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Showing 1 to 18 of 18 for “"Ground structure"”.
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Performance of defected ground structure for rectangular microstrip patch antenna
… constant r=4.3 and thickness 1.6 mm. The defect ground structure (DGS) has gained much attention over the last few years for its ability to increase the performance of wireless system by effectively suppressing harmonics DGS shows a better result compared to the conventional antenna. It …
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An implementation of the ground structure method considering buckling and nodal instabilities
The ground structure method is used to find an optimal solution for the layout optimization problem. The problem domain is discretized with a union of highly connected members, which is called a ground structure. The objective typically is to minimize the total volume of material while satisfying …
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Macro-element approach for topology optimization of trusses using a ground structure method
In this thesis, the generation of initial ground structures for generic domains in two and three dimensions are discussed. Two methods of discretization are compared: Voronoi-based discretizations and structured quadrilateral discretizations. In addition, a simple and effective member generation …
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Reconfigurable phased microstrip antenna array with defected ground structure and defected microstrip structure for beam steering application
… However, this additional device makes the structure more complicated, bulky and it represent a great part of the production cost of a phased array antenna. Therefore, it creates new challenges to find an alternative approach. This work proposed two alternative approaches to steer the main …
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Topology optimization with simultaneous analysis and design
… Analysis and Design (SAND) are considered. The ground structure approach is used. For the truss topology optimization, a penalty function formulation of SAND is compared with an augmented Lagrangian formulation. The efficiency of SAND in handling combinations of general constraints for truss …
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Truss topology optimization of steel-timber structures for embodied carbon objectives
… tool. Most existing research on truss and frame structures focuses on single material applications, and the developments of ground structure-based topology optimization in multi-material structures are limited. This research presents a truss topology optimization algorithm that designs with a mix …
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Shear wall layout optimization for conceptual design of tall buildings
… process with an optimization system involving a ground structure program formulation, a modified evolutionary algorithm, and innovative computational techniques. Unlike existing work that focuses either exclusively on structural performance or architectural layout, this research integrates both. …
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Analysis of Ground and Building Response Around Deep Excavations in Sand
Ground-structure interaction around deep excavations is investigated by superposing different types of structures in the zone of influence of excavation, in 2D and three-dimensional (3D) models. Ground movements modified by the structures are sensitive to the assumptions regarding one of the state …
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The surface propagation of ground vibration
… model, which idealises the source of the ground vibration as a strip of pressure varying harmonically in time. The ground below the strip is modelled as homogeneous, isotropic and elastic, with hysteric internal damping characterised by a loss factor. For an infinite strip load, which …
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Shear wall layout optimization of dynamically loaded three-dimensional tall building structures
… the shear wall layout of a three-dimensional structure using a linearized modal analysis and a modified genetic algorithm. The presented design scheme uses a ground structure approach as it allows for architectural constraints to be embedded in the design. The objective is defined as a cost …
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An Evolutionary Based Methodology for Representing and Evolving Structural Design Solutions
… support the synthesis of design solutions in unstructured problem domains. The implicit redundant representation genetic algorithm (IRR GA) used redundancy to support the self-organization of the representation by encoding a variable number of location independent design parameters. Using an …
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Structural optimization: from continuum and ground structures to additive manufacturing
… by giving cheaper, stronger, lighter and safer structures. Gradient--based optimization is the preferred approach in this work, for it consciously improves a design using the gradient information, as opposed to making random guesses. The optimization problem has an internal dependency on …
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Segmental multi-point linearization for topology optimization and reliability analysis
… topology optimization (RBTO) of structures under loading and material uncertainties. Topology optimization is a powerful design tool as it can provide the most efficient material layout for structural design problems under given conditions and limitations. However, most attempts …
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The application of dynamic relaxation to the design of modular space structures
… and sizing of large modular building space structures suitable for urban development. The contents of the Chapters are summarised as follows: 1: An introduction to conceptual and computer aided design of large building space structures. 2: A review of topological computer design methods. 3: …
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Investigation of Integrated Decoupling Methods for MIMO Antenna Systems. Design, Modelling and Implementation of MIMO Antenna Systems for Different Spectrum Applications with High Port-to-Port Isolation Using Different Decoupling Techniques
… coupling caused by the surface current in the ground plane and between the radiating antenna elements. The minimum achieved isolation between the MIMO antennas is found to be better than 15 dB and in some bands exceeds 30 dB. The matching impedance is improved and the correlation coefficient …
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Development of a Low-Cost System for Monitoring Root Growth Dynamics
… remain difficult to study because of their below-ground structure. Minirhizotrons – root imaging tools that use transparent tubes installed in the soil to allow for the non-destructive, in situ observation of plant roots – offer a non-invasive solution for capturing root images over time. However, …
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Design of electromagnetic band-gap structures using planar technology for Rfid and microwave applications
… se ha presentado. Una estructura Defected Ground Structure (DGS) se desarrolla y se coloca directamente debajo de las líneas de alimentación de entrada 1 sal ida del filtro paso banda para obtener la supresión del segundo armónico. Varios prototipos han sido fabricados y medidos para la …
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Reliability−based topology optimization frameworks for the design of structures subjected to random excitations
Embargo set by: Seth Robbins for item 95486 Lift date: 2018-11-10T18:43:22Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system