bluuebunny/crossref_metadata_2025_split huggingface dataset:
High voltage gain bi‐directional Z‐source inverters with dual‐loop feed‐forward peak DC‐link voltage compensation for fuel cell vehicles
Authors: Wang Can , Yang Dewei , Pang Zhicong , Pan Xuewei , Zhao Fei 
Published: December 2021

AbstractHigh boost inverter is an essential part to interface the fuel cell stack and traction motor for fuel cell vehicles (FCVs). This paper proposes two novel high voltage gain bi‐directional Quasi‐ZSIs (QZSI) with new active switched inductor cells for FCVs application. The disadvantages of low voltage boost ratio, large start up current, unfavourable mode operations and unidirectional power flow in conventional Z‐source inverter (ZSI) are eliminated. The proposed Z‐source inverters are combined with active switched inductor cells to achieve a higher voltage gain and lower voltage stress over capacitors, which can be widely applied in energy storage systems. A small signal model is derived by dynamic analysis. In order to achieve a constant peak dc‐link voltage, a dual‐loop feed‐forward peak dc‐link voltage control strategy for the proposed QZSI is introduced in this paper. Simulation and experiment waveforms are presented to verify the theoretic analysis of the designed QZSIs and the proposed control strategy.
Adaptive channel estimation for cognitive fully adaptive radar
Authors: Kang Bosung , Gogineni Sandeep , Rangaswamy Muralidhar , Guerci Joseph R. , Blasch Erik 
Published: December 2021

AbstractThe paper addresses channel state information estimation for a cognitive radar system. The underlying radar signal model considered in this paper is based on a stochastic Green's function approach. In the radar model, the clutter returns can be expressed as a convolution of the stochastic Green's function impulse response with the transmit radar waveform. The paper proposes and solves constrained channel estimation algorithms that exploit the cosine similarity constraint and the inner product constraint to improve conventional least squares solutions. Using the fact that adjacent channel transfer functions have a close relationship in terms of a cosine similarity metric, the cosine similarity constraint can be exploited in the least squares problem. It turns out that the derived optimisation problem under the cosine similarity constraint is non‐convex. However, since strong duality holds for the non‐convex optimisation problem, it can be solved using the semi‐definite relaxation (SDR) approach. The paper also proposes a new optimisation problem with an additional inner product constraint, which results in a convex second‐order cone programming (SOCP) and is robust to the signal‐to‐noise ratio (SNR) in terms of the cosine similarity measurement. Numerical simulations are provided to verify the performance of the proposed methods on a challenge dataset generated using the high‐fidelity modelling and simulation tool, RFView®.
Full‐time domain deformation characteristics of water drop on sheds edge causing insulation failure of large‐diameter composite post insulators under heavy rainfall
Authors: Yang Lin , Shang Gaofeng , Liao Yifan , Sun Yijie , Hao Yanpeng , Li Licheng 
Published: December 2021

AbstractInsulation failures caused by water drops deformation on insulator sheds edge greatly threaten the stable operation of power grid. However, only few studies have focused on water drops deformation characteristics on insulator sheds edge. In this paper, full‐time domain deformation of water drop was defined. The rain tests were performed to study the deformation of water drops and obtain water drops parameters under DC voltage. The water drops deformation parameter was selected according to the state of water drops when arc is generated. A fluid‐electric field coupling method is employed to establish simulation model to study the influence of water drops initial diameter, initial mass flow rate, DC voltage, and conductivity on water drops deformation. It is indicated that water drops maximum deformation length before first break in simulation is in good consistency with that obtained from rain tests. The water drops initial diameter, initial mass flow rate, and DC voltage significantly influence the deformation of water drops on sheds edge. Moreover, the water drops may even bridge adjacent sheds in some cases. In contrast, the effect of water drops conductivity on the water drops deformation is not apparent.
Design and evaluation of innovative protocols for LoRa
Authors: Zhong Chen , Springer Andreas 
Published: December 2021

AbstractThis paper proposes a low power application dedicated protocol stack which consists of a contention‐constrained p‐CSMA (CCP) protocol over the LoRa modulation technique and a consecutive successful transmission controlled transport (CSTCT) protocol. The aim of these innovative protocols is to boost the network performance in terms of throughput and energy consumption while the transmission latency is still acceptable. As a reference, firstly, p‐CSMA is evaluated with the consideration of under‐noise‐level communication. Then, the CCP protocol is proposed with the consideration of the speciality of the carrier sensing feature provided by the LoRa modem, which differs from the traditional energy level detection carrier sensing method. The CSTCT protocol resides at the CCP MAC layer which is light‐weight and devised to further improve the overall throughput. The performance of the protocol stack is evaluated in simulations using various settings with predefined parameters that are drawn from experiments. The results show that our CCP MAC protocol and CSTCT transport protocol provide 10% higher throughput compared to the classic p‐CSMA when the offered load is lower than 1.3 while the energy consumption is reduced by a factor of 2 and it remains latency limited.
A Retrospective Study of Disparities in an Academic Ophthalmic Emergency Department
Authors: Szypko Colleen , Hall Nathan , Ta Thong , Gardiner Matthew F. , Lorch Alice C. 
Published: December 2021

Abstract
Purpose Emergency medicine is a common access point to health care; disparities in this care by demographic characteristics, including race and ethnicity, may affect outcomes. The Massachusetts Eye and Ear (MEE) Emergency Department (ED) is a subspecialty emergency department; data from this site can be utilized to better understand social determinants of quality ophthalmic care.
Design This is a retrospective cross sectional cohort study in the MEE ED examining patient visits from June 1, 2016 to June 30, 2019.
Methods Using the electronic medical record system, all unique visits were identified between June 1, 2016 and June 30, 2019 (inclusive); patient demographics (sex, race, ethnicity [Hispanic vs. non-Hispanic], primary care provider [PCP] status, insurance type, zip code, primary language), date of visit, triage category and outcomes (final diagnosis, visit duration, and next visit at MEE within 3 months of the ED visit) were collected. Kaplan-Meier plots were used to visualize likelihood of follow-up visit to MEE for urgent patients based on demographics. Multivariate linear regression was used to examine factors affecting visit durations, as stratified by urgency, and Cox proportional hazards regression was used to establish hazard ratios for next visit to MEE.
Results Of the 46,248 ophthalmology ED initial visits, only triage status, season of visit, out-of-state residency, Medicare coverage, and Medicaid coverage led to statistically significant differences in visit durations for urgent visits compared with the respective reference groups. Similar trends persisted within the non-urgent visit cohort for visit durations. Residency, insurance coverage, season of visit, race, PCP status, and sex were identified as statistically significant predictors of the likelihood of a follow-up visit.
Conclusion Data from an ophthalmic emergency department suggest that demographic factors do impact patient visit duration and time to follow-up visit. These findings suggest a continued need for attention to social determinants of health and equitable care of patients within ophthalmology.
Duodenoscope-Acquired Infections: Risk Factors to Consider
Authors: Thornhill Grace , Dunkin Brian 
Published: December 2021

AbstractIn the wake of highly publicized duodenoscope-associated outbreaks caused by multidrug-resistant organisms (MDRO), a herculean effort was made to understand the conditions that led to these transmission events. Although there is now a clearer picture on how these outbreaks happened, there are still significant data gaps when it comes to understanding the rate of duodenoscope-acquired infections (DAIs), especially in nonoutbreak situations. Recent publications indicate that DAIs are still occurring and suggest that infection rates are higher than currently believed. Given this data gap, it is important to identify those patient populations that are most at risk of postprocedure infection, so that appropriate infection control measures may be implemented. Although those patients receiving antibiotic prophylaxis are most at risk for infection, there are additional risk factors that should be considered. For the purposes of this review, risk factors for infection were divided into three broad categories as follows: (1) those that increase patient susceptibility to infection, (2) those related to the endoscopic procedure, and (3) those factors that put reusable duodenoscope inventories at risk of contamination. Infection risk is a complex interaction between the immune status of the patient, the characteristics of the infectious agent (antibiotic sensitivity, virulence factors, and epidemiology), and the environment of care. Because of this complexity, any assessment of the risk of infection should be performed on a case-by-case basis. There is a dearth of information on infection risk for those patients undergoing endoscopic retrograde cholangiopancreatograpy (ERCP), especially in the context of the development and implementation of new device technology, and new endoscopic procedures that are increasing in complexity. This narrative review was developed using the Medical Subject Heading (MeSH) terms to perform an electronic search in PubMed with the goal of generating a summary of the patient, procedural, and duodenoscope-associated factors that increase the risk of infection in patients undergoing ERCP. This review provides practical information regarding the segmentation of ERCP patients by infection risk, so that endoscopists can make informed decisions about the risk benefits of using enhanced duodenoscope technologies in the care of their patients.
Transcystic Removal of Common Bile Duct Stones in Surgically Altered Anatomy (Roux-en-Y Gastric Bypass)
Authors: Thyloor Surakshith K. , Singla Vikas , Chowbey Pradeep 
Published: December 2021

AbstractEndoscopic retrograde cholangiopancreatography in patients with surgically altered anatomy can be technically challenging. Various techniques have been described; however, the technical success rate depends on the type of reconstruction, length of the afferent limb, access to the papilla, availability of accessories, and adequate expertise. We describe successful transcystic removal of common bile duct stones in a patient with Roux-en-Y gastric bypass using cholangioscope and SpyGlass retrieval device at the time of cholecystectomy.
Comparison between Medical Student Educators and Program Directors in 2010 and 2019
Authors: Sankar Prithvi S. , Giaconi JoAnn A. , Goyal Anju , Graubart Emily G. , Kemp Pavlina S. , Knoch Daniel W. , Rosenberg Jamie B. 
Published: December 2021

Abstract
Objective Over the last decade, prominence of the Directors of Medical Student Education in Ophthalmology (DMSEs) within the Association of University Professors of Ophthalmology (AUPO) has increased. With increased recognition of this important leadership position, an examination of the trending demographic differences between DMSEs and the Ophthalmology Program Directors (PDs) may be helpful, especially in regard to the potential for academic promotion from each track.
Design Present study is a database study.
Methods The AUPO directory was used to ascertain the DMSE and the PD members between 2010 and 2019. The demographic profile for each member was determined using publicly available resources. Chi-square analysis of the data was performed.
Main Outcome Measures Number of DMSE and PD AUPO from 2010 to 2019 in AUPO Directory, sex, geographic location, and graduation year were measured through this study.
Results There has been a steady increase in the number of DMSEs from 2010 to 2019, whereas the number of PDs have remained stable. The number of DMSEs have increased in all regions of the United States. The year of ophthalmology residency graduation was similar in the DMSE and PD cohorts in 2010 and 2019. The number of women have increased in the DMSEs in 2019 compared with 2010; the number of women who were PDs in 2019 were similar to 2010. Finally, more PDs in 2010 became Chairs in 2019, whereas no DMSEs in 2010 became Chair in 2019.
Conclusion There are a growing number of DMSEs, overall, with an increasing proportion of women in the 2019 DMSE group compared with 2010. In contrast, the overall number of PDs have remained stable, as has the proportion of female PDs in 2019 compared with 2010. DMSEs, compared with PDs, are less likely to become Chairs. The increased opportunity for academic leadership with the growing DMSE group may help change leadership patterns overall in academic ophthalmology.
Long-Term Outcome Up To 40 Years after Single Patch Repair of Complete Atrioventricular Septal Defect in Infancy or Childhood
Authors: Reynen Stefanie , Hövels-Gürich Hedwig H. , Vazquez-Jimenez Jaime F. , Messmer Bruno J. , Sachweh Joerg S. 
Published: December 2021

Abstract
Objectives Patients with repaired complete atrioventricular septal defect (CAVSD) represent an increasing portion of grown-ups with congenital heart disease. For repair of CAVSD, the single-patch technique has been employed first. This technique requires division of the bridging leaflets, thus, among other issues, long-term function of the atrioventricular valves is of particular concern.
Methods Between 1978 and 2001, 100 consecutive patients with isolated CAVSD underwent single-patch repair in our institution. Hospital mortality was 11%. Primary endpoints were clinical status, atrioventricular valve function, and freedom from reoperation in long term. Follow-up was obtained contacting the patient and/or caregiver, and the referring cardiologist.
Results Eighty-three patients were eligible for long-term follow-up (21.0 ± 8.7, mean ± standard deviation [21.5; 2.1–40.0, median; min–max] years after surgical repair). Actual long-term mortality was 3.4%. Quality of life (QoL; self- or caregiver-reported in patients with Down syndrome) was excellent or good in 81%, mild congestive heart failure was present in 16%, moderate in 3.6% as estimated by New York Heart Association classification. Echocardiography revealed normal systolic left ventricular function in all cases. Regurgitation of the right atrioventricular valve was mild in 48%, mild–moderate in 3.6%, and moderate in 1.2%. The left atrioventricular valve was mildly stenotic in 15% and mild to moderately stenotic in 2%; regurgitation was mild in 54%, mild to moderate in 13%, and moderate in 15% of patients. Freedom from left atrioventricular-valve-related reoperation was 95.3, 92.7, and 89.3% after 5, 10, and 30 years, respectively. Permanent pacemaker therapy, as an immediate result of CAVSD repair (n = 7) or as a result of late-onset sick sinus syndrome (n = 5), required up to six reoperations in single patients. Freedom from pacemaker-related reoperation was 91.4, 84.4, and 51.5% after 5, 10, and 30 years, respectively.
Conclusion Up to 40 years after single-patch repair of CAVSD, clinical status and functional results are promising, particularly, in terms of atrioventricular valve function. Permanent pacemaker therapy results in a life-long need for surgical reinterventions.
The Impact of Virtual Interviews on the Geographic Distribution of Ophthalmology Match Results in the 2020–2021 Cycle
Authors: Rasendran Chandruganesh , Rahman Sarah , Younis Uthman , Wadhwa Raoul , Kapadia Manasvee , Lass Jonathan H. , Ohsie-Bajor Linda H. 
Published: December 2021

Abstract
Background Instead of the traditional in-person interviews, the 2020 to 2021 ophthalmology application cycle was conducted with virtual interviews due to coronavirus disease 2019 (COVID-2019). Little is known about differences between the results of this application cycle with previous years.
Objectives The aim of this study was to determine the effect of virtual interviews on the geographic distribution of matched ophthalmology residency applicants.
Methods Information was collected on the medical school location and matched residency program location for 2020 to 2021 applicants as well as applicants during the 2016 to 2017, 2017 to 2018, and 2018 to 2019 cycles from publicly available Web sites. Pearson chi-squared tests were conducted to determine whether there was a significant difference in the proportion of applicants matching in the same region, state, and institution as their medical schools in the 2020 to 2021 interview cycle when compared with past cycles.
Results Three-hundred seventy-five applicants from 2020 to 2021 and 1,190 applicants from 2016 to 2019 application cycles were analyzed. There was no difference in the type of medical school attended (allopathic vs. osteopathic vs. international medical graduate) (p = 0.069), the likelihood of attending a residency program in the same region as the home medical school (54% for 2020–2021 vs. 57% for 2016–2019 applicants, p = 0.3), and the likelihood of attending a residency program in the same state as the home medical school (31 vs. 28%, p = 0.2). There was a higher likelihood of applicants during the 2020 to 2021 cycle matching at a residency program affiliated with their home medical school than previous cycles (23 vs. 18%, p = 0.03).
Conclusions Virtual interviews did not increase the likelihood of medical students staying in the same region or state as their medical school, while there was a higher likelihood of applicants matching at residency programs at institutions affiliated with their medical schools. A hybrid approach to maintain geographic diversity of applicants' final residency programs involving virtual interviews with the addition of in-person away rotations is suggested.
Energy quadratization Runge–Kutta method for the modified phase field crystal equation
Authors: Shin Jaemin , Lee Hyun Geun , Lee June-Yub 
Published: December 2021

Abstract
In this paper, we propose high order and unconditionally energy stable methods for a modified phase field crystal equation by applying the strategy of the energy quadratization Runge–Kutta methods. We transform the original model into an equivalent system with auxiliary variables and quadratic free energy. The modified system preserves the laws of mass conservation and energy dissipation with the associated energy functional. We present rigorous proofs of the mass conservation and energy dissipation properties of the proposed numerical methods and present numerical experiments conducted to demonstrate their accuracy and energy stability. Finally, we compare long-term simulations using an indicator function to characterize the pattern formation.
The modeling of a Tokamak plasma discharge, from first principles to a flight simulator
Authors: Fable Emiliano , Janky Filip , Treutterer W , Englberger Michael , Schramm Raphael , Muraca Marco , Angioni Clemente , Kudlacek Ondrej , Poli Emanuele , Reich Matthias , Siccinio Mattia , Tardini Giovanni , Weiland Markus , Wu Chuanren , Zohm Hartmut 
Published: December 2021

Abstract
A newly developed tool to simulate a tokamak full--discharge is presented. The tokamak "flight--simulator" Fenix couples the tokamak control system with a fast and reduced plasma model, yet realistic enough to take into account several of the plasma non--linearities. Distinguishing feature of this modeling tool is that it only requires the Pulse Schedule (PS) as input to the simulator. The output is a virtual realization of the full discharge, which time traces can then be used to judge if the PS satisfies control/physics goals or needs to be revised. This tool is thought for routine use in the control--room before each pulse is performed, but can also be used off--line to correct PS in advance, or to develop and validate reduced models, control schemes, and in general the simulation framework.
Simultaneous multiple-level magnification selective plane illumination microscopy (sMx-SPIM) imaging system
Authors: S R Rinsa , Chitre Kripa , Kurup Aditya , Nongthomba Upendra , Murty Srinivasula Srinivasa , Suheshkumar Singh Mayanglambam 
Published: December 2021

Abstract
We report an optical-based microscopy imaging technology—simultaneous multiple-level magnification selective plane illumination microscopy (sMx-SPIM) imaging system—that addresses a longstanding technological challenge of obtaining images, specifically of biological specimen non-destructively, at different field of views (FOVs) and spatial resolutions (or magnification powers) simultaneously in real-time. This imaging system provides not only 3D images but also time-resolved sequential images with temporal resolution ∼ msec. Magnification powers (or FOVs) of the individual images can be controlled independently that is achieved by housing two separate detection arms, in SPIM imaging system, fitted with objective lenses of different magnification powers. This unique feature holds promises to observe and study: (a) sub-microscopic details and entire structure of biological specimen side-by-side simultaneously and (b) spatio-temporal dynamics of functional activities of biological specimen. For validation study of robustness of the proposed sMx-SPIM imaging system, experiments are conducted in various biological samples including Danio rerio (zebrafish) embryo, Drosophila melanogaster, Allium cepa root, and A549 cell line. Experimental results demonstrate that the study is of significant impacts from two aspects, viz., technological implication and biological applications.
Understanding the Rayleigh instability in humping phenomenon during laser powder bed fusion process
Authors: Zhang Wenxuan , Hou Wenyuan , Deike Luc , Arnold Craig 
Published: December 2021

Abstract
The periodic undulation of a molten track’s height profile in laser-based powder bed fusion of metals (PBF-LB/M) is a commonly observed phenomena that can cause defects and building failure during the manufacturing process. However a quantitative analysis of such instabilities has not been fully established and so here we used Rayleigh–Plateau theory to determine the stability of a single molten track in PBF-LB/M and tested it with various processing conditions by changing laser power and beam shape. The analysis discovered that normalized enthalpy, which relates to energy input density, determines whether a molten track is initially unstable and if so, the growth rate for the instability. Additionally, whether the growth rate ultimately yields significant undulation depends on the melt duration, estimated by dwell time in our experiment.