3,804 Works

Giving CANDY to Children: User-Tailored Gesture Input Driving An Articulator Based Speech Synthesizer

Randy Pausch & R Williams
The CANDY Project (Communication Assistance to Negate Disabilities in Youth) seeks to provide a realtime speech synthesizer for disabled individuals, particularly non-vocal children with cerebral palsy. Existing speech synthesizers convert user input into discrete linguistic or phonetic symbols which are converted into sound. Complicated sentences must be created by concatenating lower level symbols, precluding real-time conversational speech. We have developed an articulator-based speech synthesizer which simulates the motion of the human tongue and produces the...

A Relational Interface to an Object Based System or Translating SQL to ADAMS

Thomas Cleary
The evolution of database technology has resulted in the widespread use of three major database models. These three most popular models are: the hierarchical model, the network model and the relational model. The existence of numerous databases and database applications has given rise to a strong desire for the ability to use the data and applications created using one database model by other database systems. The project that this report documents demonstrates that a relational...

Two Computer Graphics Systems for the Visualization of Pressure Distributions and Airflow in Wind Tunnel Experimentation

Jack Davidson, David Whalley, Carol Luan & Worthy Martin

Heuristics for Backplane Ordering

James Cohoon & Sartaj Sahni
The Board Permutation Problem, a backplane ordering problem, has been previously shown to be NP - hard. We develop here several heuristics for the Board Permutation Problem. These heuristics produce solutions that are locally optimal with respect to some nontrivial transforms. The heuristics are analytically shown to be m/3- approximate, where m is the number of nets in a problem instance. The heuristics have been shown experimentally to have quite acceptable behavior. Several of the...

Distributed Checkpointing for Globally Consistent States of Databases

Sang Son
The goal of cheokpointing in database management systems is to save database states on a separate secure device so that the database can be recovered when errors and failures occur. Recently, the possibility of having a checkpointing mechanism which does not interfere with the transaction processing has been studied[4, 7]. Users are allowed to submit transactions while the checkpointing is in progress. and the transactions are performed in the system concurrently with the checkpointing process....

Starlite: An Environment for Distributed Database Prototyping

Sang Son & Jeremiah Ratner
One of the reasons for the difficulty in evaluating new techniques for distributed database systems is the complexity involved due to a large number of system parameters that may change dynamically. Prototyping methods can be applied effectively to the evaluation of database techniques. In addition, database technology can be implemented in a modular reusable form to enhance experimentation. This paper presents a software prototyping environment for the development and evaluation of distributed database systems. The...

Development of a Set of 'Closed Laboratories' for an Undergraduate Computer Science Curriculum

Wm Wulf
As a discipline, Computer Science has seen many dramatic changes in its brief history. Through new textbooks and an evolving curriculum, the content of undergraduate Computer Science education has for the most part kept pace with these changes. But the pedagogy has hardly changed. Not only is that pedagogy out of dat - - it is profoundly wrong. It emphasizes individual skill in writing short programs in a dead language, from scratch. This emphasis is...

Supporting Teaching with Primary Sources

Krystal Appiah & Brenda Gunn
In June 2019, the University of Virginia Library joined Ithaka S+R’s study, “Supporting Teaching with Primary Sources,” which examines the pedagogical practices of humanities and social sciences faculty at participating institutions who teach with primary sources at the undergraduate level. By participating in this study, the investigators from the Albert and Shirley Small Special Collections Library seek to better understand our faculty’s use of primary sources in the classroom in order that our staff may...

The Twin Cities Innovation Ecosystem: A Study of Stakeholder Perspectives

Rider Foley
In the early 1980s, the Office of Naval Research sponsored a novel research project led by Andrew Van de Ven and colleagues (1986) called The Minnesota Innovation Research Program. That study investigated thirteen subject areas from microelectronics and medical products to multi-hospital systems and programs to commercialize outer space, all of which were underway in the state. Van de Ven and colleagues (1989) issued an edited volume that shared the lessons learned from that longitudinal...

Evaluation - Towards a Community Learning Network to Advance Economic Mobility

Stephanie Shipp, Joel Thurston & Cassandra Dorius
Through the pilot project – Towards a National Community Learning Network – we demonstrate that the Cooperative Extension System (CES) can be used to infuse data insights into local communities and accelerate the advancement of economic mobility across three states (Virginia, Iowa, and Oregon) through use of the Community Learning through Data Driven Discovery process. The project encompassed three bodies of work, including: (1) developing a rural community-based research culture to promote economic mobility; (2)...

Some Conversation Starters Concerning the Problem of Online-Only Music for Libraries

Brandon Butler
In this white paper, I discuss some of the copyright-related problems libraries face as they attempt to collect digital music, as well as possible solutions. The paper was prepared as part of an IMLS-funded project led by John Vallier and Judy Tsou at the University of Washington. Their final report for the grant is: Tsou, Judy and John Vallier. "Ether Today, Gone Tomorrow: 21st Century Sound Recording Collection in Crisis." Notes, vol. 72 no. 3,...

UVA School of Data Science Open Access Guidelines and Recommendations

Philip Bourne, Brandon Butler, Lane Rasberry, Daniel Mietchen, Timothy Clark, Nada Basit, Aidong Zhang, Brian Wright, John Van Horn, Jonathan Kropko & Claudia Scholz
On February 3, 2021 the School of Data Science's Academic Affairs Committee (AAC) officially passed the Open Access Guidelines and Recommendations. The University of Virginia School of Data Science is guided by goals to further discovery through open, collaborative, and responsible data science research. These guidelines and recommendations are adhered to by all faculty members in their research.

Code of Best Practices in Fair Use for Software Preservation

Brandon Butler, Patricia Aufderheide, Peter Jaszi & Krista Cox
The Code of Best Practices in Fair Use for Software Preservation helps ensure that the subjects, products, and tools of scholarship will continue to be accessible despite evolving technology. The code expresses a consensus view of how fair use—the legal doctrine allowing the use of copyrighted materials without permission from the copyright holder under certain circumstances—applies to core, recurring situations in software preservation. Fair use has become an increasingly vital tool for permitting cultural heritage...

What is the (social) structure? An exploration

Taro Matsuno
This project seeks to use digitized deed records as the material to construct a social graph of Locust Grove’s real estate market in order to understand the social and power structures underlying the neighborhood’s development. This quick start guide can help researchers use the platform, Graph Commons, to analyze the connections between property buyers and sellers. This was created as a part of the course, ARH8604 - Field Methods I, taught in Spring 2021 by...

The Effect of Instruction Set Complexity on Program Size and Memory Performance

Jack Davidson & Richard Vaughan

Code Generation for Streaming: an Access/Execute Mechanism

Manuel Benitez & Jack Davidson
Access/execute architectures have several advantages over more traditional architectures. Because address generation and memory access are decoupled from operand use, memory latencies are tolerated better, there is more potential for concurrent operation, and it permits the use of specialized hardware to facilitate fast address generation. This paper describes the code generation and optimization algorithms that are used in an optimizing compiler for an architecture that contains explicit hardware support for the access/execute model of computation....

Automating The Detection of Reusable Parts in Existing Software

M Dunn & J Knight
We present a model based on an expert - system approach for the scavenging of reusable components from existing software systems. We also describe a toolset called Code Miner that implements part of the model, The toolset uses Prolog as its inference engine. Code Miner is designed to assist the programmer in finding reusable components in existing software written in C. To investigate the feasibility of the approach we conducted an empirical study of the...


Rider Foley, Elise Barrella, Heather Kirkvold, Rodney Wilkins, Aaron Sloss, Elise Mazur, Claire Trevisan, Jacob Rogerson, Daniel Katleman, Catherine Mohan, Victoria Lindsey & Farrah Dang
The United States is in the midst of a transition in the production and distribution of energy. This transition was, in part, instigated by technological advancements and policy mechanisms that allowed for the recovery of unconventional fossil fuels from shale formations. In parallel, renewable energy sources such as wind and solar are becoming increasingly competitive with fossil fuels. Furthermore, the nation’s population is moving away from the Northeast and Midwest regions to southeastern and western...

A Genetic Programming Approach to Shader Simplification

Pitchaya SitthiAmorn, Nicholas Modly, Wesley Wiemer & Jason Lawrence
The programmability of modern graphics hardware has led to an enormous increase in pixel shader complexity and a commensu- rate increase in the difficulty and effort needed to optimize them. We present a framework based on Genetic Programming (GP) for automatically simplifying pixel shaders. Our approach computes a series of increasingly simplified shaders that expose the inher- ent trade-off between speed and accuracy. Compared to existing automatic methods for shader simplification [Olano et al. 2003;...

On a Constrained Bin-packing Problem

Yingfeng Oh & Sang Son
We study a bin-packing problem which is one-dimensional and is constrained in the manner items are placed into bins. The problem is motivated by a practical real-time scheduling problem, where redundant periodic tasks need to be assigned to a multiprocessor system. The problem is stated in the traditional light: to use as few bins as possible to pack a given list of items, and it is a generalization of the classical bin-packing problem. We first...

Granularity of Microprocessor Thermal Management: A Technical Report

Karthik Sankaranarayanan, Wei Huang, Mircea Stan, Hossein HajHariri, Robert Ribando & Kevin Skadron
Process technology scaling, poor supply voltage scaling and the resultant exponential increase in power density have made temperature a first-class design constraint in today�s microprocessors. An interesting question in the context of thermal management and multi-core architectures is about the correct size granularity of thermal management. It is known that the silicon substrate acts as a spatial low-pass filter for temperature. This means that if blocks with very high power density are small enough (for...

Assigning Real-Time Tasks to Homogeneous Multiprocessor Systems

Almut Burchard, Jorg Liebeherr, Yingfeng Oh & Sang Son
Optimal scheduling of real-time tasks on multiprocessor systems is known to be computationally intractable for large task sets. Any practical scheduling algorithm for assigning real-time tasks to a multiprocessor system presents a trade-off between its computational complexity and its performance. The performance of a scheduling algorithm is measured in terms of the additional number of processors required to arrive at a schedule without deadline violations as compared to an optimal algorithm. In this study, new...

SOR as a Preconditioner

M DeLong & J Ortega
We show by experimental results on some convection-diffusion type equations that the SOR iteration may be a promising preconditioner in conjunction with the GMRES method. Our results indicate that it is critical to take several Gauss-Seidel or SOR iterations, rather than just one, and that at least a factor of two improvement over Gauss-Seidel can be expected with a reasonable approximation to the optimal omega. This approximation must be on the low side of the...

Consistency Maintenance using UNIFY

Anand Natrajan, Jr Reynolds & Sudhir Srinivasan
Distributed simulations comprised of aggregated entities (AEs) and disaggregated entities (DEs) pose critical consistency issues when AEs and DEs interact. Usually, meaningful interaction cannot take place without one of the two representing itself at a level of resolution compatible with the level of the other. Any approach that employs dynamic transitions between aggregated and disaggregated resolution levels suffers from not only potential consistency problems, but also chain disaggregation, network flooding, transition latency, and mapping problems...

Caches As Filters: A Unifying Model for Memory Hierarchy Analysis

Dee Weikle, Kevin Skadron, Sally McKee & Wm Wulf
This paper outlines the new caches-as-filters framework for the analysis of caching systems, describing the functional filter model in detail. This model is more general than those introduced previously, allowing designers and compiler writers to understand why a cache exhibits a particular behavior, and in some cases indicating what compiler or hardware techniques must be employed to improve a cache hierarchy's performance. Three components of the framework, the trace-specification notation, equivalence class concept, and new...

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  • Open Society Foundations
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