Hidden Markov Models for Heart Rate Variability with Biometric Applications

The utility of hidden Markov models: HMM) for modeling individual heart rate variability: HRV) is presented. Starting with a physiologically based statistical model for HRV from the literature, we justify use of HMMs and present methods for parameterizing the model. The forward-backward algorithm and expectation-maximization algorithm are used to estimate the model and the hidden states for a given observation sequence of inter-beat intervals. Multiple initialization techniques are presented to avoid local maxima. Model order is determined from the data sequence using the Bayesian information criterion. Models are trained on twelve hour recordings. The models are then used to discriminate the identity of an individual using data from a separate set of testing data. For database from 52 individuals, true identity was verified with an equal error rate of roughly 0.36. While initial results do not demonstrate strong performance as a biometric, HMMs are able to capture some individuality in the HRV signal. Consistency in HRV over twelve hour time scales is also demonstrated

GATOR: Requirements capturing of telephony features

We are developing a natural language-based, requirements gathering system called GATOR (for the GATherer Of Requirements). GATOR assists in the development of more accurate and complete specifications of new telephony features. GATOR interacts with a feature designer who describes a new feature, set of features, or capability to be implemented. The system aids this individual in the specification process by asking for clarifications when potential ambiguities are present, by identifying potential conflicts with other existing features, and by presenting its understanding of the feature to the designer. Through user interaction with a model of the existing telephony feature set, GATOR constructs a formal representation of the new, 'to be implemented' feature. Ultimately GATOR will produce a requirements document and will maintain an internal representation of this feature to aid in future design and specification. This paper consists of three sections that describe (1) the structure of GATOR, (2) POND, GATOR's internal knowledge representation language, and (3) current research issues

Examining Multiple Methods Of Analysis To Guide The Development Of A Postsecondary Institution Rating System

Rankings of higher education institutions have been developed as a method for evaluating universities and colleges as the competition for students, faculty, and financial support grew stronger (Shin & Toutkoushian, 2011). Historically these rankings relied mostly upon institutional reputation, but recently there has been a call for quantifiable data. US President Obama (2013) discussed the need for a postsecondary institution ratings system that holds universities accountable to provide accurate information related to accessibility, affordability, and educational outcomes. Once a method of rating institutions is developed, the ratings can be utilized to rank similar institutions, which results in a ranking system providing a rubric for comparison. Also, many policymakers within (i.e., administrators) and outside (i.e., legislators who control local, federal, and state budgets) higher education institutions use information provided in rankings to develop policies, thus it is essential that any postsecondary institution ratings system be developed using relevant and reliable data. Furthermore, appropriate statistical procedures must be used as well, to reduce the possibility of policymaker bias playing a role in how data is utilized in a ratings system. The purpose of this proposed dissertation is to utilize publicly available data provided by the U.S. Department of Education to test competing models of rankings and comparing them to a current popular higher education ranking system: U.S. News and World Report. This comparison will seek to address two research questions: 1) What institutional characteristics are associated with positive higher education outcomes (i.e., graduation rate and retention rate)? and 2) How does a ranking model using these institutional characteristics compare to the current U.S. News and World Report rankings and the proposed Postsecondary Institution Ratings System model

Recovering Lost Voices: The Rappahannock Tribe and the Jamestown Festival of 1957

This thesis employs the interdisciplinary methodologies of ethnohistory and oral history to examine the legacy of the 1957 Jamestown Festival through the experiences and memories of Rappahannock people. “Recovering Lost Voices: The Rappahannock Tribe and the Jamestown Festival of 1957” adds to the historiography of Virginia Natives by revealing that Rappahannock participation in the Jamestown Festival was the culmination of centuries of cultural preservation, greatly influenced and made immediate by their experiences in “Jim Crow” Virginia during the twentieth century. This research establishes that the enduring legacy of the Festival for the Rappahannock Tribe was political influence, culminating in state and federal recognition of their community. For the first time in a scholarly setting, contemporary members of the Rappahannock Tribe share their memories of the Festival, and the meaning they give to the experiences of their relatives who worked there. Narrators include Chief Anne Richardson, tribal member Jamie Ware-Jondreau, and Tribal Council Chair Barbara Williams. These oral histories complement archival sources by documenting Rappahannock voices revealing how their involvement in the Festival built upon an existing sense of community, and inspired efforts on the part of longtime Rappahannock tribal members to publicly assert their Indianness

Composite Structure Ultimate Strength Prediction from Acoustic Emission Amplitude Data

The acoustic emission (AE) given off by a structure as it is stressed provides a passive means to characterize flaw growth activity in complex structures. This thesis demonstrates how the qualitative analysis of AE data can be refined to provide a quantitative tool for predicting the ultimate strength of composite tensile test specimens. From an original sample set of only six specimens, a multivariate statistical analysis was used to generate an ultimate strength prediction equation. The variables of the multivariate statistical analysis were obtained through the mathematical modeling of the specimen’s AE amplitude distributions produced during proof testing. Ultimate strengths were then accurately predicted at proof stresses less than 25% of the expected failure stress for five randomly drawn tensile coupons. The results of this and previously conducted composite pressure vessel research demonstrate the ability to accurately predict ultimate strengths in composite structures using AE amplitude distribution data

Librarians in an Austerity Environment

The purpose of this study was to evaluate methods used by library administrators to maintain collections to support programs at Carnegie institutions classified R1, R2, D/PU: Doctoral/Professional Universities (formerly R3) with varying degrees of research activity and selected M1 (i.e., Masters Large) institutions, and compare those data. Public institutions of higher education have seen mandatory state budget cuts for more than 20 years, with each year’s cut being larger than the previous. These statewide education cuts have affected academic libraries in a major way, resulting in purchasing cutbacks, decreased subscription renewals and cancellations. Purchasing cutbacks have meant fewer physical book purchases and more journal cancellations, while hiring freezes and job cuts have resulted in more responsibilities for individuals in the library workforce; in some cases, duties have been outsourced to specialty companies, from maintenance operations to acquisitions processing, such as cataloging and even labeling. These drastic cuts in library budgets have caused librarians and administrators to cut not only fringe elements in the budget, but to develop creative changes in the fabric of library functioning in order to remain operational, as well as maintain accreditation standards

Matching Contributions and the Voluntary Provision of a Pure Public Good: Experimental Evidence

Laboratory experiments are used to study the voluntary provision of a pure public good in the presence of an anonymous external donor. The external funds are used in two different settings, lump-sum matching and one-to-one matching, to examine how allocations to the public good are affected. The experimental results reveal that allocations to the public good under lumpsum matching are significantly higher, and have significantly lower within-group dispersion, relative to one-to-one matching and a baseline setting without external matching funds.public goods, free riding, laboratory experiments