Communication-based train control (CBTC) systems use wireless local area networks (WLANs) to transmit status and commands. Since WLANs are not originally designed for applications with high mobility, random transmission delays packet drops inevitable, which could result in unnecessary traction, brakes or even emergency of trains, loss line capacity, passenger satisfaction. In this paper, we study the introduced by errors handovers CBTC systems, analyze impact on stability performances...

The communication-based train control (CBTC) system is a typical cyber physical in urban rail transit. train-ground communication very important subsystem of the CBTC and uses wireless protocols to transmit commands. However, it faces some potential information security risks. To ensure system, an intrusion detection method based on machine learning state observer proposed detect recognize various attacks this paper. not only detects anomalies network data, but also states. This includes two...

Designing a train control system over wireless train-wayside communications is challenging task due to the packet delay and loss caused by unreliable communications. In this paper, we study performance optimization issues in communication-based (CBTC) systems with both introduced random transmission errors frequent handoffs A networked (NCS) model formulated for multitrain CBTC loss. Then, propose novel scheme enhance quality of service (QoS) systems. proposed scheme, medium-access layer...

In recent years, intelligent transportation systems and automatic train control technologies have been developed rapidly. The communication-based (CBTC) system through train-to-train communications is very important in the it uses wireless communication links to transmit commands. However, CBTC sensitive information security attacks. Therefore, a comprehensive resilient strategy proposed for under Denial of Service (DoS) As cyber physical system, includes two layers. layer, strongly robust...

Security is crucial in cyber-physical systems (CPS). As a typical CPS, the communication-based train control (CBTC) system facing increasingly serious cyber-attacks. Intrusion detection (IDSs) are vital to protect against The traditional IDS cannot distinguish between cyber-attacks and faults. Furthermore, design of does not take principles CBTC into consideration. When deployed, it effectively detect systems. In this paper, we propose novel intrusion method that considers both status...

Communication-based train control (CBTC) technologies are widely applied in order to improve the efficiency and safety of urban rail transit systems. With increase informatization automation through utilization communication, computer technologies, amounts potential security vulnerabilities introduced into CBTC systems, where malicious attacks could be implemented. Some attacks, such as data tampering cannot efficiently detected by traditional intrusion detection systems (IDS), which can...

With the rapid development of urban rail transit, energy consumption trains is increasing dramatically. The shortage electrical becoming more and serious. In this paper, a novel method proposed to better use regenerative braking for saving. A ‘time slot grid’ model set up analyze utilization among trains. Based on model, an efficient strategy that integrates train dispatch with control designed. running time in sections, dwell at stations headway can be adjusted find global optimal solution...

Communication-based train controls (CBTC) systems play a major role in urban rail transportation. As CBTC are no longer isolated from the outside world but use other networks to increase efficiency and improve productivity, they exposed huge cyber threats. This paper proposes generalized stochastic Petri net (GSPN) model capture dynamic interaction between attacker defender evaluate security of systems. Depending on characteristics system attack–defense methods, we divided our into two...

At present, the train-ground communication system based on wireless protocol is a very important component of communication-based train control (CBTC) systems in intelligent transportation. Its information security worthy attention. In order to guarantee system, this paper proposes an improved AdaBoost multi-classification intrusion detection method n-gram model. First, model used state transitions IEEE 802.11 protocol. Then, typical normal behavior set and abnormal sets are obtained by...

With the rapid development of urban rail transit, problem energy consumption is drawing more and attentions. Based on utilization regenerative braking among trains, this paper studies energy-efficient operation method. We firstly propose an strategy trains. proposed strategy, we set up energy-saving model which optimizes timetable speed profile trains simultaneous. particle swarm optimization algorithm, taking Beijing Yizhuang subway line Changping as examples short section long for...

In Communication-Based Train Control (CBTC) systems, random transmission delays and packet drops are inevitable in the wireless networks, which could result unnecessary traction, brakes or even emergency of trains, losses line capacity passenger dissatisfaction. This paper applies predictive function control technology with a mixed H 2 /∞ approach to improve performances. The controller is state feedback form satisfies requirement quadratic input constraints. A linear matrix inequality (LMI)...

This paper proposes a method to design planar first-order loudspeaker array structure for global active noise control. Compared with the traditional spherical array, provides practical flexible source locations. The is capable of achieving control, provided that loudspeakers have general variable responses in elevation. On x-y plane, we use harmonics analyze required consisting monopole and tangential dipole components. By exploiting properties associated Legendre functions its derivative,...

This letter proposes an efficient parameterization of the three-dimensional room transfer function (RTF) which is robust for position variations source and receiver in respective horizontal planes. Based on azimuth harmonic analysis, proposed method exploits underlying properties associated Legendre functions to remove a portion spherical coefficients RTF have no contribution plane. reduction leads flexible measuring-point structure consisting practical concentric circular arrays extract...

The virtual coupling approach has been proposed to improve transportation efficiency, passenger satisfaction and operational excellence for communication based train control (CBTC) systems, a formation is built named coupled sets (VCTS). In order ensure the stability of VCTS, train-to-train (T2T) wireless communications are critical provide continuous information exchange channel adjacent trains. Due unreliability communications, jamming attacks inevitable, which could bring packets loss...

Communication-Based Train Control (CBTC) Systems use bidirectional train-wayside wireless communications to ensure the safe operation of rail vehicles. The random delay and packet drop introduced by communication will lead inaccurate train status unnecessary control commands, which affect performance CBTC systems. In this paper, we study impact on We formulate a networked system (NCS)-based model for systems with drop, propose scheme based retry limit adaption guidance trajectory update...

As a typical and special cyber-physical system, Communication-Based Train Control (CBTC) systems require different security model from the traditional Information Technology(IT) systems. In this paper, we propose novel hierarchical situation awareness for CBTC The two major characteristics of are that it can achieve rapid dimensionality reduction multi-source heterogeneous data, also deal with complex variations (such as hacker attacks) by learning, classifying predicting critical data...

The purpose of this study was to evaluate endocrine therapy and chemotherapy for first-line, maintenance, second-line treatment hormone receptor-positive HER-2-negative metastatic breast cancer (HR+HER-2-MBC) the relationship between different options survival.The patients included in were all diagnosed with (MBC) at Shandong Cancer Hospital from January 2013 June 2017. Of 951 MBC, 307 HR+HER-2-MBC analysis. progression-free survival (PFS) overall (OS) various modes evaluated using...

3D audio technology based on binaural reproduction requires the Head-Related Transfer Function (HRTF) datasets to be available for all possible distance. However, due tedious work of measurement and large volume resulting datasets, HRTF is typically measured only sources located at a fixed In this paper, concept virtual loudspeaker arrays utilized achieve range extrapolation single range. The driven by Higher Order Ambisonics (HOA). Specially, restrict near-field effect HOA, compensation...

Leaky coaxial cables are widely used in tunnels for wireless communications, as they can provide stable radio signal. This paper presents the performances and advantages of 2.4GHz LCX through theoretical study field test. It is first experimental on CBTC communication based inland. The results show that able to transmit train-ground information. Compared with free space, more signal besides stronger strength.

With the wide application of information technolo-gies in communication based train control (CB TC) systems, security risks it confronts to are ever increasing. It is very difficult design an intrusion detection system (IDS) which can detect both known and unknown cyber attacks with high true positive rate (TPR) low false (FPR), simultaneously. In this paper, we propose a hybrid (RIDS) composed signature-based (SIDS) anomaly-based (AIDS). An improved stacking ensemble algorithm (ISEA)...

Communication-based train control (CBTC) systems use wireless local area networks (WLANs) for train-ground transmission. Transmission delays and packet drops may cause unnecessary tractions brakes of trains, degradation riding comfortability, rising energy consumption loss the line's capacity. In this paper, We model system to a group trains in CBTC as networked (NCS) with transmission drops. study CBTC, analyze their effects on train's control, propose method improve performance CBTC....

The reliability and safety of information transmission can be improved when leaky waveguide is used as medium train-ground wireless communication in CBTC (Communication Based Train Control). on the theory waveguide, this paper studies propagation characteristics by means magnetic dipole, compares simulation results with field tests performed Beijing subway Line 1. Simultaneously, test case covered snow are given paper, which to analyze influence quality different situations coverage.