OPTIMIZATION OF TRUSS STRUCTURES OF THE STANDART SERIES WITH CROSS GRIDS

2021 ◽  
pp. 70-81
Author(s):  
А.С. Марутян
Keyword(s):  
Comparative Analysis ◽  
Optimal Design ◽  
Bearing Capacity ◽  
Communication Systems ◽  
Truss Structures ◽  
Technical Solution ◽  
Equal Strength ◽  
Necessary And Sufficient ◽  
Patent Examination

Представлено конструктивно-компоновочное решение стержней Y-образных и Ψ-образных очертаний в фермах с перекрестной решеткой или фермах с перекрестной решеткой и полустойками (полуподвесками), техническая новизна которого подтверждена результатами патентной экспертизы. Универсальность этого решения для ферменных конструкций обеспечивает ту эффективность, с какой оно применимо к грузовым верхним поясам, грузовым нижним поясам или грузовым верхним и нижним поясам одной и той же решетки. Повышена степень унификации типовой фермы из прокатных профилей за счет использования в верхнем поясе расчетных сечений, принятых для нижнего пояса. При этом ресурсы несущей способности разнятся между ними не более чем на полтора процента, что обеспечивает необходимую и достаточную равнопрочность обоих поясов для их более рациональной унификации. Выполнен сравнительный анализ основных результатов решения вариантного и оптимального проектирования ферменных конструкций применительно к решеткам с двойными системами полураскосов и решеткам с одинарными системами раскосов. Выявлена перспективность применения нового технического решения в составе несущих и связевых систем различных зданий и сооружений. The structural and layout solution of rods of Y-shaped and Ψ-shaped outlines in trusses with a cross lattice or trusses with a cross lattice and half-posts (half-suspensions) is presented, the technical novelty of which is confirmed by the results of patent examination. The versatility of this truss solution is as effective as it is for load tops, load bottoms, or load tops and bottoms of the same grid. The degree of unification of a typical truss of rolled sections has been increased due to the use of design sections in the upper belt adopted for the lower belt. At the same time, the resources of the bearing capacity differ between them by no more than one and a half percent, which ensures the necessary and sufficient equal strength of both belts for their more rational unification. A comparative analysis of the main results of the solution of the variant and optimal design of truss structures as applied to gratings with double systems of half-braces and gratings with single systems of braces is carried out. The prospect of using a new technical solution in the composition of bearing and communication systems of various buildings and structures has been revealed.

scholarly journals OPTIMIZATION OF TREE STRUCTURES WITH HALF-DRAWER GRIDS

2020 ◽  
pp. 39-50
Author(s):  
А. С. Марутян
Keyword(s):  
Bearing Capacity ◽  
Communication Systems ◽  
Truss Structure ◽  
Truss Structures ◽  
Technical Solution ◽  
Rectangular Section ◽  
Tree Structures ◽  
Load Bearing ◽  
Different Shapes ◽  
Necessary And Sufficient

Приведено новое техническое решение в виде дополнительных стержней I-образной, Y-образной, Ψ-образной формы в полураскосных решетках для стержневых (ферменных) конструкций. Показана эффективность их применения в фермах, у которых грузовыми являются не только верхние (сжатые) пояса, но также и нижние (растянутые). Повышена степень унификации ферменной конструкции из гнутосварных профилей (профильных труб) прямоугольного сечения за счет повторного использования в верхнем поясе расчетного сечения, принятого для нижнего пояса. При этом ресурсы несущей способности разнятся между ними в пределах 3-4-процентного порога, что обеспечивает необходимую и достаточную равнопрочность обоих поясов при их унификации. Соединительные узлы верхнего пояса с дополнительными полураскосами разных очертаний позволяют опереть на них определенное количество прогонов с уменьшенными размерами грузовых площадей. Увеличение общего количества прогонов приводит к их облегчению, что представляет собой весьма важный фактор для несущих конструкций, рассчитанных на особые нагрузки и воздействия, а также для объектов повышенной ответственности. Выявлена перспективность применения нового технического решения в составе несущих и связевых систем различных зданий и сооружений. A new technical solution is presented in the form of additional I-shaped, Y-shaped, Ψ-shaped rods in half-diagonal lattices for rod (truss) structures. The effectiveness of their use in farms is shown, in which not only the upper (compressed) belts, but also the lower (extended) ones, are cargo. The degree of unification of the truss structure from bent welded profiles (profile pipes) of a rectangular section due to the reuse in the upper zone of the design section adopted for the lower belt is increased. At the same time, the resources of the bearing capacity differ between them within a 3… 4 percent threshold, which ensures the necessary and sufficient equal strength of both zones when unifying them. The connecting nodes of the upper belt with additional half-braces of different shapes allow to support a certain number of runs with reduced sizes of cargo areas. An increase in the total number of runs leads to their facilitation, which is a very important factor for load-bearing structures designed for special loads and impacts, as well as for objects of increased responsibility. The prospects of applying a new technical solution as a part of the bearing and communication systems of various buildings and structures are revealed.

OPTIMIZATION OF TREE STRUCTURES WITH RHOMBIC GRIDS

2021 ◽  
pp. 54-68
Author(s):  
А.С. Марутян
Keyword(s):  
Cross Sections ◽  
Communication Systems ◽  
Technical Solution ◽  
Building Structures ◽  
Tree Structures ◽  
Different Shapes ◽  
Support Conditions ◽  
Necessary And Sufficient ◽  
Patent Examination ◽  
Rhombic Lattice

Представлено конструктивно-компоновочное решение стержней Y-образных и Ψ-образных очертаний в фермах с ромбической решеткой или фермах с ромбической решеткой и полустойками (полуподвесками), техническая новизна которого подтверждена результатами патентной экспертизы. Универсальность этого решения для ферменных конструкций обеспечивает ту эффективность, с какой оно применимо к грузовым верхним поясам, грузовым нижним поясам или грузовым верхним и нижним поясам одной и той же решетки. Повышена степень унификации фермы из прямоугольных гнутосварных профилей (профильных труб) за счет использования в верхнем поясе форм и наружных габаритов поперечных сечений, принятых для нижнего пояса. При этом ресурсы несущей способности разнятся между ними в пределах однопроцентного порога, что обеспечивает необходимую и достаточную равнопрочность обоих поясов для их более рациональной унификации. Узловые соединения стержней разных очертаний с верхними поясами позволяют оптимизировать опорные условия настилов и прогонов с уменьшением размеров их грузовых площадей. Возрастание общего количества прогонов приводит к снижению их суммарной массы и массы кровельного ограждения, что весьма актуально для вариантного и оптимального проектирования строительных конструкций с учетом риска лавинообразного обрушения. Выявлена перспективность применения нового технического решения в составе несущих и связевых систем различных зданий и сооружений. The structural and layout solution of rods of Y-shaped and Ψ-shaped outlines in trusses with a rhombic lattice or trusses with a rhombic lattice and half-posts (half-suspensions) is presented, the technical novelty of which is confirmed by the results of patent examination. The versatility of this truss solution is as effective as it is for load tops, load bottoms, or load tops and bottoms of the same grid. The degree of unification of the truss of rectangular bent-welded profiles (shaped pipes) has been increased due to the use in the upper chord of the forms and outer dimensions of the cross-sections adopted for the lower chord. At the same time, the resources of the bearing capacity differ between them within a one- percent threshold, which ensures the necessary and sufficient equal strength of both belts for their more rational unification. Nodal connections of rods of different shapes with the upper chords allow to optimize the support conditions of decks and purlins with a decrease in the size of their cargo areas. An increase in the total number of runs leads to a decrease in their total mass and the mass of the roofing, which is very important for the variant and optimal design of building structures, taking into account the risk of an avalanche collapse. The prospect of using a new technical solution in the composition of bearing and communication systems of various buildings and structures has been revealed.

Conditions for the Introduction of Regulation for Short-Term Rentals

2021 ◽  
Vol 8 (1) ◽  
pp. 159-170
Author(s):  
Vilim Brezina ◽  
◽  
Jan Polívka ◽  
Martin Stark ◽  
◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Housing Market ◽  
Housing Stock ◽  
Qualitative Comparative Analysis ◽  
Short Term ◽  
Market Conditions ◽  
Qualitative And Quantitative ◽  
Market Situation ◽  
Necessary And Sufficient ◽  
German Cities

Most cities in major agglomerations in Europe started to address the rise of short-term accommodation rentals by introducing regulation designed to protect the local housing stock. The momentum behind the widespread introduction of such regulations can be attributed to qualitative and quantitative factors. This article examines selected fields related to short-term rentals in order to uncover the (structural) triggers or conditions that are necessary and sufficient for municipalities to initiate the regulation of their housing market. The study is based on the systematic examination of the effects of those triggers and their combinations using qualitative comparative analysis (QCA). With this method, we explore the implementation or non-implementation of regulation on a sample of major German cities. The results suggest a universal set of conditions covering three central fields: housing market situation, accommodation market conditions and tourism accommodation demand.

scholarly journals A Cultural Algorithm for Optimal Design of Truss Structures

2015 ◽  
Vol 12 (9) ◽  
pp. 1721-1747 ◽  
Author(s):  
Shahin Jalili ◽  
Yousef Hosseinzadeh
Keyword(s):  
Optimal Design ◽  
Truss Structures ◽  
Cultural Algorithm

scholarly journals COMPARATIVE ANALYSIS OF COMPACT METHODS REPRESENTATIONS OF GRAPHIC INFORMATION

2021 ◽  
Vol 1 (37) ◽  
pp. 130-143
Author(s):  
O. Gertsiy
Keyword(s):  
Comparative Analysis ◽  
Communication Systems ◽  
Video Data ◽  
Transport Infrastructure ◽  
Practical Significance ◽  
Jpeg 2000 ◽  
Advantages And Disadvantages ◽  
Graphic Information ◽  
The Cost ◽  
And Storage

The main characteristics of graphic information compression methods with losses and without losses (RLE, LZW, Huffman's method, DEFLATE, JBIG, JPEG, JPEG 2000, Lossless JPEG, fractal and Wawelet) are analyzed in the article. Effective transmission and storage of images in railway communication systems is an important task now. Because large images require large storage resources. This task has become very important in recent years, as the problems of information transmission by telecommunication channels of the transport infrastructure have become urgent. There is also a great need for video conferencing, where the task is to effectively compress video data - because the greater the amount of data, the greater the cost of transmitting information, respectively. Therefore, the use of image compression methods that reduce the file size is the solution to this task. The study highlights the advantages and disadvantages of compression methods. The comparative analysis the basic possibilities of compression methods of graphic information is carried out. The relevance lies in the efficient transfer and storage of graphical information, as big data requires large resources for storage. The practical significance lies in solving the problem of effectively reducing the data size by applying known compression methods.

scholarly journals A Highly D‑efficient Spring Balance Weighing Design for an Even Number of Objects

2019 ◽  
Vol 5 (344) ◽  
pp. 17-27
Author(s):  
Małgorzata Graczyk ◽  
Bronisław Ceranka
Keyword(s):  
Optimal Design ◽  
Sufficient Conditions ◽  
Optimality Criteria ◽  
Point Of View ◽  
Necessary And Sufficient Conditions ◽  
Optimal Designs ◽  
Efficient Design ◽  
Spring Balance ◽  
Experimental Errors ◽  
Necessary And Sufficient

The problem of determining unknown measurements of objects in the model of spring balance weighing designs is presented. These designs are considered under the assumption that experimental errors are uncorrelated and that they have the same variances. The relations between the parameters of weighing designs are deliberated from the point of view of optimality criteria. In the paper, designs in which the product of the variances of estimators is possibly the smallest one, i.e. D‑optimal designs, are studied. A highly D‑efficient design in classes in which a D‑optimal design does not exist are determined. The necessary and sufficient conditions under which a highly efficient design exists and methods of its construction, along with relevant examples, are introduced.

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