Fast classification of drones and birds with an LSTM network applied to 1D phase data

Funding: Science and Technology Facilities Council under grant ST/N006569/1.This study investigates a new type of drone classifier based on Long Short-Term Memory (LSTM) networks. As a real-time surveillance system, the classification time of a drone detection radar is crucial. The motivation for this work is to develop a classification framework which has low latency in terms of data processing for the algorithm input. Theoretical modeling of a rotary wing drone and a bird wing flapping returns were done first to exhibit the difference in the patterns of the respective phase progressions. Then, 94 GHzexperimental trial data containing 4800 sequences of drones, birds, noise and clutter were used to create a diverse training dataset of 1D phase data for supervised learning. A stackedLSTM network with tuned hyperparameters was generated to reduce the possible overfitting from a simple LSTM model. Validation accuracy of 98.1% was achieved for 2-class classification of drone and non-drone. Further performance assessment was then done with 30 unseen test data, where the network was able to correctly classify all the sequences. It is ascertained that this method can be ~10 times faster than a spectrogram based classification model, which requires additional Fast Fourier Transform (FFT) operations

Numerosity and density judgments: Biases for area but not for volume

International audienceHuman observers can rapidly judge the number of items in a scene. This ability is underpinned by specific mechanisms encoding number or density. We investigated whether judgments of number and density are biased by a change in volume, as they are by a change in area. Stimuli were constructed using nonoverlapping black and white luminance-defined dots. An eight-mirror Wheatstone stereoscope was used to present the dots as though in a volume. Using a temporal two-alternative forced-choice (2AFC) task and the Method of Constant Stimuli (MOCS), we measured the precision and bias (PSE shift) of numerosity and density judgments, separately, for stimuli differing in area or volume. For two-dimensional (2-D) stimuli, consistent with previous literature, perceived density was biased as area increased. However, perceived number was not. For three-dimensional (3-D) stimuli, despite a vivid impression of the dots filling a cylindrical volume, there was no bias in perceived density or number as volume increased. A control experiment showed that all of our observers could easily perceive disparity in our stimuli. Our findings reveal that number and density judgments that are biased by area are not similarly biased by volume changes

Buddy-motivational interviewing (buddy-MI) to Increase Physical Activity in Community Settings: Results of a Pragmatic Randomised Controlled Trial

This article describes the implementation and evaluation of a novel buddy-Motivational Interviewing intervention intended to help apparently healthy but relatively sedentary adults to adopt and maintain regular physical activity for health and fitness. This intervention is an adaptation of Motivational Interviewing which adds client-selected motivational-buddies who can provide in-session input as well as ongoing out-of-session support focused on strengthening client’s motivation for and movement toward their physical activity goals. A pragmatic parallel-group randomised controlled trial with 12-month follow-up was implemented to test the intervention. The trial demonstrated that buddy-MI was feasible and could be delivered with equivalent fidelity to standard MI and both groups demonstrated statistically significant changes across a range of behavioural and health-status outcomes. Moreover, the experimental group participants generally ‘outperformed’ the control group participants as shown by the consistent trends observed over three repeated measures out to 12-months (although these between-group differences were statistically non-significant). Qualitative data indicated participant acceptance of the programme as well as providing initial evidence of positive collateral health effects (‘ripple effects’ whereby buddies changed their behaviours also). Consideration for further development, evaluation and applications are also discussed

Buddy-Motivational Interviewing (buddy-MI) to Increase Physical Activity in Community Settings: Study Protocol for a Pragmatic Randomised Controlled Trial

This article describes the development and evaluation of a novel buddy-motivational interviewing intervention intended to help apparently healthy but relatively sedentary adults to adopt and maintain regular physical activity for health and fitness. Many people experience great difficulty in initiating physical activity (“the getting going problem”) and behavioural regression is common (“the keeping it going problem”). Typically there is a rather large gap between what people know to be healthy and what they actually do. This intervention is an adaptation of motivational interviewing in that it adds client-selected motivational-buddies who can provide in-session input as well as ongoing out-of-session support focused on strengthening clients’ motivation for and movement toward their physical activity goals. A pragmatic parallel group randomised controlled trial with 12-month follow-up aims to deliver and assess the effectiveness of the intervention in a format that could realistically be implemented within primary care, workplaces, schools or other similar setting. The study is due to report clinical effectiveness findings in 2014

Kentucky\u27s PRISM-Based Automated Ramp Screening System Evaluation

In 2010, Kentucky implemented a Performance Registration Information Systems and Management (PRISM) based automated ramp screening system (PARSS) at the Boone County inspection station on southbound I-71. The purpose of the PARSS is to identify and screen every vehicle that enters the Boone County inspection station. The system provides automated screening of trucks based on the license plate number and the USDOT number displayed on the vehicle. If it is determined that the vehicle should be stopped for inspection, that decision is communicated to the truck driver via the existing directional arrows that direct drivers to the static scale for inspection. A thorough evaluation was conducted to assess the performance of the system (i.e., does it do what it was intended to do?), the value of the system in identifying vehicles for inspection with PRISM or CVISN-related issues, and the potential for more widespread deployment of this type of screening system. In addition, the evaluation also included a side-by-side comparison of the two automated license plate reader (ALPR) systems

A Putative Multiple-Demand System in the Macaque Brain.

UNLABELLED: In humans, cognitively demanding tasks of many types recruit common frontoparietal brain areas. Pervasive activation of this "multiple-demand" (MD) network suggests a core function in supporting goal-oriented behavior. A similar network might therefore be predicted in nonhuman primates that readily perform similar tasks after training. However, an MD network in nonhuman primates has not been described. Single-cell recordings from macaque frontal and parietal cortex show some similar properties to human MD fMRI responses (e.g., adaptive coding of task-relevant information). Invasive recordings, however, come from limited prespecified locations, so they do not delineate a macaque homolog of the MD system and their positioning could benefit from knowledge of where MD foci lie. Challenges of scanning behaving animals mean that few macaque fMRI studies specifically contrast levels of cognitive demand, so we sought to identify a macaque counterpart to the human MD system using fMRI connectivity in 35 rhesus macaques. Putative macaque MD regions, mapped from frontoparietal MD regions defined in humans, were found to be functionally connected under anesthesia. To further refine these regions, an iterative process was used to maximize their connectivity cross-validated across animals. Finally, whole-brain connectivity analyses identified voxels that were robustly connected to MD regions, revealing seven clusters across frontoparietal and insular cortex comparable to human MD regions and one unexpected cluster in the lateral fissure. The proposed macaque MD regions can be used to guide future electrophysiological investigation of MD neural coding and in task-based fMRI to test predictions of similar functional properties to human MD cortex. SIGNIFICANCE STATEMENT: In humans, a frontoparietal "multiple-demand" (MD) brain network is recruited during a wide range of cognitively demanding tasks. Because this suggests a fundamental function, one might expect a similar network to exist in nonhuman primates, but this remains controversial. Here, we sought to identify a macaque counterpart to the human MD system using fMRI connectivity. Putative macaque MD regions were functionally connected under anesthesia and were further refined by iterative optimization. The result is a network including lateral frontal, dorsomedial frontal, and insular and inferior parietal regions closely similar to the human counterpart. The proposed macaque MD regions can be useful in guiding electrophysiological recordings or in task-based fMRI to test predictions of similar functional properties to human MD cortex

Prevalence of true vein graft aneurysms: Implications for aneurysm pathogenesis

AbstractBackground: Circumstantial evidence suggests that arterial aneurysms have a different cause than atherosclerosis and may form part of a generalized dilating diathesis. The aim of this study was to compare the rates of spontaneous aneurysm formation in vein grafts performed either for popliteal aneurysms or for occlusive disease. The hypothesis was that if arterial aneurysms form a part of a systemic process, then the rates of vein graft aneurysms should be higher for patients with popliteal aneurysms than for patients with lower limb ischemia caused by atherosclerosis. Methods: Infrainguinal vein grafting procedures performed from 1990 to 1995 were entered into a prospective audit and graft surveillance program. Aneurysmal change was defined as a focal increase in the graft diameter of 1.5 cm or greater, excluding false aneurysms and dilatations after graft angioplasty. Results: During the study period, 221 grafting procedures were performed in 200 patients with occlusive disease and 24 grafting procedures were performed in 21 patients with popliteal aneurysms. Graft surveillance revealed spontaneous aneurysm formation in 10 of the 24 bypass grafts (42%) for popliteal aneurysms but in only 4 of the 221 grafting procedures (2%) that were performed for chronic lower limb ischemia. Conclusion:This study provides further evidence that aneurysmal disease is a systemic process, and this finding has clinical implications for the treatment of popliteal aneurysms. (J Vasc Surg 1999;29:403-8.

Successful use of axonal transport for drug delivery by synthetic molecular vehicles

We report the use of axonal transport to achieve intraneural drug delivery. We constructed a novel tripartite complex of an axonal transport facilitator conjugated to a linker molecule bearing up to a hundred reversibly attached drug molecules. The complex efficiently enters nerve terminals after intramuscular or intradermal administration and travels within axonal processes to neuron cell bodies. The tripartite agent provided 100-fold amplification of saturable neural uptake events, delivering multiple drug molecules per complex. _In vivo_, analgesic drug delivery to systemic and to non-targeted neural tissues was greatly reduced compared to existing routes of administration, thus exemplifying the possibility of specific nerve root targeting and effectively increasing the potency of the candidate drug gabapentin 300-fold relative to oral administration

In-situ characterization of colloidal soft solution processes.

The purpose of this program was to investigate methods to characterize the colloidal stability of nanoparticles during the synthesis reaction, and to characterize their organization related to interparticle forces. Studies were attempted using Raman spectroscopy and ultrasonic attenuation to observe the nucleation and growth process with characterization of stability parameters such as the zeta potential. The application of the techniques available showed that the instrumentation requires high sensitivity to the concentration of the system. Optical routes can be complicated by the scattering effects of colloidal suspensions, but dilution can cause a lowering of signal that prevents collection of data. Acoustic methods require a significant particle concentration, preventing the observation of nucleation events. Studies on the dispersion of nanoparticles show that electrostatic routes are unsuccessful with molecular surfactants at high particle concentration due to electrostatic interaction collapse by counterions. The study of molecular surfactants show that steric lengths on the order of 2 nm are successful for dispersion of nanoparticle systems at high particle concentration, similar to dispersion with commercial polyelectrolyte surfactants