19,000 research outputs found
Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology
INE/AUTC 10.0
Fundamental remote sensing science research program. Part 1: Scene radiation and atmospheric effects characterization project
Brief articles summarizing the status of research in the scene radiation and atmospheric effect characterization (SRAEC) project are presented. Research conducted within the SRAEC program is focused on the development of empirical characterizations and mathematical process models which relate the electromagnetic energy reflected or emitted from a scene to the biophysical parameters of interest
Trick or Heat? Manipulating Critical Temperature-Based Control Systems Using Rectification Attacks
Temperature sensing and control systems are widely used in the closed-loop
control of critical processes such as maintaining the thermal stability of
patients, or in alarm systems for detecting temperature-related hazards.
However, the security of these systems has yet to be completely explored,
leaving potential attack surfaces that can be exploited to take control over
critical systems.
In this paper we investigate the reliability of temperature-based control
systems from a security and safety perspective. We show how unexpected
consequences and safety risks can be induced by physical-level attacks on
analog temperature sensing components. For instance, we demonstrate that an
adversary could remotely manipulate the temperature sensor measurements of an
infant incubator to cause potential safety issues, without tampering with the
victim system or triggering automatic temperature alarms. This attack exploits
the unintended rectification effect that can be induced in operational and
instrumentation amplifiers to control the sensor output, tricking the internal
control loop of the victim system to heat up or cool down. Furthermore, we show
how the exploit of this hardware-level vulnerability could affect different
classes of analog sensors that share similar signal conditioning processes.
Our experimental results indicate that conventional defenses commonly
deployed in these systems are not sufficient to mitigate the threat, so we
propose a prototype design of a low-cost anomaly detector for critical
applications to ensure the integrity of temperature sensor signals.Comment: Accepted at the ACM Conference on Computer and Communications
Security (CCS), 201
Microwave emissions from snow
The radiation emitted from dry and wet snowpack in the microwave region (1 to 100 GHz) is discussed and related to ground observations. Results from theoretical model calculations match the brightness temperatures obtained by truck mounted, airborne and spaceborne microwave sensor systems. Snow wetness and internal layer structure complicate the snow parameter retrieval algorithm. Further understanding of electromagnetic interaction with snowpack may eventually provide a technique to probe the internal snow propertie
Topological engineering of interfacial optical Tamm states for highly-sensitive near-singular-phase optical detection
We developed planar multilayered photonic-plasmonic structures, which support
topologically protected optical states on the interface between metal and
dielectric materials, known as optical Tamm states. Coupling of incident light
to the Tamm states can result in perfect absorption within one of several
narrow frequency bands, which is accompanied by a singular behavior of the
phase of electromagnetic field. In the case of near-perfect absorptance, very
fast local variation of the phase can still be engineered. In this work, we
theoretically and experimentally demonstrate how these drastic phase changes
can improve sensitivity of optical sensors. A planar Tamm absorber was
fabricated and used to demonstrate remote near-singular-phase temperature
sensing with an over an order of magnitude improvement in sensor sensitivity
and over two orders of magnitude improvement in the figure of merit over the
standard approach of measuring shifts of resonant features in the reflectance
spectra of the same absorber. Our experimentally demonstrated
phase-to-amplitude detection sensitivity improvement nearly doubles that of
state-of-the-art nano-patterned plasmonic singular-phase detectors, with
further improvements possible via more precise fabrication. Tamm perfect
absorbers form the basis for robust planar sensing platforms with tunable
spectral characteristics, which do not rely on low-throughput nano-patterning
techniques.Comment: 31 pages; 6 main text figures and 10 supplementary figure
Unclassified information list, 12-16 September 1966
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