Browsing by Author "Chen, Yi-Fan"

Now showing 1 - 16 of 16

A Computational Model of the Relationship Between Musical Rhythm and Heart Rhythm
(2009)
Wang, Hui-Min
;
Lin, Shih-Hsiang
;
Huang, Yu-Chieh
;
Chen, I-Cheng
;
Chou, Lei-Chun
Heart rate variability (HRV) is a measure of variation in the heart rate. Over the last 25 years, HRV analysis has became utilized more often as a non-invasive research and clinical tool for indirectly investigating both cardiac and autonomic nervous system (ANS) functions in health and disease. In our experiment, 22 healthy subjects and four testing rhythm patterns are studied. How the three musical-rhythmic characteristics of tempo, complexity and drum sample affect the performance of HRV is discussed and a computational model with four factors is proposed. This relationship can help us to improve our life and health by music.
Anchoring Energy Enhancement for Plasma Alignment Technology
(2009)
Hsu, Chih-Yi
;
Lee, Tse-Hsien
;
Chen, Huang-Ming Philip
;
Kuo, Hui-Chien J.
;
Chen, Yi-Fan
The oxygen plasma post-treatment was adopted for alignment preparation in Ar plasma alignment process. The light leakage at the dark slate was suppressed by the new treatment. The NEXAFS data suggested that the out of plane carbonyl groups have been regenerated under oxygen plasma post-treatment. The polar anchoring energy was two times increased comparing to the Ar treated PI. The cell's EO properties by new plasma treatment were comparable to the rubbed PI surface.
Anti-site defect effect on the electronic structure of a Bi2Te3 topological insulator
(2018-01-01)
Chuang, Pei-Yu
;
Su, Shu-Hsuan
;
Chong, Cheong-Wei
;
Chen, Yi-Fan
;
Chou, Yu-Heng
Tuning the Fermi level (EF) in Bi2Te3 topological-insulator (TI) films is demonstrated on controlling the temperature of growth with molecular-beam epitaxy (MBE). Angle-resolved photoemission spectra (ARPES) reveal that EF of Bi2Te3 thin films shifts systematically with the growth temperature (Tg). The key role that a Bi-on-Te(1) (BiTe1) antisite defect plays in the electronic structure is identified through extended X-ray-absorption fine-structure (EXAFS) spectra at the Bi L-3-edge. Calculations of electronic structure support the results of fitting the EXAFS, indicating that the variation of EF is due to the formation and suppression of BiTe1 that is tunable with the growth temperature. Our findings provide not only insight into the correlation between the defect structure and electronic properties but also a simple route to control the intrinsic topological surface states, which could be useful for applications in TIbased advanced electronic and spintronic devices.
Critical voltage reduction by alignment layer modification in Pi-cells
(2007)
Wu, Wei-Ching
;
Chen, Yi-Fan
;
Chen, Szu-Fen
;
Chen, Huang-Ming Philip
;
光電工程學系
A new approach which can effectively lower the critical voltage (Vcr) of pi cell has been realized in this study. New structure of pi r cell can increase the control range of driving voltage, which makes the gray scale manipulation near Vcr more stable without loosing the fast response property.
Design and fabrication of a polyimide-based microelectrode array: Application in neural recording and repeatable electrolytic lesion in rat brain
(2009-08-30)
Chen, You-Yin
;
Lai, Hsin-Yi
;
Lin, Sheng-Huang
;
Cho, Chien-Wen
;
Chao, Wen-Hung
The design and testing of a new microelectrode array, the NCTU (National Chiao Tung University) probe, was presented. Evaluation results showed it has good biocompatibility, high signal-to-noise ratio (SNR: the root mean square of background noise to the average peak-to-peak amplitude of spikes) during chronic neural recordings, and high reusability for electrolytic lesions. The probe was a flexible, polyimide-based microelectrode array with a long shaft (14.9 mm in length) and 16 electrodes (5 mu m-thick and 16 mu m in radius); its performance in chronic in vivo recordings was examined in rodents. To improve the precision of implantation, a metallic, impact-resistant layer was sandwiched between the polyimide layers to strengthen the probe. The three-dimensional (3D) structure of electrodes fabricated by electroplating produced rough textures that increased the effective surface area. The in vitro impedance of electrodes on the NCTU probe was 2.4 +/- 0.52 M Omega at 1 kHz. In addition, post-surgical neural recordings of implanted NCTU probes were conducted for up to 40 days in awake, normally behaving rats. The electrodes on the NCTU probe functioned well and had a high SNR (range: 4-5) with reliable in vivo impedance (<0.7 M Omega). The electrodes were also robust enough to functionally record events, even after the anodal current (30 mu A, 10 s) was repeatedly applied for 60 times. With good biocompatibility, high and stable SNR for chronic recording, and high tolerance for electrolytic lesion, the NCTU probe would serve as a useful device in future neuroscience research. (C) 2009 Elsevier B.V. All rights reserved.
Diode-pumped passively mode-locked 1342 nm Nd:YVO(4) laser with an AlGaInAs quantum-well saturable absorber
(2009-08-01)
Huang, S. C.
;
Cheng, H. L.
;
Chen, Yi-Fan
;
Su, K. W.
;
Chen, Y. F.
We demonstrate what we believe to be the first use of AlGaInAs quantum wells (QWs) as a saturable absorber for a diode-pumped passively mode locked Nd:YVO(4) laser at 1342 nm. The QWs are grown on a Fedoped InP substrate that is transparent at lasing wavelength. At an incident pump power of 13.5 W an average output power of 1.05 W with a continuous mode-locked pulse duration of 26.4 ps at a repetition rate of 152 MHz was generated. (C) 2009 Optical Society of America
Diode-pumped passively mode-locked 1342 nm Nd:YVO4 laser with an AlGaInAs quantum-well saturable absorber
(2009-08-01)
Huang, S. C.
;
Cheng, H. L.
;
Chen, Yi-Fan
;
Su, K. W.
;
Chen, Y. F.
We demonstrate what we believe to be the first use of AlGaInAs quantum wells (QWs) as a saturable absorber for a diode-pumped passively mode locked Nd:YVO4 laser at 1342 nm. The QWs are grown on a Fedoped InP substrate that is transparent at lasing wavelength. At an incident pump power of 13.5 W an average output power of 1.05 W with a continuous mode-locked pulse duration of 26.4 ps at a repetition rate of 152 MHz was generated. (C) 2009 Optical Society of America
Efficient high-peak-power AlGaInAs eye-safe wavelength disk laser with optical in-well pumping
(2009-07-06)
Chang, H. L.
;
Huang, S. C.
;
Chen, Yi-Fan
;
Su, K. W.
;
Chen, Y. F.
We have demonstrated an efficient high-peak-power AlGaInAs eye-safe wavelength disk laser at 1555 nm. The quantum defect and the thermal load are significantly reduced by pumping the quantum well directly. The overall conversion efficiency is enhanced over three times compared with the barrier pumping method. With a pump peak power of 3.7 kW, an output peak power of 0.52 kW is generated at a pulse repetition rate of 20 kHz. (C) 2009 Optical Society of America
Laser-Assisted Nanowetting: Selective Fabrication of Polymer/Gold Nanorod Arrays Using Anodic Aluminum Oxide Templates
(1970-01-01)
He, Hung-Chieh
;
Yan, Ai-Ling
;
Karapala, Vamsi Krishna
;
Wang, Shun-Fa
;
Shen, Ming-Hui
1D polymer nanomaterials have attracted significant interest in recent years because of their unique properties and promising applications in various fields. It is, however, still a challenge to fabricate polymer nanoarrays with desired sizes and controlled morphologies. Here, an unprecedented approach, the laser-assisted nanowetting (LAN) method, to selectively fabricate polymer nanoarrays is presented. Polystyrene (PS) is blended with gold nanorods (AuNRs), which are used to absorb the energy from the laser. After the blend films are brought in contact with AAO templates, the AuNRs at regions shone by the laser beams absorb the energy and heat the surrounding polymer chains, resulting in the formation of PS/AuNRs arrays in selected areas. This work paves a new research direction for developing template-based polymer nanomaterials.
Low-temperature study of lasing characteristics for 1.3-mu m AlGaInAs quantum-well laser pumped by an actively Q-switched Nd:YAG laser
(2010)
Su, K. W.
;
Chen, Yi-Fan
;
Huang, S. C.
;
Li, A.
;
Liu, S. C.
We report a low-temperature 1.3 mu m AlGaInAs quantum-well laser pumped by a 1.06 mu m active Q-switched laser quenched by a low-temperature vacuum system. An average power of 330mW is achieved at temperature as low as 233K compared to the average power of 50mW obtained at room-temperature without cooling device both at pumping repetition rate of 30 kHz. And the average rate of gain peak shift was found to be 0.47 nm/K between 293-133 K.
Modeling Team Performance: The Moderating Role of Passion
(2016-02-01)
Lin, Chieh-Peng
;
Chen, Yi-Fan
;
經營管理研究所
;
Institute of Business and Management
Drawing on social identity theory and conflict theory, this study develops a research model that explains the development of team performance. In the model, team performance is indirectly related to authentic leadership and empathy via the full mediation of team identity and relationship conflict. Meanwhile, the positive relationship between team identity and team performance and the negative relationship between relationship conflict and team performance are hypothetically moderated by passion. Empirical testing of this model, by investigating team personnel from high-tech firms, confirms the integrative applicability of social identity theory and conflict theory for improving team performance. Last, the managerial implications and limitations of this study based on its empirical findings are provided.
On the largest eigenvalues of bipartite graphs which are nearly complete
(2010-01-15)
Chen, Yi-Fan
;
Fu, Hung-Lin
;
Kim, In-Jae
;
Stehr, Eryn
;
Watts, Brendon
For positive integers p, q, r, s and t satisfying rt <= p and st <= q, let G(p, q; r, s; t) be the bipartite graph with partite sets {u(1), ..., u(p)} and {v(1), ..., v(q)} such that u(i) and v(j) are not adjacent if and only if there exists a positive integer k with 1 <= k <= t such that (k - 1)r + 1 <= i <= kr and (k - 1)s + 1 <= j <= ks. In this paper we study the largest eigenvalues of bipartite graphs which are nearly complete. We first compute the largest eigenvalue (and all other eigenvalues) of G(p, q: r, s: t), and then list nearly complete bipartite graphs according to the magnitudes of their largest eigenvalues. These results give an affirmative answer to [1, Conjecture 1.2] when the number of edges of a bipartite graph with partite sets U and V, having vertical bar U vertical bar = p and vertical bar V vertical bar = q for p <= q, is pq - 2. Furthermore, we refine [1, Conjecture 1.2] for the case when the number of edges is at least pq - p + 1. (C) 2009 Elsevier Inc. All rights reserved.
PEGylation Site-Dependent Structural Heterogeneity Study of MonoPEGylated Human Parathyroid Hormone Fragment hPTH(1-34)
(2014-09-30)
Liu, Chih-Ying
;
Li, Xin
;
Chen, Wen-Yih
;
Chang, Li-Chiao
;
Chen, Yi-Fan
The structures of C- and N-terminally monoPEGylated human parathyroid hormone fragment hPTH(1-34) as well as their unmodified counterparts, poly(ethylene glycol) (PEG) and hPTH(1-34), have been studied by small-angle neutron scattering (SANS). The scattering results show that free hPTH(1-34) in 100 mM phosphate buffer (pH 7.4) aggregates into clusters. After conjugation with PEG, the PEG-peptide conjugates self-assemble into a supramolecular core-shell structure with a cylindrical shape. The PEG chains form a shell around the hPTH(1-34) core to shield hPTH(1-34) from the solvent. The detailed structural information on the self-assembled structures is extracted from SANS using a model of the cylindrical core with a shell of Gaussian chains attached to the core surface. On the basis of the data, because of the charge-dipole interactions between the conjugated PEG chain and the peptide, the conjugated PEG chain forms a more collapsed conformation compared to free PEG. Moreover, the size of the self-assembled structures formed by the C-terminally monoPEGylated hPTH(1-34) is about 3 times larger than that of the N-terminally monoPEGylated hPTH(1-34). The different aggregation numbers of the self-assembled structures, triggered by different PEGylation sites, are reported. These size discrepancies because of different PEGylation sites could potentially affect the pharmacokinetics of the hPTH(1-34) drug.
Performance enhancement of sub-nanosecond diode-pumped passively Q-switched Yb:YAG microchip laser with diamond surface cooling
(2012-09-24)
Zhuang, W. Z.
;
Chen, Yi-Fan
;
Su, K. W.
;
Huang, K. F.
;
Chen, Y. F.
We experimentally confirm that diamond surface cooling can significantly enhance the output performance of a sub-nanosecond diode-end-pumped passively Q-switched Yb:YAG laser. It is found that the pulse energy obtained with diamond cooling is approximately 1.5 times greater than that obtained without diamond cooling, where a Cr4+:YAG absorber with the initial transmission of 84% is employed. Furthermore, the standard deviation of the pulse amplitude peak-to-peak fluctuation is found to be approximately 3 times lower than that measured without diamond cooling. Under a pump power of 3.9 W, the passively Q-switched Yb: YAG laser can generate a pulse train of 3.3 kHz repetition rate with a pulse energy of 287 mu J and with a pulse width of 650 ps. (C)2012 Optical Society of America
Plasma beam alignment technique for OCB mode liquid crystal display
(2007)
Chou, Hong-Chieh
;
Wu, Wei-Qing
;
Chen, Yi-Fan
;
Chen, Huang-Ming Philip
;
Lee, Chin-Yang
Plasma beam alignment technique for OCB mode was first adopted in this study. Different exposure time of OCB cells were fabricated with sheet-like accelerated Ar+ plasma generated from anode layer thruster (ALT). Fast response time (3.3 ms) was revealed and has the potential for OCB mode LCD to replace conventional rubbing process.
Reproducible and Bendable SERS Substrates with Tailored Wettability Using Block Copolymers and Anodic Aluminum Oxide Templates
(1970-01-01)
Lin, Yu-Liang
;
Karapala, Vamsi Krishna
;
Shen, Ming-Hui
;
Chen, Yi-Fan
;
He, Hung-Chieh
Surface properties are essential for substrates exhibiting high sensitivity in surface-enhanced Raman scattering (SERS) applications. In this work, novel SERS hybrid substrates using polystyrene-block-poly(methyl methacrylate) and anodic aluminum oxide templates is presented. The hybrid substrates not only possess hierarchical porous nanostructures but also exhibit superhydrophilic surface properties with the water contact angle approximate to 0 degrees. Such surfaces play an important role in providing uniform enhanced intensities over large areas (relative standard deviation approximate to 10%); moreover, these substrates are found to be highly sensitive (limit of detection approximate to 10(-12) m for rhodamine 6G (R6G)). The results show that the hybrid SERS substrates can achieve the simultaneous detection of multicomponent mixtures of different target molecules, such as R6G, crystal violet, and methylene blue. Furthermore, the bending experiments show that about 70% of the SERS intensities are maintained after bending from approximate to 30 degrees to 150 degrees.