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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Network-Based Naval Ship Distributed System Design and Mission Effectiveness using Dynamic Architecture Flow Optimization

Parsons, Mark Allen 16 July 2021 (has links)
This dissertation describes the development and application of a naval ship distributed system architectural framework, Architecture Flow Optimization (AFO), and Dynamic Architecture Flow Optimization (DAFO) to naval ship Concept and Requirements Exploration (CandRE). The architectural framework decomposes naval ship distributed systems into physical, logical, and operational architectures representing the spatial, functional, and temporal relationships of distributed systems respectively. This decomposition greatly simplifies the Mission, Power, and Energy System (MPES) design process for use in CandRE. AFO and DAFO are a network-based linear programming optimization methods used to design and analyze MPES at a sufficient level of detail to understand system energy flow, define MPES architecture and sizing, model operations, reduce system vulnerability and improve system reliability. AFO incorporates system topologies, energy coefficient component models, preliminary arrangements, and (nominal and damaged) steady state scenarios to minimize the energy flow cost required to satisfy all operational scenario demands and constraints. DAFO applies the same principles as AFO and adds a second commodity, data flow. DAFO also integrates with a warfighting model, operational model, and capabilities model that quantify tasks and capabilities through system measures of performance at specific capability nodes. This enables the simulation of operational situations including MPES configuration and operation during CandRE. This dissertation provides an overview of design tools developed to implement this process and methods, including objective attribute metrics for cost, effectiveness and risk, ship synthesis model, hullform exploration and MPES explorations using design of experiments (DOEs) and response surface models. / Doctor of Philosophy / This dissertation describes the development and application of a warship system architectural framework, Architecture Flow Optimization (AFO), and Dynamic Architecture Flow Optimization (DAFO) to warship Concept and Requirements Exploration (CandRE). The architectural framework decomposes warship systems into physical, logical, and operational architectures representing the spatial, functional, and time-based relationships of systems respectively. This decomposition greatly simplifies the Mission, Power, and Energy System (MPES) design process for use in CandRE. AFO and DAFO are a network-based linear programming optimization methods used to design and analyze MPES at a sufficient level of detail to understand system energy usage, define MPES connections and sizing, model operations, reduce system vulnerability and improve system reliability. AFO incorporates system templates, simple physics and energy-based component models, preliminary arrangements, and simple undamaged/damaged scenarios to minimize the energy flow usage required to satisfy all operational scenario demands and constraints. DAFO applies the same principles and adds a second commodity, data flow representing system operation. DAFO also integrates with a warfighting model, operational model, and capabilities model that quantify tasks and capabilities through system measures of performance. This enables the simulation of operational situations including MPES configuration and operation during CandRE. This dissertation provides an overview of design tools developed to implement this process and methods, including optimization objective attribute metrics for cost, effectiveness and risk.
2

Framework for robust design: a forecast environment using intelligent discrete event simulation

Beisecker, Elise K. 29 March 2012 (has links)
The US Navy is shifting to power projection from the sea which stresses the capabilities of its current fleet and exposes a need for a new surface connector. The design of complex systems in the presence of changing requirements, rapidly evolving technologies, and operational uncertainty continues to be a challenge. Furthermore, the design of future naval platforms must take into account the interoperability of a variety of heterogeneous systems and their role in a larger system-of-systems context. To date, methodologies to address these complex interactions and optimize the system at the macro-level have lacked a clear direction and structure and have largely been conducted in an ad-hoc fashion. Traditional optimization has centered around individual vehicles with little regard for the impact on the overall system. A key enabler in designing a future connector is the ability to rapidly analyze technologies and perform trade studies using a system-of-systems level approach. The objective of this work is a process that can quantitatively assess the impacts of new capabilities and vessels at the systems-of-systems level. This new methodology must be able to investigate diverse, disruptive technologies acting on multiple elements within the system-of-systems architecture. Illustrated through a test case for a Medium Exploratory Connector (MEC), the method must be capable of capturing the complex interactions between elements and the architecture and must be able to assess the impacts of new systems). Following a review of current methods, six gaps were identified, including the need to break the problem into subproblems in order to incorporate a heterogeneous, interacting fleet, dynamic loading, and dynamic routing. For the robust selection of design requirements, analysis must be performed across multiple scenarios, which requires the method to include parametric scenario definition. The identified gaps are investigated and methods recommended to address these gaps to enable overall operational analysis across scenarios. Scenarios are fully defined by a scheduled set of demands, distances between locations, and physical characteristics that can be treated as input variables. Introducing matrix manipulation into discrete event simulations enables the abstraction of sub-processes at an object level and reduces the effort required to integrate new assets. Incorporating these linear algebra principles enables resource management for individual elements and abstraction of decision processes. Although the run time is slightly greater than traditional if-then formulations, the gain in data handling abilities enables the abstraction of loading and routing algorithms. The loading and routing problems are abstracted and solution options are developed and compared. Realistic loading of vessels and other assets is needed to capture the cargo delivery capability of the modeled mission. The dynamic loading algorithm is based on the traditional knapsack formulation where a linear program is formulated using the lift and area of the connector as constraints. The schedule of demands from the scenarios represents additional constraints and the reward equation. Cargo available is distributed between cargo sources thus an assignment problem formulation is added to the linear program, requiring the cargo selected to load on a single connector to be available from a single load point. Dynamic routing allows a reconfigurable supply chain to maintain a robust and flexible operation in response to changing customer demands and operating environment. Algorithms based on vehicle routing and computer packet routing are compared across five operational scenarios, testing the algorithms ability to route connectors without introducing additional wait time. Predicting the wait times of interfaces based on connectors en route and incorporating reconsideration of interface to use upon arrival performed consistently, especially when stochastic load times are introduced, is expandable to a large scale application. This algorithm selects the quickest load-unload location pairing based on the connectors routed to those locations and the interfaces selected for those connectors. A future connector could have the ability to unload at multiple locations if a single load exceeds the demand at an unload location. The capability for multiple unload locations is considered a special case in the calculation of the unload location in the routing. To determine the unload location to visit, a traveling salesman formulation is added to the dynamic loading algorithm. Using the cost to travel and unload at locations balanced against the additional cargo that could be delivered, the order and locations to visit are selected. Predicting the workload at load and unload locations to route vessels with reconsideration to handle disturbances can include multiple unload locations and creates a robust and flexible routing algorithm. The incorporation of matrix manipulation, dynamic loading, and dynamic routing enables the robust investigation of the design requirements for a new connector. The robust process will use shortfall, capturing the delay and lack of cargo delivered, and fuel usage as measures of performance. The design parameters for the MEC, including the number available and vessel characteristics such as speed and size were analyzed across four ways of testing the noise space. The four testing methods are: a single scenario, a selected number of scenarios, full coverage of the noise space, and feasible noise space. The feasible noise space is defined using uncertainty around scenarios of interest. The number available, maximum lift, maximum area, and SES speed were consistently design drivers. There was a trade-off in the number available and size along with speed. When looking at the feasible space, the relationship between size and number available was strong enough to reverse the number available, to desiring fewer and larger ships. The secondary design impacts come from factors that directly impacted the time per trip, such as the time between repairs and time to repair. As the noise sampling moved from four scenario to full coverage to feasible space, the option to use interfaces were replaced with the time to load at these locations and the time to unload at the beach gained importance. The change in impact can be attributed to the reduction in the number of needed trips with the feasible space. The four scenarios had higher average demand than the feasible space sampling, leading to loading options being more important. The selection of the noise sampling had an impact of the design requirements selected for the MEC, indicating the importance of developing a method to investigate the future Naval assets across multiple scenarios at a system-of-systems level.
3

Architecture Flow Optimization - Refinement and Application for Naval Ship Concept Design

Bonsall, Jaxson Todd 31 May 2024 (has links)
This thesis describes the refinement of an Architecture Flow Optimization (AFO) tool for naval surface ship design, specifically focusing on the development of new network and matrix-based methods for AFO formulation and their application in Concept Development. The AFO tool analyzes and optimizes the flow of energy through the ship's Vital Components (VCs) interfacing with a Ship Synthesis and Product Model (SSM), ensuring that all physical and operational constraints are satisfied while minimizing system cost across multiple intact and damaged operational scenarios. The total ship system is described by physical and logical architectures in a network structure comprised of vital component nodes and arcs. These elements form the basis of a linear system of equations in matrix form, the manipulation of which relies heavily on linear algebra and matrix operations. The matrix system of equations is solved using linear programming with a significant improvement in computational efficiency. The solution supports the sizing of individual vital components and the refinement of system logical architecture. It also provides the basic AFO engine necessary to support future refinement of a dynamic architecture flow optimization (DAFO) with the computational speed necessary for rapid solution of dynamic mission scenarios insuring optimized and feasible warfighting reconfiguration, with and without damage. / Master of Science / This thesis describes the refinement of an Architecture Flow Optimization (AFO) tool for naval surface ship design, specifically focusing on the development of new network and matrix-based methods for AFO formulation and their application in naval ship Concept Development processes. The Architecture Flow Optimization tool analyzes and optimizes the flow of energy through the ship's Vital Components (VCs). The AFO tool completes this task by interfacing with a Ship Synthesis and Product Model (SSM), ensuring that all of the ship's physical and operational constraints are satisfied. This is done while minimizing the ship system cost across multiple intact and damaged operational scenarios. The total ship system is described by physical and logical architectures in a network structure comprised of vital components (nodes) and their connections (arcs). These elements form the basis of a linear system of equations in matrix form, the manipulation of which relies heavily on linear algebra and matrix operations. The matrix system of equations is solved using a linear programming algorithm with a significant improvement in computational speed. The solution provided from the optimization supports the sizing of individual vital components and the refinement of the ship system logical architecture. It also provides the basic AFO engine necessary to support future refinement of a dynamic architecture flow optimization (DAFO) with the computational speed necessary for rapid solution of dynamic mission scenarios insuring optimized and feasible warfighting reconfiguration, with and without damage.
4

Development and Application of Dynamic Architecture Flow Optimization to Assess the Impact of Energy Storage on Naval Ship Mission Effectiveness, System Vulnerability and Recoverability

Kara, Mustafa Yasin 20 May 2022 (has links)
This dissertation presents the development and application of a naval ship distributed system architecture framework, Architecture Flow Optimization (AFO), Dynamic Architecture Flow Optimization (DAFO), and Energy Storage System (ESS) model in naval ship Concept and Requirements Exploration (CandRE). The particular objective of this dissertation is to determine and assess Energy Storage System (ESS) capacity, charging and discharging capabilities in a complex naval ship system of systems to minimize vulnerability and maximize recoverability and effectiveness. The architecture framework is implemented through integrated Ship Behavior Interaction Models (SBIMs) that include the following: Warfighting Model (WM), Ship Operational Model (OM), Capability Model (CM), and Dynamic Architecture Flow Optimization (DAFO). These models provide a critical interface between logical, physical, and operational architectures, quantifying warfighting and propulsion capabilities through system measures of performance at specific capability nodes. This decomposition greatly simplifies the Mission, Power, and Energy System (MPES) design process for use in CandRE. AFO and DAFO are network-based, linear programming optimization methods used to design and analyze MPESs at a sufficient level of detail to understand system energy flow, define MPES architecture and sizing, model operations, reduce system vulnerability and improve system effectiveness and recoverability with ESS capabilities. AFO incorporates system topologies, energy coefficient component models, preliminary arrangements, and (nominal and damaged) steady state scenarios to minimize the energy flow cost required to satisfy all operational scenario demands and constraints. The refined DAFO applies the same principles as AFO, but adds two more capabilities, Propulsion and ESS charging, and maximizes effectiveness at each scenario timestep. DAFO also integrates with a warfighting model, operational model, and capabilities model that quantify the performance of tasks enabled by capabilities through system measures of performance at specific capability nodes. This dissertation provides a description of the design tools developed to implement these processes and methods, including a ship synthesis model, hullform exploration, MPES explorations and objective attribute metrics for cost, effectiveness and risk, using design of experiments (DOEs) response surface models (RSMs) and Energy Storage System (ESS) applications. / Doctor of Philosophy / This dissertation presents the development and application of a naval ship distributed system architecture framework, Architecture Flow Optimization (AFO), Dynamic Architecture Flow Optimization (DAFO), and Energy Storage System (ESS) design in naval ship Concept and Requirements Exploration (CandRE). The particular objective of this dissertation is to determine and assess Energy Storage System (ESS) capacity, charging and discharging capabilities in a complex naval ship system of systems to minimize vulnerability and maximize recoverability and effectiveness. The architecture framework is implemented through integrated Ship Behavior Interaction Models (SBIMs) that include the following: Warfighting Model (WM), Ship Operational Model (OM), Capability Model (CM), and Dynamic Architecture Flow Optimization (DAFO). These models provide a critical interface between logical, physical, and operational architectures, quantifying warfighting and propulsion capabilities through system measures of performance at specific capability nodes. This decomposition greatly simplifies the Mission, Power, and Energy System (MPES) design process for use in CandRE. AFO and DAFO are network-based, linear programming optimization methods used to design and analyze MPESs at a sufficient level of detail to understand system energy flow, define MPES architecture and sizing, model operations, reduce system vulnerability and improve system effectiveness and recoverability with ESS capabilities. AFO incorporates system topologies, energy coefficient component models, preliminary arrangements, and (nominal and damaged) steady state scenarios to minimize the energy flow cost required to satisfy all operational scenario demands and constraints. DAFO applies the same principles as AFO, but adds two more capabilities, Propulsion and ESS charging, and maximizes effectiveness at each scenario timestep. DAFO also integrates with a warfighting model, operational model, and capabilities model that quantify the performance of tasks enabled by capabilities through system measures of performance at specific capability nodes. This dissertation provides an overview of the design tools developed to implement these process and methods, including a ship synthesis model, hullform exploration, MPES explorations and objective attribute metrics for cost, effectiveness and risk, using design of experiments (DOEs) response surface models (RSMs) and Energy Storage System (ESS) applications.
5

A Study on the Integration of Multivariate MetOcean, Ocean Circulation, and Trajectory Modeling Data with Static Geographic Information Systems for Better Marine Resources Management and Protection During Coastal Oil Spill Response – A Case Study and Gap Analysis on Northeastern Gulf of Mexico Tidal Inlets

Knudsen, Richard Ray 06 November 2015 (has links)
The Oil Pollution Act of 1990 requires the development of Regional and Area Contingency Plans. For more than 20 years, the State of Florida, under both the Department of Environmental Protection and the Florida Fish and Wildlife Commission, has worked closely with the U.S. Coast Guard and the National Oceanic and Atmospheric Administration to develop these plans for coastal and marine oil spill response. Current plans, developed with local, state and federal stakeholder input, use geographic information systems (GIS) data such as location and extent of sensitive ecological, wildlife, and human-use features (termed Environmental Sensitivity Index data), pre-defined protection priorities, and spatially explicit protection strategies to support decision-making by responders (termed Geographic Response Plans). However, they are long overdue for improvements that incorporate modern oceanographic modeling techniques and integrated data from coastal ocean observing systems. Better understanding of circulation in nearshore and estuarine waters, at a scale consistent with other spatial data, is especially lacking in Area Contingency Plans. This paper identifies the gaps in readily available information on the circulation-driven causes and effects missing in current oil spill contingency planning and describes a sample methodology whereby multiple coastal and ocean spatial science disciplines are used to answer questions that no single, non-integrated discipline can answer by itself. A path forward for further integration and development of more comprehensive plans to better support coastal protection in Florida is proposed. The advances made here are applicable to other coastal regions of the world.

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