Imaging Through Random Scatterer with Spatial Coherence Structure Measurement

Optical coherence is becoming an efficient degree of freedom for light field manipulations and applications. In this work, we show that the image information hidden a distance behind a random scattering medium is encoded in the complex spatial coherence structure of a partially coherent light beam that generates after the random scatterer. We validate in experiment that the image information can be well recovered with the spatial coherence measurement and the aid of the iterative phase retrieval algorithm in the Fresnel domain. We find not only the spatial shape but also the position including the lateral shift and longitudinal distances of the image hidden behind the random scatterer can be reconstructed, which indicates the potential uses in three-dimensional optical imaging through random scattering media.

Development of the flow part of reactive type HPC of K-325-23,5 series steam turbine based on the use of modern computer technologies

The results of gas-dynamic design of a new flow part of a reactive type high-pressure cylinder (HPC) of the K-300 series condensing steam turbine are presented. The turbine was developed using a comprehensive methodology implemented in the IPMFlow software package. The methodology includes gas-dynamic calculations of various levels of complexity, as well as methods for analytical construction of the spatial shape of the blade rows based on a limited number of parameterized values. The real thermodynamic properties of water and steam were taken into account in 3D calculations of turbulent flows. At the final stage, 3D end-to-end calculations of the HPC, which consists of 18 stages, were carried out. The technology of parallel computing was applied in the said calculations. It is shown that a significant increase in efficiency and power has been achieved in the developed HPC due to the use of reactive type stages with modern smooth blade profiles and monotonic meridional contours.

An End-to-End Computer Vision Methodology for Quantitative Metallography

Metallography is crucial for a proper assessment of material's properties. It involves mainly the investigation of spatial distribution of grains and the occurrence and characteristics of inclusions or precipitates.This work presents an holistic artificial intelligence model for Anomaly Detection that automatically quantifies the degree of anomaly of impurities in alloys. We suggest the following examination process: (1) Deep semantic segmentation is performed on the inclusions (based on a suitable metallographic database of alloys and corresponding tags of inclusions), producing inclusions masks that are saved into a separated database. (2) Deep image inpainting is performed to fill the removed inclusions parts, resulting in 'clean' metallographic images, which contain the background of grains. (3) Grains' boundaries are marked using deep semantic segmentation (based on another metallographic database of alloys), producing boundaries that are ready for further inspection on the distribution of grains' size. (4) Deep anomaly detection and pattern recognition is performed on the inclusions masks to determine spatial, shape and area anomaly detection of the inclusions. Finally, the system recommends to an expert on areas of interests for further examination. The performance of the model is presented and analyzed based on few representative cases. Although the models presented here were developed for metallography analysis, most of them can be generalized to a wider set of problems in which anomaly detection of geometrical objects is desired. All models as well as the data-sets that were created for this work, are publicly available at https://github.com/MLography/MLography.

PROFILE OF STUDENTS' SPATIAL ABILITY IN SOLVING GEOMETRY PROBLEMS IN TERMS OF DAVID KEIRSEY'S PERSONALITY TYPES

This study aims to describe the ability of spatial geometry of class XI MIPA 1 SMA Negeri 2 Jember in terms of David Keirsey's personality type. Spatial ability in this study is the ability to understand the world of space based on elements of spatial abilities which include: spatial perception, mental rotation, and spatial visualization. This type of research is a descriptive study with a qualitative approach. The data collection method in this research is questionnaire, spatial test, and interview. Then, based on the results of the test and interview analysis, it was found that the Guardian students could fulfill all spatial indicators. Artisan students in imagining and rotating spaces can think quickly and answer questions correctly, compared to guardian and idealistic students. Idealistic students in the ability to see the surface of the unit cubic structure more than the point of view (from the front, right side, and top) cannot describe it precisely. Meanwhile, rational students on the mental rotation element for the first indicator are still unable to rotate a spatial shape and can imagine the rotation or rotation of a spatial shape accurately.

Electron Bernstein wave aided heating of collisional nanocluster plasma by nonlinear interactions of two super-Gaussian laser beams

In this present theoretical study, we investigate electron Bernstein wave (EBW) aided collisional nanocluster plasma heating by nonlinear interaction of two super-Gaussian laser beams. The interactions of laser beams electric field profiles with electronic clouds of nanoclusters cause the beat wave. The nonlinear ponderomotive force is generated through the beat wave. There may be good potential to excite the EBW aiding cluster plasma to lead electron heating via cyclotron damping of the Bernstein wave. An analytical scheme is proposed for the anomalous heating and evolution of electron temperature by using this mechanism. Graphical discussions were promised to achieve extreme heating rate via the spatial shape of super-Gaussian laser beams and the resonance condition of beat wave to surface plasmon frequency. The heating is controlled by tuning the laser beam width, mode index, collisional frequency, clustered radius, and density.

IMPROVING THE EFFICIENCY OF FINISHING MILLING OF CONCAVE SURFACES ON SMALL-SIZED CNC MACHINES

Pазвитие систем ЧПУ современного полногабаритного металлорежущего оборудования дало возможность корректировать режимы резания, например, величину рабочей подачи непосредственно в процессе обработки. Однако на производстве имеется значительная часть деталей, которые по своим габаритам экономически невыгодно обрабатывать на дорогостоящих крупных станках, имеющих мощную систему ЧПУ. Поэтому на предприятиях все большее применение получают относительно недорогие малогабаритные металлорежущие станки. Технологические возможности такого оборудования позволяют обрабатывать не только цветные металлы и сплавы, но и стали. Особенностью управления таким оборудованием является использование упрощенных систем ЧПУ, установленных на персональных компьютерах, которые не имеют возможности выполнять арифметические операции, и это становится препятствием для повышения производительности обработки сложных поверхностей. В то же время из-за своей простоты и низкой стоимости эти системы становятся все более востребованными. Предлагается повысить производительность обработки поверхностей сложной пространственной формы на основе расчета движения инструмента САПР системой путем преобразования реальной траектории в набор симметричных отрезков с известными координатами. Этот метод позволяет при заданной точности обработки установить значения параметров режима резания, близкие к оптимальным, исключить аварийные ситуации, связанные с выходом из строя инструмента при работе с переменной глубиной резания, сформированной после черновой обработки, и повысить производительность на 15-20% The development of CNC systems of modern full-sized metal-cutting equipment made it possible to adjust cutting modes, for example, the value of the working feed, directly during processing. However, there is a significant number of the parts in production that, according to their dimensions, are economically unprofitable to process on expensive large machines with a powerful CNC system. Therefore, relatively inexpensive small-sized metal-cutting machines are becoming increasingly used in enterprises. The technological capabilities of such equipment allow processing not only non-ferrous metals and alloys but also steels. A feature of the control of such equipment is the use of simplified CNC systems installed on personal computers that are not able to perform arithmetic operations and this becomes an obstacle to improving the productivity of processing complex surfaces. At the same time, due to their simplicity and low cost, these systems are becoming more and more popular. In the article, we proposed to increase the productivity of processing surfaces of complex spatial shape on such machines based on the calculation of the CAD tool movement by the system by converting the real trajectory into a set of symmetrical segments with known coordinates. This method allows you, with a given processing accuracy, to set the values of the cutting mode parameters close to the optimal ones, to eliminate emergencies associated with tool failure when working with a variable cutting depth formed after roughing and to increase productivity by 15-20%

Nano-Crystal and Microstructure Formation in Fluoride Photo-Thermo-Refractive Glass Using Chirp-Controlled Ultrafast Laser Bessel Beams

Nano-crystals were formed in the exposed regions of photo-thermo-refractive glass undergoing irradiation with zeroth order chirp-controlled ultrafast laser Bessel beams and subsequent heat treatment. Effects of various writing powers, pulse durations and heat treatment time on the distribution and the size of the nano-crystals were investigated. The results show that nano-crystals’ distribution depended on the laser power density spatial shape, while the size of the nano-crystals is quasi-independent. However, the average diameter of the nano-crystals was affected by the heat treatment time, decreasing from 175 to 105 nm with the time halved. In addition, using crystallographic characterization by X-ray diffraction, the nano-crystal composition in the laser-exposed regions was detected to be sodium fluoride.

APPROACH TO THE EVALUATION OF FILLING BY PEOPLE OF MOBILE MEANS AT EMERGENCY EVACUATION FROM BUILDINGS

The tasks of geometric design (of arrangement, cutting, coverage, partitioning) consist in optimization display of geometric information about objects in accordance with a given quality criterion and limitations. Geometric information about a geometric object consists of three components: spatial shape, metric shape parameters, placement parameters, and which, as a rule, is involves in the synthesis of complex systems. The configuration space of geometric objects is based on the formalization of the concept of geometric information. The mapping of objects into their configuration space according to a given set of constraints defines the spatial configuration of geometric objects. The article introduces the concept of a spatial configuration of placement, with the help of which a new model of placement of complex objects is constructed, representing the union of three loosely coupled ellipses, of which one (main) allows continuous translations and rotations, and two of auxiliary ellipses can rotate within acceptable limits (with respect to the angle of rotation of main ellipse) and relative to the points of their “gluing”. As a result of solving the optimization problem, not only the arrangement configuration of such objects is synthesized, but also the spatial form of each of them. Computer modeling of the optimization of the placement of the complex objects considered in the work was carried out and the effectiveness of the proposed approach was shown by comparing the location configurations for objects with a changing spatial shape and with constant shape parameters. Consideration of the parameters of the placement of objects, as well as additional parameters that allow us to synthesize new spatial forms of objects, as independent variables will allow us to offer new mathematical models and optimization methods for the synthesis of spatial configurations. A further direction can also be considered the development of new approaches to modeling the movement of flows of people, robots, to get upper bounds for filling areas with objects. All this increases the range of tasks to be solved according to their functional capabilities and can be used, for example, when dividing the compartments of vehicles for transporting goods and storing them, in pattern recognition systems, in robotics, etc.

TONGKONAN KE'TE' KESU’ AS A TRADITIONAL ARCHITECTURAL TOURIST ATTRACTION IN TANA TORAJA

This research aims to know the function of Traditional House of Toraja and Typology, as a unique traditional architectural tourist attraction in Ke'te 'Kesu'. The research is qualitative research. Data collection is done by observation, interview, and documentation. The research variables consist of: Function of Traditional House (Tongkonan), and it’s Typology. The data analysis technique used is descriptive qualitative analysis, that is analyzing each variable descriptively, consisting of four activity flow, that is data selection, data presentation, analyzing, , and conclusions. The results show that: In general, the main function of traditional Toraja house (Tongkonan) and its built environment is as a container of human activities supporting Toraja culture, consisting of Rambu Solo’ that is the customary ceremony associated with death, and Rambu Tuka’ or all things good lifestyle as well ceremonies related to daily life. Then typology can be viewed from aspects of Layout, Spatial, Shape, Structure and Construction, and Ornaments.