Zarządzanie i handel zagraniczny w małych i średnich przedsiębiorstwach w warunkach integracji europejskiej: materiały z konferencji

Z przedmowy: "Integracja europejska to proces łączenia, scalania się odrębnych ekonomicznie, społecznie, kulturowo gospodarek europejskich krajów. Proces integracji prowadzi do istotnych przekształceń w sferze gospodarki, strategiach organizacji i funkcjonowania przedsiębiorstw, handlu międzynarodowym, działalności marketingowej, strukturach organizacyjnych i mechanizmach ekonomicznych przedsiębiorstw i instytucji działających w krajach integrujących się. Proces integracji to w praktyce proces dostosowywania się struktur gospodarczych; tworzenia związków kooperacyjno-produkcyjnych; powstawania trwałych więzi ekonomicznych między przedsiębiorstwami integrujących się krajów a więc proces kształtowania jednolitego obszaru gospodarczego z odrębnych a często także wzajemnie konkurencyjnych krajów, gospodarek, regionów, gałęzi, branż. Proces międzynarodowej integracji gospodarczej to w dużej mierze proces tworzenia komplementamości przedsiębiorstw i instytucji, komplementamości międzygałęziowej i wewnątrz gałęziowej, w produkcji i wymianie jak też kształtowanie niezbędnej infrastruktury technicznej i ekonomicznej umożliwiającej tworzenie sytemu trwałych powiązań gospodarczych między poszczególnymi krajami."(...

Príčina požiaru - zváranie

Import 20/04/2006Prezenční výpůjčkaVysoká škola báňská. Fakulta hornicko-geologická. Katedra (527) techniky požární ochrany a bezpečnosti průmysl

The Comparison of the Modal Analysis of a Membrane Structure

This article deals with the comparison of the results of a natural oscillation. It is a membrane, which in one case represents a solitary, articulated structure, in the other case this structure is anchored to a steel frame. In general, boundary conditions are simplified in the calculations, but in dynamic specifically these approximations can negatively affect the results. Therefore, the first variant presents a simplified form and the second variant more accurately complements the real model. The observed characteristics are the basic dynamic parameters: natural frequency, natural period. The aim of this paper is to compare the influence of the secondary structure forming the support system on the overall stiffness, which can significantly contribute to the results of dynamic analyses.Tento článok sa zaoberá porovnávaním výsledkov vlastného kmitania. Ide o membránu, ktorá v jednom prípade predstavuje osamotenú, kĺbovo podopretú konštrukciu, v druhom prípade je táto konštrukcia doplnená o oceľový rám, do ktorého je uložená. Vo všeobecnosti sa pri výpočtoch zjednodušujú okrajové podmienky, avšak pri dynamike môžu tieto priblíženia negatívne ovplyvniť skúmanú problematiku. Preto prvý variant prezentuje zjednodušenú formu a druhý variant presnejšie dopĺňa predstavu o reálnom modeli. Sledovanými charakteristikami a vlastnosťami sú základné dynamické parametre: vlastná frekvencia, vlastná perióda. Cieľom tohto príspevku je porovnať vplyv okrajovej konštrukcie tvoriacej podperný systém na celkovú tuhosť, ktorá sa môže značne podieľať na výsledkoch v rámci dynamických analýz

Verification of the initial setup of experimental device compared to the FEM model

This paper compares and verifies the experimental membrane device with the model created in FEM software. At first, the experimental device needs to be properly set up and prepared. This includes settings of all input factors such as the placement of the technical fabric, the pretensioning of the edge ropes, the functionality of the actuators or load cells placed on the anchor rods. The numerical model in FEM software was created to confirm the functionality of the experimental device. Based on the results obtained by simple load cells measurements and the load results in the numerical model, it was confirmed that the behaviour of the experimental device coincided with the assumed behaviour of the membrane structure

Wind flow around buildings of basic shapes with and without a wind-adaptive envelope

Together with the natural environment, the built, artificial environment represents a barrier to the wind fluxes. Especially in the densely built cities, the wind flow pattern and the wind speed are considerably altered by buildings, which can lead to zones of an accelerated wind and turbulent flow. Incorporating the wind into the early conceptual stage of architectural design, this reciprocal interaction of the built environment and the wind fluxes can be analyzed and controlled to create zones of calmer wind around buildings. Presently, building envelopes are designed to withstand extreme load cases, which, however, demands thicker and bulkier structures. The subject of this study is a proposal and investigation of a lightweight, adaptive building envelope, which is able of a local, passive morphing in the wind. This local shape change leads to creating a textured, dimpled building surface; the final shape depends on the wind direction and force. The wind-induced dimpled surface influences the wind flow around the building, as well as surface wind pressure acting on the building, and the drag force. The analysis of three fundamental building shapes using the CFD (Computational Fluid Dynamics) simulation is performed for the variants with and without the proposed adaptive envelope. Concluding from the wind simulations, the wind flow can be decelerated, the turbulence reduced, and calmer zones around buildings can be created, by certain conditions. Moreover, the envelope, morphing with the instant wind force, can contribute to the reduction of the surface wind suction on buildings. Strikingly, the dimpled geometry of the wind-adaptive envelope can decrease the wind drag force by up to 28.4 %, which is again dependent on the global form, as well as the initial wind speed

The Comparison of the Modal Analysis of a Membrane Structure

This article deals with the comparison of the results of a natural oscillation. It is a membrane, which in one case represents a solitary, articulated structure, in the other case this structure is anchored to a steel frame. In general, boundary conditions are simplified in the calculations, but in dynamic specifically these approximations can negatively affect the results. Therefore, the first variant presents a simplified form and the second variant more accurately complements the real model. The observed characteristics are the basic dynamic parameters: natural frequency, natural period. The aim of this paper is to compare the influence of the secondary structure forming the support system on the overall stiffness, which can significantly contribute to the results of dynamic analyses

Digitally Designed Airport Terminal Using Wind Performance Analysis

Over the past few decades, digital tools have become indispensable in the field of architecture. The complex design tasks that make up architectural design methods benefit from utilizing advanced simulation software and, consequently, design solutions have become more nature-adapted and site-specific. Computer simulations and performance-oriented design enable us to address global challenges, such as climate change, in the preliminary conceptual design phase. In this paper, an innovative architectural design method is introduced. This method consists of the following: (1) an analysis of the local microclimate, specifically the wind situation; (2) the parametric shape generation of the airport terminal incorporating wind as a form-finding factor; (3) Computational Fluid Dynamics (CFD) analysis; and (4) wind-performance studies of various shapes and designs. A combination of programs, such as Rhinoceros (Rhino), and open-source plug-ins, such as Grasshopper and Swift, along with the post-processing software Paraview, are utilized for the wind-performance evaluation of a case study airport terminal in Reykjavik, Iceland. The objective of this wind-performance evaluation is to enhance the local wind situation and, by employing the proposed architectural shape, to regulate the wind pattern to find the optimal wind flow around the designed building. By utilizing the aforementioned software, or other open-source software, the proposed method can be easily integrated into regular architectural practice

Verification of the initial setup of experimental device compared to the FEM model

This paper compares and verifies the experimental membrane device with the model created in FEM software. At first, the experimental device needs to be properly set up and prepared. This includes settings of all input factors such as the placement of the technical fabric, the pretensioning of the edge ropes, the functionality of the actuators or load cells placed on the anchor rods. The numerical model in FEM software was created to confirm the functionality of the experimental device. Based on the results obtained by simple load cells measurements and the load results in the numerical model, it was confirmed that the behaviour of the experimental device coincided with the assumed behaviour of the membrane structure

Shape-changing tensegrity-membrane building skin

Building skins are persistently exposed to changes in the weather, including the cases of weather extremes, increasing in frequency due to global climate change. As a consequence of the advancements of digital design tools, the integration of the weather conditions into the design process is much smoother. The impact of the ambient conditions on buildings and their structures can be digitally analyzed as early as in the conceptual design stage. These new design tools stimulate original ideas for shape-changing building skins, actively reacting to the dynamic weather conditions. In the paper, a digital design method is introduced, leading towards the design of a building skin, able of the passive shape adaptation when subjected to the wind. The designed building skin consists of a tensegrity structure where the tensioned elements are substituted by a tensile membrane, creating a self-equilibrated building skin element. In the previous research, a small prototype of this wind-adaptive element was created. The computer simulations are employed to predict the adaptive behavior of a bigger, full-scale building skin element. The before-mentioned building envelope becomes an active player in its surrounding environment, passively reacting to the wind in real-time, thanks to the geometric and material properties. Due to the local shape changes caused by the wind force, the wind can be perceived unconventionally through the adaptive building structure

Parametric wind design

Although gradual, the changes in the weather patterns are also noticeable and impactful to architectural design. If the local microclimate is taken into account early in the conceptual stage of design, the longevity of the ultimate structure can be greatly enhanced, despite challenging environmental factors. Parametric designing enables to discover the optimal architectural shape based on specific weather data. The paper intends to investigate how this design approach, coupled with Computational Fluid Dynamics simulations, can be used to create a wind-induced architecture. Both the benefits and the limitations of this approach are explored in detail. The interaction between an architectural shape and wind flow is tested in a study called ‘FlowBrane’. The process of (1) designing a parametrically changeable geometry, (2) testing its behavior in the wind, and (3) evaluating the results allows looping back to the initial geometric design, continuing to improve the design and ultimately the performance of the architecture in the specific wind conditions of the chosen site. However, the need to test multiple geometries separately and to adjust the wind simulation for each test (and for every wind direction) remains a disadvantage that should be addressed in further research. Keywords: Parametric architecture, Computational Fluid Dynamics, Wind, Performance, Early design stag