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Full-Text Articles in Engineering
10-Bit C2c Dac Design In 65nm Cmos Technology, Jeevani Kommareddy
10-Bit C2c Dac Design In 65nm Cmos Technology, Jeevani Kommareddy
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Many wired and wireless communication systems require high-speed and high-performance data converters. These data converters act as bridge between digital signal processing blocks and power amplifiers. However, these data converters have been the bottleneck in the communication systems. This thesis presents the design of a 10-bit C2C digital to analog converter (DAC) for high resolution, wide bandwidth and low power consumption applications. The DAC is implemented in CMOS 65nm technology. The SFDR of this C2C DAC is 71.95dB at 500MHz input frequency and consumes 88.14µW of power with ENOB as 11.65 with 1.0GHz sample frequency with 0.31LSB of INL and …
Mixed Signal Detection, Estimation, And Modulation Classification, Yang Qu
Mixed Signal Detection, Estimation, And Modulation Classification, Yang Qu
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Signal detection, parameter estimation and modulation classification are widely applied to many areas and plays a very important role in civilian and military, such as bio-science, criminal psychology, communication engineering, radar system, electronic warfare and so on. In the civilian field, with the increasing number of wireless electronic devices and higher transmission data rate demand, the problem of spectrum congestion becomes more and more highlighted and urgent. In recent years, wireless industry has shown great interest in Cognitive Radio (CR) and Dynamic Spectrum Access (DSA) network, whose primary function is to use limited frequency bands to transmit own signals without …
Configurable Frequency And Voltage Three Phase Power Supply, Donald Danko
Configurable Frequency And Voltage Three Phase Power Supply, Donald Danko
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The student's employer is in need of a three phase power supply which can supply a 400Hz signal at +/- 28V at 2A. The input to the power supply is +24VDC at an unspecified current. The student's solution is a configurable frequency and voltage power supply. The student chose to utilize a full bridge DC to DC converter topology. A microcontroller was used for supplying pulse width modulated waveforms, performing analog to digital conversions, and controlling a digital to analog converter. The circuit was modeled using Matlab and tested after being manufactured to confirm proper functionality. The configurable three phase …
Stability Analysis Of Leg Configurations For Bipedal Running, Nitin Jaiswal
Stability Analysis Of Leg Configurations For Bipedal Running, Nitin Jaiswal
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A legged robot with three-segmented limbs is used to study the effects of leg compliance originating from the joint level on the stability of hopping in place and running. The three-segments allow each leg to be kinematically configured an infinite number ways that satisfy the desired landing condition parameters, total leg length and angle. These two parameters along with the amount of energy thrust during stance determine the motion of the system during a single stride. The goal of this work is to explore the potential values for the leg parameters of three-segment leg, that provide additional stability when compared …
High Security Cognitive Radio Network Via Instantaneous Channel Information, Kaiyu Huang
High Security Cognitive Radio Network Via Instantaneous Channel Information, Kaiyu Huang
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The cognitive radio network has been considered one of the most promising communication technologies for next generation wireless communication. One important aspect of cognitive radio network research is the so-called Primary User Authentication. Naturally, the primary user authentication in the cognitive radio network requires strong encryption. For the primary user identification, this dissertation provides a method which hides the user information in the header of the data frames with an underlay waveform. It is important to note that the underlay waveform will not bring redundancy data to the communication system. Using the synchronizing frequency as the underlay waveform carrier also …
Exploring Two-Dimensional Graphene And Silicene In Digital And Rf Applications, Zhonghang Ji
Exploring Two-Dimensional Graphene And Silicene In Digital And Rf Applications, Zhonghang Ji
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Since the discovery of graphene, two-dimensional (2D) materials have attracted intensive interests in the past 15 years and there has been a growing interest in exploring new materials beyond graphene, such as silicene, germanene, etc. Numerous papers have been published to demonstrate their extraordinary electronic, optical, biological, and thermal properties which render broad applications in various fields. However, the absence of band gap in graphene and silicene prohibits their uses in digital applications. This dissertation reviews recent progress on band gap opening based on mono- and bi- layer silicene and presents a new silicon atomic structure which exhibits a 0.17 …
Multifunctional Oxide Heterostructures For Next-Generation Tunable Rf/Microwave Electronics, Hyung Min Jeon
Multifunctional Oxide Heterostructures For Next-Generation Tunable Rf/Microwave Electronics, Hyung Min Jeon
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Recent advanced radio frequency (RF) microwave device demands for low power consumption, light weight, compact package, and high performance. To achieve the high performance, applying magnetic materials is becoming indispensable in many of those devices. Thus, the role of magnetism in those devices is important high-quality magnetic materials not only improves the performance of microwave devices but also opens opportunities in developing novel concepts of devices utilizing spin wave excitation, non-reciprocal wave propagation, and the electromagnetic coupling in multiferroic materials. Among all the others, manipulating magnetic properties in multiferroic material started a couple years ago. Multiferroic materials are a group …
Impact Of Near-Field-To-Far-Field Transformation On Sar Images Formed In An Indoor Non-Anechoic Environment, Jacob D. Compaleo
Impact Of Near-Field-To-Far-Field Transformation On Sar Images Formed In An Indoor Non-Anechoic Environment, Jacob D. Compaleo
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This work investigates the impact of the near-field-to-far-field transformation (NFFFT) algorithm on phase history measurement collections completed in the Sensors and Signals Exploitation Laboratory (SSEL). SSEL is an indoor non-anechoic environ- ment that is at risk to some measurement interferences such as multiple bounces. Complete 360-degree phase history measurements of scale model aircraft are con- ducted at varying range values within the near-field limit. These measurements are calibrated with the Mie series scattering solution for a sphere. After calibration, the measurements are transformed using the NFFFT, with radar cross-section (RCS) estimated. RCS of the transformed data is compared with the …
Control And Optimization Of Power In Llc Converter Using Phase Control, Nagasri Kollipara
Control And Optimization Of Power In Llc Converter Using Phase Control, Nagasri Kollipara
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LLC resonant converters are popular among resonant topologies due to their high efficiency and ability to achieve ZVS and ZCS for wide input range. LLC resonant converters are controlled by frequency modulation (FM), which makes converter difficult to optimize the system in terms of achieving efficient power conversion. FM technique also generate wide range of harmonics which leads to a wide sweep in operating frequency, which can run into regulatory EMI test limits and cause electromagnetic compatibility issues. The performance of LLC topology extends to their poor efficiency at lighter loads, due to constant high magnetization current. In order to …
Feed-Forward Compensation Of Non-Minimum Phase Systems, Venkatesh Dudiki
Feed-Forward Compensation Of Non-Minimum Phase Systems, Venkatesh Dudiki
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Due to inherent limitations posed by existence of zeros of a transfer function in the righthalfof the complex plane, known as non-minimum phase zeros, the issue of dealing withsuch zeros is extremely important in control of linear systems. Considerable literatureexists in control theory to try and minimize or eliminate the effect of non-minimum phasezeros. These include pole-zero cancellation, feedforward compensation, among others.These methods are only limited only to stable systems (systems with poles in the left halfof the complex plane); and will fail for systems that are unstable as well as non-minimumphase.This research focuses in designing feedforward compensators for unstable …
Switching Neural Network Systems For Nonlinear Tracking, Manoj Ghimire
Switching Neural Network Systems For Nonlinear Tracking, Manoj Ghimire
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In this thesis, we consider the problem of tracking in complex nonlinear dynamical systems. While the Kalman filter is known to be the mean-squared error optimal tracker under linear dynamics and linear measurements, more sophisticated models and algorithms are required for complex dynamics. Here, we consider switching systems where the dynamical properties vary (''switch modes") over time. For example, the dynamics of a vehicle may switch as it transitions from interstate to urban conditions, human speech dynamics switch as speakers change, and stock market dynamics switch with discrete news events. In this work, we use mode-dependent neural networks to capture …
Temperature Robust Longwave Infrared Hyperspectral Change Detection, Nicholas A. Durkee
Temperature Robust Longwave Infrared Hyperspectral Change Detection, Nicholas A. Durkee
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In this thesis, we develop and evaluate change detection algorithms for longwave infrared (LWIR) hyperspectral imagery. Because measured radiance in the LWIR domain depends on unknown surface temperature, care must be taken to prevent false alarms resulting from in-scene temperature differences that appear as material changes. We consider fewer variables. Examples using synthetic and measured data quantify the computational complexity of the proposed methods and demonstrate orders of magnitude reduction in false alarm rates relative to existing methods. Four strategies to mitigate this effect. In the first, pre-processing via traditional temperatureemissivity separation yields approximately temperature-invariant emissivity vectors for use in …
Chaotic Based Self-Synchronization For Rf Steganography Radar/Communication Waveform, Michael A. Gonnella
Chaotic Based Self-Synchronization For Rf Steganography Radar/Communication Waveform, Michael A. Gonnella
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In this project, we continue previous CSR project entitled RF Steganography based Joint Radar/Communication Waveform Design to develop a bio-inspired secure low probability detection (LPD) radio frequency (RF) waveform that can serve multiple purposes simultaneously. Previously, we have developed an RF steganography based RF waveform to conceal a secure digital communication within a linear frequency modulated (LFM) chirp radar signal. By exploiting novel reduced phase shift keying modulation and variable symbol duration, the new waveform is resistant to time domain analysis, frequency domain analysis and cyclostationary analysis. However, to demodulate the hidden communication message, the intended receiver has to know …
Real-Time Path Planning And Obstacle Avoidance For Mobile Robots With Actuator Faults, Ravindra Vibha Bellur
Real-Time Path Planning And Obstacle Avoidance For Mobile Robots With Actuator Faults, Ravindra Vibha Bellur
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In this research, a fault-tolerant path planning and obstacle avoidance algorithm is implemented for mobile ground robots. The fault-tolerant system architecture consists of the following three components: (1) an online fault diagnosis module for detecting and estimating actuator faults in the mobile robot; (2) a localization and mapping module for dynamic terrain mapping and obstacle detection; (3) a path planning and obstacle avoidance module for generating way points from a given point to the desired destination, avoiding the detected obstacles and moving along these way points. The online fault diagnostic information is used to compensate for the effect of faults, …
Analysis Of Evolutionary Algorithms In The Control Of Path Planning Problems, Pavlos Androulakakis
Analysis Of Evolutionary Algorithms In The Control Of Path Planning Problems, Pavlos Androulakakis
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The purpose of this thesis is to examine the ability of evolutionary algorithms (EAs) to develop near optimal solutions to three different path planning control problems. First, we begin by examining the evolution of an open-loop controller for the turn-circle intercept problem. We then extend the evolutionary methodology to develop a solution to the closedloop Dubins Vehicle problem. Finally, we attempt to evolve a closed-loop solution to the turn constrained pursuit evasion problem. For each of the presented problems, a custom controller representation is used. The goal of using custom controller representations (as opposed to more standard techniques such as …
Fpga-Based Ir Localization Sensor, Samuel I. Susanto
Fpga-Based Ir Localization Sensor, Samuel I. Susanto
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Pursuit-evasion scenarios are common in both natural and man-made systems. Often times, the pursuer and evader maneuver in response to each others actions using relative information based on the geometry of the agents and potential obstacles within the environment. The pursuer needs the target's bearing angle in order to plan a trajectory or path to capture it. We propose an FPGA-based infrared sensor array to detect up to 6 agents' bearing angles simultaneously. The final output of the sensor is the bearing angle of other agents. The sensor was tested and validated experimentally. Implementing the sensor and transmitter pair on …
Simulation Of A Mos Or Mis Structured Spatial Light Modulator For Terahertz (Thz) Imaging, Md Shahanur Alam
Simulation Of A Mos Or Mis Structured Spatial Light Modulator For Terahertz (Thz) Imaging, Md Shahanur Alam
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A large area, square-gate Metal-Oxide/Insulator-Semiconductor (MOS or MIS) structured `Spatial Light Modulator' has been proposed for the Terahertz (THz) imaging at room temperature. This theoretical study has been done entirely by using the MATLAB platform. The 1D Poisson's equation has been solved iteratively by Euler's method with the exact Fermi-Dirac integral for n-doped Si-MOS and GaAs- MIS capacitors in deep accumulation mode. Free carrier density and the potential profile have been found for the degenerate case. The results have been compared with the analytical method, which is approximated by Boltzmann statistics, and clearly, show the difference between the degenerate case …
A Robust Low Power Static Random Access Memory Cell Design, A. V. Rama Raju Pusapati
A Robust Low Power Static Random Access Memory Cell Design, A. V. Rama Raju Pusapati
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Stability of a Static Random Access Memory (SRAM) cell is an important factor when considering an SRAM cell for any application. The Static Noise Margin (SNM) of a cell, which determines the stability, varies under different operating conditions. Based on the performance of three existing SRAM cell designs, 6T, 8T and 10T, a 10 Transistor SRAM cell is proposed which has good stability and has the advantage of reduced read power when compared to 6T and 8T SRAM cells. The proposed 10T SRAM cell has a single-ended read circuit which improves SNM over the 6T cell. The proposed 10T cell …
Display And Analysis Of Tomographic Reconstructions Of Multiple Synthetic Aperture Ladar (Sal) Images, Bassirou Seck
Display And Analysis Of Tomographic Reconstructions Of Multiple Synthetic Aperture Ladar (Sal) Images, Bassirou Seck
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Synthetic aperture ladar (SAL) is similar to synthetic aperture radar (SAR) in that it can create range/cross-range slant plane images of the illuminated scatters; however, SAL has wavelengths 10,000x smaller than SAR enabling a relatively narrow real aperture, diffraction limited beam widths. The relatively narrow real aperture resolutions allow for multiple slant planes to be created for a single target with reasonable range/aperture combinations. These multiple slant planes can be projected into a single slant plane projections (as in SAR). It can also be displayed as a 3-D image with asymmetric resolutions, diffraction limited in the dimension orthogonal to the …
Leveraging 3d Models For Sar-Based Navigation In Gps-Denied Environments, Zachary A. Reid
Leveraging 3d Models For Sar-Based Navigation In Gps-Denied Environments, Zachary A. Reid
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This thesis considers the use of synthetic aperture radar (SAR) to provide absolute platform position information in scenarios where GPS signals may be degraded, jammed, or spoofed. Two algorithms are presented, and both leverage known 3D ground structure in an area of interest, e.g. provided by LIDAR data, to provide georeferenced position information to airborne SAR platforms. The first approach is based on the wide-aperture layover properties of elevated reflectors, while the second approach is based on correlating backprojected imagery with digital elevation imagery. Both of these approaches constitute the system we have designated: SARNAV. Building on 3D backprojection, localization …
Examination Of Gain Scheduling And Fuzzy Controllers With Hybrid Reachability, Aaron W. Fifarek
Examination Of Gain Scheduling And Fuzzy Controllers With Hybrid Reachability, Aaron W. Fifarek
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Modern aircraft with nonlinear flight envelopes predominately utilize gain scheduled controllers to provide stability of flight. Using gain scheduled control techniques, nonlinear envelopes can be linearized into collections of linear systems that operate under various system dynamics. Linear controllers approximate the nonlinear response over setpoints of operating conditions which allow traditional linear theory to be applied to maintain stability. Techniques to prove linear stability are well understood and realized in control systems, but when controllers are switched, interpolation methods must be used. Interpolation is necessary as gain scheduled systems do not have foundational switching paradigms as part of their realization …
A Simulation Method For Studying Effects Of Site-Specific Clutter On Sar-Gmti Performance, Marcus James Campbell
A Simulation Method For Studying Effects Of Site-Specific Clutter On Sar-Gmti Performance, Marcus James Campbell
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Synthetic aperture radar (SAR) is an invaluable tool for detection of ground moving targets when combined with processing techniques of ground moving target indication (GMTI). This work investigates a simulation methodology for studying impact of site-specific ground clutter on SAR-GMTI performance. A terrain model is proposed and is based on digital terrain elevation data (DTED) and national land-use land-cover data (NLCD) as provided by the US Geological Survey. The proposed physical optics simulation method capitalizes on high-fidelity digital target models in combination with the proposed terrain model. SAR phase history is generated for a moving commercial target in situ of …
Analysis And Design Of High-Frequency Soft-Switching Dc-Dc Converter For Wireless Power Charging Applications, Abhishek V. Danekar
Analysis And Design Of High-Frequency Soft-Switching Dc-Dc Converter For Wireless Power Charging Applications, Abhishek V. Danekar
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Wireless power transfer (WPT) technology is becoming attractive in a wide variety of applications such as electric-vehicle charging, induction heating, charging portable applications, industrial robots, and biomedical implants. Recent studies have shown various techniques to implement wireless power transfer and these techniques differ based on the type of applications. For example, for electric vehicle charging, the power levels are in the range 5 kW to 25 kW and the operating frequency is in the range 70 kHz to 110 kHz. On the other hand, for consumer applications, the power levels vary from a few watts to hundreds of watts and …
Plasma Property Estimation From Dual-Wavelength Interferometry, Andrew J. Hamilton
Plasma Property Estimation From Dual-Wavelength Interferometry, Andrew J. Hamilton
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Diagnostics are necessary for measurement of plasma parameters such as electron, ion and atomic densities, electron temperature, plasma expansion velocity and spatial resolution of density gradients. These parameters play a critical role in defining how a plasma will interact with electromagnetic radiation. For example, the plasma black-out phenomenon occurs when electromagnetic waves are at frequencies below the plasma frequency, where plasma frequency is a function of electron density. Wave propagation diagnostics can improve understanding of a plasma when measurement supports parameter estimation. In this report, the dual-wavelength interferometry method provides a single diagnostic capability to measure plasma expansion velocity, atomic …
Incorporating Passive Compliance For Reduced Motor Loading During Legged Walking, Akhil Sai Pabbu
Incorporating Passive Compliance For Reduced Motor Loading During Legged Walking, Akhil Sai Pabbu
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For purposes of travelling on all-terrains surfaces that are both uneven and discontinuous, legged robots have upper-hand over wheeled and tracked vehicles. The robot used in this thesis is a simulated hexapod with 3 degrees of freedom per leg. The main aim is to reduce the energy consumption of the system during walking by attaching a passive linear spring to each leg which will aid the motors and reduce the torque required while walking. Firstly, the ideal stiffness and location or the coordinates for mounting the spring is found out using gradient based algorithm called `Simultaneous Perturbation and Stochastic Approximation …
A Comparative Study Of Bagging And Boosting Of Supervised And Unsupervised Classifiers For Outliers Detection, Yue Dang
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The problem of outlier detection has received increasing attention recently because it plays a great role in many fields such as credit fraud detection, cyber security, etc. Machine Learning approach is an excellent choice for outlier detection due to its accuracy and efficiency. Outlier detection problem is unique due to the so-called classes imbalance: the inliers are extreme majority and the outliers are minority. Ensemble methods are popular in classification and regression task in practice to improve the performance of machine learning algorithms. Bagging and boosting are two common methods of them. In this thesis, we want to show the …
Null Values And Null Vectors Of Matrix Pencils And Their Applications In Linear System Theory, Neel Dalwadi
Null Values And Null Vectors Of Matrix Pencils And Their Applications In Linear System Theory, Neel Dalwadi
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Considerable literature exists in linear algebra to solve the generalized eigenvalue, eigenvector problem (F − [lambda]G)v = 0 where F, G 2 Rs×s, are square matrices. However, a number of applications lend themselves to the case whereF, G 2 Rs×, and s ≠ t. The existing methods cannot be used for such non-square cases. This research explores structural decomposition of a matrix pencil (F − [lambda]G), s 6≠ t to compute finite values of [lambda] for which rank (F − [lambda]G) < min(s, t). Moreover, from the decomposition of the matrix pencil, information about the order of [lambda] at infinity, the Kronecker row and column indices of a matrix pencil can also be extracted. Equally important is the computation of non-zero vectors w 2 R1×s and v 2 Rt×1 corresponding to each finite value of [lambda], such that w(F - [lambda] G) = 0 and (F - [lambda]G)v = 0. Algorithms are developed for the computation of lambda, w, and v using numerically efficient techniques. Proposed algorithms are applied to problems encountered in system theory and illustrated by means of numerical examples.
An Optimization Strategy For Hexapod Gait Transition, Naga Harika Darbha
An Optimization Strategy For Hexapod Gait Transition, Naga Harika Darbha
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Legged robots often need to move through different terrains as they function. This requires a change of gaits by the robot in order to move with better efficiency. There has been a lot of research done to find out which gait works better for a given terrain so that the robot can change its gait accordingly. A reliable analysis of when exactly should the transition take place in a walking robot is important, so that there can be an assurance of stability in the locomotion of the robot during the transition between different gaits. This work presents analysis performed on …
Layout Implementation Of A 10-Bit 1.2 Gs/S Digital-To-Analog Converter In 90nm Cmos, Vinay Kumar Chunchu
Layout Implementation Of A 10-Bit 1.2 Gs/S Digital-To-Analog Converter In 90nm Cmos, Vinay Kumar Chunchu
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Digital-to-analog converters are the interface circuits between digital and analog domains. They are used in data communication applications and different sorts of applications where transformation amongst digital and analog signals is needed. High-speed data converters are needed to match the bandwidth demands of the present-day communication systems. This thesis presents the layout implementation of a 10-bit current steering DAC with a sampling rate of about 1.2 GS/s using CMOS 90 nm technology. Current steering DAC topology is used in high-speed applications. The DAC in this thesis is designed using a segmented architecture in which 4 LSB current cells are binary …
Novel Implementation Of Finite Field Multipliers Over Gf(2m) For Emerging Cryptographic Applications, Nazeem Basha Shaik
Novel Implementation Of Finite Field Multipliers Over Gf(2m) For Emerging Cryptographic Applications, Nazeem Basha Shaik
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Cryptographic and coding theory algorithms use arithmetic operations over finite fields. Finite field multiplications over GF(2m) are critical components for these systems. Well known irreducible polynomials are all-one-polynomials (AOP), equally spaced polynomial (ESP), trinomial and pentanomial. Due to its simple structure, AOP based multiplica- tion is easy to implement and hence the AOP based multiplication of variable length can be used as a standard computation core. In this thesis, first of all, we employ low register complexity AOP based systolic multiplication core to propose multiplication over GF(2m) based on NIST recommended pentanomials. The proposed parallel and serial ar- chitectures use …