Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)proc...Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)procedure.This can be very important in defense-related applications,where optimum performance needs to be guaranteed.The quality of the Polyetherimide 3D-P specimens was examined by considering six control parameters,namely,infill percentage,layer height,deposition angle,travel speed,nozzle,and bed temperature.The quality indicators were the root mean square(Rq)and average(Ra)roughness,porosity,and the actual to nominal dimensional deviation.The examination was performed with optical profilometry,optical microscopy,and micro-computed tomography scanning.The Taguchi design of experiments was applied,with twenty-five runs,five levels for each control parameter,on five replicas.Two additional confirmation runs were conducted,to ensure reliability.Prediction equations were constructed to express the quality indicators in terms of the control parameters.Three modeling approaches were applied to the experimental data,to compare their efficiency,i.e.,Linear Regression Model(LRM),Reduced Quadratic Regression Model,and Quadratic Regression Model(QRM).QRM was the most accurate one,still the differences were not high even considering the simpler LRM model.展开更多
The Hong Kong housing authority houses a half po pulation of Hong Kong. It constructs and manages pro perty on a massive scale. In 1989, the housing authority makes the decision that by 1993, its construction proj...The Hong Kong housing authority houses a half po pulation of Hong Kong. It constructs and manages pro perty on a massive scale. In 1989, the housing authority makes the decision that by 1993, its construction project management arm, and all construction companies working for the Housing Authority would be certified to the ISO 9000 standard. This decision is to have a profound and lasting impact on the construction industry in Hong Kong. In 1996, a management enhancement programme is launched. Targeting all 15 000 staff in the housing department, the programme aims at changing the culture of the organization and its partners in delivering high calibre services to customers. This paper examines the motivation and reasons behind the initiatives. It outlines the approach and framework used as the authority changes the mindset of a large department of the civil service.展开更多
针对战役仓库综合管理能力需求分析问题,提出基于灰关联分析的质量功能展开(grey quality function deployment,GQFD)方法。依照战役仓库“任务-能力”分析需求思路建立战役仓库综合管理能力需求分析模型,在战役仓库综合管理能力需求分...针对战役仓库综合管理能力需求分析问题,提出基于灰关联分析的质量功能展开(grey quality function deployment,GQFD)方法。依照战役仓库“任务-能力”分析需求思路建立战役仓库综合管理能力需求分析模型,在战役仓库综合管理能力需求分析模型的基础上,建立灰关联分析的战役仓库综合管理能力质量屋模型,最终计算得到了以仓库业务自动化处理能力为最重要需求的战役仓库综合管理能力需求重要度排序,并通过实例分析验证了该法的可行性和有效性,为下一步战役仓库的规划和发展提供了重要依据。展开更多
文摘Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)procedure.This can be very important in defense-related applications,where optimum performance needs to be guaranteed.The quality of the Polyetherimide 3D-P specimens was examined by considering six control parameters,namely,infill percentage,layer height,deposition angle,travel speed,nozzle,and bed temperature.The quality indicators were the root mean square(Rq)and average(Ra)roughness,porosity,and the actual to nominal dimensional deviation.The examination was performed with optical profilometry,optical microscopy,and micro-computed tomography scanning.The Taguchi design of experiments was applied,with twenty-five runs,five levels for each control parameter,on five replicas.Two additional confirmation runs were conducted,to ensure reliability.Prediction equations were constructed to express the quality indicators in terms of the control parameters.Three modeling approaches were applied to the experimental data,to compare their efficiency,i.e.,Linear Regression Model(LRM),Reduced Quadratic Regression Model,and Quadratic Regression Model(QRM).QRM was the most accurate one,still the differences were not high even considering the simpler LRM model.
文摘The Hong Kong housing authority houses a half po pulation of Hong Kong. It constructs and manages pro perty on a massive scale. In 1989, the housing authority makes the decision that by 1993, its construction project management arm, and all construction companies working for the Housing Authority would be certified to the ISO 9000 standard. This decision is to have a profound and lasting impact on the construction industry in Hong Kong. In 1996, a management enhancement programme is launched. Targeting all 15 000 staff in the housing department, the programme aims at changing the culture of the organization and its partners in delivering high calibre services to customers. This paper examines the motivation and reasons behind the initiatives. It outlines the approach and framework used as the authority changes the mindset of a large department of the civil service.
文摘针对战役仓库综合管理能力需求分析问题,提出基于灰关联分析的质量功能展开(grey quality function deployment,GQFD)方法。依照战役仓库“任务-能力”分析需求思路建立战役仓库综合管理能力需求分析模型,在战役仓库综合管理能力需求分析模型的基础上,建立灰关联分析的战役仓库综合管理能力质量屋模型,最终计算得到了以仓库业务自动化处理能力为最重要需求的战役仓库综合管理能力需求重要度排序,并通过实例分析验证了该法的可行性和有效性,为下一步战役仓库的规划和发展提供了重要依据。
