Assessment and Analysis of Carrying Capacity of 350 km/h EMUs Operating on Beijing-Shanghai Highspeed Railway

This paper makes an analysis of the impact on the structure of the corridortype train working diagram by increasing the 350 km/h train pairs of Beijing-Shanghai High-speed Railway(HSR).According to the requirements of operation speed diversity,the multi-station receiving characteristics of cross-line trains and different train stopping schemes,this paper proposes a scheme of adding 350 km/h train pairs via computer analysis of carrying capability mode.The scheme is divided into three stages:(1)Initial stage:It is planned to increase trains running at 350 km/h,with 15~26 pairs of trains put into operation;(2)Rapid increase stage:27~142 pairs of 350 km/h trains are put into operation;(3)Full replacement stage:143~195 pairs of 350 km/h trains are put into operation,during which the number of cross-line trains under operation is controlled,the number of cross-line trains in each section is determined,the operation and connection scheme of cross-line trains is adjusted and the train stopping scheme is optimized.The results of this study were used for the adjustment of the train working diagram in the third quarter of June 25,2021 to increase the number of 350 km/h train pairs from 19 to 30 on Beijing-Shanghai HSR.350 km/h trains are evenly arranged during 7:00—19:00 on the train working diagram and 300 km/h trains are arranged by making full use of every time and space,to improve the travelling speed on Beijing-Shanghai HSR as a whole.

Design of an adaptive precoding/STBC baseband transceiver on a reconfigurable architecture

Precoding and space-time block coding （STBC）techniques using the uniform channel decomposition （UCD）are proposed to improve the bit error rate （BER） of themultiple-antenna communication system, but at a cost of areduced data rate. In order to achieve a higher overall systemperformance, a novel adaptive transceiver architecture whichflexibly combines both UCD and UCD ＋ STBC technologies isproposed. The channel state information （CSI） feedback pathwas added to the precoder to select which coding method wasto be used, i.e. UCD alone or UCD ＋ STBC. With thesmaller constellation sizes, Matlab simulation results showthat, the adaptive transceiver architecture will select the UCD-only mode under the higher SNR conditions in order to achievea higher bit rate. The UCD ＋ STBC mode will be selectedunder the lower SNR conditions （e. g., SNR 〈 10 dB） inorder to maintain good BER performance at the cost of areduced data rate. This architecture was implemented andverified using both UMC 0.18 ASIC process technology and aXilinx xc4vlx Virtex-4 FPGA at 150 MHz. The simulationresults demonstrate that the required number of reconfigurablearithmetic unit slices grows linearly with the channel matrixsize, while the number of adder array unit and reconfigurablelogic unit slices increases slightly with the constellation size.

Modelling of Contact Damage in Brittle Materials Based on Peridynamics

As a typical brittle material,glass is widely used in construction,transportation,shipbuilding,aviation,aerospace and other industries.The unsafe factors of glass mainly come from its rupture.Thus,establishing a set of prediction models for the cracks growth of glass under dynamic load is necessary.This paper presents a contact damage model for glass based on the ordinary state-based peridynamic theory by introducing a contact force function.The Hertz contact(nonembedded contact)problem is simulated,and the elastic contact force is determined by adjusting the penalty factor.The proposed model verifies the feasibility of penalty-based method to simulate the contact problem of glass.The failure process of glass specimen under impact is simulated,where two loading methods,the drop ball test and the split Hopkinson pressure bar are considered.Numerical results agree well with the experimental observations,thereby verifying the effectiveness of the proposed model.

Influence and impact of CAD on environmental art design paradigm under digital background

This paper briefly analyzes the common problems of the environment art design specialty in the course of setting up the courseof the specialty of environmental art and design in CAD. According to the common problems in the teaching process, we put forward the ideaof teaching design based on the application practice. CAD course is an important course of environmental art design major, should meet theprofessional characteristics of the organization of teaching content in the course teaching, knowledge using a variety of teaching methods andteaching, pay attention to the knowledge consistency.

A Comparative Study on David Hawkes and Xianyi/Gladys Yang's Translations of Chinese Common Sayings in Hong Lou Meng

Honglou Meng is an encyclopedia of Chinese language in which includes many different Chinese linguistic features, e.g. idioms, common sayings, poems etc. There are 109 Chinese common sayings in the first 80 chapters of the novel. Most Chinese common sayings contain figurative meanings and the images involved are usually vivid and culture-specific; therefore it is very difficult to translate them. It is found that David Hawkes is more creative and use more free translation while the Yangs use more literal translation. This supports Feng Qinghua's suggestion that the Yangs prefer to use literal translation while David Hawkes is inclined to use free translation.

Research on Metaverse Security and Forensics

As a subversive concept,the metaverse has recently attracted widespread attention around the world and has set off a wave of enthusiasm in academic,industrial,and investment circles.However,while the metaverse brings unprecedented opportunities for transformation to human society,it also contains related risks.Metaverse is a digital living space with information infrastructure,interoperability system,content production system,and value settlement system as the underlying structure in which the inner core is to connect real residents through applications and identities.Through social incentives and governance rules,the metaverse reflects the digital migration of human society.This article will conduct an in-depth analysis of the metaverse from the perspective of electronic data forensics.First,from the perspective of Internet development,the background and development process of the metaverse is discussed.By systematically elaborating on the concept and connotation of the metaverse,this paper summarizes the different views of current practitioners,experts,and scholars on the metaverse.Secondly,from the perspective of metaverse security,the social risk and crime risks of the metaverse are discussed.Then the importance of metaverse forensics is raised.Third,from the perspective of blockchain,smart wearable devices,and virtual reality devices,the objects and characteristics of metaverse forensics have been studied in depth.Taking smart wearable devices as an example,this paper gives the relevant experimental process of smart bracelet forensics.Finally,many challenges faced by metaverse forensics are summarized by us which provide readers with some exploratory guidance.

Analysis on D2D Heterogeneous Networks with State-Dependent Priority Traffic

In this work,we consider the performance analysis of state dependent priority traffic and scheduling in device to device(D2D)heterogeneous networks.There are two priority transmission types of data in wireless communication,such as video or telephone,which always meet the requirements of high priority(HP)data transmission first.If there is a large amount of low priority(LP)data,there will be a large amount of LP data that cannot be sent.This situation will cause excessive delay of LP data and packet dropping probability.In order to solve this problem,the data transmission process of high priority queue and low priority queue is studied.Considering the priority jump strategy to the priority queuing model,the queuing process with two priority data is modeled as a two-dimensionalMarkov chain.A state dependent priority jump queuing strategy is proposed,which can improve the discarding performance of low priority data.The quasi birth and death process method(QBD)and fixed point iterationmethod are used to solve the causality,and the steady-state probability distribution is further obtained.Then,performance parameters such as average queue length,average throughput,average delay and packet dropping probability for both high and low priority data can be expressed.The simulation results verify the correctness of the theoretical derivation.Meanwhile,the proposed priority jump queuing strategy can significantly improve the drop performance of low-priority data.

WINTERTIME MIDDLE EAST SUBTROPICAL WESTERLY JET STREAM INTERANNUAL VARIATION CHARACTERISTICS AND ITS POSSIBLE PHYSICAL FACTORS

Using National Centers for Environmental Prediction/Department of Energy(NCEP/DOE) monthly reanalysis data and an extended reconstruction of the sea surface temperature data provided by National Oceanic and Atmospheric Administration, the basic characteristics of the interannual variation in the wintertime Middle East subtropical westerly jet stream(MEJ) and its possible physical factors are studied. The results show that the climatological mean MEJ axis extends southwestward-northeastward and that its center lies in the northwest part of the Arabian Peninsula. The south-north shift of the MEJ axis and its intensity show obvious interannual variations that are closely related to the ElNio-Southern Oscillation(ENSO) and the mid-high latitude atmospheric circulation. The zonal symmetric response of the Asian jet to the ENSO-related tropical convective forcing causes the MEJ axis shift, and the Arctic Oscillation(AO)causes the middle-western MEJ axis shift. Due to the influences of both the zonal symmetric response of the Asian jet to the ENSO-related tropical convective forcing and the dynamical role of the AO, an east-west out-of-phase MEJ axis shift is observed. Furthermore, the zonal asymmetric response to the ENSO-related tropical convective forcing can lead to an anomalous Mediterranean convergence(MC) in the high troposphere. The MC anomaly excites a zonal wave train along the Afro-Asian jet, which causes the middle-western MEJ axis shift. Under the effects of both the zonal symmetric response to the ENSO-related tropical convective forcing and the wave train along the Afro-Asian jet excited by the MC anomaly, an east-west in-phase MEJ axis shift pattern is expressed. Finally, the AO affects the MEJ intensity, whereas the East Atlantic(EA) teleconnection influences the middle-western MEJ intensity. Under the dynamical roles of the AO and EA, the change in the MEJ intensity is demonstrated.

Nonmonotone adaptive trust region method based on simple conic model for unconstrained optimization

We propose a nonmonotone adaptive trust region method based on simple conic model for unconstrained optimization. Unlike traditional trust region methods, the subproblem in our method is a simple conic model, where the Hessian of the objective function is approximated by a scalar matrix. The trust region radius is adjusted with a new self-adaptive adjustment strategy which makes use of the information of the previous iteration and current iteration. The new method needs less memory and computational efforts. The global convergence and Q-superlinear convergence of the algorithm are established under the mild conditions. Numerical results on a series of standard test problems are reported to show that the new method is effective and attractive for large scale unconstrained optimization problems.

Multiple Input Multiple Output CDSK Chaotic Communication System and Its Performance Analysis

This paper propose a novel noncoherent chaotic com- munication scheme named multiple-input multiple-output correlation-delay-shill- keying （MIMO-CDSK）. In this scheme, multiple antennas are employed to strengthen the robustness in transmission, and to get more diversity gain. The bit error rate （BER） of the MIMO-CDSK is studied analytically in AWGN channel model and multipath fading channel model. The theory and simulation results show that, the performance gain can be obtained with multiple antennas allocated in the transmitter and receiver. Moreover, it is observed that MIMO-CDSK system can effectively reduce the multipath interference.

An Anti-Interference Chaotic Scheme for Cognitive Radio

Chaotic sequence has been applied in Cognitive Radio(CR)to exert the enormous potential spectral utilization and enhance the transmission security.However,since there is not strict orthogonality between chaotic signals,intra-signal interference(ISI)will be introduced into the demodulation.Here,an anti-interference orthogonal-frequency-division-multiplexing(OFDM)chaotic modulation named Walsh-sequence chaotic CR(WS-CCR)is proposed for cognitive radio.By constructing the strictly orthogonal chaotic signal based on Walsh sequence,the ISI component,which is produced by frequency offset in previous CR,can be eliminated during the demodulation.Moreover,the chaotic sequence can also be applied to scramble subcarriers to relieve the interference caused by malicious attacks.Gaussian approximation method is adopted to obtain the exact performance analysis of WS-CCR over Additive White Gaussian Noise(AWGN)channel and Rayleigh multipath fading channel.Results show that,with subcarriers scrambling by chaotic sequence,anti-interference performance and transmitting security can be signi?cantly improved in WS-CCR.Importantly,due to the absence of ISI component,the bit-error ratio(BER)performance of WS-CCR is better than that of the previous CR system.