Topology-constrained Synthesis of Vector Patterns

International audienceDecorative patterns are observed in many forms of art, typically enriching the visual aspect of otherwise simple shapes. Such patterns are especially difficult to create, as they often exhibit intricate structural details and at the same time have to precisely match the size and shape of the underlying geometry. In the field of Computer Graphics, several approaches have been proposed to automatically synthesize a decorative pattern along a curve, from an example. This empowers non expert users with a simple brush metaphor, allowing them to easily paint complex structured decorations.We extend this idea to the space of design and fabrication. The major challenge is to properly account for the topology of the produced patterns. In particular, our technique ensures that synthesized patterns will be made of exactly one connected component, so that once printed they form a single object. To achieve this goal we propose a two steps synthesis process, first synthesizing the topology of the pattern and later synthesizing its exact geometry. We introduce topology descriptors that efficiently capture the topology of the pattern synthesized so far.We propose several applications of our method, from designing objects using synthesized patterns along curves and within rectangles, to the decoration of surfaces with a dedicated smooth frame interpolation. Using our technique, designers paint structured patterns that can be fabricated into solid, tangible objects, creating unusual and surprising designs of lamps, chairs and laces from examples

Topology-Aware Surface Reconstruction for Point Clouds

We present an approach to inform the reconstruction of a surface from a point scan through topological priors. The reconstruction is based on basis functions which are optimized to provide a good fit to the point scan while satisfying predefined topological constraints. We optimize the parameters of a model to obtain likelihood function over the reconstruction domain. The topological constraints are captured by persistence diagrams which are incorporated in the optimization algorithm promote the correct topology. The result is a novel topology-aware technique which can: 1.) weed out topological noise from point scans, and 2.) capture certain nuanced properties of the underlying shape which could otherwise be lost while performing surface reconstruction. We showcase results reconstructing shapes with multiple potential topologies, compare to other classical surface construction techniques, and show the completion of real scan data

By-example synthesis of curvilinear structured patterns

International audienceMany algorithms in Computer Graphics require to synthesize a pattern along a curve. This is for instance the case with line stylization, to decorate objects with elaborate patterns (chains, laces, scratches), or to synthesize curvilinear features such as mountain ridges, rivers or roads. We describe a simple yet effective method for this problem. Our method addresses the main challenge of maintain- ing the continuity of the pattern while following the curve. It allows some freedom to the synthesized pattern: It may locally diverge from the curve so as to allow for a more natural global result. This also lets the pattern escape areas of overlaps or fold-overs. This makes our method particularly well suited to structured, detailed patterns following complex curves. Our synthesizer copies tilted pieces of the exemplar along the curve, following its orientation. The result is opti- mized through a shortest path search, with dynamic programming. We speed up the process by an efficient parallel implementation. Finally, since discontinuities may always remain we propose an optional post-processing step optimally deforming neighboring pieces to smooth the transitions

On-Chip Temperature Compensation for Small-Signal Gain Variation Reduction

Power amplifier (PA) specifications are closely related to changes in temperature; thus, the small-signal gain (S21) of PA decreases with the temperature increase. To compensate for the degradation caused by the decrease in S21, we present a compensation circuit that consists of two diodes and four resistors. At the same time, a differential stacked millimeter-wave wideband PA was designed and implemented based on this compensation circuit and 55 nm CMOS process. The post-layout simulation results showed that the fluctuation of S21 reduced from 2.4 dB to 0.1 dB in the frequency range of 25−40 GHz over the temperature range of −40 °C to 125 °C. Furthermore, the proposed on-chip temperature compensation circuit also applies to multi-stage cascaded microwave/mm-wave power amplifiers

Survival benefit of pure dose-dense chemotherapy in breast cancer: a meta-analysis of randomized controlled trials

Abstract Background Dose-dense chemotherapy is a widely accepted regimen for high-risk breast cancer patients. However, conflicting survival benefits of pure dose-dense chemotherapy have been reported in different randomized controlled trials (RCTs). This meta-analysis aimed to further assess the efficacy and safety of pure dose-dense chemotherapy in breast cancer. Methods A literature search of electronic databases and websites was performed to identify phase III RCTs reporting the efficacy and toxicity of pure dose-dense chemotherapy. The endpoints of interest were overall survival (OS), disease-free survival (DFS), and toxicities. The hazard ratios (HRs) of death and recurrence and the odds ratios (ORs) of adverse events were estimated and pooled. Results Seven studies (five trials) were eligible, encompassing a total of 9851 patients. Patients treated with dose-dense chemotherapy obtained better DFS (HR = 0.83; 95% CI 0.75–0.91; p = 0.0001) than those treated with the conventional schedule, while OS benefit of dose-dense chemotherapy was less impressive (HR = 0.86; 95% CI 0.73–1.02; p = 0.08). However, significant OS benefit was observed in node-positive patients (HR = 0.77; 95% CI 0.66–0.90; p = 0.001). The incidence of anemia, pain, and transaminase elevation was higher in the dose-dense chemotherapy arm. Conclusions Dose-dense chemotherapy leads to better prognosis; these findings suggest that it may be a potentially preferred treatment for breast cancer patients, particularly for women with lymph node involvement. However, more RCTs are warranted to better define the best candidates for dose-dense chemotherapy