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Wayne State University

2018

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Articles 1 - 13 of 13

Full-Text Articles in Physical Sciences and Mathematics

Flux Of Particulate Elements In The North Atlantic Ocean Constrained By Multiple Radionuclides, Christopher T. Hayes, Erin E. Black, Robert F. Anderson, Mark Baskaran, Ken O. Buesseler, Matthew A. Charette, Hai Cheng, J. Kirk Cochran, R. Lawrence Edwards, Patrick Fitzgerald, Phoebe J. Lam, Yanbin Lu, Stephanie O. Morris, Daniel C. Ohnemus, Frank J. Pavia, Gillian Stewart, Yi Tang Nov 2018

Flux Of Particulate Elements In The North Atlantic Ocean Constrained By Multiple Radionuclides, Christopher T. Hayes, Erin E. Black, Robert F. Anderson, Mark Baskaran, Ken O. Buesseler, Matthew A. Charette, Hai Cheng, J. Kirk Cochran, R. Lawrence Edwards, Patrick Fitzgerald, Phoebe J. Lam, Yanbin Lu, Stephanie O. Morris, Daniel C. Ohnemus, Frank J. Pavia, Gillian Stewart, Yi Tang

Environmental Science and Geology Faculty Research Publications

Sinking particles strongly regulate the distribution of reactive chemical substances in the ocean, including particulate organic carbon and other elements (e.g., P, Cd, Mn, Cu, Co, Fe, Al, and 232Th). Yet, the sinking fluxes of trace elements have not been well described in the global ocean. The U.S. GEOTRACES campaign in the North Atlantic (GA03) offers the first data set in which the sinking flux of carbon and trace elements can be derived using four different radionuclide pairs (238U:234Th ;210Pb:210Po; 228Ra:228Th; and 234U:230Th) at stations co-located with sediment trap fluxes for comparison. Particulate organic carbon, particulate P, and particulate Cd …

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A Nonlinear Systems Framework For Cyberattack Prevention For Chemical Process Control Systems, Helen Durand Sep 2018

A Nonlinear Systems Framework For Cyberattack Prevention For Chemical Process Control Systems, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Recent cyberattacks against industrial control systems highlight the criticality of preventing future attacks from disrupting plants economically or, more critically, from impacting plant safety. This work develops a nonlinear systems framework for understanding cyberattack-resilience of process and control designs and indicates through an analysis of three control designs how control laws can be inspected for this property. A chemical process example illustrates that control approaches intended for cyberattack prevention which seem intuitive are not cyberattack-resilient unless they meet the requirements of a nonlinear systems description of this property.

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Of Typicality And Predictive Distributions In Discriminant Function Analysis, Lyle W. Konigsberg, Susan R. Frankenberg Aug 2018

Of Typicality And Predictive Distributions In Discriminant Function Analysis, Lyle W. Konigsberg, Susan R. Frankenberg

Human Biology Open Access Pre-Prints

While discriminant function analysis is an inherently Bayesian method, researchers attempting to estimate ancestry in human skeletal samples often follow discriminant function analysis with the calculation of frequentist-based typicalities for assigning group membership. Such an approach is problematic in that it fails to account for admixture and for variation in why individuals may be classified as outliers, or non-members of particular groups. This paper presents an argument and methodology for employing a fully Bayesian approach in discriminant function analysis applied to cases of ancestry estimation. The approach requires adding the calculation, or estimation, of predictive distributions as the final step …

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Fingerprinting Sediment Transport In River-Dominated Margins Using Combined Mineral Magnetic And Radionuclide Methods, Jinlong Wang, Weigou Zhang, M. Baskaran, Jinzhou Du, Feng Zhou, Hui Wu Aug 2018

Fingerprinting Sediment Transport In River-Dominated Margins Using Combined Mineral Magnetic And Radionuclide Methods, Jinlong Wang, Weigou Zhang, M. Baskaran, Jinzhou Du, Feng Zhou, Hui Wu

Environmental Science and Geology Faculty Research Publications

Both magnetic properties and radionuclides are widely used to trace sediment transport in aquatic environments; however, these methods have not been used in combination. In this study, the East China Sea (ECS), a typical river-dominated margin, was chosen to demonstrate the advantages of combining these two methods to track sediment movements on a seasonal to annual timescale. The ratios between saturation isothermal remnant magnetization and anhysteretic remnant magnetization (χARM/SIRM) and 7Be/210Pbex activity ratios as well as mass balance of 7Be provide information on the seasonal transport of sediment from the Changjiang Estuary to the neighboring shelf. Both 210Pb budget and …

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State Measurement Spoofing Prevention Through Model Predictive Control Design, Helen Durand Aug 2018

State Measurement Spoofing Prevention Through Model Predictive Control Design, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Security of chemical process control systems against cyberattacks is critical due to the potential for injuries and loss of life when chemical process systems fail. A potential means by which process control systems may be attacked is through the manipulation of the measurements received by the controller. One approach for addressing this is to design controllers that make manipulating the measurements received by the controller in any meaningful fashion very difficult, making the controllers a less attractive target for a cyberattack of this type. In this work, we develop a model predictive control (MPC) implementation strategy that incorporates Lyapunov-based stability …

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On Some Ergodic Impulse Control Problems With Constraint, J. L. Menaldi, Maurice Robin Jul 2018

On Some Ergodic Impulse Control Problems With Constraint, J. L. Menaldi, Maurice Robin

Mathematics Faculty Research Publications

This paper studies the impulse control of a general Markov process under the average (or ergodic) cost when the impulse instants are restricted to be the arrival times of an exogenous process, and this restriction is referred to as a constraint. A detailed setting is described, a characterization of the optimal cost is obtained as a solution of an HJB equation, and an optimal impulse control is identified.

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Shear Wave Tomography Beneath The United States Using A Joint Inversion Of Surface And Body Waves, E. M. Golos, H. Fang, H. Yao, H. Zhang, Scott Burdick, F. Vernon, A. Schaeffer, S. Lebedev, R. D. Van Der Hilst Jun 2018

Shear Wave Tomography Beneath The United States Using A Joint Inversion Of Surface And Body Waves, E. M. Golos, H. Fang, H. Yao, H. Zhang, Scott Burdick, F. Vernon, A. Schaeffer, S. Lebedev, R. D. Van Der Hilst

Environmental Science and Geology Faculty Research Publications

Resolving both crustal and shallow-mantle heterogeneity, which is needed to study processes in and fluxes between crust and mantle, is still a challenge for seismic tomography. Body wave data can constrain deep features but often produce vertical smearing in the crust and upper mantle; in contrast, surface wave data can provide good vertical resolution of lithospheric structure but may lack lateral resolution and are less sensitive to the deeper Earth. These two data types are usually treated and inverted separately, and tomographic models therefore do not, in general, benefit from the complementary nature of sampling by body and surface waves. …

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Discrete-Time Hybrid Control In Borel Spaces: Average Cost Optimality Criterion, Héctor Jasso-Fuentes, José-Luis Menaldi, Tomás Prieto-Rumeau, Maurice Robin Jun 2018

Discrete-Time Hybrid Control In Borel Spaces: Average Cost Optimality Criterion, Héctor Jasso-Fuentes, José-Luis Menaldi, Tomás Prieto-Rumeau, Maurice Robin

Mathematics Faculty Research Publications

This paper addresses an optimal hybrid control problem in discrete-time with Borel state and action spaces. By hybrid we mean that the evolution of the state of the system may undergo deep changes according to structural modifications of the dynamic. Such modifications occur either by the position of the state or by means of the controller's actions. The optimality criterion is of a long-run ratio-average (or ratio-ergodic) type. We provide the existence of optimal average policies for this hybrid control problem by analyzing an associated dynamic programming equation. We also show that this problem can be translated into a standard …

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Discrete-Time Hybrid Control In Borel Spaces, Héctor Jasso-Fuentes, José-Luis Menaldi, Tomás Prieto-Rumeau May 2018

Discrete-Time Hybrid Control In Borel Spaces, Héctor Jasso-Fuentes, José-Luis Menaldi, Tomás Prieto-Rumeau

Mathematics Faculty Research Publications

A discrete-time hybrid control model with Borel state and action spaces is introduced. In this type of models, the dynamic of the system is composed by two sub-dynamics affecting the evolution of the state; one is of a standard-type that runs almost every time and another is of a special-type that is active under special circumstances. The controller is able to use two different type of actions, each of them is applied to each of the two sub-dynamics, and the activations of these sub-dynamics are possible according to an activation rule that can be handled by the controller. The aim …

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Cyanobacteria Reduce Quagga Mussel (Dreissena Rostriformis Bugensis) Spawning And Fertilization Success, Anna G. Boegehold, Nicholas S. Johnson, Jeffrey L. Ram, Donna R. Kashian May 2018

Cyanobacteria Reduce Quagga Mussel (Dreissena Rostriformis Bugensis) Spawning And Fertilization Success, Anna G. Boegehold, Nicholas S. Johnson, Jeffrey L. Ram, Donna R. Kashian

Environmental Science and Geology Faculty Research Publications

Quagga mussels (Dreissena rostriformis bugensis) are highly fecund broadcast spawners invasive to freshwaters of North America and western Europe. We hypothesized that environmental cues from phytoplankton can trigger gamete release in quagga mussels. Nutritious algae may stimulate dreissenid spawning, but less palatable food, such as bloom-forming cyanobacteria, could be a hindrance. The objective of our study was to test whether exposure to cyanobacteria can inhibit quagga mussel spawning and fertilization. We assessed spawning in the presence of serotonin, a known spawning inducer, where adult quagga mussels placed in individual vials were exposed to 13 cyanobacteria cultures and purified algal toxin …

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Evaluating The Effectiveness Of Biochar For Treating Wsu Parking Lot Runoff, Alan-Christian Thomas Jan 2018

Evaluating The Effectiveness Of Biochar For Treating Wsu Parking Lot Runoff, Alan-Christian Thomas

Research Opportunities for Engineering Undergraduates (ROEU) Program 2017-18

Various pollutants including pesticides, herbicides, automotive fluids, and excess nutrients from fertilizers are found in high concentrations in urban runoff. There are many technologies that can be used to control and redirect the water flow such as retention basins, constructed wetlands, and rain gardens; however, these methods are specifically focused on controlling water and not necessarily the nutrients and contaminants in the water. There has recently been an increased interest in the potential for using additional materials (e.g., compost, charcoal) to enhance the pollution treatment ability by either adding them to the soil or by engineering prefilters to remove pollutants …

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Evaluating The Effectiveness Of Bioswales In Southeast Michigan, Grace Crowe Jan 2018

Evaluating The Effectiveness Of Bioswales In Southeast Michigan, Grace Crowe

Research Opportunities for Engineering Undergraduates (ROEU) Program 2017-18

Bioswales are modern storm water management structures that utilize biological components in a traditional wale to more effectively filter out contaminants. Because of its modern nature the installation and management practices for bioswales is still developing. Perfecting the practices surrounding bioswales in southeast Michigan environment can aid in the advancement of green infrastructure in the state. Wayne State installed a bioswale in one its parking lots in New Center with the help of the Detroit Biodiversity Network (DBN). We wanted to monitor the progression of this existing bioswale throughout the year, observing the system components effecting overall bioswale performance. The …

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Sdes, Jumps And Estimates, Jose L. Menaldi Jan 2018

Sdes, Jumps And Estimates, Jose L. Menaldi

Mathematics Faculty Research Publications

Long Title: Stochastic Ordinary Differential Equations with Jumps: Theory and Estimates. Chapters: Stochastic Integrals - Initial Approach to SDEs - Estimates of SDEs - Other Formulations of SDEs - SDEs with Reflection - PDE Connections.

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