Computer vision has evolved in the last decade as a key technology for numerous applications replacing human supervision. Timely detection of traffic violations and abnormal behavior of pedestrians ...at public places through computer vision and visual surveillance can be highly effective for maintaining traffic order in cities. However, despite a handful of computer vision–based techniques proposed in recent times to understand the traffic violations or other types of on-road anomalies, no methodological survey is available that provides a detailed insight into the classification techniques, learning methods, datasets, and application contexts. Thus, this study aims to investigate the recent visual surveillance–related research on anomaly detection in public places, particularly on road. The study analyzes various vision-guided anomaly detection techniques using a generic framework such that the key technical components can be easily understood. Our survey includes definitions of related terminologies and concepts, judicious classifications of the vision-guided anomaly detection approaches, detailed analysis of anomaly detection methods including deep learning–based methods, descriptions of the relevant datasets with environmental conditions, and types of anomalies. The study also reveals vital gaps in the available datasets and anomaly detection capability in various contexts, and thus gives future directions to the computer vision–guided anomaly detection research. As anomaly detection is an important step in automatic road traffic surveillance, this survey can be a useful resource for interested researchers working on solving various issues of Intelligent Transportation Systems (ITS).
The P300 component of the event-related potential is a large positive waveform that can be extracted from the ongoing electroencephalogram using a two-stimuli oddball paradigm, and has been ...associated with cognitive information processing (e.g. memory, attention, executive function). This paper reviews the development of the auditory P300 across the lifespan.
A systematic review and meta-analysis on the P300 was performed including 75 studies (n = 2,811). Scopus was searched for studies using healthy subjects and that reported means of P300 latency and amplitude measured at Pz and mean age. These findings were validated in an independent, existing cross-sectional dataset including 1,572 participants from ages 6-87. Curve-fitting procedures were applied to obtain a model of P300 development across the lifespan. In both studies logarithmic Gaussian models fitted the latency and amplitude data best. The P300 latency and amplitude follow a maturational path from childhood to adolescence, resulting in a period that marks a plateau, after which degenerative effects begin. We were able to determine ages that mark a maximum (in P300 amplitude) or trough (in P300 latency) segregating maturational from degenerative stages. We found these points of deflection occurred at different ages.
It is hypothesized that latency and amplitude index different aspects of brain maturation. The P300 latency possibly indexes neural speed or brain efficiency. The P300 amplitude might index neural power or cognitive resources, which increase with maturation.
Combination of different satellite data will provide increased opportunities for more frequent cloud-free surface observations due to variable cloud cover at the different satellite overpass times ...and dates. Satellite data from the polar-orbiting Landsat-8 (launched 2013), Sentinel-2A (launched 2015) and Sentinel-2B (launched 2017) sensors offer 10 m to 30 m multi-spectral global coverage. Together, they advance the virtual constellation paradigm for mid-resolution land imaging. In this study, a global analysis of Landsat-8, Sentinel-2A and Sentinel-2B metadata obtained from the committee on Earth Observation Satellite (CEOS) Visualization Environment (COVE) tool for 2016 is presented. A global equal area projection grid defined every 0.05° is used considering each sensor and combined together. Histograms, maps and global summary statistics of the temporal revisit intervals (minimum, mean, and maximum) and the number of observations are reported. The temporal observation frequency improvements afforded by sensor combination are shown to be significant. In particular, considering Landsat-8, Sentinel-2A, and Sentinel-2B together will provide a global median average revisit interval of 2.9 days, and, over a year, a global median minimum revisit interval of 14 min (±1 min) and maximum revisit interval of 7.0 days.
Lower limb trauma requiring immobilization is a significant contributor to overall venous thromboembolism (VTE) burden. The clinical effectiveness of thromboprophylaxis for this indication and the ...optimal agent strategy are still a matter of debate. Our main objective was to assess the efficacy of pharmacological thromboprophylaxis to prevent VTE in patients with isolated temporary lower limb immobilization after trauma. We aimed to estimate and compare the clinical efficacy and the safety of the different thromboprophylactic treatments to determine the best strategy. We conducted a systematic review and a Bayesian network meta-analysis (NMA) including all available randomized trials comparing a pharmacological thromboprophylactic treatment to placebo or to no treatment in patients with leg immobilization after trauma. We searched Medline, Embase, and Web of Science until July 2021. Only RCT or observational studies with analysis of confounding factors including adult patients requiring temporary immobilization for an isolated lower limb injury treated conservatively or surgically and assessing pharmacological thromboprophylactic agents or placebo or no treatment were eligible for inclusion. The primary endpoint was the incidence of major VTE (proximal deep vein thrombosis, symptomatic VTE, and pulmonary embolism-related death). We extracted data according to Preferred Reporting Items for Systematic Reviews and Meta-analyses for NMA and appraised selected trials with the Cochrane review handbook. Fourteen studies were included (8,198 patients). Compared to the control group, rivaroxaban, fondaparinux, and low molecular weight heparins were associated with a significant risk reduction of major VTE with an odds ratio of 0.02 (95% credible interval (CrI) 0.00 to 0.19), 0.22 (95% CrI 0.06 to 0.65), and 0.32 (95% CrI 0.15 to 0.56), respectively. No increase of the major bleeding risk was observed with either treatment. Rivaroxaban has the highest likelihood of being ranked top in terms of efficacy and net clinical benefit. The main limitation is that the network had as many indirect comparisons as direct comparisons. This NMA confirms the favorable benefit/risk ratio of thromboprophylaxis for patients with leg immobilization after trauma with the highest level of evidence for rivaroxaban.
The two Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on-board NASA's Terra and Aqua satellites have provided nearly two decades of global fire data. Here, we describe refinements ...made to the 500-m global burned area mapping algorithm that were implemented in late 2016 as part of the MODIS Collection 6 (C6) land-product reprocessing. The updated algorithm improves upon the heritage Collection 5.1 (C5.1) MCD64A1 and MCD45A1 algorithms by offering significantly better detection of small burns, a modest reduction in burn-date temporal uncertainty, and a large reduction in the extent of unmapped areas. Comparison of the C6 and C5.1 MCD64A1 products for fifteen years (2002–2016) on a regional basis shows that the C6 product detects considerably more burned area globally (26%) and in almost every region considered. The sole exception was in Boreal North America, where the mean annual area burned was 6% lower for C6, primarily as a result of a large increase in the number of small lakes mapped (and subsequently masked) at high latitudes in the upstream C6 input data. With respect to temporal reporting accuracy, 44% of the C6 MCD64A1 burned grid cells were detected on the same day as an active fire, and 68% within 2 days, which represents a substantial reduction in temporal uncertainty compared to the C5.1 MCD64A1 and MCD45A1 products. In addition, an areal accuracy assessment of the C6 burned area product undertaken using high resolution burned area reference maps derived from 108 Landsat image pairs is reported.
•We describe the MODIS Collection 6 (C6) MCD64A1 burned area mapping algorithm.•The C6 algorithm improves upon the heritage Collection 5.1 (C5.1) MODIS algorithms.•The C6 algorithm offers significantly better detection of small burns.•The C6 product detects 26% more burned area globally.•We performed a Stage-2 validation of the C5.1 and C6 MCD64A1 products.
The concept of quantum phase transitions (QPTs) plays a central role in the description of condensed matter systems. In this Letter, we perform high-quality wave-function-based simulations to ...demonstrate the existence of a quantum phase transition in a crucially relevant molecular system, namely, water, forming linear chains of rotating molecules. We determine various critical exponents and reveal the water chain QPT to belong to the (1+1)-dimensional Ising universality class. Furthermore, the effect of breaking symmetries is examined, and it is shown that, by breaking the inversion symmetry, the ground state degeneracy of the ordered quantum phase is lifted to yield two many-body states with opposite polarization. The possibility of forming ferroelectric phases together with a thermal stability of the quantum critical regime up to ∼10 K makes the linear water chain a promising candidate as a platform for quantum devices.
The PlanetScope CubeSat constellation is providing unprecedented global coverage, visible to near infrared, atmospherically corrected, 3 m imagery. The revisit interval between successive overpasses ...varies in space and time in a complex manner because of a variety of factors and particularly because of the different sensor orbits. The temporal availability of PlanetScope imagery is quantified in this study considering all of the publicly available images acquired globally for a 12 month period from December 1st 2019 to November 30th 2020. A total of 175.8 million images were acquired by the constellation that was composed of between 100 and 133 unique PlanetScope sensors each month and three sensor generations. The local morning overpass times of the three sensor generations were quantified and the most frequently occurring times were 10:16, 10:29, and 10:03 (to the nearest minute) with 90% of the images acquired with a range of morning overpass times of 2 h and 13 min, 1 h and 30 min, and 1 h and 50 min, for PlanetScope-0, PlanetScope-1, and PlanetScope-2, respectively. Maps, histograms and summary statistics of the total number of observations and revisit intervals are derived with respect to a global grid of 4.7 million land points spaced 5.6 km apart in the equal area sinusoidal projection. The annual and monthly number of PlanetScope observations and average revisit intervals did not vary in a geographically uniform manner. This is due to several factors including the different PlanetScope orbits, seasonal high latitude darkness at the time of sensor overpass, and because of the changing number of sensors on orbit as PlanetScope sensors were decommissioned and later generations became operational over the 12 month study period. In addition, the images in each frame of sensed data are not made available if they cannot be geolocated due to cloud and/or featureless or unstructured terrain precluding ground control matching. The PlanetScope constellation provided higher temporal resolution than provided by sensors such as Landsat-8 or Sentinel-2 although 9% of the global land grid locations, predominantly in the interior of Greenland and non-coastal Antarctica, had no observations. Considering the 12 months of global observations, the median average revisit interval was only 30.3 h, and 9.6%, 71.8%, and 88.4% of the land points had average revisit intervals <24 h, <36 h, and < 48 h, respectively. Globally, the median minimum revisit interval was 25 s and the median maximum revisit interval was 9.15 days; 95.4% of the land grid points had a minimum revisit <180 s, and 89.1% had a maximum revisit <480 h (20 days). The PlanetScope images are labelled as “standard” or as “test” quality based on solar geometry, saturated pixel, and geolocation accuracy criteria. The median annual proportion of observations labelled as “standard” at each land grid point over the 12 months was 78.14%. A global cloud analysis was undertaken to quantify the probability of there being at least one and at least two cloud-free PlanetScope observations within 5, 7 and 10 day consecutive periods. Lower probabilities occurred in cloudy regions and where there were fewer observations. The global mean average probability of there being at least one cloud-free observation over the 12 study months was 0.84, 0.88 and 0.92 for the 5, 7 and 10 day periods respectively. The global mean average probability of there being at least two cloud-free observations was 0.65, 0.76 and 0.84 for the 5, 7 and 10 day periods respectively. The probabilities varied seasonally and the northern hemisphere winter (December–February) and spring (March–May) had lower and higher global mean average seasonal probabilities, respectively, than those derived over the 12 months. The high temporal global coverage provided by the PlanetScope constellation will benefit new applications in particular those concerned with assessment of rapidly changing phenomena and assessment of phenomena that cannot be resolved at moderate and coarse resolution.
•PlanetScope temporal characteristics quantified, global, 12 months, 175.8 million images•30.3 h global median average revisit interval•25 s and 9.15 day global median minimum and maximum revisit intervals•71.8% of land acquired with <36 h average revisit interval•local overpass times different among the 3 PlanetScope generations
CONTEXT: The variation in spatial distribution between ecosystem services can be high. Hence, there is a need to spatially identify important sites for conservation planning. The term ‘ecosystem ...service hotspot’ has often been used for this purpose, but definitions of this term are ambiguous. OBJECTIVES: We review and classify methods to spatially delineate hotspots. We test how spatial configuration of hotspots for a set of ecosystem services differs depending on the applied method. We compare the outcomes to a heuristic site prioritisation approach (Marxan). METHODS: The four tested hotspot methods are top richest cells, spatial clustering, intensity, and richness. In a conservation scenario we set a target of conserving 10 % of the quantity of five regulating and cultural services for the forest area of Telemark county, Norway. RESULTS: Spatial configuration of selected areas as retrieved by the four hotspots and Marxan differed considerably. Pairwise comparisons were at the lower end of the scale of the Kappa statistic (0.11–0.27). The outcomes also differed considerably in mean target achievement, cost-effectiveness in terms of land-area needed per unit target achievement and compactness in terms of edge-to-area ratio. CONCLUSIONS: An ecosystem service hotspot can refer to either areas containing high values of one service or areas with multiple services. Differences in spatial configuration among hotspot methods can lead to uncertainties for decision-making. This also has consequences for analysing the spatial co-occurrence of hotspots of multiple services and of services and biodiversity.
The population of the medicinal plant, Malabar nut (Justicia adhatoda L.) is shrinking in Dun valley due to habitat fragmentation, invasion by Lantana camara, over-exploitation, and an ...ever-increasing human population – the most important being the increasing demand on land for agriculture, industries and the urbanization. Predicting potential geographic distribution of the species is important from species and habitat restoration point of view. This paper reports the results of a study carried out in the Lesser Himalayan foothills in India (Dun valley) on potential distribution modeling for Malabar nut using Maxent model. The Worldclim bioclimatic variables, slope, aspect, elevation, and the land use/land cover (based on IRS LISS-III) data and 46 spatially well-dispersed species occurrence points were used to predict the potential distribution of J. adhatoda in ca. 1877km2 study area. Jackknife test was used to evaluate the importance of the environmental variables for predictive modeling. Maxent model was highly accurate with a statistically significant AUC value of 92.3. The approach could be promising in predicting the potential distribution of medicinal plant species and thus, can be an effective tool in species restoration and conservation planning.
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