1,784 research outputs found
Indledende hydrauliske undersøgelser af bølgeenergianlægget "Bent Ringgaards Flyder"
No full textNærværende rapport beskriver forsøg udført på Aalborg Universitet, Laboratoriet for Hydraulik & Havnebygning med bølgeenergianlægget "Bent Ringgaards Flyder"
Torsion Design Example: Inverted Tee Bent Cap
No full textThis paper provides a practical example of the torsion design of an inverted tee bent cap of a three-span bridge. A full torsional design following the guidelines of the ACI 318-19 building code is carried out and the results are compared with the outcomes from CSA-A23.3-04, AASHTO-LRFD-17, and EN 1992-1-1:2004 codes. Then, a summary of the detailing of the cross-section considering the reinforcement requirements is presented. The objective of this paper is to illustrate the application of ACI 318-19 when designing a structural element subjected to large torsional moments.Accepted Author ManuscriptConcrete Structure
Bent partitions and partial difference sets
No full textThe recently introduced concept of a bent partition of a 2m-dimensional vector space V(p) 2m over a prime field Fp exhibits similar properties as a partition from a spread. In particular, it gives rise to a large family of bent functions obtained in the same manner as spread bent functions. We show that the first non-spread construction of bent partitions introduced by Pirsic and the third author (p = 2), respectively, the first and the third author (p odd), gives rise to a large variety of different bent partitions. Especially, we show that the sets of bent functions obtained with any two such bent partitions do not intersect. We then show that every union of sets from one of these bent partitions always forms a partial difference set. This generalizes some known results on partial difference sets from spreads. Some general results on partial difference sets from bent partitions of V(2) 2m are given in the last section. IEE
On the ranks of bent functions
No full textAbstractThe rank of a bent function is the 2-rank of the associated symmetric 2-design. In this paper, it is shown that it is an invariant under the equivalence relation among bent functions. Some upper and lower bounds of ranks of general bent functions, Maiorana–McFarland bent functions and Desarguesian partial spread bent functions are given. As a consequence, it is proved that almost every Desarguesian partial spread bent function is not equivalent to any Maiorana–McFarland bent function
Vectorial bent functions and their duals
No full textCesmelioglu, Ayca/0000-0001-5049-9135Motivated by the observation that for two (weakly regular) bent functions f, g for which also f + g is bent, the sum f* + g* of their duals f and g* is sometimes but not always bent, we initiate the study of duality for vectorial bent functions. We propose and investigate two concepts of self-duality for vectorial bent functions, self-duality and weak self-duality. (C) 2018 Elsevier Inc. All rights reserved.Austrian Science Fund (FWF)Austrian Science Fund (FWF) [M 1767-N26]The second author is supported by the Austrian Science Fund (FWF) Project no. M 1767-N26
Bent up bars: assessment and implementation of outdated reinforcement configurations in existing concrete structures
No full textBent up bars were prescribed as shear reinforcement in the first half of the twentieth century, stirrups after the 1960’s. In current Eurocode, bent up bars can be applied again, but restrictions with respect to the maximum shear strength should be followed. Goal of this report is to provide background for this shear strength restriction and provide an assessment method for concrete structures reinforced with bent up bars. First part of the report analyses critical design aspects of bent up bars in the transfer of shear stresses with help of truss models. Second part explores the shear strengths of reinforcement sections and concrete struts with help of outcomes of experiments performed in the past. In last part, the obtained insights are collected and captured into a conceptual model. This model is employed to describe the expected failure mechanism of bent up bars and reflect on assessment methods and maximum shear strengths of specimen reinforced with bent up bars. Consequence of the application of bent up bars in concrete structures is the formation of cracks in the supporting concrete strut by curved sections of bent up bars. The remaining shear strength of concrete structures depends on the shear resistance of cracked concrete struts.The findings in this report implies that any model based on the tensile strength of inclined members is applicable for the analysis of bent up bars as long as the applied shear stresses are limited to ten percent of the compressive strength. Also, the application and assessment of bent up bars in concrete structures requires special attention to: shear and flexural reinforcement inclusive designs, cover spalling mechanisms, and detailing of anchorage regions flexural reinforcement bars.Civil Engineerin
Decomposing generalized bent and hyperbent functions
No full textIn this paper we introduce generalized hyperbent functions from F2n to Z2k, and investigate decompositions of generalized (hyper)bent functions. We show that generalized (hyper)bent functions from F2n to Z2k consist of components which are generalized
(hyper)bent functions from F2n to Z2k′ for some k′ < k. For odd n, we show that the Boolean functions associated to a generalized bent function form an affine space of semibent functions.
This complements a recent result for even n, where the associated Boolean functions are bent.Project number. M 1767-N26Second author is supported by the Austrian Science Fund (FWF
Thin Glass Cold Bent Sandwich Panel
No full textFrom the beginning of the 21st century, thin glass has been used as a screen protector for electronic devices and smartphones. During the last 10 years, several studies have been carried out to introduce the thin glass in the building industry. The advantages of this material are light weight, high strength and high flexibility. On the other hand, thin glass, due to its low thickness, has a limited bending stiffness. Therefore, it is challenging to apply this innovative material in the building field. Within this research, the stiffness of thin glass is increased by the realization of a thin glass cold bent sandwich panel.The proposed sandwich panel is realized by using thin glass faces and a 3D printed polymeric core. Due to the high flexibility of the glass, the material can be easily bent and glued to the core. The curved core hold the cold bent glass in shape without the use of any frame. To validate the numerical results, laboratory tests have to be carried out. The design of the curved sandwich panel revealed to be a feasible façade panel proposal. The feasibility is defined in terms of a structural façade element, which fulfill the limits of safety and comfort. The curved sandwich panel, proposed in the final design, results to be 280 times stiffer compared to a curved two layered thin glass laminated panel. Furthermore, it was demonstrated that the proposed sandwich panel could guarantee a weight reduction of more than 80% in comparison to the glass used nowadays in building façades. This characteristic not only facilitates the assemblage of the façade, but also can bring to the usage of a lighter support structure. This can bring advantages both in terms of cost of the total structure and energy required to assemble the building.Civil Engineering | Building Engineerin
Cryptographer\u27s Toolkit for Construction of -Bit Bent Functions
No full textBoolean functions form basic building blocks in various cryptographic algorithms. They are used for instance as filters in stream ciphers. Maximally non-linear (necessarily non-balanced) Boolean functions with an even number of variables are called bent functions. Bent functions can be modified to get balanced highly non-linear Boolean functions.
Recently the first author has demonstrated how bent functions can be studied in a recursive framework of certain integer-valued functions. Based on this new approach we describe the practical systematic construction of -bit bent functions. We outline also how to compute the number of all -bit bent functions
Bent and vectorial bent functions, partial difference sets, and strongly regular graphs
No full textCesmelioglu, Ayca/0000-0001-5049-9135Bent and vectorial bent functions have applications in cryptography and coding and are closely related to objects in combinatorics and finite geometry, like difference sets, relative difference sets, designs and divisible designs. Bent functions with certain additional properties yield partial difference sets of which the Cayley graphs are always strongly regular. In this article we continue research on connections between bent functions and partial difference sets respectively strongly regular graphs. For the first time we investigate relations between vectorial bent functions and partial difference sets. Remarkably, properties of the set of the duals of the components play here an important role. Seeing conventional bent functions as 1-dimensional vectorial bent functions, some earlier results on strongly regular graphs from bent functions follow from our more general results. Finally we describe a recursive construction of infinitely many partial difference sets with a secondary construction of p-ary bent functions.Austrian Science Fund (FWF)Austrian Science Fund (FWF) [M 1767-N26]The second author is supported by the Austrian Science Fund (FWF) Project no. M 1767-N26
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