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A Hybrid Methodology for Short Term Temperature Forecasting

International Journal of Intelligence Science 2020年第3期10卷 65-81页

作者： Wissam Abdallah Nassib Abdallah Jean-Marie Marion mohamad oueidat Pierre Chauvet Angevin Research Laboratory in Systems Engineering University of Angers Angers France Computer Science and Systems Laboratory Polytech Marseille Aix Marseille University Aix-en-Provence France Angevin Research Laboratory in Systems Engineering Université Catholique de l’Ouest Angers France Department of Industrial Engineering and Maintenance Faculty of Technology Lebanese University Beirut Lebanon Angevin Research Laboratory in Systems Engineering Université Catholique de l’Ouest Angers France

Developing a reliable weather forecasting model is a complicated task, as it requires heavy IT resources as well as heavy investments beyond the financial capabilities of most countries. In Lebanon, the prediction model used by the civil aviation weather service at Rafic Hariri International Airport in Beirut (BRHIA) is the ARPEGE model, (0.5) developed by the weather service in France. Unfortunately, forecasts provided by ARPEGE have been erroneous and biased by several factors such as the chaotic character of the physical modeling equations of some atmospheric phenomena (advection, convection, etc.) and the nature of the Lebanese topography. In this paper, we proposed the time series method ARIMA (Auto Regressive Integrated Moving Average) to forecast the minimum daily temperature and compared its result with ARPEGE. As a result, ARIMA method shows better mean accuracy (91%) over the numerical model ARPEGE (68%), for the prediction of five days in January 2017. Moreover, back to five months ago, in order to validate the accuracy of the proposed model, a simulation has been applied on the first five days of August 2016. Results have shown that the time series ARIMA method has offered better mean accuracy (98%) over the numerical model ARPEGE (89%) for the prediction of five days of August 2016. This paper discusses a multiprocessing approach applied to ARIMA in order to enhance the efficiency of ARIMA in terms of complexity and resources.

关键词： Time Series Analysis ARIMA Auto Regressive Integrated Moving Average Weather Forecasting Model Multiprocessing

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Feasibility of Solar Tracking System for PV Panel in Sunbelt Region

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Journal of Modern Power Systems and Clean Energy 2021年第2期9卷 395-403页

作者： Soulayman Soulayman mohamad Hamoud mohamad-Amir Hababa Wassim Sabbagh the Department of Applied Physics Higher Institute for Applied Sciences and TechnologyDamascusP O Box 31983Syria

In the study of the feasibility of solar tracking systems for crystalline silicon photovoltaic(PV)panels in hot and cold regions,it is argued recently that a tracking system is not necessary for sunbelt countries owing to the overheating that results from excessive exposure to solar *** conclusion has been formulated based on a mathematical model,which in turn is based on the assumption that the PV module temperature can be calculated using an empirical relation of this temperature to ambient temperature,available solar irradiance,and nominal operation cell temperature(NOCT).To support this conclusion,it is claimed that the mathematical model is validated ***,this assumption is vague and widely used in the *** objective of the present work is to reevaluate the above-mentioned assumption and to discuss the results deriving from *** is shown experimentally in the present work that the above-mentioned assumption overestimates the PV module *** a solar irradiance of 900 W/m2,ambient temperature of 25℃,and wind speed of 5 m/s,the measured PV module temperature is lower than the value calculated based on the mentioned assumption by 29.26%.

关键词： Photovoltaic(PV)module temperature wind speed influence PV module efficiency experimental verification Damascus clear-sky conditions

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Exploring the influence of optical and thermal parameters on the effectiveness of parabolic trough collector receiver units

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Clean Energy 2024年第4期8卷 15-33页

作者： Khaled mohamad Engineering and Natural Sciences Faculty SDU UniversityAlmatyKazakhstan

This study investigates the optimization of physical parameters in a parabolic trough collector receiver unit to improve its thermal and optical *** parameters include the transmissivity,reflectivity,absorptivity,emissivity and thermal conductivity of the outer cover and absorber *** study utilizes a novel experimental design and a simulation model that accounts for the infrared reflectivity inside the *** simulation results were validated by the experimental data,with a maximum deviation of 8%.The study analyses the effects of varying the physical parameters on the heat transfer fluid temperature,total plant efficiency,temperature profiles,temperature gradients and thermal *** study finds that increasing the reflectivity and decreasing the emissivity of the outer cover and the absorber pipe significantly enhance the performance,with maximum increases of 25.8%and 26.5%in total efficiency,*** study also finds that increasing the thermal conductivity of the absorber pipe reduces the temperature gradients and thermal stress,with maximum decreases of 42.2%and 29%,*** study provides valuable insights for optimizing the receiver design and operation in solar-thermal systems.

关键词： parabolic trough collector heat transfer fluid receiver unit outer cover absorber pipe

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Self-excitation of neurons leads to multiperiodicity of discrete-time neural networks with distributed delays

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Science China(Information Sciences) 2011年第2期54卷 305-317页

作者： SANNAY mohamad Department of Mathematics Faculty of Science Universiti Brunei Darussalam

In this paper, we investigate the interesting multiperiodicity of discrete-time neural networks with excitatory self-connections and distributed delays. Due to self-excitation of neurons, we construct 2N close regions in state space for N-dimensional networks and attain the coexistence of 2N periodic sequence solutions in these close regions. Meanwhile we estimate exponential attracting domain for each periodic sequence solution and apply our results to discrete-time analogues of periodic or autonomous neural networks. Under self-excitation of neurons, numerical simulations are performed to illustrate the effectiveness of our results.

关键词： self-excitation multiperiodicity discrete-time neural networks distributed delays

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Adaptive energy consumption scheduling of multi-microgrid using whale optimization algorithm

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第5期12卷 78-96页

作者： mohamad Abedini mohamad Mostafai Department of Electrical Engineering Faculty of Engineering Ayatollah Boroujerdi UniversityBoroujerdIran Faculty of Engineering Lorestan Branch Islamic Azad University of DoroodDoroodIran

In this paper, we investigated the day-ahead scheduling of network consisting of severaldistributed generation sources and connected loads. This scheduling is an optimization problem that has two objective functions, namely, operating costs and the costcaused by the emission of pollutants. In this scheduling, while introducing a new structure for micro-grid utilization, the possibility of exchanging power among networks andexchanging power between networks and the upstream distribution network is *** uncertainty of distributed wind generation sources and solar units has been investigated using appropriate probabilistic distributions. Incent-driven load-responsivenessmanagement programs have been used as to encourage subscribers to reduce their powerconsumption during high-load hours. Whale optimization algorithm has been used forscheduling of network.

关键词： Wind turbine battery optimization uncertainty

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Design of a high-frequency transformer based on amorphous cut cores for insulation breakdown testing

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High Voltage 2024年第5期9卷 1183-1194页

作者： Gijs Lagerweij mohamad Ghaffarian Niasar Prodrive Technologies SonThe Netherlands High Voltage Technologies Electrical Sustainable EnergyDelft University of TechnologyDelftThe Netherlands

Innovative test methods are required to keep up with the increased demand for insulation materials which can withstand the high-frequency square-wave voltages generated by power-electronic *** systems using high-voltage,high-frequency transformers have proven versatile and easy to *** authors investigate the application of amorphous cut cores in such *** and numerical models for the transformer and its frequency response are developed,aiding the design *** amorphous core-based transformer is designed for 8 kVpk output at 100 kHz and compared to two previous designs based on ferrite *** frequency and pulse response,as well as the high-voltage and thermal performance,are *** comparison shows that while the low parasitics of the amorphous-based transformer allow for superior frequency response,they are unsuitable for long-duration tests with high pulse repetition frequencies(25-100 kHz)due to increased core *** partial discharge inception and flashover voltage are comparable to the ferrite-based transformers.

关键词： ferrite amorphous high

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PREPARATION, CHARACTERIZATION AND ADHESIVE PROPERTIES OF DI-AND TRI-HYDROXY BENZOYL CHITOSAN NANOPARTICLES

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Chinese Journal of Polymer Science 2013年第4期31卷 649-659页

作者： mohamad Taghi Taghizadeh Ali Bahadori Department of Physical Chemistry Faculty of ChemistryUniversity of TabrizTabrizIran

Modified chitosans with 3,4-di-hydroxy benzoyl groups （CS-DHBA） and 3,4,5-tri-hydroxy benzoyl groups （CS- THBA） were synthesized and their nanoparticles were prepared via ionic crosslinking by tripolyphosphate （TPP）. The chemical structure and degree of substitution （DS） of di- and tri-hydroxy benzoyl chitosans are determined by FTIR and IH- NMR spectroscopy. The morphology of particles, size distribution and zeta potential of nanoparticles were studied using transmission electron microscopy （TEM） and dynamic light scattering （DLS）, respectively. The mean diameters of particles of CS-DHBA and CS-THBA nanoparticles were 144 nm and 112 nm, respectively. It was found that the particles size decreased slightly with decreasing the degree of substitution and increasing degree of deacetylation （DD）, due to increasing of ionic crosslinking of ammonium ions and polyanions of tripolyphosphate. The TEM photographs of CS-DHBA show that these particles are spherical in shape, but the particles of CS-THBA show some aggregation. In addition, the solubility and the mechanical properties of the prepared modified chitosans and their nanoparticles were evaluated for bio-adhesive and biomedical application. The results of solubility tests indicated that, the CS-DHBA and CS-THBA have higher solubility at pH 〉 7 comparing to CS. Also the CS-DHBA, CS-THBA and their nanoparticles showed a significant adhesive capacity and enhanced tensile strength and tensile modulus.

关键词： Nanoparticles Di- and tri-hydroxy benzoyl chitosans Ionic cross linking Solubility Adhesive properties.

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Application of nano silica to improve self-healing of asphalt mixes

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Journal of Central South University 2017年第5期24卷 1019-1026页

作者： Ganjei mohamad Amin Aflaki Esmail Department of Civil and Environmental Engineering Amirkabir University of TechnologyTehranIran

Nano silica due to its spherical shape, tiny size and higher density compared to bitumen, may have an inherent potential to improve hot mix asphalt(HMA) self-healing. In this research scanning electron microscopy(SEM) images were used to investigate size, morphology and dispersion of nano silica particles. Additionally, HMA self-healing mechanism was also examined by SEM. Furthermore, dynamic indirect tensile test(IDT) was used to evaluate HMA self-healing index. The SEM results indicated that bitumen mortar flowing into micro cracks may be one of the most important mechanisms of HMA self-healing. The experiment results also showed that modification of bitumen by nano silica promotes the ability of the HMA self-healing.

关键词： nano silica healing index Taguchi method hot mix asphalt

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Modeling and experimental studies of methyl methacrylate polymerization in a tubular reactor

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Chinese Journal of Chemical Engineering 2016年第12期24卷 1655-1663页

作者： mohamad-Taghi Rostami Ali Daneshgar Department of Engineering Mohaghegh Ardabili University Daneshgah Street Ardabil lran

In this study, rheological examination of the mixture of a tubular reactor in which methyl methacrylate was polymerized has been studied. The n(flow behavior index) value of Power Law Model of mixture contained in the reactor has been determined within the span of 0.3492 to 0.9889 by curve fitting. Employing these numerical data for velocity profile, the reactor has been modeled. Moreover, the functions of the reactor have been compared in the three modes of plug, mixed and laminar flow. The results obtained in this research indicate that the polymethyl methacrylate mixture contained in the reactor is pseudo-plastic. Moreover, as the conversion grows, the velocity profile starts as a parabolic profile and approaches the plug mode; although it never reaches the plug. The other conclusions borne in this study indicate that when the reactor's radius is decreased, the conversion rate grows. However, as decreasing the radius would also reduce the productions rate, this procedure is not economical. Finally, in this modeling, the amount of conversion is equal to 56.47% at the end and according to its laboratory proportion which is 55.88%, it has reached the conclusion that the modeling duly undertaken is applicable and valid.

关键词： Conversion Laminar flow MMA Modeling Tubular reactor

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Effect of laser power and deposition environment on the microstructure and properties of direct laser metal-deposited 12CrNi2 steel

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Acta Metallurgica Sinica(English Letters) 2020年第4期33卷 528-538页

作者： mohamad Ebrahimnia Yujiang Xie Changtai Chi Zhejiang Handsome Intelligent Remanufacturing Technology Co.Ltd Jiaxing 314000China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

Direct laser metal deposition was used for preparing blocks of steel 12CrNi2 using four different laser powers under two different deposition environments including atmospheric environment and Ar-protected *** results showed that microstructures and mechanical properties were significantly affected by different laser *** laser power and deposition in Ar chamber will lead to a decrease in the quantity and size of the voids,which brings more elongation to the *** microstructure was replaced by Widmanstatten ferrite and pearlite,and the amount of proeutectoid ferrite increased with increasing laser ***,microstructures of previous layers were completely altered in high laser *** heat accumulation by using high heat input can produce equiaxed ferritic grains with the pearlites in previously deposited *** of deposited samples increased from the bottom layer toward the top *** using a diode laser with a spot diameter size of 2 mm,the 900-W laser power is suitable for producing crack-and void-free ***,post-deposition heat treatment is necessary for obtaining homogeneous desired microstructure and grain size in the manufactured samples.

关键词： Direct laser metal deposition Bainite Equiaxed ferrite Void Steel Microstructure Mechanical properties Rapid solidification

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