bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave functionality of spintronic devices implemented in a hybrid complementary metal oxide semiconductor and magnetic tunnel junction technology
Authors: Ma Rui , Sidi El Valli Ahmed , Kreißig Martin , Di Pendina Gregory , Protze Florian , Ebels Ursula , Prenat Guillaume , Chavent Antoine , Iurchuk Vadym , Sousa Ricardo , Vila Laurent , Ellinger Frank , Langer Jürgen , Wrona Jerzy , Prejbeanu Ioan‐Lucian 
Published: February 2021

AbstractThis letter presents magnetic tunnel junction based spintronic devices completely implemented in a hybrid semiconductor process that comprises a complementary metal oxide semiconductor and a magnetic tunnel junction technology. To demonstrate the coexistence of both complementary metal oxide semiconductor circuits and magnetic tunnel junction based spintronic devices, a proof‐of‐concept circuit prototype comprising 40 spintronic devices and a digital complementary metal oxide semiconductor serial peripheral interface is fabricated. According to measurement results, a selected spintronic device from the magnetic tunnel junction array, when surrounded by an external out‐of‐plane magnetic field of 1 kOe, emitted microwave signals from 2.235 to 2.464 GHz with an output power from 0.88 to 0.72 nW, when the DC current was increased from 0.6 to 1.0 mA. To the authors' best knowledge, this is the first work demonstrating the functionality of spintronic oscillators fully integrated in complementary metal oxide semiconductor circuit implemented in a hybrid complementary metal oxide semiconductor and magnetic tunnel junction process.
Self‐supervised learning with randomised layers for remote sensing
Authors: Jung Heechul , Jeon Taegyun 
Published: February 2021

AbstractThis letter presents a new self‐supervised learning approach based on randomised layers for remote sensing. Our method is basically based on the Tile2Vec approach, which is one of the state‐of‐the‐art self‐supervised learning approaches for remote sensing. Unlike the original Tile2Vec algorithm, we reformulate the triplet loss as a classification loss. We use several fully connected layers with binary cross‐entropy loss instead of no fully connected layers with triplet loss of the original Tile2Vec. We observe that not updating the fully connected layers is more helpful in obtaining more robust representations. The proposed algorithm is verified and evaluated by applying it to a cropland data layer classification task. The experimental results show that our approach is superior to the original Tile2Vec approach in all experiments based on random forest, logistic regression, and multi‐layer classifiers.
Spatial attention model‐modulated bi‐directional long short‐term memory for unsupervised video summarisation
Authors: Zhong Rui , Xiao Diyang , Dong Shi , Hu Min 
Published: February 2021

AbstractCompared with surveillance video, user‐created videos contain more frequent shot changes, which lead to diversified backgrounds and a wide variety of content. The high redundancy among keyframes is a critical issue for the existing summarising methods in dealing with user‐created videos. To address the critical issue, we designed a salient‐ area‐size‐based spatial attention model (SAM) on the observation that humans tend to focus on sizable and moving objects in videos. Moreover, the SAM is taken as guidance to refine frame‐wise soft selected probability for the bi‐directional long short‐term memory model. The reinforcement learning framework, trained by the deep deterministic policy gradient algorithm, is adopted to do unsupervised training. Extensive experiments on the SumMe and TVSum datasets demonstrate that our method outperforms the state‐of‐the‐art in terms of F‐score.
Analysis of feasibility and advantages of multi‐source image registration using regional features
Authors: Zeng Liang , Lu Danwei , Zhu Qingtao , Xing Cheng , Yin Junjun , Yang Jian 
Published: February 2021

AbstractAutomatic registration of multi‐source remote sensing data is a challenging task due to the high non‐linearity of radiometric differences among various data. Feature extraction is a key enabling technique in registration algorithm design. In this letter, we prove the feasibility of using extracted regional features for multi‐source image registration. In particular, regional features can be extracted through pixel‐level image classification, and existing off‐the‐shelf algorithms can be directly adopted. Experiment results demonstrate the robustness of the regional‐feature‐based registration method.
Geometric correction code‐based robust image watermarking
Authors: Zhou Zhili , Zhu Jianyu , Su Yuecheng , Wang Meimin , Sun Xingming 
Published: February 2021

AbstractDigital image watermarking is one of the effective schemes to protect the copyrights of still images. However, the existing watermarking schemes are still not robust enough to the common geometric transformation attacks such as arbitrary rotation, scaling and shifting with desirable hiding capacity. To address this issue, we propose a robust watermarking scheme based on geometric correction codes (GCCs). In this scheme, the watermark and pre‐set GCCs are combined and embedded into a cover image to obtain the watermarked image. At the stage of watermark extraction, the watermarked image, under a variety of geometric transformation attacks, can be geometrically corrected by minimising the difference between the extracted and the original GCCs, then the watermark is extracted from the watermarked image. The experiments demonstrate that, compared to the typical watermarking schemes, the proposed scheme achieves much higher robustness to the common geometric transformation attacks and comparable invisibility with the same embedding capacity.
Cellulose nanocrystals/water‐based polyurethane nanocomposite films with excellent wear resistance and softness
Authors: Liu Rongrong , Zhu Feichao , Hu Jinqing , Li Jinzhe , Han Jian 
Published: February 2021

AbstractWaterborne polyurethane (WBPU) has the advantages of environmental, excellent film‐forming property and high bonding strength. However, the mechanical strength of waterborne polyurethane in coating products is not enough, and its wear resistance and softness are poor. In this paper, the Cellulose Nanocrystals (CNC) AQ3 obtained by acid hydrolysis of microcrystalline cellulose was successfully dispersed in the waterborne polyurethane matrix to prepare nanocomposite films with different contents. The mechanical properties, thermal properties, wear resistance and softness of the nanocomposite films were studied by Thermogravimetric (TG), tensile test, dry friction test and KES test. The morphology of CNC dispersed in waterborne polyurethane matrix was studied by Scanning electron microscope (SEM). The results show that the lower content of CNC was uniformly dispersed in the waterborne polyurethane matrix and the interaction between the two forms hydrogen bonds. Compared with waterborne polyurethane, the initial degradation temperature of the nanocomposite films made by adding only 1 wt% CNC increased by 50°C, the tensile strength increased by 179.3%, the wear resistance increased by 19%, and the minimum bending stiffness B reached 0.161 (gf·cm2). The results of this study can be used for textile coating applications, such as polyurethane synthetic leather.
Study on adsorption of Cd2+ by Ti‐pillared montmorillonite‐mixed activated carbon
Authors: Zhao Xuxia , Tuo Biyang , Long Sen , Song Xiang , Wan Li , Xiang Haichun 
Published: February 2021

AbstractIn this study, the composite of Ti‐pillared montmorillonite‐mixed activated carbon (TPM‐AC) was prepared by the water immersion method, and the adsorption of Cd2+ was studied under static conditions. A series of single experiments were conducted to determine the effects of the solution pH, adsorption time, initial Cd2+ concentration, and solution temperature on adsorption performance. The adsorption kinetics, isotherms, and thermodynamics behaviours of Cd2+ onto TPM‐AC were investigated. The results showed that the Brunauer–Emmett–Teller specific surface area and pore volume of TPM‐AC are increased, the crystallinity is greatly improved, and porous structural material with a large specific surface area is formed. The adsorption of Cd2+ by TPM‐AC is excellent and better than that of AC and TPM. The adsorption of Cd2+ by TPM‐AC, AC, and TPM can be described by the pseudo‐second‐order kinetic equation, and the adsorption isotherm is more consistent with the Langmuir isotherm model. The RL values of the dimensionless separation constants are all between 0 and 1, indicating that adsorption of Cd2+ is a relatively easy adsorption process. The values of thermodynamic parameters indicated that the adsorption is a reverse spontaneous and endothermic process.
Preparation of 2D ultrathin titanium dioxide nanosheets with enhanced visible‐light photocatalytic activity
Authors: Dai Zideng , Song Xue‐Zhi , Tang Fan , Kang Xiaolan , Liu Sihang , Abe Hiroya , Ohara Satoshi , Tan Zhenquan 
Published: February 2021

AbstractThe two‐dimensional (2D) ultrathin titanium dioxide (TiO2) nanosheets with large specific surface area and fast electron transfer are successfully fabricated by using P123 as a soft template during a conventional hydrothermal process. Ultrathin structure improves the lifetime of the photogenerated electron and hole. The bandgap of the 2D materials is reduced with the calcination treatment. The TiO2 nanosheets calcined at 300°C exhibit higher photocatalytic activity in degradation of methylene blue and rhodamine B under visible light irradiation, and excellent photoelectrochemical performance allow them a wide use in energy and environmental applications.
DC–DC Series‐resonant converter with multi‐stage current‐driven for balance charger of series‐connected lithium‐ion batteries
Authors: Farahani Gholamreza 
Published: February 2021

AbstractHere, a novel DC–DC converter based on a series‐resonant inverter and a multi‐stage current‐driven rectifier for the active balance charger of lithium‐ion series batteries is proposed. In the proposed topology, diodes are placed in a current‐driven half‐wave rectifier to regulate the voltage at the terminals of the batteries. The proposed balance charger has been compared with the Cockcroft–Walton voltage multiplier, DC–DC multilevel boost converter, chain structure using an additional capacitor, and series‐resonant voltage multiplier topologies. The cost of the proposed topology has not increased in comparison to other topologies and can be made modularly and more stages can be increased by adding capacitors and diodes. The experimental results are obtained from charging six lithium‐ion series batteries, of which one of them has been damaged. All topologies balance and charge the rest of the batteries despite the damaged battery. The results show that the proposed topology for the converter has reduced the average balancing and charging time by 40.77% and 13.33%, respectively, compared to other topologies. Therefore, the energy losses of the proposed topology are less than the other topologies. Also, the higher energy efficiency of the proposed topology is expected due to the faster‐balancing speed.
Modified natural frame control of single‐phase cascaded H‐bridge multilevel converter under distorted grid voltage
Authors: Yang Daliang , Chen Shuang , Zhang Xuan , Yang Linhang , Liu Jinbao , Shao Dashuai 
Published: February 2021

AbstractCascaded H‐bridge multilevel converter is widely applied in flexible AC transmission and grid connection of renewable energy, but its current quality decreases as the grid voltage distortion continues to deteriorate. A modified natural frame control method to enhance the harmonic elimination ability of converters is proposed in this paper. A single‐phase cascaded delayed signal cancellation operator is applied to deal with the distorted grid voltage signals. Benefit from a system structure without any feedback loops or integral items, the transient response of single‐phase cascaded delayed signal cancellation operator is faster than commonly‐used second‐order generalised integrator. The settling time of single‐phase cascaded delayed signal cancellation operator facing grid voltage phase jump is less than one grid period. After immunising the synchronisation reference against harmonic distortion by using the single‐phase cascaded delayed signal cancellation operator, the modified natural frame control method can then generate high‐quality sinusoidal current. Phase‐locked loop and coordinate transformation are unnecessary for the proposed method, which decreases the system complexity. Various simulations and experimental tests based on a down‐scaled platform demonstrate the performance of the proposed modified natural frame control method under distorted grid voltage.
Bidirectional DC–DC converter based multilevel battery storage systems for electric vehicle and large‐scale grid applications: A critical review considering different topologies, state‐of‐charge balancing and future trends
Authors: Eroǧlu Fatih , Kurtoǧlu Mehmet , Vural Ahmet Mete 
Published: February 2021

AbstractThe expanding share of renewable energy sources (RESs) in power generation and rise of electric vehicles (EVs) in transportation industry have increased the significance of energy storage systems (ESSs). Battery is considered as the most suitable energy storage technology for such systems due to its reliability, compact size and fast response. Power converters are vital for the integration of batteries into power grid and EVs as they play an active role in both power conversion and battery management. Multilevel converters (MLCs) are types of power converters and attract widespread interest due to their improved power quality, reliability and modularity. There are two main challenges in MLC based battery storage systems (BSSs) which are selecting a proper MLC topology and balancing state‐of‐charges (SOCs) of batteries. Although some research has been carried out on either MLCs or SOC balancing, no single study exists which presents a comprehensive review on MLC based BSSs for large‐scale grid and EV applications. This paper begins by reviewing several major battery storage technologies that are utilised in MLC based BSSs. Later on, a systematical review of commonly used and recently proposed MLC topologies for BSSs are provided along with different control schemes for MLCs by specifically focusing on SOC balancing techniques. Finally, potential challenges and suggestions for future improvement of MLC based BSSs are addressed.
Comprehensive coordinated control strategy of PMSG‐based wind turbine for system inertia support
Authors: Zhu Ying , Liu Sheng , Wang Wei 
Published: February 2021

AbstractWith the increasing proportion of wind energy in the power system, wind turbines (WTs) need to have a certain system inertia support capability. This paper proposes a comprehensive coordinated control strategy of permanent magnet synchronous generators (PMSGs) based wind turbines for the system inertia support. Firstly, a variable coefficient integrated inertial control method is proposed to adjust the output of the wind turbine with the size of the disturbance. Secondly, a virtual capacitor control strategy is added and then the generator‐side converter can provide a much larger virtual capacitance than the DC‐side capacitance to provide fast, transient additional power support. Furthermore, the pitch angle de‐loading control is adopted when the wind speed exceeds the rated value for maintaining the stability of the system frequency. The comprehensive coordinated control strategy proposed in this paper can effectively give the system inertia support by realizing certain frequency regulation of wind turbines under various wind conditions and frequency fluctuations. The frequency response characteristics of PMSGs based wind turbines are studied in MATLAB/Simulink and the simulation results are presented to verify the effectiveness of the comprehensive coordinated control strategy.
Performance characteristics and reliability assessment of self‐excited induction generator for wind power generation
Authors: Varshney Lokesh , Vardhan Aanchal Singh S. , Vardhan Akanksha Singh S. , Kumar Sachin , Saket R.K. , Sanjeevikumar P. 
Published: February 2021

AbstractThe
paper presents the performance analysis‐based reliability
estimation of a self‐excited induction
generator (SEIG) using the Monte‐Carlo simulation (MCS)
method with data obtained from a self‐excited induction
motor operating as a generator. The global acceptance of a SEIG depends on its
capability to improve the system's poor voltage regulation and frequency
regulation. In the grid‐connected induction
generator, the magnetizing current is drawn from the grid, making the grid
weak. In contrast, in the SEIG stand‐alone operation, an external capacitor
arrangement is implemented to render the reactive power support. This capacitor
arrangement is connected across the stator terminals during the stand‐alone configuration of SEIG. The capacitor serves two purposes,
which include voltage build‐up and power factor
improvement. Therefore, the paper deals with obtaining the minimum capacitor
value required for SEIG excitation in isolated mode applications, including
stand‐alone wind power generation. The SEIG performance
characteristics have been evaluated for different SEIG parameters. The
simulation and experimental results are then compared and found satisfactory.
Then, SEIG reliability is estimated considering the MCS method utilizing SEIG
excitation's failure and success rates during experimental work in the
laboratory. Finally, the SEIG reliability evaluation is performed considering
different wind speeds.
Controller design for DFIG‐based WT using gravitational search algorithm for wind power generation
Authors: Bharti Om Prakash , Sarita Kumari , Vardhan Aanchal Singh S. , Vardhan Akanksha Singh S. , Saket R. K. 
Published: February 2021

AbstractThis paper describes the controller design aspects of DFIG‐based wind turbine system (WTS) using gravitational search algorithm (GSA). The appropriate control schemes are required for efficient and reliable functioning of the DFIG‐based wind energy conversion system (WECS). The control algorithms are implemented in converters which are placed in the rotor end and grid side of the WECS. The controller design schemes are optimized for accurate, reliable and stable operations of WECS using GSA. The most commonly used other design techniques are bacterial foraging optimization (BFO), and particle swarm optimization (PSO). Moreover, the transfer function modeling of DFIG is also described in this paper. The results show that the proposed GSA technique with sixths order transfer function model of DFIG improves the transient performance including time of rising the response to 90%, settling time, and amplitude of peak overshoot. The proposed GSA technique is compared with the techniques already implemented in the previous research works including PSO and BFO. The DFIG‐based WTS's output waveforms of voltage at dc‐link, reactive power, and active power are improved using GSA based design technique. Finally, it is concluded that the GSA technique gives better results as compared with the PSO and BFO techniques.
EUS-guided gastroenterostomy versus enteral stenting for gastric outlet obstruction: Systematic review and meta-analysis
Authors: Chandan Saurabh , Khan Shahab R. , Mohan Babu P. , Shah Aun R. , Bilal Mohammad , Ramai Daryl , Bhogal Neil , Dhindsa Banreet , Kassab Lena L. , Singh Shailendra , Ponnada Suresh , Nguyen Andrew K. , McDonough Stephanie , Adler Douglas G. 
Published: February 2021

Abtract
Background and study aims Endoscopic and surgical techniques have been utilized for palliation of gastric outlet obstruction (GOO). Enteral stenting (ES) is an established technique with high clinical success and low morbidity rate. Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is a novel approach that aims to provide sustained palliation of GOO. We conducted a comprehensive review and meta-analysis to evaluate the effectiveness in terms of clinical and technical success, as well as the safety profile of EUS-GE and ES.
Methods We searched multiple databases from inception through July 2020 to identify studies that reported on safety and effectiveness of EUS-GE in comparison to ES. Pooled rates of technical success, clinical success, and adverse events (AEs) were calculated. Study heterogeneity was assessed using I2% and 95 % confidence interval.
Results Five studies including 659 patients were included in our final analysis. Pooled rate of technical and clinical success for EUS-GE was 95.2 % (CI 87.2-.98.3, I2 = 42) and 93.3 % (CI 84.4–97.3, I2 = 59) while for ES it was 96.9 % (CI 90.9–99, I2 = 64) and 85.6 % (CI 73–92.9, I2 = 85), respectively. Pooled rate of re-intervention was significantly lower with EUS-GE i. e. 4 % (CI 1.8–8.7, I2 = 35) compared to ES, where it was 23.6 % (CI 17.5–31, I2 = 35), p = 0.001. Pooled rates of overall and major AEs were comparable between the two techniques.
Conclusion EUS-GE is comparable in terms of technical and clinical effectiveness and has a similar safety profile when compared to ES for palliation of GOO.
Wearables bei Demenzerkrankungen
Authors: Pirker-Kees Agnes , Baumgartner Christoph 
Published: February 2021

ZusammenfassungDemenzerkrankungen führen durch den schleichenden Abbau kognitiver, sozialer und emotionaler Fähigkeiten, auch zu einem Verlust von Autonomie und Selbstbestimmtheit. Wearables sind am Körper getragene Sensoren: Akzelerometer und GPS-Tracker sind im Freizeit- und Fitnessbereich allgegenwärtig – sie zeichnen Bewegungs- und Positionsdaten auf. Das Potenzial, diese bei Demenzpatienten einzusetzen ist groß und wird intensiv beforscht. Wearables sind tlw. auch am Markt erhältlich (bspw. GPS-Tracker in Schuhsohlen). Informationen über Gangbild und Bewegungsdaten können auch Hinweise auf das Sturzrisiko, Verhaltensstörungen/Life-Events oder differenzialdiagnostische Aspekte geben. Trotz des großen Potenzials dürfen ethische Aspekte betreffend die Privatsphäre und den Datenschutz in der Entwicklung nicht außer Acht gelassen werden. Dieser Artikel gibt einen Überblick über die aktuelle Entwicklung von Wearables und damit verbundene ethische Aspekte.
3-Dimensional Ultrasound: How can the Fetal Corpus Callosum Be Demonstrated Correctly?
Authors: Pashaj Sonila , Merz Eberhard 
Published: February 2021

AbstractThe aim of this article is to outline the correct demonstration of the fetal corpus callosum with 3D ultrasound between 18 and 40 weeks of gestation. An abdominal or transvaginal 3D transducer can be used for acquisition of the fetal brain depending on the position of the fetus. The best demonstration of the corpus callosum can be achieved, when the volume with the corpus callosum is acquired from a sagittal or parasagittal sectional plane of the brain. Once the volume is stored in the memory, the multiplanar mode allows manipulation in all three dimensions until the exact median plane is seen, showing the corpus callosum as a hypo- or anechoic curved structure. Volume acquisition of the brain from an axial plane of the fetal head – typically used for biometrical measurements of the head diameters – is not recommended for clinical evaluation of the corpus callosum because the reconstructed median plane does not reveal the margins and the structure of the corpus callosum precisely. Other display modes such as volume contrast imaging (VCI), OmniView-VCI, and tomographic display may also be used for demonstration of the corpus callosum. However, these display modes only provide the operator with good image quality of the corpus callosum if the fetal brain was acquired from a sagittal and not from an axial plane.
Conclusion 3D ultrasound is an excellent clinical tool for the exact presentation of the fetal corpus callosum because it allows volume manipulation of the fetal head in all three dimensions with precise demonstration of the median plane of the brain.