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Full-Text Articles in Computer Engineering

Towards Energy-Efficient And Reliable Computing: From Highly-Scaled Cmos Devices To Resistive Memories, Soheil Salehi Mobarakeh Jan 2016

Towards Energy-Efficient And Reliable Computing: From Highly-Scaled Cmos Devices To Resistive Memories, Soheil Salehi Mobarakeh

Electronic Theses and Dissertations

The continuous increase in transistor density based on Moore's Law has led us to highly scaled Complementary Metal-Oxide Semiconductor (CMOS) technologies. These transistor-based process technologies offer improved density as well as a reduction in nominal supply voltage. An analysis regarding different aspects of 45nm and 15nm technologies, such as power consumption and cell area to compare these two technologies is proposed on an IEEE 754 Single Precision Floating-Point Unit implementation. Based on the results, using the 15nm technology offers 4-times less energy and 3-fold smaller footprint. New challenges also arise, such as relative proportion of leakage power in standby mode …


Improving Efficiency In Deep Learning For Large Scale Visual Recognition, Baoyuan Liu Jan 2016

Improving Efficiency In Deep Learning For Large Scale Visual Recognition, Baoyuan Liu

Electronic Theses and Dissertations

The emerging recent large scale visual recognition methods, and in particular the deep Convolutional Neural Networks (CNN), are promising to revolutionize many computer vision based artificial intelligent applications, such as autonomous driving and online image retrieval systems. One of the main challenges in large scale visual recognition is the complexity of the corresponding algorithms. This is further exacerbated by the fact that in most real-world scenarios they need to run in real time and on platforms that have limited computational resources. This dissertation focuses on improving the efficiency of such large scale visual recognition algorithms from several perspectives. First, to …


A Contextual Approach To Real Time, Interactive Narrative Generation, James Hollister Jan 2016

A Contextual Approach To Real Time, Interactive Narrative Generation, James Hollister

Electronic Theses and Dissertations

Oral story telling has become a lost art of family histories because social media and technology have taken over the personal interactions that once passed on the important stories and facts from generation to generation. This dissertation presents and evaluates a method of generating a narrative with input from the listener without actually forcing him or her to become an actual character in the narrative. This system is called CAMPFIRE Story Telling System (STS) and employs a contextual approach to story generation. This system uses the Cooperating Context Method (CCM) to generate and tell dynamic stories in real time and …


Developing New Power Management And High-Reliability Schemes In Data-Intensive Environment, Ruijun Wang Jan 2016

Developing New Power Management And High-Reliability Schemes In Data-Intensive Environment, Ruijun Wang

Electronic Theses and Dissertations

With the increasing popularity of data-intensive applications as well as the large-scale computing and storage systems, current data centers and supercomputers are often dealing with extremely large data-sets. To store and process this huge amount of data reliably and energy-efficiently, three major challenges should be taken into consideration for the system designers. Firstly, power conservation–Multicore processors or CMPs have become a mainstream in the current processor market because of the tremendous improvement in transistor density and the advancement in semiconductor technology. However, the increasing number of transistors on a single die or chip reveals a super-linear growth in power consumption …


Reactive Rejuvenation Of Cmos Logic Paths Using Self-Activating Voltage Domains, Navid Khoshavi Najafabadi Jan 2016

Reactive Rejuvenation Of Cmos Logic Paths Using Self-Activating Voltage Domains, Navid Khoshavi Najafabadi

Electronic Theses and Dissertations

Aggressive CMOS technology scaling trends exacerbate the aging-related degradation of propagation delay and energy efficiency in nanoscale designs. Recently, power-gating has been utilized as an effective low-power design technique which has also been shown to alleviate some aging impacts. However, the use of MOSFETs to realize power-gated designs will also encounter aging-induced degradations in the sleep transistors themselves which necessitates the exploration of design strategies to utilize power-gating effectively to mitigate aging. In particular, Bias Temperature Instability (BTI) which occurs during activation of power-gated voltage islands is investigated with respect to the placement of the sleep transistor in the header …


Computational Methods For Comparative Non-Coding Rna Analysis: From Secondary Structures To Tertiary Structures, Ping Ge Jan 2016

Computational Methods For Comparative Non-Coding Rna Analysis: From Secondary Structures To Tertiary Structures, Ping Ge

Electronic Theses and Dissertations

Unlike message RNAs (mRNAs) whose information is encoded in the primary sequences, the cellular roles of non-coding RNAs (ncRNAs) originate from the structures. Therefore studying the structural conservation in ncRNAs is important to yield an in-depth understanding of their functionalities. In the past years, many computational methods have been proposed to analyze the common structural patterns in ncRNAs using comparative methods. However, the RNA structural comparison is not a trivial task, and the existing approaches still have numerous issues in efficiency and accuracy. In this dissertation, we will introduce a suite of novel computational tools that extend the classic models …


Probabilistic-Based Computing Transformation With Reconfigurable Logic Fabrics, Mohammed Alawad Jan 2016

Probabilistic-Based Computing Transformation With Reconfigurable Logic Fabrics, Mohammed Alawad

Electronic Theses and Dissertations

Effectively tackling the upcoming "zettabytes" data explosion requires a huge quantum leap in our computing power and energy efficiency. However, with the Moore's law dwindling quickly, the physical limits of CMOS technology make it almost intractable to achieve high energy efficiency if the traditional "deterministic and precise" computing model still dominates. Worse, the upcoming data explosion mostly comprises statistics gleaned from uncertain, imperfect real-world environment. As such, the traditional computing means of first-principle modeling or explicit statistical modeling will very likely be ineffective to achieve flexibility, autonomy, and human interaction. The bottom line is clear: given where we are headed, …


Energy-Aware Reconfigurable Logic Device Using Spin-Based Storage And Carbon Nanotube Switching, Mohan Krishna Gopi Krishna Jan 2016

Energy-Aware Reconfigurable Logic Device Using Spin-Based Storage And Carbon Nanotube Switching, Mohan Krishna Gopi Krishna

Electronic Theses and Dissertations

Scaling of semiconductors to the 14-nanometer range and below nanometer range introduces serious design challenges that include high static power in memories and high leakage power, hindering further integration of CMOS devices. Thus, emerging devices are under intense analysis to overcome these drawbacks caused by transistor size scaling. Spintronics technology provides excellent features such as Non-Volatility, low read power, low read delay, higher scalability as well as easy integration with CMOS in comparison with SRAM memories. In addition, Carbon-Nanotube Field-Effect Transistors (CNFETs) provide superior electrical conductivity, low delay and low power consumption in comparison with conventional CMOS technology. Thus in …


Assessing Approximate Arithmetic Designs In The Presence Of Process Variations And Voltage Scaling, Adnan Aquib Naseer Jan 2015

Assessing Approximate Arithmetic Designs In The Presence Of Process Variations And Voltage Scaling, Adnan Aquib Naseer

Electronic Theses and Dissertations

As environmental concerns and portability of electronic devices move to the forefront of priorities, innovative approaches which reduce processor energy consumption are sought. Approximate arithmetic units are one of the avenues whereby significant energy savings can be achieved. Approximation of fundamental arithmetic units is achieved by judiciously reducing the number of transistors in the circuit. A satisfactory tradeoff of energy vs. accuracy of the circuit can be determined by trial-and-error methods of each functional approximation. Although the accuracy of the output is compromised, it is only decreased to an acceptable extent that can still fulfill processing requirements. A number of …


Adaptive Architectural Strategies For Resilient Energy-Aware Computing, Rizwan Arshad Ashraf Jan 2015

Adaptive Architectural Strategies For Resilient Energy-Aware Computing, Rizwan Arshad Ashraf

Electronic Theses and Dissertations

Reconfigurable logic or Field-Programmable Gate Array (FPGA) devices have the ability to dynamically adapt the computational circuit based on user-specified or operating-condition requirements. Such hardware platforms are utilized in this dissertation to develop adaptive techniques for achieving reliable and sustainable operation while autonomously meeting these requirements. In particular, the properties of resource uniformity and in-field reconfiguration via on-chip processors are exploited to implement Evolvable Hardware (EHW). EHW utilize genetic algorithms to realize logic circuits at runtime, as directed by the objective function. However, the size of problems solved using EHW as compared with traditional approaches has been limited to relatively …


Finding Consensus Energy Folding Landscapes Between Rna Sequences, Joshua Burbridge Jan 2015

Finding Consensus Energy Folding Landscapes Between Rna Sequences, Joshua Burbridge

Electronic Theses and Dissertations

In molecular biology, the secondary structure of a ribonucleic acid (RNA) molecule is closely related to its biological function. One problem in structural bioinformatics is to determine the two- and three-dimensional structure of RNA using only sequencing information, which can be obtained at low cost. This entails designing sophisticated algorithms to simulate the process of RNA folding using detailed sets of thermodynamic parameters. The set of all chemically feasible structures an RNA molecule can assume, as well as the energy associated with each structure, is called its energy folding landscape. This research focuses on defining and solving the problem of …


Research On High-Performance And Scalable Data Access In Parallel Big Data Computing, Jiangling Yin Jan 2015

Research On High-Performance And Scalable Data Access In Parallel Big Data Computing, Jiangling Yin

Electronic Theses and Dissertations

To facilitate big data processing, many dedicated data-intensive storage systems such as Google File System(GFS), Hadoop Distributed File System(HDFS) and Quantcast File System(QFS) have been developed. Currently, the Hadoop Distributed File System(HDFS) [20] is the state-of-art and most popular open-source distributed file system for big data processing. It is widely deployed as the bedrock for many big data processing systems/frameworks, such as the script-based pig system, MPI-based parallel programs, graph processing systems and scala/java-based Spark frameworks. These systems/applications employ parallel processes/executors to speed up data processing within scale-out clusters. Job or task schedulers in parallel big data applications such as …


Design Disjunction For Resilient Reconfigurable Hardware, Ahmad Alzahrani Jan 2015

Design Disjunction For Resilient Reconfigurable Hardware, Ahmad Alzahrani

Electronic Theses and Dissertations

Contemporary reconfigurable hardware devices have the capability to achieve high performance, power efficiency, and adaptability required to meet a wide range of design goals. With scaling challenges facing current complementary metal oxide semiconductor (CMOS), new concepts and methodologies supporting efficient adaptation to handle reliability issues are becoming increasingly prominent. Reconfigurable hardware and their ability to realize self-organization features are expected to play a key role in designing future dependable hardware architectures. However, the exponential increase in density and complexity of current commercial SRAM-based field-programmable gate arrays (FPGAs) has escalated the overhead associated with dynamic runtime design adaptation. Traditionally, static modular …


Agent-Based And System Dynamics Hybrid Modeling And Simulation Approach Using Systems Modeling Language, Asli Soyler Akbas Jan 2015

Agent-Based And System Dynamics Hybrid Modeling And Simulation Approach Using Systems Modeling Language, Asli Soyler Akbas

Electronic Theses and Dissertations

Agent-based (AB) and system dynamics (SD) modeling and simulation techniques have been studied and used by various research fields. After the new hybrid modeling field emerged, the combination of these techniques started getting attention in the late 1990's. Applications of using agent-based (AB) and system dynamics (SD) hybrid models for simulating systems have been demonstrated in the literature. However, majority of the work on the domain includes system specific approaches where the models from two techniques are integrated after being independently developed. Existing work on creating an implicit and universal approach is limited to conceptual modeling and structure design. This …


Synthetic Generators For Simulating Social Networks, Awrad Mohammed Ali Jan 2014

Synthetic Generators For Simulating Social Networks, Awrad Mohammed Ali

Electronic Theses and Dissertations

An application area of increasing importance is creating agent-based simulations to model human societies. One component of developing these simulations is the ability to generate realistic human social networks. Online social networking websites, such as Facebook, Google+, and Twitter, have increased in popularity in the last decade. Despite the increase in online social networking tools and the importance of studying human behavior in these networks, collecting data directly from these networks is not always feasible due to privacy concerns. Previous work in this area has primarily been limited to 1) network generators that aim to duplicate a small subset of …


Human Detection, Tracking And Segmentation In Surveillance Video, Guang Shu Jan 2014

Human Detection, Tracking And Segmentation In Surveillance Video, Guang Shu

Electronic Theses and Dissertations

This dissertation addresses the problem of human detection and tracking in surveillance videos. Even though this is a well-explored topic, many challenges remain when confronted with data from real world situations. These challenges include appearance variation, illumination changes, camera motion, cluttered scenes and occlusion. In this dissertation several novel methods for improving on the current state of human detection and tracking based on learning scene-specific information in video feeds are proposed. Firstly, we propose a novel method for human detection which employs unsupervised learning and superpixel segmentation. The performance of generic human detectors is usually degraded in unconstrained video environments …


Spectrum Map And Its Application In Cognitive Radio Networks, Saptarshi Debroy Jan 2014

Spectrum Map And Its Application In Cognitive Radio Networks, Saptarshi Debroy

Electronic Theses and Dissertations

Recent measurements on radio spectrum usage have revealed the abundance of underutilized bands of spectrum that belong to licensed users. This necessitated the paradigm shift from static to dynamic spectrum access. Cognitive radio based secondary networks that utilize such unused spectrum holes in the licensed band, have been proposed as a possible solution to the spectrum crisis. The idea is to detect times when a particular licensed band is unused and use it for transmission without causing interference to the licensed user. We argue that prior knowledge about occupancy of such bands and the corresponding achievable performance metrics can potentially …


Taming Wild Faces: Web-Scale, Open-Universe Face Identification In Still And Video Imagery, Enrique Ortiz Jan 2014

Taming Wild Faces: Web-Scale, Open-Universe Face Identification In Still And Video Imagery, Enrique Ortiz

Electronic Theses and Dissertations

With the increasing pervasiveness of digital cameras, the Internet, and social networking, there is a growing need to catalog and analyze large collections of photos and videos. In this dissertation, we explore unconstrained still-image and video-based face recognition in real-world scenarios, e.g. social photo sharing and movie trailers, where people of interest are recognized and all others are ignored. In such a scenario, we must obtain high precision in recognizing the known identities, while accurately rejecting those of no interest. Recent advancements in face recognition research has seen Sparse Representation-based Classification (SRC) advance to the forefront of competing methods. However, …


Human-Robot Interaction For Multi-Robot Systems, Bennie Lewis Jan 2014

Human-Robot Interaction For Multi-Robot Systems, Bennie Lewis

Electronic Theses and Dissertations

Designing an effective human-robot interaction paradigm is particularly important for complex tasks such as multi-robot manipulation that require the human and robot to work together in a tightly coupled fashion. Although increasing the number of robots can expand the area that the robots can cover within a bounded period of time, a poor human-robot interface will ultimately compromise the performance of the team of robots. However, introducing a human operator to the team of robots, does not automatically improve performance due to the difficulty of teleoperating mobile robots with manipulators. The human operator’s concentration is divided not only among multiple …


Sps: An Sms-Based Push Service For Energy Saving In Smartphone's Idle State, Erich Dondyk Jan 2014

Sps: An Sms-Based Push Service For Energy Saving In Smartphone's Idle State, Erich Dondyk

Electronic Theses and Dissertations

Despite of all the advances in smartphone technology in recent years, smartphones still remain limited by their battery life. Unlike other power hungry components in the smartphone, the cellular data and Wi-Fi interfaces often continue to be used even while the phone is in the idle state to accommodate unnecessary data traffic produced by some applications. In addition, bad reception has been proven to greatly increase energy consumed by the radio, which happens quite often when smartphone users are inside buildings. In this paper, we present a Short message service Push based Service (SPS) to save unnecessary power consumption when …


Routing, Localization And Positioning Protocols For Wireless Sensor And Actor Networks, Mustafa Akbas Jan 2013

Routing, Localization And Positioning Protocols For Wireless Sensor And Actor Networks, Mustafa Akbas

Electronic Theses and Dissertations

Wireless sensor and actor networks (WSANs) are distributed systems of sensor nodes and actors that are interconnected over the wireless medium. Sensor nodes collect information about the physical world and transmit the data to actors by using one-hop or multi-hop communications. Actors collect information from the sensor nodes, process the information, take decisions and react to the events. This dissertation presents contributions to the methods of routing, localization and positioning in WSANs for practical applications. We first propose a routing protocol with service differentiation for WSANs with stationary nodes. In this setting, we also adapt a sports ranking algorithm to …


Influence Of Task-Role Mental Models On Human Interpretation Of Robot Motion Behavior, Scott Ososky Jan 2013

Influence Of Task-Role Mental Models On Human Interpretation Of Robot Motion Behavior, Scott Ososky

Electronic Theses and Dissertations

The transition in robotics from tools to teammates has begun. However, the benefit autonomous robots provide will be diminished if human teammates misinterpret robot behaviors. Applying mental model theory as the organizing framework for human understanding of robots, the current empirical study examined the influence of task-role mental models of robots on the interpretation of robot motion behaviors, and the resulting impact on subjective ratings of robots. Observers (N = 120) were exposed to robot behaviors that were either congruent or incongruent with their task-role mental model, by experimental manipulation of preparatory robot task-role information to influence mental models (i.e., …


Life Long Learning In Sparse Learning Environments, John Reeder Jan 2013

Life Long Learning In Sparse Learning Environments, John Reeder

Electronic Theses and Dissertations

Life long learning is a machine learning technique that deals with learning sequential tasks over time. It seeks to transfer knowledge from previous learning tasks to new learning tasks in order to increase generalization performance and learning speed. Real-time learning environments in which many agents are participating may provide learning opportunities but they are spread out in time and space outside of the geographical scope of a single learning agent. This research seeks to provide an algorithm and framework for life long learning among a network of agents in a sparse real-time learning environment. This work will utilize the robust …


Robust Subspace Estimation Using Low-Rank Optimization. Theory And Applications In Scene Reconstruction, Video Denoising, And Activity Recognition., Omar Oreifej Jan 2013

Robust Subspace Estimation Using Low-Rank Optimization. Theory And Applications In Scene Reconstruction, Video Denoising, And Activity Recognition., Omar Oreifej

Electronic Theses and Dissertations

In this dissertation, we discuss the problem of robust linear subspace estimation using low-rank optimization and propose three formulations of it. We demonstrate how these formulations can be used to solve fundamental computer vision problems, and provide superior performance in terms of accuracy and running time. Consider a set of observations extracted from images (such as pixel gray values, local features, trajectories . . . etc). If the assumption that these observations are drawn from a liner subspace (or can be linearly approximated) is valid, then the goal is to represent each observation as a linear combination of a compact …


Modeling Learner Mood In Realtime Through Biosensors For Intelligent Tutoring Improvements, Keith Brawner Jan 2013

Modeling Learner Mood In Realtime Through Biosensors For Intelligent Tutoring Improvements, Keith Brawner

Electronic Theses and Dissertations

Computer-based instructors, just like their human counterparts, should monitor the emotional and cognitive states of their students in order to adapt instructional technique. Doing so requires a model of student state to be available at run time, but this has historically been difficult. Because people are different, generalized models have not been able to be validated. As a person’s cognitive and affective state vary over time of day and seasonally, individualized models have had differing difficulties. The simultaneous creation and execution of an individualized model, in real time, represents the last option for modeling such cognitive and affective states. This …


Mathematical And Computational Methods For Freeform Optical Shape Description, Ilhan Kaya Jan 2013

Mathematical And Computational Methods For Freeform Optical Shape Description, Ilhan Kaya

Electronic Theses and Dissertations

Slow-servo single-point diamond turning as well as advances in computer controlled small lap polishing enable the fabrication of freeform optics, specifically, optical surfaces for imaging applications that are not rotationally symmetric. Freeform optical elements will have a profound importance in the future of optical technology. Orthogonal polynomials added onto conic sections have been extensively used to describe optical surface shapes. The optical testing industry has chosen to represent the departure of a wavefront under test from a reference sphere in terms of orthogonal φ-polynomials, specifically Zernike polynomials. Various forms of polynomials for describing freeform optical surfaces may be considered, however, …


Measuring The Evolving Internet Ecosystem With Exchange Points, Mohammad Zubair Ahmad Jan 2013

Measuring The Evolving Internet Ecosystem With Exchange Points, Mohammad Zubair Ahmad

Electronic Theses and Dissertations

The Internet ecosystem comprising of thousands of Autonomous Systems (ASes) now include Internet eXchange Points (IXPs) as another critical component in the infrastructure. Peering plays a significant part in driving the economic growth of ASes and is contributing to a variety of structural changes in the Internet. IXPs are a primary component of this peering ecosystem and are playing an increasing role not only in the topology evolution of the Internet but also inter-domain path routing. In this dissertation we study and analyze the overall affects of peering and IXP infrastructure on the Internet. We observe IXP peering is enabling …


Recognition Of Complex Events In Open-Source Web-Scale Videos: Features, Intermediate Representations And Their Temporal Interactions, Subhabrata Bhattacharya Jan 2013

Recognition Of Complex Events In Open-Source Web-Scale Videos: Features, Intermediate Representations And Their Temporal Interactions, Subhabrata Bhattacharya

Electronic Theses and Dissertations

Recognition of complex events in consumer uploaded Internet videos, captured under realworld settings, has emerged as a challenging area of research across both computer vision and multimedia community. In this dissertation, we present a systematic decomposition of complex events into hierarchical components and make an in-depth analysis of how existing research are being used to cater to various levels of this hierarchy and identify three key stages where we make novel contributions, keeping complex events in focus. These are listed as follows: (a) Extraction of novel semi-global features – firstly, we introduce a Lie-algebra based representation of dominant camera motion …


Novelty-Assisted Interactive Evolution Of Control Behaviors, Brian G. Woolley Jan 2012

Novelty-Assisted Interactive Evolution Of Control Behaviors, Brian G. Woolley

Electronic Theses and Dissertations

The field of evolutionary computation is inspired by the achievements of natural evolution, in which there is no final objective. Yet the pursuit of objectives is ubiquitous in simulated evolution because evolutionary algorithms that can consistently achieve established benchmarks are lauded as successful, thus reinforcing this paradigm. A significant problem is that such objective approaches assume that intermediate stepping stones will increasingly resemble the final objective when in fact they often do not. The consequence is that while solutions may exist, searching for such objectives may not discover them. This problem with objectives is demonstrated through an experiment in this …


Specification And Runtime Checking Of Timing Constraints In Safety Critical Java, Ghaith Haddad Jan 2012

Specification And Runtime Checking Of Timing Constraints In Safety Critical Java, Ghaith Haddad

Electronic Theses and Dissertations

The Java platform is becoming a vital tool for developing real-time and safety-critical systems. Design patterns and the availability of Java libraries, both provide solutions to many known problems. Furthermore, the object-oriented nature of Java simplifies modular development of real-time systems. However, limitations of Java as a programming language for real-time systems are a notable obstacle to producing safe real-time systems. These limitations are found in the unpredictable execution model of the language, due to Java’s garbage collector, and the lack of support for non-functional specification and verification tools. In this dissertation I introduce SafeJML, a specification language for support …