Science Letters：Mask synthesis and verification based on geometric model for surface micro-machined MEMS

INTRODUCTION When designers develop microelectromechani- cal system (MEMS) devices with the traditional ap- proach, they should devise the mask-layouts and fabrication process instead of the function and shape of the MEMS device. The geometric model of the MEMS device is then derived based on the simulated fabrication according to the devised mask layout and the process. This is analogous to generating a geo- metric model from the NC tool paths in the macro world. Obviously it is uni…     

Multifractal analysis of surface EMG signals for assessing muscle fatigue during static contractions

This study is aimed at assessing muscle fatigue during a static contraction using multifractal analysis and found that the surface electromyographic （SEMG） signals characterized multiffactality during a static contraction. By applying the method of direct determination ofthef（a） singularity spectrum, the area of the multifractal spectrum of the SEMG signals was computed. The results showed that the spectrum area significantly increased during muscle fatigue. Therefore the area could be used as an assessor of muscle fatigue. Compared with the median frequency （MDF）--the most popular indicator of muscle fatigue, the spectrum area presented here showed higher sensitivity during a static contraction. So the singularity spectrum area is considered to be a more effective indicator than the MDF for estimating muscle fatigue.     

Intersections of two offset parametric surfaces based on topology analysis

Conventional methods for solving intersections between two offset parametric surfaces often include iteratively using computationally expensive SSI (surface/surface intersections) algorithm. In addition, these methods ignore the relations between the intersection curves of parametric surfaces with different offset distances. The algorithm presented in this paper, makes full use of the topological relations between different intersection loops and calculates intersection loops with the help of previously calculated intersection loops. It first pre-processes two parametric surfaces to obtain the characteristic points, called topology transition points (TTPs), which can help in the subsequent finding of the topologies of the intersection curves. Then these points are categorized into several distinct groups, and we can determine the calculation strategy for searching initial points by analyzing the properties of these TTPs on the surfaces. Hence, all intersection curves can be marched from initial points by the tracing algorithm. The proposed algorithm could calculate intersection curves robustly and effectively, and has been tested to be capable of overcoming the degenerate conditions such as loop and singularities leaking that occur frequently in conventional algorithms. Project supported by the National Research Foundation for the Doctoral Program (No. 2000033554) of Higher Education of China and the Natural Science Foundation of Zhejiang Province, China (No. 6001107)     

河西地区内陆河流域地表水资源及动态趋势分析

河西地区是甘肃省主要经济地区之一，是国家下世纪初大规模开发大西北的纽带与依托。河西地区未来的经济发展规模，在很大的程度上取决于本地区水资源的承载能力。本文对河西地区内陆河流域天然地表水资源进行了计算和评价；对天然地表径流的变化特征进行了分析；并对河西地区>河西地区、内陆河流域、地表水资源、变化特征、动态过程、趋势预测     

激光雷达遥感进展

本文综述激光雷达在遥感方面的发展,分别介绍各种激光雷达的基本原理,并指出今后激光雷达的发展方向.     

土壤和建筑材料表面氡析出率对室内氡浓度的影响

采用监测数据可靠的RAD7测氡仪,选择深圳市某平房为研究对象,检测到平房周围为土壤氡低背景区,且土壤表面氡析出率较大,约为房间内水泥地板的2倍,说明土壤是室内氡的最大来源;而水泥地板表面氡析出率较瓷砖地板大,约为瓷砖地板的4倍。铺有水泥地板的房间室内氡浓度大于铺有瓷砖地板的房间,这是由于水泥地板表面氡析出率较大。因此,为了减少室内氡浓度,应该尽可能选择表面氡析出率低的材料铺设地板,并保持开窗通风。     

逆向工程及其关键技术概述

逆向工程是一门集CAD、激光、精密机械、数控及图像采集与处理为一体的新技术,在工业领域中,逆向工程技术有着广泛的应用前景,利用逆向工程技术可以给现代工业带来巨大变化。本文简要介绍了逆向工程的基本内容及其与传统正向工程的区别,同时简述了逆向工程在工业领域的应用范围。详细地介绍了在逆向工程的四个基本阶段中所涉及到的关键技术,如三维数据采集方法、模型重构等,总结并分析了该领域需要重点解决的问题。     

音位与思想共鸣--英语诗歌欣赏探析

音位是具有辩义功能的最小语音单位。音位与文体的关系密切,具有明显的文体特征,音位的文体特征在诗歌中尤为明显。诗作者为表达其独特的思想,从而选择含有某些特殊音位的词来表达,使诗歌的外在形式与思想内容完美结合起来,达到音位与思想共鸣的效果。     

Search on surfaces: Exploring the potential of interactive tabletops for collaborative search tasks

Collaborative information seeking often takes place in co-located settings; such opportunities may be planned (business colleagues meeting in a conference room or students working together in a library) or spontaneous (family members gathered in their living room or friends meeting at a café). Surface computing technologies (i.e., interactive tabletops) hold great potential for enhancing collaborative information seeking activities. Such devices provide engaging direct manipulation interactions, facilitate awareness of collaborators’ activities, and afford spatial organization of content. However, current tabletop technologies also present several challenges that creators of collaborative information seeking system must account for in their designs. In this article, we explore the design space for collaborative search systems on interactive tabletops, discussing the benefits and challenges of creating search applications for these devices. We discuss how features of our tabletop search prototypes TeamSearch, FourBySix Search, Cambiera, and WeSearch, illustrate different aspects of this design space.     

ART2网络在民航气象数据库业务系统维护中的应用

基于人工神经网络AKT2的维护经验收集子系统作为民航气象业务维护支持系统的子系统,集故障识别、方法记录等功能于一体,充分发挥了ART2网络边学习边回想、在线学习的优势,为维护经验的收集提供一个强有力的平台。