bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pole Placement for Delay Differential Equations With Time-Periodic Delays Using Galerkin Approximations
Authors: Kandala Shanti Swaroop , Uchida Thomas K. , Vyasarayani C. P. 
Published: June 2021

AbstractMany practical systems have inherent time delays that cannot be ignored; thus, their dynamics are described using delay differential equations (DDEs). The Galerkin approximation method is one strategy for studying the stability of time-delay systems (TDS). In this work, we consider delays that are time-varying and, specifically, time-periodic. The Galerkin method can be used to obtain a system of ordinary differential equations (ODEs) from a second-order time-periodic DDE in two ways: either by converting the DDE into a second-order time-periodic partial differential equation (PDE) and then into a system of second-order ODEs, or by first expressing the original DDE as two first-order time-periodic DDEs, then converting into a system of first-order time-periodic PDEs, and finally converting into a first-order time-periodic ODE system. The difference between these two formulations in the context of control is presented in this paper. Specifically, we show that the former produces spurious Floquet multipliers at a spectral radius of 1. We also propose an optimization-based framework to obtain feedback gains that stabilize closed-loop control systems with time-periodic delays. The proposed optimization-based framework employs the Galerkin method and Floquet theory and is shown to be capable of stabilizing systems considered in the literature. Finally, we present experimental validation of our theoretical results using a rotary inverted pendulum apparatus with inherent sensing delays as well as additional time-periodic state-feedback delays that are introduced deliberately.
Assessment of Spray and Pool Scrubbing Efficiencies for Means of Mitigation Against Aerosol Dispersion in the Context of Fuel Debris Retrieval at Fukushima Daiichi: Part I
Authors: Porcheron Emmanuel , Leblois Yohan , Gelain Thomas , Chagnot Christophe , Journeau Christophe , Roulet Damien 
Published: June 2021

Abstract
The general context of this paper is an evaluation of strategies that can be used to mitigate aerosol dispersion during fuel debris or corium retrieval in damaged Fukushima Daiichi reactors. Knowledge of the aerosol source terms released during fuel debris retrieval operations is one of the key factors for assessing aerosol dispersion leading to the potential dissemination of radionuclides into the environment. Our approach is to couple experimental results from integral tests obtained during laser cutting experiments, analytical tests performed in a dedicated facility to reproduce two-phase flow such as flows representative of pool scrubbing and spray scrubbing conditions, and numerical simulations. Integral tests provide relevant information on the airborne particle release fraction during laser cutting for underwater conditions at different water depths, such as the particle concentration and particle size distribution. However, the detailed characterization of two-phase flows, such as the size and velocity of gas bubble and water droplets, is not possible during laser cutting integral tests. Therefore, a more analytical approach is necessary to obtain detailed information on two-phase flow, composed of bubbles in water, inducing pool scrubbing phenomenon, and droplets in gas generated by spray scrubbing systems, which are essential to the physical mechanisms of both processes and enable their respective efficiencies to be evaluated. The main objectives of this work were to develop models and ensure their validation based on experimental approach for predicting the pool scrubbing and spray scrubbing efficiencies in the context of fuel debris removal at Fukushima Daiichi.
Entropy Generation and Poiseuille Number Link in Developing Isothermal Laminar Micro-Flow
Authors: Rastogi Pallavi , Mahulikar Shripad P. 
Published: June 2021

Abstract
It is well-known that Poiseuille number (Po, hitherto viewed mainly as a fluid mechanics parameter) decreases along a hydrodynamically developing flow, from infinity at inlet to a fixed value downstream. This study reveals that the dimensionless entropy generation rate per unit length due to fluid friction (S˙¯′gen,fr) varies exactly the same way; hence, Po and S˙¯gen,fr′ are jointly studied for their dependence. Laminar hydrodynamic development of isothermal flow of incompressible fluid (water) in a circular micro-tube (diameter, D) is examined. Results are obtained for a given flow velocity for different D, and then, numerical experiments are conducted for different flow velocities for the same D-values. Striking similarity in trends of Po and S˙¯gen,fr′ shows a unique linear relation between them for the hydrodynamically developing region. It is theoretically shown that Po is a direct measure of entropy generation due to fluid friction, which explains its numerically obtained linear relation with S˙¯gen,fr′. It is found that in hydrodynamically developing region, both Po and S˙¯gen,fr′, decrease with decreasing D, which is the identified micro-effect.
Individual Drive Cross-Coupled Control System to Compensate for Measurement Error for Roll-to-Roll Contact Pressure Uniformization
Authors: Kim Daehyeon , Kim Youngjin , Park Jimin , Kim Hyeongrae , Kim Juyeon , Oh Dongho 
Published: June 2021

Abstract
Commercialization of printed electronics products requires uniform line width and thickness of the print pattern, which can be accomplished only by uniformization of the contact pressure in the roll-to-roll processs [1]. The conventional contact pressure control system has limitations in compensation, because the indirect measurement of the contact pressure performed by using the load cell generates time-delay error and magnitude error. In this study, a transfer function between the load cell signals and the actual contact pressure is derived to calculate the measurement time-delay, and the error was compensated by using a time-delay predictor. In addition, individual drive cross-coupled control system with time-delay compensator is designed in consideration of the effect that two servo motors have on the pressure on the other side of the impression roll to perform contact pressure uniformization.
Concept of a System Architecture for a Simulation Data Management In the Digital Twin
Authors: Röhm Benjamin , Anderl Reiner 
Published: June 2021

Abstract
The Department of Computer Integrated Design (DiK) at the TU Darmstadt deals with the Digital Twin topic from the perspective of virtual product development. A concept for the architecture of a Digital Twin was developed, which allows the administration of simulation input and output data. The concept was built under consideration of classical CAE process chains in product development. The central part of the concept is the management of simulation input and output data in a simulation data management system in the Digital Twin (SDM-DT). The SDM-DT takes over the connection between Digital Shadow and Digital Master for simulation data and simulation models.
The concept is prototypically implemented. For this purpose, real product condition data were collected via a sensor network and transmitted to the Digital Shadow. The condition data were prepared and sent as a simulation input deck to the SDM-DT in the Digital Twin based on the product development results. Before the simulation data and models are simulated, there is a comparison between simulation input data with historical input data from product development. The developed and implemented concept goes beyond existing approaches and deals with a central simulation data management in Digital Twins.
Design of a 3D Printed Micro-Transmission System for a Detachable Bronchoscope
Authors: Kohanfars Matthew , Li Yu , Morris Karcher , Ahadian Farshad , Talke Frank E. 
Published: June 2021

Abstract
Bronchoscopes are used across a wide range of medical procedures. It is highly desirable for a medical practitioner to have a bronchoscope insertion section that can be detached and reattached to its handle. In this study, a novel detachable bronchoscope with a micro-transmission is proposed, manufactured by 3D printing. The micro-transmission allows for the bronchoscope to be detached and reattached to the insertion section during a medical procedure, while maintaining control of the articulating distal end. The equations for calculating the load of the micro-transmission design are reviewed. The maximum load from different screw lead arrangements is determined experimentally.
Cohort profile: the Westlake BioBank for Chinese (WBBC) pilot project
Authors: Zhu Xiao-Wei , Liu Ke-Qi , Wang Ping-Yu , Liu Jun-Quan , Chen Jin-Yang , Xu Xue-Jin , Xu Jin-Jian , Qiu Mo-Chang , Sun Yi , Liu Chun , Bai Wei-Yang , Zhao Pian-Pian , Xia Jiangwei , Gai Si-Rui , Guan Peng-Lin , Qian Yu , Cong Pei-Kuan , Xie Shu-Yang , Zheng Hou-Feng 
Published: June 2021

PurposeThe Westlake BioBank for Chinese (WBBC) pilot cohort is a population-based prospective study with its major purpose to better understand the effect of genetic and environmental factors on growth and development from adolescents to adults.ParticipantsA total of 14 726 participants (4751 males and 9975 females) aged 14–25 years were recruited and the baseline survey was carried out from 2017 to 2019. The pilot cohort contains rich range of information regarding of demographics and anthropometric measurements, lifestyle and sleep patterns, clinical and health outcomes. Visit the WBBC website for more information (https://wbbc.westlake.edu.cn/index.html).Findings to dateThe mean age of the study samples were 18.6 years for males and 18.5 years for females, respectively. The mean height and weight were 172.9 cm and 65.81 kg for males, and 160.1 cm and 52.85 kg for females. Results indicated that the prevalence of underweight in female was much higher than male, but the prevalence of overweight and obesity in female was lower than male. The mean serum 25(OH)D level in the 14 726 young participants was 22.4±5.3 ng/mL, and male had a higher level of serum 25(OH)D than female, overall, 33.5% of the participants had vitamin D deficiency and even more participants suffered from vitamin D insufficiency (58.2%). The proportion of deficiency in females was much higher than that in males (41.8 vs 16.4%). The issue of underweight and vitamin D deficiency in young people should be paid attention, especially in females. These results reflected the fact that thinness and paler skin are preferred in modern aesthetics of Chinese culture.Future plansWBBC pilot is designed as a prospective cohort study and provides a unique and rich data set analysing health trajectories from adolescents to young adults. WBBC will continue to collect samples with old age.
Comparative efficacy and acceptability of psychosocial treatments for disruptive behaviour disorders in children and adolescents: study protocol for a systematic review and network meta-analysis
Authors: Zhang Lin , Ren Zhihong , Ma Xueyao , Hazer-Rau Dilana , Jiang Guangrong , Zhao Chunxiao , Zhao Ziyi , Liu Qianzi , Yuan Fenghui 
Published: June 2021

IntroductionDisruptive behaviour disorders are common among children and adolescents, with negative impacts on the youths, their families and society. Although multiple psychosocial treatments are effective in decreasing the symptoms of disruptive behaviour disorders, comprehensive evidence regarding the comparative efficacy and acceptability between these treatments is still lacking. Therefore, we propose a systematic review and network meta-analysis, integrating both direct and indirect comparisons to obtain a hierarchy of treatment efficacy and acceptability.Methods and analysisThe present protocol will be reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. Ten databases, including Web of Science, PubMed, PsycINFO, MEDLINE, APA PsycArticles, Psychology and Behavioral Sciences Collection, OpenDissertations, The Cochrane Library, Embase and CINAHL, will be searched from inception for randomised controlled trials of psychosocial treatments for children and adolescents with disruptive behaviour disorders, without restrictions on language, publication year and status. The primary outcomes will be efficacy at post-treatment (severity of disruptive behaviour disorders at post-treatment) and acceptability (dropout rate for any reason) of psychosocial treatments. The secondary outcomes will involve efficacy at follow-up, severity of internalising problems and improvement of social functioning. Two authors will independently conduct the study selection and data extraction, assess the risk of bias using the revised Cochrane Collaboration’s Risk of Bias tool and evaluate the quality of the evidence using the Grading of Recommendations Assessment, Development and Evaluation framework to network meta-analysis. We will perform Bayesian network meta-analyses with a random effects model. Subgroup and sensitivity analyses will be performed to evaluate the robustness of the findings.Ethics and disseminationThe research does not require ethical approval. Results are planned to be published in journals or presented at conferences. The network meta-analysis will provide information on a hierarchy of treatment efficacy and acceptability and help make a clinical treatment choice.PROSPERO registration numberCRD42020197448.
How do participatory methods shape policy? Applying a realist approach to the formulation of a new tuberculosis policy in Georgia
Authors: Marchal Bruno , Abejirinde Ibukun-Oluwa Omolade , Sulaberidze Lela , Chikovani Ivdity , Uchaneishvili Maia , Shengelia Natia , Diaconu Karin , Vassall Anna , Zoidze Akaki , Giralt Ariadna Nebot , Witter Sophie 
Published: June 2021

ObjectivesThis paper presents the iterative process of participatory multistakeholder engagement that informed the development of a new national tuberculosis (TB) policy in Georgia, and the lessons learnt.MethodsGuided by realist evaluation methods, a multistakeholder dialogue was organised to elicit stakeholders’ assumptions on challenges and possible solutions for better TB control. Two participatory workshops were conducted with key actors, interspersed by reflection meetings within the research team and discussions with policymakers. Using concept mapping and causal mapping techniques, and drawing causal loop diagrams, we visualised how actors understood TB service provision challenges and the potential means by which a results-based financing (RBF) policy could address these.SettingThe study was conducted in Tbilisi, Georgia.ParticipantsA total of 64 key actors from the Ministry of Labour, Health and Social Affairs, staff of the Global Fund to Fight AIDS, TB and Malaria Georgia Project, the National Centre for Disease Control and Public Health, the National TB programme, TB service providers and members of the research team were involved in the workshops.ResultsFindings showed that beyond provider incentives, additional policy components were necessary. These included broadening the incentive package to include institutional and organisational incentives, retraining service providers, clear redistribution of roles to support an integrated care model, and refinement of monitoring tools. Health system elements, such as effective referral systems and health information systems were highlighted as necessary for service improvement.ConclusionsDeveloping policies that address complex issues requires methods that facilitate linkages between multiple stakeholders and between theory and practice. Such participatory approaches can be informed by realist evaluation principles and visually facilitated by causal loop diagrams. This approach allowed us leverage stakeholders’ knowledge and expertise on TB service delivery and RBF to codesign a new policy.
Sleep Apnea and Fetal Growth Restriction (SAFER) study: protocol for a pragmatic randomised clinical trial of positive airway pressure as an antenatal therapy for fetal growth restriction in maternal obstructive sleep apnoea
Authors: Hincker Alex , Nadler Jacob , Karan Suzanne , Carter Ebony , Porat Shay , Warner Barbara , Ju Yo-El S , Ben Abdallah Arbi , Wilson Elizabeth , Lockhart Ellen M , Ginosar Yehuda 
Published: June 2021

IntroductionFetal growth restriction (FGR) is a major contributor to fetal and neonatal morbidity and mortality with intrauterine, neonatal and lifelong complications. This study explores maternal obstructive sleep apnoea (OSA) as a potentially modifiable risk factor for FGR. We hypothesise that, in pregnancies complicated by FGR, treating mothers who have OSA using positive airway pressure (PAP) will improve birth weight and neonatal outcomes.Methods and analysisThe Sleep Apnea and Fetal Growth Restriction study is a prospective, block-randomised, single-blinded, multicentre, pragmatic controlled trial. We enrol pregnant women aged 18–50, between 22 and 31 weeks of gestation, with established FGR based on second trimester ultrasound, who do not have other prespecified known causes of FGR (such as congenital anomalies or intrauterine infection). In stage 1, participants are screened by questionnaire for OSA risk. If OSA risk is identified, participants proceed to stage 2, where they undergo home sleep apnoea testing. Participants are determined to have OSA if they have an apnoea-hypopnoea index (AHI) ≥5 (if the oxygen desaturation index (ODI) is also ≥5) or if they have an AHI ≥10 (even if the ODI is <5). These participants proceed to stage 3, where they are randomised to nightly treatment with PAP or no PAP (standard care control), which is maintained until delivery. The primary outcome is unadjusted birth weight; secondary outcomes include fetal growth velocity on ultrasound, enrolment-to-delivery interval, gestational age at delivery, birth weight corrected for gestational age, stillbirth, Apgar score, rate of admission to higher levels of care (neonatal intensive care unit or special care nursery) and length of neonatal stay. These outcomes are compared between PAP and control using intention-to-treat analysis.Ethics and disseminationThis study has been approved by the Institutional Review Boards at Washington University in St Louis, Missouri; Hadassah Hebrew University Medical Center, Jerusalem; and the University of Rochester, New York. Recruitment began in Washington University in November 2019 but stopped from March to November 2020 due to COVID-19. Recruitment began in Hadassah Hebrew University in March 2021, and in the University of Rochester in May 2021. Dissemination plans include presentations at scientific conferences and scientific publications.Trial registration numberNCT04084990.
Impact of the first COVID-19 lockdown on study satisfaction and burnout in medical students in Split, Croatia: a cross-sectional presurvey and postsurvey
Authors: Žuljević Marija Franka , Jeličić Karlo , Viđak Marin , Đogaš Varja , Buljan Ivan 
Published: June 2021

ObjectivesTo evaluate the impact of the first COVID-19 lockdown in 2020 on the burnout and study satisfaction of medical students.DesignA cross-sectional study with a presurvey and postsurvey.SettingUniversity of Split School of Medicine (USSM), Split, Croatia. The lockdown in the COVID-19 pandemic lasted from late March to mid-May 2020. There was a full switch to e-learning at the USSM during this period, and all clinical teaching was stopped.ParticipantsStudents enrolled in the 2019/2020 academic year. Data were collected before lockdown in December 2019 and January 2020 and again after the end of lockdown in June 2020.Primary and secondary outcome measuresStudy satisfaction was assessed using the study satisfaction survey. Burnout was assessed using two instruments: Oldenburg Burnout Inventory and Copenhagen Burnout Inventory. We used Bayesian statistics to compare before-and-after differences.Results437 independent responses (77.2% response rate) were collected before and 235 after lockdown (41.5% response rate). 160 participant responses were eligible for pairing. There was no significant difference for both paired and unpaired participants in study satisfaction before (3.38 on a 1–5 scale; 95% credible interval (95% CrI) 3.32 to 3.44) and after (3.49, 95% CrI 3.41 to 3.57) lockdown. We found no evidence (Bayes factor (BF10) >3.00 as a cut-off value) for an increase in the level of burnout before and after lockdown, both in independent and paired samples.ConclusionsIt seems that the first pandemic-related lockdown and a switch to e-learning did not affect burnout levels among medical students or their perception of their study programme. More insight is needed on the short-term and long-term effects of the COVID-19 pandemic on medical students and their education. Well-structured longitudinal studies on medical student burnout during the COVID-19 pandemic are needed.
Relationship between trajectories of post-stroke disability and self-rated health (NeuroAdapt): protocol for a prospective observational study
Authors: Schäfer Sarah K , Fleischmann Robert , von Sarnowski Bettina , Bläsing Dominic , Flöel Agnes , Wurm Susanne 
Published: June 2021

IntroductionStroke is the leading neurological cause of adult long-term disability in Europe. Even though functional consequences directly related to neurological impairment are well studied, post-stroke trajectories of functional health according to the International Classification of Functioning, Disability and Health are poorly understood. Particularly, no study investigated the relationship between post-stroke trajectories of activities of daily living (ADL) and self-rated health (SRH). However, such knowledge is of major importance to identify patients at risk of unfavourable courses. This prospective observational study aims to investigate trajectories of ADL and SRH, and their modifying factors in the course of the first year after stroke.Methods and analysisThe study will consecutively enrol 300 patients admitted to a tertiary care hospital with acute ischaemic stroke or transient ischaemic attack (TIA; Age, Blood Pressure, Clinical Features, Duration of symptoms, Diabetes score ≥3). Patient inclusion is planned from May 2021 to September 2022. All participants will complete an interview assessing ADL, SRH, mental health, views on ageing and resilience-related concepts. Participants will be interviewed face-to-face 1–5 days post-stroke/TIA in the hospital; and will be followed up after 6 weeks, 3 months, 6 months and 12 months via telephone. The 12-month follow-up will also include a neurological assessment. Primary endpoints are ADL operationalised by modified Rankin Scale scores and SRH. Secondary outcomes are further measures of ADL, functional health, physical activity, falls and fatigue. Views on ageing, social support, resilience-related concepts, affect, frailty, illness perceptions and loneliness will be examined as modifying factors. Analyses will investigate the bidirectional relationship between SRH and ADL using bivariate latent change score models.Ethics and disseminationThe study has been approved by the institutional review board of the University Medicine Greifswald (Ref. BB 237/20). The results will be disseminated through scientific publications, conferences and media. Moreover, study results and potential implications will be discussed with patient representatives.Trial registration numberNCT04704635.