Статьи журнала - Вестник Донского государственного технического университета
Все статьи: 1552
Статья научная
Each society is faced with the decision of how to provide the well-being and high quality of life of its citizens best. Increasingly, cities, states, and nations are turning to tourism as an important element in their economic portfolio as they recognize the potentially significant economic rewards at stake. Much of tourism development entails community development. If handled appropriately, tourism can become an important engine for achieving broader social goals. Whereas societies may aspire to achieve these goals, communities are struggling to manage tourism development effectively. Modern innovative management trends in tourism cluster modernization and diversification processes of the business have been launched: tourism business has grown significantly, the new functional structure has changed, and national tourism services sector broadened and consolidation is the main priority. In this case, Russian MICE-tourism development has recently gained greater urgency. Congress bureau as one of the important element of business tourism and MICE industry development has become a strategic factor of territory brand creation, according to the regional economy diversifications.
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Organization of walking of the lower-extremity exoskeleton using the control of the supporting foot
Статья научная
Introduction. The development of robotics in many advanced countries has raised various industries to a high level. The demand for robots increases the share of their use in production tasks, mainly in the motor-vehicle and electronics industries. Advanced robotics can increase productivity in many industries by 30%, while reducing labor costs. Automation of technological processes of electronics production has a positive impact on the use of robots. Robots are used in construction, logistics, oil and gas, aerospace, plant engineering and construction, mining, healthcare, etc. The authors consider robots from the point of view of their application in medicine for the rehabilitation of musculoskeletal patients. This paper describes the mechanisms for controlling the feet and the center of mass of a humanoid robot.Materials and Methods. The authors chose the simplest algorithm for searching for the law of motion control of a humanoid robot. The robot movement was presented as a reverse pendulum. Using the large kinematic redundancy of walking robots, we have developed a way to control the robot in such a way as to bring the dynamics of its movement to the reverse pendulum as close as possible. At the same time, the problem of determining the generalized coordinates is considered, at which a given position and orientation of the transferred foot and a given position of the projection of the center of mass (CM) of the robot onto the reference surface are provided.Results. The authors have developed a digitalized automatic control scheme for the movement of the feet and the center of mass of the human exoskeleton, which will largely reduce the load on a sick person.Discussion and Conclusions. When discussing the results, comparing the data of the tables obtained during the calculation, the following conclusion was made. The scheme for controlling the feet movement of a human exoskeleton developed by the authors is most effective when designing an automatic scheme for controlling the movement of the feet and the center of mass of a human exoskeleton using digital technology, which will largely reduce the load on a sick person.
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Статья научная
The article is intended to cover the new strategies to individual activity of students dealing with the self-management of study process organization providing quality higher education, strengthening mobility for better learning in the framework of competence/learning outcome-based, student-centered approaches to learning, teaching and assessment. It presents the main competences of individual activity throughout students’ careers, major tasks and trends of individual activity, essential criteria for individual work assessment and modern teaching technologies.
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Статья научная
Introduction. The use of probabilistic analysis is important when the input data are random, that leads to stochastic results. This paper describes the integration of a probabilistic design strategy of the solid and hollow stems implanted in a proximal femur in order to compare their advantages. The used hollow stem is called “Improved Austin-Moore” (IAM) model. Materials and Methods. Probabilistic methods allow variations in factors which control the biomechanical effects of the implanted femur to be taken into account while determining its performance. Different material properties were generated randomly using Monte Carlo simulation (MCS). Monte Carlo sampling techniques were applied, and different von Mises stresses of the layers (bone and metal) were chosen as a performance indicator. Results. A simple 2D implant-bone study of solid and IAM stem design was carried out with a high level of confidence, 99.87%, which corresponds to a target reliability index with regard to statistical uncertainties. The probabilistic design results show that the input and output parameters for the IAM stem are highly correlated relative to those for the solid stem. Discussion and Conclusions. The sensitivity analysis shows that the input parameters for the IAM stem play a much larger part in the output parameters relative to the solid stem. The IAM stem is much more advantageous than the solid stem which causes an increase in the performance of the hip prosthesis.
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Rational possibility of generating power laws in the synthesis of cam mechanisms
Статья научная
Introduction.The generation of polynomial power laws of motion for the synthesis of cam mechanisms is complicated by the need to determine the coefficients of power polynomials. The study objective is to discover a rational capability of generating power law swith arbitrary terms number under s with an rbitrary number of terms under the synthesis of cam mechanisms.Materials and Methods.A unified formula for determining the values of coefficients of power polynomials with any number of integers and/or non-integer exponents is derived through the so-called transfinite mathematical induction. Results.A unified formula for determining the values of coefficients, which gives correct results for any number of even and/or odd exponents, is presented. The correctness of the derived formula is validated by the results on the multiple checks for different numbers, even and odd values of the exponents of quinquinomial and hexanomial power functions. Discussion and Conclusions. A unified formula for determining the values of coefficients of power polynomials makes it possible to rationally define the laws of motion without finite and infinite spikes in the synthesis of elastic cam-lever systems. This provides a rational determination of the laws of motion without finite and infinite spikes in the synthesis of elastic cam-lever systems, and simple verification of the accuracy of the results obtained. The functions are particularly suitable for the synthesis of polydyne cams, as well as cams, since one polynomial can be used throughout the entire geometric mechanism cycle.
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Статья научная
The objective of this work is to provide an efficient tool of Reliability-Based Design Optimization (RBDO) for soil tillage machine design process in order to achieve designs with a required reliability (safety) level. An efficient methodology that controls the reliability levels for different statistical distribution cases of random soil properties is developed. This developed strategy is based on design sensitivity concepts in order to determine the influence of each random parameter. The application of this method consists in taking into account the uncertainties on the soil tillage forces. The tillage forces are calculated in accordance with analytical model of McKyes and Ali with some modifications to include the effect of both soil-metal adhesion and tool speed. The different results show the importance of the developed strategy to improve the performance of the soil tillage equipments considering both random geometry and loading parameters.
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Статья научная
Introduction. Perianal fistula rapidly develops an abscess, requiring surgical decompression. However, simple cases must be managed. However, for patients with renal insufficiency, MRI with contrast is contraindicated. It is proposed to use diffusion-weighted images that can diagnose anal fistulae, showing areas of high signal intensity (inflammatory tissues). The aim is to determine sensitivity of diffusion-weighted image combined with T2 turbo inversion recovery magnitude and as an alternative technique to contrast-enhanced MRI using clinical examination as a reference.Materials and Methods. Study included fifty patients with a clinical diagnosis of perianal fistula. MRI sequences were T2 turbo inversion recovery magnitude in oblique coronal and axial planes, diffusion-weighted image, and T1 weighted image turbo spin echo (fat suppression) pre- and post-administration of contrast agents in oblique axial planes. Three radiologists evaluated the MR imaging data using a questionnaire of parameters that necessitated a binary response, “yes” or “no” answer.Results. Diffusion-weighted image combined with axial T2 turbo inversion recovery magnitude sequence had 96.7 %. All raters agreed that it is sensitive enough to correctly identify perianal fistula with a moderate Kappa agreement (k = 0.586) and p-value function show_abstract() { $('#abstract1').hide(); $('#abstract2').show(); $('#abstract_expand').hide(); }
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Simulation of vibration and noise of belt gearing
Статья научная
The aim of this work is to find the methods of reducing noise and vibration in the belt drive of the electromechanical drive of the selected technological equipment. Thus, we are having more comfortable working conditions in the workplace in compliance with the sanitary standards of noise and vibration. The noise abatement techniques and the simulation of the vibration of the grinding woodworker flexible gearing are considered. Modeling was performed with the introduction of Euler variables. The simulated dependences allow by calculation determine noise levels and load characteristics of the selected equipment. The comparison between the expected noise levels and the sanitary standards allow determining the exceedance and the sources of its generation. All this is the basis for selecting the engineering solutions to observe the noise code.
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Smart-паспорт мехатронного технологического объекта. Концепт
Статья научная
Представлен инновационный подход к интеллектуальному электронному интерактивному документированию мехатронных технологических объектов — созданию smart-паспортов. Актуальность подхода продиктована необходимостью для таких объектов организованного документооборота технологических данных, информационного обмена данными, содержащими, в частности, результаты испытаний на геометрическую точность технологического объекта и точность обработки изделий. Специфические особенности, которыми обладает каждый технологический объект, как правило, не учитываются при программировании обработки. Перспективным направлением развития является наделение информационной среды сопровождения таких объектов в виде smart-паспортов интеллектуальными возможностями с индивидуальной системы знаний для управления процессом обработки и, в целом, эксплуатации, включая обслуживание, ремонт. Обеспечивается возможность подключения к внешней сетевой коммуникационной среде. Приводится миссия smart-паспорта и задачи, решаемые при его функционировании. Особое внимание уделено методологическим вопросам формированию системы знаний паспорта. Приведены характеристики проблемной ситуации и задач планирования операций управления по состояниям продукта производства и решаемых подзадач в пространстве состояний технологической системы. Рекомендован подход к формированию методов получения последовательности решений в системе знаний. Обращено внимание на специфику терминологического характера построения системы знаний, свойственного такой предметной области мехатронного технологического оборудования как металлорежущие станки.
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Статья научная
Introduction. Truss structures are widespread in construction due to a number of advantages, such as economy, versatility, and scalability. Accordingly, their modeling and calculation are urgent tasks in the design of building structures. Automatic solution to these problems causes an increase in design efficiency, calculation accuracy, and lower costs. The objective of the study is to examine the functionality and operation algorithm of the software module developed by the authors that generates the geometry of two-dimensional truss structures for subsequent modeling.Materials and Methods. Following the research of the widespread truss configurations, the classification of chords available in the software under consideration is given. The method of parameterizing a truss structure is provided. This method includes base geometric parameters of the structure such as dimensions, model construction rules, and additional features, as well as a comprehensive algorithm. The software is developed in JavaScript.Results. The software module has been integrated into a web application for calculating two-dimensional rod structures. To illustrate the functionality of the software, the examples of user interface are given as well as an example problem. The example includes configuration and calculation of an inclined truss structure. The results, such as support reactions and internal forces with axial force diagram, are provided.Discussion and Conclusions. Using this software module within the framework of the tool for calculating rod structures allows for the simplified process of modeling and calculating complex truss structures, design time, and resource reduction. The software module provides tools for specifying various types of structures, applying loads and assigning properties of a rod system, which makes it a useful instrument for design engineers.
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Статья научная
The term Insert cross-sector technologies for the cohesive bonding of materials are summarized, such as welding, gluing, and soldering, without which modern technical products will no longer be displayed. Examples from different industries are considered. The economic significance in exemplary countries of Europe and the world is pointed out. The required personnel qualification and the international standardization are discussed.
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Three-dimensional contact problem for a two-layered extra loaded elastic base
Статья научная
The three-dimensional Galin’s type contact problem for a two-layered elastic base (a layer completely attached to a half-space from another material) is investigated when an extra loading (concentrated force) is applied outside the contact area. The contact zone is supposed to be unknown. The punch foot form is an elliptic paraboloid. The problem is reduced to an integral equation with respect to the unknown contact pressure distributed in the unknown contact zone. Galanov’s method of nonlinear boundary integral equations is used to determine the contact pressure and the contact zone simultaneously. Calculations made for various values of elastic and geometric parameters allow estimating an extra force input to the dependence between the punch settlement and the force applied to the punch. The problem is important for the strength analysis of coated surfaces of various elastic solids subjected to contact and extra loadings. The solution can be also useful in the frame of the discrete contact theory for bodies with rough surfaces.
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Статья научная
The paper covers the description of role of business reputation (goodwill) in the assessment of the investment attractiveness of a business entity. The methodology of the goodwill valuation which allows making investment decisions is taken into account. Advantages and disadvantages of the methods are stated. The fact that the discounted cash flows method is the most reliable method of the goodwill valuation is concluded.
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Web-приложение для математического моделирования нестационарного течения нефти в пористой среде
Статья научная
Введение. Основу для анализа и интерпретации данных гидродинамических исследований составляют теоретические модели и вычислительные алгоритмы. Но, несмотря на востребованность данной тематики, многие вопросы, связанные с нестационарными течениями жидкостей в нефтяных пластах, все еще требуют решений. Поэтому математические постановки задач, связанных с учетом нестационарного течения жидкости, разработка эффективных численных методов и алгоритмов, их решение с применением современных web-технологий являются актуальными. Цель данной работы - разработка web-приложения для математического моделирования процесса фильтрации жидкости в однопоровых коллекторах при проведении гидродинамического исследования на добывающей скважине.Материалы и методы. Для решения поставленной задачи применены методы механики сплошной среды и вычислительной математики. Представлена модель течения нефти в однопоровом коллекторе. При разработке приложения использованы языки программирования Python и JavaScript. Результаты расчетов хранятся в реляционной базе данных, реализованной средствами PostgreSQL.Результаты исследования. Разработано новое web-приложение для моделирования процесса фильтрации нефти в однопоровых коллекторах, которое применимо для изучения флюидодинамических процессов и может быть использовано для прогноза дебитов, добычи и расчета оптимальных режимов работы скважин.Обсуждение и заключение. Разработанное web-приложение позволяет строить поля давления и температуры в пласте около работающей и остановленной добывающей скважины и на различных расстояниях от нее. Данная информация дает возможность оперативно оценивать длительность гидродинамических исследований, а также регулировать работу скважин. Приложение может быть развернуто в существующей сетевой инфраструктуре, пользоваться всем функционалом, подключаясь к удаленному серверу. Оно оптимизировано для использования на различных платформах и имеет широкие перспективы дальнейшего развития.
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Статья научная
Дана сущностная характеристика виртуальной реальности и ее конкретной, компьютерной формы, реализуемой через проект Интернета. Интернет рассматривается как особая сфера человеческой активности с точки зрения тех его возможностей, которые он создает для личности, стремящейся уйти от реальной социальной жизни.
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«Инновационный хаос» в транзитивном обществе (социокультурный анализ)
Статья научная
Рассматриваются инновационные процессы в современном обществе с социокультурной точки зрения. Определены кризисные явления (такие, как архаизация культуры), возникающие в условиях «инновационного хаоса» в трансформирующемся социуме.
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«Магический четырехугольник» микроэкономики
Статья научная
В экономической науке утвердился термин «магический четырехугольник» макроэкономики: экономический рост, занятость, инфляция, внешнеторговый баланс. На наш взгляд, в микроэкономике также можно выделить «магический четырехугольник»: доход - спрос - эффект замещения - предложение товаров и услуг. Статья посвящена раскрытию взаимосвязей в «магическом четырехугольнике» микроэкономики.
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«Наилучшие доступные технологии» в механизме управления социоприродохозяйственными системами
Статья научная
Сформированы предложения по адаптации зарубежного опыта регулирования негативного воздействия на окружающую среду в российских условиях с учетом региональной специфики, включающие создание региональных центров по «наилучшим доступным технологиям», определение их функций и схемы взаимодействия с федеральными структурами.
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«Открытая система маркетинга» как способ поддержания инновационной активности предприятия
Статья научная
Рассмотрена «открытая система маркетинга», с помощью которой современное предприятие способно динамично реагировать на рыночные изменения. За основу взят проект Open Source, принципиально новый маркетинговый подход подачи и реализации инновационного товара или услуги.
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Статья научная
Предложен алгоритм автоматизации идентификации законов распределения на основе аппроксимативного анализа экспериментальных данных. Метод основан на разложении эмпирических данных в ряд Фурье в пространстве L2 через полиномы Лежандра. Приведены два необходимых и достаточных критерия для автоматического выдвижения гипотезы о законе распределения. Изложенный метод рассмотрен на подробном примере.
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