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roll-pitch-yaw autopilot design for nonlinear time-varying missile using partial state observer based global fast terminal sliding mode control

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Chinese Journal of Aeronautics 2016年第5期29卷 1302-1312页

作者： Ahmed awad Wang Haoping Sino-French International Joint Laboratory of Automatic Control and Signal Processing (LaFCAS) School of AutomationNanjing University of Science & Technology

The acceleration autopilot design for skid-to-turn （STT） missile faces a great challenge owing to coupling effect among planes, variation of missile velocity and its parameters, inexistence of a complete state vector, and nonlinear aerodynamics. Moreover, the autopilot should be designed for the entire flight envelope where fast variations exist. In this paper, a design of integrated roll-pitch-yaw autopilot based on global fast terminal sliding mode control （GFTSMC） with a partial state nonlinear observer （PSNLO） for STT nonlinear time-varying missile model, is employed to address these issues. GFTSMC with a novel sliding surface is proposed to nullify the integral error and the singularity problem without application of the sign function. The proposed autopilot consisting of two-loop structure, controls STT maneuver and stabilizes the rolling with a PSNLO in order to estimate the immeasurable states as an output while its inputs are missile measurable states and control signals. The missile model considers the velocity variation, gravity effect and parameters＇ variation. Furthermore, the environmental conditions＇ dynamics are mod- eled. PSNLO stability and the closed loop system stability are studied. Finally, numerical simulation is established to evaluate the proposed autopilot performance and to compare it with existing approaches in the literature.

关键词： Flight control system Global fast terminal slidingmode control Integrated autopilot Nonlinear state observer Skid-to-turn missile

Folding model calculations for ~6He+^(12)C elastic scattering

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Chinese Physics C 2016年第3期40卷 66-73页

作者： awad A.Ibraheem Physics Department King Khalid University Physics Department Al-Azhar University

In the framework of the double folding model, we used the α＋2n and di-triton configurations for the nuclear matter density of the ~6He nucleus to generate the real part of the optical potential for the system ~6He＋^（12）C. As an alternative, we also use the high energy approximation to generate the optical potential for the same system. The derived potentials are employed to analyze the elastic scattering differential cross section at energies of 38.3, 41.6 and 82.3 Me V/u. For the imaginary part of the potential we adopt the squared Woods-Saxon form. The obtained results are compared with the corresponding measured data as well as with available results in the literature. The calculated total reaction cross sections are investigated and compared with the optical limit Glauber model description.

关键词： optical model elastic scattering halo nuclei folding model glauber model

Enhancing Network Intrusion Detection Model Using Machine Learning Algorithms

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Computers, Materials & Continua 2021年第4期67卷 979-990页

作者： Nancy awadallah awad Department of Computer and Information Systems Sadat Academy for Management SciencesCairo11742Egypt

After the digital revolution,large quantities of data have been generated with time through various *** networks have made the process of data analysis very difficult by detecting attacks using suitable *** Intrusion Detection Systems(IDSs)secure resources against threats,they still face challenges in improving detection accuracy,reducing false alarm rates,and detecting the unknown *** paper presents a framework to integrate data mining classification algorithms and association rules to implement network intrusion *** experiments have been performed and evaluated to assess various machine learning classifiers based on the KDD99 intrusion *** study focuses on several data mining algorithms such as;naïve Bayes,decision trees,support vector machines,decision tables,k-nearest neighbor algorithms,and artificial neural ***,this paper is concerned with the association process in creating attack rules to identify those in the network audit data,by utilizing a KDD99 dataset anomaly *** focus is on false negative and false positive performance metrics to enhance the detection rate of the intrusion detection *** implemented experiments compare the results of each algorithm and demonstrate that the decision tree is the most powerful algorithm as it has the highest accuracy(0.992)and the lowest false positive rate(0.009).

关键词： Intrusion detection association rule data mining algorithms KDD99

Machine Learning Techniques in Predicting Hot Deformation Behavior of Metallic Materials

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 713-732页

作者： Petr Opela Josef Walek Jaromír Kopecek Department of Metallurgical Technologies Faculty of Materials Science and TechnologyVSB–Technical University of OstravaOstrava70800Czech Republic FZU—Institute of Physics of the Czech Academy of Sciences Prague18200Czech Republic

In engineering practice,it is often necessary to determine functional relationships between dependent and independent *** relationships can be highly nonlinear,and classical regression approaches cannot always provide sufficiently reliable ***,Machine Learning(ML)techniques,which offer advanced regression tools to address complicated engineering issues,have been developed and widely *** study investigates the selected ML techniques to evaluate their suitability for application in the hot deformation behavior of metallic *** ML-based regression methods of Artificial Neural Networks(ANNs),Support Vector Machine(SVM),Decision Tree regression(DTr),and Gaussian Process regression(GPr)are applied to mathematically describe hot flow stress curve datasets acquired experimentally for a medium-carbon *** the GPr method has not been used for such a regression task before,the results showed that its performance is the most favorable and practically unrivaled;neither the ANN method nor the other studied ML techniques provide such precise results of the solved regression analysis.

关键词： Machine learning Gaussian process regression artificial neural networks support vector machine hot deformation behavior

Forest mapping:a comparison between hyperspectral and multispectral images and technologies

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Journal of Forestry research 2018年第5期29卷 1395-1405页

作者： Mohamad M.awad remote Sensing Center National Council for Scientific Research

Mapping forests is an important process in managing natural *** present,due to spectral resolution limitations,multispectral images do not give a complete separation between different forest *** contrast,advances in remote sensing technologies have provided hyperspectral tools and images as a solution for the determination of *** this study,spectral signatures for stone pine（Pinus pinea L.） forests were collected using an advanced spectroradiometer ＂ASD FieldSpec 4 Hi-res＂ with an accuracy of 1 *** spectral signatures are used to compare between different multispectral and hyperspectral satellite *** comparison is based on processing satellite images： hyperspectral Hyperion,hyperspectral CHrIS-Proba,Advanced Land Imager（ALI）,and Landsat *** and classification methods for hyperspectral and multispectral images are investigated and *** addition,a well-known hyperspectral image classification algorithm,spectral angle mapper（SAM）,has been improved to perform the classification process efficiently based on collected spectral *** results show that the modified SAM is 9% more accurate than the conventional *** addition,experiments indicate that the CHrIS-Proba image is more accurate than Landsat 8（overall accuracy 82%,precision 93%,and Kappa coefficient 0.43 compared to 60,67%,and 0.035,respectively）.Similarly,Hyperion is better than ALI in mapping stone pine（overall accuracy 92%,precision 97%,and Kappa coefficient 0.74 compared to 52,56%,and -0.032,respectively）.

关键词： Classification Economy Hyperspectral Multispectral Spectral signatures Stone pine

Effects of cathodic component of current on porosity and hardness characteristics of micro plasma oxidation(MPO) coatings on aluminum alloy

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中国有色金属学会会刊：英文版 2005年第1期15卷 113-118页

作者： Samir Hamid awad 钱翰城 School of Mechanical Engineering Chongqing University Chongqing 400044 China

Micro plasma oxidation(MPO) has recently been investigated as a novel, rapid and effective means to provide modified surfaces with improved properties of load bearing and wear resistance on light alloys particularly aluminum alloys. MPO is a multifactor-controlled process, these factors must be controlled to produce high quality coatings. The main research emphasis in MPO coating development over the past years seems to be the attainment of higher hardness levels and thick coatings. The porosity of MPO coating is the most complex phenomenon affecting the distribution, levels and the measurements of the hardness; and it is controlled by suitable selection of important parameters such as the electrical conditions. Ceramics coatings were synthesized on Al substrate by MPO to examine the effects of adding a cathodic phase alternated with anodic-cathodic current on the porosity and hardness characteristics of coatings by X-ray diffraction(XrD), scanning electron microscopy(SEM), and microhardness tester. The coatings produced by the combined mode are more dense and less porous than that by the anodic-cathodic mode. (Microhardness) test shows that the coatings produced by the combined mode exhibit both the highest hardness, and less reduction percentage in hardness with increasing the coatings thickness. These improvements become more significant for the polished and thicker coatings.

关键词：微观等离子体氧化铝合金硬度多孔材料

Improving reconstructed Image Quality via Hybrid Compression Techniques

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Computers, Materials & Continua 2021年第3期66卷 3151-3160页

作者： Nancy awadallah awad Amena Mahmoud Department of Computer and Information Systems Sadat Academy for Management SciencesCairo11742Egypt Department of Computer Science Kafr el Sheikh University33511Egypt

Data compression is one of the core fields of study for applications of image and video *** raw data to be transmitted consumes large bandwidth and requires huge storage space as a result,it is desirable to represent the information in the data with considerably fewer bits by the mean of data compression techniques,the data must be reconstituted very similarly to the initial *** this paper,a hybrid compression based on Discrete Cosine Transform(DCT),DiscreteWavelet Transform(DWT)is used to enhance the quality of the reconstructed *** techniques are followed by entropy encoding such as Huffman coding to give additional *** coding is optimal prefix code because of its implementation is more simple,faster,and easier than other *** needs less execution time and it is the shortest average length and the measurements for analysis are based upon Compression ratio,Mean Square Error(MSE),and Peak Signal to Noise ratio(PSNr).We applied a hybrid algorithm on(DWT–DCT 2×2,4×4,8×8,16×16,32×32)***,we show that by using a hybrid(DWT–DCT)compression technique,the PSNr is reconstructed for the image by using the proposed hybrid algorithm(DWT–DCT 8×8 block)is quite high than DCT.

关键词： Image compression discrete cosine transform PSNr discrete wavelet transform hybrid algorithm

Heterogeneity of mature oligodendrocytes in the central nervous system

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Neural regeneration research 2025年第5期20卷 1336-1349页

作者： Chao Weng Adam M.r.Groh Moein Yaqubi Qiao-Ling Cui Jo Anne Stratton G.r.Wayne Moore Jack P.Antel Neuroimmunology Unit Montreal Neurological Institute-HospitalDepartment of Neurology and NeurosurgeryMcGill UniversityMontrealQCCanada Department of Neurology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

Mature oligodendrocytes form myelin sheaths that are crucial for the insulation of axons and efficient signal transmission in the central nervous *** evidence has challenged the classical view of the functionally static mature oligodendrocyte and revealed a gamut of dynamic functions such as the ability to modulate neuronal circuitry and provide metabolic support to *** the recognition of potential heterogeneity in mature oligodendrocyte function,a comprehensive summary of mature oligodendrocyte diversity is *** delve into early 20th-century studies by robertson and río-Hortega that laid the foundation for the modern identification of regional and morphological heterogeneity in mature ***,recent morphologic and functional studies call into question the long-assumed homogeneity of mature oligodendrocyte function through the identification of distinct subtypes with varying myelination ***,modern molecular investigations,employing techniques such as single cell/nucleus rNA sequencing,consistently unveil at least six mature oligodendrocyte subpopulations in the human central nervous system that are highly transcriptomically diverse and vary with central nervous system *** and disease related mature oligodendrocyte variation denotes the impact of pathological conditions such as multiple sclerosis,Alzheimer's disease,and psychiatric ***,caution is warranted when subclassifying mature oligodendrocytes because of the simplification needed to make conclusions about cell identity from temporally confined *** studies leveraging advanced techniques like spatial transcriptomics and single-cell proteomics promise a more nuanced understanding of mature oligodendrocyte *** research avenues that precisely evaluate mature oligodendrocyte heterogeneity with care to understand the mitigating influence of species,sex,central nervous system region,age,and disease,

关键词： aging central nervous system diseases electron microscopy heterogeneity immunohistochemistry myelin sheath natural history neuroglia oligodendroglia single-cell gene expression analysis

Analyzing Customer reviews on Social Media via Applying Association rule

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Computers, Materials & Continua 2021年第8期68卷 1519-1530页

作者： Nancy awadallah awad Amena Mahmoud Department of Computer and Information Systems Sadat Academy for Management SciencesCairo11742Egypt Faculty of computers and Information Department of Computer ScienceKafr el Sheikh UniversityKafr El Sheikh33511Egypt

The rapid growth of the use of social media opens up new challenges and opportunities to analyze various aspects and patterns in ***-text mining,several techniques are available such as information clustering,extraction,summarization,*** this study,a text mining framework was presented which consists of 4 phases retrieving,processing,indexing,and mine association rule *** is applied by using the association rule mining technique to check the associated term with the Huawei P30 Pro *** reviews are extracted from many websites and Facebook groups,such as ***,*** and *** technology,where customers from all over the world placed their notes on cell *** this analysis,a total of 192 reviews of Huawei P30 Pro were collected to evaluate them by text mining *** findings demonstrate that Huawei P30 Pro,has strong points such as the best safety,high-quality camera,battery that lasts more than 24 hours,and the processor is very *** paper aims to prove that text mining decreases human efforts by recognizing significant *** will lead to improving the awareness of customers to choose their products and at the same time sales managers also get to know what their products were accepted by customers suspended.

关键词： Machine learning text mining social media big data association rule document clustering