@proceedings {38545, title = {Transforming men into mice (polynomial algorithm for genomic distance problem)}, year = {1995}, month = {1995}, publisher = {IEEE Computer Society}, type = {http://doi.ieeecomputersociety.org/10.1109/SFCS.1995.492588}, address = {Los Alamitos, CA, USA}, abstract = {Many people believe that transformations of humans into mice happen only in fairy tales. However, despite some differences in appearance and habits, men and mice are genetically very similar. In the pioneering paper, J.H. Nadeau and B.A. Taylor (1984) estimated that surprisingly few genomic rearrangements (178/spl plusmn/39) happened since the divergence of human and mouse 80 million years ago. However, their analysis is nonconstructive and no rearrangement scenario for human-mouse evolution has been suggested yet. The problem is complicated by the fact that rearrangements in multi chromosomal genomes include inversions, translocations, fusions and fissions of chromosomes, a rather complex set of operations. As a result, at first glance, a polynomial algorithm for the genomic distance problem with all these operations looks almost as improbable as the transformation of a (real) man into a (real) mouse. We prove a duality theorem which expresses the genomic distance in terms of easily computable parameters reflecting different combinatorial properties of sets of strings. This theorem leads to a polynomial time algorithm for computing most parsimonious rearrangement scenarios. Based on this result and the latest comparative physical mapping data we have constructed a scenario of human-mouse evolution with 131 reversals/translocaitons/fusions/fissions. A combination of the genome rearrangement algorithm with the recently proposed experimental technique called ZOO FISH suggests a new constructive approach to the 100 year old problem of reconstructing mammalian evolution.}, keywords = {biology computing, combinatorial properties, comparative physical mapping data, computable parameters, duality (mathematics), duality theorem, evolution (biological), Genetics, genome rearrangement algorithm, genomic distance problem, genomic rearrangements, human-mouse evolution, mammalian evolution, multi chromosomal genomes, parsimonious rearrangement scenarios, pattern matching, polynomial algorithm, polynomial time algorithm, set theory, sorting, string matching, strings, zoo fish}, author = {Sridhar Hannenhalli and Pevzner, P. A.} } @proceedings {38208, title = {A distributed algorithm for ear decomposition}, year = {1993}, month = {1993}, publisher = {IEEE}, type = {10.1109/ICCI.1993.315382}, abstract = {A distributed algorithm for finding an ear decomposition of an asynchronous communication network with n nodes and m links is presented. At the completion of the algorithm either the ears are correctly labeled or the nodes are informed that there exists no ear decomposition. First we present a novel algorithm to check the existence of an ear decomposition which uses O(m) messages. We also present two other algorithms, one which is time-optimal and the other which is message-optimal to determine the actual ears and their corresponding numbers after determining the existence of an ear decomposition}, keywords = {Asynchronous communication, asynchronous communication network, Automata, Communication networks, computational complexity, Computer networks, Computer science, decomposition graph, distributed algorithm, distributed algorithms, Distributed computing, Ear, ear decomposition, graph theory, message-optimal, network decomposition, sorting, Testing, time-optimal}, isbn = {0-8186-4212-2}, author = {Sridhar Hannenhalli and Perumalla, K. and Chandrasekharan, N. and Sridhar, R.} } @proceedings {38419, title = {Parallel transitive closure computations using topological sort}, year = {1991}, month = {1991}, publisher = {IEEE}, type = {10.1109/PDIS.1991.183079}, abstract = {Deals with parallel transitive closure computations. The sort-based approaches introduced sorts the tuples of the relation into topological order, and the sorted relation is then horizontally partitioned and distributed across several processing nodes of a message passing multiprocessor system. This data partitioning strategy allows the transitive closure computation of the local data fragments to be computed in parallel with no interprocessor communication. The construction of the final result then requires only a small number of joins. Extensive analytical results are included in the paper as well. They show that the proposed techniques leads to a speedup that is essentially linear with the number of processors. Its performance is significantly better than the recently published hashless parallel algorithm}, keywords = {Computer science, Concurrent computing, data partitioning, Database systems, database theory, deductive databases, File systems, horizontal partitioning, joins, local data fragments, message passing multiprocessor system, Multiprocessing systems, Parallel algorithms, PARALLEL PROCESSING, parallel programming, parallel transitive closure, processing nodes, relation tuples, Relational databases, sorting, topological sort}, isbn = {0-8186-2295-4}, author = {Hua, K. A. and Sridhar Hannenhalli} }