In an integrated energy system(IES) composed of multiple subsystems, energy coupling causes an energy supply blockage or shutdown in one subsystem, thereby affecting the energy flow distribution optimization of other ...In an integrated energy system(IES) composed of multiple subsystems, energy coupling causes an energy supply blockage or shutdown in one subsystem, thereby affecting the energy flow distribution optimization of other subsystems.The energy supply should be globally optimized during the IES energy supply restoration process to produce the highest restoration net income. Mobile emergency sources can be quickly and flexibly connected to supply energy after an energy outage to ensure a reliable supply to the system, which adds complexity to the decision. This study focuses on a powergas IES with mobile emergency sources and analyzes the coupling relationship between the gas distribution system and the power distribution system in terms of sources, networks, and loads, and the influence of mobile emergency source transportation. The influence of the transient process caused by the restoration operation of the gas distribution system on the power distribution system is also discussed. An optimization model for power-gas IES restoration was established with the objective of maximizing the net income. The coordinated restoration optimization decision-making process was also built to realize the decoupling iteration of the power-gas IES, including system status recognition, mobile emergency source dispatching optimization, gas-to-power gas flow optimization, and parallel intra-partition restoration scheme optimization for both the power and gas distribution systems. A simulation test power-gas IES consisting of an 81-node medium-voltage power distribution network, an 89-node medium-pressure gas distribution network, and four mobile emergency sources was constructed. The simulation analysis verified the efficiency of the proposed coordinated restoration optimization method.展开更多
A multipath source self repair routing (MSSRR) algorithm for mobile ad hoc networks is proposed. By using multiple paths which can be repaired by themselves to transmit packets alternately, the network's load is b...A multipath source self repair routing (MSSRR) algorithm for mobile ad hoc networks is proposed. By using multiple paths which can be repaired by themselves to transmit packets alternately, the network's load is balanced, the link state in the network can be checked in time, the number of the times the route discovery mechanism starts is decreased. If only one route which will be broken can be used to transmit the packets, the route discovery mechanism is restarted.The algorithm is implemented on the basis of dynamic source routing (DSR). The effect of MSSRR on lifetime of the access from the source to the destination and the overhead is discussed. Compared with the performance of DSR,it can be seen that the algorithm can improve the performance of the network obviously and the overhead almost does not increase if the average hop count is larger.展开更多
A simple negative ion mobility spectrometer (IMS) is designed and used to investi- gate the factors that influence the number and efficiency of electrons generated by the needle-ring pulsed corona discharge electron...A simple negative ion mobility spectrometer (IMS) is designed and used to investi- gate the factors that influence the number and efficiency of electrons generated by the needle-ring pulsed corona discharge electron source. Simulation with Ansoft Maxwell 12 is carried out to analyze the electric field distribution within the IMS, and to offer the basis and foundation for analyzing the measurement results. The measurement results of the quantities of electrons show that when the drift electric field strength and the ring inner diameter rise, both the number of ef- fective electrons and the effective electron rate are increased. When the discharge voltage becomes stronger, the number of effective electrons goes up while the effective electron rate goes down. In light of the simulation results, mechanisms underlying the effects of drift electric field strength, ring inner diameter, and discharge voltage on the effective electron number and effective electron rate are discussed. These will make great sense for designing negative ion mode IMS using the needle-ring pulsed corona discharge as the electron source.展开更多
Continuous power supply of urban power networks(UPNs)is quite essential for the public security of a city because the UPN acts as the basis for other infrastructure networks.In recent years,UPN is threatened by extrem...Continuous power supply of urban power networks(UPNs)is quite essential for the public security of a city because the UPN acts as the basis for other infrastructure networks.In recent years,UPN is threatened by extreme weather events.An accurate modeling of load loss risk under extreme weather is quite essential for the preventive action of UPN.Con-sidering the forecast intensity of a typhoon disaster,this paper proposes analytical modeling of disaster-induced load loss for preventive allocation of mobile power sources(MPSs)in UPNs.First,based on the topological structure and fragility model of overhead lines and substations,we establish an analytical load loss model of multi-voltage-level UPN to quantify the spatial dis-tribution of disaster-induced load loss at the substation level.Second,according to the projected load loss distribution,a preventive allocation method of MPS is proposed,which makes the best use of MPS and dispatches the limited power supply to most vulnerable areas in the UPN.Finally,the proposed meth-od is validated by the case study of a practical UPN in China.展开更多
Increasing attention is being paid to the reduction of emissions from non-road mobile machinery,and many policies to promote the reduction have been established in countries and regions around the world,including the ...Increasing attention is being paid to the reduction of emissions from non-road mobile machinery,and many policies to promote the reduction have been established in countries and regions around the world,including the United States,Canada,the European Union,and China.This paper reviews these policies and analyzes two successful grant programs in the USA.Depending on the findings from the research,it is suggested that the Chinese government should tighten emission standards,introduce more financial subsidies,and strengthen supervision.展开更多
The paper investigated a new method of analyzing perfume odors.The study adopted IMS with glow dischargeas ion source and with positive ion mode.We got the quality characteristics of perfume odors in this way without ...The paper investigated a new method of analyzing perfume odors.The study adopted IMS with glow dischargeas ion source and with positive ion mode.We got the quality characteristics of perfume odors in this way without any collection and concentration process.The quality of perfume odors can be identified by IMS peak characteristics,and the characteristics of different quality of perfume also can be identified.In summary,the IMS is an effective technique in the perfume odor detection,it is also a new way of gas sample analysis.展开更多
We propose an on-demand multipath routing algorithm in a mobile ad hoc network for video transmission and evaluate its real world performance in video streaming application. There have been a number of multipath routi...We propose an on-demand multipath routing algorithm in a mobile ad hoc network for video transmission and evaluate its real world performance in video streaming application. There have been a number of multipath routing protocols extended from AODV which is a well-known single path routing protocol. Multipath routing protocols indicate good performance in the reduction of route discovery latency and unnecessary routing packets in simulations. We show that the route establishment using source route lists provided by us (Hu and Johnson, 2002) can reduce the route discovery latency, select stable routes automatically, and work well for live video streaming without limitation of the hop count based approaches. We evaluate this proposed method compared with the original AODV by using eight laptop PCs and demonstrate live streaming experiments.展开更多
The goal of this study is to analyze the relative contribution of different emission source categories to ozone in the Houston-Galveston-Brazoria (HGB) area of Texas. Emission Processing System (EPS3) is used to prepa...The goal of this study is to analyze the relative contribution of different emission source categories to ozone in the Houston-Galveston-Brazoria (HGB) area of Texas. Emission Processing System (EPS3) is used to prepare the emission files for five different source combination cases (Base case, Biogenic, Area + Biogenic, Mobile + Biogenic, Low-level Point + Biogenic). These emission files are used to perform photochemical modeling with Comprehensive Air Quality Model with Extensions (CAMx), and the results are analyzed with Visual Environment for Rich Data Interpretation (VERDI) tool. The daily maximum ozone concentrations and individual contributions of the source categories were analyzed over a 15-day study period between June 1-15, 2012, at three locations (University of Houston-Sugarland, Bayland Park and Conroe). Biogenic sources contributed an average of 49.7% ± 12.8%, 43.1% ± 12.0%, and 39.9% ± 9.28% at Sugarland, Bayland Park and Conroe sites respectively, indicating the significance of isoprene emissions from the vegetation in northeast Houston. On peak ozone days, contribution of Mobile + Biogenic source category averages about 80.1% ± 12.6%, 79.9% ± 6.50%, and 75.9% ± 10.9% at Sugarland, Bayland Park and Conroe sites respectively, indicating the dominance of mobile source NOX emissions and the necessity for regulatory focus on mobile source emissions control.展开更多
There exists a lack of detailed empirical studies to assess the relevance of WebMapping applications. Despite this fact, it is quite common to note that importance and influence of WebMapping applications have increas...There exists a lack of detailed empirical studies to assess the relevance of WebMapping applications. Despite this fact, it is quite common to note that importance and influence of WebMapping applications have increased over the last years. This paper presents the result of an empirical study to analyze the importance of a Desktop-WebMapping application for a gastronomic web 2.0 portal for the city of Osnabrück. An exploratory focus is to evaluate how often geospatial information (in a broader information context) from this web portal is used and how important the WebMapping applications are for the users of the web portal. Furthermore, it is evaluated which WebMapping functions (e.g. routing, queries, printing) are of relevance to the users and what the order of importance is for the provided functions. To-date, just a few mobile WebMapping applications for handheld devices exist. Consequently, for OsnaGo we developed a mobile WebMapping component that can be used with mobile phones, PDAs and other handheld devices to access the web portal (http://www.osnago-mobil.de). Development and user based evaluation is presented in this paper.展开更多
In recent years,great efforts have been devoted to reducing emissions from mobile sources with the dramatic growth of motor vehicle and nonroad mobile source populations.Compilation of a mobile source emission invento...In recent years,great efforts have been devoted to reducing emissions from mobile sources with the dramatic growth of motor vehicle and nonroad mobile source populations.Compilation of a mobile source emission inventory is conducive to the analysis of pollution emission characteristics and the formulation of emission reduction policies.This study summarizes the latest compilation approaches and data acquisition methods for mobile source emission inventories.For motor vehicles,a high-resolution emission inventory can be developed based on a bottom-up approach with a refined traffic flow model and real-world speed-coupled emission factors.The top-down approach has advantages when dealing with macroscale vehicle emission estimation without substantial traffic flow infrastructure.For nonroad mobile sources,nonroad machinery,inland river ships,locomotives,and civil aviation aircraft,a top-down approach based on fuel consumption or power is adopted.For ocean-going ships,a bottom-up approach based on automatic identification system(AIS)data is adopted.Three typical cases are studied,including emission reduction potential,a cost-benefit model,and marine shipping emission control.Outlooks and suggestions are given on future research directions for emission inventories for mobile sources:building localized emission models and factor databases,improving the dynamic updating capability of emission inventories,establishing a database of emission factors of unconventional pollutants and greenhouse gas from mobile sources,and establishing an urban high temporalspatial resolution volatile organic compound(VOC)evaporation emission inventory.展开更多
Monocyclic aromatic hydrocarbons(MAHs)and polycyclic aromatic hydrocarbons(PAHs)are both well known as hazardous air pollutants and also important anthropogenic precursors of tropospheric ozone(O3)and secondary organi...Monocyclic aromatic hydrocarbons(MAHs)and polycyclic aromatic hydrocarbons(PAHs)are both well known as hazardous air pollutants and also important anthropogenic precursors of tropospheric ozone(O3)and secondary organic aerosols(SOA).In recent years,there have been intensive studies covering MAHs emission from various sources and their behavior under stimulated photochemical conditions.Yet in-situ measurements of PAHs presence and variations in ambient air are sparse.Herein we conducted large geometrical scale mobile measurements for 16 aromatic hydrocarbons(AHs,including 7 MAHs and 9 PAHs)in eastern China between October 27 and November 8,2019.This unique dataset has allowed for some insights in terms of AHs concentration variations,accompanying chemical composition,source contributions and spatial distributions in eastern China.In general,AHs showed a clear concentration variability between the south and the north of the Yangtze River Delta(YRD).The concentrations of PAHs were approximately 9%of AHs,but contributed 23%of SOA formation potential.Source apportionment via positive matrix factorization(PMF)model revealed that industrial processes as the largest source(44%)of observed AHs,followed by solvent usage(21%),vehicle exhaust(19%),coal combustion(11%)and coking processes(6%).In the perspective of PAHs sources,coal combustion emissions were identified as the dominating factor of a share of 41%–52%in eastern China.Our findings complemented the simultaneously monitoring information of PAHs and MAHs in eastern China,revealed the importance of PAHs to SOA formation and highlighted the necessity of formulating strategies to reduce emissions from anthropogenic sources and reduce risks to human health.展开更多
基金supported by the Open Research Fund of Jiangsu Collaborative Innovation Center for Smart Distribution Network (XTCX202001)National Natural Science Foundation of China (52077061)。
文摘In an integrated energy system(IES) composed of multiple subsystems, energy coupling causes an energy supply blockage or shutdown in one subsystem, thereby affecting the energy flow distribution optimization of other subsystems.The energy supply should be globally optimized during the IES energy supply restoration process to produce the highest restoration net income. Mobile emergency sources can be quickly and flexibly connected to supply energy after an energy outage to ensure a reliable supply to the system, which adds complexity to the decision. This study focuses on a powergas IES with mobile emergency sources and analyzes the coupling relationship between the gas distribution system and the power distribution system in terms of sources, networks, and loads, and the influence of mobile emergency source transportation. The influence of the transient process caused by the restoration operation of the gas distribution system on the power distribution system is also discussed. An optimization model for power-gas IES restoration was established with the objective of maximizing the net income. The coordinated restoration optimization decision-making process was also built to realize the decoupling iteration of the power-gas IES, including system status recognition, mobile emergency source dispatching optimization, gas-to-power gas flow optimization, and parallel intra-partition restoration scheme optimization for both the power and gas distribution systems. A simulation test power-gas IES consisting of an 81-node medium-voltage power distribution network, an 89-node medium-pressure gas distribution network, and four mobile emergency sources was constructed. The simulation analysis verified the efficiency of the proposed coordinated restoration optimization method.
文摘A multipath source self repair routing (MSSRR) algorithm for mobile ad hoc networks is proposed. By using multiple paths which can be repaired by themselves to transmit packets alternately, the network's load is balanced, the link state in the network can be checked in time, the number of the times the route discovery mechanism starts is decreased. If only one route which will be broken can be used to transmit the packets, the route discovery mechanism is restarted.The algorithm is implemented on the basis of dynamic source routing (DSR). The effect of MSSRR on lifetime of the access from the source to the destination and the overhead is discussed. Compared with the performance of DSR,it can be seen that the algorithm can improve the performance of the network obviously and the overhead almost does not increase if the average hop count is larger.
基金supported by National Natural Science Foundation of China(No.51077062)
文摘A simple negative ion mobility spectrometer (IMS) is designed and used to investi- gate the factors that influence the number and efficiency of electrons generated by the needle-ring pulsed corona discharge electron source. Simulation with Ansoft Maxwell 12 is carried out to analyze the electric field distribution within the IMS, and to offer the basis and foundation for analyzing the measurement results. The measurement results of the quantities of electrons show that when the drift electric field strength and the ring inner diameter rise, both the number of ef- fective electrons and the effective electron rate are increased. When the discharge voltage becomes stronger, the number of effective electrons goes up while the effective electron rate goes down. In light of the simulation results, mechanisms underlying the effects of drift electric field strength, ring inner diameter, and discharge voltage on the effective electron number and effective electron rate are discussed. These will make great sense for designing negative ion mode IMS using the needle-ring pulsed corona discharge as the electron source.
基金supported by National Natural Science Foundation of China(No.52307094).
文摘Continuous power supply of urban power networks(UPNs)is quite essential for the public security of a city because the UPN acts as the basis for other infrastructure networks.In recent years,UPN is threatened by extreme weather events.An accurate modeling of load loss risk under extreme weather is quite essential for the preventive action of UPN.Con-sidering the forecast intensity of a typhoon disaster,this paper proposes analytical modeling of disaster-induced load loss for preventive allocation of mobile power sources(MPSs)in UPNs.First,based on the topological structure and fragility model of overhead lines and substations,we establish an analytical load loss model of multi-voltage-level UPN to quantify the spatial dis-tribution of disaster-induced load loss at the substation level.Second,according to the projected load loss distribution,a preventive allocation method of MPS is proposed,which makes the best use of MPS and dispatches the limited power supply to most vulnerable areas in the UPN.Finally,the proposed meth-od is validated by the case study of a practical UPN in China.
基金Environment and Conservation Fund:Environmental Research,Technology Demonstration and Conference of the Hong Kong Special Administrative Region,China(Project Ref.55/2019)。
文摘Increasing attention is being paid to the reduction of emissions from non-road mobile machinery,and many policies to promote the reduction have been established in countries and regions around the world,including the United States,Canada,the European Union,and China.This paper reviews these policies and analyzes two successful grant programs in the USA.Depending on the findings from the research,it is suggested that the Chinese government should tighten emission standards,introduce more financial subsidies,and strengthen supervision.
文摘The paper investigated a new method of analyzing perfume odors.The study adopted IMS with glow dischargeas ion source and with positive ion mode.We got the quality characteristics of perfume odors in this way without any collection and concentration process.The quality of perfume odors can be identified by IMS peak characteristics,and the characteristics of different quality of perfume also can be identified.In summary,the IMS is an effective technique in the perfume odor detection,it is also a new way of gas sample analysis.
文摘We propose an on-demand multipath routing algorithm in a mobile ad hoc network for video transmission and evaluate its real world performance in video streaming application. There have been a number of multipath routing protocols extended from AODV which is a well-known single path routing protocol. Multipath routing protocols indicate good performance in the reduction of route discovery latency and unnecessary routing packets in simulations. We show that the route establishment using source route lists provided by us (Hu and Johnson, 2002) can reduce the route discovery latency, select stable routes automatically, and work well for live video streaming without limitation of the hop count based approaches. We evaluate this proposed method compared with the original AODV by using eight laptop PCs and demonstrate live streaming experiments.
文摘The goal of this study is to analyze the relative contribution of different emission source categories to ozone in the Houston-Galveston-Brazoria (HGB) area of Texas. Emission Processing System (EPS3) is used to prepare the emission files for five different source combination cases (Base case, Biogenic, Area + Biogenic, Mobile + Biogenic, Low-level Point + Biogenic). These emission files are used to perform photochemical modeling with Comprehensive Air Quality Model with Extensions (CAMx), and the results are analyzed with Visual Environment for Rich Data Interpretation (VERDI) tool. The daily maximum ozone concentrations and individual contributions of the source categories were analyzed over a 15-day study period between June 1-15, 2012, at three locations (University of Houston-Sugarland, Bayland Park and Conroe). Biogenic sources contributed an average of 49.7% ± 12.8%, 43.1% ± 12.0%, and 39.9% ± 9.28% at Sugarland, Bayland Park and Conroe sites respectively, indicating the significance of isoprene emissions from the vegetation in northeast Houston. On peak ozone days, contribution of Mobile + Biogenic source category averages about 80.1% ± 12.6%, 79.9% ± 6.50%, and 75.9% ± 10.9% at Sugarland, Bayland Park and Conroe sites respectively, indicating the dominance of mobile source NOX emissions and the necessity for regulatory focus on mobile source emissions control.
文摘There exists a lack of detailed empirical studies to assess the relevance of WebMapping applications. Despite this fact, it is quite common to note that importance and influence of WebMapping applications have increased over the last years. This paper presents the result of an empirical study to analyze the importance of a Desktop-WebMapping application for a gastronomic web 2.0 portal for the city of Osnabrück. An exploratory focus is to evaluate how often geospatial information (in a broader information context) from this web portal is used and how important the WebMapping applications are for the users of the web portal. Furthermore, it is evaluated which WebMapping functions (e.g. routing, queries, printing) are of relevance to the users and what the order of importance is for the provided functions. To-date, just a few mobile WebMapping applications for handheld devices exist. Consequently, for OsnaGo we developed a mobile WebMapping component that can be used with mobile phones, PDAs and other handheld devices to access the web portal (http://www.osnago-mobil.de). Development and user based evaluation is presented in this paper.
基金supported by the National Key Research and Development Program of China(Nos.2016YFC0208000,2019YFC0214800 and 2016YFC0201504)the National Natural Science Foundation of China(No.62033012)。
文摘In recent years,great efforts have been devoted to reducing emissions from mobile sources with the dramatic growth of motor vehicle and nonroad mobile source populations.Compilation of a mobile source emission inventory is conducive to the analysis of pollution emission characteristics and the formulation of emission reduction policies.This study summarizes the latest compilation approaches and data acquisition methods for mobile source emission inventories.For motor vehicles,a high-resolution emission inventory can be developed based on a bottom-up approach with a refined traffic flow model and real-world speed-coupled emission factors.The top-down approach has advantages when dealing with macroscale vehicle emission estimation without substantial traffic flow infrastructure.For nonroad mobile sources,nonroad machinery,inland river ships,locomotives,and civil aviation aircraft,a top-down approach based on fuel consumption or power is adopted.For ocean-going ships,a bottom-up approach based on automatic identification system(AIS)data is adopted.Three typical cases are studied,including emission reduction potential,a cost-benefit model,and marine shipping emission control.Outlooks and suggestions are given on future research directions for emission inventories for mobile sources:building localized emission models and factor databases,improving the dynamic updating capability of emission inventories,establishing a database of emission factors of unconventional pollutants and greenhouse gas from mobile sources,and establishing an urban high temporalspatial resolution volatile organic compound(VOC)evaporation emission inventory.
基金supported by the National Natural Science Foundation of China(No.42175135)the Science and Technology Commission of the Shanghai Municipality(No.20ZR1447800).
文摘Monocyclic aromatic hydrocarbons(MAHs)and polycyclic aromatic hydrocarbons(PAHs)are both well known as hazardous air pollutants and also important anthropogenic precursors of tropospheric ozone(O3)and secondary organic aerosols(SOA).In recent years,there have been intensive studies covering MAHs emission from various sources and their behavior under stimulated photochemical conditions.Yet in-situ measurements of PAHs presence and variations in ambient air are sparse.Herein we conducted large geometrical scale mobile measurements for 16 aromatic hydrocarbons(AHs,including 7 MAHs and 9 PAHs)in eastern China between October 27 and November 8,2019.This unique dataset has allowed for some insights in terms of AHs concentration variations,accompanying chemical composition,source contributions and spatial distributions in eastern China.In general,AHs showed a clear concentration variability between the south and the north of the Yangtze River Delta(YRD).The concentrations of PAHs were approximately 9%of AHs,but contributed 23%of SOA formation potential.Source apportionment via positive matrix factorization(PMF)model revealed that industrial processes as the largest source(44%)of observed AHs,followed by solvent usage(21%),vehicle exhaust(19%),coal combustion(11%)and coking processes(6%).In the perspective of PAHs sources,coal combustion emissions were identified as the dominating factor of a share of 41%–52%in eastern China.Our findings complemented the simultaneously monitoring information of PAHs and MAHs in eastern China,revealed the importance of PAHs to SOA formation and highlighted the necessity of formulating strategies to reduce emissions from anthropogenic sources and reduce risks to human health.