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Full-Text Articles in Computer Engineering

A Continous Rotary Actuation Mechanism For A Powered Hip Exoskeleton, Matthew C. Ryder Jul 2015

A Continous Rotary Actuation Mechanism For A Powered Hip Exoskeleton, Matthew C. Ryder

Masters Theses

This thesis presents a new mechanical design for an exoskeleton actuator to power the sagittal plane motion in the human hip. The device uses a DC motor to drive a Scotch yoke mechanism and series elasticity to take advantage of the cyclic nature of human gait and to reduce the maximum power and control requirements of the exoskeleton. The Scotch yoke actuator creates a position-dependent transmission that varies between 4:1 and infinity, with the peak transmission ratio aligned to the peak torque periods of the human gait cycle. Simulation results show that both the peak and average motor torque can …


Function Verification Of Combinational Arithmetic Circuits, Duo Liu Jul 2015

Function Verification Of Combinational Arithmetic Circuits, Duo Liu

Masters Theses

Hardware design verification is the most challenging part in overall hardware design process. It is because design size and complexity are growing very fast while the requirement for performance is ever higher. Conventional simulation-based verification method cannot keep up with the rapid increase in the design size, since it is impossible to exhaustively test all input vectors of a complex design. An important part of hardware verification is combinational arithmetic circuit verification. It draws a lot of attention because flattening the design into bit-level, known as the bit-blasting problem, hinders the efficiency of many current formal techniques. The goal of …


Design And Implementation Of Digital Information Security For Physical Documents, Pengcheng Wang Jul 2015

Design And Implementation Of Digital Information Security For Physical Documents, Pengcheng Wang

Masters Theses

The objective of this thesis is to improve the security for physical paper documents. Providing information security has been difficult in environments that rely on physical paper documents to implement business processes. Our work presents the design of a digital information security system for paper documents, called "CryptoPaper", that uses 2-dimensional codes to represent data and its security properties on paper. A special scanner system is designed for "CryptoPaper" which uses image recognition techniques and cloud-based access control to display plaintext of encrypted and encoded data to authorized users.


Performance Analysis Of Distance Relay On Shunt/Series Facts-Compensated Transmission Line, Ahmed Kareem Lafta Al-Behadili Jun 2015

Performance Analysis Of Distance Relay On Shunt/Series Facts-Compensated Transmission Line, Ahmed Kareem Lafta Al-Behadili

Masters Theses

Flexible Alternating Current Transmission Systems (FACTS) are increasingly being used to enhance the efficiency and reliability of power system networks. FACTS devices can influence the performance of existing protective system components (specifically distance relays) due to the fact that FACTS change power system quantities such as line impedances, voltages, and currents. Distance relay may mal-operate when FACTS devices are connected since they cause some of the tripping characteristics to change. This thesis investigates the impact on distance relay performance due to compensations using two types of FACTS controllers: Static Synchronous Compensator (STATCOM) and Static Synchronous Series Compensator (SSSC). Analytical study …


Reliabilibity Aware Thermal Management Of Real-Time Multi-Core Systems, Shikang Xu Mar 2015

Reliabilibity Aware Thermal Management Of Real-Time Multi-Core Systems, Shikang Xu

Masters Theses

Continued scaling of CMOS technology has led to increasing working temperature of VLSI circuits. High temperature brings a greater probability of permanent errors (failure) in VLSI circuits, which is a critical threat for real-time systems. As the multi-core architecture is gaining in popularity, this research proposes an adaptive workload assignment approach for multi-core real-time systems to balance thermal stress among cores. While previously developed scheduling algorithms use temperature as the criterion, the proposed algorithm uses reliability of each core in the system to dynamically assign tasks to cores. The simulation results show that the proposed algorithm gains as large as …


Energy Agile Cluster Communication, Muhammad Zain Mustafa Mar 2015

Energy Agile Cluster Communication, Muhammad Zain Mustafa

Masters Theses

Computing researchers have long focused on improving energy-efficiency?the amount of computation per joule? under the implicit assumption that all energy is created equal. Energy however is not created equal: its cost and carbon footprint fluctuates over time due to a variety of factors. These fluctuations are expected to in- tensify as renewable penetration increases. Thus in my work I introduce energy-agility a design concept for a platform?s ability to rapidly and efficiently adapt to such power fluctuations. I then introduce a representative application to assess energy-agility for the type of long-running, parallel, data-intensive tasks that are both common in data …


Direct Torque Control Of An Lnduction Machine Using Multi-Layer Perceptron Network, Adithya Chandrashekharan Dec 2014

Direct Torque Control Of An Lnduction Machine Using Multi-Layer Perceptron Network, Adithya Chandrashekharan

Masters Theses

In conventional direct torque control (DTC) scheme of induction motor (lM), Proportional Integral Controller (PI) is used as the speed controller. PI controller is more suitable in steady state condition and for linear system but both DTC and IM are mostly nonlinear. Multi-Layer perceptron neural network. (MLPNN) controller is more suitable and performs better than PI controller. The switching table of the conventional DTC is replaced by the MLPNN controller. The MLPNN inputs are, the magnitude of the stator flux, torque and the Voltage sectors. Levenberg-Marquardt back propagation technique has been used to train the MLPNN. The output of the …


Ubot-7: The Design Of A Compliant Dexterous Mobile Manipulator, Jonathan Cummings Nov 2014

Ubot-7: The Design Of A Compliant Dexterous Mobile Manipulator, Jonathan Cummings

Masters Theses

This thesis presents the design of uBot-7, the latest version of a dexterous mobile manipulator. This platform has been iteratively developed to realize a high performance-to-cost dexterous whole body manipulator with respect to mobile manipulation. The semi-anthropomorphic design of the uBot is a demonstrated and functional research platform for developing advanced autonomous perception, manipulation, and mobility tasks. The goal of this work is to improve the uBot’s ability to sense and interact with its environment in order to increase the platforms capability to operate dexterously, through the incorporation of joint torque feedback, and safely, through the implementation of passive and …


Statistical Analysis Of Disturbances In Power Transmission Systems, Liu Liu Aug 2014

Statistical Analysis Of Disturbances In Power Transmission Systems, Liu Liu

Masters Theses

Disturbance analysis is essential to the study of the power transmission systems. Traditionally, disturbances are described as megawatt (MW) events, but the access to data is inefficient due to the slow installation and authorization process of the monitoring device. In this paper, we propose a novel approach to disturbance analysis conducted at the distribution level by exploiting the frequency recordings from Frequency Disturbance Recorders (FDRs) of the Frequency Monitoring Network (FNET/GridEye), based on the relationship between frequency change and the power loss of disturbances - linearly associated by the Frequency Response. We first analyze the real disturbance records of North …


Improved Accuracy In Real-Time Rfid Localization Systems Using Kalman Filtering, Benjamin J. Sanda Jun 2014

Improved Accuracy In Real-Time Rfid Localization Systems Using Kalman Filtering, Benjamin J. Sanda

Masters Theses

The use of Radio Frequency Identification (RFID) has become widespread in industry as a means to quickly and wirelessly identify and track packages and equipment. Now there is a commercial interest in using RFID to provide real-time localization. Efforts to use RFID technology for this purpose experience localization errors due to noise and multipath effects inherent to these environments. This paper presents the use of both linear Kalman filters and non-linear Unscented Kalman filters to reduce error effects inherent to real-time RFID localization systems and provide more accurate localization results in indoor environments. A commercial RFID localization system designed for …


Improved Forensic Medical Device Security Through Eating Detection, Nathan Lee Henry May 2014

Improved Forensic Medical Device Security Through Eating Detection, Nathan Lee Henry

Masters Theses

Patients are increasingly reliant on implantable medical device systems today. For patients with diabetes, an implantable insulin pump system or artificial pancreas can greatly improve quality of life. As with any device, these devices can and do suffer from software and hardware issues, often reported as a safety event. For a forensic investigator, a safety event is indistinguishable from a potential security event. In this thesis, we show a new sensor system that can be transparently integrated into existing and future electronic diabetes therapy systems while providing additional forensic data to help distinguish between safety and security events. We demonstrate …


A Secure Reconfigurable System-On-Programmable-Chip Computer System, William Herbert Collins Aug 2013

A Secure Reconfigurable System-On-Programmable-Chip Computer System, William Herbert Collins

Masters Theses

A System-on-Programmable-Chip (SoPC) architecture is designed to meet two goals: to provide a role-based secure computing environment and to allow for user reconfiguration. To accomplish this, a secure root of trust is derived from a fixed architectural subsystem, known as the Security Controller. It additionally provides a dynamically configurable single point of access between applications developed by users and the objects those applications use. The platform provides a model for secrecy such that physical recovery of any one component in isolation does not compromise the system. Dual-factor authentication is used to verify users. A model is also provided for tamper …


An Fpga Based Implementation Of The Exact Stochastic Simulation Algorithm, Phani Bharadwaj Vanguri Dec 2010

An Fpga Based Implementation Of The Exact Stochastic Simulation Algorithm, Phani Bharadwaj Vanguri

Masters Theses

Mathematical and statistical modeling of biological systems is a desired goal for many years. Many biochemical models are often evaluated using a deterministic approach, which uses differential equations to describe the chemical interactions. However, such an approach is inaccurate for small species populations as it neglects the discrete representation of population values, presents the possibility of negative populations, and does not represent the stochastic nature of biochemical systems. The Stochastic Simulation Algorithm (SSA) developed by Gillespie is able to properly account for these inherent noise fluctuations. Due to the stochastic nature of the Monte Carlo simulations, large numbers of simulations …