We consider differentiated timecritical task scheduling in a N×N input queued optical packet s w itch to ens ure 100% throughput and meet different delay requirements among various modules of data center. Existin...We consider differentiated timecritical task scheduling in a N×N input queued optical packet s w itch to ens ure 100% throughput and meet different delay requirements among various modules of data center. Existing schemes either consider slot-by-slot scheduling with queue depth serving as the delay metric or assume that each input-output connection has the same delay bound in the batch scheduling mode. The former scheme neglects the effect of reconfiguration overhead, which may result in crippled system performance, while the latter cannot satisfy users' differentiated Quality of Service(Qo S) requirements. To make up these deficiencies, we propose a new batch scheduling scheme to meet the various portto-port delay requirements in a best-effort manner. Moreover, a speedup is considered to compensate for both the reconfiguration overhead and the unavoidable slots wastage in the switch fabric. With traffic matrix and delay constraint matrix given, this paper proposes two heuristic algorithms Stringent Delay First(SDF) and m-order SDF(m-SDF) to realize the 100% packet switching, while maximizing the delay constraints satisfaction ratio. The performance of our scheme is verified by extensive numerical simulations.展开更多
目的:系统评价超声引导下浅层前锯肌阻滞(SSAPB)与深层前锯肌阻滞(DSAPB)用于乳腺及胸部手术镇痛的安全性和有效性。方法:采用计算机检索英文数据库PubMed、Embase、Cochrane和Web of science,中文数据库中国知网、万方、维普和中国生...目的:系统评价超声引导下浅层前锯肌阻滞(SSAPB)与深层前锯肌阻滞(DSAPB)用于乳腺及胸部手术镇痛的安全性和有效性。方法:采用计算机检索英文数据库PubMed、Embase、Cochrane和Web of science,中文数据库中国知网、万方、维普和中国生物医学数据库,收集建库至2022年4月12日发表的关于浅层前锯肌阻滞(S组)与深层前锯肌阻滞(D组)用于乳腺及胸部手术镇痛比较的随机对照试验。采用Revman 5.4软件对符合纳入标准的文献进行Meta分析。结果:最终纳入7项随机对照实验(RCT)研究,共计410例患者;Meta分析结果显示,S组与D组术后1、6、12、24 h静息疼痛评分和12、24 h活动疼痛评分差异无统计学意义;2篇文献认为S组与D组在术后1 h和6 h活动疼痛评分略有差异,但差异均无统计学意义;2组术后补救性镇痛率及不良反应发生率差异无统计学意义。结论:浅层与深层前锯肌阻滞均能为乳腺和胸部手术提供满意的镇痛条件,两者镇痛效果和不良反应无明显差别。展开更多
基金supported by the Major State Basic Research Program of China (973 project No. 2013CB329301 and 2010CB327806)the Natural Science Fund of China (NSFC project No. 61372085, 61032003, 61271165 and 61202379)+1 种基金the Research Fund for the Doctoral Program of Higher Education of China (RFDP project No. 20120185110025, 20120185110030 and 20120032120041)supported by Tianjin Key Laboratory of Cognitive Computing and Application, School of Computer Science and Technology, Tianjin University, Tianjin, P. R. China
文摘We consider differentiated timecritical task scheduling in a N×N input queued optical packet s w itch to ens ure 100% throughput and meet different delay requirements among various modules of data center. Existing schemes either consider slot-by-slot scheduling with queue depth serving as the delay metric or assume that each input-output connection has the same delay bound in the batch scheduling mode. The former scheme neglects the effect of reconfiguration overhead, which may result in crippled system performance, while the latter cannot satisfy users' differentiated Quality of Service(Qo S) requirements. To make up these deficiencies, we propose a new batch scheduling scheme to meet the various portto-port delay requirements in a best-effort manner. Moreover, a speedup is considered to compensate for both the reconfiguration overhead and the unavoidable slots wastage in the switch fabric. With traffic matrix and delay constraint matrix given, this paper proposes two heuristic algorithms Stringent Delay First(SDF) and m-order SDF(m-SDF) to realize the 100% packet switching, while maximizing the delay constraints satisfaction ratio. The performance of our scheme is verified by extensive numerical simulations.
