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Delay Compensation Observer with Sliding Mode Controller for Rotary Electro-hydraulic Servo System

Transactions of Nanjing University of Aeronautics and Astronautics 2021年第S1期38卷 49-56页

作者： ZAKARYA omar khalid Hussein WANG Xingsong ORELAJA Olusyi Adwale School of Mechanical Engineering Southeast UniversityNanjing 211189P.R.China Faculty of Engineering Sana’a UniversitySanaaYemen

The hip’s lower limb exoskeleton essential and most important function is to support human’s payload as well as to enhance and assist human’s motion. It utilizes an electro-hydraulic servo manipulator which is required to achieve precise trajectory tracking and positioning operations. Nevertheless,these tasks require precise and robust control,which is very difficult to attain due to the inherent nonlinear dynamic behavior of the electro-hydraulic system caused by flow-pressure characteristics and fluid volume control variations of the servo valve. The sliding mode controller(SMC)is a widely used nonlinear robust controller,yet uncertainties and delay in the output degrade the closed-loop system performance and cause system instability. This work proposes a robust controller scheme that counts for the output delay and the inherent parameter uncertainties. Namely,a sliding mode controller enhanced by time-delay compensating observer for a typical electro-hydraulic servo system is adapted. SMC is utilized for its robustness against servo system parameters’ uncertainty whereas a time-delay observer estimates the variable states of the controller(velocity and acceleration). The main contribution of this paper is improving on the closed loop performance of the electro hydraulic servo system and mitigating the delay time effects. Simulation results prove the robustness of this controller,which forces the position to track the desired path regardless of the changes of the amount of transport delay of the system’s states. The performance of the proposed controller is validated by repeating the simulation analysis while varying the amount of delay time.

关键词： sliding mode controller rotary electro-hydraulic servo system delay compensating observer transport delay

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The Awareness of Keratoconus among General Population in Saudi Arabia

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Open Journal of Ophthalmology 2021年第1期11卷 49-59页

作者： Rahaf Mohammed Alruwaili Abeer Surihan Alharbi omar Ali Alghamdi Yahya Abdulrahman Alyahya Nouf Mohammed Albalawi Sameer Sohail Alostaz omar Ahmed Asiri khalid Alarfaj College of Medicine Jouf University Sakaka Saudi Arabia Ophthalmology Department Ohud Hospital Madina Saudi Arabia Ophthalmology Department King Fahad Hospital Albaha Saudi Arabia Ophthalmology Department Burydah Central Hospital Qassim Saudi Arabia College of Medicine Tabuk University Tabuk Saudi Arabia Batterjee Medical College Jeddah Saudi Arabia Faculty of Medicine Taif University Taif Saudi Arabia Ophthalmology Department Imam Abdulrahman Bin Faisal University Dammam Saudi Arabia

Introduction: Keratoconus (KCN) is one of the degenerative corneal disorders, which causes impairment in normal visual acuity with a higher prevalence in Saudi Arabia. The study aimed to assess the awareness and knowledge regarding KCN, its risk factors, and management among the Saudi population. Materials and Methods: A survey was conducted using a pre-tested and validated questionnaire distributed through online platforms. A mixture of convenience and snowball sampling techniques was adopted for sample collection. Our analysis included a final sample size of 837 participant responses. The questionnaire had items related to sociodemographic characteristics (5 items), knowledge (10 items), and source of information (1 item). The mean knowledge scores were calculated and categorized (good, fair, and poor) to assess each participant’s knowledge. Pearson’s chi-square test was used to determine the statistical association between categorical variables. Results: The mean knowledge score was found to be 4.12 ± 2.6, and 67.5% of the participants showed “poor” scores. There was no statistically significant association of knowledge scores observed with any of the sociodemographic details. It was agreed by 76% and 42.5% that genetic predisposition and chronic eye inflammation could predispose to KCN. Only 38.1% (n = 157) agreed that KCN could be treated with optical glasses or contact lenses in the initial stages. Conclusion: The knowledge regarding KCN was not satisfactory among our study population. There is a need to create an increased level of awareness for KCN. Health awareness programs and community campaigns should be organized to raise awareness regarding KCN and better eye health care utilization.

关键词： Ophthalmology Inflammation Keratoconus Blindness

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Functional Nonparametric Predictions in Food Industry Using Near-Infrared Spectroscopy Measurement

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Computers, Materials & Continua 2023年第3期74卷 6307-6319页

作者： Ibrahim M.Almanjahie omar Fetitah Mohammed Kadi Attouch Tawfik Benchikh Department of Mathematics College of ScienceKing Khalid UniversityAbha62529Saudi Arabia Statistical Research and Studies Support Unit King Khalid UniversityAbha62529Saudi Arabia Laboratory of Statistics and Stochastic Processes University of Djillali Liabes BP 89 Sidi Bel Abbes22000Algeria Medical Faculty Djillali Liabes University BP 89Sidi Bel Abbes22000Algeria

Functional statistics is a new technique for dealing with data thatcan be viewed as curves or images. Parallel to this approach, the Near-InfraredReflectance (NIR) spectroscopymethodology has been used in modern chemistryas a rapid, low-cost, and exact means of assessing an object’s chemicalproperties. In this research, we investigate the quality of corn and cookiedough by analyzing the spectroscopic technique using certain cutting-edgestatistical models. By analyzing spectral data and applying functional modelsto it, we could predict the chemical components of corn and cookie *** Functional Classical Estimation (KFCE), Kernel Functional QuantileEstimation (KFQE), Kernel Functional Expectile Estimation (KFEE),Semi-Partial Linear Functional Classical Estimation (SPLFCE), Semi-PartialLinear Functional Quantile Estimation (SPLFQE), and Semi-Partial LinearFunctional Expectile Estimation (SPLFEE) are models used to accuratelyestimate the different quantities present in Corn and Cookie dough. Theselection of these functional models is based on their ability to constructa forecast region with a high level of confidence. We demonstrate that theconsidered models outperform traditional models such as the partial leastsquaresregression and the principal component regression in terms of predictionaccuracy. Furthermore, we show that the proposed models are morerobust than competing models such as SPLFQE and SPLFEE in the sensethat data heterogeneity has no effect on their efficiency.

关键词： Functional statistics NIR chemical component kernel estimation

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Industrial Food Quality Analysis Using New k-Nearest-Neighbour methods

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Computers, Materials & Continua 2021年第5期67卷 2681-2694页

作者： omar Fetitah Ibrahim M.Almanjahie Mohammed Kadi Attouch Salah Khardani Laboratory of Statistics and Stochastic Processes University of Djillali LiabesSidi Bel Abbes22000Algeria Department of Mathematics College of ScienceKing Khalid UniversityAbha62529Saudi Arabia Statistical Research and Studies Support Unit King Khalid UniversityAbha62529Saudi Arabia Facultédes sciences de Tunis Laboratoire des Réseaux Intelligents et NanotechnologieTunisTunisia

The problem of predicting continuous scalar outcomes from functional predictors has received high levels of interest in recent years in many fields,especially in the food *** k-nearest neighbor(k-NN)method of Near-Infrared Reflectance(NIR)analysis is practical,relatively easy to implement,and becoming one of the most popular methods for conducting food quality based on NIR *** k-NN is often named k nearest neighbor classifier when it is used for classifying categorical variables,while it is called k-nearest neighbor regression when it is applied for predicting noncategorical *** objective of this paper is to use the functional Near-Infrared Reflectance(NIR)spectroscopy approach to predict some chemical components with some modern statistical models based on the kernel and k-Nearest Neighbour *** this paper,three NIR spectroscopy datasets are used as examples,namely Cookie dough,sugar,and tecator ***,we propose three models for this kind of data which are Functional Nonparametric Regression,Functional Robust Regression,and Functional Relative Error Regression,with both kernel and k-NN approaches to compare between *** experimental result shows the higher efficiency of k-NN predictor over the kernel *** predictive power of the k-NN method was compared with that of the kernel method,and several real data sets were used to determine the predictive power of both methods.

关键词： Functional data analysis classical regression robust regression relative error regression kernel method k-NN method near-infrared spectroscopy

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Calcified Abdominal Pregnancy with Five Years of Evolution (Lithopedion): A Case Report

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Open Journal of Obstetrics and Gynecology 2016年第8期6卷 515-519页

作者： Nafisa A. Mohamed Ikram A. Hajji Salah A. omar khalid S. Kalib Abdirizak H. Ali Department of Obstetrics and Gynecology Benadir Hospital Mogadishu Somalia

Lithopedion is a rare phenomenon resulting from an extra-uterine pregnancy that advances to fetal demise and calcification and there are less than 300 cases reported in 400 years of medical literature. This rare condition was first described by a surgeon of the Arabic era of medicine in the 10th century. This case report is a 26-year-old, multiparous woman who had presented a lower abdominal pain for long time and she had never attended in pre-natal clinic. She came to our hospital with pain and tumoral mass in infra-umbilical area and then we referred to radiology center, after that ultrasound examination of radiology center demonstrated an extra-uterine abdominal 30-week pregnancy measuring the femoral length, this for first diagnosis of radiology center. After laparotomy was performed we met an oval shaped mass that attached the omentum in peritoneal cavity and this mass was a fetus retention of 5 years without calcified ovular membranes but the fetus was calcified so this type is called lithopedion that describes according to the Kuechenmeister classification in 1881. She made good post-operative recovery after extraction the stone baby.

关键词： Abdominal Pregnancy Lithopedion

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Primary Anorectal Melanomas Interest of Targeting C-KIT in Two Cases from a Series of 11 Patients

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Journal of Cancer Therapy 2014年第3期5卷 225-230页

作者： Karima Oualla Nawfel Mellas Fatimazahra El’mrabet Samia Arifi Afaf Amarti khalid Ait Taleb Siham Tizniti omar Elmesbahi Department of Medical Oncology Hassan II University Hospital Fez Morocco Department of Pathology Hassan II University Hospital Fez Morocco Department of Radiology Hassan II University Hospital Fez Morocco Department of Visceral Surgery Hassan II University Hospital Fez Morocco

Background: The anorectal location of melanomas is extremely rare (1% - 3% of all melanomas), and the prognosis remains poor because of the aggressiveness and the high metastatic potential of those tumors. The discovery that the KIT oncogene may be aberrantly activated in a subset of patients with anorectal melanoma creates a realm of possibility for the development of targeted molecular therapy. Aim: to show the epidemiologic, clinico-radiological, histological features and treatment management especially in patients with over-expression of C-KIT treated by Imatinib. Methods: It is a retrospective study conducted in the department of medical oncology at Hassan II University Hospital between January 2007 and January 2012, including all patients with histologically proven melanoma of the anorectal area. Results: 11 cases were collected, with slight female predominance. Nine patients were metastatic at the moment of diagnosis, and only two with local stage, but evolution was marked by local and distant recurrence less than 12 months after abdo-minoperineal resection. First line of chemotherapy was based mainly on paclitaxel, carboplatine and dacarbazine. Response was modest with only 3 partial responses, 4 patients with disease stability, and 4 patients with disease progression. Two patients, with over expression of C-KIT, received Imatinib as second line of treatment with significant improvement of symptoms and radiological response reaching 50%. Seven patients died with a median survival of 11 months from diagnosis to the date of death. Conclusion: Primary anorectal melanomas are very rare, with high aggressiveness and poor prognosis. Treatment management is still a big challenge given to the modest efficacy of conventional chemotherapy. Better understanding of carcinogenesis and signaling pathways will allow development of new targeted therapies.

关键词： Melanoma Anorectal Area Surgery Chemotherapy C-KIT Imatinib

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Tympanometry Comparison of Diabetic Type I and Diabetic Type II Rats

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Journal of Diabetes Mellitus 2023年第1期13卷 58-67页

作者： Susan Amin Ahmed Alaradi Ahmed Alekri Ali Alaysreen Ammar Kheyami Hasan Baksh khalid Nazzal Abdullah Altamimi omar Alhamdan Amer Kamal School of Medicine Royal College of Surgeons in Ireland (RCSI-Bahrain) Busaiteen Bahrain Department of Physiology Arabian Gulf University (AGU) Manama Bahrain

Hearing impairment affects over two-thirds of adults with diabetes. We investigated whether rat models of type 1 and type 11 diabetes display impaired auditory function. Tympanometry measurements were conducted in Sprague-Dawley rats (control, n = 20), streptozotocin-induced type I diabetic Sprague-Dawley rats (n = 20) at 42 - 56 days old;Zucker rats (Hos: ZFDM-Lean (fa/+, n = 20) and Zucker Type 2 Diabetic rats (ZFDM (Hos: ZFDM-fa/fa);n = 20)), 90 days old. All rats were male. Control animals had normal type A tympanograms. Tweny one (75%) of the tympanic membranes in the diabetic type I group produced abnormal tympanograms: 46% were type B, 28% had no peak found, and 1% were type C. The ear canal measurements were lower in the left ear in type I mice (0.19 ± 0.07) and higher in the left ear for type II mice (0.23 ± 0.15 ml) compared to the controls of 0.39 ± 0.14 ml) and (0.2 ± 0.12 ml) respectively (P < 0.0001). The compliances for the right ear and left ear were lower for the type II diabetic group (0.18 ± 0.05 ml) and (0.18 ± 0.05 ml) compared to the control group (0.28 ± 0.19 ml) and (0.28 ± 0.49 ml) (P < 0.0001) respectively. In conclusion, control rats exhibited type A tympanograms with a highly functional middle ear system. Diabetic type I rats (n = 20) mostly exhibited type B tympanograms with a less compliant middle ear system. Compliance was reduced in the diabetic type I and II animals compared to the control. Future studies should utilise histological methods alongside tympanometry. Sections of the middle ear could be used to analyze ossicle size and confirm size differences. This information would be useful in avenues for treatment options for hearing loss in diabetes.

关键词： Diabetes Tympanometry Auditory Function Compliance Ear Canal

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Primary breast leiomyosarcoma: case report and literature review

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Health 2011年第10期3卷 620-622页

作者： Fatima Zahra EL M’rabet Hanane El kacemi omar El Mesbahi khalid El Hassouni Brahim khalil El Gueddari 不详

PURPOSE: Leiomyosarcoma of the breast is extremely rare. To date, the factors that are predictive of patient prognosis have not been identified. To clarify the nature of leiomyosarcoma of the breast, and also to establish the proper treatment strategy, we report this case We report this case while discussing The Clinical presentation, diagnosis, therapy and pathologic feature. INTRODUCION: Sarcomas comprise less than 1% of all primary breast neoplasms and only a minority of these are leiomyosarcomas. There were only 35 cases being reported in English literature. The mainstay of treatment is surgical excision with clear margins and longterm followup is essential. Its prognosis is better compared to other breast sarcoma. CASE PRESENTATION: We report a case of primary leiomyosarcoma of the breast occurring in young female patient which was successfully treated by surgery and radiotherapy. CONCLUSION: According to literature data, primary leiomyosarcoma is characterized by a better prognosis compared with other breast sarcomas, To date, the factors that are predictive of patient prognosis have not been identified. .The rarity and diagnostic difficulty imposed a multidisciplinary approach.

关键词： leiomyosarcoma Breast Immunohistochemistry Mastectomy

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Nutritional status of children with inflammatory boweldisease in Saudi Arabia

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World Journal of Gastroenterology 2016年第5期22卷 1854-1858页

作者： Mohammad Issa El Mouzan Mohammed Hadi Al Edreesi Abdulrahman Abdullah Al-Hussaini omar Ibrahim Saadah Abdulaziz Abdullatif Al Qourain Mohammad Abdullah Al Mofarreh khalid Abdulrahman Al Saleem Department of Pediatrics HeadPediatric IBD Research GroupMember of Prince Abdullah Bin Khalid Celiac Disease Research ChairKing Saud UniversityRiyadh 11461Saudi Arabia Department of Pediatrics Saudi Aramco Medical Services Organization Dhahran Health CenterDhahran 31311Saudi Arabia Division of Gastroenterology HepatologyKing Saud Bin Abdul Aziz University for Health SciencesThe Children’s HospitalKing Fahad Medical CityRiyadh 11525Saudi Arabia Department of Pediatrics Faculty of Medicine&Inflammatory Bowel Disease Research GroupKing Abdul Aziz UniversityJeddah 21589Saudi Arabia Department of Medicine Division of GastroenterologyKing Fahad Hospital of the UniversityDammam UniversityDammam 31952Saudi Arabia Department of Gastroenterology Mofarreh Poly ClinicRiyadh 11423Saudi Arabia Section of Pediatric Gastroenterology Department of PediatricsKing Faisal Specialist Hospital&Research CentreRiyadh 11525Saudi Arabia

AIM: To assess the prevalence of nutritional disorders in children with inflammatory bowel disease(IBD) in Saudi ***: The data from a national cohort of children newly diagnosed with IBD between 2003 and 2012 were analyzed. The diagnosis of IBD and the differentiation between Crohn's disease(CD) and ulcerative colitis(UC) were confirmed by gastroenterologists according to the standard criteria. The body mass index(BMI) of each child [weight(kg)/height^2(m)] was calculated at the time of diagnosis. The World Health Organization standards and references were used and the BMI for age > +1 and <-2 standard deviation score were used to define overweight and thinness, respectively. Age stratification analysis was performed to investigate any age-related variation in the prevalence of nutritional status between children < 10 years of age and ***: There were 374 children from 0.33 to 17 years of age, including 119(32%) children with UC and 255(68%) with CD. All of the children were Saudi nationals, and 68(57%) of the UC and 150(59%) of the CD children were males. A positive history of anorexia at the time of diagnosis was found in 30(25%) patients with UC and 99(39%) patients with CD. The prevalence of thinness was 31%, 35% and 24% in children with IBD, CD and UC, respectively, with a significantly higher prevalence of thinness in children with CD than in children with UC(P = 0.037) only in the age group of 10-17 years(P = 0.030). The prevalence of overweight was 16 %, 15% and 20 % in the children with IBD, CD and UC, respectively, indicating a higher prevalence in UC that was statistically significant only in the age group of 10-17 years(P = 0.020). CONCLUSION: A high proportion of children with IBD presented with overweight instead of the classical underweight. Awareness of this finding is important for patient care.

关键词： Overweight Thinness Ulcerative colitis Crohn disease Children Saudi Arabia

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Efficient Resource Allocation Algorithm in Uplink OFDM-Based Cognitive Radio Networks

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Computers, Materials & Continua 2023年第5期75卷 3045-3064页

作者： omar Abdulghafoor Musbah Shaat Ibraheem Shayea Ahmad Hamood Abdelzahir Abdelmaboud Ashraf Osman Ibrahim Fadhil Mukhlif Herish Badal Norafida Ithnin Ali Khadim Lwas Electronic&Telecommunications Engineering Department The American University of KurdistanDuhokKurdistan RegionIraq CTTC BarcelonaSpain Faculty of Electrical and Electronics Engineering Istanbul Technical UniversityIstanbulTurkey Department of Information Systems King Khalid UniversityMuhayel AseerSaudi Arabia Faculty of Computing and Informatics University Malaysia SabahKota KinabaluMalaysia Information Assurance and Security Research Group(IASRG) School of ComputingFaculty of EngineeringUniversiti Teknologi MalaysiaJohorMalaysia R&D Ministry of Industry and MineralsBaghdadIraq

The computational complexity of resource allocation processes,in cognitive radio networks(CRNs),is a major issue to be ***,the complicated solution of the optimal algorithm for handling resource allocation in CRNs makes it unsuitable to adopt in real-world applications where both cognitive users,CRs,and primary users,PUs,exist in the identical geographical ***,this work offers a primarily price-based power algorithm to reduce computational complexity in uplink scenarioswhile limiting interference to PUs to allowable ***,this paper,compared to other frameworks proposed in the literature,proposes a two-step approach to reduce the complexity of the proposed mathematical *** the first step,the subcarriers are assigned to the users of the CRN,while the cost function includes a pricing scheme to provide better power control algorithm with improved reliability proposed in the second *** main contribution of this paper is to lessen the complexity of the proposed algorithm and to offer flexibility in controlling the interference produced to the users of the primary networks,which has been achieved by including a pricing function in the proposed cost ***,the performance of the proposed power and subcarrier algorithm is confirmed for orthogonal frequency-division multiplexing(OFDM).Simulation results prove that the performance of the proposed algorithm is better than other algorithms,albeit with a lesser complexity of O(NM)+O(Nlog(N)).

关键词： Cognitive radio resource allocation OFDM pricing

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