210 research outputs found
Land Use And Land Cover Classification And Change Detection Using Naip Imagery From 2009 To 2014: Table Rock Lake Region, Missouri
Land use and land cover (LULC) of Table Rock Lake (TRL) region has changed over the last half century after the construction of Table Rock Dam in 1959. This study uses one meter spatial resolution imagery to classify and detect the change of LULC of three typical waterside TRL regions. The main objectives are to provide an efficient and reliable classification workflow for regional level NAIP aerial imagery and identify the dynamic patterns for study areas. Seven class types are extracted by optimal classification results from year 2009, 2010, 2012 and 2014 of Table Rock Village, Kimberling City and Indian Point. Pixel-based post-classification comparison generated from-to” confusion matrices showing the detailed change patterns. I conclude that object-based random trees achieve the highest overall accuracy and kappa value, compared with the other six classification approaches, and is efficient to make a LULC classification map. Major change patterns are that vegetation, including trees and grass, increased during the last five years period while residential extension and urbanization process is not obvious to indicate high economic development in the TRL region. By adding auxiliary spatial information and object-based post-classification techniques, an improved classification procedure can be utilized for LULC change detection projects at the region level
A Multilevel Method for Many-Electron Schr\"{o}dinger Equations Based on the Atomic Cluster Expansion
The atomic cluster expansion (ACE) (Drautz, 2019) yields a highly efficient
and intepretable parameterisation of symmetric polynomials that has achieved
great success in modelling properties of many-particle systems. In the present
work we extend the practical applicability of the ACE framework to the
computation of many-electron wave functions. To that end, we develop a
customized variational Monte-Carlo algorithm that exploits the sparsity and
hierarchical properties of ACE wave functions. We demonstrate the feasibility
on a range of proof-of-concept applications to one-dimensional systems
Pre-train, Adapt and Detect: Multi-Task Adapter Tuning for Camouflaged Object Detection
Camouflaged object detection (COD), aiming to segment camouflaged objects
which exhibit similar patterns with the background, is a challenging task. Most
existing works are dedicated to establishing specialized modules to identify
camouflaged objects with complete and fine details, while the boundary can not
be well located for the lack of object-related semantics. In this paper, we
propose a novel ``pre-train, adapt and detect" paradigm to detect camouflaged
objects. By introducing a large pre-trained model, abundant knowledge learned
from massive multi-modal data can be directly transferred to COD. A lightweight
parallel adapter is inserted to adjust the features suitable for the downstream
COD task. Extensive experiments on four challenging benchmark datasets
demonstrate that our method outperforms existing state-of-the-art COD models by
large margins. Moreover, we design a multi-task learning scheme for tuning the
adapter to exploit the shareable knowledge across different semantic classes.
Comprehensive experimental results showed that the generalization ability of
our model can be substantially improved with multi-task adapter initialization
on source tasks and multi-task adaptation on target tasks
Germanium-lead perovskite light-emitting diodes.
Reducing environmental impact is a key challenge for perovskite optoelectronics, as most high-performance devices are based on potentially toxic lead-halide perovskites. For photovoltaic solar cells, tin-lead (Sn-Pb) perovskite materials provide a promising solution for reducing toxicity. However, Sn-Pb perovskites typically exhibit low luminescence efficiencies, and are not ideal for light-emitting applications. Here we demonstrate highly luminescent germanium-lead (Ge-Pb) perovskite films with photoluminescence quantum efficiencies (PLQEs) of up to ~71%, showing a considerable relative improvement of ~34% over similarly prepared Ge-free, Pb-based perovskite films. In our initial demonstration of Ge-Pb perovskite LEDs, we achieve external quantum efficiencies (EQEs) of up to ~13.1% at high brightness (~1900 cd m-2), a step forward for reduced-toxicity perovskite LEDs. Our findings offer a new solution for developing eco-friendly light-emitting technologies based on perovskite semiconductors
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