7,524 research outputs found

    An introduction of dominant genes in genetic algorithm for scheduling of FMS

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    This paper proposed a new idea named Dominant Genes (DGs) in Genetic Algoriths (GAs) to deal with FMS scheduling problem with alternative production routing. In traditional GAs approach, the crossover mechanism will randomly select a number of genes to undergo crossover. However, these selected genes may not contain or contain only part of the critical structure of its original chromosome. In addition, since the inherited complexity of the scheduling nature, the changes in the structure of the selected genes will further influence its strength. To tackle this problem, the proposed DGs in this paper are to identify and record the best genes in the chromosome. A new crossover mechanism is also designed to ensure the best genes will undergo crossover, and retain the originality of the structure of the crossover genes. The performance of the proposed DGs is testified by comparing it with other heuristic optimizations. The shows that DGs perform better than other approaches. ©2005 IEEE.published_or_final_versio

    Transmit/receive beamformer design and power control in MIMO MC-CDMA systems

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    IEEE International Symposium on Circuits and Systems, Island of Kos, Greece, 21-24 May 2006In this paper, a joint transmitter and receiver beamformers design algorithm for downlink multiple input multiple output multicarrier code-division multiple access (MIMO MC-CDMA) system is proposed. The algorithm is iterative in nature where the transmitter beamformers and the receiver beamformers are determined alternately. The transmitter beamforming problem with a given receiver beamformer is formulated as a convex programming problem, which can be solved optimally using second order cone programming (SOCP), while the receiver beamforming problem is formulated as a constrained optimization problem with an analytical solution. The convergence of the algorithm is analyzed and the performance of the proposed algorithm is evaluated by computing simulation. © 2006 IEEE.published_or_final_versio

    Design and multiplierless realization of digital synthesis filters for hybrid-filter-bank A/D converters

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    This paper studies the optimal least squares and minimax design and realization of digital synthesis filters for hybrid-filter-bank analog-to-digltal converters (HFB ADCs) to meet a given spurious-free dynamic range (SFDR). The problem for designing finite-impulse-response synthesis filters is formulated as a second-order cone-programming problem, which is convex and allows linear and quadratic constraints such as peak aliasing error to be incorporated. The fixed coefficients of the designed synthesis filters are efficiently implemented using sum-of-power-of-two (SOPOT) coefficients, while the internal word length used for each intermediate data is minimized using geometric programming. The main sources of error are analyzed, and a new formula of SFDR in terms of these errors is derived. The effects of component variations of analog analysis filters on the HFB ADC are also addressed by means of two new robust HFB ADC design algorithms based on stochastic uncertainty and worst case uncertainty models. Design results show that the proposed approach offers more flexibility and better performance than conventional methods in achieving a given SFDR and that the robust design algorithms are more robust to parameter uncertainties than the nominal design in which the uncertainties are not taken into account. © 2009 IEEE.published_or_final_versio

    Clinicopathological study of renal biopsies after liver transplantation

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    Hole-transporting spirothioxanthene derivatives as donor materials for efficient small-molecule-based organic photovoltaic devices

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    Poster: no. 30Taking the advantages of the 3D structure and rigid spiro-conjugation, spirobifluorene and its derivatives are a benchmark class of p-type semiconductors in organic electronic devices because of their good charge-transporting properties. However, their low absorption coefficients within the visible spectrum render their application as photoactive materials in the fabrication of organic photovoltaic (OPV) devices. A new class of heterocyclic spirothioxanthene derivatives has been designed and synthesized by the functionalization of the spiro core with various triarylamine groups and the modification of the heteroatom of the spiro core. The photophysical, electrochemical and thermal properties of these spirothioxanthene derivatives have been fully characterized. Of particular interest, all of these compounds exhibit high hole mobilities of up to 10–3 cm2V–1s–1, as determined from thin film transistor measurement. More importantly, these spirothioxanthene derivatives are promising donor materials for the fabrication of high performance OPV devices. With a very low dopant concentration of 7 % doped into fullerene matrix, efficient small molecular-based OPV devices with high open-circuit voltage of 0.94 V and high power conversion efficiency of 5.40 % (the highest PCE of 5.46 %) have been realized. This demonstrates for the first time their application studies as photovoltaic donor materials in OPV devices.published_or_final_versio

    Is vocal cord asymmetry seen on transcutaneous laryngeal ultrasonography a significant predictor of voice quality changes after thyroidectomy?

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    Background: Vocal cord asymmetry (VCA) on laryngoscopic examination (LE) may suggest voice impairment after thyroidectomy, but LE may cause patient discomfort. We aimed to correlate the presence of postoperative VCA assessed by noninvasive transcutaneous laryngeal ultrasonography (TLUSG) with voice quality changes after thyroidectomy. Methods: A total of 169 patients scheduled for thyroidectomy completed two validated voice symptoms questionnaires - the GRBAS (grade, roughness, breathiness, asthenia, strain) scale and the voice impairment score (VIS) - and underwent TLUSG and LE at 1 day before and 7-10 days after thyroidectomy. Postoperative VCA was apparent in 51 patients on TLUSG (group I), whereas there was no VCA in the other 118 patients (group II, controls). The GRBAS scale and VIS results were compared between the groups. Results: Before operation, the two groups had comparable preoperative GRBAS and VIS status. After operation, the "grade" and "roughness" components on the GRBAS scale were significantly worse in group I than in group II: 0.24 versus 0.07 (p = 0.016) and 0.33 versus 0.14 (p = 0.022), respectively. "Grade" and "roughness" in the GRBAS scale significantly worsened after the operation in group I: from 0.04 to 0.24 (p = 0.008) and from 0.02 to 0.33 (p = 0.001), respectively. They did not change in group II. Also, the overall VIS was significantly worse after thyroidectomy in group I: 4.97 versus 12.97 (p < 0.001). Conclusions: VCA seen on TLUSG significantly correlated with "grade" and "roughness" components on the GRBAS scale and the overall VIS. Thus, VCA might be used as a surrogate of postoperative voice changes. © 2013 Société Internationale de Chirurgie.postprin

    Improved hybrid particle swarm optimized wavelet neural network for modeling the development of fluid dispensing for electronic packaging

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    Author name used in this publication: H. H. C. IuAuthor name used in this publication: F. H. F. Leung2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Piezoelectric ceramic composition and the method for preparing the same

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    US7494601; US7494601 B2; US7494601B2; US7,494,601; US 7,494,601 B2; 7494601; Application No. 11/362,793Inventor name used in this publication: Kin Wing KwokInventor name used in this publication: Helen Lai Wah ChanInventor name used in this publication: Siu Hong ChoyUSVersion of Recor

    Magnetoelectric effect in lead-free BNKLBT ceramic/terfenol-D continue fiber composite laminates

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    Author name used in this publication: C. Y. LoAuthor name used in this publication: S. H. ChoyAuthor name used in this publication: S. W. OrAuthor name used in this publication: H. L. W. Chan2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Word learning deficit among Chinese dyslexic children

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    The present study examined word learning difficulties in Chinese dyslexic children, readers of a nonalphabetic script. A total of 105 Hong Kong Chinese children were recruited and divided into three groups: Dyslexic (mean age 8;8), CA control (mean age 8;9), and RL control (mean age 6;11). They were given a word learning task and a familiar word writing task. It was found that the Dyslexic group performed less well than the RL group in learning irregular words over trials but not the regular ones. Error analyses showed that the Dyslexic group made more orthographic and word association errors but less intra-wordlist interference errors than the RL control group. The Dyslexic group also performed significantly less well than both control groups in writing familiar words (e.g. their own name). These findings suggest that Chinese dyslexic children have difficulty learning new words, especially irregular ones, and retaining overlearned words in long-term memory. We conclude that Chinese dyslexic children have a specific impairment in word learning like their alphabetic counterparts. © 2006 Cambridge University Press.published_or_final_versio
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