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Depth factors for undrained bearing capacity of circular footing by numerical approach

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第4期9卷 761-766页

作者： Sadok Benmebarek insaf Saifi Naima Benmebarek NMISSI Laboratory Biskra University BP 145 Biskra 07000 Algeria

The undrained vertical bearing capacity of embedded foundation has been extensively studied using analytical and numerical *** comparing the results of a circular embedded foundation in the literature,a significant difference between the bearing capacity factors and depth factors is *** on the previous research findings,numerical computations using FLAC code are carried out in this study to evaluate the undrained bearing capacity of circular foundations with embedment ratios up to five for different base and side foundation roughness *** the foundation base,the roughness of the foundation side has a significant effect on the bearing *** comparison of the present results with numerical studies available in the literature shows that the discrepancy is related to the procedures used to simulate the foundation side interface conditions and to the estimation of the bearing capacity.

关键词： Circular footing Bearing capacity Embedment depth Numerical modeling Plasticity

An Access Control Scheme Using Heterogeneous Signcryption for IoT Environments

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Computers, Materials & Continua 2022年第3期70卷 4307-4321页

作者： insaf Ullah Hira Zahid Fahad Algarni Muhammad Asghar Khan Hamdard Institute of Engineering and Technology Islamabad44000Pakistan Department of Information Technology Abbottabad University of Science and TechnologyAbbottabadPakistan College of Computing and Information Technology The University of BishaBishaSaudi Arabia

When the Wireless Sensor Network(WSN)is combined with the Internet of Things(IoT),it can be employed in a wide range of applications,such as agriculture,industry 4.0,health care,smart homes,among *** the big data generated by these applications in Cloud Servers(CSs),requires higher levels of authenticity and confidentiality during communication conducted through the *** is one of the most promising approaches nowadays for overcoming such obstacles,due to its combined nature,i.e.,signature and encryption.A number of researchers have developed schemes to address issues related to access control in the IoT literature,however,the majority of these schemes are based on homogeneous *** will be neither adequate nor practical for heterogeneous IoT *** addition,these schemes are based on bilinear pairing and elliptic curve cryptography,which further requires additional processing time and more communication overheads that is inappropriate for real-time ***,this paper aims to solve the above-discussed issues,we proposed an access control scheme for IoT environments using heterogeneous signcryption scheme with the efficiency and security hardiness of hyperelliptic *** the security services such as replay attack prevention,confidentiality,integrity,unforgeability,non-repudiations,and forward secrecy,the proposed scheme has very low computational and communication costs,when it is compared to existing *** is primarily because of hyperelliptic curve lighter nature of key and other *** AVISPA tool is used to simulate the security requirements of our proposed scheme and the results were under two backbends(Constraint Logic-based Attack Searcher(CL-b-AtSER)and On-the-Fly Model Checker(ON-t-FL-MCR))proved to be SAFE when the presented scheme is coded in HLPSL *** scheme was proven to be capable of preventing a variety of attacks,including confidentiality,integrity,unforge

关键词： Internet of Things(IoT) access control big data heterogeneous signcryption

Performance analysis of a 2D numerical model in estimating minimum fluidization velocity for fluidized beds

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Particuology 2023年第6期77卷 116-127页

作者： Nazmul hossain Ralph Metcalfe Department of Mechanical Engineering University of HoustonHoustonTX77004USA

The minimum fluidization velocity of a fluid-solid particle fluidized bed is the primary focus of this *** computationally economic Eulerian Granular model has been used to analyze fluidization for both gas-solid particle and liquid-solid particle fluidized *** conventional approach of finding minimum fluidization velocity(umf)is either with a pressure drop across the particle bed or the change in bed ***,these parameters are often unstable and cannot be used to generalize the degree of fluidization *** this paper,the dominant factor of unstable pressure drop estimation in the 2D Two-Fluid Model(TFM)and a key non-dimensional Euler number has been investigated in deter-mining minimum fluidization velocity for different quasi-2D fluidized beds for different bed sizes,par-ticle sizes,and particle *** assumptions and limitations of these numerical models are discussed in detail for four different fluidized bed cases.A comparative study of the drag model shows little to no influence in unstable pressure drop estimation near fluidization velocity,and all drag models perform *** is observed that particle-particle collision is not the dominant reason for unstable pressure drop near minimum ***,wall effects on the particle bed including frictional losses and wall-particle collision play a key role in unstable pressure drop calculation for the quasi-2D fluidized *** drop characteristics alone do not suffice to obtain minimum fluidization ve-locity with 2D TFM using existing ***,a different approach has been proposed to investigate minimum fluidization involving the Euler number,which has shown promising performance in deter-mining minimum fluidization velocity and characterizing fluidization with 2D *** show con-sistency in Euler number characteristics for all different fluidized bed cases considered in this *** can revitalize computationally economic 2D Eulerian simulatio

关键词： Fluidized bed Minimum fluidization velocity Fluid-solid particle flow Eulerian granularmultiphase model

An Efficient Proxy Blind Signcryption Scheme for IoT

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Computers, Materials & Continua 2022年第3期70卷 4293-4306页

作者： Aamer Khan insaf Ullah Fahad Algarni Muhammad Naeem M.Irfan Uddin Muhammad Asghar Khan Department of Information Technology Abbottabad University of Science and TechnologyAbbotabadPakistan Hamdard Institute of Engineering and Technology Islamabad44000Pakistan College of Computing and Information Technology University of BishaBishaSaudi Arabia Institute of Computing Kohat University of Science and TechnologyKohatPakistan

Recent years have witnessed growing scientific research interest in the Internet of Things(IoT)technologies,which supports the development of a variety of applications such as health care,Industry 4.0,agriculture,ecological data management,and other various *** utilizes the Internet as a prime medium of communication for both single documents as well as multi-digital ***,due to the wide-open nature of the Internet,it is important to ensure the anonymity,untraceably,confidentiality,and unforgeability of communication with efficient computational complexity and low *** designed a light weight and secure proxy blind signcryption for multi-digital messages based on a hyperelliptic curve(HEC).Our results outperform the available schemes in terms of computational cost and communication *** designed scheme also has the desired authentication,unforgeability of warrants and/or plaintext,confidentiality,integrity,and blindness,***,our scheme is more suitable for devices with low computation power such as mobiles and tablets.

关键词： Proxy signcryption multi-digital-documents proxy blind signcryption hyperelliptic curve IoT

Machine Learning Accelerated Real-Time Model Predictive Control for Power Systems

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IEEE/CAA Journal of Automatica Sinica 2023年第4期10卷 916-930页

作者： Ramij Raja hossain Ratnesh Kumar Department of Electrical and Computer Engineering Iowa State UniversityAmesIA 50011 USA

This paper presents a machine-learning-based speedup strategy for real-time implementation of model-predictive-control(MPC)in emergency voltage stabilization of power *** success in various applications,real-time implementation of MPC in power systems has not been successful due to the online control computation time required for large-sized complex systems,and in power systems,the computation time exceeds the available decision time used in practice by a large *** long-standing problem is addressed here by developing a novel MPC-based framework that i)computes an optimal strategy for nominal loads in an offline setting and adapts it for real-time scenarios by successive online control corrections at each control instant utilizing the latest measurements,and ii)employs a machine-learning based approach for the prediction of voltage trajectory and its sensitivity to control inputs,thereby accelerating the overall control computation by multiple ***,a realistic control coordination scheme among static var compensators(SVC),load-shedding(LS),and load tap-changers(LTC)is presented that incorporates the practical delayed actions of the *** performance of the proposed scheme is validated for IEEE 9-bus and 39-bus systems,with±20%variations in nominal loading conditions together with *** show that our proposed methodology speeds up the online computation by 20-fold,bringing it down to a practically feasible value(fraction of a second),making the MPC real-time and feasible for power system control for the first time.

关键词： Machine learning model predictive control(MPC) neural network perturbation control voltage stabilization

The Double Edge Sword Based Distributed Executor Service

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Computer Systems Science & Engineering 2022年第8期42卷 589-604页

作者： Faisal Bahadur Arif Iqbal Umar insaf Ullah Fahad Algarni Muhammad Asghar Khan Department of Information Technology Hazara UniversityMansehra21300Pakistan Hamdard Institute of Engineering and Technology Islamabad 44000Pakistan College of Computing and Information Technology The University of BishaBishaSaudi Arabia

Scalability is one of the most important quality attribute of softwareintensive systems,because it maintains an effective performance parallel to the large fluctuating and sometimes unpredictable *** order to achieve scalability,thread pool system(TPS)(which is also known as executor service)has been used extensively as a middleware service in software-intensive *** optimization is a challenging problem that determines the optimal size of thread pool dynamically on *** case of distributed-TPS(DTPS),another issue is the load balancing b/w available set of TPSs running at backend *** DTPSs are overloaded either due to an inappropriate TPS optimization strategy at backend servers or improper load balancing scheme that cannot quickly recover an ***,the performance of software-intensive system is ***,in this paper,we propose a new DTPS that follows the collaborative round robin load balancing that has the effect of a double-edge *** the one hand,it effectively performs the load balancing(in case of overload situation)among available TPSs by a fast overload recovery procedure that decelerates the load on the overloaded TPSs up to their capacities and shifts the remaining load towards other gracefully running *** on the other hand,its robust load deceleration technique which is applied to an overloaded TPS sets an appropriate upper bound of thread pool size,because the pool size in each TPS is kept equal to the request rate on it,hence dynamically optimizes *** evaluated the results of the proposed system against state of the art DTPSs by a clientserver based simulator and found that our system outperformed by sustaining smaller response times.

关键词： Software-intensive systems distributed executor service load balancing overload monitoring multi-threading thread pool performance

An Efficient Medium Access Control Mechanism for Flying Ad-hoc Networks

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Computer Systems Science & Engineering 2021年第7期38卷 47-63页

作者： Muhammad Asghar Khan Fazal Noor insaf Ullah Sajjad ur Rehman Shibli Nisar Mohaira Ahmad Department of Electronic Engineering ISRA UniversityIslamabad44000Pakistan Department of Computer Science and Information Systems Islamic University of MadinahMadinah400411Saudi Arabia Hamdard Institute of Engineering&Technology Islamabad44000Pakistan Department of Electrical Engineering Namal InstituteMianwali42200Pakistan Department of Electrical Engineering National University of Sciences and Technology(NUST)Islamabad44000Pakistan

The Flying Ad-hoc Networks(FANETs)is characterized by the transition from a single large Unmanned Aerial Vehicle(UAV)to multiple small UAVs connected in an ad-hoc *** high mobility is the core feature of such networks,they are prone to route breaks within the *** issue of connectivity loss can be coped with,to some extent,by making use of omnidirectional *** modification,however,curtails Quality-of-Service(QoS)requirements of networks in terms of bandwidth,media access delay,coverage and ***,directional antennas have advantages over omnidirectional antennas such as improved transmission range,spatial reuse and high ***,its introduction raises location-dependent issues to the Medium Access Control(MAC)*** calls for an efficient MAC protocol that can cater to new directional antenna models and,at the same time,can counter the constraints associated with the dynamic ***,in this article,we consider a UAV interconnection mechanism that lets the UAVs execute the communication tasks using the directional MAC *** technique is advantageous as compared to the approach of utilizing the MAC protocol using omnidirectional *** scheme is being implemented as a case study for Industry 4.0 inventory and traceability applications in the *** modeling and simulation purposes,we use the Optimized Network Engineering Tool(OPNET)and aim to seek an evaluation with respect to throughput,media access delay,retransmission attempts and data *** results obtained demonstrate the effectiveness of the proposed scheme.

关键词： FANETs QoS Industry 4.0 IEEE 802.11 MAC OPNET mobility models directional antenna

Crystallization Conditions and Petrogenesis of the Paleoproterozoic Basement Rocks in Bangladesh:An Evaluation of Biotite and Coexisting Amphibole Mineral Chemistry

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Journal of Earth Science 2014年第1期25卷 87-97页

作者： Ismail hossain Toshiaki Tsunogae Department of Geology and Mining University of Rajshahi Faculty of Life and Environmental Sciences (Earth Evolution Sciences) University of Tsukuba Department of Geology University of JohannesburgAuckland Park 2006

The Paleoproterozoic （-1.73 Ga） basement rocks from Maddhapara, Bangladesh show a large range of chemical variations including diorite, quartz diorite, monzodiorite, quartz monzonite and granite. These are composed of varying proportions of quartz＋plagioclase＋K-feldspar＋biotite＋ hornblende±epidote＋titanite＋magnetite＋apatite and zircon. Amphibole and biotite, dominant ferro- magnesian minerals, have been analyzed with an electron microprobe. The biotite, Mg-dominant trioc- tahedral micas, is classified as phlogopitic nature. Relatively high Mg （1.33-1.53 pfu）, Mg^# （0.52-0.59） and low AIw （0.13-0.25 pfu） contents in the biotite reflect slightly fractionated magma, which might be a relative indicator for the origin of the parental magma. Biotite is also a very good sensor of oxidation state of the parental magma. Oxygen fugacity of the studied biotites estimate within the QFM and HM buffers and equilibrate at about -12.35 and -12.46, which exhibit the source materials were relatively higher oxidation state during crystallization and related to arc magmatism. Whereas, calcic amphi- boles, a parental member of arc-related igneous suite, display consistent oxygen fugacity values （-11.7 to -12.3）, low Al^# （0.16-0.21） with H2Omelt （5.6 wt.%-9.5 wt.%） suggest their reliability with the typical values of calc-alkaline magma crystallization. The oxygen fugacity of magma is related to its source material, which in turn depends on tectonic setting. Discrimination diagrams and chemical indices of both biotite and amphibole of dioritic rocks reveal calc-alkaline orogenic complexes; mostly I-type suite formed within subduction-related environments. Moreover, igneous micas are used as metal- logenic indicator. The biotites with coexisting amphibole compositions show an apparent calc-alkaline trend of differentiation. The study suggests that the trend of oxidized magmas is commonly associated with compressive tectonic and convergent plate boundaries.

关键词： oxygen fugacity biotite Paleoproterozoic basement rock Columbia supercontinent Bangladesh.

Rice Aroma: A Natural Gift Comes with Price and the Way Forward

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Rice science 2020年第2期27卷 86-100页

作者： Zakaria hossain PRODHAN SHU Qingyao National Key Laboratory of Rice Biology/Institute of Crop Science College of Agriculture and BiotechnologyZijingang CampusZhejiang UniversityHangzhou 310058China

Aromatic rice belongs to a small but important sub-group of rice,which is highly regarded for its excellent aroma and superior grain *** rice,especially Basmati-and Jasmine-type rice,is being traded at a high price in the local and global ***,rice aroma is a phenotypical expression of spontaneous recessive mutations of the OsBadh2 gene(also known as fgr/badh2/osbadh2/os2AP gene).These mutations inhibit the flow ofγ-aminobutyraldehyde(GAB-ald)toγ-aminobutyric acid(GABA),and consequently,the accumulated GAB-ald is diverted to a potent flavour component 2-acetyl-1-pyrroline(2AP)by a non-enzymatic reaction with *** natural incidence of non-functional osbadh2 mutation along with selection and nursing by the farmer from the ancient time makes rice aroma as a prominent natural *** GABA and methylglyoxal play significant roles in stress tolerance,and their biosynthesis is strictly regulated in rice plants,the accumulation of 2AP in aromatic rice depends on the interaction of various genetic and environmental factors,and its production may come at some costs of sacrificing *** review focused on some potential underlying genes in the 2AP and GABA biosynthesis pathways,and analyzed most aspects of aroma formation in rice,and summarized the molecular mechanism of aroma production together with its genetic and non-genetic influencing *** present review also stated approaches to produce high-quality aromatic rice via developing novel cultivars and with good agronomic knowledge-based practice.

关键词： aromatic rice aroma biosynthesis 2-acetyl-1-pyrroline(2AP)pathway γ-aminobutyric acid(GABA)pathway genome editing