bluuebunny/crossref_metadata_2025 huggingface dataset:
Underwater color restoration and dehazing based on deep neural network
Authors: Wang Nan
Published: April 2022

In real-world underwater environment, exploration of seabed resources, underwater archaeology, and underwater fishing rely on a variety of sensors, vision sensor is the most important one due to its high information content, non-intrusive, and passive nature. However, wavelength-dependent light attenuation and back-scattering result in color distortion and haze effect, which degrade the visibility of images. To address this problem, firstly, we proposed an underwater unsupervised generative adversarial network call UWGAN for generating realistic underwater fake images from paired images in air and their corresponding depth maps based on an improved underwater imaging model. Secondly, U-Net, which is trained efficiently using synthetic underwater dataset, is adopted for color restoration and dehazing. Our model directly reconstructs underwater clear images using end-to-end autoencoder networks, while maintaining the structural similarity of underwater scenes. The results obtained by our method were compared with existing methods qualitatively and quantitatively. Experimental results obtained by the proposed model demonstrate well performance on open real-world underwater datasets, and the processing speed can reach up to 125FPS running on one NVIDIA 1060 GPU.
Research on Anomaly Detection of Train Communication Network Based on Long and Short-term Memory Network
Authors: Guo Jianing
Published: April 2022

Aiming at the intrusion detection algorithm based on traditional machine learning, which can not effectively deal with the problems of large quantity, strong timing and high dimension in the train communication network system, this paper proposes an intrusion detection algorithm based on adaptive momentum estimation optimization of long and short-term memory networks. This article first introduces the principles and characteristics of the long and short-term memory network, and then preprocesses the train communication network information according to the characteristics of the train communication network mode, proposes a train communication network anomaly detection model based on the long and short-term memory network, and studies different parameters The impact on the performance of anomaly detection, and the comparison of multiple intrusion detection performance indicators with other traditional shallow machine learning methods, proves the effectiveness of the algorithm proposed in this paper.
Design and Mechanical Performance Analysis of Vibration Reduction and Isolation Platform
Authors: Yang Hongping , Che Xiaowei , Yang Chen , Wang Wenwen , Pu Jiao
Published: April 2022

Vibration reduction and isolation platform is a device that can effectively reduce or isolate vibration in space environment. It is widely used in precision equipment fields such as mechanical structure, precision machining, optical instruments. A three-stage mechanical active vibration reduction and isolation platform is designed. The static analysis is carried out using professional software. The research results show that when 3000N concentrated load is applied on the working platform, the maximum deformation is 0.0073mm, the maximum stress is 2.82MPa. And when 4000N asymmetric load is applied, the maximum deformation is 0.048mm, the maximum stress is 200MPa. The modal analysis results show that the first frequency is 40Hz and the sixth frequency is 180Hz. The product has certain engineering application value.
Research on Generating Method of On-board Equipment Test Sequence in ATO System of High Speed Railway
Authors: Shen Xiangyin , Kuang Wenzhen
Published: April 2022

With the development of railway technology, the Train control system of Beijing-Zhangjiakou high-speed railway, which was opened in 2019, applies CTCS-3+ATO (Automatic Train Operation) technology to realize automatic driving at 350km/h, including automatic train opening, automatic and precise parking, and the linkage between train doors and platform doors. To ensure the safety and reliability of train control system, it is necessary to test the system. In this paper, the test cases used in the testing work are concatenated into test sub-sequences according to certain principles, and the concatenation problems of test sub-sequences are converted into TSP (Travelling Salesman Problem) for solving. PSO (Particle Swarm Optimization) algorithm was used to obtain the test sequence of ATO system in high-speed railway, which provided guidance for the test work.
Magnetic coupled ultra-low frequency piezoelectric energy harvester for self-powered sensors
Authors: Li Yuanhua , Han Minglei , Jiang Lei
Published: April 2022

Harvesting human motion energy to power various sensors has attracted more and more attention of researchers. Aiming to harvest the ultra-low frequency vibration energy generated by human motion, this paper proposes a magnetic coupled scheme which consists of two flextensional transducers with two endmost magnets, a center magnet, and a tube. Through magnetic coupling effect, the ultra-low frequency vibration energy is amplified and effectively harvested, and the output voltage amplitude at 5Hz reaches 22V under the initial distance of 48mm and the acceleration of 1g. The output voltage amplitude of the harvester is related to the initial distance and excitation acceleration which are theoretically analyzed in this paper.
Design of the Gradually Defect Patch Fractal Array Antenna for Unmanned Aerial Vehicle
Authors: Huang Yuting , Lin Bin , Zhang Zhiwei , Chen Haoyuan , Zheng Meijie , Wen Shuyao
Published: April 2022

This paper creatively proposes a new fractal iterative structure of a gradual defect patch and combines it with a rectangular array structure. Aiming at the performance requirements of the UAV system for multi-band compatible antennas, a gradual defect patch fractal array is designed. The radiation performance of the fractal array antenna was simulated by the method of moments, and antenna samples were made and the radiation performance was tested. Both simulation and actual measurement results show that this antenna has a working bandwidth of 5.5 GHz or more, a minimum return loss as low as -44 dB and excellent omnidirectional radiation capability. This antenna is compatible with the GPS system frequency band, Beidou system frequency band, all working frequency bands of the second to fifth generation mobile communication systems and the three working frequency bands of the RFID system, and is expected to be widely used as an unmanned aerial vehicle system antenna.
Hydrodynamic Performance and Vibration and Noise of Machine-pump Integration Device
Authors: Zhang Chi , Qiao Mingzhong , Lu Xihao
Published: April 2022

As a new type of drainage equipment or underwater propeller, the machine pump integrated device composed of permanent magnet motor and pump blade of Halbach structure has many advantages and wide application prospects. Starting from the hydrodynamic analysis method of the machine pump integrated device, this paper reviews the research progress in this field at home and abroad in recent years. The results are summarized and analyzed. Finally, according to the current problem needs and the shortcomings of the research status, some ideas are put forward for the vibration and noise suppression method of the machine pump integrated device, which provides a reference for the follow-up related research.
Unmanned Aerial Vehicle conflict detection based on spatiotemporal data grid
Authors: Yang Jianhua , Hu Minghua , Su Fangzheng
Published: April 2022

—The increasing number of unmanned aerial vehicles (UAVs) and the complexity of the low-altitude airspace operation environment have also increased. How to efficiently solve the pre-flight UAV conflict detection problem is an important link in the low altitude airspace operation environment. This paper combines the global airspace grid coding system and the relational spatio-temporal data structure to propose a method based on spatio-temporal data grid, establishes the grid size applicable to conflict detection, and verifies the feasibility and effectiveness of the proposed UAV conflict detection type in different environments through simulation experiments. The results also show that the seventh level grid of the global airspace grid is the most suitable basic grid size, and the time consumption is reduced by about 50-75% compared with the traditional method in different scenarios.
Research on mode-coupled multi-mode Fiber mode-division in multiplexing transmission system
Authors: Zhou Yang , Su Han
Published: April 2022

The mode coupling and random loss between different modes have important effects on the reliability of the multimode fiber-based mode division multiplexing transmission system. Using the VPI optical communication simulation platform, a short-distance analog-division multiplexing transmission system based on multimode fiber was designed and built. By setting the relevant parameters of mode coupling and random loss caused by bending, the quality of the eye diagram of the received signal is analyzed by the photoelectric signal analyzer at the receiving end. The experimental results show that the mode coupling has great influence on the anti-noise performance and anti-inter-symbol interference performance of the multimode fiber-based transmission system, and the random loss has great influence on the anti-noise performance of the system, this effect is more obvious in high-order linear polarization mode fiber.
Calculation and Structure Optimization of Electric Field Distribution of The 10kV Solid-sealed Polar Pole
Authors: Wang Shuo , Xuan Yingying , Lu Yu , Zhang Yan , Zheng Ziyao , Zhang Ji
Published: April 2022

As one of the core modules of the ring - net switch cabinet, the solid-sealed polar pole was used to seal the three-station isolation ground switch and vacuum arcing chamber together. The electric equipment was concentrated, which was prone to electric field distortion. In this paper, a three-dimensional simulation model was established based on the drawings of the solid-sealed polar pole. The electric field distribution under the initial structure was calculated based on the finite element method, and it was optimized by adjusting the thickness of the moving contact and epoxy layer, changing the radius of the metal pull rod in the control mechanism and adding the equalizing ring on the shell surface. The results showed that when the inner diameter of the moving contact was 20mm, the outer diameter of the air layer was 43mm, and the radius of the metal tie rod in the control mechanism was 18mm, the field intensity in the solid-sealed polar pole was relatively reasonable, but the maximum E-field intensity in the arc-extinguishing chamber gap between the contacts was up to 5041V/mm. It was necessary to carry out pressure withstand test to ensure insulation safety. The results of this paper could provide reference for the optimal design of the solid-sealed polar pole.
Control and realization of intelligent fishing system based on PLC and fuzzy PID algorithm
Authors: Hao Zongrui , Li Chao , Zhang Hao , Ren Wanlong
Published: April 2022

In this paper, based on the frequency conversion constant speed control principle theory, to control the stability of the number of fish pipe to fish for the technical means, to control the number of fish to ensure catch efficiency and damage rate as the main purpose, research and design based on the fuzzy PID controller of intelligent pump suction fishing control system, determine the system platform, sucking fish overall frame structure of the control system is given, A complete electrical control system is designed. The purpose of this paper is to obtain a fully functional fish suction equipment control system, specifically realize the intelligent catch count, control fish suction switch, lossless fish transfer speed control system switch and automatic cycle control.
The application of an integrated monitoring system for power distribution and consumption
Authors: Gu Zhanlei , Wang Jun , Han Linfeng
Published: April 2022

In view of the fact that the traditional integrated power distribution and consumption monitoring system and power information acquisition system are independent of each other, and the data between the two systems are not shared and reused, which brings great obstacles to the construction of new power systems, this paper proposes an integrated power distribution and consumption monitoring system. The system can simultaneously collect distribution monitoring data and power consumption information data, and accurately perceive the panoramic data of power systems such as high voltage power line, distribution transformer area, low voltage power line, metering tank and so on. Through big data statistical analysis and accurate prediction of fault events, realize the two-way interaction between distribution side and power consumption side, reduce power maintenance costs, improve power supply quality, it provides a strong guarantee for the safe operation of power distribution and electrical equipment.
Research on Coordinated DC voltage Control Strategy of DC Microgrid based on Photovoltaic Power Generation System
Authors: Zhou Ke , Qiu Xiaoying , Song Yi , Jin Qingren , Mo Zhiyue
Published: April 2022

DC microgrid system is a flexible and commonly used renewable power generation system. Among them, the energy storage system (ESS) can reduce the waste light of the photovoltaic (PV) power generation system and provide stable power output for the power grid. However, a reasonable control strategy is needed to realize the energy balance of PV, grid-connected converter and ESS, so as to ensure the safe and stable operation of DC microgrid. Therefore, this paper proposes a DC voltage coordination control strategy without communication. The control strategy can automatically coordinate the working state of each converter of DC microgrid, which according to the change of DC voltage and the ESS’s state of charge (SOC), At the same time, the inertia of DC voltage in each working state is analyzed, and the stability of DC microgrid is improved through the backup inertia support of ESS. Finally, the effectiveness of the proposed method is verified by simulation and experiments.
A store-and-forward neural network to solve multicriteria optimal path problem in time-dependent networks
Authors: Liu Jin , Chen Li , Zhang Honghao , Huang Wei , Jiang Kaiwen , Zhang Hongmin
Published: April 2022

This paper introduces the constrained multi-objective optimal path problem in time-dependent networks. In the existing literatures, the constraints are all imposed on the objective function while the problem constraints are related to the non-objective function. It is the difference that makes the traditional algorithm unable to get a better solution quality. In this light, we propose a store-and-forward neural network (SFNN) that finds the better result. In the design of SFNN, the topology of neural network is the same as that of time-varying network, and each node is designed as store-and-forward neuron. Each neuron transmits information to other neurons by sending signals. The experimental results show that compared with the traditional methods, the accuracy is significantly improved when the calculation time is acceptable.
Research on quality inspection model of spot welding of equal-thickness three-layer sheets based on ultrasonic A-scan
Authors: Liu Yali , Pan Yulong , Chen Haishan , Wang Wenzhe , An Tong , Chen Xu
Published: April 2022

To judge the spot welding quality automatically and effectively, this thesis uses the conventional ultrasonic A-scanning to study the mathematical model of nugget diameter for equal-thickness three-layer sheets. The finite element simulation model of the spot welding ultrasonic nondestructive (NDT) testing for equal-thickness three-layer low carbon sheets is established. The calculated values of the nugget diameter between different laminates are studied. Finally, the experiment of the spot welding ultrasonic nondestructive testing is carried out. This thesis verifies the correctness of the finite element simulation and the mathematical calculation model. The research results are of great significance to ultrasonic automatic inspection technology of spot welding.
Fingertip pulse rate variability extraction based on extreme-point symmetric mode decomposition
Authors: Wei Zijian , Li Min , Tang Youyuan
Published: April 2022

To solve shortcomings of being sensitive to noise and waveform when using threshold method to extract pulse rate variability (PRV) at this stage, a method using extreme-point symmetric mode decomposition to extract PRV signals from pulse waves with noise is proposed. A Butterworth filter is used to remove the baseline drift, the DC mode and power frequency noise, which can effectively avoid noise interference when identifying peak points. The pre-processed data is decomposed by extreme-point symmetric mode decomposition to select the corresponding mode of the main wave, thereby reducing the difficulty of feature point extraction. Compared with the threshold method, the extraction method proposed in this paper is more intuitive and can self-adaptively select the best decomposition layer. This method is suitable for the extraction of fingertip PRV under complex noise and some disease statuses.
Health evaluation methodology of remote maintenance control system of natural gas pipeline based on ACWGAN-GP algorithm
Authors: Zhang Shibin , Song Fei , Zhang Xiaojun , Jia Lidong , Shi Wei , Ai Yueqiao , Hei Weichun
Published: April 2022

The remote maintenance system of natural gas pipeline is of great significance to ensure the safe and stable operation of the pipeline network. The multi-classification method based on machine learning is more effective for the health evaluation of remote maintenance control system than the traditional evaluation method based on expert experience. In view of the sev ere imb alance i n the nu mber of s amples of f ive health levels, a health evaluation methodology of remote maintenance control system based on Wasserstein distance sand auxiliary classification generative adversarial network (ACWGAN-GP) is proposed. Firstly, the model stability is improved by introducing Wasserstein distance and gradient penalty. The generator generates balanced data, while the discriminator trains with generated and actual data. In this way, several ACWGAN-GP sub-models are trained. Then, the health levels of the sub-model are directly obtained by using the discriminator to classify the samples. Finally, according to the hierarchical relationship of the system, a parallel-serial combined evaluation method is adopted. By this means, the health evaluation model of remote maintenance control system including ACWGAN-GP sub-models is constructed. The experimental results based on 13 sets of KEEL and UCI multi-class imbalanced datasets and actual sampling data show that the effectiveness and advancement of the proposed method improved significantly compared with the existing similar typical algorithms.
Study on Dielectric and Thermal Properties of ABS / multilayer graphene Composites
Authors: Song Bo
Published: April 2022

ABS / multilayer graphene (MLGN) composites were prepared by melt blending ABS and multilayer graphene masterbatch,and their dielectric and thermal properties were studied. The results show that the dielectric constant, dielectric loss, conductivity, thermal decomposition temperature and thermal conductivity of ABS / MLGN composites increase with the increase of MLGN content. The content of MLGN in ABS / MLGN composites with conductive percolation is between 7-8%. When the mass content of MLGN increased to 7%, the dielectric constant of the composite increased from 3.01 to 103.23, the dielectric loss increased from 0.058 to 0.83 at 100Hz, the 5% mass loss temperature of the composite increased by 17.0°C and the thermal conductivity increased by 1.9 times. The research results can provide reference for the preparation of thermally conductive polymer dielectric composites.
Research on Short-term Wind Power Forecasting Based on Stacking Integrated Model
Authors: Wang Haoyue , Zhao Hongtao
Published: April 2022

With the large-scale use of wind farms, wind power has become an indispensable energy source. However, due to the influence of internal instability factors of wind, it poses a huge threat to the economic efficiency and reliability of power system operation. In order to solve this problem, according to the random volatility of wind power, this paper establishes a wavelet threshold noise reduction model to process wind speed characteristics. Because the wind power is very different when the wind speed is the same, many of the wind turbine’s own attributes are added to the input characteristics. Based on the strong generalization ability of decision tree models, the gradient descent tree, extreme gradient boost tree, and lightGBM algorithm are used as the base learner, and the multiple linear regression model is used as the meta-learner to construct a stacking integrated learning model. Compared with methods such as long and short-term memory neural networks, the performance and generalization ability of the cascading generalization algorithm combination model is relatively good.
Study on the influence of different thickness of armature structure on the emission performance of electromagnetic induction coil launcher
Authors: Zheng Fangzheng , Jiang Runxiang , Lu Mengkun , Qian Hanning , Yue Feihong
Published: April 2022

In the armature structure of traditional electromagnetic induction coil launcher, the armature tail melted due to heat accumulation. In this paper, three new armature structures are proposed. Based on the finite element software maxwell2D, the single-stage electromagnetic induction coil launcher, model is established. The performance indexes of traditional and new armature structures are compared, and the influence of the thickness of traditional armature structure and the side thickness of new structure on temperature rise and electromagnetic performance is studied. On the basis of Maxwell-thermal finite element, the correctness of the temperature field conclusion is verified. The simulation results show that the traditional armature structure has the optimal thickness and the armature performance remains unchanged when the weight ratio and the mechanical strength of the armature are considered. Structure 3 and Structure 4 of the new structure significantly improve the temperature rise of the armature and enhance its emission performance. Due to the eddy current, the optimum side thickness of the new structure 3 and structure 4 is slightly larger than 1/2 of the armature length.
Research and application of power system operation risk assessment method considering new energy grid connection
Authors: Mu Zhijun , Song Liang , Li Zhenkai , Mu Wanli , Geng Hongbin
Published: April 2022

The traditional distribution network operation risk assessment does not fully consider the intermittency and volatility of new energy sources, which has an adverse impact on the security management of the power grid. Therefore, combined with the probabilistic characteristics of new energy power generation, this paper establishes a distribution network operation risk assessment model and a comprehensive risk index system including new energy grid-connected, mainly including voltage over-limit, voltage collapse, line active power over-limit, system load loss, abandoning the wind and abandoning the light, exceeding the frequency limit, etc. On this basis, this paper formulates the weighting factors of each risk index, and comprehensively judges the weak points of the system. The example analysis shows that the risk assessment method proposed in this paper can quantitatively analyze the weak links after the new energy is connected to the distribution network. This verifies the effectiveness of the proposed method and provides a reference for the future development of new energy grid-connected security.
Research and Application of “Transparency” System for Sampling Inspection of Power Materials
Authors: Liu WenYe , Zhu Ting , Zhang Ting , Qin LiangLiang , Chen LingPin
Published: April 2022

Aiming at the problem of insufficient transparency in the process of sampling inspection of power materials, the research and application of transparency system for sampling inspection of power materials are proposed. Based on the browser / server mode, the “transparent” system architecture of power material sampling inspection is designed. This article is based on the working principle of the B/S architecture server. This paper analyzes the working mode of the power material sampling server, designs the power material sampling server, and completes the hardware design of the system. Based on the corresponding power material time weight and power material sampling data, this paper analyzes the historical quality of the system. According to the correlation between independent variables and dependent variables, the quality pass rate of power materials is predicted by calculating the sum of residual squares. Combined with the design of power material sampling process, the software design of the system is completed, and the power material sampling is realized. The test results show that the proposed “transparent” system has better sampling effect in the maximum completion time and the non sampling rate of the deadline.
Lightning Disturbance Analysis and Improvement Measures for “Generation-Grid-Load-Storage” Type Distribution Line
Authors: Huang Zhidu , Zhang Wei , Li Shan , Cui Zhimei , Tan Siyuan
Published: April 2022

For economy, the traditional lightning protection method is simple and the lightning protection effect is unsatisfactory. With China’s call and demand for energy transformation, a new distribution network based on “Generation-Grid-Load-Storage” will be the general direction of China’s distribution network development. The new distribution network puts forward higher requirements for the stability, and its lightning protection problem must be solved. In this paper, the overhead ground wire is proposed as the main lightning protection measure of the new distribution network, and the optimal erection range of the overhead ground wire of the distribution line is proposed through simulation, which can effectively reduce the amplitude of lightning overvoltage by 24.1%, which provides an application reference for the lightning protection concept of the new distribution line in the future.
Synthetic vascular graft with spatially distinct architecture for rapid biomimetic cell organisation in a perfusion bioreactor
Authors: Michael Praveesuda L , Yang Nianji , Moore Matthew , Santos Miguel , Lam Yuen Ting , Ward Annabelle , Hung Jui Chien , Tan Richard P , Wise Steven G
Published: April 2022

Access to lab-grown fully functional blood vessels would provide an invaluable resource to vascular medicine. The complex architecture and cellular makeup of native vessels, however, makes this extremely challenging to reproduce in vitro. Bioreactor systems have helped advanced research in this area by replicating many of the physiological conditions necessary for full-scale tissue growth outside of the body. A key element underpinning these technologies are 3D vascular graft templates which serve as temporary scaffolds to direct cell growth into similar cellular architectures observed in native vessels. Grafts further engineered with appropriate physical cues to accommodate the multiple cell types that reside within native vessels may help improve the production efficiency and physiological accuracy of bioreactor-grown vessel substitutes. Here, we engineered two distinct scaffold architectures into an electrospun vascular graft aiming to encourage the spatial organisation of human vascular endothelial cells (hCAECs) in a continuous luminal monolayer, co-cultured with human fibroblasts (hFBs) populating the graft wall. Using an electrospun composite of polycaprolactone and gelatin, we evaluated physical parameters including fibre diameter, fibre alignment, and porosity, that best mimicked the spatial composition and growth of hCAECs and hFBs in native vessels. Upon identifying the optimal scaffold architectures for each cell type, we constructed a custom-designed mandrel that combined these distinct architectures into a single vascular graft during a single electrospinning processing run. When connected to a perfusion bioreactor system, the dual architecture graft spatially oriented hCAECs and hFBs into the graft wall and lumen, respectively, directly from circulation. This biomimetic cell organisation was consistent with positive graft remodelling with significant collagen deposition in the graft wall. These findings demonstrate the influence of architectural cues to direct cell growth within vascular graft templates and the future potential of these approaches to more accurately and efficiency produce blood vessel substitutes in bioreactor systems.
Changing ocean seasonal cycle escalates destructive marine heatwaves in a warming climate
Authors: Wang Shengpeng , Jing Zhao , Wu Lixin , Wang Hong , Shi Jian , Chen Zhaohui , Ma Xiaohui , Gan Bolan , Yang Haiyuan , Liu Xin
Published: April 2022

Marine heatwaves (MHWs) can cause various adverse effects on marine ecosystems associated with complicated social ramifications. It has been well established that the gradually rising sea surface temperature (SST) due to anthropogenic carbon emission will cause an increase of the MHW duration and intensity. However, for species with strong adaptation capacity or mobility, MHW changes due to the altered SST variability under greenhouse warming are more crucial but so far remain poorly assessed. Under the high carbon emission scenario, we show that the cumulative duration (intensity) of MHWs, with the effect of secular SST increase excluded, is projected to be 60% (100%) higher by the end of this century than in the 1990s due to an amplified SST seasonal cycle. This increase becomes more evident for stronger MHWs, reaching up to 8 (30) folds for the extreme MHW category. The amplified SST seasonal cycle also causes pronounced seasonality of MHWs, making them more active in summer-autumn than winter-spring. Our results suggest that MHWs are likely to have increasingly devastating impacts on a wide range of marine species in the future without taking effective steps for carbon emission reduction.
An adaptive geographic meshing and coding method for remote sensing data
Authors: Huang Xiaohui , Li Jiabao , Yan Jining , Wang Lizhe
Published: April 2022

Spatial indexing techniques, inherently data structures, are generally used in portals opened by institutions or organizations to efficiently filter RS images according to their spatial extent, thus providing researchers with fast Remote Sensing (RS) image data discovery ability. Specifically, space-based spatial indexing approaches are widely adopted to index RS images in distributed environments by mapping RS images in two-dimensional space into several one-dimensional spatial codes. However, current spatial indexing approaches still suffer from the boundary objects problem, which leads to multiple spatial codes for a boundary-crossing RS image and thus alleviates the performance of spatial indexes built on top of these spatial codes. To solve this problem, we propose an adaptive geographic meshing and coding method (AGMD) by combining the famous subdivision model GeoSOT and XZ-ordering to generate only one spatial code for RS images with different spatial widths. Then, we implement our proposed method with a unified big data programming model, (i.e., Apache Beam), to enable its execution in various distributed computing engines (e.g., MapReduce, and Apache Spark, etc.) in distributed environments. Finally, we conduct a series of experiments on real datasets, the archived Landsat metadata collection in level 2. The results show that the proposed AGMD method performs well on metrics, including the following aspects: the effectiveness of the storage overhead and the time cost are up to 359.7% and 58.02 %, respectively.
Travel-mode classification based on GPS-trajectory data and geographic information using an XGBoost classifier
Authors: Jin Huiling , Wu Hangbin , Xu Zeran , Huang Wei , Liu Chun
Published: April 2022

Massive Global Positioning System (GPS) trajectory datasets are being produced owing to the advances in mobile sensors, the Internet, and GPS devices. Accurately inferring travel modes from GPS trajectory data can be helpful in transportation planning and modeling, infrastructure design, etc. However, adverse factors such as data noise, differences in sampling rate, and inadequate features have a negative impact on the results of travel mode classification. In this paper, to address such issues, we first propose a preprocessing workflow, which includes data cleaning, segmentation, and resampling, to preprocess raw trajectories. Then, we add new features related to the road and bus stop information for travel mode classification using an XGBoost (eXtreme Gradient Boosting) classifier, along with various basic features of the trajectories. We conducted a set of experiments on the GeoLife dataset using a group of state-of-the-art methods. The results showed that the proposed methods can improve the classification accuracy by using all the classifiers we compared and the classification accuracy using the XGBoost classifier can reach a maximum of 90.41%.
Urban forest canopy height modeling using spaceborne laser ICESAT-2 LIDAR
Authors: Shufan Wang , Chun Liu
Published: April 2022

Urban forests are an important part of urban ecosystems. Carbon sequestration in urban forests helps reduce the concentrations of greenhouse gases in the region where they are present. Forest height is an important structural parameter for calculating the forest carbon sequestration capacity. Based on this, our study proposes a space-borne laser fusion multi-source remote sensing inversion model of urban forest tree height based on urban space environmental characteristics. This paper mainly consists of three parts:
(1) First, a variety of highly correlated tree feature factors were extracted from ICESat2 satellite-borne laser data, LandSat8 multi-spectral data, and spatial environment auxiliary data, and a feature database was constructed. (2) The importance of the feature factors in the feature base was analyzed, and a large-scale forest height inversion model of Shanghai was constructed using a support vector machine (SVM), random forest (RF), and backward propagation neural network (BP-ANN). (3) The accuracy of the urban forest height inversion model was improved by introducing urban spatial environmental features such as texture features. Ablation experiments show that the texture features considered in this study can improve the accuracy of each model to varying degrees, and the accuracy of the BP neural network can reach
R2

=0.61, RMSE=3.6589. The accuracy of the urban tree height inversion model was
R2

=0.6433, RMSE=1.0967, which proves the effectiveness of the space-borne laser fusion multi-source remote sensing urban forest height inversion model considering the characteristics of the space environment.
Single-time power frequency modulation and peak -modulation market combined clearing method considering new energy absorption capacity
Authors: Jin Luosong , He Letian , Lv Ruiyang
Published: April 2022

In order to support the transaction clearing business of power frequency modulation and peak load modulation market in China and improve the absorption capacity of new energy, the coupling relationship between power frequency modulation and peak load modulation auxiliary service is studied, and the combined clearing method of single time period power frequency modulation and peak load modulation market considering the absorption of new energy is proposed. The coupling relationship between power frequency modulation and power peak modulation auxiliary services is reflected in that the two auxiliary services are mutually exclusive. Considering the important promoting effect of peak regulation capacity on new energy consumption, the index of residual depth peak regulation capacity was proposed as the evaluation basis of the clearance result on new energy consumption capacity. On this basis, a single time combined clearing model of power frequency modulation and peak-shaving market is constructed, which takes the minimum clearing cost as the main optimization objective and the maximum remaining peak-shaving capacity as the secondary optimization objective. Numerical examples show that the proposed method has significant advantages over the current sequential cleaning method and the combined cleaning method without considering the consumption of new energy in terms of transaction cost and residual depth peak-shaving capacity. The results show that the method proposed in this paper meets the requirements of promoting the construction of new power system with new energy as the main body in China, and has significant benefits in promoting the reform of power market and improving the consumption of new energy.
Analysis of food nitrogen footprint in Guangdong Province
Authors: Wang Senchao , Xu Meng
Published: April 2022

Global anthropogenic emissions of reactive nitrogen (Nr) from food production and consumption were regarded as main contributors to nitrogen-related pollution. Food nitrogen footprint analysis could help quantify the amount of Nr release to the environment during the processes of food production and consumption, which plays an important role in nitrogen emission management. In this study, the N-Calculator model was used to quantify the food nitrogen footprint in Guangdong province from 2013 to 2017. The results indicated that: nitrogen footprint of anaimal-sourced food was higher than that of others, and with the increase of animal-sourced food consumption in Guangdong province during the research period, the amount of per capita food nitrogen footprint increased from 19.22 to 21.33 kg N, nearly reaching to the amount of developed countries. Food nitrogen footprint of rural residents was larger than that of urban residents in Guangdong province. Exceeding the recommended amounts of animal-sourced food in the dietary guideline, recent dietary patterns in Guangdong province should be further optimized.
Research related to the Appearance Design of Water Surface Cleaning Robot based on Bionics
Authors: Yang Huimin , Kim Chulsoo
Published: April 2022

This thesis analyzes five representative water cleaning robots selected from three countries and combines the top-down design process of bionics and the basic elements of product design to clarify the problematic points of existing water waste cleaning robots and propose a bionic design solution. The results of the analysis show that the shape design is not optimized according to the shape of the hull, and the environmental and aesthetic aspects are not satisfactory. By applying the three bionic principles of color, form and material to the appearance of the robot, a robot that meets the needs of cleaning small urban waters is designed and derived. This proposal is an optimized solution to solve the existing defects of the product and complete the solution that meets the modern market demand, aesthetic patterns, and production methods.
Research on Smart City Construction Management Evaluation System Based on Ternary Subject Theory
Authors: Huang Jiazhen , Yu Cong , Xiao guangpeng , Xiang jian
Published: April 2022

In this paper, the existing problems and optimization principles of the current smart city construction management evaluation indicator system in China are analyzed. The evaluation indicator system is selected for two rounds based on the membership and utility and constructed systematically. The distribution of weight of smart city construction management evaluation indicators in China is obtained based on empirical investigation of the government officials, experts, scholars and the public participating in the evaluation from different typical regions in eastern, central, and western China by means of surveys and questionnaire investigations. Finally, the existing problems of the evaluation indicator system are analyzed and the optimization path is proposed.
Grey water footprint assessment of domestic wastewater in Guangdong section of the Dongjiang River Basin
Authors: Zhang Jiaman , Tan Zhenkun
Published: April 2022

Water pollution in river basins has become one of the main factors in restricting regional social-economic development. Water footprint assessment at river basin level is a hot issue in the research on water for sustainable development. In this study, the grey water footprint method was introduced for domestic wastewater assessment. The approach can effectively reflect the impact of water pollution on the amount of available water resources by evaluating the degree of water pollution from the perspective of water quantity. In order to verify the approach, the region of Guangdong section of the Dongjiang River Basin (GD-DRB) was selected as a case. Based on multiple pollutants (i.e., CODCr, NH3-N, BOD5 and TP), grey water footprint of the river basin was calculated. The results showed that the grey water footprint of domestic water in the urban area of the region was higher than that in the rural area. The total amount of grey water footprint in the region was 28.41 billion m3. The main pollutants in the region were phosphorus and organic compounds.
Evolution and origin of global glaciers and their impacts on the environment
Authors: Cui Bingyu , Li Junyi , Wu Junlong
Published: April 2022

Glacier is one of the most important freshwater resources. However, the situation of glaciers is changed nowadays because of global warming. This study aimed at two types of glaciers, and analyzed their evolution, origin and impacts on the environment. As for typical melting glaciers, the Vatnajokull glacier and Urumqi Glacier No.1, Tianshan Mountains gradually melt over time. Their causes are related to atmospheric River events, black carbon pollutants, ice recycling, global warming, and human activities. The impacts of glacier retreat mainly include sea-level rise and can alleviate global warming and cause surface deformation. However, there are some “weird” glaciers because they are expanded in the past few years rather than shrinking. Those glaciers are highly concentrated in the Karakoram, Pamir Mountains, Svalbard, the Canadian Arctic islands, Alaska, and Iceland, which are called surged-type glaciers. Hydrological control, thermal regime, deformable bed hypothesis, and critical mass are reasons for glacier expansion. There is no clear and unified opinion on the advantages or disadvantages of glacier expansion.
Floristic analysis of Vascular plants in Sanzhou Island, Zhuhai, China
Authors: Huang Weigang , Liu Hui
Published: April 2022

The uninhabited island in Guangdong is rich in vascular plant flora. In order to enrich the understanding of the zonal vegetation, a comprehensive survey of the plant resources of Sanzhou Island was carried out by using the survey method of the combination of sample line method and quadrat method. The vegetation types, floristic composition of vascular plants and the distribution types of families, genera and species were analyzed. The natural vegetation of Sanzhou Island could be divided into three types: coastal semi-mangrove, evergreen shrub and evergreen seasonal rainforest. The results showed that there were 68 species of vascular plants in 39 families, 62 genera. There were 4 families, 4 genera and 5 species of pteridophytes, accounting for 10.26%, 6.45% and 7.35% of the vascular plants; 63 species of angiosperms, 58 genera and 35 families, accounting for 89.74%, 93.55% and 92.65% of the vascular plants in the island. The floristic composition of the island showed obvious tropical nature. The main flora of the island was composed of 4 distribution types: pantropic, old world tropical, tropical Asia to tropical Australasia and tropical Asia. It showed the floristic components were diverse with strong adaptability which was suitable for the poor soil and harsh environment of the island. This study could provide a theoretical basis for the protection, development and management of plant resources in Sanzhou Island.
A Summary of the Transporting Mechanism of Microplastics in Marine Food Chain and its Effects to Humans
Authors: Zhao Songdi
Published: April 2022

Microplastics are ubiquitously present in the oceanic environment and, though unrecognizable to the public, pose perilous effects to animals in all trophic levels as well as to human beings. For this study, we emphasized the wide-ranging effects of oceanic microplastics to animals and to humans. The transportation mechanism of microplastics in oceanic food chain was analysed and the negative effects to animals in all trophic levels including humans are specified. Then, two approaches to mitigate the perilous effects are illustrated. Further, by reviewing the previous research, some knowledge gaps appeared. Therefore, four suggestions for future research were proposed. Unlike previous research, this review paper serves as an overview of the perilous effects created by the microplastics from cosmetic products to animals across all trophic levels, including human, and the transporting mechanism of microplastics through the marine food chain was elaborated as well. Hence, this review paper can raise people’s awareness to the microplastic pollution caused by cosmetics and further promote the banning of the microplastics in cosmetic industries and the propagating of potential alternative materials that are more sustainable.
Ionization process and distinctive characteristic of atmospheric pressure cold plasma jet driven resonantly by microwave pulses
Authors: HONG Lingli , CHEN Zhaoquan , YANG Jie , CHENG Tao , CHEN Sile , ZHOU Yuming , WANG Bing , LU Xinpei
Published: April 2022

In the present study, a coaxial transmission line resonator is constructed, which is always capable of generating cold microwave plasma jet plumes in ambient air in spite of using argon, nitrogen, or even air, respectively. Although the different kinds of working gas induce the different discharge performance, their ionization processes all indicate that the ionization enhancement has taken place twice in each pulsed periods, and the electron densities measured by the method of microwave Rayleigh scattering are higher than the amplitude order of 1018 m−3. The tail region of plasma jets all contain a large number of active particles, like NO, O, emitted photons, etc, but without O3. The formation mechanism and the distinctive characteristics are attributed to the resonance excitation of the locally enhanced electric fields, the ionization wave propulsion, and the temporal and spatial distribution of different particles in the pulsed microwave plasma jets. The parameters of plasma jet could be modulated by adjusting microwave power, modulation pulse parameters (modulation frequency and duty ratio), gas type and its flow rate, according to the requirements of application scenarios.