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Institution

National Cheng Kung University

EducationTainan City, Taiwan
About: National Cheng Kung University is a education organization based out in Tainan City, Taiwan. It is known for research contribution in the topics: Population & Thin film. The organization has 49723 authors who have published 69799 publications receiving 1437420 citations. The organization is also known as: NCKU.


Papers
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Journal ArticleDOI
TL;DR: In this article, an approach to make wind power become a more reliable source on both energy and capacity by using energy storage devices is presented. But, it is difficult to predict and control the output of wind generation, its potential impacts on the electric grid are different from the traditional energy sources.
Abstract: With the advancements in wind turbine technologies, the cost of wind energy has become competitive with other fuel-based generation resources. Due to the price hike of fossil fuel and the concern of global warming, the development of wind power has rapidly progressed over the last decade. The annual growth rate has exceeded 26% since the 1990s. Many countries have set a goal for high penetration levels of wind generation. Recently, several large-scale wind generation projects have been implemented all over the world. It is economically beneficial to integrate very large amounts of wind capacity in power systems. Unlike other traditional generation facilities, using wind turbines presents technical challenges in producing continuous and controllable electric power. A distinct feature of wind energy is its nature of being ldquointermittent.rdquo Since it is difficult to predict and control the output of wind generation, its potential impacts on the electric grid are different from the traditional energy sources. At a high penetration level, an extrafast response reserve capacity is needed to cover the shortfall of generation when a sudden deficit of wind takes place. To enable a proper management of the uncertainty, this paper presents an approach to make wind power become a more reliable source on both energy and capacity by using energy storage devices. Combining the wind power generation system with energy storage will reduce fluctuation of wind power. Since it requires capital investment for the storage system, it is important to estimate the reasonable storage capacities for the desired applications. In addition, an energy storage application for reducing the output variation during the gust wind is also studied.

235 citations

Journal ArticleDOI
TL;DR: In this article, a probabilistic approach is developed to establish a drought severity-duration-frequency (SDF) relationship, where copulas are employed to construct the joint distribution function of drought severity and duration, in terms of recurrence interval of drought events, is then related to the copula-based distribution function via a conditional distribution function.
Abstract: Drought is a complex and multi-attribute natural hazard that has worldwide effects. Defined by a commonly used standardized precipitation index (SPI), each drought event is characterized by three correlated attributes: severity, duration and frequency. A probabilistic approach is developed to establish a drought severity-duration-frequency (SDF) relationship. Copulas are employed to construct the joint distribution function of drought severity and duration. Drought frequency, in terms of recurrence interval of drought events, is then related to the copula-based distribution function via a conditional distribution function. The derived analytic drought SDF thus becomes a function of univariate distribution functions of drought severity and duration, a copula function which links the fitted univariate models, and the arrival rate of drought events. In this study, rainfall data for the period of 1954–2003 from two gauge stations in Iran, Abadan in the southwestern semi-arid region and Anzali in the north humid region, are employed as an example to illustrate the proposed approach. From the derived drought SDF, drought severity in Anzali station is greater than those in Abadan station for given drought duration and recurrence interval. The results imply that the drought severity in humid region might be more severe if high rainfall fluctuations exist in that region. Copyright © 2009 Royal Meteorological Society

235 citations

Journal ArticleDOI
TL;DR: It is demonstrated that prM antibodies facilitate efficient binding and cell entry of immature particles into Fc-receptor-expressing cells and enzymatic activity of furin is critical to render the internalized immature virus infectious.
Abstract: Cells infected with dengue virus release a high proportion of immature prM-containing virions. In accordance, substantial levels of prM antibodies are found in sera of infected humans. Furthermore, it has been recently described that the rates of prM antibody responses are significantly higher in patients with secondary infection compared to those with primary infection. This suggests that immature dengue virus may play a role in disease pathogenesis. Interestingly, however, numerous functional studies have revealed that immature particles lack the ability to infect cells. In this report, we show that fully immature dengue particles become highly infectious upon interaction with prM antibodies. We demonstrate that prM antibodies facilitate efficient binding and cell entry of immature particles into Fc-receptor-expressing cells. In addition, enzymatic activity of furin is critical to render the internalized immature virus infectious. Together, these data suggest that during a secondary infection or primary infection of infants born to dengue-immune mothers, immature particles have the potential to be highly infectious and hence may contribute to the development of severe disease.

235 citations

Journal Article
TL;DR: This review study surveyed recent researches including context awareness, pedagogical strategy-enhanced learning scenarios, as well as collaborative and socially networked mobile learning to identify essential characteristics of mobile learning.
Abstract: Mobile devices are more powerful and portable nowadays with plenty of useful tools for assisting people handle daily life. With the advance of mobile technology, the issue of mobile learning has been widely investigated in e-learning research. Many researches consider it is important to integrate pedagogical and technical strengths of mobile technology into learning environments. This review study focuses on the investigation of add-on impact of mobile applications in learning strategies. We surveyed recent researches including context awareness, pedagogical strategy-enhanced learning scenarios, as well as collaborative and socially networked mobile learning. Through this review study, essential characteristics of mobile learning were identified and discussed. With the essential characteristics, we emphasized on the add-on impact of mobile learning and elaborated mobile learning model in learning strategies.

235 citations

Journal ArticleDOI
TL;DR: In this article, the synthesis of nickel nanoparticles by the reduction of nickel chloride with hydrazine in an aqueous solution of cationic surfactants CTAB/TC12AB was studied.
Abstract: The synthesis of nickel nanoparticles by the reduction of nickel chloride with hydrazine in an aqueous solution of cationic surfactants CTAB/TC12AB was studied. It was found that an appropriate amount of NaOH, trace acetone, and an elevated temperature were necessary for the formation of pure nickel nanoparticles. Also, it was not necessary to perform the reaction under a nitrogen atmosphere. X-ray diffraction revealed the resultant particles were pure nickel crystalline with a face-centered cubic (fcc) structure. Their mean diameter was 10–36 nm, increasing with increasing nickel chloride concentration or decreasing hydrazine concentration. When the concentration ratio of hydrazine to nickel chloride was above 40, the mean diameter approached a constant value. The magnetic measurement on a typical sample with a mean diameter of 12 nm showed that the resultant nickel nanoparticles were superparamagnetic due to their extremely small size. The saturation magnetization, remanent magnetization, and coercivity were 32 emu g−1, 5.0 emu g−1, and 40 Oe, respectively. Also, the magnetization was observed to increase with decreasing temperature. All the observed magnetic properties essentially reflected the nanoparticle's nature.

234 citations


Authors

Showing all 49872 results

NameH-indexPapersCitations
Yi Chen2174342293080
Yang Yang1642704144071
R. E. Hughes1541312110970
Mercouri G. Kanatzidis1521854113022
Thomas J. Smith1401775113919
Hui Li1352982105903
Gerald M. Reaven13379980351
Chi-Huey Wong129122066349
Joseph P. Vacanti11944150739
Kai Nan An10995351638
Ding-Shinn Chen10477446068
James D. Neaton10133164719
David C. Christiani100105255399
Jo Shu Chang9963937487
Yu Shyr9854239527
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202373
2022315
20213,425
20203,154
20192,895
20182,764