Computer Engineering Commons^™

Asymptotic Analysis Of Random Wireless Networks: Broadcasting, Secrecy, And Hybrid Networks, Cagatay Capar

Doctoral Dissertations

This thesis work is concerned with communication in large random wireless ad hoc networks. We mathematically model the wireless network as a collection of randomly located nodes, and explore how its performance scales as the network size increases. In particular, we study three important properties: broadcasting ability, rate of information exchange, and secret communication capability. In addition, we study connectivity properties of large random graphs in a more general context, where the graph does not necessarily represent a wireless communication network. Broadcasting, i.e., delivering a message from a single node to the entire network in a wireless ad hoc network …

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 …

Network-On-Chip Synchronization, Mark Buckler

Masters Theses

Technology scaling has enabled the number of cores within a System on Chip (SoC) to increase significantly. Globally Asynchronous Locally Synchronous (GALS) systems using Dynamic Voltage and Frequency Scaling (DVFS) operate each of these cores on distinct and dynamic clock domains. The main communication method between these cores is increasingly more likely to be a Network-on-Chip (NoC). Typically, the interfaces between these clock domains experience multi-cycle synchronization latencies due to their use of “brute-force” synchronizers. This dissertation aims to improve the performance of NoCs and thereby SoCs as a whole by reducing this synchronization latency.

First, a survey of NoC …

Reliable And Efficient Multithreading, Tongping Liu

Doctoral Dissertations

The advent of multicore architecture has increased the demand for multithreaded programs. It is notoriously far more challenging to write parallel programs correctly and efficiently than sequential ones because of the wide range of concurrency errors and performance problems. In this thesis, I developed a series of runtime systems and tools to combat concurrency errors and performance problems of multithreaded programs. The first system, Dthreads, automatically ensures determinism for unmodified C/C++ applications using the pthreads library without requiring programmer intervention and hardware support. Dthreads greatly simplifies the understanding and debugging of multithreaded programs. Dthreads often matches or even exceeds the …

Interpreting, Stephanie Jo Kent

Doctoral Dissertations

What do community interpreting for the Deaf in western societies, conference interpreting for the European Parliament, and language brokering in international management have in common? Academic research and professional training have historically emphasized the linguistic and cognitive challenges of interpreting, neglecting or ignoring the social aspects that structure communication. All forms of interpreting are inherently social; they involve relationships among at least three people and two languages. The contexts explored here, American Sign Language/English interpreting and spoken language interpreting within the European Parliament, show that simultaneous interpreting involves attitudes, norms and values about intercultural communication that overemphasize information and discount …

Integrating Non-Topical Aspects Into Information Retrieval, Elif Aktolga

Doctoral Dissertations

When users investigate a topic, they are often interested in results that are not just relevant, but also strongly opinionated or covering a range of times. To get such results, users are forced to formulate ambiguous, complex, or longer queries. Commonly this becomes a burden, since users need to issue several queries with reformulations if initial search results are not completely satisfactory. In this thesis, we focus on those two non-topical dimensions: opinionatedness and time. We develop measures for quantifying them in documents and incorporate them into search results. For improving search results with respect to non-topical dimensions, we use …

Parallel Multi-Core Verilog Hdl Simulation, Tariq B. Ahmad

Doctoral Dissertations

In the era of multi-core computing, the push for creating true parallel applications that can run on individual CPUs is on the rise. Application of parallel discrete event simulation (PDES) to hardware design verification looks promising, given the complexity of today’s hardware designs. Unfortunately, the challenges imposed by lack of inherent parallelism, suboptimal design partitioning, synchronization and communication overhead, and load balancing, render this approach largely ineffective. This thesis presents three techniques for accelerating simulation at three levels of abstraction namely, RTL, functional gate-level (zero-delay) and gate-level timing. We review contemporary solutions and then propose new ways of speeding up …

Exploiting Energy Harvesting For Passive Embedded Computing Systems, Jeremy Joel Gummeson

Doctoral Dissertations

The key limitation in mobile computing systems is energy - without a stable power supply, these systems cannot process, store, or communicate data. This problem is of particular interest since the storage density of battery technologies do not follow scaling trends similar to Moore's law. This means that depending on application performance requirements and lifetime objectives, a battery may dominate the overall system weight and form factor; this could result in an overall size that is either inconvenient or unacceptable for a particular application. As device features have scaled down in size, entire embedded systems have been implemented on a …