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Parameterized and Adaptive Modelling of Mechanical Connections in Timber Frame StructuresGikonyo, Joan, Modig, Pierre January 2018 (has links)
This study investigates the global stiffness of a timer frame structure under wind loading using the finite element method by creating parameterized script files. Of key interest was the accuracy of the global stiffness determined from an adaptive 3D beam model in comparison to a 2D beam model and, the stiffness of a 3D beam model when subjected to different types of bracing in the presence of internal bracing provided by a lift shaft structure. Investigation of contact forces on the surfaces between the fastener and the timber at the connection was carried out and a design check for the specified bolts shear capacity done with respect to Eurocode 5. A 3D adaptive connection was created for a 2D frame model and the stiffness of the structure was studied. A comparison of the maximum displacement of the structure in the x direction, under the same wind loading, spring stiffness and boundary conditions, with a 2D beam structure without the adaptive connection initially showed a difference in the displacement. This implied that the rotational stiffness in the beam model was greater than that of the adaptive connection created. Therefore after altering the rotational stiffness of the beam model to achieve similar displacement as in the adaptive model, the rotational stiffness of the created connection was found to be 33.4 · 106Nm. The study also determined the contact forces generated at the surfaces between the fasteners and the timber using the finite element method to integrate over the surfaces and calculate the forces. The results were generated using the History Output in the step module. The only disadvantage of acquiring the contact forces was that, the contact surface simulation caused larger run times for the model to complete the time step. For the adaptive model it took 18 hours to complete each step. Further investigation into the stiffness of a 3D frame structure was conducted. The model of the 3D structure was created by a parameterized script which makes it easy to change input variables such as number of internal walls, geometry in x-z-plane, number of storeys, cross-sectional dimensions, material properties number of diagonals and location of diagonals. A variety of models with different conditions was analyzed. This showed that stiffness has a major impact on the magnitude of reaction forces and displacements.
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Understandability of General Versus Concrete Test Cases / Understandability of General Versus Concrete Test CasesJafar, Ali, Maharjan, Mohan January 2009 (has links)
One possibility to automate more of software testing is to have developers write more general test cases. Given a general (parameterized test case), that holds in many situations, software can generate many different test instances and execute them automatically. Thus, even though the developers write fewer and smaller tests they can test more. However, it is not clear what other effects the use of generalized test cases has. One hypothesis is that “More general test cases are harder to understand than concrete ones and thus would lead to overall tests that are harder to understand”. Software understandability can be defined as the system that is written by one person is easy to read and understand by another person easily without any resistance. However, software understandability is hard to measure because understandability depends on the cognitive behavior of human. Software understandability assists in software reusability and software maintainability.
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Parameterized verification of networks of many identical processesVérification paramétrée de réseaux composés d'une multitude de processus identiques / Vérification paramétrée de réseaux composés d'une multitude de processus identiquesFournier, Paulin 17 December 2015 (has links)
Ce travail s'inscrit dans le cadre de la vérification formelle de programmes. La vérification de modèle permet de s'assurer qu'une propriété est vérifiée par le modèle du système. Cette thèse étudie la vérification paramétrée de réseaux composés d'un nombre non borné de processus identiques où le nombre de processus est considéré comme un paramètre. Concernant les réseaux de protocoles probabilistes temporisés nous montrons que les problèmes de l'accessibilité et de synchronisation sont indécidables pour des topologies de communication en cliques. Cependant, en considérant des pertes et créations probabiliste de processus ces problèmes deviennent décidables. Pour ce qui est des réseaux dans lequel les messages n'atteignent qu'une sous partie des composants choisie de manière non-déterministe, nous prouvons que le problème de l'accessibilité paramétrée est décidable grâce à une réduction à un nouveau modèle de jeux à deux joueurs distribué pour lequel nous montrons que l'on peut décider de l'existence d'une stratégie gagnante en coNP. Finalement, nous considérons des stratégies locales qui permettent d'assurer que les processus effectuent leurs choix non-déterministes uniquement par rapport a leur connaissance locale du système. Sous cette hypothèse de stratégies locales, nous prouvons que les problèmes de l'accessibilité et de synchronisation paramétrées sont NP-complet. / This thesis deals with formal verification of distributed systems. Model checking is a technique for verifying that the model of a system under study fulfills a given property. This PhD investigates the parameterized verification of networks composed of many identical processes for which the number of processes is the parameter. Considering networks of probabilistic timed protocols, we show that the parameterized reachability and synchronization problems are undecidable when the communication topology is a clique. However, assuming probabilistic creation and deletion of processes, the problems become decidable. Regarding selective networks, where the messages only reach a subset of the components, we show decidability of the parameterized reachability problem thanks to reduction to a new model of distributed two-player games for which we prove decidability in coNP of the game problem. Finally, we consider local strategies that enforce all processes to resolve the non-determinism only according to their own local knowledge. Under this assumption of local strategy, we were able to show that the parameterized reachability and synchronization problems are NP-complete.
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Timber Shear Wall Analysis : Parameterized Finite Element ModellingKormendy, Imre, Muwaili, Mustafa January 2018 (has links)
This paper investigates the linear elastic behavior of timber shear walls under monotonic prescribed displacement. ABAQUS© 16.4-5, is a numerical finite element software used as the primary analysis methodology. Parameterized models are created for two shear wall specimens of different geometry concerning door and window configurations. The shear walls are simulated as solid timber framing which is mechanically connected to gypsum sheathing board through fasteners. The primary findings are the linear elastic shear force distribution of the mechanical joints. Additionally, deformations and reaction forces of the shear walls are determined. The overall horizontal shear wall behavior of each specific wall was also studied in the presence of door and window openings. The simulations indicate there is a clear deformation difference in the behaviors of the two shear walls. Furthermore, the highest shear force values of the fasteners are located around the corners of the openings. The findings are supported by other researcher’s experiments and analytical tests, timber shear wall theory and Eurocode design requirements.
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QBank: A Web-Based Dynamic Problem Authoring ToolPaul, Ann Molly 08 July 2013 (has links)
Widespread accessibility to the Internet and the proliferation of Web 2.0 technologies has led to the growth of online tools for educational content creation, delivery, and assessment. Maintaining high quality of assessment using this medium is made more practical by using tools to author and represent a broad range of assessment problems. A survey of existing problem-authoring tools uncovered two main deficiencies: (a) lack of support for authoring "dynamic" (parameterized) problems, and (b) lack of tools that are independent of a specific publishing format, persistence format, and/or authoring platform.
Dynamic problems are assessment problem templates that support parameterization of the problems by the use of variables. Variables dynamically take values assigned at random to generate different instances of a problem from a template. This provides for greater diversity of authored problems, and permits students to practice with different variations of a problem. In existing problem authoring tools, the problem types supported are often limited to static problems.
A formal definition of an assessment problem structure is presented. This formal definition served as a design aide for a new problem authoring system named QBank, a web-based tool that supports authoring dynamic problems. The proof-of-concept implementation of QBank supports export of questions in CSV format and the Khan Academy Exercise format. The extensible nature of the framework allows future development of features supporting export of authored problems into other publishing and/or persistence formats. / Master of Science
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Courcelle's Theorem: Overview and ApplicationsBarr, Samuel Frederic 18 May 2020 (has links)
No description available.
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3D Mapping of Islamic Geometric MotifsSayed, Zahra January 2017 (has links)
In this thesis a novel approach in generating 3D IGP is applied using shape grammar, an effective pattern generation method. The particular emphasis here is to generate the motifs (repeat unit) in 3D using parameterization, which can then be manipulated within 3D space to construct architectural structures. Three unique distinctive shape grammar algorithms were developed in 3D; Parameterized Shape Grammar (PSG), Auto-Parameterized Shape Grammar (APSG) and Volumetric Shell Shape Grammar (VSSG).
Firstly, the PSG generates the motifs in 3D. It allows one to use a single changeable regular 3D polygon, and forms a motif by given grammar rules including, Euclidean transformations and Boolean operations. Next, APSG was used to construct the architectural structures that manipulates the motif by automating the grammar rules. The APSG forms a wall, a column, a self-similarity star and a dome, the main features of Islamic architecture. However, applying Euclidean transformations to create non-Euclidean surfaces resulted in gaps and or overlaps which does not form a perfect tessellation. This is improved upon by the VSSM, which integrates two key methods, shell mapping and coherent point drift, to map an aesthetically accurate 3D IGM on a given surface.
This work has successfully presented methods for creating complex intricate 3D Islamic Geometric Motifs (IGM), and provided an efficient mapping technique to form visually appealing decorated structures. / Partially funded by the Centre of Visual Computing (CVC)
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Alliances In Graphs: Parameterized Algorithms And On Partitioning Series-parallel GraphsEnciso, Rosa 01 January 2009 (has links)
Alliances are used to denote agreements between members of a group with similar interests. Alliances can occur between nations, biological sequences, business cartels, and other entities. The notion of alliances in graphs was first introduced by Kristiansen, Hedetniemi, and Hedetniemi in . A defensive alliance in a graph G = (V, E) is a non empty set S ⊆ V where, for all x ∈ S, |N[x] ∩ S| ≥ |N[x] − S|. Consequently, every vertex that is a member of a defensive alliance has at least as many vertices defending it as there are vertices attacking it. Alliances can be used to model a variety of applications such as classification problems, communities in the web distributed protocols, etc [Sha01, FLG00, SX07]. In [GK98, GK00], Gerber and Kobler introduced the problem of partitioning a graph into strong defensive alliances for the first time as the "Satisfactory Graph Partitioning (SGP)" problem. In his dissertation , Shafique used the problem of partitioning a graph into alliances to model problems in data clustering. Decision problems for several types of alliances and alliance partitions have been shown to be NP-complete. However, because of their applicability, it is of interest to study methods to overcome the complexity of these problems. In this thesis, we will present a variety of algorithms for finding alliances in different families of graphs with a running time that is polynomial in terms of the size of the input, and allowing exponential running time as a function of a chosen parameter. This study is guided by the theory of parameterized complexity introduced by Rod Downey and Michael Fellows in [DF99]. In addition to parameterized algorithms for alliance related problems, we study the partition of series-parallel graphs into alliances. The class of series-parallel graphs is a special class in graph theory since many problems known to be NP-complete on general graphs have been shown to have polynomial time algorithms on series-parallel graphs [ZLL04, Hoj95, DS99, HHL87, TNS82]. For example, the problem of finding a minimum defensive alliance has been shown to have a linear time algorithm when restricted to series-parallel graphs . Series-parallel graphs have also been to focus of study in a wide range of applications including CMOS layout and scheduling problems [ML86, Oud97]. Our motivation is driven by clustering properties that can be modeled with alliances. We observe that partitioning series-parallel graphs into alliances of roughly the same size can be used to partition task graphs to minimize the communication between processors and balance the workload of each processor. We present a characterization of series-parallel graphs that allow a partition into defensive alliances and a subclass of series-parallel graphs with a satisfactory partitions.
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QUANTUM ALGORITHMS FOR SUPERVISED LEARNING AND OPTIMIZATIONRaja Selvarajan (14210861) 06 December 2022 (has links)
<p>We demonstrate how quantum machine learning might play a vital role in achieving moderate speedups in machine learning problems and might have scope for providing rich models to describe the distribution underlying the observed data. We work with Restricted Boltzmann Machines to demonstrate the same to supervised learning tasks. We compare the relative performance of contrastive divergence with sampling from Dwave annealer on bars and stripes dataset and then on imabalanced network security data set. Later we do training using Quantum Imaginary Time Evolution, that is well suited for the Noisy Intermediate-Scale Quantum era to perform classification on MNIST data set. </p>
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Effects of wave load models on the uplift risk of ports exposed to hurricanes.Efstathopoulos, Georgios January 2022 (has links)
Pile-supported ports allow seawater to run below the deck, and thus may suffer structural
damages during extreme coastal events such as hurricanes. These structural damages, in
turn, may result to port closures that can cause significant economic losses. Risk analysis
can predict the post-hazard functionality of ports though the structural damage assessment
of these structures prior to coastal events. However, assumptions on the selected demand
estimates may affect the estimated probability of structural damage.
This research aims to shed light on the sensitivity of the wave model selection for the risk
assessment of pile-supported ports when subjected to storm surge and waves. The
examined structural damage is the uplift of the deck, and the risk assessment is conducted
through the development of fragility curves for a typical deck-pile connection, for which
fragility curves are developed for different wave models. Uncertainties are also considered
in parameters affecting the demand and capacity of the examined deck-pile connection and
are propagated through the Monte Carlo simulation using the Latin Hypercube Sampling.
The results indicate changes to the uplift probability as a result of the selected wave model.
Thus, wave model selection can alter the uplift failure probability. In addition, the study
proposes parameterized fragility models to enable the uplift risk assessment across a
region. The presented results aim to throw light on the proper model selection to produce
more realistic risk assessment estimates towards the resilience of coastal infrastructure. / Thesis / Master of Applied Science (MASc)
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