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External-memory algorithms with applications in GIS [chapter]

Lars Arge
1997 Lecture Notes in Computer Science  
In this note we survey the recent developments in external-memory algorithms with applications in GIS.  ...  We then go on and survey externalmemory algorithms for computational geometry problems-with special emphasis on problems with applications in GIS-and techniques for designing such algorithms: Using the  ...  In this note we consider basic paradigms for designing efficient external-memory algorithms and external-memory computational geometry algorithms with applications in GIS.  ... 
doi:10.1007/3-540-63818-0_8 fatcat:q72ixxt6cjadlnlmnnldtqxyea

I/O-Efficient Algorithms for Problems on Grid-Based Terrains

Lars Arge, Laura Toma, Jeffrey Scott Vitter
2001 ACM Journal of Experimental Algorithmics  
However, the use of these massive datasets also exposes scalability problems with existing GIS algorithms.  ...  Our experiments show that while our new algorithm scales nicely with dataset size, the previously known algorithm \breaks down" once the size of the dataset becomes bigger than the available main memory  ...  Finally, we thank Je Chase, Andrew Gallatin, and Rajiv Wickremesinghe for help with the numerous system problems encountered when working with gigabytes of data.  ... 
doi:10.1145/945394.945395 fatcat:wcatskku7jhk5oq4zvs2op4cxe

Contract & Expand: I/O Efficient SCCs Computing

Zhiwei Zhang, Lu Qin, Jeffrey Xu Yu
2014 2014 IEEE 30th International Conference on Data Engineering  
In this paper, we study new I/O efficient external algorithms to find all SCCs for a directed graph G whose nodes cannot fit entirely in the main memory.  ...  The contraction phase stops when all nodes of the graph can fit in the main memory, such that the semi-external algorithm can be used in SCC computation.  ...  An in-memory algorithm requires G to reside entirely in memory and a semi-external algorithm requires all nodes of G to reside entirely in memory.  ... 
doi:10.1109/icde.2014.6816652 dblp:conf/icde/ZhangQY14 fatcat:k6bt3wuaxvhtzlwnynoj5pg4ji

Efficient viewshed computation on terrain in external memory

Marcus V. A. Andrade, Salles V. G. Magalhães, Mirella A. Magalhães, W. Randolph Franklin, Barbara M. Cutler
2009 Geoinformatica  
In this paper, we present an efficient algorithm to compute viewsheds on terrain stored in external memory.  ...  the minimum number of I/O operations 1 required to read n 2 contiguous items from external memory.  ...  This algorithm can be used to compute the viewshed on terrain in external memory.  ... 
doi:10.1007/s10707-009-0100-9 fatcat:qautch7l3zhxdb53jqlp6ga7fu

Sorting on architecturally diverse computer systems

Roger D. Chamberlain, Narayan Ganesan
2009 Proceedings of the Third International Workshop on High-Performance Reconfigurable Computing Technology and Applications - HPRCTA '09  
Here, we explore the design space of sorting algorithms in reconfigurable hardware, looking to maximize the benefit associated with high-bandwidth, multiple-port access to memory.  ...  Sorting is an important problem that forms an essential component of many high-performance applications.  ...  Chamberlain is a principal in BECS Technology, Inc., and Exegy, Inc.  ... 
doi:10.1145/1646461.1646466 dblp:conf/sc/ChamberlainG09 fatcat:lkqn77pp6rg7lnkrvxv4webtii

Instant Ghost Imaging: Algorithm and On-chip Implementation [article]

Zhe Yang, Wei-Xing Zhang, Yi-Pu Liu, Dong Ruan, Jun-Lin Li
2019 arXiv   pre-print
Conventional GI algorithms require large memory space to store the measured data and perform complicated offline calculations, limiting practical applications of GI.  ...  This algorithm uses the signal between consecutive temporal measurements to reduce the memory requirements without degradation of image quality compared with conventional GI algorithms.  ...  This means that IGI is applicable to GI in general.  ... 
arXiv:1912.02181v1 fatcat:uziqkrryarcznap5trvr5wka3a

Computing visibility on terrains in external memory

Herman Haverkort, Laura Toma, Yi Zhuang
2009 ACM Journal of Experimental Algorithmics  
We give the first I/Oefficient algorithm to compute the viewshed of v on a grid terrain in external memory.  ...  Our algorithm is based on Van Kreveld's O(n lg n) time algorithm for the same problem in internal memory.  ...  We implemented the algorithms in C++ using the g++ 4.0.1 compiler with optimization level -O3. For the I/O-efficient algorithm we used an external memory library IOStreams.  ... 
doi:10.1145/1412228.1412233 fatcat:bivogghnpraaxobuopvuv47f6a

Support for create 3D computer graphics images in GIS systems using externals renders algorithm

Mateusz Ilba
2014 Geomatics and Environmental Engineering  
In ArcScene, all available data are automatically stored in the computer memory, we have quick access to them. The downside of  ...  Knowing how to do the main task of particular programs we can say that the CAD software is better suited for the visualization of data than GIS applications.  ...  Knowing how to do the main task of particular programs we can say that the CAD software is better suited for the visualization of data than GIS applications.  ... 
doi:10.7494/geom.2014.8.2.37 fatcat:jgyf2ohahfbedptzany3xy6yya

A VGA 30fps Affine Motion Model Estimation VLSI for Real-Time Video Segmentation

Yoshiki YUNBE, Masayuki MIYAMA, Yoshio MATSUDA
2010 IEICE transactions on information and systems  
The core size is 5.0 × 5.0 mm 2 in 0.18 μm process, standard cell technology. The ASIC can accommodate a VGA 30 fps video with 120 MHz clock frequency.  ...  The processor estimates the dominant motion of a target region with affine parameters. The processor is based on the Pseudo-M-estimator algorithm.  ...  This work was supported by the VLSI Design and Education Center (VDEC) and The University of Tokyo, in collaboration with Celoxica, Ltd. and Synopsys, Inc.  ... 
doi:10.1587/transinf.e93.d.3284 fatcat:ikihbvvc4naz7gvmrwkp4pw6hu

Divide & Conquer

Zhiwei Zhang, Jeffrey Xu Yu, Lu Qin, Zechao Shang
2015 Proceedings of the 2015 ACM SIGMOD International Conference on Management of Data - SIGMOD '15  
Here, like the existing semiexternal algorithms, we assume that a spanning tree of G can be held in main memory and the remaining edges of G are kept on disk, and compute the DFS-Tree in main memory with  ...  In this paper, we focus on I/O efficiency and study semi-external algorithms to DFS a graph G which is on disk.  ...  entirely in the main memory, which is widely used in many real applications.  ... 
doi:10.1145/2723372.2723740 dblp:conf/sigmod/ZhangYQS15 fatcat:vvizzfurtreqnosdjimvjfxu5a

External-Memory Algorithms for Processing Line Segments in Geographic Information Systems

Lars Arge, Darren E. Vengroff, Jeffery S. Vitter
1996 BRICS Report Series  
In this paper we develop efficient new external-memory algorithms for a number of important problems involving line segments in the plane, including trapezoid decomposition, batched planar point location  ...  In the design of algorithms for large-scale applications it is essential to consider the problem of minimizing I/O communication.  ...  In this paper, we present efficient external-memory algorithms for large-scale geometric problems involving collections of line segments in the plane, with applications to GIS systems.  ... 
doi:10.7146/brics.v3i12.19975 fatcat:bq343vgbbbhkbgiapamlecawci

Computing Visibility on Terrains in External Memory [chapter]

Herman Haverkort, Laura Toma, Yi Zhuang
2007 2007 Proceedings of the Ninth Workshop on Algorithm Engineering and Experiments (ALENEX)  
In this paper we consider the problem of computing the viewshed of a point on a very large grid terrain in external memory.  ...  1.1 billion points in less than 4 hours on a low-cost machine compared to more than 32 hours with the internal-memory algorithm.  ...  Evidence of the practical advantages of cache-oblivious algorithms in external memory is not yet convincing.  ... 
doi:10.1137/1.9781611972870.2 dblp:conf/alenex/HaverkortTZ07 fatcat:tf44vvevfrgwbdhxezxmtpsk3y

Efficiently computing the drainage network on massive terrains using external memory flooding process

Thiago L. Gomes, Salles V. G. Magalhães, Marcus V. A. Andrade, W. Randolph Franklin, Guilherme C. Pena
2015 Geoinformatica  
We present EMFlow , a very efficient algorithm and its implementation, to compute the drainage network (i.e. the flow direction and flow accumulation) on huge terrains stored in external memory.  ...  Its utility lies in processing the large volume of high resolution terrestrial data newly available, which internal memory algorithms cannot handle efficiently.  ...  Algorithms for Computing Drainage Network in External Memory Several GIS implement algorithms for flow direction and flow accumulation.  ... 
doi:10.1007/s10707-015-0225-y fatcat:ocopunc4rrg4reldigmxox4tom

Computing the drainage network on huge grid terrains

Thiago L. Gomes, Salles V. G. Magalhães, Marcus V. A. Andrade, W. Randolph Franklin, Guilherme C. Pena
2012 Proceedings of the 1st ACM SIGSPATIAL International Workshop on Analytics for Big Geospatial Data - BigSpatial '12  
We present a very efficient algorithm, named EMFlow , and its implementation to compute the drainage network, that is, the flow direction and flow accumulation on huge terrains stored in external memory  ...  Because of the recent increase in the volume of high resolution terrestrial data, the internal memory algorithms do not run well on most computers and, thus, optimizing the massive data processing algorithm  ...  Many important applications in Geographical Information Science (GIS) as hydrology, visibility, routing, etc require terrain data processing and these applications have become a challenge for GIS because  ... 
doi:10.1145/2447481.2447488 dblp:conf/gis/GomesMAFP12 fatcat:a2oerzc6kjh4lanr2euudg4msy

Evaluation of Algorithms for Low Energy Mapping onto NoCs

Cesar A. M. Marcon, Edson I. Moreno, Ney L. V. Calazans, Fernando G. Moraes
2007 2007 IEEE International Symposium on Circuits and Systems  
The main goal of this work is to propose some algorithms and evaluate its results and performance with regard to low energy NoC mappings.  ...  In addition, one heuristic provided average reductions in execution time above 90% when compared to pure stochastic algorithms, and obtained better energy saving than combined approaches.  ...  Simulated Annealing (SA) Algorithm SA is a stochastic approach implementing the external mapping algorithm with two nested loops.  ... 
doi:10.1109/iscas.2007.378471 dblp:conf/iscas/MarconMCM07 fatcat:wfff62uqsvdlloekadq7ksjte4
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