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61.
In this paper, a method is proposed to reject disturbances in the model predictive control (MPC) strategy. In addition, uncertainties in the system parameters (i.e., internal disturbances) are considered as well. To achieve these goals, adaptive neural networks are designed as the predictor model and as the nonlinear disturbance observer, respectively. The disturbances are rejected via the optimization problem of the MPC. Stability of the closed-loop system is studied based on the Input-to-State Stability method. The proposed method is applied to the pH neutralization process and CSTR system and its effectiveness in optimal rejection of the disturbances and satisfying the system constrains is compared with the feed-forward control method.  相似文献   
62.
Measurement and control of pressure-driven flow (PDF) has a great potential to enhance the performance of chemical and biological experiments in Lab on a Chip technology. In this paper, we present an optofluidic flow sensor for real-time measurement and control of PDF. The optofluidic flow sensor consists of an on-chip micro Venturi and two optical Fabry-Pérot (FP) interferometers. Flow rate was measured from the fringe shift of FP interferometers resulted from movement fluid in the on-chip micro Venturi. The experimental results show that the optofluidic flow sensor has a minimum detectable flow change of 5 nl/min that is suitable for real time monitoring and control of fluids in many chemical and biological experiments. A Finite Element Method is used to solve the three dimensional (3D) Navier–Stokes and continuity equations to validate the experimental results.  相似文献   
63.
Research in natural language processing has increasingly focused on normalizing Twitter messages. Currently, while different well-defined approaches have been proposed for the English language, the problem remains far from being solved for other languages, such as Malay. Thus, in this paper, we propose an approach to normalize the Malay Twitter messages based on corpus-driven analysis. An architecture for Malay Tweet normalization is presented, which comprises seven main modules: (1) enhanced tokenization, (2) In-Vocabulary (IV) detection, (3) specialized dictionary query, (4) repeated letter elimination, (5) abbreviation adjusting, (6) English word translation, and (7) de-tokenization. A parallel Tweet dataset, consisting of 9000 Malay Tweets, is used in the development and testing stages. To measure the performance of the system, an evaluation is carried out. The result is promising whereby we score 0.83 in BLEU against the baseline BLEU, which scores 0.46. To compare the accuracy of the architecture with other statistical approaches, an SMT-like normalization system is implemented, trained, and evaluated with an identical parallel dataset. The experimental results demonstrate that we achieve higher accuracy by the normalization system, which is designed based on the features of Malay Tweets, compared to the SMT-like system.  相似文献   
64.
Contrary to the common belief of Arabic language users that the Arabic writing system has descenders as an inherent quality, some historical examples demonstrate that there were some artistic attempts to create non-descender, all-cap calligraphic systems, but they have never been studied as a phenomenon. This article draws attention to the existence of these examples, and analyses and classifies them according to their form.

The article begins with an analysis of the current Arabic writing system in terms of descenders, differentiating between artistic and functional writing, defining the need for harmonious balance in artistic writing, and demonstrating that descenders do disrupt the balance in Arabic writing, which could be considered as an ascender-system.

Then, historical examples of the non-descender system are introduced, categorised into four visual stages, and the descender handling for each stage is described; all-capital letter examples are then introduced.

Finally, some historical texts describing the beauty of calligraphy in this specific system of writing are analysed.

Abbreviations: MET: The Metropolitan Museum of Art, www.metmuseum.org; LACMA: The Los Angeles County Museum of Art, www.lacma.org; No. : Accession Number  相似文献   

65.
This study examines the uses and gratifications of language in social media among the Indian subcontinental diaspora in the United States, based on data collected from an online survey of 535 adult immigrants following a snowballing technique. Results showed the use of native language is related to the use of home country media, while the use of English language is related to emotional adjustment. This study contributes to the literature on social media, community, and language preference by opening avenues for conducting further research on the usage of language in social media among the Indian subcontinental diaspora in the United States. The findings of this study contribute to an understanding of the influence of social media on language preference.  相似文献   
66.
Whether screening tests or teacher ratings best predict children at risk for reading failure continues to be an area of disagreement in the early identification literature. Our early studies confirmed low positive identification rates (30%) when kindergarten teachers were asked to predict future reading achievement using a traditional rating scale, while a project-developed, theory-based screening battery correctly identified 81% of poor readers. Construction of a teacher rating scale of current skill levels on research-validated precursors to reading improved prediction in the current study, although results were still inferior to the screening test (64% and 80% valid positives, respectively). Combining test results and teacher ratings resulted in 88% identification of those who failed in first, second, or third grade, suggesting that both teacher ratings and screening tests should be used to identify the largest number of those who will later fail in reading. © 1998 John Wiley & Sons, Inc.  相似文献   
67.
With the latest revolution of technology in information, communications, and media, the need for computerization has been identified in most countries. Many social and technical advantages and problems come along with it. As a result, the Information Society concept has been created. There exist certain principles for building such a society, but in Arab regions it has unique challenges and obstacles. Jordan, responding to a royal vision, has established the goal of becoming a leader in information and economic developments among other countries in the region. Several plans and initiatives have been developed for this purpose. One of these initiatives is the implementation of e-Government, which offers several benefits for both the government and society. e-Government has five building blocks to achieve the expected results and the process of implementation involves passing through certain stages. Jordan, as an Arab country, faces several obstacles in the area of implementation. A readiness study for Jordan has been accomplished and implementation and achievements have been made in Jordanian e-Government.  相似文献   
68.
This study investigates the role of social capital in raising research productivity in academic institutions. Social capital as a strategic resource embedded in social relationships can be utilised towards decreasing pressures from external environmental conditions, such as the global financial crisis. A survey was sent to academic staff in five universities in Victoria, to collect data regarding their frequency of communications and research productivity. The findings indicated that there is a significant and positive correlation between social interactions and research productivity. Regression analysis demonstrated that social interactions as an independent variable predict research productivity of academics.  相似文献   
69.
This study examines predictors of online content purchases through media dependency theory and comparing young and older people. It focuses on actual online content purchases instead of willingness-to-pay used in previous studies. The effects of two dimensions of media dependencies are compared: intensity and referent scopes. Social media dependency and mobile media dependency are examined specifically, in addition to general Internet dependency as new media dependency. Our results show young people make more actual purchases of online content than older people. Predictors of online content purchases include age group, online shopping habits, ownership of mobile applications and mobile devices, Internet referent dependency, and social media intensity dependency. New media referent dependency is more important than intensity dependency for predicting online content purchases.  相似文献   
70.
This study examines the roles of partisanship, partisan media use, and political discussion in the development of belief gaps. Using national survey data, we construct models of political identity, media use, and discussion factors predicting beliefs on five contested political issues and find that ideology and partisanship are generally stronger predictors of beliefs than is education. Notably, each has independent effects on belief outcomes. Contrary to some concerns that the Internet especially promotes partisan clustering, use of partisan traditional media—television and radio—is by far the strongest information-related predictor of belief outcomes, whereas partisan social media use and partisan discussion are relatively weak and inconsistent. These findings suggest that political elites continue to exert significant influence over the perceptions of rank and file partisans.  相似文献   
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