Data stream management system (DSMS) provides convenient solutions to the problem of processing continuous queries on data streams.Previous approaches for scheduling these queries and their operators assume that each ...Data stream management system (DSMS) provides convenient solutions to the problem of processing continuous queries on data streams.Previous approaches for scheduling these queries and their operators assume that each operator runs in separate thread or all operators combine in one query plan and run in a single thread.Both approaches suffer from severe drawbacks concerning the thread overhead and the stalls due to expensive operators.To overcome these drawbacks,a novel approach called clustered operators scheduling (COS) is proposed that adaptively clusters operators of the query plan into a number of groups based on their selectivity and computing cost using S-mean clustering.Experimental evaluation is provided to demonstrate the potential benefits of COS scheduling over the other scheduling strategies.COS can provide adaptive,flexible,reliable,scalable and robust design for continuous query processor.展开更多
This research aimed to determine instruments for analysis of knowledge management in operators companies of metropolitan transport systems. How much the goal was an exploratory research, how much the procedure was a l...This research aimed to determine instruments for analysis of knowledge management in operators companies of metropolitan transport systems. How much the goal was an exploratory research, how much the procedure was a literature search, how much as nature was an applied research, and how much as approach was qualitative research？ The following instruments were identified and selected： （a） the methodology for the analysis of metropolitan transport systems; （b） the knowledge management maturity model （Siemens）; and （c） Documentation and Information Centre. The simulation, using the tools in the knowledge management to analyze the Company Metropolitan of S^io Paulo--METRO, identified the need for improvements in eight areas and the problems： （1） rethink the knowledge management area; （2） develop new knowledge management policies; （3） define responsibilities in knowledge management area; （4） implement new knowledge management processes; （5） explore new ways and structures of knowledge; （6） consider the internal and external actors in knowledge management actions; （7） expand the dissemination of the collaborative culture; and （8） integrate in the knowledge management area current and future initiatives. The analysis shows that the transposition of the current situation to the desired situation for the company can be obtained with the implementation of an Information and Documentation Centre. The conclusion is that this set of tools allows to characterize, evaluate, and model the knowledge management in this business.展开更多
基金Project(50275150) supported by the National Natural Science Foundation of ChinaProject(20040533035) supported by the National Research Foundation for the Doctoral Program of Higher Education of China
文摘Data stream management system (DSMS) provides convenient solutions to the problem of processing continuous queries on data streams.Previous approaches for scheduling these queries and their operators assume that each operator runs in separate thread or all operators combine in one query plan and run in a single thread.Both approaches suffer from severe drawbacks concerning the thread overhead and the stalls due to expensive operators.To overcome these drawbacks,a novel approach called clustered operators scheduling (COS) is proposed that adaptively clusters operators of the query plan into a number of groups based on their selectivity and computing cost using S-mean clustering.Experimental evaluation is provided to demonstrate the potential benefits of COS scheduling over the other scheduling strategies.COS can provide adaptive,flexible,reliable,scalable and robust design for continuous query processor.
文摘This research aimed to determine instruments for analysis of knowledge management in operators companies of metropolitan transport systems. How much the goal was an exploratory research, how much the procedure was a literature search, how much as nature was an applied research, and how much as approach was qualitative research？ The following instruments were identified and selected： （a） the methodology for the analysis of metropolitan transport systems; （b） the knowledge management maturity model （Siemens）; and （c） Documentation and Information Centre. The simulation, using the tools in the knowledge management to analyze the Company Metropolitan of S^io Paulo--METRO, identified the need for improvements in eight areas and the problems： （1） rethink the knowledge management area; （2） develop new knowledge management policies; （3） define responsibilities in knowledge management area; （4） implement new knowledge management processes; （5） explore new ways and structures of knowledge; （6） consider the internal and external actors in knowledge management actions; （7） expand the dissemination of the collaborative culture; and （8） integrate in the knowledge management area current and future initiatives. The analysis shows that the transposition of the current situation to the desired situation for the company can be obtained with the implementation of an Information and Documentation Centre. The conclusion is that this set of tools allows to characterize, evaluate, and model the knowledge management in this business.
