Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

2019

Uncertainty

Discipline
Institution
Publication
Publication Type
File Type

Articles 1 - 20 of 20

Full-Text Articles in Engineering

Modeling Of Multicomponent Rectification Under Uncertainty, Nodirbek Rustambekovich Yusupbekov, Djalol Patxiddinovich Mukhitdinov, Yorkin Bakhodirovich Kadirov Dec 2019

Modeling Of Multicomponent Rectification Under Uncertainty, Nodirbek Rustambekovich Yusupbekov, Djalol Patxiddinovich Mukhitdinov, Yorkin Bakhodirovich Kadirov

Chemical Technology, Control and Management

This paper presents a complete computer model for an industrial distillation column, which considers the input, output and model (nonlinearity and high-frequency dynamics of the process) uncertainties. The proposed model has a great advantage of covering the entire working range of the distillation column. This model can be used as a main tool for the analysis and synthesis of distillation process control systems.


Uncertainty And Error In Combat Modeling, Simulation, And Analysis, Jason A. Blake Dec 2019

Uncertainty And Error In Combat Modeling, Simulation, And Analysis, Jason A. Blake

Theses and Dissertations

Due to the infrequent and competitive nature of combat, several challenges present themselves when developing a predictive simulation. First, there is limited data with which to validate such analysis tools. Secondly, there are many aspects of combat modeling that are highly uncertain and not knowable. This research develops a comprehensive set of techniques for the treatment of uncertainty and error in combat modeling and simulation analysis. First, Evidence Theory is demonstrated as a framework for representing epistemic uncertainty in combat modeling output. Next, a novel method for sensitivity analysis of uncertainty in Evidence Theory is developed. This sensitivity analysis method ...


A Collaborative Visual Localization Scheme For A Low-Cost Heterogeneous Robotic Team With Non-Overlapping Perspectives, Benjamin Abruzzo, David Cappelleri, Philippos Mordohai Nov 2019

A Collaborative Visual Localization Scheme For A Low-Cost Heterogeneous Robotic Team With Non-Overlapping Perspectives, Benjamin Abruzzo, David Cappelleri, Philippos Mordohai

West Point Research Papers

This paper presents and evaluates a relative localization scheme for a heterogeneous team of low-cost mobile robots. An error-state, complementary Kalman Filter was developed to fuse analytically-derived uncertainty of stereoscopic pose measurements of an aerial robot, made by a ground robot, with the inertial/visual proprioceptive measurements of both robots. Results show that the sources of error, image quantization, asynchronous sensors, and a non-stationary bias, were sufficiently modeled to estimate the pose of the aerial robot. In both simulation and experiments, we demonstrate the proposed methodology with a heterogeneous robot team, consisting of a UAV and a UGV tasked with ...


Groundwater Management Optimization And Saltwater Intrusion Mitigation Under Uncertainty, Jina Yin Sep 2019

Groundwater Management Optimization And Saltwater Intrusion Mitigation Under Uncertainty, Jina Yin

LSU Doctoral Dissertations

Groundwater is valuable to supply fresh water to the public, industries, agriculture, etc. However, excessive pumping has caused groundwater storage degradation, water quality deterioration and saltwater intrusion problems. Reliable groundwater flow and solute transport modeling is needed for sustainable groundwater management and aquifer remediation design. However, challenges exist because of highly complex subsurface environments, computationally intensive groundwater models as well as inevitable uncertainties. The first research goal is to explore conjunctive use of feasible hydraulic control approaches for groundwater management and aquifer remediation. Water budget analysis is conducted to understand how groundwater withdrawals affect water levels. A mixed integer multi-objective ...


A Novel Ruminant Emission Measurement System: Part Ii. Commissioning, Guilherme D. N. Maia, Brett C. Ramirez, Angela R. Green, Yi Sun, Luis F. Rodríguez, Daniel W. Shike, Richard S. Gates Aug 2019

A Novel Ruminant Emission Measurement System: Part Ii. Commissioning, Guilherme D. N. Maia, Brett C. Ramirez, Angela R. Green, Yi Sun, Luis F. Rodríguez, Daniel W. Shike, Richard S. Gates

Brett Ramirez

The Ruminant Emission Measurement System (REMS) supports research on the relationships between bovine nutrition, genetics, and management strategies by measuring eructated CH4 emissions from ruminal activity. Part I of this series provides the description and design evaluation of the newly developed REMS using uncertainty analysis tools. Part II of this series describes REMS commissioning and documents the whole system and subsystem performance. Subsystem assessments included verification of chamber positive pressurization, thermal environmental control performance, and integrity of the gas sampling system. Integrity of the entire system was verified through a steady-state mass recovery percent (SSMRP) analysis, which compared the ...


A Novel Ruminant Emission Measurement System: Part I. Design Evaluation And Description, Guilherme D. N. Maia, Brett C. Ramirez, Angela R. Green, Luis F. Rodríguez, Jacob R. Segers, Daniel W. Shike, Richard S. Gates Aug 2019

A Novel Ruminant Emission Measurement System: Part I. Design Evaluation And Description, Guilherme D. N. Maia, Brett C. Ramirez, Angela R. Green, Luis F. Rodríguez, Jacob R. Segers, Daniel W. Shike, Richard S. Gates

Brett Ramirez

Methane (CH4) generated by cattle is both a major source of greenhouse gas emissions and a powerful indicator of feed conversion efficiency; thus, accurate quantification of CH4 production is required for addressing future global food security without neglecting environmental impacts. A newly developed Ruminant Emission Measurement System (REMS) supports research on the relationships between bovine nutrition, genetics, and management strategies by measuring eructated CH4 emissions from ruminal activity. REMS is a substantial improvement and extension of the chamber technique, which is considered the standard method to quantify ruminant CH4 generation. Part I of this two-part series describes the design and ...


Engineering Valuation Of Blockchain Technology In The Context Of Petroleum Supply Chain: A Real Options Approach, Farshad Niayeshpour Jan 2019

Engineering Valuation Of Blockchain Technology In The Context Of Petroleum Supply Chain: A Real Options Approach, Farshad Niayeshpour

Graduate Theses and Dissertations

In this paper, we mathematically model and analyze occurrence of trade disputes in the context of a petroleum supply chain network which includes a seller, a buyer and an arbitrator. We study how switching from conventional trading system to a blockchain-based system could help decrease the number of disputes while maintaining the profitability of trading. Specifically, we determine what is the optimal timing to switch to blockchain technology through arbitrator’s perspective under petroleum price uncertainty. The way blockchain technology aids trade irrefutability is to provide a secure and immutable distributed ledger which ensures each trade is recorded and timestamped ...


Modeling Cascading Failures In Power Systems In The Presence Of Uncertain Wind Generation, Mir Hadi Athari Jan 2019

Modeling Cascading Failures In Power Systems In The Presence Of Uncertain Wind Generation, Mir Hadi Athari

Theses and Dissertations

One of the biggest threats to the power systems as critical infrastructures is large-scale blackouts resulting from cascading failures (CF) in the grid. The ongoing shift in energy portfolio due to ever-increasing penetration of renewable energy sources (RES) may drive the electric grid closer to its operational limits and introduce a large amount of uncertainty coming from their stochastic nature. One worrisome change is the increase in CFs.

The CF simulation models in the literature do not allow consideration of RES penetration in studying the grid vulnerability. In this dissertation, we have developed tools and models to evaluate the impact ...


First Approach To Coupling Of Numerical Lifting-Line Theory And Linear Covariance Analysis For Uav State Uncertainty Propagation, Cory D. Goates, Randall S. Christensen, Robert Leishman Jan 2019

First Approach To Coupling Of Numerical Lifting-Line Theory And Linear Covariance Analysis For Uav State Uncertainty Propagation, Cory D. Goates, Randall S. Christensen, Robert Leishman

Faculty Publications

Numerical lifting-line is a computationally efficient method for calculating aerodynamic forces and moments on aircraft. However, its potential has yet to be tapped for use in guidance, navigation, and control (GN&C). Linear covariance analysis is becoming a popular GN&C design tool and shows promise for pairing with numerical lifting-line. Pairing numerical lifting-line with linear covariance analysis allows for forward propagation of state uncertainty for real-time decision making. We demonstrate this for select state variables in a drone aerial recapture situation. Linear covariance analysis uses finite difference derivatives obtained from numerical lifting-line to calculate force and moment variances. These ...


Life Cycle Cost Evaluation Strategy For High Performance Control Systems Under Uncertainties, Laura Micheli, Ling Cao, Simon Laflamme, Alice Alipour Jan 2019

Life Cycle Cost Evaluation Strategy For High Performance Control Systems Under Uncertainties, Laura Micheli, Ling Cao, Simon Laflamme, Alice Alipour

Civil, Construction and Environmental Engineering Publications

High-performance control systems (HPCSs), including active, hybrid, and semi-active control strategies, can perform over a wide excitation bandwidth and are therefore good candidates for multi-hazard mitigation. However, the number of HPCS applications in the field is very limited. This is likely due the perceived high costs of installation, maintenance, possible malfunction, and lack of tools to financially justify their implementation. Such financial justifications could be conducted through life cycle cost (LCC) analysis, but would result in a computationally demanding task due to the very large number of simulations required given the large number of uncertainties. In this paper, two sets ...


Short-Term Operation Of The Power System And The Natural Gas System Considering Uncertainties, Dan Hu Jan 2019

Short-Term Operation Of The Power System And The Natural Gas System Considering Uncertainties, Dan Hu

Graduate Theses and Dissertations

Electricity generation increasingly relies on natural gas for fuel. The competing demands for gas by natural gas-fueled generators and other users, the differences in the timing of short-term operations and markets between the natural gas system and the power system, and the deepening penetration of variable renewable energy in the power system cause difficulties in operating the two systems economically and reliably. This dissertation consists of three papers which present different models and methods for the short-term operation of the natural gas and power systems considering different sources of uncertainty.

From the viewpoint of a centralized system operator, who can ...


Propagation Of Uncertainty Through Coning, Sculling, And Scrolling Corrections For Inertial Navigation, James Daniel Alan Brouk Jan 2019

Propagation Of Uncertainty Through Coning, Sculling, And Scrolling Corrections For Inertial Navigation, James Daniel Alan Brouk

Masters Theses

"This thesis investigates the propagation of estimation errors through generalized coning, sculling, and scrolling algorithms used in modern day inertial navigation systems, in order to accurately quantify the uncertainty in the estimation of position, velocity, and attitude. The corrections for coning, sculling, and scrolling algorithms have an often unaccounted for effect on documented and empirically derived error statistics for measurements used to predict the uncertainty in a vehicle's position, velocity, and attitude estimates. Through the development of an error analysis for these generalized algorithms, mappings of the measurement and estimation errors through the correction termare generated. Using the developed ...


Guest Editorial Special Issue On Using Enquiry-And-Design-Based Learning To Spur Epistemological And Identity Development Of Engineering Students, Shannon Chance, Bill Williams, Tom Goldfinch, Robin S. Adams, Lorraine N. Fleming Jan 2019

Guest Editorial Special Issue On Using Enquiry-And-Design-Based Learning To Spur Epistemological And Identity Development Of Engineering Students, Shannon Chance, Bill Williams, Tom Goldfinch, Robin S. Adams, Lorraine N. Fleming

Articles

This Special Issue of the IEEE Transactions on Education focuses on using enquiry-based design projects to spur engineering students’ development, so as to increase understanding and application of the relevant theories, foster higher rates of student development and achieve this in healthy and productive ways.


Study On The Performance Of Distributed Energy Systems Based On Historical Loads Considering Parameter Uncertainties For Decision Making., Chong Zhang, Xue Xue, Qianzhou Du, Yimo Luo, Wenjie Gang Jan 2019

Study On The Performance Of Distributed Energy Systems Based On Historical Loads Considering Parameter Uncertainties For Decision Making., Chong Zhang, Xue Xue, Qianzhou Du, Yimo Luo, Wenjie Gang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Distributed energy systems (DESs) are becoming increasingly popular because of their high-energy efficiency and low pollution emissions. Accurate performance evaluation of such systems is critical for processes at the early design stages. However, there are considerable uncertainties in terms of the parameters used for performance evaluation and design optimization, including component efficiencies, customer demands, and energy markets. These uncertainties can significantly influence the performance of DESs. Without consideration of these uncertainties, the performance of DESs can be overestimated or underestimated, which leads to inaccurate decision-making. Therefore, this paper presents a comprehensive evaluation of the performance of DESs by considering uncertainties ...


Time-Dependent Reliability Methodologies With Saddlepoint Approximation, Zhangli Hu Jan 2019

Time-Dependent Reliability Methodologies With Saddlepoint Approximation, Zhangli Hu

Doctoral Dissertations

"Engineers always encounter time-dependent uncertainties that ubiquitously exist, such as the random deterioration of material properties and time-variant loads. Therefore the reliability of engineering systems becomes time-dependent. It is crucial to predict the time-dependent reliability in the design stage, given possible catastrophic consequences of a failure. Although extensive research has been conducted on reliability analysis, estimating the reliability accurately and efficiently is still challenging. The objective of this work is to develop accurate and efficient reliability methodologies for engineering design. The basic idea is the integration of traditional reliability methods with saddlepoint approximation (SPA), which can accurately approximate the tail ...


Effects Of Uncertainty Refinement On Satellite Collision Probability, Bruce Thomas Morrison Jan 2019

Effects Of Uncertainty Refinement On Satellite Collision Probability, Bruce Thomas Morrison

Masters Theses

"Due to the drastic increase in orbital debris about the Earth, the likelihood for new and current mission satellites to collide with other objects grows. When a mission satellite is placed in a highly populated orbit in the vicinity of other satellites or debris, it is necessary to consider the probability of collision to assess any possible conjunctions. The computation of the collision probability is heavily dependent on the relative position and velocity of the objects during conjunction, as well as the combined covariance. There are two main types of analytic collision probability computations; the first assumes that the objects ...


Forecast Model For Return Quality In Reverse Logistics Networks, Aamira Mohammed Ashraf Jan 2019

Forecast Model For Return Quality In Reverse Logistics Networks, Aamira Mohammed Ashraf

Electronic Theses and Dissertations

Giving rise to the field of reverse logistics are the governmental legislations mandating used electronics take-backs and sustainable recovery, which often burden manufacturers with the challenge of high implementation costs but no guaranteed profitability. One way to tackle this challenge is to demystify the multi-faceted uncertainties of product returns, namely timing, quantity and quality, that currently inhibit optimal design and operations of reverse logistics networks (RLN). In recognition of the limitations particularly caused by uncertainty of returns’ quality in the strategic, tactical and operational planning of the RLN, this research seeks to develop a forecast model for the prediction of ...


Assessing The Influence Of Manufacturing Flexibility On Facility Construction Costs, S. Gregory, A. Bastias, K. R. Molenaar, K. Madson, B. Franz, Leslie Potter, Gül E. Okudan Kremer Jan 2019

Assessing The Influence Of Manufacturing Flexibility On Facility Construction Costs, S. Gregory, A. Bastias, K. R. Molenaar, K. Madson, B. Franz, Leslie Potter, Gül E. Okudan Kremer

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

Uncertainty in product development and market demand can affect facility design and construction. Adding flexibility in manufacturing processes can mitigate this uncertainty, but can also create costly solutions. This is particularly true when manufacturing facilities have long design and construction lead times. In these cases, manufacturers take risks by starting facility construction before the product development is complete to meet time-to-market needs. Similarly, uncertain market demand can create the need to build facilities with additional volume or the ability to expand. This paper presents an analysis of how manufacturing flexibility affects building system costs and proposes a solution for understanding ...


On The Stability Analysis Of Linear Continuous-Time Distributed Systems, Mohammad Shekaramiz Jan 2019

On The Stability Analysis Of Linear Continuous-Time Distributed Systems, Mohammad Shekaramiz

Electrical and Computer Engineering Faculty Publications

This paper discusses the stability problem of linear continuous-time distributed systems. When dealing with large-scale systems, usually there is not thorough knowledge of the interconnection models between different parts of the entire system. In this case, a useful stability analysis method should be able to deal with high dimensional systems accompanied with bounded uncertainties for its interconnections. In this paper, in order to formulate the stability criterion for large-scale systems, stability analysis of LTI systems is first considered. Based on the existing methods for estimating the spectra of square matrices, sufficient criteria are proposed to guarantee the asymptotic stability of ...


Simple Stability Criteria For Uncertain Continuous-Time Linear Systems, Mohammad Shekaramiz Jan 2019

Simple Stability Criteria For Uncertain Continuous-Time Linear Systems, Mohammad Shekaramiz

Electrical and Computer Engineering Faculty Publications

This paper mainly deals with the stability problem of continuous-time linear systems having uncertainties. Instead of using the tradition types of Lyapunov functions, this paper provides a very different method to investigate the stability of such systems. Hence, it reduces the conservativeness of having structured uncertainties belonging to convex sets. Based on a famous theorem that specifies regions containing all the eigenvalues of a complex square matrix, sufficient criteria are proposed to guarantee the asymptotic stability of linear systems. The main merit of this method is in analyzing linear systems having uncertainties. Moreover, the proposed criteria can also be used ...