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Phyton-International Journal of Experimental Botany 2019年第3期88卷 239-252页

作者： Dhouha Belhaj Sghaier insaf bankaji Sylvia Pedro Isabel Caçador Noomene Sleimi LR.RME-Ressources Matériaux et EcosystèmesFaculty of Sciences of BizerteUniversity of Carthage7021 JarzounaBizerteTunisie MARE-Marine and Environmental Sciences Centre Faculty of Sciences of the University of LisbonPortugal

The lack of knowledge of plant tolerance and differential response to aluminum(Al)encouraged many researchers,in the last decade,to elucidate Al toxicity and tolerance *** current study reported the impact of Al,a toxic element with negative effects on plant growth and development,in halophytic plant Tamarix *** were subjected to different Al concentrations(0,200,500 and 800μM)with or without NaCl(200 mM)***,photosynthesis and mineral content were *** stress had a significant decrease on shoots’biomass production between 19 to 41%,and a little variation on chlorophyll content and photosynthetic efficiency(Fo,Fm,Fv fluorescence’s and Fv/Fm).Furthermore,the Al-treatments did not affect significantly the content of potassium,calcium,and magnesium in different plant parts,whereas NaCl addition to the medium induced a decrease in these elements’*** results have shown that *** is able to accumulate the high levels of Al in shoots and roots,6288μg.g^(-1) DW and 7834μg.g^(-1) DW *** is considered as a hyperaccumulator plant of *** addition,Na+contents in shoots and roots exceed 23000μg.g^(-1) ***,*** presents a high tolerance at the same time to Al and NaCl phytotoxicity,so it is interesting to use in phytoremediation programs.

关键词： Halophyte tolerance combined stress photosynthetic pigments chlorophyll fluorescence Al-accumulation nutrients uptake

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

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

Speech Recognition-Based Automated Visual Acuity Testing with Adaptive Mel Filter Bank

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Computers, Materials & Continua 2022年第2期70卷 2991-3004页

作者： Shibli Nisar Muhammad Asghar Khan Fahad Algarni Abdul Wakeel M.Irfan Uddin insaf Ullah Department of Electrical Engineering National University of Sciences and Technology(NUST)Islamabad44000Pakistan Hamdard Institute of Engineering&Technology Islamabad44000Pakistan College of Computing and Information Technology University of BishaBishaSaudi Arabia Institute of Computing Kohat University of Science and TechnologyKohatPakistan

One of the most commonly reported disabilities is vision loss,which can be diagnosed by an ophthalmologist in order to determine the visual system of a *** procedure,however,usually requires an appointment with an ophthalmologist,which is both time-consuming and expensive *** issues that can arise include a lack of appropriate equipment and trained practitioners,especially in rural *** on a cognitively motivated attribute extraction and speech recognition approach,this paper proposes a novel idea that immediately determines the eyesight *** proposed system uses an adaptive filter bank with weighted mel frequency cepstral coefficients for feature *** adaptive filter bank implementation is inspired by the principle of spectrum sensing in cognitive radio that is aware of its environment and adapts to statistical variations in the input stimuli by learning from the *** performance evaluation demonstrates the potential of our automated visual acuity test method to achieve comparable results to the clinical ground truth,established by the expert ophthalmologist’s *** overall accuracy achieved by the proposed model when compared with the expert ophthalmologist test is 91.875%.The proposed method potentially offers a second opinion to ophthalmologists,and serves as a cost-effective pre-screening test to predict eyesight loss at an early stage.

关键词： Eyesight test speech recognition HMM SVM feature extraction

Preliminary study of an open-air water-contacting discharge for direct nitrogen fixation

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Plasma Science and Technology 2021年第3期23卷 93-101页

作者： Zhan SHU Chuanqi WANG insaf HOSSAIN Qiang CHEN Wanlian LI Jinqi WANG Pengfei LIU Qing XIONG State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing UniversityChongqing 400044People's Republic of China Shenzhen Research Institute of Xiamen University Institute of Electromagnetics and AcousticsFujianProvincial Key Laboratory of Plasma and Magnetic ResonanceKey Laboratory of Electromagnetic Wave Science and Detection TechnologyXiamen UniversityXiamen 361005People's Republic of China

Efficient nitrogen fixation through a reactive plasma process attracts intense interest due to the environmental issues induced by the conventional Haber–Bosch method. In this work, we present a direct and simple fixation routine without any catalysts for nitrogen in open air using an atmospheric-pressure pin-to-solution plasma electrolytic system. Nitrate, nitrite, and ammonia as the nitrogen-derived chemicals in solution were analyzed as indicators under various discharge conditions to estimate the energy efficiency of this process. The results show that the nitrogen fixation process was much more efficient by the pin-positive discharge compared to the negative one. N chemicals preferred to be formed when the solution was of negative polarity. It was also found that, with the help of solution circulation, the energy efficiency was enhanced compared to that of static liquid. However, an inverse trend was observed with the increase of the discharge current. Further study by optical emission spectroscopy indicates the important roles of active N2* and water vapour and their derived species near the plasma–water interface in the fixation process.

关键词： nitrogen fixation air-water discharge energy efficiency active species plasma-water interface

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

A Perfect Knob to Scale Thread Pool on Runtime

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Computers, Materials & Continua 2022年第7期72卷 1483-1493页

作者： Faisal Bahadur Arif Iqbal Umar insaf Ullah Fahad Algarni Muhammad Asghar Khan Samih M.Mostafa Department of Information Technology Hazara UniversityMansehra21300Pakistan Hamdard Institute of Engineering and Technology Islamabad CampusPakistan College of Computing and Information Technology The University of BishaBishaSaudi Arabia Faculty of Computers and Information South Valley UniversityQena83523Egypt

Scalability is one of the utmost nonfunctional requirement of server applications,because it maintains an effective performance parallel to the large fluctuating and sometimes unpredictable *** order to achieve scalability,thread pool system(TPS)has been used extensively as a middleware service in server *** size of thread pool is the most significant factor,that affects the overall performance of *** the optimal size of thread pool dynamically on runtime is a challenging *** most widely used and simple method to tackle this problem is to keep the size of thread pool equal to the request rate,i.e.,the frequencyoriented thread pool(FOTP).The FOTPs are the most widely used TPSs in the industry,because of the implementation simplicity,the negligible overhead and the capability to use in any ***,the frequency-based schemes only focused on one aspect of changes in the load,and that is the fluctuations in request *** request rate alone is an imperfect knob to scale thread ***,this paper presents a workload profiling based FOTP,that focuses on request size(service time of request)besides the request rate as a knob to scale thread pool on runtime,because we argue that the combination of both truly represents the load fluctuation in server-side *** evaluated the results of the proposed system against state of the art TPS of Oracle Corporation(by a client-server-based simulator)and concluded that our system outperformed in terms of both;the response times and throughput.

关键词： Scalability performance middleware workload profiling multithreading thread pool

Ambiguity Resolution in Direction of Arrival Estimation with Linear Antenna Arrays Using Differential Geometry

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Computers, Materials & Continua 2022年第1期70卷 581-599页

作者： Alamgir Safi Muhammad Asghar Khan Fahad Algarni Muhammad Adnan Aziz M.Irfan Uddin insaf Ullah Tanweer Ahmad Cheema Department of Electronic Engineering ISRA UniversityIslamabad44000Pakistan Hamdard Institute of Engineering&Technology Islamabad44000Pakistan College of Computing and Information Technology University of BishaBishaSaudi Arabia Institute of Computing Kohat University of Science and TechnologyKohatPakistan

Linear antenna arrays(LAs)can be used to accurately predict the direction of arrival(DOAs)of various targets of interest in a given ***,under certain conditions,LA suffers from the problem of ambiguities among the angles of targets,which may result inmisinterpretation of such *** order to cope up with such ambiguities,various techniques have been ***,none of them fully resolved such a problem because of rank deficiency and high computational *** aimed to resolve such a problem by proposing an algorithm using differential *** proposed algorithm uses a specially designed doublet antenna array,which is made up of two individual linear *** angle observation models,ambiguous observation model(AOM)and estimated observation model(EOM),are derived for each individual *** ambiguous set of angles is contained in the AOM,which is obtained from the corresponding array elements using differential *** EOM for each array,on the other hand,contains estimated angles of all sources impinging signals on each array,as calculated by a direction-finding algorithm such as the genetic *** algorithm then contrasts the EOM of each array with its AOM,selecting the output of that array whose EOM has the minimum correlation with its corresponding *** comparison to existing techniques,the proposed algorithm improves estimation accuracy and has greater precision in antenna aperture selection,resulting in improved resolution capabilities and the potential to be used more widely in practical *** simulation results using MATLAB authenticates the effectiveness of the proposed algorithm.

关键词： Antenna array direction of arrival ambiguity resolution doublet antenna array ambiguous observation model estimated observation model