Open Research Oklahoma (Oklahoma State Univ.)
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Artificial breeding of dairy cattle in Oklahoma
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
Fatigue-based posture and motion predictions
No full textThis dissertation presents two predictive biomechanics studies, fatigue-based posture and motion predictions. For the fatigue-based posture prediction study, the three-compartment
controller fatigue model is integrated with an inverse dynamics optimization routine to
predict the optimal posture, joint fatigue, and endurance time for a box carrying task. A
two-dimensional human model with 10 degrees of freedom is used. For the box carrying task,
the feet are stationary on the ground, and the hand location and box weight are given. The
joint fatigue-based posture prediction formulation considers joint angles, three-compartment
control values, and total box carrying duration (endurance time) as design variables. The
objective is to maximize the total time while adhering to task and fatigue constraints,
including compartment unity constraint, residual capacity constraint, and a novel coupled
failure constraint. The optimization predicts the optimal posture, joint torque, endurance
time, joint fatigue progression, and joint failure conditions. The novel joint fatigue-based
formulation suggests the optimal posture to maximize endurance time with a given box weight.
The simulation is efficient and provides optimal results in about 5 seconds of CPU time on a
regular computer.
The fatigue-based motion prediction study investigates the progression of
fatigue and forecasts the optimal motion trajectory in a repetitive lifting task. The lifting
problem is mathematically formulated as an optimization problem to minimize dynamic effort
and joint acceleration subject to physical and task-specific constraints. The design variables
include control points that determine joint angle profiles using quartic B-splines. Additionally,
profiles of the dimensions of the three and four compartments for spinal, shoulder, elbow,
hip, and knee joints are treated as additional design variables. The study involves numerical
simulations and experiments, using a 20 kg box as an external load for repetitive lifting.
Simulation outcomes include detailed joint angle profiles, joint torques, and the progression
of joint fatigue. The profiles of joint angles and torques follow distinct periodic patterns.
Simulation results suggest a maximum of 11 (3CC) and 13 (4CCr) lifting cycles before the
repetitive lifting task with a 20 kg box becomes unfeasible. Notably, these projected outcomes
match observations from the experiments (predicted 13 cycles). Fatigue-based posture and
motion predictions have significant contributions for ergonomic design and injury prevention
in workplace
Extending the ASHRAE method to a 25-year horizon through the Tp8 model for temperature penalty accurate estimation
No full textThe accurate design of Borehole Heat Exchangers (BHE) fields in ground-coupled heat pump (GCHP) systems is crucial for ensuring long-term performance. Traditional sizing methods, such as the ASHRAE method as modified by ASHRAE-Tp8 version, consider the annual building heating and cooling demand over a 10-year time horizon by applying the temporal superposition of 3 aggregated thermal pulses of different durations.
The present paper aims to clarify how the ASHRAE-Tp8 method could be adapted to be employed over a 25-year plant operation horizon. Temperature penalty estimations are compared with "real" precalculated temperature response factors (g-functions) through the minimization of a suitable objective function.
Optimized constants for the present new ASHRAE-Tp8 method are derived, enabling its easy adaptation for the 25-year time period. Comparisons with EED and GLHEPRO commercial software results demonstrate the reliability of this improved method, with borefield length estimations accurate within 7% and 6% respectively.
The results reported in the present paper lead to easily inferring the error in terms of overall length and borehole depth that would be obtained by employing the design process proper of the 10-year reference period when the 25-year time horizon is considered.
The methodology is in general demonstrated to be applicable to different time frames
Broom corn in Oklahoma
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
Statistics on cyclic permutations avoiding two patterns
No full textIn this paper I calculate nine statistics on cyclic permutations in one-line notation that avoid two patterns in their cycle notation (namely 231 and 312), including peaks, inversions, descents and idescents, excedances, and left to right and right to left minima and maxima. Furthermore, I prove formulas for the number of such statistics for each permutation of any given n. Finally, I end the paper by proposing similar formulas for the 5 other interesting pairs of patterns, with their corresponding statistics coming in a subsequent paper
On the interaction between a geothermal borehole and groundwater flows
No full textThe presence of aquifers can highly affect the heat exchange between geothermal boreholes and the ground. To optimally design them, theoretical models for the thermal interaction of geothermal boreholes with groundwater flows are required. The present work exploits the presence of large disparities in time and length scales, using matched asymptotic expansion techniques, to build a mathematically rigorous and physically sound model that accounts for the presence of creeping groundwater flows. The derived model not only exhibits great performance compared to detailed numerical simulations but also serves to critically assess the merits and limits of the state of the art
Calendario para productores de nueces pecanas
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
Grapes for Oklahoma
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
Instructional practice needs of Oklahoma SBAE teachers based on certification type
No full textFor decades, a persistent national teacher shortage has impacted every aspect of the education
system (Bowling & Ball, 2018; Coleman et al, 2020; Harris, 2023; Wilkin & Nwoke, 2011). As a
result, many individuals are entering the profession through alternative certification pathways.
Researchers who have compared outcomes of teachers with and without formal preparation have
resulted in higher ratings and greater student learning gains for teachers with formal preparation
(Darling-Hammond, 2000). The teacher shortage and utilization of other teacher preparation
programs has been a major cause of the diverse needs of alternatively certified teachers and
traditionally certified teachers (Bowling & Ball, 2018; Coleman et al., 2020; Darling-Hammond,
2000; Wilkin & Nwoke, 2011). The purpose behind this study was to identify the instructional
practice needs of Oklahoma school-based agricultural education (SBAE) teachers based on their
certification type
House plants in the home
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311