Three-dimensional profile stitching based on the fiducial markers for microfluidic devices

Profile acquisition of microfluidic devices is a challenging task due to the competing requirements of both large field of view (FOV) and high-resolution. One strategy for obtaining such measurement is linking or stitching high-resolution profiles, possibly from multiple instruments, into a large FOV profile. As opposed to current stitching techniques relying on precise control and measurement of the translation of the sample stage, our approach presented in this paper takes advantage of the overlapping of fiducial markers, to align and stitch the separately measured profiles of a device. This method allows three-dimensional profiles transformed in six degrees of freedom, so that the pitch, roll and yaw among measurements are compensated, and stitching can be processed in both in-plane and out-of plane directions. Measurements of microfluidic channels recorded by an atomic force microscope and a white-light interferometer are stitched with accuracies evaluated to be 0.086 μm and 0.094 μm, respectively. Stitching experiments for large-scale profile gets an accuracy of 0.047 μm. Special form of stitching for profiles acquired by different tools, i.e. key parts of a device profile measured by a small FOV high-resolution instrument are stitched into a large FOV low-resolution profile by another instrument, is also carried out with an accuracy of 0.224 μm.     

Development and assessment of a single-image fringe projection method for dynamic applications

A single-image fringe projection profiling method suitable for dynamic applications was developed by combining an accurate camera calibration procedure and improved phase extraction procedures. The improved phase extraction process used a modified Hilbert transform with Laplacian pyramid algorithms to improve measurement accuracy. The camera calibration method used an accurate pinhole camera model and pixel-by-pixel calibration of the phase-height relationship. Numerical simulations and controlled baseline experiments were performed to quantify key error sources in the measurement process and verify the accuracy of the approach. Results from numerical simulations indicate that the resulting phase error can be reduced to less than 0.02 radians provided that parameters such as fringe spacing, random measured intensity noise, fringe contrast and frequency of spatial intensity noise are carefully controlled. Experimental results show that the effects of random temporal and spatial noise in typical CCD cameras for single fringe images limits the accuracy of the method to 0.04 radians in most applications. Quantitative results from application of the fringe projection method are in very good agreement with numerical predictions, demonstrating that it is possible to design both a fringe projection system and a measurement process to achieve a prespecified accuracy and resolution in the point-to-point measurement of the spatial (X, Y, Z) positions.     

Integrating Data Transformation in Principal Components Analysis

Principal component analysis (PCA) is a popular dimension-reduction method to reduce the complexity and obtain the informative aspects of high-dimensional datasets. When the data distribution is skewed, data transformation is commonly used prior to applying PCA. Such transformation is usually obtained from previous studies, prior knowledge, or trial-and-error. In this work, we develop a model-based method that integrates data transformation in PCA and finds an appropriate data transformation using the maximum profile likelihood. Extensions of the method to handle functional data and missing values are also developed. Several numerical algorithms are provided for efficient computation. The proposed method is illustrated using simulated and real-world data examples. Supplementary materials for this article are available online.     

The PRALINE online server: optimising progressive multiple alignment on the web

We introduce the online server for PRALINE (http://ibium.cs.vu.nl/programs/pralinewww/), an iterative versatile progressive multiple sequence alignment (MSA) tool. PRALINE provides various MSA optimisation strategies including weighted global and local profile pre-processing, secondary structure-guided alignment and a reliability measure for aligned individual residue positions. The latter can also be used to optimise the alignment when the profile pre-processing strategies are iterated. In addition, we have modelled the server output to enable comprehensive visualisation of the generated alignment and easy figure generation for publications. The alignment is represented in five default colour schemes based on: residue type, position conservation, position reliability, residue hydrophobicity and secondary structure; depending on the options set. We have also implemented a custom colour scheme that allows the user to select which colour will represent one or more amino acids in the alignment. The grouping of sequences, on which the alignment is based, can also be visualised as a dendrogram. The PRALINE algorithm is designed to work more as a toolkit for MSA rather than a one step process.     

Digital correlation of grainy shadow images for surface profile measurement

An optical method, combining the projection of a structured light pattern with the digital correlation technique, is discussed in this paper. This method allows measurement of full-field profile on object surface of about 20 mm square size. Tests on a rotated plane surface have been performed in order to quantify the method capabilities. It is shown that this technique leads to an accuracy of about 1 μm for a spatial resolution of around half a millimeter. Profile measurements of a micro-engraved object and at the crack tip of a polymer sample are also presented. Results give proof that this technique remains efficient even in presence of important height slope.     

硬盘录像机在数字转播车中的应用

以实际应用为基础简略介绍了PDR204D硬盘录像机及其在数字转播车中的多种应用。     

Plasma Induced Wiggler Magnetic Field in a Cavity: II-FDTD Method for a Switched Lossy Plasma

The transformation of an elliptically polarized standing source wave in a cavity by a lossy plasma created with arbitrary space and time profiles is numerically computed using the Finite-Difference Time-Domain (FDTD) method. The FDTD equations derived are shown to be very robust and results are presented for several practical scenarios.     

铝在镀锌板镀层中的分布

用ＧＤ－ＡＥＳ法测定镀锌板镀层中的Ｚｎ，Ａｌ，Ｆｅ的分布，看到在镀层界面上Ａｌ的富集现象，而且富集程度随锌液中Ａｌ含量的增加而更显著，认为这可能与热浸时首先生成Ｆｅ－Ａｌ相有关。     

p—GaP与Au／Zn／AuSb的欧姆接触

用 SEM,AES 和 XRD 研究了 Au/Zn/AuSb 多层金属结构与 p-GaP 在525℃合金化4min 后,它们所形成的金属一半导体层的基本特性。当 GaP 的 p 型层空穴浓度是5×1.0~(18)cm~(-3)时,测量出它的比接触电阻是4×10~(-4)Ω·cm~(-2)。它比 AuZn 合金所形成的比接触电阻降低了一个数量级,从而形成了良好的金属-半导体欧姆接触。     

Twelve-Month Clinical Follow-Up Study of Voice Patients' Recovery Using the Voice Activity and Participation Profile (VAPP)

Objective

To study the effects of voice treatment including brief voice therapy for 12 months in two groups of voice patients: organic and functional.

Design and Methods

A clinical prospective follow-up study with repeated measurements in five phases: medical session, first voice therapy session, last voice therapy session, and 6 months and 12 months after voice therapy. The mean number of voice therapy sessions was 3.4. The main outcome measures were the Voice Activity and Participation Profile (VAPP) and the Symptom Questionnaire.Of consenting patients (n = 141) with chronic voice disorders, 46 dropped out during follow-up. Ninety-five patients formed the study group. Forty-one of them received only voice therapy, but the rest of them received combined treatment (medication, amplifiers, and voice massage), but also experienced life events affecting voice. Patients with any laryngeal pathology formed the organic group (n = 47), others had a functional voice disorder.

Results

Using the improvement criterion that the change of the VAPP score should exceed standard error of measurement, the percentage of individual patients achieving improvement was 47% in the mild, 59% in the moderate, and 75% in the severe disorder groups. Effect size for VAPP total score was 0.89. The positive effect continued to progress after the therapy ended. Patients with functional or organic voice disorder improved almost equally, although minor findings indicate that functional patients benefited more.

Conclusions

Voice treatment had a progressive effect for 1 year in half of our patients. No statistical difference was found between the functional and organic patient groups.