452 research outputs found
Toxic Baby Furniture: The Latest Case for Making Products Safe From the Start
Estimates indoor pollution levels of formaldehyde -- linked to increased risks of allergies, asthma, and cancer -- emitted by cribs, changing tables, and other baby furniture. Makes suggestions for avoiding exposure and for regulatory action
Closed-loop Reference Models for Output-Feedback Adaptive Systems
Closed-loop reference models have recently been proposed for states
accessible adaptive systems. They have been shown to have improved transient
response over their open loop counter parts. The results in the states
accessible case are extended to single input single output plants of arbitrary
relative degree.Comment: v1 Submitted to European Control Conference 2013, v2 Typos correcte
The Shelf to Basin Transition and Tectonostratigraphy of the Atoka Formation (Lower Pennsylvanian) in the Arkoma Basin, Northwest Arkansas
The east-to-west oriented Arkoma Basin is a peripheral foreland basin or depositional trough that developed during the Carboniferous Period. This formation covers an aerial extent of approximately 33,800 square miles and spans from west-central Arkansas into southeastern Oklahoma (McGilvery, Manger, and Zachry, 2016; Perry, 1995). The Atoka Formation, deposited during the early Pennsylvanian, is the largest Paleozoic formation by aerial extent in the state of Arkansas and is located within and comprises the bulk of Arkoma Basin sediments (McFarland, 2004; Nance, 2018). This formation has been informally divided into three divisions, the lower, middle, and upper, based on their stratigraphic response to differing tectonic processes.
A tectonostratigraphic interpretation was made for each division of the Atoka Formation using high resolution cross sections; correlated using well log, seismic, and surface data. Five condensed regional transects were constructed that aided in the development of a cross section “grid” meant to represent the deep marine to shallow marine depositional hinge lines.
Each of the three Atoka divisions have a different dominant depositional force. The Lower Atoka deposition was dominated by eustasy, and with sediment supply from the start of Arkoma Basin tectonics, the middle division was dominated by tectonic subsidence and the upper was dominated by sediment supply. The transition between the Atoka divisions and the magnitude of migration between each deep marine hinge line indicates the progradation of the Upper Atoka depositional cycles occurred more rapidly than the retrogradation of the Middle Atoka. The maximum flooding of the formation occurred within the Middle Atoka’s uppermost informal member, the Morris Member. The Lower Atoka was deposited on an extensive tectonically stable structural platform, which is supported by no lithostratigraphic transition to deep marine deposits within this project’s study area. The deep marine deposition is characterized by shales encapsulating tumultuously distributed and isolated sandstone complexes. These sandstone complexes are not correlated to the shallow marine sandstones by anything but a condensed geologic timeline
Connections Between Adaptive Control and Optimization in Machine Learning
This paper demonstrates many immediate connections between adaptive control
and optimization methods commonly employed in machine learning. Starting from
common output error formulations, similarities in update law modifications are
examined. Concepts in stability, performance, and learning, common to both
fields are then discussed. Building on the similarities in update laws and
common concepts, new intersections and opportunities for improved algorithm
analysis are provided. In particular, a specific problem related to higher
order learning is solved through insights obtained from these intersections.Comment: 18 page
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