Surface Patches from Unorganized Space Curves

Recent 3D sketch tools produce networks of three‐space curves that suggest the contours of shapes. The shapes may be non‐manifold, closed three‐dimensional, open two‐dimensional, or mixed. We describe a system that automatically generates intuitively appealing piecewise‐smooth surfaces from such a curve network, and an intelligent user interface for modifying the automatically chosen surface patches. Both the automatic and the semi‐automatic parts of the system use a linear algebra representation of the set of surface patches to track the topology. On complicated inputs from ILoveSketch [ [BBS08] ], our system allows the user to build the desired surface with just a few mouse‐clicks.     

美国线路共享政策的实施与现状

线路共享指的是，用户除了从自己归属的本地电话公司（ILEC）以外还能选择从其它运营公司（主要指CLEC）为自己提供数据业务，并且不必安装第二条电话线。线路共享为现有电话线路上开展数据业务竞争铺平了道路，它在美国被视作能否成功开放DSL市场的关键因素。本文对美国针对DSL发展问题出台线路共享政策以及线路共享政策出台后的实施状况加以报道。对于我国制定线路共享政策和实施管理提供参考。     

New Line Intersection Procedure for the Equivalent Point Method of Thermal Evaluation

A new Line Intersection (LI) procedure for determining sterilization value (F_o) and quality or nutrient retention (cook value: C_o) was developed using the original Equivalent Point Method (O-EPM). Analysis of 30 conventional and 5 simulated thermal curves showed excellent agreement between F_o values determined by the new LI method and the traditional General Method (GM). The new LI method performed better than the O-EPM in yielding more accurate estimates of F_o and C_o values as shown by the relatively low errors. The difference between F_o (GM) and F_o (LI) expressed as percent of F_o (GM) for conventional curves ranged from -0.01% to 0.78% while that between F_o (GM) and F_o (O-EPM) ranged from -0.18% to 38.78%. Similar results were obtained for C_o values.     

3D elasticity analysis of sandwich panels with graded core under distributed and concentrated loadings

Sandwich panels are a type of panel offering weight savings over standard single layer panels, whilst remaining both strong and stiff. However, due to the mismatch of properties between the face sheets and the core, stress concentrations can occur at the face sheet/core interfaces, often leading to delamination. One possible solution to this problem is the introduction of a functionally graded core—a core in which the properties vary gradually from the face sheets to the centre, eliminating any abrupt changes in properties. This paper presents a three-dimensional elasticity analysis for a sandwich panel with stiffness of the core graded in the thickness direction, on the basis of the recently developed 3D elasticity solution. A comparative study of panels with homogeneous and functionally graded cores is carried out to examine the effect of introducing a graded core on the stress and displacement fields under five different loading configurations (uniformly distributed, patch, point, hydrostatic and line).     

管线钢奥氏体晶界的浸蚀及测定

介绍一种显示管线钢奥氏体晶界的浸蚀剂及奥氏体晶粒平均尺寸的测定方法。结果表明，此浸蚀剂是管线钢一种理想的奥氏体晶界浸蚀剂，所采用的测定方法的精确度较高。     

A note on the divergence problem arising in calculation of Green’s function for a 2D piezoelectric thin film strip containing straight line defects and free boundaries: Fourier approach for bodies of unrestricted anisotropy

In this paper we derive a set of novel formulas for computation of the Green’s function and the coupled electro-elastic fields in a 2D piezoelectric strip with free boundaries and containing a distribution of straight line defects. The strip is assumed to be of unrestricted anisotropy, but allowing piezoelectricity, and in this sense situation is more general than in the available literature where only cubic symmetry was investigated. We employ a set of already known analytic formulas for the Fourier amplitude of the Green’s function and the corresponding electro-elastic fields. The key novelty of this paper is solution for the divergence problem occurring during integration of the Fourier amplitude. This problem is caused by poles at k = 0 in various matrix components of the amplitude. From purely mathematical point of view such poles lead to quantities which do not tend to zero at infinity, and this situation is clearly unphysical. To resolve this issue it is demonstrated by means of rigorous analysis that when some additional physical conditions are imposed, physical fields exhibit regular behavior at infinity - the poles do not contribute. Nevertheless, they lead to irremovable numerical ∞ − ∞ uncertainties spreading over the whole domain of integration. This motivates us to compute exact formulas for all these poles to enable engineering calculations involving the system in question.     

Prototyping Dynamic Software Product Lines to evaluate run-time reconfigurations

Dynamic Software Product Lines (DSPL) encompass systems that are capable of modifying their own behavior with respect to changes in their operating environment by using run-time reconfigurations. A failure in these reconfigurations can directly impact the user experience since the reconfigurations are performed when the system is already under the users control. In this work, we prototype a Smart Hotel DSPL to evaluate the reliability-based risk of the DSPL reconfigurations, specifically, the probability of malfunctioning (Availability) and the consequences of malfunctioning (Severity). This DSPL prototype was performed with the participation of human subjects by means of a Smart Hotel case study which was deployed with real devices. Moreover, we successfully identified and addressed two challenges associated with the involvement of human subjects in DSPL prototyping: enabling participants to (1) trigger the run-time reconfigurations and to (2) understand the effects of the reconfigurations. The evaluation of the case study reveals positive results regarding both Availability and Severity. However, the participant feedback highlights issues with recovering from a failed reconfiguration or a reconfiguration triggered by mistake. To address these issues, we discuss some guidelines learned in the case study. Finally, although the results achieved by the DSPL may be considered satisfactory for its particular domain, DSPL engineers must provide users with more control over the reconfigurations or the users will not be comfortable with DSPLs.     

Efficient and Dynamic Simplification of Line Drawings

In this paper we present a pipeline for rendering dynamic 2D/3D line drawings efficiently. Our main goal is to create efficient static renditions and coherent animations of line drawings in a setting where lines can be added, deleted and arbitrarily transformed on‐the‐fly. Such a dynamic setting enables us to handle interactively sketched 2D line data, as well as arbitrarily transformed 3D line data in a unified manner. We evaluate the proximity of screen projected strokes to simplify them while preserving their continuity. We achieve this by using a special data structure that facilitates efficient proximity calculations in a dynamic setting. This on‐the‐fly proximity evaluation also facilitates generation of appropriate visibility cues to mitigate depth ambiguities and visual clutter for 3D line data. As we perform all these operations using only line data, we can create line drawings from 3D models without any surface information. We demonstrate the effectiveness and applicability of our approach by showing several examples with initial line representations obtained from a variety of sources: 2D and 3D hand‐drawn sketches and 3D salient geometry lines obtained from 3D surface representations.     

微电脑数据采集处理系统及其应用

阐明了微电脑数据采集处理系统、原理、软件设计及其特点，强调了系统于在线质量统计分析中可用来实现零件制造过程质量管理的重要意义。     

A new geometrical approach to one-parameter spatial motion

The geometry and kinematics of one-parameter dual spherical motions is presented using Study’s dual-line coordinates. The relations between invariants of the axodes are expressed in simple form with geometrical reasoning and explanation. In terms of this, the dual version of associated space curves is demonstrated for a ruled surface to be associated with the axodes of the motion. The relative motion between the axodes is used for deriving the geometry and kinematics of the paths instantaneously traced in the fixed space by a line associated with the moving axode. Especially, the distribution parameter and the inflection-line congruence are investigated. Furthermore, a new metric is developed and used to investigate the geometrical properties and kinematics of line trajectory as well as Disteli axis. Finally, as an application an example is put forward and explained in detail.