Space Frame Research Articles

“That market has no quality”: Performative place frames, racialisation, and affective re‐inscriptions in an outdoor retail market in Amsterdam

AbstractThis paper interrogates the performative and affective aspects of relational place‐making processes by which people construct the everyday geographies of public space. Based on ethnographic fieldwork in and around an outdoor retail market in Amsterdam, the research findings show that the hegemonic frame of this public space is deeply racialised, mediating the way in which traders, market managers, and visitors encounter one another on a daily basis. By drawing on a shift from a discursive conception of relational place‐making to a performative and affective one, the results show how racialised place frames come into being through day‐to‐day performative practices, and how this is confirmed and brokered by people confronted with racialised place discourses. The findings on traders social networks through which they sustain access to public space highlight the importance of attending to the affective dimensions of place‐making in academic work focused on place politics.

Factorable weak operator-valued frames

The notion of operator-valued frames (OVFs) by Kaftal et al. (Trans Am Math Soc 361(12):6349–6385, 2009) and G-frames by Sun (J Math Anal Appl 322(1):437–452, 2006) do not include all generalizations of notions of frames for Hilbert spaces. For this purpose, we introduce the notion of weak operator-valued frames (weak OVFs) which covers all known generalizations of frames for Hilbert spaces. Theory of weak-OVFs is more demanding than the theory of OVFs due to the following: One, the weak frame operator may not factor and another, weak frame operator may not be positive. As a first step towards a reasonable theory, we impose factorability condition on weak frame operator. We then characterize and derive dilation results. Similarity and orthogonality notions are introduced and characterized. The notion is connected with groups as well as group-like unitary systems. We also derive stability results.

Spherical gravitational waves and quasi-spherical waves scattered from black string in massive gravity

Spherical gravitational wave is strictly forbidden in vacuum space in frame of general relativity by the Birkhoff theorem. We prove that spherical gravitational waves do exist in non-linear massive gravity, and find the exact solution with a special singular reference metric. Further more, we find exact gravitational wave solution with a singular string by meticulous studies of familiar equation, in which the horizon becomes non-compact. We analyze the properties of the congruence of graviton rays of these wave solution. We clarify subtle points of dispersion relation, velocity and mass of graviton in massive gravity with linear perturbations. We find that the graviton ray can be null in massive gravity by considering full back reaction of the massive gravitational waves to the metric. We demonstrate that massive gravity has deep and fundamental discrepancy from general relativity, for whatever a tiny mass of the graviton.

New inequalities for weaving frames in Hilbert spaces

In this paper, we establish Parseval identities and surprising new inequalities for weaving frames in Hilbert spaces which involve scalar lambda in {mathcal{R}}. With suitable choices of λ, one obtains the previous results as special cases. Our results generalize and improve the remarkable results obtained by Balan et al. and Găvruţa.

How to use the Omni-Wrist III for dexterous motion: An exposition of the forward and inverse kinematic relationships

The Omni-Wrist III, invented by Ross-Hime Designs, Inc. (Rosheim, 1999, 2002), is a well known two-degree of freedom wrist mechanism that incorporates parallel links with double universal joints (N-UU). It has the advantage of singularity-free operation over the entire hemispherical work-space and maintains a constant axial distance between the two joints. These characteristics make it an appealing choice for mobile robotic appendages that require dexterous maneuvers. While the two active input joint angles are coupled, this paper presents an accessible exposition of the forward and inverse kinematics for the position and velocity of the mechanism. The novelty of this analysis lies in the parameterization of the kinematics in terms of the vector between the origins of the tool and space frames. The results of this paper provide concise equations that are readily implementable in simulation and on low power microcontrollers enabling the use of the Omni-Wrist III for highly dynamic mobile robot maneuvers.

Analysis and compensation of shrinkage and distortion in wire-arc additive manufacturing of thin-walled curved hollow sections

Curved hollow sections are used in numerous applications from lightweight space frames to pipings in process engineering. In conventional manufacturing, such structures are produced mainly by metal forming or casting. Despite ongoing efforts in rapid tooling technologies for casting and flexible forming processes, there is a demand for dieless manufacturing of curved hollow structures, as this would allow to produce parts with greatly reduced lead-times, e.g., as on-demand spare parts and on construction sites using mobile equipment. Wire-arc additive manufacturing (WAAM) processes with multi-axis deposition can be used in this case. This process typically draws upon the gas metal arc welding (GMAW) process with cold metal transfer (CMT) technology. Thin-walled metal parts produced by WAAM may show deviations to the target geometry due to material shrinkage and distortion, which may entail tedious trial-and-error compensation. This study analyses shrinkage and distortion in curved hollow sections with different cross sections and curvature radii both experimentally and with a thermo-mechanical finite element model. Based on these findings, a novel method for the compensation of shrinkage and distortion for thin-walled hollow parts is put forward and validated. The correction method draws upon the geometrical deviations that occur when the part is produced based on the CAD geometry, and computes a correction to the CAD geometry, which is used to define the welding path for a part with improved accuracy. The results show that the geometry of the manufactured part can be corrected to tolerances in the range of the waviness of the surface by applying the proposed correction.

Design Method for End-Plate Bolted Connections

The design of buildings envelopes is more elaborate than it has ever been. Starting from the design method of nodal space frames made of one layer of structure and covered in glass, this paper presents e new type of end-plate beam to beam connection. Specific to this is the fact that both end-plates are welded inside of the tubes, having a minimum gap between them of 2 mm. This will reduce considerably the in-surface and welding-induced end plates tolerances which appear at classical end-plate connections. Through the pre-tensioning of the bolts, a continuous contact surface is assured along the cross-sections of the hollow profiles. Several tests were run with the software Gas Win in order to establish the maximum capacity of the connection. This condition is achieved when the neutral axis goes out of the crosssection and the entire cross-section is compressed. Installation hand-holes were also considered. In order to get a better understanding about the force flow, an FEM analysis was run using the Abaqus software. A comparison between the results followed.

Investigating the Effect of Screw Size on the Stress Level in MERO Joint for Space Frame Structures

Space frame structures satisfy the ever-increasing requirements of societies for providing a variety of structural forms and architectural spaces with special characteristics, such as aesthetic and free-form features, population-wise capacities, and structural performance, among others. Structural behavior of these systems largely depend on the type of joints and their components which are to be considered appropriately in design and analysis. Screws comprise one of the key components of joints in these structures and play a pivotal role in the total cost of the structure, as well as the maximum stress level created in joints. The present study aims to evaluate the effect of screw size on the maximum stress generated in three MERO double-layer ball joints with diameters of 98, 110, and 132 mm as a sample numerical analysis case to pinpoint this fact. Numerical simulations were conducted using ANSYS workbench software. Based on the results, in order to achieve the maximum factor of safety (FOS), the minimum stress, and keeping the total construction cost optimal, it is recommended to use M16, M20, and M24 screws for the ball joints of diameters 98, 110, and 132 mm, respectively.

Magnetic flux flows of optical quasi binormal magnetic flows with flux density

In this paper, we extract distinctive determination for quasi magnetic flux of the quasi binormal magnetic flows of magnetic quasi b q -particle by considering directional frame in 3D ordinary space. Also, we construct some advanced optical qualifications for magnetic quasi Lorentz flux for magnetic quasi- b q particle along with the quasi directional frame fields. Then, we calculate quasi magnetic Lorentz flux with directional-quasi magnetic fields. Besides, we obtain original simulations with regard to directional potentials for directional-quasi magnetic binormal flows with Heisenberg optical ferromagnetic model. Magnetic optical flux surfaces are demonstrated in a homogeneous optical flux surface by fractional numerical and applied developments. By using above models, we get new fractional model with q-homotopy analysis transform method (qHATM) and its illustrative presentation to consider magnetic optical flux surface.

Approximation and localized polynomial frame on conic domains

Highly localized kernels constructed by orthogonal polynomials have been fundamental in the recent development of approximation and computational analysis on the unit sphere, unit ball, and several other regular domains. In this work, we first study homogeneous spaces that are assumed to contain highly localized kernels and establish a framework for approximation and localized tight frames in such spaces, which extends recent works on bounded regular domains. We then show that the framework is applicable to homogeneous spaces defined on bounded conic domains, which consists of conic surfaces and the solid domains bounded by such surfaces and hyperplanes. The highly localized kernels on conic domains require precise estimates that rely on recently discovered addition formulas for orthogonal polynomials with respect to special weight functions on each domain and an intrinsic distance that takes into account the boundary of the domain, the latter is not comparable to the Euclidean distance at around the apex of the cone.The main results provide construction of semi-discrete localized tight frame in weighted L2 norm and characterization of best approximation by polynomials on conic domains. The latter is achieved by using a K-functional, defined via the differential operator that has orthogonal polynomials as eigenfunctions, as well as a modulus of smoothness defined via a multiplier operator that is equivalent to the K-functional. Several intermediate results are of interest in their own right, including the Marcinkiewicz-Zygmund inequalities, positive cubature rules, Christoeffel functions, and Bernstein type inequalities. Moreover, although the highly localizable kernels hold only for special families of weight functions on each domain, many intermediate results are shown to hold for doubling weights defined via the intrinsic distance on the domain.

Raising the regularity of generalized Abel equations in fractional Sobolev spaces with homogeneous boundary conditions

The generalized (or coupled) Abel equations on the bounded interval have been well investigated in H$\ddot{\text{o}}$lderian spaces that admit integrable singularities at the endpoints and relatively inadequate in other functional spaces. In recent years, such operators have appeared in BVPs of fractional-order differential equations such as fractional diffusion equations that are usually studied in the frame of fractional Sobolev spaces for weak solution and numerical approximation; and their analysis plays the key role during the process of converting weak solutions to the true solutions. This article develops the mapping properties of generalized Abel operators $\alpha {_aD_x^{-s}}+\beta {_xD_b^{-s}}$ in fractional Sobolev spaces, where $0<\alpha,\beta$, $\alpha+\beta=1$, $ 0<s<1$ and $ {_aD_x^{-s}}$, $ {_xD_b^{-s}}$ are fractional Riemann-Liouville integrals. It is mainly concerned with the regularity property of $(\alpha {_aD_x^{-s}}+\beta {_xD_b^{-s}})u=f$ by taking into account homogeneous boundary conditions. Namely, we investigate the regularity behavior of $u(x)$ while letting $f(x)$ become smoother and imposing homogeneous boundary restrictions $u(a)=u(b)=0$.

SMARANDACHE Π1B CURVES OF BIHARMONIC NEW TYPE CONSTANT Π2 - SLOPE CURVES ACCORDING TO TYPE-2 BISHOP FRAME IN THE SOL SPACE

In this paper, we study Smarandache Π1B curves of biharmonic new type constant Π2 -slope curves according to type-2 Bishop frame in the Sol space. Type-2 Bishop equations of Smarandache Π1B curves are obtained in terms of base curve's type-2 Bishop invariants. Subsequently, we express some interesting relations.

Optical hybrid electric and magnetic B[formula omitted]-phase with Landau Lifshitz approach

In this study, we derive different characterization for hybrid electric and magnetic flow B1-density of hybrid B1-magnetic particles by hybrid frame in ordinary space. Also, we construct some new optical hybrid conditions of hybrid electric and magnetic B1-phase with hybrid optical fields. We construct hybrid magnetic Lorentz B1-flux for hybrid fields with hybrid Landau Lifshitz approach. Finally, electric and magnetic B1-phases of hybrid B1-surface are presented in uniform magnetic B1-surfaces by optical results with hybrid Landau Lifshitz approach.

Experimental study of fire effects on out-of-plane bending strength/flexibility of steel tubular T-joints

Steel tubular structures are popular in ocean and offshore structures, buildings, bridges, space frames, mining equipment, recreation structures and transportation vehicles. A tubular joint has a critical role in maintaining the integrity of a steel tubular structure under operational and extreme loading conditions. This paper reports the first experimental investigation on the out-of-plane bending (OPB) strength and stiffness of steel tubular T-joints under fire conditions. The tubular specimens were tested to failure under OPB at ambient temperature and under ISO-834 standard fire. The moment rotation response, critical temperature, fire endurance time, structural strength and flexibility of the T-joint specimens were explored. The failure mode of the specimens was noticed to change from “development of a plastic hinge in the brace” at ambient temperature to “the chord face plastification” under fire conditions. Temperature adjustments were made to available parametric equations, basically proposed for the OPB capacity and stiffness of steel tubular joints at ambient temperature. The temperature-modified OPB capacity equations somewhat under-predicted the test results for OPB strength under fire conditions. The temperature-modified OPB stiffness equations showed satisfactory correlation with the test results under fire conditions.

Construction of infinite frames with some given redundancy

This paper is concerned with the lower and upper redundancy of infinite frames in a separable Hilbert space. Using unit norm linear operators, a new representation of upper redundancy is given. Also, we show that there is no frame such that its lower redundancy is less than one and its upper redundancy is one. Moreover, for given , we construct a frame such that its lower redundancy is μ and its upper redundancy is λ.

다중적 국경경관(Multi-scalar Borderscapes)과 접경의 재현정치

This paper noted the politics of representation of multi-scalar and multilateral borderscapes to examine the possibility of contact zones as research texts and a methodology. The process by which borderscapes make thought about borders multi-scalar and multilateral makes them see contact zones as an alternative space and dynamic frame of thought that clearly reveals the limits of national, ethnic, and dichotomous thinking.<BR>Borderscapes exist in the borderlands and at the same time make the border and borderlands exist away from it. Art Hotel Re:maker recently installed in Goseong is an example of the former, the documentary film All live Olive with the West-Eastern Divan Orchestra is examples of the latter. Art Hotel Re:maker transforms the national and security-oriented borderlands’ landscape into a multi-scalar and multilateral platform. Orchestra and documentary film also acquire the meaning of borderscapes as devices for revisiting borders and representing transboundary life by infiltrating borders or borderlands into the daily life of everyone in the world. This aspect of existence of the borderscape extends the borders to contact zones with the borders and suggests the possibility as a methodology seeking liberation from borders.<BR>The contact zones study is distinguished from the existing border study in that it distances the border from the existing marginalized image. Multi-scalar bordercapes make contact zones into nearby subjective place rather than distant other’s space, and approach the possibility of contact zones as a methodology by juxtaposing the origins of pre-border and the future of trans-borders. Contact Zones research and contact zones as a methodology are closely linked with social practice that eventually discovers multi-scalar and multilateral borderscapes and creates a variety of platforms for reciprocating the values of reconciliation and coexistence.

Design and Analysis of Chassis of Four-Seater Car

Abstract: The initial dimensions and weight for the vehicle is considered from the Audi A8 vehicle as a reference. The specifications for the motor and battery are considered for the Mahindra e2o electric vehicle of similar dimensions. The main objective of this paper is to model and perform static analysis on the chassis of a four-seater car. The initial design for the chassis was a space frame body which is very rigid and had very less deflection. The second and final chassis is a ladder type chassis which is most common chassis type being used in Nepal and India. The difference in deflection between both the chassis type is very less, which is about 0.3235 mm for a reasonable reduction in weight which is about 120 Kg. The simulation part is carried out in ANSYS software. The result is selection of best suitable material for chassis on the basis of ANSYS and theoretically calculated result. Keywords: Chassis, Structural Analysis, Optimization, Four seater car

Finite Element Method Analysis Applied to the Study of a Corner Joint in Reinforced Concrete Structures

The principal objective for this work was to extend the field of application of FEM to space frame beam-column connections under static loading and with lateral displacements. A four-storey building was modelled under static load condition. Horizontal and vertical structural elements were designed according to Eurocode 2. In order to understand the behavior of the external node made by under column, two beam and upper column, two models using correct boundary condition and nonlinear behavior of materials have been done using Abaqus Software The analysis was performed on an interior and an exterior joint models each in two conditions: unconfined and confined joint varying the distributions of number of stirrups for the beam reinforcement and the column reinforcement .A sup structural model to submit to numerical analysis have been performed, the Concrete Damage Plasticity model (CDPM) has been chosen for fit the nonlinear behavior for the concrete and the elastoplastic model has been adopted for the nonlinear behavior for the reinforcement (stirrups, longitudinal and vertical bars). The models were then verified against already existing and validated analytical results and results of experiments conducted on specimens.

Optical tangent hybrid electromotives for tangent hybrid magnetic particle

In this paper, we construct new approach of tangent hybrid optical magnetic Lorentz flux by hybrid frame in 3D space. We express the tangent hybrid optical electromotives and its properties. Thus, we get new conditions for hybrid Heisenberg ferromagnetic optical induced electromotives for the flux linked with poles coils. Tangent hybrid optical magnetic flux surface is demonstrated in an uniform magnetic surface by using fractional optical and numerical results.

On a surface pencil with a common new type of special surface curve in Galilean space G 3

In this study, we investigate a new type of surface curve called a D-type special curve. We also show that this special curve is more general than a geodesic curve or an asymptotic curve. Then, we give the necessary and sufficient conditions for a curve to be the new D-type special curve using Frenet frame in Galilean space. Moreover, we investigate some results by taking account of a D-type special curve as a helix, a Salkowski curve and an anti-Salkowski curve. After then, for the sake of visualizing this study, we plot some examples for this surface pencil (i.e. surface family).