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Chen W.T.,National Taiwan University | Chen C.J.,National Taiwan University | Wu P.C.,National Taiwan University | Sun S.,National Taiwan University | And 9 more authors.
Optics Express | Year: 2011

We report the first three-dimensional photonic metamaterial, an array of erected U-shape plasmonic gold meta-molecules, that exhibits a profound response to the magnetic field of light incident normal to the array. The metamaterial was fabricated using a double exposure e-beam lithographic process. It was investigated by optical measurements and finite-element simulations, and showed that the magnetic field solely depends on the plasmonic resonance mode showing either enhanced in the centre of the erected U-shape meta-molecule (16 times enhancement) or enhanced around two prongs of erected U-shape meta-molecule (4 times enhancement). © 2011 Optical Society of America.

Lin K.-M.,National Chiao Tung University | Hu M.-H.,National Chiao Tung University | Hung C.-T.,National Chiao Tung University | Wu J.-S.,National Chiao Tung University | And 3 more authors.
Computer Physics Communications | Year: 2012

Development of a hybrid numerical algorithm which couples weakly with the gas flow model (GFM) and the plasma fluid model (PFM) for simulating an atmospheric-pressure plasma jet (APPJ) and its acceleration by two approaches is presented. The weak coupling between gas flow and discharge is introduced by transferring between the results obtained from the steady-state solution of the GFM and cycle-averaged solution of the PFM respectively. Approaches of reducing the overall runtime include parallel computing of the GFM and the PFM solvers, and employing a temporal multi-scale method (TMSM) for PFM. Parallel computing of both solvers is realized using the domain decomposition method with the message passing interface (MPI) on distributed-memory machines. The TMSM considers only chemical reactions by ignoring the transport terms when integrating temporally the continuity equations of heavy species at each time step, and then the transport terms are restored only at an interval of time marching steps. The total reduction of runtime is 47% by applying the TMSM to the APPJ example presented in this study. Application of the proposed hybrid algorithm is demonstrated by simulating a parallel-plate helium APPJ impinging onto a substrate, which the cycle-averaged properties of the 200th cycle are presented. The distribution patterns of species densities are strongly correlated by the background gas flow pattern, which shows that consideration of gas flow in APPJ simulations is critical. © 2012 Elsevier B.V. All rights reserved.

Lai Y.-A.,National Cheng Kung University | Chen C.-N.,National Cheng Kung University | Chang Y.-H.,National Cheng Kung University | Wang Y.-H.,National Cheng Kung University | Wang Y.-H.,National Applied Research Laboratory
IEEE Microwave and Wireless Components Letters | Year: 2011

A novel planar dual 180° hybrid using multicoupled line technology is presented. The proposed structure adopts the power divider and two types of multicoupled lines to improve the return loss and isolation at the balance outputs of a traditional dual Marchand balun. The proposed hybrid allows output ports to be located arbitrarily, which eliminates the complex layout while the dual 180° hybrid applied to balanced radio frequency circuits. This hybrid is designed and implemented on an FR-4 printed circuit board at 2.4 GHz. The measured return loss is lower than - 19.7 dB, and the isolation between the two-pair balanced output ports are lower than - 28.2 dB from 2.2 to 2.7 GHz. The measured insertion loss and phase imbalance between the two-pair balanced output ports are lower than 8.7 dB and 4.5°, respectively, at the operating frequency of 2.12.9 GHz. © 2010 IEEE.

Lo L.Y.I.-S.,Central Taiwan University of Science and Technology | Lin S.-W.,National Applied Research Laboratory
Proc. - 6th Intl. Conference on Advanced Information Management and Service, IMS2010, with ICMIA2010 - 2nd International Conference on Data Mining and Intelligent Information Technology Applications | Year: 2010

Word-of-mouth (WOM) is recognized as an effective communication channel among consumers. The Internet provides consumers with richer sales information and more online associates than do brick-and-mortar stores but makes complex the assessment of the shaping of electronic WOM (eWOM) intention. Thus, our research questions are as follows. (1) Do price presentation and sales restriction strategies, which are used by brick-and-mortar stores, affect eWOM intention through deal evaluation in online settings? (2) Is the effect of price presentation on deal evaluation moderated by the properties of social networks? (3) Is the effect of sales restrictions on deal evaluation moderated by the properties of social networks? (4) Is the effect of deal evaluation on eWOM intention moderated by the properties of social networks? To answer these questions, we will explore the research model from the perspective of eWOM senders in a laboratory setting. This experiment will allow us to control for variables that are difficult to control in the field and examine the mechanisms behind eWOM intention. The preliminary validation of the research model will increase its explanatory power in the field and allow us examine the value of eWOM associated with eWOM intention in the future research.

Hsieh W.-H.,National Chiao Tung University | Hsieh W.-H.,St. Jude Medical | Chang C.-F.,National Applied Research Laboratory | Kao M.-S.,National Chiao Tung University
IEEE Transactions on Aerospace and Electronic Systems | Year: 2014

In this paper, a novel method termed the phase coherence acquisition (PCA) is proposed for pseudorandom (PN) sequence acquisition. By employing complex phasors, the PCA requires only complex additions in the order of N , the length of the sequence, whereas the conventional method using fast Fourier transform (FFT) requires complex multiplications and additions both in the order of N log2N . To combat noise, the input and local sequences are partitioned and mapped into complex phasors in PCA. The phase differences between pairs of input and local phasors are used for acquisition; thus, complex multiplications are avoided. For more noise-robustness capability, the multilayer PCA is developed to extract the code phase step-by-step. The significant reduction of computational loads makes the PCA an attractive method, especially when the sequence length of N is extremely large, which becomes intractable for the FFT-based acquisition. © 2014 IEEE.

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