bluuebunny/crossref_metadata_2025_split huggingface dataset:
Designing matching waveform pair with sparse frequency and low autocorrelation sidelobes
Authors: Chen Xiaoying , Chen Baixiao , Wu Chuanzhang 
Published: December 2020

AbstractSparse frequency waveform is widely used to suppress the narrowband interferences. The performance that can be achieved with a single waveform is limited. The authors study the approach to design a pair of matching waveforms with low autocorrelation sidelobes and arbitrary frequency stopbands. Two algorithms based on the minimum mean square error (MMSE) between the actual waveform characteristics and the desired waveform characteristics are proposed to deal with this problem. The constrained optimization problem is solved by an alternating iteration method. Numerical experiments show that the proposed algorithms can provide better performance than the existing methods.
Nearest feature line classifier based on collaborative representation with nearest neighbour search algorithm
Authors: Zhuang Zhongjie , Pan Jeng‐Shyang , Chu Shu‐Chuan , Luo Hao 
Published: December 2020

AbstractNearest feature line is an effective classification algorithm. However, if a test sample cannot be linear represented by the training samples, the algorithm may not work very well. Moreover, another problem is that it will have a large computation complexity. Therefore, the authors propose a novel algorithm. To begin with, the test sample is linear represented by all the training samples, and the errors between the test sample and every training sample are calculated. The authors only keep the training samples with small errors. In this way, on the one hand, training samples are not suitable for the test sample will be ignored, on the other hand, running time can be reduced. To further reduce the computing time of the algorithm, nearest neighbour search technique is applied to the algorithm. Experiments on numerical and image database show the algorithm cannot only improve the classification accuracy, but also reduce runtime.
A self‐biased and all‐in‐one voltage and current reference
Authors: Wang Yuanfei , Luo Ping , Yang Bingzhong , Tang Tianyuan , Zhang Bo 
Published: December 2020

AbstractThis Letter presents a high‐performance self‐biased and all‐in‐one voltage and current reference without BJT and V–I converter exploiting the zero‐temperature‐coefficient point of the N‐type MOSFET. With the help of the low‐temperature‐coefficient resistors and the self‐biased two‐stage OTA structure, the all‐in‐one reference can achieve the average temperature coefficients of 6.6 and 34 ppm/°C of voltage and current reference from −40 to 125 °C, respectively. Meanwhile, the line sensitivities are 0.08%/V and 0.23%/V of voltage and current reference. And the power supply rejection ratio of the voltage reference is −93 dB@100 Hz with the power consumption of 12.6 μW@tt corner and VDD = 2.5 V. The reference circuit is realized in a standard 180 nm CMOS process with the area of 0.0621 mm × mm.
Short‐term load demand forecasting through rich features based on recurrent neural networks
Authors: Zhao Dongbo , Ge Qian , Tian Yuting , Cui Jia , Xie Boqi , Hong Tianqi 
Published: December 2020

AbstractWith the emerging penetration of renewables and dynamic loads, the understanding of grid edge loading conditions becomes increasingly substantial. Load modelling researches commonly consist of explicitly expressed load models and non‐explicitly expressed techniques, of which artificial intelligence approaches turn out to be the major path. This paper reveals the artificial intelligence‐based load modelling technique to enhance the knowledge of current and future load information considering geographical and weather dependencies. This paper presents a recurrent neural network based sequence to sequence (Seq2Seq) model to forecast the short‐term power loads. Also, a feature attention mechanism, which is along channel and time directions, is developed to improve the efficiency of feature learning. The experiments over three publicly available datasets demonstrate the accuracy and effectiveness of the proposed model.
The stability control for isolated wind‐diesel power system based on the cross coupling effect model
Authors: Mi Yang , Lang Zhongjie , Chen Xin , Fu Yang , Jin Chi , Shi Shuai , Zhao Yao , Jiang Enyu 
Published: December 2020

AbstractIn the isolated wind‐diesel hybrid power system, the system voltage and frequency may be affected simultaneously by the fluctuated wind turbine output power and variable load, which can make the system crash in extreme cases without control strategy. Therefore, in order to reduce the voltage and frequency deviation caused by system power fluctuation, both the battery and super twisting algorithm sliding mode state observer (STATCOM) are equipped to adjust the active power and reactive power for load power demand in the isolated small‐scale power system. Then, the system mathematical model is established which considers the cross‐coupling effect exist in the small‐scale power system. In order to improve the control effect of battery and STATCOM, the unified control strategy is designed for battery and STATCOM by using the super twisting sliding mode state observer and the adaptive sliding mode controller according to the constructed cross‐coupling effect model. Furthermore, the parameters of controller are further optimized by using the fuzzy method. Finally, the simulation experiments are performed by the real‐time digital simulator to validate the effectiveness of the proposed control strategy under different operation points.
Analytical approximation for macroscopic fundamental diagram of urban corridor with mixed human and connected and autonomous traffic
Authors: Hu Guojing , Lu Weike , Whalin Robert W. , Wang Feng , Kwembe Tor A. 
Published: December 2020

AbstractAdvances in connected and autonomous vehicles have the promise to reshape the future of the transportation system. How and when the benefits associated with automation and connectivity technology will start to impact the performance of an urban corridor is an issue of interest for traffic operators. This paper proposes an analytical capacity model for urban corridors with mixed traffic based on the concept of macroscopic fundamental diagram. The model incorporates the full spectrum of connected and autonomous vehicle penetration rates as well as the reaction times of different vehicle following patterns. The connected and autonomous vehicle platoon intensity, formulated as an exponential function of the connected and autonomous vehicle penetration rate, is also considered in the proposed analytical capacity model. Numerical experiments are conducted to verify that different reaction time settings yield disparate results. Some reaction time settings were found to cause the corridor capacity to increase monotonically with the connected and autonomous vehicle penetration rate while others led to decreases in corridor capacity with connected and autonomous vehicle penetration rates. Finally, the validity of the proposed methodology is verified via simulation tests in VISSIM 2020.
Synthesis of multi‐band filters based on multi‐prototype transformation
Authors: Chen Xianhong 
Published: December 2020

AbstractIn this article, a new synthesis method for generalized multi‐band filters has been proposed. Different from the traditional frequency transformation method, which transforms a low‐pass prototype into a multi‐band filter, multiple low‐pass prototypes have been transformed into a multi‐band filter. This study introduces the idea of transforming more than two lowpass prototypes into a filter, called multi‐prototype transformation. It divides the multi‐band filter to be synthesized into different segments each of which corresponds to a low‐pass prototype. After frequency transformation, these segments are combined together to get the final transfer function. The multi‐band filter synthesized by this method can have different orders, bandwidths or return losses in different passbands. Prescribed transmission zeros can also be realized. The return loss adjustment, segment boundary estimation and equal‐ripple realization of this method are further explained in theory. To verify this method, an asymmetric quad‐band filter is synthesized as an example and a symmetric triple‐band filter is synthesized, designed, fabricated and measured. The obtained results show good agreement with the simulation.
Compact parallel‐plate waveguide half‐Luneburg geodesic lens in the Ka‐band
Authors: Fonseca Nelson J.G. , Liao Qingbi , Quevedo‐Teruel Oscar 
Published: December 2020

AbstractA parallel‐plate waveguide half‐Luneburg geodesic lens is designed and experimentally validated in the Ka‐band. The geodesic lens profile is modulated using spline functions to reduce its height, while the symmetry halving the lens enables reduction of its in‐plane dimensions. This design provides high gain, equivalent to that of a full‐Luneburg lens, over a reduced angular range of ±20° to ±30° in azimuth. The specific design reported here has a maximum realized gain of 23.3 dBi in measurement, compared with 23.8 dBi for a full‐Luneburg lens twice the size of this design. Very wideband operation is demonstrated both in simulations and measurements. This design is of interest for applications having limited space like millimetre‐wave systems on board cubesats and small satellites.
Novel single‐armed modular multilevel converter for reducing total converter capacitance
Authors: Pourgharibshahi Hamed , Jafarishiadeh Seyyedmahdi , Mahmoudi Hamid , Zargarzadeh Hassan , Ahmadi Reza 
Published: December 2020

AbstractDuring normal operation of a conventional Modular Multilevel Converter (MMC), half of its capacitors remain bypassed at any time instant, increasing the total required capacitance for converter operation, and in turn leading to a larger size and volume MMC for a target capacitor voltage ripple limit. This paper presents a novel MMC topology that utilizes all converter capacitors at all times during the operation. Therefore, the total required capacitance for generating a voltage waveform with the same number of levels and the same target capacitor voltage ripple limit is greatly reduced compared to conventional MMCs. The new topology inherits all the desirable features of conventional MMCs such as modularity, reliability, and scalability, and is compatible with many of the previously proposed control techniques for conventional MMCs. The process of synthesizing the proposed MMC topology and a new voltage balancing scheme as well as the dynamic model and capacitor sizing procedure for the proposed MMC are reported in the paper. Furthermore, experimental results are presented to evaluate the performance of the proposed converter.
A family of high voltage gain quasi‐Δ‐source impedance networks
Authors: Rezazadeh Hamed , Monfared Mohammad , Nikbahar Ali , Sharifi Saeed 
Published: December 2020

AbstractThis paper proposes a class of impedance networks, called quasi‐Δ‐source, as an improvement to the successful Δ‐source one. Compared to their origin, the three proposed networks offer higher voltage gains with a better magnetic circuit utilization and a smooth continuous input current. A lower magnetizing and total inductance required for the Δ‐shaped coupled inductors of the proposed networks allows smaller and cheaper magnetic cores utilization. Also, a lower total power loss of the magnetically coupled elements is another interesting advantage of the proposed networks. Moreover, the total required capacitance of the proposed networks is the same and even slightly lower than that of the conventional Δ‐source one. All these improve the performance of the proposed class of networks with the smaller size of components compared to their conventional competitor. The principles of operation are developed and the theoretical analysis is performed. Also, by using the circuit averaging technique, the small‐signal models of the Δ‐source and the proposed networks are derived as well as their control‐to‐output transfer function is achieved. Finally, the experiments on a 300 W rated power prototype of the proposed networks successfully confirm the theoretical achievements.
Observing the changing surface structures of the active K giant
σ Geminorum with SONG
Authors: Korhonen H. , Roettenbacher R. M. , Gu S. , Grundahl F. , Andersen M. F. , Henry G. W. , Jessen-Hansen J. , Antoci V. , Pallé P. L. 
Published: December 2020

Aims. We aim to study the spot evolution and differential rotation in the magnetically active cool K-type giant star σ Gem from broadband photometry and continuous spectroscopic observations that span 150 nights.
Methods. We use high-resolution, high signal-to-noise ratio spectra obtained with the Hertzsprung SONG telescope to reconstruct surface (photospheric) temperature maps with Doppler imaging techniques. The 303 observations span 150 nights and allow for a detailed analysis of the spot evolution and surface differential rotation. The Doppler imaging results are compared to simultaneous broadband photometry from the Tennessee State University T3 0.4 m Automated Photometric Telescope. The activity from the stellar chromosphere, which is higher in the stellar atmosphere, is also studied using SONG observations of Balmer Hα line profiles and correlated with the photospheric activity.
Results. The temperature maps obtained during eight consecutive stellar rotations show mainly high-latitude or polar spots, with the main spot concentrations above latitude 45°. The spots concentrate around phase 0.25 near the beginning of our observations and around phase 0.75 towards the end. The photometric observations confirm a small jump in spot phases that occurred in February 2016. The cross-correlation of the temperature maps reveals rather strong solar-like differential rotation, giving a relative surface differential rotation coefficient of α = 0.10 ± 0.02. There is a weak correlation between the locations of starspots and enhanced emission in the chromosphere at some epochs.
Vacuum ultraviolet photoabsorption spectroscopy of space-related ices: formation and destruction of solid carbonic acid upon 1 keV electron irradiation
Authors: Ioppolo S. , Kaňuchová Z. , James R. L. , Dawes A. , Ryabov A. , Dezalay J. , Jones N. C. , Hoffmann S. V. , Mason N. J. , Strazzulla G. 
Published: December 2020

Context. Carbonic acid (H2CO3) is a weak acid relevant to astrobiology which, to date, remains undetected in space. Experimental work has shown that the β-polymorph of H2CO3 forms under space relevant conditions through energetic (UV photon, electron, and cosmic ray) processing of CO2- and H2O-rich ices. Although its α-polymorph ice has been recently reassigned to the monomethyl ester of carbonic acid, a different form of H2CO3 ice may exist and is synthesized without irradiation through surface reactions involving CO molecules and OH radicals, that is to say γ-H2CO3.
Aims. We aim to provide a systematic set of vacuum ultraviolet (VUV) photoabsorption spectroscopic data of pure carbonic acid that formed and was destroyed under conditions relevant to space in support of its future identification on the surface of icy objects in the Solar System by the upcoming Jupiter ICy moons Explorer mission and on interstellar dust by the James Webb Space Telescope spacecraft.
Methods. We present VUV photoabsorption spectra of pure and mixed CO2 and H2O ices exposed to 1 keV electrons at 20 and 80 K to simulate different interstellar and Solar System environments. Ices were then annealed to obtain a layer of pure H2CO3 which was further exposed to 1 keV electrons at 20 and 80 K to monitor its destruction pathway. Fourier-transform infrared (FT-IR) spectroscopy was used as a secondary probe providing complementary information on the physicochemical changes within an ice.
Results. Our laboratory work shows that the formation of solid H2CO3, CO, and O3 upon the energetic processing of CO2:H2O ice mixtures is temperature-dependent in the range between 20 and 80 K. The amorphous to crystalline phase transition of H2CO3 ice is investigated for the first time in the VUV spectral range by annealing the ice at 200 and 225 K. We have detected two photoabsorption bands at 139 and 200 nm, and we assigned them to β-H2CO3 and γ-H2CO3, respectively. We present VUV spectra of the electron irradiation of annealed H2CO3 ice at different temperatures leading to its decomposition into CO2, H2O, and CO ice. Laboratory results are compared to Cassini UltraViolet Imaging Spectrograph observations of the 70−90 K ice surface of Saturn’s satellites Enceladus, Dione, and Rhea.
Ligand-Driven Advances in Iridium-Catalyzed sp3 C–H Borylation: 2,2′-Dipyridylarylmethane
Authors: Schley Nathan D. , Jones Margaret R. 
Published: December 2020

AbstractThe field of catalytic C–H borylation has grown considerably since its founding, providing a means for the preparation of synthetically versatile organoborane products. Although sp2 C–H borylation methods have found widespread and practical use in organic synthesis, the analogous sp3 C–H borylation reaction remains challenging and has seen limited application. Existing catalysts are often hindered by incomplete consumption of the diboron reagent, poor functional-group tolerance, harsh reaction conditions, and the need for excess or neat substrate. These challenges acutely affect the C–H borylation chemistry of unactivated hydrocarbon substrates, which has lagged in comparison to methods for the C–H borylation of activated compounds. Herein, we discuss recent advances in the sp3 C–H borylation of undirected substrates in the context of two particular challenges: (1) utilization of the diboron reagent and (2) the need for excess or neat substrate. Our recent work on the application of dipyridylarylmethane ligands in sp3 C–H borylation has allowed us to make contributions in this space and has presented an additional ligand scaffold to supplement traditional phenanthroline ligands.
Indispensability of Clinical Bioinformatics for Effective Implementation of Genomic Medicine in Pathology Laboratories
Authors: Chamala Srikar , Majety Siddardha , Mishra Shesh Nath , Newsom Kimberly J. , Gothi Shaileshbhai Revabhai , Walton Nephi A. , Dolin Robert H. , Starostik Petr 
Published: December 2020

AbstractPatient care is rapidly evolving toward the inclusion of precision genomic medicine when genomic tests are used by clinicians to determine disease predisposition, prognosis, diagnosis, and improve therapeutic decision-making. However, unlike other clinical pathology laboratory tests, the development, deployment, and delivery of genomic tests and results are an intricate process. Genomic technologies are diverse, fast changing, and generate massive data. Implementation of these technologies in a Clinical Laboratory Improvement Amendments-certified and College of American Pathologists-accredited pathology laboratory often require custom clinical grade computational data analysis and management workflows. Additionally, accurate classification and reporting of clinically actionable genetic mutation requires well-curated disease/application-specific knowledgebases and expertise. Moreover, lack of “out of the box” technical features in electronic health record systems necessitates custom solutions for communicating genetic information to clinicians and patients. Genomic data generated as part of clinical care easily adds great value for translational research. In this article, we discuss current and future innovative clinical bioinformatics solutions and workflows developed at our institution for effective implementation of precision genomic medicine across molecular pathology, patient care, and translational genomic research.
Pharmacologic Thromboprophylaxis and Thrombosis in Hospitalized Patients with COVID-19: A Pooled Analysis
Authors: Patell Rushad , Chiasakul Thita , Bauer Ethan , Zwicker Jeffrey I. 
Published: December 2020

AbstractBackground Coronavirus disease 2019 (COVID-19) increases thrombosis in hospitalized patients prompting adoption of different thromboprophylaxis strategies. Safety and efficacy of escalated-dose pharmacologic thromboprophylaxis are not established.Objectives To determine the pooled incidence of thrombosis/bleeding in hospitalized patients with COVID-19 for standard-dose, intermediate-dose, therapeutic anticoagulation, and no pharmacologic thromboprophylaxis.Methods MEDLINE, EMBASE, and Cochrane CENTRAL were searched up to August 29, 2020 for studies reporting pharmacologic thromboprophylaxis and thrombosis or bleeding. Pooled event rates were calculated using a random-effects model.Results Thirty-five observational studies were included. The pooled incidence rates of total venous thromboembolism (N = 4,685) were: no prophylaxis 41.9% (95% confidence interval [CI]: 28.1–57.2, I 2 = 76%), standard-dose prophylaxis 19.8% (95% CI: 13.2–28.6, I 2 = 95%), intermediate-dose prophylaxis 11.9% (95% CI: 4.3–28.6, I 2 = 91%), and therapeutic-dose anticoagulants 10.5% (95% CI: 4.2–23.8, I 2 = 82%, p = 0.003). The pooled incidence rates of arterial thrombosis (N = 1,464) were: no prophylaxis 11.3% (95% CI: 5.2–23.0, I 2 = 0%), standard-dose prophylaxis 2.5% (95% CI: 1.4–4.3, I 2 = 45%), intermediate-dose prophylaxis 2.1% (95% CI: 0.5–7.7, I 2 = 45%), and therapeutic-dose anticoagulants 1.3% (95% CI: 0.2–8.8, I 2 = 0, p = 0.009). The pooled bleeding event rates (N = 6,393) were nonsignificantly higher in therapeutic-dose anticoagulants compared with standard-dose prophylaxis, (6.3 vs. 1.7%, p = 0.083).Conclusion Thrombosis rates were lower in hospitalized COVID-19 patients who received pharmacologic thromboprophylaxis. Thrombosis and bleeding rates for patients receiving intermediate-dose thromboprophylaxis or therapeutic anticoagulation were similar to those who received standard-dose pharmacologic thromboprophylaxis.
The Association between Blood-Based Global DNA Methylation and Venous Thromboembolism
Authors: Wang Xiao , Memon Ashfaque A. , Palmér Karolina , Svensson Peter J. , Sundquist Jan , Sundquist Kristina 
Published: December 2020

AbstractAlterations in DNA methylation patterns have been associated with many diseases. However, the role of DNA methylation in venous thromboembolism (VTE) is not well established. The aim of this study was to investigate a possible association between global DNA methylation and VTE. The study participants consisted of 168 individuals including 74 patients with primary VTE from the Malmö Thrombophilia Study (MATS) and 94 healthy controls. Among 74 primary VTE patients, 37 suffered VTE recurrence during the follow-up period; 37 nonrecurrent VTE patients were included for comparison. Blood-based global DNA methylation was assessed by an enzyme-linked immunosorbent assay. Global DNA methylation was significantly higher in primary VTE patients compared with the healthy controls (median: 0.17 vs. 0.08%; p < 0.001). After stratification of data from primary VTE patients according to sex, the association between higher global DNA methylation and shorter recurrence-free survival time was of borderline statistical significance in males (β = –0.2; p = 0.052) but not in females (β = 0.02; p = 0.90). Our results show that global DNA methylation is associated with primary VTE and that higher levels of global DNA methylation may be associated with early VTE recurrence in males but not in females. Further investigation on the role of DNA methylation as a diagnostic or preventive biomarker in VTE is warranted.