Showing papers on "Antisymmetry published in 2010"

Why Are There No Directionality Parameters

Abstract: A “why”-question such as the one in the title can be interpreted in at least two ways. On the one hand it can be interpreted as asking for evidence supporting the assertion that there are no directionality parameters. I touch on some crosslinguistic evidence of this sort in the first part of this paper (introduction and sections 2 and 3). A second interpretation of the title question takes it for granted that there are no directionality parameters, and then asks why the language faculty should be put together in that fashion. In section 4, I argue that a derivational approach to antisymmetry can provide an answer.

An oriented flux symmetry based active contour model for three dimensional vessel segmentation

Abstract: This paper proposes a novel approach to segment three dimensional curvilinear structures, particularly vessels in angiography, by inspecting the symmetry of image gradients. The proposed method stresses the importance of simultaneously considering both the gradient symmetry with respect to the curvilinear structure center, and the gradient antisymmetry with respect to the object boundary. Measuring the image gradient symmetry remarkably suppresses the disturbance introduced by rapid intensity changes along curvilinear structures. Meanwhile, considering the image gradient antisymmetry helps locate the structure boundary. The gradient symmetry and the gradient antisymmetry are evaluated based on the notion of oriented flux. By utilizing the aforementioned gradient symmetry information, an active contour model is tailored to perform segmentation. On the one hand, by exploiting the symmetric image gradient pattern observed at structure centers, the contours expand along curvilinear structures even through there exists intensity fluctuation along the structures. On the other hand, measuring the antisymmetry of the image gradient conveys strong detection responses to precisely drive contours to the structure boundaries, as well as avoiding contour leakages. The proposed method is capable of delivering promising segmentation results. This is validated in the experiments using synthetic data and real vascular images of different modalities, and through the comparison to two well founded and published methods for curvilinear structure segmentation.

An oriented flux symmetry based active contour model for three dimensional vessel segmentation

Abstract: This paper proposes a novel approach to segment three dimensional curvilinear structures, particularly vessels in angiography, by inspecting the symmetry of image gradients. The proposed method stresses the importance of simultaneously considering both the gradient symmetry with respect to the curvilinear structure center, and the gradient antisymmetry with respect to the object boundary. Measuring the image gradient symmetry remarkably suppresses the disturbance introduced by rapid intensity changes along curvilinear structures. Meanwhile, considering the image gradient antisymmetry helps locate the structure boundary. The gradient symmetry and the gradient antisymmetry are evaluated based on the notion of oriented flux. By utilizing the aforementioned gradient symmetry information, an active contour model is tailored to perform segmentation. On the one hand, by exploiting the symmetric image gradient pattern observed at structure centers, the contours expand along curvilinear structures even through there exists intensity fluctuation along the structures. On the other hand, measuring the antisymmetry of the image gradient conveys strong detection responses to precisely drive contours to the structure boundaries, as well as avoiding contour leakages. The proposed method is capable of delivering promising segmentation results. This is validated in the experiments using synthetic data and real vascular images of different modalities, and through the comparison to two well founded and published methods for curvilinear structure segmentation.

A center-of-mass principle for the multiparticle Schrödinger equation

Abstract: The center-of-mass principle is the key to the rapid computation of the interaction of a large number of classical particles. Electrons governed by the multiparticle Schrodinger equation have a much more complicated interaction mainly due to their spatial extent and the antisymmetry constraint on the total wave function of the combined electron system. We present a center-of-mass principle for quantum particles that accounts for this spatial extent, the antisymmetry constraint, and the potential operators. We use it to construct an algorithm for computing a size-consistent approximate wave function for large systems with simple geometries.

Japanese Multiple Nominative Constructions: The View of Antisymmetry

Abstract: This paper focuses on multiple nominative constructions (MNCs) in Japanese, pursuing the question of how nominative ga-marked phrases are syntactically licensed MNCs in Japanese, in which more than one gamarked phrase can occur within a clause, have widely been studied by a number of linguists (eg Fukui, 1986; Heycock, 1993; Kuno, 1973; Takezawa, 1987; Tateshi, 1994; Vermeulen, 2005; Whitman, 2001) A previous view with regard to syntactic positions for ga-marked phrases in Japanese MNCs is that each ga-phrase appears in multiple specifiers (Specs) (or multiple adjunction) of TP (eg Hiraiwa, 2001; Ura, 1996; Vermeulen 2005) I argue, however, that each ga-marked phrase does not occur in multiple Spec positions, but rather, they occur in different projections Following Kayne’s (1994) Antisymmetry approach, the analysis presented here provides good evidence that multiple Specs are not available at PF, which accordingly shows that (i) the LCA is a PF constraint and that (ii) phrase structure follows Antisymmetry It naturally follows that each ga-marked phrase and its predicate in an MNC are always mediated by a (functional) head This working paper is available in University of Pennsylvania Working Papers in Linguistics: http://repositoryupennedu/pwpl/ vol16/iss1/17 U Penn Working Papers in Linguistics, Volume 161, 2010 Japanese Multiple Nominative Constructions: The View of Antisymmetry

Central symmetry and antisymmetry of the microwave background inhomogeneities on Wilkinson Microwave Anisotropy Probe maps

Abstract: We performed a visual and numeric analysis of the deviation of the microwave background temperature on WMAP maps. We proved that the microwave background inhomogeneities possess the property of the central symmetry resulting from the two kinds of central symmetry of the opposite signs. After the computer modeling we have established the relation between the coefficient of the central symmetry and the values of the symmetrical and antisymmetrical components of the deviation of the temperature. The obtained distribution of the symmetry coefficient on the map of the celestial sphere in Mollweide projection testifies on a contribution of both kinds of central symmetry which is approximately equal on the average in absolute magnitude but opposite by sign and where one kind of the central symmetry prevails on some sections of the celestial sphere and another kind - on the others. The average resulting value of the symmetry coefficient on the sections with angular measures less than 15-200 varies within the range from -50% to +50% with some prevalence of the antisymmetry - the average coefficient of the central symmetry for the whole celestial sphere is -4 +/- 1%. (antisymmetry 4%). Small scale structure of the distribution indicates that it is the result of the combined action of the mechanisms of the central symmetry and central antisymmetry, close to 100%.