scholarly journals Improving Hydrologic Modeling Using Cloud-Free MODIS Flood Maps

2019 ◽  
Vol 20 (11) ◽  
pp. 2203-2214 ◽  
Author(s):  
Hoang Tran ◽  
Phu Nguyen ◽  
Mohammed Ombadi ◽  
Kuolin Hsu ◽  
Soroosh Sorooshian ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Skill Score ◽  
Hydrologic Model ◽  
Probability Of Detection ◽  
Landsat 8 ◽  
Inundation Maps ◽  
Flood Maps

Abstract Flood mapping from satellites provides large-scale observations of flood events, but cloud obstruction in satellite optical sensors limits its practical usability. In this study, we implemented the Variational Interpolation (VI) algorithm to remove clouds from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) Snow-Covered Area (SCA) products. The VI algorithm estimated states of cloud-hindered pixels by constructing three-dimensional space–time surfaces based on assumptions of snow persistence. The resulting cloud-free flood maps, while maintaining the temporal resolution of the original MODIS product, showed an improvement of nearly 70% in average probability of detection (POD) (from 0.29 to 0.49) when validated with flood maps derived from Landsat-8 imagery. The second part of this study utilized the cloud-free flood maps for calibration of a hydrologic model to improve simulation of flood inundation maps. The results demonstrated the utility of the cloud-free maps, as simulated inundation maps had average POD, false alarm ratio (FAR), and Hanssen–Kuipers (HK) skill score of 0.87, 0.49, and 0.84, respectively, compared to POD, FAR, and HK of 0.70, 0.61, and 0.67 when original maps were used for calibration.

Large- and small-scale vortical motions in a shear layer perturbed by tabs

1999 ◽  
Vol 382 ◽  
pp. 307-329 ◽  
Author(s):  
JUDITH K. FOSS ◽  
K. B. M. Q. ZAMAN
Keyword(s):  
Shear Layer ◽  
Pitch Angle ◽  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Small Scale ◽  
Streamwise Vortices ◽  
Streamwise Vorticity ◽  
Cross Sectional ◽  
Scale Population

The large- and small-scale vortical motions produced by ‘delta tabs’ in a two-stream shear layer have been studied experimentally. An increase in mixing was observed when the base of the triangular shaped tab was affixed to the trailing edge of the splitter plate and the apex was pitched at some angle with respect to the flow axis. Such an arrangement produced a pair of counter-rotating streamwise vortices. Hot-wire measurements detailed the velocity, time-averaged vorticity (Ωx) and small-scale turbulence features in the three-dimensional space downstream of the tabs. The small-scale structures, whose scale corresponds to that of the peak in the dissipation spectrum, were identified and counted using the peak-valley-counting technique. The optimal pitch angle, θ, for a single tab and the optimal spanwise spacing, S, for a multiple tab array were identified. Since the goal was to increase mixing, the optimal tab configuration was determined from two properties of the flow field: (i) the large-scale motions with the maximum Ωx, and (ii) the largest number of small-scale motions in a given time period. The peak streamwise vorticity magnitude [mid ]Ωx−max[mid ] was found to have a unique relationship with the tab pitch angle. Furthermore, for all cases examined, the overall small-scale population was found to correlate directly with [mid ]Ωx−max[mid ]. Both quantities peaked at θ≈±45°. It is interesting to note that the peak magnitude of the corresponding circulation in the cross-sectional plane occurred for θ≈±90°. For an array of tabs, the two quantities also depended on the tab spacing. An array of contiguous tabs acted as a solid deflector producing the weakest streamwise vortices and the least small-scale population. For the measurement range covered, the optimal spacing was found to be S≈1.5 tab widths.

scholarly journals Phosphatidylinositol-4,5-Bisphosphate-Rich Plasma Membrane Patches Organize Active Zones of Endocytosis and Ruffling in Cultured Adipocytes

2004 ◽  
Vol 24 (20) ◽  
pp. 9102-9123 ◽  
Author(s):  
Shaohui Huang ◽  
Larry Lifshitz ◽  
Varsha Patki-Kamath ◽  
Richard Tuft ◽  
Kevin Fogarty ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Large Scale ◽  
Plasma Membranes ◽  
Fluorescent Protein ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Actin Dynamics ◽  
Ph Domain ◽  
Membrane Ruffling ◽  
Green Fluorescent

ABSTRACT A major regulator of endocytosis and cortical F-actin is thought to be phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P2] present in plasma membranes. Here we report that in 3T3-L1 adipocytes, clathrin-coated membrane retrieval and dense concentrations of polymerized actin occur in restricted zones of high endocytic activity. Ultrafast-acquisition and superresolution deconvolution microscopy of cultured adipocytes expressing an enhanced green fluorescent protein- or enhanced cyan fluorescent protein (ECFP)-tagged phospholipase Cδ1 (PLCδ1) pleckstrin homology (PH) domain reveals that these zones spatially coincide with large-scale PtdIns(4,5)P2-rich plasma membrane patches (PRMPs). PRMPs exhibit lateral dimensions exceeding several micrometers, are relatively stationary, and display extensive local membrane folding that concentrates PtdIns(4,5)P2 in three-dimensional space. In addition, a higher concentration of PtdIns(4,5)P2 in the membranes of PRMPs than in other regions of the plasma membrane can be detected by quantitative fluorescence microscopy. Vesicular structures containing both clathrin heavy chains and PtdIns(4,5)P2 are revealed immediately beneath PRMPs, as is dense F actin. Blockade of PtdIns(4,5)P2 function in PRMPs by high expression of the ECFP-tagged PLCδ1 PH domain inhibits transferrin endocytosis and reduces the abundance of cortical F-actin. Membrane ruffles induced by the expression of unconventional myosin 1c were also found to localize at PRMPs. These results are consistent with the hypothesis that PRMPs organize active PtdIns(4,5)P2 signaling zones in the adipocyte plasma membrane that in turn control regulators of endocytosis, actin dynamics, and membrane ruffling.

A method for the identification of trees with unusually colored foliage

1996 ◽  
Vol 26 (9) ◽  
pp. 1548-1555 ◽  
Author(s):  
John L. Innes ◽  
Sucharita Ghosh ◽  
Andreas Schwyzer
Keyword(s):  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Crown Condition ◽  
Normal Expectation ◽  
Three Dimensional Space

A method is presented for recognizing trees with unusually colored foliage, based on the use of Munsell plant color charts. Color assessments are made by scoring the crown of each tree for hue, value, and chroma. These values are plotted in three-dimensional space for each species, and a threshold is identified marking the border of an ellipsoid. Trees with foliage outside this ellipsoid are considered as unusual. The method means that assessments of discoloration can cover a range of colors and moves the decision over the color status of a tree from a subjective field decision to a statistically defined decision at the analytical stage. It takes into account that a tree may still be classified as green (previously classed as without discoloration) when its color of green lies outside the normal expectation for the species. The method represents a significant improvement on the discoloration assessments currently being used in large-scale inventories of crown condition in Europe.

scholarly journals The Group Evacuation Behavior Based on Fire Effect in the Complicated Three-Dimensional Space

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jun Hu ◽  
Huijun Sun ◽  
Ge Gao ◽  
Juan Wei ◽  
Lei You
Keyword(s):  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Target Position ◽  
Velocity Change ◽  
Evacuation Time ◽  
Evacuation Strategy ◽  
Average System ◽  
Evacuation Behavior ◽  
Three Dimensional Space

In order to effectively depict the group evacuation behavior in the complicated three-dimensional space, a novel pedestrian flow model is proposed with three-dimensional cellular automata. In this model the calculation methods of floor field and fire gain are elaborated at first, and the transition gain of target position at the next moment is defined. Then, in consideration of pedestrian intimacy and velocity change, the group evacuation strategy and evolution rules are given. Finally, the experiments were conducted with the simulation platform to study the relationships of evacuation time, pedestrian density, average system velocity, and smoke spreading velocity. The results had shown that large-scale group evacuation should be avoided, and in case of large pedestrian density, the shortest route of evacuation strategy would extend system evacuation time.

ANALYSIS AND SIMULATION OF LONG-RANGE CORRELATIONS IN CURVED SPACE

2009 ◽  
Vol 20 (08) ◽  
pp. 1211-1232 ◽  
Author(s):  
ALI REZA MEHRABI ◽  
MUHAMMAD SAHIMI
Keyword(s):  
Long Range ◽  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Amorphous Semiconductors ◽  
Curved Space ◽  
Long Range Correlations ◽  
Planar Surfaces ◽  
Positively Curved ◽  
Industrial Problem

Numerical simulation and analysis of long-range correlations in curved space are studied. The study is motivated by the problem of constructing accurate models of large-scale porous media which usually contain long-range correlations in their various properties (such as their permeability, porosity, and elastic moduli) within and between their strata that are typically curved layers. The problem is, however, relevant to many other important models and phenomena in which extended correlations in curved space play a prominent role. Examples include the nonlinear σ-model in a curved space, models for describing the long-range structural correlations of amorphous semiconductors that consist of polytopes (tilings of positively-curved three-dimensional space), long-range correlations in the extrapolar total zone, and models in which the Universe is created by bubble nucleations and contain long-range correlations in the fluctuations in the curved spacetime. The study is also relevant to the important industrial problem of designing highly curved objects, such as cars and ships, which use composite materials that contain extended correlations in their property values. We study such correlations along two- and three-dimensional curves, as well as curved surfaces. We show that such correlations are well-defined only on developable surfaces, i.e. those that can be flattened to form planar surfaces without any stretching or distortion, and preserve the distance between two points on such surfaces after the stretching. If a given curved surface is not developable, but can be approximated as piecewise developable, one may still define and analyze extended correlations on it. Representative examples are presented and analyzed.

Large-scale dynamics in turbulent mixing and the three-dimensional space–time behaviour of outer fluid interfaces

2002 ◽  
Vol 471 ◽  
pp. 381-408 ◽  
Author(s):  
HARIS J. CATRAKIS ◽  
ROBERTO C. AGUIRRE ◽  
JESUS RUIZ-PLANCARTE ◽  
ROBERT D. THAYNE ◽  
BRENDA A. McDONALD ◽  
...  
Keyword(s):  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Space Time ◽  
Mixing Efficiency ◽  
Fluid Interfaces ◽  
Ambient Fluid ◽  
Wide Range ◽  
Dimensional Space Time ◽  
Three Dimensional Space

Experiments have been conducted to investigate turbulent mixing and the dynamics of outer fluid interfaces, i.e. the interfaces between mixed fluid and pure ambient fluid. A novel six-foot-diameter octagonal-tank flow facility was developed to enable the optical imaging of fluid interfaces above the mixing transition, corresponding to fully developed turbulence. Approximately 10003 whole-field three-dimensional space– time measurements of the concentration field were recorded using laser-induced- fluorescence digital-imaging techniques in turbulent jets at a Reynolds number of Re ∼ 20 000, Schmidt number of Sc ∼ 2000, and downstream distance of ∼ 500 nozzle diameters. Multiple large-scale regions of spatially nearly uniform-concentration fluid are evident in instantaneous visualizations, in agreement with previous findings above the mixing transition. The ensemble-averaged probability density function of concentration is found to exhibit linear dependence over a wide range of concentration thresholds. This can be accounted for in terms of the dynamics of large-scale well- mixed regions. Visualization of the three-dimensional space–time concentration field indicates that molecular mixing of entrained pure ambient fluid is dynamically initiated and accomplished in the vicinity of the unsteady large scales. Examination of the outer interfaces shows that they are dynamically confined primarily near the instantaneous large-scale boundaries of the flow. This behaviour is quantified in terms of the probability density of the location of the outer interfaces relative to the flow centreline and the probability of pure ambient fluid as a function of distance from the centreline. The current measurements show that the dynamics of outer interfaces above the mixing transition is significantly different from the behaviour below the transition, where previous studies have shown that unmixed ambient fluid can extend across a wide range of transverse locations in the flow interior. The present observations of dynamical confinement of the outer interfaces to the unsteady large scales, and considerations of entrainment, suggest that the mechanism responsible for this behaviour must be the coupling of large-scale flow dynamics with the presence of small-scale structures internal to the large-scale structures, above the mixing transition. The dynamics and structure of the outer interfaces across the entire range of space–time scales are quantified in terms of a distribution of generalized level-crossing scales. The outer-interface behaviour determines the mixing efficiency of the flow, i.e. fraction of mixed fluid. The present findings indicate that the large-scale dynamics of the outer interfaces above the mixing transition provides the dominant contribution to the mixing efficiency. This suggests a new way to quantify the mixing efficiency of turbulent flows at high Reynolds numbers.

scholarly journals Study on Application of Solar Energy in Highway

2021 ◽  
Vol 261 ◽  
pp. 01060
Author(s):  
Jianfu Xu ◽  
Zhiqiang Liu ◽  
Haifeng Jiang
Keyword(s):  
Solar Energy ◽  
Energy Supply ◽  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Clean Energy ◽  
Green Energy ◽  
Solar Photovoltaic ◽  
Supply Network ◽  
Highway Network

In recent years, the construction of large-scale electromechanical facilities and smart roads in the highway network has not only improved the level of operation safety but also generated a huge demand for electric energy, the highway transportation industry has become one of the key energy consumption industries second only to industry and construction. Solar energy has become a kind of green energy that has attracted more and more attention among various new energy sources due to its energy-saving, clean, zero-emission, wide-ranging and safe characteristics. This paper analyzes the distribution of solar photovoltaic resources in China’s highway network; puts forward the solar energy three-dimensional clean energy supply network technology which is suitable for highway scene, fully relying on and optimize the use of road network linear areas such as road surface space, three-dimensional space along the road to develop solar photovoltaic resources. Solar-powered roads, solar photovoltaic slopes, photovoltaic sound barriers, photovoltaic isolation barriers, etc. can be developed along the line, so as to build a three-dimensional road solar clean energy network that combines “points, lines and sections”, so that green and clean energy can be provided to a large number of electricity facilities and equipment along the highway, as well as to surrounding cities and villages, making the highway become the transport network carrying the flow of people and logistics, vehicle-road cooperative intelligent information network and clean energy supply network.

Dynamic Characteristic Analysis of Transmission Tower

2014 ◽  
Vol 494-495 ◽  
pp. 1719-1722
Author(s):  
Xiang Zan Xie ◽  
Ke Lun Wei
Keyword(s):  
Large Scale ◽  
Power Transmission ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Modern Society ◽  
The Finite Element Method ◽  
Transmission Tower ◽  
Characteristic Analysis ◽  
Safety And Reliability ◽  
Three Dimensional Space

Transmission tower is a widely used higher order statically indeterminate spatial structure, as the pillar of power transmission, modern society are increasingly concerned about its safety and reliability. This paper establishes a large-scale three-dimensional space model of transmission tower by using the finite element method, calculate and analyse the first six vibration modes and frequencies of this transmission tower, study the characteristics of each order vibration mode. These research results provide some references of design for the large-scale transmission tower.

scholarly journals Canopy Cover Estimation in Lowland Forest in South Sumatera, Using LiDAR and Landsat 8 OLI imagery

2021 ◽  
Vol 27 (1) ◽  
pp. 50-58
Author(s):  
M B Saleh ◽  
◽  
R W Dewi ◽  
L B Prasetyo ◽  
N A Santi
Keyword(s):  
Dimensional Space ◽  
Vegetation Indices ◽  
Three Dimensional ◽  
Canopy Cover ◽  
Landsat 8 ◽  
Landsat 8 Oli ◽  
Estimation Model ◽  
Large Area ◽  
Lowland Forest ◽  
Three Dimensional Space

Canopy cover is one of the most important variables in ecology, hydrology, and forest management, and useful as a basis for defining forests. LiDAR is an active remote sensing method that provides the height information of an object in three-dimensional space. The method allows for the mapping of terrain, canopy height and cover. Its only setback is that it has to be integrated with Landsat to cover a large area. The main objective of this study is to generate the canopy cover estimation model using Landsat 8 OLI and LiDAR. Landsat 8 OLI vegetation indices and LiDAR-derived canopy cover estimation, through First Return Canopy Index (FRCI) method, were used to obtain a regression model. The performance of this model was then assessed using correlation, aggregate deviation, and raster display. Lastly, the best canopy cover estimation was obtained using equation, FRCI = 2.22 + 5.63Ln(NDVI), with R2 at 0.663, standard deviation at 0.161, correlation between actual and predicted value at 0.663, aggregate deviation at -0.182 and error at 56.10%.

scholarly journals Fabrication of a Porous Three-Dimensional Scaffold with Interconnected Flow Channels: Co-Cultured Liver Cells and In Vitro Hemocompatibility Assessment

2021 ◽  
Vol 11 (6) ◽  
pp. 2473
Author(s):  
Muxin Li ◽  
Rubina Rahaman Khadim ◽  
Mitsuru Nagayama ◽  
Marie Shinohara ◽  
Kousuke Inamura ◽  
...  
Keyword(s):  
Liver Tissue ◽  
Large Scale ◽  
Blood Compatibility ◽  
Platelet Rich Plasma ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Lactate Production ◽  
Hep G2 ◽  
Adhesion Properties ◽  
Flow Channels

The development of large-scale human liver scaffolds equipped with interconnected flow channels in three-dimensional space offers a promising strategy for the advancement of liver tissue engineering. Tissue-engineered scaffold must be blood-compatible to address the demand for clinical transplantable liver tissue. Here, we demonstrate the construction of 3-D macro scaffold with interconnected flow channels using the selective laser sintering (SLS) fabrication method. The accuracy of the printed flow channels was ensured by the incorporation of polyglycolic acid (PGA) microparticles as porogens over the conventional method of NaCl salt leaching. The fabricated scaffold was populated with Hep G2, followed by endothelization with endothelial cells (ECs) grown under perfusion of culture medium for up to 10 days. The EC covered scaffold was perfused with platelet-rich plasma for the assessment of hemocompatibility to examine its antiplatelet adhesion properties. Both Hep G2-covered scaffolds exhibited a markedly different albumin production, glucose metabolism and lactate production when compared to EC-Hep G2-covered scaffold. Most importantly, EC-Hep G2-covered scaffold retained the antiplatelet adhesion property associated with the perfusion of platelet-rich plasma through the construct. These results show the potential of fabricating a 3-D scaffold with interconnected flow channels, enabling the perfusion of whole blood and circumventing the limitation of blood compatibility for engineering transplantable liver tissue.

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