bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on Parameters of P-20 Steel in CNC milling machine
Authors: Vardhan M Vishnu , Mohanty Chinmay P , Dhanraj B
Published: June 2020

Milling is the most common form of machining process used in the production of moulds/dies, due to the high tolerances and surface finishes by cutting away the unwanted material. The selection of Pre-hardened steel (P-20) is widely used in production of moulds/dies because of less wear resistance and are used for large components. Due to extensive use of highly automated machine tools in the industry, manufacturing requires reliable models and methods for the prediction of output performance of machining processes. The major objective of the present study is experimental analysis of machining parameters in end milling for surface roughness by considering the input parameters such as cutting speed, feed rate, depth of cut, cryogenic soaking duration.
CYGNO: Triple-GEM Optical Readout for Directional Dark Matter Search
Authors: Abritta Costa I. , Baracchini E. , Bedogni R. , Bellini F. , Benussi L. , Bianco S. , Caponero M. , Cavoto G. , Di Marco E. , D’Imperio G. , Maccarrone G. , Marafini M. , Mazzitelli G. , Messina A. , Petrucci F. , Piccolo D. , Pinci D. , Renga F. , Saviano G. , Tomassini S.
Published: June 2020

CYGNO is a project realising a cubic meter demonstrator to study the scalability of the performance of the optical approach for the readout of large-volume, GEM-equipped TPC. This is part of the CYGNUS proto-collaboration which aims at constructing a network of underground observatories for directional Dark Matter search. The combined use of high-granularity sCMOS and fast sensors for reading out the light produced in GEM channels during the multiplication processes was shown to allow on one hand to reconstruct 3D direction of the tracks, offering accurate energy measurements and sensitivity to the source directionality and, on the other hand, a high particle identification capability very useful to distinguish nuclear recoils. Results of the performed R&D and future steps toward a 30-100 cubic meter experiment will be presented.
Development of a time projection chamber for J-PARC hadron physics program
Authors: Kim Shin Hyung , Ichikawa Yudai , Sako Hiroyuki , Ahn Jung Keun
Published: June 2020

A time projection chamber (HypTPC) has been newly developed for the various hadron physics experiments at J-PARC. The design of HypTPC was carefully considered to cope with the J-PARC high intensity beam. The triple-layered GEM has been adopted as a signal amplification and the gating grid plane for an ion backflow suppression. The octagonal drift volume is defined by the cathode plane and the field cage structure with the height of 55 cm. A target is located inside the drift volume in order to have a large acceptance. The GET (General Electronic System for TPCs) is utilized for the data acquisition. The HypTPC was first commissioned with 230 MeV proton beam at HIMAC. The obtained position resolution is 400–700 µm, which gives the expected resolution of 230–300 µm under a magnetic field of 1 T. We have confirmed the high rate capability of the TPC up to 1 MHz with a good suppression of the ion backflow under the gate operation.
Test Beam Results from sPHENIX prototype Time Projection Chamber
Authors: Ram Niveditha
Published: June 2020

The sequential melting of Upsilon states gives us information about the Debye Screening length of Quark Gluon Plasma (QGP). To observe this sequential melting at RHIC energies of 200GeV, a Time Projection Chamber, as part of the sPHENIX detector assembly, with ability to resolve the Upsilon states is proposed. This paper details the construction of the prototype TPC, the method of analysis of test beam data and its results.
Overview and design of the sPHENIX TPC
Authors: Klest H
Published: June 2020

The proposed sPHENIX detector at RHIC is being designed to study with unprecedented precision the nature of the Quark Gluon Plasma, or QGP, at RHIC through measurement of jets, jet correlations, and Y particles. To reach the goal of producing a high mass-resolution reconstruction of the Y(nS) states, a compact TPC covering pseudorapidities < |1.1| is under construction to provide sPHENIX with the necessary invariant mass resolution. Similar to the ALICE-TPC upgrade, the sPHENIX TPC design presently utilizes quadruple-GEM detectors. As an alternative solution, a double-GEM-Micromega hybrid arrangement is currently being tested. Utilizing novel zigzag patterned readout pads, a modified SAMPA readout chip, and an optimized Ne-CF4 gas mixture immersed in a 1.4 T magnetic field to reduce ion backflow, sPHENIX will have a unique lens into the QGP. The motivation behind the design and innovations of the TPC will be presented, along with the current status of the project.
A numerical investigation on the discharges in Micromegas
Authors: Bhattacharya Deb Sankar , Ströhmer Raimund , Trefzger Thomas
Published: June 2020

The Micro-Pattern Gaseous Detectors (MPGD) have been widely adopted in nuclear and particle physics experiments, for their fast response and other excellent characteristics. To achieve the required signal strength and detection effciency, sometimes they are operated at a high voltage range. This often challenges the limit of high voltage stability of the detector. Discharge in gaseous detectors is a complex process and involves several responsible factors. The microscopic geometrical structures of the MPGDs may itself sometimes induce discharges.

In this study, we are numerically investigating the discharge phenomena in non-resistive Micromegas. Within the COMSOL framework, a 3-dimensional model is developed to observe the occurrence and the development of discharge in Micromegas. The effect of space charge has been taken into account in the calculation. The model allows to vary the geometrical parameters of the detector as well as to study the effects of gas impurities and different number of primary charges.
The triple-GEM detector for the Laser Polarimeter facility at VEPP4-M collider
Authors: Blinov V E , Ivakin V O , Kaminskiy V V , Kudryavtsev V N , Yu Muchnoi N , Nikitin S A , Nikolaev I B , Shekhtman L I , Zakharov S A
Published: June 2020

The Laser Polarimeter is being developed at VEPP-4M collider for beam energy calibration by Resonant Depolarization technique. The essential part of this facility is a photon-tracking detector measuring coordinates of backscattered gammas.
Fast neutron spectroscopy with Mimac-FastN : a mobile and directional fast neutron spectrometer, from 1 MeV up to 15 MeV
Authors: Sauzet N , Santos D , Guillaudin O , Bosson G , Bouvier J , Descombes T , Marton M , Muraz JF
Published: June 2020

In the frame of direct dark matter search, the fast neutrons producing elastic collisions are the ultimate background. The MIMAC (MIcro-tpc MAtrix Chambers) project has developed a directional detector providing the directional signature to discriminate them based on 3D nuclear tracks reconstruction. The MIMAC team of the LPSC has adapted one MIMAC chamber as a portable fast neutron spectrometer, the Mimac-FastN detector, having a very large neutron energy range (10 keV - 200 MeV) with different gas mixtures and pressures. The present paper shows its main features and functionality and demonstrates its potential in the energy range from 1 MeV to 15 MeV.
Micromegas for beam loss monitoring
Authors: Segui L , Alves H , Aune S , Beltramelli J , Bertrand Q , Combet M , Dano-Daguze A. , Desforge D , Dolenc-Kittelmann I , Gougnaud F , Joannem T , Kebbiri M , Lahonde-Hamdoun C , Legou P , Maillard O , Marcel A , Mariette Y , Marroncle J , Nadot V , Papaevangelou T , Shea T J
Published: June 2020

The early detection of beam losses and the alarm to the machine protection system in accelerators are crucial for the safe operation of the machine. In the low energy region of the hadron accelerators, only neutrons and photons are produced in the case of a beam loss. However, photons are also emitted by electrons at the RF cavities, becoming a natural background for losses identification. A new kind of beam loss monitors have been conceived to extend the sensitivity to the low energy region of the high intensity hadron accelerators. They are based on Micromegas detectors sensitive to fast neutrons. The appropriate configuration of the Micromegas operating conditions will allow a fast response, a sensitivity to small beam losses and a suppressed sensitivity to photons. In this paper the operation principle and the system developed for the European Spallation Source will be presented, with focus on the results obtained at different irradiation facilities. First time proof of operation in real conditions, with the detection of beam losses, will be also shown with measurements performed at LINAC4 (CERN).
Means for monitoring the dielectric parameters of liquid media based on quasiperiodic Bragg microwave structures in a coaxial waveguide
Authors: Nasybullin A R , Morozov O G , Morozov G A , Farkhutdinov R V , Gavrilov P V , Makarov I A
Published: June 2020

The main characteristic of the converter element in resonant microwave sensors that determines the sensitivity of the conversion is the quality factor of the resonance line. In structures with periodic inhomogeneity of the classical topology, the quality factor of the circuit at high values of the signal-to-noise ratio may turn out to be low, which entails the emergence of restrictions on the maximum achievable conversion parameters. One of the ways to increase both the Q factor and the modification of other properties of the microwave structure that affect the overall efficiency of the converter element is the use of quasiperiodic elements. The coaxial cable, where the holes in the dielectric act as inhomogeneity, is presented, forming structure with phase shift. Using the method of flow graphs, we obtained the analytical dependence of the reflection coefficient for this structure. The analysis of the frequency response of the microwave reflection coefficient was carried out for different values of the phase shift and the location of the phase shift section along the length of the cable. A numerical and physical experiments were carried out to determine the frequency dependence of the microwave reflection coefficient with a π-phase shift for various values of the automobile fuel permittivity introduced into the cells.
Experimental modelling of apokamp discharge formation under outer electric field
Authors: Kuznetsov V S , Panarin V A , Skakun V S , Sosnin E A , Tarasenko V F
Published: June 2020

A laboratory setup has been created for modeling certain aspects of the initiation process of blue jets in the Earth’s atmosphere. With its help, the influence of an electric field on the apokamp discharge in air at pressures of 180-260 Torr was established. It is shown that the formation of a negatively charged zone located above the channel of a pulse-periodic discharge with a positive potential leads to both initiation and lengthening of the apokamps starting from the channel, and also reduces the voltage amplitude necessary for their formation.
Local video-positioning system for industrial GPR
Authors: Ponomarev O G , Khmelevand V L , Satarov R N
Published: June 2020

This article presents a local positioning system working with the industrial GPR OKO-2 (LOGIS) in the process of radio measurements. Here we discuss principles of the positioning system and the method of transferring location data into the GPR system as satellite data. The location uses a video recording of special tapes, which limit the scanning area. Tapes contain the special periodic pattern. A pair of video cameras are placed directly on the GPR body, cameras will register images of the limiting tapes. Results of experimental approbation of the GPR complex confirm the applicability of the system.
System of automated weather stations to collect and transmit environmental parameters
Authors: Yuzhakov M S , Pavlova A A , Pidotova D A , Badin A V , Filchenko D I
Published: June 2020

Results of the development and application of a weather registration system presented in the article. Concept of creating of distributed automated LoraWAN network of weather sensors to monitor climate parameters in real time is described. The time dependences of temperature, pressure and humidity in the southern part of the Tomsk city (Russia) for the period April-May 2019 are shown. The rate of change of temperature, pressure and air humidity on the night of April 18-19, 2019 was calculated. The possibilities of weather prediction based on meteorological data were estimated.
Possibility and application of all-weather lidar-radio sensing complexes
Authors: Boreysho A S , Ilyin M Y , Kim A A , Konyaev M A , Shchukin G G , Zhukov V Y
Published: June 2020

The article discusses the main problems of the development and applying of all-weather meteorological complexes of remote optical and radar atmospheric sensing. Discussed different areas of application depending on type of airports. The concept of a new mobile three-band true all-weather meteorological single platform complex for operational measurements in airports is proposed. Shown the results of multi-bands systems measurements in PPI mode and vertical profiler performed under various conditions.
Ultrashort pulse decomposition in reflection symmetric meander lines of two cascaded half-turns
Authors: Chernikova E B , Belousov A O , Gazizov T R
Published: June 2020

The paper presents the analysis of the time response of reflection symmetric meander lines of two cascaded half-turns to the excitation of an ultrashort pulse (USP). The analysis is based on simulating 3 circuit diagrams of half-turns connections for a length of 1 m. The simulations revealed the possibility of additional pulses in the time response to appear at the output. It is shown that the delay values of the additional pulses are equal to the arithmetic mean values of the two mode delays in different versions. The results of the work are useful for further study of additional pulses in the time response and to establish the nature of their occurrence.
Antenna for radar “Radio Dozor-M”
Authors: Satarov R N , Tseplyaev I S , Shipilov S E , Buyanov Y
Published: June 2020

The article presents a new antenna for “Radio Dozor-M” device, which uses for a searching people behind the obstacles. The antenna is maded with a printing on a foil PCB, mounted on a copper base. The antenna is part of an array with serial perquisition and it’s a combination of electrical and magnetic emitters. The calculated characteristics of the simulated antenna are presented. Also presents the results of the oscillogram obtained by probing a person behind the wall.
Experimental modeling of radio information systems for solving the problem of failures forecasting
Authors: Perlov A , Zyuzin A , Kokuev A , Kochkarov A , L’vov K , Tymoshenko A
Published: June 2020

We report a simulation model of technical condition data of radio information systems at solving the problem of failures forecasting. Time cost analysis on sampling for high-accuracy forecasting of radio information systems failures showed that the performance of samples accumulation by testing the equipment at the stands does not allows us to create radio information systems with automated operation management system on time. The existing level of product unification allows the use of both data from previous generation stations and current data from of the built-in control of new generation radar stations, due to their correlation connections. These features create the conditions for operative formation of a large amount of data on the technical states of the stations due to the development of a simulation data model of the built-in control. A feature of such a model concludes in its versatility, i.e. the formation of the data stream on both binary sensors (operational or not) and sensors of physical parameters. An analysis of the temperature recorded during the development process of the components was carried out to determine the minimum sample size required. The temperature prediction model described above was trained on samples of various volumes for determination of the influence of the training sample volume on forecast accuracy. The developed methodological apparatus for formation of data from the station’s built-in control provides a solution of the problem of high-precision failure prediction.
Combined treatment of energy-saturated materials in external fields
Authors: Kuzmina L , Gazenaur E , Krasheninin V , Mixel O , Galtseva O , Gazenaur N
Published: June 2020

The paper analyses the effect lead and iron ions have on slow and explosive decomposition in crystals of silver azide initiated by a contact electric filed, local physical impact and UV-radiation. The reaction of decomposition registered immediately in the process of impact was examined according to gas release. This method provides accuracy of 10−12 mole. A stop-watch was used to determine time-to-explosion. The outcomes of experiments show that introduction of lead and iron ions into crystals of silver azide deteriorates strength of samples under local physical impact; furthermore, gas release caused by this type of impact stimulates fracture of samples. Experimental data indicate that crystals of silver azide with introduced lead and iron tend to decompose more intensively in a contact electric field. As for UV-radiation, it also has a significant decomposing effect on samples with introduced impurity substances, however, no explosion is registered, i.e. a maximal amount of gas is emitted at a certain period of time; afterwards gas release becomes less intensive and stops in approximately 20 minutes after the treatment starts. Any external impact generates misbalanced charge carriers (holes). Holes are localized on cation vacancies associated with generation of reactive centres. The number of reactive centres grows due to the increased concentration of impurity defects and might become critical. Data of experiments suggest that crystals of silver azide with introduced impurities are less stable and chemically inactive in external fields.
Electrons accelerator for research Cherenkov radiation in different specimens
Authors: Tarasenko V F , Alekseev S B , Kh Baksht E , Burachenko A G , Lomaev M I
Published: June 2020

Cherenkov radiation is widely used to register charged particles with high energy. This paper describes the design and parameters of an electrons accelerator, as well as the results of studies of the spectra and amplitude-time characteristics of sapphire and quartz KU1 radiation under the excitation of electrons with an energy of up to 350 keV. It was shown that in the UV and visible spectral regions a wide band is recorded, the intensity of which increases with decreasing wavelength. It was established that the duration and shape of the radiation pulse of this band coincides with the pulse of the electron beam. All this allows us to attribute the registered emission to the Cherenkov radiation.
Digital 3d x-ray microtomographic scanners for electronic equipment testing
Authors: Klestov S A , Syryamkin V I , Suntsov S B
Published: June 2020

The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. In conclusion, the main applications of X-ray tomography are presented.
Development of microstrip ferrite decoupling devices for mm-wave range microwave equipment
Authors: Semenov A S , Nalogin A G , Alekseev A A
Published: June 2020

This article considers structural and technological features, which developers encounter during the creation of microstrip ferrite devices for mm-range microwave equipment. The development results of a 8-mm range microstrip ferrite circulator and isolator are presented in the article.
The ProtoDUNE-SP LArTPC electronics production, commissioning, and performance
Authors: Adams D. , Bass M. , Bishai M. , Bromberg C. , Calcutt J. , Chen H. , Fried J. , Furic I. , Gao S. , Gastler D. , Hugon J. , Joshi J. , Kirby B. , Liu F. , Mahn K. , Mooney M. , Morris C. , Pereyra C. , Pons X. , Radeka V. , Raguzin E. , Shooltz D. , Spanu M. , Timilsina A. , Tufanli S. , Tzanov M. , Viren B. , Gu W. , Williams Z. , Wood K. , Worcester E. , Worcester M. , Yang G. , Zhang J.
Published: June 2020

The ProtoDUNE-SP detector is a large-scale prototype of the Single-Phase (SP) Liquid Argon Time Projection Chamber (LArTPC) design proposed for the Deep Underground Neutrino Experiment (DUNE). 15,360 LArTPC wires are instrumented with low electronic noise pre-amplifier and digitization ASICs integrated into Front End Motherboards (FEMBs) operating at cryogenic temperature within the cryostat. The large number of electronics channels and high performance specifications required a large-scale production electronics quality control effort, careful installation into Anode Plane Assemblies (APAs), and rigorous detector commissioning. This successful collaboration-wide effort achieved a working LArTPC electronics channel percentage of 99.7% (15,318 of 15,360 channels in total), whose operating performance exceeded expectations. We summarize the ProtoDUNE-SP cold electronics design and quality control, installation, and commissioning efforts that enabled this excellent electronics performance.
Do recent NDVI trends demonstrate boreal forest decline in Alaska?
Authors: Fiore N M , Goulden M L , Czimczik C I , Pedron S A , Tayo M A
Published: June 2020

Remote sensing analyses of boreal forest regions have found widespread decreasing or increasing trends in normalized difference vegetation index (NDVI). Initially, these trends were attributed to climate change induced shifts in primary productivity. It is emerging, however, that fire disturbance and subsequent succession also strongly impact the optical properties of boreal forests. Here we use NDVI time series data from Landsat (1999–2018) paired with surveys of 102 forest stands with known recent fire history to investigate the relationship between NDVI and forest structure during succession. We found that NDVI varies systematically with stand age as a result of successional changes in forest structure and composition and that the proportion of deciduous (broad-leaved) trees in the upper canopy is a better predictor of NDVI than leaf area index. Recent fire disturbance led to strong NDVI decreases and early post-fire recovery of herbaceous and deciduous vegetation to strong NDVI increases. The mid-succession transition from deciduous to evergreen (needle-leaved) stands led to weak NDVI decreases, while mid-to-late succession thinning of evergreen canopies led to weak NDVI increases. Thus, both increasing and decreasing NDVI stands occur naturally across the landscape, and do not necessarily reflect a large-scale shift in boreal forest productivity.
GIS Partial Discharge Patterns Recognition with Spherical Convolutional Neural Network
Authors: Yang Wei , Zhang Guobao , Zhu Taiyun , Cai Mengyi , Zhao Hengyang , Yan Jing , Wang Yanxin
Published: June 2020

The ubiquitous construction of the power Internet of Things provides a new idea for the real-time and accurate diagnosis of GIS partial discharge online monitoring fault diagnosis. However, the traditional partial discharge fault diagnosis method is difficult to solve the problem that the fault information of different online monitoring systems is different from the reference axis. In order to solve the problem that the fault information is difficult to identify in rotation and transformation, and improve the accuracy of fault diagnosis, this paper proposes a spherical convolutional neural network based on complex data sources. First, the PRPS picture transmitted to the ubiquitous power Internet of Things terminal is selected as the fault feature information. Secondly, a generalized Fourier algorithm (GFT) algorithm is used to construct a spherical convolution structure for PD pattern recognition. The algorithm can perform automatic feature extraction. Thirdly, the spherical convolutional neural network-based PD recognition method is applied to processing of the complex data sources with 84.88% average accuracy rate. It shows that the PRPS 3D map is one of effective way to avoid the complexity of artificial feature extraction for spherical CNN and in the meantime, it can also improve the accuracy of fault diagnosis.
Analysis of The Influence of Flux Detector on the Subsynchronous Oscillation Characteristics of DFIG
Authors: Jin Haiqiang , Wen Jun , Wang Tongtong , Zhang Hanhua
Published: June 2020

There is a risk of subsynchronous oscillation after grid connection of doubly fed wind farm. The accurate detection of stator flux amplitude and phase will determine the accuracy of stator flux vector oriented control method, and then affect the subsynchronous oscillation characteristics of grid connected doubly fed wind turbine. Therefore, in PSCAD/EMTDC, this paper establishes the model of grid connected doubly fed wind turbine with u-i flux detector and u-ω flux detector respectively, and studies the influence of different flux detector on the subsynchronous oscillation. Simulation results show that different flux detector will participate in the subsynchronous oscillation to different extent.
Coordinated generation and transmission expansion planning approach considering probabilistic available transfer capability
Authors: Zhou Ping , Kang Peng , Chen Ruiguo , Tian Hao
Published: June 2020

The available transmission capacity of the network has a great impact on the safety and reliability of the whole system. After the reform of electricity market, the grid is required to have the highest available transmission capacity (ATC) based on the existing load due to the uncertain factors. Therefore, it is necessary to consider the growing demand for available transmission capacity from the grid planning stage. Meanwhile, considering the uncertain factors have a great influence on the available transmission capacity (ATC), this paper first models the three uncertain factors and introduces the solving method of probabilistic available transfer capability, then proposes a grid expansion planning model considering the probabilistic available transmission capacity under the influence of uncertainties, which is applied to the six-node test system. Finally, the genetic algorithm is used to solve the final planning scheme. Compared with other planning schemes, this method can consider the comprehensive investment cost and the probability available transmission capacity. The case study shows that the method is effective and can achieve good results.
Coordinated generation and transmission expansion planning approach based on chance-constraints using genetic algorithm
Authors: Zhou Ping , Kang Peng , Zhu Yuan , Chen Ruiguo
Published: June 2020

The grid planning is a crucial and basic work in the power system, but there are various uncertain factors in the power system, which cause dramatic influences to the size of the grid power investment, as well as the power system security and stability for next few years. Traditional planning methods are gradually hard to adapt the grid planning under situations especially with large amounts of uncertainties. To reduce the impact of uncertain factors of the power system, it is necessary to consider increasingly significant uncertainties in system planning. However, if all extreme scenarios all taken into account, generally, the optimization results will be really conservative. Therefore, to prevent a relatively conservative optimization scheme, this paper proposes a grid-based expansion planning model based on chance constraints which take fully considerations of system uncertain factors using genetic algorithm. Compared with other planning schemes, this method comprehensively considers the investment cost and the level of load loss. Finally, a test system with six nodes is used to verify the effectiveness of the proposed method. The economics of the optimization scheme using the proposed approaches are observed using the test system.
Double-layer Electricity Market Trading Strategy for Microgrids Based on Multi-agent System
Authors: Du Le , Zhu Xiaofei
Published: June 2020

Aiming at the power generation and consumption of microgrid, this paper proposes a double-layer electricity market trading model for microgrids(MGs) based on multi-agent system(MAS). In the upper level, MG conducts power transactions with other MGs and grid companies in the electricity market. In the lower layer, the various components within the MG coordinate and cooperate to obtain the maximum profit. In order to the uncertainty problem in power forecasting, a rolling optimization model based on chance constrained programming is established by combining interruptible load and demand response in the real-time market. And the consequence of the case analyses by MATLAB simulation proves the rationality and validity of the model for optimal dispatch of virtual power plants given by this paper.
Research on Optimizing the Recovery Strategy of a Distribution Network Communication System Under Extreme Disasters
Authors: Lin Husheng , Zhou Xia , Lu Jianqiang
Published: June 2020

Extreme disasters, such as typhoons, cause great damage to distribution network communication systems, affecting the perception of disaster situations and the repair speed of the distribution networks. To realize the rapid recovery of a distribution network, an optimal recovery strategy of the distribution network communication system is proposed in this paper from the perspectives of predisaster prediction and postdisaster rush repair. First, based on multivariate data, the space-time mesh fusion method is used to predict the fault position of the distribution network communication system, guiding the accurate allocation of emergency repair resources, and the fault position is corrected using man-made statistics after a disaster. Then, combining fiber optics, mobile nets and emergency communication vehicles, rush repair rules for the distribution network communication system after extreme disasters are put forward, and the shortest route search algorithm is used to solve the minimum rush repair time under the rules, which is the optimal rush repair scheme for the distribution network communication system after an extreme disaster. Finally, the proposed strategy is applied to a practical topology, and the results demonstrate that the strategy is reasonable and effective.
Prediction of Short-term PV output power Based on PCA-Stacking under different weather conditions
Authors: Xiaofei Zhu
Published: June 2020

With the continuous expansion of photovoltaic scale, the accurate prediction of photovoltaic power generation is increasingly important for grid dispatching and grid optimization operations. In this paper, the photovoltaic power generation mainly uses meteorological factors and historical data as the input and output of the neural network. The input quantity is large, the data is redundant, and the network is difficult to converge, which always has a great adverse effect on the accuracy of photovoltaic output prediction. Firstly, different weather types are classified according to the trend graphs of different weather types. Principal components analysis (PCA) is used to analyze less comprehensive features from multiple meteorological factors and reduce the input of predictive models. At the same time, aiming at the problem that the prediction accuracy of a single prediction model such as the existing neural network and wavelet analysis method is limited, the idea and method of integrated learning are introduced, and a short-term prediction method based on Stacking method combined with SVM and Xgboost is proposed. Compared with the single model of SVM and Xgboost, the results show that the proposed method has a significant improvement compared with the accuracy of a single prediction model.
Study on Characteristics of no-load Converter Transformer closing Accessing to High-Cable Rate Network
Authors: Wang Tongtong , Zhu Shengyi , Jin Haiqiang , Wen Jun
Published: June 2020

When the converter transformer is closed at no load state, the transient voltage is too large, which may cause the transformer core to saturate; meanwhile, the capacitance of the cable line to the ground is much larger than that of the overhead line, which may cause ferromagnetic resonance phenomenon. Taking the parameters of typical transmission line and 500kV converter transformer as an example, the simulation results of Matlab are used to analyze the possible effects of no-load closing of converter transformer under different cable-forming rates and different outlet modes, and put forward targeted measures, which have certain reference value for the future design of the converter station outline.
Simulation Analysis of Magnetizing Inrush Current of 500kV Transformer
Authors: Zhu Shengyi , Wang Tongtong , Jin Haiqiang , Wen Jun
Published: June 2020

The 500kV power grid is the most important high-power AC power system in China. The 500kV transformer is responsible for the regular uploading and sending tasks. It is important electrical primary equipment that connects two or even three different voltage levels. Taking a new 500kV transformer in Chongqing as an example, this paper discusses the influencing factors of 500kV transformer inrush current when connected to the grid through PSCAD/EMTDC software, and puts forward feasible measures to suppress the inrush current.
Kalman Filter Based Sensor Fusion for Altitude Estimation of Aerial Vehicle
Authors: Bashir Muhammad Asad , Malik Fahad Mumtaz , Akbar Zeeshan Ali , Uzair Muhammad
Published: June 2020

Stabilization of Aerial Vehicles requires altitude estimation. In this paper sensor fusion method is developed for aerial vehicles which focuses on estimation of the altitude. Altitude measurement using sensors is too noisy and biased so Kalman filter based sensor fusion is used to estimate altitude. The proposed method is divided into two parts: attitude estimation and altitude estimation. The method is implemented using IMU and barometer sensors. The results show that altitude is estimated accurately and errors are modelled in few seconds after initialization.
3-D Localization of UAV and Detection based on Harmonics Index and Spectral Entropy Criteria
Authors: Iqbal Muhammad Amjad , Zhao Zhao , ZhiYong Xu , Rehman Saad Ur
Published: June 2020

The popularity of drones or unmanned aerial vehicles (UAVs) will be increased enormously in future smart cities due to their usage in several domains. Significantly it’s an emerging research to localize and timely detect such kinds of objects to avoid threats. This paper considered to deploy an array of 4-microphones for acoustics localization enhancement and UAV detection optimization. For high accuracy of acoustics localization in 3-D, the cumulative algorithm of GCC-PHAT and least square (LS) based on TDOA is implemented to estimate acoustic direction of arrivals (DOAs). However, detection optimization is achieved by a spectral framework, where harmonics index estimation effectively determined sound and noise range in each frame, while spectral entropy featured noise and sound correlation, the least possible value of entropy verified the presence of UAV and optimize its detection. Moreover, experimental results confirmed the efficiency of proposed techniques, our system has robust performance for localization as it featured less than 5% errors, while detection accuracy is more than 75%.
Gait Phase Classification Based on sEMG Signals Using Long Short-Term Memory for Lower Limb Exoskeleton Robot
Authors: Yuan Ye , Guo Ziming , Wang Can , Duan Shengcai , Zhang Lufeng , Wu Xinyu
Published: June 2020

In this work, we present a Long Short-Term Memory Model (LSTMM) for gait phase classification based on sEMG signals to control the lower limb exoskeleton robot which can recognize 2 phases (Stand and Swing) of leg phases between the foot and ground. This model only needs four sEMG signals to control the lower limb exoskeleton robot helping the hemiplegia patient walking. Compared with the existing methods, the proposed model not only avoids the complex sensor systems but also enhances the accuracy of gait phase classification. The experimental results first verify the availability of sEMG data acquisition system on the lower limb exoskeleton robot made by the Shenzhen Institutes of Advanced Technologies (SIAT) by quantify the system with gold standard optoelectronic system Vicon, then show that the proposed LSTMM is significantly higher on prediction accuracy and has better robustness for gait phase classification to control the lower limb exoskeleton robot with different speeds. Finally, the maximum accuracy of LSTMM on the gait phase classification is 97.89%.
Research on gait planning of Hexapod wheel legged robot based on STM32 single chip microcomputer
Authors: Zenan Chu , Wei Wang , Yu Caisheng
Published: June 2020

In this paper, the rectangular wheel legged hexapod robot is used as the experimental robot, the STM32 single-chip microcomputer is used as the main control core, the steering control board is used as the auxiliary board, the upper computer programming is used to write the action group of the hexapod robot, the command is sent to the single-chip microcomputer through the PS2 handle, the single-chip microcomputer controls the steering board to achieve the corresponding action group, and the Arduino control board is used to change the environment through the sensor in the later stage The control of action group can be realized by the detection. In addition, in order to solve the gait planning problem of hexapod robot and realize the optimal learning of robot’s free gait on specific terrain, based on the discretization of the robot’s single foot distance, integrating the time rhythm principle of CPG model and the space rule constraint mechanism of reflection model, a discrete gait model of Hexapod robot is constructed. Ant colony algorithm is used to study the gait path planning of the robot. MATLAB and C language technology are used to realize the simulation of the gait planning of the hexapod robot.
New Design of All-terrain Smart Car Based on Arduino
Authors: He ZhengYang , Zhang Ying , Zheng HongMing , Zhang Yi , Yu HongTao , Luo MingNan
Published: June 2020

Due to bad working environment, the flexibility and steering stability of all-terrain vehicles have become the main factors affecting the performance. Designing a new all-terrain electric vehicle is aimed at improving the stability of driving on low-attach roads and maneuverability at low speeds. Compared with traditional internal combustion engines, four-wheel-drive all-terrain vehicles have obvious advantages in vehicle motion control and optimal allocation of driving force, thus making it play an important role in all-terrain vehicle technology in the future. Within the scope of the requirements of the “Explorer” modular component equipment, by means of prototype design, assembly, commissioning, operation, the smart vehicles that can automatically and smoothly pass through the obstacles of ten different characteristics and different difficulty without any intervention are designed and completed.
A review of artificial intelligence techniques for selection & evaluation
Authors: Ahmad Ijaz , Liu Yan , Javeed Danish , Shamshad Nadia , Sarwr Danish , Ahmad Shahab
Published: June 2020

Today, supplier selection &evaluation has been an important issue of strategic planning for a long time. Various artificial intelligence (AI) methods have been applied in the methodology of supplier section & evaluation from different researchers. This paper provides a review of past various artificial intelligence methods (AI) from 2010 to 2018 in the area supplier selection & evaluation problems. The review report is based on the literature of fifty articles include six review papers. Our survey presents and tries to find out the most useful and prominent AI method recommendable for the future in the problem of supplier selection &evalution.
Fatigue detection based on multi-feature fusion of fatigue behavior
Authors: Xing Chen , Lumei Su , Meixin Qin
Published: June 2020

The research of fatigue driving detection is of great significance due to the contribution in fatigue driving prevention. However, most of current fatigue detection study are limited to unavailable real-time performance, unsatisfied accuracy rate, rough fatigue level and complicated implementation. In this paper, a novel method based on multi fatigue behavior features are proposed to improve the accuracy of fatigue detection. First of all, multi facial behavior features including eyes, mouth and head features are extracted. And then a new multi-feature fusion fatigue detection approach based on specific fatigue behavior feature anaylsis is proposed to recognize the previously extracted features. For better accuracy and applicability, a more detailed fatigue levels are newly used to subdivide fatigue behavior into three degree of fatigue. The experimental results based Matlab simulation and Android App indicate that the proposed method could accurately and real-time detect whether the tester is in a state of fatigue driving, and also determine the fatigue level.
Mechanical and tribological properties of AA7075-T6 metal matrix composite reinforced with ceramic particles and aloevera ash via Friction stir processing
Authors: Tyagi Lakshay , Butola Ravi , Jha Avinash Kumar
Published: June 2020

Mechanical and wear properties of AA7075-T6 reinforced with SiC and Aloevera ash, fabricated using Friction stir processing (FSP) are investigated in this study. Due to less density, easy availability, and cost-effectiveness, aloevera ash is considered as one of the reinforcements. FSP is done using a square tool pin profile, at different tool rotational speeds. To study wear behaviour, pin on disc test is carried out on High Temperature Rotary Tribometer at 20N, 30N and 40N applied load. Wear increases on increasing the applied load and at 20N load Al+SiC/Aloevera ash composite, processed at 600 tool rpm gave the best results due to the formation of oxide tribolayer. At 30N and 40N applied load Al+SiC composite, processed at 900 tool rpm showed the least wear because of proper scattering of ceramic particles due to high tool rotational speed. Coefficient of friction increases on increasing the applied load and all fabricated composite samples showed a lesser coefficient of friction than the base metal. Microhardness, ductility and Ultimate tensile strength increases on the addition of reinforcement and had a direct relation with tool rpm. Wear morphology was analysed using Scanning Electron Microscope (SEM). Energy Dispersive Spectroscopy (EDS) analysis after wear shows the presence of C, Fe, O, Mg, Zn, Si, Al elements and confirms the formation of an oxide layer which is responsible for decreasing wear loss.
Study on the influence of ion doping on the crystal structure and magnetic properties of YFeO3
Authors: Ji Lingxian , Jiang Guojian , Wu Dandan , Chen Jianbin
Published: June 2020

A series of pure phase YFeO3 sample powders doped with Eu3+ and Nd3+ were synthesized by sol-gel method. The influence of different ions doping on the crystal structure and magnetic properties of YFeO3 were investigated. The prepared sample powders were characterized by powder x-ray diffractometer, scanning electron microscope, energy dispersive spectrometer, Fourier transform infrared spectrometer, differential thermal analyzer and vibrating sample magnetometer. The results demonstrate that all sample powders are pure phase orthogonal perovskite structures, the crystal structure and the magnetization have changed. The lattice parameters and the saturation magnetization increases with the increase of ion radius or ion concentration in single doping system. In the case of double doping, the influence of the crystal structure and magnetic properties of YFeO3 is more complicated than that of single doping according to the change of ions concentration.
Effect of multiple deep cryo-treating and tempering on microstructure and property evolution of high carbon bearing steel
Authors: Zhou Guanghua , Deng Song , Wei Wenting , Liu Qinglong
Published: June 2020

Interest has been shown in cryogenic treatments over the last seven decades mainly due to the transformation of retained austenite and the precipitation of fine carbides. By changing the microstructure, cryogenic treatments can improve wear resistance and hardness to some extent. In this work, the effect of multiple deep cryo-treating and tempering (DCTT) on microstructural evolution in 52100 bearing steel has been investigated using x-ray diffraction (XRD) and scanning electron microscopy (SEM). The Rockwell hardness tests were also conducted to verify the microstructure evolution. Moreover, the dilatometry was used to estimate the dimensional stability. The results demonstrated that DCTT not only contributes to the precipitation of nano-size carbides, but also leads to a more homogeneous size distribution. It was also proved that the variation of carbides and hardness could be attributed to the synergy of decrease of retained austenite and movement of carbon atoms brought in DCTT. Furthermore, the sample subjected to DCTT exhibits the highest wear resistance property.
Understanding dynamic properties of materials using neutron spectroscopy and atomistic simulation
Authors: Armstrong Jeff , O’Malley Alexander J , Ryder Matthew R , Butler Keith T
Published: June 2020

Recent developments in first-principles lattice dynamics and classical force field based molecular dynamics are revolutionising the field of neutron spectroscopy. Herein we present a short review of these methods, their critical role in the supporting of cutting-edge experiments, and how they are improved by matching experimental data. We begin with a brief overview of how lattice dynamics calculations can be compared to inelastic neutron scattering (INS) and molecular dynamics simulations to both INS and quasi-elastic neutron scattering (QENS). We then provide a series of exemplar applications where lattice dynamics and molecular dynamics have been used in conjunction with neutron spectroscopy to bring significant understanding to topical areas of materials science namely: (i) lattice dynamics and INS for the study of hybrid organic-inorganic perovskites (ii) lattice dynamics and INS for the study of flexible porous solids and (iii) molecular dynamics and QENS for probing molecular behaviour in zeolite catalysis. In all three cases, the understanding gained through the synergy of experiment and computation would have been significantly reduced using either in isolation. Finally, we consider the current state of the art, describing outstanding challenges and suggesting future directions in this exciting and fertile area of physical science.
Simulation study of a fluorine spectrums induced by laser sublimation
Authors: Daoui H , Benmebrouk L , Tlili S , Kaddour A , Mohammedi L , Achouri A
Published: June 2020

This paper aims to numerical study of the experimental spectrum, in the context of the diagnosis of solid materials by spectroscopy; the resulting spectrum of fluorine plasma has beenanalyzed. The plasma is generated after the sublimation of the solid sample the fluorine by Laser Induced Breakdown Spectroscopy (LIBS technique). The theoretical spectra and the electronic temperature of a obtained plasma have been calculated, this temperature (1.92 eV) is well matched to the laboratory plasma criteria. The main results also are showed that the resulting medium consisted of 96.63% Calcium and 3.36% Fluor.