Parallel Rendering for Large-Scale Crowd Based on Dynamic Feedback

2011 ◽  
Author(s):  
Yanfeng Zhang ◽  
Tianlu Mao ◽  
Zhaoqi Wang
Keyword(s):  
Large Scale ◽  
Parallel Rendering ◽  
Dynamic Feedback

Evaluating the “Rich-Get-Richer” Mechanism in Tropical Precipitation Change under Global Warming

2009 ◽  
Vol 22 (8) ◽  
pp. 1982-2005 ◽  
Author(s):  
Chia Chou ◽  
J. David Neelin ◽  
Chao-An Chen ◽  
Jien-Yi Tu
Keyword(s):  
Global Warming ◽  
Vertical Velocity ◽  
Large Scale ◽  
Climate Models ◽  
Global Climate Models ◽  
Dynamic Feedback ◽  
Precipitation Anomalies ◽  
The Rich ◽  
Convergence Zones ◽  
Gross Moist Stability

Abstract Examining tropical regional precipitation anomalies under global warming in 10 coupled global climate models, several mechanisms are consistently found. The tendency of rainfall to increase in convergence zones with large climatological precipitation and to decrease in subsidence regions—the rich-get-richer mechanism—has previously been examined in different approximations by Chou and Neelin, and Held and Soden. The effect of increased moisture transported by the mean circulation (the “direct moisture effect” or “thermodynamic component” in respective terminology) is relatively robust, while dynamic feedback is poorly understood and differs among models. The argument outlined states that the thermodynamic component should be a good approximation for large-scale averages; this is confirmed for averages across convection zones and descent regions, respectively. Within the convergence zones, however, dynamic feedback can substantially increase or decrease precipitation anomalies. Regions of negative precipitation anomalies within the convergence zones are associated with local weakening of ascent, and some of these exhibit horizontal dry advection associated with the “upped-ante” mechanism. Regions of increased ascent have strong positive precipitation anomalies enhanced by moisture convergence. This dynamic feedback is consistent with reduced gross moist stability due to increased moisture not being entirely compensated by effects of tropospheric warming and a vertical extent of convection. Regions of reduced ascent with positive precipitation anomalies are on average associated with changes in the vertical structure of vertical velocity, which extends to higher levels. This yields an increase in the gross moist stability that opposes ascent. The reductions in ascent associated with gross moist stability and upped-ante effects, respectively, combine to yield reduced ascent averaged across the convergence zones. Over climatological subsidence regions, positive precipitation anomalies can be associated with a convergence zone shift induced locally by anomalous heat flux from the ocean. Negative precipitation anomalies have a contribution from the thermodynamic component but can be enhanced or reduced by changes in the vertical velocity. Regions of enhanced subsidence are associated with an increased outgoing longwave radiation or horizontal cold convection. Reductions of subsidence are associated with changes of the vertical profile of vertical velocity, increasing gross moist stability.

Control Method of Inverter for Large-Scale Grid-Connected Photovoltaic Generation System

2013 ◽  
Vol 448-453 ◽  
pp. 2507-2510
Author(s):  
Zhuo Zhang ◽  
Hong Wei Li
Keyword(s):  
Power Factor ◽  
Feedback Linearization ◽  
Large Scale ◽  
Reactive Power ◽  
Control Method ◽  
Solar Irradiation ◽  
Dynamic Feedback ◽  
Photovoltaic Array ◽  
Grid Connected Inverter ◽  
Photovoltaic Plant

A grid-connected inverter control method to analyze dynamic process of large-scale and grid-connected photovoltaic (PV) power station is proposed. The reference values of control variables are composed of maximum power output of the photovoltaic array in the photovoltaic power plant and power factor specified by dispatching. Control strategy of dynamic feedback linearization is adopted. Nonlinear decoupling controller is designed for realizing decoupling control of real-and reactive-power. The cascade PI regulation is proposed to avoid inaccurate parameter estimation which generates the system static error. Simulation is carried out based on the simplified power system with large-scale photovoltaic plant model, the power factor, and solar irradiation, and bus fault are considered for the further research. Its demonstrated that the parameter adjustment of PI controller is simple and convenient, dynamic response of system is transient, and the stability of the inverter control is verified.

scholarly journals An Interactive 3D Visualization Tool for Large Scale Data Sets for Quantitative Atom Probe Tomography

2011 ◽  
Vol 1349 ◽  
Author(s):  
Hari Dahal ◽  
Michael Stukowski ◽  
Matthias J. Graf ◽  
Alexander V. Balatsky ◽  
Krishna Rajan
Keyword(s):  
User Interface ◽  
Open Source ◽  
Real Time ◽  
Atom Probe Tomography ◽  
Large Scale ◽  
3D Visualization ◽  
Atom Probe ◽  
Parallel Rendering ◽  
Data Sets ◽  
Process Data

ABSTRACTSeveral visualization schemes have been developed for imaging materials at the atomic level through atom probe tomography. The main shortcoming of these tools is their inability to parallel process data using multi-core computing units to tackle the problem of larger data sets. This critically handicaps the ability to make a quantitative interpretation of spatial correlations in chemical composition, since a significant amount of the data is missed during subsequent analysis. In addition, since these visualization tools are not open-source software there is always a problem with developing a common language for the interpretation of data. In this contribution we present results of our work on using an open-source advanced interactive visualization software tool, which overcomes the difficulty of visualizing larger data sets by supporting parallel rendering on a graphical user interface or script user interface and permits quantitative analysis of atom probe tomography data in real time. This advancement allows materials scientists a codesign approach to making, measuring and modeling new and nanostructured materials by providing a direct feedback to the fabrication and designing of samples in real time.

scholarly journals mSwap: a large-scale image-compositing method with optimal m-ary tree

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Min Hou ◽  
Chongke Bi ◽  
Fang Wang ◽  
Liang Deng ◽  
Gang Zheng ◽  
...  
Keyword(s):  
Large Scale ◽  
Scientific Visualization ◽  
Parallel Rendering ◽  
Well Performance ◽  
Medium Scale ◽  
Image Compositing ◽  
Novel Method ◽  
Classical Image ◽  
Large Scale Simulations

AbstractWith the increasing of computing ability, large-scale simulations have been generating massive amounts of data in aerodynamics. Sort-last parallel rendering is the most classical image compositing method for large-scale scientific visualization. However, in the stage of image compositing, the sort-last method may suffer from scalability problem on large-scale processors. Existing image compositing algorithms tend to perform well in certain situations. For instance, Direct Send is well on small and medium scale; Radix-k gets well performance only when the k-value is appropriate and so on. In this paper, we propose a novel method named mSwap for scientific visualization in aerodynamics, which uses the best scale of processors to make sure its performance at the best. mSwap groups the processors that we can use with a (m,k) table, which records the best combination of m (the number of processors in subgroup of each group) and k (the number of processors in each group). Then in each group, using a m-ary tree to composite the image for reducing the communication of processors. Finally, the image is composited between different groups to generate the final image. The performance and scalability of our mSwap method is demonstrated through experiments with thousands of processors.

Study on the Parallel Rendering Technology Used in Virtual Prototype System

2011 ◽  
Vol 201-203 ◽  
pp. 69-74
Author(s):  
Ming Qiang Yin ◽  
Shi Qi Li
Keyword(s):  
Large Scale ◽  
Virtual Prototype ◽  
Parallel Rendering ◽  
Prototype System ◽  
System Transformation ◽  
Virtual Design ◽  
Pc Cluster ◽  
Immersive Virtual Environment ◽  
Processing Power ◽  
Graph Management

With continuous expansion of manufacturing scale, the scene data that virtual prototype system has to deal with is far beyond a single computer's processing power. To meet the requirements of large-scale simulation, this study designs a virtual prototype system based on PC cluster. The problems including software architecture of virtual prototype system, transformation of CAD model, scene graph management, real-time rendering of huge dataset, and so on are investigated in detail in this paper. Finally a prototype system has been implemented. The system is constructed by PC cluster and gigabit LAN. The aim of the system is to build a large-scale, high resolution, immersive virtual environment supporting users' virtual design and manufacture.

scholarly journals mSwap: A Large-Scale Image-Compositing Method with Optimal m-ary Tree

2020 ◽  
Author(s):  
Min Hou ◽  
Chongke Bi ◽  
Fang Wang ◽  
Liang Deng ◽  
Gang Zheng ◽  
...  
Keyword(s):  
Large Scale ◽  
Scientific Visualization ◽  
Parallel Rendering ◽  
Well Performance ◽  
K Value ◽  
Medium Scale ◽  
Image Compositing ◽  
Novel Method ◽  
Classical Image ◽  
Large Scale Simulations

Abstract With the increasing of computing ability, large-scale simulations have been generating massive amounts of data in aerodynamics. Sort-last parallel rendering is the most classical image compositing method for large-scale scientific visualization. However, in the stage of image compositing, the sort-last method may suffer from scalability problem on large-scale processors. Existing image compositing algorithms tend to perform well in certain situations. For instance, Direct Send is well on small and medium scale; Radix-k gets well performance only when the k-value is appropriate and so on. In this paper, we propose a novel method named mSwap for scientific visualization in aerodynamics, which uses the best scale of processors to make sure its performance at the best. mSwap groups the processors that we can use with a (m, k) table, which records the best combination of m (the number of processors in subgroup of each group) and k (the number of processors in each group). Then in each group, using a m-ary tree to composite the image for reducing the communication of processors. Finally, the image is composited between different groups to generate the final image. The performance and scalability of our mSwap method is demonstrated through experiments with thousands of processors.

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