结合集散控制系统的特点,设计了一种嵌入式啤酒发酵控制系统。该系统采用自主研发的智能化SOC(System on Chip)嵌入式数据终端处理器作为控制终端;通过差动中值定标的方法实现现场高精度检测;使用固定周期预测增量控制方法对啤酒发酵的...结合集散控制系统的特点,设计了一种嵌入式啤酒发酵控制系统。该系统采用自主研发的智能化SOC(System on Chip)嵌入式数据终端处理器作为控制终端;通过差动中值定标的方法实现现场高精度检测;使用固定周期预测增量控制方法对啤酒发酵的温度进行控制;采用时间隧道数据处理器处理的方法而使数据处理系统化,提高了系统的稳定性和连贯性;数据终端处理器配置通用串行口,与工控计算机组成局域网实现集散式控制。实践证明,该系统不仅成本低、功能强,而且灵活、可靠。展开更多
A DMVOCC-MVDA （distributed multiversion optimistic concurrency control with multiversion dynamic adjustment） protocol was presented to process mobile distributed real-time transaction in mobile broadcast environment...A DMVOCC-MVDA （distributed multiversion optimistic concurrency control with multiversion dynamic adjustment） protocol was presented to process mobile distributed real-time transaction in mobile broadcast environments. At the mobile hosts, all transactions perform local pre-validation. The local pre-validation process is carried out against the committed transactions at the server in the last broadcast cycle. Transactions that survive in local pre-validation must be submitted to the server for local final validation. The new protocol eliminates conflicts between mobile read-only and mobile update transactions, and resolves data conflicts flexibly by using multiversion dynamic adjustment of serialization order to avoid unnecessary restarts of transactions. Mobile read-only transactions can be committed with no-blocking, and respond time of mobile read-only transactions is greatly shortened. The tolerance of mobile transactions of disconnections from the broadcast channel is increased. In global validation mobile distributed transactions have to do check to ensure distributed serializability in all participants. The simulation results show that the new concurrency control protocol proposed offers better performance than other protocols in terms of miss rate, restart rate, commit rate. Under high work load （think time is ls） the miss rate of DMVOCC-MVDA is only 14.6%, is significantly lower than that of other protocols. The restart rate of DMVOCC-MVDA is only 32.3%, showing that DMVOCC-MVDA can effectively reduce the restart rate of mobile transactions. And the commit rate of DMVOCC-MVDA is up to 61.2%, which is obviously higher than that of other protocols.展开更多
文摘结合集散控制系统的特点,设计了一种嵌入式啤酒发酵控制系统。该系统采用自主研发的智能化SOC(System on Chip)嵌入式数据终端处理器作为控制终端;通过差动中值定标的方法实现现场高精度检测;使用固定周期预测增量控制方法对啤酒发酵的温度进行控制;采用时间隧道数据处理器处理的方法而使数据处理系统化,提高了系统的稳定性和连贯性;数据终端处理器配置通用串行口,与工控计算机组成局域网实现集散式控制。实践证明,该系统不仅成本低、功能强,而且灵活、可靠。
基金Project(20030533011)supported by the National Research Foundation for the Doctoral Program of Higher Education of China
文摘A DMVOCC-MVDA （distributed multiversion optimistic concurrency control with multiversion dynamic adjustment） protocol was presented to process mobile distributed real-time transaction in mobile broadcast environments. At the mobile hosts, all transactions perform local pre-validation. The local pre-validation process is carried out against the committed transactions at the server in the last broadcast cycle. Transactions that survive in local pre-validation must be submitted to the server for local final validation. The new protocol eliminates conflicts between mobile read-only and mobile update transactions, and resolves data conflicts flexibly by using multiversion dynamic adjustment of serialization order to avoid unnecessary restarts of transactions. Mobile read-only transactions can be committed with no-blocking, and respond time of mobile read-only transactions is greatly shortened. The tolerance of mobile transactions of disconnections from the broadcast channel is increased. In global validation mobile distributed transactions have to do check to ensure distributed serializability in all participants. The simulation results show that the new concurrency control protocol proposed offers better performance than other protocols in terms of miss rate, restart rate, commit rate. Under high work load （think time is ls） the miss rate of DMVOCC-MVDA is only 14.6%, is significantly lower than that of other protocols. The restart rate of DMVOCC-MVDA is only 32.3%, showing that DMVOCC-MVDA can effectively reduce the restart rate of mobile transactions. And the commit rate of DMVOCC-MVDA is up to 61.2%, which is obviously higher than that of other protocols.
