bluuebunny/crossref_metadata_2025 huggingface dataset:
Alignment between outcomes and minimal clinically important differences in the Dutch type 2 diabetes mellitus guideline and healthcare professionals’ preferences
Authors: Dankers Marloes , Nelissen‐Vrancken Marjorie H. J. M. G. , Hart Bertien H. , Lambooij Anke C. , van Dijk Liset , Mantel‐Teeuwisse Aukje K.
Published: May 2021

To evaluate the clinical benefit of new medicines for type 2 diabetes mellitus (T2DM), the Dutch guideline committee T2DM in primary care established the importance of outcomes and minimal clinically important differences (MCIDs). The present study used an online questionnaire to investigate healthcare professionals’ opinions about the importance of outcomes and preferences for MCIDs. A total of 211 physicians, pharmacists, practice nurses, diabetes nurses, nurse practitioners and physician assistants evaluated the importance of mortality, macro‐ and microvascular morbidity, HbA1c, body weight, quality of life, (overall) hospital admissions and severe and other hypoglycemia on a 9‐point scale. All outcomes were considered critical (mean scores 7–9), except for body weight and other hypoglycemia (mean scores 4–6). Only HbA1c and hospital admissions were valued differently by the guideline committee (not critical). Other relevant outcomes according to the respondents were adverse events, ease of use and costs. Median MCIDs were 4 mmol/mol for HbA1c (guideline: 5 mmol/mol) and 3 kg for body weight (guideline: 5 kg weight gain and 2,5 kg weight loss). Healthcare professionals preferred relative risk reductions of 20% for mortality (guideline: 10%) and macrovascular morbidity (guideline: 25%) and 50% for other hypoglycaemia (guideline: 25%). The MCID of 25% for microvascular morbidity, hospital admissions and severe hypoglycaemia corresponded to the guideline‐MCID. Healthcare professionals’ preferences were thus comparable to the views of the guideline committee. However, healthcare professionals had a stricter view on the importance of HbA1c and hospital admissions and the MCIDs for mortality and other hypoglycemia.
Power on! Low‐energy electrophysical treatment is an effective new weed control approach
Authors: Lati Ran Nisim , Rosenfeld Lavi , David Inbar Ben , Bechar Avital
Published: May 2021

BACKGROUND

Environmental concerns are driving the call for adoption of alternative nonchemical weeding approaches. This study aimed to develop and evaluate a novel, precise, low‐energy electrophysical treatment weeding systems and to provide new insight into their control mechanism. Two electrophysical treatment systems, based on AC (2.2 kV) and DC (40 kV) energy sources, were developed and evaluated. The impacts of various operational and biological factors on the weed control effectiveness were evaluated. Additionally, thermal images were taken during the treatments to document plant temperature.

RESULTS

Treatments via direct leaf contact caused greater damage to Amaranth plants than the stem contact treatments, with 75% and 20% biomass reduction compared to control, respectively. Treatment of early growth stages was favorable over later growth stages, with 100% and 75% biomass reduction for Trifolium pretense plants treated with 0.0125 W h 2 and 4 weeks after seeding, respectively, compared to control. Additionally, the applied energy affected treatment performance, with its impact varying across the growth stages and species; at the two‐leaf growth stage, 0.0025 W h treatment was sufficient for plant death. A >40 °C increase in plant temperature was measured during the electrophysical treatment, with the temperature of some plant organs reaching ~70 °C.

CONCLUSION

Results from this study demonstrate the potential use of electrophysical treatment as an effective weed control tool. The low energetic demands in the new systems provide suitable control results when applied at early stages. Temperature increase seemed to be one of the main control factors, yet efficacy was affected by various biological factors.
Identifying the drivers and constraints to adoption of IPM among arable farmers in the UK and Ireland
Authors: Creissen Henry E , Jones Philip J , Tranter Richard B , Girling Robbie D , Jess Stephen , Burnett Fiona J , Gaffney Michael , Thorne Fiona S , Kildea Steven
Published: May 2021

BACKGROUND

Arable crops in temperate climatic regions such as the UK and Ireland are subject to a multitude of pests (weeds, diseases and vertebrate/invertebrate pests) that can negatively impact productivity if not properly managed. Integrated pest management (IPM) is widely promoted as a sustainable approach to pest management, yet there are few recent studies assessing adoption levels and factors influencing this in arable cropping systems in the UK and Ireland. This study used an extensive farmer survey to address both these issues.

RESULTS

Adoption levels of various IPM practices varied across the sample depending on a range of factors relating to both farm and farmer characteristics. Positive relationships were observed between IPM adoption and farmed area, and familiarity with IPM. Choice of pest control information sources was also found to be influential on farmer familiarity with IPM, with those who were proactive in seeking information from impartial sources being more engaged and reporting higher levels of adoption.

CONCLUSION

Policies that encourage farmers to greater levels of engagement with their pest management issues and more proactive information seeking, such as through advisory professionals, more experienced peers through crop walks, open days and discussion groups should be strongly encouraged.
Dual oxidase‐dependent reactive oxygen species are involved in the regulation of UGT overexpression‐mediated clothianidin resistance in the brown planthopper, Nilaparvata lugens
Authors: Zhang Yunhua , Liu Chaoya , Jin Ruoheng , Wang Yue , Cai Tingwei , Ren Zhijie , Ma Kangsheng , He Shun , Lee Kwang S , Jin Byung R , Li Jianhong , Wan Hu
Published: May 2021

BACKGROUND

Uridine diphosphate‐glycosyltransferases (UGTs) are phase II metabolic enzymes involved in metabolism of toxins and resistance to insecticides in insect pests. Reactive oxygen species (ROS) induced by xenobiotics are important for activation of detoxification pathways. However, relationships between ROS and UGTs involved in toxin metabolism and insecticide resistance remain unclear.

RESULTS

Here, involvement of dual oxidase (Duox)‐dependent ROS in regulating UGT expression‐mediated insecticide resistance in the brown planthopper (Nilaparvata lugens) was investigated. The overexpression of NlUGT386F2 contributed to the resistance of N. lugens to clothianidin. Furthermore, the ROS inhibitor (N‐acetylcysteine) significantly reduced the expression of NlUGT386F2 and increased the susceptibility of N. lugens to clothianidin. Silencing the ROS producer Duox significantly increased the susceptibility of N. lugens to clothianidin through the down‐regulation of NlUGT386F2 expression.

CONCLUSION

NlDuox‐dependent ROS regulates NlUGT386F2 expression‐mediated clothianidin resistance in brown planthopper. These observations further our understanding of the metabolism of toxins and of insecticide‐resistance in insect pests.
Health costs and benefits associated with economic transitions: Linking records of address change, property value, and self‐reported health
Authors: Moriarty John , Maguire Aideen , Edgar‐Fitzsimons Nicole , McCann Mark
Published: May 2021

Deprivation is a major risk to population health, in particular when experienced during childhood. Poor health in the early years accumulates and is expressed in adult health inequalities. Policy makers may aim to mitigate against the ill effects of deprivation by trying to increase social mobility and facilitating moves towards better earnings and living conditions or by protecting against the effects of downward moves and the experience of deprivation. This paper uses address change and property value data at the individual and family level to examine whether poor health outcomes occur more frequently among people who move between addresses and particularly those who move to properties with lower property values. We use the Northern Ireland Longitudinal Study, linking health and demographic data from 2001 and 2011 Censuses to house valuations for a representative 28% of the population aged 10–64 years (N = 342,681). Young persons (aged 10–15 years) living in a house valued at over £160,000 were half as likely to be reported as having mental ill health as those living in a house valued under £75,000 (OR = 0.49, CI: 0.31–0.78). There was no strong evidence that upward or downward mobility affected mental health or physical health for young people, but ill health of working aged persons showed a strong association with moving to houses of lower value. Results are discussed in terms of their implications for understanding the dynamics of social mobility and health and in terms of how various policies towards poverty may influence population health.
Integrative chemogenomic analysis identifies small molecules that partially rescue ΔF508‐CFTR for cystic fibrosis
Authors: Hodos Rachel A. , Strub Matthew D. , Ramachandran Shyam , Meleshkevitch Ella A. , Boudko Dmitri Y. , Bridges Robert J. , Dudley Joel T. , McCray Paul B.
Published: May 2021

Rare diseases affect 10% of the first‐world population, yet over 95% lack even a single pharmaceutical treatment. In the present age of information, we need ways to leverage our vast data and knowledge to streamline therapeutic development and lessen this gap. Here, we develop and implement an innovative informatic approach to identify therapeutic molecules, using the Connectivity Map and LINCS L1000 databases and disease‐associated transcriptional signatures and pathways. We apply this to cystic fibrosis (CF), the most common genetic disease in people of northern European ancestry leading to chronic lung disease and reduced lifespan. We selected and tested 120 small molecules in a CF cell line, finding 8 with activity, and confirmed 3 in primary CF airway epithelia. Although chemically diverse, the transcriptional profiles of the hits suggest a common mechanism associated with the unfolded protein response and/or TNFα signaling. This study highlights the power of informatics to help identify new therapies and reveal mechanistic insights while moving beyond target‐centric drug discovery.
Helium transmission rate as a rapid and reliable method for assessing the water vapour transmission rate of transparent PET‐SiOx barrier foils
Authors: Herbst Florian , Großer Stephan , With Patrick C. , Prager Lutz , Pander Matthias
Published: May 2021

A single quadrupole mass spectrometer coupled measuring setup was developed for the investigation of the helium transmission rate (HeTR) of SiOx‐coated polyethylene terephthalate (PET) barrier films. The setup allows the pressure‐less and time‐resolved measurements of the helium permeation at transient and steady‐state conditions. Whereas standard water vapour transmission rate (WVTR) experiments took extended test times (in the range of several days), HeTR measurements were finished after 1 h. For the material system investigated here, an excellent linear correlation of WVTR and HeTR was proven over two orders of magnitude (regarding WVTR). Experiments with application of different strain loads on the coated films revealed a significant increase of both, HeTR and WVTR. Scanning electron microscope (SEM) measurements evidenced multiple ruptures of the SiOx coating depending on the applied strain and initial thickness of the SiOx layer. Considering virgin barrier films and strain‐ruptured barrier films, a good correlation of WVTR and HeTR was shown.
Elementary Teachers’ Knowledge of Foundational Literacy Skills: A Critical Piece of the Puzzle in the Science of Reading
Authors: Hudson Alida K. , Moore Karol A. , Han Bing , Wee Koh Poh , Binks-Cantrell Emily , Malatesha Joshi R.
Published: May 2021

Equipping elementary (i.e., grades K–5) teachers with adequate content and pedagogical knowledge to promote effective reading instruction based on the science of reading is a crucial piece of the reading education puzzle. We reviewed 20 empirical studies to examine the impact of teacher preparation and training programs on elementary teachers’ knowledge of the science of reading, focusing on the foundational pillars of reading instruction, namely, phonological and phonemic awareness, phonics, and morphological awareness, as well as student outcomes in reading. We also identified program characteristics that promoted positive growth in teacher knowledge. Generally, findings support the effectiveness of training and preparation programs in increasing elementary teachers’ knowledge of foundational constructs. Training in which teachers have the opportunity to apply their learned knowledge and skills under expert guidance produced the largest growth in teacher knowledge. Implications of findings are discussed.
Mono‐ and Bimetallic Ni−Co Catalysts in Dry Reforming of Methane
Authors: Zhang Xuliang , Vajglova Zuzana , Mäki‐Arvela Päivi , Peurla Markus , Palonen Heikki , Murzin Dmitry Yu. , Tungatarova Svetlana A. , Baizhumanova Tolkyn S. , Aubakirov Yermek A.
Published: May 2021

Several bimetallic Ni−Co catalysts supported on θ‐Al2O3 together with 10 wt % Ni and 10 wt % Co on θ‐Al2O3 were prepared via the incipient wetness method, characterized by X‐ray diffraction (XRD), nitrogen adsorption, transmission electron microscopy, temperature programmed reduction, temperature programmed CO2 desorption, Fourier Transformed Infrared Spectroscopy (FTIR) with pyridine adsorption‐desorption and tested in dry methane reforming at 700 °C in a fixed bed reactor. According to XRD the metal oxide crystallite sizes decreased from 20 nm for 10 wt % Co/θ‐Al2O3 to 13 nm for 5 wt % Ni‐5 wt % Co/θ‐Al2O3, which also showed formation of a mixed oxide alloy. The unit cell parameters for spinel in the fresh catalyst and fcc metal formed during the reaction followed the Vegard's rule. Although monometallic 10 wt % Co/θ‐Al2O3 exhibited high hydrogen consumption, desorption temperature was also high resulting in a rather low activity of 10 wt % Co/θ‐Al2O3 in comparison to bimetallic 5 wt % Ni‐5 wt % Co/θ‐Al2O3. The latter exhibited the highest initial activity for hydrogen formation due to its relatively small metal particle size. This catalyst suffered, however, from extensive coking. The most stable catalyst was 10 wt % Ni/θ‐Al2O3 for which the hydrogen yield decreased form 56 % to 45 % during 100 h time‐on‐stream. For this catalyst no sintering occurred, opposite to 10 wt % Co/θ‐Al2O3.
The effects of board expertise‐risk misalignment and subsequent strategic board reconfiguration on firm performance
Authors: Schnatterly Karen , Calvano Felipe , Berns John P. , Deng Chaoqun
Published: May 2021

Research Summary

Boards are unlikely to be effective if they do not have sufficient collective expertise to understand, monitor, and address future risks. This begs the question, does the board, in fact, have this expertise? If not, can they reconfigure their expertise to address those risks? Building on agency theory, we analyze the alignment between the board's expertise and the firm's future risks, with the expectation that board composition will change over time to reflect the firm's future risks—strategic reconfiguration. Our results show that misalignment has negative implications for firm performance, misalignment also motivates appropriate board reconfiguration, and that this reconfiguration positively effects firm performance.

Managerial Summary

Our study illustrates the need for board expertise to be aligned with firm risks. While there has been increasing pressure for firms to assess their directors' expertise (i.e., skill matrices), simply identifying expertise which is present or absent does not speak to whether that expertise is actually needed (or not) by the firm given the risks faced. We analyze boards' collective expertise, compare that with the risks that firms are facing, and identify the gaps which may detrimentally impact the monitoring ability of the board and cause firm performance to suffer. Consequently, understanding the degree of (mis)alignment is of paramount importance for boards to be effective monitors and positively influence firm performance.
Lessons from a Decade of Research on Multifaceted Vocabulary Instruction
Authors: Manyak Patrick C. , Manyak Ann‐Margaret , Kappus Ellen M.
Published: May 2021

The authors look back on their participation in three successful multiyear research studies focused on multifaceted vocabulary instruction and distill four overarching lessons that provide practical guidance to schools and teachers interested in implementing effective comprehensive vocabulary instruction. Specifically, they elaborate on the value of instruction that addresses quality, quantity, and strategy dimensions of vocabulary learning; teaching many types of high‐value words; employing versatile instructional strategies such as using visual images and creating vocabulary collections; and seizing opportunities to foster students’ word consciousness. The authors also describe and illustrate a number of practical activities that teachers can employ to enhance their students’ word learning.
Efficacy of high‐intensity interval training compared with moderate‐intensity continuous training on maximal aerobic potency in dogs: Trial protocol for a randomised controlled clinical study
Authors: Orozco Sonia C. , Arias María P. , Carvajal Pablo A. , Gallo‐Villegas Jaime , Olivera‐Angel Martha
Published: May 2021

Background

High‐intensity interval training (HIIT) is a more efficient method to improve exercise capacity than moderate‐intensity continuous training (MICT) because of its greater physiological stimulus.

Objective

The aim of this protocol is to evaluate the efficacy of HIIT on maximal aerobic potency in dogs as compared to MICT.

Methods

This protocol is for a randomised, blinded controlled clinical trial, with three parallel groups for the purpose of demonstrating superiority. Thirty dogs aged between 12 and 84 months of both sexes and different breeds will be included. Dogs, before initiating and after finalising the training will perform an incremental exercise test on a treadmill to obtain maximal speed and lactate threshold; resting parameters of heart and respiratory rate, left ventricle chamber and systolic function will be measured. Dogs assigned to each intervention will endure a 42‐min session of HIIT or MICT during 12 weeks. HIIT comprises four intervals of 4 min each at a load of 85%, alternating with a 4‐min resting period. MICT group will have a continuous load of 60%. The control group will remain in a cage. An intention‐to‐treat statistical analysis will be implemented. Analysis of covariance will be used to estimate the effect of HIIT compared with MICT training on maximal aerobic potency, aerobic resistance, systolic function at rest, left ventricle chamber measurements and indexes, respiratory rate and HR at rest.

Conclusion

Significant time and effort are invested into training sports/working dogs, which could benefit from improving physical capacity by means of the HIIT methodology.
Constructing a nitrogen-doped carbon and nickel composite derived from a mixed ligand nickel-based a metal–organic framework toward adjustable microwave absorption
Authors: Qiu Yun , Yang Haibo , Cheng Yan , Bai Xiaoyu , Wen Bo , Lin Ying
Published: May 2021

Mixed ligands nickel-based metal–organic frameworks derived nitrogen-doped carbon and nickel composites exhibit tunable microwave absorption capabilities.
Visible-light-promoted photocatalyst-free alkylation and acylation of benzothiazoles
Authors: Jiang Pengxing , Liu Li , Tan Jiajing , Du Hongguang
Published: May 2021

A visible-light-mediated alkylation/acylation reaction of benzothiazoles was described using the BF3·Et2O/Na2S2O8 system.
Development of a pendulum machine for measuring contact lens friction
Authors: Mabuchi Kiyoshi , Iwashita Hiroko , Sakai Rina , Ujihira Masanobu , Hori Yuichi
Published: May 2021

The lubrication ability of a contact lens is one of its most essential properties because high friction on an eyelid causes discomfort during blinking. Friction measurements allow assessment of lubrication ability. So far, several apparatuses have been developed to measure contact lens friction. However, thus far, ocular physiological conditions including sliding speed and area have been imperfectly realised. Herein, a pendulum‐type friction tester was developed for the assessment of contact lenses under physiological conditions. A high sliding speed of 90 mm/s was achieved thanks to the short oscillation period of the small pendulum. Physiologically, the sliding surface on a contact lens was realised at the fulcrum of the pendulum. The coefficient of friction for the interaction between a contact lens and plastic hemisphere was directly calculated from the decay in potential energy during the free libration of the pendulum. Friction coefficient of a commercially available contact lens in saline solution, 0.1% and 0.3% HA solutions were 0.036, 0.039 and 0.050, respectively. These results were reliable because they ranged within the low levels reported by previous studies. It was shown that the present pendulum machine represents a major advancement in the realisation of physiologically realistic contact lens friction measurement.
Finite‐time synchronization and identification of the Markovian switching delayed network with multiple weights
Authors: Xie Qian , Guo Duo , Wang Tong , Yang Xiaoping
Published: May 2021

This paper focuses on finite‐time synchronization and parameters identification in the Markovian switching complex delayed network with multiple weights. Considering the control cost required for network synchronization, finite‐time control technique and pinning control strategy are adopted. Based on these methods, when finite‐time synchronization of the network is achieved, the unknown parameters of the system can also be identified in finite time. In addition, in order to solve the problem of the network performance change caused by network topology switching, an Optimal Nodes Selection Control Strategy (ONSCS) is proposed. On the one hand, finite‐time synchronization and identification of the network can be realized faster, on the other hand, it also further reduces the energy consumption and control cost of the network. Finally, two sets of comparative numerical simulations are given to prove the superiority and applicability of the proposed ONSCS.
Fault detection for asynchronous T–S fuzzy networked Markov jump systems with new event‐triggered scheme
Authors: Aslam Muhammad Shamrooz , Li Qianmu , Hou Jun
Published: May 2021

In this article, an adaptive event‐triggered fault detection problem for the asynchronous Takagi–Sugeno fuzzy networked Markov jump systems is investigated based upon the time‐varying delays. The purpose of designing a fault detection filter is to detect the fault signal under the influence of disturbance with network transmission. In the design process, one essential factor, time‐varying delay in the fuzzy filter with appearing in the residual signal, is taken into consideration. In order to rationally utilise network resources and elaborately avoid unnecessary continuous monitoring, an adaptive event‐triggered scheme is designed to guarantee the Takagi–Sugeno fuzzy networked Markov jump systems. Thus it helps to lower the energy consumption of communication while ensuring the performance of the system. Different from the conventional triggering mechanism, in this article, the parameters of the triggering function are based on a new adaptive law which is obtained online rather than a predefined constant. Based on the associated Lyapunov stability theory and appropriate inequality, some sufficient criteria in the form of linear matrix inequalities are obtained to ensure the stability of the resulting error system. Finally, a tunnel diode example is employed to illustrate the effectiveness of the proposed methods.
Enhanced three‐dimensional U‐Net with graph‐based refining for segmentation of gastrointestinal stromal tumours
Authors: Wang Qiong , Li Zhipeng , Zhao Wanqing , Wu Hao , Xie Fei , Guan Ziyu , Zhao Wei
Published: May 2021

The gastrointestinal stromal tumour (GIST) is a common mesenchymal tumour that lacks specificity of clinical manifestations. Therefore, preoperative accurate localization and accurate prediction of tumour risk are of important clinical value. At present, the diagnosis of GIST relies mainly on manual annotation of CT by professional doctors, which is inefficient and affected by subjective factors. A GIST segmentation algorithm is proposed based on a convolutional neural network to fuse multi‐scale features. The algorithm is applied to GIST segmentation with an improved 3‐D U‐Net method. Skip connections are introduced between encoders and decoders at different layers to account for the obvious differences in tumour size between different cases, which increases the path of information transmission in the network and solves the problem that U‐Net is too weak to simultaneously extract the features of different scales. In addition, due to the difficulty of tumour labelling and the correlation between small intestine segmentation and GIST segmentation, the model of small intestine segmentation is transferred to the model of GIST segmentation. Experiments show that the proposed method achieves better performance than that of the traditional U‐Net. Finally, the graph neural network is introduced to reduce the repetitive work of doctors in refining the segmentation results.
Adaptive weighting for estimation of the mean of the merged measurement for multi‐target bearing tracking
Authors: Li Quanrui , Qiu Longhao , Qi Bin , Liang Guolong
Published: May 2021

In multi‐target tracking, sensor with finite resolution generates merged measurements, which means that a group of targets might produce only one measurement, and such phenomenon could lead to degraded tracking performance if it is not considered. The generalised labelled multi‐Bernoulli filter for merged measurement (GLMB‐M) provides a promising solution for such problem. However, the merged measurement likelihood it used was modelled as a Gaussian density with its mean being the uniform weighted mean of the measurements generated by the merging targets. Such uniform weighting strategy might fail if the merged measurements deviate severely from the uniform weighted position due to significant difference of the strengths of the merging targets. To avoid such deviation, an adaptive weighting strategy for estimation of the mean of the merged bearing measurement is proposed, which uses the bearing measurement error to obtain the adaptive weighting factors. Simulation results show that the proposed adaptive weighting strategy outperforms the uniform weighting strategy when the strengths of the targets vary greatly, although both strategies provide similar performance when the strengths of the target are equal.
Photonics‐based de‐chirp processor with the capability of processing dual‐band signals
Authors: Liu Jiang , Zhu Dan , Chen Wenjuan , Pan Shilong
Published: May 2021

A photonics‐based de‐chirp processor with the capability of processing dual‐band linearly frequency‐modulated (LFM) waveforms is proposed and demonstrated. Two de‐chirped signals will be output simultaneously and independently, while no special requirement of the input signals' chirp rates is needed. A proof‐of‐concept experiment is carried out. De‐chirp processing of dual‐band signals (X‐ and Ku‐band) is successfully implemented. The crosstalk suppression ratio of more than 40 dB is achieved with de‐chirped results in the two bands.
On non‐destructive detection of hidden passive radio‐frequency eavesdroppers
Authors: Zhang Q. Y. , Liang M. L.
Published: May 2021

This paper investigates the possibility of detecting the presence of hidden radio‐frequency eavesdroppers embedded in modern electronic devices. The detection of such cyber security threats is quite difficult as they intercept wireless signals passively and never transmit them. The proposed detection approach relies on the fact that the impedance of active radio‐frequency components in the eavesdropper circuit depends on their biased voltage, and that scattering characteristics of the eavesdropper can be affected by its internal impedance change. Using the device under test as a reflector, scattering characteristics and channel state information are measured. By comparing channel state information differences for the device under test in different power supply states, the presence of hidden eavesdroppers can be identified. Full‐wave numerical simulations are performed to verify the effectiveness of the proposed method. As a non‐destructive testing approach, the proposed method exhibits a robust and easy way to detect hidden eavesdroppers.
Rigorous design method for distributed‐element bandpass filter with reflectionless response at two ports
Authors: Lee Gyuwon , Lee Jongheun , Lee Boyoung , Lee Juseop
Published: May 2021

This letter reports an accurate and rigorous design method for a distributed‐element reflectionless bandpass filter capable of producing a reflectionless response at two ports simultaneously. The design method relies on novel transmission‐line reflectionless filter prototypes. This work presents a stub‐based reflectionless filter prototype and its design formulas in terms of a target transmission response. It also provides a stub‐less coupled‐line reflectionless filter prototype equivalent to the stub‐based prototype in case where stubs are not feasible. A second‐order bandpass filter has been designed and fabricated to verify the design method. Reasonable agreement between the measured performance and the simulated one has been obtained, confirming that the proposed design is valid.
Inscription methods for co‐located fibre Bragg gratings using small spot direct UV writing
Authors: Jantzen S. L. , Smith D. H. , Bannerman R. H. S. , Boyd L. J. , Gates J. C. , Smith P. G. R. , Holmes C.
Published: May 2021

Two methods to inscribe co‐located fibre Bragg gratings using the small spot direct UV writing technique are described and compared, namely: superimposed gratings, which are written one over the other at the same spatial location, and superstructured gratings, where a refractive index modulation is digitally designed and all spectral signatures are written in a single step writing process. In this letter, we report a record number of 45 superimposed and 39 superstructured gratings being inscribed with an interference spot of only 14 μm in diameter.
Simple modelling of S‐type NbOx locally active memristor
Authors: Liang Yan , Wang Guangyi , Xia Chenyang , Lu Zhenzhou
Published: May 2021

Nanoscale S‐type NbOx locally active memristors (LAMs) open up new opportunities in the brain‐inspired neuromorphic computing. Simple yet accurate models for these memristors can provide benefits for designing related circuits and systems. Considering that the DC voltage–current plot of the NbOx LAM under current sweeping is composed of three regions, that is, high resistance region, negative differential resistance region, and low resistance region, a three‐segment piecewise‐linear method is applied to fit these three regions. Based on this developed relation of the voltage and current at DC, a simple model for the NbOx LAM is proposed. The parameters of the proposed model can be easily identified in terms of the quasi‐static and dynamic electrical characteristics. A series of numerical simulations corroborate that the proposed model can accurately emulate the quasi‐static voltage–current characteristics and oscillating behaviours of the NbOx LAM.
Improved adaptive parameters estimation considering transient‐state estimation error in sensorless control system of IPMSM
Authors: Kawamura Naoki , Zanma Tadanao , Nomura Yuta , Koiwa Kenta , Liu Kang‐Zhi , Hasegawa Masaru
Published: May 2021

Position sensorless vector control of interior permanent magnet synchronous motors (IPMSMs) has been used for downsizing, cost reduction, and high reliability. In the position sensorless vector control, the q‐axis inductance decreases as the q‐axis current increases due to the load variation, which results in deterioration of the position estimation performance without considering the q‐axis inductance. Here, the authors propose an innovative adaptive estimation based on the dynamic certainty equivalence principle for high‐performance position sensorless control for IPMSMs. The effectiveness of the proposed adaptive scheme is verified through experiments.
Transfer learning based dynamic security assessment
Authors: Lam Hoi Andy , Dong Zhao Yang
Published: May 2021

With the increasing deployment of wide‐area monitoring systems (WAMS) and phasor measurement units (PMUs), along with artificial neural network (ANN) and high‐performance distributed computation technique for smart grid and smart metering environment, online dynamic security assessment (DSA) plays a key role for early unstable event detection on power system security. It is especially important at a post‐fault operation that the timing by DSA to detect an unstable event is critical to emergency remedial control action. However, excessive update training is one of the constraints for ANN to be effectively performed at pre‐fault and post‐fault operations on online DSA. This paper describes how transfer learning is successfully employed to shorten the training time for online DSA. It also helps to improve the validation accuracy if the training dataset of scratch ANN model is insufficient. Besides, a new approach of using the densely connected convolutional network with kernel principal component analysis (KPCA) is proposed to eliminate the traditional step of dimensionality reduction.
Down‐sampling template curve to accelerate LDDMM‐curve with application to shape analysis of the corpus callosum
Authors: Huang Weikai , Tang Xiaoying
Published: May 2021

Large deformation diffeomorphic metric mapping for curve (LDDMM‐curve) has been widely used in deformation based statistical shape analysis of the mid‐sagittal corpus callosum. A main limitation of LDDMM‐curve is that it is time‐consuming and computationally complex. In this study, down‐sampling strategies for accelerating LDDMM‐curve are investigated and tested on two large datasets, one on Alzheimer's disease (155 Alzheimer's disease, 325 mild cognitive impairment and 185 healthy controls) and the other on first‐episode schizophrenia (92 first‐episode schizophrenia and 106 healthy controls). For both datasets a variety of down‐sampling factors are tested in terms of registration accuracy, registration speed, and most importantly disease‐related patterns. Experimental results revealed that down‐sampling template curve by a factor of 2 can significantly reduce the running time of LDDMM‐curve without sacrificing the registration accuracy. Also, the disease‐induced patterns, or more specifically the group comparison results, were almost identical before and after down‐sampling. It is also shown that there was no need to down‐sample the target population curves but only the single template curve of the study of interest. Comprehensive analyses were conducted.
Surface discharge imaging in presence of deposited space charges in non‐uniform DC electric field
Authors: Florkowski Marek , Krześniak Dariusz , Kuniewski Maciej , Zydroń Paweł
Published: May 2021

An investigation is made of the influence of an accumulated charge sprinkled on the surface of an epoxy resin plate in corona mode on partial discharge inception and its forms as analyzed by optical imaging at DC voltage. The effects of the polarities of both the deposited hetero‐ and homocharges were investigated. The occurrence of first streamer discharges was detected electrically and observed by optical imaging. The various forms of streamers were acquired by optical imaging and associated with the polarity and intensity of the accumulated surface charges. Surface charge sprinkling on the epoxy specimen surface was quantitatively evaluated by surface charge mapping. In addition, the effect of the subsequent discharges occurring in a heterocharge configuration above the inception voltage was observed. In terms of their directions and lengths, the kinetics of the streamer filaments revealed a strong dependence on both the polarity and the intensity of an accumulated charge. Compared with the reference charge‐free surface, the strongest drop in dielectric strength in the interelectrode space with a sprinkled charge was obtained for the heterocharge configuration. The presented results provide a contribution to the assessment of streamer behaviour in the presence of accumulated surface charges, including its polarity and intensity.
Automatic detection of safety helmet wearing based on head region location
Authors: Gu Yuwan , Wang Yusheng , Shi Lin , Li Ning , Zhuang Lihua , Xu Shoukun
Published: May 2021

In order to solve the problem of difficult and low precision in the detection of safety helmet wearing in the complex pose of construction worker, a detection method of safety helmet wearing based on pose estimation is proposed. In the pose estimation model of OpenPose, the residual network optimized feature extraction is introduced to obtain the skeletal point information of the construction worker, and then the pose of the construction worker is estimated based on the skeletal point information, three‐point localization method is proposed for the front and back pose, and skin colour detection method is proposed for the side pose, and then to determine the head region. The YOLO v4 is used to detect the safety helmet region, and then the construction worker's safety helmet wearing is judged according to whether the head region intersects the safety helmet region or not. Experimental results show that the detection accuracy of the method is higher than other methods, and the adaptability to the environment is stronger.
Multi‐view intrinsic low‐rank representation for robust face recognition and clustering
Authors: Wang Zhi‐yang , Abhadiomhen Stanley Ebhohimhen , Liu Zhi‐feng , Shen Xiang‐jun , Gao Wen‐yun , Li Shu‐ying
Published: May 2021

In the last years, subspace‐based multi‐view
face recognition has attracted increasing attention and many related methods have been proposed. However, the most existing methods ignore the specific local structure of different views. This drawback can cause these methods' discriminating ability to degrade when many noisy samples exist in data. To tackle this problem, a multi‐view low‐rank representation method is proposed, which exploits both intrinsic relationships and specific local structures of different views simultaneously. It is achieved by hierarchical Bayesian methods that constrain the low‐rank representation of each view so that it matches a linear combination of an intrinsic representation matrix and a specific representation matrix to obtain common and specific characteristics of different views. The intrinsic representation matrix holds the consensus information between views, and the specific representation matrices indicate the diversity among views. Furthermore, the model injects a clustering structure into the low‐rank representation. This approach allows for adaptive adjustment of the clustering structure while pursuing the optimization of the low‐rank representation. Hence, the model can well capture both the relationship between data and the clustering structure explicitly. Extensive experiments on several datasets demonstrated the effectiveness of the proposed method compared to similar state‐of‐the‐art methods in classification and clustering.
Automatic image segmentation based on label propagation
Authors: Belizario Ivar Vargas , Linares Oscar Cuadros , Neto João do Espirito Santo Batista
Published: May 2021

This article introduces an automatic approach for the segmentation of coloured natural scene images based on graphs and the propagation of labels originally designed for communities detection in complex networks. Images are initially pre‐segmented with super‐pixels, followed by feature extraction using colour information of each super‐pixels. The resulting graph consists of vertices which represent super‐pixels, whereas the edge weights are a measure of similarity between super‐pixels. The resulting segmentation corresponds to the propagation of labels among the vertices. In this article, three strategies for propagating labels have been formulated: (i) iterative propagation (ILP), (ii) recursive propagation (RLP) and (iii) a weighted recursive propagation (WRLP). The experiments have shown that the proposed methods, when compared to other state‐of‐the‐art methods, produce better results in terms of segmentation quality and processing time.
SeqFace: Learning discriminative features by using face sequences
Authors: Hu Wei , Huang Yangyu , Zhang Fan , Li Ruirui , Li Hengchao
Published: May 2021

Deep convolutional neural networks (CNNs) have greatly improved the Face Recognition (FR) performance in recent years. Almost all CNNs in FR are trained on the carefully labeled datasets containing plenty of identities. However, such high‐quality datasets are very expensive to collect, which restricts many researchers to achieve state‐of‐the‐art performance. In this paper, a framework, called SeqFace, for learning discriminative face features is proposed. Besides a traditional identity training dataset, the designed SeqFace can train CNNs by using an additional dataset which includes a large number of face sequences collected from videos. Moreover, the label smoothing regularization (LSR) and a new proposed discriminative sequence agent (DSA) loss are employed to enhance the discrimination power of deep face features via making full use of the sequence data. Only with a single ResNet model, the method achieves very competitive performance on several face recognition benchmarks, including LFW, YTF, CFP, AgeDB, and MegaFace. The code and model are publicly available at the website https://github.com/huangyangyu/SeqFace.
Second‐kind Fredholm integral‐equation analysis of scattering by layered dielectric gratings
Authors: Tsitsas Nikolaos L.
Published: May 2021

Scattering of the E‐polarised plane electromagnetic wave from two different but of the same‐period all‐dielectric rectangular bar gratings on substrates is analysed using a volume‐integral‐equation (VIE) method. Here, VIE is a Fredholm integral equation of the second kind with unknown function being the electric field in the gratings regions. Discretisation of the VIE is performed by applying an entire‐domain Galerkin technique. The developed algorithm possesses guaranteed convergence, provides accuracy, and is easily controlled by the order of discretisation. Numerical results for frequency‐selective reflection, manipulation of light to propagate in prescribed directions, and the ultrahigh‐Q lattice‐modes resonances are presented and discussed.
A non‐isolated high step‐up DC–DC converter using magnetic coupling and voltage multiplier circuit
Authors: Pourjafar Saeed , Shayeghi Hossien , Hashemzadeh Seyed Majid , Sedaghati Farzad , Maalandish Mohammad
Published: May 2021

This paper introduces a new DC–DC structure with a high voltage gain. The proposed structure can achieve higher voltage gain by using magnetic coupling and voltage multiplier circuit (VMC). The VMC is also used as a clamp circuit to suppress the voltage spike through the switch which leads to increase the overall system efficiency. Moreover, the peak voltage through the semiconductors of the proposed converter is low. The existence of soft‐switching such as zero‐current switching (ZCS) in OFF‐state and zero‐voltage switching (ZVS) in ON‐state of diodes is another merit of the proposed converter. The recommended structure uses one power MOSFET with low on‐state resistance (RDS‐ON) that leads to decrease the conduction loss. For demonstrating the proficiency of the proposed structure, technical analysis, mathematical survey, and comparison results with other similar previous structures are carried out. Finally, laboratory results with 200 W output power and 50 kHz switching frequency are provided, which prove the usefulness of the suggested converter. The proposed converter's efficiency in 200 W output power is 96.98 %. Also, the voltage gain, maximum voltage stress across the power switch and didoes for n (turn‐ratio) = 2 and D (duty‐cycle) = 0.6 are equal to 10, 0.25, and 0.75, respectively.
Design and optimization of deflection type dual‐stator switched reluctance wind power generator
Authors: Li Zheng , Wang Xin , Yu Xuze , Wang Xueting , Sun Hexu
Published: May 2021

In this paper, a deflection type dual‐stator switched reluctance wind power generator is proposed. This kind of generator can effectively improve the power generation efficiency and response speed of the generator with development potential. The generator consists of an external generator and an internal generator, which can be coordinated to improve the efficiency of the generator. In this paper, with the goal of reducing the loss of the generator core, Taguchi algorithm is used to screen out the parameter variables that has a great impact on the loss of the generator core. Based on the method of central composite design (CCD), the experimental sample data set is constructed and the rationality of the model is evaluated by analysis of variance and the optimal parameters of the generator are determined. The test results of the prototype verify the correctness of design, core loss calculation and optimization scheme.
Current stress and switching loss evaluation of a unified expandable power converter used for grid‐integration of renewable energy sources
Authors: Bizhani Hamed , Muyeen S. M. , Tatari Fatemeh R. , Techato Kuaanan , Ben‐Brahim Lazhar , Blaabjerg Frede
Published: May 2021

Due to the intermittent nature of the renewable energy systems (RESs), more specifically, solar panels and wind turbines, their sole use does not lead to a smooth and reliable power. To overcome this issue, the concurrent grid‐integration of RESs to form a microgrid is reported. In the DC‐bus microgrid, the produced power by RES is initially given to the shared DC‐bus through an individual source‐side converter and then transmitted to the utility via a common grid‐side converter. By increasing the number of RESs, the number of required power converters, and therefore, the investment cost also increase. Using the cost‐effective multi‐input low‐switch converters is a promising alternative to alleviate this significant need for individual converters. Recently, a nine‐switch‐based unified expandable power converter (UEPC) has been presented for concurrent integration of AC and DC sources with a tangible fewer switch count. This unified structure has been utilized in two configurations named AC‐AC‐AC and AC‐AC‐DC. In this paper, both configurations are evaluated and compared in terms of current stress and switching loss. Considering the current stress analysis, the best port for interfacing with the grid to lower the total current rating of power switching devices is also determined. The high‐performance capability of both configurations is finally verified using MATLAB/Simulink.