bluuebunny/crossref_metadata_2025 huggingface dataset:
Learning‐based CBCT correction using alternating random forest based on auto‐context model
Authors: Lei Yang , Tang Xiangyang , Higgins Kristin , Lin Jolinta , Jeong Jiwoong , Liu Tian , Dhabaan Anees , Wang Tonghe , Dong Xue , Press Robert , Curran Walter J. , Yang Xiaofeng
Published: November 2018

Purpose

Quantitative Cone Beam CT (CBCT) imaging is increasing in demand for precise image‐guided radiotherapy because it provides a foundation for advanced image‐guided techniques, including accurate treatment setup, online tumor delineation, and patient dose calculation. However, CBCT is currently limited only to patient setup in the clinic because of the severe issues in its image quality. In this study, we develop a learning‐based approach to improve CBCT's image quality for extended clinical applications.

Materials and methods

An auto‐context model is integrated into a machine learning framework to iteratively generate corrected CBCT (CCBCT) with high‐image quality. The first step is data preprocessing for the built training dataset, in which uninformative image regions are removed, noise is reduced, and CT and CBCT images are aligned. After a CBCT image is divided into a set of patches, the most informative and salient anatomical features are extracted to train random forests. Within each patch, alternating RF is applied to create a CCBCT patch as the output. Moreover, an iterative refinement strategy is exercised to enhance the image quality of CCBCT. Then, all the CCBCT patches are integrated to reconstruct final CCBCT images.

Results

The learning‐based CBCT correction algorithm was evaluated using the leave‐one‐out cross‐validation method applied on a cohort of 12 patients’ brain data and 14 patients’ pelvis data. The mean absolute error (MAE), peak signal‐to‐noise ratio (PSNR), normalized cross‐correlation (NCC) indexes, and spatial nonuniformity (SNU) in the selected regions of interest (ROIs) were used to quantify the proposed algorithm's correction accuracy and generat the following results: mean MAE = 12.81 ± 2.04 and 19.94 ± 5.44 HU, mean PSNR = 40.22 ± 3.70 and 31.31 ± 2.85 dB, mean NCC = 0.98 ± 0.02 and 0.95 ± 0.01, and SNU = 2.07 ± 3.36% and 2.07 ± 3.36% for brain and pelvis data.

Conclusion

Preliminary results demonstrated that the novel learning‐based correction method can significantly improve CBCT image quality. Hence, the proposed algorithm is of great potential in improving CBCT's image quality to support its clinical utility in CBCT‐guided adaptive radiotherapy.
Toughness enhancers for bone scaffold materials based on biocompatible photopolymers
Authors: Orman Sandra , Hofstetter Christoph , Aksu Adem , Reinauer Frank , Liska Robert , Baudis Stefan
Published: November 2018

Providing access to the benefits of additive manufacturing technologies in tissue engineering, vinyl esters recently came into view as appropriate replacements for (meth)acrylates as precursors for photopolymers. Their low cytotoxicity and good biocompatibility as well as favorable degradation behavior are their main assets. Suffering from rather poor mechanical properties, particularly in terms of toughness, several improvements have been made over the last years. Especially, thiol–ene chemistry has been investigated to overcome those shortcomings. In this study, we focused on additional means to further improve the toughness of an already established biocompatible vinyl ester‐thiol formulation, eligible for digital light processing‐based stereolithography. All molecules were based on poly(ε‐caprolactone) as building block and the formulations were tested regarding their reactivity and the resulting mechanical properties. They all performed well as toughness enhancer, ultimately doubling the impact resistance of the reference system. © 2018 The Authors. Journal of Polymer Science Part A: Polymer Chemistry published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 110–119
Rh6 gene modulates the visual mechanism of host utilization in fruit fly Bactrocera minax
Authors: Wang Yaohui , Andongma Awawing A , Dong Yongcheng , Chen Zhenzhong , Xu Penghui , Ren Xueming , Krosch Matthew N , Clarke Anthony R , Niu Changying
Published: November 2018

BACKGROUND

Vision plays a critical role in host location and oviposition behavior for herbivorous insects. However, the molecular mechanisms underlying visual regulation in host recognition and oviposition site selection in insects remains unknown. The aim of this study was to explore the key visual genes that are linked to the host plant location of the fruit fly, Bactrocera minax.

RESULTS

Using a host specialist fruit fly, B. minax, which lays eggs only into immature green citrus fruit, we undertook behavioral, transcriptomic, and RNAi research to identify the molecular basis for host fruit color recognition. In laboratory and field assays we found that adults prefer green over other colors, and this preference is significantly increased in sexually mature over immature flies. Furthermore, we identified that the Rh6 gene, responsible for green spectral sensitivity, has elevated expression in mature flies over immature flies. RNAi suppression of Rh6 eliminated the preference for green, resulting in a significant decrease in the number of eggs laid by B. minax in green unripe citrus.

CONCLUSION

These results show that the Rh6 gene modulates the visual mechanism of host utilization in B. minax, providing a genetic basis for visual host location in a non‐model insect herbivore. © 2018 Society of Chemical Industry
Effects of the wind–mass balance constraint on ensemble forecasts in the hybrid‐4DEnVar
Authors: Song Hyo‐Jong , Kang Jeon‐Ho
Published: November 2018

Ensemble forecast covariance plays an important role in the hybridized background error covariance framework to improve the resultant analysis
quality. However, a localization of ensemble samples is needed to fully take advantage of flow‐dependent error modes. In this regard, it is an interesting and practical issue as to which variables, composing the ensemble perturbation, the localization should be applied to. This study examines this issue in a boreal‐summer month by comparing two experimental sets: (a) a set of model variables, and (b) another set of model wind variables and unbalanced dry mass (temperature and surface pressure) used for the control variables. In the comparison, it is shown that imposing the wind–mass balance on the ensemble perturbation improves the Antarctic lower‐stratospheric temperature and tropical mid‐/lower‐tropospheric humidity. The nonlinear wind–mass balance relationship smooths an evolution of humidity forecast forced by the resultant analysis increments.
Synthesis of g‐C3N4‐Decorated Magnesium Ferrite Nanoparticle Composites for Improved Ethanol Sensing
Authors: Zhang Run , Wang Yan , Zhang Zhanying , Cao Jianliang
Published: November 2018

The nanocomposites of g‐C3N4 nanosheet decorated magnesium ferrite nanoparticles were synthesized by a facile solvothermal method. X‐ray diffraction (XRD), field‐emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and thermal gravimetric analysis and differential scanning calorimeter (TG‐DSC) techniques were used to characterize the structure and morphology of the as‐prepared nanocomposites. The results indicated that the MgFe2O4 nanoparticles were highly dispersed on the surface of the g‐C3N4 nanosheet. The gas‐sensing properties of the samples were tested, and the response value (Ra/Rg) of the MgFe2O4/g‐C3N4 nanocomposite with 15 wt.% g‐C3N4 content‐based sensor to 500 ppm of ethanol was 112 at 300 °C, which is 5 times higher than that of pure MgFe2O4. Moreover, the MgFe2O4/g‐C3N4‐15‐based sensor showed impressive selectivity, fast response and recovery characteristics, and good linearity in range of ethanol concentration (10–500 ppm).
The Tetrahydroxydicarbenium Cation [(HO)2CC(OH)2]2+: Synthesis and Structure
Authors: Schickinger Manuel , Saal Thomas , Zischka Florian , Axhausen Joachim , Stierstorfer Karin , Morgenstern Yvonne , Kornath Andreas J.
Published: November 2018

Oxalic acid forms in superacidic solutions HF/MF5 (M = As, Sb) its corresponding mono‐ and diprotonated salts [HOOCC(OH)2][MF6] and [(HO)2CC(OH)2][MF6]2 (M = As, Sb). The number of protonations is strongly dependent on the stoichiometric ratio of the Lewis acid with regard to oxalic acid. Mono‐ and diprotonated salts were characterized by vibrational spectroscopy and in the case of [HOOCC(OH)2][AsF6] (1) and [(HO)2CC(OH)2][SbF6]2 (4) by a single‐crystal X‐ray structure analysis. The salts crystallize in the monoclinic space groups P21/c and P21/n with eight, respectively four, formula units per unit cell. The vibrational spectra were compared to quantum chemical calculations of the cations [HOOCC(OH)2]+ and [(OH)2CC(OH)2]2+⋅4HF. In addition to this, an MEP analysis together with the NPA charges of [(OH)2CC(OH)2]2+, [(OH)2CC(OH)2]2+⋅6HF and oxalic acid were calculated to locate the positive charge. The protonation of oxalic acid does not lead to a remarkable change of the C‐C bond length, which is discussed for the entire series of the oxalic skeleton, starting with the dianion and ending with the tetrahydroxy dication.
Preconcentration of Uranium(VI) from Aqueous Solution by Amidoxime‐Functionalized Microspheres Silica Material: Kinetics, Isotherm and Mechanism Study
Authors: Xiao Jiang , Jing Yan , Wang Xingquan , Yao Ying , Jia Yongzhong
Published: November 2018

In present study, amidoxime‐functionalized MCM‐41 microspheres silica materials (denoted as MCM‐41‐AO) were synthesized and applied to enrich uranium from aqueous mediums. The adsorbents were characterized in detail by SEM, TEM, EDS, FT‐IR, elemental analysis and the zero point of change (pHzpc) test. The effects of the pH, ionic strength, contact time, coexisting cations and temperature on the adsorption properties of U(VI) were investigated. The highest sorption capacity of U(VI) on MCM‐41‐AO was evaluated to be 384.59 mg⋅g−1 by Langmuir isotherms model at pH=5.00 ± 0.05 and T=298 ± 2 K. The adsorption thermodynamics and thermodynamic studies suggest that the U(VI) adsorbed on the amidoxime functionalized microspheres silicas is a chemisorption, spontaneous and endothermic process. In addition, the adsorption mechanism for U(VI) on MCM‐41‐AO also has been explored by the XPS and FT‐IR. The results manifest that the effective adsorption U(VI) is mainly ascribed to the steady formation of surface complexes between uranium ions and the amidoxime ligands.
CePd‐Nanoparticles‐Incorporated Carbon Nanofibers as Efficient Counter Electrode for DSSCs
Authors: Ghouri Zafar Khan , Elsaid Khaled , Abdala Ahmed , Abdullah Abdulmuin M. , Akhtar Mohammed Shaheer
Published: November 2018

In this study, the cerium‐palladium (CePd) incorporated carbon nanofibers (CNFs) were manufactured by low‐cost and versatile electrospinning technique and successfully applied as a counter electrode to fabricate the dye‐sensitized solar cells (DSSCs). The utilized physiochemical techniques, X‐ray diffractometer (XRD), X‐ray photoelectron spectroscopy (XPS), field‐emission scanning electron microscope (FESEM), and transmission electron microscope (TEM) confirmed the formation of carbon nanofibers (CNFs) incorporated by Ce and Pd nanoparticles. CePd incorporated CNFs were preliminary presented good electrocatalytic activity towards the iodide redox couple, as investigated by cyclic voltammetry. The DSSC fabricated using CePd incorporated CNFs based counter electrode (CE) attained an applicable power conversion efficiency (PCE) of 4.52% along with open circuit voltage (VOC) of 0.739 V, a short‐circuit current density (JSC) of 11.42 mA/cm2 and fill factor (FF) of 0.54. According to primary results, the CePd incorporated CNFs based CE is a promising, and cost‐effective alternative CE for photoelectrochemical devices.
Carbon‐Enriched Cobalt Phosphide with Assorted Nanostructure as a Multifunctional Electrode for Energy Conversion and Storage Devices
Authors: Surendran Subramani , Shanmugapriya Sathyanarayanan , Lee Yun Sung , Sim Uk , Selvan Ramakrishnan Kalai
Published: November 2018

A single‐step hydrothermal technique is applied to prepare cobalt phosphide with multifarious nanostructures to signify its multifunctional capabilities. The prepared electrodes were intensely analysed for both the energy conversion and energy storage systems. The acquired Co−P with the assorted morphology of scaffolds and spherical of Co2P/C electrode inspires with a significantly lower oxygen evolution reaction (OER) (271 mV
) and hydrogen evolution reaction (HER) (207 mV
) overpotentials to accelerate progressive electrocatalytic activity. Additionally, the energy storage capacity was revealed with the Co2P electrode delivering an enriched specific capacity (322 C g−1 at 1 A g−1) in conjunction with noteworthy rate capability (83%) and durable cycling stability (10000 cycles). Overall, an aqueous supercapattery device (Co2P/C∥AC) was fabricated providing superior energy density (35 Wh kg−1) and an improved power density (5333 W kg−1). The assembled water splitting system demanded a low cell voltage of 1.63 V to afford a high current density of 10 mA cm−2. Moreover, the fabricated Co2P/C∥AC supercapattery coupled with the assembled water splitting system, to promote a supercapattery driven water splitting system profoundly proving the Co2P propensity of handling the multifunctional challenges in terms of both storage and conversion aspects.
A Flexible Reversible Material Curing at Room Temperature Based on Diels‐Alder Reversible Reaction Characteristics
Authors: Xu Jianan , Li Zhiying , Wang Bao , Liu Fengya , Liu Yudong , Liu Fengqi
Published: November 2018

Reversible materials have been extensively studied for their good application potential. In this work, a series of materials with thermal reversible properties were synthesized by Diels‐Alder (DA) reaction of furan/BMI. The main structure of the thermoreversible polymer was poly (propylene glycol) diglycidyl ether (PPGGE) which was chain‐extended by furfurylamine. Bismaleimide (BMI) was set as crosslinking agent. The conversion rates of DA reaction and retro‐DA reaction were calculated by Fourier Transform Infrared Spectroscopy. The material could react quickly at room temperature and achieve high conversion rate to 90%. Differential Scanning Calorimetry and Thermogravimetric Analysis were used to study the thermal properties of the materials, and the obvious reversible transformation temperature of the materials occurred in the range of 90 °C to 120 °C. The thermomechanical properties and tensile properties of the materials were obtained by DMA and tensile tests, respectively. Compared to the previous studies, these materials exhibited a relatively high breaking elongation of 230%.
Colour reconnection from soft gluon evolution
Authors: Gieseke Stefan , Kirchgaeßer Patrick , Plätzer Simon , Siodmok Andrzej
Published: November 2018

Abstract

We consider soft gluon evolution at the amplitude level to expose the structure of colour reconnection from a perturbative point of view. Considering the cluster hadronization model and an universal Ansatz for the soft anomalous dimension we find strong support for geometric models considered earlier. We also show how reconnection into baryonic systems arises, and how larger cluster systems evolve. Our results provide the dynamic basis for a new class of colour reconnection models for cluster hadronization.
NNLOPS accurate associated HZ production with $$ H\to b\overline{b} $$ decay at NLO
Authors: Astill William , Bizoń Wojciech , Re Emanuele , Zanderighi Giulia
Published: November 2018

Abstract

We present a next-to-next-to-leading order (NNLO) accurate description of associated HZ production, followed by the Higgs boson decay into a pair of b-quarks treated at next-to-leading order (NLO), consistently matched to a parton shower (PS). The matching is achieved by performing reweighting of the HZJ-MiNLO events, using multi-dimensional distributions that are fully-differential in the HZ Born kinematics, to the NNLO results obtained by using the MCFM-8.0 fixed-order calculation. Additionally we include the gg → HZ contribution to the discussed process that appears at the

$$ \mathcal{O}\left({\alpha}_s^2\right) $$

O

α
s
2

. We present phenomenological results obtained for 13 TeV hadronic collisions.
Identifying discrete behavioural types: a re-analysis of public goods game contributions by hierarchical clustering
Authors: Fallucchi Francesco , Luccasen R. Andrew , Turocy Theodore L.
Published: November 2018

We propose a framework for identifying discrete behavioural types in experimental data. We re-analyse data from six previous studies of public goods voluntary contribution games. Using hierarchical clustering analysis, we construct a typology of behaviour based on a similarity measure between strategies. We identify four types with distinct stereotypical behaviours, which together account for about 90% of participants. Compared to the previous approaches, our method produces a classification in which different types are more clearly distinguished in terms of strategic behaviour and the resulting economic implications.
Premature Mortality Due to PM2.5 Over India: Effect of Atmospheric Transport and Anthropogenic Emissions
Authors: David Liji M. , Ravishankara A. R. , Kodros John K. , Pierce Jeffrey R. , Venkataraman Chandra , Sadavarte Pankaj
Published: November 2018

The annual premature mortality in India attributed to exposure to ambient particulate matter (PM2.5) exceeds 1 million (Cohen et al., 2017, https://doi.org/10.1016/S0140‐6736(17)30505‐6). Studies have estimated sector‐specific premature mortality from ambient PM2.5 exposure in India and shown residential energy use is the dominant contributing sector. In this study, we estimate the contribution of PM2.5 and premature mortality from six regions of India in 2012 using the global chemical‐transport model. We calculate how premature mortality in India is determined by the transport of pollution from different regions. Of the estimated 1.1 million annual premature deaths from PM2.5 in India, about ~60% was from anthropogenic pollutants emitted from within the region in which premature mortality occurred, ~19% was from transport of anthropogenic pollutants between different regions within India, ~16% was due to anthropogenic pollutants emitted outside of India, and ~4% was associated with natural PM2.5 sources. The emissions from Indo Gangetic Plain contributed to ~46% of total premature mortality over India, followed by Southern India (13%). Indo Gangetic Plain also contributed (~8%) to the most premature mortalities in other regions of India through transport. More than 50% of the premature mortality in Northern, Eastern, Western, and Central India was due to transport of PM2.5 from regions outside of these individual regions. Our results indicate that reduction in anthropogenic emissions over India, as well as its neighboring regions, will be required to reduce the health impact of ambient PM2.5 in India.
Rapid identification of specific DNA aptamers precisely targeting CD33 positive leukemia cells through a paired cell-based approach
Authors: Yang Chang , Wang Yun , Ge Ming Hua , Fu Yu Jie , Hao Rui , Islam Khairul , Huang Ping , Chen Fu , Sun Jie , Hong De Fei , Naranmandura Hua
Published: November 2018

Aptamer S30 selected using modified paired cell-based approach can precisely target CD33-positive cancer cells and deliver anticancer drugs.
Identification of a new natural gastric lipase inhibitor from star anise
Authors: Kamoun Jannet , Rahier Renaud , Sellami Mohamed , Koubaa Imed , Mansuelle Pascal , Lebrun Régine , Berlioz-Barbier Alexandra , Fiore Michele , Alvarez Karine , Abousalham Abdelkarim , Carrière Frédéric , Aloulou Ahmed
Published: November 2018

The flavonoid myricitrin-5-methyl ether is a potential drug candidate as a gastric lipase inhibitor for the treatment of obesity.
An excellent full sodium-ion capacitor derived from a single Ti-based metal–organic framework
Authors: Chen Hao , Dai Chunlong , Li Yanan , Zhan Renming , Wang Min-Qiang , Guo Bingshu , Zhang Youquan , Liu Heng , Xu Maowen , Bao Shu-juan
Published: November 2018

Hybrid ion capacitors, especially sodium ion capacitors (SICs), have recently attracted enormous attention due to their combined merits of high energy density from the battery-type anode and high power density from the capacitor-type cathode.
Selenium-containing polyurethane with elevated catalytic stability for sustained nitric oxide release
Authors: Qu Baoliu , Yuan Liguang , Li Jinge , Wang Jie , Lv Hongying , Yang Xiaoniu
Published: November 2018

A novel strategy was developed by incorporating diselenide bonds into the polymer backbone to enhance the catalytic stability of NO-catalytic materials.
A simple and efficient phosphorescent probe for iodide-specific detection based on crystallization-induced phosphorescence of organic ionic crystals
Authors: Chen Guilin , Zhou Jin , Feng Hui , Feng Feifei , Xu Pengfei , Pan Saifei , Xu Jing , Qian Zhaosheng
Published: November 2018

A novel time-gated detection method for iodide ions based on the unique crystallization-induced phosphorescence of tetraphenylphosphonium iodide was developed.
Dynamic symbol allocation for spectral and energy efficient millimetre wave multi‐antenna systems
Authors: Kayani A. , Naqvi I. H. , Shakir M. Z.
Published: November 2018

In this Letter, the authors investigate the relationship between a number of parallel transmit symbols and the spectral efficiency of a millimetre wave (downlink) massive MIMO system with multiple antenna array sizes and a hybrid beamforming strategy. The proposed approach determines the optimal number of parallel data symbols that maximises both spectral efficiency and energy efficiency. A heuristic algorithm is proposed that adapts the number of symbols at the transmitter based on the instantaneous channel state information. The proposed algorithm outperforms non‐adaptive strategies for multiple array sizes and achieves a significant improvement in spectral and energy efficiency.
Waveguide coupler for resonant‐tunnelling diode oscillator at 420 GHz
Authors: Matsumoto H. , Suzuki S. , Asada M. , Monnai Y.
Published: November 2018

The authors proposed a waveguide coupler that extracts the radiation from a resonant‐tunnelling diode (RTD) oscillator at 420 GHz as the fundamental mode of a rectangular waveguide compatible to the WR‐2.2 standard. In the proposed structure, an RTD oscillator chip is embedded inside a hyper hemispherical silicon lens to reshape the radiation from the tiny chip into a collimated beam, which is subsequently converted into the waveguide mode using a linear horn. The authors estimate the transmission efficiency of the coupler to be −3 dB. Integrated in one package, this approach enables handy use of RTD oscillators as a platform for various terahertz applications.
Separate analysis of cell‐edge and cell‐centre user performance for irregular massive MIMO network with interference cancellation
Authors: Chen Changshan , Zhao Xinsheng
Published: November 2018

How much performance gain for the user equipment (UE) located at cell‐edge can be obtained, from the interference cancellation (IC) by exploiting extra degrees of freedom in multi‐user massive multiple‐input multiple‐output (MIMO), needs to be investigated. Also, it is necessary to reveal the impact of this IC on the performance of cell‐centre UE (CCU). In this study, the authors separately analyse the coverage probability of cell‐edge UE (CEU) and CCU under the IC in irregular network utilising tools from stochastic geometry. Specifically, the closed‐form expressions for the upper bound of CEU coverage probability and the lower bound of coverage probability for CCU are given out. For large threshold scenario, the authors show the potential of massive MIMO with IC on achieving the cell‐centre‐like experience in a more simple closed‐form formula. Analytical and numerical results show that a reasonable balance between the CEU performance enhancement and the CCU performance degradation under the IC can be reached. Moreover, slight influence of cell‐edge area on the coverage probability for both CEU and CCU is observed. Finally, it is found that the coverage probability of CEU is more sensitive to the variation of density of UEs and the base stations than that of CCU.
Performance analysis for non‐orthogonal multiple access (NOMA)‐based two‐way relay communication
Authors: Agarwal Akash , Jagannatham Aditya K.
Published: November 2018

This study analyses the performance of a non‐orthogonal multiple access‐based two‐way relaying system. Analytical expressions are obtained to characterise the outage probability and outage floor of the system for end‐to‐end communication over Rayleigh fading channels. Furthermore, results are also presented for the resulting individual user and sum ergodic capacities. A user power allocation technique is proposed for sum‐rate maximisation with user quality of service constraints by transforming the original non‐convex problem into a difference of convex program that can be readily solved. Finally, simulation results are presented to authenticate the analytical expressions obtained for the various quantities and illustrate the efficacy of the proposed scheme.
Robust approach for AMC in frequency selective fading scenarios using unsupervised sparse‐autoencoder‐based deep neural network
Authors: Shah Maqsood Hussain , Dang Xiaoyu
Published: November 2018

Application of deep learning in the area of automatic modulation classification (AMC) is still evolving. An unsupervised sparse‐autoencoder‐based deep neural network (SAE‐DNN) is proposed to deal with the problem of AMC for much neglected frequency selective fading scenarios with Doppler shift. The authors propose a set of low complexity spectral and cumulant based features for training SAE‐DNN. The network is designed using forced dimensionality reduction and sparsity constraint to achieve a low complexity solution with improved ability to learn more refined and robust features from the input training data. A unique training method is presented in this study which incorporates a range of SNR values for the entire span of the training dataset, as compared to the conventional approach which only uses a single SNR value for all the training examples. A comprehensive performance analysis shows that the proposed method outperforms many conventional counterparts in the literature. Generalisation test verifies that network is feasible for all channel conditions. A robust classification behaviour is observed against phase‐frequency impairments and Doppler shift for frequency selective fading scenarios.
Deep pixel‐to‐pixel network for underwater image enhancement and restoration
Authors: Sun Xin , Liu Lipeng , Li Qiong , Dong Junyu , Lima Estanislau , Yin Ruiying
Published: November 2018

Turbid underwater environment poses great difficulties for the applications of vision technologies. One of the biggest challenges is the complicated noise distribution of the underwater images due to the serious scattering and absorption. To alleviate this problem, this work proposes a deep pixel‐to‐pixel networks model for underwater image enhancement by designing an encoding–decoding framework. It employs the convolution layers as encoding to filter the noise, while uses deconvolution layers as decoding to recover the missing details and refine the image pixel by pixel. Moreover, skip connection is introduced in the networks model in order to avoid low‐level features losing while accelerating the training process. The model achieves the image enhancement in a self‐adaptive data‐driven way rather than considering the physical environment. Several comparison experiments are carried out with different datasets. Results show that it outperforms the state‐of‐the‐art image restoration methods in underwater image defogging, denoising and colour enhancement.
Single image fast deblurring algorithm based on hyper‐Laplacian model
Authors: Hongbo Zheng , Liuyan Ren , Lingling Ke , Xujia Qin , Meiyu Zhang
Published: November 2018

An improved single image fast deblurring algorithm based on hyper‐Laplacian constraint is proposed. The algorithm is improved in three aspects: image blur kernel estimation sub‐region selection, blur kernel precise estimation, and fast non‐blind deconvolution. First, image amplitude and gradient are used as the basis of blur kernel estimation. On the basis of analysing the edge amplitude and gradient of the image, the image sub‐region for blur kernel estimation is selected. Then the sparsity of the blur kernel is restricted by hyper‐Laplacian, and the fast solving mode of alternately solving different variables is designed. The blur kernel information is accurately estimated. In the fast non‐blind deconvolution restoration phase of the image, the regularised constraint term of the hyper‐Laplacian model is improved and the image gradient distribution is constrained. The blind growth trend of the regional gradient near the strong edge can be suppressed well, and the deblurred image with clear edge structure is generated. Experimental results show that the proposed algorithm can achieve better image deblurring effect and high efficiency.
Projected state‐wide traffic forecast parameters using artificial neural networks
Authors: Ghanim Mohammad S. , Abu‐Lebdeh Ghassan
Published: November 2018

Design‐hour volume (DHV) and directional DHV (DDHV) are important traffic forecast parameters for both planning and operational studies. They are used for roads and intersection design and operational analysis. Estimating these two parameters requires a record of hourly volumes for every hour in a year. Therefore, permanent traffic counters are usually used to keep a record of those hourly volumes. The use of permanent counters faces several challenges because of adjacent construction activities and hardware or communication failure. These challenges result in the missing part of the collected data. Moreover, estimating DHV and DDHV based on short‐term traffic counts is often needed. In this research, an artificial intelligence approach is used to estimate DHV and DDHV for roadways with different functional classifications. An artificial neural network model, which utilises historical records of annual average daily traffic along with other road characteristics, such as number of lanes and functional classification, is developed. Results show that the model was able to achieve a highly accurate and reliable DHV and DDHV estimates.
Intrusion detection system for detecting wireless attacks in IEEE 802.11 networks
Authors: Sethuraman Sibi Chakkaravarthy , Dhamodaran Sangeetha , Vijayakumar Vaidehi
Published: November 2018

Sophisticated wireless attacks such as Wifiphishing, Evil twin and so on are a serious threat to Wi‐Fi networks. These attacks are tricky enough to spoof users by launching a fake access point (AP) pretending to be a legitimate one. The existing intrusion detection schemes are prone to a high rate of false positives as they depend on restricted features. Hence, an efficient intrusion detection system, which considers many more features is needed. Kernel density estimation (KDE) statistically models the distribution of data and detects the attacks in active mode. However, in passive mode (without any connectivity to the AP), detecting the attack is complicated and it requires prior knowledge of attack signatures. The other intrusion detection model which is used in passive mode, namely hidden Markov model (HMM), does not need knowledge of initial probabilities. In this study, a novel wireless intrusion detection system is proposed, by combining KDE and HMM through a tandem queue with feedback. The proposed KDE‐HMM technique/method combines the advantages of both statistical and probabilistic properties to yield better results. The performance of the proposed KDE‐HMM technique has been experimentally validated and it is found that the proposed KDE‐HMM detects the aforementioned attacks with 98% accuracy.
Interleaved multi‐level power converter for a battery energy storage system
Authors: Wu Jinn‐Chang , Jou Hurng‐Liahng , Chiu I‐Husan
Published: November 2018

This study proposes an interleaved multi‐level power converter (IMPC) for a battery energy storage system. The proposed IMPC is composed of two power‐electronic legs. The first power‐electronic leg is an interleaved multi‐level leg that contains eight power‐electronic switches. Four power‐electronic switches constitute a two‐phase interleaved switch set and these are switched in a high‐frequency interleaved pulse‐width modulation. The other four power‐electronic switches constitute a level‐selection switch set that determines the dc bus voltage for the two‐phase interleaved switch set according to the magnitude of the utility voltage. The second power‐electronic leg is the low‐frequency switching leg, which is composed of two power‐electronic switches. Since the proposed IMPC integrates the performances of the multi‐level power converter and interleaved power converter, the effective switching frequency is twice the practical switching frequency and the output voltage has five voltage levels. The ripple of the output current is significantly attenuated and the power capacity of the output filter is reduced. The proposed IMPC can also be used to adjust the real and the reactive power flows, in order to control the charging/discharging of battery sets and to compensate for the reactive power. A hardware prototype is developed to verify the performance of the proposed IMPC.
Waveform design for a dual‐function radar‐communication system based on CE‐OFDM‐PM signal
Authors: Zhang Qiuyue , Zhou Yu , Zhang Linrang , Gu Yabin , Zhang Juan
Published: November 2018

Owing to the exponentially increasing spectrum demand for commercial communication, radar and communication are increasingly encouraged to share spectrum. One approach is to incorporate information bearing communication sequences into radar waveforms. However, the varying radar/communication waveforms in a coherent processing interval lead to a range sidelobe modulation (RSM) that cause a loss of coherence when the Doppler processing operation is applied, thus leading to reduced target visibility. In this study, a new approach of embedding communication into radar waveform is proposed. Based on the scheme of constant envelope orthogonal frequency division multiplexing phase modulation (CE‐OFDM‐PM) and the orthogonality among trigonometric function, information bearing sequences are implemented using CE‐OFDM‐PM signal and then phase attached to a radar modulation term with a weighted coefficient. Also, the radar modulation term is synthesised by multiple sinusoidal functions where the coefficients of each sinusoidal modulation function are generated using random variables to achieve a thumbtack‐like ambiguity function. The weighted coefficient of a communication modulation term provides a direct control of the degree of RSM. Theoretic analysis and simulation results show that a satisfactory communication bit error rate performance can be achieved without sacrificing the radar performance.
Estimating stellar ages and metallicities from parallaxes and broadband photometry: successes and shortcomings
Authors: Howes Louise M. , Lindegren Lennart , Feltzing Sofia , Church Ross P. , Bensby Thomas
Published: November 2018

A deep understanding of the Milky Way galaxy, its formation and evolution requires observations of huge numbers of stars. Stellar photometry, therefore, provides an economical method to obtain intrinsic stellar parameters. With the addition of distance information – a prospect made real for more than a billion stars with the second Gaia data release – deriving reliable ages from photometry is a possibility. We have developed a Bayesian method that generates 2D probability maps of a star’s age and metallicity from photometry and parallax using isochrones. Our synthetic tests show that including a near-UV passband enables us to break the degeneracy between a star’s age and metallicity for certain evolutionary stages. It is possible to find well-constrained ages and metallicities for turn-off and sub-giant stars with colours including a U band and a parallax with uncertainty less than ∼20%. Metallicities alone are possible for the main sequence and giant branch. We find good agreement with the literature when we apply our method to the Gaia benchmark stars, particularly for turn-off and young stars. Further tests on the old open cluster NGC 188, however, reveal significant limitations in the stellar isochrones. The ages derived for the cluster stars vary with evolutionary stage, such that turn-off ages disagree with those on the sub-giant branch, and metallicities vary significantly throughout. Furthermore, the parameters vary appreciably depending on which colour combinations are used in the derivation. We identify the causes of these mismatches and show that improvements are needed in the modelling of giant branch stars and in the creation and calibration of synthetic near-UV photometry. Our results warn against applying isochrone fitting indiscriminately. In particular, the uncertainty on the stellar models should be quantitatively taken into account. Further efforts to improve the models will result in significant advancements in our ability to study the Galaxy.
Detection of nitrogen gas in the β Pictoris circumstellar disc
Authors: Wilson P. A. , Kerr R. , Lecavelier des Etangs A. , Bourrier V. , Vidal-Madjar A. , Kiefer F. , Snellen I. A. G.
Published: November 2018

Context. The gas composition of the debris disc surrounding β Pictoris is rich in carbon and oxygen relative to solar abundances. Two possible scenarios have been proposed to explain this enrichment. The preferential production scenario suggests that the produced gas may be naturally rich in carbon and oxygen, while the alternative preferential depletion scenario states that the enrichment has evolved to the current state from a gas with solar-like abundances. In the latter case, the radiation pressure from the star expels the gas outwards, leaving behind species that are less sensitive to stellar radiation such as C and O. Nitrogen is not sensitive to radiation pressure either as a result of its low oscillator strength, which would make it also overabundant under the preferential depletion scenario. The abundance of nitrogen in the disc may therefore provide clues to why C and O are overabundant.

Aims. We aim to measure the nitrogen column density in the direction of β Pictoris (including contributions by the interstellar medium and circumstellar disc), and use this information to distinguish these different scenarios to explain the C and O overabundance.

Methods. Using far-UV spectroscopic data collected by the Hubble Space Telescope’s Cosmic Origins Spectrograph (COS) instrument, we analysed the spectrum and characterised the NI triplet by modelling the absorption lines.

Results. We measure the nitrogen column density in the direction of β Pictoris for the first time, and find it to be log(NNI/1 cm2) = 14.9 ± 0.7. The nitrogen gas is found to be consistent with solar abundances and Halley dust. We also measure an upper limit for the column density of MnII in the disc at log(NMnII/1 cm2)CS = 12.7+0.1 and calculate the column density of SIII** in the disc to be log(NSIII★★/1 cm2)CSX = 14.2 ± 0.1. Both results are in good agreement with previous studies.

Conclusions. The solar nitrogen abundance supports the preferential production hypothesis, in which the composition of gas in β Pictoris is the result of photodesorption from icy grains that are rich in C and O or collisional vaporisation of C- and O-rich dust in the disc. It does not support the hypothesis that C and O are overabundant because C and O are insensitive to radiation pressure, which would cause them to accumulate in the disc.
Endoscopic ultrasound-guided choledochoduodenostomy with a lumen-apposing metal stent through an uncovered metal duodenal stent
Authors: Sportes Adrien , Airinei Gheoghe , Kamel Ralph , Raynaud Jean , Benamouzig Robert
Published: November 2018

Background and study aims Endoscopic retrograde cholangiopancreatography (ERCP) in patients with a preexisting duodenal stent is particularly challenging and has a low success rate. Endoscopic ultrasound (EUS)-guided biliary drainage (EUS-BD) has been increasingly used as an alternative to percutaneous transhepatic biliary drainage after failed ERCP. EUS-guided choledochoduodenostomy (EUS-CD) and EUS-guided hepaticogastrostomy (EUS-HGS) have been reported to have similar efficacity. Recently, a novel dedicated fully-covered lumen-apposing metal stent (LAMS) has been developed for EUS-CD (Hot AXIOS; Boston Scientific, Massachusetts, United States). It seems that this new device decreases the morbidity of EUS-CD. We present a case in which EUS-CD with LAMS through an uncovered metal duodenal stent was used successfully.
Comparison of early and delayed EUS-guided drainage of pancreatic fluid collection
Authors: Chantarojanasiri Tanyaporn , Yamamoto Natsuyo , Nakai Yousuke , Saito Tomotaka , Saito Kei , Hakuta Ryunosuke , Ishigaki Kazunaga , Takeda Tsuyoshi , Uchino Rie , Takahara Naminatsu , Mizuno Suguru , Kogure Hirofumi , Matsubara Saburo , Tada Minoru , Isayama Hiroyuki , Koike Kazuhiko
Published: November 2018

Background and study aims While endoscopic ultrasound (EUS)-guided drainage of pancreatic fluid collection (PFC) is recommended to be performed ≥ 4 weeks after onset of acute pancreatitis (AP), early (< 4 weeks) interventions are needed in some symptomatic cases. Despite feasibility of early percutaneous drainage, there have been few studies about early EUS-guided drainage of PFC.

Patients and methods Consecutive patients who received EUS-guided drainage (EUS-PCD) of infected or symptomatic PFC at the University of Tokyo were retrospectively studied. Contraindications for EUS-PCD are lack of encapsulation or adhesion to the gastrointestinal tract. Safety and effectiveness of early vs delayed (≥ 4 weeks) EUS-PCD were compared.

Results A total of 35 patients underwent EUS-PCD (12 early and 23 delayed) using 19 large-bore fully-covered metallic stent and 16 plastic stents. The median diameter of PFC was 110 mm (40 – 180) and 122 mm (17 – 250) in the early and delayed drainage groups, respectively. Median time from onset of AP to drainage was 23 and 85 days for early and delayed drainage, respectively. The technical success rate of EUS-guided drainage was 100 %. Endoscopic necrosectomy was performed in six early and 16 cases of delayed drainage. The adverse event rate was 25 % (3 bleeding) and 13 % (2 perforations and 1 CO2 retention) in the early and delayed drainage groups, respectively. Two patients died (1 early and 1 delayed) due to multiorgan failure.

Conclusion Endoscopic drainage and subsequent necrosectomy of symptomatic PFC within 4 weeks after onset of acute pancreatitis was feasible, given that the collection was encapsulated and attached to the gastrointestinal tract.
Resident Stress Level during Steps of Cataract Surgery
Authors: Rali Aditya , Fontus Jerry , Ward Laura , Aaron Maria , Jones Jeremy , Moore Elliot , Khalifa Yousuf
Published: November 2018

Purpose To investigate intraoperative stress levels using heart rate monitoring during each step of cataract surgery.

Setting Single tertiary hospital.

Design Observational study recording resident heart rate as a measure of acute stress level during cataract surgeries.

Methods Emory ophthalmology postgraduate year (PGY) 3 and PGY-4 residents operating at Grady Memorial Hospital during the time period of the study were eligible to participate. Chest-strapped Bluetooth devices recorded heart rate during the surgeries. The mean, maximum, and minimum heart rates were then analyzed individually for the following steps of surgery: incisions, continuous curvilinear capsulorhexis, hydrodissection, nucleus disassembly, quadrant removal, cortical cleanup, intraocular lens insertion, and closure. Data collection started in April 2017 and ended in February 2018.

Results Out of the 549 surgeries recorded, 427 yielded viable data. Across that dataset, quadrant removal had the highest adjusted mean heart rate value (90.3; 95% confidence interval [CI]: 82.9–97.7; p < 0.0001), highest adjusted maximum heart rate value (97.3; 95% CI: 89.5–105.3; p < 0.0001), and highest adjusted minimum heart rate value (82.1; 95% CI: 75.2–89; p < 0.0001). Nuclear disassembly and incisions were second and third highest, respectively.

Conclusions Quadrant removal, nucleus disassembly, and incisions are the three most stressful steps for resident surgeons. This knowledge should be applied to enhance the resident experience by emphasizing these steps during surgical preparation and training. Future studies using intraoperative heart rate monitoring may be warranted to better understand the resident and attending experience and ultimately improve surgical outcomes.
Characterisation and properties of Ni–W–Y2O3–ZrO2 nanocomposite coating
Authors: Zhang Ruiyu , Li Zili , Yu Xin , Cui Gan
Published: November 2018

In this work, nickel-based composite coatings were deposited using ultrasonic electrodeposition under pulse current condition at different current densities, temperatures and concentrations of Y2O3 and/or ZrO2 dispersed in the plating solution. The morphology and electrochemical properties were investigated. The electrochemical test methods (such as chronopotentiometry, potentiodynamic polarisation and electrochemical impedance spectroscopy) were used to investigate the stability of electrode potential during deposition and the corrosion resistance of Ni-based coating reinforced using Y2O3 and ZrO2. It was demonstrated that, when the deposition current density was 1.5 A dm−2, the temperature was 60°C and the added amount of Y2O3 and ZrO2 nanoparticles was 10 g L−1 each, the coating was compact, stable and free of cracks. The results of electrochemical tests showed that, under the optimal deposition parameters, the deposition process was stable, while the corrosion current density decreased by an order of magnitude compared to Ni–W alloy.
Apolipoprotein A-I directly interacts with extracellular domain 1 of human ABCA1
Authors: Kawanobe Takaaki , Shiranaga Naoko , Kioka Noriyuki , Kimura Yasuhisa , Ueda Kazumitsu
Published: November 2018

ATP-binding cassette transporter A1 (ABCA1) is critical for the generation of nascent high-density lipoprotein (HDL) and plays important roles in cholesterol homeostasis. ABCA1 has two large extracellular domains (ECDs), which may interact directly with apolipoprotein A-I (apoA-I). However, the molecular mechanisms underlying HDL formation and the importance of ABCA1–apoA-I interactions in HDL formation remain unclear. We investigated the ABCA1–apoA-I interaction in photo-activated crosslinking experiments using sulfo-SBED–labeled apoA-I. ApoA-I bound to cells expressing ABCA1, but not to untransfected cells or cells expressing non-functional ABCA1. Binding was inhibited by sulfo-SBED–labeled apoA-I, and crosslinking of sulfo-SBED–labeled apoA-I with ABCA1 was inhibited by non-labeled apoA-I, suggesting that sulfo-SBED–labeled apoA-I specifically binds and crosslinks with functional ABCA1. Proteolytic digestion of crosslinked ABCA1 revealed that apoA-I bound the N-terminal half of ABCA1, and that the first ECD of ABCA1 is an apoA-I binding site.

Abbreviations: ABC: ATP-binding cassette; apoA-I: apolipoprotein A-I; ATP: adenosine triphosphate; CHAPS: 3-(3-cholamidepropyl)dimethylammonio-1- propanesulphonate; DTT: dithiothreitol; ECD: extra cellular domain; EDTA: ethylenediaminetetraacetic acid; GFP: green fluorescent protein; HA: hemagglutinin; HDL: high density lipoprotein; HEK: human embryonic kidney; HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; sulfo-SBED: (sulfosuccinimidyl-2-[6-(biotinamido)-2-(p-azidobenzamido)hexanoamido] ethyl-1,3ʹ-dithiopropionate; NHS-ester, N-hydroxysuccinimide-ester