bluuebunny/crossref_metadata_2025 huggingface dataset:
Catalyst-free aerobic oxidation of aldehydes into acids in water under mild conditions
Authors: Zhang Yue , Cheng Yujia , Cai Huizhuo , He Shaopo , Shan Qiheng , Zhao Hongwei , Chen Yiping , Wang Bo
Published: October 2017

The first example of catalyst-free aerobic oxidation of aldehydes in water under respective acidic, neutral and alkaline conditions was developed.
Host immune evasion strategies of malaria blood stage parasite
Authors: Yam Xue Yan , Preiser Peter R.
Published: October 2017

Host immune evasion is a key strategy for the continual survival of many microbial pathogens including Apicomplexan protozoan:Plasmodiumspp., the causative agent of Malaria.
Electronic properties of single-layer tungsten disulfide on epitaxial graphene on silicon carbide
Authors: Forti Stiven , Rossi Antonio , Büch Holger , Cavallucci Tommaso , Bisio Francesco , Sala Alessandro , Menteş Tevfik Onur , Locatelli Andrea , Magnozzi Michele , Canepa Maurizio , Müller Kathrin , Link Stefan , Starke Ulrich , Tozzini Valentina , Coletti Camilla
Published: October 2017

This work reports an electronic and micro-structural study of an appealing system for optoelectronics: tungsten disulphide (WS2) on epitaxial graphene (EG) on SiC(0001).
Porous germanene as a highly efficient gas separation membrane
Authors: Bian Ang , Dai Yafei , Yang Jinlong
Published: October 2017

Using a gas separation membrane as a simple gas separation device has an obvious advantage because of the low energy consumption and pollution-free manufacturing.
A facile strategy for enzyme immobilization with highly stable hierarchically porous metal–organic frameworks
Authors: Liu Xiao , Qi Wei , Wang Yuefei , Su Rongxin , He Zhimin
Published: October 2017

Enzymes were efficiently immobilized on highly stable hierarchically porous MOFs and applied to the colorimetric detection of glucose and uric acid.
On-demand electrically controlled drug release from resorbable nanocomposite films
Authors: Samanta Devleena , Mehrotra Rohan , Margulis Katy , Zare Richard N.
Published: October 2017

A resorbable nanofilm that dissolves with local pH changes induced by electrical stimuli has been developed for electroresponsive drug delivery.
Fabrication of tough photonic crystal patterns with vivid structural colors by direct handwriting
Authors: Su Xin , Jiang Yu , Sun Xiaoqian , Wu Suli , Tang Bingtao , Niu Wenbin , Zhang Shufen
Published: October 2017

A simple strategy for fabricating tough composite photonic crystal films is demonstrated and patterns with vivid structural colors are created by hand writing or drawing.
Enhanced ionic conductivity in electroceramics by nanoscale enrichment of grain boundaries with high solute concentration
Authors: Bowman William J. , Kelly Madeleine N. , Rohrer Gregory S. , Hernandez Cruz A. , Crozier Peter A.
Published: October 2017

The enhancement of grain boundary oxygen ionic conductivity by four orders of magnitude in an electroceramic is explicitly shown to result from modulation of local grain boundary composition at the atomic level.
Multicomponent, fragment-based synthesis of polyphenol-containing peptidomimetics and their inhibiting activity on beta-amyloid oligomerization
Authors: Lambruschini Chiara , Galante Denise , Moni Lisa , Ferraro Francesco , Gancia Giulio , Riva Renata , Traverso Alessia , Banfi Luca , D'Arrigo Cristina
Published: October 2017

A new and short fragment-based approach towards artificial (but “natural-based”) complex polyphenols has been developed, exploiting the Ugi multicomponent reaction of phenol-containing simple substrates.
A low-temperature, photoinduced thiol–ene click reaction: a mild and efficient method for the synthesis of sugar-modified nucleosides
Authors: Bege Miklós , Bereczki Ilona , Herczeg Mihály , Kicsák Máté , Eszenyi Dániel , Herczegh Pál , Borbás Anikó
Published: October 2017

While studying the radical mediated hydrothiolation of nucleoside enofuranosides, an unusual temperature effect was observed by the exploitation of which various thio-substituted nucleoside analogues were produced.
Experimental and mechanistic insights into copper(ii)–dioxygen catalyzed oxidative N-dealkylation of N-(2-pyridylmethyl)phenylamine and its derivatives
Authors: Wang Yang , Liu Haixiong , Zhang Xiaofeng , Zhang Zilong , Huang Deguang
Published: October 2017

An efficient Cu(ii)/O2 catalytic system was experimentally explored for the N-dealkylation of PyCH2NHPh and its derivatives via C–H bond activation.
The iso-Nazarov reaction
Authors: Riveira Martín J. , Marsili Lucía A. , Mischne Mirta P.
Published: October 2017

The acid-promoted cycloisomerization of conjugated dienals and linearly-conjugated dienones for the synthesis of five-membered ring systems is reviewed.
Tetrazolylpyrene unnatural nucleoside as a human telomeric multimeric G-quadruplex selective switch-on fluorescent sensor
Authors: Bag Subhendu Sekhar , Pradhan Manoj Kumar , Talukdar Sangita
Published: October 2017

Specific sensing of dimeric H45 G-quadruplex DNA using a fluorescence light-up probe, tetrazolylpyrene nucleoside (TzPyBDo), is reported.
Cycloadduct formation of α,β-unsaturated esters with azides catalyzed by NHC systems
Authors: Yuan Huijun , Gao Hua , Liu Kun , Liu Zhantao , Wang Jian , Li Wenjun
Published: October 2017

NHC-catalyzed cycloadduct formation of α,β-unsaturated esters with azides has been developed. This strategy could generate 1,2,3-triazoles and dihydropyrazoles with high yields and regioselectivities. The broad substrate scope and mechanistic survey of this process are also presented.
Correction: Waste activated sludge (WAS) dewatering properties of an original hydrophobically modified polyacrylamide containing a cationic microblock structure
Authors: Zhou Yuhao , Zheng Huaili , Gao Baoyu , Gua Yingpeng , Lia Xiang , Liu Bingzhi , Navarro Jiménez Andrea
Published: October 2017

Correction for ‘Waste activated sludge (WAS) dewatering properties of an original hydrophobically modified polyacrylamide containing a cationic microblock structure’ by Yuhao Zhou et al., RSC Adv., 2017, 7, 28733–28745.
Determination of the local density of polydisperse nanoparticle assemblies
Authors: Genix Anne-Caroline , Oberdisse Julian
Published: October 2017

We propose a simple tool based on numerical simulations to extract the local density of nanoparticle assemblies from a scattering experiment.
Exploring the potential of ionic bipolar diodes for chemical neural interfaces
Authors: Tybrandt K.
Published: October 2017

Ionic bipolar diodes can suppress passive leakage and provide fast delivery, making them ideal for chemically specific neural interfaces.
Gene expression profiling of the Notch-AhR-IL22 axis at homeostasis and in response to tissue injury
Authors: Weidenbusch Marc , Rodler Severin , Song Shangqing , Romoli Simone , Marschner Julian A. , Kraft Franziska , Holderied Alexander , Kumar Santosh , Mulay Shrikant R. , Honarpisheh Mohsen , Kumar Devarapu Satish , Lech Maciej , Anders Hans-Joachim
Published: October 2017

Notch and interleukin-22 (IL-22) signaling are known to regulate tissue homeostasis and respond to injury in humans and mice, and the induction of endogenous aryl hydrocarbon receptor (Ahr) ligands through Notch links the two pathways in a hierarchical fashion. However in adults, the species-, organ- and injury-specific gene expression of the Notch-AhR-IL22 axis components is unknown. We therefore performed gene expression profiling of DLL1, DLL3, DLL4, DLK1, DLK2, JAG1, JAG2, Notch1, Notch2, Notch3, Notch4, ADAM17/TNF-α ADAM metalloprotease converting enzyme (TACE), PSEN1, basigin (BSG)/CD147, RBP-J, HES1, HES5, HEY1, HEYL, AHR, ARNT, ARNT2, CYP1A1, CYP24A1, IL-22, IL22RA1, IL22RA2, IL10RB, and STAT3 under homeostatic conditions in ten mature murine and human organs. Additionally, the expression of these genes was assessed in murine models of acute sterile inflammation and progressive fibrosis. We show that there are organ-specific gene expression profiles of the Notch-AhR-IL22 axis in humans and mice. Although there is an overall interspecies congruency, specific differences between human and murine expression signatures do exist. In murine tissues with AHR/ARNT expression CYP1A1 and IL-22 were correlated with HES5 and HEYL expression, while in human tissues no such correlation was found. Notch and AhR signaling are involved in renal inflammation and fibrosis with specific gene expression changes in each model. Despite the presence of all Notch pathway molecules in the kidney and a model-specific induction of Notch ligands, IL-22 was only up-regulated in acute inflammation, but rapidly down-regulated during regeneration. This implies that for targeting injury responses, e.g. via IL-22, species-specific differences, injury type and time points have to be considered.
α-Mangostin protects against high-glucose induced apoptosis of human umbilical vein endothelial cells
Authors: Luo Yanli , Lei Minxiang
Published: October 2017

Diabetic vascular complications result from high-glucose induced vascular endothelial cell dysfunction. There is an emerging need for novel drugs with vascular endothelial cell protective effects for the treatment of diabetic vascular complications. The present study aimed to investigate the protective effect of α-mangostin against high-glucose induced apoptosis of cultured human umbilical vein endothelial cells (HUVECs). HUVECs were treated with glucose to induce apoptosis. The expression of the apoptosis-related proteins, Bcl-2, Bax, and cleaved caspase-3, were detected by Western blotting. Ceramide concentration and acid sphingomyelinase (ASM) activity were assayed by HPLC. The cell apoptosis rate was detected by flow cytometry after staining with annexin V/propidium iodide (PI). Compared with HUVECs cultured in 5 mM glucose, cells cultured in 30 mM glucose exhibited a higher apoptosis rate, up-regulation of cleaved caspase-3 and Bax (proapoptotic proteins), down-regulation of Bcl-2 (anti-apoptotic protein), increased ceramide concentration, and enhanced ASM activity (all P<0.05). α-Mangostin (15 µM) significantly attenuated the high-glucose induced increase in apoptosis rate (8.64 ± 2.16 compared with 19.6 ± 3.54%), up-regulation of cleaved caspase-3 and Bax, down-regulation of Bcl-2, elevation of ceramide level, and enhancement of ASM activity (all P<0.05). The effects of desipramine were similar to those of α-mangostin. The protective effect of α-mangostin on high-glucose induced apoptotic damage may be mediated by an inhibition of ASM and thus a decreased level of ceramide.
Biomolecular coevolution and its applications: Going from structure prediction toward signaling, epistasis, and function
Authors: Zerihun Mehari B. , Schug Alexander
Published: October 2017

Evolution leads to considerable changes in the sequence of biomolecules, while their overall structure and function remain quite conserved. The wealth of genomic sequences, the ‘Biological Big Data’, modern sequencing techniques provide allows us to investigate biomolecular evolution with unprecedented detail. Sophisticated statistical models can infer residue pair mutations resulting from spatial proximity. The introduction of predicted spatial adjacencies as constraints in biomolecular structure prediction workflows has transformed the field of protein and RNA structure prediction toward accuracies approaching the experimental resolution limit. Going beyond structure prediction, the same mathematical framework allows mimicking evolutionary fitness landscapes to infer signaling interactions, epistasis, or mutational landscapes.
Surface roughness estimation and visualisation using force feedback
Authors: Lim J. H. , Choi S. L. , Kim C. B. , Lim E. G. , Hong H. B. , Park J. W.
Published: October 2017

The authors suggest a simple visualisation system for the surface roughness information, with being highly cost‐effective, non‐destructive for the surface, curved‐surface measurable, and standard‐compensated. This system utilises a force sensor with a flexible stylus as a scanning tip, converting the surface property into a two‐dimensional grey scale image through an imaging analysis process. The authors acquire a linear coordination for standard surfaces, scan normal surfaces using the proposed novel system, and reconstruct the two‐dimensional images for the surfaces on the basis of the calibration curve. The authors can experience virtual roughness of a material with a reconstructed two‐dimensional image by comparing with the standard surface images.
Performance analysis of improved ZF algorithm for massive MIMO in uplink
Authors: Younas Talha , Li Jiandong , Arshad Jehangir , Tulu Muluneh Mekonnen
Published: October 2017

Performance of large‐scale MIMO systems is restricted by pilot contamination, coherence block length, hardware impairments and other system parameters. In this Letter, the authors aim to improve the bandwidth efficiency (BE) of massive MIMO systems in multi‐cell scenarios. An improved version of the zero forcing (ZF) algorithm is proposed, based on that new expressions for BE are derived. The authors have compared the proposed algorithm with the conventional ZF algorithm and simulation results show sufficient improvement of performance in terms of BE.
Out‐of‐plane continuous electrowetting actuation of liquid metal
Authors: Sarabia K. J. , Yamada S. S. , Gough R. C. , Moorefield M. R. , Combs A. W. , Shiroma W. A. , Ohta A. T.
Published: October 2017

Liquid metal is actuated against the force of gravity using low‐voltage, low‐power continuous electrowetting. The liquid metal moves from a lower reservoir to an upper reservoir, a distance of 12 mm, in 1.66 s. This demonstrates that the electrokinetic actuation of liquid metal is not limited to two‐dimensional movement.
Increased beam tilt angle from a patch antenna with three inhomogeneous loop‐based plates
Authors: Nakano H. , Kameta Y. , Yamauchi J.
Published: October 2017

An antenna system composed of an activated patch backed by a ground plane and three square parasitic plates with inhomogeneous loops is analysed using the finite‐difference time‐domain method. Analysis of an antenna with an infinite ground plane reveals that a tilted beam of ∼60° from the broadside direction is obtained with a gain of ∼18 dBi. For confirmation, an antenna system with a finite‐sized ground plane that approximates the antenna characteristics for the infinite ground plane is fabricated and measured. The measured results are in good agreement with the analysis results.
Improved ‐RLS adaptive filter
Authors: Das B.K. , Chakraborty M.
Published: October 2017

In this Letter, the authors present an improved sparse recursive least squares (RLS) algorithm, which employs a novel approximation of the norm of the filter coefficient vector for regularising the RLS cost function. The proposed algorithm achieves improved performance over existing algorithms as demonstrated via numerical simulations.
Magnetic field probes for time‐domain monitoring of RF exposure within tissue‐mimicking materials for MRI‐compatible medical device testing
Authors: Attaran Ali , Handler William B. , Menon Ravi S. , Chronik Blaine A.
Published: October 2017

A new RF B/H field probe for time‐domain monitoring of RF electromagnetic‐radiated exposure during medical device testing inside the lossy tissue‐mimicking material is presented. The probe was tuned and matched for a centre frequency of 127.6 MHz to optimise the response for testing within typical 3T MRI scanners or RF exposure platforms. A 5 mm radius loop was chosen as a trade‐off between spatial resolution and sensitivity and fabricated on a double‐sided FR4 PCB. In the presented scheme, a low‐noise RF amplifier was employed to reduce the sensitivity of the probe to induce voltage on the transmission lines and to improve accuracy. The implemented probe was found to provide acceptable spatial resolution and sensitivity for reliable B/H field mapping for this application.
Inverter‐based low‐power delta–sigma modulator using correlated level shifting technique
Authors: Zhang H. , Tan Z. , Nguyen K.
Published: October 2017

A low‐power delta–sigma modulator based on inverter operational‐transconductance amplifiers (OTAs) using correlated level shifting technique (CLS) is presented. The CLS technique boosts the DC gain of inverter‐based OTA from 42 to 79 dB and extends the linear output swing from 55 to 80% of the full scale. Simulation results show that design in 180 nm CMOS technology, the proposed second‐order delta–sigma modulator achieves a signal‐to‐quantisation‐noise ratio improvement of 10.4 dB compared to a conventional inverter‐based modulator implementing the identical loop filter with the same oversampling ratio.
On‐chip data strobe transmission with short‐circuit current protection scheme for dynamic random access memory
Authors: Lee Won‐Young , Jung Chae‐Young
Published: October 2017

This Letter proposes an on‐chip data strobe transmission circuit for dynamic random access memory (DRAM). The on‐chip differential repeaters with cross‐coupled latches are adopted to prevent the sampling margin reduction. A node monitoring circuit has been proposed to prevent short‐circuit currents of the on‐chip differential repeaters and cross‐coupled latches caused by high impedance inputs. When compared with the conventional differential signalling, the proposed circuit can save the short‐circuit current of 6.2 mA per a single write operation. The chip has been fabricated in 350 nm CMOS technology and the active chip area is 0.189 mm2.
Utility‐based cooperative spectrum leasing scheme for CR networks with hybrid energy supplies
Authors: Zeng Fanzi , Zhong Jing
Published: October 2017

As cognitive radio (CR) technologies developed, cooperative CR networks (CCRNs) have become a potential way to increase the spectrum efficiency. Moreover, as the authors face the problem of energy shortage nowadays, energy harvesting (EH) is considered to be an effective method to alleviate this problem. However, with fitful and random energy arrivals, the energy harvested from natural energy source cannot guarantee satisfactory quality of service in EH networks. Hybrid energy supplies system has emerged as a promising way to solve unstable power supply problems, which mean that the communication terminals in these networks are powered by both fixed power supply and harvested energy. In this study, they propose a novel utility‐based cooperative spectrum leasing scheme for CCRNs with hybrid energy supplies. The secondary user (SU) is a cooperative relay powered largely by harvested energy extracted from the radio‐frequency signal of the primary user (PU). In this way, SU can shorten the primary data transmission period, and then win the access opportunities for secondary data transmission. They formulate this model as a Stackelberg game. In such a scenario, the PU intends to enhance its revenue and save energy by cooperating with the SU, while the SU tries to improve throughput and minimise the fixed energy consumption. The Stackelberg equilibrium for the proposed scheme is analysed. The experimental results show that the utility of both PU and SU can be improved under this scheme.
Phase noise in broadcasting: an outer bound for capacity region and corresponding simulations
Authors: Vahedi‐Tabas Hamed , Abed Hodtani Ghosheh
Published: October 2017

Point‐to‐point communication channels with phase noise have been studied extensively. To the best of the authors’ knowledge, the broadcast channel (BC) with phase noise has not been studied yet. In this study, having reviewed definitions of the channels with phase noise, the authors analyse capacity region of the BC impaired by Wiener phase noise and additive white Gaussian noise and obtain an outer bound for the capacity region. Also, its high signal‐to‐noise ratio analysis is presented. Their outer bound includes the known outer bound for the point‐to‐point phase noise channel as its special case. Mathematical findings are explained more by simulation results.
Efficient caching resource allocation for network slicing in 5G core network
Authors: Jia Qingmin , Xie Renchao , Huang Tao , Liu Jiang , Liu Yunjie
Published: October 2017

Network slicing has been considered as one of the key technologies in the next generation mobile network (fifth generation – 5G), which can create virtual network and provide customised services on demand. Most of the current work on network slicing mainly focuses on virtualisation technology, especially in virtual resource allocation. However, caching as a significant approach to improve the content delivery and quality of experience for end‐users has not been well considered in network slicing. In this study, the authors consider in‐network caching combining with network slicing, and propose an efficient caching resource allocation scheme for network slicing in 5G core network. They first formulate the caching resource allocation issue as an integer linear programming model, and then propose a caching resource allocation scheme based on chemical reaction optimisation (CRO) algorithm, which can significantly improve the caching resource utilisation. The CRO algorithm is a population‐based optimisation metaheuristic, which has advantages in searching optimal solution and computation complexity. Finally, extensive simulation results are presented to illustrate the performance of the proposed scheme.
Optimal beamforming for dual‐hop MIMO AF relay networks with imperfect CSI
Authors: Li Min , Bai Lin , Yu Quan , Choi Jinho
Published: October 2017

In this study, the authors take into account the imperfect channel state information for beamforming (BF) scheme in a dual‐hop multiple‐input multiple‐output (MIMO) amplify‐and‐forward (AF) relay network. Since the overall performance has been decided by the signal‐to‐interference‐plus‐noise ratio (SINR) at the destination, the authors derive the optimal BF weights that maximise the SINR at the desination. To evaluate the performance of the relay network, the authors also derive closed‐form expressions for the outage probability and probability density function of the received SINR. Computer simulations are carried out, which show the superiority of the designed optimal BF scheme, the impacts of channel errors and antenna configurations on the performance of the MIMO AF relay systems, and the validity of the analytical expressions. It is shown that due to the channel errors, the performance of the relay network is bounded no matter how much power is injected into the system.
Hierarchical resource allocation and consolidation framework in a multi‐core server cluster using a Markov decision process model
Authors: Zhao Pu , Lin Xue , Wang Yanzhi , Chen Shuang , Pedram Massoud
Published: October 2017

This paper investigates a service level agreements (SLAs)‐based resource allocation problem in a server cluster. The objective is to maximise the total profit, which is the total revenue minus the operational cost of the server cluster. The total revenue depends on the average request response time, whereas the operating cost depends on the total energy consumption of the server cluster. A joint optimisation framework is proposed, comprised of request dispatching, dynamic voltage and frequency scaling (DVFS) for individual cores of the servers, as well as server‐ and core‐level consolidations. Each DVFS‐enabled core in the server cluster is modelled by using a continuous‐time Markov decision process (CTMDP). A near‐optimal solution comprised of a central manager and distributed local agents is presented. Each local agent employs linear programming‐based CTMDP solving method to solve the DVFS problem for the corresponding core. On the other hand, the central manager solves the request dispatch problem and finds the optimal number of ON cores and servers, thereby achieving a desirable tradeoff between service response time and power consumption. To reduce the computational overhead, a two‐tier hierarchical solution is utilized. Experimental results demonstrate the outstanding performance of the proposed algorithm over the baseline algorithms.
Developing IoT applications: challenges and frameworks
Authors: Udoh Itorobong S. , Kotonya Gerald
Published: October 2017

Internet of things (IoT) is creating new opportunities for developing innovative applications by leveraging on existing and new technologies. In recent years, a variety of consumer and industrial IoT applications have been developed and deployed. Despite much progress, developing IoT applications is still a complex, time‐consuming and challenging activity. This is because IoT systems involve a wide range of hardware and software components, depending on a variety of communication and distributed system technologies. Many IoT application frameworks of varying approaches have been developed to manage the complexities of developing IoT applications. However, there remains a paucity of surveys on these IoT application development frameworks. This study presents a comprehensive review and a comparative analysis of existing IoT application development frameworks and toolkits, illustrating their strengths and weaknesses. This study will assist in finding the most appropriate IoT application development paradigm for the desired IoT application. Finally, future research directions are highlighted to improve existing and future frameworks and toolkits for IoT applications.
Improved relaxation method for control design of non‐homogeneous Markovian jump fuzzy systems with general transition descriptions
Authors: Kim Sung Hyun
Published: October 2017

The aim of this study is to develop an improved relaxation technique (especially in terms of conservatism and computational complexity) for the control design of a class of non‐homogeneous Markovian jump fuzzy systems with general transition descriptions. With this point of view, novel component‐summation‐based constraints are introduced to stringently establish the overall constraints on completely unknown transition rates, which play a key role in making relaxation techniques less conservative. Further, to reduce the computational complexity of relaxation processes with multiple slack variables, this study provides a method of replacing all self‐mode‐transitions with other transitions.
Effect of voltage unbalance and distortion on the loss characteristics of three‐phase cage induction motor
Authors: Zhang Dongdong , An Ruichi , Wu Thomas
Published: October 2017

Voltage unbalance and distortion become one of the most common power quality problems in industrial utilities, which cause significant increase of the electromagnetic losses in induction motors. For energy saving of the induction motor system, there is a need for a detailed research of the loss characteristics of induction motor under unbalanced and distorted supply voltage. For accurate and fast prediction of the induction motor losses, this study proposes a method to identify rotor harmonics using the data from one supply cycle. The slip‐frequency rotor harmonics are determined by using the space‐time symmetrical characteristics of the induction motor. And based on a numerical method, the higher order harmonics of rotor flux density or current density are determined from data within one supply cycle. The electromagnetic losses are then calculated from those harmonics. With this method, the electromagnetic losses of a 5.5 kW induction motor under unbalanced and distorted supply voltage are calculated and analyzed. The proposed method and the analysis results are validated by comparing the predicted and measured motor losses of the 5.5 kW induction motor under different supply conditions.
Fuzzy‐supervisory control of a hybrid system to improve contractual grid support with fuzzy proportional–derivative and integral control for power quality improvement
Authors: Bhattacharjee Chayan , Roy Binoy Krishna
Published: October 2017

This paper investigates on an additional active power compensation of a microgrid to a weak grid using fuzzy‐supervisory control. This reduces the economic penalty of microgrid for going over‐contract with the grid in terms of power demand. The objectives of this work are (a) to maximise grid support during periods of over‐contract, (b) to minimise distortions and increase dynamic stability of dc link voltage and (c) to improve the total harmonic distortion (THD) of the dispatched power. The microgrid comprises of a wind energy conversion system (WECS) and Li‐ion battery energy storage system (BESS). During variations in wind speed, power feed into the point of common coupling (PCC) depends upon deviations in the wind power, dc link voltage, violations in grid contract power and the state of charge (SOC) of the battery. The deviations in these inputs are utilised by the supervisory controller to compute additional power support to the grid, by discharging the battery. Performances of the fuzzy‐supervisory controller are compared with a classical‐supervisory controller with similar power dispatch parameters. Further, inverter currents are regulated using a fuzzy proportional‐derivative and integral (FPD + I) controller to reduce distortions and improve dynamic response of the dispatched power.
Nature of fault determination on transmission lines for single phase autoreclosing applications
Authors: Nikoofekr Iman , Sadeh Javad
Published: October 2017

Maintaining system stability and power supply need to have an efficient detection and fast elimination of faults on transmission lines by the protection system. To clear transient single‐phase faults on high voltage (HV) and extra high voltage (EHV) transmission lines, involving electrical arcs, single phase auto‐reclosure (SPAR) has been pointed out as the most recommended device. However, SPARs cannot distinguish between transient and permanent faults. In the presented study, a new algorithm has been proposed to tackle this issue, identifying transient and permanent faults, for the purpose of single‐pole auto‐reclosing applications. In this method, the arc‐voltage amplitude has been calculated using voltage harmonics at the fault location. Provided that this amplitude is large enough, the transient fault state will be immediately declared, enabling the AR; otherwise, the scheme deduces that a permanent fault has occurred and AR will be blocked. To evaluate the accuracy of the proposed scheme, rigorous simulations have been performed considering a wide array of different conditions including fault location, fault resistance and arc‐voltage gradient, where, in all cases, the highest reliability has been achieved.
Optimal day‐ahead demand response contract for congestion management in the deregulated power market considering wind power
Authors: Wu Jiasi , Zhang Buhan , Jiang Yazhou
Published: October 2017

In the liberalised electricity market, congestion management (CM) with a high penetration of wind energy is a challenging task for Independent System Operators (ISOs). Even though demand response (DR) provides an opportunity to alleviate transmission congestion, strategic selection of aggregated loads to contract with for DR in the day‐ahead economic dispatch is still under‐investigated. To solve this problem, this study proposes a bi‐level optimisation model to determine the optimal DR buses for CM in the day‐ahead market considering the uncertainty of wind power. The upper model serves to compute the available transfer capability (ATC), while the lower model is to calculate the stochastic dynamic optimal power flow. Through converting the stochastic ATC values to a summation of load supply capability of each load node, the loads which will deteriorate transmission congestion if the corresponding demand grows are determined. The corresponding loads with DR are selected as the optimal candidates. Furthermore, this study constructs a two‐stage optimisation model for optimal load dispatch by incorporating both price‐based DR and incentive‐based DR. The result can be used to assist system operators in decision‐making of electricity biddings from DRs for load curtailment and shift in the market clearing. As a result, the difference of peak and valley loads is reduced; ISOs as well as DR participators can both get economic benefits. Simulation results from the PJM 5‐bus training system and the modified IEEE 30‐bus system demonstrate the effectiveness of the proposed algorithm for DR contracting in CM.
Comparison of performance between Virtual Controller Interface Device and Controller Interface Device
Authors: Wang Daobin , Tian Zong , Yang Guangchuan , Gholami Ali
Published: October 2017

A Controller Interface Device (CID) is a hardware that connects a signal controller to simulation software. Running traffic simulation with an actual controller is called hardware‐in‐the‐loop simulation (HILS) and is an important tool for simulating the operations of traffic signals. In practice, it has been found that the existing traditional CIDs have some limitations, particularly when simulating multiple signals. In this regard, a Virtual CID (VCID) is proposed in this study. VCID can connect traffic signal controllers to a micro‐simulation software through the National Transportation Communications for ITS Protocol (NTCIP). A case study is conducted that uses the same traffic networks to compare the performance of VCID to CID. Queue length, travel time and simulation stability are considered in the evaluation. Results show that VCID could provide accurate and reliable simulation results. In comparison to traditional CIDs, VCID has more advantages as it does not depend on any hardware device and is easy to operate. In addition, since the communications are transformed through Ethernet, thus providing a convenient learning and testing environment for those who do not own a physical signal control laboratory. Therefore, VCID will have a broader prospect for development than CID.
Miniaturised stretch processed radar transceiver
Authors: Taghadosi Mansour , Albasha Lutfi , Mir Hasan
Published: October 2017

A miniaturisation of an architecture novel for an S‐band radar testbed is reported. The fabricated radar is a low‐cost, high‐performance and printed circuit board (PCB)‐based system. The system and its individual sub‐stages along with the miniaturised radar prototype have been simulated using advanced design system and applied wave research. Printed filters replacing bulky microwave components and impedance matching techniques to minimise power losses in the amplifiers are reported. The measured results are compared with electromagnetic simulations. The reduction in the overall system package size is significant, without degrading performance. The insertion loss and signal reflections through different stages are reduced, which contributed significantly to the enhancement of the measurement. The implemented radar PCB prototype used stretch processing technique to achieve high dynamic range of 75 dB, experimentally measured over a wide signal bandwidth of 600 MHz. This achieves a range resolution of 0.25 m. The overall dynamic range of the new single‐type‐substrate system has been improved by 15 dB, while miniaturising the overall size to enable light weight portable packaging. The achieved performance is, to the best of the authors’ knowledge, the highest reported in literature for similar type of radar testbeds that can be used for advanced industrial and military applications.
Numerical verification of the dispersion relation of trapezoidally corrugated slow wave structure for backward wave oscillators
Authors: Al‐Amin Md. Rasheduzzaman , Amin Md. Ruhul , Sagor Rakibul Hasan
Published: October 2017

The dispersion relation of beam‐free trapezoidally corrugated periodic metallic slow wave structure (TCSWS) has been numerically verified using a synthetic technique. The dispersion curves for both the fundamental and the higher order passband modes (TM01–TM03) are computed for an axisymmetric‐corrugated structure. The periodic structure resonates at specific frequencies when shorted appropriately at both ends. From the specific frequency values of these resonant peaks, a dispersion curve is determined for each transverse magnetic (TM) mode. The obtained dispersion curve is compared with both the experimental and analytical results using the same number of periods. The comparisons with analytical results and their experimental counterpart agree excellently with a maximum deviation of 1.94% for the TM01 mode, 1.29% for the TM02 mode and 2.38% for the TM03 mode. The radial and longitudinal electromagnetic field patterns of TCSWS are also calculated and compared with analytical field patterns for a six‐period slow wave structure. Comparative results validate both the obtained dispersion curves and field patterns of TCSWS.
On the application of support vector machines to the prediction of propagation losses at 169 MHz for smart metering applications
Authors: Uccellari Martino , Facchini Francesca , Sola Matteo , Sirignano Emilio , Vitetta Giorgio M. , Barbieri Andrea , Tondelli Stefano
Published: October 2017

Recently, the need of deploying new wireless networks for smart gas metering has raised the problem of radio planning in the 169 MHz band. Unluckily, software tools commonly adopted for radio planning in cellular communication systems cannot be employed to solve this problem because of the substantially lower transmission frequencies characterising this application. In this study, a novel data‐centric solution, based on the use of support vector machine techniques for classification and regression, is illustrated. The proposed method requires the availability of a limited set of received signal strength measurements and the knowledge of a three‐dimensional map of the propagation environment of interest and generates both an estimate of the coverage area and a prediction of the field strength within it. Various numerical results show that the proposed method is able to achieve good accuracy at the price of an acceptable computational cost and of a limited effort for the acquisition of measurements in the considered environments.
Gain‐enhanced EH1‐mode microstrip leaky‐wave antenna with periodical loading of shorting pins
Authors: Xie Danpeng , Zhu Lei , Zhang Xiao , Liu Neng‐Wu
Published: October 2017

A gain‐enhanced EH1‐mode microstrip leaky‐wave antenna (MLWA) with periodical loading of shorting pins to improve the radiation gain is proposed. Owing to the equivalent shunt inductive effect of the periodically installed shorting pins, the cut‐off frequency of the proposed pin‐loaded EH1‐mode microstrip line (MSL) is effectively tuned up; in other words, the lateral electric dimension of the proposed MLWA is effectively enlarged. Therefore, the distance of a pair of in‐phase equivalent magnetic‐current line sources in two sides of the MSL is widened, resulting to increase the radiation gain of the proposed MLWA. For the sake of theoretical explanation, an analytical model is built up for analysis. Then, numerical investigation is executed to reveal the effect of pins position on the tuning ratio of both the EH1‐mode cut‐off frequencies and strip widths. After extensive analysis, a pin‐loaded EH1‐mode MLWA under width tuning ratio of 1.78 and periodicity of 10.0 mm is designed, fabricated, and tested. Simulated and measured results both demonstrate that the radiation gain could be successfully raised up from 10.1 dBi (conventional EH1‐mode MLWA) to 13.1 dBi (the proposed pin‐loaded one) at the same operating frequency of 4.0 GHz.
Design of multi‐polarised quad‐band planar antenna with parasitic multistubs for multiband wireless communication
Authors: Kumar Ashok , Deegwal Jitendra Kumar , Sharma Mahendra Mohan
Published: October 2017

A multi‐polarised quad‐band planar circular disc monopole antenna consisting of a parasitic double T‐stub and parasitic long and short inverted L‐stubs is presented. By loading parasitic multistubs along the y‐axis behind a circular patch, the antenna can yield four resonance modes at 2.5, 4.5, 5.7, and 7.7 GHz frequencies while keeping the size of 30 × 40 mm2. The proposed antenna has been fabricated and experimentally studied. The measured impedance bandwidths of 290 MHz (2.36–2.65 GHz), 540 MHz (4.28–4.82 GHz), 530 MHz (5.47–6.0 GHz), and 780 MHz (7.28–8.06 GHz), for Bluetooth, 2.4/5.8 GHz wireless local area network, 2.5/5.5 GHz worldwide interoperability for microwave access, 5.9 GHz intelligent transportation systems (ITS), downlink of Indian National Satellite System and X‐band satellite applications. The 3 dB axial ratio bandwidth is 280 MHz (5.79–6.07 GHz) for the 5.9 GHz ITS band. The antenna E‐field radiation has y‐directed (vertical linear) polarisation at first, second, third resonance bands and slant + 45° linear polarisation at the fourth resonance band. At the ITS band, the E‐field radiation has right‐handed circular polarisation. In addition, the design procedure, electrical model and effects of parasitic stub dimensions on the antenna characteristics are discussed.
Reconfigurable cross dipole: hash frequency selective surface
Authors: de Oliveira Manuelle R. T. , de Melo Marcos T. , Llamas‐Garro Ignacio , G. Neto Alfredo
Published: October 2017

The authors present a reconfigurable frequency selective surfaces (RFSS) structure with two states based on the cross‐dipole element. The structure is designed to behave as an array of cross‐dipole elements in one state, and as an array of hash elements in the other state. The cross‐dipole patch array has a stop‐band filter response, and the hash array behaves as a pass band filter at the design frequency of 12.5 GHz. The frequency response of these filters is analysed using the equivalent circuit method. Computer simulation technology (CST) software simulations and experimental results are used to validate the RFSS design.
High‐directivity microstrip antenna with Mandelbrot fractal boundary
Authors: Anguera Jaume , Andújar Aurora , Benavente Sergio , Jayasinghe Jeevani , Kahng Sungtek
Published: October 2017

High‐directivity is a needed feature for small base station antennas in order to provide coverage to a certain geographic area. For wireless communications, arrays of microstrip antennas are frequently used as radiating elements due to their thin profile. In this study, a single microstrip element is proposed to achieve the same directivity as an array with a similar area but without using the complex feeding network usually required. A microstrip antenna inspired by the Mandelbrot fractal is designed achieving a narrow beamwidth in the vertical plane and a wide beamwidth in the horizontal plane, which is especially suitable for hot‐spots.
Accuracy and von Neumann stability of several highly accurate FDTD approaches for modelling Debye‐type dielectric dispersion
Authors: Lin Zhili , Qiu Weibin , Pu Jixiong , Fang Yuntuan , Hu Jiandong
Published: October 2017

A comparative study of the accuracy and stability of several highly accurate finite‐difference time‐domain (FDTD) approaches, the bilinear transform (BT) approach, the modified Z‐transform (MZT) approach and the piecewise linear recursive convolution (PLRC) approach, in modelling the Debye‐type dielectric dispersion is conducted with the given numerical models of relative permittivities and compared with their theoretical counterpart. The obtained results from two examples in modelling liquid water and human muscle show that the newly proposed MZT approach has the highest accuracy in modelling the real part of complex permittivity, while the BT approach has the highest accuracy in modelling the imaginary part of permittivity. When combined with the second‐order accurate FDTD algorithm, the MZT approach is a little more accurate than the BT and PLRC approaches. It is also demonstrated that all the three approaches are numerically stable with the von Neumann stability limits equal to or a little larger than the Courant stability limit.
New challenges to wind energy voltage control. Survey of recent practice and literature review
Authors: Sáiz‐Marín Elena , Lobato Enrique , Egido Ignacio
Published: October 2017

Implementing sophisticated voltage controls of wind farms may provide manifold benefits such as reducing losses of the distribution network (DNET) and harvesting network (HNET), increasing the wind hosting capacity of transmission networks (TNETs) and reducing wind curtailments. However, it represents an enormous challenge since wind energy is dispersed increasing the complexity of the required centralised control systems. This study contains a comprehensive state‐of‐the‐art review of the huge research that is available in the literature in order to foster the participation of on‐shore wind energy in voltage control. The current situation is described by the actual technological developments of control devices and the regulatory framework of a set of European countries with high wind penetration figures. A classification of key wind voltage control concepts will be proposed in order to understand and organise the available literature references. The state‐of‐the‐art review covers the integration of wind energy through DNETs, smart grids and dedicated HNETs into the TNET, covering research from a steady state and also dynamic perspective. The new requirements of theTransmission system operators tend to suggest that wind farms should have a similar performance compared with conventional plants. Thus, in this study, special attention will be given to the literature review of HNETs since it has been the most promising alternative of integrating wind voltage control into the existing transmission grid hierarchical control schemes. A set of relevant field experiences and international projects will be described, showing some effort to implement academic research into practice.
Risk‐averse bidding of energy and spinning reserve by wind farms with on‐site energy storage
Authors: Rodrigues Tiago , Ramírez Pedro J. , Strbac Goran
Published: October 2017

The increased net‐demand uncertainty and volatility observed in power systems with large‐scale penetration of intermittent renewables has translated into the deployment of larger volumes of reserve and into the need for procuring new sources of flexibility. In order to cope with increased uncertainty and risk of experiencing low profits, wind farm owners must adopt flexible bidding strategies such as coordinating its operation with energy storage systems (ESS). Besides managing wind imbalances, ESS are also capable of providing ancillary services such as spinning reserve (SPR) and frequency response to improve profitability. In this context, this paper proposes a novel two‐stage stochastic mathematical programming model that allows considering different degrees of risk aversion when optimising the day‐ahead energy and SPR bidding strategy of a wind farm with on‐site ESS. Uncertainty is modelled through prices and wind generation forecasts, while the conditional‐value‐at‐risk metric is used to handle day‐ahead profit risk. The developed case studies provide evidence of the value of combined wind farm and ESS bidding not only through increased daily profits but also through reduced offer uncertainty which improves the position of a wind farm in the day‐ahead markets.
Comparison of clustering approaches with application to dual colour protein data
Authors: Siebert Sabrina , Ickstadt Katja , Schäfer Martin , Radon Yvonne , Verveer Peter J.
Published: October 2017

Cells communicate with their environment via proteins, located at the plasma membrane separating the interior of a cell from its surroundings. The spatial distribution of these proteins in the plasma membrane under different physiological conditions is of importance, since this may influence their signal transmission properties. In this study, the authors compare different methods such as hierarchical clustering, extensible Markov models and the gammics method for analysing such a spatial distribution. The methods are examined in a simulation study to determine their optimal use. Afterwards, they analyse experimental imaging data and extend these methods to simulate dual colour data.