MEMs

Using Dempster-Shafer Fusion for Personnel Intrusion Detection

The Dempster-Shafer (D-S) mass function is used in effect as a common representation of heterogeneous sensor data. In order to cast each data source in this form, first the raw data is reduced to points in a multi-dimensional feature space specific to each sensor. From there, an approach is outlined that uses a distance metric in the feature space to assign mass to each state in the class hierarchy. This hierarchy begins with the full frame of discernment which represents complete uncertainty. From there it proceeds as an n-array tree broken down into further subclasses until the finest granularity of classification for the specific sensor is reached.

Posted in: Briefs, Aerospace, Defense, Detectors, Sensors, Mathematical models, Sensors and actuators, Data management, Reliability
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Angular Random Walk Estimation of a Time-Domain Switching Micromachined Gyroscope

The primary metrics that prohibit the use of microelectromechanical systems (MEMS) gyroscopes for navigation-grade inertial navigation units (IMUs) are angle random walk (ARW), bias instability, and scale factor instability. The need for MEMS gyroscopes is due to their decreased cost, size, weight, and power (CSWaP) constraints compared to current navigation-grade solutions. Note that to avoid confusion, while in a statistical context a random walk describes a particular type of random process, ARW is used herein to quantify the effects of white, or Gaussian, noise processes on the rate estimate of a gyroscope.

Posted in: Briefs, Aerospace, Sensors, Mathematical analysis, Microelectricmechanical device, Navigation and guidance systems, Noise, Reliability
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Using Fisher Information Criteria for Chemical Sensor Selection via Convex Optimization Methods

The design of chemical sensor arrays from the standpoint of chemical sensor selection and error quantification has historically proceeded as an ad hoc process. Frequently, chemical sensors are developed not as general purpose sensing devices, but as analyte or chemical class specific detectors. When such single purpose devices are integrated together as a chemical sensor array, it is unclear a priori how well they will function in concert with each other to provide expanded capabilities, an observation that is true of the integration of analytical instruments as well.

Posted in: Briefs, Aerospace, Sensors, Optimization, Neural networks, Sensors and actuators, Identification, Chemicals
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Luminescence Materials as Nanoparticle Thermal Sensors

The purpose of this research program was to create and study novel luminescence particles (phosphors} capable of sensing and retaining the time-temperature information to which they were exposed, therefore acting as nano- and microsized thermosensors. The thermometric property is the latent thermoluminescence (TL) signal associated with electron/hole pairs trapped at defect energy levels, which are differently affected by the environmental temperature.

Posted in: Briefs, Aerospace, Data Acquisition, Defense, Nanotechnology, Photonics, Sensors, Architecture, Sensors and actuators, Research and development, Nanomaterials, Thermal testing
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New Products: April 2017 Aerospace & Defense Techonology

Rate Indicator/Totalizer

The Hoffer (Elizabeth City, NC) HIT-4U Rate Indicator/Totalizer is being offered with additional options providing the user with enhanced functionality and flexibility in a compact enclosure. The choice of a NEMA 4X enclosure joins the explosion-proof enclosure options and is now available flow meter mounted or remote mounted on a 2" or smaller pipe. The NEMA 4X enclosure offers options for local Modbus access ports via USB port or hardwired access through strain relief for data log retrieval and configuration of the unit.

Additional user friendly features of the unit include 12-point linearization, dual set point alarm output configurable for rate or total and a wide range of engineering unit display icons. The HIT-4U is offered in battery or loop-power with a lithium battery backup to ensure continuous, reliable performance.

Posted in: Products, Aerospace, Defense
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Submarine Radar Technology

Kelvin Hughes
Enfield, UK
+44 19 9280 5200
www.kelvinhughes.com

Kelvin Hughes recently announced that it has developed a way to bring all the benefits of its innovative SharpEye™ radar technology to submarines.

Posted in: Application Briefs, Defense, Radar, Marine vehicles and equipment
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Morphing Wings Make Jets More Efficient

University of Michigan engineers have developed improved wing designs capable of burning less fuel, as well as tools that help the aerospace industry build more efficient aircraft. In areas where new technologies are being applied – such as for wings made of composite materials or wings that morph during flight – improved design tools can provide insights when intuitive understanding is lacking.

Posted in: News, Aviation, Defense
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NASA Tests Engines That Reduce Drag and Fuel Burn

Boundary Layer Ingestion (BLI) is a promising idea NASA researchers are studying to reduce fuel burn in jet engines, thus reducing emissions and the cost of operating the aircraft. Thrust makes an airplane go forward, while drag tries to slow it down. Lift offsets the weight to keep an airplane in the sky. BLI deals specifically with the drag part of the equation by trying to reduce the total drag an airplane experiences in the sky.

Posted in: News, Aeronautics, Aerospace, Aviation, Defense
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Technique Enables 3D Printing of Aerospace-Grade Carbon Fiber Composites

Researchers from Lawrence Livermore National Laboratory have become the first to 3D print aerospace-grade carbon fiber composites, representing a significant advance in the development of micro-extrusion 3D printing techniques for carbon fiber.

Posted in: News, Defense, Manufacturing & Prototyping, Rapid Prototyping & Tooling
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NASA Test Flights Will Study Improved Efficiency of Supersonic Aircraft

NASA is set to begin a series of supersonic flights that will examine efforts to improve the efficiency of future supersonic aircraft. Future supersonic aircraft seeking to achieve a low boom will rely on a swept wing design in order to fly at supersonic speeds without producing a loud sonic boom. The swept wing design generally produces airflow disturbances that run along the span of the wing, resulting in turbulent flow, increased drag, and ultimately, higher fuel consumption.

Posted in: News, Aviation, Defense
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