Highly AC Voltage Fluctuation-Resistant LED Driver with Sinusoid-Like Reference

Ning Ning,Zhenxiao Tong,Dejun Yu,Shuangyi Wu,Wenbin Chen,Chunyi Feng 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.2

A novel converter-free AC LED driver that is highly resistant to the fluctuation of AC voltage is proposed in this study. By removing large passive components, such as the bulky capacitor and the large-value inductor, the integration of the driver circuit is enhanced while the driving current remains stable. The proposed circuit provides LED lamps with a driving current that can follow the sinusoid waveform to obtain a very high power factor (PF) and low total harmonic distortion (THD). The LED input current produced by this driving current is insensitive to fluctuations in the AC voltage. Users will thus not feel that LED lamps are flashing during the fluctuation. Experiment results indicate that the proposed system can obtain PF of 0.999 and THD as low as 3.3% for a five-string 6 W LED load under 220 V at 50 Hz.

Improvement of Interlaminar Fracture Toughness in Glass Fiber Reinforced Plastic Laminates with Inorganic Nanofiber Sheet Interleaf

Ning Wu,Jie Yang,Shanshan Zheng,Jing Wang,Li Chen 한국섬유공학회 2019 Fibers and polymers Vol.20 No.10

The present study developed a new type of nanofibrous structure-TiO2 nanofiber sheets (TNFS) to increase theinterlaminar fracture toughness of glass fiber reinforced polymer (GFRP) laminates. SEM was employed to characterize thenanofibers before and after calcination. In order to quantify TNFS, the thickness and the crevice area of TNFS were analyzed,the results showed that the thickness and the proportion of crevice area were increased with the increase of TNFS contents. Mode I and Mode II interlaminar fracture toughness were investigated for GFRP laminates toughened by different massfraction of TNFS. The highest Mode I fracture toughness value achieved by inserting 5 wt.% TNFS in the interleaf. GIc valuewas 74.35 % higher than those of base GFRP laminates. Meanwhile, with 6 wt.% addition of TNFS, the GFRP laminatesshowed the highest Mode II fracture toughness, which is 60.76 % higher than those of base GFRP laminates. Theimprovement mechanism of toughness was illustrated by the fracture surface analysis of TNFS interlayered laminates.

Synthesis of CNx nanocrystals and nanotubes on Co/Ni-covered substrate by nitrogen-atom-beam-assisted pulsed laser ablation

Ning Xu,Aimin Wu,Fuming Li,Hao Lin,Jiada Wu,Peinan Wang,Yuancheng Du,Zhifeng Ying 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.44 No.32

CNx nanocrystals and nanotubes were synthesized on Co/Ni-covered Si(100) wafers using a nitrogen-atom-beam-assisted pulsed laser ablation deposition method. Transimission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy showed that nanometer-sized CNx nanocrystals and nanotubes were contained in the as-deposited lms. The co-catalyzation by the cobalt and nickel in the synthesis process is considered to play an important role in the formation of CNx nanocrystals and nanotubes. The reasons for the formation of CNx nanocrystals and nanotubes have been analyzed.

Overcome energy loss of exciplex-sensitized fluorescence OLEDs with separating exciton generation and fluorescence emission zone

Ning ShuYa,Wu Yuan,Wu ChuanMing,Zhang YiFan,Luo MeiTing,Wang XinYe,Wang DongDong 한국물리학회 2022 Current Applied Physics Vol.39 No.-

TADF-sensitizing-fluorescence (TSF) strategy suffered a disturbing energy loss causing by the T1 states of fluorescence dopant (FD) due to its low T1-state energy and forbidden of radiative transition. In this manuscript, we used TCTA/PO-T2T planar heterojunction (PHJ) interface as exciton generation zone and adjacent PO-T2T layer doped with rubrene as fluorescence emission zone, achieved the maximum EQE and CE of 8.3% and 26.1 cd A-1, respectively for rubrene-based device. Our experiments show the necessary PO-T2T thickness doped with rubrene is 15 nm and thicker doping layer over 15 nm would destroy device efficiency. It was further found that the exciplex exciton begin to decay within the time of 4 nm diffusion distance in PO-T2T layer and most of exciplex excitons were restrained in TCTA/PO-T2T heterojunction interface in PHJ device. The about 1.1 eV barrier for hole injection from TCTA to PO-T2T and bad hole-transporting capability of PO-T2T made exciple exciton only generate on this interface. Thus, even if the rubrene doped PO-T2T layer is right after the TCTA layer, FD in PO-T2T layer are well separated to the exciplex excitons in TCTA/PO-T2T interface, overcoming T1 energy loss caused by FD. Our approach provides a beneficial path towards overcome energy loss causing by the T1 states of FD in TSF-OLEDs based on exciplex as TADF sensitizer.

Mobilizing Voluntary Organizations in Taiwanese Emergency Response: Citizen Engagement and Local Fire Branch Heads

Wu, Wei-Ning,Chang, Ssu-Ming,Collins, Brian K. World Association for Triple Helix and Future Stra 2015 Journal of Contemporary Eastern Asia Vol.14 No.2

This article assesses factors that affect the ability of local fire branch heads in Taiwan to mobilize volunteer organizations in local emergency responses. Data from a survey of local fire branch heads in Taiwan is analyzed by using an OLS model to test three hypotheses regarding the relationship between the dependent variable, perceived ability to mobilize volunteer organizations in emergency response, and three explanatory variables: organizational capacity, quality of communication, and the quality of citizen engagement ex-ante to emergency response. The model indicates a positive relationship between the ability to mobilize volunteer organizations in emergency response, the quality of communications, and the quality of citizen engagement in preparedness. The research suggests that local fire branch heads and volunteer organizations should begin the process of emergency response mobilization in the preparedness stage. The quality of the citizen engagement in preparedness stages should increase the ability of local fire branch managers to mobilize external resources in emergency response.

Cloning, Expression, and Characterization of Protease-resistant Xylanase from Streptomyces fradiae var. K11

( Ning Li ),( Pei Long Yang ),( Ya Ru Wang ),( Hui Ying Luo ),( Kun Meng ),( Ning Feng Wu ),( Yun Liu Fan ),( Bin Yao ) 한국미생물 · 생명공학회 2008 Journal of microbiology and biotechnology Vol.18 No.3

A Novel Image Change Detection Model and Optimization Algorithm based on Game Theory under the Bounded Rationality Conditions

Ning Wu,Harry Scott 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.4

In this paper, we propose novel image change detection model and optimization algorithm based on game theory under the bounded rationality conditions. In the field of remote sensing image application, change detection is of the same area is analyzed by two different periods of remote sensing images, testing to determine the region in a period of change information. To enhance the traditional change detection algorithms we modify the method as the follows. Firstly, we analyze the mathematical forms of the game theory as the co-evolution has the basic characteristics of game theory and the dynamic characteristics of co-evolution through continuous evolution and eventually reaches a stable equilibrium state because of the feature. Later, we discuss the novel mathematical optimization approaches for the change detection based on the proposed game theory prior. Then, we combine independent component analysis and the bounded rationality conditions to finalize the detection algorithm. The independent component analysis is a data processing method appeared in recent years which can be as an extension of PCA and it will be the data transform into each other on the direction of the independence with higher robustness. In the experiment part, we simulate the experiment with the other state-of-the-art algorithms. The result reflects that our algorithm outperforms under various conditions and enhances the detection accuracy from 95.8% to 97.9% which has made the new breakthrough.

Ammonia etched petroleum pitch-based porous carbon as efficient catalysts for CO2 electroreduction

Ning Hui,Guo Zhihao,Wang Wenhang,Wang Xiaoshan,Yang Zhongxue,Ma Zhengguang,Tian Yangming,Wu Chenghao,Hao Jian,Wu Mingbo 한국탄소학회 2022 Carbon Letters Vol.32 No.3

Electrochemical reduction of carbon dioxide to valuable chemicals is a promising way of storing renewable energy through electric-to-chemical energy conversion, while its large-scale application is in urgent need of cheap and high-performance catalysts. Herein, we invent a convenient method to synthesize N-doped porous carbon by ammonia etching the pyrolysis carbon of petroleum pitch. We found the ammonia etching treatment not only increase the pyridinic-N content, but also enlarge the specific surface area of the petroleum pitch-based porous carbon. As a cheap and easily available catalyst for carbon dioxide electroreduction, up to 82% of Faradaic efficiency towards carbon monoxide was obtained at − 0.9 V vs the reversible hydrogen electrode in 0.1 M KHCO3. After a long time electrocatalysis of more than 20 h, the Faradaic efficiency of carbon monoxide remains 80%, indicating the porous carbon as made have an ultra-high stability as catalyst for carbon dioxide reduction. Our work provides a new technology to economically prepare efficient electrocatalysts for carbon dioxide reduction.

Catalysts for Cross-sector Collaboration in Disaster Response

Wei-Ning Wu 위기관리 이론과 실천 2017 위기관리 이론과 실천 세미나발표논문집 Vol.2018 No.-

Cross-sector collaboration has been considered a practical approach for enhancing the capacity of local governments to deliver public services and respond wicked problems of catastrophic events. Taiwan is prone to various natural and man-made disasters, and many countries have learned greatly from the emergency management experiences of Taiwan. While much has been written about the importance and functions of collaboration, very few has examined systematically what factors determine the effective collaboration in emergency response among different municipalities or various public agencies from the perspectives of emergency agencies. This study identifies factors that impact the effectiveness of collaborating emergency services with other public agencies in the local level of Taiwan. Using survey data from local fire branch heads, this research demonstrates that the ability of local fire branch heads to mobilize resources in emergency management process and the quality of citizen engagement in emergency exercise would influence the effective cross-sector collaboration in emergency response with other local fire branches.

Mechanistic Analysis of Taxol-induced Multidrug Resistance in an Ovarian Cancer Cell Line

Wang, Ning-Ning,Zhao, Li-Jun,Wu, Li-Nan,He, Ming-Feng,Qu, Jun-Wei,Zhao, Yi-Bing,Zhao, Wan-Zhou,Li, Jie-Shou,Wang, Jin-Hua Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Objectives: To establish a taxol-resistant cell line of human ovarian carcinoma (A2780/Taxol) and investigate its biological features. Methods: The drug-resistant cell line (A2780/Taxol) was established by continuous stepwise selection with increasing concentrations of Taxol. Cell morphology was assessed by microscopy and growth curves were generated with in vitro and in vivo tumor xenograft models. With rhodamine123 (Rh123) assays, cell cycle distribution and the apoptotic rate were analyzed by flow cytometry (FCM). Drug resistance-related and signal associated proteins, including P-gp, MRPs, caveolin-1, PKC-${\alpha}$, Akt, ERK1/2, were detected by Western blotting. Results: A2780/Taxol cells were established with stable resistance to taxol. The drug resistance index (RI) was 430.7. Cross-resistance to other drugs was also shown, but there was no significant change to radioresistance. Compared with parental cells, A2780/Taxol cells were significantly heteromorphous, with a significant delay in population doubling time and reduced uptake of Rh123 (p<0.01). In vivo, tumor take by A2780 cells was 80%, and tumor volume increased gradually. In contrast, with A2780/Taxol cells in xenograft models there was no tumor development. FCM analysis revealed that A2780/Taxol cells had a higher percentage of G0/G1 and lower S phase, but no changes of G2 phase and the apoptosis rate. Expression of P-gp, MRP1, MRP2, BCRP, LRP, caveolin-1, PKC-${\alpha}$, Phospho-ERK1/2 and Phospho-JNK protein was significantly up-regulated, while Akt and p38 MARK protein expression was not changed in A2780/Taxol cells. Conclusion: The A2780/Taxol cell line is an ideal model to investigate the mechanism of muti-drug resistance related to overexpression of drug-resistance associated proteins and activation of the PKC-${\alpha}/ERK$ (JNK) signaling pathway.