Analysis of vibration of beams with regularly located openings

В справочной литературе содержатся расчетные зависимости для частот свободных колебаний балок со сплошной стенкой, но отсутствуют данные по собственным колебаниям перфорированных балок. В то же время в судостроении и строительной практике широко распространены балки с перфорированной стенкой, содержащей вырезы круглой, овальной и прямоугольной формы. В статье проведен анализ влияния вырезов на частоту свободных колебаний перфорированных свободно опертых балок. При этом первоначально рассматривались балки со сплошной стенкой, а затем балки таких же размеров с вырезами. Для удобства практических вычислений известная зависимость была трансформирована к виду, позволяющему оценить частоту колебаний только по соотношению площадей полки и стенки и габаритным размерам балки без необходимости определения ее момента инерции и погонной массы. Аналогичные зависимости были получены и для перфорированных балок с круглыми и прямоугольными вырезами, в которых дополнительными факторами являлись параметры перфорации: относительная высота вырезов и относительная ширина перемычек. При отсутствии вырезов формулы для перфорированных балоксводятся к формуле для балки со сплошной стенкой.Сравнительный анализ частот проводился путем расчета по аналитическим зависимостям и методом конечных элементов с использованием программного комплекса ANSYS. На основе проведенного анализа сделан вывод, что наличие регулярно расположенных вырезов с высотой, не превышающей рекомендации Морского Регистра РФ, в зависимости от параметров перфорации приводит к разному повышению частот собственных колебаний однопролетных балок, хотя степень их повышения невелика. Предложенные аналитические зависимости для балок разного конструктивного оформления удовлетворительно согласуются с результатами расчетов МКЭ. In manual on the ship structural mechanics the analytical relations for determination of the natural frequencies of the beams with solid web are given, but there are no data about proper vibration of perforated beams. At the same time in shipbuilding and in structural industry the perforated beams with circular, rectangular and oval openings are widely used. In this article the analysis of influence of openings on the natural frequencies of the simply supported perforated beams is performed. Initially it was considered beams with solid web and then beams of the same dimensions with openings. For commodity of practical calculations, the well-known relation was transformed to the form allowing to appreciate frequency of vibration only with knowledge of ratio of areas of shelves and web without necessity of finding their moment of inertia and running mass of beam. Similar relations were obtained for perforated beams with circular and rectangular openings, in which additional arguments were such parameters of perforation as related depth of openings and related width of web-posts. In case of absence of openings, the formulas for perforated beams are reduced to formula for beam with solid web. Comparative analysis was performed by calculations according to analytical relations and with the finite element method using the program complex ANSYS. On base of performed analysis it was made conclusion that existence of regularly located openings with depth not extending recommendations of Russian Maritime Register, in dependence on parameters of perforation brings to different increasing of natural frequencies of vibration of one span beams, although degree of this increasing is not high. Suggested analytical relations for beams of different constructive design are in a good correlation with results obtained by the finite element method.

Development of an Information System for Monitoring Attractiveness of Municipalities in the Republic of Bashkortostan

At present, most regions of the Russian Federation are experiencing an increase in migration flows, which has a significant impact on the overall decline in population. At the same time most of them have already developed regional migration policies containing basic guidelines for migration regulation. One of such regions is the Republic of Bashkortostan, where in the recent period the number of active population taking part in both intraregional and external migration has increased significantly. At the same time, the spatial mobility of the population has an impact on the social and economic development of territories. These circumstances lead to increased attention on the part of regional authorities in state regulation improvement. In this connection, the main goal of the paper is to develop an information system for monitoring the attractiveness of municipalities of the Republic of Bashkortostan using geoinformation technologies. The conceptual model “Informational system of attractiveness monitoring of municipalities of the Republic of Bashkortostan” is presented during the research, in which units of visualization, parametric analysis and spatial scaling are described. An algorithm information system was also developed which describes its functionality, such as: assessment of the level of migration attractiveness of the territory, zoning the territory according to the level of migration attractiveness; editing and search of data; scenario prediction of the level of migration activity of the population (number of departures, number of arrivals, migration growth); visual representation of the direction of migration flows; reporting. With the help of this tool, the forecast of the level of attractiveness of the municipalities of the Republic of Bashkortostan is made taking into account the realization of the regional program “Complex development of monocities”. The information system for monitoring the attractiveness of municipalities of the Republic of Bashkortostan can serve as a scientific and methodological basis for state migration policy improvement. The information system for attractiveness monitoring of municipalities of the Republic of Bashkortostan can serve as a scientific and methodological basis for the improvement of state migration policy.

Program Complex for Automated Calculation of the Geometry of Impact Units of Machines

Improving the designs of impact mining machines in order to increase the productivity of drilling operations requires calculations of the geometric parameters of impact units. The greatest effect when the impact is applied to the rock is given by an impact pulse corresponding to the resistance forces of the object being destroyed. In turn, the shape and parameters of the impact pulse are determined by the geometry of the colliding bodies. Analytical methods for analyzing dynamic processes in impact systems involve the use of a very complex mathematical apparatus, which does not allow us to quickly solve the problems of engineering design of machines and mechanisms. The authors of this article have developed a numerical method for calculating and analyzing impact pulses generated in the machine system by bodies of any geometric complexity. The reliability of the theoretical approaches is confirmed by the results of a physical experiment. The developed software allows you to quickly and accurately solve the problem of finding and justifying rational geometric parameters of impact nodes of machines.

Operative Training in a General Surgery Program: Residents’ perspective and analysis of a web-based log-book - Retrospective Cohort Study

BackgroundSurgical education evolves through time, and it's related to the number and type of procedures that residents are exposed to. Hour regulations in resident training affect learning curves, and recording surgical exposure remains to be an effective method to assess and keep track of surgical training. Web-based logbooks have proven to be useful to monitor and follow surgical training in general surgery residents. This study aims to evaluate surgical proficiency in general surgery residents by quantifying their operative exposure and experience by using data collected in a web-based logbook.MethodsA retrospective study from a prospectively collected data base between September 2018 to September 2019 was performed. All surgery residents were surveyed.ResultsA total of 13160 surgical procedures were performed by residents. Laparoscopic cholecystectomy was the most frequent procedure performed 7404 times (52,6%), followed by open appendectomy in 34,6%. Trauma context procedures represent 4.9% of surgical training in our program. Complex procedures such as whipple or distal pancreatectomy represent less than 1% of the training. 70% of residents are confident to perform the surgical procedures proposed for their year of residency, 90% agree that logbooks have a positive impact in their formation.ConclusionWeb based logbooks are a feasible method to follow operative experience in general surgery residents, with adequate record of procedures, its complexity, and trauma context. General surgery residents in our program are confident to perform surgical procedures based on the year of residency. Nevertheless, there is no consensus regarding the best way to measure resident experience and meanwhile we keep relying on proxies.

Innovative programming product for work architect-urbanist with Big Data of city

The article substantiates the necessity of creating an innovative programming product "Program complex for modelling the city as a dynamic system". The methodological basics of writing a technical task as the basis for the complex development are described. The aspects of its use as a tool for information support of strategic decision-making processes related to the transition of the city to an intensive type of development are disclosed. The purpose of the program complex: information support for strategic decision-making processes to optimize the principles of the city. The purpose of the program complex is to analyze the processes of city functioning as a complex dynamic system. In this case, it is possible to diagnose the current state of the city as a system in real-time, the state of its subsystems and elements, as well as to predict changes in the dynamic processes of their functioning. The specified program package is based on a combination of two trends in modern science: optimization of the city functioning processes and management of large arrays of city data (Big Data). The Program simulates positive and negative dynamics of the transition of the city, its subsystems and individual elements from a state of stability to crisis and a possible pre-catastrophic state.

Formalization of tasks generation for complex of interactive web-tests on math

The approach to the formalization of the generation of problem situations applicable to the development of tutoring programs consisting of many tasks is considered. The main errors arising during the software-based generation of parameters are specified. Mathematical modeling of parametrical generation algorithms examined by examples of tasks that make up complex tests on mathematics for secondary schools. The parametric generation method proposed in the article allows getting the large quantitative variations in task problem situations. Thereby, every learner will get a personal unique set of tasks. The structure and functionality of web-tests complex consisting of tasks generated via the proposed method are described. The subject of research in the article is the process of computer training in mathematics. The goal is to develop a method for task generation for mathematical disciplines. Tasks. Research and analysis of the set of mathematical problems. Parameterization of each task and development method and algorithms for automated generation parameters with the determination of incorrect combinations of parameters or problem situations that have no solution. Estimation of borders of admissible for approximate answers. Evaluation of the user solution of a single task and a sequence of tasks. The general objective of the work is to make the software product consisting of a sequence of mathematics tasks. The software should have an extended user interface for the graphical presentation of various problem situations in various mathematical topics. The program must be accessible via the Internet. The following results were obtained: developed methods and algorithms of task generation, which provide correct problem situations and unique parameter sets for each user; described the program complex structure and developed the software system of mathematical web-tests provides two levels of difficulty. Conclusion. The scientific novelty lies in the development of the method of task generation for interactive web tests on the mathematics and its computer implementation with the possibility of graphical representation of tasks and checking of tasks correctness.

Program complex for optimization of surface hardening of steel billets

The aim of the paper is to develop program complex in software MATLAB with integrated numerical 2D nonlinear FLUX model, which is used for solving optimal inductor design and control problems for heating stage of surface induction hardening. Considered program complex is based on alternance method, that allows to write systems of transcendental equations, closed with respect to all unknown design and control parameters of the process. The suggestion for implementation of obtained optimal control algorithm is presented.

BayCANN: Streamlining Bayesian Calibration With Artificial Neural Network Metamodeling

Purpose: Bayesian calibration is generally superior to standard direct-search algorithms in that it estimates the full joint posterior distribution of the calibrated parameters. However, there are many barriers to using Bayesian calibration in health decision sciences stemming from the need to program complex models in probabilistic programming languages and the associated computational burden of applying Bayesian calibration. In this paper, we propose to use artificial neural networks (ANN) as one practical solution to these challenges.Methods: Bayesian Calibration using Artificial Neural Networks (BayCANN) involves (1) training an ANN metamodel on a sample of model inputs and outputs, and (2) then calibrating the trained ANN metamodel instead of the full model in a probabilistic programming language to obtain the posterior joint distribution of the calibrated parameters. We illustrate BayCANN using a colorectal cancer natural history model. We conduct a confirmatory simulation analysis by first obtaining parameter estimates from the literature and then using them to generate adenoma prevalence and cancer incidence targets. We compare the performance of BayCANN in recovering these “true” parameter values against performing a Bayesian calibration directly on the simulation model using an incremental mixture importance sampling (IMIS) algorithm.Results: We were able to apply BayCANN using only a dataset of the model inputs and outputs and minor modification of BayCANN's code. In this example, BayCANN was slightly more accurate in recovering the true posterior parameter estimates compared to IMIS. Obtaining the dataset of samples, and running BayCANN took 15 min compared to the IMIS which took 80 min. In applications involving computationally more expensive simulations (e.g., microsimulations), BayCANN may offer higher relative speed gains.Conclusions: BayCANN only uses a dataset of model inputs and outputs to obtain the calibrated joint parameter distributions. Thus, it can be adapted to models of various levels of complexity with minor or no change to its structure. In addition, BayCANN's efficiency can be especially useful in computationally expensive models. To facilitate BayCANN's wider adoption, we provide BayCANN's open-source implementation in R and Stan.

THE FOLLICLEGENESIS IN THE THYROID GLAND IN THE POSTNATAL PERIOD OF ONTOGENESIS UNDER PRENATAL ANTIGENIC INFLUENCE

Antigenic influence at critical terms of ontogenesis can cause significant changes in the child's immune system. It is known that the entry of antigens into the fetus causes premature release of T-lymphocytes from the thymus and their migration to various organs. The paper was aimed at the study of the folliclegenesis of the thyroid gland in postnatal period at norm and after prenatal influence of staphylococcal toxoid. In the experimental research as a material were thyroid glands of Wistar rats aged 1 to 60 days of postnatal development (162 animals), about 6 animals in each group. Three animals groups were studied on 1, 3, 7, 11, 14, 21, 30, 45, 60 days after bith. I gr. - intact animals (norm); ІІ gr. - control, animals which were injected intrauterine 0.9% NaCl solution; III - experimental animals injected with staphylococcal toxoid liquid purified adsorbed (10-14 units of binding in 1 ml, diluted 10 portions) by operation intrauterinely on the 18th day of dated pregnancy. Histological sections 3-5 μm thick were stained by hematoxylin and eosin, histochemicaly by alcian blue and azan staining. Immunohistochemical study was performed according to the protocol recommended for a particular antibody of the manufacturer. Used ki-67 (Ki-67), TTF-1 (8G7G3/1), Fox-1 (A-12) monoclonal antibodies by Santa Cruz Biotechnology, Inc. A set of morphometric studies was performed by microscope Carl Zeiss Primo Star equipped with the Axiocam digital microphoto attachment with using program complex Zeiss Zen 2011. The results were considered reliable at p≤0,05. For processing of statistical material was used the standard software package Microsoft Office Excel and Statistica 10.0.The results were obtained about morphogenesis of rat’s thyroid after intrauterine antigenic action of staphylococcal toxoid. Morphofunctional homeostasis and stromal-parenchymal proportional relationship to thyroid gland closely associated with the activity of immune cells, including special role of lymphocytes, macrophages, and mast cells. Prenatal influence of staphylococcal toxoid led to the formation of a more pronounced structure of the parenchyma and stroma, but they showed signs of functional immaturity after birth. During the sucking period, the simultaneous presence of intra-, extrafollicular, septal and intramural types of folliculogesis is determined, which is a local reaction to systemic antigenic irritation with activation of compensatory-adaptive reactive folliclegenesis. The revealed changes in the process of folliclegenesis, accompanied by venous plethora, the formation of intraorgan diffuse lymphoid tissue and nodules, desquamation of the follicular epithelium, redistribution of the follicle diameter is a reaction to the systemic antigenic effect on the body during the critical period of prenatal development and normalizes by 45 days.Keywords: morphogenesis, thyroid gland, antigen, staphylococcal toxoid, experiment.

METHOD FOR APPROXIMATE CALCULATION OF FUNCTIONAL CHARACTERISTICS OF GAS PUMPING UNITS

Is described the method of approximate calculation of the functional characteristics of gas-pumping units and the method of diagnostics of the value of the impairment of the working wheel of the central center of the main gas pipelines is described. It is clear that the deposits are inflated with the impairment of productivity and productivity, and that is efficiency factor of superchargers. The architecture of the program complex is described, as well as the necessary system and technical facilities for carrying out the transfer for fragmentation at the warehouse of the automatic transmission system of the gas transmission system. Experimentally, the accuracy of the value of the radial prominence in the gaps of the working wheel on the buttstock of the "Demag" 655 P2 type was verified. The revision of the growth rates from the results of the straight lines to the open flow part was not shifted 0.15 mm. Descriptions of the method of implementation by a complex of programs, allow to carry out the development of the main indicators of the functional and technical mill of the VCN GPA: vitreous-pressure, forceful, polytropic KKD characteristics. These indicators are used for the purpose of determining the overall performance of the energy efficiency of the robotic skin GPU: the effective effort of the gas turbines, the vitrates of the fired gas from the of the coated gas pump, which is displayed in the real demand. The economics of the robotics of compressor stations, the supply of the pumped gas, the confirmation of the plans for the supply of gas to the residents and the safe functioning of the gas transportation system (GTS) of Ukraine, a significant world of possessing the functional To this, it is of particular importance to build up the development of new methods and to provide diagnostics, to ensure that the actual FCS possesses an assessment. At present, there is evidence of the actual state of possession of a more efficient operation of the plant in the transition from a traditional technical service to a resource-saving one. The obtained results show that the calculation of the actual characteristics of the VCN using the proposed method allows to take into account the influence of seal wear on the actual parameters of the regime over the entire range of workloads of single-stage and multistage superchargers.