Multi-resolution data-structures and algorithms are key in visualization to achieve real-time interaction with large data-sets. Research has been primarily focused on the off-line construction of such representations ...
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Multi-resolution data-structures and algorithms are key in visualization to achieve real-time interaction with large data-sets. Research has been primarily focused on the off-line construction of such representations mostly using decimation schemes. Drawbacks of this class of approaches include: (i) the inability to maintain interactivity when the displayed surface changes frequently, (ii) inability to control the global geometry of the embedding (no self-intersections) of any approximated level of detail of the output surface. In this paper we introduce a technique for on-line construction and smoothing of progressive isosurfaces (see Figure 1). Our hybrid approach combines the flexibility of a progressive multi-resolution representation with the advantages of a recursive subdivision scheme. Our main contributions are: (i) a progressive algorithm that builds a multi-resolution surface by successive refinements so that a coarse representation of the output is generated as soon as a coarse representation of the input is provided, (ii) application of the same scheme to smooth the surface by means of a 3D recursive subdivision rule, (iii) a multi-resolution representation where any adaptively selected level of detail surface is guaranteed to be free of self-intersections.
A computer simulation model of electrodeposition of polymer chains on an impenetrable wall is used to evaluate the power-law scaling exponents ( νx(y)) for the longitudinal and transverse spread, Rgx(y)∼Lcνx(y); we...
A computer simulation model of electrodeposition of polymer chains on an impenetrable wall is used to evaluate the power-law scaling exponents ( νx(y)) for the longitudinal and transverse spread, Rgx(y)∼Lcνx(y); we find that the exponents νx(y) depend on the field strength, i.e., they are nonuniversal. A conformational crossover is observed for the transverse spread from the bulk with νy≃1/3–2/3 to the wall with νy≃2/3–1. A similar crossover also occurs for the longitudinal component of Rg but with an opposite trend, i.e., magnitude of νx is larger in bulk than at the wall.
The conformations of interacting polymer chains driven by a biased field in heterogeneous media are studied using Monte Carlo simulations in three dimensions. In addition to excluded volume, a nearest-neighbor interac...
The conformations of interacting polymer chains driven by a biased field in heterogeneous media are studied using Monte Carlo simulations in three dimensions. In addition to excluded volume, a nearest-neighbor interaction is considered with polymer-polymer repulsion and polymer-solvent attraction. Two types of heterogeneous media are considered: (i) a homogeneous-annealed system consisting of mobile polymer chains and solvents and (ii) quenched porous media, generated by adding a random distribution of quenched barriers. Effects of polymer concentration (p), bias (B), temperature (T), and porosity (ps) on the magnitude of the radius of gyration (Rg) of the chains and its scaling with the chain length (Lc) are studied. In an annealed system, we observe a crossover in power-law variation of the radius of gyration with the chain length, Rg∼Lcγ, from an extended conformation with γ≃0.7 at low bias (B=0.2), low p, and high T to a collapsed conformation with γ∼0.20-0.31 at high bias (B⩾0.5) and low T. In a quenched porous medium, we observe a somewhat lower value of the power-law exponent, γ∼0.60-0.70, from its annealed value at high T and low bias. At low temperatures, in contrast, the magnitude of γ∼0.39-0.47 is enhanced with respect to its annealed value. Various nonlinear responses of Rg to bias are observed in different ranges of B, Lc, ps, and T. In particular, we find that the response is nonmonotonic at low temperatures (T≃0.1) in the annealed system and at high temperatures (T≃100.0) in a porous medium with a relatively high barrier concentration (pb⩾0.3).
Addresses the needs and requirements of integrating visualization and geographic information system technologies. There are three levels of integration methods: rudimentary, operational and functional. The rudimentary...
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ISBN:
(纸本)9780780325210
Addresses the needs and requirements of integrating visualization and geographic information system technologies. There are three levels of integration methods: rudimentary, operational and functional. The rudimentary approach uses the minimum amount of data sharing and exchange between these two technologies. The operational level attempts to provide consistency of the data while removing redundancies between the two technologies. The functional form attempts to provide transparent communication between these respective software environments. At this level, the user only needs to request information and the integrated system retrieves or generates the information depending upon the request. This paper examines the role and impact of these three levels of integration. Stepping further into the future, the paper also questions the long-term survival of these separate disciplines.< >
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