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121.
This paper presents our work towards developing a new speech corpus for Modern Standard Arabic (MSA), which can be used for implementing and evaluating Arabic speaker-independent, large vocabulary, automatic, and continuous speech recognition systems. The speech corpus was recorded by 40 (20 male and 20 female) Arabic native speakers from 11 countries representing three major regions (Levant, Gulf, and Africa). Three development phases were conducted based on the size of training data, Gaussian mixture distributions, and tied states (senones). Based on our third development phase using 11 hours of training speech data, the acoustic model is composed of 16 Gaussian mixture distributions and the state distributions tied to 300 senones. Using three different data sets, the third development phase obtained 94.32% and 8.10% average word recognition correctness rate and average Word Error Rate (WER), respectively, for same speakers with different sentences (testing sentences). For different speakers with same sentences (training sentences), this work obtained 98.10% and 2.67% average word recognition correctness rate and average WER, respectively, whereas for different speakers with different sentences (testing sentences) this work obtained 93.73% and 8.75% average word recognition correctness rate and average WER, respectively.  相似文献   
122.
The purpose of the present study was to investigate the impact of feedback on writing accuracy over time and examine the relevance of the students’ mother tongue to the feedback effect. To this end, the study compared two groups of Iranian English majors (N = 56) over a period of four months: one with indirect grammar feedback and the other with no grammar feedback whatsoever. The results of the study did not show a significant effect for the teachers’ feedback. However, the results showed a main effect for practice and the interaction of practice and feedback as a result of which both groups improved their writing accuracy over the course of one semester, with the feedback group making more improvement. The results also showed significant differences between the two groups in reducing their errors in various grammatical categories. The study further revealed that the success ratio of error reduction in each category was highly sensitive to cross-linguistic differences. The students’ views, elicited after the study, support the findings obtained from the analysis of the quantitative data.  相似文献   
123.
This study has determined the determinants of the perceived ease of use and perceived usefulness and their influence on campus portal usage. A quantitative approach was employed, using a five-point Likert scale questionnaire, adapted from previous studies. Data were gathered through a survey conducted with 341 staff working in the University of Malaya and were analysed using the partial least squares technique. The results indicate that the ease of finding and ease of understanding have a positive impact on the perceived ease of use of the campus portal. Furthermore, this study also reported a significant positive effect of service quality, information, and process on perceived usefulness of the campus portal. Our study suggests that the perceived ease of use and usefulness are vital towards enhancing the usage frequency and volume of the campus portal. This study broadens the knowledge concerning factors that increase campus portal usage which will enable academic institutions to refine the campus portal thus enhancing the portal usage.  相似文献   
124.
In this paper, a new direct method based on the Chebyshev cardinal functions is proposed to solve a class of variable-order fractional optimal control problems (V-OFOCPs). To this end, a new operational matrix (OM) of variable-order (V-O) fractional derivative in the Caputo sense is derived for these basis functions and is used to obtain an approximate solution for the problem under study. In the proposed method, the state and the control variables are expanded in terms of the Chebyshev cardinal functions with unknown coefficients, at first. Then, the OM of V-O fractional derivative and some properties of the Chebyshev cardinal functions are employed to achieve a nonlinear algebraic equation corresponding to the performance index and a nonlinear system of algebraic equations corresponding to the dynamical system in terms of the unknown coefficients. Finally, the method of constrained extremum is applied, which consists of adjoining the constraint equations derived from the given dynamical system and the initial conditions to the performance index by a set of undetermined Lagrange multipliers. As a result, the necessary conditions of optimality are derived as a system of algebraic equations in the unknown coefficients of the state variable, control variable, and Lagrange multipliers. Furthermore, some numerical examples of different types are demonstrated with their approximate solutions for confirming the high accuracy and applicability of the proposed method.  相似文献   
125.
This paper proposes a fuzzy model predictive control (FMPC) combined with the modified Smith predictor for networked control systems (NCSs). The network delays and data dropouts are problems, which greatly reduce the controller performance. For the proposed controller, the model of the controlled system is identified on-line using the Takagi – Sugeno (T-S) fuzzy models based on the Lyapunov function. There are two internal loops in the proposed structure. The first is the loop around the FMPC, which predicts the future outputs. The other is the loop around the plant to give the error between the system model and the actual plant. The proposed controller is designed for controlling a DC servo system through a wireless network to improve the system response. The practical results based on MATLAB/SIMULINK are established. The practical results are indicated that the proposed controller is able to respond the networked time delay and data dropouts compared to other controllers.  相似文献   
126.
Hepatitis B virus (HBV) infection is a worldwide health concern which is associated with significant morbidity and mortality. Both viral and host factors have a significant effect on infection, replication and pathogenesis of HBV. The aim of this study was to investigate the effect of CYP2E1 and CYP1A1 genetic variants on susceptibility to HBV. 143 individuals including 54 chronic HBV patients and 89 healthy controls were enrolled in the genotyping procedure. rs2031920 and rs3813867 at CYP2E1 as well as rs4646421 and rs2198843 at CYP1A1 loci were studied in all subjects using PCR–RFLP (restriction fragment length polymorphism) analysis. Both variants at CYP2E1 locus were monomorphic in all studied subjects. Genotype frequency of rs4646421 was significantly different between chronic HBV patients and healthy blood donors (P = 0.04, OR 4.31; 95% CI 1.04–17.7). Furthermore, individuals carrying at least one C allele (CC or CT genotypes) for rs4646421 seemed to have a decrease risk of hepatitis in comparison with TT genotype (P = 0.039). Our results showed a relationship between rs4646421 TT genotype (rare genotype) and the risk for developing chronic HBV infection (four times higher). Further studies are needed to examine the role of CYP1A1 polymorphism in susceptibility to chronic HBV infection.  相似文献   
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128.
Abstract

International Telecommunication Union’s ICT Development Index and related measures of a country’s ICT development maturity suffer from several limitations, including subjective estimation of the weights of individual indicators and sub-indices, use of inappropriate quantitative models, specification bias arising from the exclusion of potential predictors from the estimation models, and a failure to capture the disparities among different groups of countries. To overcome these problems and provide a more reliable measure of ICT development, this study develops the Modified ICT Maturity Level Index using the 2015 data of 166 countries. This index adds affordability, efficiency, and quality to the existing sub-indices of access, use, and skills. Sub-index and indicator weights are determined in an outcome-orientated way using Partial Least Squares Structural Equation Modeling. We find that affordability, quality, and efficiency significantly explain the variation in the level of maturity of ICT development in addition to the previously used dimensions of International Telecommunication Union’s ICT Development Index and modified ICT Development Index (mIDI) developed by Gerpott and Ahmadi, and that their explanatory power differ by a country’s level of economic development. The new index produces significantly different country rankings. This has important implications for ICT policy priorities and provides a measure of ICT development maturity less prone to the innocent or intentional distortion of such policy priorities.  相似文献   
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130.
Seeds of a Chinese traditional medicine plant, Cochinchina momordica were used in the present study for the improvement of influenza vaccine (HSN 1) in chicken. Crude extraction from Cochinchina momordica seed (ECMS) was obtained by ethanol extraction method. In experiment No. 1, two weeks old chickens were immunized with influenza vaccine (HSN1) alone or combined with ECMS (5, 10, 20, 40 and 80 μg/dose). Serum IgG antibody levels (by ELISA) as well as effects on dally weight gain were measured on 0, 7, 14 and 28th day after immunization. Results revealed that all ECMS groups numerically increased the antibody levels while 10 and 20 μg/dose groups significantly (P〈0.05) enhanced total IgG antibody on day 28, when compared with control. Average daily weight gain was also significantly higher in 20 μg/dose ECMS group. Adjuvant effect was also confirmed in experiment No. 2 when chickens were immunized with 20 μg/dose ECMS and antibody titer was measured through hemagglutination inhibition (HI). It is concluded that ECMS has potential to improve the immune responses and deserve further study as an adjuvant.  相似文献   
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