Recent years have seen renewed interest in the six and eight-vertex model at rational coupling values, that is when the crossing parameter is evaluated at roots of unity. Deguchi, Fabricius and McCoy pointed out that the extra degeneracies in the spectrum of the six-vertex transfer matrix can be understood in terms of an affine symmetry algebra in certain commensurate spin-sectors [1]. This rai...

Numerical evaluation of functional integrals usually involves a finite (Lslice) discretization of the imaginary-time axis. In the auxiliary-field method, the L-slice approximant to the density matrix can be evaluated as a function of inverse temperature at any finite L as ρ̂L(β) = [ρ̂1(β/L)] , if the density matrix ρ̂1(β) in the static approximation is known. We investigate the convergence of the ...

Let J be a Jacobi matrix with elements bk on the main diagonal and elements ak on the auxiliary ones. We suppose that J is a compact perturbation of the free Jacobi matrix. In this case the essential spectrum of J coincides with [−2, 2], and its discrete spectrum is a union of two sequences {xj }, x + j > 2, x − j < −2, tending to ±2. We denote sequences {ak+1 − ak} and {ak+1 + ak−1 − 2ak} by ∂...

In this paper, we deal with the problem of designing a filter for discrete-time systems subject to error variance and circular pole constraints. Specifically, we aim to design a filter such that the norm of the filtering error-transfer function is not less than a given upper bound, while the poles of the filtering matrix are assigned within a prespecified circular region, and the steady-state e...

Can only a handful of structural features and no knowledge of link-level connectivity threaten privacy of individuals in a social network? Specifically, can we use a small number of local structural features defined on nodes (such as degree, clustering coefficient, average degree of neighbors, average clustering coefficient of neighbors, etc) to reduce the uncertainty of individuals’ identities...

An analysis of Dunlap's robust fitting approach reveals that the resulting two-electron integral matrix is not manifestly positive semidefinite when local fitting domains or non-Coulomb fitting metrics are used. We present a highly local approximate method for evaluating four-center two-electron integrals based on the resolution-of-the-identity (RI) approximation and apply it to the constructio...

The Algebraic Bethe Ansatz, which is the essence of the quantum inverse scattering method, emerges as a natural development of the following different directions in mathematical physics: the inverse scattering method for solving nonlinear equations of evolution [GGK1967], quantum theory of magnets [Bet1931], the method of commuting transfer-matrices in classical statistical mechanics [Bax1982]]...

As the desire to explore opaque materials is ordinarily frustrated by multiple scattering of waves, attention has focused on the transmission matrix of the wave field. This matrix gives the fullest account of transmission and conductance and enables the control of the transmitted flux; however, it cannot address the fundamental issue of the spatial profile of eigenchannels of the transmission m...

The aim of a modern Building Automation System (BAS) is to enhance interactive control strategies for energy efficiency and user comfort. In this context, we develop a novel control algorithm that uses a stochastic building occupancy model to improve mean energy efficiency while minimizing expected discomfort. We compare by simulation our Stochastic Model Predictive Control (SMPC) strategy to t...

A ooIIaboIation of reseaJdlers at 1he Mayo Medical Center and Olmsted MedIcal Center created a BAS"' daIa warehousa of deIaIed billing dais. This ur1que warehouse conIains billing daIa for most of 0ImsIed Coun\y from 198710 present The chaIenge for 1he developels was 10 create a warehouse of all hisIcricaI data from five different institutions 1hat was stored on a variety of different pIatfonns...