25 research outputs found

    Nonlinear spectral calculus and super-expanders

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    Nonlinear spectral gaps with respect to uniformly convex normed spaces are shown to satisfy a spectral calculus inequality that establishes their decay along Cesaro averages. Nonlinear spectral gaps of graphs are also shown to behave sub-multiplicatively under zigzag products. These results yield a combinatorial construction of super-expanders, i.e., a sequence of 3-regular graphs that does not admit a coarse embedding into any uniformly convex normed space.Comment: Typos fixed based on referee comments. Some of the results of this paper were announced in arXiv:0910.2041. The corresponding parts of arXiv:0910.2041 are subsumed by the current pape

    Calculation of elements subjected to bending moments made of cross laminated timber (CLT) according to PN-EN 1995-1-1

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    W artykule przedstawiono spos贸b wymiarowania element贸w zginanych wykonanych z drewna klejonego krzy偶owo CLT w uj臋ciu normy PN-EN 1995-1-1. Do wymiarowania wykorzystano adaptacj臋 normowej metody opartej na teorii belek zespolonych mechanicznie. Jako uzupe艂nienie opisanej metody przedstawiono przyk艂ad obliczeniowy wykorzystuj膮cy pokazane podej艣cie.The article presents the method of calculating elements subjected to bending moments made of cross laminated timber CLT according to PN-EN 1995-1-1. The modification of the standard method based on the theory of mechanically joined beams is used for calculations. A calculation example using the shown approach is presented

    Verification of the stability of the construction of steel lattice towers of OHL power line 110 kV

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    W pracy dokonano analizy wp艂ywu smuk艂o艣ci wzgl臋dnej efektywnej na no艣no艣膰 pr臋t贸w 艣ciskanych w stalowych wie偶ach kratowych. Smuk艂o艣膰 efektywna obliczana jest z uwzgl臋dnieniem sposobu zamocowania ko艅c贸w element贸w 艣ciskanych. Om贸wiono implementacj臋 tych zasad oblicze艅 w odniesieniu do nowych s艂up贸w linii elektroenergetycznych 110 kV. Weryfikacj臋 za艂o偶e艅 teoretycznych oblicze艅 no艣no艣ci element贸w s艂up贸w kratowych przeprowadzono podczas test贸w kompletnych konstrukcji na poligonie badawczym. Badania prowadzono w ramach realizacji projektu wsp贸艂finansowanego ze 艣rodk贸w Europejskiego Funduszu Rozwoju Regionalnego Wojew贸dztwa Mazowieckiego Nr RPMA.01.02.00-14-5672/16. Wyniki test贸w potwierdzi艂y z du偶膮 dok艂adno艣ci膮 zgodno艣膰 oszacowania teoretycznej no艣no艣ci pr臋t贸w 艣ciskanych z realnie wyznaczon膮 no艣no艣ci膮 graniczn膮 ustroj贸w kratowych, ulegaj膮cych zniszczeniu w wyniku utraty stateczno艣ci. Potwierdzono praktyczn膮 skuteczno艣膰 procedur normowych zawartych w PN-EN 1993-3-1 w zakresie modyfikacji wymiarowania pr臋t贸w 艣ciskanych o sta艂ych przekroju. Celem artyku艂u by艂o wskazanie efektywno艣ci innowacyjnych zasad oblicze艅 ustroj贸w kratowych zapewniaj膮cych stosown膮 no艣no艣膰 element贸w przy uwzgl臋dnieniu ekonomicznych aspekt贸w rozwi膮za艅.In the work one made sensitivity studies the relative effective slenderness on the compression capacity of the elements used in steel lattice鈥搕owers. The effective slenderness is counted with the regard of the type of of the end connections of the elements. One discussed the implementation of these rules of calculations in reference to new tower of overheading power lines 110kV. The verification of foundations of theoretical calculations of the capacity of elements of latticed towers one carried out during tests of complete constructions on the field tests. Tests were driven within the framework of the realization of the project partially financed from measures of the of the European Fund of the Development of the Regional Province of Mazovia No. RPMA.01.02.00-14-5672/16. Results of tests confirmed with the large accuracy the conformity of the estimation of the theoretical capacity of elements with the really designated limit capacity of systems lattice-tower, consumable as result of the loss of the stability. One confirmed the practical effectiveness of standard procedures contained in standard PN-EN 1993-3-1 within the range the modification of the dimensioning of compressed elements with constant cross section. For purposes of the article was the indication of the efficiency of innovative rules of calculations of lattice鈥搕owers systems providing the appropriate compression capacity of elements at the regard of economic aspects of solutions

    Models of heat conduction in solids

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    W pracy przedstawiono modele przep艂ywu ciep艂a w cia艂ach sta艂ych w zale偶no艣ci od pr臋dko艣ci propagacji fal ciep艂a, k艂ad膮c nacisk na praktyczne wykorzystanie r贸wna艅 opisuj膮cych przedstawione zagadnienie. Praca ma charakter przegl膮dowy.The paper presents a model of heat transfer in solids, depending on the propagation speed of thermal waves, with an emphasis on the practical use of the equations governing the presented issue. Work is a review

    SEMANTIC METADATA FOR HETEROGENEOUS SPATIAL PLANNING DOCUMENTS

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    Spatial planning documents contain information about the principles and rights of land use in different zones of a local authority. They are the basis for administrative decision making in support of sustainable development. In Poland these documents are published on the Web according to a prescribed non-extendable XML schema, designed for optimum presentation to humans in HTML web pages. There is no document standard, and limited functionality exists for adding references to external resources. The text in these documents is discoverable and searchable by general-purpose web search engines, but the semantics of the content cannot be discovered or queried. The spatial information in these documents is geographically referenced but not machine-readable. Major manual efforts are required to integrate such heterogeneous spatial planning documents from various local authorities for analysis, scenario planning and decision support. This article presents results of an implementation using machine-readable semantic metadata to identify relationships among regulations in the text, spatial objects in the drawings and links to external resources. A spatial planning ontology was used to annotate different sections of spatial planning documents with semantic metadata in the Resource Description Framework in Attributes (RDFa). The semantic interpretation of the content, links between document elements and links to external resources were embedded in XHTML pages. An example and use case from the spatial planning domain in Poland is presented to evaluate its efficiency and applicability. The solution enables the automated integration of spatial planning documents from multiple local authorities to assist decision makers with understanding and interpreting spatial planning information. The approach is equally applicable to legal documents from other countries and domains, such as cultural heritage and environmental management
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