Current status and prospects of research on safety situation awareness of high speed railway operation environment

Purpose–The safety of high-speed rail operation environments is an important guarantee for the safe operation of high-speed rail.The operating environment of the high-speed rail is complex,and the main factors affecting the safety of high-speed rail operating environment include meteorological disasters,perimeter intrusion and external environmental hazards.The purpose of the paper is to elaborate on the current research status and team research progress on the perception of safety situation in high-speed rail operation environment and to propose directions for further research in the future.Design/methodology/approach–In terms of the mechanism and spatio-temporal evolution law of the main influencing factors on the safety of high-speed rail operation environments,the research status is elaborated,and the latest research progress and achievements of the team are introduced.This paper elaborates on the research status and introduces the latest research progress and achievements of the team in terms of meteorological,perimeter and external environmental situation perception methods for high-speed rail operation.Findings–Based on the technical route of“situational awareness evaluation warning active control,”a technical system for monitoring the safety of high-speed train operation environments has been formed.Relevant theoretical and technical research and application have been carried out around the impact of meteorological disasters,perimeter intrusion and the external environment on high-speed rail safety.These works strongly support the improvement of China’s railway environmental safety guarantee technology.Originality/value–With the operation of CR450 high-speed trains with a speed of 400 kmper hour and the application of high-speed train autonomous driving technology in the future,new and higher requirements have been put forward for the safety of high-speed rail operation environments.The following five aspects of work are urgently needed:(1)Research the single factor disaster mechanism of wind,rain,snow,lightning,etc.for high-speed railways with a speed of 400 kms per hour,and based on this,study the evolution characteristics of multiple safety factors and the correlation between the high-speed driving safety environment,revealing the coupling disastermechanism ofmultiple influencing factors;(2)Research covers multi-source data fusion methods and associated features such as disaster monitoring data,meteorological information,route characteristics and terrain and landforms,studying the spatio-temporal evolution laws of meteorological disasters,perimeter intrusions and external environmental hazards;(3)In terms of meteorological disaster situation awareness,research high-precision prediction methods for meteorological information time series along high-speed rail lines and study the realization of small-scale real-time dynamic and accurate prediction of meteorological disasters along high-speed rail lines;(4)In terms of perimeter intrusion,research amulti-modal fusion perception method for typical scenarios of high-speed rail operation in all time,all weather and all coverage and combine artificial intelligence technology to achieve comprehensive and accurate perception of perimeter security risks along the high-speed rail line and(5)In terms of external environment,based on the existing general network framework for change detection,we will carry out research on change detection and algorithms in the surrounding environment of highspeed rail.

KL-SG High-Speed Rail-a catalyst for national economic development Sri Viknesh Permalu and Karthigesu Nagarajoo

Purpose-In an increasingly interconnected world,transportation infrastructure has emerged as a critical determinant of economic growth and global competitiveness.High-speed rail(HSR),characterized by its exceptional speed and efficiency,has garnered widespread attention as a transformative mode of transportation that transcends borders and fosters economic development.The Kuala Lumpur-Singapore(KL-SG)HSR project stands as a prominent exemplar of this paradigm,symbolizing the potential of HSR to serve as a catalyst for national economic advancement.Design/methodologylapproach-This paper is prepared to provide an insight into the benefits and advantages of HSR based on proven case studies and references from global HSRs,including China,Spain,France and Japan.Findings-The findings that have been obtained focus on enhanced connectivity and accessibility,attracting foreign direct investment,revitalizing regional economies,urban development and city regeneration,boosting tourism and cultural exchange,human capital development,regionai integration and environmental and sustainability benefits.Originality/value-The KL-SG HSR,linking Kuala Lumpur and Singapore,epitomizes the potential for HSR to be a transformative agent in the realm of economic development.This project encapsulates the aspirations of two dynamic Southeast Asian economies,united in their pursuit of sustainable growth,enhanced connectivity and global competitiveness.By scrutinizing the KLSG High-Speed Rail through the lens of economic benchmarking,a deeper understanding emerges of how such projects can drive progress in areas such as cross-border trade,tourism,urban development and technological innovation.

TCP-LTE/5G Cross-layer performance analysis tool for high mobility data networking and a case study on high-speed railway

Nowadays,high mobility scenarios have become increasingly common.The widespread adoption of High-speed Rail(HSR)in China exemplifies this trend,while more promising use cases,such as vehicle-to-everything,continue to emerge.However,the Internet access provided in high mobility environments stllstruggles to achieve seamless connectivity.The next generation of wireless cellular technology 5 G further poses more requirements on the endto-end evolution to fully utilize its ultra-high band-width,while existing network diagnostic tools focus on above-IP layers or below-IP layers only.We then propose HiMoDiag,which enables flexible online analysis of the network performance in a cross-layer manner,i.e.,from the top(application layer)to the bottom(physical layer).We believe HiMoDiag could greatly simplify the process of pinpointing the deficiencies of the Internet access delivery on HSR,lead to more timely optimization and ultimately help to improve the network performance.

Mobile Ubiquitous Service Environment

The Mobile Ubiquitous Service Environment (MUSE),established through the coordination and integration of mobile telecommunications and ubiquitous network,in the pursuit of Always Best Experience (ABE),represents the major development trend for the next generation mobile wireless network. Research on MUSE will involve the integration of the computing model system,service platform system,operating system and terminal structure system,all of which involve exploration and innovation of a new networking structure,its control and management as well as way of measuring. The change in network resources triggers the change in network computing models. To let readers have a basic understanding of MUSE,this lecture introduces it in four sections. This section focuses on the development and demand analysis of the service platform.

A Mobile Agent-Based Prototype of HeterogeneousDistributed Virtual Environment Systems

Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of heterogeneous computer's distributed virtual environment system (HCWES) designed to populate some mobile agents as well as stationary agents. Finally, the paper introduces how heterogeneous computer network communication is to be realized.

Lightweight SOA-Based Twin-Engine Architecture for Enterprise Systems in Fixed and Mobile Environments

Mobile devices as a popular computing platform for enterprise systems have enabled certain tasks to be executed out of office.However,the work may be interrupted due to the server shutdown or network disconnection when employees access traditional single-engine Business Process Management System.To overcome this defect,we present a lightweight twin-engine architecture based on Service Oriented Architecture(SOA).In this paper,we discuss in detail the design and implementation of the architecture,and present a trigger mechanism to activate engines according to the states of hybrid environments since it is critical for the two types of engines to cooperate closely in hybrid environments with fixed and mobile computing resources.The experimental results validate the usability of the architecture.

Mobile Ubiquitous Network Environment

The Mobile Ubiquitous Service Environment (MUSE), established through the coordination and integration of mobile telecommunications and ubiquitous network in the pursuit of Always Best Experience (ABE), represents the major development trend for the next generation mobile wireless network. Research on MUSE will involve the integration of computing model system, service platform system, operating system and terminal structure system, all of which involve exploration and innovation of new networking structure, its control and management as well as way of measuring. The change in network resources triggers the change in network computing models. To make readers have a basic understanding of mobile ubiquitous network environment, this lecture will introduce MUSE in two sections. The first section describes the background of MUSE and its future development prospect. The second section focuses on the design principles and key technologies in MUSE model, which make services realized, as well as the networking structure of MUSE model, and the key technologies and design principles of networking.

A New Dynamic Self-Organizing Method for Mobile Robot Environment Mapping

To solve the mapping problem for the mobile robots in the unknown environment, a dynamic growing self-organizing map with growing-threshold tuning automatically algorithm (DGSOMGT) based on Self-organizing Map is proposed. It introduces a value of spread factor to describe the changing process of the growing threshold dynamically. The method realizes the network structure growing by training through mobile robot movement constantly in the unknown environment. The proposed algorithm is based on self-organizing map and can adjust the growing-threshold value by the number of network neurons increasing. It avoids tuning the parameters repeatedly by human. The experimental results show that the proposed method detects the complex environment quickly, effectively and correctly. The robot can realize environment mapping automatically. Compared with the other methods the proposed mapping strategy has better topological properties and time property.

A Novel Inter-Carrier Interference Cancellation Scheme in Highly Mobile Environments

In the current multi-carrier communications,Orthogonal Frequency Division Multiplexing(OFDM)is widely considered as a leading technology.For mobile applications,however,the orthogonality between subcarriers is deteriorated by Doppler frequency shift,which will introduce serious subcarrier phase rotation in the received signals and degrade the system performance.Thus,a method of differential grouping weighted symmetry data-conjugate(DWSCC)have been previously presented to obtain a better inter-carrier interference(ICI)suppressing effect and Bit Error Rate(BER)performance with no loss of spectral efficiency.In this paper,a novel scheme applying a completely different method of subcarrier interactive mapping is put forward.By mapping two different symbols which are both conjugated or multiplied by a complex weighting factor onto a pair of symmetric subcarriers,the presented scheme can greatly reduce the influence of subcarriers phase rotation caused by Doppler frequency shift in highly mobile environments.Analysis and simulation results indicate that comparing with the DWSCC method,our formulated scheme can not only maintain the spectrum utilization with no loss,but also have the advantages of an improvement on reduction effect and BER performance as well as a lower computational complexity in highly mobile environments.

Information behavior in the mobile environment:A study of undergraduate smartphone users in China

Purpose:As smartphones become ubiquitous,it is important to understand emerging information behavior as a result of wide spread use of smartphones.The purpose of this study is to investigate information behavior in the mobile environment by studying undergraduate smartphone users in China.Design/methodology/approach:This study is based on a survey of 205 undergraduate students in China.Findings:Smartphones are used predominantly for accessing news and connecting to social media,rather than for academic purposes such as accessing library resources or researching.While students use smartphones for reading e-books,much of this reading is recreational during their spare time.Research limitations:The inherent limitations of self-reported measures and the small sample size of this study mean that the results cannot be generalized across different age groups and cultures.Practical implications:When targeting users on the move,information professionals should be aware that the needs and behaviors of smartphone readers are significantly different compared to users of fixed devices,and should provide services in a mobile-friendly way.Originality/value:The younger generation is accustomed to instant information access.For libraries to relevant,they must redesign their services.It is important for libraries to leverage the strengths of mobile technology and to balance traditional services with mobile delivery.Even though many mobile users will use desktop or laptop computers to access library resources,they will benefit from the availability of mobile-friendly library services.

Analysis of Accuracy of a High-speed Mobile Platform Control System

The efficient manufacture technique involves a high-speed control of platform mobile system. A linear acutor is presented in this paper. The linear acutor is constructed as a linear stepper motor. However, to sustain both high accuracy and high speed for the position and speed control, A single-stack computer system is constructed and a special control algorithm is prescribed to controled the linear actuator continuously. In this paper, the nonlinear errors resulted from the magnetic saturation and the hysteresis is anaysis and discussed. In the view of electromagnetic propotional control, the actuator is a stage proportional magnet, because the driving current to the linear acuator changes for a number of cycles and a series of reset points will occur as the current undergoes cyclic changes. At each reset point the original starting characteristics of the system are re-established. A large number of reset points across the full stroke of the platform results in a significant reduction in the nonlinear behavior. The stage control is first discussed. Experiments carried out to obtain the characteristics of the mobile platform control system. It is demonstrated that with the introduction of stage control, nonlinearities, such as saturation and hysteresis, are greatly reduced, system stiffness is increased, and the positioning accuracy and resolution are improved. The effect of dither due to a "digital fragment" signal is also examined and found to be crucial in reducing the hysteresis and in improving the resolution accuracy.

Mobile Ubiquitous Service Environment(3)

The Mobile Ubiquitous Service Environment (MUSE),established through the coordination and integration of mobile telecommunications and ubiquitous network,in the pursuit of Always Best Experience (ABE),represents the major development trend for the next generation mobile wireless network. Research on MUSE will involve the integration of the computing model system,service platform system,operating system and terminal structure system,all of which involve exploration and innovation of a new networking structure,its control and management as well as its measurement. The change in network resources triggers the change in network computing models. To let readers have a basic understanding of MUSE,this lecture introduces MUSE in four sections. This section focuses on the system structure of the MUSE service platform.

Mobile Ubiquitous Service Environment (4)

The Mobile Ubiquitous Service Environment(MUSE),established through the coordination and integration of mobile telecommunications and ubiquitous network,in the pursuit of Always Best Experience(ABE),represents the major development trend for the next generation mobile wireless network.Research on MUSE will involve the integration of the computing model system,service platform system,operating system and terminal structure system;and each involves exploration and innovation of a new networking structure,its control and management as well as its measurement.The change in network resources triggers the change in network computing models.To let readers have a basic understanding of MUSE,this lecture introduces MUSE in four sections.This section focuses on the MUSE network architecture and its key technologies.

The Trade-Off Between Performance and Security of Virtualized Trusted Execution Environment on Android

Nowadays,with the significant growth of the mobile market,security issues on the Android Operation System have also become an urgent matter.Trusted execution environment(TEE)technologies are considered an option for satisfying the inviolable property by taking advantage of hardware security.However,for Android,TEE technologies still contain restrictions and limitations.The first issue is that non-original equipment manufacturer developers have limited access to the functionality of hardware-based TEE.Another issue of hardware-based TEE is the cross-platform problem.Since every mobile device supports different TEE vendors,it becomes an obstacle for developers to migrate their trusted applications to other Android devices.A software-based TEE solution is a potential approach that allows developers to customize,package and deliver the product efficiently.Motivated by that idea,this paper introduces a VTEE model,a software-based TEE solution,on Android devices.This research contributes to the analysis of the feasibility of using a virtualized TEE on Android devices by considering two metrics:computing performance and security.The experiment shows that the VTEE model can host other software-based TEE services and deliver various cryptography TEE functions on theAndroid environment.The security evaluation shows that adding the VTEE model to the existing Android does not addmore security issues to the traditional design.Overall,this paper shows applicable solutions to adjust the balance between computing performance and security.

IHMP:an improved hierarchical motion planner for mobile manipulator in static environment

Mobile manipulators are used in a variety of fields because of their flexibility and maneuverability.The path planning capability of the mobile manipulator is one of the important indicators to evaluate the performance of the manipulator,but it is greatly challenged in the face of maps with narrow channel.To address the problem,an improved hierarchical motion planner(IHMP)is proposed,which consists of a two-dimensional(2D)path planner for the mobile base,and a three-dimensional(3D)trajectory planner for the on-board manipulator.Firstly,a hybrid sampling strategy is proposed,which can reduce invalid nodes of the generated probabilistic roadmap.Bridge test is used to locate the narrow channel areas,and a Gaussian sampler is deployed in these areas and the boundaries.Meanwhile,a random sampler is deployed in the rest areas.Trajectory planner for on-board manipulator is to generate a collision-free and safe trajectory in the narrow channel with collaboration of the 2D path planner.The experimental results show that IHMP is effective for mobile manipulator motion planning in complex static environments,especially in narrow channel.

Sequential Extraction and Mobility Factor of Metals in the Urban Soil of Warri-Nigeria (A Case Study of the Environment of Esisi Open Dump)

Sequential fractionation of Cr, Zn, Pb and Mn in soil samples collected 5 m - 104 m away from Esisi open dump was determined to evaluate the potential health danger posed by the metals. Spatial test soil samples were collected at various increasing distances (5 m - 104 m) from the epicentre of the dump using a stainless steel auger. Tessier’s sequential extraction protocols were employed. The concentrations of the metals in the various fractions were determined, the fractions are exchangeable fraction, carbonate fraction, Fe-Mn oxide fraction, organic fraction and residual fraction. The metals were found mostly concentrated in the Fe-Mn oxide fraction. This study has provided information on the mobility factors and chemical forms of Cr, Zn, Pb and Mn in the soil of the environment of Esisi open dump and the environmental risk of the metals in the environment of Esisi open dump.

MOBILE计算中国机动车CO排放因子时的计算年确定

在使用MOBILE计算机动车排放因子时,一个较为重要的计算参数——计算年,在美国是根据实际年份来确定的,但是由于我国机动车排放发展水平与美国的不同,其值的确定是比较困难的关键问题。文章利用我国的实测机动车排放因子数据,在同等条件下使用MOBILE计算排放因子,并与道路实测数据对比,得到不同测试年份对应的MOBILE计算年,从而回归出使用MOBILE计算机动车排放因子的计算年公式。在今后利用MOBILE计算机动车排放时,可以方便的使用公式得到对应的MOBILE计算年,从而提高计算的精确度。

Mobile Agent在分布式数据库信息查询的应用研究

本文运用移动代理构建分布式异构数据库管理系统,利用移动代理跨平台、自治性、可移动的特点,支持分布式异构数据库管理系统在不确定网络上对松耦合的分布式数据库做信息查询。

一种新的基于Mobile Agent的3G VHE架构设计

从移动终端受限性出发,基于M ob ile A gent以实现个人移动性,对移动代理平台进行提取,将其作为移动终端操作系统的一部分。提出了使用与WAP协议有良好接口,且扩展性很强的外部功能接口(EF I)实现的移动代理平台以及提供业务和接口的移动代理。并给出了一个使用EF I实现的流媒体下载的实例。

Dynamic behavior of new cutting subgrade structure of expensive soil under train loads coupling with service environment

Expansive soil is sensitive to dry and wet environment change. And the volume deformation and inflation pressure of expansive soil may induce to cause the deformation failure of roadbed or many other adverse effects. Aimed at a high-speed railway engineering practice in the newly built Yun-Gui high-speed railway expansive soil section in China, indoor vibration test on a full-scaled new cutting subgrade model is carried out. Based on the established track-subgrade-foundation of expansive soil system dynamic model test platform, dynamic behavior of new cutting subgrade structure under train loads coupling with extreme service environment(dry, raining, and groundwater level rising) is analyzed comparatively. The results show that the subgrade dynamic response is significantly influenced by service conditions and the dynamic response of subgrade gradually becomes stable with the increasing vibration times under various service environment conditions. The vertical dynamic soil stress is related with the depth in an approximate exponential function, and the curves of vertical dynamic soil stress present a "Z" shape distribution along transverse distance. The peak value of dynamic soil stress appears below the rail, and it increases more obviously near the roadbed surface. However, the peak value of dynamic soil stress is little affected outside 5.0 m of center line. The vibration velocity and acceleration are in a quadratic curve with an increase in depth, and the raining and groundwater level rising increase both the vibration velocity and the acceleration. The vertical deformations at different depths are differently affected by service environment in roadbed. The deformation of roadbed increases sharply when the water gets in the foundation of expansive soil, and more than 60% of the total deformation of roadbed occurs in expansive soil foundation. The laid waterproofing and drainage structure layer, which weakens the dynamic stress and improves the track regularity, presents a positive effect on the control deformation of roadbed surface. An improved empirical formula is then proposed to predict the dynamic stress of ballasted tracks subgrade of expansive soil.