density model
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2021 ◽  
Author(s):  
Huijun Le ◽  
Tingwei Han ◽  
Libo Liu ◽  
Yiding Chen ◽  
Hui Zhang

2021 ◽  
Author(s):  
Huijun Le ◽  
Tingwei Han ◽  
Libo Liu ◽  
Yiding Chen ◽  
Hui Zhang

2021 ◽  
Vol 72 (6) ◽  
Author(s):  
Dominika Godová ◽  
Miroslav Bielik ◽  
Pavla Hrubcová ◽  
Barbora Šimonová ◽  
Jana Dérerová ◽  
...  

2021 ◽  
Vol 3 (3) ◽  
pp. 345-386
Author(s):  
Oleg V. Lepski ◽  
Gilles Rebelles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fernando R. Tortato ◽  
Rafael Hoogesteijn ◽  
Allison L. Devlin ◽  
Howard B. Quigley ◽  
Fábio Bolzan ◽  
...  

AbstractConservation of carnivores involves finding solutions to minimize habitat loss and human-wildlife conflict. Understanding the nature of land-use economics can allow us to mitigate both threats. In the Pantanal, the two main economic activities are cattle ranching and ecotourism, each of which directly and indirectly affect the persistence of jaguars (Panthera onca). To understand how the geography of these economic activities is related to jaguar populations, we developed a jaguar distribution model (JDM), livestock density model, and ecotourism lodge density model for the Pantanal. Due to the recent wildfires within the Pantanal, we also assess the impact of burnt areas that are suitable for jaguars, cattle ranching, and tourism. Our JDM indicate that 64% of the Pantanal holds suitable habitat for jaguars. However, jaguar habitat suitability was positively correlated with ecotourism, but negatively correlated with areas most suitable for intensive cattle-ranching. This demonstrates a biome-wide scenario compatible with jaguar conservation. Of particular concern, recent wildfires overlap most suitable areas for jaguars. If wildfires become increasingly frequent, this would represent a serious threat to jaguars and many other wildlife populations. We emphasize the global importance of the Pantanal wetland ecoregion as a key stronghold for long-term jaguar conservation.


Author(s):  
M Mainul Hoque ◽  
Norbert Jakowski ◽  
Fabricio S. Prol

The ionosphere is the ionized part of the Earth atmosphere, ranging from about 60 km up to several Earth radii whereas the upper part above about 1000 km height up to the plasmapause is usually called the plasmasphere. We present a new three-dimensional electron density model aiming for supporting space weather services and mitigation of propagation errors for trans-ionospheric signals. The model is developed by superposing the Neustrelitz Plasmasphere Model (NPSM) to an ionosphere model composed of separate F and E-layer distributions. It uses the Neustrelitz TEC model (NTCM), Neustrelitz Peak Density Model (NPDM) and the Neustrelitz Peak Height Model (NPHM) for the total electron content (TEC), peak ionization and peak height information. These models describe the spatial and temporal variability of the key parameters as function of local time, geographic/geomagnetic location, solar irradiation and activity. The model is particularly developed to calculate the electron concentration at any given location and time in the ionosphere for trans-ionospheric applications and named as the Neustrelitz Electron Density Model (NEDM2020). A comprehensive validation study is conducted against electron density in-situ data from DMSP and Swarm, Van Allen Probes and ICON missions, and topside TEC data from COSMIC/FORMOSAT-3 mission, bottom side TEC data from TOPEX/Poseidon mission and ground-based TEC data from International GNSS Service (IGS) covering both high and low solar activity conditions. Additionally, the model performance is compared with the 3D electron density model NeQuick2. Our investigation shows that the NEDM2020 performs better than the NeQuick2 when compared with the in-situ data from Van Allen Probes and ICON satellites and TEC data from COSMIC and TOPEX/Poseidon missions. When compared with DMSP and IGS TEC data both NEDM2020 and NeQuick2 perform very similarly.


Space Weather ◽  
2021 ◽  
Author(s):  
Daniel R. Weimer ◽  
W. Kent Tobiska ◽  
Piyush M. Mehta ◽  
R. J. Licata ◽  
Douglas P. Drob ◽  
...  

Author(s):  
Lina Fu ◽  
Jie Fang ◽  
Yunjie Lyu ◽  
Huahui Xie

Freeway control has been increasingly used as an innovative approach to ease traffic congestion, improve traffic safety and reduce exhaust emissions. As an important predictive model involved in freeway control, the predictive performance of METANET greatly influences the effect of freeway control. This paper focuses on modifying the METANET model by modeling the critical density. Firstly, the critical density model is deduced based on the catastrophe theory. Then, the perturbation wave and traveling wave that are obtained using the macro and micro data, respectively, have been developed to modify the above proposed critical density model. Finally, the numerical simulation is established to evaluate the effectiveness of the modified METANET model based on the field data from the realistic motorway network. The results show that overall, the predicted data from the modified METANET model are closer to the field data than those obtained from the original model.


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