The goal of this paper is to provide an approach to investigate the variation of fiber quantity in a certain cross-section of the drafting zone. This model with discrete-event simulation( DES)method was presented to s...The goal of this paper is to provide an approach to investigate the variation of fiber quantity in a certain cross-section of the drafting zone. This model with discrete-event simulation( DES)method was presented to simulate the dynamic drafting process. This model described the behavior of individual fibers,which was divided into four phases and simulated by corresponding modules. Three sets of processing conditions in industry were simulated and demonstrated the applications of this model. The comparison between experiments and simulation results could also validate this model. This model could be used to simulate various drafting process with appropriate drafting settings.展开更多
Fault detection and diagnosis(FDD) facilitates reliable operation of systems. Various approaches have been proposed for FDD like Analytical redundancy(AR), Principal component analysis(PCA), Discrete event system(DES)...Fault detection and diagnosis(FDD) facilitates reliable operation of systems. Various approaches have been proposed for FDD like Analytical redundancy(AR), Principal component analysis(PCA), Discrete event system(DES) model etc., in the literature. Performance of FDD schemes greatly depends on accuracy of the sensors which measure the system parameters.Due to various reasons like faults, communication errors etc.,sensors may occasionally miss or report erroneous values of some system parameters to FDD engine, resulting in measurement inconsistency of these parameters. Schemes like AR, PCA etc.,have mechanisms to handle measurement inconsistency, however,they are computationally heavy. DES based FDD techniques are widely used because of computational simplicity, but they cannot handle measurement inconsistency efficiently. Existing DES based schemes do not use Measurement inconsistent(MI)parameters for FDD. These parameters are not permanently unmeasurable or erroneous, so ignoring them may lead to weak diagnosis. To address this issue, we propose a Measurement inconsistent discrete event system(MIDES) framework, which uses MI parameters for FDD at the instances they are measured by the sensors. Otherwise, when they are unmeasurable or erroneously reported, the MIDES invokes an estimator diagnoser that predicts the state(s) the system is expected to be in, using the subsequent parameters measured by the other sensors. The efficacy of the proposed method is illustrated using a pumpvalve system. In addition, an MIDES based intrusion detection system has been developed for detection of rogue dynamic host configuration protocol(DHCP) server attack by mapping the attack to a fault in the DES framework.展开更多
This paper offers preliminary work on system dynamics and Data mining tools. It tries to understand the dynamics of carrying out large-scale events, such as Hajj. The study looks at a large, recurring problem as a var...This paper offers preliminary work on system dynamics and Data mining tools. It tries to understand the dynamics of carrying out large-scale events, such as Hajj. The study looks at a large, recurring problem as a variable to consider, such as how the flow of people changes over time as well as how location interacts with placement. The predicted data is analyzed using Vensim PLE 32 modeling software, GIS Arc Map 10.2.1, and AnyLogic 7.3.1 software regarding the potential placement of temporal service points, taking into consideration the three dynamic constraints and behavioral aspects: a large population, limitation in time, and space. This research proposes appropriate data analyses to ensure the optimal positioning of the service points with limited time and space for large-scale events. The conceptual framework would be the output of this study. Knowledge may be added to the insights based on the technique.展开更多
In Discrete Event System Specification(DEVS),the dynamics of a network is constituted only by the dynamics of its basic components.The state of each component is fully encapsulated.Control in the network is fully dece...In Discrete Event System Specification(DEVS),the dynamics of a network is constituted only by the dynamics of its basic components.The state of each component is fully encapsulated.Control in the network is fully decentralized to each component.At dynamic structure level,DEVS should permit the same level of decentralization.However,it is hard to ensure structure consistency while letting all components achieve structure changes.Besides,this solution can be complex to implement.To avoid these difficulties,usual dynamic structure approaches ensure structure consistency allowing structure changes to be done only by the network having newly added dynamics change capabilities.This is a safe and simple way to achieve dynamic structure.However,it should be possible to simply allow components of a network to modify the structure of their network,other components and/or their own structure—without having to modify the usual definition a DEVS network.In this manuscript,it is shown that a simple fully decentralized approach is possible while ensuring full modularity and structure consistency.展开更多
基金the Key Grant Project of Ministry of Education of the People’s Republic of China through Project,China(No.113027A)the Fundamental Research Funds for the Central Universities,China
文摘The goal of this paper is to provide an approach to investigate the variation of fiber quantity in a certain cross-section of the drafting zone. This model with discrete-event simulation( DES)method was presented to simulate the dynamic drafting process. This model described the behavior of individual fibers,which was divided into four phases and simulated by corresponding modules. Three sets of processing conditions in industry were simulated and demonstrated the applications of this model. The comparison between experiments and simulation results could also validate this model. This model could be used to simulate various drafting process with appropriate drafting settings.
基金supported by TATA Consultancy Services(TCS),India through TCS Research Fellowship Program
文摘Fault detection and diagnosis(FDD) facilitates reliable operation of systems. Various approaches have been proposed for FDD like Analytical redundancy(AR), Principal component analysis(PCA), Discrete event system(DES) model etc., in the literature. Performance of FDD schemes greatly depends on accuracy of the sensors which measure the system parameters.Due to various reasons like faults, communication errors etc.,sensors may occasionally miss or report erroneous values of some system parameters to FDD engine, resulting in measurement inconsistency of these parameters. Schemes like AR, PCA etc.,have mechanisms to handle measurement inconsistency, however,they are computationally heavy. DES based FDD techniques are widely used because of computational simplicity, but they cannot handle measurement inconsistency efficiently. Existing DES based schemes do not use Measurement inconsistent(MI)parameters for FDD. These parameters are not permanently unmeasurable or erroneous, so ignoring them may lead to weak diagnosis. To address this issue, we propose a Measurement inconsistent discrete event system(MIDES) framework, which uses MI parameters for FDD at the instances they are measured by the sensors. Otherwise, when they are unmeasurable or erroneously reported, the MIDES invokes an estimator diagnoser that predicts the state(s) the system is expected to be in, using the subsequent parameters measured by the other sensors. The efficacy of the proposed method is illustrated using a pumpvalve system. In addition, an MIDES based intrusion detection system has been developed for detection of rogue dynamic host configuration protocol(DHCP) server attack by mapping the attack to a fault in the DES framework.
文摘This paper offers preliminary work on system dynamics and Data mining tools. It tries to understand the dynamics of carrying out large-scale events, such as Hajj. The study looks at a large, recurring problem as a variable to consider, such as how the flow of people changes over time as well as how location interacts with placement. The predicted data is analyzed using Vensim PLE 32 modeling software, GIS Arc Map 10.2.1, and AnyLogic 7.3.1 software regarding the potential placement of temporal service points, taking into consideration the three dynamic constraints and behavioral aspects: a large population, limitation in time, and space. This research proposes appropriate data analyses to ensure the optimal positioning of the service points with limited time and space for large-scale events. The conceptual framework would be the output of this study. Knowledge may be added to the insights based on the technique.
文摘In Discrete Event System Specification(DEVS),the dynamics of a network is constituted only by the dynamics of its basic components.The state of each component is fully encapsulated.Control in the network is fully decentralized to each component.At dynamic structure level,DEVS should permit the same level of decentralization.However,it is hard to ensure structure consistency while letting all components achieve structure changes.Besides,this solution can be complex to implement.To avoid these difficulties,usual dynamic structure approaches ensure structure consistency allowing structure changes to be done only by the network having newly added dynamics change capabilities.This is a safe and simple way to achieve dynamic structure.However,it should be possible to simply allow components of a network to modify the structure of their network,other components and/or their own structure—without having to modify the usual definition a DEVS network.In this manuscript,it is shown that a simple fully decentralized approach is possible while ensuring full modularity and structure consistency.
