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Combination of Model-based Observer and Support Vector Machines for Fault Detection of Wind Turbines

International Journal of Automation and computing 2014年第3期11卷 274-287页

作者： Nassim Laouti sami othman Mazen Alamir Nida Sheibat-othman Université de Lyon Université Lyon 1 CNRS CPE Lyon UMR 5007 LAGEP F-69616 Villeurbanne France Gipsa-lab/CNRS University of Grenoble Rue de la Houille Blanche 38400 Saint Martin d Heres France

Support vector machines and a Kalman-like observer are used for fault detection and isolation in a variable speed horizontalaxis wind turbine composed of three blades and a full converter. The support vector approach is data-based and is therefore robust to process knowledge. It is based on structural risk minimization which enhances generalization even with small training data set and it allows for process nonlinearity by using flexible kernels. In this work, a radial basis function is used as the kernel. Different parts of the process are investigated including actuators and sensors faults. With duplicated sensors, sensor faults in blade pitch positions,generator and rotor speeds can be detected. Faults of type stuck measurements can be detected in 2 sampling periods. The detection time of offset/scaled measurements depends on the severity of the fault and on the process dynamics when the fault occurs. The converter torque actuator fault can be detected within 2 sampling periods. Faults in the actuators of the pitch systems represents a higher difficulty for fault detection which is due to the fact that such faults only affect the transitory state(which is very fast) but not the final stationary state. Therefore, two methods are considered and compared for fault detection and isolation of this fault: support vector machines and a Kalman-like observer. Advantages and disadvantages of each method are discussed. On one hand, support vector machines training of transitory states would require a big amount of data in different situations, but the fault detection and isolation results are robust to variations in the input/operating point. On the other hand, the observer is model-based, and therefore does not require training, and it allows identification of the fault level, which is interesting for fault reconfiguration. But the observability of the system is ensured under specific conditions, related to the dynamics of the inputs and outputs. The whole fault detection

关键词： Fault detection and isolation wind turbine Kalman-like observer support vector machines data-based classification

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1.56 kV/30 A vertical β-Ga2O3 Schottky barrier diodes with composite edge terminations

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Science China(Information Sciences) 2025年第2期68卷 389-390页

作者： Yitao FENG Hong ZHOU sami ALGHAMDI Hao FANG Xiaorong ZHANG Yanbo CHEN Guotao TIAN Saud WASLY Yue HAO Jincheng ZHANG Key Lab of Wide Band Gap Semiconductor Materials and Devices School of MicroelectronicsXidian University Center of Excellence in Intelligent Engineering Systems (CEIES) King Abdulaziz University China Resources Microelectronics Limited

In recent years, large-area wide-bandgap（WBG） semiconductor materials have achieved numerous notable breakthroughs [1,2]. The ultra-WBG semiconductor β-Ga2O3,with its excellent material properties, is ideally suited for the fabrication of power devices. Moreover, it offers easily obtainable large-area substrates, with reported sizes up to 6 inches, produced through melt-grown crystal growth methods. These characteristics make β-Ga2O3highly attractive for future low-cost commercialization. Despite these advances, most research has focused on low-current and small-size diodes, with few studies addressing high-current and large-size diodes.

关键词： Schottky barrier diodes

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24.4 THz·V fT ×BV figure-of-merit AlN/GaN/AlN MISHEMTs with thin AlN buffer layer

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Science China(Information Sciences) 2025年

作者： Chaoqun ZHANG Hong ZHOU sami ALGHAMDI Kun ZHANG Zhihong LIU Yue HAO Jingcheng ZHANG State Key Laboratory of Wide-Bandgap Semiconductor Devices and Integrated Technology Xidian University Guangzhou Wide Bandgap Semiconductor Innovation Center Guangzhou Institute of TechnologyXidian University Electrical and Computer Engineering Department King Abdulaziz University

Gallium nitride-based high-electron-mobility-transistors(HEMTs) have gained widespread interest and become primary candidates for next-generation high-frequency and high-power RF electronics, due to their wide bandgap,high breakdown field, and strong polarization-induced highdensity 2-dimensional electron gas (2DEG) at the heterojunction interface. AlGaN-based barriers and GaN-based buffers have become the dominant commercialized device structures for radar, satellite, and 5G communications [1, 2].

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A Novel Reliable and Trust Objective Function for RPL-Based IoT Routing Protocol

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Computers, Materials & Continua 2025年第2期82卷 3467-3497页

作者： Mariam A.Alotaibi sami S.Alwakeel Aasem N.Alyahya Department of Computer Engineering College of Computer ScienceKing Saud UniversityRiyadh11543Saudi Arabia Department of Computer Science and Information Technology Shaqra UniversityShaqra11961Saudi Arabia

The Internet of Things (IoT) integrates diverse devices into the Internet infrastructure, including sensors, meters, and wearable devices. Designing efficient IoT networks with these heterogeneous devices requires the selection of appropriate routing protocols, which is crucial for maintaining high Quality of Service (QoS). The Internet Engineering Task Force’s Routing Over Low Power and Lossy Networks (IETF ROLL) working group developed the IPv6 Routing Protocol for Low Power and Lossy Networks (RPL) to meet these needs. While the initial RPL standard focused on single-metric route selection, ongoing research explores enhancing RPL by incorporating multiple routing metrics and developing new Objective Functions (OFs). This paper introduces a novel Objective Function (OF), the Reliable and Secure Objective Function (RSOF), designed to enhance the reliability and trustworthiness of parent selection at both the node and link levels within IoT and RPL routing protocols. The RSOF employs an adaptive parent node selection mechanism that incorporates multiple metrics, including Residual Energy (RE), Expected Transmission Count (ETX), Extended RPL Node Trustworthiness (ERNT), and a novel metric that measures node failure rate (NFR). In this mechanism, nodes with a high NFR are excluded from the parent selection process to improve network reliability and stability. The proposed RSOF was evaluated using random and grid topologies in the Cooja Simulator, with tests conducted across small, medium, and large-scale networks to examine the impact of varying node densities. The simulation results indicate a significant improvement in network performance, particularly in terms of average latency, packet acknowledgment ratio (PAR), packet delivery ratio (PDR), and Control Message Overhead (CMO), compared to the standard Minimum Rank with Hysteresis Objective Function (MRHOF).

关键词： IoT LLNs RPL objective function OF MRHOF OF0 routing metrics reliability trustworthiness

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Relativistic solutions for diatomic molecules subject to pseudoharmonic oscillator in arbitrary dimensions

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Chinese Physics B 2013年第7期22卷 64-69页

作者： sami Ortakaya Institute of Natural and Applied Sciences Department of PhysicsErciyes University

The exact solutions of the N-dimensional Klein–Gordon equation in the presence of an exactly solvable potential of V（r）=De（r/re-re/r）2 type have been obtained. The N dimensional Klein-Gordon equation has been reduced to a first-order differential equation via Laplace transformation. The exact bound state energy eigenvalues and corresponding wave functions for CH,H2,and HCl molecules interacting with pseudoharmonic oscillator potential in the arbitrary N dimensions have been determined. Bound state eigenfunctions used in applications related to molecular spectroscopy are obtained in terms of confluent hypergeometric functions.

关键词： Klein–Gordon equation Laplace integral transform bound states

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Exact solutions of the Klein-Gordon equation with ring-shaped oscillator potential by using the Laplace integral transform

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Chinese Physics B 2012年第7期21卷 108-112页

作者： sami Ortakaya Institute of Natural and Applied Sciences Erciyes University

We present exact solutions for the Klein Gordon equation with a ring-shaped oscillator potential. The energy eigenvalues and the normalized wave functions are obtained for a particle in the presence of non-central oscillator potential. The angulm＂ functions are expressed in terms of the hypergeometric functions. The radial eigenfunetions have been obtained by using the Laplace integral transform. By means of the Laplace transform method, which is efficient and simple, the radial Klein-Gordon equation is reduced to a first-order differential equation.

关键词： ring-shaped oscillator Klein-Gordon equation Laplace integral transform bound states

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Role of quantum paths in generation of attosecond pulses

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Chinese Physics B 2020年第10期29卷 276-281页

作者： M R sami A Shahbaz Department of Physics Government College UniversityP.O.Box 54000 LahorePakistan

We investigate the role of core potential in high ionization potential systems on high harmonic generation (HHG) spectra and obtain attosecond pulses. In our scheme, we use a standard soft core potential to model high ionization potential systems and irradiated these systems with fixed laser parameters. We observe the role of these systems on all the three steps involved in HHG process including ionization, propagation and recombination. In our study, the results illustrate that for high ionization potential systems, the HHG process is more sensitive to the ionization probability compared to the recombination amplitude. We also observe that due to the stronger core potential, small oscillations of the electrons during the propagation do not contribute to the HHG spectrum, which implies the dominance of only long quantum paths in the HHG spectrum. Our results, for attosecond pulse generation, show that long quantum path electrons are responsible for the supercontinuum region near the cutoff, which is suitable for the extraction of a single attosecond pulse in this region.

关键词： high-order harmonic generation attosecond pulses quantum paths strong nuclear potential

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DOF:a generic approach of domain ontology fuzzification

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Frontiers of Computer Science 2021年第3期15卷 97-108页

作者： Houda AKREMI sami ZGHAL Faculty of Sciences of Tunis University of Tunis El ManarTunis 2092Tunisia Faculte des Sciences Juridiques Universite de JendoubaJendouba 8189Tunisia

Although recent studies on the Semantic Web have focused on crisp ontologies and knowledge representation,they have paid less attention to imprecise ***,the results of these studies constitute a Semantic Web that can answer requests almost perfectly with respect to ***,they ensure low *** such,we propose in this re-search work a new generic approach of fuzzification that which allows a semantic representation of crisp and fuzzy data in a domain *** the framework of our real case study,the obtained illustrate that our approach is highly better than the crisp one in terms of completeness,comprehensiveness,generality,comprehension and shareability.

关键词： crisp ontology fuzzy ontology fuzzy logic fuzzy reasoning domain ontology

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Methanolic extract from Lespedeza bicolor： potential candidates for natural antioxidant and anticancer agent

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Journal of Traditional Chinese Medicine 2017年第4期37卷 444-451页

作者： sami Ullah Department of Botany University of PeshawarPeshawar 24420 Pakistan

OBJECTIVE: To evaluate the anticancer, antioxidant and antimicrobial activities along with total phenolic and flavonoids contents extracted from Lespedeza bicolor indigenous to Khyber Pukhtoonkhwa ***: Anticancer activity against human lung carcinoma(LU-1) and human prostate carcinoma(Ln Cap), antimicrobial against Aspergillus fumigates, Aspergillus niger, Fusarium solani, Mucor sp Klebsiella pneumonia and Enterococcus and antioxidant activity on 1,1-Diphenyl-2-picryl-hydrazy(DPPH) and Hydrogen peroxide radicals scavenging activity were assessed in methanol extract o Lespedeza ***: Lespedeza bicolor aerial parts and root extract showed IC_(50)value of 12.5 and 50 μg/m L against LU-1 whereas, ≤ 12.5 and 12 μg/m L were calculated against Ln Cap cell line. Minimum inhibition concentration(MIC) value of 20-35 μg/m L has been observed against Aspergillus fumigates, Aspergillus niger, Fusarium solani and Mucor sp in comparision with 1-2.5 μg/m L of Terbinafine used as a standard fungicide. MIC value of 20 and 35 μg/m L of Lespedeza bicolor aerial parts and root extract against bacterial pathogen Klebsiella pneumonia and 20-50 μg/m L against Enterococcus has been measured. DPPH radical scavenging activity of Lespedeza bicolor with IC_(50)values of ≤ 50 μg/m L and ≤ 200 μg/m L was observed whereas, hydrogen peroxide scavenging activity with IC_(50)values of ≤25 μg/m L for aerial parts and ≤ 50 μg/m L for the root extract of Lespedeza bicolor has been ***: These data suggested that the methanolic extract of Lespedeza bicolor could be potential candidates for natural antioxidants and anticancer.

关键词： Lespedeza Antineoplastic agents Antioxidants Anti-infective agents

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Saudi Consensus Report on Chronic Kidney Disease Management: Integrating the Latest Evidence and Clinical Practice Guidelines

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International Journal of Clinical Medicine 2025年第1期16卷 54-88页

作者： Abdulrahman Alsheikh Ahmed Aljedai Hajer Almudaiheem Salwa Alaidarous Ali Alshehri Hussein Elbadawi Saeed Alghamdi Faisal Aljehani sami Alobaidi Talal A. Altuwaijri Khalid Almatham Saud Alsifri Emad R. Issak King Abdulaziz University Hospital Jeddah Saudi Arabia Ministry of Health Riyadh Saudi Arabia Ministry of National Guards Hospital Jeddah Saudi Arabia King Fahad Medical City Riyadh Saudi Arabia Private Clinic My Clinic Jeddah Saudi Arabia College of Medicine University of Jeddah Jeddah Saudi Arabia College of Medicine King Saud University Riyadh Saudi Arabia College of Medicine Alfaisal University Riyadh Saudi Arabia Alhada Armed Forces Hospital Taif Saudi Arabia Faculty of Medicine Ain Shams University Cairo Egypt

Chronic Kidney Disease (CKD) poses a significant healthcare challenge in Saudi Arabia, necessitating a structured approach to management and treatment. Recent consensus guidelines in Saudi Arabia emphasize a comprehensive strategy for CKD management, tailored to local needs and healthcare resources. The guidelines advocate for early detection and stratified care to mitigate the progression of CKD and improve patient outcomes. Key recommendations include the routine assessment of albuminuria and estimated glomerular filtration rate (eGFR) for accurate diagnosis and staging of CKD. The consensus underscores the importance of utilizing updated tools like the CKD-EPI 2021 equation for eGFR calculation and incorporating cystatin C measurements for enhanced diagnostic accuracy. Management strategies focus on controlling underlying conditions such as diabetes and hypertension, which are prevalent risk factors in the Saudi population. Personalized treatment plans are recommended, incorporating lifestyle modifications, pharmacological interventions including SGLT-2 inhibitors and GLP 1 RA, and regular monitoring to manage CKD complications effectively. The guidelines also highlight the need for specialized care and referral pathways for advanced CKD stages, including the role of nephrologists in the comprehensive management of CKD patients. In addition, the consensus addresses the need for improving public awareness and education about CKD, emphasizing early screening and preventive measures, particularly in high-risk groups. The implementation of these guidelines aims to optimize CKD management across Saudi Arabia, reduce the burden of kidney disease, and enhance overall patient care in the region.

关键词： Chronic Kidney Disease

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