The design of the two-step gear reducer is a tedious and time-consuming process. For the purpose of improving the efficiency and intelligence of design process, case-based reasoning（CBR） technology was applied to th...The design of the two-step gear reducer is a tedious and time-consuming process. For the purpose of improving the efficiency and intelligence of design process, case-based reasoning（CBR） technology was applied to the design of the two-step gear reducer. Firstly, the current design method for the two-step gear reducer was analyzed and the principle of CBR was described. Secondly, according to the characteristics of the reducer, three key technologies of CBR were studied and the corresponding methods were provided, which are as follows： （a） an object-oriented knowledge representation method, （b） a retrieval method combining the nearest neighbor with the induction indexing, and （c） a case adaptation algorithm combining the revision based on rule with artificial revision. Also, for the purpose of improving the credibility of case retrieval, a new method for determining the weights of characteristics and a similarity formula were presented, which is a combinatorial weighting method with the analytic hierarchy process（AHP） and roughness set theory. Lastly, according to the above analytic results, a design system of the two-step gear reducer on CBR was developed by VC＋＋, UG and Access 2003. A new method for the design of the two-step gear reducer is provided in this study. If the foregoing developed system is applied to design the two-step gear reducer, design efficiency is improved, which enables the designer to release from the tedious design process of the gear reducer so as to put more efforts on innovative design. The study result fully reflects the feasibility and validity of CBR technology in the process of the design of the mechanical parts.展开更多
本文研究了各种级别Petri网与模态逻辑之间的关系.Petri网的Enlogy是研究这些关系的基础.状况(case)和可达(Reachability)概念已经成功地用于以条件/事件(Condition/Event,简称C/E)网作知识表示.本文引用上述两个概念,使位置/变迁(Place...本文研究了各种级别Petri网与模态逻辑之间的关系.Petri网的Enlogy是研究这些关系的基础.状况(case)和可达(Reachability)概念已经成功地用于以条件/事件(Condition/Event,简称C/E)网作知识表示.本文引用上述两个概念,使位置/变迁(Place/Transition,简称P/T)网和高级Petri网(High Level Petri Net,简称HLPN)可作知识表示.为了增强以 HLPN网作知识表示的能力,我们引用了状况变量和等价状况变量的概念.文中我们还以例子说明这些方法是可用的和有效的.展开更多
目的观察以问题为基础的教学法(problem based learning,PBL)联合步进式案例教学法(case based learning,CBL)与传统的以讲授为基础的教学法(lecture based learning,LBL)在心血管内科临床实习教学中的教学效果。方法2016年6月—2017年...目的观察以问题为基础的教学法(problem based learning,PBL)联合步进式案例教学法(case based learning,CBL)与传统的以讲授为基础的教学法(lecture based learning,LBL)在心血管内科临床实习教学中的教学效果。方法2016年6月—2017年6月将在该院进行临床实习的临床医学专业本科生70名,随机分为两组,对照组应用以讲授为基础教学法;干预组应用以PBL教学法联合步进式CBL教学法进行临床实习教学。并采用调查表方式对实习前后学生对心血管内科专业相关认知水平进行调查。在实习结束后进行带教老师满意度调查,并采取理论考试方式对实习学生实习效果进行评价。并随访本科生毕业后参加临床执业医师考试通过率情况。结果应用PBL教学法联合步进式CBL教学法的学生实习结束时的考试成绩高于传统的LBL教学法(84.1±6.7)分vs(80.1±7.4)分,差异有统计学意义(P<0.05)。对带教老师的满意度两组间比较,差异无统计学意义(P>0.05)。应用PBL教学法联合步进式CBL教学法组的学生参加执业医师通过率高于对照组,但两组比较差异无统计学意义(P>0.05)。结论应用PBL教学法联合步进式CBL教学法可以提高学生的学习成绩,提高学生对心血管内科相关知识掌握水平,提高学生对心血管内科专业的兴趣程度。展开更多
基金This project is supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2008AA04Z115)Science and Technology Program of the Ministry of Construction of China (Grant No. 2008-K8-2)+1 种基金Jiangsu Provincial Natural Science Foundation of China (Grant No. BK2007042)Open Fund of State Key Lab of CAD&CG, Zhejiang University, China (Grant No. A0914)
文摘The design of the two-step gear reducer is a tedious and time-consuming process. For the purpose of improving the efficiency and intelligence of design process, case-based reasoning（CBR） technology was applied to the design of the two-step gear reducer. Firstly, the current design method for the two-step gear reducer was analyzed and the principle of CBR was described. Secondly, according to the characteristics of the reducer, three key technologies of CBR were studied and the corresponding methods were provided, which are as follows： （a） an object-oriented knowledge representation method, （b） a retrieval method combining the nearest neighbor with the induction indexing, and （c） a case adaptation algorithm combining the revision based on rule with artificial revision. Also, for the purpose of improving the credibility of case retrieval, a new method for determining the weights of characteristics and a similarity formula were presented, which is a combinatorial weighting method with the analytic hierarchy process（AHP） and roughness set theory. Lastly, according to the above analytic results, a design system of the two-step gear reducer on CBR was developed by VC＋＋, UG and Access 2003. A new method for the design of the two-step gear reducer is provided in this study. If the foregoing developed system is applied to design the two-step gear reducer, design efficiency is improved, which enables the designer to release from the tedious design process of the gear reducer so as to put more efforts on innovative design. The study result fully reflects the feasibility and validity of CBR technology in the process of the design of the mechanical parts.
文摘本文研究了各种级别Petri网与模态逻辑之间的关系.Petri网的Enlogy是研究这些关系的基础.状况(case)和可达(Reachability)概念已经成功地用于以条件/事件(Condition/Event,简称C/E)网作知识表示.本文引用上述两个概念,使位置/变迁(Place/Transition,简称P/T)网和高级Petri网(High Level Petri Net,简称HLPN)可作知识表示.为了增强以 HLPN网作知识表示的能力,我们引用了状况变量和等价状况变量的概念.文中我们还以例子说明这些方法是可用的和有效的.
文摘目的观察以问题为基础的教学法(problem based learning,PBL)联合步进式案例教学法(case based learning,CBL)与传统的以讲授为基础的教学法(lecture based learning,LBL)在心血管内科临床实习教学中的教学效果。方法2016年6月—2017年6月将在该院进行临床实习的临床医学专业本科生70名,随机分为两组,对照组应用以讲授为基础教学法;干预组应用以PBL教学法联合步进式CBL教学法进行临床实习教学。并采用调查表方式对实习前后学生对心血管内科专业相关认知水平进行调查。在实习结束后进行带教老师满意度调查,并采取理论考试方式对实习学生实习效果进行评价。并随访本科生毕业后参加临床执业医师考试通过率情况。结果应用PBL教学法联合步进式CBL教学法的学生实习结束时的考试成绩高于传统的LBL教学法(84.1±6.7)分vs(80.1±7.4)分,差异有统计学意义(P<0.05)。对带教老师的满意度两组间比较,差异无统计学意义(P>0.05)。应用PBL教学法联合步进式CBL教学法组的学生参加执业医师通过率高于对照组,但两组比较差异无统计学意义(P>0.05)。结论应用PBL教学法联合步进式CBL教学法可以提高学生的学习成绩,提高学生对心血管内科相关知识掌握水平,提高学生对心血管内科专业的兴趣程度。
