The path loss analysis model based on 5 rays in vacancy indoor environment is proposed. The relationship between multipath overlapping and the path loss is analyzed mathematically. Time-domain technique is introduced ...The path loss analysis model based on 5 rays in vacancy indoor environment is proposed. The relationship between multipath overlapping and the path loss is analyzed mathematically. Time-domain technique is introduced to compute reflection coefficient in a very short time interval. A 5 rays path loss calculation method, which is satisfactory accurate, is developed. 5 typical environments are involved to analyze and generalize the common path loss characteristics in vacancy indoor environment. The simulation result shows that the path loss can be characterized as 3 zones with different path loss exponent as distance between transmitter and receiver increasing.展开更多
Probabilistic Seismic Loss Estimation is a methodology used as a quantitative and explicit expression of the performance of buildings using terms that address the interests of both owners and insurance companies. Appl...Probabilistic Seismic Loss Estimation is a methodology used as a quantitative and explicit expression of the performance of buildings using terms that address the interests of both owners and insurance companies. Applying the ATC 58 approach for seismic loss assessment of buildings requires using Incremental Dynamic Analysis （IDA）, which needs hundreds of time-consuming analyses, which in turn hinders its wide application. The Endurance Time Method （ETM） is proposed herein as part of a demand propagation prediction procedure and is shown to be an economical alternative to IDA. Various scenarios were considered to achieve this purpose and their appropriateness has been evaluated using statistical methods. The most precise and efficient scenario was validated through comparison against IDA driven response predictions of 34 code conforming benchmark structures and was proven to be sufficiently precise while offering a great deal of efficiency. The loss values were estimated by replacing IDA with the proposed ETM-based procedure in the ATC 58 procedure and it was fotmd that these values suffer from varying inaccuracies, which were attributed to the discretized nature of damage and loss prediction functions provided by ATC 58.展开更多
In this paper,a fault tolerant control with the consideration of actuator fault for a networked control system （NCS） with packet loss is addressed.The NCS with data packet loss can be described as a switched system ...In this paper,a fault tolerant control with the consideration of actuator fault for a networked control system （NCS） with packet loss is addressed.The NCS with data packet loss can be described as a switched system model.Packet loss dependent Lyapunov function is used and a fault tolerant controller is proposed respectively for arbitrary packet loss process and Markovian packet loss process.Considering a controlled plant with external energy-bounded disturbance,a robust H ∞ fault tolerant controller is designed for the NCS.These results are also expanded to the NCS with packet loss and networked-induced delay.Numerical examples are given to illustrate the effectiveness of the proposed design method.展开更多
The objective of this paper is to present the advantages of Model reference adaptive control (MRAC) motion cueing algorithm against the classical motion cueing algorithm in terms of biomechanical reactions of the part...The objective of this paper is to present the advantages of Model reference adaptive control (MRAC) motion cueing algorithm against the classical motion cueing algorithm in terms of biomechanical reactions of the participants during the critical maneuvers like chicane in driving simulator real-time. This study proposes a method and an experimental validation to analyze the vestibular and neuromuscular dynamics responses of the drivers with respect to the type of the control used at the hexapod driving simulator. For each situation, the EMG (electromyography) data were registered from arm muscles of the drivers (flexor carpi radialis, brachioradialis). In addition, the roll velocity perception thresholds (RVT) and roll velocities (RV) were computed from the real-time vestibular level measurements from the drivers via a motion-tracking sensor. In order to process the data of the EMG and RVT, Pearson’s correlation and a two-way ANOVA with a significance level of 0.05 were assigned. Moreover, the relationships of arm muscle power and roll velocity with vehicle CG (center of gravity) lateral displacement were analyzed in order to assess the agility/alertness level of the drivers as well as the vehicle loss of control characteristics with a confidence interval of 95%. The results showed that the MRAC algorithm avoided the loss of adhesion, loss of control (LOA, LOC) more reasonably compared to the classical motion cueing algorithm. According to our findings, the LOA avoidance decreased the neuromuscular-visual cues level conflict with MRAC algorithm. It also revealed that the neuromuscular-vehicle dynamics conflict has influence on visuo-vestibular conflict;however, the visuo-vestibular cue conflict does not influence the neuromuscular-vehicle dynamics interactions.展开更多
INSITE(Integrated System for Information Technology and Engineering)软件是哈里伯顿公司支持其随钻测井服务的地面系统,其核心部分是一个庞大的开放式数据库(ODBC)连接的数据库系统。通过探索INSITE软件的隐藏功能,可以在广域网和...INSITE(Integrated System for Information Technology and Engineering)软件是哈里伯顿公司支持其随钻测井服务的地面系统,其核心部分是一个庞大的开放式数据库(ODBC)连接的数据库系统。通过探索INSITE软件的隐藏功能,可以在广域网和局域网内让全球INSITE工作站实时连接在一起,在任何地方都可以共享到这些数据库,从而实现24小时的实时监控,为现场作业提供强大的实时支持。主要介绍的随钻测井、测量相关模块的数据库原理。同时通过现场对隐藏功能的开发应用,实现现场作业难题的解决,减少因故障造成的经济损失。展开更多
基金This project was supported by the key programof the Nationed Natural Science Foundation of China (60432040)
文摘The path loss analysis model based on 5 rays in vacancy indoor environment is proposed. The relationship between multipath overlapping and the path loss is analyzed mathematically. Time-domain technique is introduced to compute reflection coefficient in a very short time interval. A 5 rays path loss calculation method, which is satisfactory accurate, is developed. 5 typical environments are involved to analyze and generalize the common path loss characteristics in vacancy indoor environment. The simulation result shows that the path loss can be characterized as 3 zones with different path loss exponent as distance between transmitter and receiver increasing.
文摘Probabilistic Seismic Loss Estimation is a methodology used as a quantitative and explicit expression of the performance of buildings using terms that address the interests of both owners and insurance companies. Applying the ATC 58 approach for seismic loss assessment of buildings requires using Incremental Dynamic Analysis （IDA）, which needs hundreds of time-consuming analyses, which in turn hinders its wide application. The Endurance Time Method （ETM） is proposed herein as part of a demand propagation prediction procedure and is shown to be an economical alternative to IDA. Various scenarios were considered to achieve this purpose and their appropriateness has been evaluated using statistical methods. The most precise and efficient scenario was validated through comparison against IDA driven response predictions of 34 code conforming benchmark structures and was proven to be sufficiently precise while offering a great deal of efficiency. The loss values were estimated by replacing IDA with the proposed ETM-based procedure in the ATC 58 procedure and it was fotmd that these values suffer from varying inaccuracies, which were attributed to the discretized nature of damage and loss prediction functions provided by ATC 58.
基金supported by National Natural Science Foundation of China (No. 60874052)
文摘In this paper,a fault tolerant control with the consideration of actuator fault for a networked control system （NCS） with packet loss is addressed.The NCS with data packet loss can be described as a switched system model.Packet loss dependent Lyapunov function is used and a fault tolerant controller is proposed respectively for arbitrary packet loss process and Markovian packet loss process.Considering a controlled plant with external energy-bounded disturbance,a robust H ∞ fault tolerant controller is designed for the NCS.These results are also expanded to the NCS with packet loss and networked-induced delay.Numerical examples are given to illustrate the effectiveness of the proposed design method.
文摘The objective of this paper is to present the advantages of Model reference adaptive control (MRAC) motion cueing algorithm against the classical motion cueing algorithm in terms of biomechanical reactions of the participants during the critical maneuvers like chicane in driving simulator real-time. This study proposes a method and an experimental validation to analyze the vestibular and neuromuscular dynamics responses of the drivers with respect to the type of the control used at the hexapod driving simulator. For each situation, the EMG (electromyography) data were registered from arm muscles of the drivers (flexor carpi radialis, brachioradialis). In addition, the roll velocity perception thresholds (RVT) and roll velocities (RV) were computed from the real-time vestibular level measurements from the drivers via a motion-tracking sensor. In order to process the data of the EMG and RVT, Pearson’s correlation and a two-way ANOVA with a significance level of 0.05 were assigned. Moreover, the relationships of arm muscle power and roll velocity with vehicle CG (center of gravity) lateral displacement were analyzed in order to assess the agility/alertness level of the drivers as well as the vehicle loss of control characteristics with a confidence interval of 95%. The results showed that the MRAC algorithm avoided the loss of adhesion, loss of control (LOA, LOC) more reasonably compared to the classical motion cueing algorithm. According to our findings, the LOA avoidance decreased the neuromuscular-visual cues level conflict with MRAC algorithm. It also revealed that the neuromuscular-vehicle dynamics conflict has influence on visuo-vestibular conflict;however, the visuo-vestibular cue conflict does not influence the neuromuscular-vehicle dynamics interactions.
文摘INSITE(Integrated System for Information Technology and Engineering)软件是哈里伯顿公司支持其随钻测井服务的地面系统,其核心部分是一个庞大的开放式数据库(ODBC)连接的数据库系统。通过探索INSITE软件的隐藏功能,可以在广域网和局域网内让全球INSITE工作站实时连接在一起,在任何地方都可以共享到这些数据库,从而实现24小时的实时监控,为现场作业提供强大的实时支持。主要介绍的随钻测井、测量相关模块的数据库原理。同时通过现场对隐藏功能的开发应用,实现现场作业难题的解决,减少因故障造成的经济损失。
