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Spectral reflectance and transmission properties of a multi-layered camouflage net: Comparison with natural birch leaves and mathematical models
(2020-09-20)
With improved specifications and capabilities of modern sensors and detectors, concealment is an increasingly challenging endeavor. Concealment from modern sensors requires advanced camouflage material that can provide low ...
Particle-resolved simulations of shock-induced flow through particle clouds at different Reynolds numbers
(2020-01-27)
This study investigates the Reynolds-number dependence of shock-induced flow through stationary particle clouds at 10% volume fraction, using ensemble-averaged results from three-dimensional particle-resolved large eddy ...
Three-dimensional signal decomposition of infrared image sequences and large-scale non-uniformity analysis
(2020-09-20)
The three-dimensional noise model is a methodology to analyse the noise of a thermal imaging sensor, such as an infrared (IR) camera. This allows us to decompose a noisy signal into components and quantify properties such ...
In-operation calibration of clock-bias and intrinsic parameters for pan-tilt-zoom cameras based on keypoint tracking
(2020-09-20)
We propose a method for jointly estimating intrinsic calibration and internal clock synchronisation for a pantilt- zoom (PTZ) camera using only data that can be acquired in the field during normal operation. Results show ...
Detection: how many pixels are required?
(2020-09-23)
In this work, we studied how detection range of a small target changes as a function of the number of defined target pixels. The intuitively simplest method to look for a target in IR images is to look for the “hottest” ...
Weeping in Modern Jihadi Groups
(2020-09-14)
This article, using a wide range of primary sources, describes the practice of weeping (bukā) in contemporary jihadi groups. It shows that weeping is widespread and encouraged in militant Islamist groups such as al-Qaida ...
Radar imager for Mars’ subsurface experiment—RIMFAX
(2020-11-03)
The Radar Imager for Mars’ Subsurface Experiment (RIMFAX) is a Ground Penetrating Radar on the Mars 2020 mission’s Perseverance rover, which is planned to land near a deltaic landform in Jezero crater. RIMFAX will add a ...
When the noise goes on: received sound energy predicts sperm whale responses to both intermittent and continuous navy sonar
(2020-04-08)
Anthropogenic noise sources range from intermittent to continuous, with seismic and navy sonar technology moving towards near-continuous transmissions. Continuous active sonar (CAS) may be used at a lower amplitude than ...
Performance of drag force models for shock-accelerated flow in dense particle suspensions
(2021-04)
Models for prediction of drag forces within a particle cloud following shock-acceleration are evaluated with the aid of results from particle-resolved simulations in order to quantify how much the disturbances introduced ...
Understanding Influence Operations in Social Media: A Cyber Kill Chain Approach
(2020-11-14)
Discussions about recent state-run influence operations in social media often focus only on quantitative elements—the number of people interacting with fake news or how many tweets were sent by bots. This article suggests ...