A Precedent Approach to Assigning Access Rights

To design a discretionary access control policy, a technique is proposed that uses the principle of analogies and is based on both the properties of objects and the properties of subjects. As attributes characterizing these properties, the values of the security attributes of subjects and objects are chosen. The concept of precedent is defined as an access rule explicitly specified by the security administrator. The problem of interpolation of the access matrix is formulated: the security administrator defines a sequence of precedents, it is required to automate the process of filling the remaining cells of the access matrix. On the family of sets of security attributes, a linear order is introduced. The principles of filling the access matrix on the basis of analogy with the dominant precedent in accordance with a given order relation are developed. The analysis of the proposed methodology is performed and its main advantages are revealed.

The algorithm of the impulse noise filtration in images based on an algorithm of community detection in graphs

This article suggests an algorithm of impulse noise filtration, based on the community detection in graphs. The image is representing as non-oriented weighted graph. Each pixel of an image is corresponding to a vertex of the graph. Community detection algorithm is running on the given graph. Assumed that communities that contain only one pixel are corresponding to noised pixels of an image. Suggested method was tested with help of computer experiment. This experiment was conducted on grayscale, and on colored images, on artificial images and on photos. It is shown that the suggested method is better than median filter by 20% regardless of noise percent. Higher efficiency is justified by the fact that most of filters are changing all of image pixels, but suggested method is finding and restoring only noised pixels. The dependence of the effectiveness of the proposed method on the percentage of noise in the image is shown.

The algorithm of formation of a training set for an artificial neural network for image segmentation

This article suggests an algorithm of formation a training set for artificial neural network in case of image segmentation. The distinctive feature of this algorithm is that it using only one image for segmentation. The segmentation performs using three-layer perceptron. The main method of the segmentation is a method of region growing. Neural network is using for get a decision to include pixel into an area or not. Impulse noise is using for generation of a training set. Pixels damaged by noise are not related to the same region. Suggested method has been tested with help of computer experiment in automatic and interactive modes.