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Investigating acoustic correlates of human vocal fold vibratory phase asymmetry through modeling and laryngeal high-speed videoendoscopy

Published in:
J. Acoust. Soc. Am., Vol. 130, No. 6, December 2011, pp. 3999-4009.

Summary

Vocal fold vibratory asymmetry is often associated with inefficient sound production through its impact on source spectral tilt. This association is investigated in both a computational voice production model and a group of 47 human subjects. The model provides indirect control over the degree of left-right phase asymmetry within a nonlinear source-filter framework, and high-speed videoendoscopy provides in vivo measures of vocal fold vibratory asymmetry. Source spectral tilt measures are estimated from the inverse-filtered spectrum of the simulated and recorded radiated acoustic pressure. As expected, model simulations indicated that increasing left-right phase asymmetry induces steeper spectral tilt. Subject data, however, reveal that none of the vibratory asymmetry measures correlates with spectral tilt measures. Probing further into physiological correlates of spectral tilt that might be affected by asymmetry, the glottal area waveform is parameterized to obtain measures of the open phase (open/plateau quotient) and closing phase (speed/closing quotient). Subjects' left-right phase asymmetry exhibits low, but statistically significant, correlations with speed quotient (r=0.45) and closing quotient (r=-0.39). Results call for future studies into the effect of asymmetric vocal fold vibrartion on glottal airflow and the associated impact on voice source spectral properties and vocal efficiency.
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Summary

Vocal fold vibratory asymmetry is often associated with inefficient sound production through its impact on source spectral tilt. This association is investigated in both a computational voice production model and a group of 47 human subjects. The model provides indirect control over the degree of left-right phase asymmetry within a...

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Face recognition despite missing information

Published in:
HST 2011, IEEE Int. Conf. on Technologies for Homeland Security, 15-17 November 2011, pp. 475-480.

Summary

Missing or degraded information continues to be a significant practical challenge facing automatic face representation and recognition. Generally, existing approaches seek either to generatively invert the degradation process or find discriminative representations that are immune to it. Ideally, the solution to this problem exists between these two perspectives. To this end, in this paper we show the efficacy of using probabilistic linear subspace modes (in particular, variational probabilistic PCA) for both modeling and recognizing facial data under disguise or occlusion. From a discriminative perspective, we verify the efficacy of this approach for attenuating the effect of missing data due to disguise and non-linear speculars in several verification experiments. From a generative view, we show its usefulness in not only estimating missing information but also understanding facial covariates for image reconstruction. In addition, we present a least-squares connection to the maximum likelihood solution under missing data and show its intuitive connection to the geometry of the subspace learning problem.
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Summary

Missing or degraded information continues to be a significant practical challenge facing automatic face representation and recognition. Generally, existing approaches seek either to generatively invert the degradation process or find discriminative representations that are immune to it. Ideally, the solution to this problem exists between these two perspectives. To this...

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Cyber situational awareness through operational streaming analysis

Published in:
MILCOM 2011, IEEE Military Communications Conf., 7-10 November 2011, pp. 1152-1157.

Summary

As the scope and scale of Internet traffic continue to increase the task of maintaining cyber situational awareness about this traffic becomes ever more difficult. There is strong need for real-time on-line algorithms that characterize high-speed / high-volume data to support relevant situational awareness. Recently, much work has been done to create and improve analysis algorithms that operate in a streaming fashion (minimal CPU and memory utilization) in order to calculate important summary statistics (moments) of this network data for the purpose of characterization. While the research literature contains improvements to streaming algorithms in terms of efficiency and accuracy (i.e. approximation with error bounds), the literature lacks research results that demonstrate streaming algorithms in operational situations. The focus of our work is the development of a live network situational awareness system that relies upon streaming algorithms for the determination of important stream characterizations and also for the detection of anomalous behavior. We present our system and discuss its applicability to situational awareness of high-speed networks. We present refinements and enhancements that we have made to a well-known streaming algorithm and improve its performance as applied within our system. We also present performance and detection results of the system when it is applied to a live high-speed mid-scale enterprise network.
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Summary

As the scope and scale of Internet traffic continue to increase the task of maintaining cyber situational awareness about this traffic becomes ever more difficult. There is strong need for real-time on-line algorithms that characterize high-speed / high-volume data to support relevant situational awareness. Recently, much work has been done...

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A usable interface for location-based access control and over-the-air keying in tactical environments

Published in:
MILCOM 2011, IEEE Military Communications Conf., 7-10 November 2011, pp. 1480-1486.

Summary

This paper presents a usable graphical interface for specifying and automatically enacting access control rules for applications that involve dissemination of data among mobile tactical devices. A specific motivating example is unmanned aerial vehicles (UAVs), where the mission planner or operator needs to control the conditions under which specific receivers can access the UAV?s video feed. We implemented a prototype of this user interface as a plug-in for FalconView, a popular mission planning application.
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Summary

This paper presents a usable graphical interface for specifying and automatically enacting access control rules for applications that involve dissemination of data among mobile tactical devices. A specific motivating example is unmanned aerial vehicles (UAVs), where the mission planner or operator needs to control the conditions under which specific receivers...

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Dedicated vs. distributed: a study of mission survivability metrics

Published in:
MILCOM 2011, IEEE Military Communications Conf., 7-10 November 2011, pp. 1345-1350.

Summary

A traditional trade-off when designing a mission critical network is whether to deploy a small, dedicated network of highly reliable links (e.g. dedicated fiber) or a largescale, distributed network of less reliable links (e.g. a leased line over the Internet). In making this decision, metrics are needed that can express the reliability and security of these networks. Previous work on this topic has widely focused on two approaches: probabilistic modeling of network reliabilities and graph theoretic properties (e.g. minimum cutset). Reliability metrics do not quantify the robustness, the ability to tolerate multiple link failures, in a distributed network. For example, a fully redundant network and a single link can have the same overall source-destination reliability (0.9999), but they have very different robustness. Many proposed graph theoretic metrics are also not sufficient to capture network robustness. Two networks with identical metric values (e.g. minimum cutset) can have different resilience to link failures. More importantly, previous efforts have mainly focused on the source-destination connectivity and in many cases it is difficult to extend them to a general set of requirements. In this work, we study network-wide metrics to quantitatively compare the mission survivability of different network architectures when facing malicious cyber attacks. We define a metric called relative importance (RI), a robustness metric for mission critical networks, and show how it can be used to both evaluate mission survivability and make recommendations for its improvement. Additionally, our metric can be evaluated for an arbitrarily general set of mission requirements. Finally, we study the probabilistic and deterministic algorithms to quantify the RI metric and empirically evaluate it for sample networks.
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Summary

A traditional trade-off when designing a mission critical network is whether to deploy a small, dedicated network of highly reliable links (e.g. dedicated fiber) or a largescale, distributed network of less reliable links (e.g. a leased line over the Internet). In making this decision, metrics are needed that can express...

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Efficient transmission of DoD PKI certificates in tactical networks

Published in:
MILCOM 2011, IEEE Military Communications Conf., 7-10 November 2011, pp. 1739-1747.

Summary

The DoD vision of real-time information sharing and net-centric services available to warfighters at the tactical edge is challenged by low-bandwidth and high-latency tactical network links. Secured tactical applications require transmission of digital certificates that contribute a major portion of data in most secure sessions, which further increases response time for users and drains device power. In this paper we present a simple and practical approach to alleviating this problem. We develop a dictionary of data common across DoD PKI certificates to prime general-purpose data compression of certificates, resulting in a significant reduction (about 50%) of certificate sizes. This reduction in message size translates in to faster response times for the users. For example, a mutual authentication of a client and a server over the Iridium satellite link is expected to be sped up by as much as 3 sec. This approach can be added directly to tactical applications with minimal effort, or it can be deployed as part of an intercepting network proxy, completely transparent to applications.
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Summary

The DoD vision of real-time information sharing and net-centric services available to warfighters at the tactical edge is challenged by low-bandwidth and high-latency tactical network links. Secured tactical applications require transmission of digital certificates that contribute a major portion of data in most secure sessions, which further increases response time...

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MCE training techniques for topic identification of spoken audio documents

Published in:
IEEE Trans. Audio, Speech, Language Proc., Vol. 19, No. 8, November 2011, pp. 2451-2461.

Summary

In this paper, we discuss the use of minimum classification error (MCE) training as a means for improving traditional approaches to topic identification such as naive Bayes classifiers and support vector machines. A key element of our new MCE training techniques is their ability to efficiently apply jackknifing or leave-one-out training to yield improved models which generalize better to unseen data. Experiments were conducted using recorded human-human telephone conversations from the Fisher Corpus using feature vector representations from word-based automatic speech recognition lattices. Sizeable improvements in topic identification accuracy using the new MCE training techniques were observed.
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Summary

In this paper, we discuss the use of minimum classification error (MCE) training as a means for improving traditional approaches to topic identification such as naive Bayes classifiers and support vector machines. A key element of our new MCE training techniques is their ability to efficiently apply jackknifing or leave-one-out...

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On-chip nonlinear digital compensation for RF receiver

Published in:
HPEC 2011: Conf. on High Performance Embedded Computing, 21-22 September 2011.

Summary

A system-on-chip (SOC) implementation is an attractive solution for size, weight and power (SWaP) restricted applications, such as mobile devices and UAVs. This is partly because the individual parts of the system can be designed for a specific application rather than for a broad range of them, like commercial parts usually must be. Co-design of the analog hardware and digital processing further enhances the benefits of SOC implementations by allowing, for example, nonlinear digital equalization to further enhance the dynamic range of a given front-end component. This paper presents the implementation of nonlinear digital compensation for an active anti-aliasing filter, which is part of a low-power homodyne receiver design. The RF front-end circuitry and the digital compensation will be integrated in the same chip. Co-design allows the front-end to be designed with known dynamic range limitations that will later be compensated by nonlinear equalization. It also allows nonlinear digital compensation architectures matched to specific circuits and dynamic range requirements--while still maintaining some flexibility to deal with process variation--as opposed to higher power general purpose designs.
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Summary

A system-on-chip (SOC) implementation is an attractive solution for size, weight and power (SWaP) restricted applications, such as mobile devices and UAVs. This is partly because the individual parts of the system can be designed for a specific application rather than for a broad range of them, like commercial parts...

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A new perspective on GMM subspace compensation based on PPCA and Wiener filtering

Published in:
2011 INTERSPEECH, 27-31 August 2011, pp. 145-148.

Summary

We present a new perspective on the subspace compensation techniques that currently dominate the field of speaker recognition using Gaussian Mixture Models (GMMs). Rather than the traditional factor analysis approach, we use Gaussian modeling in the sufficient statistic supervector space combined with Probabilistic Principal Component Analysis (PPCA) within-class and shared across class covariance matrices to derive a family of training and testing algorithms. Key to this analysis is the use of two noise terms for each speech cut: a random channel offset and a length dependent observation noise. Using the Wiener filtering perspective, formulas for optimal train and test algorithms for Joint Factor Analysis (JFA) are simple to derive. In addition, we can show that an alternative form of Wiener filtering results in the i-vector approach, thus tying together these two disparate techniques.
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Summary

We present a new perspective on the subspace compensation techniques that currently dominate the field of speaker recognition using Gaussian Mixture Models (GMMs). Rather than the traditional factor analysis approach, we use Gaussian modeling in the sufficient statistic supervector space combined with Probabilistic Principal Component Analysis (PPCA) within-class and shared...

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Automatic detection of depression in speech using Gaussian mixture modeling with factor analysis

Summary

Of increasing importance in the civilian and military population is the recognition of Major Depressive Disorder at its earliest stages and intervention before the onset of severe symptoms. Toward the goal of more effective monitoring of depression severity, we investigate automatic classifiers of depression state, that have the important property of mitigating nuisances due to data variability, such as speaker and channel effects, unrelated to levels of depression. To assess our measures, we use a 35-speaker free-response speech database of subjects treated for depression over a six-week duration, along with standard clinical HAMD depression ratings. Preliminary experiments indicate that by mitigating nuisances, thus focusing on depression severity as a class, we can significantly improve classification accuracy over baseline Gaussian-mixture-model-based classifiers.
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Summary

Of increasing importance in the civilian and military population is the recognition of Major Depressive Disorder at its earliest stages and intervention before the onset of severe symptoms. Toward the goal of more effective monitoring of depression severity, we investigate automatic classifiers of depression state, that have the important property...

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