Publications
Security challenges of intent-based networking
July 1, 2024
Journal Article
Published in:
Communications of the ACM, Vol. 67, No. 7, July 2024, pp. 56-65.
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Summary
Intent-based networking (IBN) offers advantages and opportunities compared with SDN, but IBN also poses new and unique security challenges that must be overcome.
Summary
Intent-based networking (IBN) offers advantages and opportunities compared with SDN, but IBN also poses new and unique security challenges that must be overcome.
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Microbubble contrast agents improve detection of active hemorrhage
June 18, 2024
Journal Article
Published in:
IEEE Open Journal of Engineering in Medicine and Biology, doi: 10.1109/OJEMB.2024.3414974
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Assessment of trauma-induced hemorrhage with ultrasound is particularly challenging outside of the clinic, where its detection is crucial. The current clinical standard for hematoma detection – the focused assessment with sonography of trauma (FAST) exam – does not aim to detect ongoing blood loss, and thus is unable to detect injuries of increasing severity. To enhance detection of active bleeding, we propose the use of ultrasound contrast agents (UCAs), together with a novel flow phantom and contrast-sensitive processing techniques, to facilitate efficient, practical characterization of internal bleeding. Within a the custom phantom, UCAs and processing techniques enabled a significant enhancement of the hemorrhage visualization (mean increase in generalized contrast-to-noise ratio of 17 %) compared to the contrast-free case over a range of flow rates up to 40 ml/min. Moreover, we have shown that the use of UCAs improves the probability of detection: the area under the receiver operating characteristic curve for a flow rate of 40 ml/min was 0.99, compared to 0.72 without contrast. We also demonstrate how additional processing of the spatial and temporal information further localizes the bleeding site. UCAs also enhanced Doppler signals over the non-contrast case. These results show that specialized nonlinear processing (NLP) pipelines together with UCAs may offer an efficient means to improve substantially the detection of slower hemorrhages and increase survival rates for trauma-induced injury in pre-hospital settings.
Summary
Assessment of trauma-induced hemorrhage with ultrasound is particularly challenging outside of the clinic, where its detection is crucial. The current clinical standard for hematoma detection – the focused assessment with sonography of trauma (FAST) exam – does not aim to detect ongoing blood loss, and thus is unable to detect...
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Satellite remote sensing in disaster relief: FY23 HADR Technical Investment Program(9.12 MB)
June 13, 2024
Project Report
Published in:
MIT Lincoln Laboratory Report MIT-LIN-TIP-197
Summary
Disasters annually cost the U.S. billions of dollars in direct costs and economic loss. In particular, the increasing frequency and intensity of natural hazard incidents, such as hurricanes, tornadoes, floods, and wildfires, strains the nation's emergency management enterprise. Knowing that the current approach to emergency management is unsustainable, practitioners and policy makers look to use new tools and technologies to mitigate, prepare for, respond to, and recover from disasters. One of those technologies is satellite remote sensing. As persistent assets with a wide area collection ability and a variety of viable sensing modalities, satellites seem positioned to shed light on the nature of disaster impacts and support decisions made in the first 24 hours after disasters happen. Satellites are particularly promising for providing information on incidents that occur slowly and in rural areas. However, satellite imagery supports early response decisions and operations for only the most severe incidents in the U.S. This report explores reasons satellite imagery is under-utilized in domestic disaster response and proposes ideas toward solutions. Through systems engineering, combined with quantitative modeling and prototyping, this report offers the following. 1. An analysis of stakeholder decisions and use cases for satellite remote sensing in disasters 2. An evaluation of requirements for imagery and derived data products to support decisions 3. A description and demonstration of a concept of operations and high-level system architecture.
Summary
Disasters annually cost the U.S. billions of dollars in direct costs and economic loss. In particular, the increasing frequency and intensity of natural hazard incidents, such as hurricanes, tornadoes, floods, and wildfires, strains the nation's emergency management enterprise. Knowing that the current approach to emergency management is unsustainable, practitioners and...
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An exploratory characterization of speech- and fine-motor coordination in verbal children with Autism spectrum disorder
May 22, 2024
Journal Article
Published in:
Comput. Speech Lang., Vol. 89, 2025, 101665.
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Autism spectrum disorder (ASD) is a neurodevelopmental disorder often associated with difficulties in speech production and fine-motor tasks. Thus, there is a need to develop objective measures to assess and understand speech production and other fine-motor challenges in individuals with ASD. In addition, recent research suggests that difficulties with speech production and fine-motor tasks may contribute to language difficulties in ASD. In this paper, we explore the utility of an off-body recording platform, from which we administer a speech- and fine-motor protocol to verbal children with ASD and neurotypical controls. We utilize a correlation-based analysis technique to develop proxy measures of motor coordination from signals derived from recordings of speech- and fine-motor behaviors. Eigenvalues of the resulting correlation matrix are inputs to Gaussian Mixture Models to discriminate between highly-verbal children with ASD and neurotypical controls. These eigenvalues also characterize the complexity (underlying dimensionality) of representative signals of speech- and fine-motor movement dynamics, and form the feature basis to estimate scores on an expressive vocabulary measure. Based on a pilot dataset (15 ASD and 15 controls), features derived from an oral story reading task are used in discriminating between the two groups with AUCs > 0.80, and highlight lower complexity of coordination in children with ASD. Features derived from handwriting and maze tracing tasks led to AUCs of 0.86 and 0.91, however features derived from ocular tasks did not aid in discrimination between the ASD and neurotypical groups. In addition, features derived from free speech and sustained vowel tasks are strongly correlated with expressive vocabulary scores. These results indicate the promise of a correlation-based analysis in elucidating motor differences between individuals with ASD and neurotypical controls.
Summary
Autism spectrum disorder (ASD) is a neurodevelopmental disorder often associated with difficulties in speech production and fine-motor tasks. Thus, there is a need to develop objective measures to assess and understand speech production and other fine-motor challenges in individuals with ASD. In addition, recent research suggests that difficulties with speech...
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A neurophysiological-auditory "listen receipt" for communication enhancement
April 14, 2024
Conference Paper
Published in:
49th IEEE Intl. Conf. on Acoustics, Speech, and Signal Processing, ICASSP, 14-19 April 2024.
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Information overload, and specifically auditory overload, is common in critical situations and detrimental to communication. Currently, there is no auditory equivalent of an email read receipt to know if a person has heard a message, other than waiting for a reply. This work hypothesizes that it may be possible to decode whether a person has indeed heard a message, or in other words, create an an auditory "listen receipt," through use of non-invasive physiological or neural monitoring. We extracted a variety of features derived from Electrodermal activity (EDA), Electroencephalography (EEG), and the correlations between the acoustic envelope of the radio message and EEG to use in the decoder. We were able to classify the cases in which the subject responded correctly to the question in the message, versus the cases where they missed or heard the message incorrectly, with an accuracy of 79% and a receiver operating characteristic (ROC) area under the curve (AUC) of 0.83. This work suggests that the concept of a "listen receipt" may be possible, and future wearable machine-brain interface technologies may be able to automatically determine if an important radio message has been missed for both human-to-human and human-to-machine communication.
Summary
Information overload, and specifically auditory overload, is common in critical situations and detrimental to communication. Currently, there is no auditory equivalent of an email read receipt to know if a person has heard a message, other than waiting for a reply. This work hypothesizes that it may be possible to...
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Quantifying speech production coordination from non- and minimally-speaking individuals
April 13, 2024
Journal Article
Published in:
J. Autism Dev. Disord., 13 April 2024.
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Purpose: Non-verbal utterances are an important tool of communication for individuals who are non- or minimally-speaking. While these utterances are typically understood by caregivers, they can be challenging to interpret by their larger community. To date, there has been little work done to detect and characterize the vocalizations produced by non- or minimally-speaking individuals. This paper aims to characterize five categories of utterances across a set of 7 non- or minimally-speaking individuals. Methods: The characterization is accomplished using a correlation structure methodology, acting as a proxy measurement for motor coordination, to localize similarities and differences to specific speech production systems. Results: We specifically find that frustrated and dysregulated utterances show similar correlation structure outputs, especially when compared to self-talk, request, and delighted utterances. We additionally witness higher complexity of coordination between articulatory and respiratory subsystems and lower complexity of coordination between laryngeal and respiratory subsystems in frustration and dysregulation as compared to self-talk, request, and delight. Finally, we observe lower complexity of coordination across all three speech subsystems in the request utterances as compared to self-talk and delight. Conclusion: The insights from this work aid in understanding of the modifications made by non- or minimally-speaking individuals to accomplish specific goals in non-verbal communication.
Summary
Purpose: Non-verbal utterances are an important tool of communication for individuals who are non- or minimally-speaking. While these utterances are typically understood by caregivers, they can be challenging to interpret by their larger community. To date, there has been little work done to detect and characterize the vocalizations produced by...
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Securing the satellite software stack
March 1, 2024
Conference Paper
Published in:
Workshop on Security of Space and Satellite Systems, SpaceSec, 1 March 2024.
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Satellites and the services enabled by them, like GPS, real-time world-wide imaging, weather tracking, and worldwide communication, play an increasingly important role in modern life. To support these services satellite software is becoming increasingly complex and connected. As a result, concerns about its security are becoming prevalent. While the focus of security for satellites has historically been on encrypting the communications link, we argue that a fuller consideration of the security of satellites is necessary and presents unique challenges. Satellites are becoming increasingly accessible to attackers–thanks to supply chain attacks and Internet connected ground stations–and present a unique set of challenges for security practitioners. These challenges include the lack of any real ability for a human to be physically present to repair or recover these systems, a focus on safety and availability over confidentiality and integrity, and the need to deal with radiation-induced faults. This work characterizes the cyber threats to satellite systems, surveys the unique challenges for satellite software, and presents a future vision for research in this area.
Summary
Satellites and the services enabled by them, like GPS, real-time world-wide imaging, weather tracking, and worldwide communication, play an increasingly important role in modern life. To support these services satellite software is becoming increasingly complex and connected. As a result, concerns about its security are becoming prevalent. While the focus...
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Covariance estimation with scanning arrays: FY23 RF Systems Technical Investment Program
December 21, 2023
Project Report
Published in:
MIT Lincoln Laboratory Report TIP-194
Summary
Analog arrays with steerable beams can be capable of angle estimation and sometimes even adaptive beamforming based on power measurements taken at the outputs of multiple beam dwells. In the interesting case of a reflectarray, where beams are formed using a large collection of programmable, passive phase shifters, it is possible to use multiple dwells to estimate signal correlations among the phase shifters. These correlations form an estimated covariance matrix at the phase centers of the shifters. Adaptive beamforming and geolocation can be based on this covariance matrix. Various methods for estimating full-rank and approximately rank-deficient covariance matrices using power measurements from multiple dwells are introduced and evaluated. In some cases, the performance of an estimator can be shown to be optimal in the sense of achieving Cramer-Rao bounds for the estimated covariance parameters.
Summary
Analog arrays with steerable beams can be capable of angle estimation and sometimes even adaptive beamforming based on power measurements taken at the outputs of multiple beam dwells. In the interesting case of a reflectarray, where beams are formed using a large collection of programmable, passive phase shifters, it is...
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WSR-88D microburst detection performance evaluation
November 28, 2023
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-455
Summary
An empirical study of Weather Surveillance Radar 1988-Doppler (WSR-88D) microburst detection performance is conducted using Integrated Terminal Weather System (ITWS) microburst detections as reference. Data from 14 airport regions during 181 independent time periods spanning the years 2015–2022 are utilized for the evaluation. Results show that the detection and false alarm probabilities depend on event range from the WSR-88D. ITWS-level detection (~95%) and false alarm (~5%) probabilities are achieved for 0 to 20 km range, while at 20 to 30 km range, detection (~80%) and false alarm (~5%) rates meeting or exceeding Weather Systems Processor (WSP) microburst detection (≥80%) and false alarm (≤15%) probability requirements are observed. Beyond ~30 km from the radar, the WSR-88D microburst detection performance falls to operationally unacceptable levels. Timing analysis indicates that, on average, WSR-88D microburst detections lag ITWS microburst detections with a median value on the order of 30 s. The detection time difference distribution shows a normal symmetric form around zero with a thin tail extending in the positive lag direction, implying that the thin tail is responsible for the positive median lag time. The lag distribution tail is shown to be shortened, and the median lag time reduced to ~10 s, if the WSR-88D's slower base scan update modes are eliminated. The study shows that the WSR-88D (and its future replacement) could generate operationally useful microburst alerts for airports that are located close enough (less than ~20 km) to the radar. The long detection lag times for a small fraction of cases that are associated with WSR-88D scan strategies that have long base (lowest elevation angle) scan update periods is an issue that may need to be addressed if the current system is to be considered for operational air traffic control purposes. Also, the unavailability of output data from the first eight range gates (2 km) should be addressed for a future replacement radar by adding a minimum observation range requirement comparable to the Terminal Doppler Weather Radar's (TDWR; 0.5 km) to the follow-on radar program requirements.
Summary
An empirical study of Weather Surveillance Radar 1988-Doppler (WSR-88D) microburst detection performance is conducted using Integrated Terminal Weather System (ITWS) microburst detections as reference. Data from 14 airport regions during 181 independent time periods spanning the years 2015–2022 are utilized for the evaluation. Results show that the detection and false...
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Security-as-a-service for embedded systems
October 30, 2023
Conference Paper
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In order to promote competition and technology refresh, the Department of Defense (DoD) has required the use of a Modular Open Systems Approach (MOSA) for the acquisition and implementation of embedded systems. Designing security and mission assurance for MOSA systems often relies upon payload specific, potentially inadequate, and difficult to update schemes. Our goal is to develop a physically separated Embedded Security-as-a-Service (ESaaS) function as a payload agnostic, updatable security manager for MOSA systems. In this paper, we describe the ongoing development of an ESaaS module for securing embedded systems that align with DoD standards, OpenVPX and Sensor Open Systems Architecture (SOSA).
Summary
In order to promote competition and technology refresh, the Department of Defense (DoD) has required the use of a Modular Open Systems Approach (MOSA) for the acquisition and implementation of embedded systems. Designing security and mission assurance for MOSA systems often relies upon payload specific, potentially inadequate, and difficult to...
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