23671 research outputs found
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Safety-critical control of robotic systems in webots using control barrier functions
No full textThesis (M.S.)-- Wichita State University, College of Engineering, Dept. of Mechanical EngineeringThis thesis develops and validates a safety-critical control framework for autonomous differential-drive robots using Control Barrier Functions (CBFs), integrating idealized Pnumerical case studies in Python with physics-based simulations of an e-puck robot in Webots environment. Reduced-order kinematic models are utilized for control design to achieve obstacle avoidance, and CBF-based safety filters are applied at the velocity level to enforce forward-invariance of safety sets in real time. Sensitivity analyses on control parameters reveal the trade-offs clearance to obstacles and the trajectory smoothness. In Webots, the e-puck executes both avoidance and braking maneuvers under realistic sensor latencies, actuator delays, and friction, confirming that safety constraints remain invariant and that key metrics (path length, and minimum clearance) deviate by less than 7 % from Python results. The findings yield practical parameter guidelines and demonstrate a pipeline from simplified models to real systems, laying a scalable foundation for deploying CBF-based safety controllers on real robotic systems
Impact of remittances from the Afghan diaspora: a case study on the effects in the Samangan province
No full textClick on the DOI link to access this article at the publishers website (may not be free).Purpose: The study examines the relationship between international remittances and income inequality in Afghanistan by analysing how remittances affect income inequality in the Samangan province. Design/methodology/approach: Primary data were collected by administering a questionnaire to 325 households in the Samangan province using a multi-stage sampling approach. Income distribution was measured using the Gini coefficient. Findings: There were an average of 8 members and 1.5 migrants in each household, with the mean age of respondents being 35. Remittances formed about 25% of the household income and had a slight negative effect on income inequality, with a 1% increase in remittances leading to a 0.04% decrease in inequality. Research limitations/implications: The data were collected in one province. The findings underline the need to develop policies that foster peace and stability through reducing inequality. Practical implications: International remittances can form a significant portion of household income in conflict-affected and post-conflict societies. The effect of remittances on income distribution can help us understand where development efforts need to be channelled and how businesses can best operate in challenging circumstances. Originality/value: This is the only study to our knowledge that looks at the effects of migration and remittances on income inequality in Afghanistan. © 2024, Emerald Publishing Limited
Analysis of wildlife strikes using control charts
No full textPublished in SOAR: Shocker Open Access Repository by the Wichita State University Libraries Technical Services, October 2025.Strikes between wildlife and aircraft pose many risks to aviators, aircraft, and passengers. Data on reported strikes in the US within the past twenty-five years is available from the Federal Aviation Administration (FAA) Wildlife Strike Database. Employing appropriate control charts for analyzing such data can expose temporal patterns and contributing factors, providing insights for effective mitigation strategies. This paper presents control charting techniques suited for the data reported, aiming to inform policy decisions and enhance air travel safety
Rejecting genetic reductionism and embracing relationism and the complexity of dynamic systems
No full textClick on the DOI link to access this article at the publishers website (may not be free).[No abstract available
Estimating location premia using fixed effects—A semi-local approach
No full textClick on the DOI link to access this article at the publishers website (may not be free).In this article, we develop a novel method for measuring the value of location within a metropolitan area. By estimating overlapping “semi-local” regressions and exploiting the symmetry among them, we are able to construct a surface of the relative value of location within a metropolitan area. This methodology maintains the simplicity of using location fixed effects while resolving the omitted variable bias that arises from the traditional application in hedonic regressions. We demonstrate our semi-local approach using a flexible, hex-based geography. We also show that it can be generalized and applied to other geographies such as census tracts. Using data from Maricopa County (Phoenix), we find that every geography we employ supports the same conclusion: the premium for location is decidedly nonmonocentric, asymmetric, and highly dynamic. This dynamism conflicts with the typical assumptions associated with the use of fixed effects in the construction of aggregate price indexes, and potentially complicates the interpretation of difference-in-difference methods. © 2025 American Real Estate and Urban Economics Association
Department of Dental Hygiene Class of 2001
No full textFirst row (left to right): Barbara Gonzalez, RDH, MHS, Assistant Professor; Lourdes Vazquez, Assistant Professor; Patty Seery, Assistant Professor; Scott W. Wiggins, DDS, Supervising Dentist; Denise Maseman, RDH, MS, Assistant Professor/Chairperson; Diane E. Huntley, RDH, PhD, Associate Professor; Pamela Bumpurs, RDH, MHS; Mary Casey, Clinic ManagerSecond row (left to right): Jennifer Freeman, President; Talisha Sherry, Vice Presdent; Alicia Rippert, Treasurer/Secretary; Alicia Kranz, SADHA President; Sharon Simons, Class Liaisons; Kimberly Ford, SADHA TreasurerThird row (left to right): Lisa Babbidge, Ashley Barkman, Lacie Bartel, Niki Browning, Kerry Bruce, Dawn BussFourth row (left to right): Karen Calhoun, M. Emily Dennes, Amber Emerson, Kristy Ford, Rosalie Gaulier, Joanna Ging, Lesah Grubb, Sara Gumpenberger, Genny Hall, Tammy HopkinsFifth row (left to right): Jennifer Irwin, Staci Krieg, Sonya Lowry, Annie Marin, Angela McPherson, Katie Miller, Hoang Nguyen, Ronda Owens, Crystal Reichenbergr, Apryl TurnerDigitized by University Libraries' Technical Services Institutional Repository & Digitization group.Personal and non-profit use only
Framework for multicomponent mechanobiological modeling of adherent endothelial cells in parallel plate flow chambers
No full textThesis (M.S.)-- Wichita State University, College of Engineering, Dept. of Biomedical EngineeringEndothelial cells (ECs) are heterogeneous structures lining the blood vessels of the vasculature exposed to a complex microenvironment of forces due to blood flow such as fluid shear stress (FSS) which impacts cell morphology, mechanics, physiology, and pathology. Gaining insight into the forces cells are exposed to and the process of mechanotransduction is key to better understanding these impacts. Therefore, the objective of this research was to develop a one-way fluid structure interaction (FSI) co-simulation framework that can predict the FSS distribution on the EC surface and the resulting displacement and von Mises stress distributions in an idealized multicomponent EC finite element analysis (FEA). A computational fluid dynamics (CFD) FEA of a parallel plate flow chamber was validated for steady, unidirectional, and laminar flow resulting in FSS values of 0.3, 16, and 32 dyn/cm2. Additionally, an idealized multicomponent (cell membrane, nucleus, cytoplasm, focal adhesions) EC structural FEA with viscoelastic material properties was verified for predicting displacement and von Mises stress distribution under shear load. These two FEA models were then used to conduct a one-way FSI co-simulation. The FSS distribution on the EC was found to be heterogeneous, with max FSS occurring at the peak height of the EC and increasing as the inlet flow rate increased. Furthermore, as the FSS increased, displacement and von Mises stress distributions in the EC also increased with max displacements corresponding to the location of max FSS. Additionally, stress amplifications were observed at focal adhesions and the nucleus-cytoplasm interface. The results presented show the effectiveness of the developed co-simulation framework to expose an idealized EC FEA to physiological microvasculature FSS values. The co-simulation framework can be expanded to predict FSS for different flow conditions and the resultant deformation and von Mises stress distribution of an EC with cell-specific geometry, other subcellular structures, or other types of adherent cells
Decreased pain sensitivity after exercise with blood flow restriction: 24-hours
No full textPoster and abstract presented at the FYRE in STEM Showcase, 2025.Research project completed at the Department of Human Performance Studies.Exercise induced hypoalgesia (EIH) is the observed effect of lowered pain sensitivity following high-intensity or long-duration exercise. Blood flow restriction (BFR) is the procedure of using inflatable cuffs to partially reduce blood flow to the extremities. When BFR is combined with low-intensity exercise, it mimics the effects of high-intensity exercise; this makes it easier for populations that cannot tolerate high-intensity exercise, such as recovering patients, to relieve their pain. Recent studies have shown that the effects of BFR exercise can last up to one hour post-exercise. However, little evidence has been gathered studying the duration and magnitude of EIH due to BFR exercise across a 24-hour period. Therefore, this study aims to assess pain sensitivity in a 24-hour period following exercise to gain an understanding of the EIH response following BFR exercise. The change from pre-exercise values for pain pressure tolerance of the biceps brachii and quadriceps muscle group was calculated 4-, 8-, and 24-hours post-exercise. Within the control intervention, where patients remained seated with no exercise, the average change in quadricep pain pressure tolerance was 0.25 kg of force (Δkgf) at 4-hours, 1.14 Δkgf at 8-hours, and 1.26 Δkgf at 24-hours. The average change in biceps brachii pain pressure tolerance during the control intervention was 0.37 Δkgf at 4-hours, 0.68 Δkgf at 8-hours, and 0.52 Δkgf at 24-hours. Within the BFR intervention, where patients completed leg extensions at 30% maximal strength with the cuffs inflated to 60% maximum occlusion pressure, the average change in quadricep pain pressure tolerance was –0.07 Δkgf at 4-hours, 0.34 Δkgf at 8-hours, and 1.28 Δkgf at 24-hours. The average change in biceps brachii pain pressure tolerance during the BFR intervention was 0.12 Δkgf at 4-hours, 0.11 Δkgf at 8-hours, and 1.07 Δkgf at 24-hours. While a small sample size (n=4) means inconclusive data, more data is being collected and analyzed. With larger numbers, this study could help develop more accessible pain management in rehabilitation settings
