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This paper presents an optofluidic tunable lens using laser-induced thermal gradient to focus the light to one point. By use of the thermo-optics effect, we demonstrated a tunable focal length from infinite to 1.3 mm.
In this paper, aimed at the assembly business of spacecrafts such as satellites and airships, the author has analyzed the the new demands in the management of spacecraft assembly, including the change of design and manufacturing mode and the optimization of workflow, put forward the overall framework and core function module design for MES of spacecraft assembly, and provided ideas and methods on...
A broadband variable optical delay line is proposed based on the discrete harmonic oscillation in waveguide lattices with a quadratic distribution of coupling coefficients. Theoretical analysis and numerical simulations are performed with the sample design.
Photocatalysis and optofluidics have an intrinsic synergy as both deal with the same objects — light, fluids and solvents. This study presents different designs of optofluidic microreactors to solve some major problems of current photocatalytic technology.
the near-field enhancement of localized surface plasmon resonance (SPR) in the metal nanoparticles can improve the photocatalytic activity of the semiconductor connected to it. The SPR effect of the Au nanoparticles and the coupling effect of the neighboring Au nanoparticles and the gold film improves the visible-light absorption of TiO2. The simulation result is consistent with the measured absorption...
This paper reports a biomimetic method inspired by clam to immobilize nanoparticles easily on microfluidic chips. In nature, clam predation is benefit from a mucus-covered system, used for trapping suspended plankton. Through mimicking the mucus-covered system by a common adhesive tape, we immobilized TiO2 nanoparticles easily and environmental friendly, obtaining a better immobilization amount than...
As a noninvasive technique, electrocardiogram (ECG) plays a significant role in the diagnosis of many cardiac diseases. However, ECG signals are usually corrupted with baseline wander and high-frequency noise. Numerous approaches have been proposed to suppress noise in ECG signals such as finite impulse response (FIR) filter, infinite impulse response (IIR) filter and wavelet method. These methods...
The EMAT is a non-contact transducer, but it is sensitive to the lift off. To study the lift off effect on the feature cut off frequency in the Rayleigh wave, a finite element method (FEM) is used. Based on different hypotheses of the source current density, three formulations are realized with the simulation software COMSOL. Ignoring the skin and proximity effects will yield enormous errors. The...
This paper analyzes the different reaction pathways that play major roles in the process of photocatalytic degradation, and presents a novel microfluidic photoelectrocatalytic reactor for selective control of them. This is accomplished by applying positive or negative bias potential to the photocatalytic reaction chamber and to select either the hole-driven or electron-driven oxidation pathway. The...
In this paper, the experimental studies utilize the photoelectrocatalytic effect to eliminate another fundamental limit of photocatalysis - the recombination of photo-excited electrons and holes. Two transparent ITO glass slides are used as eletrodes and both the positive and negative bias potentials are applied across the reaction chamber. It turns out that the negative bias always exhibits higher...
One of the most difficult problems in cluster analysis is the identification of the number of groups in a given data set. In this paper we offer the randomized approach in the rate distortion framework. A randomized algorithm has been suggested to allocate this position. The scenario approach is used to significantly reduce the computational complexity. With ability to determine the true number of...
A hybrid method is used to evaluate atherosclerosis through a mathematical morphology approach and GVF-Snake method. Common carotid artery (CCA) segmentation requires outlining the intima and adventitia contours on the transverse view of B-mode ultrasound (US) images. The lumen and adventitia contours are segmented using a morphology and GVF-Snake methods, respectively. Upon analyzing ten separate...
Traditional image matching algorithm based on gray correlation provides accurate results but it is time-consuming because of large amount of calculation. An improved gray correlation based image matching algorithm based on multi-core DSP is proposed to speed up the matching velocity with the acceptable margin of errors. With the development of portable embedded image processer, especially the multi-core...
A three dimensional transrectal ultrasound imaging system has been developed. The proposed system is aimed at monitoring for the prostate and providing three-dimensional ultrasound image for prostate biopsy and therapy. The device contains mechanical device and control circuit for the rotation of the probe. In addition, a two dimensional ultrasound machine for 2D ultrasound imaging is used and the...
The intersecting cortical model(ICM) is driven from the pulse-coupled neural networks (PCNN), and a lot of works have been done on it. In this paper, we have proposed a method, which is modified from the PCNN, to retrieval the image. This method uses the iteration times of the ICM as the feature, and we do it repeatedly. So we will get the feature vectors and utilize the features to retrieval the...
Image quality assessment is a hot topic in image processing and can be applied to evaluate the image processing methods and the performance of imaging system. In this paper, a new method of regional mutual information is proposed to assess image quality. Furthermore, this algorithm is compared with peak of signal-to-noise ratio (PSNR) and structure similarity (SSIM) that are universal assessment methods...
This paper gives an overview of three different geometric active contour models with the focus on the application to carotid plaque detection from cross-sectional ultrasound images of the carotid artery. On one hand, basic principles of these geometric active contour models are presented. On the other hand, performance of these models are tested on 16 images and compared with the manual delineations.
Speckle is a granular noise that inherently exists in all types of coherent imaging systems. This paper presents a quantitative study on five despeckling methods such as frost filter, kuan filter, speckle reducing an isotropic diffusion, homomorphic filter and wavelet filter. We select six objective evaluation parameters, such as signal-to-ratio, contrast signal-to-noise ratio, figure of merit, least...
An improvement to the efficiency of the nonlocal means (NLM) denoising method is proposed in this paper. The NLM denoising method replaces each pixel by the weighted average of pixels with the surrounding neighborhoods. We employ a cosine weighting function instead of the original exponential function used in the weight calculation. Experiments comparing the proposed function against the original...
A low-cost device using acoustic method for measuring open-end tube length is developed. The proposed device is aimed to get the length of the tubes which are piled up together, and only one end of which is available in the warehouse or dumping areas. The device contains the emitting and receiving probes to echo the sound pulse and receive the reflection sound wave, and has been developed with discrete...
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