检索结果-南通市图书馆

Journal of Modern Power Systems and Clean Energy 2022年第2期10卷 450-458页

作者： ahmed S.A.Awad Dave Turcotte Tarek H.M.el-Fouly Natural Resources Canada Can-metENERGYVarennesCanadaon leave from the Electrical Power and Machines DepartmentFaculty of EngineeringAin Shams UniversityCairo 11566Egyp Natural Resources Canada CanmetENERGYVarennesCanada Advanced Power and Energy Center Khalifa UniversityAbu DhabiUnited Arab Emirates

The integration of renewable distributed generation(RDG)into distribution networks is promising and increasing ***,high penetration levels of distributed generation(DG)are often limited as they may have an adverse effect on the operation of distribution *** of the operation challenges is the interaction between DG and voltage-control equipment,e.g.,an under-load tap changer(ULTC),which is basically designed to compensate for voltage changes caused by slow load *** integration of variable DGs leads to rapid voltage fluctuations,which can negatively affect the tap operation of *** paper investigates the impact of high penetration levels of RDG on the tap operation of ULTC in distribution networks through *** mitigation techniques that can alleviate this impact are also *** these techniques,constant power-factor mode is regarded as the best trade-off between the simplicity and effectiveness of minimizing the number of tap *** are performed on a Canadian benchmark rural distribution feeder using OpenDSS software.

关键词： Renewable energy distributed generation(DG) voltage regulator load tap changer distribution network.

An Efficient Encryption and Compression of Sensed IoT Medical Images Using Auto-Encoder

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2023年第2期134卷 909-926页

作者： Passent el-kafrawy Maie Aboghazalah Abdelmoty M.ahmed Hanaa Torkey Ayman el-Sayed School of Information Technology and Computer Science Nile UniversityGiza12677Egypt Math and Computer Science Department Faculty of ScienceMenoufia UniversityMenoufia32511Egypt Department of Computer Engineering College of Computer ScienceKing Khalid UniversityAbha61421Saudi Arabia Computer Science and Engineering Department Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt

Healthcare systems nowadays depend on IoT sensors for sending data over the internet as a common *** ofmedical images is very important to secure patient *** these images consumes a lot of time onedge computing;therefore,theuse of anauto-encoder for compressionbefore encodingwill solve such a *** this paper,we use an auto-encoder to compress amedical image before encryption,and an encryption output(vector)is sent out over the *** the other hand,a decoder was used to reproduce the original image back after the vector was received and *** convolutional neural networks were conducted to evaluate our proposed approach:The first one is the auto-encoder,which is utilized to compress and encrypt the images,and the other assesses the classification accuracy of the image after decryption and *** hyperparameters of the encoder were tested,followed by the classification of the image to verify that no critical information was lost,to test the encryption and encoding *** this approach,sixteen hyperparameter permutations are utilized,but this research discusses three main cases in *** first case shows that the combination of Mean Square Logarithmic Error(MSLE),ADAgrad,two layers for the auto-encoder,and RelU had the best auto-encoder results with a Mean Absolute Error(MAE)=0.221 after 50 epochs and 75%classification with the best result for the classification *** second case shows the reflection of auto-encoder results on the classification results which is a combination ofMean Square Error(MSE),RMSprop,three layers for the auto-encoder,and RelU,which had the best classification accuracy of 65%,the auto-encoder gives MAE=0.31 after 50 *** third case is the worst,which is the combination of the hinge,RMSprop,three layers for the auto-encoder,and RelU,providing accuracy of 20%and MAE=0.485.

关键词： Auto-encoder cloud image encryption IoT healthcare

Low-voltage ride-through capability improvement of Type-3 wind turbine through active disturbance rejection feedback control-based dynamic voltage restorer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Clean Energy 2023年第5期7卷 1091-1109页

作者： el Mahfoud Boulaoutaq Asma Aziz Abdelmounime el Magri ahmed Abbou Mohamed Ajaamoum Azeddine Rachdy Ibn Zohr University Higher School of Technology Agadir School of Engineering Edith Cowan UniversityJoondalupWAaustralia Hassan II University of Casablanca National School of Technical Education Mohammed V University of Rabat Mohammadia School of Engineering

Disconnections due to voltage drops in the grid cannot be permitted if wind turbines(WTs)contribute significantly to electricity pro-duction,as this increases the risk of production loss and destabilizes the *** mitigate the negative effects of these occurrences,WTs must be able to ride through the low-voltage conditions and inject reactive current to provide dynamic voltage *** paper investigates the low-voltage ride-through(LVRT)capability enhancement of a Type-3 WT utilizing a dynamic voltage restorer(DVR).During the grid voltage drop,the DVR quickly injects a compensating voltage to keep the stator voltage *** paper proposes an active disturbance rejection control(ADRC)scheme to control the rotor-side,grid-side and DVR-side converters in a wind–DVR integrated *** performance of the Type-3 WT with DVR topology is evaluated under various test conditions using MATLAB®/Simulink®.These simulation results are also compared with the experimental results for the LVRT capability performed on a WT emulator equipped with a crowbar and direct current(DC)*** simulation results demonstrate a favourable transient and steady-state response of the Type-3 wind turbine quantities defined by the LVRT codes,as well as improved reactive power support under balanced fault *** the most severe voltage drop of 95%,the stator currents,rotor currents and DC bus voltage are 1.25 pu,1.40 pu and 1.09 UDC,respectively,conforming to the values of the LVRT *** controlled by the ADRC technique significantly increases the LVRT capabilities of a Type-3 doubly-fed induction generator-based WT under symmetrical voltage dip *** setting up ADRC controllers might be challenging,the proposed method has been shown to be extremely effective in reducing all kinds of internal and external disturbances.

关键词： active disturbance rejection controller(ADRC) dynamic voltage restorer(DVR) low-voltage ride-through(LVRT) Type-3 wind turbines(WTs) doubly-fed induction generator(DFIG)

Gut microbiota predicts the diagnosis of celiac disease in Saudi children

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2023年第13期29卷 1994-2000页

作者： Mohammad el Mouzan Asaad Assiri ahmed Al Sarkhy Department of Pediatrics(Gastroenterology Unit) King Saud UniversityRiyadh 11461Saudi Arabia

BACKGROUND Celiac disease(CeD)is a multisystem immune-mediated multifactorial condition strongly associated with the intestinal *** To evaluate the predictive power of the gut microbiota in the diagnosis of CeD and to search for important taxa that may help to distinguish CeD patients from *** Microbial DNA from bacteria,viruses,and fungi,was isolated from mucosal and fecal samples of 40 children with CeD and 39 *** samples were sequenced using the HiSeq platform,the data were analyzed,and abundance and diversities were *** this analysis,the predictive power of the microbiota was evaluated by calculating the area under the curve(AUC)using data for the entire *** Kruskal-Wallis test was used to evaluate the significance of the difference between *** Boruta logarithm,a wrapper built around the random forest classification algorithm,was used to identify important bacterial biomarkers for *** In fecal samples,AUCs for bacterial,viral,and fungal microbiota were 52%,58%,and 67.7%respectively,suggesting weak performance in predicting ***,the combination of fecal bacteria and viruses showed a higher AUC of 81.8%,indicating stronger predictive power in the diagnosis of *** mucosal samples,AUCs for bacterial,viral,and fungal microbiota were 81.2%,58.6%,and 35%,respectively,indicating that mucosal bacteria alone had the highest predictive *** bacteria,Bacteroides intestinalis and Burkholderiales bacterium 1-1-47,in fecal samples and one virus,Human_endogenous_retrovirus_K,in mucosal samples are predicted to be“important”biomarkers,differentiating celiac from nonceliac disease *** intestinalis is known to degrade complex arabinoxylans and xylan which have a protective role in the intestinal ***,several Burkholderiales species have been reported to produce peptidases that hydrolyze gluten peptides,with the potential to reduce the gluten content of ***,a role fo

关键词： Celiac disease Microbial signature Children Saudi Arabia

Role of the injected water salinity and ion concentrations on the oil recovery in carbonate reservoirs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Research 2022年第3期7卷 394-400页

作者： M.Fouad Snosy Mahmoud Abu el ela ahmed el-Banbi Helmy Sayyouh Petroleum Engineer General Petroleum CompanyEgypt Professor of Petroleum Engineering Cairo UniversityEgypt Professor of Petroleum Engineering The American University in CairoEgypt

Low salinity water flooding(LSWF)was initially considered using water with a low concentration of dissolved salts and was later extended to include modifying the ionic content of injected *** work investigates the effects of changing water salinity and composition along with the concentration of sulfate and iodide ions on oil recovery in carbonate reservoirs during the tertiary recovery *** experimental study was carried out using crude oil of 29°API,8 core samples extracted from the Eocene carbonate reservoir(Egypt),and 6 different water *** results showed additional oil recovery up to 5%of the original oil in place(OOIP)in the tertiary recovery stage with changing water salinity and water *** of high salinity(HS)and low salinity(LS)brines with high sulfate concentrations increased the incremental oil recovery by a value ranging from 1.7 to 3.8%of the *** the contrary,injection of HS and LS brines with low sulfate concentrations showed insignificant incremental oil recovery(less than 1%of the OOIP).Furthermore,injection of water with potassium iodide(KI)after injection of water with high sulfate brines showed additional oil recovery of about 1.7%of the *** the other hand,injection of water with KI after injection of water with low sulfate concentration showed insignificant incremental oil recovery(less than 0.4%of the OOIP).The concentration of sulfate in the injected water appeared to be key parameter to achieve effective waterflooding(WF)projects in carbonate ***,the results revealed that the multi-component ion exchange(MIE)mechanism seems to be the primary recovery mechanism for LSWF in carbonate *** results and conclusions of this study can be used to develop guidelines for designing waterflooding projects in carbonate reservoirs with optimum salinity.

关键词： Low salinity waterflooding Carbonate reservoirs Waterflooding LSWF

Geochemical characterization of rare earth elements in sediment profiles from the Oualida lagoon(Morocco)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geochimica 2023年第6期42卷 1051-1064页

作者： Nezha Mejjad Abdelmourhit Laissaoui Ouafa el Hammoumi ahmed Fekri Hamid Amsil National Center for Energy Sciences and Nuclear Techniques(CNESTEN)RabatMorocco LGAGE Faculty of Sciences Ben M'sikUniversity of Hassan IICasablancaMorocco

The present work assesses the temporal distribution pattern and geochemical changes of rare earth elements and Yttrium, Scandium, Thorium, and Uranium delivery into the Oualidia lagoon. Two sediment cores were retrieved from the Oualidia lagoon and analyzed using neutron activation analysis. The results indicated that heavy rare earth elements are slightly enriched the sediment cores over light rare earth elements. The highest values of REEs were recorded in the top layers of the cores and depleted with depth, suggesting a possible change in factors controlling their accumulation, including mechanical, chemical, and environmental parameters such as weathering intensity, grain size, and Fe-Mn oxides. The sediments display positive Ce anomalies, which are probably related to the submarine weathering process and detrital input. Noting also the variation of hydrodynamics conditions and confinement of the upstream part of the lagoon played a key role in changing the sediment ***, further investigation of REEs origin in the Oualidia lagoon sediment is required to identify their sources,provenances, and the factors controlling their spatial and vertical distributions. However, these results provide baseline data of occurring changes in REEs geochemical composition and constitute a typical study case to understand the link between sedimentary and geochemistry processes in a lagoonal ecosystem.

关键词： Geochemical characterization Rare earth elements Sediment Oualidia lagoon

Dissolved gas analysis and dissipation factor measurement of mineral oil-based nanofluids under thermal and electrical faults

在线全文

学校读者我要写书评

暂无评论

High Voltage 2023年第3期8卷 455-465页

作者： ahmed Maher Diaa-eldin A.Mansour Khaled Helal Ramadan A.A.Abd el Aal Department of electrical Engineering Faculty of EngineeringPort-Said UniversityPort-SaidEgypt Department of electrical Power Engineering Faculty of EngineeringEgypt-Japan University of Science and Technology(E-JUST)New Borg El-Arab CityAlexandriaEgypt Department of electrical Power and Machines Engineering Faculty of EngineeringTanta UniversityTantaEgypt

Mineral oil is the most frequent insulating liquid used in oil-immersed transformers for electrical insulation and heat ***,oil-based nanofluids are becoming more popular in scientific research as they have proved to have better dielectric and thermal *** applying these nanofluids into actual transformers,they would be exposed to thermal and electrical ***,The aim of the authors is to investigate the generation pattern of dissolved gases in nanofluids under thermal and electrical faults and to assess the applicability of traditional Dissolved Gas Analysis(DGA)techniques if oil-based nanofluids are used in ***-based nanofluid samples were prepared using a magnetic stirrer and an ultrasonic homogeniser and then subjected to simulated thermal and electrical faults in the laboratory using properly sealed test *** types of metal oxides,Silicon dioxide,Titanium dioxide,and Aluminium oxide nanoparticles,have been used to prepare nanofluids with 0.02 g/L and 0.04 g/L *** gases released and dissolved into oil due to the simulated faults were analysed and compared to traditional mineral oil as a *** dielectric dissipation factor was obtained and analysed for all *** to the findings,the presence and concentration of nanoparticles were shown to influence the amount of gases *** a result,this research is crucial in guaranteeing that traditional DGA techniques can be employed in transformers that use oil-based nanofluids.

关键词： electrical thermal dioxide

A New Approach to University IT Project Portfolio Management Based on Multi-Criteria Methods and the COBIT 5 Governance Framework

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science and Information 2023年第5期11卷 636-654页

作者： Majida LAAZIRI Khaoula BENMOUSSA Abdelaziz el ALAOUI el AMRANI ahmed MOUCHTACHI Structural Engineering Intelligent Systems and Electrical Energy LaboratoryNational Graduate School of Arts and CraftsHassan Ⅱ UniversityCasablanca 20670Morocco Higher Normal School Moulay Ismail UniversityMeknes 50050Morocco

Project portfolio management is a major challenge for some *** most organizations,there are a large number of projects active at the same time,some not necessarily delivering value or not aligned with their strategic *** universities face a lot of uncertainties when selecting and prioritizing the projects that make up their *** addition,the achievement of those who are aligned with the strategy of the university becomes a great *** to ensure good project portfolio management,the implementation of selection and prioritization methods and processes becomes *** the project portfolio management to be effective,it is necessary to establish a structured method adapted to the needs and strategy of the *** this context,this paper proposes a method for selecting and prioritizing projects within the framework of the portfolio management dedicated to universities,which can promote harmony between the university’s strategy,the needs and the priority objectives for enable better *** method is based on the processes of the COBIT 5 good practice framework,and on the multi-criteria decision-making methods AHP,TOPSIS and the WSM technique,thus,it proposes seven project selection criteria based on the five axes IT governance strategies and two catalysts derived from COBIT 5 *** evaluation and validation of this method was applied in the portfolio management of the Abdelmalek Essaadi Moroccan University(AUE).The result shows that this proposed method has made it possible to make a better selection and prioritization of the portfolio of projects of Abdelmleek Essaadi University having the most value.

关键词： IS governance information systems project portfolio management university governance project prioritization information technology(IT) good practice framework COBIT 5 APO05 multi-criteria decision-making method AHP TOPSIS WSM

A Machine Learning Based Framework for a Stage-Wise Classification of Date Palm White Scale Disease

在线全文

学校读者我要写书评

暂无评论

Big Data Mining and Analytics 2023年第3期6卷 263-272页

作者： Abdelaaziz Hessane ahmed el Youssefi Yousef Farhaoui Badraddine Aghoutane Fatima Amounas STI Laboratory IDMSFaculty of Sciences and TechniquesMoulay Ismail University of MeknesErrachidia 52000Morocco. IA Laboratory Department of Computer ScienceFaculty of SciencesMoulay Ismail University of MeknesMeknes 50070Morocco. RO.AL&I Group Computer Sciences DepartmentFaculty of Sciences and TechniquesMoulay Ismail University of MeknesErrachidia 52000Morocco.

Date palm production is critical to oasis agriculture,owing to its economic importance and nutritional *** diseases endanger this precious tree,putting a strain on the economy and *** scale Parlatoria blanchardi is a damaging bug that degrades the quality of *** an infestation reaches a specific degree,it might result in the tree’s *** counter this threat,precise detection of infected leaves and its infestation degree is important to decide if chemical treatment is *** decision is crucial for farmers who wish to minimize yield losses while preserving production *** this purpose,we propose a feature extraction and machine learning(ML)technique based framework for classifying the stages of infestation by white scale disease(WSD)in date palm trees by investigating their leaflets images.80 gray level co-occurrence matrix(GLCM)texture features and 9 hue,saturation,and value(HSV)color moments features are extracted from both grayscale and color images of the used *** classify the WSD into its four classes(healthy,low infestation degree,medium infestation degree,and high infestation degree),two types of ML algorithms were tested;classical machine learning methods,namely,support vector machine(SVM)and k-nearest neighbors(KNN),and ensemble learning methods such as random forest(RF)and light gradient boosting machine(LightGBM).The ML models were trained and evaluated using two datasets:the first is composed of the extracted GLCM features only,and the second combines GLCM and HSV *** results indicate that SVM classifier outperformed on combined GLCM and HSV features with an accuracy of 98.29%.The proposed framework could be beneficial to the oasis agricultural community in terms of early detection of date palm white scale disease(DPWSD)and assisting in the adoption of preventive measures to protect both date palm trees and crop yield.

关键词： machine learning feature extraction ensemble learning diseases precision agriculture date palm

Some aspects affecting the response of RC compartment structures subjected to internal blast loads

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2022年第1期21卷 135-148页

作者： Osman M.O.Ramadan M.Galal el Sherbiny ahmed M.Khalil Faculty of Engineering Cairo UniversityCairo 12411Egypt Higher Technological Institute(HTI)at 10th of Ramadan City Sharqia 13658Egypt Structural Engineering and Construction Management Department Faculty of Engineering&TechnologyFutureUniversity in Egypt-FUECairo 16383Egypt

Protective compartments are typically used to protect some specific structures from internal explosions,such as industrial buildings that contain devices that may explode in certain *** research investigates how the response of reinforced concrete(RC)compartment structures subjected to internal blast loads are affected by the following aspects:introduction of material nonlinearity in the analysis,reinforcement ratio,and aspect ratio of the *** achieve this goal,a calibrated and sophisticated FE numerical model is introduced,and a parametric study for the intended aspects is carried out.A discussion of the results and conclusions are offered,which show the role of each aspect in the dynamic performance of the compartment *** main conclusions are as follows:introduction of material nonlinearity in this type of analysis and for these structures is very important and significant in obtaining accurate outputs that are similar to actual behavior;the reinforcement ratio has a significant effect on the response and its effect varies depending on the thickness of the compartment;in general,increasing the reinforcement ratio enhances the behavior and reduces the stresses in the compartment;and the aspect ratio of the compartment does not show a clear pattern on the response of such structures under internal blast loads.

关键词： blast loads protective structures nonlinear analysis explicit dynamic analysis