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951.
Hyun Uk Yun Chul Jin Kim Sung Joo Kim No Cheol Park Hyunseok Yang Young-Pil Park 《Microsystem Technologies》2009,15(10-11):1531-1538
Microactuators for micromirror system have found many applications in various areas including projection displays, optical switches, RF switches and so on. In this paper we demonstrated micromirror actuator using ionic polymer metal composites (IPMC) that is a suitable candidate, since it has many attractive qualities such as durability, aquatic, miniature and light-weighted. Specially, IPMC has extraordinary advantages which are simple bending motion for low driving voltage (1–2 V), low power consumption, and simple structure. The IPMC actuator is made of Nafion NE-1110 (Dupont Co, Ltd., 260 µm thick) layer and electrode (platinum) layers and driven by 1–4 V. The displacement measured vertically is 0.25 mm and tilting angle is 11.3°. The angular motion, which is more than 10°, is a good advantage in the field of display module. This paper shows that the IPMC actuator has enough possibility for other applications. 相似文献
952.
In this article, based on the standard linear solid model, the Euler-Bernoulli hypothesis and the Galerkin method, an analysis
of the nonlinear dynamic stability for a clamped-guided viscoelastic microbeam under both a periodic axial force and a symmetric
electrostatic load is presented. By using the incremental harmonic balanced method, the boundary of the principal region of
instability is got. In the numerical calculation, the effect of the environmental and inner damping, geometric nonlinear,
creep quantity and the symmetric electrostatic load on the principal region of instability is discussed. 相似文献
953.
Structure identification of Bayesian classifiers based on GMDH 总被引:1,自引:0,他引:1
This paper introduces group method of data handing (GMDH) theory to Bayesian classification, and proposes GMBC algorithm for structure identification of Bayesian classifiers. The algorithm combines two structure identification ideas of search & scoring and dependence analysis, and is able to accomplish the process of adaptive structure identification. We experimentally test two versions of Bayesian classifiers (GMBC-BDe and GMBC-BIC) over 25 data sets. The results show that, the structure identification of the two Bayesian classifiers especially GMBC-BDe is very effective. And when the data sets contain lots of noise, the superiority of Bayesian classifiers learned by GMBC is more obvious. Finally, giving a classification domain without any prior information about the noise, we recommend adopting GMBC-BDe rather than GMBC-BIC. 相似文献
954.
The traditional way of state estimation in semiconductor manufacturing, known as “threaded” state estimation, segregates the process data into different bins and uses the ones that match the current event of the specific context information (such as tools, layers, products) to update the process state. The limitation of threaded state estimation is that a narrowly defined process stream can result in too many different threads and insufficient data for each thread. This limitation becomes more severe in high-mix manufacturing, where there can be many products and many tools. Hence there is great interest in estimation methods that utilize all available data in the analysis. In this work, the characteristics inherent in state estimation of high-mix semiconductor manufacturing processes are analyzed, and a general framework is introduced for the non-threaded state estimation methods, i.e., state estimation without segregating the process data into different bins. The framework is based on the best linear unbiased estimate (BLUE) of a simplified stationary singular Gauss–Markov process, and non-threaded state estimation methods based on the Kalman filter, least squares and recursive least squares (RLS) are analyzed using the general framework. Simulation examples are presented to illustrate the equivalence between different algorithms. As real processes are rarely stationary, modifications to the Kalman filter and RLS are discussed. We show that in non-threaded state estimation, how to regulate the estimate covariance plays a significant role in estimation performance. To handle nonstationary disturbances that often occur in semiconductor processes, Bayesian-enhanced adaptive versions of the Kalman filter and RLS are proposed. Both simulated and industrial nonstationary processes are used to demonstrate the effectiveness of the proposed adaptive methods. 相似文献
955.
956.
957.
基于粒子系统和音频系统的烟花模拟 总被引:2,自引:1,他引:1
针对模糊物体的模拟方法存在着粒子数量绘制巨大、粒子运动状态复杂、计算耗时、实时性及逼真性不够等问题,提出了一种基于粒子系统和音频系统的烟花模拟方法,以三角形格作为绘制烟花粒子的基本图元,结合纹理映射,色彩融合技术来绘制烟花粒子,在显示列表中生成纹理,再结合FMOD引擎技术,加入音频系统,实验结果表明提出的方法增强了模拟的逼真性. 相似文献
958.
为在需求分析阶段验证软件是否满足非功能质量要求,本文提出一种基于场景行为的需求建模及质量特性检测方案。该方案首先定义能够建立高精度、可推理、易理解的需求行为模型的行为描述语言BDL。然后构造需求行为模型到状态迁移模型CCS的模型转换函数。接着以互模拟的定义为前提,验证转换函数的正确性,进而开发可信建模检测工具MTS。该工具导出的行为模型能够与质量特性表达式一起导入特性检测工具CWB实现质量检测。最后,本文使用该工具对手机软件升级这一需求进行行为建模,成功验证手机软件的一致性、安全性、行为可信性及行为非终止性。 相似文献
959.
手部跟踪技术是实现自然人机交互的关键。针对现有跟踪方法易受光照、环境等影响及鲁棒性差的不足,提出一种融合深度与肤色特征的自适应手部跟踪算法。考虑手部运动过程的形变,该算法首先利用深度平滑连续性选取深度阈值以实现跟踪区域的自适应尺度变化,获得手部候选区域。在此基础上建立YCbCr空间肤色归一化直方图,在粒子滤波框架下将跟踪问题转换为贝叶斯估计问题,基于最大后验准则确定手部位置,并通过监测粒子重要性权值的方差解决跟踪失效问题,实现复杂观测环境下的鲁棒跟踪。实验结果表明,该跟踪算法可适应不同复杂环境,鲁棒性良好。 相似文献
960.
Zhi Qiao Meiyan Zhao Fang Wang Luo Liu 《International journal of remote sensing》2016,37(10):2433-2450
Forests account for more than 23% of China’s total area. As the most important terrestrial ecosystem, forests have tremendous ecological value. However, it remains difficult to classify forest subcategories at the national scale. In this study, a newly developed binary division procedure was used to categorize forest areas, including their spatiotemporal dynamics, during the period 2000–2010. Time-series images acquired using the Moderate Resolution Imaging Spectroradiometer (MODIS), together with auxiliary data on land use, climate zoning, and topography, were utilized. Hierarchical classification and zoning were combined with remote-sensing auto-classification. Based on the forest extent mask, the state-level forest system was divided into four classes and 18 subcategories. The method achieved an acceptable overall accuracy of 73.1%, based on a comparison to the sample points of China’s fourth forest general survey data set. In 2010, the total forest area was 1.755 × 106 km2, and the total area of and shrubs was 4.885 × 105 km2. The total area of woodland increased by 2536.25 km2 during the decade 2000–2010. The shrub subcategories exhibited almost no change during this time period; however, significant changes in forest area occurred in the mountainous region of Northeast China as well as in the hilly regions of Southern China. The main transformations took place in cold-temperate and temperate mountainous deciduous coniferous forest, subtropical deciduous coniferous forest, subtropical evergreen coniferous forest, and temperate and subtropical deciduous broadleaved mixed forests. The binary division procedure proposed herein can be used not only to rapidly classify more forest subcategories and monitor their dynamic changes, but also to improve the classification accuracy compared with global and national land-cover maps. 相似文献