Dissertations / Theses: 'Concrete construction – Mathematical models'

1

Hon, Alan 1976. "Compressive membrane action in reinforced concrete beam-and-slab bridge decks." Monash University, Dept. of Civil Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/5629.

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Liu, Chi-hong, and 廖志航. "Time-dependent behaviour of concrete structures with special referenceto podium and frame structures." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B38674245.

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Lam, Wai-yin, and 林慧賢. "Plate-reinforced composite coupling beams: experimental and numerical studies." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B37311797.

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4

Ng, Pui-lam, and 吳沛林. "Constitutive modelling and finite element analysis of reinforced concrete structures." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B3897566X.

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5

Choi, Joonho. "Concurrent fire dynamic models and thermomechanical analysis of steel and concrete structures." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26679.

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6

Thölken, Denise. "Efeito da rigidez de pilar parede no comportamento sísmico de edifício de concreto armado." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/962.

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Este trabalho tem como objeto o estudo do efeito da rigidez de pilar parede no comportamento estrutural de edifícios de concreto armado submetidos a sismos. Foram consideradas as premissas da norma brasileira ABNT NBR15421:2006, que apresenta os critérios para projeto de estruturas resistentes a sismo. A análise linear com emprego dos métodos da norma - método das forças horizontais equivalentes, método espectral e histórico de aceleração no tempo - foi aplicada em edifícios com dois tipos de sistemas estruturais, sendo eles pórtico de concreto e sistema dual pórtico de concreto e pilar parede. Os resultados foram analisados nos pórticos de extremidade das estruturas nos sentidos longitudinal (x) e transversal (y), comparando-se os deslocamentos de cada pavimento e esforços cortantes, momento fletor e normal nas bases dos pilares. A comparação foi realizada entre os três métodos aplicados e os sistemas estruturais analisados.
The aim of this work is to study the stiffness effect of wall columns on structural behavior of reinforced concrete buildings subjected to seismic action. The premises of the Brazilian standard ABNT NBR14521:2006 were considered, which presents criteria for earthquake resistant design of structures. The linear analysis employed the methods of the Brazilian standard - equivalent static load method, response spectrum analysis and time history method - were applied to buildings with two types of structural systems, namely concrete frame and dual system concrete frame and wall columns. The results were analyzed in edge frames structures in the longitudinal and transverse directions, comparing the displacement of each floor and shear, bending moment and axial forces on the bases of the columns. A comparison was made between the three methods applied and the structural systems analyzed.

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Destrebecq, Jean-François. "Modele d'endommagement d'elements de structures en beton soumis a des sollicitations de fatigue." Clermont-Ferrand 2, 1987. http://www.theses.fr/1987CLF21070.

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A partir d'une etude bibliographique, elaboration d'un modele de comportement a la fatigue, base sur la theorie de l'endommagement, pour chacun des materiaux constitutifs du beton arme. Resolution numerique apres discretisation des equations d'equilibre une section de poudre fissuree endommagee, equations ramenees a celles d'une section fictive elastique homogene. Sous forme adimensionnelle, le modele permet d'obtenir les courbes s-n de sections flechies ne dependant que du pourcentage d'armatures dans la section: influence de ce pourcentage

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8

Wares, Arsalan Jones Graham A. Cottrill James F. "Middle school students' construction of mathematical models." Normal, Ill. Illinois State University, 2001. http://wwwlib.umi.com/cr/ilstu/fullcit?p3064487.

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Thesis (Ph. D.)--Illinois State University, 2001.
Title from title page screen, viewed March 30, 2006. Dissertation Committee: Graham A. Jones, James Cottrill (co-chairs), Linnea Sennott. Includes bibliographical references (leaves 107-111) and abstract. Also available in print.

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9

Khadka, Chandra. "PENALIZED REGRESSION MODELS FOR CONCRETE STRENGTH ESTIMATION." OpenSIUC, 2021. https://opensiuc.lib.siu.edu/theses/2818.

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Concrete compressive strength is one of the most important material properties affectingthe design of concrete structures. Strength that will be achieved once the concrete sets should be correctly predicted prior to pouring the concrete. Regression techniques can be used to calculate the 28-day concrete strength with a level of certainty. This thesis deals with the data modelling and analysis of 28-day compressive strength of high-performance concrete. Historical data on various mix compositions of high-performance concrete was obtained from University of California, Irvine repository. The data had 8 predictors and 1 response variable. In this thesis, three penalized regression approaches, namely, ridge, lasso, and elastic net were used to create a predictive model for compressive strength, and the performance of these model were compared to the traditional multiple linear regression model. Holdout sets from 2% to 40% at an increment of 2% were taken. Every regression algorithm was designed to conduct regression on 30 sets of randomly partitioned data. The performance of models was assessed using coefficient of multiple determination, RMSE, and residual plots. All regression techniques were able to predict the concrete strength with about 75% accuracy level.

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10

Keenan, David Wayne 1955. "BLOCK PLAN CONSTRUCTION FROM A DELTAHEDRON-BASED ADJACENCY GRAPH." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/292025.

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11

Ozturk, Hande Isik. "Parametric Study On Selected Mathematical Models For Dynamic Creep Behavior Of Asphalt Concrete." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12609023/index.pdf.

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Rut formation has long been recognized as a distress mechanism in flexible pavements. One of the causes of rut formation in flexible pavements is permanent deformation of uppermost asphalt concrete layers due to repeatedly applied traffic loading. The long term permanent deformation of asphalt concrete under repeated load is commonly called as dynamic creep. The primary objective of this thesis is to examine dynamic creep behavior of asphalt concrete specimens tested in laboratory and also study some suitable mathematical models for representing dynamic creep behavior. In this study, a set of uniaxial repeated load creep tests were performed on standard Marshall specimens prepared at three different bitumen contents. The effects of bitumen content and test condition parameters on dynamic creep behavior are examined. Among several mathematical creep models suggested by researchers, two well known models and a model proposed by the author are selected for representing the laboratory creep behavior. For each of these models, the interactions of the model parameters with varying bitumen content and test conditions are studied to detect probable definite trends, and to evaluate whether some relations for the model parameters as functions of bitumen content and test conditions can be developed or not. The results of analyses showed that all three mathematical models used in this study are successful in representing the laboratory dynamic creep behavior of asphalt concrete. The Power Model which has only two parameters is found to be the most stable and suitable model for parametric study among the three selected models. More consistent and definite interactions are observed between the parameters of this model and test conditions. However, within the scope of this study, no relations could be developed for the parameters of selected models as functions of bitumen content and test conditions because of limited test data.

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12

Ferdjani, Aissam. "Behaviour of concrete under generalized biaxial loadings." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63762.

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13

Tucker, Gayle. "Mathematical modelling in neurophysiology : neuronal geometry in the construction of neuronal models." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414405.

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14

Williams, Robert C. "The Development of Mathematical Models for Preliminary Prediction of Highway Construction Duration." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/29483.

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Knowledge of construction duration is pertinent to a number of project planning functions prior to detailed design development. Funding, financing, and resource allocation decisions take place early in project design development and are significantly influenced by the construction duration. Currently, there is not an understanding of the project factors having a statistically significant relationship with highway construction duration. Other industry sectors have successfully used statistical regression analysis to identify and model the project parameters related to construction duration. While the need is seen for such work in highway construction, there are very few studies which attempt to identify duration-influential parameters and their relationship with the highway construction duration. This research identifies the project factors, known early in design development, which influence highway construction duration. The factors identified are specific to their respective project types and are those factors which demonstrate a statistically-significant relationship with construction duration. This work also quantifies the relationship between the duration-influential factors and highway construction duration. The quantity, magnitude, and sign of the factor coefficient yields evidence regarding the importance of the project factor to highway construction duration. Finally, the research incorporates the duration-influential project factors and their relationship with highway construction duration into mathematical models which assist in the prediction of construction duration. Full and condensed models are presented for Full-Depth Section and Highway Improvement project types. This research uses statistical regression analysis to identify, quantify, and model these early-known, duration-influential project factors. The results of this research contribute to the body of knowledge of the sponsoring organization (Virginia Department of Transportation), the highway construction industry, and the general construction industry at large.
Ph. D.

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15

Ranasinghe, Kulatilaka Arthanayake Malik Kumar. "Quantification of risks during feasibility analysis for capital projects." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26730.

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The purpose of this thesis is to propose a consistent theory and a model based on it to estimate the uncertainty of project duration, cost, revenue, and net present value probabilistically. The model can be used to assist decision making on such strategic, feasibility analysis issues as contingency provision, reliability of an estimate for the "go-no go" decision, adopting phased or fast-track construction, etc. Project cost and revenue are evaluated in terms of current and discounted dollars, thereby emphasising the economic effect of time and inflation on net present value which is considered as the decision criterion. The model is derived mathematically by treating all the issues which effect the estimation of project cost, duration and revenue through the mechanism of linked work packages. Issues found to be significant in the evaluation of work package duration are: the scope of work, the productivity, and the labour usage. For work package cost they are: the duration and the starting time, unit rates for labour, equipment, and materials, labour and equipment usage, sub-contractor and indirect cost, inflation and interest rates. For revenue the issues are: the gross revenue, operating & maintenance cost, inflation rates, duration, and the starting time. Moments of work package cost, duration and revenue streams are first evaluated using subjective estimates of percentiles for the independent variables, deriving moment information from these estimates, and then processing this information using the expectation operator on the Taylor series expansion of the performance measure about the mean. These moments along with the Pearson family of distributions are used to quantify the uncertainty of project duration, cost, revenue, and net present value. The decision maker is provided with probabilistic estimates, of duration, cost and revenue at both the work package/revenue stream and project levels and of the net present value. A computer program is developed to implement the proposed theory and to organise and simplify the calculation process.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

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Chen, Zebin. "Framework-based model construction with AOP assistance /." Connect to title online (ProQuest), 2008. http://proquest.umi.com/pqdweb?did=1588418351&sid=1&Fmt=2&clientId=11238&RQT=309&VName=PQD.

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Thesis (Ph. D.)--University of Oregon, 2008.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 123-127). Also available online in ProQuest, free to University of Oregon users.

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17

Amidon, Bruce Douglas. "An economic analysis of counterfeit threaded fasteners in the construction industry." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA231492.

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Thesis (M.S. in Management)--Naval Postgraduate School, June 1990.
Thesis Advisor(s): Carrick, Paul M. Second Reader: Gates, William R. "June 1990." Description based on signature page on October 16, 2009. DTIC Descriptor(s): Mathematical models, industries, problem solving, screw threads, engineering, fastenings, game theory, force(mechanics), economic analysis, construction DTIC Indicator(s): Threaded fasteners, fasteners, game theory, theses Author(s) subject terms: Threaded fasteners; substandard fasteners; game theory Includes bibliographical references (p. 50-51). Also available online.

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18

Lanzas, Lourdes Eneida 1962. "A parametric study on the behavior of slender reinforced concrete frames." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/276945.

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By using a nonlinear computer analysis, a parametric study is developed in order to examine the accuracy of the Moment Magnifier Method of the American Concrete Institute Code (ACI 318-83). The variables used in the parametric study are: axial load intensity, P/Po; column reinforcement ratio, rho; slenderness ratio, klu; shape of column cross section, flexural stiffness ratio, and distribution of axial loads. In the parametric study, 216 cases of single bay fixed-base portal frames are examined. The higher moment for each one of these frames at failure are then compared with the design moment predicted by the Moment Magnifier Method of the American Concrete Institute Code (ACI 318-83). The Moment Magnifier Method proved to be very conservative when the columns are subjected to high level of axial loads and when the slenderness ratio is increased.

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Malone, Brett. "Multidisciplinary optimization in aircraft design using analysis technology models." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10102009-020042/.

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Gonzalez, Julian Santiago Sr. "Using Fuzzy Mathematical Models for construction project scheduling with time, cost and material restrictions." Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1180987976.

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21

Chen, Xi, and 陈曦. "On construction and control of probabilistic Boolean networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48329605.

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Modeling gene regulation is an important problem in genomic research. The Boolean network (BN) and its generalization Probabilistic Boolean network (PBN) have been proposed to model genetic regulatory interactions. BN is a deterministic model while PBN is a stochastic model. In a PBN, on one hand, its stationary distribution gives important information about the long-run behavior of the network. On the other hand, one may be interested in system synthesis which requires the construction of networks from the observed stationary distribution. This results in an inverse problem of constructing PBNs from a given stationary distribution and a given set of Boolean Networks (BNs), which is ill-posed and challenging, because there may be many networks or no network having the given properties and the size of the inverse problem is huge. The inverse problem is first formulated as a constrained least squares problem. A heuristic method is then proposed based on the conjugate gradient (CG) algorithm, an iterative method, to solve the resulting least squares problem. An estimation method for the parameters of the PBNs is also discussed. Numerical examples are then given to demonstrate the effectiveness of the proposed methods. However, the PBNs generated by the above algorithm depends on the initial guess and is not unique. A heuristic method is then proposed for generating PBNs from a given transition probability matrix. Unique solution can be obtained in this case. Moreover, these algorithms are able to recover the dominated BNs and therefore the major structure of the network. To further evaluate the feasible solutions, a maximum entropy approach is proposed using entropy as a measure of the fitness. Newton’s method in conjunction with the CG method is then applied to solving the inverse problem. The convergence rate of the proposed method is demonstrated. Numerical examples are also given to demonstrate the effectiveness of our proposed method. Another important problem is to find the optimal control policy for a PBN so as to avoid the network from entering into undesirable states. By applying external control, the network is desired to enter into some state within a few time steps. For PBN CONTROL, people propose to find a control sequence such that the network will terminate in the desired state with a maximum probability. Also, the problem of minimizing the maximum cost is considered. Integer linear programming (ILP) and dynamic programming (DP) in conjunction with hard constraints are then employed to solve the above problems. Numerical experiments are given to demonstrate the effectiveness of our algorithms. A hardness result is demonstrated and suggests that PBN CONTROL is harder than BN CONTROL. In addition, deciding the steady state probability in PBN for a specified global state is demonstrated to be NP-hard. However, due to the high computational complexity of PBNs, DP method is computationally inefficient for a large size network. Inspired by the state reduction strategies studied in [86], the DP method in conjunction with state reduction approach is then proposed to reduce the computational cost of the DP method. Numerical examples are given to demonstrate both the effectiveness and the efficiency of our proposed method.
published_or_final_version
Mathematics
Doctoral
Doctor of Philosophy

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Phaobunjong, Kan. "Parametric cost estimating model for conceptual cost estimating of building construction projects." Thesis, Full text (PDF) from UMI/Dissertation Abstracts International, 2002. http://wwwlib.umi.com/cr/utexas/fullcit?p3086790.

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Chan, Ka-ho Enoch, and 陳家灝. "Experimental and numerical studies of concrete beams prestressed with unbonded tendons." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40988004.

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24

Yousuf, Saif. "Structural Low Cement Content (LCC) Concrete: An Eco-friendly Alternative for Construction Industry." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37590.

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Pressure is mounting in the construction industry to adopt more environmentally sustainable methods to reduce CO2 emissions. Portland cement (PC) often constitutes to more than two-thirds of the embodied energy of concrete, and its production generates 5% of global greenhouse gas emissions. One efficient strategy to reduce the cement content without sacrificing performance is the use of particle packing models (PPM) to mix- proportion concrete mixtures with low cement content, the so-called low cement content (LCC) concrete. If on the one hand LCC was seen to be an effective sustainable alternative to the construction industry, its mechanical behaviour, durability and long-term performance are still under debate and thus further research is needed in the area. In this project, continuous PPM theories were used to mix- design structural concrete mixes presenting distinct mechanical properties (i.e. 25 & 35 MPa) and cement contents. Their performance was evaluated in the fresh and hardened states, and gaps, recommendations, and further needs were highlighted. Results show that the use of PPM enables the development of LCC systems, showing impressive hardened state performance (i.e. higher compressive strength and modulus of elasticity and lower electrical resistivity) and low carbon footprint. However, challenges in the fresh state were faced, which may be potentially solved with the use of chemical admixtures, fillers and/or supplementary cementing materials (SCMs).

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25

Kilic, Mustafa Hakan. "Three-dimensional micromechanical models for the nonlinear analysis of pultruded composite structures." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/20735.

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26

Chang, Min-Yung. "Active vibration control of composite structures." Diss., This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-09162005-115021/.

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27

Mirjalili, Vahid. "Modelling the structural efficiency of cross-sections in limited torsion stiffness design." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99780.

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Most of the current optimization techniques for the design of light-weight structures are unable to generate structural alternatives at the concept stage of design. This research tackles the challenge of developing an optimization method for the early stage of design. The main goal is to propose a procedure to optimize material and shape of stiff shafts in torsion.
Recently introduced for bending stiffness design, shape transformers are presented in this thesis for optimizing the design of shafts in torsion. Shape transformers are geometric parameters defined to classify shapes and to model structural efficiency. The study of shape transformers are centered on concept selection in structural design. These factors are used to formulate indices of material and shape selection for minimum mass design. An advantage of the method of shape transformers is that the contribution of the shape can be decoupled from the contribution of the size of a cross-section. This feature gives the designer insight into the effects that scaling, shape, as well as material have on the overall structural performance.
Similar to the index for bending, the performance index for torsion stiffness design is a function of the relative scaling of two cross-sections. The thesis examines analytically and graphically the impact of scaling on the torsional efficiency of alternative cross-sections. The resulting maps assist the selection of the best material and shape for cross-sections subjected to dimensional constraints. It is shown that shape transformers for torsion, unlike those for bending, are generally function of the scaling direction.
The efficiency maps ease the visual contrast among the efficiency of open-walled cross-sections and that of close-walled cross-sections. As expected, the maps show the relative inefficiency of the former compared to the latter. They can also set the validity range of thin- and thick-walled theory in torsion stiffness design. The analytical results are validated with the numerical data obtained from ANSYS to guarantee the consistency of the models. The thesis concludes with three case studies that demonstrate the method.

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28

Tsang, Yick-tat, and 曾億達. "Modelling and forecasting the general financial performance of listed construction firms in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/198814.

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It is well recognised that construction firms encounter risk and are sensitive to trends and volatility in the business environment. Measuring the financial performance of a firm serves as the basis of monitoring and evaluating its management competence, resource allocation and corporate strategy in response to environmental change. Forecasting is paramount in responding to potential problems and perpetuating positive developments that result in sustainable competitiveness. Thus, an enriched understanding and prediction of the financial performance of construction firms are desirable for decision makers and other industry stakeholders. Notwithstanding that, little research attention has been paid to this premise conceptually and empirically. Thus, the overall aim of this study was to model and forecast the general financial performance of Hong Kong construction firms under the dynamic influence of the business environment. This study involved the application of quantitative modelling using various statistical and econometric techniques. Multidimensional firm financial performance was first approximated using factor analysis based on the financial data of local publicly listed construction firms from 1992 to 2010. The factor model uncovers five common financial factors: liquidity, asset, leverage, profitability and activity. The time trends of these factors display diverse and cyclical patterns with irregular cycle periods. Autoregressive integrated moving average (ARIMA) models were then constructed based on the Box-Jenkins approach, which provided univariate forecasts of the financial factors. The results reaffirmed that ARIMA models were highly effective in forecasting. In conjunction with cross-correlation analysis, multiple linear regression (MLR) models were next used to explore the influence of environmental determinants on firm financial performance. The findings identified different sets of significant leading determinants for different financial factors. They further justified the dominance of sectoral factors in the determination of firm performance. Supported by empirical verification, a theoretical framework depicting the relationships between business environment and firm performance was proposed. In conjunction with cross-correlation analysis, multiple linear regression (MLR) models were next used to explore the influence of environmental determinants on firm financial performance. The findings identified different sets of significant leading determinants for different financial factors. They further justified the dominance of sectoral factors in the determination of firm performance. Supported by empirical verification, a theoretical framework depicting the relationships between business environment and firm performance was proposed. This study is among the first to apply advanced econometric techniques to develop reliable performance measurement and forecasting models. The results improve the theoretical framework by explaining the dynamic relationships between the financial performance and business environment of construction firms. The empirical findings of the quantitative analysis offer new implications for firms’ financial performance and the significant leading determinants in a local context. The outcomes of this study make seminal contributions to current knowledge and practice.
published_or_final_version
Civil Engineering
Doctoral
Doctor of Philosophy

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29

Bairrão, Rogério. "Modèle de comportement à la ruine des structures constituées de poutres en béton armé : prise en compte des phénomènes d'endommagement et de plasticité." Paris 6, 1986. http://www.theses.fr/1986PA066014.

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Mise au point d'un modèle non linéaire caractérisant la tenue ultime des structures constituées de poutres en béton armé. Analyse critique des théories actuelles (plasticité globale et endommagement). Nécessité d'une formulation nouvelle incluant les deux non-linéarités. Formulation d'un modèle complet applicable aux situations accidentelles les plus courantes en particulier aux sollicitations sismiques. Après son implémentation dans un programme de calcul par éléments finis, on effectue deux calculs de démonstration dans le cas d'une poutre en flexion 4 points avec dilatation de membrane libre ou bloquée.

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30

Ramachandran, Selvaraj. "Hypoid gear optimization." PDXScholar, 1992. https://pdxscholar.library.pdx.edu/open_access_etds/4419.

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A hypoid gear optimization procedure using the method of feasible directions has been developed. The objective is to reduce the gear set weight with bending strength, contact strength and facewidth-diametral pitch ratio as constraints. The objective function weight, is calculated from the geometric approximation of the volume of the gear and pinion. The design variables selected are number of gear teeth, diametral pitch, and facewidth. The input parameters for starting the initial design phase are power to be transmitted, speed, gear ratio, type of application, mounting condition, type of loading, and the material to be used. In the initial design phase, design parameters are selected or calculated using the standard available procedures. These selected values of design parameters are passed on to the optimization routine as starting points.

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31

繆泉明 and Quanming Miao. "Effect of submerged vertical structures on ship waves." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B3025176X.

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Law, Gordon Ki-Wai. "Decision support system for construction cycle design." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26715.

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The objective of this thesis is to develop a conceptual design of a computerized environment for detailed design of construction activities associated with projects characterized by significant repetition. High-rise building construction is used as the example of repetitive construction projects. The construction cycle design of a typical floor structure is studied to gain an understanding of the difficulty and complexity involved in the activity design process. Modeling techniques currently used in construction planning, modeling techniques developed in the field of operations research, and assembly line balancing techniques used in industrial engineering are reviewed to determine their applicability for detailed construction cycle design. Using the concept of decision support systems developed in the fields of management science and knowledge engineering for solving ill-structured and ill-defined problems, a conceptual design of a decision support system for construction cycle design is developed.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

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33

Zhang, Mingyang 1981. "Macromodeling and simulation of linear components characterized by measured parameters." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112589.

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Recently, microelectronics designs have reached extremely high operating frequencies as well as very small die and package sizes. This has made signal integrity an important bottleneck in the design process, and resulted in the inclusion of signal integrity simulation in the computer aided design flow. However, such simulations are often difficult because in many cases it is impossible to derive analytical models for certain passive elements, and the only available data are frequency-domain measurements or full-wave simulations. Furthermore, at such high frequencies these components are distributed in nature and require a large number of poles to be properly characterized. Simple lumped equivalent circuits are therefore difficult to obtain, and more systematic approaches are required. In this thesis we study the Vector Fitting techniques for obtaining such equivalent model and propose a more streamlined approach for preserving passivity while maintaining accuracy.

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Ma, Ho-yin, and 馬浩然. "Competitive tendering in construction: a study of some theoretical bidding models and their application in thelocal construction industry." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1987. http://hub.hku.hk/bib/B31262314.

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35

Wu, Ching-Tang. "Construction of Brownian Motions in Enlarged Filtrations and Their Role in Mathematical Models of Insider Trading." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 1999. http://dx.doi.org/10.18452/14364.

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In dieser Arbeit untersuchen wir die Struktur von Gausschen Prozessen, die durch gewisse lineare Transformationen von zwei Gausschen Martingalen erzeugt werden. Die Klasse dieser Transformationen ist durch nanzmathematische Gleichgewichtsmodelle mit heterogener Information motiviert. In Kapital 2 bestimmen wir für solche Prozesse, die zunächst in einer erweiterten Filtrierung konstruiert werden, die kanonische Zerlegung als Semimartin-gale in ihrer eigenen Filtrierung. Die resultierende Drift wird durch Volterra-Kerne beschrieben. Insbesondere charakterisieren wir diejenigen Prozesse, die in ihrer eigenen Filtrierung eine Brownsche Bewegung bilden. In Kapital 3 konstruieren wir neue orthogonale Zerlegungen der Brownschen Filtrierungen. In den Kapitaln 4 bis 6 wenden wir unsere Resultate zur Charakterisierung Brownscher Bewegungen im Kontext nanzmathematischer Modelle an, in denen es Marktteilnehmer mit zusätzlicher Insider-Information gibt. Wir untersuchen Erweiterungen eines Gleichgewichtsmodells von Kyle [42] und Back [7], in denen die Insider-Information in verschiedener Weise durch Gaussche Martingale spezifiziert wird. Insbesondere klären wir die Struktur von Insider-Strategien, die insofern unaufallig bleiben, als sich die resultierende Gesamtnachfrage wie eine Brownsche Bewegung verhält.
In this thesis, we study Gaussian processes generated by certain linear transformations of two Gaussian martingales. This class of transformations is motivated by nancial equilibrium models with heterogeneous information. In Chapter 2 we derive the canonical decomposition of such processes, which are constructed in an enlarged ltration, as semimartingales in their own ltration. The resulting drift is described in terms of Volterra kernels. In particular we characterize those processes which are Brownian motions in their own ltration. In Chapter 3 we construct new orthogonal decompositions of Brownian ltrations. In Chapters 4 to 6 we are concerned with applications of our characterization results in the context of mathematical models of insider trading. We analyze extensions of the nancial equilibrium model of Kyle [42] and Back [7] where the Gaussian martingale describing the insider information is specified in various ways. In particular we discuss the structure of insider strategies which remain inconspicuous in the sense that the resulting cumulative demand is again a Brownian motion.

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36

Lee, Chun-Sho. "A process simulation model for the manufacture of composite laminates from fiber-reinforced, polyimide matrix prepreg materials." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/40298.

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A numerical simulation model has been developed which describes the manufacture of composite laminates from fiber-reinforced polyimide (PMR-15) matrix prepreg materials. The simulation model is developed in two parts. The first part is the volatile formation model which simulates the production of volatiles and their transport through the composite microstructure during the imidization reaction. The volatile formation model can be used to predict the vapor pressure profile and volatile mass flux. The second part of the simulation model, the consolidation model, can be used to determine the degree of crosslinking, resin melt viscosity, temperature, and the resin pressure inside the composite during the consolidation process. Also, the model is used to predict the total resin flow, thickness change, and total process time. The simulation model was solved by a finite element analysis. Experiments were performed to obtain data for verification of the model. Composite laminates were fabricated from ICI Fiberite HMF2474/66C carbon fabric, PMR-15 prep reg and cured with different cure cycles. The results predicted by the model correlate well with experimental data for the weight loss, thickness, and fiber volume fraction changes of the composite. An optimum processing cycle for the fabrication of PMR-15 polyimide composites was developed by combining the model generated optimal imidization and consolidation cure cycles. The optimal cure cycle was used to manufacture PMR-15 composite laminates and the mechanical and physical properties of the laminates were measured. Results showed that fabrication of PMR-15 composite laminates with the optimal cure cycle results in improved mechanical properties and a significantly reduced the processing time compared with the manufacturer's suggested cure cycle.
Ph. D.

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Hove, Darlington. "Finite element analysis of a composite sandwich beam subjected to a four point bend." Thesis, Nelson Mandela Metropolitan University, 2011. http://hdl.handle.net/10948/1465.

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The work in this dissertation deals with the global structural response and local damage effects of a simply supported natural fibre composite sandwich beam subjected to a four-point bend. For the global structural response, we are investigating the flexural behaviour of the composite sandwich beam. We begin by using the principle of virtual work to derive the linear and nonlinear Timoshenko beam theory. Based on these theories, we then proceed to develop the respective finite element models and then implement the numerical algorithm in MATLAB. Comparing the numerical results with experimental results from the CSIR, the numerical model correctly and qualitatively recovers the underlying mechanics with some noted deviances which are explained at the end. The local damage effect of interest is delamination and we begin by reviewing delamination theory with more emphasis on the cohesive zone model. The cohesive zone model relates the traction at the interface to the relative displacement of the interface thereby creating a material model of the interface. We then carry out a cohesive zone model delamination case study in MSC.Marc and MSC.Mentat software packages. The delamination modelling is carried out purely as a numerical study as there are no experimental results to validate the numerical results.

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Mason, Brian H. "Analysis and design of composite curved frames." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06102009-063304/.

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Carey, Mara L. "An enhanced integrated-circuit implementation of muscular contraction." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/15507.

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Le, Riche Rodolphe. "Optimization of composite structures by genetic algorithms." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-164513/.

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Ahmed, Hasim Abdalla Obaid. "Construction and analysis of efficient numerical methods to solve Mathematical models of TB and HIV co-infection." Thesis, University of the Western Cape, 2011. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_3704_1325661141.

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In this thesis, we study these models and design and analyze robust numerical methods to solve them. To proceed in this direction, first we study the sub-models and then the full model. The first sub-model describes the transmission dynamics of HIV that accounts for behavior change. The impact of HIV educational campaigns is also studied. Further, we explore the effects of behavior change and different responses of individuals to educational campaigns in a situation where individuals may not react immediately to these campaigns. This is done by considering a distributed time delay in the HIV sub-model. This leads to Hopf bifurcations around the endemic equilibria of the model. These bifurcations correspond to the existence of periodic solutions that oscillate around the equilibria at given thresholds. Further, we show how the delay can result in more HIV infections causing more increase in the HIV prevalence. Part of this study is then extended to study a co-infection model of HIV-TB. A thorough bifurcation analysis is carried out for this model. Robust numerical methods are then designed and analyzed for these models. Comparative numerical results are also provided for each model.

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Holgado, Alejo J. "Construction and study of mathematical models firmly based on neurophysiological data to investigate Parkinson's disease and epilepsy." Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540899.

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Chen, Jou-Jun Robert. "Load and resistance factor design of shallow foundations for bridges." Thesis, Virginia Tech, 1989. http://hdl.handle.net/10919/44627.

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Load Factor Design (LFD), adopted by AASHTO in the mid-1970, is currently used for bridge superstructure design. However, the AASHTO specifications do not have any LFD provisions for foundations. In this study, a LFD format for the design of shallow foundations for bridges is developed.

Design equations for reliability analysis are formulated. Uncertainties in design parameters for ultimate and serviceability limit states are evaluated. A random field model is employed to investigate the combined inherent spatial variability and systematic error for serviceability limit state. Advanced first order second moment method is then used to compute reliability indices inherent in the current AASHTO specifications. Reliability indices for ultimate and serviceability limit states with different safety factors and dead to live load ratios are investigated. Reliability indices for ultimate limit state are found to be in the range of 2.3 to 3.4, for safety factors between 2 and 3. This is shown to be in good agreement with Meyerhof's conclusion (1970). Reliability indices for serviceability limit state are found to be in the range of 0.43 to 1.40, for ratios of allowable to actual settlement between 1.0 to 2.0. This appears to be in good agreement with what may be expected. Performance factors are then determined using target reliability indices selected on the basis of existing risk levels.

Master of Science

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Qin, Hong. "Construction of uniform designs and usefulness of uniformity in fractional factorial designs." HKBU Institutional Repository, 2002. http://repository.hkbu.edu.hk/etd_ra/456.

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Yang, Dong-Shan. "Deformation-based seismic design models for waterfront structures." Thesis, online access from Digital Dissertation Consortium access full-text, 1999. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?9933214.

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Ramoneda, Igor M. "Force modeling in surface grinding based on the wheel topography analysis." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/18845.

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Klostermeier, Christian. "Investigation into the capability of large eddy simulation for turbomachinery design." Thesis, University of Cambridge, 2008. https://www.repository.cam.ac.uk/handle/1810/252106.

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Snyman, M. F. "Numerical modelling of an offshore pipeline laid from a barge." Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/21804.

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Bibliography: pages 81-85.
This thesis addresses some of the issues involved in using numerical methods to simulate the laying of an offshore pipeline, the objective being to contribute to the expertise of the South African offshore technology. Of particular interest is the prediction of the stresses in the pipe during such an event. The thesis concentrates on the use and suitability of the finite element method to simulate the important aspects of the pipelaying problem. ABAQUS, a nonlinear general purpose finite element code, was chosen as numerical tool, and nonlinear effects such as geometry and drag, as well as contact and lift-off at the boundaries, are included in the models. The analysis is performed in two parts: in the static analysis the displaced equilibrium position of the pipeline under self weight, buoyancy and barge tension is sought, whilst the response due to wave action and barge motion is of interest in the dynamic analysis. Numerical experiments show the suitability of ABAQUS to model the behaviour of slender structures under both static loads and dynamic excitations.

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Cornelissen, Belinda m. "Pre-service mathematics teachers’ engagement with the evaluation and construction of alternative mathematical models for the same phenomena." University of Western Cape, 2020. http://hdl.handle.net/11394/8172.

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Doctor Educationis
The overarching purpose of this research study was to ascertain the deliberations preservice mathematics teachers engage with when they construct alternative mathematical models for social phenomena. The study is situated within the mathematical competencies and, in particular, on the evaluation competency with the possibility of developing alternative models flowing from the evaluation. Twenty fourth-year pre-service mathematics teachers participated in the completion of three different mathematical modelling tasks on which the analysis was based. The data collected was analysed qualitatively. The researcher exploited a thematic analysis design to investigate how pre-service mathematics teachers build alternative models.

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Hendrickson, Eric B. "Morphologically simplified conductance based neuron models: principles of construction and use in parameter optimization." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33905.

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The dynamics of biological neural networks are of great interest to neuroscientists and are frequently studied using conductance-based compartmental neuron models. For speed and ease of use, neuron models are often reduced in morphological complexity. This reduction may affect input processing and prevent the accurate reproduction of neural dynamics. However, such effects are not yet well understood. Therefore, for my first aim I analyzed the processing capabilities of 'branched' or 'unbranched' reduced models by collapsing the dendritic tree of a morphologically realistic 'full' globus pallidus neuron model while maintaining all other model parameters. Branched models maintained the original detailed branching structure of the full model while the unbranched models did not. I found that full model responses to somatic inputs were generally preserved by both types of reduced model but that branched reduced models were better able to maintain responses to dendritic inputs. However, inputs that caused dendritic sodium spikes, for instance, could not be accurately reproduced by any reduced model. Based on my analyses, I provide recommendations on how to construct reduced models and indicate suitable applications for different levels of reduction. In particular, I recommend that unbranched reduced models be used for fast searches of parameter space given somatic input output data. The intrinsic electrical properties of neurons depend on the modifiable behavior of their ion channels. Obtaining a quality match between recorded voltage traces and the output of a conductance based compartmental neuron model depends on accurate estimates of the kinetic parameters of the channels in the biological neuron. Indeed, mismatches in channel kinetics may be detectable as failures to match somatic neural recordings when tuning model conductance densities. In my first aim, I showed that this is a task for which unbranched reduced models are ideally suited. Therefore, for my second aim I optimized unbranched reduced model parameters to match three experimentally characterized globus pallidus neurons by performing two stages of automated searches. In the first stage, I set conductance densities free and found that even the best matches to experimental data exhibited unavoidable problems. I hypothesized that these mismatches were due to limitations in channel model kinetics. To test this hypothesis, I performed a second stage of searches with free channel kinetics and observed decreases in the mismatches from the first stage. Additionally, some kinetic parameters consistently shifted to new values in multiple cells, suggesting the possibility for tailored improvements to channel models. Given my results and the potential for cell specific modulation of channel kinetics, I recommend that experimental kinetic data be considered as a starting point rather than as a gold standard for the development of neuron models.

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Dissertations / Theses on the topic 'Concrete construction – Mathematical models'

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