National Cheng Kung University

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.

Synergistic effect in an Au-Ag alloy nanocatalyst: CO oxidation.

Abstract: Au−Ag alloy nanoparticles supported on mesoporous aluminosilicate have been prepared by one-pot synthesis using hexadecyltrimethylammonium bromide (CTAB) both as a stabilizing agent for nanoparticles and as a template for the formation of mesoporous structure. The formation of Au−Ag alloy nanoparticles was confirmed by X-ray diffraction (XRD), ultraviolet−visible (UV−vis) spectroscopy, and transmission electron microscopy (TEM). Although the Au−Ag alloy nanoparticles have a larger particle size than the monometallic gold particles, they exhibited exceptionally high activity in catalysis for low-temperature CO oxidation. Even at a low temperature of 250 K, the reaction rate can reach 8.7 × 10-6 mol·gcat.-1·s-1 at an Au/Ag molar ratio of 3/1. While neither monometallic Au@MCM-41 nor Ag@MCM-41 shows activity at this temperature, the Au−Ag alloy system shows a strongly synergistic effect in high catalytic activity. In this alloy system, the size effect is no longer a critical factor, whereas Ag is believed to...

Dynamic Bus Arrival Time Prediction with Artificial Neural Networks

Abstract: Transit operations are interrupted frequently by stochastic variations in traffic and ridership conditions that deteriorate schedule or headway adherence and thus lengthen passenger wait times. Providing passengers with accurate vehicle arrival information through advanced traveler information systems is vital to reducing wait time. Two artificial neural networks (ANNs), trained by link-based and stop-based data, are applied to predict transit arrival times. To improve prediction accuracy, both are integrated with an adaptive algorithm to adapt to the prediction error in real time. The bus arrival times predicted by the ANNs are assessed with the microscopic simulation model CORSIM, which has been calibrated and validated with real-world data collected from route number 39 of the New Jersey Transit Corporation. Results show that the enhanced ANNs outperform the ones without integration of the adaptive algorithm.

FHM: Faster High-Utility Itemset Mining using Estimated Utility Co-occurrence Pruning

Abstract: High utility itemset mining is a challenging task in frequent pattern mining, which has wide applications. The state-of-the-art algorithm is HUI-Miner. It adopts a vertical representation and performs a depth-first search to discover patterns and calculate their utility without performing costly database scans. Although, this approach is effective, mining high-utility itemsets remains computationally expensive because HUI-Miner has to perform a costly join operation for each pattern that is generated by its search procedure. In this paper, we address this issue by proposing a novel strategy based on the analysis of item co-occurrences to reduce the number of join operations that need to be performed. An extensive experimental study with four real-life datasets shows that the resulting algorithm named FHM (Fast High-Utility Miner) reduces the number of join operations by up to 95 % and is up to six times faster than the state-of-the-art algorithm HUI-Miner.

Methotrexate Conjugated to Gold Nanoparticles Inhibits Tumor Growth in a Syngeneic Lung Tumor Model

Abstract: Methotrexate (MTX), a stoichiometric inhibitor of dihydrofolate reductase, is a chemotherapeutic agent for treating a variety of neoplasms Impairment of drug import into cells and increase in drug export from cells may render cells resistant to MTX MTX, when locally administered in a soluble form, is rapidly absorbed through capillaries into the circulatory system, which may also account for therapeutic failure in patients To retain MTX within tumor cells for longer duration and alter its pharmacokinetic behavior, we proposed a new formulation of MTX bound to the gold nanoparticle (AuNP) that serves as drug carriers In this study, we developed the MTX-AuNP conjugate and examined its cytotoxic effect in vitro and antitumor effect in vivo Spectroscopic examinations revealed that MTX can be directly bound onto AuNP via the carboxyl group (-COOH) to form the MTX-AuNP complex and kinetically released from the nanoparticles The accumulation of MTX is faster and higher in tumor cells treated with MTX-AuNP than that treated with free MTX Notably, MTX-AuNP shows higher cytotoxic effects on several tumor cell lines compared with an equal dose of free MTX This can be attributed to the "concentrated effect" of MTX-AuNP Administration of MTX-AuNP suppresses tumor growth in a mouse ascites model of Lewis lung carcinoma (LL2), whereas an equal dose of free MTX had no antitumor effect In conclusion, these results suggest that by combining nanomaterials with anticancer drugs MTX-AuNP may be more effective than free MTX for cancer treatment