Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

Articles

Series

Discipline
Institution
Keyword
Publication Year

Articles 1 - 30 of 1351

Full-Text Articles in Physical Sciences and Mathematics

Comparing Thin And Volume Regimes Of Analog Holograms For Wavefront Sensing, Emma Branigan, Andreas Zepp, Suzanne Martin, Matthew Sheehan, Szymon Gladysz, Kevin Murphy Jul 2024

Comparing Thin And Volume Regimes Of Analog Holograms For Wavefront Sensing, Emma Branigan, Andreas Zepp, Suzanne Martin, Matthew Sheehan, Szymon Gladysz, Kevin Murphy

Articles

Two analog holographic wavefront sensors, for measurement of defocus, have been fabricated as both thin and volume phase transmission holograms in a self-developing photopolymer. This represents the first reported direct comparison of hologram regimes when designed for wavefront sensing. An analysis of the effect of crosstalk in the presence of one other aberration mode (astigmatism X (0/90°), coma X (horizontal), and primary spherical aberration) was carried out with each version of the sensor. The performance of thin and volume analog holographic wavefront sensors was characterized under emulated conditions associated with moderate atmospheric turbulence.


Photopolymer Material Durability And Safety In Holographic Diffusers For Visual Applications, Matthew Hellis, Alan Casey, Edoardo Splendi, Suzanne Martin, Matthew Sheehan, Kevin Murphy Jun 2024

Photopolymer Material Durability And Safety In Holographic Diffusers For Visual Applications, Matthew Hellis, Alan Casey, Edoardo Splendi, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

This study introduces novel holographic diffuser applications employing acrylamide- or diacetone acrylamide-based photopolymers, patterned within the volume on a micron scale by a single-beam holographic recording process. These diffusers have previously been presented as potential treatments for amblyopia and diplopia. This work has now been extended to spectrometric analysis to determine their properties under broadband light. Diffusive elements with higher diffusion efficiencies exhibited a marginal reduction (< 5%) in diffusion efficiency across most of the visible spectrum. Given the intended application of these holographic diffusers, cytotoxicity assessments were also performed. This is significant as there is a difference in toxicity between the crystalline acrylamide (classified as a category 3 material) and diacetone acrylamide (classified as a category 4 material). The findings indicated substantially lower toxicity in holograms produced with diacetone acrylamide-based photopolymer. The accelerated ageing of both formulations of holographic diffusers indicated that the acrylamide-based holographic diffusers did not reduce efficacy in the 292 days of ageing. The diacetone acrylamide-based holographic diffusers exhibited reduced efficacy by day 182. Despite this, both formulations have been shown to perform for prolonged periods as the treatment modality would require. These results emphasise that holographic diffusers exhibit minimal spectral impact, and longevity on the scale of treatment regimes which are crucial considerations for their prospective use case as treatments for amblyopia and diplopia.


Investigation Of The Uv-Resistance Of Photopolymerisable Glass For Space Applications, Luca Sorridente, Tatsiana Mikulchyk, Izabela Naydenova, Kevin Murphy Jun 2024

Investigation Of The Uv-Resistance Of Photopolymerisable Glass For Space Applications, Luca Sorridente, Tatsiana Mikulchyk, Izabela Naydenova, Kevin Murphy

Articles

The progress of space based scientific research leads to an increasing demand for more efficient and less bulky instruments. Conventional refractive elements make up a critical part of many optical instruments launched into space; however, they can be bulky and heavy. Holographic optical elements are an efficient alternative to replace the conventional optical elements as they are lightweight and can be miniaturized. Current materials typically used for volume holographic optical elements are not robust enough for use in space environment. Recently a promising photopolymerisable glass has been developed using a sol-gel technique, which can provide dry layers suitable for holographic …


Holographic Multiplexing In A Photopolymerisable Hybrid Sol-Gel, Pamela Stoeva, Tatsiana Mikulchyk, Izabela Naydenova, Kevin Murphy May 2024

Holographic Multiplexing In A Photopolymerisable Hybrid Sol-Gel, Pamela Stoeva, Tatsiana Mikulchyk, Izabela Naydenova, Kevin Murphy

Articles

Holographic multiplexing techniques enhance functionality and information storage by leveraging the inherent selectivity of holograms. This is crucial for advancing holographic sensors, which excel in simultaneously detecting multiple parameters from a single input signal. This study explores the potential of the recent photopolymerisable hybrid sol-gel (PHSG) material for application in Space sensing systems through the investigation of its holographic angular multiplexing capabilities. For the first time, to the best of our knowledge, we report the successful recording of up to five angularly multiplexed gratings with diffraction efficiencies (DE) ≥ 15% in 187 ± 18 µm PHSG layers. A 3 mW/cm2 …


A Central Limit Theorem For The Number Of Excursion Set Components Of Gaussian Fields, Dmitry Beliaev, Michael Mcauley, Stephen Muirhead May 2024

A Central Limit Theorem For The Number Of Excursion Set Components Of Gaussian Fields, Dmitry Beliaev, Michael Mcauley, Stephen Muirhead

Articles

For a smooth stationary Gaussian field f on Rd and level ℓ ∈ R, we consider the number of connected components of the excursion set {f ≥ ℓ} (or level set {f = ℓ}) contained in large domains. The mean of this quantity is known to scale like the volume of the domain under general assumptions on the field. We prove that, assuming sufficient decay of correlations (e.g. the Bargmann-Fock field), a central limit theorem holds with volume-order scaling. Previously such a result had only been established for ‘additive’ geometric functionals of the excursion/level sets (e.g. the volume or …


Arsenic Contamination Needs Serious Attention: An Opinion And Global Scenario, Abhijnan Bhat School Of Food Science And Environmental Health, Kamna Ravi Health, Engineering & Materials Sciences (Hems) Hub, Furong Tian Nanolab Research Centre, Baljit Singh Micra Biodiagnostics Technology Gateway Apr 2024

Arsenic Contamination Needs Serious Attention: An Opinion And Global Scenario, Abhijnan Bhat School Of Food Science And Environmental Health, Kamna Ravi Health, Engineering & Materials Sciences (Hems) Hub, Furong Tian Nanolab Research Centre, Baljit Singh Micra Biodiagnostics Technology Gateway

Articles

Arsenic (As) contamination is a serious global concern, polluting our natural resources, including water and soil, and posing a danger to the environment and public health. Arsenic is present in the groundwater of several countries and this contaminated water is used for irrigation, drinking, and food preparation, which poses the greatest threat to public health. Nearly 106 countries are affected by groundwater arsenic contamination and an estimated 230 million individuals worldwide are exposed to its adverse health effects, including increased cancer risks, associated cardiovascular disease and diabetes, skin lesions, neurological effects, kidney damage, and foetal or cognitive development-related complications. Arsenic …


Spectralomics – Towards A Holistic Adaptation Of Label Free Spectroscopy, Hugh Byrne Mar 2024

Spectralomics – Towards A Holistic Adaptation Of Label Free Spectroscopy, Hugh Byrne

Articles

Vibrational spectroscopy, largely based on infrared absorption and Raman scattering techniques, is much vaunted as a label free approach, delivering a high content, holistic characterisation of a sample, with demonstrable applications in a broad range of fields, from process analytical technologies and preclinical drug screening, to disease diagnostics, therapeutics, prognostics and personalised medicine. However, in the analysis of such complex systems, a trend has emerged in which spectral analysis is reduced to the identification of individual peaks, based on reference tables of assignments derived from literature, which are then interpreted as biomarkers. More sophisticated analysis attempts to unmix the spectrum …


Modelling Hoe Performance With An Extended Source; Experimental Investigation Using Misaligned Point Sources, Jorge Lasarte, Kevin Murphy, Izabela Naydenova, Maria Victoria Collados, Jesús Atencia, Suzanne Martin Feb 2024

Modelling Hoe Performance With An Extended Source; Experimental Investigation Using Misaligned Point Sources, Jorge Lasarte, Kevin Murphy, Izabela Naydenova, Maria Victoria Collados, Jesús Atencia, Suzanne Martin

Articles

Holographic optical elements (HOEs) have the potential to enable more compact, versatile, and lightweight optical designs, but many challenges remain. Volume HOEs have the advantage of high diffraction efficiency, but they present both chromatic selectivity and chromatic dispersion, which impact their use with wide spectrum light sources. Single-color light emitting diode (LED) sources have a narrow spectrum that reduces these issues and this makes them better suited for use with volume HOEs. However, the LED source size must be taken into consideration for compact volume HOE-LED systems. To investigate the design limits for compact HOE-LED systems, a theoretical and experimental …


An Image Processing Approach For Real-Time Safety Assessment Of Autonomous Drone Delivery, Assem A. Abdelhak, Dan Moss, Alan Hicks, Susan Mckeever Jan 2024

An Image Processing Approach For Real-Time Safety Assessment Of Autonomous Drone Delivery, Assem A. Abdelhak, Dan Moss, Alan Hicks, Susan Mckeever

Articles

The aim of producing self-driving drones has driven many researchers to automate various drone driving functions, such as take-off, navigation, and landing. However, despite the emergence of delivery as one of the most important uses of autonomous drones, there is still no automatic way to verify the safety of the delivery stage. One of the primary steps in the delivery operation is to ensure that the dropping zone is a safe area on arrival and during the dropping process. This paper proposes an image-processing-based classification approach for the delivery drone dropping process at a predefined destination. It employs live streaming …


Knowledge Commons Past, Present, And Future, Michael J. Madison Jan 2024

Knowledge Commons Past, Present, And Future, Michael J. Madison

Articles

The project now known as Governing Knowledge Commons, or GKC, was launched more than 15 years ago on the intuition that skepticism of intellectual property law and information exclusivity was grounded in anecdote and ideology rather than in empiricism. Structured, systematic, empirical research on mechanisms of knowledge sharing was needed. GKC aimed to help scholars produce it. Over multiple books, case studies, and other work, the scope of GKC has expanded considerably, from innovation to governance; from invention and creativity to data, privacy, and markets; and from social dilemmas focused on things to governance strategies directed to communities and collectives. …


Generalised Zero-Shot Learning For Action Recognition Fusing Text And Image Gans, Kaiqiang Huang, Susan Mckeever, Luis Miralles-Pechuán Jan 2024

Generalised Zero-Shot Learning For Action Recognition Fusing Text And Image Gans, Kaiqiang Huang, Susan Mckeever, Luis Miralles-Pechuán

Articles

Generalized Zero-Shot Action Recognition (GZSAR) is geared towards recognizing classes that the model has not been trained on, while still maintaining robust performance on the familiar, trained classes. This approach mitigates the need for an extensive amount of labeled training data and enhances the efficient utilization of available datasets. The main contribution of this paper is a novel approach for GZSAR that combines the power of two Generative Adversarial Networks (GANs). One GAN is responsible for generating embeddings from visual representations, while the other GAN focuses on generating embeddings from textual representations. These generated embeddings are fused, with the selection …


Use Of Artificial Intelligence In Drug Development, Louise C. Druedahl, Nicholson Price, Timo Minssen, Dipl Jur, Ameet Sarpatwari Jan 2024

Use Of Artificial Intelligence In Drug Development, Louise C. Druedahl, Nicholson Price, Timo Minssen, Dipl Jur, Ameet Sarpatwari

Articles

Considerable focus has been placed on the health care applications of artificial intelligence (AI). Already, machine learning, a subset of AI that involves “the use of data and algorithms to imitate the way that humans learn” has been used to predict diseases, while AI-powered smartphone apps have been developed to promote mental health and weight loss. Owing in part to such successes, the market for AI in health care has been forecasted to increase more than 1000% between 2022 and 2029, from $13.8 billion to $164.1 billion. One area of substantial promise is drug development, which is poised to benefit …


Locating Liability For Medical Ai, W. Nicholson Price Ii, I. Glenn Cohen Jan 2024

Locating Liability For Medical Ai, W. Nicholson Price Ii, I. Glenn Cohen

Articles

When medical AI systems fail, who should be responsible, and how? We argue that various features of medical AI complicate the application of existing tort doctrines and render them ineffective at creating incentives for the safe and effective use of medical AI. In addition to complexity and opacity, the problem of contextual bias, where medical AI systems vary substantially in performance from place to place, hampers traditional doctrines. We suggest instead the application of enterprise liability to hospitals—making them broadly liable for negligent injuries occurring within the hospital system—with an important caveat: hospitals must have access to the information needed …


Disaggregating Longer-Term Trends From Seasonal Variations In Measured Pv System Performance, Chibuisi Chinasaokwu Okorieimoh, Brian Norton, Michael Conlon Jan 2024

Disaggregating Longer-Term Trends From Seasonal Variations In Measured Pv System Performance, Chibuisi Chinasaokwu Okorieimoh, Brian Norton, Michael Conlon

Articles

Photovoltaic (PV) systems are widely adopted for renewable energy generation, but their performance is influenced by complex interactions between longer-term trends and seasonal variations. This study aims to remove these factors and provide valuable insights for optimising PV system operation. We employ comprehensive datasets of measured PV system performance over five years, focusing on identifying the distinct contributions of longer-term trends and seasonal effects. To achieve this, we develop a novel analytical framework that combines time series and statistical analytical techniques. By applying this framework to the extensive performance data, we successfully break down the overall PV system output into …


Exploring The Impact Of Signal Quality Enhancement On Heart Sound Classification Models, Davoud Shariat Panah, Andrew Hines, Susan Mckeever Dec 2023

Exploring The Impact Of Signal Quality Enhancement On Heart Sound Classification Models, Davoud Shariat Panah, Andrew Hines, Susan Mckeever

Articles

Limited cardiology resources increase the urgency for automated heart disease screening for the general public. Heart sound diagnostic models have been recently employed as a cost-effective solution for the initial screening of heart disease. Noise in heart sound recordings, however, can reduce the performance of such data-driven models. Various quality enhancement approaches have been adopted to alleviate the destructive impact of noise on model performance. One approach is universal noise reduction which applies denoising techniques to recordings, irrespective of their noise level. The second approach is targeted noise reduction, which applies denoising solely to recordings deemed to need it, based …


Renormalized Stress-Energy Tensor For Scalar Fields In Hartle-Hawking, Boulware, And Unruh States In The Reissner-Nordström Spacetime, Julio Arrechea, Cormac Breen, Adrian Ottewill, Peter Taylor Dec 2023

Renormalized Stress-Energy Tensor For Scalar Fields In Hartle-Hawking, Boulware, And Unruh States In The Reissner-Nordström Spacetime, Julio Arrechea, Cormac Breen, Adrian Ottewill, Peter Taylor

Articles

In this paper, we consider a quantum scalar field propagating on the Reissner-Nordström black hole spacetime. We compute the renormalized stress-energy tensor for the field in the Hartle-Hawking, Boulware and Unruh states. When the field is in the Hartle-Hawking state, we renormalize using the recently developed “extended coordinate” prescription. This method, which relies on Euclidean techniques, is very fast and accurate. Once, we have renormalized in the Hartle-Hawking state, we compute the stress-energy tensor in the Boulware and Unruh states by leveraging the fact that the difference between stress-energy tensors in different quantum states is already finite. We consider a …


Raman Spectroscopic Analysis Of Human Serum Samples Of Convalescing Covid-19 Positive Patients, Hugh Byrne, Naomi Jackson, Jaythoon Hassan Dec 2023

Raman Spectroscopic Analysis Of Human Serum Samples Of Convalescing Covid-19 Positive Patients, Hugh Byrne, Naomi Jackson, Jaythoon Hassan

Articles

Rapid screening, detection and monitoring of viral infection is of critical importance, as exemplified by the rapid spread of SARS-CoV-2, leading to the worldwide pandemic of COVID-19. This is equally the case for the stages of patient convalescence as for the initial stages of infection, to understand the medium and long terms effects, as well as the efficacy of therapeutic interventions. Optical spectroscopic techniques potentially offer an alternative to currently employed techniques of screening for the presence, or the response to infection. In this study, the ability of Raman spectroscopy to distinguish between samples of the serum of convalescent COVID-19 …


A Primer On The Legendre Transformation, Steven J. Kilner, David L. Farnsworth Nov 2023

A Primer On The Legendre Transformation, Steven J. Kilner, David L. Farnsworth

Articles

Guidance is offered for understanding and using the Legendre transformation and its associated duality among functions and curves. The genesis of this paper was encounters with colleagues and students asking about the transformation. A main feature is simplicity of exposition, while keeping in mind the purpose or application for using the transformation.


The Unreasonable Effectiveness Of Large Language Models In Zero-Shot Semantic Annotation Of Legal Texts, Jaromir Savelka, Kevin D. Ashley Nov 2023

The Unreasonable Effectiveness Of Large Language Models In Zero-Shot Semantic Annotation Of Legal Texts, Jaromir Savelka, Kevin D. Ashley

Articles

The emergence of ChatGPT has sensitized the general public, including the legal profession, to large language models' (LLMs) potential uses (e.g., document drafting, question answering, and summarization). Although recent studies have shown how well the technology performs in diverse semantic annotation tasks focused on legal texts, an influx of newer, more capable (GPT-4) or cost-effective (GPT-3.5-turbo) models requires another analysis. This paper addresses recent developments in the ability of LLMs to semantically annotate legal texts in zero-shot learning settings. Given the transition to mature generative AI systems, we examine the performance of GPT-4 and GPT-3.5-turbo(-16k), comparing it to the previous …


Probability Distributions Arising In Connection With The Inspection Paradox For Bernoulli Trials., James E. Marengo, Anne Marino Himes, W. Cade Reinberger, David L. Farnsworth Nov 2023

Probability Distributions Arising In Connection With The Inspection Paradox For Bernoulli Trials., James E. Marengo, Anne Marino Himes, W. Cade Reinberger, David L. Farnsworth

Articles

In renewal theory, the Inspection Paradox refers to the fact that an interarrival period in a renewal process which contains a fixed inspection time tends to be longer than one for the corresponding uninspected process. We focus on the paradox for Bernoulli trials. Probability distributions and moments for the lengths of the interarrival periods are derived for the inspected process, and we compare them to those for the uninspected case.


Dynamic Influence Diagram-Based Deep Reinforcement Learning Framework And Application For Decision Support For Operators In Control Rooms, Joseph Mietkiewicz, Ammar N. Abbas, Chidera Winifred Amazu, Anders L. Madsen, Gabriele Baldissone Sep 2023

Dynamic Influence Diagram-Based Deep Reinforcement Learning Framework And Application For Decision Support For Operators In Control Rooms, Joseph Mietkiewicz, Ammar N. Abbas, Chidera Winifred Amazu, Anders L. Madsen, Gabriele Baldissone

Articles

In today’s complex industrial environment, operators are often faced with challenging situations that require quick and accurate decision-making. The human-machine interface (HMI) can display too much information, leading to information overload and potentially compromising the operator’s ability to respond effectively. To address this challenge, decision support models are needed to assist operators in identifying and responding to potential safety incidents. In this paper, we present an experiment to evaluate the effectiveness of a recommendation system in addressing the challenge of information overload. The case study focuses on a formaldehyde production simulator and examines the performance of an improved Human-Machine Interface …


A Method For Generating A Non-Manual Feature Model For Sign Language Processing, Robert G. Smith Dr, Markus Hofmann Dr Aug 2023

A Method For Generating A Non-Manual Feature Model For Sign Language Processing, Robert G. Smith Dr, Markus Hofmann Dr

Articles

While recent approaches to sign language processing have shifted to the domain of Machine Learning (ML), the treatment of Non-Manual Features (NMFs) remains an open question. The principal challenge facing this method is the comparatively small sign language corpora available for training machine learning models. This study produces a statistical model which may be used in future ML, rules-based, and hybrid-learning approaches for sign language processing tasks. In doing so, this research explores the emerging patterns of non-manual articulation concerning grammatical classes in Irish Sign Language (ISL). The experimental method applied here is a novel implementation of an association rules …


Optical Characterisation Of Holographic Diffusers And Bangerter Foils For Treatment Of Amblyopia, Matthew Hellis, Suzanne Martin, Matthew Sheehan, Kevin Murphy Jun 2023

Optical Characterisation Of Holographic Diffusers And Bangerter Foils For Treatment Of Amblyopia, Matthew Hellis, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

Amblyopia is a significant issue for children worldwide, and current treatment methods have drawbacks that can hinder treatment effectiveness and/or patient experience. This study proposes a new treatment method using holographic diffusers while also comparing their optical characteristics to a current treatment method (Bangerter foils). Holographic diffusers were developed by optically patterning thin polymer layers on a micron scale. Two compositions of photopolymer (acrylamide and diacetone acrylamide based) are analysed herein. Characterisation shows that holographic diffusers of either composition can achieve a wide range of on-axis intensity reductions, allowing for precise and customisable treatment levels by altering recording exposure time …


The State Of Accessibility In Blackboard: Survey And User Reviews Case Study, Mohamed Wiem Mkaouer, Wajdi Aljedaani, Stephanie Ludi, Mohammed Alkahtani, Marcelo M. Eler, Marouane Kessentini, Ali Ouni Apr 2023

The State Of Accessibility In Blackboard: Survey And User Reviews Case Study, Mohamed Wiem Mkaouer, Wajdi Aljedaani, Stephanie Ludi, Mohammed Alkahtani, Marcelo M. Eler, Marouane Kessentini, Ali Ouni

Articles

Context: Nowadays, mobile applications (or apps) have become vital in our daily life, particularly within education. Many institutions increasingly rely on mobile apps to provide access to all their students. However, many education mobile apps remain inaccessible to users with disabilities who need to utilize accessibility features like talkback or screen reader features. Accessibility features have to be considered in mobile apps to foster equity and inclusion in the educational environment allowing to use of such apps without limitations. Gaps in the accessibility to educational systems persist.

Objective: In this paper, we focus on the accessibility of the Blackboard mobile …


Complete Genome Sequences Of Chop, Delrio, And Grandslam, Three Gordonia Phages Isolated From Soil In Central Arkansas, Heidi N. Mathes, Elijah I. Christenson, John H. Crum, Emme M. Edmondson, Kassidy E. Gray, Luke W. Lawson, Lauren E. Lee, Michael P. Lee, Jackson A. Lipscomb, Morgan E. Masengale, Hannah G. Matthews, Charles M. Mcclain 4th, Tuesday N. Melton, Trace H. Morrow, Alexis M. Perry, David R. Rainwater, Grace E. Renois, Maryann F. Rettig, Duncan C. Troup, Allie J. Wilson, Nathan Reyna, Ruth Plymale Apr 2023

Complete Genome Sequences Of Chop, Delrio, And Grandslam, Three Gordonia Phages Isolated From Soil In Central Arkansas, Heidi N. Mathes, Elijah I. Christenson, John H. Crum, Emme M. Edmondson, Kassidy E. Gray, Luke W. Lawson, Lauren E. Lee, Michael P. Lee, Jackson A. Lipscomb, Morgan E. Masengale, Hannah G. Matthews, Charles M. Mcclain 4th, Tuesday N. Melton, Trace H. Morrow, Alexis M. Perry, David R. Rainwater, Grace E. Renois, Maryann F. Rettig, Duncan C. Troup, Allie J. Wilson, Nathan Reyna, Ruth Plymale

Articles

Chop, DelRio, and GrandSlam are phage with a Siphoviridae morphotype isolated from soil in Arkansas using the host Gordonia terrae 3612. All three are temperate, and their genomes share at least 96% nucleotide identity. These phage are assigned to cluster DI based on gene content similarity to other sequenced actinobacteriophage.


Analog Holographic Wavefront Sensor For Defocus And Spherical Aberration Measurement Recorded In A Photopolymer, Emma Branigan, Suzanne Martin, Matthew Sheehan, Kevin Murphy Feb 2023

Analog Holographic Wavefront Sensor For Defocus And Spherical Aberration Measurement Recorded In A Photopolymer, Emma Branigan, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

An analog holographic wavefront sensor (AHWFS), for measurement of low and high order (defocus and spherical aberration) aberration modes has been developed as volume phase holograms in a photopolymer recording medium. This is the first time that high order aberrations such as spherical aberration can be sensed using a volume hologram in a photosensitive medium. Both defocus and spherical aberration were recorded in a multi-mode version of this AHWFS. Refractive elements were used to generate a maximum and minimum phase delay of each aberration which were multiplexed as a set of volume phase holograms in an acrylamide based-photopolymer layer. The …


Fair4pghd: A Framework For Fair Implementation Over Pghd, Abdullahi Abubakar Kawu, Dympna O'Sullivan, Lucy Hederman, Mirjam Van Reisen Feb 2023

Fair4pghd: A Framework For Fair Implementation Over Pghd, Abdullahi Abubakar Kawu, Dympna O'Sullivan, Lucy Hederman, Mirjam Van Reisen

Articles

Patient Generated Health Data (PGHD) are being considered for integration with health facilities, however little is known about how such data can be made machine-actionable in a way that meets FAIR guidelines. This article proposes a 5-stage framework that can be used to achieve this.


Modeling And Fitting Two-Way Tables Containing Outliers, David L. Farnsworth Feb 2023

Modeling And Fitting Two-Way Tables Containing Outliers, David L. Farnsworth

Articles

A model is proposed for two-way tables of measurement data containing outliers. The two independent variables are categorical and error free. Neither missing values nor replication are present. The model consists of the sum of a customary additive part that can be fit using least squares and a part that is composed of outliers. Recommendations are made for methods for identifying cells containing outliers and for fitting the model. A graph of the observations is used to determine the outliers’ locations. For all cells containing an outlier, replacement values are determined simultaneously using a classical missing-data tool. The result is …


Determining The Proportionality Of Ischemic Stroke Risk Factors To Age, Elizabeth Hunter, John D. Kelleher Jan 2023

Determining The Proportionality Of Ischemic Stroke Risk Factors To Age, Elizabeth Hunter, John D. Kelleher

Articles

While age is an important risk factor, there are some disadvantages to including it in a stroke risk model: age can dominate the risk score and lead to over-or under-predictions in some age groups. There is evidence to suggest that some of these disadvantages are due to the non-proportionality of other risk factors with age, eg, risk factors contribute differently to stroke risk based on an individual’s age. In this paper, we present a framework to test if risk factors are proportional with age. We then apply the framework to a set of risk factors using Framingham heart study data …


Electromechanical Coupling In Collagen Measured Under Increasing Relative Humidity, Arwa Bazaid, Fengyuan Zhang, Qiancheng Zhang, Sabine Neumayer, Denise Denning, Stefan Habelitz, Ana Marina Ferreira, Brian J. Rodriguez Jan 2023

Electromechanical Coupling In Collagen Measured Under Increasing Relative Humidity, Arwa Bazaid, Fengyuan Zhang, Qiancheng Zhang, Sabine Neumayer, Denise Denning, Stefan Habelitz, Ana Marina Ferreira, Brian J. Rodriguez

Articles

The functional role of collagen piezoelectricity has been under debate since the discovery of piezoelectricity in bone in 1957. The possibility that piezoelectricity plays a role in bone remodelling has generated interest in the investigation of this effect in relevant physiological conditions; however, there are conflicting reports as to whether collagen is piezoelectric in a humid environment. In macroscale measurements, the piezoelectricity in hydrated tendon has been shown to be insignificant compared to dehydrated tendon, whereas, at the nanoscale, the piezoelectric effect has been observed in both dry and wet bone using piezo response force microscopy (PFM). In this work, …