Projecting or moving up a chemical gradient is a universal behavior of living organisms. We tested the ability of S. cerevisiaea-cells to sense and respond to spatial gradients of the mating pheromone alpha-factor produced in a microfluidics chamber; the focus was on bar1Delta strains, which do not degrade the pheromone input. The yeast cells exhibited good accuracy with the mating projection t...

Chemotaxis, the directional migration of cells in a chemical gradient, is robust to fluctuations associated with low chemical concentrations and dynamically changing gradients as well as high saturating chemical concentrations. Although a number of reports have identified cellular behavior consistent with a directional memory that could account for behavior in these complex environments, the qu...

Contourlet transform is an efficient directional multiscale decomposition of images that combines the Laplacian pyramid (LP) with directional filter banks (DFBs). The LP decomposes the input image into multiple scales, whereas the DFBs applied on bandpass images of the pyramid yields directional localization. Similar to wavelets in 1-D, the key feature of contourlets is that they can quickly “f...

The directed cell migration towards a chemotactic source, chemotaxis, involves three complex and interrelated processes: directional sensing, cell polarization and motility. Directional sensing allows migrating eukaryotic cells to chemotax in extremely shallow gradients (<2% across the cell body) of the chemoattractant. Although directional sensing has been observed as spatially restricted resp...

Distributional word similarity is most commonly perceived as a symmetric relation. Yet, directional relations are abundant in lexical semantics and in many Natural Language Processing (NLP) settings that require lexical inference, making symmetric similarity measures less suitable for their identification. This paper investigates the nature of directional (asymmetric) similarity measures that a...

-In this paper proposed a method for extracting Contrast, Correlation, Energy, and, Local homogeneity features on Central Local Directional Pattern Value Flooding Matrix for face recognition. Local Directional Pattern is computed on the image and then Central Local Directional Pattern Value Flooding Matrix is formed, and on this matrix Contrast, correlation, energy and homogeneity features are ...

Abs t rac t The optimal design parameters of classifiers for omni-font machine-printed numeral recognition based on the minimum classification error (MCE) criterion are determined experimentall y. The design parameters that influence the accuracy of an optical character reader (OCR) are: similarity measure (or distance measure), kinds of features, dimension of the feature vector, method of trai...

In this paper, we present a methodology for off-line Isolated handwritten Devanagari character recognition. The proposed methodology relies on a three feature extraction techniques. The first technique is based on recursive subdivisions of the character image so that the resulting sub-images at each iteration have balanced (approximately equal) numbers of foreground pixels, as far as this is po...

The directionality of light is defined as the balance between the diffuse and directional components of light within an environment. It is an indicator about the spatial distribution of light flow onto an element or into a space. This paper presents a new luminance based metric that quantifies the directionality of light. The diffuse and directional components of the luminous environment are is...