Design and Implementation of Online Experimental Platform for Computer Networks Course

Practice training is very important for students learning Computer networks.But building a real laboratory is constrained and expensive.In this paper,we present an online experimental platform for computer networks course based on Dynamips simulator.Instructors and students can access the platform by IE Browser to manage and take router experiments.On the basis of deployment and testing,the platform is effective and flexible.

Intelligent radio access networks:architectures,key techniques,and experimental platforms

Intelligent radio access networks(RANs)have been seen as a promising paradigm aiming to better satisfy diverse application demands and support various service scenarios.In this paper,a comprehensive survey of recent advances in intelligent RANs is conducted.First,the efforts made by standard organizations and vendors are summarized,and several intelligent RAN architectures proposed by the academic community are presented,such as intent-driven RAN and network with enhanced data analytic.Then,several enabling techniques are introduced which include AI-driven network slicing,intent perception,intelligent operation and maintenance,AI-based cloud-edge collaborative networking,and intelligent multi-dimensional resource allocation.Furthermore,the recent progress achieved in developing experimental platforms is described.Finally,given the extensiveness of the research area,several promising future directions are outlined,in terms of standard open data sets,enabling AI with a computing power network,realization of edge intelligence,and software-defined intelligent satellite-terrestrial integrated network.

Wall slip behavior of cemented paste backfill slurry during pipeline based on noncontact experimental detection

Wall slip is a microscopic phenomenon of cemented paste backfill(CPB)slurry near the pipe wall,which has an important influence on the form of slurry pipe transport flow and velocity distribution.Directly probing the wall slip characteristics using conventional experimental methods is difficult.Therefore,this paper established a noncontact experimental platform for monitoring the microscopic slip layer of CPB pipeline transport independently based on particle image velocimetry(PIV)and analyzed the effects of slurry temperature,pipe diameter,solid concentration,and slurry flow on the wall slip velocity of the CPB slurry,which refined the theory of the effect of wall slip characteristics on pipeline transport.The results showed that the CPB slurry had an extensive slip layer at the pipe wall with significant wall slip.High slurry temperature improved the degree of particle Brownian motion within the slurry and enhanced the wall slip effect.Increasing the pipe diameter was not conducive to the formation of the slurry slip layer and led to a transition in the CPB slurry flow pattern.The increase in the solid concentration raised the interlayer shear effect of CPB slurry flow and the slip velocity.The slip velocity value increased from 0.025 to 0.056 m·s^(-1)when the solid content improved from 55wt%to 65wt%.When slurry flow increased,the CPB slurry flocculation structure changed,which affected the slip velocity,and the best effect of slip layer resistance reduction was achieved when the transported flow rate was 1.01 m^(3)·h^(-1).The results had important theoretical significance for improving the stability and economy of the CPB slurry in the pipeline.

ERP Virtual Simulation Experiment Teaching Platform based on UFIDA Cloud Computing

Economic Management Professional Academic Education are increasingly becoming personalization,intelligence and application.Colleges and universities should actively use cloud computing and big data.Also Internet of Things and other advanced information technologies to build an economics and management ERP virtual simulation experiment teaching platform.Cloud computing and big data,virtual simulation experiment teaching resources with"resource library+project library+enterprise management simulation sandbox training"as the core can build an online and offline collaborative and practical experiment teaching platform.It is expected to achieve the ideal effect of integration of three spaces.Such as physics and resources and social digital teaching.Moreover,it can also benefit human-computer collaboration and interactive teaching and inquiry learning.

Discussion and Research on Information Security Attack and Defense Platform Construction in Universities Based on Cloud Computing and Virtualization

This paper puts forward the plan on constructing information security attack and defense platform based on cloud computing and virtualization, provides the hardware topology structure of the platform and technical framework of the system and the experimental process and technical principle of the platform. The experiment platform can provide more than 20 attack classes. Using the virtualization technology can build hypothesized target of various types in the laboratory and diversified network structure to carry out attack and defense experiment.

Improved Sobel algorithm for defect detection of rail surfaces with enhanced efficiency and accuracy

A more effective and accurate improved Sobel algorithm has been developed to detect surface defects on heavy rails. The proposed method can make up for the mere sensitivity to X and Y directions of the Sobel algorithm by adding six templates at different directions. Meanwhile, an experimental platform for detecting surface defects consisting of the bed-jig, image-forming system with CCD cameras and light sources, parallel computer system and cable system has been constructed. The detection results of the backfin defects show that the improved Sobel algorithm can achieve an accurate and efficient positioning with decreasing interference noises to the defect edge. It can also extract more precise features and characteristic parameters of the backfin defect. Furthermore, the BP neural network adopted for defects classification with the inputting characteristic parameters of improved Sobel algorithm can obtain the optimal training precision of 0.0095827 with 106 iterative steps and time of 3 s less than Sobel algorithm with 146 steps and 5 s. Finally, an enhanced identification rate of 10% for the defects is also confirmed after the Sobel algorithm is improved.

Design and Validation of a Hardware-In-The-Loop Based Automated Driving Simulation Test Platform

With the iterative development of autonomous driving technology,selfdriving cars will be one of the most competitive areas in the future.In order to provide students with a better understanding and more comprehensive grasp of autonomous driving technology,a hardware-in-the-loop based autonomous driving simulation test platform has been built.The hardware-in-the-loop system integrates MATLAB/Simulink to build the core control algorithm model,CarMaker simulation software to provide a virtual display interface and vehicle dynamics model,and NVIDIA Jetson to deploy the ECU(Electronic Control Unit)to improve the algorithm power and Logitech G29 series driving simulators providing signal input.It provides a simulation test platform for the development and testing of advanced driver assistance systems,the development and testing of upper layer control algorithms and underlying actuators for autonomous driving,and can provide a teaching and experimental platform for undergraduate students and a development foundation for postgraduate practice.

临近空间探测和科学试验平台需求展望

It is an important scientific research activity in China to carry out near-space exploration and scientific experiments via aerospace carriers.Early near-space exploration projects mainly used aircraft,balloons,sounding rockets and Earth satellites to carry out space environment exploration.With the development of China’s space science and technology,microgravity science has become a frontier science that has developed rapidly in the past 20 years.With the continuous progress of national space science and technology,the demand for near-space exploration and scientific experiments is increasing year by year.In the next 2 to 3 years,many advanced science activities and the associated technologies need to conduct corresponding experimental research work.This paper mainly analyzes the significance of scientific research and the ways to realize near-space exploration at home and abroad,and analyzes the directions and innovations that can be carried out in the future.

Limited tree richness effects on herb layer composition,richness and productivity in experimental forest stands

Aims In forests,the herbaceous understory vegetation plays an important role for ecosystem functioning as it represents a significant component of total aboveground productivity.In addition,the herb layer contributes to overall forest species richness and controls tree species regeneration.Vice versa,trees in the overstory control understory herb and shrub growth through competition for resources.Using an experimental forest plantation with manipulated tree richness,we asked to which degree tree species richness and identity affect herb layer composition,richness and productivity and how these relationships across strata change with abiotic environmental conditions and competition intensity.Methods In the context of the Biodiversity-Ecosystem Functioning project in subtropical China(BEF-China),we made use of the integrated BEFmod experiment arranged along a tree species richness gradient at two sites,with additional subplot treatments of phosphorus addition,herb layer weeding and no weeding.We recorded the understory vegetation and determined herb layer biomass production on a total of 201 subplots.Important Findings We found only minor effects of tree layer richness on herb layer species composition and no significant effect on herb layer richness or productivity yet.However,there were strong tree layer identity effects on all response variables,which were partly explained by differences in leaf area index and by a high share of woody species both in total herb layer species richness and biomass.There were strong treatment effects,which were largest in the‘no weeding’treatment but we did not find any treatment×tree layer richness interaction in herb layer responses.Thus,these effects are mainly explained by increased competition intensity within the herb layer in the absence of weeding.Despite the young age of the experiment,the interactions between tree species identity,tree richness and the herb layer did already emerge and can be expected to become stronger with ongoing runtime of the experiment.

Research on Protection of Tuning Area Equipment Disconnection in the ZPW-2000A Track Circuit

To overcome the problem of tuning area faults influencing the normal operation of the ZPW-2000A track circuit,protector models are established to protect the track circuit from interference.First,the parameters of the protector models are calculated according to the circuit resonance principle.Second,a four-terminal network model of the track circuit in a normal state is established according to transmission-line theory and the transmission equations are derived.Third,the rail voltage is simulated,and an experimental platform is built to verify the models.Finally,the transmission equations of the protectors are derived,and the variation of the rail voltage is analyzed.The results indicate that tuning area faults have significant influence on the rail voltage.However,the installation of protectors can effectively reduce the influence,and not bear on the normal operation and maintenance of the track circuit,which significantly improves the protection ability of the track circuit against tuning area faults.