bluuebunny/crossref_metadata_2025 huggingface dataset:
Year in Review: Synopsis of Selected Articles in Neuroanesthesia and Neurocritical Care from 2019
Authors: Leong KokWeng , Dalby Tara , Venkatraghavan Lashmi
Published: January 2020

This review is a synopsis of selected articles from neuroscience, neuroanesthesia, and neurocritical care from 2019 (January–November 2019). The journals reviewed included anesthesia journals, critical care medicine journals, neurosurgical journals, as well as high-impact medical journals such as the Lancet, Journal of American Medical Association, New England Journal of Medicine, and Stroke. This summary of important articles will serve to update the knowledge of anesthesiologists and other perioperative physicians who provide care to neurosurgical and neurocritical cases.
The magnet sorting of APTRON
Authors: Xie Xiucui , Zhang Manzhou , Qiao Jian
Published: January 2020

The magnetic field error caused by imperfection during the manufacturing process of magnets is inevitable. Therefore, the field error of both dipole and quadrupole magnets and their alignment errors will cause the synchrotron closed orbit distortion. In order to minimize the influence of the beam, a sorting method is applied to both dipole and quadrupole magnets with integral consideration of different excitation currents, covering both low and high field situations. The commissioning result shows that we can achieve the designed beam intensity.
Study of gasdynamic electron cyclotron resonance plasma vacuum ultraviolet emission to optimize negative hydrogen ion production efficiency
Authors: Lapin R. L. , Skalyga V. A. , Izotov I. , Razin S. V. , Shaposhnikov R. A. , Vybin S. S. , Bokhanov A. F. , Kazakov M. Yu. , Tarvainen O.
Published: January 2020

Negative hydrogen ion sources are used as injectors into accelerators and drive the neutral beam heating in ITER. Certain processes in low-temperature hydrogen plasmas are accompanied by the emission of vacuum ultraviolet (VUV) emission. Studying the VUV radiation, therefore, provides volumetric rates of plasma-chemical processes and plasma parameters. In the past, we have used gasdynamic ECR discharge for volumetric negative ion production and investigated the dependencies between the extracted H− current density and various ion source parameters. It was shown that it is possible to reach up to 80 mA/cm2 of negative ion current density with a two electrode extraction. We report experimental studies on negative hydrogen ion production in a high-density gasdynamic ECR discharge plasma consisting of two simple mirror traps together with the results of VUV emission measurements. The VUV-power was measured in three ranges—Lyα, Lyman band, and molecular continuum—varying the source control parameters near their optima for H− production. It was shown that the molecular continuum emission VUV power is the highest in the first chamber while Lyα emission prevails in the second one. Modifications for the experimental scheme for further optimization of negative hydrogen ion production are suggested.
Near- and far-field Raman spectroscopic studies of nanodiamond composite films deposited by coaxial arc plasma
Authors: M. Ali Ali , Deckert-Gaudig Tanja , Egiza Mohamed , Deckert Volker , Yoshitake Tsuyoshi
Published: January 2020

Raman spectroscopic studies on nanodiamond composite (NDC) films, comprising nano-sized diamond grains and an amorphous carbon (a-C) matrix, deposited by coaxial arc plasma deposition are challenging because the scattering of the nano-sized diamond grains competes with the strong signal of the a-C matrix. To unravel the nanocomposite structure of NDC films, both far- and near-field Raman spectroscopy were employed. Based on the comparison of visible and ultraviolet far-field Raman data, component spectra based on either nanodiamond or a-C were estimated by a peak-decomposition procedure based on band fitting. Near-field optical resolution achieved via tip-enhanced Raman spectroscopy reveals sharper peaks of both the nanodiamond and the amorphous carbon than the far-field spectra. Consequently, the peak-decomposition procedure is not required, which evidently indicates the effective detection of nanodiamond grains embedded in a-C matrices and is a direct result of the high spatial resolution that limits the number of probed grains. The size of the nanocrystals could additionally be estimated from the profile and position of a diamond peak. This work demonstrates that tip-enhanced Raman spectroscopy is a powerful nondestructive method for nanodiamond composite films, which allows direct access to parameters hitherto only available via average data.
Non-stationary thermoelectric effect in He II and how it is affected by the thermal vibrations’ transition from laminar to the turbulent regime
Authors: Natsik V. D. , Rybalko A. S.
Published: January 2020

The observation of the thermoelectric effect, which is the spontaneous electric polarization of a cell with liquid He II during the thermal excitation of standing second-sound waves, has been confirmed [Low Temperature Physics 30, 1321 (2004)]. The relationship of this effect with the thermal and hydrodynamic properties of He II is studied in detail in the temperature range of 1.4 K < T < 2 K. It is established that the dependence of the amplitude of electric potential oscillations on the excitation intensity changes significantly during the thermal vibrations’ transition from the laminar to the turbulent regime. The threshold value of the excitation power w = w0 (T) is recorded: in the region w < w0, the potential oscillations are regular and their amplitude increases in proportion to the power; at w > w0, the electric response becomes random in nature as the fluctuations increase and the amplitude decreases to zero, with a peculiar electromagnetic “noise” being observed. The experimental results are compared with the conclusions drawn from the theory of flexoelectric polarization of liquid helium. The polarization of liquid helium upon excitation of the first-sound waves, as well as pressure and temperature shock waves, has also been discussed.
Infrared absorption by achiral carbon nanotubes
Authors: Korotun A. V. , Karandas Ya. V.
Published: January 2020

This work analyzes the effect of chirality on the frequency dependences of the real and imaginary parts of the dielectric function and the absorption coefficient of a single-walled carbon nanotube composite within the one-electron approximation. The calculations are performed for zigzag and armchair configurations of nanotubes. It is shown that the real part of the dielectric function and absorption coefficient for armchair-type nanotubes oscillate at lower frequencies because the energy intervals between the size-quantization levels decrease in this type of nanotube. When the frequencies of incident radiation coincide with the frequencies of interband transitions there is a resonant increase in the absorption coefficient of an achiral nanotube array. The size dependences of the absorption coefficient of the zigzag and armchair nanotube arrays are calculated, and their evolution with a change in the frequency of the incident electromagnetic wave is analyzed.
Low-temperature sensibilization of naphthalene phosphorescence using ortho-bromobenzophenone
Authors: Zloba D. I. , Pyshkin O. S. , Strzhemechny M. A. , Stepanian S. G. , Adamowicz L. , Buravtseva L. M.
Published: January 2020

The standard approach involving the sensibilization of naphthalene phosphorescence is employed to study the mono-substituted ortho-bromobenzophenone (2-BrBP). A new feature of the approach is the use of octane as the passive neutral matrix. This matrix is chosen due to the absence of the triplet-excitation mobility in pure 2-BrBP crystal. The problem of common phosphorescence kinetics of 2-BrBP and naphthalene is solved in analytic form. Unlike in the classical problem involving unsubstituted benzophenone, the relevant phosphorescence measurements have been performed at low temperatures (as low as 1.6 K). A new approach is suggested to account for the large difference between the typical experimental pulse-delay time and the slow naphthalene phosphorescence. Relevant computations allow us to explain the nature of the two sets of phosphorescence lines of 2-BrBP.
Vacuum-desorption method for separating the H2 + D2 isotope mixture using a quantum ortho–para-conversion process at hydrogen temperature
Authors: Zhun H. H. , Borshch O. Ye.
Published: January 2020

The effective evacuation and separation (at helium temperature) of a model gas mixture consisting of He, H2, D2, N2, Ar and other components (close to that formed in a thermonuclear reactor) yielding up to 44% of D2 during desorption, is implemented using a newly developed vacuum pump-separator with a non-isothermal multilayer (up to 100 layers) system of working elements (consisting of perforated screening and spacing materials). Improvements to the vacuum-pump separator design and the use of an ortho-para conversion catalyst made it possible to increase the yield of D2 from the model mixture to 64–69% at hydrogen temperature.
Anisotropy of charge and heat transport in zinc oxide at high temperatures
Authors: Kim Meeri
Published: January 2020

A new article reveals anisotropy of charge and heat transport at and above room temperature, up to 750 K, in crystalline zinc oxide.
Syntheses and Binding Testing of N1-Alkylamino-Substituted 2-Aminobenzimidazole Analogues Targeting the Hepatitis C Virus Internal Ribosome Entry Site
Authors: Schmit David , Milewicz Urszula , Boerneke Mark A. , Burley Scott , Walsworth Kevin , Um Joann , Hecht David , Hermann Thomas , Bergdahl B. Mikael
Published: January 2020

A series of 2-aminobenzimidazole analogues have been synthesised and tested for binding to a previously established RNA target for viral translation inhibitors in the internal ribosome entry site (IRES) of the hepatitis C virus (HCV). Synthesis of new inhibitor compounds followed a highly convergent strategy which allowed for incorporation of diverse tertiary amino substituents in high overall yields (eight-steps, 4–22%). Structure–activity relationship (SAR) studies focussed on the tertiary amine substituent involved in hydrogen bonding with the RNA backbone at the inhibitor binding site. The SAR study was further correlated with in silico docking experiments. Analogous compounds showed promising activities (half maximal effective concentration, EC50: 21–89µM). Structures of the synthesised analogues and a correlation to their mode of binding, provided the opportunity to explore parameters required for selective targeting of the HCV IRES at the subdomain IIa which acts as an RNA conformational switch in HCV translation.
Surface-positioned double-ring to improve traditional infiltrometer for measuring soil infiltration
Authors: Zhang Jing , Li Shaopeng
Published: January 2020

The installation of a traditional double-ring infiltrometer (DRI) into soil is difficult and time consuming. It results in reduced accuracy because of soil disturbance and water leakage along the gaps between the ring wall and the soil. In this study, a surface-positioned DRI (SPDRI) was suggested to improve measurement accuracy and convenience of the DRI. Laboratory experiments were conducted to evaluate performance of the method in terms of the influence of the lateral flow of water on the accuracy of infiltration rate, average vertical wetting front depth and saturated hydraulic conductivity. A cylindrical soil column was used to simulate the ideal ring infiltrometer (IRI) of the one-dimensional vertical infiltration process for comparison purposes. Experimental results indicated that the infiltration rates measured by the SPDRI and IRI were nearly identical, with maximum relative error (RE) of 18.75%. The vertical wetting front depth of the SPDRI was nearly identical to that of the IRI, with proportional coefficients of 0.97 and R2 > 0.95. Comparison of the soil saturated hydraulic conductivity with those from IRI indicated that the REs were 7.05–10.63% for the SPDRI. Experimental results demonstrated that the SPDRI could improve the measurement accuracy and facilitate the soil water infiltration measurement process.
Transformation of speech sequences in human sensorimotor circuits
Authors: Müsch Kathrin , Himberger Kevin , Tan Kean Ming , Valiante Taufik A. , Honey Christopher J.
Published: January 2020

Significance

When we hear a series of words, it is not only the auditory pathways of our brains that respond, but also the pathways that organize speech and action. What is the purpose of “motor” activity during language perception? We recorded electrical signals from the surfaces of the brain as people heard, mentally rehearsed, and spoke natural sentences. We found that human motor pathways generated precise, time-locked representations of sentences during listening. When listening was complete, the motor activity transformed to a distinct representation while people repeated the sentence in their heads and as they spoke the sentence aloud. Thus, motor circuits generate representations that can bridge from perception to short-term memory of spoken language.
Critical Assesment 37: Harmonic-structure materials - idea, status and perspectives
Authors: Orlov Dmytro , Ameyama Kei
Published: January 2020

Recent efforts in engineering metals with high structural efficiency have resulted in developing a new category of artificial materials with heterogeneous microstructures architected across multiple scales. In this critical assessment, a relatively new concept of heterogeneous bimodal harmonic-structure (bHS) materials is introduced and analysed. It is shown that the bHS concept is applicable to a large variety of metallic materials and is most efficient in scenarios where changes in the chemical composition of materials are restricted for some reason. Basic principles, weaknesses and advantages along with present development status and perspectives are discussed. The overview of critical performance characteristics of various bHS materials is provided, and interesting directions for future research, development and applications are proposed.
Spatiotemporal control of phosphatidic acid signaling with optogenetic, engineered phospholipase Ds
Authors: Tei Reika , Baskin Jeremy M.
Published: January 2020

Phosphatidic acid (PA) is both a central phospholipid biosynthetic intermediate and a multifunctional lipid second messenger produced at several discrete subcellular locations. Organelle-specific PA pools are believed to play distinct physiological roles, but tools with high spatiotemporal control are lacking for unraveling these pleiotropic functions. Here, we present an approach to precisely generate PA on demand on specific organelle membranes. We exploited a microbial phospholipase D (PLD), which produces PA by phosphatidylcholine hydrolysis, and the CRY2–CIBN light-mediated heterodimerization system to create an optogenetic PLD (optoPLD). Directed evolution of PLD using yeast membrane display and IMPACT, a chemoenzymatic method for visualizing cellular PLD activity, yielded a panel of optoPLDs whose range of catalytic activities enables mimicry of endogenous, physiological PLD signaling. Finally, we applied optoPLD to elucidate that plasma membrane, but not intracellular, pools of PA can attenuate the oncogenic Hippo signaling pathway. OptoPLD represents a powerful and precise approach for revealing spatiotemporally defined physiological functions of PA.
Impact of inversion symmetry on a quasi-1D S  =  1 system
Authors: Kim J K , Ranjith K M , Burkhardt U , Prots Yu , Baenitz M , Valldor M
Published: January 2020

Here, we report the synthesis and magnetic properties of a novel, centrosymmetric, quasi-1D spin chain system La3VWS3O6, with hexagonal crystal structure (P63/m, a  =  9.460 76(3), c  =  5.518 09(2) Å). Pure powders were obtained by solid-state reactions from La2O3, WO3 and metal powders of V and W. X-ray powder diffraction, specific heat, magnetization, 139La-nuclear magnetic resonance (NMR), and electric resistivity measurements indicate that the compound is a low dimensional magnet with an S  =  1 spin chain that exhibits no sign of magnetic ordering above 2 K. A single ion anisotropy (D/k
B ~ 10 K), caused by magneto-crystalline effects, is probably responsible for a thermodynamic entropy release at lower temperatures, which concurs with 139La-NMR data. By detailed comparison with non-centrosymmetric Ba3V2S4O3, having a very similar magnetic lattice, it is obvious that the presence of crystallographic inversion symmetry has an effect on the behaviour of the magnetic chains.
Developing cold-resistant high-adhesive electronic substrate for WIMPs detectors at CDEX*
Authors: Liu Yuanyuan , Cheng Jianping , Pang Pan , Liao Bin , Wu Bin , Ying Minju , Zhang Fengshou , Chen Lin , Lv Shasha , Liu Yandong , Sun Tianxi
Published: January 2020

Herein we report a prototypical electronic substrate specifically designed to serve the weakly interacting massive particles (WIMPs) detectors at the China Dark Matter Experiment (CDEX). Because the bulky high-purity germanium (HPGe) detectors operate under liquid-nitrogen temperatures and ultralow radiation backgrounds, the desired electronic substrates must maintain high adhesivity across different layers in such cold environment and be free from any radioactive nuclides. To conquer these challenges, for the first time, we employed polytetrafluoroethylene ((C2F4)
n
) foil as the base substrate, in conjunction with ion implantation and deposition techniques using an independently developed device at Beijing Normal University for surface modification prior to electroplating. The remarkable peeling strengths of 0.88±0.06 N/mm for as-prepared sample and 0.75±0.05 N/mm for that after 2.5-days of soaking inside the liquid nitrogen were observed, while the regular standards commonly require 0.4 N/mm ∼ 0.6 N/mm for electronic substrates.
A Web-based blood donation and Medical Monitoring System Integrating Cloud services and Mobile Application
Authors: Nabil Moh. , Ihab R. , El Masry H. , Said S. , Youssef S.
Published: January 2020

Medical monitoring requires instant visibility across data sources and access to dynamic analyses. However medical monitoring among patients, perform in-stream medical advice, remains a challenging problem. Blood banks suffer frequent shortage of blood due to lack of blood donations, hence blood donation requests are frequently seen on social media for patients who urgently require blood transfusion with specific blood group. Recently, worldwide efforts have been undertaken to utilize social media and smart phone applications to make the blood donation process more convenient and provide a concrete information system that allows donors and blood donation centers to communicate efficiently and coordinate with each other to minimize time and effort required for blood donation process. This paper aims at developing a Cloud medical monitoring and Web-Based Blood Donation System which will allow blood donors and patients to offer/request blood donation from blood banks. Additionally, a new method is proposed for continuous observation and communication among doctors and patients. Using IOT cloud platform, simple medical devices equipped with medical sensors can monitor health status of patients and update the electronic medical records of patients’ information. Medical experts can remotely monitor patients dynamic status and give prompt medical advice. The developed Web-Based application utilizes a cloud based hosting platform to enhance system performance and ensure high availability. A mobile application has been developed where users will be able to use as an application installed on their smart phones to help them complete blood donation process with minimum effort and time. This application helps people receive remotely medical advices and helps establish a blood donation community through social networks. This paper also presents various tools that were used to measure system performance.
Performance Analysis and Evaluation of Software Defined Networking Controllers against Denial of Service Attacks
Authors: Abdullah Ahmed F , Salem Fatty M , Tammam Ashraf , Abdel Azeem Mohamed H
Published: January 2020

The Software defined networking (SDN) utilization within networking architecture represents a way of looking at how networks are configured, controlled, and operated. Managed services such as routing, load balancing, and security can be automated and centralized dynamically in SDN controllers. Controllers act as the centralized repository of policy and control instructions for the network that packets are transmitted through it. Any transmitted packets flooded from an attacker that intends to access the controller will result to Denial of Service (DoS) attack. Thus, this paper is devoted to simulate and examine the impact of DoS attack on the bandwidth of two different linked hosts (Server/client) by SDN controllers as POX, RYU, and Opendaylight (ODL) controllers. The network performance is tested and emulated by using different testing tools of simulation in Mininet such as Hping3, iperf, jperf, wireshark and miniedit. Also, the performances of the controllers against DoS attack proposed by different protocols using user datagram protocol (UDP) and transmission control protocol (TCP) which will be assess via OpenFlow switch.
A novel approach of image encryption using pixel shuffling and 3D chaotic map
Authors: Benlashram Arwa , Al-Ghamdi Maryam , AlTalhi Rawan , Kaouther Laabidi Pr.
Published: January 2020

– In recent years, with rapid development in information and communication technologies, sharing digital images in social media have facilitated. However, since images privacy matters in our society, keeping images protected became a big challenge we have to deal with. In this paper, we propose a new image encryption method using Image Pixel Shuffling and 3D Chaotic map. First, the plain image is encoded using pixel shuffling, then the result is XORed with a key, and finally, the 3D chaotic map is performed on it. The security will be increased by using three steps to encrypt the image. Our results show that the proposed approach has a good performance and it is better than those of some notable image encryption algorithms. We got entropy value 7.9901 of cipher image, NPCR of 99.6628%, and UACI of 33.6781%. MATLAB was used to implement the proposed image encryption approach.
Performance Analysis of MIMO-NOMA Systems Based on Dynamic User Pairing Scheme
Authors: Deraz Shady A , Rizk Mohamed R M , Shaaban Shawky , Moussa Karim H
Published: January 2020

Multiple input multiple output (MIMO) structure can enhance the total capacity of the modern communication systems without using consuming excess power or bandwidth. Non-orthogonal multiple access (NOMA) configuration is a good nominee to accommodate with MIMO structure to fulfil the demands to extra user data rates and enriched spectral efficiencies. The dynamic uniform channel gain difference (DUCGD) user pairing technique plays an important role to maximize the capacity of all the paired and served users. The DUCGD is implemented by calculating the channel gain of every prospected user and sorting it in descending order to pair ones with the highest difference in channel gains to be functioned together. In this paper, the performance analysis of MIMO-NOMA systems by means of DUCGD is presented. The numerical analysis showed that, the increase of the number of users leads to an increase in the systems’ gain and the total achieved sum rates. This improvement is shown to be due to using DUCGD and an increased number of transmitting and receiving antennas, jointly.
Multi-class Image Classification Using Deep Learning Algorithm
Authors: Ezat W A , Dessouky M M , Ismail N A
Published: January 2020

Classifying images is a complex problem in the field of computer vision. The deep learning algorithm is a computerized model simulates the human brain functions and operations. Training the deep learning model is a costly process in machine resources and time. Investigating the performance of the deep learning algorithm is mostly needed. The convolutional neural network (CNN) is most commonly used to build a structure of the deep learning models. In this paper convolutional neural network (CNN) model pre-trained on Image-Net is used for classification of images of the PASCAL VOC 2007 data-set. The transfer learning approach is used to improve the performance of the deep learning CNN model where classification works fairly well with the smallest amount of computation time and fewer machine resources. The behavior of the Deep learning CNN model is studied and the performance has been measured. The obtained results are compared with the obtained test results from the Super-vector coding of local image descriptors method, SVM method, and Region Ranking SVM method, which tested with the PASCAL VOC 2007 data-set. The final results evaluate the deep learning algorithm as a state-of-the-art method for an image classification task.
Effect of phase noise on two-angle DoA estimation using planar arrays
Authors: Farahat A E , Hussein K F A
Published: January 2020

The effect of phase noise on the accuracy of the two-angle direction of arrival (DoA) is investigated. For this purpose, an efficient technique that depends on the correlation between the signals received by the 2D array and its steering matrix is proposed to estimate the DoA. A new model of the phase noise is proposed to get the consequent phase error in the received signals. The effect of the phase noise power and the array size on the accuracy of the estimated two-angle DoA is investigated. The average error in the estimation of the two-angles DoA is found to increase by increasing the power of the phase noise and by decreasing the array size. The numerical investigations are performed through electromagnetic simulation of a multiple plane waves incident on a 2D planar array of printed patch antennas.
Optimal Distributed Generation Allocation and Sizing Using Genetic and Ant Colony Algorithms
Authors: Zakaria Yousef Y. , Swief R. A. , El-Amary Noha H. , Ibrahim Amr M.
Published: January 2020

Distributed generators (DG) which installed into distribution network to face the increasing of load demand. DG can used to enhance power generation systems and improve distribution network efficiency. However, the distributed generators units’ implementation at not convenient position and sizing can lead to negative impacts such as a growing in power losses and invasion of system constraints. Because the rising of demand in energy. The appropriate placement and sizing of DG’s units is a credible solution to much problems in distribution system, for example power loss reduction and voltage regulation. The allocation of distributed generators into the distribution network can significantly impact in the transmission and distribution systems. Therefore, a method, which can identify an optimum DG location and size, is necessary. In this paper, Genetic Algorithm (GA) and Ant colony Algorithm (ACO) optimization techniques are proposed to find optimal sizing and location for distributed generation in electrical networks. The objective function of the work relies upon a linearized model to compute the active power losses as a function of power supplied from the generators. This strategy based on a strong coupling between active power and power flow taking into consideration the voltage angles. With the end goal to exhibit the adequacy of the proposed method, the proposed strategy is applied on IEEE 57-bus standard systems. Different maximum penetration level capacity of DG units and various possible places of DG units among several types of DG (active, reactive or active and reactive power) are considered. Results show that the optimization tools employing GA and ACO are effective in reducing active power losses by finding the optimal placement and sizing of DG units
Low Complexity Viterbi Decoder for RSCC Concatenated Codes
Authors: Samy Ramy , Mahran Ashraf
Published: January 2020

One of the primary obstacles to achieving reliable communication transmission for aerospace applications is the power constraints. Therefore, it is appealing to use powerful channel coding techniques with small complexity of decoding. The robust forward error correction scheme using Reed-Solomon as outer code concatenated with convolutional as inner code is an appealing scheme whose apps are commonly used in wireless and space transmissions. In this work we aim to reduce the complexity of the convolutional code decoding process as the number of computations and memory need increases exponentially with the code’s constraint length. We use the Adaptive Viterbi Algorithm to bring Viterbi decoder with small complexity. The proposed work yields approximately the same error performance as the conventional concatenated Reed-Solomon convolutional, while requiring a substantially smaller average number of computations for the convolutional code decoding process.
Detecting spam campaign in twitter with semantic similarity
Authors: Mostafa M , Abdelwahab A , Sayed H M
Published: January 2020

Twitter is a widespread supply for real-time news distribution between individuals. Furthermore, spammers could post any kinds of spam content to users, and a variant of incidents are committed on Twitter against users. These threats aren’t restricted to the social media platforms however they threaten the safety of Twitter users. Most of the researches use deep learning techniques to detect Twitter spammer activities. The traditional solutions check the behavior of each account or campaign of similar purpose accounts. The number of solutions concentrate on detecting spam campaign based on URL only and ignoring text in a tweet. In this paper, the lightweight framework is proposed to take tweet text into consideration for optimizing spam campaign detection methods based on deep learning techniques. The main contribution of this work summarized in two key points. First one is to summarize text of the tweets to cluster them. The second one is to find similar tweets based on Siamese Recurrent Network. Experimental results show the ability of the proposed technique to extract the right candidate campaign and classify them as spam or not with high recall and precision.
Towards Multi Robot Task Allocation and Navigation using Deep Reinforcement Learning
Authors: Elfakharany A , Yusof R , Ismail Z
Published: January 2020

Developing algorithms for multi robot systems to reach target positions and navigate safely in the environment is an open field of research. Most systems treat Multi Robot Task Allocation (MRTA) and Multi Robot Path Planning (MRPP) as two separate steps each with its own set of algorithms in which the MRTA algorithm assigns each robot to a task and the MRPP algorithm guides each robot through the environment towards the assigned goal position while avoiding both static and dynamic obstacles. In this paper, we present a method that combines both steps by using a deep reinforcement learning model. The model consists of a decentralized sensor level policy which outputs the robot’s velocity to guide it through the environment towards the selected goal position and avoiding collisions. The model was trained in a simulation environment and all the robots are homogenous differential drive robots. The objective is to ensure that each robot reaches a unique goal position with the number of goal positions is equal to the number of robots. The results of training the policy in an environment is presented with both static and dynamic obstacles with four robots and four goal positions.
Waste Tire Carbon Adsorbent for Active Removal of Paracetamol in Aqueous Solution
Authors: Jusoh N. W. C. , Choo T.Y. , Masudi A. , Ali R. R.
Published: January 2020

Waste tyre carbon adsorbent was prepared via three different calcination temperatures (500°C, 700°C and 900°C) and activated by sodium hydroxide solution. The phase and crystallinity analysis of each adsorbent is determined using X-ray diffraction analysis. The study revealed that different crystallinity of prepared adsorbent were obtained when calcination temperature is varied. Next, the effect of calcination temperature was investigated on the removal of paracetamol in aqueous solution. The highest percentage removal (99.37%) was obtained when the waste tire carbon adsorbent is calcined at 900°C for paracetamol initial concentration of 10 mg/L at pH 3 and 120 mins of contact time. In this case, the result obtained can be contributed to the production of adsorbent using waste tire with suitable calcination temperature for the paracetamol removal in aqueous solution.
Discovering Hate Sentiment within Twitter Data through Aspect-Based Sentiment Analysis
Authors: Zainuddin Nurulhuda , Selamat Ali , Ibrahim Roliana
Published: January 2020

Aspect-based sentiment analysis is a vital issue in fine-grained sentiment evaluation, which intends to provide an automatic prediction of the sentiment polarity, given a particular aspect in its context. This paper presents an aspect-based sentiment analysis to find hate sentiment inside twitter data. Word embeddings have had prevalent utilisation in Natural Language Processing (NLP) applications because their vector representations have the ability to capture useful linguistic relationships and semantic properties between words with the help of deep neural networks. Word embeddings have often been used in machine learning models as feature input, which allows for the contextualisation of raw text data in machine learning techniques. The model has the ability to represent the relationship between the word embedding features and the aspects as feature representation within the suggested model. To assess the efficacy of the proposed method, extensive experiments were performed on the dataset of the researcher, as well as on widely utilised datasets. It was demonstrated by the experimental results that the proposed method was able to obtain impressive results among the three datasets.
Multi-decadal patterns of vegetation succession after tundra fire on the Yukon-Kuskokwim Delta, Alaska
Authors: Frost Gerald V , Loehman Rachel A , Saperstein Lisa B , Macander Matthew J , Nelson Peter R , Paradis David P , Natali Susan M
Published: January 2020

Alaska’s Yukon-Kuskokwim Delta (YKD) is one of the warmest parts of the Arctic tundra biome and tundra fires are common in its upland areas. Here, we combine field measurements, Landsat observations, and quantitative cover maps for tundra plant functional types (PFTs) to characterize multi-decadal succession and landscape change after fire in lichen-dominated upland tundra of the YKD, where extensive wildfires occurred in 1971–1972, 1985, 2006–2007, and 2015. Unburned tundra was characterized by abundant lichens, and low lichen cover was consistently associated with historical fire. While we observed some successional patterns that were consistent with earlier work in Alaskan tussock tundra, other patterns were not. In the landscape we studied, a large proportion of pre-fire moss cover and surface peat tended to survive fire, which favors survival of existing vascular plants and limits opportunities for seed recruitment. Although shrub cover was much higher in 1985 and 1971–1972 burns than in unburned tundra, tall shrubs (>0.5 m height) were rare and the PFT maps indicate high landscape-scale variability in the degree and persistence of shrub increase after fire. Fire has induced persistent changes in species composition and structure of upland tundra on the YKD, but the lichen-dominated fuels and thick surface peat appear to have limited the potential for severe fire and accompanying edaphic changes. Soil thaw depths were about 10 cm deeper in 2006–2007 burns than in unburned tundra, but were similar to unburned tundra in 1985 and 1971–1972 burns. Historically, repeat fire has been rare on the YKD, and the functional diversity of vegetation has recovered within several decades post-fire. Our findings provide a basis for predicting and monitoring post-fire tundra succession on the YKD and elsewhere.
Behavioral responses to spring snow conditions contribute to long-term shift in migration phenology in American robins
Authors: Oliver Ruth Y , Mahoney Peter J , Gurarie Eliezer , Krikun Nicole , Weeks Brian C , Hebblewhite Mark , Liston Glen , Boelman Natalie
Published: January 2020

Migratory birds have the capacity to shift their migration phenology in response to climatic change. Yet the mechanistic underpinning of changes in migratory timing remain poorly understood. We employed newly developed global positioning system (GPS) tracking devices and long-term dataset of migration passage timing to investigate how behavioral responses to environmental conditions relate to phenological shifts in American robins (Turdus migratorius) during spring migration to Arctic-boreal breeding grounds. We found that over the past quarter-century (1994–2018), robins have migrated ca. 5 d/decade earlier. Based on GPS data collected for 55 robins over three springs (2016–2018), we found the arrival timing and likelihood of stopovers, and timing of arrival to breeding grounds, were strongly influenced by dynamics in snow conditions along migratory paths. These findings suggest plasticity in migratory behavior may be an important mechanism for how long-distance migrants adjust their breeding phenology to keep pace with advancement of spring on breeding grounds.
When savannas recover from overgrazing, ecohydrological connectivity collapses
Authors: Basant Shishir , Wilcox Bradford P , Leite Pedro M , Morgan Cristine L
Published: January 2020

Grasslands and savannas across the globe have undergone a dramatic transition over the past century. Historical overgrazing has set in motion a cascade of events ranging from desertification in arid climates to woody plant encroachment (WPE) in semiarid and subhumid climates. In recent decades, grazing pressure on many of these landscapes has declined significantly, and where rainfall is sufficient (as in most semiarid and subhumid settings), herbaceous vegetation in intercanopy areas will recover. An important question is, how has this transition altered ecohydrological connectivity (overland flow and runoff–runon dynamics)? A woody-plant-encroached, subhumid savanna site in South Texas with a history of heavy grazing (but ungrazed since 1981) was used as a model landscape to address this question. Overland flow, soil moisture, and field saturated hydraulic conductivity (K
fs) were measured along a catena extending from the upland savanna-parkland areas to the downslope, more densely wooded areas. For comparison, K
fs and infiltrability were also measured at a moderately grazed upland site 14 km east of our study site, selected as a surrogate for past conditions at our site. In contrast to the prevailing hypothesis that the downslope areas (‘drainage-woodlands’) at our study site have continued to be supported by runoff generated from the upland areas, our measurements yielded no evidence for the redistribution of water from the uplands to the drainage areas under the current ungrazed conditions. Further, K
fs at the ungrazed study site was two orders of magnitude higher than that at the grazed site and infiltrability was twice as high at the ungrazed site than the grazed site. These findings, coupled with historical information from the site, strongly suggest that historical overgrazing amplified the runoff–runon process, resulting in significant subsidies of water from the uplands to the drainage areas. Then, with the relaxation of grazing pressure and subsequent landscape recovery, redistribution of water via surface runoff was relatively rare. We believe that our results are generalizable for savannas that have recovered from overgrazing. When these savannas are heavily grazed, ecohydrological connectivity is greatly increased; but if grazing pressure relaxes, ecohydrological connectivity will collapse. These changes in ecohydrological connectivity have important, but not always well understood, ecological consequences.
Species- and elevation-dependent productivity changes in East Asian temperate forests
Authors: Kim Moonil , Ham Bo-Young , Kraxner Florian , Shvidenko Anatoly , Schepaschenko Dmitry , Krasovskii Andrey , Park Taejin , Lee Woo-Kyun
Published: January 2020

The velocity and impact of climate change on forest appear to be site, environment, and tree species-specific. The primary objective of this research is to assess the changes in productivity of five major temperate tree species (Pinus densiflora, PD; Larix kaempferi, LK; Pinus koraiensis, PK; Quercus variabilis, QV; and Quercus mongolica, QM) in South Korea using terrestrial inventory and satellite remote sensing data. The area covered by each tree species was further categorized into either lowland forest (LLF) or high mountain forest (HMF) and investigated. We used the repeated Korean national forest inventory (NFI) data to calculate a stand-level annual increment (SAI). We then compared the SAI, a ground-based productivity measure, to MODerate resolution Imaging Spectroradiometer (MODIS) net primary productivity as a measure of productivity based on satellite imagery. In addition, the growth index of each increment core, which eliminated the effect of tree age on radial growth, was derived as an indicator of the variation in primary productivity by tree species over the past four decades. Based on our result from NFI plots and increment core data sets, the productivity of PD, QV, and QM in LLF was relatively higher than those in HMF, while LK and PK in HMF were more productive than lowland ones. Our analysis of the increment core data revealed a contrasting pattern of long-term productivity changes between coniferous and oak tree species. While the productivity of oak tree species tended to increase after the 1990s, the productivity in coniferous forests tended to decrease. These differences across forest types and their altitudinal classes are also noticeable from the MODIS product. The results of our study can be used to develop climate-smart forest management strategies to ensure that the forests continue to be resilient and continue to provide a wide range of ecosystem services in the Eastern Asian region.
Detection of type2 biomarkers for response in COPD
Authors: Yamaji Yoshikazu , Oishi Keiji , Hamada Kazuki , Ohteru Yuichi , Chikumoto Ayumi , Murakawa Keita , Matsuda Kazuki , Suetake Ryo , Murata Yoriyuki , Ito Kosuke , Asami-Noyama Maki , Edakuni Nobutaka , Hirano Tsunahiko , Matsunaga Kazuto
Published: January 2020

Chronic obstructive pulmonary disease (COPD) is a heterogeneous inflammatory lung disease. It is important to identify patients who would respond to anti-inflammatory treatment. This prospective study aims to determine how inflammatory biomarkers could be used to predict the potential effect of inhaled corticosteroids (ICS) in terms of symptoms and lung function. We evaluated the levels of blood eosinophils, exhaled nitric oxide fraction at a flow rate of 50 ml s−1 (FeNO), alveolar nitric oxide concentration (Calv), immunoglobulin E and atopy in 43 patients with symptomatic COPD and correlated these expression levels with the changes in the COPD Assessment Test (CAT) and lung function by 12 weeks of add-on therapy with ciclesonide 400 μg d−1 on bronchodilators. The mean changes in the CAT score and FEV1 were −1.4 points and +90 ml, respectively, with significant variation in the levels of change. The area under the receiver’s operating characteristic curve (AUC) for FeNO in predicting improvements in both the CAT score and FEV1 was 0.92. The AUC for Calv and blood eosinophils was 0.82 and 0.65. Two cutoffs were chosen, one corresponding to a high value of FeNO associated with certainty for response inclusion (FeNO = 35 ppb; sensitivity = 0.67, specificity = 0.94; positive predictive value = 0.80) and the other with certainty for response exclusion (FeNO = 20 ppb; sensitivity = 1.00, specificity = 0.58, negative predictive value = 1.00). Baseline FeNO values were significantly correlated with changes in FEV1 and CAT (all p < 0.0001). FeNO could be a valuable biomarker for identifying individuals who respond to steroid therapy among patients with symptomatic COPD in terms of symptoms and airflow limitation. The study was prospectively registered with the University Hospital Medical Information Network (UMIN) in Japan (protocol ID 000010711).
An Analysis of GaN-based Ultraviolet Photodetector
Authors: Fan Zitong
Published: January 2020

The GaN-based UV photodetectors have been a hot topic in semiconductor field. To present the existing research, this paper introduces the development of GaN-based UV photodetectors and the common types of detectors. The difficulties and new technologies of UV photodetector are also introduced. About the difficulties, the whole paper would focus on the substrate of the GaN. To solve this problem, this paper have introduced the PSS, an enhancement of sapphire substrate. Also this paper have put a hypothesis on the shape of PSS. The surface plasmon, which is not a common technology in photodetectors is also introduced. It is hoped that this paper will provide research background and direction for researchers who want to enter this field.
Dynamics and strain-based design of the large-diameter pipe under the impact of a falling rock
Authors: Shao Bing , Yan Yifei , Wang Xiaomei , Yan Xiangzhen
Published: January 2020

Falling rocks are one of the essential causes to pipeline failures in the most frequently occurring geological disasters and the pipes in a thin-shell structure can hardly resist the huge impact energy. The traditional design are conducted by keeping the maximum stress smaller than the material strength which is too conservative to make a full use of the pipeline. In this work, codes for the explicit dynamics based on the Lagrange algorithm are adopted to numerically simulate the impact of falling spherical stones on the large diameter pipe with the consideration of nonlinearity of big deformation. Dynamic responses of the pipe as well as strains on pipe’s cross section are discussed in detail. Influences on the pipe strains from factors like impact speed, stone size and moving direction are investigated. Results show that, most significant effect is from the diameter-thickness ratio of the pipe and it shows the resistant capability of the pipe drops exponentially with the decreasing of the thickness and the ratio is recommended to be chosen in a range of 40∼60. Eccentricity also effects the strains exponentially and the impact extent is greatly reduced with the eccentricity being smaller than 50%. Safety check is carried out by an ultimate-strain criterion and so, the ultimate size and velocity of the falling stone are got. What is done in this paper is expected to be of referential values for geological disaster resistant design of pipeline.
Design and Development of Electric Locomotive Converter Technology Integrated Experiment Platform
Authors: Chen Rui , Wang Shudong , Liang Chao , Zhao Shuo , Wu Yongyong
Published: January 2020

Devices for power electronic technology experiment are generally backward and fail to satisfy the need of teaching and technology development nowadays. The design and manufacture of comprehensive experimental platform combined with traditional experiment and advanced electric locomotive converter technology. This platform realized the operation of converter system of electric locomotive. The platform is used for experimental operation of undergraduate and research and innovation of graduate.
Study of Hydrothermally Lignite and Rice Husk blend: Thermogravimetric Analysis
Authors: Mehdi Miqdad , Hamid Siddiqi Muhammad
Published: January 2020

The increased realization in greenhouse emission has encouraged to grow new technologies to accommodate the confinement and seizure of CO2. Keeping this situation, the thermal behaviour of lignite, Rice husk, besides their mergers throughout pyrolysis and combustion procedures, was examined in the study for their possible usage as a sustainable and substitute energy resource. The experiments were done in a thermo-gravimetric analyser at a heating rate of 40 °C/min and range from standard room-temp up to 950°C. These blends presented diverse ignition as well as combustion actions dependent on the proportion of rice husk and atmosphere (Oxy-fuel or Nitrogen). These investigational outcomes support to describe as well as expect the performance of lignite and rice husk blends in real applications.