Mask image projection-based vat photopolymerization(MIP-VPP)offers advantages like low cost,high resolution,and a wide material range,making it popular in industry and education.Recently,MIP-VPP employing liquid cryst...Mask image projection-based vat photopolymerization(MIP-VPP)offers advantages like low cost,high resolution,and a wide material range,making it popular in industry and education.Recently,MIP-VPP employing liquid crystal displays(LCDs)has gained traction,increasingly replacing digital micromirror devices,particularly among hobbyists and in educational settings,and is now beginning to be used in industrial environments.However,LCD-based MIP-VPPsuffers from pronounced pixelated aliasing arising from LCD’s discrete image pixels and itsdirect-contact configuration in MIP-VPP machines,leading to rough surfaces on the 3D-printed parts.Here,we propose a vibration-assisted MIP-VPP method that utilizes a microscalevibration to uniformize the light intensity distribution of the LCD-based mask image on VPP’s building platform.By maintaining the same fabrication speed,our technique generates asmoother,non-pixelated mask image,reducing the roughness on flat surfaces and boundary segments of 3D-printed parts.Through light intensity modeling and simulation,we derived an optimal vibration pattern for LCD mask images,subsequently validated by experiments.We assessed the surface texture,boundary integrity,and dimensional accuracy of componentsproduced using the vibration-assisted approach.The notably smoother surfaces and improved boundary roughness enhance the printing quality of MIP-VPP,enabling its promisingapplications in sectors like the production of 3D-printed optical devices and others.展开更多
This paper presents a novel approach to improve aliasing rejection in comb-based decimation filters. The method is established on certain palindromic polynomials with all zeros on the unit circle and the sharpening te...This paper presents a novel approach to improve aliasing rejection in comb-based decimation filters. The method is established on certain palindromic polynomials with all zeros on the unit circle and the sharpening technique. As a result, aliasing rejection and the passband characteristic are improved. The method is illustrated with various examples and compared with the methods from the literature. .展开更多
以人机工程学、设计表达和产品设计为中心形成的三大核心课程群,都需要利用各种Alias Studio Tools软件来完成课程教学和学习。如何实现各课程群内部信息共享,课程群之间信息交换,进而提高教学和学习效率?利用Alias Studio Tools软件技...以人机工程学、设计表达和产品设计为中心形成的三大核心课程群,都需要利用各种Alias Studio Tools软件来完成课程教学和学习。如何实现各课程群内部信息共享,课程群之间信息交换,进而提高教学和学习效率?利用Alias Studio Tools软件技术建立信息化平台可以较好地解决这一问题。展开更多
To avoid spatial aliasing problems in broad band high resolution seismic sections, I present a high density migration processing solution. I first analyze the spatial aliasing definition for stack and migration seismi...To avoid spatial aliasing problems in broad band high resolution seismic sections, I present a high density migration processing solution. I first analyze the spatial aliasing definition for stack and migration seismic sections and point out the differences between the two. We recognize that migration sections more often show spatial aliasing than stacked sections. Second, from wave propagation theory, I know that migration output is a new spatial sampling process and seismic prestack time migration can provide the high density sampling to prevent spatial aliasing on high resolution migration sections. Using a 2D seismic forward modeling analysis, I have found that seismic spatial aliasing noise can be eliminated by high density spatial sampling in prestack migration. In a 3D seismic data study for Daqing Oilfield in the Songliao Basin, I have also found that seismic sections obtained by high-density spatial sampling （10 ×10 m） in prestack migration have less spatial aliasing noise than those obtained by conventional low density spatial sampling （20 × 40 m） in prestack migration.展开更多
2006年6月27日，一场有关数字创新的“特殊”高峰对话在上海古象酒店的会议室内展开，而对话双方则是Autodesk公司全球CEO Carl Bass先生和来自制造企业、学界的十几位嘉宾。多家媒体的记者也受到了Autodesk公司的邀请，饶有兴致地旁听...2006年6月27日，一场有关数字创新的“特殊”高峰对话在上海古象酒店的会议室内展开，而对话双方则是Autodesk公司全球CEO Carl Bass先生和来自制造企业、学界的十几位嘉宾。多家媒体的记者也受到了Autodesk公司的邀请，饶有兴致地旁听了这场优雅的“论战”。在论战热身阶段，CarlBass先生发表的演讲以及随后安排的概念设计技术产品演示，似乎表明此次活动是Autodesk公司收购Alias之后，打出的一张“创意工业”牌。展开更多
文摘Mask image projection-based vat photopolymerization(MIP-VPP)offers advantages like low cost,high resolution,and a wide material range,making it popular in industry and education.Recently,MIP-VPP employing liquid crystal displays(LCDs)has gained traction,increasingly replacing digital micromirror devices,particularly among hobbyists and in educational settings,and is now beginning to be used in industrial environments.However,LCD-based MIP-VPPsuffers from pronounced pixelated aliasing arising from LCD’s discrete image pixels and itsdirect-contact configuration in MIP-VPP machines,leading to rough surfaces on the 3D-printed parts.Here,we propose a vibration-assisted MIP-VPP method that utilizes a microscalevibration to uniformize the light intensity distribution of the LCD-based mask image on VPP’s building platform.By maintaining the same fabrication speed,our technique generates asmoother,non-pixelated mask image,reducing the roughness on flat surfaces and boundary segments of 3D-printed parts.Through light intensity modeling and simulation,we derived an optimal vibration pattern for LCD mask images,subsequently validated by experiments.We assessed the surface texture,boundary integrity,and dimensional accuracy of componentsproduced using the vibration-assisted approach.The notably smoother surfaces and improved boundary roughness enhance the printing quality of MIP-VPP,enabling its promisingapplications in sectors like the production of 3D-printed optical devices and others.
文摘This paper presents a novel approach to improve aliasing rejection in comb-based decimation filters. The method is established on certain palindromic polynomials with all zeros on the unit circle and the sharpening technique. As a result, aliasing rejection and the passband characteristic are improved. The method is illustrated with various examples and compared with the methods from the literature. .
文摘To avoid spatial aliasing problems in broad band high resolution seismic sections, I present a high density migration processing solution. I first analyze the spatial aliasing definition for stack and migration seismic sections and point out the differences between the two. We recognize that migration sections more often show spatial aliasing than stacked sections. Second, from wave propagation theory, I know that migration output is a new spatial sampling process and seismic prestack time migration can provide the high density sampling to prevent spatial aliasing on high resolution migration sections. Using a 2D seismic forward modeling analysis, I have found that seismic spatial aliasing noise can be eliminated by high density spatial sampling in prestack migration. In a 3D seismic data study for Daqing Oilfield in the Songliao Basin, I have also found that seismic sections obtained by high-density spatial sampling （10 ×10 m） in prestack migration have less spatial aliasing noise than those obtained by conventional low density spatial sampling （20 × 40 m） in prestack migration.
文摘2006年6月27日，一场有关数字创新的“特殊”高峰对话在上海古象酒店的会议室内展开，而对话双方则是Autodesk公司全球CEO Carl Bass先生和来自制造企业、学界的十几位嘉宾。多家媒体的记者也受到了Autodesk公司的邀请，饶有兴致地旁听了这场优雅的“论战”。在论战热身阶段，CarlBass先生发表的演讲以及随后安排的概念设计技术产品演示，似乎表明此次活动是Autodesk公司收购Alias之后，打出的一张“创意工业”牌。
