Task Scheduling for Multiprocessor Systems Using Queuing Theory

This research focuses on comparing different multi-processor task scheduling algorithms. Each algorithm has been simulated using one of queuing theory models in Operations Research (OR) science to evaluate its behavior and efficiency. The comparison includes an analysis of the behavior of central processing unit (CPU) when receiving number of jobs at four random job duration patterns that are; (random, ascending, descending, and volatile low-high). Microsoft Excel 2010 was used to form the data of each case, and the result shows convergence and divergence among the studied algorithms at different patterns. Also it has been found that the Fleischer algorithm is very efficient in enhancing and minimizing the waiting duration for each job at the total job queue of the CPU. Keywords: Operations Research, Queuing Theory, Multiprocessor, Scheduling Algorithms, Simulation

Constructing a model to determine the most important factors affecting diabetes disease

Diabetes occurs as a result of the inability of the pancreatic gland to produce an adequate amount of insulin, or as a result of the body's inability to use the insulin it produces as required. For the purpose of presenting an explanatory study on blood sugar disease and determining the most important factors that affect the incidence of this disease, a mathematical model was built, which is a two-response logistic regression model when the correlation function is of type (logit, Normal, or Gompartz). Then, they were compared to determine the best model using Aic standard and R2. It has been shown that the two-response logistic regression model with a correlation function (logit) is the best because it has the lowest Aic coefficient and the highest R2. Likewise, it was found that the effect of the age variable x1 is more significant than the effect of the gender variable x2 on the incidence of diabetes, and that the risk is high between the response variable blood sugar (y) and the age variable (x1). While the risk is low between the response variable (y) and the gender variable (x2)

Decolorization of Phenol Red Dye by Immobilized Laccase in Chitosan Beads Using Laccase - Mediator - System Model

 يصف هدا العمل قصر الصبغة الحمراء من خلال تقييد  انزيم اللاكييز بالكايتوسان.  يتكون انزيم اللاكييزالتجاري من فطر العفن الابيض (Tvlac) حيث  يقيد بطريقة سهلة التحضير بحبيبات الكايتوسان المنشط  بالكلوترالديهايد . لقد تم تعزيز  توصيف الكايتوسان المحضر باستخدام تقنيات الـ  FTIR وال .SEMلقد قيد (46.2  وحدة/ مل) من انزيم  Laccase تماما في حبيبات الكايتوسان المحضره   بنسبة 0.8%  (v:v) من الكلوترالدهيد خلال (24) ساعة, استخدمت العوامل الوسطية الصناعية(HBT) والطبيعيةvanillin) ) لتعزيز عملية قصر  صبغة الفينول الاحمر من خلال انزيم اللاكييز المقيد. حيث وجد ان عملية القصر لحبيبات الكايتوسان تصل الى قيمتها العظمى %89 خلال180  دقيقة في حين تصل عملية القصر لحبيبات الانزيم المقيد بلكايتوسان الى(100%) خلال 120 دقيقة ولكن باستخدام HBT  وال vanillin  كمواد وسطية تصل عملية القصر 100% في 25 دقيقة و50 دقيقة على التوالي .ومن ناحية اخرى اعادة استخدام حبيبات  الانزيم المقيد بلكايتوسان  اعطت   نتيجة قصر 100% عند اول دورة ومن ثم بدت تتناقص تدريجيا النتائج مع عدد الدورات الى ان تصل الى فعالية 70% بعد 9 مرات للإعادة الاستخدام في عميلة قصر الصيغة.This work describes the enhancement of phenol red decolorization through immobilizing of laccase in chitosan and enzyme recycling. Commercial laccase from white rot fungus, Trametesversicolor (Tvlac), was immobilizedin to freshly prepared chitosan beads by using glutaraldehyde as a cross linker. Characterization of prepared chitosan was confirmed by FTIR and scanning electron microscope (SEM). Tvlac (46.2 U/mL) immobilized into chitosan beads at 0.8 % glutaraldehyde (v/v) within 24 hrs. Synthetic (HBT) and natural (vanillin) mediators were used to enhance dye decolorizoation. It was found that 89 % of phenol red was decolorized by chitosan beads within 180 min. in the absence of enzyme and mediator, while decolorization percentage of the dye was completed (100%) at 120 min. when chitosan immobilizedlaccase was applied. Moreover, the decolorization was completed within 25 and 50 min. in the presence of chitosan immobilized laccase and of HBT or vanillin respectively. On the other hand, the recycling of chitosan immobilized laccase was still decolorize phenol red and continued up to ninth cycle to reach  70% of dye decolorization

An Optimal LFC in Two-Area Power Systems Using a Meta-heuristic Optimization Algorithm

In this study, an optimal meta-heuristic optimization algorithm for load frequency control (LFC) is utilized in two-area power systems. This meta-heuristic algorithm is called harmony search (HS), it is used to tune PI controller parameters ( ) automatically. The developed controller (HS-PI) with LFC loop is very important to minimize the system frequency and keep the system power is maintained at scheduled values under sudden loads changes. Integral absolute error (IAE) is used as an objective function to enhance the overall system performance in terms of settling time, maximum deviation, and peak time. The two-area power systems and developed controller are modelled using MATLAB software (Simulink/Code). As a result, the developed control algorithm (HS-PI) is more robustness and efficient as compared to PSO-PI control algorithm under same operation conditions

PERIODIC SOLUTION FOR A CLASS OF DOUBLY DEGENERATE PARABOLIC EQUATION WITH NEUMANN PROBLEM

In this article, we study the periodic solution for a class of doubly degenerate parabolic equation with nonlocal terms and Neumann boundary conditions. By using the theory of Leray-Schauder degree, we obtain the existence of nontrivial nonnegative time periodic solution

SOME TYPES OF COMPLETELY REGULAR SPACE AND IT’S RELATIONS

In this paper , we introduced a new definitions of semi completely regular space and semi regular space . And we study some relations among the( s , g , s g, g s , g* , s g* , g*s )of completely regular space

Implementation of variational iteration method for various types of linear and nonlinear partial differential equations

There are various linear and nonlinear one-dimensional partial differential equations that are the focus of this research. There are a large number of these equations that cannot be solved analytically or precisely. The evaluation of nonlinear partial differential equations, even if analytical solutions exist, may be problematic. Therefore, it may be necessary to use approximate analytical methodologies to solve these issues. As a result, a more effective and accurate approach must be investigated and analyzed. It is shown in this study that the Lagrange multiplier may be used to get an ideal value for parameters in a functional form and then used to construct an iterative series solution. Linear and nonlinear partial differential equations may both be solved using the variational iteration method (VIM) method, thanks to its high computing power and high efficiency. Decoding and analyzing possible Korteweg-De-Vries, Benjamin, and Airy equations demonstrates the method’s ability. With just a few iterations, the produced findings are very effective, precise, and convergent to the exact answer. As a result, solving nonlinear equations using VIM is regarded as a viable option