Theses/Dissertations
http://hdl.handle.net/11141/2868
Sat, 29 Feb 2020 06:45:36 GMT
20200229T06:45:36Z

Design of an Environmentally Responsive Grooming Tool to Aid in Underwater Navigation
http://hdl.handle.net/11141/3066
Design of an Environmentally Responsive Grooming Tool to Aid in Underwater Navigation
Walker, Bruce Huntress
Underwater hull grooming is a proactive approach to ship hull husbandry. It has been
defined as the frequent and gentle wiping of a ship hull coating to maintain it free of fouling.
One of the challenges to implementing a grooming schedule is the control and navigation of
the devices over the surface of the hull. This thesis presents prior research that has developed
selfattaching rotating brushes as an effective method to groom fouling control coatings and
the results from several years of implementation in the marine environment. The hypothesis
of this thesis is that the condition of the ship hull surface can be interpreted by monitoring the
current draw of the grooming tool and that this information can be used to aid in navigation.
The present grooming tool design comprises five selfattaching rotating brushes that maintain
constant RPM by regulating current through a control system which monitors the back EMF
of a brushless DC motor. Experiments were performed to investigate the relationship between
current draw and surface condition by operating the grooming tool on artificial roughnessâ€™s
and fouling control coatings with known levels of biofouling. The results demonstrated that
coating type, coating roughness and biofouling type all contributed to the current draw by the
brush motor. This knowledge may be used to help locate the grooming device when
operating in a lawn mower type pattern.
Thesis (M.S.)  Florida Institute of Technology, 2020.
Fri, 01 May 2020 00:00:00 GMT
http://hdl.handle.net/11141/3066
20200501T00:00:00Z

Optimal Control of the Second Order Elliptic Equations with Biomedical Applications
http://hdl.handle.net/11141/3065
Optimal Control of the Second Order Elliptic Equations with Biomedical Applications
Seif, Saleheh
Dissertation analyzes optimal control of systems with distributed parameters described
by the general boundary value problems in a bounded Lipschitz domain for the linear
second order uniformly elliptic partial differential equations (PDE) with bounded measurable coefficients. Broad class of elliptic optimal control problems under Dirichlet or
Neumann boundary conditions are considered, where the control parameter is the density of sources, and the cost functional is the L2norm difference of the weak solution
of the elliptic problem from measurement along the boundary or subdomain. The optimal control problems are fully discretized using the method of finite differences. Two
types of discretization of the elliptic boundary value problem depending on Dirichlet
or Neumann type boundary condition are introduced. Convergence of the sequence of
finitedimensional discrete optimal control problems both with respect to the cost functional and the control is proved. The methods of the proof are based on energy estimates
in discrete Sobolev spaces, LaxMilgram theory, weak compactness and convergence of
interpolations of solutions of discrete elliptic problems, and delicate estimation of the
cost functional along the sequence of interpolations of the minimizers for the discrete
optimal control problems. Dissertation pursues application of the optimal control theory
of elliptic systems with distributed parameters to biomedical problem on the identification of cancerous tumor. The Inverse Electrical Impedance Tomography (EIT) problem on recovering electrical conductivity tensor and potential in the body based on the measurement of the boundary voltages on the m electrodes for a given electrode current is
analyzed. A PDE constrained optimal control framework in Besov space is developed,
where the electrical conductivity tensor and boundary voltages are control parameters,
and the cost functional is the norm difference of the boundary electrode current from the
given current pattern and boundary electrode voltages from the measurements. The state
vector is a solution of the second order elliptic PDE in divergence form with bounded
measurable coefficients under mixed Neumann/Robin type boundary condition. The
novelty of the control theoretic model is its adaptation to clinical situation when additional "voltagetocurrent" measurements can increase the size of the input data from
m up to m! while keeping the size of the unknown parameters fixed. Existence of
the optimal control is established. FrĂ©chet differentiability in the BanachBesov spaces
framework is proved and the formula for the Frechet gradient expressed in terms of the
adjoined state vector is derived. Optimality condition is formulated, and gradient type
iterative algorithm in HilbertBesov spaces setting is developed. EIT optimal control
problem is fully discretized using the method of finite differences. New SobolevHilbert
space is introduced, and the convergence of the sequence of finitedimensional optimal
control problems to EIT coefficient optimal control problem is proved both with respect
to functional and control in 2 and 3dimensional domains.
Thesis (Ph.D.)  Florida Institute of Technology, 2020.
Fri, 01 May 2020 00:00:00 GMT
http://hdl.handle.net/11141/3065
20200501T00:00:00Z

Development of Plane Rotating Traction System: Based on the Highspeed Rail (72+128+72) m Continuous Prestressed Concrete Beam Bridge
http://hdl.handle.net/11141/3064
Development of Plane Rotating Traction System: Based on the Highspeed Rail (72+128+72) m Continuous Prestressed Concrete Beam Bridge
Wang, Weinan
With the advent of rotate construction techniques, it is easy to build a new bridge
crossing over existing structures, rivers and valleys quickly, easily and safely. Although the
general concept of the rotating method is similar for different engineering characteristics,
it is necessary to make some changes, which are more in line with the requirements of the
particular project.
Based on a 3spans (72+128+72)m continuous concrete bridge, this paper presents a
new rotation method, the downslideway unbalanced rotation system, which can save time
and reduce cost compared to the upslideway rotation method. Through the improvements
of the traction system and the travel system, the rotation construction period and costeffectively saved, yet the construction quality is still guaranteed. The construction
technology of this new method will also reduce construction risks and simplify the process.
Thesis (M.S.)  Florida Institute of Technology, 2020.
Fri, 01 May 2020 00:00:00 GMT
http://hdl.handle.net/11141/3064
20200501T00:00:00Z

Applying Formal Methods for Integrating Advanced Algorithms in Safety Critical Systems
http://hdl.handle.net/11141/3063
Applying Formal Methods for Integrating Advanced Algorithms in Safety Critical Systems
Stafford, Milton
In software engineering it is essential that updates are deployed for continual improvement. While software updates bring new functionality, updates also may
introduce instability. This leads to failures of various kinds. This is especially
problematic in safetycritical systems where there is a potential for injury or loss
of life. However, newer and more sophisticated software carries potential advantages, including higher performance and reliability. Therefore, there are benefits
in adopting newer software if the integration process is assured. In this thesis, I
present a framework for assured integration; one that links requirements, design,
and implementation. The proposed framework includes a new design approach and
new software design tools. The approach calls for an embedded decisionmaking
architecture in an autonomous system which contains constrained variants of the
desired complex software. The modules are subject to an authoritative module
that observes their behavior. Constrained modules are developed by creating verified formal models from underlying component requirements. Those models are
used to generate runtime validation code that detects requirement failures.
Thesis (M.S.)  Florida Institute of Technology, 2019.
Sun, 01 Dec 2019 00:00:00 GMT
http://hdl.handle.net/11141/3063
20191201T00:00:00Z