scholarly journals A Parallel Method for Open Hole Filling in Large-Scale 3D Automatic Modeling Based on Oblique Photography

2021 ◽  
Vol 13 (17) ◽  
pp. 3512
Author(s):  
Fei Wang ◽  
Zhendong Liu ◽  
Hongchun Zhu ◽  
Pengda Wu
Keyword(s):  
Success Rate ◽  
Large Scale ◽  
Hole Filling ◽  
Memory Consumption ◽  
Large Area ◽  
Parallel Method ◽  
Automatic Modeling ◽  
Open Hole ◽  
Topological Closure ◽  
Filling Method

Common methods of filling open holes first reaggregate them into closed holes and then use a closed hole filling method to repair them. These methods have problems such as long calculation times, high memory consumption, and difficulties in filling large-area open holes. Hence, this paper proposes a parallel method for open hole filling in large-scale 3D automatic modeling. First, open holes are automatically identified and divided into two categories (internal and external). Second, the hierarchical relationships between the open holes are calculated in accordance with the adjacency relationships between partitioning cells, and the open holes are filled through propagation from the outer level to the inner level with topological closure and height projection transformation. Finally, the common boundaries between adjacent open holes are smoothed based on the Laplacian algorithm to achieve natural transitions between partitioning cells. Oblique photography data from an area of 28 km2 in Dongying, Shandong, were used for validation. The experimental results reveal the following: (i) Compared to the Han method, the proposed approach has a 12.4% higher filling success rate for internal open holes and increases the filling success rate for external open holes from 0% to 100%. (ii) Concerning filling efficiency, the Han method can achieve hole filling only in a small area, whereas with the proposed method, the size of the reconstruction area is not restricted. The time and memory consumption are improved by factors of approximately 4–5 and 7–21, respectively. (iii) In terms of filling accuracy, the two methods are basically the same.

scholarly journals Rapid Single Image-Based DTM Estimation from ExoMars TGO CaSSIS Images Using Generative Adversarial U-Nets

2021 ◽  
Vol 13 (15) ◽  
pp. 2877
Author(s):  
Yu Tao ◽  
Siting Xiong ◽  
Susan J. Conway ◽  
Jan-Peter Muller ◽  
Anthony Guimpier ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Imaging System ◽  
Landing Site ◽  
Parameter Tuning ◽  
Processing Parameters ◽  
Input Image ◽  
Large Area ◽  
Laser Altimeter ◽  
Imaging Science

The lack of adequate stereo coverage and where available, lengthy processing time, various artefacts, and unsatisfactory quality and complexity of automating the selection of the best set of processing parameters, have long been big barriers for large-area planetary 3D mapping. In this paper, we propose a deep learning-based solution, called MADNet (Multi-scale generative Adversarial u-net with Dense convolutional and up-projection blocks), that avoids or resolves all of the above issues. We demonstrate the wide applicability of this technique with the ExoMars Trace Gas Orbiter Colour and Stereo Surface Imaging System (CaSSIS) 4.6 m/pixel images on Mars. Only a single input image and a coarse global 3D reference are required, without knowing any camera models or imaging parameters, to produce high-quality and high-resolution full-strip Digital Terrain Models (DTMs) in a few seconds. In this paper, we discuss technical details of the MADNet system and provide detailed comparisons and assessments of the results. The resultant MADNet 8 m/pixel CaSSIS DTMs are qualitatively very similar to the 1 m/pixel HiRISE DTMs. The resultant MADNet CaSSIS DTMs display excellent agreement with nested Mars Reconnaissance Orbiter Context Camera (CTX), Mars Express’s High-Resolution Stereo Camera (HRSC), and Mars Orbiter Laser Altimeter (MOLA) DTMs at large-scale, and meanwhile, show fairly good correlation with the High-Resolution Imaging Science Experiment (HiRISE) DTMs for fine-scale details. In addition, we show how MADNet outperforms traditional photogrammetric methods, both on speed and quality, for other datasets like HRSC, CTX, and HiRISE, without any parameter tuning or re-training of the model. We demonstrate the results for Oxia Planum (the landing site of the European Space Agency’s Rosalind Franklin ExoMars rover 2023) and a couple of sites of high scientific interest.

Disocclusion-type aware hole filling method for view synthesis

2021 ◽  
Author(s):  
Xiaodong Chen ◽  
Haitao Liang ◽  
Huaiyuan Xu ◽  
Siyu Ren ◽  
Huaiyu Cai ◽  
...  
Keyword(s):  
View Synthesis ◽  
Hole Filling ◽  
Filling Method

scholarly journals Efficient and large-area all vacuum-deposited perovskite light-emitting diodes via spatial confinement

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peipei Du ◽  
Jinghui Li ◽  
Liang Wang ◽  
Liang Sun ◽  
Xi Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Scale Production ◽  
Nonradiative Recombination ◽  
Large Area ◽  
Spatial Confinement ◽  
Light Emitting ◽  
Large Scale Production

AbstractWith rapid advances of perovskite light-emitting diodes (PeLEDs), the large-scale fabrication of patterned PeLEDs towards display panels is of increasing importance. However, most state-of-the-art PeLEDs are fabricated by solution-processed techniques, which are difficult to simultaneously achieve high-resolution pixels and large-scale production. To this end, we construct efficient CsPbBr3 PeLEDs employing a vacuum deposition technique, which has been demonstrated as the most successful route for commercial organic LED displays. By carefully controlling the strength of the spatial confinement in CsPbBr3 film, its radiative recombination is greatly enhanced while the nonradiative recombination is suppressed. As a result, the external quantum efficiency (EQE) of thermally evaporated PeLED reaches 8.0%, a record for vacuum processed PeLEDs. Benefitting from the excellent uniformity and scalability of the thermal evaporation, we demonstrate PeLED with a functional area up to 40.2 cm2 and a peak EQE of 7.1%, representing one of the most efficient large-area PeLEDs. We further achieve high-resolution patterned perovskite film with 100 μm pixels using fine metal masks, laying the foundation for potential display applications. We believe the strategy of confinement strength regulation in thermally evaporated perovskites provides an effective way to process high-efficiency and large-area PeLEDs towards commercial display panels.

Pattern Writing by Implantation in a Large-Scale PSII System With Planar Inductively Coupled Plasma Source

2000 ◽  
Vol 624 ◽  
Author(s):  
Lingling Wu ◽  
Hongjun Gao ◽  
Dennis M. Manos
Keyword(s):  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Lateral Diffusion ◽  
Plasma Source ◽  
Direct Writing ◽  
Large Area ◽  
Depth Profiles ◽  
Geometric Patterns ◽  
Planar Coil ◽  
Rf Antenna

ABSTRACTA large-scale plasma source immersion ion implantation (PSII) system with planar coil RFI plasma source has been used to study an inkless, deposition-free, mask-based surface conversion patterning as an alternative to direct writing techniques on large-area substrates by implantation. The apparatus has a 0.61 m ID and 0.51 m tall chamber, with a base pressure in the 10−8 Torr range, making it one of the largest PSII presently available. The system uses a 0.43 m ID planar rf antenna to produce dense plasma capable of large-area, uniform materials treatment. Metallic and semiconductor samples have been implanted through masks to produce small geometric patterns of interest for device manufacturing. Si gratings were also implanted to study application to smaller features. Samples are characterized by AES, TEM and variable-angle spectroscopic ellipsometry. Composition depth profiles obtained by AES and VASE are compared. Measured lateral and depth profiles are compared to the mask features to assess lateral diffusion, pattern transfer fidelity, and wall-effects. The paper also presents the results of MAGIC calculations of the flux and angle of ion trajectories through the boundary layer predicting the magnitude of flux as a function of 3-D location on objects in the expanding sheath

Large-Scale Parallel Method of Moments on CPU/MIC Heterogeneous Clusters

2017 ◽  
Vol 65 (7) ◽  
pp. 3782-3787 ◽  
Author(s):  
Yan Chen ◽  
Sheng Zuo ◽  
Yu Zhang ◽  
Xunwang Zhao ◽  
Huanhuan Zhang
Keyword(s):  
Method Of Moments ◽  
Large Scale ◽  
Parallel Method ◽  
Heterogeneous Clusters

scholarly journals Comparison of Three Different Parallel Computation Methods for a Two-Dimensional Dam-Break Model

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Shanghong Zhang ◽  
Wenda Li ◽  
Zhu Jing ◽  
Yujun Yi ◽  
Yong Zhao
Keyword(s):  
Parallel Computation ◽  
Data Exchange ◽  
Large Scale ◽  
Good Choice ◽  
Dam Break ◽  
Two Dimensional ◽  
Parallel Method ◽  
Parallel Methods ◽  
Storage Area ◽  
Speedup Factor

Three parallel methods (OpenMP, MPI, and OpenACC) are evaluated for the computation of a two-dimensional dam-break model using the explicit finite volume method. A dam-break event in the Pangtoupao flood storage area in China is selected as a case study to demonstrate the key technologies for implementing parallel computation. The subsequent acceleration of the methods is also evaluated. The simulation results show that the OpenMP and MPI parallel methods achieve a speedup factor of 9.8× and 5.1×, respectively, on a 32-core computer, whereas the OpenACC parallel method achieves a speedup factor of 20.7× on NVIDIA Tesla K20c graphics card. The results show that if the memory required by the dam-break simulation does not exceed the memory capacity of a single computer, the OpenMP parallel method is a good choice. Moreover, if GPU acceleration is used, the acceleration of the OpenACC parallel method is the best. Finally, the MPI parallel method is suitable for a model that requires little data exchange and large-scale calculation. This study compares the efficiency and methodology of accelerating algorithms for a dam-break model and can also be used as a reference for selecting the best acceleration method for a similar hydrodynamic model.

CSMC

2021 ◽  
Vol 5 (4) ◽  
pp. 1-22
Author(s):  
Hai Wang ◽  
Baoshen Guo ◽  
Shuai Wang ◽  
Tian He ◽  
Desheng Zhang
Keyword(s):  
Large Scale ◽  
Mobile Network ◽  
Signal Propagation ◽  
Spectrum Management ◽  
External Information ◽  
Temporal Uncertainty ◽  
Large Area ◽  
Fine Grained ◽  
Map Construction ◽  
Spatio Temporal

The rise concern about mobile communication performance has driven the growing demand for the construction of mobile network signal maps which are widely utilized in network monitoring, spectrum management, and indoor/outdoor localization. Existing studies such as time-consuming and labor-intensive site surveys are difficult to maintain an update-to-date finegrained signal map within a large area. The mobile crowdsensing (MCS) paradigm is a promising approach for building signal maps because collecting large-scale MCS data is low-cost and with little extra-efforts. However, the dynamic environment and the mobility of the crowd cause spatio-temporal uncertainty and sparsity of MCS. In this work, we leverage MCS as an opportunity to conduct the city-wide mobile network signal map construction. We propose a fine-grained city-wide Cellular Signal Map Construction (CSMC) framework to address two challenges including (i) the problem of missing and unreliable MCS data; (ii) spatio-temporal uncertainty of signal propagation. In particular, CSMC captures spatio-temporal characteristics of signals from both inter- and intra- cellular base stations and conducts missing signal recovery with Bayesian tensor decomposition to build large-area fine-grained signal maps. Furthermore, CSMC develops a context-aware multi-view fusion network to make full use of external information and enhance signal map construction accuracy. To evaluate the performance of CSMC, we conduct extensive experiments and ablation studies on a large-scale dataset with over 200GB MCS signal records collected from Shanghai. Experimental results demonstrate that our model outperforms state-of-the-art baselines in the accuracy of signal estimation and user localization.

Fabrication of large area nanogap electrodes for sensing applications

2013 ◽  
Vol 1530 ◽  
Author(s):  
A. Bendavid ◽  
L. Wieczorek ◽  
R. Chai ◽  
J. S. Cooper ◽  
B. Raguse
Keyword(s):  
Large Scale ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Current ◽  
Fabrication Method ◽  
Large Area ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Lift Off ◽  
Nanogap Electrodes

ABSTRACTA large area nanogap electrode fabrication method combinig conventional lithography patterning with the of focused ion beam (FIB) is presented. Lithography and a lift-off process were used to pattern 50 nm thick platinum pads having an area of 300 μm × 300 μm. A range of 30-300 nm wide nanogaps (length from 300 μm to 10 mm ) were then etched using an FIB of Ga+ at an acceleration voltage of 30 kV at various beam currents. An investigation of Ga+ beam current ranging between 1-50 pA was undertaken to optimise the process for the current fabrication method. In this study, we used Monte Carlo simulation to calculate the damage depth in various materials by the Ga+. Calculation of the recoil cascades of the substrate atoms are also presented. The nanogap electrodes fabricated in this study were found to have empty gap resistances exceeding several hundred MΩ. A comparison of the gap length versus electrical resistance on glass substrates is presented. The results thus outline some important issues in low-conductance measurements. The proposed nanogap fabrication method can be extended to various sensor applications, such as chemical sensing, that employ the nanogap platform. This method may be used as a prototype technique for large-scale fabrication due to its simple, fast and reliable features.

scholarly journals Design and Demonstration of Large Scale Cu2O Photocathodes with Metal Grid Structure for Photoelectrochemical Water Splitting

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7422
Author(s):  
Min-Kyu Son
Keyword(s):  
Water Splitting ◽  
Large Scale ◽  
Grid Structure ◽  
Large Area ◽  
Intrinsic Conductivity ◽  
Metal Grid ◽  
Splitting System ◽  
Insight Into ◽  
Better Than

Upscaling of photoelectrode for a practical photoelectrochemical (PEC) water splitting system is still challenging because the PEC performance of large-scale photoelectrode is significantly low, compared to the lab scale photoelectrode. In an effort to overcome this challenge, sputtered gold (Au) and copper (Cu) grid lines were introduced to improve the PEC performance of large-scale cuprous oxide (Cu2O) photocathode in this work. It was demonstrated that Cu grid lines are more effective than Au grid lines to improve the PEC performance of large-scale Cu2O photocathode because its intrinsic conductivity and quality of grid lines are better than ones containing Au grid lines. As a result, the PEC performance of a 25-cm2 scaled Cu2O photocathode with Cu grid lines was almost double than one without grid lines, resulting in an improved charge transport in the large area substrate by Cu grid lines. Finally, a 50-cm2 scaled Cu2O photocathode with Cu grid lines was tested in an outdoor condition under natural sun. This is the first outdoor PEC demonstration of large-scale Cu2O photocathode with Cu grid lines, which gives insight into the development of efficient upscaled PEC photoelectrode.

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