Exploring Non‐Linear Relationship of Blendshape Facial Animation

Human face is a complex biomechanical system and non‐linearity is a remarkable feature of facial expressions. However, in blendshape animation, facial expression space is linearized by regarding linear relationship between blending weights and deformed face geometry. This results in the loss of reality in facial animation. To synthesize more realistic facial animation, aforementioned relationship should be non‐linear to allow the greatest generality and fidelity of facial expressions. Unfortunately, few existing works pay attention to the topic about how to measure the non‐linear relationship. In this paper, we propose an optimization scheme that automatically explores the non‐linear relationship of blendshape facial animation from captured facial expressions. Experiments show that the explored non‐linear relationship is consistent with the non‐linearity of facial expressions soundly and is able to synthesize more realistic facial animation than the linear one.     

Discriminative Sketch‐based 3D Model Retrieval via Robust Shape Matching

We propose a sketch‐based 3D shape retrieval system that is substantially more discriminative and robust than existing systems, especially for complex models. The power of our system comes from a combination of a contour‐based 2D shape representation and a robust sampling‐based shape matching scheme. They are defined over discriminative local features and applicable for partial sketches; robust to noise and distortions in hand drawings; and consistent when strokes are added progressively. Our robust shape matching, however, requires dense sampling and registration and incurs a high computational cost. We thus devise critical acceleration methods to achieve interactive performance: precomputing kNN graphs that record transformations between neighboring contour images and enable fast online shape alignment; pruning sampling and shape registration strategically and hierarchically; and parallelizing shape matching on multi‐core platforms or GPUs. We demonstrate the effectiveness of our system through various experiments, comparisons, and user studies.     

Simulation-based two-stage estimation for multiple nonparametric regression

To reduce the curse of dimensionality arising from nonparametric estimation procedures for multiple nonparametric regression, in this paper we suggest a simulation-based two-stage estimation. We first introduce a simulation-based method to decompose the multiple nonparametric regression into two parts. The first part can be estimated with the parametric convergence rate and the second part is small enough so that it can be approximated by orthogonal basis functions with a small trade-off parameter. Then the linear combination of the first and second step estimators results in a two-stage estimator for the multiple regression function. Our method does not need any specified structural assumption on the regression function and it is proved that the newly proposed estimation is always consistent even if the trade-off parameter is designed to be small. Thus when the common nonparametric estimator such as local linear smoothing collapses because of the curse of dimensionality, our estimator still works well.     

有界控制下单向收敛滑模控制

提出一种控制有界情况下状态单向收敛的滑模控制方法.对于二阶系统,单向收敛是指初始状态与状态到达滑动模态的位置位于相平面同一象限的过程.通过分析到达阶段的动态特性,揭示了状态非单向收敛的原因,并提出了一种单向收敛条件,给出了系统状态单向收敛的区域.将所提出的方法应用于具有单向收敛要求的交会对接控制系统,结果验证了所提出方法的有效性.     

基于NetCDF的数据交换平台研究

针对异构海洋观测数据交互困难的问题,提出基于NetCDF的海洋观测数据交换格式,定义海洋观测数据交互规范,实现海洋观测数据灵活装载和随机访问。基于此,设计海洋观测数据交换平台框架,通过分层架构模式实现海洋观测数据用户"一站式"访问。最后,开发原型系统加以验证。     

多点快速采集系统中信号可靠转贮技术研究

在直径为10cm的受光面上均匀分布有256个光电探测器,需要将这些探测器所反映的激光能量分布及变化情况的数据即时采集并传送到上位机实时显示。以数据采集和快速传输为目的,介绍了以W77E58为CPU的256点快速采集系统构成及工作原理,讨论了以FT245BM为核心构成的USB接口电路进行实时传送的电路原理及实现过程,较好地解决了对多个监测点实时快速采集和快速传送问题。     

基于粒子滤波和过程模型的动态数据校正

针对所有的基于粒子滤波的动态数据校正中粒子滤波方法仅仅是针对数据的,本文提出了一种基于粒子滤波和过程模型的动态数据校正方法(DDRPFPM)。该方法将过程模型引入到动态数据校正中,作为约束条件来更新粒子的权值,有效提高了粒子的信任度,解决了基于粒子滤波的动态数据校正(DDRPF)过程中存在的粒子退化问题。通过CSTR仿真证明,DDRPFPM能够较好的应用于动态数据校正,与DDRPF相比无论是对温度噪声还是离群值都有更强的校正能力。     

HEDP及其取代物对碳酸钙阻垢机理的研究

采用分子动力学方法,模拟计算了阻垢剂HEDP及其取代物与方解石(104,(102),(202),(113)面的相互作用,计算并分析了阻垢剂与方解石(104),(102),(202),(113)面作用的相互作用能,包括结合能,库仑能和范德华作用能.并且分析了方解石(104)晶面上的钙离子与阻垢剂中双键氧原子、整个(104)晶面与阻垢剂中所有氧原子之间和整个(104)晶面与整个阻垢剂分子之间的对关联函数,结果表明:阻垢剂分子中的氧原子与碳酸钙的Ca2+形成的离子键对吸附起到了主要作用,同时阻垢剂与晶面间存在较弱的范德华力相互作用,阻垢剂与各晶面的的结合能强弱顺序为(102)＞(202)≥(113)≈(104).苯环的大π键有利于阻垢效果的提高.     

COS和H_2S毒化F-T合成催化剂热力学分析

利用热力学基础数据和相关软件对F-T合成催化剂COS和H_2S中毒的热力学进行了计算。在热力学上,Ru、Fe、Co的COS中毒在F-T合成反应可以发生的条件下均是自发过程。F-T合成反应体系中10~(-9)级的COS即可使Ru基催化剂中的金属Ru生成RuS_2而中毒。Fe和Co毒化后生成的硫化物种类较多,对这些反应的热力学计算结果表明,对于不同的反应,其平衡常数的差异很大,对应中毒反应发生时,所需的COS和H_2S的浓度也不同,对COS的要求更为严格。由于Fe基F-T合成催化剂活性相的复杂性,利用对催化剂相关性质的修饰开发具有一定抗硫性的铁基F-T合成催化剂是可行的;对于Co催化剂,利用F-T合成的反应特点和催化剂改性开发具有一定抗硫性催化剂是可能的。     

基于延时比较仲裁的模拟I~2C多主通信的软件设计实现

根据模拟I2C总线多主节点通信原理,提出采用延时接收比较来实现仲裁的软件实现方法,为不具备I2C接口的普通微控制器（MCU）实现模拟I2C总线的多主节点通信,促进对I2C总线的推广应用。