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You searched for subject:(scaling up method). Showing records 1 – 3 of 3 total matches.

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Delft University of Technology

1. Huang, X. (author). A Scaling-upMethod for Assessing the Impacts of ITS on Traffic Efficiency.

Degree: 2015, Delft University of Technology

Human beings today have to face a series of problems brought by transport development — severe urban congestion, increasing number of injuries and fatalities as well as global warming caused by excessive emissions. Intelligent Transport Systems (ITS), as effective tools to solve these problems, thus have drawn much attention. In the future, it is expected that more and more ITS would be developed and applied in real practice. Before adopting ITS measures, it is necessary for policy makers to know the impacts of the ITS measure on on a large scale (e.g. national/European level). In many cases, the impacts of ITS are evaluated on a much smaller scale, for example from a microscopic traf- fic simulation or a field experiment. These effects need to be scaled up to the larger scale. There are two known scaling-up methods. The modelling method can accurately represent the large scale scenario, but requires considerable effort and a large amount of data which may not be available. Furthermore, it requires a macroscopic model of the ITS, which may be a challenge to derive. The statistical method describes the local scenarios via situational variables (like road types, vehicle types and traffic situations), classifies the local scenar- ios into categories and calculates the impacts on large scale as the weighted average of the local impacts. This method is easier and faster than the modelling method. However, the statistical method is only applicable for cases which only consider categorical situational variables, because the classification of the local scenarios into categories is not feasible when numerical situational variables are used. As a result, the statistical method is only suitable for ITS whose impacts are on the microscopic mechanisms (e.g speed and headway) and thus mainly affected by categorical situational variables (e.g road type and vehicle type). A scaling-up method to assess the impacts of ITS on traffic efficiency which is generally suitable for all ITS is still missing. To start filling this gap, this study develops a new scaling-up method for ITS that have direct network-wide influences to assess their large-scale impacts on traffic efficiency. The framework of the new scaling-up method is shown in Figure 2.2 and the graphical and mathematical interpretations are presented in Figure 2.3 and Figure 2.4. In brief, the new scaling-up method firstly chooses the suitable indicator of the impacts and situational vari- ables, then collects needed data and builds deterministic relationships between the indi- cator and the numerical situational variables, at last uses scaling sideways to calculate all local impacts and aggregates the local impacts to large scale. From the theoretical perspec- tive, the designed method is considered to be able to evaluate the impacts of ITS measures with direct network-wide influence on traffic efficiency in a large-scale scenario. To provide an evidence of the quality of the new scaling-up method, this study applies it to a specific ITS measure, that is the on-trip dynamic… Advisors/Committee Members: Hoogendoorn, S.P. (mentor), Pel, A.J. (mentor), van Noort, M. (mentor), Annema, J.A. (mentor).

Subjects/Keywords: scaling-up method; impacts of ITS; ITS evaluation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Huang, X. (. (2015). A Scaling-upMethod for Assessing the Impacts of ITS on Traffic Efficiency. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:002ee5ed-f355-425c-b871-97c1a055349b

Chicago Manual of Style (16th Edition):

Huang, X (author). “A Scaling-upMethod for Assessing the Impacts of ITS on Traffic Efficiency.” 2015. Masters Thesis, Delft University of Technology. Accessed August 14, 2020. http://resolver.tudelft.nl/uuid:002ee5ed-f355-425c-b871-97c1a055349b.

MLA Handbook (7th Edition):

Huang, X (author). “A Scaling-upMethod for Assessing the Impacts of ITS on Traffic Efficiency.” 2015. Web. 14 Aug 2020.

Vancouver:

Huang X(. A Scaling-upMethod for Assessing the Impacts of ITS on Traffic Efficiency. [Internet] [Masters thesis]. Delft University of Technology; 2015. [cited 2020 Aug 14]. Available from: http://resolver.tudelft.nl/uuid:002ee5ed-f355-425c-b871-97c1a055349b.

Council of Science Editors:

Huang X(. A Scaling-upMethod for Assessing the Impacts of ITS on Traffic Efficiency. [Masters Thesis]. Delft University of Technology; 2015. Available from: http://resolver.tudelft.nl/uuid:002ee5ed-f355-425c-b871-97c1a055349b


University of Melbourne

2. Kandel, Yadav Prasad. LiDAR estimation of aboveground tree biomass in native sclerophyll forest.

Degree: 2011, University of Melbourne

Accurate estimation of aboveground tree biomass is a fundamental aspect of studies on carbon stocks of forest ecosystems. Destructive sampling is the most accurate method of estimation of biomass. However, because of its destructive nature and being both labor intensive and time consuming, destructive sampling cannot be applied for large areas. Alternatively, allometric equations developed for a particular species of trees or a general allometric equation for a specific type of forest can be used to estimate aboveground biomass for larger areas. This requires massive fieldwork, which itself is problematic, and it is not always possible to carry out field inventory in forests which are remote and inaccessible. Advanced remote sensing technology is now in the process of being established as the best and most practical alternative of the field-based methods of biomass estimation for large areas and is being used in the study of forests at the regional and national levels of a growing number of countries. Light Detection And Ranging (LiDAR) is a relatively new, active, remote sensing technology, which is capable of providing three-dimensional structural information of forests and, therefore, can be used to estimate various structural and biophysical parameters of forest stands more accurately than by other optical and RADAR-based remote sensing technologies. The development of hardware and software for the LiDAR system has rapidly advanced during the last decade and has matured to a degree that it is now possible to analyze LiDAR points, which are from individual tree crowns. As a result, LiDAR has now been used as an operational tool in European and North American forestry. In Australia, the use of LiDAR is still in an initial, research phase and there are only a few studies that have investigated its applicability in the broadleaf evergreen forests that dominate the forested lands of Australia. The main focus of this study was the LiDAR-estimation of aboveground tree biomass in two different types of Eucalyptus-dominated sclerophyll forests of the Central Highlands of Victoria, Australia. The applicability of LiDAR remote sensing in predicting stem density, canopy height indices (mean dominant height, Lorey's mean height and quadratic mean canopy height) and basal area was also explored in this research. Furthermore, the scaling-up of LiDAR estimates of biomass across the landscape and biomass mapping for large areas were also demonstrated. Using LiDAR data for the respective sampling plots, the mean dominant height for the Central Highlands Ash Regrowth (CHAR) forest was estimated with an R2 of 87.1 % and an RMSE of 3.9 m (9.5 %) and for the Black Range Mixed Species (BRMS) forest with an R2 of 92.1 % and an RMSE of 1.9 m (6 %). The R2 of the model predicting Lorey's mean height for the CHAR forest had 84.6 % with an RMSE of 4.03 m (11.1 %) and for the BRMS forest, it was 94.6 % with an RMSE of 1.7 m (5.9 %). Similarly, the…

Subjects/Keywords: LiDAR; LiDAR metrics; laser scanning; stem density; basal area; biomass; individual tree isolation; multistage porcessing of LiDAR data; biomass mapping; indirect method; scaling-up of biomass

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Kandel, Y. P. (2011). LiDAR estimation of aboveground tree biomass in native sclerophyll forest. (Doctoral Dissertation). University of Melbourne. Retrieved from http://hdl.handle.net/11343/37095

Chicago Manual of Style (16th Edition):

Kandel, Yadav Prasad. “LiDAR estimation of aboveground tree biomass in native sclerophyll forest.” 2011. Doctoral Dissertation, University of Melbourne. Accessed August 14, 2020. http://hdl.handle.net/11343/37095.

MLA Handbook (7th Edition):

Kandel, Yadav Prasad. “LiDAR estimation of aboveground tree biomass in native sclerophyll forest.” 2011. Web. 14 Aug 2020.

Vancouver:

Kandel YP. LiDAR estimation of aboveground tree biomass in native sclerophyll forest. [Internet] [Doctoral dissertation]. University of Melbourne; 2011. [cited 2020 Aug 14]. Available from: http://hdl.handle.net/11343/37095.

Council of Science Editors:

Kandel YP. LiDAR estimation of aboveground tree biomass in native sclerophyll forest. [Doctoral Dissertation]. University of Melbourne; 2011. Available from: http://hdl.handle.net/11343/37095

3. Yetisir, Michael. Up-Scaling Distinct Element Method Simulations of Discontinua.

Degree: 2017, University of Waterloo

Pre-existing fractures significantly influence the geomechanical response of the rock mass at the reservoir scale. For geomechanical applications, these natural fractures need to be considered in the mechanical response of the system. Distinct Element Methods (DEM) are often used to explicitly model the mechanics of Naturally Fractured Rock (NFR); however, they are often too computationally prohibitive for reservoir-scale problems. A DEM up-scaling framework is presented that facilitates estimating a representative parameter set for continuum constitutive models that capture the salient feature of Naturally Fractured Rock (NFR) behaviour. Up-scaling is achieved by matching homogenized DEM stress-strain curves from multiple load paths to those of continuum constitutive models using a Particle Swarm Optimization (PSO) algorithm followed by a Damped Least-Squares (DLS) algorithm. The effectiveness of the framework is demonstrated by up-scaling a DEM model of a NFR to a Drucker-Prager damage-plasticity model; the up-scaled model is shown to capture well the effect of confinement on the the yielding and sliding of natural fractures in the rock mass. The goal of this thesis is to present a framework to facilitate effective simulation of fine-scale behaviour in full-scale NFR systems while significantly reducing the computational demands associated with modelling these systems with DEM. As such, four main research objectives have been identified and achieved: 1) Develop and implement stress and strain homogenization algorithms for DEM models with deformable blocks, 2) present a methodology to parameterize complex nonlinear continuum constitutive models, 3) develop and implement an automated modular software framework for up-scaling DEM simulations, and 4) demonstrate that the performance of the up-scaled continuum models are accurate and significantly more computationally efficient. The up-scaling methodology is verified through a case study on a naturally fractured granite slope in which the top surface is loaded until failure. The up-scaled continuum model is shown to compare quite well to Direct Numerical Simulation (DNS) in a slope stability analysis and requires two orders of magnitude less computational effort.

Subjects/Keywords: Up-Scaling; Homogenization; FEA; FEM; Finite Element Method; Finite Element Analysis; Damage Mechanics; CDM; DEM; Discrete Element Method; Computational Mechanics; Computational Homogenization; Optimization; Drucker-Prager; Fracture; Fracture Mechanics; Naturally Fractured Rock; NFR; Multi-scale

…interfaces drive the various components of the up-scaling framework. 2.2 Distinct Element Method… …List of Figures 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 Up-scaling workflow used to… …scaling in this investigation can be considered to be a hierarchical multiscale method using… …goal of up-scaling is to formulate simplified coarse-scale governing equations that… …DEM simulations in this investigation, the aim of up-scaling is to identify the parameters… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Yetisir, M. (2017). Up-Scaling Distinct Element Method Simulations of Discontinua. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/11235

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Yetisir, Michael. “Up-Scaling Distinct Element Method Simulations of Discontinua.” 2017. Thesis, University of Waterloo. Accessed August 14, 2020. http://hdl.handle.net/10012/11235.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Yetisir, Michael. “Up-Scaling Distinct Element Method Simulations of Discontinua.” 2017. Web. 14 Aug 2020.

Vancouver:

Yetisir M. Up-Scaling Distinct Element Method Simulations of Discontinua. [Internet] [Thesis]. University of Waterloo; 2017. [cited 2020 Aug 14]. Available from: http://hdl.handle.net/10012/11235.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Yetisir M. Up-Scaling Distinct Element Method Simulations of Discontinua. [Thesis]. University of Waterloo; 2017. Available from: http://hdl.handle.net/10012/11235

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.