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In geometric modeling, surface parameterization plays an important role for converting triangle meshes to spline surfaces. Parameterization will introduce distortions. Conventional parameterization methods emphasize on angle-preservation, which may induce huge area distortions and cause large spline fitting errors and trigger numerical instabilities.To overcome this difficulty, this work proposes a novel area-preserving parameterization method, which is based on an optimal mass transport theory and convex geometry. Optimal mass transport mapping is measure-preserving and minimizes the transportation cost. According to Brenier’s theorem, for quadratic distance transportation costs, the optimal mass transport map is the gradient of a convex function. The graph of the convex function is a convex polyhedron with prescribed normal and areas. The existence and the uniqueness of such a polyhedron have been proved by the Minkowski-Alexandrov theorem in convex geometry. This work gives an explicit method to construct such a polyhedron based on the variational principle, and formulates the solution to the optimal transport map as the unique optimum of a convex energy. In practice, the energy optimization can be carried out using Newton’s method, and each iteration constructs a power Voronoi diagram dynamically. We tested the proposal algorithms on 3D surfaces scanned from real life. Experimental results demonstrate the efficiency and efficacy of the proposed variational approach for the optimal transport map.  相似文献   

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通过大量实验证明了公安110报警事件具备可预测性。该预测模型具备适用性特点,可应用于公安机关实战指挥及政府应急管理部门的预测应用,并辅助决策支持。该创新建模预测过程称为先重构后建模预测法。  相似文献   

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Since most of miniaturized surface plasmon resonance (SPR) sensing systems need commercially available peristaltic or syringe pumps, it is difficult to reduce the system size, biosample volume, and the production cost. In this paper, a compact biochip for clinical diagnosis is presented. The proposed biochip is integrated traveling wave micropumps and SPR imaging sensors on one chip. The micropump is composed of flexible microchannel and piezoelectric bimorph actuator array, and achieved the maximum flow rate 336 μl/min. The SPR imaging biosensor can quantitatively measure biosamples with multi microchannels, i.e. one biosample and two reference flows to obtain an analytical curve. The SPR imaging measurements with bovine serum albumin solutions were carried out using the prototype of the proposed diagnostic system composed of a pair of the micropump and the sensor. Since the clear SPR signal curve was observed, it was confirmed that the proposed system can be applicable to the clinical diagnosis.  相似文献   

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A model simulation of dynamic behavior of thermopneumatic micropump is presented. The model uses conservation of energy, mass, and momentum to predict the behavior of existing thermopneumatic micropumps. Applied to existing micropumps, simulation predicts trends similar to those reported experimentally. Dynamic simulation of effect of design parameters on performance of micropump is, then, carried out through the article. Results suggest that increasing operating frequencies results in higher volume flow rates until a critical frequency is reached. At higher frequencies volume flow rates decrease. Critical frequencies are dependent on damping. The higher the damping coefficient the lower the critical frequency becomes. For high frequency operation the performance of the micropump is dominated by both damping and heat capacity of micropump components. For low frequency operation the performance is dominated by heat losses from walls of air-chamber. The model provides general guidelines for building and operating the micropump.  相似文献   

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An introductory computer science course is developed, much as calculus is a basic course for mathematics and the physical sciences, concerned primarily with theoretical foundations and methodology rather than apprenticeship through applications. In this work, the principles taught in the course are described and an example illustrating them is given  相似文献   

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基于模型诊断(model-based diagnosis,MBD)是人工智能诊断领域中著名的诊断求解方法之一,旨在识别诊断问题的根本原因.由于求解诊断解在计算上具有挑战性,一些MBD算法提出通过修改模型的编码来提高诊断效率,如面向统治者的编码(dominator-oriented encoding, DOE)方法.面向观察的编码(observation-oriented encoding,OOE)方法使用2种方法对MBD模型进行约简. 首先,利用系统观测和统治组件输出的一些过滤边来约简系统描述和观测.其次,通过查找基于观测的过滤节点来过滤更多的组件, 进而有效约简组件的编码规模. 此外,在ISCAS85和ITC99基准测试用例上的实验结果表明,与目前最新的MBD编码方法DOE和传统的基础编码(basic encoding , BE)相比,上述2种约简方法有效减少了MBD实例的编码子句数量比,降低MaxSAT求解器求解诊断的难度,进而能在更短的时间内返回一个诊断解.

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应用第一原理的故障诊断思想,基于故障测试矩阵,提出了一种根据系统每一个故障都可检测的行为与系统所有故障不能检测的行为之间的不相容推理技术,来判断和求取系统存在的所有最小完全测试集的方法。方法分两步:一是根据系统的结构和测试矢量等知识,结合故障测试矩阵,识别冲突集候选;二是根据冲突集候选,确定最小命中集合组,生成最小完全测试集。该方法可有效求解最小完全测试集,减少测试矢量施加的工作量,提高故障诊断的效率。  相似文献   

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Hybrid fuzzy-first principles models can be attractive if a complete physical model is difficult to derive. These hybrid models consist of a framework of dynamic mass and energy balances, supplemented with fuzzy submodels describing additional equations, such as mass transformation and transfer rates. In this paper, a structured approach for designing this type of model is presented. The modeling problem is reduced to several simpler problems, which are solved independently: hybrid model structure and subprocess determination, subprocess behavior estimation, identification and integration of the submodels to form the hybrid model. The hybrid model is interpretable and transparent. The approach is illustrated using data from a (simulated) fed-batch bioreactor.  相似文献   

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In this paper, we report a novel capillary-driven self-assembly technique which proceeds in an air environment and demonstrate it by assembling square piezoelectric transducer (PZT) actuators for 28 diffuser valve micropumps on a 4-inch pyrex/silicon substrate: on the substrate, binding sites are wells of 24 /spl mu/m in depth and the only hydrophilic areas; on the bonding face of the PZT actuator, the central hydrophilic area is a square identical in size to the binding site, and the rim is hydrophobic; acrylate-based adhesive liquid is dispensed across the substrate and wets only the binding sites; the hydrophilic areas on the introduced PZT actuators self-align with the binding sites to minimize interfacial energies by capillary forces from the adhesive droplets; the aligned PZT actuators are pressed to contact the gold coated substrate by their rims and the adhesive is polymerized by heating to 85 /spl deg/C for half an hour, so permanent mechanical and electrical connections are established, respectively, at the center and rim of each PZT actuator. These pumps perform with high uniformity, which is indicated by a small standard deviation of their resonant frequencies to pump ethanol: the average resonant frequency is 6.99 kHz and the standard deviation is 0.1 kHz. Compared with the conventional bonding process with highly viscous silver epoxy, this assembly method has several major advantages: highly accurate placement with self-alignment, controllable adhesive thickness, tilt free bonding, low process temperature and high process repeatability.  相似文献   

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Increasing demands for lower cost of goods, due to international competition, has developed a new area of rationalization for increased productivity which can be achieved by applying new radical methods of production principles. Design for Assembly (DFA) is one of such methods that should be considered in the early design stage in order to cope with the increasing demands of lower cost, improved working environment, and higher wages. When Axiomatic Design (AD) is implemented with DFA in an intelligent way, a new area of design concepts would be realized. This study examines some elements of intelligent design systems to assess manufacturability of a product through the development of a knowledge based expert system for assembly (KBESA). The knowledge base has been acquired from DFA along with AD concepts with emphasis on the conceptual design stage where the structure of the product as a whole is considered. These concepts have been implemented in a case study illustrating its applicability.  相似文献   

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基于Web的化工原理虚拟仿真实验系统   总被引:4,自引:1,他引:3  
为了提高实验安全性,实现化工原理课程的网络化教学,运用虚拟仿真技术和多种图像、动画表现形式构造了常规虚拟实验设备模型,设计了相关实验过程,开发了专用实验数据处理与绘图模块,结合CAT(Computer Aided Test)理论和人工智能方法研究了实验操作过程的自动评判技术。实践证明,虚拟设备能再现各种实验场景,仿真实验过程,实验系统能在人机交互条件下训练用户组装实验设备、进行实验操作和测取实验数据,并自动评判实验成绩。  相似文献   

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提出一种基于免疫原理的人工免疫算法,用于模糊关联规则的挖掘.该算法通过借鉴生物免疫系统中的克隆选择原理来实施优化操作,它直接从给出的数据中,通过优化机制自动确定每个属性对应的模糊集合,使推导出的满足条件的模糊关联规则数目最多.将实际数据集和相关算法进行性能比较,实验结果表明了所提出算法的有效性.  相似文献   

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基于构件的动态工作流建模方法研究   总被引:2,自引:0,他引:2  
针对目前工作流管理系统在描述能力和动态性上存在的不足,提出了一种基于构件的动态工作流建模方法。该方法扩展了传统的活动网络模型,引入了新的建模元素,提出了新的建模机制。详细描述了模型的实现机制和应用场景,同时给出了一个模型实例。与传统的活动网络模型相比,该模型方法在提高模型描述能力、降低模型复杂性、提高系统动态性及适应性方面有明显的优点,对于设计开发高可靠性、动态性和适应性的工作流管理系统具有重要的应用价值。  相似文献   

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We present design principles for conceiving tangible user interfaces for the interactive physically-based deformation of 3D models. Based on these design principles, we developed a first prototype using a passive tangible user interface that embodies the 3D model. By associating an arbitrary reference material with the user interface, we convert the displacements of the user interface into forces required by physically-based deformation models. These forces are then applied to the 3D model made out of any material via a physical deformation model. In this way, we compensate for the absence of direct haptic feedback, which allows us to use a force-driven physically-based deformation model. A user study on simple deformations of various metal beams shows that our prototype is usable for deformation with the user interface embodying the virtual beam. Our first results validate our design principles, plus they have a high educational value for mechanical engineering lectures.  相似文献   

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Summary Two language design methods based on principles derived from the denotational approach to programming language semantics are described and illustrated by an application to the language Pascal. The principles are, firstly, the correspondence between parametric and declarative mechanisms, and secondly, a principle of abstraction for programming languages adapted from set theory. Several useful extensions and generalizations of Pascal emerge by applying these principles, including a solution to the array parameter problem, and a modularization facility.  相似文献   

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针对目前国内在信息显示原理教学方面相关实验仪器的空白,本文设计了一种信息显示原理的演示仪。该演示仪以发光二极管为显示屏,以嵌入式微处理器SamsungS3C44BOX为控制核心,采用通用计算机和嵌入式微处理器组成的上位机和下位机架构,其人机交互界面友好,使用方便。经测试证明,该仪器运行可靠。  相似文献   

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为了解决软件开发中建模对于系统级关注点被忽略的问题,提出了面向方面的UML建模模型。对面向方面技术和UML进行全面介绍,使其了解它们的主要构成及参数,并基于AspectJ语言扩展UML中的特征文件(profile),来实现面向方面UML建模(AUML)。该扩展是UML体系的一种扩充,它既结合了UML面向对象的特点,又对面向方面横切关注点在语义和结构上进行了规范。最后就图书管理系统进行举例说明,总结了面向方面软件开发(AOSD)profile的参数。  相似文献   

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