple output current controlled current amplifier (MOCCCA) and four passive grounded elements is proposed which can realize all the five basic filtering functions namely, low-pass (LP), high-pass (HP), band-pass (BP), band-stop (BR) and all-pass (AP) in current mode from the same configuration. The centre frequency\"\" can be set by the passive elements of the circuit and the quality factor Q0 is electronically tunable through bias currents of the MOCCCA. Therefore, the biquad filter has independent tenability for the\"\" and Q0. The active and passive sensitivities of Q0 and\"\" are low. The workability of the new configuration has been demonstrated by PSPICE simulation results based upon a CMOS CCII in0.35μm technology.

Teoria quantica da gravita??o: cordas e teoria M
Abdalla, Elcio;
Revista Brasileira de Ensino de Física , 2005, DOI: 10.1590/S1806-11172005000100017
Abstract: we discuss the merging of general relativity and quantum mechanics as a theoretical as well as experimental necessity in physics, and the consequences in the comprehension of the universe, its beginning and evolution.
Ultrastructural study of the effect of air pollution by SO2 on the respiratory air-ways
IL Abdalla
African Journal of Health Sciences , 2007,
Abstract: Sulfur dioxide (SO2) has been associated with excessive mortality during air pollution disasters such as that which occurred in Meuse Valley, Belgium in 1930, Donora Pennsylvania, in 1948 and London in 1952. The SO2 particulate complex results chiefly from the burning of fossil fuels. Exposure can cause irritant and toxic effects on the human airways and result in broncho- constriction. It also can aggravate existing pulmonary or cardiac problems. A positive interaction between particles and SO2 to produce morphologic changes in airways has been suggested by smog incidents, but has not been evaluated by experiments. So, this study was done to answer the following questions: (1) What morphologic changes are produced by repeated injury to airway epithelial cells by SO2? (2) What is the time course of these morphologic features? (3) Can a model of acute bronchitis be created which is not due to infection? Ultrastructural changes occurring in the epithelial cells lining the airways of the experimental rats were studied. A sequence of epithelial changes was seen with exposure to 100, 200 or 400 p.p.m. for up to 4 weeks. For example: loss of cilia, vacuolation, pyknosis, goblet cell hyperplasia and the development of stratified squamous epithelium after 2 to 7 days at 200 p.p.m Higher doses (400 p.p.m.) produced squamous cell metaplasia after 2 weeks. Exposure to 40 p.p.m. SO2 alone for 4 hours per day for 6 weeks produced no changes, but 24 hours after a 4 hours exposure to 40 p.p.m. SO2 plus 0.74 gm of carbon dust per cu.m. of air, neutrophils were recruited into airway epithelium. It is suggested that this synergistic effect is due to the carbon particles adsorbing SO2, which leaches off slowly, perhaps within macrophages, to recruit Leucocytes in airways. African Journal of Health Sciences Vol. 14 (3-4) 2007: pp. 129-136
Experience with Penile Circular Fasciocutaneous Flap in the Treatment of Long Anterior Urethral Strictures
MA Abdalla
African Journal of Urology , 2008,
Abstract: Objective: To evaluate our experience with penile circular fasciocutaneous flap urethroplasty for the repair of long penile and bulbar strictures. Patients and Methods: Between February 2003 and April 2005, a total of 21 circumcised patients with a mean age of 39 (range 11 – 79) years underwent penile circular fasciocutaneous flap urethroplasty for urethral strictures involving the penile and bulbar tracts. The average stricture length was 7 cm. Follow-up included retrograde urethrography at 3 weeks, 3 months and 12 to 18 months, and thereafter when needed, and evaluation of the urinary flow. The mean follow-up was 25.6 months (range 7 to 44 months). The clinical outcome was defined as success when the patient had a good urinary stream, a post void residual urine <50 cc, a peak urinary flow speed >20 ml/sec, a normal and smooth caliber of the urethra as shown on retrograde urethrography and no urinary tract infection. Results: Our initial success rate was 86% (18/21 patients). An immediate successful outcome was achieved in 15/21 (71%) patients. Three patients had an unsatisfactory urinary stream in the immediate post-operative period which resolved after a single dilation or optical urethrotomy. With a mean follow-up of 26 months 2 patients developed a stricture at the proximal site of the repaired urethra necessitating resection and re-anastomosis. One patient with lichen sclerosus developed recurrence of the stricture and was subjected to suprapubic cystostomy, then further staged reconstruction was done. Immediate post-operative complications were encountered in 4 patients in the form of secondary hemorrhage, ischemia and sloughing of the penile skin, urethrocutaneous fistula which closed spontaneously and a decreased sensation at the lower limb in one patient each. Conclusion: Circular fasciocutaneous flap urethroplasty is a highly effective single-stage method of reconstructing long urethral strictures. It provides ample tissue for urethral substitution Africain Journal of Urology Vol. 14 (2) 2008: pp. 81-85
Efficacy of limbal-conjunctival autograft surgery with stem cells in pterygium treatment
Abdalla Walid
Middle East African Journal of Ophthalmology , 2009,
Abstract: Purpose: To determine the efficacy of limbal-conjunctival autograft surgery with stem cells in the management of primary and recurrent pterygium and determine the best corrected visual acuity after surgery. Materials and Methods: Surgical excision of pterygium and limbal-conjunctival transplantation with stem cells was of 40 eyes (of 31 patients) with pterygium. Thirty one cases were primary and nine cases were recurrent pterygia. Graft margins were secured to the recipient site while stem cells aspect was sutured to the limbus. Results: After one year of follow-up, 37 of 40 (92.5%) eyes were free of recurrence. One of the three recurrent cases was aggressive (recurrence occurred two months after surgery) and the other two showed 2 mm corneal extension at 12 months follow-up. In 24 patients, out of 40 (60%), best corrected visual acuity improved more than two lines. Conclusion: Limbal-conjunctival autograft surgery, including stem cells, appears to be an effective surgical technique in preventing pterygium recurrence and it can also help in improving the best corrected visual acuity.
Effect of erythrocytes oscillations on dielectric properties of human diabetic-blood
S. Abdalla
AIP Advances , 2011, DOI: 10.1063/1.3556986
Abstract: It has been demonstrated that the erythrocytes (RBCs) oscillate during their tank-treading motion with high-frequency oscillations. This oscillatory motion drastically affects the dielectric and electrical properties of RBCs. Moreover, the glucose level in blood affects the electrical and dielectric properties of blood. It has been, also, shown that the frequency of these oscillations exponentially decrease from 1.2 MHz down to 0.85 MHz with variation of glucose level from 85 mg/dL up to 346.1 mg/dL. It is expected that these oscillations strongly affect the general physiological properties of blood and would stimulate the curiosity of scientists and bioengineers to present new, more efficient, rapid, safe and viable diagnostic and/or therapeutic methods for blood disorders; in particular diabetes.
Operator solutions of two-dimensional chiral gauge theories
E. Abdalla
Physics , 1996,
Abstract: The exact operator solutions of two-dimensional anomaly-free chiral abelian gauge theories are obtained. We show that anomaly-cancellation conditions arise as consistency requirements of these solutions. For a certain class of flavour symmetries, fermion condensates are constructed. These are shown to violate the fermion-number conservation rule. The models are extended to include massive fermions. We propose a bosonised lagrangian for the massive theory and verify that it complies with the Gupta-Bleuler condition.
Towards a solution of two dimensional QCD
E. Abdalla
Physics , 1995,
Abstract: Using the well-known result for the fermionic determinant in terms of a WZW theory, we write QCD$_2$ in bosonized form. After some manipulations we give two versions of the theory, where it is factorized as a product of the conformally invariant WZW models, ghost terms, and a WZW action perturbed off criticality. We first prove that the latter is an integrable model. Furthermore, as a consequence of the BRST analysis, there are several constraints. Second-class constraints also show up. Using the integrability condition we find higher conservation laws, their action on the asymptotic states, and we propose an exact $S$-matrix for the physical excitations. The vacuum structure is analysed, and we prove that a finite number of different vacua exist. An outline of possible generalizations of the procedure is given.
Two-dimensional Quantum Field Theory, examples and applications
E. Abdalla
Physics , 1997,
Abstract: The main principles of two-dimensional quantum field theories, in particular two-dimensional QCD and gravity are reviewed. We study non-perturbative aspects of these theories which make them particularly valuable for testing ideas of four-dimensional quantum field theory. The dynamics of confinement and theta vacuum are explained by using the non-perturbative methods developed in two dimensions. We describe in detail how the effective action of string theory in non-critical dimensions can be represented by Liouville gravity. By comparing the helicity amplitudes in four-dimensional QCD to those of integrable self-dual Yang-Mills theory, we extract a four dimensional version of two dimensional integrability.
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