PDE-Based Medial Axis Extraction and Shape Manipulation of Arbitrary Meshes

Shape skeletonization （i.e., medial axis extraction） is powerful in many visual computing applications, such as pattern recognition, object segmentation, registration, and animation. In this paper, the authors expand the use of diffusion equations combined with distance field information to approximate medial axes of arbitrary 3D differential properties. It offers an alternative solids represented by polygonal meshes based on their but natural way for medial axis extraction for commonly used 3D polygonal models. By solving the PDE along time axis, this system can not only quickly extract diffusion-based medial axes of input meshes, but also allow users to visualize the extraction process at each time step. In addition, the proposed model provides users a set of manipulation toolkits to sculpt extracted medial axes, then use diffusion-based techniques to recover corresponding deformed shapes according to the original input datasets. This skeleton-based shape manipulation offers a fast and easy way for animation and deformation of complicated mesh objects.     

非开挖地下工程施工风险评估

针对非开挖地下工程影响因素的随机性和模糊性特点,采用模糊综合评定法与可信性风险分析方法相结合分析非开挖工程.通过一个工程实例,说明模糊综合评定法可以在一定程度上加深对可能产生风险的认识;最后根据可信性风险分析理论,分析了非开挖工程的总体风险.     

Systemic Intervention in a University Department: Reflections on Arrested Action Research

This paper reflects on my experience as an insider researcher attempting to use critical systems ideas and practices to promote quality improvement in a university engineering department. Reflection is a key part of learning. This paper is intended to contribute to critically, self-reflective learning for the community of systems practitioners. These reflections on my questions about participation, ethics, politics of process, and the choices and actions resulting from them may help others to formulate their own. The complexity of systems practice places substantial demands on the researcher, particularly in the case of insider, practitioner research. Nevertheless, the exploration of critical systems approaches to critique boundaries and structure ‘problems’ in the core aspects of higher education in locally meaningful ways should continue. While demanding, it still can work to promote learning about authentic quality.     

调和NA群上的Hardy不确定原理

首先介绍了调和NA群的基本结构和球函数的性质.其次基于调和NA群上的Helgason-Fourier变换及相应于Laplace-Beltrami算子的热核,在NA群上建立了Hardy不确定原理.所得结论推广了Thangavelu（2002年）的部分结果.     

均值不等式的推广及应用

本文对均值不等式在指数方面作了推广,并举例说明本文的推广拓宽了均值不等式的应用,使一些问题简化.     

陈骥《文则》的现代修辞观

陈骏的《文则》是中国历史上第一部谈及文法修辞的专著，其价值是多方面的，本文从陈骏创作实践中运用多种积极辞格阐述相关的修辞理论，以评价他的积极修辞观；《文则》“虽以事出创造，不无瑕疵”，但论及了语法、句法、辞格、文章、风格、文体等多方面内容，初步建立了大修辞学体系，体现了现代修辞学界所倡导的广义修辞观；陈骏虽是对《诗》《书》《礼》《易》《春秋》等静态书面语言的考察，但用动态的辩证的眼光提出了不少真知灼见，体现了动态的辩证的修辞观。     

PEAK COVARIANCE STABILITY OF A RANDOM RICCATI EQUATION ARISING FROM KALMAN FILTERING WITH OBSERVATION LOSSES

We consider the stability of a random Riccati equation with a Markovian binary jump coefficient. More specifically, we are concerned with the boundedness of the solution of a random Riccati difference equation arising from Kalman filtering with measurement losses. A sufficient condition for the peak covariance stability is obtained which has a simpler form and is shown to be less conservative in some cases than a very recent result in existing literature. Furthermore, we show that a known sufficient condition is also necessary when the observability index equals one.     

CONSTRUCTIVE KISSING NUMBERS IN HIGH-DIMENSIONAL SPACES

In the present paper, we focus on constructive spherical codes. By employing algebraic geometry codes, we give an explicit construction of spherical code sequences. By making use of the idea involved in the proof of the Gilbert-Varshamov bound in coding theory, we construct a spherical code sequence in exponential time which meets the best-known asymptotic bound by Shamsiev and Wyner.