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Deceptive jamming suppression in multistatic radar based on coherent clustering

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Journal of Systems Engineering and Electronics 2018年第2期29卷 269-277页

作者： abdalla ahmed ahmed Mohaned Giess Shokrallah ZHAO Yuan XIONG Ying TANG Bin School of Electronic Engineering University of Electronic Science and Technology of China

This paper proposes a suppression method of the deceptive false target(FT) produced by digital radio frequency memory(DRFM) in a multistatic radar system. The simulated deceptive false targets from DRFM cannot be easily discriminated and suppressed with traditional radar systems. Therefore, multistatic radar has attracted considerable interest as it provides improved performance against deception jamming due to several separated receivers. This paper first investigates the received signal model in the presence of multiple false targets in all receivers of the multistatic radar. Then, obtain the propagation time delays of the false targets based on the cross-correlation test of the received signals in different receivers. In doing so, local-density-based spatial clustering of applications with noise(LDBSCAN) is proposed to discriminate the FTs from the physical targets(PTs) after compensating the FTs time delays, where the FTs are approximately coincident with one position, while PTs possess small *** simulations are carried out to demonstrate the feasibility and validness of the proposed method.

关键词： multistatic radar clustering analysis electronic counter-countermeasure(ECCM) deceptive jamming

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ON LIMITING DISTRIBUTION FOR TIME FAILURE OF DUPLEX STANDBY REDUNDANT SYSTEM WITH PREVENTIVE MAINTENANCE

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Acta Mathematica Scientia 1983年第3期3卷 295-298页

作者： EI-Sharnduby,M A.Saddika,ahmed abdalla King Abdulaziz University King Abdulaziz University King Abdulaziz University

We consider a standby redundant model of two units under Difficult maintenance policy. We shall prove that under the condition that the mean life time of the system is much larger than the mean repair time and the mai... 详细信息

关键词： time ON LIMITING DISTRIBUTION FOR TIME FAILURE OF DUPLEX STANDBY REDUNDANT SYSTEM WITH PREVENTIVE MAINTENANCE

Numerical Investigation of TBM Jamming in Fault Zones and Control Measures

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Numerical Investigation of TBM Jamming in Fault Zones and Co...

作者： Alaa Jalal abdalla ahmed 山东大学

学位级别：硕士

目前隧洞建设呈现长洞身、大洞径、大埋深、地质复杂、灾害频发的发展趋势,对于深长隧洞施工,TBM在掘进速度、成洞质量、造价与环保方面具有显著优势。然而TBM地质适应性差,在穿越断层等不良地质时极易遭遇突水突泥、塌方、大变形等地... 详细信息

目前隧洞建设呈现长洞身、大洞径、大埋深、地质复杂、灾害频发的发展趋势,对于深长隧洞施工,TBM在掘进速度、成洞质量、造价与环保方面具有显著优势。然而TBM地质适应性差,在穿越断层等不良地质时极易遭遇突水突泥、塌方、大变形等地质灾害,诱发TBM卡机,造成工期延误和严重经济损失。因此,对TBM卡机机理及安全控制措施研究很有必要。本研究利用3DEC软件,构建了隧洞穿越断层TBM卡机防控措施优化数值计算模型,开展了 TBM穿越断层破碎带支护参数优化和卡机安全防控关键技术研究,并取得了以下成果:(1)研究了断层几何参数对围岩变形和破坏特征的影响规律通过开展不同断层倾角(30°、60°、90°、120°和150)、不同断层带宽度(4m、8m、12m、16m和20m)和不同断层影响带宽度(12m、24m、36m、48m和60m)的数值计算,研究了断层倾角、断层带宽度和断层影响区宽度对TBM穿越断层断裂带时围岩变形和破坏特征的影响规律。(2)提出了围岩变形控制最优支护体系分析了不同支护参数和防控体系下的围岩变形控制效果,揭示了围岩纵横向表面位移特征、围岩内部应力场和围岩破坏特征。研究发现,增大衬砌厚度对围岩变形的控制效果优于增大衬砌刚度,减小锚杆间距对围岩变形的控制效果优于增加锚杆长度,施加锚杆+混凝土衬砌可有效降低围岩变形,并综合围岩控制效果优化了围岩支护体系。(3)形成了 TBM卡机防控技术研究了刀盘扩挖、超前管棚、超前注浆、应力释放率等防控措施下TBM和围岩的相互作用关系,揭示了掘进过程中TBM刀盘、护盾的摩擦阻力演化特征。研究表明,刀盘扩挖+超前管棚+超前注浆+应力释放率组合措施可有效预防TBM卡机,并结合实际工程在TBM卡机防控中进行了验证和应用。

关键词：隧道开挖断层数值模拟防控措施 TBM卡机

Adaptive Power Control Aware Depth Routing in Underwater Sensor Networks

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Computers, Materials & Continua 2021年第10期69卷 1301-1322页

作者： Ghufran ahmed Saiful Islam Ihsan Ali Isra Adil Hayder Abdelmuttlib Ibrahim abdalla ahmed Muhammad Talha Sultan S.Alshamrani Ag Asri Ag Ibrahim Department of Computer Science FAST National University of Computer and Emerging Sciences(NUCES)KarachiPakistan Dr.A.Q.Khan Institute of Computer Sciences and Information Technology KahutaPakistan Faculty of Computer Science and Information Technology University of MalayaKuala Lumpur50603Malaysia Department of Computer Science COMSATS University IslamabadIslamabadPakistan Deanship of Scientific Research King Saud UniversityRiyadhSaudi Arabia Department of Information Technology College of Computer and Information TechnologyTaif UniversityTaif21944Saudi Arabia Faculty of Computing and Informatics Universiti Malaysia SabahKota KinabaluSabahMalaysia

Underwater acoustic sensor network(UASN)refers to a procedure that promotes a broad spectrum of aquatic *** can be practically applied in seismic checking,ocean mine identification,resource exploration,pollution checking,and disaster *** confronts many difficulties and issues,such as low bandwidth,node movements,propagation delay,3D arrangement,energy limitation,and high-cost production and arrangement costs caused by antagonistic underwater *** wireless sensor networks(UWSNs)are considered a major issue being encountered in energy management because of the limited battery power of their ***,the harsh underwater environment requires vendors to design and deploy energy-hungry devices to fulfil the communication requirements and maintain an acceptable quality of ***,increased transmission power levels result in higher channel interference,thereby increasing packet *** the facts mentioned above,this research presents a controlled transmission power-based sparsity-aware energy-efficient clustering in *** contributions of this technique is ***,it uses the adaptive power control mechanism to utilize the sensor nodes’battery and reduce channel interference ***,thresholds are defined to ensure successful ***,clustering can be implemented in dense areas to decrease the repetitive transmission that ultimately affects the energy consumption of nodes and interference ***,mobile sinks are deployed to gather information locally to achieve the previously mentioned *** suggested protocol is meticulously examined through extensive simulations and is validated through comparison with other advanced UWSN *** show that the suggested protocol outperforms other procedures in terms of network lifetime and packet delivery ratio.

关键词： UWSNs UASNs QoS

The Dilemma of the Nile Transboundary Water and the Way Forward

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Journal of Earth Science and Engineering 2013年第5期3卷 301-313页

作者： abdalla Abdelsalam ahmed Omdurman Islamic University Khartoum P.O.Box 1244 Sudan

The NB （Nile River Basin） is considered one of the most population lives in its riparian countries. Out of the latter about 50% live important basins in Africa, as over 33% of the African in the NB. In this paper a historical background on the NB cooperation evolvement including the recent NBI （NB Initiative） is briefly reported. The natural and human challenges facing the Nile water management are examined and discussed. The present dilemma among the Nile riparian countries is highlighted and its reasons are explained. The latter includes the NB CFA （Cooperative Framework Agreement）, which has been signed by six countries （Burundi, Ethiopia, Kenya, Rwanda, Tanzania and Uganda） while rejected by Egypt, Sudan and not signed by DR of Congo. Eretria and the newly established country ＂South Sudan＂ stands are not yet clear. Based on scientific methodology and analytical discussion, a number of solutions for better management of the trans-boundary Nile waters are drawn; taking into consideration the experiences of other international rivers shared basins. Finally, the paper concludes with recommendations and guidelines that may help in the way forward.

关键词： River Nile riparian countries trans-boundary waters NBI CFA dilemma way forward.

Validation of High Performance Liquid Chromatography with Fluorescence Detector Methods for Determination of Aflatoxins in Different Food and Animal Feed Samples

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Journal of Analytical Sciences, Methods and Instrumentation 2023年第1期13卷 1-11页

作者： Salah Eldeen Abass Ali ahmed abdalla ahmed Elbashir National Chemical Laboratories National Public Health Laboratory Federal Ministry of Health Khartoum Sudan Department of Chemistry Faculty of Science University of Khartoum Khartoum Sudan

Method validation for quantitative analysis of aflatoxins, AFB1, AFB2, AFG1 and AFG2 in sorghum, peanut butter, groundnut and animals feed is presented. Aflatoxins were extracted with a mixture of methanol: acetonitrile: water (60:30:10) and cleaned with Alfa test IAC chromatography before analysis by High Performance Liquid Chromatography coupled with fluorescence detection (HPLC-FLD) by adopting an isocratic chromatographic system using a mobile phase consisting acetic acid: acetonitrile: methanol (59:14:27), the separation of the four aflatoxins was achieved in less than 15 minutes. Calibration curves were linear over the concentration range from 2 - 18 ng/mL for AFB1 and AFG1, 0.4 - 3.6 ng/mL for AFB2 and AFG2, respectively. The LOD and LOQ in spiked samples were found to be 0.02 and 0.05 μg/kg for both AFB1 and AFG1, 0.01 and 0.03 μg/kg for both AFB2 and AFG2. The mean recovery values were in range from 84.2% to 96.9% was obtained. Five samples were found to be contaminated with aflatoxins and the total aflatoxins ranged from 0.02 to 3.26 μg/kg were obtained. Nineteen different samples were found to be contaminated with aflatoxins;the total aflatoxins ranged from 0.27 to 10.48 μg/kg were obtained. The highest total aflatoxins value was obtained in animal feeds.

关键词： Aflatoxins HPLC-FLD Peanut Peanut Butter Sorghum and Animal Feeds

Human Kallikrein-2 and Free Prostate Specific Antigen as Biomarkers for Early Detection of Prostate Cancer, Sudan: A Case-Control Study

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Open Journal of Clinical Diagnostics 2023年第1期13卷 9-21页

作者： Osman Khalid Yousif Badreldin Elsonni abdalla Mohammed Alimam M. ahmed Sami Mahjoub Taha ahmed Al Siddiq Ebraheem Muawia Mohamed ahmed Elhadi abdalla ahmed Departmentof Biochemistry and Nutrition Faculty of Medicine University of Gezira Wad Madani Sudan Department of Surgery Faculty of Medicine University of Gezira Wad Madani Sudan Department of Internal Medicine Faculty of Medicine University of Gezira Wad Madani Sudan Basic Sciences Department Faculty of Applied Medical Sciences University of Gezira Wad Madani Sudan Department of Medical Microbiology Faculty of Medical Laboratory Sciences University of Gezira Wad Madani Sudan

Background: Prostate cancer (PCa) is considered one of the major health threats facing males in Sudan. Prostate-specific antigen (PSA) test is the most important laboratory test used in the diagnosis of prostate cancer, the main disadvantage of PSA is its limited specificity, which triggered a lot of interest in development, more research on other markers such as serum human kallikrein-2 (KLK-2) and free prostate specific antigen (fPSA). Objectives: To evaluate the validity of serum kallikrein-2 (KLK-2) and free prostate specific antigen (fPSA) in the early detection of prostate cancer among Sudanese patients. Method: In this study seventy men were considered as a case subject, who were diagnosed as cancer prostate at Gezira Hospital for Renal Disease and Surgery (GHRDS), Sudan during the period February 2018 to July 2019. Randomly selected sixty patients of BPH patients and forty-five apparently healthy men as control subject. KLK-2, fPSA and PSA estimations were performed from serum samples using the principle of Enzyme Linked Immunosorbent Assay (ELISA). Results: The results revealed a highly significant difference between the serum levels individual biomarkers (KLK-2, fPSA, PSA) and multiple biomarkers (fPSA/PSA, KLK-2/fPSA, KLK-2/PSA) for patients with prostate cancer when compared with the control groups. Furthermore, the fPSA/PSA ratio was lower in the patients with prostate cancer (P value = 0.00) than in the control group, the fPSA/PSA ratio showed that best accuracy to differentiate prostate cancer from control group, fPSA cut-off value was found to be more than (18 ng/ml), with sensitivity (93%), specificity (80%), and odds ratio (55). Conclusions: The use of multiple biomarkers rather than individual biomarkers especially fPSA/PSA ratio improves the specificity as well as maintenance of higher sensitivity for early diagnosis of the prostate cancer.

关键词： Kallikrein-2 PSA fPSA Prostate Cancer Sudan

Early Results of Coronary Artery Bypass Graft (CABG) in Patients with Low Ejection Fraction

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World Journal of Cardiovascular Diseases 2020年第5期10卷 319-328页

作者： Wassam El-Din Hadad El-Shafey Taher Mohamed ahmed Elnagar ahmed abdalla Mostafa Kamal abdalla Mostafa Kamal Cardiology Department Faculty of Medicine Menoufia University Al Minufya Egypt Cardiology Department National Heart Institute Cairo Egypt Cardiology Department Police Academy Cairo Egypt

Background: Patients with ischemic heart disease and reduced ejection fraction have increased risk for postoperative complications and mortality. Our aim was to evaluate the effect of low EF (on the early outcomes after CABG and identify the predictors of mortality. Methods: From August 2018 to November 2019, 170 consecutive patients underwent CABG. Group 1 included 120 patients with EF ( EF (>40;57.90% ± 2.27%), 41 were men (82.0%), and the mean age was 54.30 ± 7.01 years and used as a control group. Results: Overall 30-day mortality was 10/120 patients (8.3%). Factors associated with higher mortality were females (70.0% vs. 17.3%, P Conclusion: CABG in EF < 40% is associated with more complications compared with those had EF higher than 40%;however, the clinical and echocardiographic parameters improved over time.

关键词： Coronary Artery Bypass Graft Low Ejection Fraction

ON LIMITING DISTRIBUTION FOR TIME FAILURE OF DUPLEX STANDBY REDUNDANT SYSTEM WITH PREVENTIVE MAINTENANCE

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数学物理学报 1983年第3期 351-354页

作者： EI-Sharrtduby M A.,Saddika ahmed abdalla King Abdulaziz University King Abdulaziz University

关键词： ON LIMITING DISTRIBUTION FOR TIME FAILURE OF DUPLEX STANDBY REDUNDANT SYSTEM WITH PREVENTIVE MAINTENANCE