混合集总—分布参数微波功率分配器的机助设计

在本文中,将微波功率分配器看做用多个两端口网络构成的多端口匹配网络,用集总与分布参数元件混合组成的模块来综合这种网络,从而得到了一种新型的混合集中分布参数微波功率分配器及其机助设计方法。     

Exact probabilistic testability measures for multi-output circuits

The computation of probabilistic testability measures has become increasingly important and some methods have been proposed, although the exact solution of the problem is NP-hard. An exact analytical method for singleoutput combinational circuits is extended to deal with multi-output circuits. Such circuits are reduced to singleoutput ones by introducing a dummy gate, the X-gate, and applying to the resulting graph the analysis based on supergates.     

A novel method for the classification of Alzheimer's disease from normal controls using magnetic resonance imaging

Alzheimer's disease (AD) is the most prevalent form of dementia. Although fewer people, who suffer from AD are correctly and promptly diagnosed, due to a lack of knowledge of its cause and unavailability of treatment, AD is more manageable if the symptoms of mild cognitive impairment (MCI) are in an early stage. In recent years, computer‐aided diagnosis has been widely used for the diagnosis of AD. The main motive of this paper is to improve the classification and prediction accuracy of AD. In this paper, a novel approach is developed to classify MCI, normal control (NC), and AD using structural magnetic resonance imaging (sMRI) from the Alzheimer's disease Neuroimaging Initiative (ADNI) dataset (50 AD, 50 NC, 50 MCI subjects). FreeSurfer is used to process these MRI data and obtain cortical features such as volume, surface area, thickness, white matter (WM), and intrinsic curvature of the brain regions. These features are modified by normalizing each cortical region's features using the absolute maximum value of that region's features from all subjects in each group of MCI, NC, and AD independently. A total of 420 features are obtained. To address the curse of dimensionality, the obtained features are reduced to 30 features using a sequential feature selection technique. Three classifiers, namely the twin support vector machine (TSVM), least squares TSVM (LSTSVM), and robust energy‐based least squares TSVM (RELS‐TSVM), are used to evaluate the classification accuracy from the obtained features. Five‐fold and 10‐fold cross‐validation are used to validate the proposed method. Experimental results show an accuracy of 100% for the studied database. The proposed approach is innovative due to its higher classification accuracy compared to methods in the existing literature.     

基于Multipath的煤矿巷道三维模型构建方法

针对现有煤矿巷道三维模型存在灵活性和可移植性差、数据更新维护困难等问题,提出了一种基于Multipath的煤矿巷道三维模型构建方法。该方法通过定义点弧拓扑数据模型,将煤矿CAD格式数据转换为Geodatabase中的要素类,利用开发的ArcGIS Engine程序、通过插入节点坐标生成巷道三维模型,实现了煤矿巷道自动建模,有效减少了巷道三维建模的工作量。     

Response correction techniques for surrogate‐based design optimization of microwave structures

Simulation‐based optimization has become an important design tool in microwave engineering. However, using electromagnetic (EM) solvers in the design process is a challenging task, primarily due to a high‐computational cost of an accurate EM simulation. In this article, we present a review of EM‐based design optimization techniques exploiting response‐corrected physically based low‐fidelity models. The surrogate models created through such a correction can be used to yield a reasonable approximation of the optimal design of the computationally expensive structure under consideration (high‐fidelity model). Several approaches using this idea are reviewed including output space mapping, manifold mapping, adaptive response correction, and shape‐preserving response prediction. A common feature of these methods is that they are easy to implement and computationally efficient. Application examples are provided. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

经食道心房调搏的放射性核素心血管造影

本文应用反符合电路剔除调搏脉冲干扰的方法,制成经食道心房调搏心电心音门电路触发装置,用于经食道心房调搏的核素心血管造影。参考Tzivoni标准,当逐级增加调搏心率至140次/min或亚极量心率后发现:冠心病人有调搏后EF降低;急性心肌梗塞病人EF减低更为明显,并呈室壁反向运动。因此,心房调搏核素心血管造影有助于冠心病,特别是心肌梗塞的诊断。     

CAD与CAPP集成研究回转体类零件特征识别

本文研究了回转体轴类,轴套类零件的特征识别。对这类零件常用的特征单元进行了定义,描述了这类零件的特征模型:介绍了它的识别方法和特征参数定义方法。     

多目标多约束的集成电路统计优化策略

对于集成电路设计、生产过程中的多目标、多约束统计优化问题,本文提出了“合格率足够高”的优化宗旨,并从概率论的基本原理出发,结合集成电路的特点,导出了一种合格率的近似表述方法,提出的变权重Monte Carlo法编程简便,效率高。采用这些优化策略设计的集成电路合格率优化系统取得了比较好的结果。     

基于标准件库的螺钉联接自适应设计

提出一种AutoCAD环境中基于标淮件库的螺钉联接自适应设计算法。利用螺钉和垫片以及被联接件之间设计信息的相关性自动确定装配方位及联接件的几何参数，自动检测和复原被联接件的剖面线，简化了设计过程。     

三维CAD在成形车刀截形设计中的应用

介绍了运用投影原理，在三维CAD中作出零件的三维造型，并依此生成二维工程图，在二维工程图中进行标注，从而得到准确的成形车刀截形尺寸数据的方法。该方法兼具作图法直观与计算法准确的优点，为工程设计与计算提供了一种新的思路。