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1.
Ketz, Philipp M.
Inference When the True Parameter Vector Is near or at the
Boundary of the Parameter Space.
Degree: PhD, Economics, 2015, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:419522/ 
► This dissertation examines several standard testing problems under the nonstandard condition that the true parameter vector is near or at the boundary of the parameter…
(more)
▼ This dissertation examines several standard testing
problems under the nonstandard condition that the true parameter
vector is near or at the
boundary of the parameter space. In
particular, it analyzes the problem of subvector inference and the
problem of testing overidentifying restrictions. Standard testing
procedures, such as those based on the t-statistic and the
J-statistic, rely on the asymptotic normality of the underlying
estimator. However, when the true parameter vector is near or at
the
boundary, the commonly employed estimator ceases to be
asymptotically normal. As a result, standard testing procedures
suffer from size-distortions. Even if, in some cases, size-control
is maintained or can be established by adjusting the critical
values, the corresponding tests are conservative and display poor
power in large parts of the parameter space. To address the lack of
testing procedures that appropriately account for
boundary effects
on the distribution of the estimator, this dissertation proposes
new testing procedures. They are based on a novel estimator that is
asymptotically normally distributed when the true parameter vector
is near or at the
boundary and the objective function is not
defined outside the parameter space. The new testing procedures
control size by construction and offer power improvements over
standard testing procedures, when the latter control size. The
results of this dissertation apply, for example, in the context of
random coefficient models, where variance parameters are restricted
below by zero.
Advisors/Committee Members: Kleibergen, Frank (Director), McCloskey, Adam (Reader), Norets, Andriy (Reader), Renault, Eric (Reader).
Subjects/Keywords: Boundary
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APA (6th Edition):
Ketz, P. M. (2015). Inference When the True Parameter Vector Is near or at the
Boundary of the Parameter Space. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:419522/
Chicago Manual of Style (16th Edition):
Ketz, Philipp M. “Inference When the True Parameter Vector Is near or at the
Boundary of the Parameter Space.” 2015. Doctoral Dissertation, Brown University. Accessed January 23, 2021.
https://repository.library.brown.edu/studio/item/bdr:419522/.
MLA Handbook (7th Edition):
Ketz, Philipp M. “Inference When the True Parameter Vector Is near or at the
Boundary of the Parameter Space.” 2015. Web. 23 Jan 2021.
Vancouver:
Ketz PM. Inference When the True Parameter Vector Is near or at the
Boundary of the Parameter Space. [Internet] [Doctoral dissertation]. Brown University; 2015. [cited 2021 Jan 23].
Available from: https://repository.library.brown.edu/studio/item/bdr:419522/.
Council of Science Editors:
Ketz PM. Inference When the True Parameter Vector Is near or at the
Boundary of the Parameter Space. [Doctoral Dissertation]. Brown University; 2015. Available from: https://repository.library.brown.edu/studio/item/bdr:419522/
2.
Wang, Chien-Kai.
Grain Boundary Field Projection Method and Atomic Lattice
Interferometer for Nanometrology.
Degree: PhD, Mechanics of Solids, 2014, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:386259/
► The aim of this thesis is to investigate how grain boundary (GB) strength and separation mechanisms affect strength and ductility of nanocrystalline materials. Such nanoscale…
(more)
▼ The aim of this thesis is to investigate how grain
boundary (GB) strength and separation mechanisms affect strength
and ductility of nanocrystalline materials. Such nanoscale
materials are highly nonlinear and thus have different energy
profiles in different atomic configurations. Therefore, failure of
GBs under straining is highly cooperative and process-dependent in
nano-granular materials. To ascertain the strength and toughness of
GBs, accurate and quantitative assessments of GB field descriptions
with atomic features are required. Two new means of establishing
connections between global loadings to nanoscale GB traction
distributions are developed: the interior and exterior field
projection methods of GBs for computation and experiment
respectively. Three mechanisms of Cu symmetric tilt GB deformation
are introduced through the GB field projection methods. First,
symmetric atomic rearrangement reduces concentrated compression of
the GB tractions due to the ease of intergranular incompatibility.
Second, asymmetric atomic rearrangement or dislocation emission
decreases the concentrated tension leading GB opening and triggers
the shear traction fluctuations as a new strain energy reservoir.
Thus the GB separation toughness is enhanced. Third, Pb impurities
at the GBs maintain the tension peaks of normal traction
fluctuations and then retard the traction transformation. Hence,
the GB becomes brittle. In addition to the GB field projection
methods, we introduce an invention of an experimental instrument –
atomic lattice interferometer, which can give us sub-angstrom scale
resolution of deformation measurement. The corresponding
calibration experiments were implemented on highly ordered
pyrolytic graphite (HOPG), and the atomic-scale strain fields of a
crinkle structure in HOPG were successfully measured. The
measurement results show that the crinkle ridge line has a highly
concentrated surface curvature involving localized atomic-scale
deformations. With the help of simulation-assisted data analyses,
the experimental data reveal that the typical width, the kink angle
and the minimum radius of the ridge as 1.76 nm, 6.2° and 8.51 nm,
respectively. In summary, this thesis develops novel scientific
computational projection methods and experimental metrology
instrument for investigating unexplored global physical phenomena
of materials associated with minute and localized atomic
deformation at nanometer scales.
Advisors/Committee Members: Kim, Kyung-Suk (Director), Gao, Huajian (Reader), Kumar, Sharvan (Reader).
Subjects/Keywords: Grain boundary
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APA (6th Edition):
Wang, C. (2014). Grain Boundary Field Projection Method and Atomic Lattice
Interferometer for Nanometrology. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:386259/
Chicago Manual of Style (16th Edition):
Wang, Chien-Kai. “Grain Boundary Field Projection Method and Atomic Lattice
Interferometer for Nanometrology.” 2014. Doctoral Dissertation, Brown University. Accessed January 23, 2021.
https://repository.library.brown.edu/studio/item/bdr:386259/.
MLA Handbook (7th Edition):
Wang, Chien-Kai. “Grain Boundary Field Projection Method and Atomic Lattice
Interferometer for Nanometrology.” 2014. Web. 23 Jan 2021.
Vancouver:
Wang C. Grain Boundary Field Projection Method and Atomic Lattice
Interferometer for Nanometrology. [Internet] [Doctoral dissertation]. Brown University; 2014. [cited 2021 Jan 23].
Available from: https://repository.library.brown.edu/studio/item/bdr:386259/.
Council of Science Editors:
Wang C. Grain Boundary Field Projection Method and Atomic Lattice
Interferometer for Nanometrology. [Doctoral Dissertation]. Brown University; 2014. Available from: https://repository.library.brown.edu/studio/item/bdr:386259/
Rice University
3.
Gomez, Veronica.
Claiming the Line: Ephemeral Boundary.
Degree: M. Arch., Architecture, 2019, Rice University
URL: http://hdl.handle.net/1911/105387
► This thesis claims architecture (and specific forms of architectural practice) as a tool of advocacy to engage relevant political and social issues of great urgency…
(more)
▼ This thesis claims architecture (and specific forms of architectural practice) as a tool of advocacy to engage relevant political and social issues of great urgency around the world. The project critiques international border walls and the dehumanizing conditions generated urbanistically, economically, and socially through their divisive nature. To address this complex political and social topic, three forms of design research and representation are used to explore, demonstrate and question political futures through architecture. This diverse set of formats —a research map, a medium-scale building and a small-scale object or piece of furniture — are independent trajectories that operate collectively, synthetically, and equally in this investigation.
Advisors/Committee Members: Finley, Dawn (advisor).
Subjects/Keywords: border; boundary
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APA (6th Edition):
Gomez, V. (2019). Claiming the Line: Ephemeral Boundary. (Masters Thesis). Rice University. Retrieved from http://hdl.handle.net/1911/105387
Chicago Manual of Style (16th Edition):
Gomez, Veronica. “Claiming the Line: Ephemeral Boundary.” 2019. Masters Thesis, Rice University. Accessed January 23, 2021.
http://hdl.handle.net/1911/105387.
MLA Handbook (7th Edition):
Gomez, Veronica. “Claiming the Line: Ephemeral Boundary.” 2019. Web. 23 Jan 2021.
Vancouver:
Gomez V. Claiming the Line: Ephemeral Boundary. [Internet] [Masters thesis]. Rice University; 2019. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1911/105387.
Council of Science Editors:
Gomez V. Claiming the Line: Ephemeral Boundary. [Masters Thesis]. Rice University; 2019. Available from: http://hdl.handle.net/1911/105387
NSYSU
4.
CHEN, CHUN-MAO.
Understanding the role of boundaries spanning in IT outsourcing project management.
Degree: Master, Information Management, 2014, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0713114-203335
► With the advance of technology and Internet, information system (IS) has become prevalent in organizations nowadays. But not every company possesses capability to develop information…
(more)
▼ With the advance of technology and Internet, information system (IS) has become prevalent in organizations nowadays. But not every company possesses capability to develop information system independently. Therefore outsourcing of information system has become an important issue in both private and government organizations. However, there might be a lot of risks that caused by the divergence between venders and clients in the information system development process. This study aims to explore how an IS outsourcing project cross boundaries to reduce project risks, and further improve project performance and decrease delay. We review past studies of
boundary spanning and define three boundaries (social
boundary, knowledge
boundary, and operational
boundary) and the role, process, and objects of each
boundary. The study result, based on data collected from 105 IS outsourcing project developers, supports our hypotheses that effectively
boundary spanning can reduce project risks and lead to enhance project performance and decrease project delay. This study provides clear definition of social
boundary, knowledge
boundary, and operational
boundary for future studies. Also, the specific practices of role, process, and object provide practical implications for managers
Advisors/Committee Members: SHIH,SHENG-PAO (chair), Hui-Mei Hsu (chair), Hsieh-Hong Huang (chair), Shih-Chieh Hsu (committee member).
Subjects/Keywords: risks; operational boundary; knowledge boundary; information systems (IS) outsourcing; boundary spanning; social boundary
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APA ·
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APA (6th Edition):
CHEN, C. (2014). Understanding the role of boundaries spanning in IT outsourcing project management. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0713114-203335
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):
CHEN, CHUN-MAO. “Understanding the role of boundaries spanning in IT outsourcing project management.” 2014. Thesis, NSYSU. Accessed January 23, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0713114-203335.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
CHEN, CHUN-MAO. “Understanding the role of boundaries spanning in IT outsourcing project management.” 2014. Web. 23 Jan 2021.
Vancouver:
CHEN C. Understanding the role of boundaries spanning in IT outsourcing project management. [Internet] [Thesis]. NSYSU; 2014. [cited 2021 Jan 23].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0713114-203335.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
CHEN C. Understanding the role of boundaries spanning in IT outsourcing project management. [Thesis]. NSYSU; 2014. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0713114-203335
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
NSYSU
5.
Tsai, Chia-chun.
A Study of the Problems and Influences of Team Boundary Spanning in the Different Phases of Information System Development Projects.
Degree: Master, Information Management, 2017, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0114117-235653
► Given the high complexity of current information system development projects, it has been essential for development teams to assume a cross-disciplinary profile. However, the multitude…
(more)
▼ Given the high complexity of current information system development projects, it has been essential for development teams to assume a cross-disciplinary profile. However, the multitude of stakeholders involved in the development have divergent perceptions (knowledge boundaries) and modes of operation (operational boundaries), which can pose substantial challenges, or prevent the team from accessing or safeguarding the required resources (social boundaries). These are obstacles that can cause the project to fall behind schedule, overrun its budget, or even fail to achieve its goals. Therefore, mitigating the aforementioned boundaries is imperative to enhance project efficiency.
This study explored (1) the boundaries a project team would likely encounter in each phase of the development, and (2) which methods a team should adopt to traverse these boundaries to advance the project. A qualitative case study method was adopted to investigate project teams from three corporations, each developing a particular type of information system. More specifically, three team members in different positions were selected from each team for an in-depth interview. First, the
boundary problems encountered during the three primary phases in a system development project were identified. Subsequently, the system process, roles, and objects adopted to cross over the various boundaries were determined. The findings were aggregated for a meta-analysis to outline the boundaries encountered in each phase of an information system development project, as well as the issues pertaining to overcoming such boundaries.
The present study is expected to serve as a foundation for further investigations, and as practical reference for the development of information systems.
Advisors/Committee Members: Hsieh-Hong Huang (chair), Sheng-Pao Shih (chair), Shih-Chieh Hsu (committee member), Hui-Mei Hsu (chair).
Subjects/Keywords: boundary spanning; social boundary; operational boundary; knowledge boundary; information system development project; project development phase
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APA ·
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Manager
APA (6th Edition):
Tsai, C. (2017). A Study of the Problems and Influences of Team Boundary Spanning in the Different Phases of Information System Development Projects. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0114117-235653
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):
Tsai, Chia-chun. “A Study of the Problems and Influences of Team Boundary Spanning in the Different Phases of Information System Development Projects.” 2017. Thesis, NSYSU. Accessed January 23, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0114117-235653.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Tsai, Chia-chun. “A Study of the Problems and Influences of Team Boundary Spanning in the Different Phases of Information System Development Projects.” 2017. Web. 23 Jan 2021.
Vancouver:
Tsai C. A Study of the Problems and Influences of Team Boundary Spanning in the Different Phases of Information System Development Projects. [Internet] [Thesis]. NSYSU; 2017. [cited 2021 Jan 23].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0114117-235653.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Tsai C. A Study of the Problems and Influences of Team Boundary Spanning in the Different Phases of Information System Development Projects. [Thesis]. NSYSU; 2017. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0114117-235653
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
6.
Lai, Xin.
Modeling and Numerical Simulations of Active and Passive Forces Using Immersed Boundary Method.
Degree: MS, 2019, Worcester Polytechnic Institute
URL: etd-3076
;
https://digitalcommons.wpi.edu/etd-theses/1334
► This thesis uses the Immersed Boundary Method (IBM) to simulate the movement of a human heart. The IBM was developed by Charles Peskin in…
(more)
▼ This thesis uses the Immersed
Boundary Method (IBM) to simulate the movement of a human heart. The IBM was developed by Charles Peskin in the 70’s to solve Fluid-Structure Interaction models (FSI). The heart is embedded inside a fluid (blood) which moves according to the Navier-Stokes equation. The Navier-Stokes equation is solved by the Spectral Method. Forces on the heart muscle can be divided into two kinds: Active Force and Passive Force. Passive includes the effect of curvature (Peskin’s model), spring model, and the torsional spring (or beam) model. Active force is modeled by the 3-element Hill model, which was used in the 30’s to model skeletal muscle. We performed simulations with different combinations of these four forces. Numerical simulations are performed using MATLAB. We downloaded Peskin’s code from the Internet and modified the Force.m file to include the above four forces. This thesis only considers heart muscle movement in the organ (macroscopic) scale.
Advisors/Committee Members: Roger Y. Lui, Advisor.
Subjects/Keywords: immersed boundary method
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APA (6th Edition):
Lai, X. (2019). Modeling and Numerical Simulations of Active and Passive Forces Using Immersed Boundary Method. (Thesis). Worcester Polytechnic Institute. Retrieved from etd-3076 ; https://digitalcommons.wpi.edu/etd-theses/1334
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):
Lai, Xin. “Modeling and Numerical Simulations of Active and Passive Forces Using Immersed Boundary Method.” 2019. Thesis, Worcester Polytechnic Institute. Accessed January 23, 2021.
etd-3076 ; https://digitalcommons.wpi.edu/etd-theses/1334.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lai, Xin. “Modeling and Numerical Simulations of Active and Passive Forces Using Immersed Boundary Method.” 2019. Web. 23 Jan 2021.
Vancouver:
Lai X. Modeling and Numerical Simulations of Active and Passive Forces Using Immersed Boundary Method. [Internet] [Thesis]. Worcester Polytechnic Institute; 2019. [cited 2021 Jan 23].
Available from: etd-3076 ; https://digitalcommons.wpi.edu/etd-theses/1334.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lai X. Modeling and Numerical Simulations of Active and Passive Forces Using Immersed Boundary Method. [Thesis]. Worcester Polytechnic Institute; 2019. Available from: etd-3076 ; https://digitalcommons.wpi.edu/etd-theses/1334
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Florida
7.
John Thalakkottor, Joseph.
Developing a Unified Velocity Boundary Condition for Fluid Flows.
Degree: PhD, Mechanical Engineering - Mechanical and Aerospace Engineering, 2019, University of Florida
URL: https://ufdc.ufl.edu/UFE0052624
► Determining the correct matching boundary condition is fundamental to our understanding of several everyday problems. Despite over a century of scientific work, existing velocity boundary…
(more)
▼ Determining the correct matching
boundary condition is fundamental to our understanding of several everyday problems. Despite over a century of scientific work, existing velocity
boundary conditions are unable to consistently explain and capture the complete physics associated with certain common but complex problems such as moving contact lines and corner flows. The widely used Maxwell and Navier slip
boundary conditions make three major implicit assumptions. First, that slip length is a constant for a given interface. Second, that the flow is steady. Finally, that velocity varies only in the wall normal direction. This makes their
boundary condition inapplicable for flows with high shear rates, unsteady flows and flows in the vicinity of contact lines and corner points where, velocity gradient exists both in the wall normal and wall tangential directions. In this work, by identifying this implicit assumptions we are able to extend Maxwell's slip model. Here, we present an unsteady slip model for single phase fluid flows. Furthermore, we also present a generalized velocity
boundary condition that shows that slip velocity is a function of not only the shear rate but also the linear strain rate. In addition, we present a universal relation for slip length which shows that, for a general flow, slip length is a function of the principal strain rate. The universal relation for slip length along with the generalized velocity
boundary condition provides a unified slip
boundary condition to model a wide range of steady Newtonian fluid flows. We validate the unified slip
boundary for simple Newtonian liquids, by using molecular dynamics simulations and studying both, the moving contact line and corner flow problems. We also implement this newly developed
boundary condition in a continuum solver. ( en )
Advisors/Committee Members: Mohseni,Kamran (committee chair), Kopelevich,Dmitry I (committee member), Phillpot,Simon R (committee member).
Subjects/Keywords: boundary – multiphase – slip
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APA (6th Edition):
John Thalakkottor, J. (2019). Developing a Unified Velocity Boundary Condition for Fluid Flows. (Doctoral Dissertation). University of Florida. Retrieved from https://ufdc.ufl.edu/UFE0052624
Chicago Manual of Style (16th Edition):
John Thalakkottor, Joseph. “Developing a Unified Velocity Boundary Condition for Fluid Flows.” 2019. Doctoral Dissertation, University of Florida. Accessed January 23, 2021.
https://ufdc.ufl.edu/UFE0052624.
MLA Handbook (7th Edition):
John Thalakkottor, Joseph. “Developing a Unified Velocity Boundary Condition for Fluid Flows.” 2019. Web. 23 Jan 2021.
Vancouver:
John Thalakkottor J. Developing a Unified Velocity Boundary Condition for Fluid Flows. [Internet] [Doctoral dissertation]. University of Florida; 2019. [cited 2021 Jan 23].
Available from: https://ufdc.ufl.edu/UFE0052624.
Council of Science Editors:
John Thalakkottor J. Developing a Unified Velocity Boundary Condition for Fluid Flows. [Doctoral Dissertation]. University of Florida; 2019. Available from: https://ufdc.ufl.edu/UFE0052624
Universiteit Utrecht
8.
Mourik, A.L. van.
Boundary crossing en boundary objects in het middelbaar beroepsonderwijs.
Degree: 2016, Universiteit Utrecht
URL: http://dspace.library.uu.nl:8080/handle/1874/335884
► Een tekort aan beroepskennis bij studenten in het beroepsonderwijs volgens een rapport van de Onderwijsraad, docenten in het beroepsonderwijs met te weinig actuele beroepskennis en…
(more)
▼ Een tekort aan beroepskennis bij studenten in het beroepsonderwijs volgens een rapport van de Onderwijsraad, docenten in het beroepsonderwijs met te weinig actuele beroepskennis en een onlangs herzien kwalificatiedossier voor opleidingen in het beroepsonderwijs zijn onderwerpen die de aanleiding vormen voor dit onderzoek. Uitgaande van de theorie van
boundary crossing is onderzocht hoe docenten in het middelbaar beroepsonderwijs en praktijkbegeleiders uit het bedrijfsleven zich herkennen in dit gebrek aan beroepskennis. Vervolgens is gekeken hoe docenten omgaan met deze discontinuïteit tussen middelbaar beroepsonderwijs en bedrijfsleven en tot slot is onderzocht of een herzien kwalificatiedossier docenten kan ondersteunen bij deze tekortkoming. Hiermee beoogt dit onderzoek meer inzicht te krijgen in de onbekende processen van
boundary crossing in het beroepsonderwijs. Om een goed beeld te krijgen van
boundary crossing in het beroepsonderwijs is een kwalitatief onderzoek uitgevoerd middels interviews onder docenten en praktijkbegeleiders. Het blijkt dat de docenten in het beroepsonderwijs zich over het algemeen herkennen in het tekort aan kennis bij studenten. Dit in tegenstelling tot de praktijkbegeleiders. Zij herkennen dit tekort aan beroepskennis bij studenten in mindere mate. Verder blijkt dat de docenten dit probleem hoofdzakelijk individueel aanpakken. Er vindt weinig communicatie plaats tussen de docenten onderling en er is weinig inhoudelijke communicatie met de praktijkbegeleiders. Tot slot blijkt dat een kleine meerderheid van docenten positief is over hoe een herzien kwalificatiedossier ondersteuning kan bieden bij een discontinuïteit van beroepskennis bij studenten.
Advisors/Committee Members: Khaled, A..
Subjects/Keywords: beroepskennis; beroepsonderwijs; boundary crossing; boundary crossers; boundary objects; discontinuïteit
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Manager
APA (6th Edition):
Mourik, A. L. v. (2016). Boundary crossing en boundary objects in het middelbaar beroepsonderwijs. (Masters Thesis). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/335884
Chicago Manual of Style (16th Edition):
Mourik, A L van. “Boundary crossing en boundary objects in het middelbaar beroepsonderwijs.” 2016. Masters Thesis, Universiteit Utrecht. Accessed January 23, 2021.
http://dspace.library.uu.nl:8080/handle/1874/335884.
MLA Handbook (7th Edition):
Mourik, A L van. “Boundary crossing en boundary objects in het middelbaar beroepsonderwijs.” 2016. Web. 23 Jan 2021.
Vancouver:
Mourik ALv. Boundary crossing en boundary objects in het middelbaar beroepsonderwijs. [Internet] [Masters thesis]. Universiteit Utrecht; 2016. [cited 2021 Jan 23].
Available from: http://dspace.library.uu.nl:8080/handle/1874/335884.
Council of Science Editors:
Mourik ALv. Boundary crossing en boundary objects in het middelbaar beroepsonderwijs. [Masters Thesis]. Universiteit Utrecht; 2016. Available from: http://dspace.library.uu.nl:8080/handle/1874/335884
University of Wisconsin – Milwaukee
9.
Moran, Molly Ann.
On the Dimension of Group Boundaries.
Degree: PhD, Mathematics, 2015, University of Wisconsin – Milwaukee
URL: https://dc.uwm.edu/etd/900
► The goal of this dissertation is to find connections between the small-scale dimension (i.e. covering dimension and linearly controlled dimension) of group boundaries and…
(more)
▼ The goal of this dissertation is to find connections between the small-scale dimension (i.e. covering dimension and linearly controlled dimension) of group boundaries and the large scale dimension (i.e. asymptotic dimension and macroscopic dimension) of the group. We first show that generalized group boundaries must have finite covering dimension by using finite large-scale dimension of the space. We then restrict our attention to CAT(0) group boundaries and develop metrics on the
boundary that allow us to study the linearly controlled dimension. We then obtain results relating the linearly controlled dimension of CAT(0) boundaries to the large scale dimension of the CAT(0) space.
Advisors/Committee Members: Craig Guilbault.
Subjects/Keywords: Cat(0) Space; Group Boundary; Visual Boundary; Z-Boundary; Z-Structure; Mathematics
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APA (6th Edition):
Moran, M. A. (2015). On the Dimension of Group Boundaries. (Doctoral Dissertation). University of Wisconsin – Milwaukee. Retrieved from https://dc.uwm.edu/etd/900
Chicago Manual of Style (16th Edition):
Moran, Molly Ann. “On the Dimension of Group Boundaries.” 2015. Doctoral Dissertation, University of Wisconsin – Milwaukee. Accessed January 23, 2021.
https://dc.uwm.edu/etd/900.
MLA Handbook (7th Edition):
Moran, Molly Ann. “On the Dimension of Group Boundaries.” 2015. Web. 23 Jan 2021.
Vancouver:
Moran MA. On the Dimension of Group Boundaries. [Internet] [Doctoral dissertation]. University of Wisconsin – Milwaukee; 2015. [cited 2021 Jan 23].
Available from: https://dc.uwm.edu/etd/900.
Council of Science Editors:
Moran MA. On the Dimension of Group Boundaries. [Doctoral Dissertation]. University of Wisconsin – Milwaukee; 2015. Available from: https://dc.uwm.edu/etd/900
University of Texas – Austin
10.
Taus, Matthias Franz.
Isogeometric Analysis for boundary integral equations.
Degree: PhD, Computational Science, Engineering, and Mathematics, 2015, University of Texas – Austin
URL: http://hdl.handle.net/2152/32824
► Since its emergence, Isogeometric Analysis (IgA) has initiated a revolution within the field of Finite Element Methods (FEMs) for two reasons: (i) geometry descriptions originating…
(more)
▼ Since its emergence, Isogeometric Analysis (IgA) has initiated a revolution within the field of Finite Element Methods (FEMs) for two reasons: (i) geometry descriptions originating from Computer Aided Design (CAD) can be used directly for analysis purposes, and (ii) the availability of smooth exact geometry descriptions and smooth basis functions can be used to develop new, highly accurate and highly efficient numerical methods. Whereas in FEMs the first issue is still open, it has already been shown that Isogeometric BEMs (IBEMs) provide a complete design-through-analysis framework. However, in contrast to FEMs, the effect of smoothness provided by IgA has not yet been explored in IBEMs. In this dissertation, we address this aspect of IgA. We show that the smoothness and exactness properties provided by the IgA framework can be used to design highly accurate and highly efficient BEMs which are not accessible with conventional BEMs. We develop Collocation IBEMs on piecewise smooth geometries. This allows us to show that IBEMs converge in the expected rates and result in system matrices with mesh-independent condition numbers. The latter property is particularly beneficial for large-scale problems that require iterative linear solvers. However, using conventional Collocation BEMs, this approach is not accessible because hyper-singular integrals have to be evaluated. In contrast, using Collocation IBEMs, the smoothness properties of the IgA framework can be used to regularize the hyper-singular integrals and reduce them to weakly singular integrals which can be evaluated using well-known techniques. We perform several numerical examples on canonical shapes to show these results. In addition, we use well-known mathematical results to develop a sound theoretical foundation to some of our methods, a result that is very rare for Collocation discretizations. Finally, using the exactness of IgA geometry descriptions, we design Patch Tests that allow one to rigorously test IBEM implementations. We
subject our implementation to these Patch Tests which not only shows the reliability of our method but also shows that IBEMs can be as accurate as machine precision. We apply our IBEMs to Laplace's equation and the equations of linear elasticity. In addition, input files for our implementation can be automatically obtained from commercial CAD packages. These practical aspects allow us to apply IBEMs to analyze a propeller under a wind load.
Advisors/Committee Members: Rodin, G. J. (Gregory J.) (advisor), Hughes, Thomas J. R. (advisor), Demkowicz, Leszek F. (committee member), Biros, George (committee member), Sayas, Francisco Javier (committee member).
Subjects/Keywords: Boundary integral equations; Isogeometric Analysis; Boundary element methods; Isogeometric boundary element methods; Collocation
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APA (6th Edition):
Taus, M. F. (2015). Isogeometric Analysis for boundary integral equations. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/32824
Chicago Manual of Style (16th Edition):
Taus, Matthias Franz. “Isogeometric Analysis for boundary integral equations.” 2015. Doctoral Dissertation, University of Texas – Austin. Accessed January 23, 2021.
http://hdl.handle.net/2152/32824.
MLA Handbook (7th Edition):
Taus, Matthias Franz. “Isogeometric Analysis for boundary integral equations.” 2015. Web. 23 Jan 2021.
Vancouver:
Taus MF. Isogeometric Analysis for boundary integral equations. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2015. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/2152/32824.
Council of Science Editors:
Taus MF. Isogeometric Analysis for boundary integral equations. [Doctoral Dissertation]. University of Texas – Austin; 2015. Available from: http://hdl.handle.net/2152/32824
NSYSU
11.
Liu, Kai-Meng.
Cross-Boundary Learning of Professional Planner.
Degree: Master, Business Management, 2014, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0630114-132006
► This research starts with the life-stories of three professional planners, and raised the question that how do planners learn. With narrative for research method and…
(more)
▼ This research starts with the life-stories of three professional planners, and raised the question that how do planners learn. With narrative for research method and the viewpoint of becoming for theory view, the researcher begins to discuss about the learning process of three planners. Firstly, this research finds that planners are working in a multi-
boundary habitat. Planners work together with, for instance, lighting, designer, stage staff, and artist. Based on this, the research finally gets two findings:
1.connection as learning
2.culture translation as learning.
Instead of traditional opinion that learning is knowledge acquisition, learning in this research is defined as a process of becoming others. In this way, connection and culture translation are recognized as self-creation and self-recreation.
Advisors/Committee Members: Ching-fang Lee (chair), Jack Wang (chair), Ted Yu-chung Liu (committee member), Stephen D. Tsai (committee member).
Subjects/Keywords: cross-boundary; planner; becoming; learning
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APA (6th Edition):
Liu, K. (2014). Cross-Boundary Learning of Professional Planner. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0630114-132006
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):
Liu, Kai-Meng. “Cross-Boundary Learning of Professional Planner.” 2014. Thesis, NSYSU. Accessed January 23, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0630114-132006.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Liu, Kai-Meng. “Cross-Boundary Learning of Professional Planner.” 2014. Web. 23 Jan 2021.
Vancouver:
Liu K. Cross-Boundary Learning of Professional Planner. [Internet] [Thesis]. NSYSU; 2014. [cited 2021 Jan 23].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0630114-132006.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Liu K. Cross-Boundary Learning of Professional Planner. [Thesis]. NSYSU; 2014. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0630114-132006
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Edinburgh
12.
Mowat, Emma.
Making Psychology a Science: A Discourse Analysis upon the history of psychology within introductory psychology textbooks.
Degree: 2013, University of Edinburgh
URL: http://hdl.handle.net/1842/8694
► Abstract The history of psychology within introductory psychology textbooks is the focus of a discourse analysis (DA), to explore how it constructs the scientific status…
(more)
▼ Abstract
The history of psychology within introductory psychology textbooks is the focus of a discourse analysis (DA), to explore how it constructs the scientific status of the discipline that it is chronicling. Given the importance of Psychology’s scientific status to retain its cultural authority, and the lack of a clear demarcation between science and other forms of knowledge producing activities, there is a need to understand better how psychological knowledge came to be seen as scientific. The current projects proceeds on the constructivist premise that science is a contextual cultural phenomenon, rather than an immutable social structure. The history of psychology within introductory textbooks provides a site in which the social construction of science operates through the rhetorical process of
boundary work. With reference to specific extracts, the analysis will consider how five interrelated themes are deployed, and the rhetorical function they serve to present a particular version of psychology as a science. It is hoped that the paper will show how DA can offer an insight into the way in which the history of psychology does not just describe, but constructs psychology’s scientific status, and is thus a suitable approach to explore historical and conceptual issues.
Advisors/Committee Members: Lamont, Paul.
Subjects/Keywords: discourse analysis; boundary work
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APA (6th Edition):
Mowat, E. (2013). Making Psychology a Science: A Discourse Analysis upon the history of psychology within introductory psychology textbooks. (Thesis). University of Edinburgh. Retrieved from http://hdl.handle.net/1842/8694
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):
Mowat, Emma. “Making Psychology a Science: A Discourse Analysis upon the history of psychology within introductory psychology textbooks.” 2013. Thesis, University of Edinburgh. Accessed January 23, 2021.
http://hdl.handle.net/1842/8694.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mowat, Emma. “Making Psychology a Science: A Discourse Analysis upon the history of psychology within introductory psychology textbooks.” 2013. Web. 23 Jan 2021.
Vancouver:
Mowat E. Making Psychology a Science: A Discourse Analysis upon the history of psychology within introductory psychology textbooks. [Internet] [Thesis]. University of Edinburgh; 2013. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1842/8694.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mowat E. Making Psychology a Science: A Discourse Analysis upon the history of psychology within introductory psychology textbooks. [Thesis]. University of Edinburgh; 2013. Available from: http://hdl.handle.net/1842/8694
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Alberta
13.
Mukherjee, Satarupa.
A Novel Framework for Unique People Count from Monocular
Videos.
Degree: PhD, Department of Computing Science, 2014, University of Alberta
URL: https://era.library.ualberta.ca/files/2f75r8900
► Counting unique number of people in a video (i.e., counting a person only once while the person passes through the field of view (FOV)), is…
(more)
▼ Counting unique number of people in a video (i.e.,
counting a person only once while the person passes through the
field of view (FOV)), is required in many video analytic
applications, such as transit passenger and pedestrian volume count
in railway stations, malls and road intersections, aid in security
and resource management, urban planning, advertising and many
others. In this PhD thesis I have developed a robust algorithm to
generate unique people count from monocular videos taken from an
arbitrary angle. From applications point of view, my algorithm is
one of the most economical ones, because it can work with existing
video cameras already mounted. Within a region of interest (ROI) on
the FOV of the camera, I compute influx/outflux rate of people,
i.e., number of people coming in or going out of the ROI per unit
time. Then, I sum the influx/outflux rate between any two time
points to estimate the number of people that entered and/or left
the ROI within that time interval. I employ two well-known computer
vision techniques for this purpose: Gaussian process regression
(GPR) to estimate the number of people present within a ROI and
optical flow-based tracking of the boundary of the ROI. The
principle roadblock in most of computer vision problems is
occlusion. To avoid this bottleneck, we adopt the combination of
(a) the concept of influx and outflux of fluid mass from
computational fluidics, (b) the GPR to estimate the number of
people within a ROI and (c) ROI boundary tracking (as opposed to
object or feature tracking) for a short period. Thus, the principal
contribution of the thesis is to successfully handle occlusions by
computing the average influx and/or outflux of people and avoiding
people detection and tracking. We validate the proposed algorithm
on 19 publicly available monocular benchmark videos. Occlusions are
abundant in these videos, yet we obtain more than 95% accuracy for
most of these videos. We also extend our proposed framework beyond
monocular videos and apply it on multiple views of a publicly
available dataset with about 99% accuracy.
Subjects/Keywords: boundary tracking; occlusion; people counting
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APA (6th Edition):
Mukherjee, S. (2014). A Novel Framework for Unique People Count from Monocular
Videos. (Doctoral Dissertation). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/2f75r8900
Chicago Manual of Style (16th Edition):
Mukherjee, Satarupa. “A Novel Framework for Unique People Count from Monocular
Videos.” 2014. Doctoral Dissertation, University of Alberta. Accessed January 23, 2021.
https://era.library.ualberta.ca/files/2f75r8900.
MLA Handbook (7th Edition):
Mukherjee, Satarupa. “A Novel Framework for Unique People Count from Monocular
Videos.” 2014. Web. 23 Jan 2021.
Vancouver:
Mukherjee S. A Novel Framework for Unique People Count from Monocular
Videos. [Internet] [Doctoral dissertation]. University of Alberta; 2014. [cited 2021 Jan 23].
Available from: https://era.library.ualberta.ca/files/2f75r8900.
Council of Science Editors:
Mukherjee S. A Novel Framework for Unique People Count from Monocular
Videos. [Doctoral Dissertation]. University of Alberta; 2014. Available from: https://era.library.ualberta.ca/files/2f75r8900
Oregon State University
14.
Smoot, Alexander R.
Linking dynamics of the near-surface flow to deeper boundary layer forcing in the nocturnal boundary layer.
Degree: MS, Atmospheric Science, 2012, Oregon State University
URL: http://hdl.handle.net/1957/30361
► Weak-wind flow in the nocturnal boundary is one of the most poorly understood problems in the field of meteorology. The understanding of weak-wind flows is…
(more)
▼ Weak-wind flow in the nocturnal
boundary is one of the most poorly understood problems in the field of meteorology. The understanding of weak-wind flows is essential for the improvement of regulatory dispersion models which are currently rendered invalid under weak-wind conditions and stable stratification. Recently there have been increased efforts directed towards improving the understanding nocturnal
boundary layer dynamics. The results of these studies have shown that nocturnal
boundary layer flows are often dominated by intermittent turbulence and motions occurring on horizontal scales ranging from hundreds of meters to several kilometers and on time scales of 1 minute to 1 hour. We refer to these scales as sub-meso. This connection has led to the hypothesis that intermittent turbulence generation may be the result of sub-meso motions that are
subject to external forcing originating in the deeper
boundary layer. However, these processes have proven difficult to measure as traditional sensor networks have failed to provide the vertical and horizontal coverage necessary to observe the driving forces on these scales. This study sought to close this knowledge gap using SOund Detection And Ranging (SODAR). SODAR is a ground based acoustic remote sensing technology that is capable of measuring wind and turbulence at multiple heights in the
boundary layer. Data were collected with a pair of SODAR systems with sequentially increasing separation distance at the Oregon State University Botany and Plant Pathology lab during the summer of 2010. The data have indicated that motion occurring on time scales of 2 minutes to 32 minutes are isolated to the lowest 50 meters of the nocturnal
boundary layer. Surface-layer measurements were collected using a pair of sonic anemometers placed at heights of 1.5 and 7 meters above ground level. Comparisons of surface-layer measurements and deeper
boundary layer measurements have shown that when the surface layer stratification is stable, processes within the surface layer are not likely to be influenced by external forcing from aloft. In contrast external forcing from the deeper
boundary layer may still have an influence on weak, nocturnal surface flows when the surface layer is weakly stratified as is shown for the case of low-level jets.
Advisors/Committee Members: Thomas, Christoph K. (advisor), Skyllingstad, Eric (committee member).
Subjects/Keywords: atmosphere; Boundary layer (Meteorology)
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APA (6th Edition):
Smoot, A. R. (2012). Linking dynamics of the near-surface flow to deeper boundary layer forcing in the nocturnal boundary layer. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/30361
Chicago Manual of Style (16th Edition):
Smoot, Alexander R. “Linking dynamics of the near-surface flow to deeper boundary layer forcing in the nocturnal boundary layer.” 2012. Masters Thesis, Oregon State University. Accessed January 23, 2021.
http://hdl.handle.net/1957/30361.
MLA Handbook (7th Edition):
Smoot, Alexander R. “Linking dynamics of the near-surface flow to deeper boundary layer forcing in the nocturnal boundary layer.” 2012. Web. 23 Jan 2021.
Vancouver:
Smoot AR. Linking dynamics of the near-surface flow to deeper boundary layer forcing in the nocturnal boundary layer. [Internet] [Masters thesis]. Oregon State University; 2012. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1957/30361.
Council of Science Editors:
Smoot AR. Linking dynamics of the near-surface flow to deeper boundary layer forcing in the nocturnal boundary layer. [Masters Thesis]. Oregon State University; 2012. Available from: http://hdl.handle.net/1957/30361
Cornell University
15.
Bomarito, Geoffrey.
A Computational Investigation Of Ductile Failure In Al5083-H116 And The Shear Strengths Of Pure Aluminum Grain Boundaries.
Degree: PhD, Civil and Environmental Engineering, 2015, Cornell University
URL: http://hdl.handle.net/1813/39335
► Computational models, besides their relatively low cost, offer the benefit of complete control over all testing variables (e.g., atmospheric conditions, loading rates, applied stress states),…
(more)
▼ Computational models, besides their relatively low cost, offer the benefit of complete control over all testing variables (e.g., atmospheric conditions, loading rates, applied stress states), which can be difficult to control in experiments. This control can be used to identify key controlling parameters and improve our understanding of the deformation and failure processes. This dissertation investigates how modern computational resources can be leveraged to improve both the understanding and prediction of material deformation and failure. Because of its widespread use and variability of application, aluminum and its alloys are the focus of the investigation. Specifically, the applications of ductile failure and grain
boundary shear strength were chosen for this dissertation. Though these phenomena are quite different, the same theme is present in the approach to both problems. In both cases, we were able to run numerous simple simulations of the phenomenon in concern. A large computational effort was required in all cases to run the sets of simulations, but the results of these simulations were synthesized into a simple model which can be used at larger scales. In the case of ductile failure, a unit cell was designed to simulate the microstructural evolution of an aluminum alloy. The population of second phase particles in the alloy was represented as a spherical void surrounded by an alu- minum matrix. Many different loadings were applied to the cell which were characterized by a stress state and orientation. The results of these tests were used to form a simple model for the dependence of ductile failure on applied stress state. By refining the model microstructure, it was found that increasing the fidelity of the model microstructure leads to increased predictive capability of the model. In the case of grain
boundary shear strength, atomistic models of interface structures were subjected to shear in many directions in the
boundary plane. The simulation of a large number of these interface structures showed that shear yield strengths were relatively independent of the macroscopic parameters describing each interface. Subsequently, it was shown that a statistical approach to predicting grain
boundary shear strengths could be used.
Advisors/Committee Members: Warner, Derek H. (chair), Ingraffea, Anthony R (committee member), Baker, Shefford P. (committee member).
Subjects/Keywords: Ductile Failure; Aluminum; Grain Boundary
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APA (6th Edition):
Bomarito, G. (2015). A Computational Investigation Of Ductile Failure In Al5083-H116 And The Shear Strengths Of Pure Aluminum Grain Boundaries. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/39335
Chicago Manual of Style (16th Edition):
Bomarito, Geoffrey. “A Computational Investigation Of Ductile Failure In Al5083-H116 And The Shear Strengths Of Pure Aluminum Grain Boundaries.” 2015. Doctoral Dissertation, Cornell University. Accessed January 23, 2021.
http://hdl.handle.net/1813/39335.
MLA Handbook (7th Edition):
Bomarito, Geoffrey. “A Computational Investigation Of Ductile Failure In Al5083-H116 And The Shear Strengths Of Pure Aluminum Grain Boundaries.” 2015. Web. 23 Jan 2021.
Vancouver:
Bomarito G. A Computational Investigation Of Ductile Failure In Al5083-H116 And The Shear Strengths Of Pure Aluminum Grain Boundaries. [Internet] [Doctoral dissertation]. Cornell University; 2015. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1813/39335.
Council of Science Editors:
Bomarito G. A Computational Investigation Of Ductile Failure In Al5083-H116 And The Shear Strengths Of Pure Aluminum Grain Boundaries. [Doctoral Dissertation]. Cornell University; 2015. Available from: http://hdl.handle.net/1813/39335
Cornell University
16.
Johnson, Blair.
Turbulent Boundary Layers And Sediment Resuspension In The Absence Of Mean Shear.
Degree: M.S., Civil and Environmental Engineering, Civil and Environmental Engineering, 2012, Cornell University
URL: http://hdl.handle.net/1813/29226
► Sediment resuspension is initiated through a variety of mechanisms across the wave breaking, run-up, and run-down stages that occur in the wave breaking, surf, and…
(more)
▼ Sediment resuspension is initiated through a variety of mechanisms across the wave breaking, run-up, and run-down stages that occur in the wave breaking, surf, and swash zones. When a wave breaks offshore, the plunging jet rarely reaches the bed directly; however, this injection of momentum generates turbulence that propagates through the water column, creating local stresses as turbulent eddies interact with the seafloor. When these stresses are sufficient to resuspend sediment from the bed, the sediment can become entrained in the flow, and thus both turbulence and sediment are advected shoreward during onshore directed phases of the wave cycle. It is at this time that the fluid is highly turbid, filled with sediment and debris. As the flow enters the swash zone, it runs upshore and slows, and the sediment settles out of entrainment and is deposited onshore. Then, as this relatively clear fluid flow retreats and regains speed in flowing down the beach face, sediment is again resuspended into the flow. But upon careful observation, the turbid region is constrained to the base of the water column due to shear-dominated resuspenions as a
boundary layer grows. The resuspension during the latter event can be attributed to an increased bed shear stress, due to the uniform mean flow along the sediment bed. This mechanism for resuspension is well-understood, as thorough experimental research has led to well-characterized parameters such as the Shields Curve that identify requisite shear stresses for sediment resuspension. However, the former mechanism, in which sediment is resuspended due to the interaction of large-scale turbulent motions, has seen far less research, because of the difficulty in isolating this particular flow in the laboratory and identifying meaningful parameters of the flow necessary for incipient particle motion from the bed. We have chosen to isolate the phenomenon of sediment resuspension by turbulence absent mean shear in the laboratory to better understand this fundamental process. By adapting a turbulence chamber in the DeFrees Hydraulics Lab developed by Variano & Cowen (2008), in which a Randomly Actuated Synthetic Jet Array (RASJA; Variano and Cowen, 2008) is suspended above a tank of water, with jets directed downward, we have a nearly ideal facility for examining decaying horizontally homogeneous isotropic turbulence above a bed. The jets fire according to a specified random algorithm to generate homogeneous isotropic turbulence without inducing mean flows. With a solid glass bottom
boundary in place, data were collected with Acoustic Doppler Velocimetry (ADV) and Particle Image Velocimetry (PIV) measurements to characterize profiles of the mean flow, turbulence intensity, and kinetic energy. Statistics such as spatial and temporal spectra and parameters of mean flow strength were computed to understand the nature of the turbulence in the facility, revealing a well developed inertial subrange and very weak mean flows.. The glass was then replaced with a sediment bed, and the tests were…
Advisors/Committee Members: Cowen III, Edwin Alfred (chair), Louge, Michel Yves (committee member), Jenkins, James Thomas (committee member).
Subjects/Keywords: sediment resuspension; boundary layer; turbulence
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APA (6th Edition):
Johnson, B. (2012). Turbulent Boundary Layers And Sediment Resuspension In The Absence Of Mean Shear. (Masters Thesis). Cornell University. Retrieved from http://hdl.handle.net/1813/29226
Chicago Manual of Style (16th Edition):
Johnson, Blair. “Turbulent Boundary Layers And Sediment Resuspension In The Absence Of Mean Shear.” 2012. Masters Thesis, Cornell University. Accessed January 23, 2021.
http://hdl.handle.net/1813/29226.
MLA Handbook (7th Edition):
Johnson, Blair. “Turbulent Boundary Layers And Sediment Resuspension In The Absence Of Mean Shear.” 2012. Web. 23 Jan 2021.
Vancouver:
Johnson B. Turbulent Boundary Layers And Sediment Resuspension In The Absence Of Mean Shear. [Internet] [Masters thesis]. Cornell University; 2012. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1813/29226.
Council of Science Editors:
Johnson B. Turbulent Boundary Layers And Sediment Resuspension In The Absence Of Mean Shear. [Masters Thesis]. Cornell University; 2012. Available from: http://hdl.handle.net/1813/29226
Texas A&M University
17.
Peltier, Scott Jacob.
Behavior of Turbulent Structures within a Mach 5 Mechanically Distorted Boundary Layer.
Degree: PhD, Aerospace Engineering, 2013, Texas A&M University
URL: http://hdl.handle.net/1969.1/151397
► High-resolution particle image velocimetry (PIV) is employed to resolve the velocity fields within a Mach 4.9 mechanically distorted turbulent boundary layer (Reθ ≈ 40,000). The…
(more)
▼ High-resolution particle image velocimetry (PIV) is employed to resolve the velocity fields within a Mach 4.9 mechanically distorted turbulent
boundary layer (Reθ ≈ 40,000). The goal of this study is to directly observe the mechanisms responsible for the modified turbulent stresses present in mechanically distorted
boundary layers. This is achieved by measuring the effects of the mechanical distortions upon the distribution, population, size, orientation, and energy content of the turbulent structures, and how the perturbed state of these structures is manifested within the ensemble-averaged turbulent stresses. The two mechanical distortions under investigation are 1) streamline curvature-induced favorable pressure gradients (Ip = {-0.08; -0.49}), and 2) periodic arrays of diamond roughness elements (k/δ ≈ 0.07). A smooth-wall, flat-plate
boundary layer is also included to establish the unperturbed state of the turbulent structures. The response of the mean turbulence statistics is investigated through ensemble-averaged profiles of Reynolds stresses, indicating the respective influences of pressure gradient effects and surface roughness upon the turbulent statistics. The distortion and reorientation of the large-scale coherent motions is quantified through the determination of the integral length scale and local structure angle from two-point correlations. Detection of individual vortices through the swirling strength criterion λci allows the population distribution of the turbulent eddies to be examined, along with the conditionally averaged hairpin structure.
The baseline and rough-wall stresses showed good agreement when scaled by the smooth-wall friction velocity. Two-point correlations indicate that the reorientation of the large-scale [i.e. O(δ)] coherent structures, coupled with the modified wall-normal fluctuations, is primarily responsible for the modification of the rough-wall Reynolds stresses. The reduced Reynolds stresses observed in the favorable pressure gradients is partially due to the attenuation of the local flowfield around the near-wall hairpin structures, mitigating the mechanism for “producing” turbulence. The rotational rate of the hairpin vortices, measured through the mean prograde swirling strength, was reduced for the favorable pressure gradient models.
Advisors/Committee Members: Bowersox, Rodney D.W. (advisor), White, Edward B. (committee member), Rediniotis, Othon K. (committee member), North, Simon W. (committee member).
Subjects/Keywords: boundary layer; turbulence; coherent structures
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APA (6th Edition):
Peltier, S. J. (2013). Behavior of Turbulent Structures within a Mach 5 Mechanically Distorted Boundary Layer. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151397
Chicago Manual of Style (16th Edition):
Peltier, Scott Jacob. “Behavior of Turbulent Structures within a Mach 5 Mechanically Distorted Boundary Layer.” 2013. Doctoral Dissertation, Texas A&M University. Accessed January 23, 2021.
http://hdl.handle.net/1969.1/151397.
MLA Handbook (7th Edition):
Peltier, Scott Jacob. “Behavior of Turbulent Structures within a Mach 5 Mechanically Distorted Boundary Layer.” 2013. Web. 23 Jan 2021.
Vancouver:
Peltier SJ. Behavior of Turbulent Structures within a Mach 5 Mechanically Distorted Boundary Layer. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1969.1/151397.
Council of Science Editors:
Peltier SJ. Behavior of Turbulent Structures within a Mach 5 Mechanically Distorted Boundary Layer. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151397
Texas A&M University
18.
Kocian, Travis Scott.
Computational Hypersonic Boundary-Layer Stability and the Validation and Verification of EPIC.
Degree: PhD, Aerospace Engineering, 2018, Texas A&M University
URL: http://hdl.handle.net/1969.1/173633
► Laminar-to-turbulent transition is a process that is critical in determining the system drag and surface heating of a flight vehicle, and the ability to predict,…
(more)
▼ Laminar-to-turbulent transition is a process that is critical in determining the system drag and surface heating of a flight vehicle, and the ability to predict, and possibly control, this process has become an essential component in vehicle design. The linear and nonlinear parabolized stability equations provide a method of analyzing different regions of the flowfield around a vehicle in a way that is both efficient and accurate. These methods have continued to evolve in terms of both capability and robustness. Coupled with data from wind tunnel experiments, they provide a powerful tool in understanding and addressing flow phenomena involved in the process of laminar-to-turbulent transition.
EPIC is a parabolized stability equations (PSE) solver developed within the Computational Stability and Transition laboratory at Texas A&M University that can address both the linear and nonlinear aspects of the stability problem. This capability provides a means to evaluate different instabilities and the underlying physics that drives them. PSE results are computed for several hypersonic geometries including the Langley 93-10 cone, Purdue compression cone, yawed straight cone, and HIFiRE-5 elliptic cone. Disturbances that are both two-dimensional and three-dimensional in nature are analyzed and compared with results obtained from direct numerical simulations, wind tunnel experiments, and alternate PSE codes. In addition, techniques for modeling stationary crossflow vortex paths and the evolution of spanwise wavenumber from the basic-state solution are formulated.
Advisors/Committee Members: Reed, Helen L (advisor), Bowersox, Rodney (committee member), White, Edward (committee member), Daripa, Prabir (committee member).
Subjects/Keywords: Hypersonics; stability; boundary-layer; CFD
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APA (6th Edition):
Kocian, T. S. (2018). Computational Hypersonic Boundary-Layer Stability and the Validation and Verification of EPIC. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173633
Chicago Manual of Style (16th Edition):
Kocian, Travis Scott. “Computational Hypersonic Boundary-Layer Stability and the Validation and Verification of EPIC.” 2018. Doctoral Dissertation, Texas A&M University. Accessed January 23, 2021.
http://hdl.handle.net/1969.1/173633.
MLA Handbook (7th Edition):
Kocian, Travis Scott. “Computational Hypersonic Boundary-Layer Stability and the Validation and Verification of EPIC.” 2018. Web. 23 Jan 2021.
Vancouver:
Kocian TS. Computational Hypersonic Boundary-Layer Stability and the Validation and Verification of EPIC. [Internet] [Doctoral dissertation]. Texas A&M University; 2018. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1969.1/173633.
Council of Science Editors:
Kocian TS. Computational Hypersonic Boundary-Layer Stability and the Validation and Verification of EPIC. [Doctoral Dissertation]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/173633
Texas A&M University
19.
Dadi, Sireesh Kumar.
A Study to Verify the Material Surface Concept of Water Table by Examining Analytical and Numerical Models.
Degree: MS, Geology, 2011, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8243
► The highly nonlinear nature of unsaturated flow results in different ways to approximate the delayed or instantaneous movement of the water table. In nearly all…
(more)
▼ The highly nonlinear nature of unsaturated flow results in different ways to approximate the delayed or instantaneous movement of the water table. In nearly all the approaches, the water table is conceptually treated as a “material surface”. This term defines the water table as having two simultaneous properties: 1) the pressure along the surface is atmospheric pressure, and 2) the water table is fixed to the material, i.e., a set of water particles. This article makes an attempt to explain that the water table, defined as the surface at atmospheric pressure, is not a material
boundary, and the water table can move independent of the water particles.
Velocity of the water table and velocity of drainage are compared with three analytical models: the Neuman model, which assumes instantaneous drainage from the unsaturated zone; the Moench model, which considered gradual drainage from the unsaturated zone using a series of exponential terms in the water table
boundary condition; and the Mathias-Butler model, which obtained a new drainage function based on a linearized Richard’s equation but limited the variation of soil moisture and hydraulic conductivity in the unsaturated zone to exponential functions. Numerical analysis was conducted with VS2DT and both the numerical and the analytical results were compared with a 7-day, constant rate pumping test conducted by University of Waterloo researchers at Canadian Air Force Base Borden in Ontario, Canada.
Advisors/Committee Members: Zhan, Hing-Bin (advisor), Sparks, David (advisor), Sun, Yuefeng (committee member).
Subjects/Keywords: material boundary; water table
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APA (6th Edition):
Dadi, S. K. (2011). A Study to Verify the Material Surface Concept of Water Table by Examining Analytical and Numerical Models. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8243
Chicago Manual of Style (16th Edition):
Dadi, Sireesh Kumar. “A Study to Verify the Material Surface Concept of Water Table by Examining Analytical and Numerical Models.” 2011. Masters Thesis, Texas A&M University. Accessed January 23, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8243.
MLA Handbook (7th Edition):
Dadi, Sireesh Kumar. “A Study to Verify the Material Surface Concept of Water Table by Examining Analytical and Numerical Models.” 2011. Web. 23 Jan 2021.
Vancouver:
Dadi SK. A Study to Verify the Material Surface Concept of Water Table by Examining Analytical and Numerical Models. [Internet] [Masters thesis]. Texas A&M University; 2011. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8243.
Council of Science Editors:
Dadi SK. A Study to Verify the Material Surface Concept of Water Table by Examining Analytical and Numerical Models. [Masters Thesis]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8243
Texas A&M University
20.
Smith, Jason D.
Bijective Parameterization with Free Boundaries.
Degree: PhD, Computer Science, 2015, Texas A&M University
URL: http://hdl.handle.net/1969.1/156497
► When displaying 3D surfaces onto computer screens, additional information is often mapped onto the surface to enhance the quality of the rendering. Surface parameterization generates…
(more)
▼ When displaying 3D surfaces onto computer screens, additional information is often mapped onto the surface to enhance the quality of the rendering. Surface parameterization generates a correspondence, or mapping, between the 3D surface and 2D parameterization space. This mapping has many applications in computer graphics, but in most cases cannot be performed without introducing large distortions in the 2D parameterization. Along with problems of distortion, the mapping of the 2D space to 3D for many applications can be invalidated if the property of bijectivity is violated. While there is previous research guaranteeing bijectivity, these methods must constrain or modify the
boundary of the 2D parameterization. This dissertation, describes a fully automatic method for generating guaranteed bijective surface parameterizations from triangulated 3D surfaces. In particular, a new isometric distortion energy metric is introduced preventing local folds of triangles in the parameterization as well as a barrier function that prevents intersection of the 2D boundaries. By using a computationally efficient isometric metric energy, the dissertation achieves fast and comparable optimization times to previous methods. The
boundary of the parameterization is free to change shape during the optimization to minimize distortion. A new optimization approach is introduced called singularity aware optimization and in conjunction with an interior point approach and barrier energy functions guarantee bijectivity. This optimization framework is then modified to allow for an importance weighting allowing for customizable and more efficient texel usage.
Advisors/Committee Members: Schaefer, Scott (advisor), Keyser, John (committee member), Chai, Jinxiang (committee member), Akleman, Ergun (committee member).
Subjects/Keywords: Parameterization; Bijectivity; Boundary; Mapping
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APA (6th Edition):
Smith, J. D. (2015). Bijective Parameterization with Free Boundaries. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156497
Chicago Manual of Style (16th Edition):
Smith, Jason D. “Bijective Parameterization with Free Boundaries.” 2015. Doctoral Dissertation, Texas A&M University. Accessed January 23, 2021.
http://hdl.handle.net/1969.1/156497.
MLA Handbook (7th Edition):
Smith, Jason D. “Bijective Parameterization with Free Boundaries.” 2015. Web. 23 Jan 2021.
Vancouver:
Smith JD. Bijective Parameterization with Free Boundaries. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1969.1/156497.
Council of Science Editors:
Smith JD. Bijective Parameterization with Free Boundaries. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/156497
Texas A&M University
21.
Kuester, Matthew Scott.
Distributed Roughness Receptivity in a Flat Plate Boundary Layer.
Degree: PhD, Aerospace Engineering, 2014, Texas A&M University
URL: http://hdl.handle.net/1969.1/152606
► Surface roughness can affect boundary layer transition by acting as a receptivity mechanism for transient growth. Several experiments have investigated transient growth created by discrete…
(more)
▼ Surface roughness can affect
boundary layer transition by acting as a receptivity mechanism for transient growth. Several experiments have investigated transient growth created by discrete roughness elements; however, very few experiments have studied transient growth initiated by distributed surface roughness. Some of the work in this field predicts a "shielding" effect, where smaller distributed roughness displaces the
boundary layer away from the wall and shields larger roughness peaks from the incoming
boundary layer.
This dissertation describes an experiment specifically designed to study the shielding effect. Three roughness configurations, a deterministic distributed roughness patch, a slanted rectangle, and the combination of the two, were manufactured using rapid prototyping and installed flush with the wall in a flat plate
boundary layer. The main objective was to compare the wakes of the discrete roughness and the combined roughness to examine if the distributed roughness shields the discrete roughness. Naphthalene flow visualization and hotwire anemometry were used to characterize
the
boundary layer in the wakes of the different roughness configurations.
For roughness Reynolds numbers (Re_(k)) between 113 and 230, the distributed roughness initiated small amplitude disturbances that underwent transient growth. The discrete roughness element created a pair of high- and low-speed streaks in the
boundary layer at a sub-critical Reynolds number (Re_(k) = 151). At a higher Reynolds number (Re_(k) = 220), the discrete element created a turbulent wedge 15
boundary layer thicknesses downstream.
When the distributed roughness was added around the discrete roughness, the wake amplitude decreased at the sub-critical Reynolds number, and transition was delayed by two
boundary layer thicknesses at the higher Reynolds number. The distributed roughness redirects energy from longer spanwise wavelength modes to shorter spanwise wavelength modes. The presence of the distributed roughness also decreased the growth rate of secondary instabilities in the roughness wake.
This dissertation documents the first detailed measurements of transient growth over streamwise-extended distributed roughness and demonstrates that the shielding effect has the potential to delay roughness-induced transition. The results from this experiment lay the ground work for future studies of roughness receptivity and transient growth.
Advisors/Committee Members: White, Edward B (advisor), Saric, William S (committee member), Bowersox, Rodney (committee member), Morrison, Gerald (committee member).
Subjects/Keywords: Boundary Layers; Roughness; Transition
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APA (6th Edition):
Kuester, M. S. (2014). Distributed Roughness Receptivity in a Flat Plate Boundary Layer. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/152606
Chicago Manual of Style (16th Edition):
Kuester, Matthew Scott. “Distributed Roughness Receptivity in a Flat Plate Boundary Layer.” 2014. Doctoral Dissertation, Texas A&M University. Accessed January 23, 2021.
http://hdl.handle.net/1969.1/152606.
MLA Handbook (7th Edition):
Kuester, Matthew Scott. “Distributed Roughness Receptivity in a Flat Plate Boundary Layer.” 2014. Web. 23 Jan 2021.
Vancouver:
Kuester MS. Distributed Roughness Receptivity in a Flat Plate Boundary Layer. [Internet] [Doctoral dissertation]. Texas A&M University; 2014. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1969.1/152606.
Council of Science Editors:
Kuester MS. Distributed Roughness Receptivity in a Flat Plate Boundary Layer. [Doctoral Dissertation]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/152606
Texas A&M University
22.
Zhang, Wenxia.
Stratification Prediction and Bottom Boundary Layer Dynamics over the Texas-Louisiana Continental Shelf.
Degree: PhD, Oceanography, 2015, Texas A&M University
URL: http://hdl.handle.net/1969.1/155027
► The bottom boundary layer is an unstratified thin layer above the sea floor, separated from the more strongly stratified interior. Formation of a thin bottom…
(more)
▼ The bottom
boundary layer is an unstratified thin layer above the sea floor, separated from the more strongly stratified interior. Formation of a thin bottom
boundary layer in the presence of stratification and a sloping bottom is common, and well characterized by theory. This thin layer is an important source of mixing over the continental shelf, and it plays a fundamental role in several continental shelf physical and biogeochemical processes, such as buoyancy advection, bottom material transport and hypoxia formation.
In this research, Both observations and numerical models are used to study models' ability of reproducing observed stratification and bottom
boundary layer dynamics over the Texas-Louisiana shelf. Simulated vertical stratification, which is also representing the vertical density structure, was first evaluated since it directly controls the bottom
boundary layer structure itself and is important for other bottom
boundary layer dynamics. A new metric, the histogram of vertical stratification, is introduced in this research to evaluate the models' ability of reproducing observed stratification in a bulk sense. The improvement in model performance is attributed to the finer horizontal and temporal resolutions of a model, while factors like open
boundary conditions and vertical resolutions are modified without any improvement in the ability of the model to simulate observed stratification. Towed, undulating CTD profiles collected during Mechanisms Controlling Hypoxia (MCH) program also detected mid-water oxygen minima in many transects. These intrusions are connected with the bottom
boundary layer and follows the pycnocline seaward as a mid-water column tongue of low oxygen. We calculate convergence within the bottom
boundary layer relative to density surfaces using the simulated results; there is a convergence in the bottom
boundary layer at the location where the pycnocline intercepts the bottom, creating an injection of bottom
boundary layer water into the pycnocline. Convergent flow at the bottom, relative to isopycnal surfaces, is strongest in the density classes associated with the oxygen minimum layer. We believe these mid-water oxygen minima are actually intrusions of low oxygen protruding from the bottom
boundary layer via buoyancy advection driven convergence, following the main pycnocline.
Advisors/Committee Members: Hetland, Robert D. (advisor), Lin, Xiaopei (advisor), DiMarco, Steven F. (committee member), Socolofsky, Scott A. (committee member).
Subjects/Keywords: stratification; bottom boundary layer
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APA (6th Edition):
Zhang, W. (2015). Stratification Prediction and Bottom Boundary Layer Dynamics over the Texas-Louisiana Continental Shelf. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155027
Chicago Manual of Style (16th Edition):
Zhang, Wenxia. “Stratification Prediction and Bottom Boundary Layer Dynamics over the Texas-Louisiana Continental Shelf.” 2015. Doctoral Dissertation, Texas A&M University. Accessed January 23, 2021.
http://hdl.handle.net/1969.1/155027.
MLA Handbook (7th Edition):
Zhang, Wenxia. “Stratification Prediction and Bottom Boundary Layer Dynamics over the Texas-Louisiana Continental Shelf.” 2015. Web. 23 Jan 2021.
Vancouver:
Zhang W. Stratification Prediction and Bottom Boundary Layer Dynamics over the Texas-Louisiana Continental Shelf. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1969.1/155027.
Council of Science Editors:
Zhang W. Stratification Prediction and Bottom Boundary Layer Dynamics over the Texas-Louisiana Continental Shelf. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155027
Texas A&M University
23.
Downs, Robert 1982-.
Environmental Influences on Crossflow Instability.
Degree: PhD, Aerospace Engineering, 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/148060
► The laminar-to-turbulent transition process in swept-wing boundary layers is often dominated by an inflectional instability arising from crossflow. It is now known that freestream turbulence…
(more)
▼ The laminar-to-turbulent transition process in swept-wing
boundary layers is often dominated by an inflectional instability arising from crossflow. It is now known that freestream turbulence and surface roughness are two of the key disturbance sources in the crossflow instability problem. Recent experimental findings have suggested that freestream turbulence of low intensity (less than 0.2%) may have a larger influence on crossflow instability than was previously thought. The present work involves experimental measurement of stationary and traveling crossflow mode amplitudes in freestream turbulence levels between 0.02% and 0.2%. A 1.83 m chord, 45-degree swept-wing model is used in the Klebanoff-Saric Wind Tunnel to perform these experiments. The turbulence intensity and length scales are documented. Although a significant amount of research on the role of turbulence has been completed at higher turbulence levels, comparatively little has been done at the low levels of the present experiments, which more closely reflect the flight environment. It is found that growth of the traveling crossflow mode is highly dependent on small changes to the freestream turbulence. Additionally, previously studied attenuation of saturated stationary disturbance amplitudes is observed at these low turbulence levels. The extent of laminar flow is also observed to decrease in moderate freestream turbulence.
Advisors/Committee Members: White, Edward (advisor), Bowersox, Rodney (committee member), Duggleby, Andrew (committee member), Saric, William (committee member).
Subjects/Keywords: boundary-layer stability; Crossflow instability
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APA (6th Edition):
Downs, R. 1. (2012). Environmental Influences on Crossflow Instability. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/148060
Chicago Manual of Style (16th Edition):
Downs, Robert 1982-. “Environmental Influences on Crossflow Instability.” 2012. Doctoral Dissertation, Texas A&M University. Accessed January 23, 2021.
http://hdl.handle.net/1969.1/148060.
MLA Handbook (7th Edition):
Downs, Robert 1982-. “Environmental Influences on Crossflow Instability.” 2012. Web. 23 Jan 2021.
Vancouver:
Downs R1. Environmental Influences on Crossflow Instability. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1969.1/148060.
Council of Science Editors:
Downs R1. Environmental Influences on Crossflow Instability. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/148060
Leiden University
24.
Blank, D.A.F.
Mediating Trans-Boundary Water Conflicts: Issues and Approaches to Long-Term Resources Management and Conflict Resolution.
Degree: 2012, Leiden University
URL: http://hdl.handle.net/1887/19391
► Trans-boundary rivers are shared by multiple sovereign states, creating conflicting demands on the river’s resources and further complicating already difficult political legacies. This combination hinders…
(more)
▼ Trans-
boundary rivers are shared by multiple sovereign states, creating conflicting demands on the river’s resources and further complicating already difficult political legacies. This combination hinders cooperation over the communal resource and makes trans-
boundary river basins areas of conflict. To resolve such conflicts, the involvement of a third party mediator with the capabilities to offer incentives to reluctant riparians, coupled with the creation of a management institution to address conflicts as they arise, offers the best means of addressing both the short term issues of getting states to agree to a cooperative arrangement for the river and the long term commitment problems that would lead states to renege on the agreement. This thesis will explore the utility of the combined short and long-term approach to mediate trans-
boundary river conflicts by examining the mediation and resolution of the Indus River conflict between India and Pakistan. The lessons learned are then used to investigate the unresolved conflict between Turkey, Syria, and Iraq over the Euphrates and Tigris rivers and offer ways of managing the conflict.
Advisors/Committee Members: Melissen, Jan (advisor), Melissen, Prof.Dr. J (advisor).
Subjects/Keywords: Trans-Boundary Water Conflicts; Mediation
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APA (6th Edition):
Blank, D. A. F. (2012). Mediating Trans-Boundary Water Conflicts: Issues and Approaches to Long-Term Resources Management and Conflict Resolution. (Masters Thesis). Leiden University. Retrieved from http://hdl.handle.net/1887/19391
Chicago Manual of Style (16th Edition):
Blank, D A F. “Mediating Trans-Boundary Water Conflicts: Issues and Approaches to Long-Term Resources Management and Conflict Resolution.” 2012. Masters Thesis, Leiden University. Accessed January 23, 2021.
http://hdl.handle.net/1887/19391.
MLA Handbook (7th Edition):
Blank, D A F. “Mediating Trans-Boundary Water Conflicts: Issues and Approaches to Long-Term Resources Management and Conflict Resolution.” 2012. Web. 23 Jan 2021.
Vancouver:
Blank DAF. Mediating Trans-Boundary Water Conflicts: Issues and Approaches to Long-Term Resources Management and Conflict Resolution. [Internet] [Masters thesis]. Leiden University; 2012. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1887/19391.
Council of Science Editors:
Blank DAF. Mediating Trans-Boundary Water Conflicts: Issues and Approaches to Long-Term Resources Management and Conflict Resolution. [Masters Thesis]. Leiden University; 2012. Available from: http://hdl.handle.net/1887/19391
University of Johannesburg
25.
Du Plessis, P.
Simulering van aspekte van die atmosferiese grenslaag deur middel van turbulente Couette-stroming.
Degree: 2014, University of Johannesburg
URL: http://hdl.handle.net/10210/10186
► M.Ing.
The goal of the project was to stimulate aspects of the atmospheric boundary layer. As a result of the complexity of the derived models,…
(more)
▼ M.Ing.
The goal of the project was to stimulate aspects of the atmospheric boundary layer. As a result of the complexity of the derived models, it was decided to rather do an experiment on turbulent Couette flow to simulate. some aspects of the atmospheric boundary layer. A Couette flow channel with a maximum wall speed of 1 m/s was built. Experiments were done at two Reynolds numbers, l600 and 2500, corresponding to a channel height of 0.06 m and belt speeds of 0.4 mI and 0.58 m/s, respectively. The Coutte channel has the facility that the supper stationary wall can be heated or cooled. Experiments were carried out with positive and negative temperature gradients for both the Reynolds numbers giving the following results. By heating the top wall a stratified flow results which leads to no mixing of the flow properties. This phenomena is analogous to night time conditions in the atmosphere, when layers at different temperatures form a layered structure with little mixing between layers.
Subjects/Keywords: Boundary layer (Meteorology); Turbulence
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APA (6th Edition):
Du Plessis, P. (2014). Simulering van aspekte van die atmosferiese grenslaag deur middel van turbulente Couette-stroming. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/10186
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):
Du Plessis, P. “Simulering van aspekte van die atmosferiese grenslaag deur middel van turbulente Couette-stroming.” 2014. Thesis, University of Johannesburg. Accessed January 23, 2021.
http://hdl.handle.net/10210/10186.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Du Plessis, P. “Simulering van aspekte van die atmosferiese grenslaag deur middel van turbulente Couette-stroming.” 2014. Web. 23 Jan 2021.
Vancouver:
Du Plessis P. Simulering van aspekte van die atmosferiese grenslaag deur middel van turbulente Couette-stroming. [Internet] [Thesis]. University of Johannesburg; 2014. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/10210/10186.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Du Plessis P. Simulering van aspekte van die atmosferiese grenslaag deur middel van turbulente Couette-stroming. [Thesis]. University of Johannesburg; 2014. Available from: http://hdl.handle.net/10210/10186
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Addis Ababa University
26.
TAMENE, MEKONNEN.
THE INFLUENCE OF REGCM4 LATERAL BOUNDARY SCHEMES ON EAST AFRICAN RAINFALL
.
Degree: 2013, Addis Ababa University
URL: http://etd.aau.edu.et/dspace/handle/123456789/1319
► The latest version of the International Center for Theoretical Physics (ICTP) Regional climate model version 4 (RegCM4) is used to study the in uences of…
(more)
▼ The latest version of the International Center for Theoretical Physics (ICTP)
Regional climate model version 4 (RegCM4) is used to study the in
uences of
ve di erent Lateral
Boundary Schemes (LBSs) on the simulated rainfall for
a period of 20 years. The rainfall from RegCM4 simulations under the ve
LBSs are compared with the observed rainfall in Climate Research Unit (CRU)
and Global Precipitation Climatology Project (GPCP) dataset. The spatial
domain encompasses the whole continental Africa and includes the Indian
and south Atlantic ocean basins to capture the major circulation features
dominating eastern Africa. The comparison of the model results of rainfall
with observations from CRU and GPCP indicates a wet bias over east African
highlands while a dry bias is observed over the east African lowlands for all
cases. The mean annual cycle of rainfall is well captured over east African
subregions for each LBSs. The mean annual cycle also indicates that some
part of the east African countries are characterized by bimodal rainfall trend
which is well captured by all simulations. The observed precipitation inter-
annual variability is well reproduced by the regional model over most regions,
although RegCM4 simulations show some de ciencies. It is found that the
use of sponge as well as the exponential LBSs reproduces realistic rainfall as
exhibited by good agreement with GPCP and CRU rainfall.
Advisors/Committee Members: Dr. Gizaw Mengistu (advisor).
Subjects/Keywords: rainfall;
Lateral Boundary Schemes
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APA (6th Edition):
TAMENE, M. (2013). THE INFLUENCE OF REGCM4 LATERAL BOUNDARY SCHEMES ON EAST AFRICAN RAINFALL
. (Thesis). Addis Ababa University. Retrieved from http://etd.aau.edu.et/dspace/handle/123456789/1319
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):
TAMENE, MEKONNEN. “THE INFLUENCE OF REGCM4 LATERAL BOUNDARY SCHEMES ON EAST AFRICAN RAINFALL
.” 2013. Thesis, Addis Ababa University. Accessed January 23, 2021.
http://etd.aau.edu.et/dspace/handle/123456789/1319.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
TAMENE, MEKONNEN. “THE INFLUENCE OF REGCM4 LATERAL BOUNDARY SCHEMES ON EAST AFRICAN RAINFALL
.” 2013. Web. 23 Jan 2021.
Vancouver:
TAMENE M. THE INFLUENCE OF REGCM4 LATERAL BOUNDARY SCHEMES ON EAST AFRICAN RAINFALL
. [Internet] [Thesis]. Addis Ababa University; 2013. [cited 2021 Jan 23].
Available from: http://etd.aau.edu.et/dspace/handle/123456789/1319.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
TAMENE M. THE INFLUENCE OF REGCM4 LATERAL BOUNDARY SCHEMES ON EAST AFRICAN RAINFALL
. [Thesis]. Addis Ababa University; 2013. Available from: http://etd.aau.edu.et/dspace/handle/123456789/1319
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Oregon State University
27.
Corsiglia, Victor R.
A calculation of the suction requirements to prevent boundary layer separation on a circular cyclinder.
Degree: MS, Civil Engineering, 1963, Oregon State University
URL: http://hdl.handle.net/1957/48894
► An investigation was made to test the method of Head on the flow about a circular cylinder with suction. The method of Head is an…
(more)
▼ An investigation was made to test the method of Head on the
flow about a circular cylinder with suction. The method of Head is an
approximate method of obtaining solutions to the
boundary layer equations.
The method was adapted to the digital computer to facilitate
performing the calculations, and a variety of suction distributions
were studied. In the cases where an exact solution of the
boundary
layer equations was available the results were compared.
The method predicted a point of separation comparable to exact
solutions for the case in which the suction velocity was zero. However,
for the large suction velocities and large adverse pressure gradients
associated with the circular cylinder, the method broke down.
Enough information was obtained before breakdown to indicate that
another approximate method due to Ando underestimates the suction
required to prevent separation.
Advisors/Committee Members: Geller, Edward W. (advisor).
Subjects/Keywords: Boundary layer
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CSE |
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APA (6th Edition):
Corsiglia, V. R. (1963). A calculation of the suction requirements to prevent boundary layer separation on a circular cyclinder. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/48894
Chicago Manual of Style (16th Edition):
Corsiglia, Victor R. “A calculation of the suction requirements to prevent boundary layer separation on a circular cyclinder.” 1963. Masters Thesis, Oregon State University. Accessed January 23, 2021.
http://hdl.handle.net/1957/48894.
MLA Handbook (7th Edition):
Corsiglia, Victor R. “A calculation of the suction requirements to prevent boundary layer separation on a circular cyclinder.” 1963. Web. 23 Jan 2021.
Vancouver:
Corsiglia VR. A calculation of the suction requirements to prevent boundary layer separation on a circular cyclinder. [Internet] [Masters thesis]. Oregon State University; 1963. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1957/48894.
Council of Science Editors:
Corsiglia VR. A calculation of the suction requirements to prevent boundary layer separation on a circular cyclinder. [Masters Thesis]. Oregon State University; 1963. Available from: http://hdl.handle.net/1957/48894
Oregon State University
28.
Newton, John Francis.
An application of the Newtonian boundary condition to supersonic jets exhausting into a hypersonic stream.
Degree: MS, Mechanical Engineering, 1959, Oregon State University
URL: http://hdl.handle.net/1957/50214
Subjects/Keywords: Boundary layer
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CSE |
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Manager
APA (6th Edition):
Newton, J. F. (1959). An application of the Newtonian boundary condition to supersonic jets exhausting into a hypersonic stream. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/50214
Chicago Manual of Style (16th Edition):
Newton, John Francis. “An application of the Newtonian boundary condition to supersonic jets exhausting into a hypersonic stream.” 1959. Masters Thesis, Oregon State University. Accessed January 23, 2021.
http://hdl.handle.net/1957/50214.
MLA Handbook (7th Edition):
Newton, John Francis. “An application of the Newtonian boundary condition to supersonic jets exhausting into a hypersonic stream.” 1959. Web. 23 Jan 2021.
Vancouver:
Newton JF. An application of the Newtonian boundary condition to supersonic jets exhausting into a hypersonic stream. [Internet] [Masters thesis]. Oregon State University; 1959. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1957/50214.
Council of Science Editors:
Newton JF. An application of the Newtonian boundary condition to supersonic jets exhausting into a hypersonic stream. [Masters Thesis]. Oregon State University; 1959. Available from: http://hdl.handle.net/1957/50214
Oregon State University
29.
Myers, Gary Allen.
Estimation of momentum, heat and mass transfer in laminar boundary layers.
Degree: PhD, Chemical Engineering, 1969, Oregon State University
URL: http://hdl.handle.net/1957/46007
► Sisson's formally exact series solution for momentum, heat and mass transfer in steady two-dimensional or axi-symmetrical constant-property, laminar boundary layer flow was examined. A new…
(more)
▼ Sisson's formally exact series solution for momentum, heat and
mass transfer in steady two-dimensional or axi-symmetrical constant-property,
laminar
boundary layer flow was examined. A new series
was proposed for the
boundary condition accounting for the mass
transfer at the surface of the body on which the
boundary layer is
formed. This series circumvents certain anomalies experienced by
the original method and improves the accuracy of the solutions for
those flows with suction occurring at the wall. The perturbation
theory upon which the original method was based was examined. It
was found that the treatment followed in the original work was the
better of the two alternatives available.
The theory was developed to extend Sisson's formally exact
series solution method to flows with a non-constant wall temperature.
This new theory yields a more general heat and mass transfer similar
flow equation, which contains a temperature parameter that is of
the same form as the β parameter in the general momentum
similar equation. This general heat and mass transfer similar flow
equation was solved for a wide range of the new parameter, the 1
parameter and the mass flux parameter K. An approximation was
introduced for simplifying practical calculations. Calculations using
this extended method agreed well with the exact solutions with which
they were compared. In addition, many flows not considered by
Sisson were shown to be accurately solved with the original method.
The method of Sisson was found to agree with exact theory for
limits of large suction and limits of small Prandtl or Schmidt numbers
with little or no mass transfer at the wall. The exact limit
of large Prandtl or Schmidt numbers with little or no mass transfer
at the surface was approached very closely by the Sisson similar
method.
A rapid, general, approximate method for the calculation of
an average Nusselt number was investigated. It was found to be
quite accurate for a wide range of flow conditions.
Advisors/Committee Members: Wicks, C. E. (advisor).
Subjects/Keywords: Boundary layer
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APA (6th Edition):
Myers, G. A. (1969). Estimation of momentum, heat and mass transfer in laminar boundary layers. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/46007
Chicago Manual of Style (16th Edition):
Myers, Gary Allen. “Estimation of momentum, heat and mass transfer in laminar boundary layers.” 1969. Doctoral Dissertation, Oregon State University. Accessed January 23, 2021.
http://hdl.handle.net/1957/46007.
MLA Handbook (7th Edition):
Myers, Gary Allen. “Estimation of momentum, heat and mass transfer in laminar boundary layers.” 1969. Web. 23 Jan 2021.
Vancouver:
Myers GA. Estimation of momentum, heat and mass transfer in laminar boundary layers. [Internet] [Doctoral dissertation]. Oregon State University; 1969. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1957/46007.
Council of Science Editors:
Myers GA. Estimation of momentum, heat and mass transfer in laminar boundary layers. [Doctoral Dissertation]. Oregon State University; 1969. Available from: http://hdl.handle.net/1957/46007
Oregon State University
30.
Bakhshi, Vidya Sagar.
Boundary layer transition.
Degree: PhD, Mathematics, 1968, Oregon State University
URL: http://hdl.handle.net/1957/17210
► Transition phenomena commonly occur in nature. These arise either due to structural or behavioral changes in the medium. Examples for these abound in all applied…
(more)
▼ Transition phenomena commonly occur in nature. These arise
either due to structural or behavioral changes in the medium. Examples
for these abound in all applied sciences and to mention a few
of these, we have,
boundary layer, elastic-plastic deformation, and
shocks. The present work is devoted to the study of laminar
boundary layer transition. In this case, transition from the region
near the surface of the body to the main stream takes place within
a thin layer called the
boundary layer. Although the basic properties
of the fluid remain the same its behavior changes appreciably fro:
the surface of the body to the main stream. Owing to the presence of
spin, rotation or vorticity effects, the transition phenomenon is nonlinear,
irreversible and non-conservative and hence it cannot be
treated satisfactorily by superposition or perturbation techniques. In
this thesis an attempt is made to study the transition as an asymptotic
phenomenon from the
boundary layer. The flow in the presence of any body is divided into two regions,
(a)
boundary layer, (b) all the region excepting the
boundary layer,
called the transition region. The classical
boundary layer theory due
to Prandtl, is based on his main assumptions that (a) in the
boundary
layer, the viscous and inertial forces are of the same order, (b) the
transverse velocity in the case of a flat plate is taken of the same
order as that of the transverse coordinate, (c) the variation of pressure
in the
boundary layer is negligible. On careful examination, it
becomes clear that the above assumptions are not quite reasonable.
In the present investigation the
boundary layer thickness is estimated
without making any of these assumptions since the ratio of the viscous
to the inertial forces varies continuously from infinity near the
boundary
to zero at the outer edge of the
boundary layer. Also the order of
the transverse velocity need not be the same as that of the transverse
coordinate and the continuity of pressure across the
boundary layer
comes out from the transition analysis and therefore it is not necessary
to assume it.
By making an order of magnitude analysis, the
boundary layer
thickness for two dimensional flow is estimated in terms of two parameters.
One of these parameters depends upon the relative order
of magnitude of the viscous and inertia forces at the outer edge of the
boundary layer and the other depends upon the order of vorticity allowable
at the outer edge of the
boundary layer. The transition phenomenon in
boundary flow is treated as an
asymptotic phenomenon from the
boundary layer. In order to study
the transition region, a limiting form of the Navier-Stokes equations
in three dimensions is obtained, which is called the transition equation.
Owing to the importance of vorticity in the transition region,
the transition equation is solved for the vorticity. The form of vorticity
shows that in general the functions which govern the transition
region are either subharmonic or superharmonic functions.
In classical…
Advisors/Committee Members: Narasimhan, M. N. L. (advisor).
Subjects/Keywords: Boundary layer
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APA ·
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Manager
APA (6th Edition):
Bakhshi, V. S. (1968). Boundary layer transition. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/17210
Chicago Manual of Style (16th Edition):
Bakhshi, Vidya Sagar. “Boundary layer transition.” 1968. Doctoral Dissertation, Oregon State University. Accessed January 23, 2021.
http://hdl.handle.net/1957/17210.
MLA Handbook (7th Edition):
Bakhshi, Vidya Sagar. “Boundary layer transition.” 1968. Web. 23 Jan 2021.
Vancouver:
Bakhshi VS. Boundary layer transition. [Internet] [Doctoral dissertation]. Oregon State University; 1968. [cited 2021 Jan 23].
Available from: http://hdl.handle.net/1957/17210.
Council of Science Editors:
Bakhshi VS. Boundary layer transition. [Doctoral Dissertation]. Oregon State University; 1968. Available from: http://hdl.handle.net/1957/17210
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