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Parallel Graph Algorithms in Constant Adaptive Rounds: Theory meets Practice [article]

Soheil Behnezhad, Laxman Dhulipala, Hossein Esfandiari, Jakub Łącki, Vahab Mirrokni, Warren Schudy
2020 arXiv   pre-print
We show the first AMPC algorithms for all of the studied problems that run in a constant number of rounds and use only O(n^ϵ) space per machine, where 0 < ϵ < 1.  ...  We empirically evaluate our algorithms on a set of large real-world graphs and show that our AMPC algorithms can achieve improvements in both running time and round-complexity over optimized MPC baselines  ...  Acknowledgements We would like to thank Greg Cipriano, Milo Martin, and Florentina Popovici for their work on the key-value store used in this paper, and Raimondas Kiveris for his contributions to earlier  ... 
arXiv:2009.11552v1 fatcat:dk33465mxjbp7k6htajcq5ngqq

Transmission-Line Properties of a Round Wire in a Polygon Shield

H.A. Wheeler
1979 IEEE transactions on microwave theory and techniques  
The same forrmrfa is adapted for different shapes by entry of different constants depending on the number of shield planes and the degree of symmetry.  ...  A family of transmission fines is based on a roond wire in a cyliidricaf shield of polygon cross-section.  ...  The approximationhas been close enough for practical sizes of wire not too close to contact with the shield.For either extreme case of a shield made of one or is graphed in [2] and [3].  ... 
doi:10.1109/tmtt.1979.1129712 fatcat:pekhvpjtnfcrjatu4f2l2id7du

Reducing asynchrony to synchronized rounds [article]

Andrei Damien, Cezara Dragoi, Alexandru Militaru, Josef Widder
2019 arXiv   pre-print
In this paper, we bridge the gap between these two worlds.  ...  We introduce a (synchronous) round-based computational model and we prove a reduction for a class of asynchronous protocols to our new model.  ...  While in theory this is a restriction, the benchmarks in Fig. 11 show that well-known algorithms are rewritten by our tool.  ... 
arXiv:1804.07078v2 fatcat:qpgbeq5defan3mmce7ieto7sxa

Bounding Variable Values and Round-Off Effects Using Handelman Representations

D. Boland, G. A. Constantinides
2011 IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems  
The precision used in an algorithm affects the error and performance of individual computations, the memory usage and the potential parallelism for a fixed hardware budget.  ...  This paper describes a new method to determine the minimum precision required to meet a given error specification for an algorithm that consists of the basic algebraic operations.  ...  ACKNOWLEDGEMENTS Supported in part by EU FP7 Project REFLECT.  ... 
doi:10.1109/tcad.2011.2161307 fatcat:4aqsnca3lbfutn35g44r4mbqtm

Structural Evaluation of AES and Chosen-Key Distinguisher of 9-Round AES-128 [chapter]

Pierre-Alain Fouque, Jérémy Jean, Thomas Peyrin
2013 Lecture Notes in Computer Science  
We obtain these results by revisiting algorithmic theory and graph-based ideas to compute all the best differential characteristics in SPN ciphers, with a special focus on AES-like ciphers subject to related-keys  ...  We use a variant of Dijkstra's algorithm to efficiently find the most efficient related-key attacks on SPN ciphers with an algorithm linear in the number of rounds.  ...  , in practice we do not use the graph G directly, but two separate graphs G BC and G KS .  ... 
doi:10.1007/978-3-642-40041-4_11 fatcat:4c33qsv6sjfipcnz644mswmkuy

The FAST Algorithm for Submodular Maximization [article]

Adam Breuer, Eric Balkanski, Yaron Singer
2019 arXiv   pre-print
Recent algorithms have comparable guarantees in terms of asymptotic worst case analysis, but their actual number of rounds and query complexity depend on very large constants and polynomials in terms of  ...  Our main contribution is a design that is extremely efficient both in terms of its non-asymptotic worst case query complexity and number of rounds, and in terms of its practical runtime.  ...  Experiments Our goal in this section is to show that in practice, Fast finds solutions whose value meets or exceeds alternatives in less parallel runtime than both state-of-the-art low-adaptivity algorithms  ... 
arXiv:1907.06173v1 fatcat:uzvt7mnxzjgatkme6vcyfx244e

Parallelizing flow-accumulation calculations on graphics processing units—From iterative DEM preprocessing algorithm to recursive multiple-flow-direction algorithm

Cheng-Zhi Qin, Lijun Zhan
2012 Computers & Geosciences  
Therefore, we designed a parallelization strategy based on graph theory.  ...  In recent years, rapid increases in hardware capacity of the graphics processing units (GPUs) provided in modern PCs have made it possible to meet this challenge in a PC environment.  ...  Therefore, a parallelization strategy based on graph theory has been proposed, and a graph-theory-based parallel MFDmd algorithm has been designed.  ... 
doi:10.1016/j.cageo.2012.02.022 fatcat:roonbfvdgfbbtkvv7z4ppyrhgi

The Topology of Biological Networks from a Complexity Perspective [article]

Ali Atiia, François Major, Jérôme Waldispühl
2018 arXiv   pre-print
The more distant (in degree distribution) a synthetic network is from biological networks the lower its achieved ratio.  ...  A simple graph representation is used where molecules (DNA, RNA, proteins and chemicals) are vertices and relations between them are directed and signed (promotional (+) or inhibitory (-)) edges.  ...  Simulation time runs exponentially (days of execution time on 128 parallel CPUs).  ... 
arXiv:1505.02348v4 fatcat:zwjk6232vfdrbinw4a6dwy5v3a

Distributed Computing Column 60

Jennifer L. Welch
2015 ACM SIGACT News  
a constant number of rounds?  ...  The organist played an improvisation on the Graph Theory Hymn which was originally created for Czechoslovak graph theory 1 .  ... 
doi:10.1145/2852040.2852055 fatcat:hlayo67wurfjhexvgbejt4cwdm

Delaunay Triangulations on the Word RAM: Towards a Practical Worst-Case Optimal Algorithm

Okke Schrijvers, Frits van Bommel, Kevin Buchin
2013 2013 10th International Symposium on Voronoi Diagrams in Science and Engineering  
We explore ways to obtain a practical algorithm for Delaunay triangulations in the plane that runs in linear time for small integers.  ...  We implement the first O(n)-time algorithm for constructing Delaunay triangulations and found that our implementations are practical.  ...  Integer sorting algorithms like radix sort are not only fast in theory, but also run fast in experiments (see for example [17] ).  ... 
doi:10.1109/isvd.2013.10 dblp:conf/isvd/SchrijversBB13 fatcat:hzxt72fxr5fvvlpapjeerfxfg4

Parallel randomized load balancing

Micah Adler, Soumen Chakrabarti, Michael Mitzenmacher, Lars Rasmussen
1998 Random structures & algorithms (Print)  
We then demonstrate parallelizations of the sequential strategy presented in Azar et al. that achieve loads within a constant factor of the lower bound for two communication rounds and almost match the  ...  This strategy matches the lower bounds up to a constant factor for any constant number of rounds.  ...  We thank Claire Kenyon and Orli Waarts for suggesting the random graph model, pointing us to [1] , and several helpful related ideas.  ... 
doi:10.1002/(sici)1098-2418(199809)13:2<159::aid-rsa3>;2-z fatcat:almja2jawzhexipf6cezggghru

Enhanced Ant Colony-Inspired ParallelAlgorithm to Improve Cryptographic PRNGs

J�rg Keller, Gabriele Spenger, Steffen Wendzel
2017 Journal of Cyber Security and Mobility  
The runtime of the parallel algorithm is improved by an analogy to ant colony behavior: if two paths meet, the resulting path is followed at accelerated speed just as ants tend to reinforce paths that  ...  We present and motivate a parallel algorithm to compute promising candidate states for modifying the state space of a pseudo-random number generator in order to increase its cycle length.  ...  Acknowledgement We thank Christoph Kessler of Linköpings Universitet in Sweden for his help modeling the exploration of unknown trees and the distinction of the online and offline case.  ... 
doi:10.13052/jcsm2245-1439.623 fatcat:rh7etiwuxbdflnq63ljozf5ova

Geometric ad-hoc routing

Fabian Kuhn, Roger Wattenhofer, Yan Zhang, Aaron Zollinger
2003 Proceedings of the twenty-second annual symposium on Principles of distributed computing - PODC '03  
In particular we consider two aspects: We propose a new geometric routing algorithm which is outstandingly efficient on practical average-case networks, however is also in theory asymptotically worst-case  ...  All too often a seemingly insurmountable divide between theory and practice can be witnessed. In this paper we try to contribute to narrowing this gap in the field of ad-hoc routing.  ...  Thereibre, the cost of any algorithm ,.4 is unbounded with respect to the best path p*, which has constant cost. [] CONCLUSION Trying to help bridging the chasm between theory and practice in the field  ... 
doi:10.1145/872035.872044 dblp:conf/podc/KuhnWZZ03 fatcat:ujyzrkf4avaqhhlkogiw2ynecq

Breaking the Linear-Memory Barrier in MPC: Fast MIS on Trees with Strongly Sublinear Memory [article]

Sebastian Brandt and Manuela Fischer and Jara Uitto
2019 arXiv   pre-print
Recently, studying fundamental graph problems in the Massively Parallel Computation (MPC) framework, inspired by the MapReduce paradigm, has gained a lot of attention.  ...  In particular, we show that the Maximal Independent Set (MIS) problem can be solved efficiently, that is, in O(log^3 log n) rounds, when the input graph is a tree.  ...  Even for dense graphs, where in theory the sublinear memory constraint is met, practicability of the parameter range does not need to be ensured; linear or slightly sublinear in n might be prohibitively  ... 
arXiv:1802.06748v3 fatcat:njedklaufrgndnz6nv4hubhmda

Distributed Graph Diameter Approximation

Matteo Ceccarello, Andrea Pietracaprina, Geppino Pucci, Eli Upfal
2020 Algorithms  
than the one exhibited by a natural approximation algorithm based on the state-of-the-art Δ-stepping SSSP algorithm, which is its only practical, linear-space competitor in the distributed setting.  ...  Theoretically, our algorithm uses linear space and yields a polylogarithmic approximation guarantee; most importantly, for a large family of graphs, it features a round complexity asymptotically smaller  ...  The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.  ... 
doi:10.3390/a13090216 fatcat:744uvadkf5benfu5zjumiwloie
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