1,721,159 research outputs found
Removal of Potassium Chloride from Potassium Clavulanate solution by Diafiltration and Its Modelling
No full textRecovery of potassium clavulanate from ion-exchanged solution by diafiltration and its modeling
No full textObject-oriented concept analysis for software imodularisation
No full textModularity is one of the most important principles in software engineering and a necessity for every practical software. Since the design space of software is generally quite large, it is valuable to provide automatic means to help modularising it. An automatic technique for software modularisation using object-oriented concept analysis (OOCA) is proposed. The proposed technique is strongly inspired by the success of reverse engineering techniques based on formal concept analysis (FCA). However, our experience shows that FCA-based techniques generally result in fine-grained modules and, thus, may be inadequate for modularising large-scale designs. To overcome this weakness, the authors employ OOCA, a recent proposal for concept formulations. OOCA enables to provide coarse concepts as module candidates while keeping the advantage of FCA techniques. To the best of the authors' knowledge, it is the first work to apply OOCA in software engineering research. To illustrate the potential of the approach, the authors perform a software modularisation case study on a real insurance software design with comparison
A preconditioner for the FETI-DP formulation with mortar methods in two dimensions
Full text linkIn this paper, we consider a dual-primal FETI (FETI-DP) method for elliptic problems on nonmatching grids. The FETI-DP method is a domain decomposition method that uses Lagrange multipliers to match solutions continuously across subdomain boundaries in the sense of dual-primal variables. We use the mortar matching condition as the continuity constraints for the FETI-DP formulation. We construct a preconditioner for the FETI-DP operator and show that the condition number of the preconditioned FETI-DP operator is bounded by C max/i=1,...,N {(1 + log (H-i/h(i)))(2)}, where H-i and h(i) are sizes of domain and mesh for each subdomain, respectively, and C is a constant independent of H-i's and h(i)'s. We allow jumps of coefficients of elliptic problems across subdomain boundaries. Numerical results are included.This work was partially supported by KRF-2001-041-D0003
Effects of operating voltage waveforms and power control methods on the light emission from a Xe plasma flat lamp
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Multi-particle trapping and manipulation by a high-frequency array transducer
No full textWe report the multiple micro-particle trapping and manipulation by a single-beam acoustic tweezer using a high-frequency array transducer. A single acoustic beam generated by a 30 MHz ultrasonic linear array transducer can entrap and transport multiple micro-particles located at the main lobe and the grating lobes. The distance between trapped particles can be adjusted by changing the transmit arrangement of array-based acoustic tweezers and subsequently the location of grating lobes. The experiment results showed that the proposed method can trap and manipulate multiple particles within a range of hundreds of micrometers. Due to its simplicity and low acoustic power, which is critical to protect cells from any thermal and mechanical damages, the technique may be used for transportation of cells in cell biology, biosensors, and tissue engineering. (c) 2014 AIP Publishing LLC.11108sciescopu
Frequency compounded imaging with a high-frequency dual element transducer
No full textThis paper proposes a frequency compounding method to reduce speckle interferences, where a concentric annular type high-frequency dual element transducer is used to broaden the bandwidth of an imaging system. In frequency compounding methods, frequency division is carried out to obtain sub-band images containing uncorrelated speckles, which sacrifices axial resolution. Therefore, frequency compounding often deteriorates the target-detecting capability, quantified by the total signal-to-noise ratio (SNR), when the speckle's SNR (SSNR) is not improved as much as the degraded axial resolution. However, this could be avoided if the effective bandwidth required for frequency compounding is increased. The primary goal of the proposed approach, hence, is to improve SSNR by a factor of two under the condition where axial resolution is degraded by a factor of less than two, which indicates the total SNR improvement to higher than 40% compared to that of an original image. Since the method here employs a dual element transducer operating at 20 and 40 MHz, the effective bandwidth necessary for frequency compounding becomes broadened. By dividing each spectrum of RF samples from both elements into two sub-bands, this method eventually enables four sets of the sub-band samples to contain uncorrelated speckles. This causes the axial resolution to be reduced by a factor of as low as 1.85, which means that this method would improve total SNR by at least 47%. An in vitro experiment on an excised pig eye was performed to validate the proposed approach, and the results showed that the SSNR was improved from 2.081 +/- 0.365 in the original image to 4.206 +/- 0.635 in the final compounding image. (C) 2009 Elsevier B. V. All rights reserved.1117sciescopu
Fabrication of a 40 MHz single element ultrasonic transducer using a PMN-PT single crystal
No full textPMN-PT, a piezoelectric single crystal, has been known to be a better material for transducer arrays due to its high electromechanical coupling coefficient (k(33)) and high dielectric and piezoelectric constants. It may also be good even for high frequency single element transducers using relatively high k(t), and low attenuation and velocity dispersion. However, it's challenging to fabricate high frequency transducers using PMN-PT since it is easily breakable and requires small area and thickness of the transducer. A KLM model was used to simulate a 40 MHz single element transducer including 2 matching layers and a conductive backing. The simulation showed that the PMN-PT transducer turned out to be better in sensitivity and bandwidth than a 40 MHz LiNbO3 transducer. A 40 MHz PMN-29%PT transducer was fabricated and the pulse echo signals were obtained and analyzed. Its sensitivity was found to be -48 dB and -6dB bandwidth was about 48%.111sciescopu
Effects of operating conditions on ammonium lactates recovery by desalting electrodialysis
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