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An authentication and plausibility model for big data analytic under LOS and NLOS conditions in 5G-VANET

Science China(Information Sciences) 2020年第12期63卷 67-83页

作者： S.A.SOLEYmANI m.H.ANISI A.Hanan ABDULLAH m.Asri NGADI Sh.GOUDARZI m.Khurram KHAN m.Nazri KAmA School of Computing Faculty of Engineering Universiti Teknologi Malaysia (UTM) School of Computer Science and Electronic Engineering University of Essex Centre of Artificial Intelligence National University of Malaysia (UKM) Center of Excellence in Information Assurance (CoEIA) King Saud University Advanced Informatics School Menara Razak Universiti Teknologi Malaysia (UTM)

The exchange of correct and reliable data among legitimate nodes is one of the most important challenges in vehicular ad hoc networks(VANETs). malicious nodes and obstacles, by generating inaccurate information, have a negative impact on the security of 5G-VANET. The big data generated in the vehicular network is also an issue in the security of VANET. To this end, a security model based on authentication and plausibility is proposed to improve the safety of network named ‘AFPm’. In the first layer, an authentication mechanism using edge nodes along with 5G is proposed to deal with the illegitimate nodes who enter the network and broadcast wrong information. In the authentication mechanism, because of the growth of the connected vehicles to the edge nodes that lead to generating big data and hence the inappropriateness of the traditional data structures, cuckoo filter, as a space-efficient probabilistic data structure, is used. In the second layer, a plausibility model by performing fuzzy logic is presented to cope with inaccurate information. The plausibility model is based on detection of inconsistent data involved in the event message. The plausibility model not only tackles with inaccurate, incomplete, and inaccuracy data but also deals with misbehaviour nodes under both line-of-sight(LOS) and non-line-of-sight(NLOS) conditions. All obtained results are validated through well-known evaluation measures such as F-measure and communication overhead. The results presented in this paper demonstrate that the proposed security model possesses a better performance in comparison with the existing studies.

关键词： authentication plausibility fuzzy logic cuckoo filter 5G-VANET big data

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Calculation of photon shielding properties for some neutron shielding materials

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Nuclear Science and Techniques 2017年第5期28卷 74-80页

作者： A. m. El-Khayatt Physics Department College of Science Al Imam Mohammad Ibn Saud Islamic University (IMSIU) RiyadhSaudi Arabia Reactor Physics Department NRC Atomic Energy Authority 13759 Cairo Egypt

The objective of the present study is to calculate photon shielding parameters for seven polyethylene-based neutron shielding materials. The parameters include the effective atomic number(Z_(eff)), the effective electron density(N_(eff)) for photon interaction and photon energy absorption,and gamma-ray kerma coefficient(kc). The calculations of Z_(eff)are presented as a single-valued and are energy dependent. While Z_(eff)values were calculated via simplistic powerlaw method, the energy-dependent Z_(eff)for photon interaction(Z_(PI-eff)) and photon energy absorption(Z_(PEA-eff)) are obtained via the direct method for energy ranges of 1 keV–100 GeV and 1 keV–20 me V, respectively. The kccoefficients are calculated by summing the contributions of the major partial photon interactions for energy range of 1 keV–100 meV. In most cases, data are presented relative to pure polyethylene to allow direct comparison over a range of energy. The results show that combination of polyethylene with other elements such as lithium and aluminum leads to neutron shielding material with more ability to absorb neutron and crays. Also, the kerma coefficient first increases with Z of the additive element at low photon energies and then converges with pure polyethylene at energies greater than 100 keV.

关键词： Neutron shielding materials Effective atomic number Kerma coefficient c-rays

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The Effect of Non-Contact Conditions in a Splinted Fixed Partial Denture on the Load Sharing mechanism： A Finite Element Study

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Journal of Bionic Engineering 2012年第3期9卷 336-342页

作者： m. Z. Bendjaballah Biomedical Technology Department College of Applied Medical Sciences King Saud University Riyadh Saudi Arabia

A computer-aided design model for a fixed partial denture was constructed and used in a finite element analysis to study the overall load sharing mechanism between the fixed partial denture and oral structures while the denture base rested on the al- veolar ridge. To investigate the consequences of non-contact conditions, three additional models were generated incorporating a uniform clearance of 0.125 mm, 0.25 mm, and 0.5 mm, respectively. A 100 N static load located at the free end of the prosthesis was applied while the distal portion of the jaw was set fixed. The results show that whilst releasing the ridge almost entirely, the presence of the clearance drastically increased the load on the splinting teeth. A pull-out force on the canine tooth of about 44 N was computed, accompanied by a mesio-distal moment of about 500 ***. The combination of which was similar to the tooth extraction maneuver performed by the dentist. In contrast, the second premolar was found to bear a push-in force of almost 115 N. The first molar, though barely solicited in the contact condition, became substantially loaded in non-contact conditions, which validates the choice of sacrificing three teeth to support the denture.

关键词： finite element analysis splinted fixed partial denture hygienic space load transfer mechanism contact problem

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青藏高原及其周边成冰纪-埃迪卡拉纪综合地层、生物群与古地理演化

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中国科学：地球科学 2024年第4期54卷 936-967页

作者：孙郎 malik muhammad saud Sajid KHAN 杨传孙智新潘兵 Shehryar AHmED 苗兰云孙玮辰胡春林孙晓娟罗翠陈波殷宗军赵方臣李国祥朱茂炎中国科学院南京地质古生物研究所现代古生物学和地层学国家重点实验室南京210008 中国科学院大学地球与行星科学学院北京100049

青藏高原及其周边的块体,包括印度板块、拉萨地块、羌塘地块、塔里木板块、欧龙布鲁克地块、中祁连地块、阿拉善地块、华北板块、扬子板块、中伊朗地块和阿曼等,以及各块体之间造山带的复杂演化历史是地球科学研究的前沿和热点.成冰系... 详细信息

青藏高原及其周边的块体,包括印度板块、拉萨地块、羌塘地块、塔里木板块、欧龙布鲁克地块、中祁连地块、阿拉善地块、华北板块、扬子板块、中伊朗地块和阿曼等,以及各块体之间造山带的复杂演化历史是地球科学研究的前沿和热点.成冰系和埃迪卡拉系广泛分布于该地区的各个构造单元,其中阿曼、印度板块、扬子板块以及塔里木板块发育有相对完整的成冰系和埃迪卡拉系;而在中伊朗地块、南羌塘地块、中祁连地块、阿拉善地块及华北板块,目前已知仅有埃迪卡拉系发育.基于前人对青藏高原及其周边地区成冰系和埃迪卡拉系的研究,结合第二次青藏高原综合科学考察研究项目开展以来获得的新资料和研究进展,本文建立了该地区成冰系和埃迪卡拉系代表性地层序列对比表.在此基础上,本文梳理了该地区这一时期生物群和重大地质事件的研究现状和存在的问题.结果表明,该地区各板块埃迪卡拉纪化石的保存和组合面貌各具特色,但普遍发现有典型埃迪卡拉纪末期化石分子Cloudina和Shaanxilithes;除成冰纪两次全球性冰期事件外,在青藏高原北缘各块体(华北板块、阿拉善地块、北祁连构造带、中祁连地块、欧龙布鲁克地块、塔里木板块)以及伊朗中南部普遍记录了一次埃迪卡拉纪晚期的冰川事件,但该事件的时限、分布范围和成因有待进一步揭示;同时,埃迪卡拉纪中期DOUNCE/Shruam碳同位素负异常事件在青藏高原周边地区也具有广泛记录.综合现有研究资料发现,在成冰纪-埃迪卡拉纪期间,青藏高原及其周边地区大多数块体从罗迪尼亚超大陆裂解出来后,可能通过泛非运动构成东冈瓦纳大陆的一部分,而部分板块(如华北板块)位于冈瓦纳大陆和劳伦大陆之间.总体而言,该地区的主要块体在成冰纪-埃迪卡拉纪期间具体的古地理演化模型存在较多争议,亟需开展进一步的研究工作.

关键词：青藏高原成冰系埃迪卡拉系地层古地理生物群冈瓦纳大陆

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microstructure and mechanical properties of hot extruded 6016 aluminum alloy/graphite composites

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Journal of materials Science & Technology 2018年第9期34卷 1580-1591页

作者： mohamed m.El-Sayed Seleman mohamed m.Z.Ahmed Sabbah Ataya Department of metallurgical and materials Engineering Faculty of Petroleum and Mining Engineering Suez University 43518 Suez Egypt Suez and Sinai metallurgical and materials Research Center of Scientific Excellence (SSmmR-CSE) 43518 Suez Egypt The British University in Egypt Mechanical Engineering Deportment El-Sherouk City 11837 Cairo Egypt Department of mechanical Engineering College of Engineering AI Imam Mohammad Ibn Saud Islamic University Riyadh 11432 saudi Arabia

The incorporation of graphite particles into AA6016 aluminum alloy matrix to fabricate metal/ceramic composites is still a great challenge and various parameters should be considered. In this study, dense AA6016 aluminum alloy/（0-20 wt%） graphite composites have successfully been fabricated by powder metallurgy process. At first, the mixed aluminum and graphite powders were cold compacted at 200 mPa and then sintered at 500 ℃ for 1 h followed by hot extrusion at 450 ℃. The influence of ceramic phases（free graphite and in-situ formed carbides） on microstructure, physical and mechanical properties of the produced composites were finally investigated. The results show that the fabricated composites have a relative density of over 98%. SEm observations indicate that the graphite has a good dispersion in the alloy matrix even at high graphite content. Hardness of all the produced composites was higher than that of aluminum alloy matrix. No cracks were observed at strain less than 23% for all hot extruded *** strength, reduction in height, ultimate tensile stress, fracture stress, yield stress, and fracture strain of all Al/graphite composites were determined by high precision second order equations. Both compressive and ultimate tensile strengths have been correlated to microstructure constituents with focusing on the in-situ formed ceramic phases, silicon carbide（SiC） and aluminum carbide（Al4 C3）. The ductile fracture mode of the produced composites became less dominant with increasing free graphite content and in-situ formed carbides. Wear resistance of Al/graphite composites was increased with increasing graphite content. Aluminum/20 wt% graphite composite exhibited superior wear resistance over that of AA6016 aluminum alloy.

关键词： AA6016/graphite composites Hot extrusion In-situ carbides mechanical properties Wear resistance Fracture behavior

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mosquito autogeny in Aedes caspius （Diptera： Culicidae）： alterations of larval nourishments reservation upon bacterial infection

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Insect Science 2013年第4期20卷 472-484页

作者： Ashraf m. Ahmed Zoology Department College of Science King Saud University SaudiArabia Zoology Department College of Science Minia UniversityEl-Minia Egypt

The present study recorded mosquito autogeny for the first time amongst Aedes caspius species in the Eastern region of saudi Arabia. Laboratory rearing showed an obligatory autogenous species of Ae. caspius since it foregoes blood feeding during its first ovarian cycle, even in the presence of the hosts （CD mouse）, but produces its second egg batch only if ingested a blood meal. Both morphological and molecular identification confirmed that both autogenous and anautogenous strains belong to the same species of Ae. caspius. Data from biochemical analysis showed significant 2, 1.6, and 1.4 folds higher total carbohydrates, proteins, and lipids reserves respectively in the fourth larval instar of the autogenous strain compared to that of the anautogenous ones. In addition, exposing the fourth larval instars of autogenous strain to the infection stress by the mosquito larvicidal bacterium, Bacillus thuringiensis var kurstaki has significantly reduced total carbohydrates, proteins and lipids reserves by 29%, 35%, and 46%, respectively, at 12 h postinfection compared to those of uninfected ones. These reductions in nourishment reserves were more pronounced at 24 h postinfection in the case of proteins and lipids, but not carbohydrates. These results may indicate that bacterial infection is a health stress that significantly reduced nourishments reservation, which may interrupt the success of adult autogeny. However, the impact of infection-induced decline in larval nourishments reservation on successful adult autogeny is still to be investigated.

关键词： Aedes caspius anautogeny autogeny Bacillus thuringiensis nourishmentsreservation

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multi-Step Detection of Simplex and Duplex Wormhole Attacks over Wireless Sensor Networks

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Computers, materials & Continua 2022年第3期70卷 4241-4259页

作者： Abrar m.Alajlan Self-Development Skills Department Common First Year DeanshipKing Saud UniversityRiyadhKSA

Detection of thewormhole attacks is a cumbersome process,particularly simplex and duplex over thewireless sensor networks(WSNs).Wormhole attacks are characterized as distributed passive attacks that can destabilize or disable *** distributed passive nature of these attacks makes them enormously challenging to *** main objective is to find all the possible ways in which how the wireless sensor network’s broadcasting character and transmission medium allows the attacker to interrupt network within the distributed *** further to detect the serious routing-disruption attack“Wormhole Attack”step by step through the different network *** this paper,a new multi-step detection(mSD)scheme is introduced that can effectively detect the wormhole attacks for *** mSD consists of three algorithms to detect and prevent the simplex and duplex wormhole ***,the proposed scheme integrated five detection modules to systematically detect,recover,and isolate wormhole *** results conducted inOmNET++show that the proposedmSDhas lower false detection and false toleration ***,mSDcan effectively detect wormhole attacks in a completely distributed network environment,as suggested by the simulation results.

关键词： Wireless sensor network wormhole attack node validation multi-step detection

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Variation in metabolic enzymatic activity in white muscle and liver of blue tilapia,Oreochromis aureus,in response to long-term thermal acclimatization

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Chinese Journal of Oceanology and Limnology 2015年第3期33卷 696-704页

作者： Elsayed m.YOUNIS Zoology Department College of Science King Saud University

The effects of rearing temperature on white muscle and hepatic phosphofructokinase （PFK）, pyruvate kinase （PK）, lactate dehydrogenase （LDH）, aspartate aminotransferase （AST） and alanine aminotransferase （ALT） were examined in fingerlings of blue tilapia, Oreochromis aureus. The experiment was conducted for 14 weeks at temperatures of 18, 22, 26, 30, and 34℃. The activity of the glycolytic enzymes PFK, PK, and LDH in white muscle increased significantly with increase in water temperature. A reverse trend was observed for these enzymes in the liver, except for LDH, which behaved in the same manner as in white muscle. Cytosolic AST and ALT activity increased in both white muscle and liver in response to warm thermal acclimatization, while a reduction in mitochondrial AST and ALT activity was noticed at high temperatures in comparison with those at a lower temperature.

关键词： Nile tilapia thermal acclimatization metabolism enzymes

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Water equivalence of some 3D dosimeters:a theoretical study based on the effective atomic number and effective fast neutron removal cross section

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Nuclear Science and Techniques 2017年第12期28卷 170-181页

作者： A.m.El-Khayatt Department of Physics College of Science Al Imam Mohammad Ibn Saud Islamic University (IMSIU) Reactor Physics Department NRC Atomic Energy Authority

Effective atomic numbers for photon energy absorption(ZPEA_(eff)) and their corresponding electron numbers (NPEA_(eff)), and effective macroscopic removal cross sections of fast neutrons(RR) were calculated for 27 different types of three-dimensional dosimeters, four types of phantom materials, and water. The values of ZPEA_(eff) and NPEA_(eff) were obtained using the direct method for energies ranging from 10 keV to 20 meV. Results are presented relative to water, for direct comparison over the range of examined energies. The effect of monomers that are used in polymer gel dosimeters on the water equivalence is discussed. The relation between Σ_R and hydrogen content was studied. micelle gel dosimeters are highly promising because our results demonstrate perfect matching between the effective atomic number, electron density number, and fast neutron attenuation coefficient of water.

关键词： 3D dosimeters Water equivalence Effective atomic number Photon energy absorption Removal cross section Fast neutrons

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COVID-19 and Unemployment: A Novel Bi-Level Optimal Control model

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Computers, materials & Continua 2021年第4期67卷 1153-1167页

作者： Ibrahim m.Hezam Department of Statistics and Operations Research College of SciencesKing Saud UniversityRiyadhSaudi Arabia Department of mathematics Ibb UniversityIbbYemen

Since COVID-19 was declared as a pandemic in march 2020,the world’s major preoccupation has been to curb it while preserving the economy and reducing *** paper uses a novel Bi-Level Dynamic Optimal Control model(BLDOC)to coordinate control between COVID-19 and *** COVID-19 model is the upper level while the unemployment model is the lower level of the bi-level dynamic optimal control *** BLDOC model’s main objectives are to minimize the number of individuals infected with COVID-19 and to minimize the unemployed individuals,and at the same time minimizing the cost of the containment *** use the modified approximation Karush–Kuhn–Tucker(KKT)conditions with the Hamiltonian function to handle the bi-level dynamic optimal control *** consider three control variables:The first control variable relates to government measures to curb the COVID-19 pandemic,i.e.,quarantine,social distancing,and personal protection;and the other two control variables relate to government interventions to reduce the unemployment rate,i.e.,employment,making individuals qualified,creating new jobs reviving the economy,reducing *** investigate four different cases to verify the effect of control *** results indicate that rather than focusing exclusively on only one problem,we need a balanced trade-off between controlling each.

关键词： Bi-level optimal control COVID-19 Hamiltonian function Karush-Kuhn-Tucker unemployment

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