bluuebunny/crossref_metadata_2025 huggingface dataset:
Theroy of magnetic inertial dynamics in two-sublattice ferromagnets
Authors: Mondal Ritwik
Published: April 2021

The magnetic inertial dynamics have previously been investigated for one sublattice ferromagnets. Here, we develop the magnetization dynamics in two-sublattice ferromagnets including the intra- and inter-sublattice inertial dynamics. First, we derive the magnetic susceptibility of such a ferromagnet. Next, by finding the poles of the susceptibility, we calculate the precession and nutation resonance frequencies. Our results suggest that while the resonance frequencies show decreasing behavior with the increasing intra-sublattice relaxation time, the effect of inter-sublattice inertial dynamics has an opposite effect.
A cost-effective planning method for automatic measurement based on task similarity and octopus optimization
Authors: Li Shuanggao , Zeng Qi , Chen Fang , Huang Xiang
Published: April 2021

Measurement planning is vital for automatic and digitalized aircraft assembly, and in particular, for the key execution sequences. In this article, a novel planning method that considers both order and efficiency is proposed. General rules are defined for the analysis of measurement tasks and their elements. A Laplace kernel function is then utilized for similarity quantification, and based on iterative two-step elementary transformations of the similarity matrix, the clustering of measurement tasks is achieved. A virtual task is proposed to bridge task clusters, and the preliminary sequences are obtained naturally. Given that the adjacent association results may not be the most efficient, octopus optimization is proposed to solve this special case of the traveling salesman problem. The measurement tasks and clusters are shops and cities, respectively. The octopus has multiple tentacles that traverse all shops, and each tentacle carries one feasible execution order. Experiments performed using aircraft inspection indicate that the proposed method can output multiple orderly measurement sequences. Compared with the preliminary sequences, the efficiency is obviously improved in terms of a decrease in the total measurement time. In addition, the optimal sequences are more even, and the duty ratio of the measurement device is decreased.
Towards a precision calculation of the effective number of neutrinos Neff in the Standard Model. Part II. Neutrino decoupling in the presence of flavour oscillations and finite-temperature QED
Authors: Bennett Jack J. , Buldgen Gilles , de Salas Pablo F. , Drewes Marco , Gariazzo Stefano , Pastor Sergio , Wong Yvonne Y.Y.
Published: April 2021

We present in this work a new calculation of the standard-model benchmark value for the effective number of neutrinos, Neff
SM, that quantifies the cosmological neutrino-to-photon energy densities.
The calculation takes into account neutrino flavour oscillations, finite-temperature effects in the quantum electrodynamics plasma to O(e3), where e is the elementary electric charge, and a full evaluation of the neutrino-neutrino collision integral.
We provide furthermore a detailed assessment of the uncertainties in the benchmark Neff
SM value, through testing the value's dependence on (i) optional approximate modelling of the weak collision integrals, (ii) measurement errors in the physical parameters of the weak sector, and (iii) numerical convergence, particularly in relation to momentum discretisation.
Our new, recommended standard-model benchmark is Neff
SM 3.0440 ±0.0002, where the nominal uncertainty is attributed predominantly to errors incurred in the numerical solution procedure (|δ Neff| ∼10-4), augmented by measurement errors in the solar mixing angle sin2θ
12 (|δ Neff| ∼10-4).
Scalar-tensor mixing from icosahedral inflation
Authors: Nicolis Alberto , Sun Guanhao
Published: April 2021

We study the mixed scalar-tensor two-point function in icosahedral inflation. Within the regime of validity of the effective field theory, this has to be perturbatively small; in particular, much smaller than the scalar spectrum. However, it can be much bigger that the tensor spectrum itself. We discuss observational implications for the CMB temperature-polarization spectrum.
Preparation of graphene on SiC by laser-accelerated pulsed ion beams*
Authors: Zhou Danqing , Li Dongyu , Chen Yuhan , Wu Minjian , Yang Tong , Cheng Hao , Li Yuze , Chen Yi , Li Yue , Geng Yixing , Zhao Yanying , Lin Chen , Yan Xueqing , Zhao Ziqiang
Published: April 2021

Laser-accelerated ion beams (LIBs) have been increasingly applied in the field of material irradiation in recent years due to the unique properties of ultra-short beam duration, extremely high beam current, etc. Here we explore an application of using laser-accelerated ion beams to prepare graphene. The pulsed LIBs produced a great instantaneous beam current and thermal effect on the SiC samples with a shooting frequency of 1 Hz. In the experiment, we controlled the deposition dose by adjusting the number of shootings and the irradiating current by adjusting the distance between the sample and the ion source. During annealing at 1100 °C, we found that the 190 shots ion beams allowed more carbon atoms to self-assemble into graphene than the 10 shots case. By comparing with the controlled experiment based on ion beams from a traditional ion accelerator, we found that the laser-accelerated ion beams could cause greater damage in a very short time. Significant thermal effect was induced when the irradiation distance was reduced to less than 1 cm, which could make partial SiC self-annealing to prepare graphene dots directly. The special effects of LIBs indicate their vital role to change the structure of the irradiation sample.
Validation of quasi-linear turbulent transport models against plasmas with dominant electron heating for the prediction of ITER PFPO-1 plasmas
Authors: Kiefer C.K. , Angioni C. , Tardini G. , Bonanomi N. , Geiger B. , Mantica P. , Pütterich T. , Fable E. , Schneider P.A.
Published: April 2021

Kinetic profile predictions of ITER PFPO-1 plasmas require high accuracy in the central electron temperatures to be applied to the calculation of third harmonic electron cyclotron absorption. Correctly predicting the transition from L-mode to H-mode further requires precise estimates of the ion heat flux in the periphery of the plasma. Recent versions of the quasi-linear transport models TGLF and QuaLiKiz were tested against an extensive set of experimental results from ASDEX Upgrade (AUG) and JET-ILW, where the focus was put on AUG plasmas heated by ECRH. Spectra obtained from TGLF are compared to a set of linear gyrokinetic simulations performed with GKW. Electron and ion temperature profiles obtained with TGLF-SAT1geo show good agreement with the experimental profiles, but there is a slight tendency to underpredict central T
e and T
i at high ratios T
e/T
i. QuaLiKiz yields reasonable results for T
e and T
i profiles in plasmas where the ion temperature gradient mode is dominant, but predicts a significantly too weak transport in the presence of dominant trapped electron modes in conditions of strong central electron heating.
Research on Classroom Lighting Energy Saving System Based on YOLOv3
Authors: Yuan Bingjie , Li Juan , Liu Ziyi , Zhao Delong
Published: April 2021

After class, there are frequent cases of people walking but still lighting. In order to reduce the occurrence of this phenomenon, this paper proposes a classroom lighting energysaving system based on YOLOv3. The system uses the installed monitoring equipment in the existing public area as the information collector, controls the lamps through the wireless control switch, and uses the Internet as a bridge to intelligently control the lamps. The system can judge the area where the lights need to be turned off and automatically turn off the equipment in the case of people leaving the lights. While ensuring lighting, the system not only prolongs the service life of lamps, but also reduces the cost of school funds. When the system is popularized to the country, it will save a lot of electric energy, and the future development force cannot be underestimated. It is of great significance to carry out energy conservation and emission reduction in China.
The harmonic characteristics analysis of offshore wind farms transmitted by the submarine cable based on time domain simulation
Authors: Li Jingyi , Yang Jianjun , Shi Zhaohui , Wang Ke , Li Haozhi , Xie Xiaorong , Li Fangfeng
Published: April 2021

The harmonic amplitude may exceed the limit when the large scale of wind farm is connected to the weak AC system through AC submarine cable. The harmonic with high amplitude will endanger the safety of power equipment, and even affect the normal integration of large-scale wind farm. This paper takes an actual offshore wind power connected to the system through AC submarine cable as an example. On the basis of building the model of the system in the PSCAD/EMTDC simulation software. The simulation calculation is systematically carried out. The effect of multiple factors on the harmonic characteristics is analyzed. The preliminary explanation for the harmonic amplitude out of limit is given for the actual large scale of wind farm connected to the weak AC system through AC submarine cable.
A Novel Wind DC Microgrid Energy Management Strategy Based on LSTM forecast Model
Authors: Hui Liu , Fang Lin , Dihuang Chen
Published: April 2021

In order to improve the accuracy of wind power DC microgrid scheduling, especially in the case of LSTM prediction errors, this paper proposes a WOA optimized DC microgrid energy scheduling control strategy based on LSTM prediction algorithm. MATLAB software is used to simulate the scheduling process. Compared with the traditional LSTM-PID method, the WOA scheduling control strategy reduces the average absolute deviation of the SOC from 0.7043 to 0.1755, a reduction of 75.08%. While the median absolute deviation decreases from 0.5812 to 0.1316, a reduction of 77.36%.
Coordinative Optimal Operation Mode of Regional Energy Internet
Authors: Li Congcong , Wang Qing , Zhu Hongxia , Wang Xinping , Yu Chao , Wang Zhixue , Guo Wei
Published: April 2021

Distributed energy has the limitation of “point-to-point” supply. The regional Energy Internet is a multi-dimensional energy network system with energy producers and consumers as nodes, electricity, gas, cold and hot energy networks as links, connecting the production, transmission, distribution, storage and use of energy. The regional Energy Internet realizes the full utilization of distributed energy through the operation mode of multi-source complementary, “energy network load storage” coordination, and optimized control technology.
Optimization and Control Strategy Technology for User Comprehensive Energy Consumption
Authors: Li Congcong , Wang Qing , Zhu Hongxia , Wang Xinping , Yu Chao
Published: April 2021

This paper studies the application of the exclusive energy controller for comprehensive energy consumption. Users’ various energy consumption data such as water, gas, electricity, heat, cold are collected by controller. Various energy consumption information collection and sharing of park, community, building and other types of users can be realized by using data optimization and data fusion technology. The coupling optimization model is designed and the optimization strategy is studied, so as to realize the comprehensive state perception of energy consumption equipment and intelligent optimization control of comprehensive energy consumption.
Research on efficiency optimization control strategy of WPT system based on optimal load matching
Authors: Xueying Qiu , Kangheng Qiao , Lei Wang , Yan Liang , Hailang Xie
Published: April 2021

Aiming at the problem that the transmission efficiency of SS-compensated MCR-WPT (Magnetic resonance wireless power transmission) is affected by load changes, this paper uses mutual inductance theory to analyze the equivalent circuit model, obtains the relationship between load and transmission efficiency, and proposes a controllable rectifier bridge for load matching, the front-end cascaded buck converter makes the output voltage regulation control scheme. Finally, modeling and simulation are used to verify the correctness of the load matching theory and control strategy.
A Focused Microwave Power Transmission Scheme Based on Phase Adjustable Microwave Source
Authors: Peng Wenxin , Li Songnong , Zhang Huaiqing , Chen Jianyu , Xiao Hui
Published: April 2021

In this paper, an electric filed focus scheme based on phase adjustable microwave source is used to improve the power transmission efficiency. A microwave power transmission system is consisted of the microwave source, a transmitting antenna and a receiving antenna. Measurement results proved that when compared with the same phases condition, the output DC power of the receiving antenna is increased from 23.5W to 31.5W and the relative increment of power is 34% under the focal phase condition. In addition, the system-level MW-DC power transmission efficiency is increased by 2.7%.
Application of laser displacement measurement system in thermal test of aircraft
Authors: Wanqing An , Guanghui Li , Xiaoning Liu , Tao Wang , Yi Li , Qingyu Wang
Published: April 2021

At present, there is no research on nanosecond displacement measurement technology for spacecraft thermal test in China. Firstly, the principle of laser displacement sensor measurement is introduced. A system of hardware and software design and implementation was designed. Finally, a set of test system is built to verify the application of laser displacement meter in the spacecraft vacuum thermal test displacement measurement system. The experimental results and data analysis show that the laser displacement meter can meet the nanosecond displacement measurement requirements of spacecraft in vacuum and low temperature environment.
The Optimal EV Charging Strategy in Smart Grid and Insight into Practical Solutions
Authors: Wang Jianmin , Wu Jiang
Published: April 2021

In recent years, the massive increase in electric vehicles (EV) and renewable energy (RER) has caused serious problems in the power system network. During peak hours of electricity consumption, the soaring demand for electricity from variable renewable energy sources severely undermines the stability and efficiency of the power supply. This article first reviews the infrastructure and charging strategies of electric vehicle batteries. After modeling and analyzing the charging activities, the results show that the charging behavior can transform the charging demand from the peak time period to the off-peak time period, and the online MSS optimization of electric vehicle charging is extracted through the Jacobian matrix. Finally, it provides a practical overview of the existing and future solutions to manage the large-scale integration of EVs into the network.
Blind Quality Index for Tone-mapped HDR Images and Multi-Exposure Fused Images
Authors: Fang Jingli , Jiang Mingxing
Published: April 2021

Tone mapping operators (TMOs) and multi-exposure fusion algorithms (MEFs) are employed to visualize the informative contents of high dynamic range (HDR) images on the standard dynamic range (SDR) devices, but also lead to visual quality degradation. Thus, it is urgent to evaluate the perceptual quality of tone-mapped images (TMIs) and multi-exposure fusion images (MEFIs). This paper proposes a blind quality index for TMIs/MEFIs by capturing exposure, colorfulness and structure characteristic features. The connection between feature space and associated subjective ratings is established via a regression model. The proposed method is tested on the public database and compared to the state-of-the-art blind image quality assessment (IQA) methods. The experimental results show that the proposed method achieves superior performance.
An unsupervised learning method for named entity relation extraction of space knowledge graph
Authors: Wei Zhanji , Huang Lingyong , Wan Gang , Mu Yao , Yin Yunxia
Published: April 2021

Knowledge graph is a kind of typical artificial intelligence technology, which can improve cognitive ability of machines. Space is a booming domain for human beings. In this paper, space knowledge graph is proposed in order to improve intelligence of space information system. A major obstacle of space knowledge graph construction is to identify and extract core named entities and relations in space domain. An unsupervised learning method to extract core named entities and relations is proposed in this paper. Firstly, confidence level index used to measure importance of entities and conditional confidence level index used to measure credibility of relations between entities are defined and investigated. Then, an entity and relation extraction procedure based on maximum likelihood estimation and apriori algorithm is designed. Finally, a case study is carried out and influence of super parameter setting on the extraction result is discussed. The method proposed in this paper can be used to construct space knowledge graph at a lower cost compared to supervised method, and can be extended to other domain knowledge graph construction.
Kent-PSO optimized ELM fault diagnosis model in analog circuits
Authors: Liu Zongpeng , Lin Zhiwei , Wang Chengji
Published: April 2021

Fault information in analog circuits is complex and diverse, so as to improve the accuracy of fault diagnosis, a Kent mapping and Particle Swarm Optimization (PSO) combined optimization Extreme Learning Machine (ELM) model is proposed. Firstly, the original data set of the circuit is normalized to obtain the fault data set. Secondly, Kent mapping is used to initialize the position of particles in the particle swarm, which makes the initial particle swarm more evenly distributed in the search space and enhances the global optimization ability. Third, aiming at the problem of the input weight and hidden layer bias generated randomly by the ELM are easy to lead to poor generalization ability, the Kent-PSO algorithm is used to optimize the input weight and hidden layer bias of ELM to obtain better and more stable ELM network parameters and improve the fault diagnosis ability. The diagnosis example of Sallen-Key bandpass filter shows that the proposed method has better fault diagnosis performance than PSO-ELM model.
Study of a method to reduce the harmonics of the output voltage of medium frequency power supply
Authors: Zhang Yinfeng , Shao Ying , Liu Xinzhi , Sun Pan , Lei Kang
Published: April 2021

Since the electrical equipment with nonlinear load began to be used, the harmonic suppression technology has become the focus of research. In this paper, a robust multi resonance servo control method is proposed and applied to the medium frequency power supply. The method can not only perform the closed-loop system stability and asymptotic tracking, but also make the power supply output possess the advantage of rapid dynamic response, and low-order strong harmonic suppression. First, this paper presents a mathematical model, analyzes the time-domain robust control - linear matrix inequality and regional D stability and turns the analysis of the problem of robust control problem to a one of linear matrix inequality (LMI) convex optimization problem through the augmentation of system matrix dimension. Then, the YALMIP toolbox is used to solve for the status feedback gain matrix. Finally the whole system is simulated and tested. The results show that the designed controller makes the dynamic recovery time of the closed-loop system less than 5ms, and the output voltage THD is reduced to less than 4.5% with the nonlinear load.
Method of Enhancing the Accuracy of Indoor Positioning (RSSI to UL-AOA)
Authors: Xu Ganqi
Published: April 2021

Nowadays, with the rapid development of urbanization worldwide, the indoor area has become complex. Even with floor maps and guidance signs, people waste time on self-location in an unfamiliar building for the reason that the mature location services like GPS are limited as outdoor positioning series, and the method of indoor positioning is relatively missing or rough. Therefore, the better indoor positioning systems are in a highly command. The indoor positioning system has the goals for realizing the location marked and tracking of people and objects in indoor scenes. This paper focused on the main positioning method in use, which is distance-based positioning algorithm. Then, the advantages and disadvantages of the mainstream algorithms RSSI and AOA were discussed. At last, by comparing the current research, the author put forward an optimized indoor positioning algorithm based on AOA, which may become the mainstream in the future.
Research on fault line selection method for distribution network in small current grounding system
Authors: Liu Guanhua , Bai Jieyu , Li Lusheng
Published: April 2021

When a single-phase-to-ground fault occurs in the distribution network, there is a wealth of information in the transient process of the fault line, from which the fault line selection criterion can be extracted. In this paper, based on the analysis of the related principle of wavelet transform and the concept of entropy, the comprehensive wavelet entropy is defined, and the principle and process of fault line selection are put forward by analyzing the variation coefficients of a group of comprehensive wavelet entropy. Finally, the simulation software is used to verify the fault line selection method under different fault conditions to prove its applicability and feasibility.
SA RCNN for Occluded Damper Detection in the Inspection of Power Transmission Line
Authors: Zhou Feng , Wang Guoyou , Zheng Yi
Published: April 2021

Dampers can prevent wires from breaking due to vibration, so it plays an important role in ensuring the stable operation of transmission lines. But the accuracy of popular object detection algorithm is still very low, because the occlusion phenomenon of dampers is serious due to the variable shooting angle. In this paper, we introduce our Supervised Attention RCNN (SA RCNN) to improve the detection effect of occluded dampers. SA RCNN mainly consists of two components: Box Supervised Attention Module (BSAM) and One Proposal Multiple Predictions (OPMP). In order to solve the problem of false detection caused by similarity of features, BSAM enhances features by using ground truths as supervised information to guide the generation of attention. In order to solve the problem of missed detection due to the NMS strategy, OPMP predicts a set of instances for one proposal rather than a single one. Experiments show that SA RCNN obtains 4.2% AP improvements on the dataset of occluded dampers compared to FPN.
Research on the Construction Method of 3D Dense Map Based on Visual Slam
Authors: Sun Tianfang , Shi Xiangbin
Published: April 2021

Aiming at the problem that visual SLAM (Simultaneous Localization and Mapping) cannot satisfy both high-precision positioning and rapid mapping in large scenes, this paper proposes a map construction method. First, when calculating the pose, the method of combining EPNP and graph optimization is used to optimize the pose estimation to improve the accuracy of the pose. Then, the paper uses Lie algebra to define the vertices and edges of the pose graph, which improves the convergence speed of the model. Finally, when constructing a three-dimensional map, a divide-and-conquer map method is proposed, which uses multiple sub-maps that contain each other for point cloud registration and down-sampling filtering, so as to improve the accuracy of map construction. Experimental results show that the algorithm in this paper has good performance. In the TUM test set, the speed can reach 0. 139s/frame, which is about 0.2s higher than the original method, and the accuracy error RMSE value is reduced to 0.055m. The feasibility of the algorithm is proved, and it can meet the accuracy and speed requirements of 3D dense map construction in large scenes.
Multi label image retrieval based on depth hash
Authors: Qin Zihui
Published: April 2021

In recent years, hash is a popular method of image retrieval. Convolutional neural network is used to generate image features and hash codes, so as to achieve fast and effective image retrieval. In order to solve the problem of poor image retrieval effect caused by complex background of Multi-target Image, this paper proposes a hash generation method based on the combination of target region recommendation network and convolutional neural network. The RPN network is selected as the target region recommendation algorithm. After the image passes through the RPN network, multiple target regions and the four-dimensional coordinates of each region will be generated. According to the four-dimensional coordinates, the main target region will be filtered and extracted. Then, the feature of the largest target area is extracted by the convolutional neural network (GoogleNet), and the corresponding hash code is generated, which is finally retrieved in the database. Experiments are carried out on voc2012 data set and self collected data set to verify the algorithm. When the number of test images is 1000, the experimental results show that the total correct rate of the retrieval results of this method is 95.5%, which is about 5 percentage points higher than the existing methods.
Multi-Granularity Matching Network for Multi-Paragraph Machine Reading Comprehension
Authors: Chen Xu
Published: April 2021

Multi-paragraph aims to allow machines to read multiple paragraphs and infer the answer to the given question. Usually, the model needs to use the selector to narrow the range of candidate paragraphs, and then use the reader to find the answer. For the selector, the previous work generally matches the question and the paragraph on the word level and the paragraph level. In this paper, we study the encoding and matching algorithm at the chunk level, which is supposed to make our model more accurate. Combining it with gated self matching mechanism, we design a multi-granularity matching network as the selector. The experimental results show that our model achieves competitive performance on Quasar-T.
A Skewness Fitting Model for Noise Level Estimation and the Applications in Image Denoising
Authors: Zhou Bin , Zhong Biying , Feng Jun
Published: April 2021

In this paper, a novel noise level estimation technique is presented based on skewness fitting. The difference between exact skewness and observed value on each channel contributes to an objective function. The skewness concentration is helpful to guarantee the reasonability of the model. The optimal solution means an estimation of the noise variance and it is easy to be applied in some parametric denoising model. The accuracy and efficiency of proposed algorithm were verified by the numerical experiments.
Research on mail classification algorithm based on improved convolutional neural network
Authors: dan Song , Kui Lu , Xufan Dai
Published: April 2021

Aiming at the problems of high dimension and sparse data in traditional text classification methods, this paper proposes an e-mail classification method based on i-cnn model by combining convolutional neural network (CNN) and inception V1 model. In the convolution and pooling operation, 1 * 1 convolution kernel is added to reduce the thickness of eigenvectors, reduce the parameters and improve the computational performance. Through data validation, i-cnn model for e-mail classification results as high as 92.18%, in the comparative experiment, i-cnn model compared with several machine learning classification models, achieved the highest classification accuracy, in the comparison with or without the emergence structure model, i-cnn model accuracy is higher than CNN model. It shows that the model has a good classification effect, and the integration of inception V1 model can improve the accuracy of text classification.
An Improved Algorithm of D-S Evidence Fusion
Authors: Lei Hongxuan , Sheng Li
Published: April 2021

In the theory of evidence fusion, it is a very important task to deal with the conflicts between evidences correctly. Based on the credibility degree of evidence proposed in [10], in order to increase the credibility degree of each group of evidence, the concept of falsity is introduced, which is another concept to represent the conflict between two groups of evidence, this treatment makes up for the deficiency of normalized evidence weight coefficient when one group of evidence credibility degree is zero. Because we consider not only the credibility degree of evidence, but also the falsity of evidence, the weight coefficient of unreliable information is effectively reduced. The numerical simulation results show that the algorithm has the advantages of simple idea, fast convergence speed and strong focusing.
Sparse representation algorithm for fusion error
Authors: Li Zijun
Published: April 2021

In recent years, face recognition technology has been widely used in security, finance, media data retrieval and other fields due to its convenience, concealment, and stability, and has become a popular research field in various scientific research institutions. Among them, face recognition under complex conditions under different lighting, different expressions, and partial occlusion has become a research hotspot. Sparse representation algorithm, as the mainstream algorithm to solve the problem of face recognition under complex conditions, although it improves the recognition accuracy compared with other algorithms, there is still room for improvement. Aiming at the partial occlusion problem in face recognition, this paper conducted many experiments under different training samples through the sparse representation algorithm of fusion error. The experimental results show that the algorithm improves the recognition rate and provides a new solution for the problem of face recognition under partial occlusion.
Lightweight design of SM4 algorithm and realization of threshold scheme
Authors: Chen B W , Xia X , Liang Q M , Zhong W D
Published: April 2021

Aiming at the lightweight design of SM4 cryptographic algorithm, a lightweight cryptographic algorithm scheme is proposed and implemented in hardware. Based on the work of Li et al., a 4-bit S-box is selected. The original 8-bit look-up table S-box in the SM4 algorithm is replaced with a 4-bit cyclic shift S-box, and the same circuit structure is used to save resources in hardware implementation. A threshold scheme based on the principle of secret sharing is proposed to improve the overall security of the scheme against side-channel attacks. The input information is divided into three groups, and all operations are converted from GF(24) to GF(22) through a multiplier and a squarer, which further reduces the circuit consumption and improves the security of the algorithm. In the realization of the threshold scheme, virtual values are intro-duced to ensure that the scheme meets the uniformity, and the decomposition method is used in the inverter to re-duce the number of operations and the proportion of space. After theoretical deduction, the threshold scheme as a whole has the ability to resist first-order and second-order DPA attacks. The overall hardware implementation of the program uses a total of 2803 logic elements, which proves that it achieves the goal of lightweight while ensuring safety.
Design and Application of Home Fire Alarm System
Authors: Xie WenLan , Haoming Huang
Published: April 2021

With the application and development of Internet of things technology, the demand for home intelligent devices is higher and higher. Home fire safety is particularly important. In view of the current home fire safety problems, this paper proposes a home fire alarm system based on the combination of microcontroller and sensor. The system takes microcontroller and sensor as the main components, and uses the combination of combustible gas detection module, temperature detection module and flame detection module to form a fire alarm system. The functions of gas leakage early warning exhaust, fire sound and light alarm exhaust and high temperature detection alarm are realized. Combustible gas detection, temperature detection and flame detection all collect data through sensors, and then compare with the preset alarm value to judge whether the fire occurs. The design has the advantages of accurate detection, high degree of intelligence, convenient installation, strong scalability and so on. It gives a new solution to the fire safety of the home.
Coordination of Preventive Dispatch and Black-Startunder Extreme Operational Conditionsusing Robust Optimization
Authors: Kai Saijiang , Zhang Feng , Huang Ping
Published: April 2021

Extreme operational conditions, e.g., wind storms and ice storms, have been posing great challenges for power grid operation. The extreme conditions are likely to cause widespread blackout, therefore a black-startprocedure is needed to restore the non-blackstart generating untis and transmission assets. To falicilate the balck-start procedure, the coordination between post-event preventive dispatch and post-event black-start dispatch is established, considering the uncertainty of forced transmission line outage scenarios. A two-stage robust optimization model is built to coordinate the preventive dispatch and black-start procedure. An iterative decompostion algorithm is applied to solve the proposed model. A synthesized Chinese 372-bus system is used to illustrate the proposed method. It is shown that, in the worst-case blackout scenario, the coordinated black-start procedure can accelerate the entire process by 15% and reduce the black-start capacity requirements.
A Dialogue State Tracking Model with Slot Embedding
Authors: Qiu Boyu , Sun Yingfei
Published: April 2021

Dialogue State Tracking (DST) is the core component of the task-oriented dialogue systems. Although recent neural DST models have made great progress, they often ignore the phenomenon that the current dialogue state is closely related to the earlier dialogue states. In this paper, we try to introduce the slot embedding into the transformer to focus on those special tokens, which ever appear in earlier dialogue states. On the basis, we leverage the copy mechanism to predict the state over the dialogue utterances. Our model also imitates the architecture of reading comprehension model to make full use of the current utterances. The experimental results verify the benefits of the slot embedding, and our model achieves significant improvements than baselines on MultiWOZ 2.0 and MultiWOZ 2.1 datasets.
Inactivation of lead and zinc in sediment using lanthanum modified zeolite
Authors: Wang Zhe , Li Wen , Ji Pengfei , Liu Yuling , Miao Xiaobiao , Li Jiake
Published: April 2021

Access accumulation of zinc and lead in sediment would be harmful to human beings. In the present study, Lanthanum Modified Zeolite (LMZ) was developed with fly ash and its binding capabilities toward zinc and lead were investigated. The Langmuir adsorption maximum of LMZ for Zn2+ and Pb2+ were 22.78 and 105.26 mg/g, higher or at least comparable to adsorbents developed in recent studies. Dosing LMZ to polluted sediment could transfer zinc and lead from environmental available forms to refractory form, and higher dosage would enhance the immobilization performance.
Application of Co Ni intercalated vermiculite catalyst in pyrolysis of plastics
Authors: Chen Zicai , Wang Yiqian , Sun Zhipeng
Published: April 2021

Currently, the amount of municipal solid wastes that are hardly degradable in nature keep increasing, of which the waste plastics account for a large proportion. There is no doubt that it will generate severer environmental issues. Therefore, we are expected to develop an efficient way to recycle the useful components in the mixed plastics to reduce the waste of energy and protect the environment. Thermal cracking, as a key technology for plastic recycling, can convert plastics into high value-added fuel products and broaden the sources of raw materials for ethylene, propylene and high value fuel production. For general catalysts, its catalytic activity is affected not only by the specific surface area and pore volume, but also by the acidity. In this paper, we try to construct an adjustable acidity catalyst by adopting vermiculite as the support, and sodium chloride, cetyltrimethylammonium bromide as modifier. That can provide exposed environment for the active sites in the bulk phase. At the same time, cobalt and nickel were used as intercalation to load on vermiculite. Ultimately, we obtained BET, XRD characterization data to determine the structure and properties of the catalyst, and analyzed the cracking products by GC quantitatively and qualitatively to build a reasonable structure-activity relationship.
Analysis for the welding crack leakage of deethanizer
Authors: Jiang Chengjun , Wang Xin , Xue xiaolong , Du Yannan , Wang Wei
Published: April 2021

A deethanizer made of 16MnDR steel was found medium leakage used by a company shortly after weld repair. The cause of the welding crack leakage was analyzed by means of morphology examination, chemical composition analysis and hardness test, residual stress test, metallographic examination, and microscopic metallographic analysis. The results show that the crack produced by the 16MnDR pressure vessel after weld repair is a typical liquefaction crack of weld metal. Improper control of repair operation process results in abnormal microstructure, excessive hardness and excessive residual stress at repair welding position, which leads to the formation of longitudinal microcrack, and further expansion in use to form penetrative crack leakage.
Free vibration of conical shells under arbitrary elastic boundary and simulation verification
Authors: Li Xinghong , Wang Ting , Zhao Yang , Wang Hui
Published: April 2021

This paper presents an analysis of free vibration characteristics of truncated conical shells under complex boundary conditions. Firstly, the geometric equation of conical shells are obtained by using Reissner shell theory. Then, by using Rayleigh- Ritz method with improved Fourier series, the motion equations of modal parameters (modal stiffness, modal mass, natural frequency and model shapes) with elastic boundary are obtained. The mode shapes and natural frequencies of conical shells can be obtained by solving the motion equations. Moreover, by comparing the results for simulation numerical method and finite element method(FEM) respectively, the validity of present methodology has been verified.
Simulation and Parameter Optimization of Pilot Internal Flow Overflow Valve
Authors: Li Guanghui , Wang Lipeng , Qiao Jing , Wei Guanju , Han Xinmiao , Hou Dingqi , Guo Jungang
Published: April 2021

Aiming at the pilot internal overflow valve, the working principle is introduced, and the simulation model is established by AMESim. The pre-compression force of pilot spring is calculated by NLPQL. The influence on the dynamic characteristics of the pilot spring stiffness, damping hole diameter, the diameter of main valve core is analyzed by batch processing. Then the Genetic Algorithm(GA) is used to obtain optimal valve of structural parameters, which can provide a theoretical basis for dynamic characteristics.
Flow Stress Behavior and Microstructural Evolution of DC Cast 7065 Aluminum Alloy During Hot Compression Deformation
Authors: He Kezhun , Tan Zimeng , Zheng Xu , Zhang Xinming , Chen Biao , Zhou Kechao
Published: April 2021

The deformation behavior and microstructure evolution of DC cast 7065 aluminum alloy was investigated in the temperature range of 340-460 ℃ and strain rate range of 0.1-8 s-1. The flow stresses of the 7065 alloy are forceful function of deformation strain rate and temperature. The peak stress raises with reducing compression temperature, and at a designated deformation temperature, the peak stress increases with the increasing of strain rate. The hot deformation equation of the alloy is generated, and the deformation activation energy of the alloy is 117.869 kJ/mol. When the samples were deformed above 380℃, the α-aluminum dendrite in the initial microstructure was replaced by recrystallized grains, dynamic recrystallisation occurred during compression.
Effects of Sloped Trench Casing Treatment Combined with Air Injection on Aerodynamic Performance of a 1.5 Stage Axial Flow Compressor
Authors: Kai-kai Zou , Yong-bao Liu , You-hong Yu , Xing He
Published: April 2021

A new mode, sloped trench casing treatment combined with air injection, was designed and introduced in a 1.5 stage axial compressor. To reveal the effects of this mode on the aerodynamic performance, a three-dimensional numerical simulation was carried out. Three air injection configurations were set to reflect the influence of injected flow velocity and injected mass flow rate. Results show that sloped trench casing treatment combined with air injection could improve the stall margin, total pressure ratio, and adiabatic efficiency of the compressor simultaneously. Moreover, injected flow velocity has a more significant influence on the effectiveness of extending stability than the injected mass flow rate. The optimal configuration obtains the stall margin improvement of 8.37% by using only 0.69% of the whole annulus mass flow rate. Based on a detailed analysis of the rotor flow field, it is found that the high-speed jet causes axial momentum of the incoming flow upstream the rotor blade tip to increase and load of the forepart chord of the rotor blade tip to reduce. The blockage in the tip region of the rotor passage is thus suppressed effectively, which results in the stall margin of the compressor enhanced.
Computational Fluid Dynamics(CFD) of Drag Force for Bullet’s Shape Design
Authors: Gan Chenjie
Published: April 2021

The factors in bullet’s shape design which affect the drag force of bullets are important in aerodynamics, especially in ballistics. In this paper, based on traditional researches about different bullet shape designs, nose cone design of the bullet is mainly discussed, as well as the hollow tip and the rifling on the appearance of the bullet are also included. This paper adopts Fusion 360 and Ansys fluent to calculate and model. This research verifies the similarity of the drag coefficient of different bullet shape design at a low speed and figures out the best shape characteristic coefficient in Haack series design, while some problems still exists in the influence of hollow tips of the bullet to the drag force.
An Empirical Study on Process Management System using YOLO-Based Parts Recognition
Authors: Park Jongcheol , Jang Wonho , Yoo Namhyun
Published: April 2021

The process of assembling the engines used in medium and large ships appears to be a continuous production process, but it is not the process through which numerous workers perform work with automated equipment or simple assembly work, but rather a process through which skilled workers, who can effectively perform various tasks, perform multiple aspects of the assembly process. Due to this characteristic, it was difficult to assess the work process rate during the engine assembly process through real-time analysis of the process because it was difficult to shorten the lead time or improve the process, and most of stages of the process depend on manual reports or operators’ work data input. Therefore, in this study, we developed and applied a system capable of recognizing the current process rate by identifying specific engine parts using YOLO.
Numerical investigations of the minimum-B effect in Electron Cyclotron Resonance Ion Source
Authors: Mironov V. , Bogomolov S. , Bondarchenko A. , Efremov A. , Loginov V. , Pugachev D.
Published: April 2021

The three-dimensional particle-in-cell model NAM-ECRIS is used for investigation of how the DECRIS-PM Electron Cyclotron Resonance Ion Source is reacting to changes in the source magnetic configuration. The accent is made on changes in the magnetic field at the magnetic trap center, the minimum-B value. It is calculated that the optimal normalized value of the field is ∼0.8, close to the experimental observations. The reasons for existence of the optimum are discussed. It is observed that the electron energies are increasing with the increased minimum-B values due to enhanced confinement of the energetic electrons in the plasma. Bumps in energy spectra of the radially lost electrons are observed and explained to be due to nonadiabatic losses of electrons.
Study on secondary deepening design of exterior wall panel of Substation Prefabricated Building
Authors: Wang Yamin , Wu Hailiang , Zhang Wuchen , Liu Zhong , Cheng Nan , Su Jizhi
Published: April 2021

With the continuous progress of the manufacturing industry and the urgent demand for new building forms in the electric power industry, the prefabricated steel structure buildings have been widely applied in the substation design of State Grid Corporation of China, which can effectively reduce the wet operation on site and the project cost. This paper takes the exterior panel design of prefabricated steel structure building in substation as the research object, and explores the technical application of the secondary design of exterior panel of prefabricated steel structure building through combining the actual project and the existing wall panel type, which provides a reference for the development direction of prefabricated building in the future.
Three problems of the spatial organization of urbanized territories
Authors: Krasheninnikov A V
Published: April 2021

The article examines the methodological problems of modern urban planning exemplified by the next “new” initiative. The weakness of the declared goals, of methods and means of the modern urban planning practice is shown. The root of the problem lies in the elimination of professionally trained people from all spheres of urban planning. The problems of the spatial organization of urbanized areas are concentrated today around the issues of social comfort of the urban environment. Therefore, the study of the peculiarities of people’s perception of the surrounding architectural space can become a methodological platform for overcoming urgent problems of urban planning. The path to the development of a comfortable urban environment runs through the development of a program to obtain a meaningful, expressive, memorable system of images. Cognitive urban studies allow one to give a systematic assessment of models of urban spaces and add a humanitarian aspect to the algorithms for the spatial organization of urbanized territories.
“Poetics of the urban environment” in the context of the global aestheticization
Authors: Rukavishnikov A G , Ganat S A
Published: April 2021

The article focuses on the importance of using the developments of aesthetics as a theoretical framework for applied urban research. The need for this is prompted by the internal logic of the process of “global aestheticization” now taking place in the field of the humanities. According to a number of reputable scientists (in particular, one of the most famous modern German philosophers Wolfang Welsch), in the context of the revision of the usual forms of experience and the spread of virtual communication practices, aesthetics has the potential to become a kind of a synthetic science, interpreting the rapidly spreading “derealization of “reality”. At the same time, it is obvious that aesthetics can no longer remain within the narrow framework of philosophical discourse, but is called upon to go beyond it into the realm of existence and conduct a comprehensive analysis of specific manifestations of the sociocultural life of a modern person, in particular, heterogeneous urban processes, “poetics of the urban environment.”
Contemporary geniuses of place as a phenomenon of urban development
Authors: Markwart E , Vinogradov I , Guryanov G
Published: April 2021

The concept of genius loci has been widely studied in the scientific literature, mainly in relation to the “spirit of place” concept, and outstanding personalities of the past. The paper examines the phenomenon of the “genius of place” as a living person acting here and now, and highlights a specific role he plays in the development of “place”. The authors argue that the role of the “geniuses” is especially noticeable in small towns and settlements. A number of studied cases allow us to identify found “geniuses of places” mostly as “varangians” (outlanders). The paper draws initial conclusions regarding the interaction of “genius” and “place”, formulates possible hypotheses and directions for further research.