572 research outputs found

    An Overview on Evaluation of E-Learning/Training Response Time Considering Artificial Neural Networks Modeling

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    The objective of this piece of research is to interpret and investigate systematically an observed brain functional phenomenon which associated with proceeding of e-learning processes. More specifically, this work addresses an interesting and challenging educational issue concerned with dynamical evaluation of e-learning performance considering convergence (response) time. That's based on an interdisciplinary recent approach named as Artificial Neural Networks (ANNs) modeling. Which incorporate Nero-physiology, educational psychology, cognitive, and learning sciences. Herein, adopted application of neural modeling results in realistic dynamical measurements of e-learners' response time performance parameter. Initially, it considers time evolution of learners' experienced acquired intelligence level during proceeding of learning / training process. In the context of neurobiological details, the state of synaptic connectivity pattern (weight vector) inside e-learner's brain-at any time instant-supposed to be presented as timely varying dependent parameter. The varying modified synaptic state expected to lead to obtain stored experience spontaneously as learner's output (answer). Obviously, obtained responsive learner's output is a resulting action to any arbitrary external input stimulus (question). So, as the initial brain state of synaptic connectivity pattern (vector) considered as pre-intelligence level measured parameter. Actually, obtained e-learner’s answer is compatibly consistent with modified state of internal / stored experienced level of intelligence. In other words, dynamical changes of brain synaptic pattern (weight vector) modify adaptively convergence time of learning processes, so as to reach desired answer. Additionally, introduced research work is motivated by some obtained results for performance evaluation of some neural system models concerned with convergence time of learning process. Moreover, this paper considers interpretation of interrelations among some other interesting results obtained by a set of previously published educational models. The interpretational evaluation and analysis for introduced models results in some applicable studies at educational field as well as medically promising treatment of learning disabilities. Finally, an interesting comparative analogy between performances of ANNs modeling versus Ant Colony System (ACS) optimization presented at the end of this paper

    Power Sharing Method Based on Droop Control for Three-Phase UPS Systems

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    The main objective of this paper is to improve the power sharing capability and to achieve synchronization between three-phase Uninterruptible power supply (UPS) units in the presence of load interruption. This paper presents a droop-controlled scheme in such a way that the computation of the instantaneous value of the active power and the reactive power are taken as feedback signals to the frequency and voltage restoration control system. The restored frequency and voltage are introduced to voltage controller circuit, which produces a suitable control signal to sinusoidal pulse width modulation circuit (SPWM). Thus producing a suitable trigger pulses to the inverter gate in order to guarantee synchronization between three-phase UPS units. Simulation of two UPS units with the same ratings (4 KW) are carried out using MATLAB. The results show the effectiveness of the proposed control system in achieving synchronization and improving the power sharing capability in the presence of load interruption. Keywords: Uninterruptible power supply; power sharing; parallel operation; droop control. DOI: 10.7176/JETP/9-4-02 Publication date: April 30th 201

    (R, S) conjugate solution to coupled Sylvester complex matrix equations with conjugate of two unknowns

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    In this work, we are concerned with (R, S) – conjugate solutions to coupled Sylvester complex matrix equations with conjugate of two unknowns. When the considered two matrix equations are consistent, it is demonstrated that the solutions can be obtained by utilizing this iterative algorithm for any initial arbitrary (R,S) – conjugate matrices V1,W1. A necessary and sufficient condition is established to guarantee that the proposed method converges to the (R,S) – conjugate solutions. Finally, two numerical examples are provided to demonstrate the efficiency of the described iterative technique

    Respuesta química y eficacia agronómica de cultivos de girasol (Helianthus agnnuus L.) a fuentes de nitrógeno orgánico y fertilizantes convencionales nitrogenados en suelos áridos

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    Sunflower (Helianthus annuus L.) is an option for oilseed production, particularly in dry land areas due to good root system development. In this study, two field experiments were performed in the El-Khattara region (Sharkia Governorate, Egypt) during the 2005 season. The objective of this research was to determine the effect of organicnitrogen (ON) sources and their combinations as well as to compare the effect of ON and ammonium sulfate (AS) as a conventional fertilizer added individually or in combination on growth, yield components, oil percentage and the uptake of some macronutrients by sunflowers grown on sandy soil. The treatments of chicken manure (CM) and a mixture of farmyard manure (FYM) with CM were superior to the other treatments and gave the highest yield, dry matter yield, NPK uptake by plants at all growth stages along with seed yield at the mature stage. The effect of the different ON on crop yield and its components may follow the order; CM> palma residues (PR)> FYM. This was more emphasized when the materials were mixed with AS at a ratio of 3:1 and 1:1. The uptake of nitrogen (N), phosphorus (P) and potassium (K) by plants was affected by the addition of different N sources and treatments. The highest nutrient content and uptake by straw were obtained when treated with CM followed by PR at all growth stages, while it was PR followed by CM for seeds. Oil recovery was shown to respond to the N supply and the changes in individual fatty acids were not statistically different. However, it seems that the application of organic fertilizers resulted in an increase in total unsaturated fatty acids compared to the control.El girasol (Helianthus annuus) es una opción para la producción de semillas oleaginosas, en particular en terrenos arenosos debido al buen desarrollo de sus raíces. En este trabajo, dos estudios de campo fueron realizados en la región de El-Ishattara (Sharkia Governorate, Egypt) durante la estación 2005. El efecto de diversas fuentes de nitrógeno orgánico (ON) y el de su combinación, así como el efecto de ON y sulfato amónico (AS) como fertilizante convencional añadido individualmente o en combinación ha sido estudiado en base a su crecimiento, rendimiento de los componentes, porcentaje de aceite y consumo de micronutrientes en girasoles crecidos en suelos arenosos. El tratamiento con estiércol de pollo (CM) y una mezcla de estiércol de corral (FYM) con CM fue superior a otros tratamientos y dio el más alto rendimiento, la mayor cantidad de materia seca, y el mayor consumo de NPK por la planta en todos los estadios de crecimiento, así como en el rendimiento de la semilla en el estado de madurez El efecto promotor de los diferentes ON en el rendimiento del cultivo y sus componentes puede seguir el orden siguiente: CM> residuos de palma (PR)> FYM. Este efecto fue mayor cuando los materiales fueron mezclados con AS en una proporción 3:1 y 1:1. El consumo de nitrógeno (N), fósforo (P) y potasio (K) por la plantas dependió de la adición de diferentes fuentes de nitrógeno y tratamientos. El consumo y contenido de nutrientes más alto del tallo fue obtenido cuando se trató con CM seguido por PR en todos los estadios de crecimiento, mientras que PR fue seguido por CM para semillas. Se ha encontrado que la recuperación del aceite responde a la adición de nitrógeno, pero los cambios en los ácidos grasos no fueron significativamente diferentes. Sin embargo la aplicación de fertilizantes orgánicos resultó en un incremento de los ácidos grasos insaturados

    Effect of FSW Parameters on The Microstructure and Mechanical Properties of T-joints between Dissimilar Al-Alloys

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    The main purpose of this research is to develop T-joints between the aluminum AA 2024-T4 and AA 7075-T6 using friction stir welding.  The effect of tool geometries, tool traveling speed, and rotational rate in the welded T-joints were investigated and discussed. Three different tools were used with different shoulder to pin ratios 3.28, 3.36, and 4.31. After optimization, the best tool dimension has used with the different rotational and welding speeds. Three tool traverse speeds of 50, 75, and 100 mm/min were used. Two rotation rates of 800 rpm and 1000 rpm were applied. After FSW, at a number of the above FSW parameters' combinations, macrostructure and microstructure analyses were done using optical microscopy. In order to have an insight into the mechanical properties, hardness measurements and tensile testing were carried out. Using small shoulder to pin ratio produced visually unacceptable T-joint. Opposite happened by using the tool with 4.31 of shoulder to pin ratio. Furthermore, the results showed sound T-welds with no obvious defects at high rotational rate of 1000 rpm with the two used traveling speeds. Asymmetric temperature distribution was observed between the two sides, advance side (AS) and retreating side (RS

    Transparency of law making and fiscal democracy in the Middle East

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    Fiscal democracy is the capacity of the legislature to make budgetary choices in response to the emerging needs of citizens. This study indicates that, in Middle Eastern countries, there are specific limitations to fiscal democracy in the process of law-making: most notably the lack of attention to financial impact assessments (FIAs). Without systematic FIAs, mandatory out-of-budget allocations are inadvertently included in public spending, as they do not require parliamentary approval within the regular budgeting process. The low level of effective citizens’ engagement in the process of law-making worsens the situation. Budgetary decisions are not well informed by national priorities and preferences. This study utilizes the dataset of the Open Budget Index (OBI) to measure the quality of the law-making process of the budget law in a sample of Middle Eastern countries. The study concludes with recommendations on mapping the law-making process to increase budget transparency

    Removing of heavymetals from water by chitosan nanoparticles

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    Chitosan was prepared by deacetylation of chitin. The prepared chitosan has characterized bymolecular weight, degree of deacetylation, and ash %. Chitosan nanoparticles were prepared byionotropic gelation of chitosan with tripolyphosphate anions. The structure and particle size of chitosan nanoparticles have confirmed via FTIR analysis and TEM imaging.The chitosan nanoparticles were used in water treatment to remove metal ions from sample contains 20 ppm from each Fe+2, Mn+2, Zn+2 and Cu+2.The optimum conditions for this study were at 2 g/l of chitosan nanoparticles, pH 7 and 30 min of mixing time. Chitosan showed the highest performance under these conditions with removing percent 99.94% 80.85% 90.49% and 95.93% from Fe+2, Mn+2, Zn+2 and Cu+2 respectively

    Removing of heavymetals from water by chitosan nanoparticles

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    Chitosan was prepared by deacetylation of chitin. The prepared chitosan has characterized bymolecular weight, degree of deacetylation, and ash %. Chitosan nanoparticles were prepared byionotropic gelation of chitosan with tripolyphosphate anions. The structure and particle size of chitosan nanoparticles have confirmed via FTIR analysis and TEM imaging.The chitosan nanoparticles were used in water treatment to remove metal ions from sample contains 20 ppm from each Fe+2, Mn+2, Zn+2 and Cu+2.The optimum conditions for this study were at 2 g/l of chitosan nanoparticles, pH 7 and 30 min of mixing time. Chitosan showed the highest performance under these conditions with removing percent 99.94% 80.85% 90.49% and 95.93% from Fe+2, Mn+2, Zn+2 and Cu+2 respectively

    Comparison between physical properties of ring-spun yarn and compact yarns spun from different pneumatic compacting systems

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    A comparative study pertaining to physical and mechanical properties of ring-spun yarn vis-à-vis compact yarns spun using three different compacting systems has been reported. Rieter (K-44), Toyota (RX-240) and Suessen (Fiomax) spinning machines have been used and the condensing process of the fibres in the yarn cross-section as per these compact spinning systems is accomplished pneumatically. Thus, a yarn of linear density 5.9 tex (100 Ne) is spun on the spinning systems using Egyptian cotton of the type Giza 86. One way Anova together with least significant difference are employed to feature the means of the properties of spun yarns and a significant difference among them is observed. According to the performed statistical analysis, there is a significant difference between ring - spun yarn properties and each of the pnuematic compact spun yarns. These compact-spun yarns are also found to differ significantly in terms of their physical and mechanical properties; however, they are all found superior to the ring-spun yarn

    The potentiality of hydrocarbon generation of the Jurassic source rocks in Salam-3x well, North Western Desert, Egypt

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    AbstractThe present work deals with the identification of the potential and generating capability of oil generation in the Jurassic source rocks in the Salam-3x well. This depending on the organo-geochemical analyses of cutting samples representative of Masajid, Khatatba and Ras Qattara formations, as well as, representative extract samples of the Khatatba and Ras Qattara formations. The geochemical analysis suggested the potential source intervals within the encountered rock units as follows: Masajid Formation bears mature source rocks and have poor to fair generating capability for generating gas (type III kerogen). Khatatba Formation bears mature source rock, and has poor to good generating capability for both oil and gas. Ras Qattara Formation constituting mature source rock has good to very good generating capability for both oil and gas. The burial history modeling shows that the Masajid Formation lies within oil and gas windows; Khatatba and Ras Qattara formations lie within the gas window. From the biomarker characteristics of source rocks it appears that the extract is genetically related as the majority of them were derived from marine organic matters sources (mainly algae) deposited under reducing environment and take the direction of increasing maturity and far away from the direction of biodegradation. Therefore, Masajid Formation is considered as effective source rocks for generating hydrocarbons, while Khatatba and Ras Qattara formations are the main source rocks for hydrocarbon accumulations in the Salam-3x well
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