Objectives:To access the effectiveness of our modified right-ventricular overhauling procedure on tricuspid valve(TV)growth in patients with pulmonary atresia with intact ventricular septum(PAIVS).Methods:We retrospec...Objectives:To access the effectiveness of our modified right-ventricular overhauling procedure on tricuspid valve(TV)growth in patients with pulmonary atresia with intact ventricular septum(PAIVS).Methods:We retrospectively reviewed 21 patients with PAIVS who underwent modified right ventricular overhauling(mRVoh)between 2008 and 2019 at two institutions.Our mRVoh consisted of wide resection of hypertrophied infundibular and trabecular muscle,peeling off fibrotic endocardial tissue in the right ventricle(RV)cavity,surgical pulmonary valvotomy,and Blalock-Taussig shunt or banding of ductus arteriosus under cardiopulmonary bypass.The TV annulus sizes were measured and analyzed using echocardiography before and after mRVoh.Results:No mortalities were observed during a median follow-up of 3 years(interquartile range:1.3–4.7 years)of follow-up were noted.mRVoh was performed at a median age of 163.5 days(range:21–560 days),including seven neonates and two infants(<60 days).During follow-up,the median TV annular z-score increased significantly from−2.24 to−1.15 before and after mRVoh(p=0.004).In ten patients with a prior history of percutaneous interventions for RV outflow tract(RVOT)widening at least 6 months before mRVoh,the TV annular z-score significantly changed during the period after mRVoh(−2.03 to−1.61,p=0.028)compared with the period before mRVoh(−2.51→–2.03,p=0.575)after percutaneous intervention only.Conclusions:mRVoh in PAIVS patients was positively associated with TV annular growth,and it was more effective than percutaneous RVOT widening interventions without mRVoh.展开更多
The purpose of this research was to develop a new approach in determination of overhaul and maintenance cost of loading equipment in surface mining. Two statistical models including univariate exponential regression (...The purpose of this research was to develop a new approach in determination of overhaul and maintenance cost of loading equipment in surface mining. Two statistical models including univariate exponential regression (UER) and multivariate linear regression (MLR) were used in this study. Loading equipment parameters such as bucket capacity, machine weight, engine power, boom length, digging depth, and dumping height were considered as variables. The results obtained by models and mean absolute error rate indicate that these models can be applied as the useful tool in determination of overhaul and maintenance cost of loading equipment. The results of this study can be used by the decision-makers for the specific surface mining operations.展开更多
Cable fire is one of the most important events for operation and maintenance(O&M)safety in underground utility tunnels(UUTs).Since there are limited studies about cable fire risk assessment,a comprehensive assessm...Cable fire is one of the most important events for operation and maintenance(O&M)safety in underground utility tunnels(UUTs).Since there are limited studies about cable fire risk assessment,a comprehensive assessment model is proposed to evaluate the cable fire risk in different UUT sections and improve O&M efficiency.Considering the uncertainties in the risk assessment,an evidential reasoning(ER)approach is used to combine quantitative sensor data and qualitative expert judgments.Meanwhile,a data transformation technique is contributed to transform continuous data into a five-grade distributed assessment.Then,a case study demonstrates how the model and the ER approach are established.The results show that in Shenzhen,China,the cable fire risk in District 8,B Road is the lowest,while more resources should be paid in District 3,C Road and District 25,C Road,which are selected as comparative roads.Based on the model,a data-driven O&M process is proposed to improve the O&M effectiveness,compared with traditional methods.This study contributes an effective ER-based cable fire evaluation model to improve the O&M efficiency of cable fire in UUTs.展开更多
为满足轨道交通装备服役周期运用维修保障的安全性和可靠性要求,设计并实现了面向服役周期管理的轨道交通装备维修、修理、大修和运行保障(MRO,Maintenance,Repair and Overhaul/Operation)系统。文章给出了该系统的总体架构和技术架构...为满足轨道交通装备服役周期运用维修保障的安全性和可靠性要求,设计并实现了面向服役周期管理的轨道交通装备维修、修理、大修和运行保障(MRO,Maintenance,Repair and Overhaul/Operation)系统。文章给出了该系统的总体架构和技术架构,融合基于物料清单(BOM,Bill of Materials)的服役周期数据贯通等技术,设计了配置管理、服务管理、检修管理、物资管理等4个功能模块,实现贯穿现场服务和检修业务主线的轨道交通装备服役周期管理。该系统在株洲中车时代电气股份有限公司进行了现场应用。应用情况表明,该系统可有效提升装备服役周期管理及技术服务能力,有力支撑企业服务数字化转型。展开更多
当前针对复杂产品MRO(maintenance,repair and overhaul/operations)的相关研究已经成熟,但由于缺乏对服务BOM集成建模技术研究,使得MRO生命周期数据并没有得到有效管控。首先分析了基于SBOM的MRO业务集成模型,理清了服务BOM和MRO服务...当前针对复杂产品MRO(maintenance,repair and overhaul/operations)的相关研究已经成熟,但由于缺乏对服务BOM集成建模技术研究,使得MRO生命周期数据并没有得到有效管控。首先分析了基于SBOM的MRO业务集成模型,理清了服务BOM和MRO服务之间的关系;然后,提出SBOM结构模型和演化模型,并将SBOM与MRO业务集成;最后,基于清华大学MRO系统对SBOM进行了集成开发。完成了服务阶段的产品数据建模,支持复杂产品制造BOM向服务阶段延伸。展开更多
文摘Objectives:To access the effectiveness of our modified right-ventricular overhauling procedure on tricuspid valve(TV)growth in patients with pulmonary atresia with intact ventricular septum(PAIVS).Methods:We retrospectively reviewed 21 patients with PAIVS who underwent modified right ventricular overhauling(mRVoh)between 2008 and 2019 at two institutions.Our mRVoh consisted of wide resection of hypertrophied infundibular and trabecular muscle,peeling off fibrotic endocardial tissue in the right ventricle(RV)cavity,surgical pulmonary valvotomy,and Blalock-Taussig shunt or banding of ductus arteriosus under cardiopulmonary bypass.The TV annulus sizes were measured and analyzed using echocardiography before and after mRVoh.Results:No mortalities were observed during a median follow-up of 3 years(interquartile range:1.3–4.7 years)of follow-up were noted.mRVoh was performed at a median age of 163.5 days(range:21–560 days),including seven neonates and two infants(<60 days).During follow-up,the median TV annular z-score increased significantly from−2.24 to−1.15 before and after mRVoh(p=0.004).In ten patients with a prior history of percutaneous interventions for RV outflow tract(RVOT)widening at least 6 months before mRVoh,the TV annular z-score significantly changed during the period after mRVoh(−2.03 to−1.61,p=0.028)compared with the period before mRVoh(−2.51→–2.03,p=0.575)after percutaneous intervention only.Conclusions:mRVoh in PAIVS patients was positively associated with TV annular growth,and it was more effective than percutaneous RVOT widening interventions without mRVoh.
文摘The purpose of this research was to develop a new approach in determination of overhaul and maintenance cost of loading equipment in surface mining. Two statistical models including univariate exponential regression (UER) and multivariate linear regression (MLR) were used in this study. Loading equipment parameters such as bucket capacity, machine weight, engine power, boom length, digging depth, and dumping height were considered as variables. The results obtained by models and mean absolute error rate indicate that these models can be applied as the useful tool in determination of overhaul and maintenance cost of loading equipment. The results of this study can be used by the decision-makers for the specific surface mining operations.
基金Airport New City Utility Tunnel PhaseⅡProject,China。
文摘Cable fire is one of the most important events for operation and maintenance(O&M)safety in underground utility tunnels(UUTs).Since there are limited studies about cable fire risk assessment,a comprehensive assessment model is proposed to evaluate the cable fire risk in different UUT sections and improve O&M efficiency.Considering the uncertainties in the risk assessment,an evidential reasoning(ER)approach is used to combine quantitative sensor data and qualitative expert judgments.Meanwhile,a data transformation technique is contributed to transform continuous data into a five-grade distributed assessment.Then,a case study demonstrates how the model and the ER approach are established.The results show that in Shenzhen,China,the cable fire risk in District 8,B Road is the lowest,while more resources should be paid in District 3,C Road and District 25,C Road,which are selected as comparative roads.Based on the model,a data-driven O&M process is proposed to improve the O&M effectiveness,compared with traditional methods.This study contributes an effective ER-based cable fire evaluation model to improve the O&M efficiency of cable fire in UUTs.
文摘为满足轨道交通装备服役周期运用维修保障的安全性和可靠性要求,设计并实现了面向服役周期管理的轨道交通装备维修、修理、大修和运行保障(MRO,Maintenance,Repair and Overhaul/Operation)系统。文章给出了该系统的总体架构和技术架构,融合基于物料清单(BOM,Bill of Materials)的服役周期数据贯通等技术,设计了配置管理、服务管理、检修管理、物资管理等4个功能模块,实现贯穿现场服务和检修业务主线的轨道交通装备服役周期管理。该系统在株洲中车时代电气股份有限公司进行了现场应用。应用情况表明,该系统可有效提升装备服役周期管理及技术服务能力,有力支撑企业服务数字化转型。
文摘当前针对复杂产品MRO(maintenance,repair and overhaul/operations)的相关研究已经成熟,但由于缺乏对服务BOM集成建模技术研究,使得MRO生命周期数据并没有得到有效管控。首先分析了基于SBOM的MRO业务集成模型,理清了服务BOM和MRO服务之间的关系;然后,提出SBOM结构模型和演化模型,并将SBOM与MRO业务集成;最后,基于清华大学MRO系统对SBOM进行了集成开发。完成了服务阶段的产品数据建模,支持复杂产品制造BOM向服务阶段延伸。
