bluuebunny/crossref_metadata_2025 huggingface dataset:
Ambulante Palliativversorgung von Patienten mit Migrationshintergrund in der Städteregion Aachen – Perspektiven von Behandelnden und Angehörigen
Authors: Nowara Virginia , Krumm Norbert , Elsner Frank
Published: April 2021

Die Integration von kultureller Kompetenz gewinnt in der Palliativversorgung zunehmend an Aufmerksamkeit. Ziel ist eine gleichberechtigte Versorgung, die sich für die gleichwertige Behandlung aller ethnischen Gruppen und die Akzeptanz der kulturellen Bedürfnisse der Patienten ausspricht.

In der vorliegenden Studie wurden die Erfahrungen von Professionellen mit der ambulanten Palliativversorgung von Patienten mit Migrationshintergrund und den Erfahrungen ihrer Angehörigen mit einer solchen Versorgung in der Städteregion Aachen erfasst. In der Städteregion Aachen, einem Kommunalverband mit über 550 000 Einwohnern im Westen Deutschlands, haben 30 % der Bürger einen Migrationshintergrund. Die Ergebnisse von Fragebogen- und Interviewanteilen zeigen teilweise unterschiedliche Wahrnehmungen der Professionellen und Angehörigen. In der Untersuchung stach die Diskrepanz zwischen der Eigen- und Fremdwahrnehmung der Professionellen bezüglich des kultursensiblen Umganges mit den Patienten hervor. Bei den Behandelnden zeigte sich eine von Unsicherheit geprägte Grundhaltung, während die Angehörigen sie als kompetent beurteilten. Die Erfahrungen der Angehörigen erwiesen sich als durchweg positiv und von Dankbarkeit sowie Zufriedenheit gekennzeichnet. Sie betonten die Wichtigkeit von Empathie und der grundsätzlichen Offenheit der Professionellen im Kontakt. Die absolvierten Fortbildungen der Behandelnden zu kultureller Kompetenz wurden jedoch wegen thematischer Beschränkungen auf Rituale unterschiedlicher Religionen am Lebensende als optimierungsbedürftig beschrieben. Ein Kritikpunkt war dabei die Vermittlung allgemeinen Faktenwissens und eine fehlende individualisierte Herangehensweise. Schlüsselelemente zur Optimierung der Weiterbildungen waren vermehrte Selbstreflexion und Patienten-Partnering-Programme, die eine reale, direkte Interaktion von Patienten und Professionellen im Rahmen von Trainingseinheiten beinhalten und somit die Individualität wie auch die Patientenbegegnung selbst in den Fokus rücken.
Thionation of Aminophthalimide Hindered Carbonyl Groups and Application to the Synthesis of 3,6′-Dithionated Pomalidomides
Authors: Scerba Michael T. , Siegler Maxime A. , Greig Nigel H.
Published: April 2021

Herein, we present a new one-pot procedure for the 3,6′-dithionation of pomalidomide derivatives in which the key 3-position sulfur atom is preferentially installed at the desired (but sterically congested) carbonyl of the aminophthalimide system and with regiochemistry distinct from Lawesson’s Reagent thionation methods. When heated in 1,4-dioxane with P4S10–pyridine complex, pomalidomides are smoothly and reproducibly converted into their 3,6′-dithionated analogues in roughly 30% isolated yield and at various scales. While detrimental to the desired 3,6′-type outcome when employing Lawesson’s Reagent, we hypothesize that the pomalidomide aniline group instead facilitates P4S10-type thionation at the otherwise hindered 3-position carbonyl, contributing to the selectivity observed. When paired with classical methods of thionation, this approach offers an interesting and appealing addition to the synthetic toolbox, permitting facile late-stage access to complementary thionated pomalidomides in direct single-flask procedures.
Cutting performance of micro-textured PCBN tool
Authors: Fan Lin , Deng Zilong , Gao Xingjun , He Yang
Published: April 2021

To study the effect of micro-texture on the cutting performance of polycrystalline cubic boron nitride (PCBN) tools, five types of micro-textures (circular pits, elliptical grooves, transverse grooves, composite grooves, and wavy grooves) were applied to the rake surface of PCBN tools by an optical fiber laser marking machine. Through a combination of three-dimensional cutting simulations and experiments, the influences of micro-texture on chip–tool contact area, cutting force, chip morphology, shear angle, and surface roughness during the cutting process were analyzed. The results indicated that the chip–tool contact area and cutting force of both non-textured and micro-textured tools increased with increasing cutting speed, while the shear angle decreased with increasing cutting speed. The chip–tool contact area and cutting force of the five types of micro-textured tools were smaller than those of the non-textured tool. The chip–tool contact area and cutting force obtained by the wavy-groove micro-textured tool were the smallest. The chip radius produced by the five types of micro-textured tools was smaller than that produced by the non-textured tool, and the chip morphology was more stable. The transverse-groove micro-textured tool had a better chip breaking effect. The chip radius generated by the elliptical-groove micro-textured tool was 0.96 cm, while that generated by the wavy-groove tool varied from 0.55 cm to 1.26 cm. The presence of a micro-texture reduced the surface roughness of the workpiece by 11.73%–56.7%. Under the same cutting conditions, the five types of micro-textured tools gave a smaller chip–tool contact area, cutting force, chip radius, and surface roughness and a larger shear angle than the non-textured tool. In addition, the elliptical-groove and wavy-groove micro-textured tools had better cutting performance.
Effect of adiabatic index on Richtmyer–Meshkov flows induced by strong shocks
Authors: Wright Cameron E. , Abarzhi Snezhana I.
Published: April 2021

Richtmyer–Meshkov Instability is an instability that develops at the interface between fluids of distinct acoustic impedance when impacted by a shock wave. Its applications include inertial confinement fusion, supernovae explosions, and the evolution of blast waves. We systematically study the effect of the adiabatic index of the fluids on the dynamics of strong-shock-driven flows, particularly the amount of shock energy available for interfacial mixing. Only limited information is currently available about the dynamic properties of matter at these extreme regimes. We employ smooth particle hydrodynamics simulations to ensure accurate shock capturing and interface tracking. A range of adiabatic indexes is considered, approaching limits which, to the best of the author's knowledge, have never been considered before. We analyze the effect of the adiabatic indexes on the interface speed and growth rate immediately after the shock passage. The simulation results are compared wherever possible with rigorous theories, achieving good quantitative and qualitative agreement. We find that the more challenging cases for simulations arise where the adiabatic indexes are further apart, and that the initial growth rate is a non-monotone function of the initial perturbation amplitude, which holds across all adiabatic indexes of the fluids considered. The applications of these findings on experiment design are discussed.
Radiative modulator based on Moiré hybridization with elliptic plasmons
Authors: Zhou Cheng-Long , Wu Xiao-Hu , Zhang Yong , Xie Ming , Yi Hong-Liang
Published: April 2021

Periodic variations in the alignment between two layers can lead to the formation of a Moiré pattern, which causes many unusual phenomena associated with Moiré physics. We propose a theoretical model for near-field radiative heat transfer (NFRHT) between two Moiré superlattices that are mirror images of each other. Each Moiré superlattice is composed of two strain-induced graphene sheets with a twisted angle φi between them. We find that as the twisted angle increases, the plasmon hybridization effect effectively changes the shape and intensity of the surface states, which modulates and enhances the NFRHT between them. Our results not only provide insight into the NFRHT induced by the Moiré hybridization of elliptic plasmons but also look forward to applications in dynamic thermal management at the nanoscale.
Genome-wide association among soybean accessions for the genetic basis of salinity-alkalinity tolerance during germination
Authors: Cao Yongce , Zhang Xincao , Jia Shihao , Karikari Benjamin , Zhang Mingjun , Xia Zhangyi , Zhao Tuanjie , Liang Fuqin
Published: April 2021

Salinity-alkalinity stress is one of the main factors limiting crop growth and production. However, few genetic sources that can be used to improve soybean salinity-alkalinity tolerance are available. The objective of this study was to determine the genetic mechanisms for salinity-alkalinity tolerance in soybean during germination by a genome-wide association study (GWAS) using 281 accessions with 58 112 single nucleotide polymorphisms (SNPs). Four salinity-alkalinity tolerance (ST) indices namely ST-GR (germination ratio), ST-RFW (root fresh weight), ST-DRW (root dry weight), and ST-RL (root length) were used to assess soybean salinity-alkalinity tolerance. A total of 8, 4, 6, and 4 quantitative trait loci (QTL) accounted for 3.83–8.01% phenotypic variation in ST-GR, ST-RL, ST-RFW, and ST-RDW, respectively. Two common QTL (qST.5.1 and qST.16.1) associated with at least three indices located on chromosome 5 (~38.4 Mb) and chromosome 16 (~29.8 Mb), were determined as important loci for controlling salinity-alkalinity tolerance in soybean. We also predicted candidate genes for the two QTL. The significant SNPs and common QTL as well as the salinity-alkalinity tolerant accessions will improve the efficiency of marker-assisted breeding and candidate gene discovery for soybean salinity-alkalinity tolerance.
Oracella acuta (loblolly pine mealybug).
Authors: Lambdin Paris
Published: April 2021

This species has had limited distribution from its native habitats in the southern region of the USA since its discovery and description (Lobdell, 1930). O. acuta appears to be restricted to feeding on species of pines and loblolly pine, Pinus taeda, is its preferred food source. In its native habitat, populations seldom reach pest status due to the presence of natural enemies. In 1988, it was transported to a pine seed orchard in China on slash pine, Pinus elliottii, scions purchased in the USA. Sun et al. (1996) noted that O. acuta-infested slash pine scions leaving the USA and entering China in 1988 were not subjected to the quarantine restrictions of either country. The loblolly pine mealybug quickly became established and rapidly spread throughout pine plantations in the Guangdong Province, China where it threatens both native and introduced species of pines in the region.
Depth encoded input polarisation independent swept source cross-polarised optical coherence tomography probe
Authors: Blessing Katharina , Schirmer Judith , Parmar Asha , Singh Kanwarpal
Published: April 2021

Within the last decades, several studies have been published that prove the benefit of polarisation sensitive optical coherence (psOCT) tomography for the field of biomedical diagnostics. However, polarisation sensitive imaging typically requires careful control of the polarisation state of the input illumination, which leads to bulky and delicate systems. While psOCT provides quantitative information, it is mostly sufficient to analyse the images qualitatively in the field of biomedical diagnostics. Therefore, a reduced form of this technique, cross-polarised optical coherence tomography (cpOCT), moves into the focus of interest that serves to visualise the birefringence properties of a sample. Despite the low requirements for the illumination’s polarisation, most of the proposed systems still include complex illumination control mechanisms. Here, we propose a common path probe based endoscopic system with an lateral resolution of 30 µm and a sensitivity of 103 dB comprising a commercially available swept-source OCT system and a free-space module which does not require any polarisation controlling elements. A Faraday mirror substitutes the complex polarisation control apparatus. We demonstrate the independence of the approach from the polarisation state of the light source by monitoring the illumination power in the orthogonal channels while varying the source polarisation. Furthermore, we validate the ability of the system to reveal the birefringence properties of different samples, starting from a quarter-wave plate, since its properties are fully characterised. Additionally, we present imaging results from several tissues to demonstrate its feasibility for the field of biomedical diagnostics.
Controlled lateral epitaxial growth in vertical β-Ga2O3 nanowires on sapphire by MOCVD
Authors: Ma Yongjian , Zhang Xiaodong , Li Junshuai , Cao Xu , He Tao , Zhang Li , Tang Wenbo , Xu Kun , Fan Yaming , Cai Yong , Fu Houqiang , Zhang Baoshun
Published: April 2021

Lateral epitaxial growth in vertical β-Ga2O3 nanowires was studied on sapphire substrates via metal organic chemical vapor deposition by controlling growth temperature and O2 flow rate. The lateral epitaxial growth rate of β-Ga2O3 rise up with increasing growth temperature and decreasing O2 flow rate, which are related to reaction kinetics and parasitic reaction, respectively. In addition, a growth model is proposed to explain the morphology of nanowires when growth condition changes. These results can provide important guidance on addressing slow coalescence rate of β-Ga2O3 nuclear islands on heterogeneous substrates and open new doors to β-Ga2O3 optoelectronic and electronic devices on cost-effective foreign substrates.
Thermal interface material with graphene enhanced sintered copper for high temperature power electronics
Authors: Deng Shaojia , Zhang Xin , Xiao Guowei David , Zhang Kai , He Xiaowu , Xin Shihan , Liu Xinlu , Zhong Anhui , Chai Yang
Published: April 2021

Sintered nano-copper is becoming a promising candidate as thermal interface material (TIM) for die attaching in high power electronics. It exhibits much higher thermal conductivity and operating temperature than conventional TIMs based on polymer and solder joints, and higher electromigration resistance and lower cost than sintered nano-silver TIM. However, the performance of existing sintered nano-copper is lower than expected because of high porosity resulted from poor sintering of copper particles with oxide shell. Here we demonstrate a method of improving the thermal conductivity of sintered copper by addition of graphene/Cu–Cu
x
O with controllable diameter of ∼163 nm. The measured thermal conductivity of the sintered composite TIM is enhanced by up to 123.5% compared with that of sintered pure copper. It can be understood as a result of the formation of graphene heat transfer network in sintered TIM. In addition, the C–O–Cu bonds formed at the interface between graphene and copper nanoparticles are critical for improving thermal performance as well as electrical and mechanical performance of the TIM. The developed TIM can be widely used in high power electronic packaging especially for high temperature applications, including IGBT, SiC and GaN power devices.
Controlling solid–liquid–solid GeSn nanowire growth modes by changing deposition sequences of a-Ge:H layer and SnO2 nanoparticles
Authors: Gong Ruiling , Azrak Edy , Castro Celia , Duguay Sébastien , Pareige Philippe , Roca i Cabarrocas Pere , Chen Wanghua
Published: April 2021

Alloying Ge with Sn is one of the promising ways for achieving Si compatible optoelectronics. Here, GeSn nanowires (NWs) are realized via nano-crystallization of a hydrogenated amorphous Ge (a-Ge:H) layer with the help of metal Sn droplets. The full process consists of three steps: (1) SnO2 nanoparticle (NP) reduction in a hydrogen plasma to produce Sn catalyst; (2) a-Ge:H deposition at 120 °C and (3) annealing. GeSn alloys with rich morphologies such as discrete nanocrystals (NCs), random, and straight NWs were successfully synthesized by changing process conditions. We show that annealing under Ar plasma favors the elaboration of straight GeSn NWs in contrast to the conventional random GeSn NWs obtained when annealing is performed under a H2 atmosphere. Interestingly, GeSn in the form of discrete NCs can be fabricated during the deposition of a-Ge:H at 180 °C. Even more, the synthesis of out-of-plane GeSn NWs has been demonstrated by reversing the deposition sequence of SnO2 NPs and a-Ge:H layer.
Radiochromic film dosimetry for protons up to 10 MeV with EBT2, EBT3 and unlaminated EBT3 films
Authors: Sanchez-Parcerisa Daniel , Sanz-García Irene , Ibáñez Paula , España Samuel , Espinosa Andrea , Gutiérrez-Neira Carolina , López Alfonso , Vera Juan Antonio , Mazal Alejandro , Fraile Luis Mario , Udías José Manuel
Published: April 2021

Passive dosimetry with radiochromic films is widely used in proton radiotherapy, both in clinical and scientific environments, thanks to its simplicity, high spatial resolution and dose-rate independence. However, film under-response for low-energy protons, the so-called linear-energy transfer (LET) quenching, must be accounted and corrected for. We perform a meta-analysis on existing film under-response data with EBT, EBT2 and EBT3 GAFchromic™ films and provide a common framework to integrate it, based on the calculation of dose-averaged LET in the active layer of the films. We also report on direct measurements with the 10 MeV proton beam at the Center for Microanalysis of Materials (CMAM) for EBT2, EBT3 and unlaminated EBT3 films, focusing on the 20–80 keV μm−1 LET range, where previous data was scarce. Measured film relative efficiency (RE) values are in agreement with previously reported data from the literature. A model on film RE constructed with combined literature and own experimental values in the 5–80 keV μm−1 LET range is presented, supporting the hypothesis of a linear decrease of RE with LET, with no remarkable differences between the three types of films analyzed.
Effect of collisions on the plasma sheath in the presence of an inhomogeneous magnetic field
Authors: Deka K , Adhikari S , Moulick R , Kausik S S , Saikia B K
Published: April 2021

A low-pressure magnetized plasma is studied to find the dependency of sheath properties on ion-neutral collisions in presence of an inhomogeneous magnetic field. A self-consistent one-dimensional two-fluid hydrodynamic model is considered, and the system of equations is solved numerically. The study reveals that the width of the plasma sheath expands and space charge increases with collisions. The ion-neutral collisions and the inhomogeneous magnetic field restrict the ions to move towards the surface. The movement of the ions towards the wall can be controlled by choosing a suitable configuration of the magnetic field and ion-neutral collision frequency. A comparison between two different magnetic field configurations has been presented alongside to differentiate the commonly found scenarios in the field. The outcome of the study is supposed to help in understanding the complex dynamics of ions in plasma confinement and plasma processing of materials. Furthermore, the present work seeks to create a framework for two-fluid modeling of magnetized plasmas with any arbitrary magnetic field profiles. The analysis provided here is supposed to act as a basis for any future work in the respective field.
A dark matter telescope probing
the 6 to 60 GHz band
Authors: De Miguel Javier
Published: April 2021

In this article we present the Dark-photons&Axion-Like particles Interferometer (DALI),
a novel experiment designed for the detection of photon-mixing cold dark matter in the microwave
band between 6 and 60 GHz. DALI is a haloscope for the simultaneous search for axions, axion-like particles and dark
photons, with a number of novelties that make it unique. First, it is a dark matter telescope, with a
capacity for pointing, tracking and rastering objects and areas in the sky. This potentially
allows one to detect relativistic dark matter particles, substructures and flows, without
compromising the simultaneous scanning for dark matter relic particles present in the laboratory. Second, it has been designed using commercial technology. This will allow feasible manufacture
at a reasonable cost, thereby mitigating the need for R&D and facilitating maintenance. Finally,
it benefits from a high sensitivity over a broad band of frequencies with only minimal reconfiguration.
Warm-assisted natural inflation
Authors: Reyimuaji Yakefu , Zhang Xinyi
Published: April 2021

We consider natural inflation in a warm inflation framework with a temperature-dependent dissipative coefficient Γ∝ T3. Natural inflation can be compatible with the Planck 2018 results with such warm assistance. With no a priori assumptions on the dissipative effect's magnitude, we find that the Planck results prefer a weak dissipative regime for our benchmark scale f=5 Mpl, which lies outside the 2σ region in the cold case. The inflation starts in the cold regime and evolves with a growing thermal fluctuation that dominates over quantum fluctuation before the end of the inflation. The observed spectral tilt puts stringent constraints on the model's parameter space. We find that f< 1 M_ pl is excluded. A possible origin of such dissipative coefficient from axion-like coupling to gauge fields and tests of the model are also discussed.
Comparative investigation of 5-aminolevulinic acid and hexyl aminolevulinate-mediated photodynamic diagnostics and therapy of cervical dysplasia and vulvar leukoplakia
Authors: Efendiev K T , Alekseeva P M , Bikmukhametova I R , Piterskova L S , Orudzhova K F , Agabekova U D , Slovokhodov E K , Loschenov V B
Published: April 2021

This study aims to conduct a comparative analysis of aminolevulinic acid and its hexyl aminolevulinate (HAL) for photodynamic diagnostics and therapy of cervical dysplasia and vulvar leukoplakia in continuous and pulsed laser irradiation mode. The fluorescence intensity of protoporphyrin IX (PpIX) in the cervix epithelium was five times higher after the application of HAL compared with the application of aminolevulinic acid. Increased intensity of fluorescence of PpIX in vulvar tissues complicated by leukoplakia was not observed with 5-aminolevulinic acid and its HAL. Intraepithelial changes in patients with cervical dysplasia were absent after photodynamic therapy (PDT) in continuous irradiation mode. Repeated PDT was prescribed to several patients with vulvar leukoplakia after pulsed light irradiation. Pulse irradiation made it possible to avoid the use of various types of anesthesia in patients. In the regime of continuous irradiation, pain sensations of varying degrees from a burning sensation to sharp pains were observed in patients in the zone of photodynamic exposure. The results presented in this paper will help to optimize the PDT process of cervical dysplasia and leukoplakia using 5-aminolevulinic acid or HAL.
Electromagnetic Compatibility Simulation Analysis of Helicopter Engine Irradiated by EMP
Authors: Haoyang Chen , Yutang Fan
Published: April 2021

Due to the rapid development of battlefield complex electromagnetic environment research in recent years, electromagnetic pulse (EMP) environment has gradually stepped onto the stage of information war. To make low altitude flying electronic equipment engine plays its normal combat performance in the EMP radiation environment and ensure the integrity of electronic equipment, it is urgent to research in this field. In this paper, according to GJB-1389A and other standards, CST simulation software is used for simulation analysis. Through simulation, field strength and cable coupling with the airborne engine of an armed helicopter under EMP irradiation are predicted. The conclusions have a certain guiding significance of the further study of the protection against the complex electromagnetic environment of the engine.
Research on power exchange flexibility optimization of urban AC/DC distribution network
Authors: Sun Ke , Ye Gangjin , Yang Xuan , Weng Hua , Wang Xiran , Chen Zhiyuan
Published: April 2021

After large-scale access to distributed generation of new energy generation in urban AC/DC distribution network, its own randomness and uncertainty affect the supply-demand balance mechanism of distribution network. Therefore, this paper studies the power exchange flexibility optimization method of urban AC/DC distribution network to provide reference for the operation and scheduling of distribution network and main network. First, the active power exchange model of distribution network is established, the extreme value of power exchange of distribution network is obtained, and the flexible range of exchange power is calculated. Next, the flexibility evaluation index is established, and the operation characteristics of energy storage are transformed to complete the research on power exchange flexibility optimization of urban AC/DC distribution network. Through the actual example analysis, the results show that after the optimization of the design method, the net load curve is smoother, the effect of reducing the peak valley difference is more significant, and the overall curve is relatively smooth, which shows that the design method has certain effectiveness.
Analysis and Suppression Strategy of Transient Frequency Deviation by Soft Guide Vane Control in Hydro Turbine
Authors: Cai Weijiang , Shi Xinlei , Shi Haidong , Rong Hong , Zhao Yong , Wang Yongtan , Zhang Meijun
Published: April 2021

The hydro-dominant characteristic is notable after the asynchronous operation in Southwest China Power Grid which brings worse transient frequency deviation caused by water hammer effect. To prevent the possible cascading failure due to the worse transient frequency deviation in the secondary frequency regulation, the soft guide vane control law is proposed to suppress the water hammer effect in the transient regulation process based on the detailed turbine-penstock model. The discrete state space expression of the turbine-penstock model is built to simulate the regulation effect in the time domain and the PSO (Particle Swarm Optimization) algorithm is applied to optimize the soft guide vane control adjustment factor considering multi-object. Finally, the emergency AGC (Automatic Generation Control) adjustment in the single machine with load transmission system is conducted to verify the effect of transient frequency deviation suppression by optimized soft guide vane control.
Research on Attack Penetration Prevention Techniques of Power Terminal Network
Authors: Zhou Xiaojun , Wang Liming , Cai Yupeng , Ren Shuai , Li Tong , Yuan Yidong , Li Qi
Published: April 2021

After the power terminal network is attacked, it is necessary to adopt effective security strategies to block the attack in time to prevent further expansion of the attack damage. At this time, not only the availability of the system must be considered, but also the impact of the attack must be minimized. Traditional network isolation methods may cause excessive protection problems such as excessive isolation range and high isolation strength, and affect the continuity of power system business. Therefore, this paper conducts research on the attack penetration prevention techniques of power terminal network, under the condition of minimally affecting the real-time business continuity of the power grid, blocking low-risk terminals’ control commands and/or isolating high-risk terminals’ communication to realize accurate attack penetration prevention.
Research on shell magnetic shielding based on finite element method
Authors: Li Jiaqi , Jin Shilong
Published: April 2021

In this paper, several different magnetic shielding schemes are proposed, the finite element static magnetic field analysis method is introduced, and the finite element method is used to simulate these methods. According to the calculation results, we analysed different magnetic shielding schemes, the results show that the opening will significantly reduce the magnetic shielding efficiency; under the same materials, the multi-layer magnetic shielding effect is significantly improved; when the opening is parallel to the direction of the magnetic induction intensity, the magnetic shielding has a better effect; when the direction of the magnetic field is unknown, the two-layer magnetic shielding opening direction can be orthogonal to improve the magnetic shielding effect.
On the Adaptive Damper System of the Electric Reactor Based on Magnetorheological Fluid
Authors: Tian Tian , Zhou Yuan , Yang Qiong , Wang Jingang , Xu Changjian
Published: April 2021

The electric reactor will generate irregular electromagnetic vibration during the onsite operation of substation. If so for a long time, it will cause problems such as broken indoor floor and loose connecting parts, endanger the building structure or damage to the building, thus leading to waste of land resources in indoor substation. In order to effectively suppress the irregular electromagnetic vibration of the electric reactor, this paper proposed an adaptive damper system of the electric reactor based on magnetorheological fluid to realize the all-around vibration suppression of reactor field vibration. This system placed the homemade damper in the center of each surface of the reactor, and used external filter circuit and signal amplification circuit to process the vibration signal and transform it into electrical signal, which controlled the single-chip microcomputer to regulate the damper to output the damping force, forming an adaptive damper system based on the magnetorheological fluid. Then, the good performance of vibration reduction of the system was verified by the onsite vibration reduction test of the reactor. And the adaptive regulate ability of the system is superior and is of good engineering application value.
Modeling and Simulation of Solid Oxide Fuel Cell Based On Neural Network
Authors: Wang Qianru , Wang Caixia
Published: April 2021

In order to study the effects of hydrogen input molar flow, oxygen input molar flow, water vapor input molar flow and real-time temperature on the output voltage of solid oxide fuel cell (SOFC), this paper proposes a method to model SOFC using a BP neural network optimized by immunogenetic algorithm (IA). MATLAB simulation results show that the SOFC model established in this paper can more accurately reflect the actual SOFC input and output characteristics. And the model has a high fit to the real data.
Research on Energy Storage Development Adapting to Large-scale Access to renewable Energy
Authors: Qing Ran Wang
Published: April 2021

Energy storage is the key technology for large-scale renewable energy access and energy Internet construction. Among the numerous energy storage technologies, the pumped storage and electrochemical energy storage are the fastest developing. In the paper, the present application status of the pumped storage and electrochemical energy storage is introduced. In this paper, the development prospect of energy storage and its impact on power system are analyzed, and the overall strategies and ideas to deal with the development of energy storage are put forward.
LiveEar: An Efficient and Easy-to-use Liveness Detection System for Voice Assistants
Authors: Yue Ling , Cao Chenhong , Li Yufeng , Li Jiangtao , Liu Qi
Published: April 2021

Voice assistants, such as Amazon Alexa, Apple Siri and Tmall Genie, using voice biometrics for the identity authentication, are becoming pervasive in our daily lives. However, voice assistants are vulnerable to reply attack due to the open nature of voice-input channels. An attacker can record the voice commands of victims and replay them to spoof voice assistants. Existing liveness detection approaches are mostly based on machine learning methods, which are expensive and complex. Recently, several approaches are proposed to leverage the human specific voice features or the distinctness of voice played by loudspeaker. However, they require the users and the voice assistant to be in a fixed position and at a very close distance, which is not user-friendly in practice. This paper proposes LiveEar, an efficient and easy-to-use liveness detection system for voice assistant. LiveEar utilizes the differences in phoneme positions between live-human voices and voices replayed through loudspeakers. Specifically, it calculates the time-difference-of-arrival (TDoA) in a sequence of phoneme sounds to the microphone on the voice assistant. Then, an SVM-based classification model is trained with the extracted TDoA features. This paper implements a prototype of LiveEar and evaluates its performance using real-world data. Results show that LiveEar achieves high detection accuracy in various flexible positions, with negligible runtime overhead.
A Robust Watermarking Scheme based on Delaunay Image Reconstruction Robust to Affine Transformation
Authors: Feng Liu , Gong Daofu , Wang Wenbing
Published: April 2021

This paper proposes a sub-channel image reconstruction algorithm based on Delaunay triangle. First, according to the different sensitivity of the human eye to the three color channels, different channels are used to avoid the influence of watermark embedding on pixels around the feature points. Then, feature points should be selected on the selected channel to make them have sufficient robustness. At this time, the location of the feature points extracted on the corresponding channel can be used as the watermark embedding position. Finally, considering the influence of geometric attacks such as affine transformation, this paper proposes a reconstruction algorithm based on Delaunay triangle, which uses feature point information to reconstruct the image before the watermark extraction, and extract the watermark on the reconstructed image. The effect of watermark extraction has been improved.
Design of Fast Locking and Locking Detection System of Frequency Synthesizer
Authors: Ge Yili , Jin Lingling , Shen Fei
Published: April 2021

In some electronic reconnaissance fields, fast frequency switching is required. A radio frequency signal generator with fast lock and accurate lock time appears to be of great significance. Traditional detection requires additional equipment, which is expensive and cumbersome to operate without portability. This paper designs a simple, portable and easy-to-operate lock detection method, uses a timer to monitor the LD pin of the phase lock chip in real time, optimizes the algorithm for capturing signal edge transitions, and calculates the frequency switching time. The ADF4351 fast lock mode is combined with lock detection to improve the topology of the loop filter and speed up the lock time. With the keyboard and LCD module, a radio frequency signal source system capable of self-checking and locking time is constructed. Simulation and actual results verify that after changing the filter structure to achieve quick lock, the lock time is optimized by 16%, which verifies the effectiveness of quick lock and the accuracy of lock detection, and realizes efficient and convenient lock time detection.
Transmission line image mosaic based on improved SIFT-LATCH
Authors: Dong Shilin , Lu Li
Published: April 2021

In the transmission line inspection, in order to obtain wide-view and large-scale images, it is necessary to stitch images taken by drones. This article proposes an improved SIFT-LATCH-based UAV aerial transmission line image stitching algorithm. First, the image is processed in parallel through multi-threading. The SIFT algorithm is used to extract the feature points in the image, and the LATCH descriptor is used to describe the feature points. The sampling consensus algorithm is used to purify the feature points, and finally the translational homography matrix is used to solve the problem of black lines in the stitched image. Experiments show that the algorithm proposed in the article has the advantages of good real-time and high accuracy in splicing UAV aerial pictures of transmission lines.
Phase Object Tomography Reconstruction Based on high-order Transport of Intensity Equation
Authors: Cheng Hong , Zhang Xiaolong , Wang Tianxiang , Zhu Xiaotian
Published: April 2021

The phase of the object contains the depth, shape, refractive index and other information of the object surface, which is more important than the intensity. As a classical phase retrieval algorithm, the Transport of Intensity Equation(TIE) can directly obtain the phase calculated from the known intensity. In this paper, a new algorithm is proposed to reconstruct the three-dimensional phase information of an object by tomography. The algorithm obtains high-precision phase input through the high-order TIE, and then reconstructs the three-dimensional phase information of the object by using Fourier slice theorem backprojection tomography. The experimental results show that the algorithm can solve the problem of low phase accuracy caused by intensity differential approximation constraints, and can obtain high-precision 3D phase reconstruction results of objects.
Design and Implementation of Convolutional Neural Network Accelerator Based on RISCV
Authors: He Yangyang
Published: April 2021

Internet of Things devices are faced with ever-increasing amounts of data, and they can no longer only do data collection as they did in the past, and hand over computing tasks to servers on the cloud. The growing computing requirements in the field of Internet of Things and the diversity of its scenarios put forward configurable and flexible customization requirements for customized processors. This paper conducts in-depth analysis and research on configurable customized processors, and analyzes related work in the field of RISC-V chips and deep convolutional neural networks in the field of device-side optimization at home and abroad. Based on this, this paper proposes an instruction and hardware design of a customizable deep convolutional neural network accelerator attached to Rocket-Chip Generator based on the RISC-V modular instruction set.
An Automatic Recognition Method of Fruits and Vegetables Based on Depthwise Separable Convolution Neural Network
Authors: Yuhui Zhan , Mengyao Chen , Yuefen Chen , Zhaoqian Luo , Yao Luo , Kedi Li
Published: April 2021

Traditional fruit and vegetable classification is mostly based on manual operation, which is inefficient. Deep convolution neural network shows excellent performance in feature learning and expression. In this paper, an automatic recognition system of fruits and vegetables based on deep convolution neural network is designed. By using depthwise separable convolution instead of the traditional standard convolution, a neural network is constructed with less parameters, which is suitable for equipment with limited resources. A small data set including 12 kinds of common fruits and 8 kinds of common vegetables is established for training and testing through network download and physical shooting. The experimental results show that the recognition accuracy reaches 95.67%.
Influence of different wavelet bases and threshold estimation on noise reduction of substation fault signals under different SNR
Authors: Zhang Na , Zhang Chenwei’ , Gao Xian
Published: April 2021

With the rapid development of power industry, the number of substations is also increasing, and the voltage level is also higher and higher, and the types of equipment are diverse. The detection of equipment fault signal in substation is an important part to ensure the normal operation of electric power. Only timely detection of fault signal and corresponding processing can ensure the overall operation of substation. But the fault signal often contains a lot of white noise, which will interfere with our judgment of the fault point. How to extract the effective signal from the noisy signal becomes particularly important, but under different signal-to-noise ratio, the selection of different wavelet basis and threshold estimation also have a great impact on the noise reduction effect. In this paper, we choose different wavelet bases and threshold estimation under several different signal-to-noise ratios to study their influence on the effect of signal denoising.
Design of Prescribed Performance Controller for Load Disturbance Interconnected Power System Based on Fuzzy Adaptive Backstepping
Authors: Lanzheng Chen , Guopeng Zhou , Xin Xia , Danping Sun
Published: April 2021

The complex structure of interconnected power system and the existence of external load disturbance make it difficult to establish accurate system model and realize stability control with preset performance. In this paper, a fuzzy adaptive controller design method with preset performance is proposed for uncertain interconnected power systems. Firstly, the system approximation model is obtained by using the fuzzy approximation principle, then the preset performance control strategy is introduced to transform the steady-state preset performance of the system into an error performance function. Finally, the adaptive controller design with preset performance is realized based on the Backstepping method. For the validity of the algorithm, the Simulink simulation is carried out. The results show that the controller can make the output of the system uniformly bounded, that is, the tracking error can always be controlled within the specified performance range.
Grasping points detection of garments based on deep learning
Authors: Shan Chunhua , Xie Yongping
Published: April 2021

Robotic manipulation for rigid objects is a relatively easy task, while grasping highly deformable objects, such as garments, is still a big challenge for robots. This research detects the grasping points of hanging garment using deep learning to facilitate robot manipulation. A neural network is proposed to predict the cartesian coordinates and visibility of predefined grasping points. In order to reduce the impact of different clothing colors, depth images are used for the input of the model. It is inaccurate and unrealistic to label data manually because of complex dynamics of clothes; therefore, synthetic dataset is leveraged to train the neural network. This paper makes use of generative adversarial network (GAN) to translate synthetic data to real data. A real dataset is acquired taken by Azure Kinect sensor as the test dataset. The experimental results indicate that our method can provide accurate prediction of the grasping points and can be applied to real scenarios.
Design and Test of a Multifunctional Mobile Manipulator Control System on an Experimental Platform
Authors: Ling Chen , Xing Xiaoyue , Li Zhe , Liu Liwu , Li Xiaolong , Guo Jie
Published: April 2021

Mobile manipulators (MMs) performing the tasks of autonomous navigation, object grasp and transportation are widely used in industrial production and other domains. This paper presents a control system with multiple functions and good extendibility for a commonly configured MM, which controls the multi-degrees of freedom (DOF) movement of the MM while navigating, positioning, pose estimating and object grasp. This system has shown desirable control performance on an experimental platform.
Modelling and Scheduling for Tier-to-Tier Multi-Shuttle Warehousing System
Authors: Zhu Chengtao , Wu Yaohua , Chen GuoZhen , Wu ShaSha
Published: April 2021

Tier-to-tier Multi-Shuttle Systems (TT-MSS) become increasingly adopted due to their high flexibility and efficiency. In the Tier-to-tier MSS, shuttles work across different tiers with the help of lifts. How to schedule these devices matters a lot in terms of lowering the expected order cycle time. In this paper, we propose a time sequence task scheduling model considering the movements of shuttles and lifts. The model describes the task scheduling problem between shuttles and lifts, which is generated in a specified time window. An improved genetic algorithm is proposed to solve the objective optimization function in the task scheduling problem. Finally, we illustrate the advantages of the Tier-to-tier MSS by conducting experiments, and the results indicate that with the increase of retrieval tasks, the efficiency of Tier-to-tier MSS is approaching that of TC-MSS with fewer shuttles used.
Research on Path Planning of Mobile Disinfection Robot Based on Improved A * Algorithm
Authors: Jiang Haojie , Sun Yuan , Wang Xinwei , zhang Peng
Published: April 2021

The traditional A* algorithm uses Euclidean distance as the heuristic function in the path planning of mobile disinfection robot. This method may lead to the generation of a certain number of useless nodes, which makes the search time longer. To solve this problem, this paper proposes an improved A* algorithm, starting from the heuristic function, adding additional value to the heuristic function, using the cosine value of the angle as the additional parameter. This method effectively reduces the comparison of useless points with the same F value, and significantly reduces the number of visited nodes. The simulation results show that the improved A* algorithm can significantly improve the path planning efficiency of mobile disinfection robot.
Self-Adaptive PID Control Based on RBF Network for Trajectory Tracking of Dual-Mass Servo System
Authors: Hu Weiwen , Zhang Shengguo , Niu Lu
Published: April 2021

This paper presents a state-of-the-art algorithm of self-adaptive RBF network PID control and aims at achieving the precise and fast trajectory tracking for a dual-mass servo system. To increase the robustness of servo system parameter varying and external disturbances, a classical PID algorithm with enhanced structure based on RBF neural network is proposed. Extensive simulations show that it practically validates the superiority of the proposed RBF adaptive PID controller. The experiment was simulated respectively under the external disturbance, which indicates that accurate tracking performance of the servo system with dual-mass load has been achieved and also verifies the effectiveness of self-adaptive PID control strategy.
Research on feature selection algorithm of unknown wireless protocol based on mutual information
Authors: Liu Zhiguo , Yao Qiaoyu , Guo Meilin , Zha Xueli
Published: April 2021

Aiming at the problem of unknown wireless protocol identification methods that focus on the application layer, but the wireless network application layer data is difficult to capture, and the existing method research stays at the signal level and the identification effect is poor, this paper proposes an identification method for feature selection of wireless protocol data from the data link layer. This paper extracts the protocol features of the data frame set by improving the AC algorithm and the association rule algorithm, using mutual information theory, and combining the definition of information correlation and redundancy with the normalization idea, further screening and verification of frame features are carried out to achieve effective extraction of protocol features, effectively improve the accuracy of feature sets, and thereby improve the efficiency and accuracy of protocol recognition.
Diagnosis system of sleep apnea based on wearable sensor
Authors: Xue Yazhuo , Shan Yunge , Ji Xiaoqiang
Published: April 2021

Sleep Apnea Syndrome (SAS) is a serious threat to the life and health of patients. In this paper, a breathing coil is used as a flexible sensor, and a breathing signal conditioning circuit is designed to collect breathing signals. At the same time, an algorithm for determining the incidence of apnea is designed. First, all the maximum points in the respiratory signal and the corresponding extreme positions are found; then the cubic spline interpolation function is used to fit the upper and lower values of the maximum and the minimum envelope, and find the average value of the upper and lower envelopes; finally, the peak or trough point by searching for the local minimum or local maximum in the average envelope was found, and then further segmented calculations was performed. The test results show that the misjudgment range between the number of sleep apneas recorded by the simulation experiment and the number of sleep apneas obtained by the algorithm is between -2 and 3 times. The designed system terminal equipment is accurate, comfortable to wear, can be monitored for a long time. And is suitable for family daily sleep monitoring.