A continuous sequence of infinitesimal unitary transformations is used to diagonalize the quantum sine-Gordon model for β2 ∈ (2π,∞). This approach can be understood as an extension of perturbative scaling theory since it links weakto strong-coupling behavior in a systematic expansion: a small expansion parameter is identified and this parameter remains small throughout the entire flow unlike th...

This paper present a segmentation of vertebral bodies from spinal MR images based on neighborhood information Gauss weighted and local contraction. First use a cut-off window (5 5) around each pixel and stack the gray values inside the window into a vector, adopt the Gaussian kernel function to incorporate local spatial information, an adaptive local scaling parameter is used to refine the segm...

Phase transitions in constraint satisfaction problems (CSP's) are the subject of intense study. We identify an order parameter for random binary CSP's. There is a rapid transition in the probability of a CSP having a solution at a critical value of this parameter. The order parameter allows diierent phase transition behaviour to be compared in an uniform manner, for example CSP's generated unde...

In order to build energy efficient digital CMOS circuits, the supply voltage must be reduced to near-threshold. Problematically, due to random parameter variation, supply scaling reduces circuit robustness to noise. Moreover, the effects of parameter variation worsen as device dimensions diminish, further reducing robustness, and making parameter variation one of the most significant hurdles to...

For the 3D gonihedric Ising models defined by Savvidy and Wegner the bare string tension is zero and the energy of a spin interface depends only on the number of bends and self-intersections, in antithesis to the standard nearest-neighbour 3D Ising action. When the parameter κ weighting the self-intersections is small the model has a first order transition and when it is larger the transition i...

We show that the parametric correlations of the conductance peak amplitudes of a chaotic or weakly disordered quantum dot in the Coulomb blockade regime become universal upon an appropriate scaling of the parameter. We compute the universal forms of this correlator for both cases of conserved and broken time reversal symmetry. For a symmetric dot the correlator is independent of the details in ...

Recently, considerable progress has been made in understanding finite-size scaling in equilibrium systems. Here, we study finite-size scaling in nonequilibrium systems at the instance of directed percolation (DP), which has become the paradigm of nonequilibrium phase transitions into absorbing states, above, at, and below the upper critical dimension. We investigate the finite-size scaling beha...