Engineering Commons^™

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.

Gcps Adaptive Scheduling Model Based On Cooperative Executor, Zhang Jing, Chen Yao, Sun Jun, Hongbo Fan

Journal of System Simulation

Abstract: Aiming at the problem that the uncertainty of grid cyber physical systems leads to chain failure, an adaptive GCPS dispatching model based on co-actuator is established. First, the constraint conditions of the system are analyzed. A model constraints of GCPS system is presented to describe the constraint conditions of the power system, and it is proved that it meets the consistency of the measure and representing methods. Second, the optimal value of approximation error is solved by PILOT, and the framework of CA-SADM is described. Finally, the performance index, output power accuracy and the influence of fault on the …

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 …

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 …

Fine Sediment Modeling During Storm-Based Events In The River Bandon, Ireland, Juan T. Garcia, Joseph R. Harrington

Publications

The River Bandon located in County Cork (Ireland) has been time-continuously monitored by turbidity probes, as well as automatic and manual suspended sediment sampling. The current work evaluates three different models used to estimate the fine sediment concentration during storm-based events over a period of one year. The modeled suspended sediment concentration is compared with that measured at an event scale. Uncertainty indices are calculated and compared with those presented in the bibliography. An empirically-based model was used as a reference, as this model has been previously applied to evaluate sediment behavior over the same time period in the River …

Identification And Reduction Of Uncertainties In Watershed-Scale Flow And Water Quality Modeling, Maryam Roostaee

LSU Doctoral Dissertations

This study identified important uncertainties affecting watershed-scale flow and water quality simulations and recommended modeling options for reducing the uncertainties by means of the Hydrological Simulation Program-FORTRAN (HSPF) model. Specifically, parameter-induced uncertainties in HSPF model were estimated along with uncertainties associated with DEM resolutions and sources. National Elevation Dataset (NED) DEMs with original and resampled resolutions of 3.5, 10, 30 and 100m were utilized for manual and automatic delineation of three watersheds with different gradients in HSPF model to identify the effects of DEM resolution, DEM resampling, delineation method and watershed gradient on the simulation of streamflow, nitrate (NO_{3 …}

Method Of Power System Energy Storage Configuration Based On Flexibility Promotion, Weiqing Sun, Li Zhen, Yiming Tan, Fenglei Lü, Wenping Qiu, Hongzhong Li

Journal of System Simulation

Abstract: To solve the problem of renewable energy access and aiming at system’s response capability to short-term uncertainty, power system flexibility and its evaluation index are defined. A method of energy storage configuration based on flexibility evaluation is proposed. The uncertainty from power supply is analyzed. Aiming at the uncertainty of renewable energy, a source flexibility evaluation index is defined. The principle and method of energy storage configuration are presented from the aspect of siting and sizing. The energy storage configuration model is created and solved considering both the system flexibility requirements and energy storage costs based on the …

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.

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 …

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 …

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 …

A Method Of Uncertainty Analysis For Whole-Life Embodied Carbon Emissions (Co2-E) Of Building Materials Of A Net-Zero Energy Building In Australia, Mehdi Robati, Daniel J. Daly, Georgios Kokogiannakis

Faculty of Engineering and Information Sciences - Papers: Part B

The construction of new buildings requires the use of a substantial amount of materials, which have an associated embodied energy for manufacturing, transport, construction and end-of-life disposal. A number of inventories have been developed to collate the typical embodied energy or carbon emissions associated with different building materials and activities, and these can be used to quantify the environmental impacts of different construction methods. However, uncertainty exists in the estimation of embodied CO2-e emissions and other environmental impact results, due to i) inconsistencies in typical embodied carbon emissions values in inventories; ii) errors in estimations of material quantities; iii) assumptions …

Transmission Expansion Planning Based On A Hybrid Genetic Algorithm Approachunder Uncertainty, Ercan Şenyi̇ği̇t, Selçuk Mutlu, Bi̇lal Babayi̇ği̇t

Turkish Journal of Electrical Engineering and Computer Sciences

Transmission expansion planning (TEP) is one of the key decisions in power systems. Its impact on the system?s operation is excessive and long-lived. The aim of TEP is to determine new transmission lines effectively for a current transmission grid to fulfill the model objectives. However, to obtain a solution, especially under uncertainty, is extremely difficult due to the nonlinear mixed-integer structure of the TEP problem. In this paper, first genetic algorithm (GA) approaches for TEP are reviewed in the literature and then a new hybrid GA with linear modeling is proposed. The proposed GA method has a flexible structure and …

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 C. 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 show agreement …

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

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 …

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 mappings, …