Reconfigurable Web wrapper agents

Web wrapper agents exploit online Web data sources, facilitating information integration and reuse. With the DeepSpot Agent Toolbox, users can automate virtually all types of Web browsing sessions simply by browsing the target Web sites.     

A multiple electrostatic electrodes torsion micromirror device with linear stepping angle effect

Torsion micromirror devices that can achieve linear stepping angle effects play an important role in optical MEMS applications. However, traditional torsion micromirror devices driven by a single electrostatic electrode have difficulty meeting this requirement due to their nonlinear angle-voltage transfer characteristics. In this regard, the concept of a multiple-electrodecontrolled micromirror is proposed to eliminate this drawback. Through this novel design, linear stepping angles can be easily achieved by a set of linearly varied or constantly applied voltages. A simple mathematical model has been developed to predict the angle-voltage transfer characteristics of the proposed device and has been simulated with finite element simulations. The corresponding control strategies of this device, named the linear control strategy and the digital control strategy, are also proposed in this paper. The Cronos/MEMSCAP Multi-User MEMS Process (MUMPs) was used in conjunction with flip-chip bonding technology to fabricate the proposed torsion micromirror device. Experimental data indicates that the relative stepping angle error, between the fabricated device and the mathematical model, are within 5%.     

The effects of surface-plasma treatment of thin-film hydrogen silesquioxane low k dielectric

Hydrogen silesquioxane (HSQ) is a low dielectric constant material and a potential substitute for conventional silicon dioxide insulator in ULSI system. In this study, the effect of plasma treatment on HSQ films is investigated. The bond structure changes of HSQ after curing, plasma treatment, and water absorption were observed with Fourier transform infrared spectroscopy. Densification of the film occurs after curing, the higher the curing temperature, the lower the dielectric constant and refractive index of the film. Both H₂- and O₂-plasma treatments are employed in this study. The H₂-plasma bombardment enhances the formation of the network structure but raises the moisture absorption of HSQ films. It is found that films subjected to both H₂- and O₂-plasma treatments have lower dielectric constant than those subjected to O₂ treatment alone. Possible mechanisms for the effects of plasma treatments are explored. The residual stress of HSQ film is also studied.     

Inverse approach for estimating rheological characteristics of adsorption layer in thin film EHL contacts

A modified Reynolds equation is derived for thin film elastohydrodynamic lubrication (TFEHL) by means of the viscous adsorption theory. This TFEHL theory can be used to explain the deviation between the measured film thickness and that predicted from the convenient elastohydrodynamic lubrication (EHL) theory under very thin film conditions. Results show that the thinner the film, the greater the ratio of the adsorption layer to the total film thickness becomes, and the greater the value of the pressure–viscosity index (z′). An inverse approach is proposed to estimate the pressure distribution based upon the film thickness measurement and to determine the pressure–viscosity index of oil film, and the thickness (δ) and the viscosity ratio (η^*) of the adsorption layer in TFEHL circular contacts. Based on TFEHL theory, the inverse approach can reduce z′ error, and provides a reasonably smooth curve of pressure profile by implementing the measurement error in the film thickness. This algorithm not only estimates the pressure, but also calibrates the film shape. Consequently, it predicts z′, η^*, and δ with very good accuracy. It can also be used to evaluate the lubrication performance from a film thickness map obtained from an optical EHL tester. Results show that the estimated value of z′ is in very good agreement with the experimental data.     

Three dimensional cutting force analysis in end milling

The analysis of cutting forces plays an important part in the design of machine tool systems as well as in the planning, optimization, and control of machining processes. This paper presents a three-dimensional model of cutting forces in peripheral end milling in terms of material properties, cutting parameters, machining configuration, and tool/work geometry. Based on the relationship of the local cutting force and the chip load, the total cutting force model is established via the angle domain convolution integration of the local forces in the feed, cross feed, and axial directions. The integration is taken along the cutter axis and summarized across the cutting flutes. The convolution integral leads to a periodic function of cutting forces in the angle domain and an explicit expression of the dynamic cutting force components in the frequency domain. The closed-form nature of the expressions allows the prediction and optimization of cutting forces to be performed without the need of numerical iterations. To assess the fidelity of the analytical model, experimental data from end milling tests are presented in the context of three dimensional time waveforms, power spectra, and phase angles, in comparison to the values predicted by the model.     

The high‐speed measurement of a partial area imaging system applied to photoresist development processing

Abstract

Among the parameters that affect photolithography, the most important are exposure and development time which affect the coating photoresist characteristics. This study further researches the relationship between the exposure and development time using a high speed image inspection system, and the relationship between the development time and photoresist depth using a Scanning Probe Microscope (SPM). A partial scan CCD camera and high speed frame capture card were used to obtain the photoresist development processing parameters. The experimental results verified that this imaging system provides an economical and effective method for producing a micro‐photo‐etched product. It is expected that these experiments can also offer some good references useful in the micro electro mechanical industrial field.     

Scalable Gaussian Normal Basis Multipliers over GF(2<Superscript><Emphasis Type="Italic">m</Emphasis></Superscript>) Using Hankel Matrix-Vector Representation

This work presents a novel scalable multiplication algorithm for a type-t Gaussian normal basis (GNB) of GF(2^m). Utilizing the basic characteristics of MSD-first and LSD-first schemes with d-bit digit size, the GNB multiplication can be decomposed into n(n + 1) Hankel matrix-vector multiplications. where n = (mt + 1)/d. The proposed scalable architectures for computing GNB multiplication comprise of one d × d Hankel multiplier, four registers and one final reduction polynomial circuit. Using the relationship of the basis conversion from the GNB to the normal basis, we also present the modified scalable multiplier which requires only nk Hankel multiplications, where k = mt/2d if m is even or k = (mt − t + 2)/2d if m is odd. The developed scalable multipliers have the feature of scalability. It is shown that, as the selected digit size d ≥ 8, the proposed scalable architectures have significantly lower time-area complexity than existing digit-serial multipliers. Moreover, the proposed architectures have the features of regularity, modularity, and local interconnection ability. Accordingly, they are well suited for VLSI implementation.     

Stability and robustness of time‐delay systems

Abstract

Using some properties of matrix measures and matrix's spectral radius, a new stability criterion for a linear time‐delay system is derived. This result is also extended to interval time‐delay systems.