A general hill-climbing attack to biometric systems based on a modification of the downhill simplex algorithm is presented. The scores provided by the matcher are used in this approach to adapt iteratively an initial estimate of the attacked template to the specificities of the client being attacked. The proposed attack is evaluated on a competitive feature-based signature verification system o...

A recent paper described a new machine translation evaluation metric, AMBER. This paper describes two changes to AMBER. The first one is incorporation of a new ordering penalty; the second one is the use of the downhill simplex algorithm to tune the weights for the components of AMBER. We tested the impact of the two changes, using data from the WMT metrics task. Each of the changes by itself i...

This paper presents two techniques for the design of digital filters with wordlength-constrained coefficients, the bit-flipping algorithm improved since it was first presented in [l] and the Downhill Simplex Method [2] modified to deliver fixed-point filter coefficients. Both techniques can be applied to design of filter coefficients from scratch or to the optimisation of their floatingpoint ve...

A photonic crystal fiber is optimized for chromatic dispersion compensation by using inner cladding modes. To this end, a photonic-oriented version of the downhill-simplex algorithm is employed. The numerical results show a dispersion profile that accurately compensates the targeted dispersion curve, as well as its dispersion slope. The presented fiber has a simple structure, while radiation lo...

This paper presents travel time geoacoustic inversion of broadband data collected on a vertical line array at short range of 230 m during the Shallow Water 2006 experiments. A ray-tracing method combined with a hybrid optimization algorithm that utilizes differential evolution and downhill simplex was used for the inversion of sediment properties. The ocean sound speed profile and geometric par...

In this contribution, we present an optimal halftoning algorithm that uniformly distributes pixels over a hexagonal grid. This method is based on a slightly modified error-diffusion approach presented at SIGGRAPH 2001. Our algorithm’s parameters are optimized using a simplex downhill search method together with a blue noise based cost function. We thus present a mathematical basis needed to per...

G eorge Dantzig, in describing the " Origins of the Simplex Method, " 1 noted that it was the availability of early digital computers that supported and invited the development of LP models to solve real-world problems. He agreed that invention is sometimes the mother of necessity. Moreover, he commented that he initially rejected the simplex method because it seemed intuitively more attractive...

Abstract Micelles and micellization appeal long lasting interest as promising drug carriers. A conventional parameter providing information about formation of micelles is critical micelle concentration (cmc). Its value roughly separates two states the surfactant solution – namely with without presence micelles. If surfactants in water approaches cmc some physical quantities abruptly change, thi...

Noise models are crucial for designing image restoration algorithms, generating synthetic training data, and predicting algorithm performance. However, to accomplish any of these tasks, an estimate of the degradation model parameters is essential. In this paper we describe a parameter estimation algorithm for a morphological, binary image degradation model. The inputs to the estimation algorith...

We develop a hybrid quantum-classical algorithm to solve an optimal population transfer problem for molecule subject laser pulse. The evolution of the molecular wave function under pulse is simulated on quantum computer, while iteratively shaped via machine learning (evolutionary) algorithm. A method encode computer $n$-electrons discussed, circuits accomplishing its simulation are derived and ...