bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of microbial fuel cells coupled with solar cells under intermittent illumination on sediment remediation
Authors: Liu Zidan , Wang Jian , Zhang Taiping , Zhou Shaoqi , Yan Keyou
Published: October 2019

The purpose of this paper was to examine the effect of microbial fuel cells coupled with solar cells (MFC-SCs).
Direct C–H sulfenylation of quinoxalinones with thiols under visible-light-induced photocatalyst-free conditions
Authors: Teng Qing-Hu , Yao Yan , Wei Wen-Xiu , Tang Hai-Tao , Li Jia-Rong , Pan Ying-Ming
Published: October 2019

We have developed a metal-free and catalyst-free visible-light-promoted direct C–H sulfenylation of quinoxalin-2(1H)-ones with thiols for the synthesis of diverse 3-sulfenylquinoxalin-2(1H)-ones.
Microelectrofluidic probe for sequential cell separation and patterning
Authors: Brimmo Ayoola T. , Menachery Anoop , Qasaimeh Mohammad A.
Published: October 2019

Cell separation and patterning are of great interest to numerous biomedical applications. This work presents the microelectrofluidic probe, which separates cells within an open microfluidic system, and patterns cells in a 2D printing approach.
The acoustofluidic focusing and separation of rare tumor cells using transparent lithium niobate transducers
Authors: Wu Zezheng , Jiang Hongqiang , Zhang Lingling , Yi Kezhen , Cui Heng , Wang Fubing , Liu Wei , Zhao Xingzhong , Zhou Fuling , Guo Shishang
Published: October 2019

Research on circulating tumor cells (CTCs) is of great significance in cancer diagnosis, prognosis and even the development of personalized therapy.
A newly designed isoindigo/thiophene medium-sized molecule containing a π (D–A–D) bridge with unexpected organic photovoltaic performance
Authors: Shaker Mohamed , El-Hendawy Morad M. , Park Byoungwook , Lee Kwanghee
Published: October 2019

A novel medium-sized moleculeBT(EDIDT3)2, has been synthesized using a Pd(AcO)2catalyzed direct C–H arylation method.
A tunable floating-base bipolar transistor based on a 2D material homojunction realized using a solid ionic dielectric material
Authors: Li Jingfeng , Chen Xiaoqing , Xiao Yu , Li Songyu , Zhang Guoqing , Diao Xungang , Yan Hui , Zhang Yongzhe
Published: October 2019

This design can avoid the interface problem in heterojunction floating-base transistors.
Core–shell tecto dendrimers formed via host–guest supramolecular assembly as pH-responsive intelligent carriers for enhanced anticancer drug delivery
Authors: Wang Jianhong , Li Du , Fan Yu , Shi Menghan , Yang Yunxia , Wang Le , Peng Yitian , Shen Mingwu , Shi Xiangyang
Published: October 2019

Core–shell tecto dendrimers can be prepared via host–guest supramolecular assembly for encapsulation and pH-sensitive release of drugs for an improved anticancer therapy.
Ru nanoclusters confined in porous organic cages for catalytic hydrolysis of ammonia borane and tandem hydrogenation reaction
Authors: Song Qiang , Wang Wei David , Hu Xiwei , Dong Zhengping
Published: October 2019

Ultrafine Ru nanoclusters were encapsulated in porous organic cages for catalytic hydrolysis of ammonia borane and tandem hydrogenation reactions.
Vertically aligned laser sliced MWCNTs
Authors: Alharbi Thaar M. D. , Vimalanathan Kasturi , Alsulami Ibrahim K. , Raston Colin L.
Published: October 2019

Applications of multi-walled carbon nanotubes (MWCNTs) benefit from the availability of specific lengths of the material while keeping the outer walls pristine, for example, for applications requiring vertically aligned tubes.
Thermal and crystalline properties of poly(2-oxazoline)s
Authors: Oleszko-Torbus Natalia , Utrata-Wesołek Alicja , Bochenek Marcelina , Lipowska-Kur Daria , Dworak Andrzej , Wałach Wojciech
Published: October 2019

The review gathers together data concerning the influence of poly(2-substituted-2-oxazoline)s structure on their thermal and crystalline properties, and how this relationship can be adjusted in controlled manner.
Carbon nanoparticle-protected RNA aptasensor for amplified fluorescent determination of theophylline in serum based on nuclease-aided signal amplification
Authors: Gong Xiaoyu , Yu Chi , Zhang Yichang , Sun Yuan , Ye Lin , Li Juan
Published: October 2019

A carbon nanoparticle (CNP) and Cryonase-aided method that realizes the amplified fluorescent detection of theophylline was proposed.
Temperature-induced structural diversity of metal–organic frameworks and their applications in selective sensing of nitrobenzene and electrocatalyzing the oxygen evolution reaction
Authors: Han Defang , Huang Kun , Li Xianglin , Peng Mengni , Jing Linhai , Yu Baoyi , Chen Zeqin , Qin Dabin
Published: October 2019

Structure diversities can be observed in four new Co-MOFs by temperature modulated hydrothermal synthesis, which show high selectivity to nitrobenzene (NB) as well as promising oxygen evolution reaction (OER) activities.
Tinospora cordifolia derived biomass functionalized ZnO particles for effective removal of lead(ii), iron(iii), phosphate and arsenic(iii) from water
Authors: Vyas Gaurav , Bhatt Shreya , Paul Parimal
Published: October 2019

Owing to the vast diversity in functional groups and cost effectiveness, biomass can be used for various applications.
Correction: MOF-5 derived carbon as material for CO2 adsorption
Authors: Kukulka Wojciech , Cendrowski Krzysztof , Michalkiewicz Beata , Mijowska Ewa
Published: October 2019

Correction for ‘MOF-5 derived carbon as material for CO2 absorption’ by Wojciech Kukulka et al., RSC Adv., 2019, 9, 18527–18537.
A quantitative assessment of the dynamic modification of lipid–DNA probes on live cell membranes
Authors: Bagheri Yousef , Chedid Sara , Shafiei Fatemeh , Zhao Bin , You Mingxu
Published: October 2019

A comprehensive and quantitative study of the dynamic process of lipid–DNA conjugate modification onto cell membranes.
Identifying high-performance catalytic conditions for carbon dioxide reduction to dimethoxymethane by multivariate modelling
Authors: Siebert Max , Krennrich Gerhard , Seibicke Max , Siegle Alexander F. , Trapp Oliver
Published: October 2019

An efficient algorithmic workflow was developed to optimize seven process parameters of a homogeneous catalytic system with minimal experimental effort.
Application of a Sn4+ doped In2S3 thin film in a CIGS solar cell as a buffer layer
Authors: Kim SeongYeon , Mina Md. Salahuddin , Kim Kiwhan , Gwak Jihye , Kim JunHo
Published: October 2019

As a Cd-free buffer, In2S3 buffer has been used in Cu(In,Ga)Se2 (CIGS) solar cells.
Recent developments in carbon nitride based films for photoelectrochemical water splitting
Authors: Xiong Wei , Huang Fei , Zhang Rui-Qin
Published: October 2019

As an emerging semiconductor for PEC cells, metal-free g-CN has generally attracted research attention from the community due to its merits, namely an appropriate bandgap, abundant composition elements, good thermal stability and non-toxicity.
Storage of Na in layered graphdiyne as high capacity anode materials for sodium ion batteries
Authors: Huang Haihua , Li Kaining , Fan Xiaofeng , Singh David J. , Zheng W. T.
Published: October 2019

The Na capacity of bulk GDY goes up to 1237 mA h g−1 and is approximately 35 times higher than that of graphite.
Long-battery-life flexible zinc–air battery with near-neutral polymer electrolyte and nanoporous integrated air electrode
Authors: Li Yuan , Fan Xiayue , Liu Xiaorui , Qu Shengxiang , Liu Jie , Ding Jia , Han Xiaopeng , Deng Yida , Hu Wenbin , Zhong Cheng
Published: October 2019

A flexible zinc–air battery based on near-neutral gel polymer electrolyte and integrated nanoporous Co3O4nanosheets exhibits long battery life.
Janus electrochemical exfoliation of two-dimensional materials
Authors: Fang Yiyun , Li Xinzhe , Li Jing , Yao Chuanhao , Hoh Hui Ying , Hai Xiao , Lu Jiong , Su Chenliang
Published: October 2019

This review focuses on the smart and effective production of atomically thin 2D materials by Janus electrochemical exfoliation.
Innovative models for in vitro detection of seizure
Authors: Rockley Kimberly L. , Roberts Ruth A. , Morton Michael J.
Published: October 2019

Data show that toxicity to the central nervous system (CNS) is the most frequent cause of safety failures during the clinical phase of drug development. CNS endpoints such as seizure pose a safety risk to patients and volunteers and can lead to a loss of competitiveness, delays, and increased costs. Current methods rely on detection in the nonclinical rodent and non-rodent studies required to support clinical trials. There are two main issues with this approach; seizure may be missed in the animal studies and, even if seizure is detected, significant resource has already been invested in the project by this stage. Thus, there is a need to develop improved screening methods that can be used earlier in drug discovery to predict seizure. Advances in stem cell biology coupled with an increased understanding of the role of ion channels in seizure offer an opportunity for a new paradigm in screening. Human derived induced pluripotent stem cells (hiPSCs) representative of almost all cellular subtypes present in the brain can be incorporated into physiologically relevant in vitro models that can be used to determine seizure risk using high-throughput methods. Akin to the success of screening against a panel of ion channels such as hERG to reduce cardiovascular safety liability, the involvement of ion channels in seizure suggests that a similar approach to early seizure detection is valid. Profiling of the ion channels expressed in hiPSC models showing the seizurogenic phenotype coupled with electrophysiological assessment of ion channel function could translate into an ion channel seizure panel for rapid and reliable in vitro detection of seizure. The mechanistic information gathered would support optimal drug design early in development before resources, animals and time have been wasted.
Flexible pilot allocation scheme for massive MIMO two‐tier heterogeneous networks
Authors: Zhi Hui , Huang Ziju , Wang Feiyue
Published: October 2019

Existing research demonstrates that pilot contamination is one major factor that restricts the system performance of time division duplex massive multiple‐input multiple‐output (MIMO) systems. Reasonable pilot allocation is an effective method to reduce pilot contamination. However, most existing pilot allocation methods (whether for one‐tier or multi‐tier networks) focus on cells with the same size, or regular shape, or fixed number of users per cell, so they are inflexible and not applicable to massive MIMO multi‐tier heterogeneous networks (HetNets) with irregular shaped cells and random distributed users. To solve this problem, this study introduces the idea of coalition game into pilot allocation and proposes a pilot allocation scheme based on coalition game. The utility function of each user for coalition game is analysed; the adjustment principle of the coalition structure and the coalition formation algorithm are given. Simulations results show that the proposed scheme can be flexibly used in many massive MIMO scene that base stations and users are randomly distributed (such as one‐tier networks, multi‐tier HetNets, ultra‐dense HetNets, etc.), and it can effectively reduce pilot contamination and improve the received signal to interference plus noise ratio (SINR) and spectral efficiency (SE) of the uplink.
Symbol‐based multi‐layer iterative successive interference cancellation for faster‐than‐Nyquist signalling
Authors: Li Qiang , Gong Feng‐Kui , Song Pei‐Yang , Zhai Sheng‐Hua
Published: October 2019

A symbol‐based multi‐layer iterative successive interference cancellation (MLISIC) algorithm is proposed to eliminate the inter‐symbol interference (ISI) for faster‐than‐Nyquist signalling. The computational complexity of the proposed MLISIC algorithm is much lower than most existing block‐based estimation algorithms. By comparison with existing symbol‐based algorithms, the proposed MLISIC algorithm has higher estimation accuracy. Furthermore, by means of utilising more accurate symbols and elaborate length of successive interference cancellation, an improved MLISIC (IMLISIC) algorithm is presented to further promote the estimation accuracy. Simulation results show in mild ISI cases, the proposed MLISIC and IMLISIC algorithms can approximate the theoretical performance even using 256‐amplitude phase‐shift keying which is adopted in digital video broadcasting‐satellite‐second generation extension, i.e. bit error rate (BER) performance degradation is about 0.03 dB when the signal‐to‐noise ratio is high. In other words, using the proposed MLISIC and IMLISIC algorithms in mild ISI cases, the spectrum efficiency can be improved with negligible BER performance degradation. Besides, compared with existing symbol‐based algorithms, the greater BER performance improvement can be achieved under severer ISI circumstances.
Joint design of interference alignment and power splitting in SWIPT networks
Authors: Chen Yan , Liu Chen , Fu Youhua , Song Yunchao , Sun Wenfeng
Published: October 2019

In this study, the authors investigate the joint design problem of interference alignment (IA) and power splitting (PS) in simultaneous wireless information and power transfer (SWIPT) networks. The existing joint design method is generally divided into two steps. First, IA is performed, and then the PS ratio is optimised. To obtain IA and SWIPT, a new joint design multi‐objective alternating optimisation (MOAO) algorithm is proposed. Different from the existing joint design method, the proposed MOAO algorithm not only maximises the sum harvested power after PS, but also maximises the sum signal‐to‐intereference‐plus‐noise ratio (SINR) by jointly designing the transmitting precoding matrices, the receiving interference suppression matrices, and the PS ratio. For this multi‐objective optimisation problem, a weighted optimisation method is proposed, which compromises between maximising the sum harvested power and maximising the sum SINR. Simulation validates that the sum achievable rate and sum harvested power of the proposed MOAO algorithm are significantly superior to those of the current scheme under the reasonable weighting coefficients.
Equalisation and performance of diffusive molecular communication systems with binary molecular‐shift keying modulation
Authors: Shi Lu , Yang Lie‐Liang
Published: October 2019

This study investigates the equalisation techniques for the diffusive molecular communication (DMC) systems with binary molecular‐shift keying (BMoSK) modulation, referred to as the BMoSK‐DMC systems, in order to mitigate the effect of inter‐symbol interference (ISI). The authors first show that in terms of receiving equalisation, a BMoSK‐DMC system is in fact equivalent to a conventional binary phase‐shift keying modulated radio communication system encountering ISI. Hence, a wealth of equalisation techniques developed with the conventional radio communication systems may be introduced for equalisation of BMoSK‐DMC signals. However, considering the limited capability of molecular transceivers on computation and storage, in this study, the authors investigate only the linear equalisers (LEQ) in the principles of matched‐filtering, zero‐forcing (ZF) and minimum mean‐square error (MMSE). They characterise the effects of the different aspects related to DMC signalling and propagation on the achievable performance of the BMoSK‐DMC systems with these LEQ. Their studies and performance results demonstrate that both the ZF‐ and MMSE‐LEQ are capable of efficiently suppressing the ISI and attaining promising performance, while still have low‐complexity to facilitate implementation.
Distributed hierarchical consensus algorithm for economic dispatch in smart grid
Authors: Wu Xiaopeng , Sun Yonghui , Wei Zhinong , Sun Guoqiang
Published: October 2019

In this study, a distributed hierarchical consensus algorithm is proposed to solve the economic dispatch problem in smart grid. In the proposed hierarchical control strategy, the upper level is the leader level, which contains the feedback elements of power difference mismatch and plays a dominant role in the whole algorithm. The lower level is the follower level, which receives information from the leader level and realises self‐adjustment based on the received information. Besides, the constraint conditions of generator nodes are considered to ensure that all of the generator nodes could operate within their limitations. With the increase of the number of leader nodes, the high convergence rate could be illustrated by the comparison between single‐leader node and multi‐leader nodes. Finally, simulation results based on 5‐node network topology and IEEE‐57 bus systems are presented to verify the validity of the proposed algorithm, respectively.
Generic frequency‐domain model for the emission of PWM‐based power converters in the frequency range from 2 to 150 kHz
Authors: Klatt Matthias , Stiegler Robert , Meyer Jan , Schegner Peter
Published: October 2019

With an increasing number of power converters using fast switching technologies, more cases of interference between devices in the frequency range from 2 to 150 kHz occur. The most widely used technique in such devices is pulse‐width modulation (PWM) [e.g. in photovoltaic inverters (PVIs), active harmonic filters, battery storage systems and some types of electric vehicle chargers]. Only little is known about the behaviour of those sources, the factors influencing their emission and the interaction with other devices and the propagation in the network. To extend such knowledge, reliable and accurate models are required. In this study, a quantitative model for the prediction of voltages and currents in this frequency range is developed and verified. Since in most cases no information about internal circuits and controls of the devices is available, a measurement‐based black‐box approach is used. The emission around the switching frequency of single‐phase voltage‐source power converters is combined into a single emission source represented by a Thévenin equivalent. The general method to parameterise the model is presented and exemplarily applied for two PVIs and one battery‐electric vehicle charger. Moreover, the interaction of two devices at a joint point of connection is simulated and compared with real measurements.
Efficient linear network model for TEP based on piecewise McCormick relaxation
Authors: Goodarzi Shahin , Gitizadeh Mohsen , Reza Abbasi Ali
Published: October 2019

This study presents a novel scheme for transmission expansion planning (TEP) based on piecewise McCormick relaxation. The model presented considers investment and operation cost and identifies the transmission lines to be built. Since the AC power flow equations are inherently non‐convex and non‐linear, the resulting TEP model will be a highly complex optimisation problem, in which the optimal global solution is not guaranteed to be found by the existing techniques. This study aims to transform the non‐linear model of the power network into a novel linear one. The model proposed is much more precise compared with the DC approach, while the global solution is guaranteed to be found by the off‐the‐shelf solvers. This accurate transformation from a non‐convex and non‐linear AC‐TEP formulation into a linear‐TEP model enables the planner to get more insight into the power flow of the power system. The TEP problem is formulated as a mixed‐integer linear programming problem and is solved using the efficient commercial solvers. The results of the case studies show the tractability and exactness of the proposed model as well as its superiority over the state‐of‐the‐art schemes.
Recovery voltage response of XLPE cables based on polarisation and depolarisation current measurements
Authors: Morsalin Sayidul , Sahoo Animesh , Phung Bao Toan
Published: October 2019

Recovery voltage measurement (RVM) is one of the common diagnostic techniques for the condition assessment of electrical insulation. The method has been used to examine the dielectric response, especially deterioration or depolymerisation of the polymeric insulation under ageing condition. In this study, a mathematical model of the RVM measurement based on the Debye equivalent circuit is elucidated. The methodology for determining the modelling parameters from the polarisation and depolarisation currents (PDCs) is described. For the experiments, two short‐sections of service‐aged 11‐kV cross‐linked polyethylene insulated (XLPE) cable are used, and the PDC of these test specimens are measured. Here, the model adapted comprises three R‐C relaxation branches, where each branch represents a polarisation type. From the derived model, the peak of the RV can be predicted and are constructed over a wide range of charging time. Bode plots of the test objects are also presented with the magnitude and phase response which assist in understanding the RVM response.
Super‐resolution mapping of hyperspectral satellite images using hybrid genetic algorithm
Authors: Cyril Amala Dhason Heltin Genitha , Muthaia Indhumathi , Sakthivel Shanmuga Priyaa , Shanmugam Sanjeevi
Published: October 2019

To assess the rate of sedimentation and the consequent reduction in the storage capacity, periodical capacity surveys of multi‐purpose reservoirs is essential. Hydrographic surveys and acoustic surveys are time‐consuming and expensive. The limited availability and high cost of the high‐resolution images require a different methodology to accurately estimate the water‐spread area of the reservoir. In this study, 30 m resolution hyperspectral image (hyperion) and multi‐spectral image (The Earth Observing One (EO‐1) advanced land imager) are used to estimate the water‐spread area of the Peechi Reservoir, South India. A hybrid genetic algorithm (GA)‐based super‐resolution mapping approach is developed and demonstrated, which incorporates the multi‐objective GA and Hopfield neural network (HNN). The hybrid GA‐based super‐resolution mapping approach gives a global optimum solution in half of the original computation time. Furthermore, mapping approach gives an error of 6.38% for the multi‐spectral image and a lesser error of 3.86% for the hyperspectral image, while the HNN‐based super‐resolution mapping approach gives an error of 8.23% for the multi‐spectral image and 5.71% for the hyperspectral image. Thus, in this work, an efficient technique based on hybrid GA is presented, which is a useful tool for accurate mapping of water bodies at the sub‐pixel scale using hyperspectral imagery.
Image segmentation algorithm based on neutrosophic fuzzy clustering with non‐local information
Authors: Wen Jinyu , Xuan Shibin , Li Yuqi , Peng Qihui , Gao Qing
Published: October 2019

To improve the boundary processing ability and anti‐noise performance of image segmentation algorithm，a neutrosophic fuzzy clustering algorithm based on non‐local information is proposed here. Initially, the proposed approach uses the data distribution of deterministic subset to determine the clustering centre of the fuzzy subset. Besides, the fuzzy non‐local pixel correlation is introduced into the neutrosophic fuzzy mean clustering algorithm. The experimental results on synthetic images, medical images and natural images show that the proposed method is more robust and more accurate than the existing clustering segmentation methods.
Integrating Taylor–Krill herd‐based SVM to fuzzy‐based adaptive filter for medical image denoising
Authors: Narasimha C. , Rao A. Nagaraja
Published: October 2019

Medical imaging systems contribute much towards effective decision‐making by the physicians, which is highly essential in the day‐to‐day life of humans. In this study, Taylor–Krill herd (KH)‐based support vector machine (SVM) is proposed for medical image denoising. The Taylor–KH‐based SVM is the integration of Taylor series in KH optimisation algorithm, which is used for tuning the optimal weights of the SVM classifier. The efficiency of KH is due to two global and two local optimisers, and the adaptive operators ensure the adaptive nature of KH. Above all, KH never uses the derivative information as it employs the stochastic search and thereby, reduces the complexity of the algorithm. The proposed method tunes the hyperplane parameters of SVM optimally so that the optimal identification of the noisy pixels in the image is ensured and replaced with adaptive weights. The proposed method is analysed based on the metrics, such as peak signal‐to‐noise ratio (PSNR), structural similarity (SSIM) and the comparative analysis is done with existing methods for showing the effectiveness of the proposed method. The simulation result shows that the proposed method acquired a PSNR of 30.36 dB and SSIM of 0.89, respectively.
Automatic thresholding using a modified valley emphasis
Authors: Xing Jiangwa , Yang Pei , Qingge Letu
Published: October 2019

Otsu's method is one of the most well‐known methods for automatic thresholding, which serves as an important algorithm category for image segmentation. However, it fails if the histogram is close to unimodal or has large intra‐class variances. To alleviate this limitation, improved Otsu's methods such as the valley emphasis method and weighted object variances method have been proposed, which still yield non‐optimal segmentation performance in some cases. In this study, a modified valley metric using second‐order derivative is proposed to improve the Otsu's algorithm. Experiments are firstly conducted on five typical test images whose histograms are unimodal, multimodal or have large intra‐class variances, and then expanded to a larger data set consisting of 22 cell images. The proposed algorithm is compared with original Otsu's method and existing improved algorithms. Four evaluation metrics including misclassification error, foreground recall, Dice similarity coefficient and Jaccard index are adopted to quantitatively measure the segmentation performance. Results show that the proposed algorithm achieves best segmentation results on both data sets quantitatively and qualitatively. The proposed algorithm adapts the Otsu's method to more image subtypes, indicating a wider application in automatic thresholding and image segmentation field.
Symplectic MRTD for solving three‐dimensional Maxwell equations based on optimised operators
Authors: Wei Min , Li Meng , Ma Zhu
Published: October 2019

A new set of symplectic operators for the symplectic multi‐resolution time‐domain (S‐MRTD) method is obtained by using the time reversible constraint and the growth factor. Then, the perfectly matched layer absorbing boundary condition based on splitting field technique is introduced into the S‐MRTD method and its iterative formula is derived. The stability and numerical dispersion of S‐MRTD method with optimised symplectic operators are discussed in detail. Finally, the optimal S‐MRTD method is applied to the calculation of electromagnetic radiation and scattering. Numerical calculation and simulation results show that the S‐MRTD is more accurate and efficient than the traditional FDTD method.
Enhancing VA sharing between the shunt and series APFs of UPQC with a modified SRF‐PAC method
Authors: Patel Ashish , Mathur Hitesh Datt , Bhanot Surekha
Published: October 2019

This study proposes a synchronous reference frame (SRF) theory‐based modified power angle control (PAC) method for unified power quality conditioner (UPQC). In the steady state of conventional UPQC, shunt active power filter (APF) supplies total reactive power demand, and series APF sits idle, leading to unbalanced VA loading of the two APFs and increase in overall VA rating of UPQC. PAC methods of UPQC have been devised for reducing the unbalance in VA loading of series and shunt APFs of UPQC by sharing reactive load power between the two APFs. SRF‐based PAC methods are robust, but existing ones support only small values of power angle, and thereby limit the improvement in unbalance of VA loading of series and shunt APFs. In this work, a modified SRF‐PAC method is proposed to support larger values of power angle, to load the two APFs in proportion to their VA ratings and thus yield smaller unbalance in VA loading of the two APFs of UPQC. Also, a modified power angle estimation is proposed to ensure that voltage and VA load on series converter does not go beyond the rated values. Controller hardware in loop simulations and hardware experiments validate the proposed control method.
Decentralised non‐linear I–V droop control to improve current sharing and voltage restoration in DCNG clusters
Authors: Mosayebi Mahdi , Sadeghzadeh Seyed Mohammad , Khooban Mohammad Hassan , Guerrero Josep M.
Published: October 2019

This study proposes a new decentralised non‐linear I–V droop control to achieve current sharing and voltage restoration for paralleled DC nanogrids (DCNGs) in a cluster. The performance of the conventional droop methods in current sharing among parallel converters degrades due to line impedances. The proposed method improves current sharing among the DCNGs with parallel‐connected converters by considering the effect of line impedance, which is an important issue in practical applications. By the proposed method, desired current sharing from the light‐load to heavy‐load condition is achieved. Since only local information (the output voltage and output current of the DCNGs) is used, the proposed method is fully decentralised, and no communication infrastructure is required, which improves the reliability and stability of the overall system. Furthermore, Lyapunov stability theory is applied to investigate the stability of the proposed method. Additionally, the plug‐and‐play feature is achieved as an important desired functionality in the DCNGs as well as the proposed method provides scalability and modularity for the DCNGs in a cluster. In the end, theoretical analysis and experimental results validate the effectiveness of the proposed control framework for different scenarios.
Communication‐awareness joint beams and power allocation scheme of radar network for manoeuvring targets tracking
Authors: Lu Yanxi , He Zishu , Liu Shuangli , Sun GuoHao
Published: October 2019

The coexistence of radar and communication system is a crucial task owing to the shortage of spectrum resources. In this study, the authors consider a multiple manoeuvring targets tracking problem via a radar network in the presence of several non‐cooperative, spatially random, and spectral overlapped communication areas (CAs). Instead of costly inner pattern optimisation, a communication awareness joint beam and power allocation (CJBPA) scheme of radar network is proposed to achieve high flexibility in coexistence. In CJBPA, radars and CAs treat the signals from each other as interference, which are formulated and discussed from the perspective of spectrum and space. The CJBPA optimises the overall tracking performance, which is characterised by the posterior Cramer‐Rao lower bound under the consideration of coexistence. The resultant non‐convex problem is relaxed and decoupled as an integrated two‐staged optimisation. To accelerate the numerical procedures of the optimisations, custom‐built primal dual interior point methods are derived by the structure information of the problems. The effectiveness of the proposed CJBPA scheme is assessed through simulations, showing that by using spatial and spectral information of undesired signals, the tracking performance can be optimised while the impacts of interference on both radars and CAs are restricted.
Development of hybrid artificial intelligence based automatic sleep/awake detection
Authors: Bozkurt Mehmet Recep , Uçar Muhammed Kürşad , Bozkurt Ferda , Bilgin Cahit
Published: October 2019

Background and Objective: Obstructive Sleep Apnea is a disease that causes respiratory arrest in sleep and reduces sleep quality. The diagnosis of the disease is made by the physician in two stages by examining the patient records taken with the polysomnography device. Because of the negative aspects of this process, new diagnostic processes and devices are needed. In this article, a new approach to sleep staging, which is one of the diagnostic steps of the disease, was proposed. An artificial intelligence‐based sleep/awake system detection was developed for sleep staging processing. Photoplethysmography (PPG) signal and heart rate variable (HRV) were used in the study. PPG records taken from patient and control groups were cleaned by the digital filter. The HRV parameter was then derived from the PPG signal. Then, 40 features from HRV signal and 46 features from PPG signal were extracted. The extracted features were classified by reduced machine learning techniques with F‐score feature selection method. In order to evaluate the performances of the classifiers, the sensitivity and specificity values, the accuracy rates for each class were computed in the test set and receiver operating characteristic curve prepared. In addition, area under the curve (AUC), Kappa coefficient and F‐score were calculated. According to the results obtained, the system can be realised with 91.09% accuracy rate using 11 PPG and HRV and with 90.01% accuracy rate using 14 HRV features. These success rates are quite enough for the system to work. When all these values are taken into consideration, it is possible to realise a practical sleep/awake detection system. This article suggests that the PPG signal can be used to diagnose obstructive sleep apnea by processing with artificial intelligence and signal processing techniques.
Method of state identification of rolling bearings based on deep domain adaptation under varying loads
Authors: Kang Shouqiang , Chen Weiwei , Wang Yujing , Na Xiaodong , Wang Qingyan , Mikulovich Vladimir Ivanovich
Published: October 2019

Large amounts of labelled vibration data of rolling bearings are difficult to acquire in full during operating conditions under varying loads. Moreover, a large divergence in data distribution exists between source and target domains for the same state. A multiple‐state identification method for rolling bearings under varying loads is proposed. The deep domain adaptation method integrates the convolutional and pooling theory with the deep belief network (DBN) that enables the construction of a convolutional Gaussian–Bernoulli DBN, which is used to extract the deep generalised features from the frequency‐domain amplitudes of the rolling bearings. The weighted mixed kernel is then used instead of the single kernel to improve the joint distribution adaptation, which is used to process the features of both the labelled source domain and the unlabelled target domain for domain adaptation, and reduce the distribution divergence. Finally, the k‐nearest neighbour algorithm is used for identification. Experimental results show that the proposed method can make full use of unlabelled data, mine the deep features of vibration signals, and reduce the divergence between data of the same state. In resolving the multiple‐state identification of rolling bearings under varying loads, a higher accuracy is attained in the identification.
Hybrid continuous circuit‐trapezoidal integration method analysis of multi‐cross structure of grounding system
Authors: Asadpourahmadchali Mohammadbagher , Niasati Mohsen , Alinejad‐Beromi Yousef
Published: October 2019

An essential requirement to improve the lightning performance of transmission line is the achievement of low impulse impedance of grounding system, which diminishes the occurrence of the external overvoltages. In this study, for the first time, a multi‐cross structure used as transmission line tower‐footing grounding system is investigated by means of hybrid continuous circuit‐trapezoidal integration method (HCCTIM). It is discovered that the angle of minimum impulse impedance or the optimal structure of multi‐cross grounding system is mainly dependent on the branch length compared to the effective length of a single horizontal conductor. Furthermore, in the current work, the trapezoidal integration method is used to solve the continuous circuit equations which elements are extracted from electromagnetic integral method, called HCCTIM. Coupling elements and soil ionisation are considered in this model. This method is an accurate, simple, and less time‐consuming computational method. The comparison of the results with measurements, other recent simulations and CDEGS software, satisfactorily validate the proposed method.
Application of unconstrained BCG extraction in VDT visual fatigue monitoring
Authors: Jiang Yongxiang , Wang Peng , Deng Sanpeng , Qi Yuming , Ma Longjia , Wang Zijing , Zhang Tianjiang
Published: October 2019

Eye diseases caused by long times of use of visual display terminal (VDT) products is considered as a serious problem in recent years. The eye fatigue monitoring is significant for early warning. Here, an unconstrained measuring method is used to extract Ballistocardiogram (BCG) by acceleration sensor. The acceleration signals are acquired by installing the sensor on seat back. Adaptive threshold wavelet transform is processed for denosing non‐linear noise interference such as power line interference, baseline drift, random movement of human body, and ground vibration. Frequency domain filtering and IFFT are applied to extract BCG from acceleration sensor. RR interval of ECG and JJ interval of BCG in time domain have the similar cycle, and the correlation coefficient is up to 0.9918, which prove the feasibility to extract BCG from vibration signals using unconstrained method.
Research on safety information terminal of household gas
Authors: Liu Xun
Published: October 2019

In this study, the important role of the household gas safety information terminal in the gas supply industry is introduced, and the necessity of studying the new type of the household gas safety information terminal is pointed out. Then, the function and specification of the terminal are introduced. The system design scheme of the terminal is described, including gas, photoelectric reading conversion device, valve, wireless communication module, pressure detection unit, gas leak detection unit, and control unit; the characteristics, functions, and performance indexes of each part of the system are described in detail. Finally, the practical application effect of the terminal is given.
Analysis and research on quality control method of global radiation observation data
Authors: Bian Zeqiang , Chong Wei , Ding Lei , Yang Wei
Published: October 2019

Radiation observation data are important basic data for assessment and research of climate change and solar energy resources. Quality control of radiation observation data is an important guarantee for accurate and reliable observation. First, the global radiation data collection method and the quality control process are introduced, and the differences and similarities between different quality control standards are compared in detail. Then, the quality control contents of the upper and lower limits and the rate of change are analysed theoretically and verified by experiments. Theoretical analysis and experimental results showed that the lower limit of the global radiation irradiance quality control should be −20 W/m2, the upper limit should be 2221 W/m2 or based on solar position, and the wrong change rate of sampling value should be 1000 W/m2. Through the unification of the global radiation quality control standards, the difference caused by the inconsistent quality control methods can be avoided, thus improving the effectiveness of the radiation observation data and ensuring the accuracy and consistency of the radiation observation data.
Green synthesis of graphene oxide‐MnFe2O4 composites and their application in removing heavy metal ions
Authors: Liao Fangli , Diao Guiqiang , Li Hao
Published: October 2019

The composites of graphene oxide (GO) decorated by MnFe2O4 have been synthesised via a green and facile strategy that the pristine GO/MnSO4 suspension prepared by Hummers method was directly utilised to convert into the GO‐MnFe2O4 composites. The as‐prepared composites were characterised using X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectra and X‐ray photoelectron spectroscopy. The results indicated that the GO‐MnFe2O4 composites were successfully synthesised. The removal behaviours of Pb2+ and Cu2+ onto GO‐MnFe2O4 were investigated, which indicated that the composites exhibited great adsorption property in aqueous solution. The adsorption process could be fitted well by the pseudo‐second‐order model and Langmuir isotherm. The thermodynamic studies indicated that the adsorption process of Pb2+ and Cu2+ onto GO‐MnFe2O4 composites was spontaneous and endothermic in nature. Furthermore, the maximum adsorption capacities for Pb2+ and Cu2+ calculated from Langmuir model were about 263.85 and 103.41 mg/g at 318 K, respectively. Based on the results from the reusability experiments, the as‐prepared GO‐MnFe2O4 composites could be used as a potential adsorbent for removing Pb2+ and Cu2+ ions from aqueous solutions.
Kinematic signatures of reverberation mapping of close binaries of supermassive black holes in active galactic nuclei
Authors: Kovačević Andjelka B. , Wang Jian-Min , Popović Luka Č.
Published: October 2019

Context. An unresolved region in the relative vicinity of the event horizon of a supermassive black holes (SMBH) in active galactic nuclei (AGN) radiates strongly variable optical continuum and broad-line emission flux. These fluxes can be processed into two-dimensional transfer functions (2DTF) of material flows that encrypt various information about these unresolved structures. An intense search for kinematic signatures of reverberation mapping of close binary SMBH (SMBBH) is currently ongoing.

Aims. Elliptical SMBBH systems (i.e. both orbits and disc-like broad-line regions (BLR) are elliptic) have not been assessed in 2DTF studies. We aim to numerically infer such a 2DTF because the geometry of the unresolved region is imprinted on their optical emission. Through this, we determine their specific kinematical signatures.

Methods. We simulated the geometry and kinematics of SMBBH whose components are on elliptical orbits. Each SMBH had a disc-like elliptical BLR. The SMBHs were active and orbited each other tightly at a subparsec distance.

Results. Here we calculate for the first time 2DTF, as defined in the velocity-time delay plane, for several elliptical configurations of SMBBH orbits and their BLRs. We find that these very complex configurations are clearly resolved in maps. These results are distinct from those obtained from circular and disc-wind geometry. We calculate the expected line variability for all SMBBH configurations. We show that the line shapes are influenced by the orbital phase of the SMBBH. Some line profiles resemble observed profiles, but they can also be much deformed to look like those from the disc-wind model.

Conclusions. First, our results imply that using our 2DTF, we can detect and quantify kinematic signatures of elliptical SMBBH. Second, the calculated expected line profiles share some intriguing similarities with observed profiles, but also with some profiles that are synthesised in disc-wind models. To overcome the non-uniqueness of the spectral line shapes as markers of SMBBH, they must be accompanied with 2DTF.
Substantiation of ways to reclaim the space of the previously mined-out quarries for the recreational purposes
Authors: Kalybekov Tursyn , Sandibekov Manarbek , Rysbekov Kanay , Zhakypbek Yryszhan
Published: October 2019

Opencast fields mining leads to land disturbance when conducting mining operations and storing of overburden rocks. The timely reclaiming of the disturbed lands according to the legislation requirements is an immediate duty of the subsoil user. The reclamation of the previously mined-out space of quarries refers to an extremely important tasks of the mining enterprise. The use of water management direction in reclamation assumes the use of previously mined-out space of a quarry to create the water reservoir through various methods of rehabilitation. There are presented various ways of designing the coastal zone of the created artificial water reservoirs in the previously mined-out space of the quarries located worldwide, which are used for the recreational purposes. The various profiles of slopes of artificial water reservoirs in a quarry with more low gradients, suitable for swimming and recreation are shown. Designing of a coastal area on the site of a quarry, intended for water reservoirs, depends on the water level position in the created body of water. The water reservoir, as the lake of artificial origin, created on the former quarry site, is shown. The purpose of the article is to substantiate the methodological approaches and engineering solutions concerning reclamation of the mined-out space after the opencast mining for the recreational purposes.
Problems of mining the prospective coal-bearing areas in Donbas
Authors: Nehrii Serhii , Nehrii Tetiana , Bachurin Leonid , Piskurska Hanna
Published: October 2019

The prospective coal-bearing areas of Donbas in Ukraine have been identified. Their development will increase the energy security of Ukraine. It has been suggested that the development of these areas will involve mining the coal seams in a weak roof and floor environment, which are characterized by low compressive strength, lower density and a tendency to plastic deformations. The stability has been assessed of the rocks outcrop on the contour of mine roadways for mines operating in these areas. It has been determined that roof rocks in most of these mines belong to a range of groups from very unstable to moderately stable, and the bottom rocks are, in most cases, prone to swelling. This complicates the intensive prospective areas mining with the use of advanced technologies, as well as secondary support for retained goaf-side gateroads with limited yielding property. The mines have been determined, for which this issue is relevant when mining the seams with further increase in the depth. The mechanism of displacement in the secondary supports and has been exemplified and studied using the numerical method. The obtained results allowed us to substantiate the necessity of developing new technical solutions for the protection of gateroads under conditions of prospective Donbas areas.
Predicting the producing well stability in the place of its curving at the underground coal seams gasification
Authors: Petlovanyi Mykhailo , Lozynskyi Vasyl , Saik Pavlo , Sai Kateryna
Published: October 2019

The relevant issues have been studied of ensuring the stability of producing wells in the place of their curving when uncovering the mining extracted area for the underground gas generator operation. It is emphasized that the design planning of efficient operation of underground gas generators in downhole gasification technology is impossible without consideration of the stress state of the rock massif, which can lead to a danger of the wellbore cutting and emergency shutdown of the technological system operation. The parameters of geomechanical models have been developed and substantiated for the study of the stress state of the “rock massif – producing well” system under the conditions of the Lviv-Volyn coal basin. A computer simulation has been performed of change in the stress state of a laminal massif around a well with a curvature radius in the range of 5 – 25 m with the use of the finite element method. The exponential function has been revealed of the tensile stresses value in the roof of the seam from the angle of the producing well entry into the coal seam. It is recommended the rational angle of a well entry into the coal seam, which is in the range of 21 – 28 degrees, and an appropriate curvature radius will be 5 – 10 m.