Lodging is still the key factor that limits continuous increases in wheat yields today,because the mechanical strength of culms is reduced due to low-light stress in populations under high-yield cultivation.The mechan...Lodging is still the key factor that limits continuous increases in wheat yields today,because the mechanical strength of culms is reduced due to low-light stress in populations under high-yield cultivation.The mechanical properties of the culm are mainly determined by lignin,which is affected by the light environment.However,little is known about whether the light environment can be sufficiently improved by changing the population distribution to inhibit culm lodging.Therefore,in this study,we used the wheat cultivar“Xinong 979”to establish a low-density homogeneous distribution treatment(LD),high-density homogeneous distribution treatment(HD),and high-density heterogeneous distribution treatment(HD-h)to study the regulatory effects and mechanism responsible for differences in the lodging resistance of wheat culms under different population distributions.Compared with LD,HD significantly reduced the light transmittance in the middle and basal layers of the canopy,the net photosynthetic rate in the middle and lower leaves of plants,the accumulation of lignin in the culm,and the breaking resistance of the culm,and thus the lodging index values increased significantly,with lodging rates of 67.5%in 2020–2021 and 59.3%in 2021–2022.Under HD-h,the light transmittance and other indicators in the middle and basal canopy layers were significantly higher than those under HD,and the lodging index decreased to the point that no lodging occurred.Compared with LD,the activities of phenylalanine ammonia-Lyase(PAL),4-coumarate:coenzyme A ligase(4CL),catechol-O-methyltransferase(COMT),and cinnamyl-alcohol dehydrogenase(CAD)in the lignin synthesis pathway were significantly reduced in the culms under HD during the critical period for culm formation,and the relative expression levels of TaPAL,Ta4CL,TaCOMT,and TaCAD were significantly downregulated.However,the activities of lignin synthesis-related enzymes and their gene expression levels were significantly increased under HD-h compared with HD.A partial least squares path modeling analysis found significant positive effects between the canopy light environment,the photosynthetic capacity of the middle and lower leaves of plants,lignin synthesis and accumulation,and lodging resistance in the culms.Thus,under conventional high-density planting,the risk of wheat lodging was significantly higher.Accordingly,the canopy light environment can be optimized by changing the heterogeneity of the population distribution to improve the photosynthetic capacity of the middle and lower leaves of plants,promote lignin accumulation in the culm,and enhance lodging resistance in wheat.These findings provide a basis for understanding the mechanism responsible for the lower mechanical strength of the culm under high-yield wheat cultivation,and a theoretical basis and for developing technical measures to enhance lodging resistance.展开更多
Buds emerge from the roots of domesticated runner bean plants (Phaseolus coccineus L.) as sprouts and give the crop its persistence. This particularity of the species seems to be associated with the environment where ...Buds emerge from the roots of domesticated runner bean plants (Phaseolus coccineus L.) as sprouts and give the crop its persistence. This particularity of the species seems to be associated with the environment where the species was cultivated during long time. Data on regrowth traits were recorded on 70 accessions of domesticated P. coccineus after overwintering at a site in the central highlands of Mexico. The characteristics recorded included fresh weight of vegetative regrowth, root length, root crown diameter, and diameter of the main root. Most accessions that sprout the following spring, after the grain harvest of the previous year, come from temperate and semi-cold sites with cambisol and andosol soils in mixed Quercus pine forest and high mountain fir trees. Those that do not sprout are from sites of semiarid temperate climate, haplic phaeozem soil in shrub grasslands with deciduous broadleaved trees, and semiwarm subhumid climate, eutrophic regosol soil in deciduous broadleaved forest. Two types of roots were differentiated: branched and thickened taproots, also associated with a different climate, and the type of soil of the collection sites.展开更多
Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of hetero...Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of heterogeneous computer's distributed virtual environment system (HCWES) designed to populate some mobile agents as well as stationary agents. Finally, the paper introduces how heterogeneous computer network communication is to be realized.展开更多
Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture ...Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture are also discussed. The architecture basically meets the need of DVGE in real-time communication, distribution, collaboration, reusing and interoperation, expansion, and standard.展开更多
This paper introduces a hierarchical real-time environment for developing ship-bornefire-control system. Advanced computer networks are used to simulate the system with the requiredengagement scenario, including own-s...This paper introduces a hierarchical real-time environment for developing ship-bornefire-control system. Advanced computer networks are used to simulate the system with the requiredengagement scenario, including own-ship and parameters, and data processing and transmission,mission calculation, graphical supervision and gunnery ballistics outputting. The simulation systemis able to receive instruction from, or send information to the command-control center. Furthermore,the system can also be used to compare various designed schemes and analyze the accuracy andeffectiveness of the system.展开更多
A new chance of developing traditional manufacturing industry comes forth with the development of network technology. Application technology oriented rapid response manufacturing in the distributed network environment...A new chance of developing traditional manufacturing industry comes forth with the development of network technology. Application technology oriented rapid response manufacturing in the distributed network environments, that is, how to take advantage of the Intranet and Internet, combine the numerous manufacturing resources spread around the region, the country and even the globe is the key to the agile design, manufacturing and the buildup of comprehensively competitive power, at the same time, is also an important research direction in the field of advanced manufacturing technology. Rapid response manufacturing in the distributed network environment is a newly manufactory pattern that can be used to implement the conception of agile design and manufacturing, but there are some new problems coming with it, which will directly influence the enterprise’s ability of rapid response in the distributed network manufacturing pattern and lead to the failure of the league and the lost of the given orders. In this paper, we establish some approaches to solve these problems in product development process. The paper then presents the research on key application technologies and solutions includes: network safety strategy which guarantees data transferring among the leaguer members, production data management based on Web/DOT (Distributed Object Technology) and XML criteria which guarantees data exchange in structure-variance characteristic environments, the network platform which provides the conversion service of different types of CAD files each other. All of these solutions are aim for technology problems existing in the distributed network environments and among the league members. Finally, the paper takes one project, that is, the establishment of the online application service system for Shanghai Advance Manufacturing Technology Research Center as a good instance.展开更多
Because most ensemble learning algorithms use the centralized model, and the training instances must be centralized on a single station, it is difficult to centralize the training data on a station. A distributed ense...Because most ensemble learning algorithms use the centralized model, and the training instances must be centralized on a single station, it is difficult to centralize the training data on a station. A distributed ensemble learning algorithm is proposed which has two kinds of weight genes of instances that denote the global distribution and the local distribution. Instead of the repeated sampling method in the standard ensemble learning, non-balance sampling from each station is used to train the base classifier set of each station. The concept of the effective nearby region for local integration classifier is proposed, and is used for the dynamic integration method of multiple classifiers in distributed environment. The experiments show that the ensemble learning algorithm in distributed environment proposed could reduce the time of training the base classifiers effectively, and ensure the classify performance is as same as the centralized learning method.展开更多
his paper examines planning management problems in a Multiagentbased Distributed Open Computing Environment Model (MDOCEM). First the meaning of planning management in MDOCEM is introduced, and then a formal method to...his paper examines planning management problems in a Multiagentbased Distributed Open Computing Environment Model (MDOCEM). First the meaning of planning management in MDOCEM is introduced, and then a formal method to describe the associated task partition problems is presented, and a heuristic algorithm which gives an approximate optimum solution is given. Finally the task coordination and integration of execution results are discussed.展开更多
In this paper, the properties of distributed virtual environment (DVE) and the requirements on computer networks is briefly reviewed. A multicast protocol, called sender initiated grouping multicast protocol for DVE...In this paper, the properties of distributed virtual environment (DVE) and the requirements on computer networks is briefly reviewed. A multicast protocol, called sender initiated grouping multicast protocol for DVE (SIGMP), is proposed. This new multicast protocol is based on a novel concept, multicast group (MG), which divides all participants in a DVE system into groups, among which there is a multicast group trustee (MGT) node to manage the group. The protocol provides unreliable/reliable, totally ordered and multiple to multiple multicast transmission service for DVE systems without sacrificing the communication efficiency heavily. At the same time, reliable unicast and one to multiple multicast transmission services are also supported. The performance analysis of the new protocols is also presented. Based on SIGMP, a simple demonstration of DVE system is designed and implemented. This demo system is running on several SGI workstations connected by a FDDI and Ethernet network.展开更多
Simulation has become the evaluation method of choice for many areas of distributing computing research. Simulation has been applied successfully for modeling small and large complex systems and understanding their be...Simulation has become the evaluation method of choice for many areas of distributing computing research. Simulation has been applied successfully for modeling small and large complex systems and understanding their behavior, especially in the area of distributed systems or parallel environment. The aim of my research is to study and qualitative analysis of simulation on a single server & on distributed environment and finding the related issues & its comparison.展开更多
To meet the authorization administration requirements in a distributedcomputer network environment, this paper extends the role-based access control model with multipleapplication dimensions and establishes a new acce...To meet the authorization administration requirements in a distributedcomputer network environment, this paper extends the role-based access control model with multipleapplication dimensions and establishes a new access control model ED-RBAC(Extended Role Based AccessControl Model) for the distributed environment. We propose an extendable hierarchical authorizationassignment framework and design effective role-registeringi role-applying and role-assigningprotocol with symmetric and asymmetric cryptographic systems. The model can be used to simplifyauthorization administration in a distributed environment with multiple applications.展开更多
Distributed virtual coal-mine geography environment(CM-DVGE) researches the virtual reality simulation of coal-mine environment in cyberspace and the performance of coal production process. The goal is to deal with ...Distributed virtual coal-mine geography environment(CM-DVGE) researches the virtual reality simulation of coal-mine environment in cyberspace and the performance of coal production process. The goal is to deal with the practical safety problems of observation, analysis, design and training during the underground coal production process. This paper first probed into the evolution of CM-DVGE from a historical point of view, then respectively analyzed the characteristics of its physical progressive levels according to the cognitivd law and its logical structure of data on the basis of data flow, and concluded by putting forward the prospect of the application of CM-DVGE, thus enriched and developed the method of synthetic study of coal mine.展开更多
Studies the design of distributed virtual environments (DVEs) for tele-multi-robotics. The proposed design, incorporating two models ( distributlon-supported model and VE-supported model), attempts to represent co...Studies the design of distributed virtual environments (DVEs) for tele-multi-robotics. The proposed design, incorporating two models ( distributlon-supported model and VE-supported model), attempts to represent common functionality, communication issues, and requirements found in multi-operator DVEs. The distribution-supported model concentrates on the introduction of computer-supported collaborative work (CSCW) to realize the coordination of multi-operators, while the VE-supported model concentrates on the utilization of an object-oriented approach to strengthen the expandability and robustness of the system. Finally, the configuration anti running environments of the system are given.展开更多
The inherent complexity and uncertainty of multi-operator multi-robot (MOMR) tele-operation system make its safeguard an essential problem. Hazardous factors in the system are analyzed using fault tree analysis(FTA...The inherent complexity and uncertainty of multi-operator multi-robot (MOMR) tele-operation system make its safeguard an essential problem. Hazardous factors in the system are analyzed using fault tree analysis(FTA) technology, and three-layer interactive safety architecture with information flow is designed in modules to control the factors according to the holistic control mode. After that, distributed virtual environment (DVE) including the characteristics of virtual guide (VG) technology is discussed to help the operators achieve some tasks through the visibility of control commands, time-delay, movement collision and operators' intentions. Finally an experiment is implemented to test the efficiency of safety control architecture by using two robots to place some building blocks in the same workspace.展开更多
Correction to:Acta Geochimica(2022)41:968–981 https://doi.org/10.1007/s11631-022-00555-w In the original publication of the article,the affi liation of“Behzad Aghabarari”was published incorrectly.The correct affi l...Correction to:Acta Geochimica(2022)41:968–981 https://doi.org/10.1007/s11631-022-00555-w In the original publication of the article,the affi liation of“Behzad Aghabarari”was published incorrectly.The correct affi liation should read as follows“Department of Nanotechnology and Advanced Materials,Material and Energy Research Center,Karaj,Iran”.展开更多
Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorptio...Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.展开更多
In the distributed environment,robots should be able to provide users with adaptive services automatically according to the situational information changing dynamically which is obtained from both users and their envi...In the distributed environment,robots should be able to provide users with adaptive services automatically according to the situational information changing dynamically which is obtained from both users and their environments.The workflow depends on situational information obtained from physical environments and provides context-aware services automatically based on the information retrieved.And the workflow in the business processes and the distributed computing environments have supported the automation of services by connecting tasks.The workflow needs to specify ubiquitous situational information as state-transition constraints.However,the delivery and use of sensor data in the workflow is a difficult problem for the robot system.In order to bridge the gap between applications and low-level constructs and to acquire raw situational information for the execution of the context-aware workflow in the robot systems,this paper presents an approach which can achieve the sensor data transmission between a sensing server and a robot system easily.展开更多
基金the National Natural Science Foundation of China(32071955)the Natural Science Foundation of Shaanxi Province,China(2018JQ3061).
文摘Lodging is still the key factor that limits continuous increases in wheat yields today,because the mechanical strength of culms is reduced due to low-light stress in populations under high-yield cultivation.The mechanical properties of the culm are mainly determined by lignin,which is affected by the light environment.However,little is known about whether the light environment can be sufficiently improved by changing the population distribution to inhibit culm lodging.Therefore,in this study,we used the wheat cultivar“Xinong 979”to establish a low-density homogeneous distribution treatment(LD),high-density homogeneous distribution treatment(HD),and high-density heterogeneous distribution treatment(HD-h)to study the regulatory effects and mechanism responsible for differences in the lodging resistance of wheat culms under different population distributions.Compared with LD,HD significantly reduced the light transmittance in the middle and basal layers of the canopy,the net photosynthetic rate in the middle and lower leaves of plants,the accumulation of lignin in the culm,and the breaking resistance of the culm,and thus the lodging index values increased significantly,with lodging rates of 67.5%in 2020–2021 and 59.3%in 2021–2022.Under HD-h,the light transmittance and other indicators in the middle and basal canopy layers were significantly higher than those under HD,and the lodging index decreased to the point that no lodging occurred.Compared with LD,the activities of phenylalanine ammonia-Lyase(PAL),4-coumarate:coenzyme A ligase(4CL),catechol-O-methyltransferase(COMT),and cinnamyl-alcohol dehydrogenase(CAD)in the lignin synthesis pathway were significantly reduced in the culms under HD during the critical period for culm formation,and the relative expression levels of TaPAL,Ta4CL,TaCOMT,and TaCAD were significantly downregulated.However,the activities of lignin synthesis-related enzymes and their gene expression levels were significantly increased under HD-h compared with HD.A partial least squares path modeling analysis found significant positive effects between the canopy light environment,the photosynthetic capacity of the middle and lower leaves of plants,lignin synthesis and accumulation,and lodging resistance in the culms.Thus,under conventional high-density planting,the risk of wheat lodging was significantly higher.Accordingly,the canopy light environment can be optimized by changing the heterogeneity of the population distribution to improve the photosynthetic capacity of the middle and lower leaves of plants,promote lignin accumulation in the culm,and enhance lodging resistance in wheat.These findings provide a basis for understanding the mechanism responsible for the lower mechanical strength of the culm under high-yield wheat cultivation,and a theoretical basis and for developing technical measures to enhance lodging resistance.
文摘Buds emerge from the roots of domesticated runner bean plants (Phaseolus coccineus L.) as sprouts and give the crop its persistence. This particularity of the species seems to be associated with the environment where the species was cultivated during long time. Data on regrowth traits were recorded on 70 accessions of domesticated P. coccineus after overwintering at a site in the central highlands of Mexico. The characteristics recorded included fresh weight of vegetative regrowth, root length, root crown diameter, and diameter of the main root. Most accessions that sprout the following spring, after the grain harvest of the previous year, come from temperate and semi-cold sites with cambisol and andosol soils in mixed Quercus pine forest and high mountain fir trees. Those that do not sprout are from sites of semiarid temperate climate, haplic phaeozem soil in shrub grasslands with deciduous broadleaved trees, and semiwarm subhumid climate, eutrophic regosol soil in deciduous broadleaved forest. Two types of roots were differentiated: branched and thickened taproots, also associated with a different climate, and the type of soil of the collection sites.
文摘Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of heterogeneous computer's distributed virtual environment system (HCWES) designed to populate some mobile agents as well as stationary agents. Finally, the paper introduces how heterogeneous computer network communication is to be realized.
基金Funded by the National Natural Science Foundation of China (No.40341011) and the National 863 Program of China(No.2002AA135230)
文摘Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture are also discussed. The architecture basically meets the need of DVGE in real-time communication, distribution, collaboration, reusing and interoperation, expansion, and standard.
文摘This paper introduces a hierarchical real-time environment for developing ship-bornefire-control system. Advanced computer networks are used to simulate the system with the requiredengagement scenario, including own-ship and parameters, and data processing and transmission,mission calculation, graphical supervision and gunnery ballistics outputting. The simulation systemis able to receive instruction from, or send information to the command-control center. Furthermore,the system can also be used to compare various designed schemes and analyze the accuracy andeffectiveness of the system.
文摘A new chance of developing traditional manufacturing industry comes forth with the development of network technology. Application technology oriented rapid response manufacturing in the distributed network environments, that is, how to take advantage of the Intranet and Internet, combine the numerous manufacturing resources spread around the region, the country and even the globe is the key to the agile design, manufacturing and the buildup of comprehensively competitive power, at the same time, is also an important research direction in the field of advanced manufacturing technology. Rapid response manufacturing in the distributed network environment is a newly manufactory pattern that can be used to implement the conception of agile design and manufacturing, but there are some new problems coming with it, which will directly influence the enterprise’s ability of rapid response in the distributed network manufacturing pattern and lead to the failure of the league and the lost of the given orders. In this paper, we establish some approaches to solve these problems in product development process. The paper then presents the research on key application technologies and solutions includes: network safety strategy which guarantees data transferring among the leaguer members, production data management based on Web/DOT (Distributed Object Technology) and XML criteria which guarantees data exchange in structure-variance characteristic environments, the network platform which provides the conversion service of different types of CAD files each other. All of these solutions are aim for technology problems existing in the distributed network environments and among the league members. Finally, the paper takes one project, that is, the establishment of the online application service system for Shanghai Advance Manufacturing Technology Research Center as a good instance.
基金the Natural Science Foundation of Shaan’xi Province (2005F51).
文摘Because most ensemble learning algorithms use the centralized model, and the training instances must be centralized on a single station, it is difficult to centralize the training data on a station. A distributed ensemble learning algorithm is proposed which has two kinds of weight genes of instances that denote the global distribution and the local distribution. Instead of the repeated sampling method in the standard ensemble learning, non-balance sampling from each station is used to train the base classifier set of each station. The concept of the effective nearby region for local integration classifier is proposed, and is used for the dynamic integration method of multiple classifiers in distributed environment. The experiments show that the ensemble learning algorithm in distributed environment proposed could reduce the time of training the base classifiers effectively, and ensure the classify performance is as same as the centralized learning method.
文摘his paper examines planning management problems in a Multiagentbased Distributed Open Computing Environment Model (MDOCEM). First the meaning of planning management in MDOCEM is introduced, and then a formal method to describe the associated task partition problems is presented, and a heuristic algorithm which gives an approximate optimum solution is given. Finally the task coordination and integration of execution results are discussed.
文摘In this paper, the properties of distributed virtual environment (DVE) and the requirements on computer networks is briefly reviewed. A multicast protocol, called sender initiated grouping multicast protocol for DVE (SIGMP), is proposed. This new multicast protocol is based on a novel concept, multicast group (MG), which divides all participants in a DVE system into groups, among which there is a multicast group trustee (MGT) node to manage the group. The protocol provides unreliable/reliable, totally ordered and multiple to multiple multicast transmission service for DVE systems without sacrificing the communication efficiency heavily. At the same time, reliable unicast and one to multiple multicast transmission services are also supported. The performance analysis of the new protocols is also presented. Based on SIGMP, a simple demonstration of DVE system is designed and implemented. This demo system is running on several SGI workstations connected by a FDDI and Ethernet network.
文摘Simulation has become the evaluation method of choice for many areas of distributing computing research. Simulation has been applied successfully for modeling small and large complex systems and understanding their behavior, especially in the area of distributed systems or parallel environment. The aim of my research is to study and qualitative analysis of simulation on a single server & on distributed environment and finding the related issues & its comparison.
文摘To meet the authorization administration requirements in a distributedcomputer network environment, this paper extends the role-based access control model with multipleapplication dimensions and establishes a new access control model ED-RBAC(Extended Role Based AccessControl Model) for the distributed environment. We propose an extendable hierarchical authorizationassignment framework and design effective role-registeringi role-applying and role-assigningprotocol with symmetric and asymmetric cryptographic systems. The model can be used to simplifyauthorization administration in a distributed environment with multiple applications.
文摘Distributed virtual coal-mine geography environment(CM-DVGE) researches the virtual reality simulation of coal-mine environment in cyberspace and the performance of coal production process. The goal is to deal with the practical safety problems of observation, analysis, design and training during the underground coal production process. This paper first probed into the evolution of CM-DVGE from a historical point of view, then respectively analyzed the characteristics of its physical progressive levels according to the cognitivd law and its logical structure of data on the basis of data flow, and concluded by putting forward the prospect of the application of CM-DVGE, thus enriched and developed the method of synthetic study of coal mine.
文摘Studies the design of distributed virtual environments (DVEs) for tele-multi-robotics. The proposed design, incorporating two models ( distributlon-supported model and VE-supported model), attempts to represent common functionality, communication issues, and requirements found in multi-operator DVEs. The distribution-supported model concentrates on the introduction of computer-supported collaborative work (CSCW) to realize the coordination of multi-operators, while the VE-supported model concentrates on the utilization of an object-oriented approach to strengthen the expandability and robustness of the system. Finally, the configuration anti running environments of the system are given.
文摘The inherent complexity and uncertainty of multi-operator multi-robot (MOMR) tele-operation system make its safeguard an essential problem. Hazardous factors in the system are analyzed using fault tree analysis(FTA) technology, and three-layer interactive safety architecture with information flow is designed in modules to control the factors according to the holistic control mode. After that, distributed virtual environment (DVE) including the characteristics of virtual guide (VG) technology is discussed to help the operators achieve some tasks through the visibility of control commands, time-delay, movement collision and operators' intentions. Finally an experiment is implemented to test the efficiency of safety control architecture by using two robots to place some building blocks in the same workspace.
文摘Correction to:Acta Geochimica(2022)41:968–981 https://doi.org/10.1007/s11631-022-00555-w In the original publication of the article,the affi liation of“Behzad Aghabarari”was published incorrectly.The correct affi liation should read as follows“Department of Nanotechnology and Advanced Materials,Material and Energy Research Center,Karaj,Iran”.
基金supported by the National Natural Science Foundation of China(Nos.61805257,41905130)in part by the China Postdoctoral Science Foundation(Nos.2020M671383,2020M681517)in part by the Science and Technology Development Plan Foundation of Suzhou(No.SS202148).
文摘Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.
基金The MSIP(Ministry of Science,ICT&Future Planning),Korea,under the ITRC(Information Technology Research Center)Support program(NIPA-2013-H0301-13-2006)supervised by the NIPA(National IT Industry Promotion Agency)
文摘In the distributed environment,robots should be able to provide users with adaptive services automatically according to the situational information changing dynamically which is obtained from both users and their environments.The workflow depends on situational information obtained from physical environments and provides context-aware services automatically based on the information retrieved.And the workflow in the business processes and the distributed computing environments have supported the automation of services by connecting tasks.The workflow needs to specify ubiquitous situational information as state-transition constraints.However,the delivery and use of sensor data in the workflow is a difficult problem for the robot system.In order to bridge the gap between applications and low-level constructs and to acquire raw situational information for the execution of the context-aware workflow in the robot systems,this paper presents an approach which can achieve the sensor data transmission between a sensing server and a robot system easily.