Internet users demand service from online websites by sending requests to website servers which process the requests and return responses to the clients. Many requests could be sent to a server at the same moment;therefore, predictingserver workload becomes one of the factors that affect its efficiency. In this paper, we applied three optimized hybrid models to predict the workload of the Portal server (Server 1) and web server (Server 2) of the Arab American University Palestine (AAUP).The models are called Recurrent Neural Networks combined (RNNs), Long-short term memory network (LSTM), and Nonlinear Auto-Regressive Exogenous Neural Networks (NARX) hybrid with Genetics Algorithms (GAs). The experimental results showed that the hybrid model (NARX-GAs) has a better performance.........

KEYWORDS: Server workload, TimeSeries Prediction, RNNs, LSTM, NARX, Hybrid Model, GAs.

In this survey, the kinematic-dynamic analysis of a 2D deployable truss (both rigid and flexible body analysis) is presented. This deployable truss is the main part of an octagonal 9-bay space deployable structure that was developed during ESA-LAGARD Project. The scope of the structure is the accommodation of parts of a space telescope for future ESA science missions. The functional specifications demand high stiffness and accuracy in the fully deployed configuration. The truss is consisted of CFRP beams, connected with rigid titanium connectors. The truss is actuated by a fully motorized mechanism controlled by electric step motors. For each bay, longerons members are rotated around a hinge point leading to the translation of a frame of batten elements. This movement leads to the 9-bay octagonal structure's deployment.......

KEYWORDS: Space telescopes; Deployable structures; Kinematic and Dynamic analysis; ADAMS.

This document shows the procedure used to determine the mathematical relationship to characterize the response of LEM® LV 25-P and LTS 25-NP transducers when used to measure AC voltage and current signals, respectively. The transducers and other components were installed on a test stand that facilitates connections and measurements of input and output signals. The tests performed consider electrical signals with a frequency range from 60 Hz to 1500 Hz, with the purpose of knowing the response of the sensors in conditions of the presence of harmonic components. Analog voltage and current signals are generated with PC-controlled test equipment.

KEYWORDS: Characterization, AC Signals, Transducers, Measure, Harmonics.

The sustainable development relies on the significant usage of natural resources and their efficiency. The concept of circular economy is implemented with the creation of new innovative technologies and paradigm shifts of the product and material reuse to extend their useful life. The use of circular economy strategies helps to close the material flows and extends the life cycle of the product with the involvement of the business realm. The new and innovative technologies include the principle of Industry 4.0 such as digitalization, prompt information, and optimize the supply chain of the resources by reducing resource utilization and environmental impacts. Digital technologies play an important role to enhance circular economy strategies and practices overcoming environmental issues. Both circular economy and Industry 4.0 concepts are interrelated. This article represents the nexus of circular economy and Industry 4.0 and demonstrates the importance of circular economy through Industry 4.0 and Artificial Intelligence to achieve the 2030 Agenda for Sustainable Development Goals.

KEYWORDS: Circular Economy; Industry 4.0; Artificial Intelligence; and Sustainable Development Goals.

In this work the mathematical modeling is done and the results of the simulation of a generator for microgeneration of electrical energy are presented. The induced voltage in the generator is calculated and compared with the voltage generated by the digital simulation model. This is done in order to analyze the viability of using a power generating system, driven by the continuous flow of passersby on a certain surface. The development of the analysis is based on the creation of a mathematical model and simulation with the help of software that operates with the finite element method. This is done in order to know and compare the voltage generated by the microgenerator and the one calculated with the mathematical model........

KEYWORDS: Mathematical modeling, Electric generator, Induced voltage, Microgeneration, Simulation.

The probabilistic modelling of extreme flood data is crucial to decision-making process in hydrological and hydraulic projects. Consequences, it is necessary to find an unbiased plotting positions which accurately the model probability distribution function. The appropriate plotting position for GEV, LP3,PR3 were evaluated using statistical goodness-of-test. The PPF were evaluated based on optimum value of the goodness-of-fit-test; Maximum absolute error (MAE), Nash-Sutcliffe efficiency (NSE), Percent bias (PBAIS) and Root-Mean Square error (RMSE). On the basis of the selected goodness-of-fit tests, 8 unbaised plotting position formula recommended of GEV, 7 for PR3, 6 for LP3 were evaluated with annual maximum series of Niger River at Bara, Kouroussa and Shinkatu. The results of the study show that Weibull, is the best plotting position formula for GEV, PR3 and LP3 distributions with overall percentage scores of 18.17%, 18.24% and 22.91% respectively. The study also indicates that Chegodayev plotting position Formula is second with 17.18% for LP3 and 17.4 for PR3 distributions. While Beard plotting position formula is second for GEV distribution with a score of 17.76%. The result of the study will complement the development of a standardised flood estimation manual for flood frequency analysis for Nigeria. .

KEYWORDS: Plotting position formulae, GEV, PR3, LP3, Goodness – of- fit tests, Parameter estimation.