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红外与毫米波学报 2014年第6期33卷 571-576页

作者： mahdi zavvari Mohammad Karimi Kambiz Abedi Department of Electrical Engineering Urmia BranchIslamic Azad University Department of Electrical Engineering Ahar BranchIslamic Azad University Department of Electrical Engineering Faculty of Electrical and Computer EngineeringShahid Beheshti University

The effect of resonant cavity structure on the performance operation of In As/Ga As quantum ring intersubband photodetector is studied for detection of terahertz radiations *** order to confinement of optical field w ithin active region and consequently enhancement in responsivity of device,tw o periods of Al2O3/Ga As distributed bragg reflectors are used as bottom dielectric mirror and a thin layer of Au material as top mirror of *** further improvement in detectivity,Al0.3Ga0.7As/In0.3Ga0.7As resonant tunneling barriers are included in absorption layers to reduce dark current of *** photodetector show s a peak responsivity of about 0.4(A/W)and quantum efficiency of 1.2%at the w avelength of 80μm(3.75 THz).Furthermore,specific detectivity(D*)of device is calculated and results are compared to conventional quantum ring inter-subband *** predict a D*of^1011(***1/2/W)for device at T=80 K and V=0.4 V w hich is tw o orders of magnitude higher than that of conventional QRIPs.

关键词：量子环理论研究辐射范围共振吸收层

InAs/GaAs far infrared quantum ring inter-subband photodetector

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Frontiers of Optoelectronics 2014年第1期7卷 84-90页

作者： Mohammad KARIMI Kambiz ABEDI mahdi zavvari Department of Electrical Engineering Mahabad Branch Islamic Azad University Mahabad Iran Department of Electrical Engineering Faculty of Electrical and Computer Engineering Shahid Beheshti University Tehran *** Iran Department of Electrical Engineering Urmia Branch islamic Azad University Urmia lran

In this paper, we presented a numerical analysis of absorption coefficient, dark current and specific detectivity for InAs/GaAs quantum ring inter-subband photodetector （QRIP）. 3D SchrSdinger equation was solved using finite difference method and based on effective mass approximation. Dimensions of quantum ring （QR） were considered that inter-subband transition was to be accomplished for radiations of 20 μm. Resonant tunneling （RT） barriers were designed with tunneling probability of unity for electrons with energy of 0.062 meV to lower dark current of conventional QRIP. Numerical analyses show that inclusion of RT barriers can reduce dark current for about two orders of magnitude. Furthermore, specific detectivities for conventional QRIP and RToQRIP were calculated respectively, and results at different temperatures were compared. It is suggested that specific detectivity for RT-QRIP is one order of magnitude higher than that for conventional QRIP. It is suggested that RT barriers considerably improve the specific detectivity of conventional QRIP at different temperatures.

关键词： quantum ring inter-subband photodetector(QRIP) dark current spacefic detectivity resonant tunnel-ing (RT)

All-optical AND/OR/NOT logic gates based on photonic crystal ring resonators

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Frontiers of Optoelectronics 2016年第4期9卷 578-584页

作者： Ashkan PASHAMEHR mahdi zavvari Hamed ALIPOUR-BANAEI Department of Electrical Engineering Urmia Branch Islamic Azad University Unnia Iran Department of Electrical Engineering Tabriz Branch Islamic Azad University Tabriz Iran

Photonic crystal based ring resonators are best choice for designing all-optical devices. In this paper, we used a basic structure of photonic crystal ring resonators and designed all optical logic gates which are working using the Kerr effect. The proposed gates consisted of upper and lower wavegnides coupled through a resonator which was designed for dropping of special wavelength. The resonance wavelength was designed for 1550 nm telecom operation wavelength. We used numerical meth- ods such as plane wave expansion and finite difference time domain （FDTD） for performing our simulations and studied the optical properties of the proposed structures. Our results showed that the critical input power for triggering the gate output was lower compared to previously reported gates.

关键词： photonic crystal (PhC) all optical logic gate,ring resonator Kerr effect

Kink-band Kinematic Analysis and its Implications for Late-stage Deformation in the Internal Parts of the Zagros Collision(Sanandaj–Sirjan Zone) in West Iran

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Acta Geologica Sinica(English Edition) 2024年第4期98卷 921-935页

作者： Maryam HEYDARI mahdi BEHYARI Department of Geology Faculty of SciencesUrmia University57153165 UrmiaIran

In the internal parts of the Zagros collision zone, several deformation phases have been superimposed. The early deformation phase caused the development of a penetrative foliation. The late-stage deformation phase was preferentially accommodated within shear zones and caused the generation of shear bands, implying a non-coaxial component of deformation, the end of this stage deformation was marked by the development of kink-bands. In the vicinity of Zagros suture zone, the kink angle increased from 40° to 60°, and the kink-bands was converted to chevron folds. In this region, the external(α) and internal(β) angular ratio is α/β ≠ 1 and kink angle increased, and deformation occurred with 10% to 30% volume loss. Farther from the suture zone in the east, α/β = 1;and total volume was constant or increased by 5% to 10%. Kink-bands kinematic analysis in the study area revealed this structures were sensitive to deformation conditions and components such that, with decreasing distance to the Zagros suture zone, shearing and rotation increased, a high kinematic vorticity dominated, and volume loss occurred during deformation.

关键词： kink-band shear zone strain vorticity Zagros Iran

Influence of the Ambient Temperature on the Efficiency of Gas Turbines

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Fluid Dynamics & Materials Processing 2024年第10期20卷 2265-2279页

作者： mahdi Goucem Laboratory of Aeronautics and Propulsive Systems University of Sciences and Technology Mohamed Boudiaf Mechanical Engineering Faculty Oran3100Algeria

In hot and arid regions like the Saharan area,effective methods for cooling and humidifying intake air are *** study explores the utilization of a water trickle cooler as a promising solution to meet this *** particular,the HASSI MESSAOUD area is considered as a *** water trickle cooler is chosen for its adaptability to arid *** results demonstrate its effectiveness in conditioning air before it enters the *** cooling system achieves a significant temperature reduction of 6 to 8 degrees Celsius,enhancing mass flow rate dynamics by 3 percent compared to standard cases without ***,the cooling system contributes to a remarkable 10 percent reduction in power consumption of gas turbines and a notable 10 percent increase in turbine *** findings highlight the potential of water trickle coolers in improving the performance and efficiency of gas turbine systems in hot and dry climates.

关键词： Gas turbine inlet cooling computational fluid dynamics(CFD) power thermal efficiency

Optimal monitoring and attack detection of networks modeled by Bayesian attack graphs

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Cybersecurity 2024年第1期7卷 1-15页

作者： Armita Kazeminajafabadi mahdi Imani Department of Electrical and Computer Engineering Northeastern UniversityBostonMAUSA

Early attack detection is essential to ensure the security of complex networks,especially those in critical *** is particularly crucial in networks with multi-stage attacks,where multiple nodes are connected to external sources,through which attacks could enter and quickly spread to other network *** attack graphs(BAGs)are powerful models for security risk assessment and mitigation in complex networks,which provide the probabilistic model of attackers’behavior and attack progression in the *** attack detection techniques developed for BAGs rely on the assumption that network compromises will be detected through routine monitoring,which is unrealistic given the ever-growing complexity of *** paper derives the optimal minimum mean square error(MMSE)attack detection and monitoring policy for the most general form of *** exploiting the structure of BAGs and their partial and imperfect monitoring capacity,the proposed detection policy achieves the MMSE optimality possible only for linear-Gaussian state space models using Kalman *** adaptive resource monitoring policy is also introduced for monitoring nodes if the expected predictive error exceeds a user-defined *** and efficient matrix-form computations of the proposed policies are provided,and their high performance is demonstrated in terms of the accuracy of attack detection and the most efficient use of available resources using synthetic Bayesian attack graphs with different topologies.

关键词： Multi-stage attacks Bayesian attack graph Attack detection Optimal monitoring

Assessment of liquefaction potential based on shear wave velocity:Strain energy approach

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3733-3745页

作者： Mohammad Hassan Baziar mahdi Alibolandi School of Civil Engineering Iran University of Science and TechnologyTehran16846-13114Iran

Liquefaction assessment based on strain energy is significantly superior to conventional stress-based *** main purpose of the present study is to investigate the correlation between shear wave velocity and strain energy capacity of silty *** dissipated energy until liquefaction occurs was calculated by analyzing the results of three series of comprehensive cyclic direct simple shear and triaxial tests on Ottawa F65,Nevada,and Firoozkuh sands with varying silt content by weight and relative ***,the shear wave velocity of each series was obtained using bender element or resonant column ***,for the first time,a liquefaction triggering criterion,relating to effective overburden normalized liquefaction capacity energy(WL=s’c)to effective overburden stresscorrected shear wave velocity(eVs1)has been *** accuracy of the proposed criteria was evaluated using in situ *** results confirm the ability of shear wave velocity as a distinguishing parameter for separating liquefied and non-liquefied soils when it is calculated against liquefaction capacity energy(WL=s’c).However,the proposed WL=s’c-Vs1 curve,similar to previously proposed cyclic resistance ratio(CRR)-Vs1 relationships,should be used conservatively for fields vulnerable to liquefaction-induced lateral spreading.

关键词： Liquefaction Strain energy capacity Shear wave velocity Cyclic triaxial test Cyclic direct simple shear test Resonant column test Bender element test

Improving mobile mass monitoring in the IoT environment based on Fog computing using an improved forest optimization algorithm

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Journal of Control and Decision 2024年第1期11卷 36-49页

作者： Tahere Motedayen mahdi Yaghoobi Maryam Kheirabadi Department of Computer Engineering Neyshabur BranchIslamic Azad UniversityNeyshaburIran

In the IoT-based users monitor tasks in the network environment by participating in the data collection process by smart *** monitor their data in the form of fog computing(mobile mass monitoring).Service providers are required to pay user rewards without increasing platform *** of the NP-Hard methods to maximise the coverage rate and reduce the platform costs(reward)is the Cooperative Based Method for Smart Sensing Tasks(CMST).This article uses chaos theory and fuzzy parameter setting in the forest optimisation *** proposed method is implemented with *** average findings show that the network coverage rate is 31%and the monitoring cost is 11%optimised compared to the CMST scheme and the mapping of the mobile mass monitoring problem to meta-heuristic *** using the improved forest optimisation algorithm can reduce the costs of the mobile crowd monitoring platform and has a better coverage rate.

关键词： Internet of Things mobile mass monitoring forest optimization algorithm chaos theory fuzzy system

Using neural network modeling to improve the detection accuracy of land subsidence due to groundwater withdrawal

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Journal of Mountain Science 2024年第7期21卷 2320-2333页

作者： Ali M.RAJABI Ali EDALAT Yasaman ABOLGHASEMI mahdi KHODAPARAST Department of Engineering Geology University of TehranTehran ***Iran Department of Civil Engineering University of QomQom ***Iran

Despite the high efficiency of remote sensing methods for rapid and large-scale detection of subsidence phenomena,this technique has limitations such as atmospheric impact and temporal and spatial decorrelation that affect the accuracy of the *** paper proposes a method based on an artificial neural network to improve the results of monitoring land subsidence due to groundwater overexploitation by radar interferometry in the Aliabad plain(Central Iran).In this regard,vertical ground deformations were monitored over 18 months using the Sentinel-1A SAR *** model the land subsidence by a multilayer perceptron(MLP)artificial neural network,four parameters,including groundwater level,alluvial thickness,elastic modulus,and transmissivity have been *** model's generalizability was assessed using data derived for 144 *** to the results,the neural network estimates the land subsidence at each ground point with an accuracy of 6.8 mm.A comparison between the predicted and actual values indicated a significant *** MLP model can be used to improve the results of subsidence detection in the study area or other areas with similar characteristics.

关键词： DInSAR Land subsidence Groundwater withdrawal Aliabad plain Artificial neural network

Detection of Real-Time Distributed Denial-of-Service (DDoS) Attacks on Internet of Things (IoT) Networks Using Machine Learning Algorithms

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Computers, Materials & Continua 2024年第8期80卷 2139-2159页

作者： Zaed mahdi Nada Abdalhussien Naba Mahmood Rana Zaki Information Technology Center University of TechnologyBaghdad00964Iraq Continuous Education Center University of TechnologyBaghdad00964Iraq Computer Science Department University of TechnologyBaghdad00964Iraq

The primary concern of modern technology is cyber attacks targeting the Internet of *** it is one of the most widely used networks today and vulnerable to ***-time threats pose with modern cyber attacks that pose a great danger to the Internet of Things(IoT)networks,as devices can be monitored or service isolated from them and affect users in one way or *** Internet of Things networks is an important matter,as it requires the use of modern technologies and methods,and real and up-to-date data to design and train systems to keep pace with the modernity that attackers use to confront these *** of the most common types of attacks against IoT devices is Distributed Denial-of-Service(DDoS)*** paper makes a unique contribution that differs from existing studies,in that we use recent data that contains real traffic and real attacks on IoT *** a hybrid method for selecting relevant features,And also how to choose highly efficient *** gives the model a high ability to detect distributed denial-of-service *** model proposed is based on a two-stage process:selecting essential features and constructing a detection model using the K-neighbors algorithm with two classifier algorithms logistic regression and Stochastic Gradient Descent classifier(SGD),combining these classifiers through ensemble machine learning(stacking),and optimizing parameters through Grid Search-CV to enhance system *** were conducted to evaluate the effectiveness of the proposed model using the CIC-IoT2023 and CIC-DDoS2019 *** evaluation demonstrated the potential of our model in robust intrusion detection in IoT networks,achieving an accuracy of 99.965%and a detection time of 0.20 s for the CIC-IoT2023 dataset,and 99.968%accuracy with a detection time of 0.23 s for the CIC-DDoS 2019 ***,a comparative analysis with recent related works highlighted the superiority of our methodology in in

关键词： DDoS Service networks