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A comparative analysis of parallel disk-based Methods for enumerating implicit graphs

Eric Robinson, Daniel Kunkle, Gene Cooperman
2007 Proceedings of the 2007 international workshop on Parallel symbolic computation - PASCO '07  
It is only in the last five years that researchers have begun to use disk-based search techniques on a large scale.  ...  In the field of parallel search, disk-based search has been forced on researchers because the historical growth in the amount of RAM per CPU core has now stopped.  ...  Then, instead of sorting these buffered states, the existing and new states are compared using the second hash function.  ... 
doi:10.1145/1278177.1278190 dblp:conf/issac/RobinsonKC07 fatcat:ahz4oylybnholausabg264vaai

An I/O Efficient Model Checking Algorithm for Large-Scale Systems

Lijun Wu, Huijia Huang, Kaile Su, Shaowei Cai, Xiaosong Zhang
2015 IEEE Transactions on Very Large Scale Integration (vlsi) Systems  
To overcome this drawback, one of the most effective solutions is to use external memory algorithms. In this paper, we propose an I/O efficient model checking algorithm for large-scale systems.  ...  Index Terms-Duplicate detection, dynamic search path management, linear hash-sorting, model checking, state space explosion.  ...  ACKNOWLEDGMENT The authors would like to thank the anonymous reviewers for their helpful comments on earlier versions of this paper.  ... 
doi:10.1109/tvlsi.2014.2330061 fatcat:v4obgax7ovbsxl5oelm3pkebzi

Flash memory efficient LTL model checking

S. Edelkamp, D. Sulewski, J. Barnat, L. Brim, P. Šimeček
2011 Science of Computer Programming  
Currently, most solid-state disks are based on NAND technology and much faster than magnetic disks in random reads, while in random writes they are generally not.  ...  In contrast to approaches relying on the delayed detection of duplicate states, in this work, we design and exploit appropriate hash functions to re-invent immediate duplicate detection.  ...  Acknowledgements We would like to thank Martin Dietzfelbinger for his help to derive the lower bound on perfect hashing, Peter Kissmann for his rigorous proof reading, and the anonymous reviewers for the  ... 
doi:10.1016/j.scico.2010.03.005 fatcat:5kkssybrs5dibhqgwyhvsv3xfi

Time-Efficient Model Checking with Magnetic Disk [chapter]

Tonglaga Bao, Michael Jones
2005 Lecture Notes in Computer Science  
The new algorithm is a variant of parallel partitioned hash table algorithms and uses a time-efficient chained hash table implementation.  ...  We present and analyze a more time-efficient algorithm for model checking with magnetic disk that requires more file IO time, but less delayed duplicate detection time and less total execution time.  ...  IO Mono is the disk IO time and DDD Mono is delayed duplicate detection time spent on comparing states in disk with states in memory.  ... 
doi:10.1007/978-3-540-31980-1_34 fatcat:v5fdchraxjhkzoy33lwoxu2ch4

Can Flash Memory Help in Model Checking? [chapter]

Jiří Barnat, Luboš Brim, Stefan Edelkamp, Damian Sulewski, Pavel Šimeček
2009 Lecture Notes in Computer Science  
We discuss verification algorithms optimized for this model and compare the performance of these algorithms with approaches known from I/O-efficient model checking on mechanical hard disks.  ...  So far, external memory model checking algorithms have been optimized for mechanical hard disks corresponding to the model of Aggarwal and Vitter [1].  ...  If inv(H f ) = O(m ) and given that we use an algorithm that exploits presorting 5 , we obtain a linear time sorting algorithm.  ... 
doi:10.1007/978-3-642-03240-0_14 fatcat:jatfcu7l4zha3eupeb6pqgzbdq

Efficient indexing of repeated n-grams

Samuel Huston, Alistair Moffat, W. Bruce Croft
2011 Proceedings of the fourth ACM international conference on Web search and data mining - WSDM '11  
We compare our proposed method to existing techniques using the 1.5 TB TREC ClueWeb-B text collection, using both single-processor and multiprocessor approaches.  ...  We consider methods for finding the repeated n-grams in text corpora, with emphasis on techniques that can be effectively scaled across a cluster of processors to handle very large amounts of text.  ...  This work was supported in part by National Science Foundation grant IIS-0534383 and in part by the Australian Research Council grant DP0880065.  ... 
doi:10.1145/1935826.1935857 dblp:conf/wsdm/HustonMC11 fatcat:zfoasczpgfgrjoahcb6jf2eb5m

Using magnetic disk instead of main memory in the Mur ϕ verifier [chapter]

Ulrich Stern, David L. Dill
1998 Lecture Notes in Computer Science  
The algorithm avoids costly random accesses to disk and amortizes the cost of linearly reading the state table from disk over all states in a given breadth-first level.  ...  In experiments with three complex cache coherence protocols, the new algorithm achieves memory savings factors of one to two orders of magnitude with a runtime overhead of typically only around 15%.  ...  Acknowledgments We would like to thank Ben Verghese for explaining some details of the Unix file system buffer cache to us and Ravi Soundararajan for his comments on a draft of this paper.  ... 
doi:10.1007/bfb0028743 fatcat:y5ijz6fxonax5jtwwoo2cxyeja

Improving the Scalability of Optimal Bayesian Network Learning with External-Memory Frontier Breadth-First Branch and Bound Search [article]

Brandon Malone, Changhe Yuan, Eric A. Hansen, Susan Bridges
2012 arXiv   pre-print
To further improve scalability, the algorithm stores most of the graph in external memory, such as hard disk, when it does not fit in RAM.  ...  Previous work has shown that the problem of learning the optimal structure of a Bayesian network can be formulated as a shortest path finding problem in a graph and solved using A* search.  ...  Acknowledgements This work was supported by NSF CAREER grant IIS-0953723 and EPSCoR grant EPS-0903787.  ... 
arXiv:1202.3744v1 fatcat:f6ts5qi54jcetc5pyne6ptgk6i

A distributed query structure to explore random mappings in parallel

J. Heichler, J. Keller
2006 14th Euromicro International Conference on Parallel, Distributed, and Network-Based Processing (PDP'06)  
Tradeoffs between different organizations using main memory or hard disks are developed and quantified with parameters.  ...  We explore the possibilities to organize a query data structure in the main memories or hard disks of a cluster computer.  ...  He is posted as missing since a ski trip in March 2005.  ... 
doi:10.1109/pdp.2006.10 dblp:conf/pdp/HeichlerK06 fatcat:hdbfyh7qavgdrcwqdm5ktkg4ky

Join algorithm costs revisited

Evan P. Harris, Kotagiri Ramamohanarao
1996 The VLDB journal  
The costs of variations of several of the standard join algorithms, including nested block, sort-merge, GRACE hash and hybrid hash, are presented.  ...  A method of analysing join algorithms based upon the time required to access, transfer and perform the relevant CPU-based operations on a disk page is proposed.  ...  , and the Key Centre for Knowledge Based Systems.  ... 
doi:10.1007/s007780050016 fatcat:rbdnau36ivf5dn5bekjoqoj4de

Improving main memory utilization for array-based datacube computation

Seigo Muto, Masaru Kitsuregawa
1998 Proceedings of the 1st ACM international workshop on Data warehousing and OLAP - DOLAP '98  
We improve on this algorithm by performing compression of arrays in main memory as well as on disk using a hashing method, which allocates main memory according to the number of non-empty array cells.  ...  We evaluate the performance of the proposed method by disk I/O analysis and demonstrate that the improved MOLAP algorithm compares well with a ROLAP algorithm.  ...  A chunk is a unit of processing used in this algorithm and compressed on disk when more than a certain number of cells are empty.  ... 
doi:10.1145/294260.294267 dblp:conf/dolap/MutoK98 fatcat:5kzbid7hnzeh5mszukgbbcdcly

Map vs. Unordered Map: An Analysis on Large Datasets

Akanksha Bindal, Prateek Narang, S. Indu
2015 International Journal of Computer Applications  
In this paper two data structures are explored: 1) Map which is implemented as self-balancing binary search trees or more commonly Red Black Trees and 2) Unordered Map which is based on hashing with chaining  ...  To tackle this problem a hierarchical hashing scheme is discussed where only one component of a big data structure resides in the memory.  ...  In case sorted output (based on keys) from Unordered Maps is desired, sorting algorithms are implemented to sort the random data obtained from them.  ... 
doi:10.5120/ijca2015906322 fatcat:2o6fghduvzduvlzey4kmjtvuu4


Kai Ren, Qing Zheng, Joy Arulraj, Garth Gibson
2017 Proceedings of the VLDB Endowment  
Modern key-value stores often use write-optimized indexes and compact in-memory indexes to speed up read and write performance.  ...  lower tail latency in read operations compared to popular LSM-tree implementations such as LevelDB and RocksDB.  ...  layouts of in-memory indexes and on-disk data storage with desired read and write amplifications.  ... 
doi:10.14778/3151106.3151108 fatcat:ossng6kv3jebvkxfqsuilmof2i

Digital Investigation using Hash-based Carving

Isabel Maria Sebastian, Noushida A, Safa Saifudeen, Surekha Mariam Varghese
2016 International Journal on Cybernetics & Informatics  
To address the problem of High false identification rate and non-probative blocks, a HASH-SETS algorithm that can help in identification of files and the HASH-RUNS algorithm that helps in reassembling  ...  This technique is demonstrated using the forensic tool: bulk_extractor along with a hash database: the has hdb and an algorithm implementation written in Python.  ...  files is detected by the HASH-SETS algorithm and the HASH-RUNS algorithm is used to report the location.  Handling of the case when the target file is on the searched media in multiple locations.  Employs  ... 
doi:10.5121/ijci.2016.5214 fatcat:k2ndjieuuvgdna7ou6bn7vsmaq

Sort vs. hash revisited

G. Graefe, A. Linville, L.D. Shapiro
1994 IEEE Transactions on Knowledge and Data Engineering  
In this article, we compare the concepts behind sort-and hash-based queryprocessing algorithms and conclude that 1) many dualities exist between the two types of algorithms, 2) their costs differ mostly  ...  by percentages rather than factors, 3) several special cases exist that favor one or the other choice, and 4) there is a strong reason why both hash-and sort-based algorithms should be available in a  ...  This led us to search for a dual in the realm of sorting.  ... 
doi:10.1109/69.334883 fatcat:ddxhl4i56zczdfrh4njk2oic6e
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