Software defect prevention is an important way to reduce the defect introduction rate.As the primary cause of software defects,human error can be the key to understanding and preventing software defects.This paper pro...Software defect prevention is an important way to reduce the defect introduction rate.As the primary cause of software defects,human error can be the key to understanding and preventing software defects.This paper proposes a defect prevention approach based on human error mechanisms：DPe HE.The approach includes both knowledge and regulation training in human error prevention.Knowledge training provides programmers with explicit knowledge on why programmers commit errors,what kinds of errors tend to be committed under different circumstances,and how these errors can be prevented.Regulation training further helps programmers to promote the awareness and ability to prevent human errors through practice.The practice is facilitated by a problem solving checklist and a root cause identification checklist.This paper provides a systematic framework that integrates knowledge across disciplines,e.g.,cognitive science,software psychology and software engineering to defend against human errors in software development.Furthermore,we applied this approach in an international company at CMM Level 5 and a software development institution at CMM Level 1 in the Chinese Aviation Industry.The application cases show that the approach is feasible and effective in promoting developers＇ ability to prevent software defects,independent of process maturity levels.展开更多
In this paper, we study an efficient asymptotically correction of a-posteriori er- ror estimator for the numerical approximation of Volterra integro-differential equations by piecewise polynomial collocation method. T...In this paper, we study an efficient asymptotically correction of a-posteriori er- ror estimator for the numerical approximation of Volterra integro-differential equations by piecewise polynomial collocation method. The deviation of the error for Volterra integro- differential equations by using the defect correction principle is defined. Also, it is shown that for m degree piecewise polynomial collocation method, our method provides O（hm＋l） as the order of the deviation of the error. The theoretical behavior is tested on examples and it is shown that the numerical results confirm the theoretical part.展开更多
目前最常用的油气管道腐蚀安全评价方法为ASME B31G Modified、DNV RP F01、PCORRC、SHELL92。为了研究腐蚀管安全评价模型的特性,根据模型中使用的主要参数,研究了腐蚀缺陷长度、深度以及管道材料力学性能参数与管道失效压力之间的关系...目前最常用的油气管道腐蚀安全评价方法为ASME B31G Modified、DNV RP F01、PCORRC、SHELL92。为了研究腐蚀管安全评价模型的特性,根据模型中使用的主要参数,研究了腐蚀缺陷长度、深度以及管道材料力学性能参数与管道失效压力之间的关系,并结合文献试验测试数据。结果表明:管道材料对模型预测结果影响最明显,四种模型中DNV RP F101的预测结果最接近实验值,SHEEL92模型预测结果最安全;ASME B31G Modified预测结果误差变化最大。本研究对于选择恰当的腐蚀管道安全评价模型,具有一定的指导意义。展开更多
文摘Software defect prevention is an important way to reduce the defect introduction rate.As the primary cause of software defects,human error can be the key to understanding and preventing software defects.This paper proposes a defect prevention approach based on human error mechanisms：DPe HE.The approach includes both knowledge and regulation training in human error prevention.Knowledge training provides programmers with explicit knowledge on why programmers commit errors,what kinds of errors tend to be committed under different circumstances,and how these errors can be prevented.Regulation training further helps programmers to promote the awareness and ability to prevent human errors through practice.The practice is facilitated by a problem solving checklist and a root cause identification checklist.This paper provides a systematic framework that integrates knowledge across disciplines,e.g.,cognitive science,software psychology and software engineering to defend against human errors in software development.Furthermore,we applied this approach in an international company at CMM Level 5 and a software development institution at CMM Level 1 in the Chinese Aviation Industry.The application cases show that the approach is feasible and effective in promoting developers＇ ability to prevent software defects,independent of process maturity levels.
文摘In this paper, we study an efficient asymptotically correction of a-posteriori er- ror estimator for the numerical approximation of Volterra integro-differential equations by piecewise polynomial collocation method. The deviation of the error for Volterra integro- differential equations by using the defect correction principle is defined. Also, it is shown that for m degree piecewise polynomial collocation method, our method provides O（hm＋l） as the order of the deviation of the error. The theoretical behavior is tested on examples and it is shown that the numerical results confirm the theoretical part.
文摘目前最常用的油气管道腐蚀安全评价方法为ASME B31G Modified、DNV RP F01、PCORRC、SHELL92。为了研究腐蚀管安全评价模型的特性,根据模型中使用的主要参数,研究了腐蚀缺陷长度、深度以及管道材料力学性能参数与管道失效压力之间的关系,并结合文献试验测试数据。结果表明:管道材料对模型预测结果影响最明显,四种模型中DNV RP F101的预测结果最接近实验值,SHEEL92模型预测结果最安全;ASME B31G Modified预测结果误差变化最大。本研究对于选择恰当的腐蚀管道安全评价模型,具有一定的指导意义。
文摘目的应用手术导航系统辅助下颌骨缺损修复重建,与单纯使用CAD/CAM导板技术对比,评价导航技术疗效。方法选择已行下颌骨肿瘤切除同期修复重建的患者22例,术中采用实时导航系统Brain Lab+CAD/CAM导板辅助自体移植骨关键部位定位的病例10例(A组);术中单独采用CAD/CAM导板辅助关键部位定位的病例12例(B组),2组均术前行计算机辅助设计、术中行模型外科技术处理。术后均予颌面部三维CT复查,与术前设计三维CT比对,选择下颌角点(A)和髁状突外极点(C)作为下颌骨重建外形的关键标志点,利用Geomagic studio 12.0软件测量两标志点在术前设计与术后完成的三维位置的直线距离(AL、CL),并进行统计学分析;术后6个月复查随访,对颜面部对称性进行手术效果比较。结果 2组均顺利完成手术,两个标志点的距离偏差为:A组AL为(1.86±0.20)mm,CL为(1.63±0.24)mm;B组AL为(3.75±1.14)mm,CL为(2.96±0.85)mm。2组AL、CL测量值分别进行独立样本t检验比较,差异具有统计学意义(P<0.05);关键标志点就位A组较B组精确,A组术后面型对称性较B组好。结论术中采用手术导航系统比单纯使用CAD/CAM导板更能提高下颌骨修复重建的手术精确度和疗效,恢复面部对称性。
