bluuebunny/crossref_metadata_2025_split huggingface dataset:
A robust deformed convolutional neural network (CNN) for image denoising
Authors: Zhang Qi , Xiao Jingyu , Tian Chunwei , Chun‐Wei Lin Jerry , Zhang Shichao 
Published: June 2022

AbstractDue to strong learning ability, convolutional neural networks (CNNs) have been developed in image denoising. However, convolutional operations may change original distributions of noise in corrupted images, which may increase training difficulty in image denoising. Using relations of surrounding pixels can effectively resolve this problem. Inspired by that, we propose a robust deformed denoising CNN (RDDCNN) in this paper. The proposed RDDCNN contains three blocks: a deformable block (DB), an enhanced block (EB) and a residual block (RB). The DB can extract more representative noise features via a deformable learnable kernel and stacked convolutional architecture, according to relations of surrounding pixels. The EB can facilitate contextual interaction through a dilated convolution and a novel combination of convolutional layers, batch normalisation (BN) and ReLU, which can enhance the learning ability of the proposed RDDCNN. To address long‐term dependency problem, the RB is used to enhance the memory ability of shallow layer on deep layers and construct a clean image. Besides, we implement a blind denoising model. Experimental results demonstrate that our denoising model outperforms popular denoising methods in terms of qualitative and quantitative analysis. Codes can be obtained at https://github.com/hellloxiaotian/RDDCNN.
Exploring reconfigurable intelligent surfaces for 6G: State‐of‐the‐art and the road ahead
Authors: Basharat Sarah , Khan Maryam , Iqbal Muhammad , Hashmi Umair Sajid , Zaidi Syed Ali Raza , Robertson Ian 
Published: June 2022

AbstractReconfigurable intelligent surfaces (RISs) are envisioned to transform the propagation space into a smart radio environment (SRE) to realize the diverse applications of sixth‐generation (6G) wireless communication. By smartly tuning the massive number of elements via controller, an RIS can passively phase‐shift the electromagnetic (EM) waves to enhance the system performance. The absence of radio‐frequency (RF) chains makes RIS an energy‐efficient and cost‐effective solution for future wireless networks. In this paper, the state‐of‐the‐art research on different aspects of RIS‐assisted communication is explored. Specifically, the fundamentals of RIS are first introduced, including the RIS's structure, operating principle, and deployment strategies. The emerging applications of RISs are then comprehensively discussed for 6G wireless networks. In addition, the crucial challenges for RIS‐assisted networks are elaborated, namely, RIS channel state information (CSI) acquisition and passive beamforming optimization. Furthermore, the recent research contributions leveraging the artificial intelligence (AI) based techniques for channel estimation, phase‐shift optimization, and resource allocation in RIS‐assisted networks are presented. Finally, to provide effective guidance for future research, important research directions for realizing RIS‐assisted network are highlighted.
On the solutions to Sylvester‐conjugate periodic matrix equations via iteration
Authors: Zhang Lei , Li Pengxiang , Han Mengqi , Zhang Yanfeng , Chang Rui , Zhang Jinhua 
Published: June 2022

AbstractThe problem of solving a class of Sylvester‐conjugate periodic matrix equations is investigated in this paper. Utilising conjugate gradient method, an iterative algorithm is provided, from which a matrix sequence can be generated to approximate the unknown matrix of the equation to be solved. Theoretical derivation proves that the proposed algorithm is convergent starting from any initial value, and simulation examples show the effectiveness of the proposed algorithm.
Characteristic analysis and optimisation of an asymmetric‐primary axial‐flux hybrid‐excitation generator for vertical‐axis wind turbines
Authors: Liu Jing , Huang Lei , Zhang Qiang , Chen Jiming 
Published: June 2022

AbstractAxial‐flux wind generators have advantages of high ratio of generator diameter to generator length and high possibility of modular construction, which make them suitable for use in vertical‐axis wind turbines. The design optimisation and analysis of an asymmetric‐primary axial‐flux hybrid‐excitation generator that can provide a controllable suspension magnetic levitation force to compensate for the ripple of axial force fluctuation are described. First, the mechanical topological operation principle of the proposed generator is introduced, and four generators with different magnetic field modulation ratios and winding distributions are investigated. Second, the levitation force and the torque model are based on the d/q axes dynamic mathematical model. Four generators are compared based on no‐load performance. Considering the polar arc coefficient, this study analyzes the no‐load performance. In addition, comprehensive analyses of the on‐load performance under two typical load conditions are conducted. Based on simulation results and by integrating the magnetic field modulation ratio, tooth width, and permanent magnet thickness, the optimal design of a 12s22p generator is obtained. Finally, a prototype of the 12s22p generator is manufactured and tested in a laboratory situation under on‐load and no‐load conditions. All of the findings are consistent with the simulation results.
Nano‐indentation investigation on nano‐twinned Cu–Ag alloys with GBAZ segregation
Authors: Zhu Dasheng , Ye Wenli , Zhang Feng , Zhou Jianqiu , Li Guo , Ni Shuang 
Published: June 2022

AbstractFor the sake of comprehending the mechanical mechanisms of nano‐twinned (NT) Cu–Ag alloys with grain boundary affect zone (GBAZ) segregation, molecular dynamics (MD) simulations were used to observe its behaviours during the nano‐indentation progress. The effect of grain size, alloying atoms (Ag) content as well as twin boundary spacing (TBS) on the deformation behaviours are considered in this investigation. The open visualization tool OVITO is used to directly observe the deformation progress of nanocrystals during nano‐indentation. The reaction between lattice dislocations and twin boundaries is recorded and analyzed in detail as the indentation deepens. The simulation results demonstrate a positive correlation between the twin boundary spacing and the occurrence of dislocations. The dislocation rings will appear more effortlessly as the TBSs increase. Meanwhile, it is frequently observed that the face centre cubic (FCC) atoms are transformed into body centre cubic (BCC) atoms. This work will help to seek for novel metal materials with high strength, high ductility and great electrical conductivity.
A review of power system dynamic equivalents for transient stability studies
Authors: Kai Saijiang , Che Yong , Zhang Feng , Wu Gaolei , Zhou Zhuan , Huang Ping 
Published: June 2022

AbstractThe increasing complexity of interconnected power system has brought challenges to detailed dynamic simulation in terms of computational effort. Therefore, for transient stability assessment, dynamic equivalents of parts of large‐scale system are required to capture the electromagnetic transients. This paper presents a review of past research on dynamic equivalencing using coherency‐based methods and system identification methods. Future topics are discussed to improve the state‐of‐art approaches.
Biomarker assessment in urgent surgical pathology of the small bowel: case-control analysis of a retrospective database
Authors: Kryvoruchko Igor A. , Briukhanova Tetiana O. , Nakonechna Oksana A. , Olefir Olexander S. 
Published: June 2022

Background: Small bowel obstruction, mesenteric thrombosis, and strangulated ventral hernia area a challenge in emergency abdominal surgery. This study aimed to evaluate biomarkers of damage to the digestive tract in patients with urgent pathology. Materials and methods: The study involved 71 patients aged 18 to 80 years who were hospitalized in the intensive care unit in the immediate postoperative period. Results: All 71 underwent emergency surgery, 27 with small bowel necrosis. Lactate level area under curve (AUC = 0.964), C-reactive protein (AUC = 0.805) and systolic blood pressure (area under curve, AUC = 0.803) on the context of Sequential Organ Failure Assessment (SOFA) score (AUC = 0.880) showed stratification of patients with complications before surgery. Small bowel necrosis patients revealed an increase in primary thiobarbituric acid (TBA) reactive products (AUC = 0.813) lipid peroxidation products, and a decrease in superoxide dismutase activity (AUC = 0.818) and catalase (AUC = 0.804). Wide variability of intestinal fatty-acid binding protein (I-FABP) from 199.8 to 2189.6 pg/mL were observed in all patients studied, with an AUC = 0.814 in small intestinal necrosis. Conclusion: Surgical pathology of the small intestine due to obstruction of various origina, mesenteric thrombosis, and strangulated ventral hernia pronounced revealed disorders of the antioxidant-prooxidant balance. This was expressed by an increase in lipid peroxidation products, and the level of TBA-reactive products, and the activities of superoxide dismutase (SOD), and catalase. Viewed against the background of an increase in I-FABP above 577 pg/mL, these variables were the most significant indicators of small intestinal necrosis.
Effect of Routine Gastric Residual Aspiration on the Preterm Infant Fecal Microbiome
Authors: Lenfestey Mary W. , Li Nan , Gauthier Josee , Winglee Kathryn , Fodor Anthony , Zeng Ke , Jobin Christian , Neu Josef , Parker Leslie A. 
Published: June 2022

Objective Enteral feeding tubes are used in neonatal intensive care units (NICUs) to assess feeding tolerance by utilizing preprandial gastric residual aspiration. This study evaluates the effect of gastric residual aspiration on the preterm infant fecal microbiome and gastrointestinal inflammation.
Study Design Fifty-one very low birth weight (VLBW) infants (≤32 weeks' gestational age and ≤1,250 g) enrolled in a larger single-center randomized controlled trial evaluating the effects of routine and nonroutine gastric residual aspiration were selected for further analysis. Of those infants, 30 had microbiome analysis performed on stools collected at 6 weeks by sequencing the bacterial V1 to V3 variable regions of the genes encoding for 16S rRNA. In an additional 21 infants, stool samples collected at 3 and 6 weeks were analyzed for intestinal inflammation using a cytokine multiplex panel.
Results Microbial communities between groups were not distinct from each other and there was no difference in intestinal inflammation between groups. Analyses using gene expression packages DESeq2 and edgeR produced statistically significant differences in several taxa, possibly indicating a more commensal intestinal microbiome in infants not undergoing gastric residual aspiration.
Conclusion Omission of routine gastric residual aspiration was not associated with intestinal dysbiosis or inflammation, providing additional evidence that monitors preprandial gastric residuals is unnecessary.
Key Points
Resolved but Not Forgotten: The Effect of Resolved Placenta Previa on Labor Management
Authors: Feldman Kristina M. , Robinson Andre , Gellman Caroline , Kaplowitz Elianna , Hussain Farrah N. , AL-Ibraheemi Zainab , Strauss Tirtza S. , Ashmead Graham , Cole David , Brustman Lois 
Published: June 2022

Objectives Placenta previa is diagnosed in up to 15% of pregnancies at the anatomy ultrasound and 0.5% persist to term. There is limited data regarding pregnancy outcomes with resolved previa. We aimed to examine patients with resolved placenta previa to determine if abnormal placentation at any time during pregnancy is associated with adverse events during labor.
Study Design Patients with placenta previa were identified after second trimester ultrasound, included if placenta previa resolved with the placental edge greater than 2 cm from the internal cervical os, and excluded if placenta previa persisted to term, resolution occurred prior to 20 weeks, patients underwent a prior cesarean delivery, or delivered at an outside institution. Time-matched controls were identified among patients with normal placental location. Demographic data and outcomes were collected. Student's t-test, Wilcoxon's rank-sum test, Chi-square, Fisher's exact test, and univariable and multivariable logistic regression were used as appropriate
Results Overall, 560 patients had placenta previa, 275 had resolved placenta previa, 285 were excluded. Resolved placenta previa patients were significantly older with lower prepregnancy body mass index (BMI), were significantly more likely to be a current smoker, have used assisted reproductive technology, and have had previous uterine surgeries. Overall, 10.2% of patients with resolved placenta previa experienced postpartum hemorrhage, compared with 2.1% in the normal placentation group. Patients with resolved placenta previa were 5.2 times more likely to have a postpartum hemorrhage (odds ratio [OR] = 5.2, 95% confidence interval [CI]: 2.1–12.7; p < 0.01) and 3.4 times more likely to require extra uterotonic medications (OR = 3.4, 95% CI: 1.9–6.2; p < 0.01). There is no difference with regard to rates of operative delivery for fetal distress (OR = 1.2, 95% CI: 0.7–1.9; p = 0.48), or category-II or-III fetal heart tracing around the time of delivery.
Conclusion Patients with resolved placenta previa had a higher rate of postpartum hemorrhage and use of uterotonic agents. This information might have important clinical implications and could be incorporated into the hemorrhage risk assessment during labor.
Key Points
Association of Maternal Body Mass Index and Maternal Morbidity And Mortality
Authors: Dinsmoor Mara J. , Ugwu Lynda G. , Bailit Jennifer L. , Reddy Uma M. , Wapner Ronald J. , Varner Michael W. , Thorp John M. , Caritis Steve N. , Prasad Mona , Tita Alan T.N. , Saade George R. , Sorokin Yoram , Rouse Dwight J. , Blackwell Sean C. , Tolosa Jorge E. ,   for the Eunice Kennedy Shriver National Institute of Child Health Human Development Maternal-Fetal Medicine Units (MFMU) Network*
Published: June 2022

Objective This study aimed to assess the association of maternal body mass index (BMI) with a composite of severe maternal outcomes.
Study Design Secondary analysis of a cohort of deliveries on randomly selected days at 25 hospitals from 2008 to 2011. Data on comorbid conditions, intrapartum events, and postpartum course were collected. The reference group (REF, BMI: 18.5–29.9kg/m2), obese (OB; BMI: 30–39.9kg/m2), morbidly obese (MO; BMI: 40–49.9kg/m2), and super morbidly obese (SMO; BMI ≥ 50kg/m2) women were compared. The composite of severe maternal outcomes was defined as death, intensive care unit (ICU) admission, ventilator use, deep venous thrombosis/pulmonary embolus (DVT/PE), sepsis, hemorrhage, disseminated intravascular coagulation (DIC), unplanned operative procedure, or stroke. Patients in the REF group were matched 1:1 with those in all other obesity groups based on propensity score using the baseline characteristics of age, race/ethnicity, previous cesarean, preexisting diabetes, chronic hypertension, parity, cigarette use, and insurance status. Multivariable Poisson's regression was used to estimate adjusted relative risks (aRRs) and 95% confidence intervals (CIs) for the association between BMI and the composite outcome. Because cesarean delivery may be in the causal pathway between obesity and adverse maternal outcomes, models were then adjusted for mode of delivery to evaluate potential mediation.
Results A total of 52,162 pregnant patients are included in the analysis. Risk of composite maternal outcomes was increased for SMO compared with REF but not for OB and MO [OB: aRR=1.06, 95% CI: 0.99–1.14; MO: aRR=1.10, 95% CI: 0.97–1.25; SMO: aRR=1.32, 95% CI: 1.02–1.70]. However, in the mediation analysis, cesarean appears to mediate 46% (95% CI: 31–50%) of the risk of severe morbidity for SMO compared with REF.
Conclusion Super morbid obesity is significantly associated with increased serious maternal morbidity and mortality; however, cesarean appears to mediate this association. Obesity and morbid obesity are not associated with maternal morbidity and mortality.
Key Points
Novel Evidence-Based Labor Induction Algorithm Associated with Increased Vaginal Delivery within 24 Hours
Authors: Kuba Kfier , Estrada-Trejo Fatima , Lambert Calvin , Vani Kavita , Eisenberg Ruth , Nathan Lisa , Bernstein Peter , Hughes Francine 
Published: June 2022

Objective This study aimed to assess whether concordance with our proposed labor induction algorithm is associated with an increased rate of vaginal delivery within 24 hours.
Study Design We conducted a retrospective review of 287 induction of labors (IOLs) at a single urban, tertiary, academic medical center which took place before we created an evidence-based IOL algorithm. We then compared the IOL course to the algorithm to assess for concordance and outcomes. Patients age 18 years or over with a singleton, cephalic pregnancy of 366/7 to 420/7 weeks' gestation were included. Patients were excluded with a Bishop's score >6, contraindication to misoprostol or cervical Foley catheter, major fetal anomalies, or intrauterine fetal death. Patients with 100% concordance were compared with <100% concordant patients, and patients with ≥80% concordance were compared with <80% concordant patients. Adjusted hazard ratios (AHRs) were calculated for rate of vaginal delivery within 24 hours, our primary outcome. Competing risk's analysis was conducted for concordant versus nonconcordant groups, using vaginal delivery as the outcome of interest, with cesarean delivery (CD) as a competing event.
Results Patients with 100% concordance were more likely to have a vaginal delivery within 24 hours, n = 66 of 77 or 85.7% versus n = 120 of 210 or 57.1% (p < 0.0001), with an AHR of 2.72 (1.98, 3.75, p < 0.0001) after adjusting for delivery indication and scheduled status. Patients with 100% concordance also had shorter time from first intervention to delivery (11.9 vs. 19.4 hours). Patients with ≥80% concordance had a lower rate of CD (11/96, 11.5%) compared with those with <80% concordance (43/191 = 22.5%; p = 0.0238). There were no differences in neonatal outcomes assessed.
Conclusion Our IOL algorithm may offer an opportunity to standardize care, improve the rate of vaginal delivery within 24 hours, shorten time to delivery, and reduce the CD rate for patients undergoing IOL.
Key Points
Characterization of a new ultra-high pressure shock tube facility for combustion and propulsion studies
Authors: Urso Justin J. , Kinney Cory , Terracciano Anthony C. , Barak Samuel , Laich Andrew , Albright Marley A. , Pierro Michael , McGaunn Jonathan , Vasu Subith S. 
Published: June 2022

A new shock tube facility has been designed, constructed, and characterized at the University of Central Florida. This facility is capable of withstanding pressures of up to 1000 atm, allowing for combustion diagnostics of extreme conditions, such as in rocket combustion chambers or in novel power conversion cycles. For studies with toxic gas impurities, the high initial pressures required the development of a gas delivery system to ensure the longevity of the facility and the safety of the personnel. Data acquisition and experimental propagation were implemented with remote access to ensure safety, paired with a LabVIEW- and Python-based user interface. Thus far, test pressures of 270 atm, blast pressures of 730 atm, and temperatures approaching 10 000 K have been achieved. The extreme limitations of this facility allow for emission spectroscopy to be performed during the oxidation of fuel mixtures, e.g., alkanes diluted in argon and carbon dioxide. Ignition delay times were determined and compared to simulations using chemical kinetic mechanisms. The design, experimental procedures, processes of analysis, and uncertainty determination are outlined, and typical pressure profiles are compared with a new gas dynamics solver and empirical correlations developed across multiple shock tube facilities. Preliminary reactive mixture analyses are included with further investigation of the mixtures outlined.
CHESS: The future direct geometry spectrometer at the second target station
Authors: Sala G. , Mourigal M. , Boone C. , Butch N. P. , Christianson A. D. , Delaire O. , DeSantis A. J. , Hart C. L. , Hermann R. P. , Huegle T. , Kent D. N. , Lin J. Y. Y. , Lumsden M. D. , Manley M. E. , Quirinale D. G. , Stone M. B. , Z Y. 
Published: June 2022

CHESS, chopper spectrometer examining small samples, is a planned direct geometry neutron chopper spectrometer designed to detect and analyze weak signals intrinsic to small cross sections (e.g., small mass, small magnetic moments, or neutron absorbing materials) in powders, liquids, and crystals. CHESS is optimized to enable transformative investigations of quantum materials, spin liquids, thermoelectrics, battery materials, and liquids. The broad dynamic range of the instrument is also well suited to study relaxation processes and excitations in soft and biological matter. The 15 Hz repetition rate of the Second Target Station at the Spallation Neutron Source enables the use of multiple incident energies within a single source pulse, greatly expanding the information gained in a single measurement. Furthermore, the high flux grants an enhanced capability for polarization analysis. This enables the separation of nuclear from magnetic scattering or coherent from incoherent scattering in hydrogenous materials over a large range of energy and momentum transfer. This paper presents optimizations and technical solutions to address the key requirements envisioned in the science case and the anticipated uses of this instrument.
Resonance and sensing characteristics of horn-shaped cavity-coupled MIM waveguide
Authors: Yang Fengying 
Published: June 2022

The resonant coupling of optical microcavities to waveguides is important in photonic devices. In this paper, a horn-shaped cavity structure is designed on the side of the metal–dielectric–metal waveguide, and the coupling between the cavity and the waveguide is simulated by the finite-difference time-domain method and the coupled mode theory. It is found that the cavity and local modes appear in the horn-shaped cavity. Second, the geometric parameters of the cavity structure are changed, and the influence of the structural parameters on the transmission spectrum is obtained by theoretical analysis. Third, the maximum refractive index sensitivity of the structure is calculated to be 1750 nm/RIU, and the temperature sensitivity is 2.455 nm/°C. Ultrafine particles are placed between the tips of the horn-shaped cavity structure, and the sensitivity of the wavelength shift of the localized mode and the change in the transmittance of the trapezoidal cavity mode to the particle size and the refractive index of the particles are obtained; the nanoparticle sensor is designed by using this characteristic. The horn-shaped resonator structure proposed in this paper provides a high-performance cavity choice for the design and application of micro-nano sensor devices.