D. Alberts, G. Cattaneo, and G.F. Italiano. An empirical study of dynamic graph algorithms. ACM Journal on Experimental Algorithmics, 2(5), 1997.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....the fully dynamic single source shortest paths problem in digraphs with positive real arc weights. We are not aware of any experimental study in the case of arbitrary arc weights. On the other hand, several papers report on experimental works concerning different dynamic graph problems (see e.g. [2, 3, 11]) In this paper we make a step toward this direction and we present the first experimental study of the fully dynamic single source shortest paths problem in digraphs with arbitrary (negative and non negative) arc weights. We implemented and experimented several algorithms for updating shortest ....

....codes. 2.63 3.034 3.864 4.484 5.481 6.549 6.941 8.261 2.318 4.037 5.068 5.547 6.647 2.816 3.328 3.813 3.882 4.501 0.757 0.729 0.907 1.052 1.265 1.491 1.574 1.873 1.588 1.387 3.008 1.969 1.944 2. 484 0 1 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 10 11 Arc Weight Interval [ 2 ,2 ] Average Running Time per Operation (msec) DFMN RR DF ALL DECR n=300, m=0.5n 2 =45000 0.78 0.9 1.46 2.03 2.84 3.65 4.02 4.89 2.09 2.14 2.84 3.21 3.78 4.35 4.45 5.16 1.79 1.77 2.35 2.75 3.32 3.98 4.2 5.05 0 1 2 3 4 5 6 2 3 4 5 6 7 8 9 10 11 Arc Weight ....

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D. Alberts, G. Cattaneo, and G. F. Italiano. An empirical study of dynamic graph algorithms. ACM Journal on Experimental Algorithmics, 2:Article 5, 1997.

.... of important theoretical results have been obtained for both fully and partially dynamic maintenance of several properties on undirected graphs (see e.g. 12, 13, 14, 15, 22, 31] Recently, an equally important e ort has started on implementing these techniques and showing their practical merits [1, 2]. These were the rst implementations concerning fully dynamic maintenance of certain properties (connectivity, minimum spanning tree) in undirected graphs, as well as the rst implementation of sparsi cation, a technique for speeding up dynamic graph algorithms [13] On the other hand, the ....

....run on the Ultra Sparc. 3.2 Non random inputs In addition to random inputs, we also wanted to test our implementations on structured, nonrandom inputs that try to enforce bad update patterns for the dynamic algorithms. The construction of our non random inputs were inspired from those proposed in [1]. We considered both non random digraphs and non random DAGs. Non random digraphs and their sequences were de ned as follows. Each such graph G(n; k) is characterized by two parameters: n being the number of vertices and an integer k, k 0. G(n; k) has exactly n vertices grouped into s = dn=ke ....

D. Alberts, G. Cattaneo, and G. F. Italiano. An empirical study of dynamic graph algorithms. ACM Journal of Experimental Algorithmics, 2:# 5, 1997.

....for the shortest paths problem (see e.g. 10, 11, 21] but nothing is known for the experimental evaluation of dynamic shortest path algorithms. On the contrary this is not the case for other important dynamic graph problems, as, for example, for connectivity and for minimum spanning tree [3, 5]. In this paper we make a first step toward this direction. We implemented the algorithms proposed by Ramalingam and Reps in [31] denoted as RR) and the one proposed by Frigioni et al. in [18, 19] denoted as FMN) and evaluated the practical performances of those algorithms in a fully dynamic ....

D. Alberts, G. Cattaneo, and G. F. Italiano. An empirical study of dynamic graph algorithms. In ACM-SIAM Symposium on Discrete Algorithms, pages 192--201, 1996. To appear on ACM Journal on Experimental Algorithmics.

....amortized expected time per update and O(log n= log log n) worst case time per query, is presented. 2 This paper also gives a simpler deterministic fully dynamic connectivity algorithm with O( p n log n) time per update. An empirical study of the dynamic connectivity algorithms is presented in [1]. 2 Edge Connectivity and Quasi k Edge Connectivity: An incremental algorithm with O(ff(m; n) amortized time per operation was given in [23, 16] A backtracking algorithm with O(log n) worst case time per operation is presented in [17] The best known deterministic fully dynamic algorithm takes ....

David Alberts, Giuseppe Cattaneo, and Giuseppe F. Italiano. An empirical study of dynamic graph algorithms. In Proceedings of the Seventh Annual ACM SIAM Symp. on Discrete Algorithms, pages 192--201, 1996.

....set representations. Since new vertex operation is only invoked during the initialization, this explanation shows why the initialization time was improved much more than the update time in Implementation IV. We also made a comparison between our implementations and those of Alberts et al. [1], the only other experimental study of dynamic graph algorithms that we knew of (see Table 5) Our implementations run significantly faster as expected theoretically, since we have shown that our implementation runs in O(log n) amortized time per update, whereas the asymptotically fastest ....

D. Alberts, G. Cattaneo, and G. F. Italiano. An Empirical Study of Dynamic Graph Algorithms. Proc. ACM-SIAM SODA (1996): 192-201.

....practical per55 formances of static algorithms for shortest path problems (see e.g. 6] but nothing is known for the experimental evaluation of dynamic shortest path algorithms. This is not the case for other important dynamic graph problems, as, for example, the minimum spanning tree problem [2, 3]. In this paper we make a first small step in this direction. We implemented the algorithms proposed by Ramalingam and Reps in [15] denoted as RR) and the one proposed by Frigioni, Marchetti and Nanni in [12] FMN) and evaluated the practical performances of those algorithms in a fully dynamic ....

D. Alberts, G. Cattaneo, G. F. Italiano, An Empirical Study of Dynamic Graph Algorithms, J. of Experimental Algorithmics, to appear.

....in the initial graph, and multiply it by two since half of the test sequence operations are find block queries. 6.3 Test Results 17 The times (given in seconds) obtained from our tests are listed in Table 1, in ascending order of vertices and edges. We used the test results from Alberts et al. [3] as reference, which to our knowledge is the only other experimental study of dynamic graph algorithms. Alberts et al. measured their implementation of four different fully dynamic algorithms that maintained graph connectivity. For random inputs they indicated that none of these four algorithms ....

D. Alberts, G. Cattaneo, and G. F. Italiano. An Empirical Study of Dynamic Graph Algorithms. ACM-SIAM SODA (1996): 192-201.

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D. Alberts, G. Cattaneo, and G.F. Italiano. An empirical study of dynamic graph algorithms. ACM Journal on Experimental Algorithmics, 2(5), 1997.

....URL: http: www.info.uniroma2.it italiano . Part of this work was done while visiting the Max Planck Institut fur Informatik, Im Stadtwald, 66123 Saarbrucken, Germany. 1 Introduction In the last years research in dynamic graph algorithms has been a blossoming field (see e.g. [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 21, 22, 24]) The main dynamic model that has been considered in the literature is the following. We are given a graph G = V; E) and we wish to maintain some property P in G during edge deletions and edge insertions. We refer to this as the dynamic edge model . If the graph represents a communication ....

D. Alberts, G. Cattaneo, G. F. Italiano. An empirical study of dynamic graph algorithms. ACM Journal on Experimental Algorithmics, 2 (1997), Article 5.

....the interested reader to [27] for the details. 6 Research Issues and Summary In this chapter we have described the most efficient known algorithms for maintaining dynamic graphs. Experimental comparison of some of the dynamic connectivity algorithms has recently been performed by Alberts et al. [1], who showed that in the average case for sufficiently random inputs, a simple sparsification tree based on edge subdivision performs as well as the vertex subdivision method we described in Theorem 6. Furthermore, they compared this simplified sparsification algorithm (having a worst case update ....

D. Alberts, G. Cattaneo, and G. F. Italiano. An empirical study of dynamic graph algorithms. In Proc. 7th ACM-SIAM Symp. Discrete Algorithms, pages 192--201, 1996.

....and it finds applications to other problems as well, including many dynamic vertex and edge connectivity problems. Many elegant solutions have been proposed for the dynamic minimum spanning tree problem, such as the partitions and topology trees of Frederickson [8, 9] and sparsification [5] In [1] we tried to make a first step toward bridging the gap between the design and theoretical analysis of dynamic graph algorithms on the one side, and their implementation, experimental tuning and practical performance evaluation on the other side. In particular, in [1] the attention was devoted to ....

....9] and sparsification [5] In [1] we tried to make a first step toward bridging the gap between the design and theoretical analysis of dynamic graph algorithms on the one side, and their implementation, experimental tuning and practical performance evaluation on the other side. In particular, in [1] the attention was devoted to simpler fully dynamic connectivity problems: in this framework, the randomized algorithm of Henzinger and King [10] and a simple version of sparsification [5] on top of a static algorithm were implemented and tested. In this paper, we make another important step ....

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D. Alberts, G. Cattaneo, G. F. Italiano, "An empirical study of dynamic graph algorithms", Proc. 7th ACMSIAM Symp. on Discrete Algorithms (1996), 192--201.

....structure for G dcsimple dyncon( G) do something with the graph G.deledge(edges[4] G.deledge(edges[5] perform a connectivity query if(dyncon.query(nodes[0] nodes[9] cout dyncon.nodesyes( n ; else cout dyncon.nodesno( n ; do some more graph updates G. newedge(nodes[1],nodes[5] G.newedge(nodes[6] nodes[2] perform a global connectivity query if(dyncon.query( cout dyncon.globalyes( n ; else cout dyncon.globalno( n ; A Software Library of Dynamic Graph Algorithms 135 5 Conclusion and Future Plans Concerning dynamic transitive ....

....algorithm in [12] and plan to perform an extensive experimental study regarding this and the other dynamic algorithms mentioned in Section 2.3. More experimental studies (on dynamic connectivity and dynamic MST) have been performed using previous versions of the implementations in the library, see [1, 2]. It remains to add more implementations to the library and do more experimental studies. A problem which arises is the current lack of benchmarks for dynamic graph algorithms. There is even no library of static graphs in a commonly agreed standard format, but this will hopefully change in the ....

D. Alberts, G. Cattaneo and G. F. Italiano. An Empirical study of Dynamic Graph Algorithms. ACM J. Experimental Algorithmics 2(5), 1997. http://www.jea.acm.org/1997/AlbertsDynamic/

....the average case running time of simple sparsification and prove that for dynamic random graphs its logarithmic overhead vanishes. Work partly supported by the Commission of the European Communities under the ESPRIT LTR Project no. 20244 (ALCOM IT) A preliminary version of this work appears in [3]. y Part of this work was supported by the Deutsche Forschungsgemeinschaft, Grant We 1265 2 1, and Grant We 1265 5 1 (Leibniz Preis) z Work supported in part by a Research Grant from Universit a di Venezia Ca Foscari and the Italian MURST Project Efficienza di Algoritmi e Progetto di ....

D. Alberts, G. Cattaneo, G. F. Italiano, "An empirical study of dynamic graph algorithms" Proc. 7th ACM-SIAM Annual Symp. on Discrete Algorithms (SODA 96), Atlanta, GA, USA, 1996.

No context found.

D. Alberts, G. Cattaneo, and G.F. Italiano. An empirical study of dynamic graph algorithms. Proc. 7th ACM-SIAM Symp. on Discrete Algorithms, 1996, 192--201.

No context found.

D. Alberts, G. Cattaneo, and G.F. Italiano. An empirical study of dynamic graph algorithms. Proc. 7th ACM-SIAM Symp. on Discrete Algorithms, 1996, 192--201.

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