The network delay of the periodic messages transmission in the network control system （NCS） based on Ethemet for plant automation （EPA） is analyzed from the theoretical and experimental perspective in this paper. ...The network delay of the periodic messages transmission in the network control system （NCS） based on Ethemet for plant automation （EPA） is analyzed from the theoretical and experimental perspective in this paper. The composition and the characteristics of the network delay of EPA periodic messages transmission in a subnet is studied through analyzing the information transmission regularity and EPA deterministic scheduling mechanism. On this basis, the queuing delay at communication schedule management entity （EPA _ CSME） that is the most important component of network delay is analyzed, during which the formulas for the queuing delay of periodic messages and other real time parameters are proposed. Furthermore, an experiment is developed to test each component of network delay of periodic messages transmission in a EPA subnet. According to the experimental and the theoretical analysis, the conclusion is drawn that the delay during which the periodic messages wait for the periodic messages transmission time slice is the main factor that causes considerable network delay, and improvement method is presented.展开更多
The uncertainty of time, quantity and quality of recycling products leads to the bad stability and flexibility of remanufacturing logistics networks, while general design only covers the minimizing logistics cost, so ...The uncertainty of time, quantity and quality of recycling products leads to the bad stability and flexibility of remanufacturing logistics networks, while general design only covers the minimizing logistics cost, so robust design is presented to solve it. The mathematical model of remanufacturing logistics networks is built on the stochastic distribution of uncontrollable factors, and robust objectives are presented. The basic elements of robust design of remanufacturing logistics are redefined, and each part of mathematical model is explained in detail as well. Robust design of remanufacturing logistics networks is a problem of multi-objective optimization in essence.展开更多
Ethernet Ring Protection (ERP) introduced by ITU-T G.8032 Recommendation is a new type of packet-switched network protection technology, which can provide ring automatic protection switch. However, the Filtering Datab...Ethernet Ring Protection (ERP) introduced by ITU-T G.8032 Recommendation is a new type of packet-switched network protection technology, which can provide ring automatic protection switch. However, the Filtering Database (FDB) flush method adopted in the current ERP standard has the drawback of introducing a large amount of transient traffic overshoot caused by flooded Ethernet frames right after protection switching. In this article, we propose a G.8032 ERP scheme that uses FDB flush based on area to resolve this issue and investigate how the proposed scheme deals with the traffic flooding problem. The theoretical analysis and simulation show that the proposed scheme can effectively improve the performance of the Ethernet ring by decreasing the unnecessary FDB flush in comparison with the existing approaches.展开更多
Recent research has revealed that human exposure to air pollutants such as CO, NO_x, and particulates can lead to respiratory diseases, especially among school-age children. Towards understanding such health impacts, ...Recent research has revealed that human exposure to air pollutants such as CO, NO_x, and particulates can lead to respiratory diseases, especially among school-age children. Towards understanding such health impacts, this work estimates local-scale vehicular emissions and concentrations near a highway traffic network, where a school zone is located in. In the case study, VISSIM traffic micro-simulation is used to estimate the source of vehicular emissions at each roadway segment. The local-scale emission sources are then used as inputs to the California line source dispersion model(CALINE4) to estimate concentrations across the study area. To justify the local-scale emissions modeling approach, the simulation experiment is conducted under various traffic conditions. Different meteorological conditions are considered for emission dispersion. The work reveals that emission concentrations are usually higher at locations closer to the congested segments, freeway ramps and major arterial intersections. Compared to the macroscopic estimation(i.e. using network-average emission factors), the results show significantly different emission patterns when the local-scale emission modeling approach is used. In particular, it is found that the macroscopic approach over-estimates emission concentrations at freeways and under-estimations are observed at arterials and local streets. The results of the study can be used to compare to the US environmental protection agency(EPA) standards or any other air quality standard to further identify health risk in a fine-grained manner.展开更多
Using copyright rules clear government of geological information property rights is the main path to realization of geological information socially sharing. For China＇s current laws have an institute basic principle ...Using copyright rules clear government of geological information property rights is the main path to realization of geological information socially sharing. For China＇s current laws have an institute basic principle of geological information protected by copyright law, we need to detailed thinking the copyright subject, write content, licensing and other aspects, combine the geological information sharing mechanism.展开更多
Global changes, including the rise of the sea level and frequent terrible disasters, are apparently threatening the living environment. For environmental mitigation, security, and sustainability, Taiwan should have re...Global changes, including the rise of the sea level and frequent terrible disasters, are apparently threatening the living environment. For environmental mitigation, security, and sustainability, Taiwan should have reliable, incorporative area-based security-information networks to protect their environments. Plural （dual） surveillance which is rooted in biologic senses, e.g., from two-eyes, can have the feature of fault-tolerance, availability and maintainability in monitoring tasks. Further, it can fit the contemporary wireless communication methods being incorporated with MIMO （multi-in multi-out）, to prevent information loss, interference, unexpected changes caused by such as clogged water and chemical reactions. Consequently, network prototypes, including SW （spider-web）network and CCC （cube-connected cycle）, are proactively suggested. More reliable capabilities, including those encouraging local ferries and drones, for efficient logistic operation and mixed-use buildings with quality assured performance, can be good for smart urban growth, resource utilization in Taiwan, which is aimed as an aerotropolis--a means for placemaking.展开更多
基金Supported by the National High Technology Research and Development Programme of China (No. 2006AA040301-4, 2007AA041301-6 2007AA041407).
文摘The network delay of the periodic messages transmission in the network control system （NCS） based on Ethemet for plant automation （EPA） is analyzed from the theoretical and experimental perspective in this paper. The composition and the characteristics of the network delay of EPA periodic messages transmission in a subnet is studied through analyzing the information transmission regularity and EPA deterministic scheduling mechanism. On this basis, the queuing delay at communication schedule management entity （EPA _ CSME） that is the most important component of network delay is analyzed, during which the formulas for the queuing delay of periodic messages and other real time parameters are proposed. Furthermore, an experiment is developed to test each component of network delay of periodic messages transmission in a EPA subnet. According to the experimental and the theoretical analysis, the conclusion is drawn that the delay during which the periodic messages wait for the periodic messages transmission time slice is the main factor that causes considerable network delay, and improvement method is presented.
基金the Shanghai National Scientific Foundation (02ZH14060)
文摘The uncertainty of time, quantity and quality of recycling products leads to the bad stability and flexibility of remanufacturing logistics networks, while general design only covers the minimizing logistics cost, so robust design is presented to solve it. The mathematical model of remanufacturing logistics networks is built on the stochastic distribution of uncontrollable factors, and robust objectives are presented. The basic elements of robust design of remanufacturing logistics are redefined, and each part of mathematical model is explained in detail as well. Robust design of remanufacturing logistics networks is a problem of multi-objective optimization in essence.
基金supported partially by National Science and Technology Major Project of the Ministry of Science and Technology of China under Grant No.2011ZX03005-004-03 a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions-Information and Communication Engineering,Natural Science Foundation of the Higher Education Institutions of Jiangsu Province,China under Grant No.10KJA510037+1 种基金 Open Research Fund of Key Lab of Broadband Wireless Communication and Sensor Network Technology（Nanjing University of Posts and Telecommunications）,Ministry of Education under Grant No.NYKL201108 Natural Science Foundation of Nanjing University of Posts and Telecommunications under Grant No.NY209002
文摘Ethernet Ring Protection (ERP) introduced by ITU-T G.8032 Recommendation is a new type of packet-switched network protection technology, which can provide ring automatic protection switch. However, the Filtering Database (FDB) flush method adopted in the current ERP standard has the drawback of introducing a large amount of transient traffic overshoot caused by flooded Ethernet frames right after protection switching. In this article, we propose a G.8032 ERP scheme that uses FDB flush based on area to resolve this issue and investigate how the proposed scheme deals with the traffic flooding problem. The theoretical analysis and simulation show that the proposed scheme can effectively improve the performance of the Ethernet ring by decreasing the unnecessary FDB flush in comparison with the existing approaches.
文摘Recent research has revealed that human exposure to air pollutants such as CO, NO_x, and particulates can lead to respiratory diseases, especially among school-age children. Towards understanding such health impacts, this work estimates local-scale vehicular emissions and concentrations near a highway traffic network, where a school zone is located in. In the case study, VISSIM traffic micro-simulation is used to estimate the source of vehicular emissions at each roadway segment. The local-scale emission sources are then used as inputs to the California line source dispersion model(CALINE4) to estimate concentrations across the study area. To justify the local-scale emissions modeling approach, the simulation experiment is conducted under various traffic conditions. Different meteorological conditions are considered for emission dispersion. The work reveals that emission concentrations are usually higher at locations closer to the congested segments, freeway ramps and major arterial intersections. Compared to the macroscopic estimation(i.e. using network-average emission factors), the results show significantly different emission patterns when the local-scale emission modeling approach is used. In particular, it is found that the macroscopic approach over-estimates emission concentrations at freeways and under-estimations are observed at arterials and local streets. The results of the study can be used to compare to the US environmental protection agency(EPA) standards or any other air quality standard to further identify health risk in a fine-grained manner.
文摘Using copyright rules clear government of geological information property rights is the main path to realization of geological information socially sharing. For China＇s current laws have an institute basic principle of geological information protected by copyright law, we need to detailed thinking the copyright subject, write content, licensing and other aspects, combine the geological information sharing mechanism.
文摘Global changes, including the rise of the sea level and frequent terrible disasters, are apparently threatening the living environment. For environmental mitigation, security, and sustainability, Taiwan should have reliable, incorporative area-based security-information networks to protect their environments. Plural （dual） surveillance which is rooted in biologic senses, e.g., from two-eyes, can have the feature of fault-tolerance, availability and maintainability in monitoring tasks. Further, it can fit the contemporary wireless communication methods being incorporated with MIMO （multi-in multi-out）, to prevent information loss, interference, unexpected changes caused by such as clogged water and chemical reactions. Consequently, network prototypes, including SW （spider-web）network and CCC （cube-connected cycle）, are proactively suggested. More reliable capabilities, including those encouraging local ferries and drones, for efficient logistic operation and mixed-use buildings with quality assured performance, can be good for smart urban growth, resource utilization in Taiwan, which is aimed as an aerotropolis--a means for placemaking.
