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‣ Terbium(III) and dysprosium(III) 8-connected 3D networks containing 2,5-thiophenedicarboxylate anion: Crystal structures and photoluminescence studies

Marques, Lippy F.; dos Santos, Moliria V.; Ribeiro, Sidney J. L.; Castellano, Eduardo Ernesto; Machado, Flavia C.
Fonte: PERGAMON-ELSEVIER SCIENCE LTD; OXFORD Publicador: PERGAMON-ELSEVIER SCIENCE LTD; OXFORD
Tipo: Artigo de Revista Científica
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Two novel coordination polymers with the formula {[Ln(2)(2,5-tdc)(3)(dmso)(2)].H2O}(n) (Ln = Tb(III) for (1) and Dy(III) for (2)), (2,5-tdc(2-) = 2,5-thiophenedicarboxylate and dmso = dimethylsulfoxide) have been synthesized by the diffusion method and characterized by thermal analysis, vibrational spectroscopy and single crystal X-ray diffraction analysis. Structure analysis reveals that 2,5-tdc(2-) play a versatile role toward different lanthanide ions to form three-dimensional metal-organic frameworks (MOFs) in which the lanthanides ions are heptacoordinated. Photophysical properties were studied using excitation and emission spectra, where the photoluminescence data show the high emission intensity of the characteristic transitions D-5(4 ->) F-7(J) (J= 6, 5, 4 and 3) for (1) and (F9/2 -> HJ)-F-4-H-6 (J = 15/2, 13/2 and 11/2) for (2), indicating that 2,5-tdc(2-) is a good sensitizer. (C) 2012 Elsevier Ltd. All rights reserved.; CNPq; CNPq; CAPES; CAPES; FAPEMIG; FAP-EMIG [CEX-APQ 01565-09]

‣ Purification and characterization of the biological effects of phospholipase A(2) from sea anemone Bunodosoma caissarum

Martins, Rene D.; Alves, Renata S.; Martins, Alice M. C.; Barbosa, Paulo Sergio F.; Evangelista, Janaina S. A. M.; Evangelista, João José F.; Ximenes, Rafael M.; Toyama, Marcos H.; Toyama, Daniela O.; Souza, Alex Jardelino F.; Orts, Diego J. B.; Marango
Fonte: Pergamon-Elsevier B.V. Ltd Publicador: Pergamon-Elsevier B.V. Ltd
Tipo: Artigo de Revista Científica Formato: 413-420
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Sea anemones contain a variety of biologically active substances. Bunodosoma caissarum is a sea anemone from the Cnidaria phylum, found only in Brazilian coastal waters. The aim of the present work was to study the biological effects of PLA(2) isolated from the sea anemone B. caissarum on the isolated perfused kidney, the arteriolar mesenteric bed and on insulin secretion. Specimens of B. caissarum were collected from the Sao Vicente Channel on the southern coast of the State of São Paulo, Brazil. Reverse phase HPLC analysis of the crude extract of B. caissarum detected three PLA(2) proteins (named BcPLA(2)1, BCPLA(2)2 and BcPLA(2)3) found to be active in B. caissarum extracts. MALDI-TOF mass spectrometry of BcPLA(2)1 showed one main peak at 14.7 kDa. The N-terminal amino acid sequence of BcPLA(2)1 showed high amino acid sequence identity with PLA(2) group III protein isolated from the Mexican lizard (PA23 HELSU, HELSU, PA22 HELSU) and with the honey bee Apis mellifera (PLA(2) and 1POC_A). In addition, BcPLA(2)1 also showed significant overall homology to bee PLA(2). The enzymatic activity induced by native BCPLA(2)1 (20 mu g/well) was reduced by chemical treatment with p-bromophenacyl bromide (p-BPB) and with morin. BcPLA(2)1 strongly induced insulin secretion in presence of high glucose concentration. In isolated kidney...

‣ Terbium(III) and dysprosium(III) 8-connected 3D networks containing 2,5-thiophenedicarboxylate anion: Crystal structures and photoluminescence studies

Marques, Lippy F.; dos Santos, Moliria V.; Ribeiro, Sidney J. L.; Castellano, Eduardo Ernesto; Machado, Flavia C.
Fonte: Pergamon-Elsevier B.V. Ltd Publicador: Pergamon-Elsevier B.V. Ltd
Tipo: Artigo de Revista Científica Formato: 149-156
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Two novel coordination polymers with the formula {[Ln(2)(2,5-tdc)(3)(dmso)(2)].H2O}(n) (Ln = Tb(III) for (1) and Dy(III) for (2)), (2,5-tdc(2-) = 2,5-thiophenedicarboxylate and dmso = dimethylsulfoxide) have been synthesized by the diffusion method and characterized by thermal analysis, vibrational spectroscopy and single crystal X-ray diffraction analysis. Structure analysis reveals that 2,5-tdc(2-) play a versatile role toward different lanthanide ions to form three-dimensional metal-organic frameworks (MOFs) in which the lanthanides ions are heptacoordinated. Photophysical properties were studied using excitation and emission spectra, where the photoluminescence data show the high emission intensity of the characteristic transitions D-5(4 ->) F-7(J) (J= 6, 5, 4 and 3) for (1) and (F9/2 -> HJ)-F-4-H-6 (J = 15/2, 13/2 and 11/2) for (2), indicating that 2,5-tdc(2-) is a good sensitizer. (C) 2012 Elsevier Ltd. All rights reserved.

‣ Liquid Mixtures Involving Hydrogenated and Fluorinated Chains: (p, ρ, T, x) Surface of (Ethanol + 2,2,2-Trifluoroethanol), Experimental and Simulation

Duarte, Pedro; Silva, Marcelo; Rodrigues, Djêide; Morgado, Pedro; Martins, Luís F. G.; Filipe, Eduardo J. M.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
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The effect of mixing hydrogenated and fluorinated molecules that simultaneously interact through strong hydrogen bonding was investigated: (ethanol + 2,2,2-trifluoroethanol) binary mixtures were studied both experimentally and by computer simulation. This mixture displays a very complex behavior when compared with mixtures of hydrogenated alcohols and mixtures of alkanes and perfluoroalkanes. The excess volumes are large and positive (unlike those of mixtures of hydrogenated alchools), while the excess enthalpies are large and negative (contrasting with those of mixtures of alkanes and perfluoroalkanes). In this work, the liquid density of the mixtures was measured as a function of composition, at several temperatures from 278.15 to 353.15 K and from atmospheric pressure up to 70 MPa. The corresponding excess molar volumes, compressibilities, and expansivities were calculated over the whole (p, ρ, T, x) surface. In order to obtain molecular level insight, the behavior of the mixture was also studied by molecular dynamics simulation, using the OPLS-AA force field. The combined analysis of the experimental and simulation results indicates that the peculiar phase behavior of this system stems from a balance between the weak dispersion forces between the hydrogenated and fluorinated groups and a preferential hydrogen bond between ethanol and 2...

‣ Autoria na Web 2.0 no contexto da educação e a ética dos hackers.

SOUZA, M. I. F.; AMARAL, S. F. do; SILVA, L. C.; ARAÚJO, I. C.
Fonte: In: AMARAL, S. F. do; PRETTO, N. de L. (Org). Ética, Hacker e a Educação. 2. ed. Campinas: Faculdade de Educação/UNICAMP, 2012. Publicador: In: AMARAL, S. F. do; PRETTO, N. de L. (Org). Ética, Hacker e a Educação. 2. ed. Campinas: Faculdade de Educação/UNICAMP, 2012.
Tipo: Capítulo em livro técnico-científico (ALICE) Formato: p. 48-61.
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Este artigo discute a importância do exercício da autoria em ambiente virtual da Web 2.0, considerando que se trata de fundamento essencial à aprendizagem, no professor e no aluno. Autoria na Web 2.0 é apresentada como estratégia pedagógica para ambientes de aprendizagem virtuais, que se utilizam principalmente de ferramentas como blog, wiki e redes sociais. Embora não sejam determinantes essas, tecnologias digitais são condicionantes para que a aprendizagem e a autoria ocorram. Autoria na Web 2.0, além do estabelecimento de novos aparatos tecnológicos, requer novos modos de produção, nos quais prevaleça a postura ética dos hackers, favorecendo a participação, a colaboração, a liberdade e o compartilhamento.; 2012; Artigo publicado na revista ETD - Educação Temática Digital, Campinas, SP, v. 12, n. esp., p. 154-173, mar. 2011.

‣ Chaconne, aus der Violin-Sonate no. 4, D moll / Joh. Seb. Bach ; für zwei Violinen übertragen von Friedrich Hermann.; Sonaten und Partiten, violin, BWV 1001-1006. Partita, no. 2. Chaconne; arr.

Bach, Johann Sebastian (1685 - 1750); Hermann, F.
Fonte: F. Kistner Publicador: F. Kistner
Tipo: Musical Score
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2 parts ; 34 cm.
Cover title.
For 2 violins.

‣ lmmunohistochemical expression of Bcl-2 oncoprotein in EBV-associated nasopharyngeal carcinoma correlated to histological type and survival

vera-Sempere, F.J.; Burgos, J.S.; Botella, M.S.; Morera, C.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
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Expression of Bcl-2 is associated with inhibition of apoptosis and extension of cell survival. In vitro Bcl-2 protein expression is up-regulated by the EBV-latency associated antigen latent membrane protein (LMP-1). We have investigated the relationship between the presence of EBV-DNA screened by means of sensitive nested-PCR, nasopharyngeal carcinoma (NPC) histological types according to two different schemata (WHO and Micheau classifications) and Bcl-2-124 immunohistochemical expression in 55 biopsy samples of NPC. EBV genome was detected in 100% of samples with sufficient DNA quality to support the previous view that al1 types of NPC are variants of EBV-infected neoplasia. Bcl-2 was observed in the basa1 layer of normal nasopharyngeal mucosa and also at cytoplasmic level in 42 of 55 (76.4%) NPC cases. Mitotic neoplastic cells usually showed strong cytoplasmic and chromosomal staining, a finding not well referred to previously. Bcl-2 expression was significantly associated (p<0.05) to undifferentiated NPC (UNPC) when a histological classification with only two major microscopical types was applied. No close correlations were found between the presence of EBV-DNA, NPC location, clinical stage and age or sex of the patients in relation to Bcl-2 positive expression. However...

‣ Minimum Opaque Covers for Polygonal Regions

Provan, J. Scott; Brazil, Marcus; Thomas, Doreen; Weng, Jia F.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/10/2012 Português
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The Opaque Cover Problem (OCP), also known as the Beam Detector Problem, is the problem of finding, for a set S in Euclidean space, the minimum-length set F which intersects every straight line passing through S. In spite of its simplicity, the problem remains remarkably intractable. The aim of this paper is to establish a framework and fundamental results for minimum opaque covers where S is a polygonal region in two-dimensional space. We begin by giving some general results about opaque covers, and describe the close connection that the OCP has with the Point Goalie Problem. We then consider properties of graphical solutions to the OCP when S is a convex polygonal region in the plane.

‣ Binar Sort: A Linear Generalized Sorting Algorithm

Gilreath, William F.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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Sorting is a common and ubiquitous activity for computers. It is not surprising that there exist a plethora of sorting algorithms. For all the sorting algorithms, it is an accepted performance limit that sorting algorithms are linearithmic or O(N lg N). The linearithmic lower bound in performance stems from the fact that the sorting algorithms use the ordering property of the data. The sorting algorithm uses comparison by the ordering property to arrange the data elements from an initial permutation into a sorted permutation. Linear O(N) sorting algorithms exist, but use a priori knowledge of the data to use a specific property of the data and thus have greater performance. In contrast, the linearithmic sorting algorithms are generalized by using a universal property of data-comparison, but have a linearithmic performance lower bound. The trade-off in sorting algorithms is generality for performance by the chosen property used to sort the data elements. A general-purpose, linear sorting algorithm in the context of the trade-off of performance for generality at first consideration seems implausible. But, there is an implicit assumption that only the ordering property is universal. But, as will be discussed and examined, it is not the only universal property for data elements. The binar sort is a general-purpose sorting algorithm that uses this other universal property to sort linearly.; Comment: PDF from Word...

‣ F-Harmonic maps as global maxima

Benallal, Mohammed Benalili Hafida
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 05/10/2012 Português
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In this note, we show that some F-harmonic maps into spheres are global maxima of the variations of their energy functional on the conformal group of the sphere. Our result extends partially those obtained in [15] and [17] for harmonic and p-harmonic maps.; Comment: 11

‣ Verification of Ptime Reducibility for system F Terms: Type Inference in
Dual Light Affine Logic

Atassi, Vincent; Baillot, Patrick; Terui, Kazushige
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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In a previous work Baillot and Terui introduced Dual light affine logic (DLAL) as a variant of Light linear logic suitable for guaranteeing complexity properties on lambda calculus terms: all typable terms can be evaluated in polynomial time by beta reduction and all Ptime functions can be represented. In the present work we address the problem of typing lambda-terms in second-order DLAL. For that we give a procedure which, starting with a term typed in system F, determines whether it is typable in DLAL and outputs a concrete typing if there exists any. We show that our procedure can be run in time polynomial in the size of the original Church typed system F term.; Comment: 32 pages, 8 figures

‣ On Structural Parameterizations of Hitting Set: Hitting Paths in Graphs Using 2-SAT

Jansen, Bart M. P.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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Hitting Set is a classic problem in combinatorial optimization. Its input consists of a set system F over a finite universe U and an integer t; the question is whether there is a set of t elements that intersects every set in F. The Hitting Set problem parameterized by the size of the solution is a well-known W[2]-complete problem in parameterized complexity theory. In this paper we investigate the complexity of Hitting Set under various structural parameterizations of the input. Our starting point is the folklore result that Hitting Set is polynomial-time solvable if there is a tree T on vertex set U such that the sets in F induce connected subtrees of T. We consider the case that there is a treelike graph with vertex set U such that the sets in F induce connected subgraphs; the parameter of the problem is a measure of how treelike the graph is. Our main positive result is an algorithm that, given a graph G with cyclomatic number k, a collection P of simple paths in G, and an integer t, determines in time 2^{5k} (|G| +|P|)^O(1) whether there is a vertex set of size t that hits all paths in P. It is based on a connection to the 2-SAT problem in multiple valued logic. For other parameterizations we derive W[1]-hardness and para-NP-completeness results.; Comment: Presented at the 41st International Workshop on Graph-Theoretic Concepts in Computer Science...

‣ The Threshold for Random k-SAT is 2^k ln2 - O(k)

Achlioptas, Dimitris; Peres, Yuval
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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Let F be a random k-SAT formula on n variables, formed by selecting uniformly and independently m = rn out of all possible k-clauses. It is well-known that if r>2^k ln 2, then the formula F is unsatisfiable with probability that tends to 1 as n tends to infinity. We prove that there exists a sequence t_k = O(k) such that if r < 2^k ln 2 - t_k, then the formula F is satisfiable with probability that tends to 1 as n tends to infinity. Our technique yields an explicit lower bound for the random k-SAT threshold for every k. For k>3 this improves upon all previously known lower bounds. For example, when k=10 our lower bound is 704.94 while the upper bound is 708.94.; Comment: Added figures and explained the intuition behind our approach. Made a correction following comments of Chris Calabro

‣ Abstract Milling with Turn Costs

Fellows, M.; Giannopoulos, P.; Knauer, C.; Paul, C.; Rosamond, F.; Whitesides, S.; Yu, N.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 05/12/2009 Português
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The Abstract Milling problem is a natural and quite general graph-theoretic model for geometric milling problems. Given a graph, one asks for a walk that covers all its vertices with a minimum number of turns, as specified in the graph model by a 0/1 turncost function fx at each vertex x giving, for each ordered pair of edges (e,f) incident at x, the turn cost at x of a walk that enters the vertex on edge e and departs on edge f. We describe an initial study of the parameterized complexity of the problem. Our main positive result shows that Abstract Milling, parameterized by: number of turns, treewidth and maximum degree, is fixed-parameter tractable, We also show that Abstract Milling parameterized by (only) the number of turns and the pathwidth, is hard for W[1] -- one of the few parameterized intractability results for bounded pathwidth.; Comment: 18 pages, 2 figures

‣ Maximum Edge-Disjoint Paths in $k$-sums of Graphs

Chekuri, Chandra; Naves, Guyslain; Shepherd, F. Bruce
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/03/2013 Português
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We consider the approximability of the maximum edge-disjoint paths problem (MEDP) in undirected graphs, and in particular, the integrality gap of the natural multicommodity flow based relaxation for it. The integrality gap is known to be $\Omega(\sqrt{n})$ even for planar graphs due to a simple topological obstruction and a major focus, following earlier work, has been understanding the gap if some constant congestion is allowed. In this context, it is natural to ask for which classes of graphs does a constant-factor constant-congestion property hold. It is easy to deduce that for given constant bounds on the approximation and congestion, the class of "nice" graphs is nor-closed. Is the converse true? Does every proper minor-closed family of graphs exhibit a constant factor, constant congestion bound relative to the LP relaxation? We conjecture that the answer is yes. One stumbling block has been that such bounds were not known for bounded treewidth graphs (or even treewidth 3). In this paper we give a polytime algorithm which takes a fractional routing solution in a graph of bounded treewidth and is able to integrally route a constant fraction of the LP solution's value. Note that we do not incur any edge congestion. Previously this was not known even for series parallel graphs which have treewidth 2. The algorithm is based on a more general argument that applies to $k$-sums of graphs in some graph family...

‣ Mantaining Dynamic Matrices for Fully Dynamic Transitive Closure

Demetrescu, Camil; Italiano, Giuseppe F.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 31/03/2001 Português
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In this paper we introduce a general framework for casting fully dynamic transitive closure into the problem of reevaluating polynomials over matrices. With this technique, we improve the best known bounds for fully dynamic transitive closure. In particular, we devise a deterministic algorithm for general directed graphs that achieves $O(n^2)$ amortized time for updates, while preserving unit worst-case cost for queries. In case of deletions only, our algorithm performs updates faster in O(n) amortized time. Our matrix-based approach yields an algorithm for directed acyclic graphs that breaks through the $O(n^2)$ barrier on the single-operation complexity of fully dynamic transitive closure. We can answer queries in $O(n^\epsilon)$ time and perform updates in $O(n^{\omega(1,\epsilon,1)-\epsilon}+n^{1+\epsilon})$ time, for any $\epsilon\in[0,1]$, where $\omega(1,\epsilon,1)$ is the exponent of the multiplication of an $n\times n^{\epsilon}$ matrix by an $n^{\epsilon}\times n$ matrix. The current best bounds on $\omega(1,\epsilon,1)$ imply an $O(n^{0.58})$ query time and an $O(n^{1.58})$ update time. Our subquadratic algorithm is randomized, and has one-side error.; Comment: 52 pages, 5 figures

‣ Seeded PageRank Solution Paths

Kloster, Kyle; Gleich, David F.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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We study the behavior of network diffusions based on the PageRank random walk from a set of seed nodes. These diffusions are known to reveal small, localized clusters (or communities) and also large macro-scale clusters by varying a parameter that has a dual-interpretation as an accuracy bound and as a regularization level. We propose a new method that quickly approximates the result of the diffusion for all values of this parameter. Our method efficiently generates an approximate $\textit{solution path}$ or $\textit{regularization path}$ associated with a PageRank diffusion, and it reveals cluster structures at multiple size-scales between small and large. We formally prove a runtime bound on this method that is independent of the size of the network, and we investigate multiple optimizations to our method that can be more practical in some settings. We demonstrate that these methods identify refined clustering structure on a number of real-world networks with up to 2 billion edges.; Comment: 29 pages, 8 figures

‣ The $Tb$-theorem on non-homogeneous spaces that proves a conjecture of Vitushkin

Nazarov, F.; Treil, S.; Volberg, A.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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This article was written in 1999, and was posted as a preprint in CRM (Barcelona) preprint series $n^0\, 519$ in 2000. However, recently CRM erased all preprints dated before 2006 from its site, and this paper became inacessible. It has certain importance though, as the reader shall see. Formally this paper is a proof of the (qualitative version of the) Vitushkin conjecture. The last section is concerned with the quantitative version. This quantitative version turns out to be very important. It allowed Xavier Tolsa to close the subject concerning Vtushkin's conjectures: namely, using the quantitative nonhomogeneous $Tb$ theorem proved in the present paper, he proved the semiadditivity of analytic capacity. Another "theorem", which is implicitly contained in this paper, is the statement that any non-vanishing $L^2$-function is accretive in the sense that if one has a finite measure $\mu$ on the complex plane ${\mathbb C}$ that is Ahlfors at almost every point (i.e. for $\mu$-almost every $x\in {\mathbb C}$ there exists a constant $M>0$ such that $\mu(B(x,r))\le Mr$ for every $r>0$) then any one-dimensional antisymmetric Calder\'on-Zygmund operator $K$ (e.g. a Cauchy integral type operator) satisfies the following "all-or-nothing" princple: if there exists at least one function $\phi\in L^2(\mu)$ such that $\phi(x)\ne 0$ for $\mu$-almost every $x\in {\mathbb C}$ and such that {\it the maximal singular operator} $K^*\phi\in L^2(\mu)$...

‣ Data Structures for Mergeable Trees

Georgiadis, Loukas; Kaplan, Haim; Shafrir, Nira; Tarjan, Robert E.; Werneck, Renato F.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 11/11/2007 Português
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Motivated by an application in computational topology, we consider a novel variant of the problem of efficiently maintaining dynamic rooted trees. This variant requires merging two paths in a single operation. In contrast to the standard problem, in which only one tree arc changes at a time, a single merge operation can change many arcs. In spite of this, we develop a data structure that supports merges on an n-node forest in O(log^2 n) amortized time and all other standard tree operations in O(log n) time (amortized, worst-case, or randomized depending on the underlying data structure). For the special case that occurs in the motivating application, in which arbitrary arc deletions (cuts) are not allowed, we give a data structure with an O(log n) time bound per operation. This is asymptotically optimal under certain assumptions. For the even-more special case in which both cuts and parent queries are disallowed, we give an alternative O(log n)-time solution that uses standard dynamic trees as a black box. This solution also applies to the motivating application. Our methods use previous work on dynamic trees in various ways, but the analysis of each algorithm requires novel ideas. We also investigate lower bounds for the problem under various assumptions.

‣ 2-manifold recognition is in logspace

Burton, Benjamin A.; Elder, Murray; Kalka, Arkadius; Tillmann, Stephan
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 02/12/2014 Português
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We prove that the homeomorphism problem for 2-manifolds can be decided in logspace. The proof relies on Reingold's logspace solution to the undirected $s,t$-connectivity problem in graphs.; Comment: 11 pages, 2 figures