SAFE: Structure‐aware facade editing

Many man‐made objects, in particular building facades, exhibit dominant structural relations such as symmetry and regularity. When editing these shapes, a common objective is to preserve these relations. However, often there are numerous plausible editing results that all preserve the desired structural relations of the input, creating ambiguity. We propose an interactive facade editing framework that explores this structural ambiguity. We first analyze the input in a semi‐automatic manner to detect different groupings of the facade elements and the relations among them. We then provide an incremental editing process where a set of variations that preserve the detected relations in a particular grouping are generated at each step. Starting from one input example, our system can quickly generate various facade configurations.     

维特鲁维机械学的科学思想起源

本文追溯维特鲁威机械学的三个来源:演绎几何学、实用几何学和机械学,在亚历山大科学传统中的表现与意图。意在说明维特鲁威和谐机械学的起源与传承。     

Interactive Exploration of Protein Cavities

We present a novel application for the interactive exploration of cavities within proteins in dynamic data sets. Inside a protein, cavities can often be found close to the active center. Therefore, when analyzing a molecular dynamics simulation trajectory it is of great interest to find these cavities and determine if such a cavity opens up to the environment, making the binding site accessible to the surrounding substrate. Our user‐driven approach enables expert users to select a certain cavity and track its evolution over time. The user is supported by different visualizations of the extracted cavity to facilitate the analysis. The boundary of the protein and its cavities is obtained by means of volume ray casting, where the volume is computed in real‐time for each frame, therefore allowing the examination of time‐dependent data sets. A fast, partial segmentation of the volume is applied to obtain the selected cavity and trace it over time. Domain experts found our method useful when they applied it exemplarily on two trajectories of lipases from Rhizomucor miehei and Candida antarctica. In both data sets cavities near the active center were easily identified and tracked over time until they reached the surface and formed an open substrate channel.     

LayTracks3D: A new approach for meshing general solids using medial axis transform

This paper presents an extension of the all-quad meshing algorithm called LayTracks to generate high quality hex-dominant meshes of general solids. LayTracks3D uses the mapping between the Medial Axis (MA) and the boundary of the 3D domain to decompose complex 3D domains into simpler domains called Tracks. Tracks in 3D have no branches and are symmetric, non-intersecting, orthogonal to the boundary, and the shortest path from the MA to the boundary. These properties of tracks result in desired meshes with near cube shape elements at the boundary, structured mesh along the boundary normal with any irregular nodes restricted to the MA, and sharp boundary feature preservation. The algorithm has been tested on a few industrial CAD models and hex-dominant meshes are shown in the Results section. Work is underway to extend LayTracks3D to generate all-hex meshes.     

Computing An Optimal Hatching Direction In Layered Manufacturing

In Layered Manufacturing (LM), a prototype of a virtual polyhedral object is built by slicing the object into polygonal layers, and then building the layers one after another. In StereoLithography, a specific LM-technology, a layer is built using a laser which follows paths along equally-spaced parallel lines and hatches all segments on these lines that are contained in the layer. We consider the problem of computing a direction of these lines for which the number of segments to be hatched is minimum, and present an algorithm that solves this problem exactly. The algorithm has been implemented and experimental results are reported for real-world polyhedral models obtained from industry.     

Geometry development of the internal duct system of a heat pump tumble dryer based on fluid mechanic parameters from a CFD software

One aspect of reducing the energy consumption of a household tumble dryer is to reduce the pressure drop of the circulating air in the internal duct system. It is, however, costly and time consuming to design several prototypes for airflow measurements. In this paper, several fluid mechanic parameters in a partial model of the internal duct system of a tumble dryer have been studied in the CFD software Comsol MultiPhysics. The purpose was to establish a numerically based design process, where the design is conducted based on visual analysis of air velocity and vorticity, and two design criteria. The geometry design was conducted by a CAD-engineer, which was the counterpart of this project. In order to enable a successful design process, it was essential to establish a strong relation between fluid parameters and design criteria in order to share knowledge effectively with the CAD-engineer. Two geometry modifications, based on a standard model, were conducted on the duct. Based on the design criteria, the pressure drop and the non-uniformity coefficient of the outlet airflow, the second modification (Modification 2) represents an improvement as the pressure drop is reduced by 23% and the uniformity at the outflow section is increased by 3%.     

钻孔刀具缠丝问题的专项改善与研究

为了保证钻削过程的正常进行,必须保证避免出现钻屑过长缠绕刀具的现象,钻屑不能及时被排除,导致孔壁质量无法保证。文章从钻屑的形成过程、刀具几何角度的设计、钻孔参数的优化三方面进行论述,彻底解决钻屑缠绕刀具的问题,为高质量的孔壁状态奠定了充实基础与有效保障。     

‘Super-Natural’: Parametricism in Product Design

As a stylistic movement, Parametricism has the scope to move beyond the limits of architecture, penetrating adjacent disciplines. Renowned industrial designer Ross Lovegrove , known as ‘Captain Organic’ for his nature-inspired designs, acknowledges the potential of ‘new codes of creation’ being incubated in architecture schools for product design, accelerating innovation across materials, structures and manufacturing technologies.     

空调用贯流风机叶轮几何建模的参数化

根据几何关系,建立了空调用贯流风机叶轮的三维数学模型,实现了空调用贯流风机叶轮几何建模的参数化.其成果极大地缩短了空调用贯流风机叶轮CFD分析的前处理时间.     

精密轴承轮廓的形成方法及其加工量的确定

论述了精密多油楔轴承轮廓的形成方法,建立了计算轮廓有关几何尺寸的数学公式,着重论述了确定轴承轮廓加工量的理论算法。