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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Otimização do Infill para redução das incertezas em um depósito sintético de cobre / Infill optimization to reduce uncertainty in a copper ore synthetic deposit

Ramos, Gustavo Zanco 19 September 2016 (has links)
A aquisição de novas informações de sondagem é realizada por intermédio do infill de furos de sonda e esta é uma prática utilizada em diversas etapas da exploração mineral. Métodos de otimização são largamente utilizados em várias fases e processos na vida da mina, por exemplo na otimização de cavas, na otimização do sequenciamento de lavra, entre outros. Contudo a utilização de métodos de otimização aplicados à locação de furos de inifill não é usual. Neste trabalho propõem-se utilizar a otimização matemática para melhorar a distribuição espacial dos novos furos, bem como para definir a quantidade adequada de furos a serem realizados. Métodos de otimização meta-heurísticos foram testados com o objetivo de minimizar duas funções objetivo que tratam das incertezas associadas à simulação dos dados, que são a soma da variância e a soma dos coeficientes de variação dos blocos simulados. O método que apresentou melhores resultados na otimização da função objetivo no menor tempo e custo computacional foi o método simulated annealing com resfriamento rápido e memória. Com base neste método de otimização comparou-se as funções objetivo propostas. Para efetuar a comparação amostraram-se os 11 furos definidos pela otimização para ambas as funções objetivo. O infill amostral foi realizado no corpo sintético e as comparações realizadas foram: a estatística descritiva - dos dados de infill comparados à população - e o gráfico Q-Q entre o e-type das simulações realizadas na base com infill e a população. A estatística descritiva do infill permitiu interpretar que a amostragem atualizada (soma das amostragens inicial e a nova) apresentou-se mais representativa do que a amostragem incial. Baseado no resultado dos gráficos Q-Q, a simulação calculada com o infill otimizando a minimização da soma dos coeficientes de variação apresentou maior aderência à população. / The acquisition of new drillhole information can be accomplished by the drill hole infill, a practice used in several steps of the mineral exploration. Optimization methods are widely used in several stages and processes of the mine life cycle, for example, mine pit optimization, mine scheduling optimization among others. However the optimization of drill hole infill locations are unusual. This work proposes the use of mathematical optimization to improve the spatial distribution and the number of the new drill holes to be made. Metaheuristics optimization methods were tested to minimize two objective functions that deal with the uncertainty associated to simulated data, the sum of the simulated blocks variance and the sum of the simulated blocks coefficient of variation. The best processing cost, processing time and results were obtained by simulated annealing method with fast cooling and memory for both objective functions. Based on this optimization method both proposed objective functions were compared. In order to perform the comparison 11 optimized drill holes locations by both objective functions were sampled. Sampling infill were done in the synthetic ore body and the made comparisons were: statistics - comparison between the infill data and population - and the QQ plot of the e-type statistics computed for simulation based on infill and population. Statistics for infill allowed to interpret that updated sample (the addition of new sampling in the initial data) was more representative than the initial sampling. Based on Q-Q plot the simulation computed for optimized infill location by the sum of the coefficient of variation minimization has more adherence to population.
22

Effects Of Masonry Infill Walls On The Seismic Performance Of Buildings

Ozturk, Mehmet Selim 01 December 2005 (has links) (PDF)
In Turkey, in most of the reinforced concrete buildings, hallow masonry infill walls are used as a non-structural element, during design stage, their contribution to overall building behavior is not well known. Observations made after the earthquakes revealed that these non-structural elements had beneficial effects on the lateral capacity of the building. In this study, the contribution of the hallow masonry infill walls to the lateral behavior of reinforced concrete buildings was investigated. For this purpose, two different buildings were chosen as case studies. Three and six story symmetric buildings are modeled as bare and infilled frames. The parameters that were investigated are column area, infill wall area, distribution of masonry infill walls throughout the story. To determine the effect of each parameter, global drift ratios are computed and are compared for each case.
23

Πειραματική και αναλυτική απόκριση τετραώροφης υφιστάμενης κατασκευής ενισχυμένη με εμφάτνωση από οπλισμένο σκυρόδεμα

Σταθάς, Νικόλαος 21 December 2012 (has links)
Στόχος της παρούσας διατριβής είναι η εξαγωγή συμπερασμάτων σχετικά με την απόκριση πολυώροφων κατασκευών ενισχυμένων με εμφάτνωση από οπλισμένο σκυρόδεμα και η αναλυτική προσέγγιση αυτών υπολογίζοντας τις χαρακτηριστικές ιδιότητες δυσκαμψίας, αντοχής και ικανότητας παραμόρφωσης του νέου τοιχώματος. Βεβαίως, ελέγχεται και η επίτευξη μονολιθικής σύνδεσης μεταξύ φατνώματος και μελών του περιμετρικού πλαισίου. Για το λόγο αυτό, κατασκευάζεται και δοκιμάζεται πειραματικά μέσω της υβριδικής μεθόδου με υποκατασκευές, ένα τετραώροφο πλαίσιο εμφατνούμενο από οπλισμένο σκυρόδεμα εξασφαλίζοντας την επαρκή σύνδεση του κορμού του τοιχώματος με το υφιστάμενο πλαίσιο. Ακολουθεί η διεξαγωγή μη - γραμμικής δυναμικής ανάλυσης προκειμένου να υπάρξει προσέγγιση των πειραματικών αποτελεσμάτων από τα αναλυτικά, καθώς και ο υπολογισμός των χαρακτηριστικών παραμορφώσεων και δυσκαμψίας του δοκιμίου σύμφωνα με τον Κανονισμό Επεμβάσεων (ΚΑΝ.ΕΠΕ.)και την υιοθέτηση ορισμένων παραδοχών, η αξιοπιστία των οποίων εξετάζεται μέσω της αναλυτικής προσέγγισης εναλλακτικού πειραματικού φορέα. / The aim of this thesis is to reach in conclusions about the response of existing multistorey reinforced concrete structures, retrofitted by reinforced condrete infill wall and also analytically approach that response computing the characteristic properties of stiffness, strength and deformation capacity of the new composite wall. Moreover, the effectiveness of the connection between the web and the surrounding frame members is under investigetion. For the aforementioned purposes, a 4-storey RC frame converted into slnder wall is constructed and tested by pseudo-dynamic method with substructures. In order to compare the experimental with the analytical results, a non-linear dynamic analysis is conducted and the deformation and stiffness of the specimen are determined by the use of some computtional assumptions, which derive from the computational procedure of the characteristic response parameters of the composite wall. Finally, the overall reliability and correctness of those assumptions is examined through the analytical procedure of a different exprimental project.
24

Otimização do Infill para redução das incertezas em um depósito sintético de cobre / Infill optimization to reduce uncertainty in a copper ore synthetic deposit

Gustavo Zanco Ramos 19 September 2016 (has links)
A aquisição de novas informações de sondagem é realizada por intermédio do infill de furos de sonda e esta é uma prática utilizada em diversas etapas da exploração mineral. Métodos de otimização são largamente utilizados em várias fases e processos na vida da mina, por exemplo na otimização de cavas, na otimização do sequenciamento de lavra, entre outros. Contudo a utilização de métodos de otimização aplicados à locação de furos de inifill não é usual. Neste trabalho propõem-se utilizar a otimização matemática para melhorar a distribuição espacial dos novos furos, bem como para definir a quantidade adequada de furos a serem realizados. Métodos de otimização meta-heurísticos foram testados com o objetivo de minimizar duas funções objetivo que tratam das incertezas associadas à simulação dos dados, que são a soma da variância e a soma dos coeficientes de variação dos blocos simulados. O método que apresentou melhores resultados na otimização da função objetivo no menor tempo e custo computacional foi o método simulated annealing com resfriamento rápido e memória. Com base neste método de otimização comparou-se as funções objetivo propostas. Para efetuar a comparação amostraram-se os 11 furos definidos pela otimização para ambas as funções objetivo. O infill amostral foi realizado no corpo sintético e as comparações realizadas foram: a estatística descritiva - dos dados de infill comparados à população - e o gráfico Q-Q entre o e-type das simulações realizadas na base com infill e a população. A estatística descritiva do infill permitiu interpretar que a amostragem atualizada (soma das amostragens inicial e a nova) apresentou-se mais representativa do que a amostragem incial. Baseado no resultado dos gráficos Q-Q, a simulação calculada com o infill otimizando a minimização da soma dos coeficientes de variação apresentou maior aderência à população. / The acquisition of new drillhole information can be accomplished by the drill hole infill, a practice used in several steps of the mineral exploration. Optimization methods are widely used in several stages and processes of the mine life cycle, for example, mine pit optimization, mine scheduling optimization among others. However the optimization of drill hole infill locations are unusual. This work proposes the use of mathematical optimization to improve the spatial distribution and the number of the new drill holes to be made. Metaheuristics optimization methods were tested to minimize two objective functions that deal with the uncertainty associated to simulated data, the sum of the simulated blocks variance and the sum of the simulated blocks coefficient of variation. The best processing cost, processing time and results were obtained by simulated annealing method with fast cooling and memory for both objective functions. Based on this optimization method both proposed objective functions were compared. In order to perform the comparison 11 optimized drill holes locations by both objective functions were sampled. Sampling infill were done in the synthetic ore body and the made comparisons were: statistics - comparison between the infill data and population - and the QQ plot of the e-type statistics computed for simulation based on infill and population. Statistics for infill allowed to interpret that updated sample (the addition of new sampling in the initial data) was more representative than the initial sampling. Based on Q-Q plot the simulation computed for optimized infill location by the sum of the coefficient of variation minimization has more adherence to population.
25

A Study of the Seismic Performance of Early Multi-Story Steel Frame Structures with Unreinforced Masonry Infill

Potterton, Kristin 01 January 2009 (has links)
Steel frame construction with unreinforced masonry infill walls is a common system found in high-rise structures built in the late nineteenth and early twentieth centuries. Recorded performance of this dual system during seismic events shows that the structures are able to resist a high level of lateral loads without collapse, primarily because a majority of damage is confined to the infill walls instead of the gravity carrying frame. To better understand expected performance of this structural system in different seismic risk regions, a prototypical building was analyzed using modal and nonlinear static procedures based on currently accepted evaluation guidelines. Nonlinear results from the computer model were compared with calculated target displacements for seventeen cities likely to have steel frame construction with unreinforced masonry infill in order to determine expected damage levels at varying levels of seismic risk. It was concluded that the structural system studied could experience damage in all seismic risk regions, including post-yield damage of the structure, although in low risk regions that damage is confined entirely to the infill walls. Practicing structural engineers should be aware that in all seismic risk zones existing steel frame buildings with unreinforced masonry infill, while able to resist a high magnitude of displacement without complete structural failure, will require additional lateral support under currently accepted rehabilitation guidelines.
26

A Proud Legacy, A New Future: Bringing Ottawa's Growth Management Strategy Into the 21st Century

Heydorn, Christina Anita January 2007 (has links)
As Canada’s capital, the City of Ottawa has benefited from several comprehensive land use planning exercises since the early 1900s. Early plans carried out by the federal government were led by Prime Ministers who, in wanting to beautify the region, initiated long range plans that spanned both sides of the Ottawa River, providing land use goals and guidance for what are today the cities of Ottawa and Gatineau. The planning context changed through the 1970s, however. The federal government played a lesser role in land use planning as regional and area municipal governments grew and an expanding technically trained staff developed local plans. It was in the absence of a strong regional plan aimed at controlling outward expansion that there was rapid growth of low density suburban communities outside of the National Capital Commission greenbelt. Today, planning policy in Ottawa recognizes the environmental, social, and economic benefits of compact development and encourages by, in part, directing growth to the existing built-up area. Unfortunately, residential intensification efforts in the City have been disappointing. While the City has developed a variety of policies and programs to encourage and support residential intensification, it appears site level constraints have prohibited it to occur in a significant way. This research is concerned with identifying weaknesses in the City of Ottawa’s current growth management strategy. The purpose of this research is to provide recommendations that can be used to strengthen Ottawa’s growth management policies and programs to more effectively achieve the compact urban form desired by the municipality. The findings demonstrate that there is some level of disconnect between what recent literature and key informant interviews identify as the barriers to residential intensification at the site level and the motherhood principles for compact development at the municipal level. More specifically, barriers can be summarized as community and political resistance, regulatory challenges, and policy vs. market realities. It is recommended that the City of Ottawa adopt a strengthened strategy that establishes achievable growth and intensification targets; encourages community support for compact development; considers growth over the longer term and with a regional perspective; and is advocated by strong leaders. Only in this way can the City create an improved strategy that will, like earlier plans, make Ottawa once again a proud leader in urban planning efforts in Canada.
27

A Proud Legacy, A New Future: Bringing Ottawa's Growth Management Strategy Into the 21st Century

Heydorn, Christina Anita January 2007 (has links)
As Canada’s capital, the City of Ottawa has benefited from several comprehensive land use planning exercises since the early 1900s. Early plans carried out by the federal government were led by Prime Ministers who, in wanting to beautify the region, initiated long range plans that spanned both sides of the Ottawa River, providing land use goals and guidance for what are today the cities of Ottawa and Gatineau. The planning context changed through the 1970s, however. The federal government played a lesser role in land use planning as regional and area municipal governments grew and an expanding technically trained staff developed local plans. It was in the absence of a strong regional plan aimed at controlling outward expansion that there was rapid growth of low density suburban communities outside of the National Capital Commission greenbelt. Today, planning policy in Ottawa recognizes the environmental, social, and economic benefits of compact development and encourages by, in part, directing growth to the existing built-up area. Unfortunately, residential intensification efforts in the City have been disappointing. While the City has developed a variety of policies and programs to encourage and support residential intensification, it appears site level constraints have prohibited it to occur in a significant way. This research is concerned with identifying weaknesses in the City of Ottawa’s current growth management strategy. The purpose of this research is to provide recommendations that can be used to strengthen Ottawa’s growth management policies and programs to more effectively achieve the compact urban form desired by the municipality. The findings demonstrate that there is some level of disconnect between what recent literature and key informant interviews identify as the barriers to residential intensification at the site level and the motherhood principles for compact development at the municipal level. More specifically, barriers can be summarized as community and political resistance, regulatory challenges, and policy vs. market realities. It is recommended that the City of Ottawa adopt a strengthened strategy that establishes achievable growth and intensification targets; encourages community support for compact development; considers growth over the longer term and with a regional perspective; and is advocated by strong leaders. Only in this way can the City create an improved strategy that will, like earlier plans, make Ottawa once again a proud leader in urban planning efforts in Canada.
28

Accessory dwelling units : an infill opportunity for Denton, Texas

King, Jessica Lee 26 November 2012 (has links)
This study explores the potential to increase housing options in the core of Denton, Texas by way of an accessory dwelling unit (ADU) housing type. Literature on ADU development, including state and local laws that enable their development, were reviewed to explore the potential for an ADU initiative in Denton. Case study cities with ADU ordinances, Santa Cruz, CA and El Paso, TX, were reviewed to gather insight on their purpose, process and ordinance. Local multi-family development in downtown Denton was reviewed to document an increase in multi-family development in the core of the city since 2003. City of Denton planning and development policies were reviewed to understand the extent to which ADUs are currently permitted. Finally, based on the literature, case study findings and existing conditions in Denton, this report suggests methods to permit ADUs at a more comprehensive scale. This study concludes with a recommendation to designate the existing infill special purpose district as a boundary to promote comprehensive accessory dwelling unit development within the City of Denton. / text
29

An alternative way to promote our built environment : more reasonable way to realize the Baby Boomers’ urban living

Kim, Hwan Yong, active 2008 04 December 2013 (has links)
Calculating the numbers of people, their age, and income demographic in our future not only gives the idea of how people’s lifestyle will change, but also provides a clue of how planners should prepare the future. In this perspective, planners should pay close attention to any possible changes in demographic profile. By closely researching the cause and effect of the changes, they are able to be more responsible to the future and design an environment that better meets the needs of the population. According to many researches about population projection, we will experience a significant shift in population pyramid and this can be traced to the Baby Boomer generation’s aging. This report starts with connecting the population change to the recent development theories in urban planning and design field. To make our living environment better, and to make the urban theories, such as Infill Development, or New Urbanism, more sustainable, I think the development patterns should be more flexible to reflect our future demographic changes. By doing so, we will be able to maximize the advantages of those theories and make our built environment more sustainable stage. / text
30

Evaluation of a statistical infill candidate selection technique

Guan, Linhua 30 September 2004 (has links)
Quantifying the drilling or recompletion potential in producing gas basins is often a challenging problem, because of large variability in rock quality, well spacing, and well completion practices, and the large number of wells involved. Complete integrated reservoir studies to determine infill potential are often too time-consuming and costly for many producing gas basins. In this work we evaluate the accuracy of a statistical moving-window technique that has been used in tight-gas formations to assess infill and recompletion potential. The primary advantages of the technique are its speed and its reliance upon well location and production data only. We used the statistical method to analyze simulated low-permeability, 100-well production data sets, then compared the moving-window infill-well predictions to those from reservoir simulation. Results indicate that moving-window infill predictions for individual wells can be off by more than 50%; however, the technique accurately predicts the combined infill-production estimate from a group of infill candidates, often to within 10%. We found that the accuracy of predicted infill performance decreases as heterogeneity increases and increases as the number of wells in the project increases. The cases evaluated in this study included real-world well spacing and production rates and a significant amount of depletion at the infill locations. Because of its speed, accuracy and reliance upon readily available data, the moving window technique can be a useful screening tool for large infill development projects.

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