During the last few years, attention in the manufacturing cycle has shifted towards concurrent engineering (CE). With this, the integration of the different product life cycle processes has become a focus in both rese...During the last few years, attention in the manufacturing cycle has shifted towards concurrent engineering (CE). With this, the integration of the different product life cycle processes has become a focus in both research and industry. However, it is obvious that the integration of all manufacturing processes, taking into account all life cycle aspects from initial functional requirements to final disposal, is hardly feasible in the traditional way. In this paper, an agent based model is proposed for the automatic computer aided process planning (CAPP)integration. The autonomy, flexibility, interoperability, modularity and scalability of agent are made use of to cooperate the whole process planning and achieve the full share of resource and information. Thus,the unnecessary waste on human, time and work quantity is reduced. On the basis of the model, an agent based automatic process implementation system of CAPP is developed for demonstration in purpose.展开更多
In this paper, the testing technology of event-driven software is focused. It is first analyzed the difference between event-driven software and the traditional procedure-oriented software, and based on the above anal...In this paper, the testing technology of event-driven software is focused. It is first analyzed the difference between event-driven software and the traditional procedure-oriented software, and based on the above analysis, the mechanism of event-driven and the effect of introduction of event-driven mechanism on software testing are unveiled. Then based on the characteristic of the event-driven software, the traditional software testing method is improved, and testing policy of event based test is presented in this paper.Moreover the event coverage criteria are defined and given here. At the same time the event executing rule are further uncovered, such as ordinal event, non-ordinal event, predecessor event and concurrent event etc., and also the methods of testing according to event executing rule are studied.展开更多
Based on the biological immune concept, immune response mechanism and expert system, a dynamic and intelligent scheduling model toward the disturbance of the production such as machine fault,task insert and cancel etc...Based on the biological immune concept, immune response mechanism and expert system, a dynamic and intelligent scheduling model toward the disturbance of the production such as machine fault,task insert and cancel etc. Is proposed. The antibody generation method based on the sequence constraints and the coding rule of antibody for the machining procedure is also presented. Using the heuristic antibody generation method based on the physiology immune mechanism, the validity of the scheduling optimization is improved, and based on the immune and expert system under the event-driven constraints, not only Job-shop scheduling problem with multi-objective can be solved, but also the disturbance of the production be handled rapidly. A case of the job-shop scheduling is studied and dynamic optimal solutions with multi-objective function for agile manufacturing are obtained in this paper. And the event-driven dynamic rescheduling result is compared with right-shift rescheduling and total rescheduling.展开更多
A new model of event and message driven Petri network(EMDPN) based on the characteristic of class interaction for messages passing between two objects was extended. Using EMDPN interaction graph, a class hierarchical ...A new model of event and message driven Petri network(EMDPN) based on the characteristic of class interaction for messages passing between two objects was extended. Using EMDPN interaction graph, a class hierarchical test-case generation algorithm with cooperated paths (copaths) was proposed, which can be used to solve the problems resulting from the class inheritance mechanism encountered in object-oriented software testing such as oracle, message transfer errors, and unreachable statement. Finally, the testing sufficiency was analyzed with the ordered sequence testing criterion(OSC). The results indicate that the test cases stemmed from newly proposed automatic algorithm of copaths generation satisfies synchronization message sequences testing criteria, therefore the proposed new algorithm of copaths generation has a good coverage rate.展开更多
SSRF is a third generation,3.5GeV synchrotron light source currently being constructed in Shanghai.The conceptual consideration of its timing system is described in this paper.Different storage ring filling patterns s...SSRF is a third generation,3.5GeV synchrotron light source currently being constructed in Shanghai.The conceptual consideration of its timing system is described in this paper.Different storage ring filling patterns such as single bunch pattern,multi-bunch filling pattern,mixed filling pattern and top-up pattern,demand a highly stable, low jitter timing system with the flexibility to recnfigure on programmable event driven basis.Based on the EPICS control system,the timing system provides digitally programmable sequencing and delay for the electron gun,the linac modulator,the booster and storage ring RF,the pulsed magnets,the instrumentation systems according to different operation pattern requirements.展开更多
Based on the daily NCEP/DOE reanalysis II data,dates of the boreal spring Stratospheric Final Warming(SFW) events during 1979–2010 are defined as the time when the zonal-mean zonal wind at the central latitudes(65...Based on the daily NCEP/DOE reanalysis II data,dates of the boreal spring Stratospheric Final Warming(SFW) events during 1979–2010 are defined as the time when the zonal-mean zonal wind at the central latitudes(65°–75°N) of the westerly polar jet drops below zero and never recovers until the subsequent autumn.It is found that the SFW events occur successively from the mid to the lower stratosphere and averagely from the mid to late April with a temporal lag of about 13 days from 10 to 50 hPa.Over the past 32 years,the earliest SFW occurs in mid March whereas the latest SFW happens in late May,showing a clear interannual variability of the time of SFW.Accompanying the SFW onset,the stratospheric circulation transits from a winter dynamical regime to a summertime state,and the maximum negative tendency of zonal wind and the strongest convergence of planetary-wave are observed.Composite results show that the early/late SFW events in boreal spring correspond to a quicker/slower transition of the stratospheric circulation,with the zonal-mean zonal wind reducing about 20/5 m s-1 at 30 hPa within 10 days around the onset date.Meanwhile,the planetary wave activities are relatively strong/weak associating with an out-of-/in-phase circumpolar circulation anomaly before and after the SFW events in the stratosphere.All these results indicate that,the earlier breakdown of the stratospheric polar vortex(SPV),as for the winter stratospheric sudden warming(SSW) events is driven mainly by wave forcing;and in contrast,the later breakdown of the SPV exhibits more characteristics of its seasonal evolution.Nevertheless,after the breakdown of SPV,the polar temperature anomalies always exhibit an out-of-phase relationship between the stratosphere and the troposphere for both the early and late SFW events,which implies an intimate stratosphere–troposphere dynamical coupling in spring.In addition,there exists a remarkable interdecadal change of the onset time of SFW in the mid 1990s.On average,the SFW onset time before the mid 1990s is 11 days earlier than that afterwards,corresponding to the increased/decreased planetary wave activities in late winter-early spring before/after the 1990s.展开更多
文摘During the last few years, attention in the manufacturing cycle has shifted towards concurrent engineering (CE). With this, the integration of the different product life cycle processes has become a focus in both research and industry. However, it is obvious that the integration of all manufacturing processes, taking into account all life cycle aspects from initial functional requirements to final disposal, is hardly feasible in the traditional way. In this paper, an agent based model is proposed for the automatic computer aided process planning (CAPP)integration. The autonomy, flexibility, interoperability, modularity and scalability of agent are made use of to cooperate the whole process planning and achieve the full share of resource and information. Thus,the unnecessary waste on human, time and work quantity is reduced. On the basis of the model, an agent based automatic process implementation system of CAPP is developed for demonstration in purpose.
文摘In this paper, the testing technology of event-driven software is focused. It is first analyzed the difference between event-driven software and the traditional procedure-oriented software, and based on the above analysis, the mechanism of event-driven and the effect of introduction of event-driven mechanism on software testing are unveiled. Then based on the characteristic of the event-driven software, the traditional software testing method is improved, and testing policy of event based test is presented in this paper.Moreover the event coverage criteria are defined and given here. At the same time the event executing rule are further uncovered, such as ordinal event, non-ordinal event, predecessor event and concurrent event etc., and also the methods of testing according to event executing rule are studied.
基金This work was supported by National Science Foundation of Shanghai(02ZF14003)
文摘Based on the biological immune concept, immune response mechanism and expert system, a dynamic and intelligent scheduling model toward the disturbance of the production such as machine fault,task insert and cancel etc. Is proposed. The antibody generation method based on the sequence constraints and the coding rule of antibody for the machining procedure is also presented. Using the heuristic antibody generation method based on the physiology immune mechanism, the validity of the scheduling optimization is improved, and based on the immune and expert system under the event-driven constraints, not only Job-shop scheduling problem with multi-objective can be solved, but also the disturbance of the production be handled rapidly. A case of the job-shop scheduling is studied and dynamic optimal solutions with multi-objective function for agile manufacturing are obtained in this paper. And the event-driven dynamic rescheduling result is compared with right-shift rescheduling and total rescheduling.
基金Project(05JT1035) supported by the Science and Technology Plan of Hunan Province
文摘A new model of event and message driven Petri network(EMDPN) based on the characteristic of class interaction for messages passing between two objects was extended. Using EMDPN interaction graph, a class hierarchical test-case generation algorithm with cooperated paths (copaths) was proposed, which can be used to solve the problems resulting from the class inheritance mechanism encountered in object-oriented software testing such as oracle, message transfer errors, and unreachable statement. Finally, the testing sufficiency was analyzed with the ordered sequence testing criterion(OSC). The results indicate that the test cases stemmed from newly proposed automatic algorithm of copaths generation satisfies synchronization message sequences testing criteria, therefore the proposed new algorithm of copaths generation has a good coverage rate.
文摘SSRF is a third generation,3.5GeV synchrotron light source currently being constructed in Shanghai.The conceptual consideration of its timing system is described in this paper.Different storage ring filling patterns such as single bunch pattern,multi-bunch filling pattern,mixed filling pattern and top-up pattern,demand a highly stable, low jitter timing system with the flexibility to recnfigure on programmable event driven basis.Based on the EPICS control system,the timing system provides digitally programmable sequencing and delay for the electron gun,the linac modulator,the booster and storage ring RF,the pulsed magnets,the instrumentation systems according to different operation pattern requirements.
基金supported by the National Basic Research Program of China(Grant Nos.2010CB428603 and 2010CB950400)National Natural Science Foundation of China(Grant No.41275094)
文摘Based on the daily NCEP/DOE reanalysis II data,dates of the boreal spring Stratospheric Final Warming(SFW) events during 1979–2010 are defined as the time when the zonal-mean zonal wind at the central latitudes(65°–75°N) of the westerly polar jet drops below zero and never recovers until the subsequent autumn.It is found that the SFW events occur successively from the mid to the lower stratosphere and averagely from the mid to late April with a temporal lag of about 13 days from 10 to 50 hPa.Over the past 32 years,the earliest SFW occurs in mid March whereas the latest SFW happens in late May,showing a clear interannual variability of the time of SFW.Accompanying the SFW onset,the stratospheric circulation transits from a winter dynamical regime to a summertime state,and the maximum negative tendency of zonal wind and the strongest convergence of planetary-wave are observed.Composite results show that the early/late SFW events in boreal spring correspond to a quicker/slower transition of the stratospheric circulation,with the zonal-mean zonal wind reducing about 20/5 m s-1 at 30 hPa within 10 days around the onset date.Meanwhile,the planetary wave activities are relatively strong/weak associating with an out-of-/in-phase circumpolar circulation anomaly before and after the SFW events in the stratosphere.All these results indicate that,the earlier breakdown of the stratospheric polar vortex(SPV),as for the winter stratospheric sudden warming(SSW) events is driven mainly by wave forcing;and in contrast,the later breakdown of the SPV exhibits more characteristics of its seasonal evolution.Nevertheless,after the breakdown of SPV,the polar temperature anomalies always exhibit an out-of-phase relationship between the stratosphere and the troposphere for both the early and late SFW events,which implies an intimate stratosphere–troposphere dynamical coupling in spring.In addition,there exists a remarkable interdecadal change of the onset time of SFW in the mid 1990s.On average,the SFW onset time before the mid 1990s is 11 days earlier than that afterwards,corresponding to the increased/decreased planetary wave activities in late winter-early spring before/after the 1990s.
