Abstract. One of the important open questions in the theory of free– surface ideal fluid flows is the dynamic stability of traveling wave solutions. In a spectral stability analysis, the first variation of the governing Euler equations is required which raises both theoretical and numerical issues. With Zakharov and Craig and Sulem’s formulation of the Euler equations in mind, this paper addres...

This paper presents an accurate and stable numerical scheme for computation of the first variation of the Dirichlet–Neumann operator in the context of Euler’s equations for ideal free-surface fluid flows. The Transformed Field Expansion methodology we use is not only numerically stable, but also employs a spectrally accurate Fourier/Chebyshev collocation method which delivers high-fidelity solu...

Locally strongly convex surfaces which are extremal for the first variation of the equiaffine area integral have been investigated on several occasions. Here we are interested in the description of their behaviour at infinity. We consider an affine maximal annular end which is a graph of vertical flux and give a detailed representation of it when its affine conormal map works well at infinity.

We discuss conformally covariant differential operators, which under local rescalings of the metric, δσg μν = 2σg , transform according to δσ∆ = r∆σ+(s−r)σ∆ for some r if ∆ is s th order. It is shown that the flat space restrictions of their associated Green functions have forms which are strongly constrained by flat space conformal invariance. The same applies to the variation of the Green fun...

Dilaton contact terms in the bosonic and heterotic strings are examined following the recent work of Distler and Nelson on the bosonic and semirigid strings. In the bosonic case dilaton two-point functions on the sphere are calculated as a stepping stone to constructing a ‘good’ coordinate family for dilaton calculations on higher genus surfaces. It is found that dilaton-dilaton contact terms a...

BACKGROUND Sawyer (1986) included three species in the nasal leech genus LimnatisMoquin-Tandon 1827: Limnatisnilotica (Savigny 1822), LimnatisbacescuiManoleli 1972 and Limnatispaluda (Tennent 1859). The first and last species have mainly been identified in Middle Eastern countries (e.g. Kinzelbach and Rückert 1985). The second species has been identified only in Romania Dobruja (Manoleli 1972)....

Problems dealing with assignment of clients to servers have been widely studied. However, they usually do not model the fact that the delay incurred by a client is a function of both the distance to the assigned server and the load on this server, under a given assignment. We study a problem referred to as the Load-Distance Balancing problem (or LDB), where the objective is assigning a set of c...

The simplest Bayesian adaptive randomization scheme is to randomize patients to a treatment with probability equal to the probability p that the treatment is better. We examine three variations on adaptive randomization which are used to compromise between this scheme and equal randomization. The first variation is to apply a power transformation to p to obtain randomization probabilities. The ...

We propose a novel multiplexing scheme for teleoperation over constant bitrate (CBR) communication links. The proposed approach uniformly divides the channel into 1ms resource buckets and controls the size of the transmitted video packets as a function of the irregular haptic transmission events generated by a perceptual haptic data reduction approach. The performance of the proposed multiplexi...

We consider a natural generalization of Borell’s isoperimetric inequality for Gaussian space for multiple sets of unequal measures. We show that this conjecture is false. The argument combines the first variation with a simple analyticity argument, the latter being a new ingredient. (joint work with Elchanan Mossel and Joe Neeman [7])