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Transmission over Cognitive Radio Channel with Novel Secure LT Code

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Communications and Network 2013年第3期5卷 198-203页

作者： elham hosseini Abolfazl Falahati Department of Electrical Engineering (DCCS Lab) Iran University of Science and Technology Tehran Iran

With the increasing of communication applications in recent years, the demand for radio spectral resources has increased significantly. Cognitive radio scenario was proposed to improve spectrum efficiency in wireless communication systems. In cognitive radio network, it is essential that control information is sent securely and reliably. Ensuring the trustworthiness of the transmitting of spectrum sensing information is important in the CR networks since spectrum sensing directly affects spectrum management and incumbent coexistence. In this paper, the first secondary link channel model is presented, then a secure LT Code is proposed to be compatible with presented channel model and acquires good QoS. As we may know, LT code overcomes packet loss when the channel of the SU is reclaimed by PU. In the new proposed combined encoding and ciphered block, a LT code matrix is used to generate a symmetric cryptographic key. Thus, less complexity observed in the processing computation. Besides, cryptographic key is not sent over the channel. As a result, an attacker has no way to eavesdrop the key unless he is prepared to consider all possible key combinations. This replaced block supplies secure controlling channel and increases spectrum efficiency too.

关键词： Cognitive Radio Symmetric Cryptographic Key Generation LT Code

Mineral Chemistry and Thermobarometry of the Volcanic Rocks in Torud, Iran

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Open Journal of Geology 2014年第9期4卷 425-435页

作者： elham Shah hosseini Afshin Ashja Ardalan Mohammad Hashem Emami Mohammad Hossein Razavi Department of Geology North Tehran branch Islamic Azad University Tehran Iran Department of Geology North Tehran Branch Islamic Azad University Tehran Iran Department of Geology Eslamshahr Branch Islamic Azad University Eslamshahr Iran Department of Geology Faculty of Sciences Kharazmi University Tehran Iran

This paper elucidates the compositional studies on clinopyroxene, plagioclase of basalts to andesitic rocks of Torud area to understand the geotectonic and geothermobarometry conditions.?Early?Eocene-Oligocene calc-alkaline volcanic rocks are exposed around Torud in the Central Iranian zone. Volcanic rocks consist of basaltic, andesite basalt, Tracyandesite, and andesite. Minerals in the volcanic rocks exhibit degrees of disequilibrium features. Plagioclase as dominant mineral in these rocks generally displays oscillatory zoning. Mineral chemistry studies show that clinopyroxenes in the volcanic rocks are diopside, augite and plotted in medium pressure field. The clinopyroxene composition yields the crystallization temperatures 900°C?- 1000°C. The mineral composition indicates that these rocks are formed in a tensional environment.

关键词： Volcanic Rocks Mineral Chemistry Clinopyroxenes Plagioclase Torud

Synthesis, Characterization and Electrochemical Study of Graphene Oxide-Multi Walled Carbon Nanotube-Manganese Oxide-Polyaniline Electrode as Supercapacitor

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Journal of Materials Science & Technology 2016年第8期32卷 763-773页

作者： Mir Ghasem hosseini elham Shahryari Electrochemistry Research Laboratory Department of Physical Chemistry Chemistry Faculty University of Tabriz

The synthesis of graphene oxide-multi walled carbon nanotube-manganese oxide-polyaniline namely （GMMP） nanocomposite for application in supercapacitor devices was investigated. Morphology of the nanocomposites was studied by X-ray diffraction （XRD）, Fourier transform infrared （FT-IR） spectrosco- py, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and energy dispersive X-ray micmanalysis （EDX）. The electrochemical properties of nanocomposite based electrodes were in- vestigated by cyclic voltammetry （CV）, galvanostatic charge-discharge and electrochemical impedance spectroscopy （EIS） techniques in 0.5 mol/L Na2SO4. The specific capacitances of 173.00, 127.85, 87.50, 58.65 and 12.00 （mF cm^-2） were obtained for GMMP, GMP （GO-MWCNT-PANI）, GMM （GO-MWCNT-MnO2）, GM （GO-MWCNT） and G （GO） at a scan rate of 10 mV s^-1, respectively. Also, GMMP nanocomposite re- tained 90% initial capacitance after 200 cycle of charge-discharge. The good electrochemical response of this nanocomposite is due to the combination of the electrical double layer capacitance of GO and MWCNT and the gradual introduction of pseudo-capacitance through the redox processes of PANI, -COOH, -OH （in MWCNT-COOH, GO-COOH and GO-OH） and MnO2. This revealed the synergistic effect of PANI, MnO2, -OH -COOH on the carbon based support.

关键词： Supercapacitor Graphene oxide In-situ polymerization Electrochemical Impedance Spectroscopy (EIS) Polyaniline

Enhancing Parkinson's disease severity assessment through voice-based wavelet scattering,optimized model selection,and weighted majority voting

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Medicine in Novel Technology and Devices 2023年第4期20卷 51-63页

作者： Farhad Abedinzadeh Torghabeh Seyyed Abed hosseini elham Ahmadi Moghadam Department of Biomedical Engineering Mashhad BranchIslamic Azad UniversityMashhadIran Department of Electrical Engineering Mashhad BranchIslamic Azad UniversityMashhadIran

Parkinson's disease(PD)is a neurodegenerative disorder characterized by motor and non-motor symptoms that significantly impact an individual's quality of *** changes have shown promise as early indicators of PD,making voice analysis a valuable tool for early detection and *** study aims to assess and detect the severity of PD through voice analysis using the mobile device voice recordings *** dataset consisted of recordings from PD patients at different stages of the disease and healthy control subjects.A novel approach was employed,incorporating a voice activity detection algorithm for speech segmentation and the wavelet scattering transform for feature extraction.A Bayesian optimization technique is used to fine-tune the hyperparameters of seven commonly used classifiers and optimize the performance of machine learning classifiers for PD severity *** and K-nearest neighbor consistently demonstrated superior performance across various evaluation metrics among the ***,a weighted majority voting(WMV)technique is implemented,leveraging the predictions of multiple models to achieve a near-perfect accuracy of 98.62%,improving classification *** results highlight the promising potential of voice analysis in PD diagnosis and *** advanced signal processing techniques and machine learning models provides reliable and accessible tools for PD assessment,facilitating early intervention and improving patient *** study contributes to the field by demonstrating the effectiveness of the proposed methodology and the significant role of WMV in enhancing classification accuracy for PD severity detection.

关键词： Parkinson's disease Speech impairment Voice activity detection Model selection Bayesian optimization Weighted majority voting

Data-Based Filters for Non-Gaussian Dynamic Systems With Unknown Output Noise Covariance

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 866-877页

作者： elham Javanfar Mehdi Rahmani the Department of Electrical Engineering Imam Khomeini International UniversityQazvin ***Iran

This paper proposes linear and nonlinear filters for a non-Gaussian dynamic system with an unknown nominal covariance of the output *** challenge of designing a suitable filter in the presence of an unknown covariance matrix is addressed by focusing on the output data set of the *** that data generated from a Gaussian distribution exhibit ellipsoidal scattering,we first propose the weighted sum of norms(SON)clustering method that prioritizes nearby points,reduces distant point influence,and lowers computational ***,by introducing the weighted maximum likelihood,we propose a semi-definite program(SDP)to detect outliers and reduce their impacts on each *** these weights paves the way to obtain an appropriate covariance of the output ***,two filtering approaches are presented:a cluster-based robust linear filter using the maximum a posterior(MAP)estimation and a clusterbased robust nonlinear filter assuming that output noise distribution stems from some Gaussian noise resources according to the ellipsoidal *** last,simulation results demonstrate the effectiveness of our proposed filtering approaches.

关键词： Data-based filter maximum likelihood estimation unknown covariance weighted maximum likelihood estimation weighted sum-of-norms clustering

Maximizing the potential applications of plasma electrolytic oxidation coatings produced on Mg-based alloys in anti-corrosion,antibacterial,and photocatalytic targeting through harnessing the LDH/PEO dual structure

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Journal of Magnesium and Alloys 2024年第7期12卷 2674-2694页

作者： elham Nikoomanzari Arash Fattah-alhosseini Department of Materials Engineering Faculty of EngineeringBu-Ali Sina UniversityHamedanIran

There is an increasing interest in the development of Mg alloys,both for industrial and biomedical applications,due to their favorable characteristics such as being lightweight and ***,the inadequate corrosion resistance and lack of antibacterial properties pose significant challenges in the industrial and biomedical applications,necessitating the implementation of advanced coating engineering *** electrolytic oxidation(PEO)has emerged as a preferred coating technique because of its distinctive properties and successful surface modification ***,there is a continuous need for further enhancements to optimize the performance and functionalities of protective surface *** integration of layered double hydroxide(LDH)into PEO coatings on Mg alloys presents a promising approach to bolstering protective *** thorough review delves into the latest developments in integrating LDH into PEO coatings for corrosion-related *** particularly emphasizes the significant improvements in corrosion resistance,antibacterial effectiveness,and photocatalytic performance resulting from the incorporation of LDH into PEO *** two key mechanisms that enhance the corrosion resistance of PEO coatings containing LDH are the anion exchangeability of the LDH structure and the pore-sealing ***,the antibacterial activity of PEO coatings with LDH stemmed from the release of antibacterial agents stored within the LDH structure,alterations in pH levels,and the photothermal conversion ***,by incorporating LDH into PEO coatings,new opportunities emerge for tackling environmental issues through boosted photocatalytic properties,especially in the realm of pollutant degradation.

关键词： Mg alloy PEO LDH Corrosion Antibacterial activity Photocatalytic degradation

Effect of Al substitution on phase evolution in synthesized Mg_(2)Cu nanoparticles

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International Journal of Minerals,Metallurgy and Materials 2023年第1期30卷 63-71页

作者： elham Mohseni-Sohi Farshid Kashani Bozorg School of Metallurgy and Materials Engineering College of EngineeringUniversity of TehranTehranPO Box 11155/4563Iran

The effect of Mg replacement with Al on the discharge capacity of Mg_(2)Cu powder mixture was *** mixture of nano-crystalline powder was prepared via mechanical alloying(MA)technique with a high energy planetary ball *** addition,different moles of Al(0.05,0.1,0.15,0.2,and 0.3 M)were substituted to Mg_(2)Cu powder.X-ray diffraction(XRD),scanning electron microscopy(SEM),and transmission electron microscopy(TEM)were used to analyze changes in structure,morphology,and grain *** obtained powder was utilized as an anode in a nickel-metal hydride battery(Ni-MH).In the specimens with 0.05 M Al content,the orthorhombic structure of Mg_(2)Cu is emerged after 5 h *** results reveal that more than 0.1 M Al substitution leads to an appearance of MgCu_(2) *** substi-tution does not affect microstructure uniformity;however,it causes a decrease in crystalline size and lattice *** selected area diffraction(SAD)pattern elucidates that the electrode with the Mg_(1.9)Al_(0.1)Cu chemical composition and 20 h milling has the maximum discharge capacity.

关键词： Mg_(2)Cu mechanical alloying nanocrystalline discharge capacity

Simplified modeling of frequency behavior in photonic crystal vertical cavity surface emitting laser with tunnel injection quantum dot in active region

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Chinese Physics B 2017年第2期26卷 260-267页

作者： Mehdi Riahinasab Vahid Ahmadi elham Darabi Department of Electrical Engineering Science and Research Branch Islamic Azad University Tehran Iran Department of Electrical Engineering Tarbiat Modares University Tehran Iran Plasma Physics Research Center Science and Research Branch Islamic Azad University Tehran Iran

In this work, the characteristics of the photonic crystal tunneling injection quantum dot vertical cavity surface emitting lasers（Ph C-TIQD-VCSEL） are studied through analyzing a modified modulation transfer function. The function is based on the rate equations describing the carrier dynamics at different energy levels of dot and injector well. Although the frequency modulation response component associated with carrier dynamics in wetting layer（WL） and at excited state（ES） levels of dots limits the total bandwidth in conventional QD-VCSEL, our study shows that it can be compensated for by electron tunneling from the injector well into the dot in TIQD structure. Carrier back tunneling time is one of the most important parameters, and by increment of that, the bias current dependence of the total bandwidth will be insignificant. It is proved that at high bias current, the limitation of the WL-ES level plays an important role in reducing the total bandwidth and results in rollovers on 3-d B bandwidth-I curves. In such a way, for smaller air hole diameter of photonic crystal, the effect of this reduction is stronger.

关键词： modulation transfer function photonic crystal(PhC) tunnel injection quantum dot(TIQD) vertical cavity surface emitting laser(VCSEL)

Identification of time-varying system and energy-based optimization of adaptive control in seismically excited structure

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 227-240页

作者： elham Aghabarari Fereidoun Amini Pedram Ghaderi Department of Civil Engineering Iran University of Science and TechnologyTehran 16844Iran

The combination of structural health monitoring and vibration control is of great importance to provide components of smart *** synthetic algorithms have been proposed,adaptive control that is compatible with changing conditions still needs to be used,and time-varying systems are required to be simultaneously estimated with the application of adaptive *** this research,the identification of structural time-varying dynamic characteristics and optimized simple adaptive control are ***,reduced variations of physical parameters are estimated online using the multiple forgetting factor recursive least squares(MFRLS)***,the energy from the structural vibration is simultaneously specified to optimize the control force with the identified parameters to be *** is also performed based on the probability density function of the energy under the seismic excitation at any ***,the optimal control force is obtained by the simple adaptive control(SAC)algorithm and energy coefficient.A numerical example and benchmark structure are employed to investigate the efficiency of the proposed *** simulation results revealed the effectiveness of the integrated online identification and optimal adaptive control in systems.

关键词： integrated online identification time-varying systems structural energy multiple forgetting factor recursive least squares optimal simple adaptive control algorithm