The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform
Arno Pauly - One of the best experts on this subject based on the ideXlab platform.
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function spaces for second order polynomial time
Conference on Computability in Europe, 2014Co-Authors: Akitoshi Kawamura, Arno PaulyAbstract:In the context of second-order polynomial-time computability, we prove that there is no general function space construction. We proceed to identify restrictions on the domain or the Codomain that do provide a function space with polynomial-time function evaluation containing all polynomial-time computable functions of that type.
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function spaces for second order polynomial time
arXiv: Computational Complexity, 2014Co-Authors: Akitoshi Kawamura, Arno PaulyAbstract:In the context of second-order polynomial-time computability, we prove that there is no general function space construction. We proceed to identify restrictions on the domain or the Codomain that do provide a function space with polynomial-time function evaluation containing all polynomial-time computable functions of that type. As side results we show that a polynomial-time counterpart to admissibility of a representation is not a suitable criterion for natural representations, and that the Weihrauch degrees embed into the polynomial-time Weihrauch degrees.
Akitoshi Kawamura - One of the best experts on this subject based on the ideXlab platform.
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function spaces for second order polynomial time
Conference on Computability in Europe, 2014Co-Authors: Akitoshi Kawamura, Arno PaulyAbstract:In the context of second-order polynomial-time computability, we prove that there is no general function space construction. We proceed to identify restrictions on the domain or the Codomain that do provide a function space with polynomial-time function evaluation containing all polynomial-time computable functions of that type.
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function spaces for second order polynomial time
arXiv: Computational Complexity, 2014Co-Authors: Akitoshi Kawamura, Arno PaulyAbstract:In the context of second-order polynomial-time computability, we prove that there is no general function space construction. We proceed to identify restrictions on the domain or the Codomain that do provide a function space with polynomial-time function evaluation containing all polynomial-time computable functions of that type. As side results we show that a polynomial-time counterpart to admissibility of a representation is not a suitable criterion for natural representations, and that the Weihrauch degrees embed into the polynomial-time Weihrauch degrees.
Edward D Sturrock - One of the best experts on this subject based on the ideXlab platform.
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characterization of domain selective inhibitor binding in angiotensin converting enzyme using a novel derivative of lisinopril
Biochemical Journal, 2010Co-Authors: Jean M Watermeyer, Wendy L Kroger, Hester G Oneill, Trevor B Sewell, Edward D SturrockAbstract:�tryptophan moiety takes a different conformation to that seen in other inhibitors having a tryptophan residue in this position. We have examined further the domain-specific interactions of this inhibitor by mutating Cdomain-specific active-site residues to their N domain equivalents, then assessing the effect of the mutation on inhibition by lisWS using a fluorescence-based assay. Kinetics analysis shows a 258-fold domain-selectivity that is largely due to the co-operative effect of C-domain-specific residues in the S2 � subsite. The high affinity and selectivity of this inhibitor make it a good lead candidate for cardiovascular drug development.
Francisco J Rodriguez - One of the best experts on this subject based on the ideXlab platform.
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on the definition of suitable orderings to generate adjunctions over an unstructured Codomain
Information Sciences, 2014Co-Authors: Francisca Garciapardo, Inma P Cabrera, Pablo Cordero, Manuel Ojedaaciego, Francisco J RodriguezAbstract:Given a mappingf:A->B from a (pre-)ordered set A into an unstructured set B, we study the problem of defining a suitable (pre-)ordering relation on B such that there exists a mapping g:B->A such that the pair of mappings (f,g) forms an adjunction between (pre-)ordered sets. The necessary and sufficient conditions obtained are then expressed in terms of closure operators and closure systems.
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generating isotone galois connections on an unstructured Codomain
International Conference Information Processing, 2014Co-Authors: Francisca Garciapardo, Inma P Cabrera, Pablo Cordero, Manuel Ojedaaciego, Francisco J RodriguezAbstract:Given a mapping f : A → B from a partially ordered set A into an unstructured set B, we study the problem of defining a suitable partial ordering relation on B such that there exists a mapping g : B → A such that the pair of mappings (f,g) forms an isotone Galois connection between partially ordered sets.
Luc Florack - One of the best experts on this subject based on the ideXlab platform.
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Finsler Streamline Tracking with Single Tensor Orientation Distribution Function for High Angular Resolution Diffusion Imaging
Journal of Mathematical Imaging and Vision, 2011Co-Authors: Laura Astola, Andrei Jalba, Evgeniya Balmashnova, Luc FlorackAbstract:We introduce a new framework based on Riemann-Finsler geometry for the analysis of 3D images with spherical Codomain, more precisely, for which each voxel contains a set of directional measurements represented as samples on the unit sphere (antipodal points identified). The application we consider here is in medical imaging, notably in High Angular Resolution Diffusion Imaging (HARDI), but the methods are general and can be applied also in other contexts, such as material science, et cetera, whenever direction dependent quantities are relevant. Finding neural axons in human brain white matter is of significant importance in understanding human neurophysiology, and the possibility to extract them from a HARDI image has a potentially major impact on clinical practice, such as in neuronavigation, deep brain stimulation, et cetera. In this paper we introduce a novel fiber tracking method which is a generalization of the streamline tracking used extensively in Diffusion Tensor Imaging (DTI). This method is capable of finding intersecting fibers in voxels with complex diffusion profiles, and does not involve solving extrema of these profiles. We also introduce a single tensor representation for the orientation distribution function (ODF) to model the probability that a vector corresponds to a tangent of a fiber. The single tensor representation is chosen because it allows a natural choice of Finsler norm as well as regularization via the Laplace-Beltrami operator. In addition we define a new connectivity measure for HARDI-curves to filter the most prominent fiber candidates. We show some very promising results on both synthetic and real data.
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Codomain scale space and regularization for high angular resolution diffusion imaging
CASA-report, 2008Co-Authors: Luc FlorackAbstract:Regularization is an important aspect in high angular resolution diffusion imaging (HARDI), since, unlike with classical diffusion tensor imaging (DTI), there is no a priori regularity of raw data in the co-domain, i.e. considered as a multispectral signal for fixed spatial position. HARDI preprocessing is therefore a crucial step prior to any subsequent analysis, and some insight in regularization paradigms and their interrelations is compulsory. In this paper we posit a Codomain scale space regularization paradigm that has hitherto not been applied in the context of HARDI. Unlike previous (first and second order) schemes it is based on infinite order regularization, yet can be fully operationalized. We furthermore establish a closed-form relation with first order Tikhonov regularization via the Laplace transform.
