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Clemson University

2013

Computer Engineering

Articles 1 - 12 of 12

Full-Text Articles in Engineering

Large Scale 3d Mapping Of Indoor Environments Using A Handheld Rgbd Camera, Brian Peasley Dec 2013

Large Scale 3d Mapping Of Indoor Environments Using A Handheld Rgbd Camera, Brian Peasley

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The goal of this research is to investigate the problem of reconstructing a 3D representation of an environment, of arbitrary size, using a handheld color and depth (RGBD) sensor. The focus of this dissertation is to examine four of the underlying subproblems to this system: camera tracking, loop closure, data storage, and integration. First, a system for 3D reconstruction of large indoor planar environments with data captured from an RGBD sensor mounted on a mobile robotic platform is presented. An algorithm for constructing nearly drift-free 3D occupancy grids of large indoor environments in an online manner is also presented. This …

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Exploring Multiple Levels Of Performance Modeling For Heterogeneous Systems, Venkittaraman Vivek Pallipuram Krishnamani Dec 2013

Exploring Multiple Levels Of Performance Modeling For Heterogeneous Systems, Venkittaraman Vivek Pallipuram Krishnamani

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The current trend in High-Performance Computing (HPC) is to extract concurrency from clusters that include heterogeneous resources such as General Purpose Graphical Processing Units (GPGPUs) and Field Programmable Gate Array (FPGAs). Although these heterogeneous systems can provide substantial performance for massively parallel applications, much of the available computing resources are often under-utilized due to inefficient application mapping, load balancing, and tuning. While several performance prediction models exist to efficiently tune applications, they often require significant computing architecture knowledge for reliable prediction. In addition, they do not address multiple levels of design space abstraction and it is often difficult to choose …

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Sociallink: A Social Network Based Trust System For P2p File Sharing Systems, Fang Qi Dec 2013

Sociallink: A Social Network Based Trust System For P2p File Sharing Systems, Fang Qi

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In peer-to-peer (P2P) file sharing systems, many autonomous peers without preexisting trust relationships share files with each other. Due to their open environment and distributed structure, these systems are vulnerable to the significant impact from selfish and misbehaving nodes. Free-riding, whitewash, collusion and Sybil attacks are common and serious threats, which severely harm non-malicious users and degrade the system performance. Many trust systems were proposed for P2P file sharing systems to encourage cooperative behaviors and punish non-cooperative behaviors. However, querying reputation values usually generates latency and overhead for every user. To address this problem, a social network based trust system …

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Hierarchical Channel-Access And Routing Protocols For Heterogeneous Multichannel Ad Hoc Networks, Crystal Jackson Aug 2013

Hierarchical Channel-Access And Routing Protocols For Heterogeneous Multichannel Ad Hoc Networks, Crystal Jackson

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In this work, we consider a heterogeneous multichannel ad hoc network consisting of frequency-agile radios with the ability to change their carrier frequency and chip rate over a wide range of possibilities. The radios in this type of network are permitted to utilize multiple non-overlapping channels, and each channel differs significantly in its characteristics such as achievable data rate and communication range. A channel-access protocol regulates access to the channels available, and a routing protocol determines how a packet should be forwarded from its source to its destination through the network. The initial focus of this research is on channel-access …

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Modeling, Control, And Motion Analysis Of A Class Of Extensible Continuum Manipulators, Apoorva Kapadia Aug 2013

Modeling, Control, And Motion Analysis Of A Class Of Extensible Continuum Manipulators, Apoorva Kapadia

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In this dissertation, the development of a kinematic model, a configuration-space controller, a master-slave teleoperation controller, along with the analysis of the self-motion properties for redundant, extensible, continuous backbone (continuum) ``trunk and tentacle' manipulators are detailed. Unlike conventional rigid-link robots, continuum manipulators are robots that can bend at any point along their backbone, resulting in new and unique modeling and control issues. Taken together, these chapters represent one of the first efforts towards devising model-based controllers of such robots, as well as characterizing their self-motion in its simplest form.
Chapter 2 describes the development of a convenient set of generalized, …

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Mobile Robot Navigation For Person Following In Indoor Environments, Ninad Pradhan Aug 2013

Mobile Robot Navigation For Person Following In Indoor Environments, Ninad Pradhan

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Service robotics is a rapidly growing area of interest in robotics research. Service robots inhabit human-populated environments and carry out specific tasks. The goal of this dissertation is to develop a service robot capable of following a human leader around populated indoor environments. A classification system for person followers is proposed such that it clearly defines the expected interaction between the leader and the robotic follower. In populated environments, the robot needs to be able to detect and identify its leader and track the leader through occlusions, a common characteristic of populated spaces. An appearance-based person descriptor, which augments the …

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Continuum Robotic Surface: Forward Kinematic Analysis And Implementation, Jessica Merino Aug 2013

Continuum Robotic Surface: Forward Kinematic Analysis And Implementation, Jessica Merino

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This thesis presents a new class of biologically inspired robots: continuum robotic surfaces. This work is fueled by the question: can the interaction between robot and environment be advanced with “programmable surfaces in space?” The novelty of continuum robotic surfaces lies in their ability to be actively controlled and reconfigured in what we believe is the current “missing dimension” in robot movements — two–dimensional space. We believe that such surfaces will lend themselves to more complex applications. However, to effectively deploy such surfaces for these complex applications, kinematic models will be necessary to plan and control desired configurations. The forward …

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Statistical Regression Methods For Gpgpu Design Space Exploration, Nimisha Raut Aug 2013

Statistical Regression Methods For Gpgpu Design Space Exploration, Nimisha Raut

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General Purpose Graphics Processing Units (GPGPUs) have leveraged the performance and power efficiency of today's heterogeneous systems to usher in a new era of innovation in high-performance scientific computing. These systems can offer significantly high performance for massively parallel applications; however, their resources may be wasted due to inefficient tuning strategies. Previous application tuning studies pre-dominantly employ low-level, architecture specific tuning which can make the performance modeling task difficult and less generic. In this research, we explore the GPGPU design space featuring the memory hierarchy for application tuning using regression-based performance prediction framework and rank the design space based on …

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An Assessment Of The Accuracy Of An Automated Bite Counting Method In A Cafeteria Setting, Ziqing Huang Aug 2013

An Assessment Of The Accuracy Of An Automated Bite Counting Method In A Cafeteria Setting, Ziqing Huang

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Advances in body-worn sensors and mobile health technology have created new opportunities for empowering people to take a more active role in managing their health. Obesity has been recognized as a target of opportunity that could particularly benefit from this approach. Self-monitoring of dietary intake is critical for weight loss/management, but currently used tools such as
food diaries require users to manually estimate and record energy intake, making them subjective, prone to error, and difficult to use for long periods of time. Our group is developing a new tool called
the 'bite counter' that automates the monitoring of caloric intake. …

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Occlusion-Aware Multi-View Reconstruction Of Articulated Objects For Manipulation, Xiaoxia Huang Aug 2013

Occlusion-Aware Multi-View Reconstruction Of Articulated Objects For Manipulation, Xiaoxia Huang

All Dissertations

The goal of this research is to develop algorithms using multiple views to automatically recover complete 3D models of articulated objects in unstructured environments and thereby enable a robotic system to facilitate further manipulation of those objects. First, an algorithm called Procrustes-Lo-RANSAC (PLR) is presented. Structure-from-motion techniques are used to capture 3D point cloud models of an articulated object in two different configurations. Procrustes analysis, combined with a locally optimized RANSAC sampling strategy, facilitates a straightforward geometric approach to recovering the joint axes, as well as classifying them automatically as either revolute or prismatic. The algorithm does not require prior …

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Sensing Highly Non-Rigid Objects With Rgbd Sensors For Robotic Systems, Robert Willimon May 2013

Sensing Highly Non-Rigid Objects With Rgbd Sensors For Robotic Systems, Robert Willimon

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The goal of this research is to enable a robotic system to manipulate clothing and other highly non-rigid objects using an RGBD sensor. The focus of this thesis is to define and test various algorithms / models that are used to solve parts of the laundry process (i.e. handling, classifying, sorting, unfolding, and folding). First, a system is presented for automatically extracting and classifying items in a pile of laundry. Using only visual sensors, the robot identifies and extracts items
sequentially from the pile. When an item is removed and isolated, a model is captured of the shape and appearance …

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Parallex File System (Pxfs): Bridging The Gap Between Exascale Processing Capabilities And I/O Performance, Shane Snyder May 2013

Parallex File System (Pxfs): Bridging The Gap Between Exascale Processing Capabilities And I/O Performance, Shane Snyder

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Due to processors reaching the maximum performance allowable by current technology, architectural trends for computer systems continue to increase the number of cores per processing chip to maximize system performance. Most estimates suggest massively parallel systems will be available within the decade, containing millions of cores and capable of exaFlops of performance. New models of execution are necessary to maximize processor utilization and minimize power costs for these exascale systems. ParalleX is one such execution model, which attempts to address inefficiencies of current execution models by exposing fine-grained parallelism, increasing system utilization using asynchronous workflow, and resolving resource contention through …

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