Q-EUGSID的优化算法及应用

针对绝对关联度、相对关联度和综合关联度的缺陷,首先,引入了可调因子以及空间距离来建立新模型。其次,证明了新模型符合灰色关联公理并研究了它的一些特殊性质。另外,提出新模型准优值所具备的几个原则,并根据灵敏性分析原理总结出准优值的算法。最后,由实例验证了:改进的模型不仅能够使关联度的取值扩展到更广的范围,而且在一定程度上改善了关联度值的分辨效果。在定量计算方面,某些参数的值也将会更精确。     

一种基于四变量模型的系统安全性建模与分析方法

近年来,基于模型的系统安全性分析与验证方法是安全关键系统工程领域中的一个重要研究方向。提出了一种基于四变量模型的系统安全性建模与分析验证方法,该方法利用AltaRica建模语言对系统进行建模。通过对四变量模型及AltaRica进行语义研究构建二者之间的映射规则,以民用飞机中机轮刹车系统(Wheel Brake System,WBS)为例来说明整个验证过程,即首先利用四变量模型从系统的需求层次上对WBS进行需求分析并根据映射关系构建AltaRica模型,接着利用故障树分析方法对WBS进行安全性研究,最后基于AltaRica配套工具ARC对系统的安全性属性进行验证。验证结果表明了该方法在系统安全工程领域中的实用性。     

基于目标检测及跟踪的视频摘要技术研究

为了能够在不丢失有用信息的前提下对海量监控视频进行摘要,提出一种基于目标检测及跟踪的视频摘要技术。首先根据混合高斯模型对视频进行背景建模,获得监控视频的背景;然后通过背景减法对运动目标进行检测,得到前景运动目标;其次对检测到的运动目标采用分层关联的思想进行目标跟踪,得到运动目标的完整信息;最后将这些运动目标及视频背景重新组装成摘要视频。实验结果表明,该方法能够有效地对监控视频进行浓缩,形成的摘要视频能够完整地保存原有视频信息,减少了存储空间,降低了成本,方便了相关人员及时获取有用信息,提高了工作效率。     

Internet建模的关键:研究AS间路由器级连接

AS-域内路由器双层建模方式是目前构建Internet规模的路由器级网络模型的最优方案,而该方案需要建模者首先了解域间路由器级连接的特点。指出AS类型对域间路由器级连接具有较大影响,通过定义域间参数映射,利用现网数据对域间参数映射进行了现象学分析,获取了不同类型AS相关参数的分布函数,解决了双层模型的组合问题。在此基础上,进一步对Internet建模尚需解决的若干问题进行了讨论。     

Boundary Detection in Particle‐based Fluids

This paper presents a novel method to detect free‐surfaces on particle‐based volume representation. In contrast to most particle‐based free‐surface detection methods, which perform the surface identification based on physical and geometrical properties derived from the underlying fluid flow simulation, the proposed approach only demands the spatial location of the particles to properly recognize surface particles, avoiding even the use of kernels. Boundary particles are identified through a Hidden Point Removal (HPR) operator used for visibility test. Our method is very simple, fast, easy to implement and robust to changes in the distribution of particles, even when facing large deformation of the free‐surface. A set of comparisons against state‐of‐the‐art boundary detection methods show the effectiveness of our approach. The good performance of our method is also attested in the context of fluid flow simulation involving free‐surface, mainly when using level‐sets for rendering purposes.     

Buoyancy Optimization for Computational Fabrication

This paper introduces a design and fabrication pipeline for creating floating forms. Our method optimizes for buoyant equilibrium and stability of complex 3D shapes, applying a voxel‐carving technique to control the mass distribution. The resulting objects achieve a desired floating pose defined by a user‐specified waterline height and orientation. In order to enlarge the feasible design space, we explore novel ways to load the interior of a design using prefabricated components and casting techniques. 3D printing is employed for high‐precision fabrication. For larger scale designs we introduce a method for stacking lasercut planar pieces to create 3D objects in a quick and economic manner. We demonstrate fabricated designs of complex shape in a variety of floating poses.     

过程工业大数据建模研究展望

人们对大数据的认识已从"3Vs" (Volume-大容量; Variety-多样性; Velocity-处理实时性)、"4Vs" ("3Vs"与Value-价值)、到现今的"5Vs" ("4Vs"与Veracity-真实性).在此背景下, 首先分析过程工业大数据的"5Vs"特性; 接下来, 综述现有数据建模方法, 并结合过程工业大数据特有性质 (包括:多层面不规则采样性、多时空时间序列性、不真实数据混杂性) 论述现有数据建模方法应用于工业大数据建模时的局限; 最后, 探讨过程工业大数据建模有待研究的问题, 包括:1) 多层面不规则采样数据的潜结构建模; 2) 用于事件发现、决策和因果分析的多时空时间序列数据建模; 3) 含有不真实数据的鲁棒建模; 4) 支持实时建模的大容量数据计算架构与方法.     

An Interactive Design System of Free‐Formed Bamboo‐Copters

We present an interactive design system for designing free‐formed bamboo‐copters, where novices can easily design free‐formed, even asymmetric bamboo‐copters that successfully fly. The designed bamboo‐copters can be fabricated using digital fabrication equipment, such as a laser cutter. Our system provides two useful functions for facilitating this design activity. First, it visualizes a simulated flight trajectory of the current bamboo‐copter design, which is updated in real time during the user's editing. Second, it provides an optimization function that automatically tweaks the current bamboo‐copter design such that the spin quality—how stably it spins—and the flight quality—how high and long it flies—are enhanced. To enable these functions, we present non‐trivial extensions over existing techniques for designing free‐formed model airplanes [ UKSI14 ], including a wing discretization method tailored to free‐formed bamboo‐copters and an optimization scheme for achieving stable bamboo‐copters considering both spin and flight qualities.     

Slippage control in soft finger grasping and manipulation

Handling objects with robotic soft fingers without considering the odds of slippage are not realistic. Grasping and manipulation algorithms have to be tested under such conditions for evaluating their robustness. In this paper, a dynamic analysis of rigid object manipulation with slippage control is studied using a two-link finger with soft hemispherical tip. Dependency on contact forces applied by a soft finger while grasping a rigid object is examined experimentally. A power-law model combined with a linear viscous damper is used to model the elastic behavior and damping effect of the soft tip, respectively. In order to obtain precise dynamic equations governing the system, two second-order differential equations with variable coefficients have been designed to describe the different possible states of the contact forces accordingly. A controller is designed based on the rigid fingertip model using the concept of feedback linearization for each phase of the system dynamics. Numerical simulations are used to evaluate the performance of the controller. The results reveal that the designed controller shows acceptable performance for both soft and rigid finger manipulation in reducing and canceling slippage. Furthermore, simulations indicate that the applied force in the soft finger manipulation is considerably less than the rigid “one.”.