Parameter design using the Taguchi methodology

This article aims to give an overview of the Taguchi methodology and more specific of its key step: parameter design. The purpose of parameter design is to bring quality into the product/process by determining the relevant parameters and their optimal settings such that the quality characteristics of the product are optimised and have minimal sensitivity to “noise” (i.e., those disturbing factors which are difficult or too expensive to control). The (mainly statistical) tools used in the methodology will be handled and some actual Bell cases will be mentioned as practical examples.     

Efficient computation of the 2-D Green's function for 1-D periodic line sources in planar multilayered media

Periodic Green's function (PGF) of an infinite 1-D periodic array of line sources in planar multilayered media is calculated by the use of the of the 3-level discrete complex image method (DCIM) together with the surface wave pole (SWP) extraction. The Ewald's method is then applied to accelerate the evaluation of the PGF. The recipe to choose the Ewald's splitting parameter is also given. It is shown that the Ewald's transformation needs a few terms to approximate the PGF with high accuracy. The SWP contributions, which are extracted before the DCIM application, are added to this approximation. The spatial domain surface wave pole contributions are observed to be highly oscillatory and converge to zero. The numerical results are provided to demonstrate the efficiency and the accuracy of the procedure followed.     

IC CAD中的图形运算算法与实现

熊猫系统是一个基于全定制ASIC,同时能完成半定制ASIC设计的完整的ICCAD系统。GOA(Geometric Operations and Analysis tool)是其中的完成图形算术、逻辑、拓扑运算的工具及软件库。本文将介绍它的作用及其与其它工具的关系,并详细介绍了其算法及我们在α测试和β测试中针对速度和精度要求所做的改进工作。     

基于容器对象的动态控件数组研究

动态控件数组是应用程序设计中经常用到的重要手段之一。合理地使用动态控件数组不但能简化程序、方便维护,还可以节约内存空间,对动态控件数组的研究有助于增加应用程序灵活性,能有效提高编程效率。鉴于此,提出了在C＋＋Builder环境下基于容器对象的动态控件数组实现方案,分别给出利用三种容器对象TList,DynamicArray和Vector实现动态控件数组的思想,对三者的性能进行比较分析,并总结了实现动态控件数组的原理、方法和技巧。     

Process simulation for HgCdTe infrared focal plane array flexible manufacturing

The strategy and status of a process simulator for the flexible manufacture of HgCdTe infrared focal plane arrays is described. It has capabilities to simulate Hg vacancy and interstitial effects and cation impurity diffusion, for various boundary conditions in one dimension. Numerical complexity of these problems stems from the necessity of solving diffusion equations for each defect that are coupled to each other via nonlinear interaction terms. The simulator has already led to the prediction of heretofore unexplained experimental data. Current extensions of the one-dimensional simulator planned over the next few years include the addition of Te antisites, antisite-Hg vacancy pairs, and In-Hg vacancy pairs, ion implantation, and various energetic processes (such as ion milling). The sequential effect of various processes will be possible with the input to the simulator looking much like a process run sheet.     

Design of a Temporal Learning Chip for Signal Generation and Classification

The design and analog VLSI implementation of a recurrent neural network with integrated temporal learning is presented. The learning algorithm is forward in time, and is implemented strictly as instantaneous, local weight updates. PSpice simulations of networks with 4 to 6 neurons demonstrate robust learning of trajectory generation and classification tasks. A scalable 2-D VLSI architecture is described and a prototupe 4-neuron recurrent neural network with learning has subsequently been fabricated in MOSIS TinyChip 2 micron technology. Experimental results of the chip validate the learning performance with convergence in the millisecond range. Specific experimental results of learning circular and figure-8 dynamic trajectories are included.     

A hierarchical design methodology for full-search block matching motion estimation

Many useful DSP algorithms have high dimensions and complex logic. Consequently, an efficient implementation of these algorithms on parallel processor arrays must involve a structured design methodology. Full-search block-matching motion estimation is one of those algorithms that can be developed using parallel processor arrays. In this paper, we present a hierarchical design methodology for the full-search block matching motion estimation. Our proposed methodology reduces the complexity of the algorithm into simpler steps and then explores the different possible design options at each step. Input data timing restrictions are taken into consideration as well as buffering requirements. A designer is able to modify system performance by selecting some of the algorithm variables for pipelining or broadcasting. Our proposed design strategy also allows the designer to study time and hardware complexities of computations at each level of the hierarchy. The resultant architecture allows easy modifications to the organization of data buffers and processing elements-their number, datapath pipelining, and complexity-to produce a system whose performance matches the video data sample rate requirements.     

驾驶员疲劳检测中的眼睛定位算法

人眼状态与疲劳程度有很好的相关性,眼睛定位在驾驶员疲劳检测中有十分重要的地位。目前眼睛定位算法都是针对睁开的眼睛,不能定位闭合的眼睛。为了能够定位任意状态下的眼睛,提出了Adaboosting算法与几何模板融合的眼睛定位算法。在眼睛粗定位区域中用Ada-boosting算法检测睁开的眼睛,修改几何模板。对于Adaboosting算法中不能检测到眼睛时则用几何模板法进行眼睛定位。实验表明该算法有较好的检测率和运算速度。     

Fabrication of carbon nanotube arrays for field emission and sensor devices by nanoimprint lithography

This work brings forth the idea of incorporating insulation in the resist used for ultraviolet (UV) curing nanoimprint lithography (NIL). Carbon nanotubes (CNTs) are grown in the space between two insulated resist patterns on the conductive substrate to make CNTs arrays. Two imprinting processes, soft UV curing NIL with DRPPR process and novel NIL without cured residual resist, are presented to achieve the insulation patterns. First the fabricating process is performed using a polydimethylsiloxane (PDMS) stamp. Subsequently, inductively coupled plasma (ICP) is essential to wipe off the residual resist film. To avoid the ICP process, a novel UV curing NIL is presented. Its special hard quartz stamp with chrome shelter can protect the residual resist film out of curing during the UV exposure process, and the uncured resist can be easily removed by ultrasonic vibration in organic solutions. The CNT arrays are prepared on the patterned substrates by the pyrolysis of iron phthalocyanine (FePc). Field emission experiments reveal that the turn-on field of those CNTs arrays is low to 1.3 V/um.