МЕТОД СТИСНЕННЯ ДАНИХ ДИФРАКЦІЙНИХ ТА ІНТЕРФЕРЕНЦІЙНИХ ЗОБРАЖЕНЬ

In the paper the diffraction and interference images received by numerical simulation and experimentally in solving fundamental and applied problems of photonics. Images are structures with a special intensity distribution formed by the initial field and the optical system. To increase the speed of processing of the image data compression method with further implementation in databases is developed. The method of diffraction and interference images compression is based on the intensity quantization. An algorithm for image quantization has been developed: target intensity values have been determined, which allow setting quantization levels, and data visualization techniques, which determine the threshold values for these levels. The algorithm also contains image segmentation by the size of the minimum size of the topological object. The vicinity of topological object is defined under the conditions of a visual registration form and do not crossing with other regions. The topological objects of the diffraction field determine as the maximum, minimum and zero intensity, and in the interference pattern such topological objects are the maximum, minimum and the region of the band splitting. Important parameters are the average value of the intensity of the whole image - which highlights its overall structure and the average value of the intensity of the local segment. The following results were obtained by compressing data from an 8-bit image in grayscale to 2 bits of color depth are enough for an interference image, and to 3 bits, which are enough for a diffraction image. The quantization differences for diffraction images and interference patterns are shown. Data compression ratios are calculated. On the one hand, the application of the obtained results and recommendations is possible in various fields of medicine, biology and pharmacy , which use laser technology, and on the other hand in the development of separate IT identification of topological objects in the light field, optical image processing and decision support in optical problems.

Spatiality of the City in Literature: Possibilities and Limits of the Semiotic Approach

The article attempts to delineate adequate ways of thinking about the spatiality of the city in literature. It examines two semiotic approaches to the problematic of the city, namely Jurij Lotman’s semiotics of culture and Algirdas Julius Greimas’ urban semiotics, and their applicability to the analysis of its literary representation. Lotman’s concept of semiosphere is invoked to outline the complex, two-way relationship between consciousness and the city. Highlighting the communicative and autocommunication processes of culture helps to establish a link with Greimas’ interpretive and generative methodological approaches. Both Greimas and Lotman treat the city as a virtual reality concentrating on the ideological, symbolical and philosophical aspects of it. Their theories regard language primarily as an acoustic phenomenon (as speech), and consequently tend to disregard its visual (e. g. graphic) features. The article considers possible combinations of the different branches of semiotics. The special attention is focused on demonstrating the importance of the (inter)medial aspects of the literary representation. A case study of the photo-essay helps to expose similarities and differences of the semiotic and the intermedial approaches. The article demonstrates how recognizing specific (inter)medial aspects of the text allows regarding the literary city as a topological object.

Knots in physics

After Dirac introduced the monopole, topological objects have played increasingly important roles in physics. In this review we discuss the role of the knot, the most sophisticated topological object in physics, and related topological objects in various areas in physics. In particular, we discuss how the knots appear in Maxwell’s theory, Skyrme theory, and multicomponent condensed matter physics.

Dynamics of the universe as a “test 3-brane” in a 5D bulk

In this paper, as a toy model, we study the dynamics of a 5D bulk space–time with our universe as a “test 3-brane” located in the bulk; an idealized model of a topological object whose physical properties are negligible in comparison with those of the bulk. We obtain the result that our universe experiences acceleration and phantom crossing as a result of the geometry of bulk space–time.

A MONOPOLE INSTANTON-LIKE EFFECT IN THE ABJM MODEL

Making use of ansatzs for the form fields in the ten-dimensional type IIA supergravity version of the ABJM model, we come with a solution in the Euclidean signature recognized as a monopole instanton-like object. Indeed we will see that we can have a (anti-)self-dual solution at a special limit. While as a topological object, its backreaction on the original background should be ignorable, we show the energy–momentum tensors vanish exactly. On the field theory side, the best counterpart is an U(1) gauge field of a gauge transformation. To adjust with bulk, the gauge field must prompt to a dynamic one without adding any kinetic term for this dual photon except a marginal, Abelian AB-type Chern–Simons term on the boundary. We will see how both side solutions match next to another confirmation from some earlier works of this vortex–particle duality.