Publications
Boston community energy study - zonal analysis for urban microgrids
April 5, 2016
Technical Report
Published in:
MIT Lincoln Laboratory Report TR-1201
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Summary
Superstorm Sandy illustrated the economic and human impact that severe weather can have on urban areas such as New York City. While flooding and wind damaged or destroyed some of the energy infrastructure, all installed microgrids in the New York City region remained operational during Sandy, including those at Princeton University, Goldman Sachs, New York University, and Co-op City. The resilience provided by these microgrids sparked renewed interest in pursuing more microgrid deployments as means to increase resiliency throughout the nation and in the face of many potential threats including severe weather events, and potentially terrorism. MIT Lincoln Laboratory has been engaged with the Department of Homeland Security (DHS), the Department of Energy (DoE), and the City of Boston in this Community Energy Study to explore the potential for microgrid deployment within Boston's thriving neighborhoods. Using hourly simulated building energy data for every building in Boston, provided by the Sustainable Design Lab on MIT campus, MIT Lincoln Laboratory was able to develop an approach that can identify zones within the city where microgrids could be implemented with a high return on investment in terms of resiliency, offering both cost savings and social benefit in the face of grid outages. An important part of this approach leverages a microgrid optimization tool developed by Lawrence Berkeley National Laboratory, with whom the MIT Lincoln Laboratory is now collaborating on microgrid modeling work. Using the microgrid optimization tool, along with building energy use data, forty-two community microgrids were identified, including ten multiuser microgrids, ten energy justice microgrids, and twenty-two emergency microgrids.
Summary
Superstorm Sandy illustrated the economic and human impact that severe weather can have on urban areas such as New York City. While flooding and wind damaged or destroyed some of the energy infrastructure, all installed microgrids in the New York City region remained operational during Sandy, including those at Princeton...
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Microhydraulic electrowetting actuators
April 1, 2016
Journal Article
Published in:
J. Microelectromech. Syst., Vol. 25, No. 2, April 2016, pp. 394-400.
Summary
The conversion of electrical to mechanical power on a sub-centimeter scale is a key technology in many microsystems and energy harvesting devices. In this paper, we present a type of a capacitive energy conversion device that uses capillary pressure and electrowetting to reversibly convert electrical power to hydraulic power. These microhydraulic actuators use a high surface-to-volume ratio to deliver high power at a relatively low voltage with an energy conversion efficiency of over 65%. The capillary pressure generated grows linearly with shrinking capillary diameter, as does the frequency of actuation. We present the pressure, frequency, and power scaling properties of these actuators and demonstrate that power density scales up as the inverse capillary diameter squared, leading to high-efficiency actuators with a strength density exceeding biological muscle. Two potential applications for microhydraulics are also demonstrated: soft-microrobotics and energy harvesting.
Summary
The conversion of electrical to mechanical power on a sub-centimeter scale is a key technology in many microsystems and energy harvesting devices. In this paper, we present a type of a capacitive energy conversion device that uses capillary pressure and electrowetting to reversibly convert electrical power to hydraulic power. These...
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2015 operational observation of CoSPA and traffic flow impact
March 15, 2016
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-429
Summary
This technical report summarizes the operational observations recorded by MIT Lincoln Laboratory (MIT LL) aviation subject matter experts during the period 13 April to 31 October 2015. Three separate field observations were conducted over four convective weather days across the eastern National Airspace System (NAS) with visits to five separate FAA facilities and five different airline operation centers. Observations of strategic management planning and decision making were documented during these visits. Specifically noted were the utilization of the deterministic convective weather forecasting model, CoSPA, and a newly developed decision support application, Traffic Flow Impact (TFI). These field evaluations were supported via the FAA AJM-334 CoSPA program.
Summary
This technical report summarizes the operational observations recorded by MIT Lincoln Laboratory (MIT LL) aviation subject matter experts during the period 13 April to 31 October 2015. Three separate field observations were conducted over four convective weather days across the eastern National Airspace System (NAS) with visits to five separate...
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Vector antenna and maximum likelihood imaging for radio astronomy
March 5, 2016
Conference Paper
Published in:
2016 IEEE Aerospace Conf., 5-12 March 2016.
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Summary
Radio astronomy using frequencies less than ~100 MHz provides a window into non-thermal processes in objects ranging from planets to galaxies. Observations in this frequency range are also used to map the very early history of star and galaxy formation in the universe. Much effort in recent years has been devoted to highly capable low frequency ground-based interferometric arrays such as LOFAR, LWA, and MWA. Ground-based arrays, however, cannot observe astronomical sources below the ionospheric cut-off frequency of ~10 MHz, so the sky has not been mapped with high angular resolution below that frequency. The only space mission to observe the sky below the ionospheric cut-off was RAE-2, which achieved an angular resolution of ~60 degrees in 1973. This work presents alternative sensor and algorithm designs for mapping the sky both above and below the ionospheric cutoff. The use of a vector sensor, which measures the full electric and magnetic field vectors of incoming radiation, enables reasonable angular resolution (~5 degrees) from a compact sensor (~4 m) with a single phase center. A deployable version of the vector sensor has been developed to be compatible with the CubeSat form factor.
Summary
Radio astronomy using frequencies less than ~100 MHz provides a window into non-thermal processes in objects ranging from planets to galaxies. Observations in this frequency range are also used to map the very early history of star and galaxy formation in the universe. Much effort in recent years has been...
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Asteroid search operations with the Space Surveillance Telescope
March 5, 2016
Conference Paper
Published in:
2016 IEEE Aerospace Conf., 5-12 March 2016.
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Summary
Over the past two years, the Lincoln Near Earth Asteroid Research (LINEAR) program, funded by the National Aeronautics and Space Administration (NASA), has transitioned to asteroid search operations using the new 3.5-meter wide-field-of-view Space Surveillance Telescope (SST) located at the Atom Site on White Sands Missile Range, N.M. The SST was developed for the Defense Advanced Research Projects Agency (DARPA) by MIT Lincoln Laboratory to help advance the nation's capabilities in space situational awareness. The goals of LINEAR using SST are to continue discovering Near-Earth objects (NEOs) especially focusing on improving knowledge of asteroids 140 meters in diameter and larger. In this paper, we will review results of the first two years of asteroid search operations, during which the SST has delivered over 9.4 million observations to the Minor Planet Center. Recent and planned system improvements will also be discussed.
Summary
Over the past two years, the Lincoln Near Earth Asteroid Research (LINEAR) program, funded by the National Aeronautics and Space Administration (NASA), has transitioned to asteroid search operations using the new 3.5-meter wide-field-of-view Space Surveillance Telescope (SST) located at the Atom Site on White Sands Missile Range, N.M. The SST...
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SoK: privacy on mobile devices - it's complicated
March 2, 2016
Conference Paper
Published in:
Proc. on Privacy Enhancing Techn., Vol. 3, 2016, pp. 96-116.
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Modern mobile devices place a wide variety of sensors and services within the personal space of their users. As a result, these devices are capable of transparently monitoring many sensitive aspects of these users' lives (e.g., location, health, or correspondences). Users typically trade access to this data for convenient applications and features, in many cases without a full appreciation of the nature and extent of the information that they are exposing to a variety of third parties. Nevertheless, studies show that users remain concerned about their privacy and vendors have similarly been increasing their utilization of privacy-preserving technologies in these devices. Still, despite significant efforts, these technologies continue to fail in fundamental ways, leaving users' private data exposed. In this work, we survey the numerous components of mobile devices, giving particular attention to those that collect, process, or protect users' private data. Whereas the individual components have been generally well studied and understood, examining the entire mobile device ecosystem provides significant insights into its overwhelming complexity. The numerous components of this complex ecosystem are frequently built and controlled by different parties with varying interests and incentives. Moreover, most of these parties are unknown to the typical user. The technologies that are employed to protect the users' privacy typically only do so within a small slice of this ecosystem, abstracting away the greater complexity of the system. Our analysis suggests that this abstracted complexity is the major cause of many privacy-related vulnerabilities, and that a fundamentally new, holistic, approach to privacy is needed going forward. We thus highlight various existing technology gaps and propose several promising research directions for addressing and reducing this complexity.
Summary
Modern mobile devices place a wide variety of sensors and services within the personal space of their users. As a result, these devices are capable of transparently monitoring many sensitive aspects of these users' lives (e.g., location, health, or correspondences). Users typically trade access to this data for convenient applications...
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Competing cognitive resilient networks
March 1, 2016
Journal Article
Published in:
IEEE Trans. Cognit. Commun. and Netw., Vol. 2, No. 1, March 2016, pp. 95-109.
Summary
We introduce competing cognitive resilient network (CCRN) of mobile radios challenged to optimize data throughput and networking efficiency under dynamic spectrum access and adversarial threats (e.g., jamming). Unlike the conventional approaches, CCRN features both communicator and jamming nodes in a friendly coalition to take joint actions against hostile networking entities. In particular, this paper showcases hypothetical blue force and red force CCRNs and their competition for open spectrum resources. We present state-agnostic and stateful solution approaches based on the decision theoretic framework. The state-agnostic approach builds on multiarmed bandit to develop an optimal strategy that enables the exploratory-exploitative actions from sequential sampling of channel rewards. The stateful approach makes an explicit model of states and actions from an underlying Markov decision process and uses multiagent Q-learning to compute optimal node actions. We provide a theoretical framework for CCRN and propose new algorithms for both approaches. Simulation results indicate that the proposed algorithms outperform some of the most important algorithms known to date.
Summary
We introduce competing cognitive resilient network (CCRN) of mobile radios challenged to optimize data throughput and networking efficiency under dynamic spectrum access and adversarial threats (e.g., jamming). Unlike the conventional approaches, CCRN features both communicator and jamming nodes in a friendly coalition to take joint actions against hostile networking entities...
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Development of a real-time hardware-in-the-loop power systems simulation platform to evaluate commercial microgrid controllers
February 23, 2016
Technical Report
Published in:
MIT Lincoln Laboratory Report TR-1203
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Summary
This report describes the development of a real-time hardware-in-the-loop (HIL) power system simulation platform to evaluate commercial microgrid controllers. The effort resulted in the successful demonstration of HIL simulation technology at a Technical Symposium organized by the Mass Clean Energy Center (CEC) for utility distribution system engineers, project developers, systems integrators, equipment vendors, academia, regulators, City of Boston officials, and Commonwealth officials. Actual microgrid controller hardware was integrated along with actual, commercial genset controller hardware in a particular microgrid configuration, which included dynamic loads, distributed energy resources (DERs), and conventional power sources. The end product provides the ability to quickly and cost-effectively assess the performance of different microgrid controllers as quantified by certain metrics, such as fuel consumption, power flow management precision at the point of common coupling, load-not-served (LNS) while islanded, peak-shaving kWh, and voltage stability. Additional applications include protection system testing and evaluation, distributed generation prime mover controller testing, integration and testing of distribution control systems, behavior testing and studies of DER controls, detailed power systems analysis, communications testing and integration, and implementation and evaluation of smart grid concepts. Microgrids and these additional applications promise to improve the reliability, resiliency, and efficiency of the nation's aging but critical power distribution systems. This achievement was a collaborative effort between MIT Lincoln Laboratory and industry microgrid controller manufacturers. This work was sponsored by the Department of Homeland Security (DHS), Science and Technology Directorate (S&T) and the Department of Energy (DOE) Office of Electricity Delivery and Energy Reliability.
Summary
This report describes the development of a real-time hardware-in-the-loop (HIL) power system simulation platform to evaluate commercial microgrid controllers. The effort resulted in the successful demonstration of HIL simulation technology at a Technical Symposium organized by the Mass Clean Energy Center (CEC) for utility distribution system engineers, project developers, systems...
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Photonic lantern adaptive spatial mode control in LMA fiber amplifiers
February 22, 2016
Journal Article
Published in:
Opt. Express, Vol. 24, No. 4, 22 February 2016, pp. 3405-13.
Summary
We demonstrate adaptive-spatial mode control (ASMC) in few-moded double-clad large mode area (LMA) fiber amplifiers by using an all-fiber-based photonic lantern. Three single-mode fiber inputs are used to adaptively inject the appropriate superposition of input modes in a multimode gain fiber to achieve the desired mode at the output. By actively adjusting the relative phase of the single-mode inputs, near-unity coherent combination resulting in a single fundamental mode at the output is achieved.
Summary
We demonstrate adaptive-spatial mode control (ASMC) in few-moded double-clad large mode area (LMA) fiber amplifiers by using an all-fiber-based photonic lantern. Three single-mode fiber inputs are used to adaptively inject the appropriate superposition of input modes in a multimode gain fiber to achieve the desired mode at the output. By...
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Raman spectra and cross sections of ammonia, chlorine, hydrogen sulfide, phosgene, and sulfur dioxide toxic gases in the fingerprint region 400-1400 cm-1
February 11, 2016
Journal Article
Published in:
AIP Advances, Vol. 6, No. 2, February 2016, 025310, doi: 10.1063/1.4942109.
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Summary
Raman spectra of ammonia (NH3), chlorine (Cl2), hydrogen sulfide (H2S), phosgene (COCl2), and sulfur dioxide (SO2) toxic gases have been measured in the fingerprint region 400-1400 cm-1. A relatively compact (< 2'x2'x2'), sensitive, 532 nm 10 W CW Raman system with double-pass laser and double-sided collection was used for these measurements. Two Raman modes are observed at 934 and 967 cm-1 in NH3. Three Raman modes are observed in Cl2 at 554, 547, and 539 cm-1, which are due to the 35/35 35/37, and 37/37 Cl isotopes, respectively. Raman modes are observed at 870, 570, and 1151 cm-1 in H2S, COCl2, and SO2, respectively. Values of 3.68 ± 0.26x10-32 cm2/sr (3.68 ± 0.26x10-36 m2/sr), 1.37 ± 0.10x10-30 cm2/sr (1.37 ± 0.10x10-34 m2/sr), 3.25 ± 0.23x10-31 cm2/sr (3.25 ± 0.23x10-35 m2/sr), 1.63 ± 0.14x10-30 cm2/sr (1.63 ± 0.14x10-34 m2/sr), and 3.08 ± 0.22x10-30 cm2/sr (and 3.08 ± 0.22x10-34 m2/sr) were determined for the differential Raman cross section of the 967 cm-1 mode of NH3, sum of the 554, 547, and 539 cm-1 modes of Cl2, 870 cm-1 mode of H2S, 570 cm-1 mode of COCl2, and 1151 cm-1 mode of SO2, respectively, using the differential Raman cross section of 3.56 ± 0.14x10-31 cm2/sr (3.56 ± 0.14x10-35 m2/sr) for the 1285 cm-1 mode of CO2 as the reference.
Summary
Raman spectra of ammonia (NH3), chlorine (Cl2), hydrogen sulfide (H2S), phosgene (COCl2), and sulfur dioxide (SO2) toxic gases have been measured in the fingerprint region 400-1400 cm-1. A relatively compact ( 2'x2'x2'), sensitive, 532 nm 10 W CW Raman system with double-pass laser and double-sided collection was used for these...
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