scholarly journals Forecasting and identifying the meteorological and hydrological conditions favoring the occurrence of severe hazes in Beijing and Shanghai using deep learning

2021 ◽  
Vol 21 (17) ◽  
pp. 13149-13166
Author(s):  
Chien Wang
Keyword(s):  
Atmospheric Aerosols ◽  
Weather Conditions ◽  
Deep Convolutional Neural Networks ◽  
Forecasting Accuracy ◽  
Hydrological Conditions ◽  
Low Visibility ◽  
Overall Performance ◽  
First Time ◽  
Unsupervised Cluster Analysis ◽  
Hydrological Regimes

Abstract. Severe haze or low-visibility events caused by abundant atmospheric aerosols have become a serious environmental issue in many countries. A framework based on deep convolutional neural networks containing more than 20 million parameters called HazeNet has been developed to forecast the occurrence of such events in two Asian megacities: Beijing and Shanghai. Trained using time-sequential regional maps of up to 16 meteorological and hydrological variables alongside surface visibility data over the past 41 years, the machine has achieved a good overall performance in identifying haze versus non-haze events, and thus their respective favorable meteorological and hydrological conditions, with a validation accuracy of 80 % in both the Beijing and Shanghai cases, exceeding the frequency of non-haze events or no-skill forecasting accuracy, and an F1 score specifically for haze events of nearly 0.5. Its performance is clearly better during months with high haze frequency, i.e., all months except dusty April and May in Beijing and from late autumn through all of winter in Shanghai. Certain valuable knowledge has also obtained from the training, such as the sensitivity of the machine's performance to the spatial scale of feature patterns, that could benefit future applications using meteorological and hydrological data. Furthermore, an unsupervised cluster analysis using features with a greatly reduced dimensionality produced by the trained HazeNet has, arguably for the first time, successfully categorized typical regional meteorological–hydrological regimes alongside local quantities associated with haze and non-haze events in the two targeted cities, providing substantial insights to advance our understandings of this environmental extreme. Interesting similarities in associated weather and hydrological regimes between haze and false alarm clusters or differences between haze and missing forecasting clusters have also been revealed, implying that factors, such as energy-consumption variation and long-range aerosol transport, could also influence the occurrence of hazes, even under unfavorable weather conditions.

scholarly journals Forecasting and Identifying the Meteorological and Hydrological Conditions Favoring the Occurrence of Severe Hazes in Beijing and Shanghai using Deep Learning

2021 ◽  
Author(s):  
Chien Wang
Keyword(s):  
Atmospheric Aerosols ◽  
Environmental Issue ◽  
Deep Convolutional Neural Networks ◽  
Hydrological Conditions ◽  
The Past ◽  
Low Visibility ◽  
First Time ◽  
Unsupervised Cluster Analysis ◽  
Hydrological Variables ◽  
Hydrological Regimes

Abstract. Severe haze or low visibility event caused by abundant atmospheric aerosols has become a serious environmental issue in many countries. A framework based on deep convolutional neural networks has been developed to forecast the occurrence of such events in two Asian megacities: Beijing and Shanghai. Trained using time sequential regional maps of meteorological and hydrological variables alongside surface visibility data over the past 41 years, the machine has achieved a good overall accuracy in associating the haze events with favorite meteorological and hydrological conditions. Furthermore, an unsupervised cluster analysis using features with a greatly reduced dimensionality produced by the trained machine has, arguably for the first time, successfully categorized typical regional meteorological-hydrological regimes alongside local quantities associated with haze and non-haze events in the two targeted cities, providing substantial insights to advance our understandings of this environmental extreme.

scholarly journals Cloud icing by mineral dust and impacts to aviation safety

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Slobodan Nickovic ◽  
Bojan Cvetkovic ◽  
Slavko Petković ◽  
Vassilis Amiridis ◽  
Goran Pejanović ◽  
...  
Keyword(s):  
Mineral Dust ◽  
Weather Conditions ◽  
Ice Nucleation ◽  
Aircraft Accidents ◽  
Ice Nuclei ◽  
Loss And Damage ◽  
Cloud Ice ◽  
Convective Weather ◽  
First Time ◽  
Engine Power

AbstractIce particles in high-altitude cold clouds can obstruct aircraft functioning. Over the last 20 years, there have been more than 150 recorded cases with engine power-loss and damage caused by tiny cloud ice crystals, which are difficult to detect with aircraft radars. Herein, we examine two aircraft accidents for which icing linked to convective weather conditions has been officially reported as the most likely reason for catastrophic consequences. We analyze whether desert mineral dust, known to be very efficient ice nuclei and present along both aircraft routes, could further augment the icing process. Using numerical simulations performed by a coupled atmosphere-dust model with an included parameterization for ice nucleation triggered by dust aerosols, we show that the predicted ice particle number sharply increases at approximate locations and times of accidents where desert dust was brought by convective circulation to the upper troposphere. We propose a new icing parameter which, unlike existing icing indices, for the first time includes in its calculation the predicted dust concentration. This study opens up the opportunity to use integrated atmospheric-dust forecasts as warnings for ice formation enhanced by mineral dust presence.

Multimodal biometric system using deep learning based on face and finger vein fusion

2021 ◽  
pp. 1-13
Author(s):  
Shikhar Tyagi ◽  
Bhavya Chawla ◽  
Rupav Jain ◽  
Smriti Srivastava
Keyword(s):  
High Performance ◽  
Recognition Accuracy ◽  
Error Rates ◽  
Facial Features ◽  
Biometric System ◽  
Deep Convolutional Neural Networks ◽  
Finger Vein ◽  
Biometric Systems ◽  
Overall Performance ◽  
Recognition Systems

Single biometric modalities like facial features and vein patterns despite being reliable characteristics show limitations that restrict them from offering high performance and robustness. Multimodal biometric systems have gained interest due to their ability to overcome the inherent limitations of the underlying single biometric modalities and generally have been shown to improve the overall performance for identification and recognition purposes. This paper proposes highly accurate and robust multimodal biometric identification as well as recognition systems based on fusion of face and finger vein modalities. The feature extraction for both face and finger vein is carried out by exploiting deep convolutional neural networks. The fusion process involves combining the extracted relevant features from the two modalities at score level. The experimental results over all considered public databases show a significant improvement in terms of identification and recognition accuracy as well as equal error rates.

To bee or not to beet with neonicotinoids

2021 ◽  
Vol 23 (2) ◽  
pp. 103-109
Author(s):  
Lynda M. Warren
Keyword(s):  
Sugar Beet ◽  
Weather Conditions ◽  
The European Union ◽  
Environmental Standards ◽  
Economic Interests ◽  
Precautionary Approach ◽  
The United Kingdom ◽  
Commercial Sugar ◽  
The Uk ◽  
First Time

In January 2021 the UK government granted an application for authorisation to use thiamethoxam, a neonicotinoid pesticide, to protect commercial sugar beet crops from attack by viruses transmitted by aphids. This was the first time such an authorisation had been granted in the United Kingdom (UK) and there were concerns that it signalled a weakening of environmental standards now that the UK was no longer part of the European Union. In fact, similar authorisations had been granted by several European Member States in the last 2 years, despite the ban on the use of neonicotinoids introduced in 2018. Nevertheless, the reasons for granting the authorisation do suggest that the balance between adopting a precautionary approach to environmental protection and taking emergency action to protect economic interests may have shifted. It was acknowledged that the proposed mitigation to safeguard bees and other wildlife was not entirely satisfactory. In the end, due to unforeseen weather conditions it meant that the pesticide is not necessary, which in itself demonstrates that short-term emergency measures are unsuitable for dealing with the problem. If the sugar beet industry is to continue to prosper in the UK, it will need to be managed in a way that provides resistance to virus infection without the use of controversial chemicals.

scholarly journals Dynamics of the abundance of cuckoo wasps (Hymenoptera, Chrysididae) in the conditions of the altitudinal-belt heterogeneity of the North Caucasus

2021 ◽  
Vol 35 ◽  
pp. 00023
Author(s):  
Nikolay Vinokurov
Keyword(s):  
Population Dynamics ◽  
New Species ◽  
Weather Conditions ◽  
Nature Management ◽  
North Caucasus ◽  
Protection Measures ◽  
Altitudinal Belt ◽  
The North ◽  
Short Period ◽  
First Time

The work provides data on the dynamics of the abundance of 205 taxa from 19 genera: Cleptes, Colpopyga, Elampus, Omalus, Philoctetes, Pseudomalus, Hedychridium, Hedychrum, Holopyga, Chrysidea, Chrysis, Euchroeus, Chrysura, Pseudochrysis, Spinolia, Spinolia, including species rare and new for the fauna of the North Caucasus and Russia. By the nature of the population dynamics, five groups of cuckoo wasps were identified: spring – represented by 7 species from 4 genera; spring-summer – 76 species from 10 genera; summer – 113 species from 16 genera; summer-autumn – 4 species from 2 genera and spring-summer-autumn – 5 species from 3 genus. According to the duration of flight, eurychronous species of cuckoo wasps were identified, which are found throughout the season from spring to autumn; mesochronous – the years of which affect the end of May and summer months and stenochronous – confined to a short period of time. Eurychronic accounted for 2.4%, mesochronous 24.9%, stenochronic 72.7%. The number of generations of cuckoo wasps is related to the dynamics of the number of the host. In the mountains, the peaks of activity shift towards the middle of summer, most species have one peak of activity; due to the frequent changes in weather conditions in the mountains, the phenological characteristics of the cuckoo wasps and their hosts do not coincide in terms with the lowland populations and the periods of activity can be extended in time. Phenological characteristics of rare and new species for the fauna of the North Caucasus and Russia are presented for the first time. The data obtained expand the understanding of the biodiversity and dynamics of the abundance of cuckoo wasps in the North Caucasus and can be used for environmental protection measures and rational nature management in the south of Russia.

Rational design of free-standing 3D porous MXene/rGO hybrid aerogels as polysulfide reservoirs for high-energy lithium–sulfur batteries

2019 ◽  
Vol 7 (11) ◽  
pp. 6507-6513 ◽  
Author(s):  
Jianjun Song ◽  
Xin Guo ◽  
Jinqiang Zhang ◽  
Yi Chen ◽  
Chaoyue Zhang ◽  
...  
Keyword(s):  
Rational Design ◽  
High Energy ◽  
Free Standing ◽  
Shuttle Effect ◽  
Lithium Sulfur Batteries ◽  
Overall Performance ◽  
Hybrid Aerogels ◽  
First Time ◽  
Lithium Sulfur ◽  
Hybrid Aerogel

A Ti3C2Tx MXene/rGO hybrid aerogel is applied for the first time as a free-standing polysulfide reservoir to inhibit the shuttle effect and improve the overall performance of Li–S batteries.

Targeted Agenda Program: An Innovative Approach to Facilitate Progress in Disaster Health

2008 ◽  
Vol 23 (S2) ◽  
pp. s43-s47
Author(s):  
Joost J.L.M. Bierens ◽  
Brigitte Nooij ◽  
Ferd Sturmans
Keyword(s):  
Health Impact Assessment ◽  
Weather Conditions ◽  
Health Impact ◽  
Health Organizations ◽  
Policy Makers ◽  
Expert Opinions ◽  
Golden Standard ◽  
First Time ◽  
Operational Aspects

AbstractThe Targeted Agenda Program (TAP) has been introduced for the first time during the 15th World Congress on Disaster and Emergency Medicine (15WCDEM) in Amsterdam in 2007 to stimulate interaction between the participants before, during and after the congress. A TAP process consists of 11 steps, starting with defining a relevant issue and ending with the publication of a TAP report based on expert opinions. Seven TAP groups participated during the 15WCDEM. The TAP issues referred to: (1) the need for health impact assessment of disasters; (2) the golden standard for preparedness for a chemical, biological, radiological and nuclear disasters; (3) the role of acute psychosocial first aid; (4) the 10 most important issues for policy makers to minimize health effects of floods; (5) the search for a golden standard in the treatment of wounded combatants; (6) the preparedness of health organizations for consequences of extreme weather conditions; and (7) the health problems of high-vulnerability groups during disasters. This article describes the motivation and operational aspects of the TAP and advocates that this concept can play an important facilitating role in focus, networking and enhancement of knowledge in the field of disaster health.

scholarly journals Vehicle Collision Prediction under Reduced Visibility Conditions

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3026 ◽  
Author(s):  
Keng-Pin Chen ◽  
Pao-Ann Hsiung
Keyword(s):  
Communication Systems ◽  
Weather Conditions ◽  
Transportation Systems ◽  
Collision Probability ◽  
Percentage Error ◽  
Collision Warning ◽  
Congested Traffic ◽  
Prediction Horizon ◽  
Low Visibility ◽  
Velocity Prediction

Rear-end collisions often cause serious traffic accidents. Conventionally, in intelligent transportation systems (ITS), radar collision warning methods are highly accurate in determining the inter-vehicle distance via detecting the rear-end of a vehicle; however, in poor weather conditions such as fog, rain, or snow, the accuracy is significantly affected. In recent years, the advent of Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) communication systems has introduced new methods for solving the rear-end collision problem. Nevertheless, there is still much left for improvement. For instance, weather conditions have an impact on human-related factors such as response time. To address the issue of collision detection under low visibility conditions, we propose a Visibility-based Collision Warning System (ViCoWS) design that includes four models for prediction horizon estimation, velocity prediction, headway distance prediction, and rear-end collision warning. Based on the history of velocity data, future velocity volumes are predicted. Then, the prediction horizon (number of future time slots to consider) is estimated corresponding to different weather conditions. ViCoWs can respond in real-time to weather conditions with correct collision avoidance warnings. Experiment results show that the mean absolute percentage error of our velocity prediction model is less than 11%. For non-congested traffic under heavy fog (very low visibility of 120 m), ViCoWS warns a driver by as much as 4.5 s prior to a possible future collision. If the fog is medium with a low visibility of 160 m, ViCoWs can give warnings by about 2.1 s prior to a possible future collision. In contrast, the Forward Collision Probability Index (FCPI) method gives warnings by only about 0.6 s before a future collision. For congested traffic under low visibility conditions, ViCoWS can warn a driver by about 1.9 s prior to a possible future collision. In this case, the FCPI method gives 1.2 s for the driver to react before collision.

Combat at High Altitude: the South African Experience in East Africa, 1941

2020 ◽  
pp. 1-36
Author(s):  
Evert Kleynhans
Keyword(s):  
High Altitude ◽  
East Africa ◽  
South African ◽  
Weather Conditions ◽  
The South ◽  
East African ◽  
African Experience ◽  
Supportive Role ◽  
Difficult Terrain ◽  
First Time

Abstract Mountainous terrain has distinctly influenced combat operations throughout history. Warfare at high altitude often takes place in extreme weather conditions and over difficult terrain, which is largely considered to be inaccessible, inhospitable, and at times lacking any apparent strategic or operational value. As a result, combat operations at high altitudes are traditionally infantry affairs. The South African deployment to East Africa during the Second World War was for the most part characterised by highly mobile operations, across deserts and scrubland, where infantry, armour and artillery deployed in a mutually supportive role. The penultimate battles of the East African campaign were, however, fought in extremely severe terrain, where the South African troops would experience the harsh realities of mountain warfare for the first time during the war. This article broadly investigates the exigencies of mountain warfare, and critically reflects on the South African wartime experience of mountain warfare in East Africa.

Off-axis propagation of a laser beam in low visibility weather conditions

1980 ◽  
Vol 19 (16) ◽  
pp. 2822 ◽  
Author(s):  
W. G. Tam ◽  
A. Zardecki
Keyword(s):  
Laser Beam ◽  
Weather Conditions ◽  
Low Visibility
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