利用响应表面方法的器件稳健性设计

器件稳健性设计本质上是一个多个目标的优化问题.将实验设计和响应表面方法相结合可用来满足减少所需的TCAD模拟次数的强烈需求.然而对一些非线性问题,RSM模型的误差可能会大到影响设计结果的有效性.为找到可行空间,提出了一种考虑RSM模型误差时,面向目标的多代设计方法.通过在由当前代中的RSM模型结果所得到的有希望空间中增加设计,使得模型误差减小并得到可行空间.对FIBMOS例子的结果显示本方法是有效的.     

非视距环境下单站定位的伪目标动态可行域约束法

 针对非视距环境下多站定位方法需要资源量大、成本高且定位精度受非视距传播影响大等问题,本文提出了单站定位的伪目标动态可行域约束法.该方法将目标周围的散射体看作伪目标,利用单个机动观测站测量伪目标信号的来波方向角和方向角变化率,得到较精确的伪目标坐标后,根据伪目标与真实目标间的位置关系构造可行域,在可行域内进行最优化求解,消除非视距引起的误差,得到真实目标位置的估计值.伪目标动态可行域约束法把通常认为是不利的多径信号转化为有利因素.仿真实验证明:该方法在对目标连续数次采样测量后,即可以快速有效地抑制定位误差.     

微电子学、集成电路

TN4 2003020689分子电子学与分子电子器件/张宏川,崔学佳,姜建壮(山东大学)!ILI-J东大学学报(自然科学版)一2 002,37(4)一339一342介绍了分子电子学与分子器件研究领域的最新进展,展望了分子电子学的发展前景,提出了一些新的想法和建议.图5表3参2(木)空间中增加设计,使得模型误差减小并得到可行空间.对FIBMOS例子的结果显示该方法是有效的.图9参18(木)TN4 2003020690利用响应表面方法的器件稳健性设计/谢晓锋,鲁勇,张文俊,杨之廉(北京大学微电子所)11半导体学报一2002,23(8)一817一824器件稳健性设计本质上是一个多目标的优化问题.将…     

基于主分量寻踪的鲁棒视觉跟踪

传统子空间跟踪易受到模型漂移的影响而导致跟踪失败.针对此问题,本文提出一种基于主分量寻踪的鲁棒视觉跟踪方法.该方法以多个模板张成的子空间作为目标表观模型,利用主分量寻踪求解候选目标的误差分量,在粒子滤波框架下利用候选目标的误差分量估计最优状态参数.为了适应目标表观变化并克服模型漂移,本文提出一种模板更新方法.当跟踪结果与目标模板相似时,该方法利用跟踪结果更新目标模板,否则利用跟踪结果的低秩分量更新目标模板.在多个具有挑战性的图像序列上的实验结果表明:与现有跟踪方法相比,文中的跟踪方法具有较优的跟踪性能.     

基于动态加权的光电经纬仪航迹测量

针对光电经纬仪测量误差因素,提出加权因子的异面交会方法。首先建立光电经纬仪异面交会测量模拟,对异面误差问题采用加权因子控制设计,引入测量误差的人为因素作为模型参数隐含在模型中,运用最优化方法求解上述约束方程,解得经纬仪的模型参数,从而从原理上消除人为因素带来的误差,提高测量模型的精度,最后建立空间目标模型并进行仿真计算,得到了航迹测量优化后的坐标。仿真结果表明误差小于交会误差,测得数据较真实的反应飞行航迹,提高对被测目标的定位精度。     

临近空间高超声速跳跃式滑翔目标跟踪模型

针对临近空间高超声速跳跃式滑翔目标跟踪问题,在分析目标运动特性的基础上提出了一种二阶时间相关的新型机动跟踪模型,该模型的核心是将加速度作为具有衰减振荡自相关的零均值随机过程,并据此构建了跟踪临近空间高超声速跳跃式滑翔目标的状态方程;为进一步分析模型的运动适应性,结合卡尔曼滤波算法推导了模型的系统动态误差稳态值,从模型参数取值的角度探讨了模型的适应性问题;为提高模型参数设计的合理性,分析了模型中两个参数的对应关系,并给出了参数设计的大致参考区间.理论分析表明,模型具备周期性与衰减性的统一,在短时间内主要表现为周期性,在长时间内主要表现为指数衰减性,这一特性提高了对临近空间高超声速跳跃式滑翔运动描述的合理性,此外,该模型跟踪临近空间高超声速跳跃式滑翔目标时的参数理论取值具有较低的系统动态误差稳态值.仿真实验表明与已有的临近空间高超声速目标单噪声机动模型相比,该模型具有较高的跟踪精度;并通过比较不同参数下的仿真结果一定程度说明了参数取值方法的合理性.     

用于SAR图像分割的第二代Bandelet域HMT-3S模型

针对传统的基于变换域隐马尔可夫树(Hidden Markov Tree,HMT)模型的SAR图像分割方法不能得到较满意的区域一致性结果和较准确的分割边缘的问题,提出了一种基于第二代Bandelet域HMT-3S模型的SAR图像分割方法(BHMT-3Sseg).HMT-3S模型是一种融合了子带间相关性的HMT模型,在描述图像纹理特征时,更具合理性.BHMT-3Sseg方法采用HMT-3S模型对图像的第二代Bandelet系数建模,通过HMT-3S模型参数的训练、各尺度似然值的计算和基于邻域背景的多尺度融合,实现对SAR图像的分割,既能得到较为准确和连续的边缘,也增强了分割结果的区域一致性.实验表明,本文方法BHMT-3Sseg对SAR图像分割是可行有效的.     

基于多站STSS重构目标辐射强度方向图的可行性

一般来说,目标的红外辐射强度方向图是用于目标识别的重要特征之一.针对STSS系统中红外目标识别的问题,本文详细分析了基于多站STSS重构目标辐射强度方向图的可行性.文中首先构建了中段目标的仿真数据生成模型,然后利用仿真数据生成模型所产生的图像数据得到目标辐射强度与目标视线夹角的关系曲线.由仿真结果可知,基于多站STSS重构目标辐射强度方向图的方案并不可行.     

基于多光谱辐射特性差异的最佳探测波段的确定方法

低信噪比情况对空间点目标的识别仍然是很困难的问题,尤其在区分卫星目标和系留诱饵等干扰时尤为困难。此时系留诱饵与目标具有相同的运动轨迹和相似的外形特性,因而所能利用的差异仅有辐射特性差异。然而提取多光谱辐射差异并不是简单的问题,尤其是辐射会受到探测距离、探测角度的影响。基于目标和诱饵等干扰具有不同辐射强度及辐射变化频率的特点,建立了空间目标等效黑体温度的概念。并相应的设计了等效黑体温度的计算模型,该模型可以有效的减小空间环境的干扰而充分体现目标和诱饵等干扰的辐射差异。然而由于噪声的干扰,此模型会产生计算误差,并且不同的探测波段组合具有不同的误差传递能力。为了使这种噪声引起的误差最小,需要确定最佳的探测波段。通过计算噪声存在情况下,误差随探测波段参数的变化趋势,获得了最佳探测双波段、最佳探测多波段和最佳探测波段数。通过分析仿真实验的结果,使用最佳探测双波段可以减小20%的误差,而最佳探测多波段会进一步的减小20%的误差,这种结果证明了文中研究结论的正确性。     

多高斯模型特征空间覆盖学习的海洋航摄图像分割

本文提出了一种新的基于多高斯特征空间覆盖学习的航摄海洋图像分割方法.通过分析,发现在RGB三维色空间中,海水背景像素点的分布尽管在不同成像条件下具有不同的分布特性,但其具有的共同特性是具有集聚性,可以被一个或多个椭球所覆盖.因此,本文在色空间中基于贝叶斯最大后验概率和3δ准则对海水背景进行多高斯分布模型覆盖建模,自学习得到其高斯分布个数并建立相对应的多高斯分布模型.最后,根据上述学习结果,从航拍海洋的图像中分离出海水背景,实现航拍海洋图像中背景和目标的分割.实验证明,该方法具有良好的背景学习性能,能够准确有效地得到海水背景多高斯分布覆盖模型.基于该背景学习模型的海洋图像分割,具有较高的正确率和较低的误差,且算法花费的时间较少,具有较好的稳定性和实时性.     

Thermal analysis for indirect liquid cooled multichip module using computational fluid dynamic simulation and response surface methodology

This paper demonstrates the application of computational fluid dynamic (CFD) simulation and response surface methodology (RSM) in analyzing the thermal performance of a high input/outputs, seven chips, indirect liquid cooled multichip module which will be applied in a kind of supercomputer. A series of similar experiments and corresponding CFD simulations are conducted firstly to evaluate the validity of CFD simulation method and determine the interfacial thermal resistance of thermal grease iteratively, and then a three-dimensional CFD model is established to investigate the heat transfer and fluid flow of the multichip module. Based on the CFD model, the individual effects of factors such as thermal conductivity of the thermal interface material and thermal grease, thickness of the chips, space between chips, solder bump patterns, solder ball patterns, flow velocity and liquid inlet temperature on the thermal performance of the module are studied with one-factor-at-a-time experimentation, and after that, four significant factors are selected to establish a response surface model of the maximum temperature of the module with central composite design based RSM and analysis of variance.     

应用遗传算法实现MOS器件综合

研究了将遗传算法应用于器件综合问题,针对参数化的器件空间设计了相应的适应度函数和遗传算子,可用来得到器件的可行设计空间及研究参数对器件性能的影响.对FIBMOS器件的综合设计研究结果显示了本方法的有效性.     

Optimizing protocol interaction using response surface methodology

Abstract-Response surface methodology (RSM) is a collection of statistical design and numerical optimization techniques traditionally used to optimize industrial processes. In this paper, we demonstrate that the methodology can be successfully applied to the domain of networking. Specifically, we obtain increased throughput with a significant decrease in delay in a ns-2 simulation model of a mobile ad hoc network (MANET) by using RSM to optimize protocol interaction found by factor screening. Whether the experimentation is with a stochastic simulation model or a physical system, such as a MANET or a wireless sensor network test-bed, RSM provides a general and practical methodology to screen factors and robustly and jointly optimize responses.     

基于响应面的红外干扰弹典型参数设计方法

借助于试验设计和响应面近似模型技术,提出了一种红外干扰弹设计方法。其基本思想是首先选取影响导弹脱靶距离的设计变量,用试验设计方法在设计变量空间里选取样本点,对各样本点进行导弹脱靶距离的计算,得到各样本点的响应值(最大脱靶距离),用这些样本点和响应值建立导弹最大脱靶距离的响应面近似模型,并对近似模型进行优化获得最优解。算例表明得到的响应面模型精度很高,可以快速得到最优解。     

Statistical methods for the estimation of process variation effects on circuit operation

In this paper, a technology computer-aided design (TCAD) driven method for accurate prediction of the performance spread of integrated circuits due to process variations is presented. The methodology starts with the development of the nominal process recipe and process simulators are calibrated to an existing process to obtain nominal device characteristics. After determining nominal process parameters, their variations are introduced followed by screening experiments to determine the relative effects of given process variations on the input-output delay and the average power dissipation in a circuit. Response surface models (RSMs) are then generated based on critical process factors identified. Process parameter optimization is performed using these RSM models to tune the mean circuit performance and to improve the yield. This methodology is demonstrated on a 33-stage ring oscillator manufactured with a CMOS design flow. The proposed methodology maps the process domain to design space, and plays a key role in design for manufacturability (DFM) to quantify direct impact of the process variations on circuits.     

The integration of simulation and response surface methodology forthe optimization of IC processes

This paper describes a methodology that can be used for the optimization of semiconductor processes. This is achieved by integrating the design of experiments and Response Surface Methodology (RSM) with process and device simulation tools. Software for automating multiple simulations has been implemented and interfaced to RS/1 to assist in the manual design and analysis of experiments and the subsequent optimization procedures. The procedure is illustrated through the optimization of part of an MOS process with multi-parameter optimization being performed by the introduction of composite responses and sensitivity analysis. These simulated results are also compared with experimental measurements     

A Novel Approach to Link Process Parameters to BSIM Model Parameters

In this paper, we demonstrate a methodology to link process parameters to BSIM model parameters. Here, we have combined well-known statistical methods like principal component analysis (PCA), design of experiments (DOE), and response surface methodology (RSM) to bridge the missing link between process parameters and model parameters. The proposed methodology uses the concept of a correlation matrix, which transforms the process level information to the device and circuit level information through the BSIM model parameters. The proposed methodology has been successfully implemented on an advanced CMOS process. Our results show a strong linear correlation for the data obtained from two techniques namely TCAD technique and the standard HSPICE simulation technique. In both cases the process conditions were kept identical for comparison.      

基于响应曲面和遗传算法-人工神经元网络的热塑性塑料激光透射连接强度的优化

采用旋转中心复合设计进行了激光透射焊接热塑性塑料聚碳酸酯的实验设计,分别建立了响应曲面法和基于遗传算法的人工神经元网络法的数学模型,运用这两种数学模型建立激光透射焊接工艺参数(激光功率、扫描速度、夹紧压力、扫描次数)和连接强度的关系模型,然后使用这两种模型分别预测了连接强度,并优化了焊接工艺参数。系统地比较了两种模型的建模能力、泛化能力和优化能力。实验结果表明,两种优化方法的试验结果较接近,但是基于遗传算法的人工神经元网络的建模、泛化和预测的准确性比响应曲面的要好,因此遗传算法-神经元网络是优化焊接质量的一种更有效的方法。     

Verification of fixed-point digital controllers using direct and delta forms realizations

The extensive use of fixed-point digital controllers demands a growing effort to prevent design errors that appear in the discrete-time domain. The present article describes a novel verification methodology, which employs bounded model checking (BMC) based on satisfiability modulo theories (SMT) to verify the occurrence of the design errors, because of the finite word-length (FWL) format, in fixed-point digital controllers. Here, the performance realizations of the digital controllers realizations that use delta operators are compared to those that use traditional direct forms. The experimental results show that the delta-form realization substantially reduces the digital controllers’ fragility when compared to the direct-form realization. Additionally, the proposed methodology can be very effective and efficient to verify real-world digital controllers, where conclusive results are obtained in nearly 98 % of the benchmarks.