137294531
Improved glass-PDMS-glass device technology for accurate measurements of electro-osmotic mobilities
We demonstrate an improved glass-PDMS-glass device technology based on reactive ion etch of a thin PDMS layer for microfluidic channel forming and glass to glass bonding. Reactive ion etch process has been optimised to achieve a high etch rate and a minimum surface roughness. Typically, microfluidic channels of 2.5µm height and 50µm width are obtained on a wafer scale, providing a patternable glass-liquid interface larger than 95% of the total channel wall surface. To illustrate the capability of this technique, electrokinetic characterization of soda-lime glass (D-263) surfaces are presented.
135614560
Gold nanohole arrays for biochemical sensing fabricated by soft UV nanoimprint lithography
We report on results of fabrication and optical characterisation of sub-250nm periodic gold nanohole arrays on glass by using UV nanoimprint lithography (UV-NIL) combined with both reactive ion etching (RIE) and Cr/Au lift-off processes. The transmission spectra of the fabricated nanohole gratings were measured for different hole diameters and periods. We also show preliminary results of chemical sensing after surface modification of the gold hole arrays. In agreement with the theoretical prediction, we found that any change in the dielectric index of the surrounding environment of the metallic array produces a transmission peak red shift.
6944670
Quality-oriented-maintenance for multiple interactive tooling components in discrete manufacturing processes
In discrete manufacturing processes such as stamping, assembly, or machining processes, product quality, often defined in terms of the dimensional integrity of work pieces, is jointly affected by multiple process variables. During the production phase, the states of tooling components, which are measured by adjustable process variables, are subject to possible random continuous drifts in their means & variances. These drifts of component states may significantly deteriorate product quality during production. Therefore, maintenance of the tooling components with consideration of both their continuous state drifts as well as catastrophic failures is crucial in assuring desired product quality & productivity. In contrast to traditional maintenance models where product quality has not been well addressed, especially for discrete manufacturing processes, a general quality-oriented-maintenance methodology is proposed in this paper to minimize the overall production costs. In this research, the total production cost includes product quality loss due to process drifts, productivity loss due to catastrophic failures, and maintenance costs. The quality-oriented-maintenance model is built based on a response model linking process variables with multidimensional product quality. It can be obtained either from engineering analysis for specific processes, or from statistical design of experiments. Three typical multi-component maintenance models are investigated under the general quality-oriented-maintenance framework. A case study for a sheet-metal stamping process is presented to demonstrate the effectiveness of the proposed methodology.
7318403
Numerical solutions of coupled Burgers equations with time- and space-fractional derivatives
In this paper, by introducing the fractional derivative in the sense of Caputo, the Adomian decomposition method is directly extended to study the coupled Burgers equations with time- and space-fractional derivatives. As a result, the realistic numerical solutions are obtained in a form of rapidly convergent series with easily computable components. The figures show the effectiveness and good accuracy of the proposed method.
37797167
A wide dynamic range CMOS image sensor with pulse-frequency-modulation and in-pixel amplification
This paper briefly examines the pros and cons of CMOS pulse-frequency-modulation (PFM) digital pixel sensors. A pulse-frequency-modulation digital pixel sensor with in-pixel amplification is proposed to improve the resolution of the pixel sensor at low illumination. The proposed PFM digital pixel sensor offers the characteristics of a reduced integration time when the level of illumination is low with the fill factor comparable to that of PFM digital pixel sensors without in-pixel amplification. The proposed digital image sensor has been designed in [email protected] 1.8V CMOS technology and validated using Spectre from Cadence Design Systems with BSIM3V3 device models. Simulation results demonstrate that the dynamic range of the proposed PFM digital pixel sensor with in-pixel amplification is 20dB larger as compared with that of PFM digital pixel sensors without in-pixel amplification. The increased dynamic range is obtained in the low illumination condition where PFM digital pixel sensors without in-pixel amplification cease the operation due to the low photo current.
38801994
Generalized Q-S (lag, anticipated and complete) synchronization in modified Chua's circuit and Hindmarsh-Rose systems
Abstract Based on symbolic computation system Maple and Lyapunov stability theory, a systematic, powerful and concrete scheme is extended to study the generalized Q – S (lag, anticipated and complete) synchronization between two identical modified Chua’s circuit with different initial values and between two different chaotic systems: Hindmarsh–Rose system and modified Chua’s circuit. Numerical simulations are used to verify the effectiveness of the obtained controller.
16631254
Using data mining techniques and rough set theory for language modeling
In this article, we propose a new postprocessing strategy, word suggestion, based on a multiple word trigger-pair language model for Chinese character recognizers. With the word suggestion strategy, Chinese character recognizers may even achieve a recognition rate greater than the top-n candidate recognition rate. To construct the multiple word trigger-pair model, data mining techniques are used to alleviate the intensive computation problem. Furthermore, rough set theory is first used in the study to discover negatively correlated relationships between words in order to prevent introducing wrong words in the process of word suggestion.