Browsing by Issue Date, starting with "2011-02-18"

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Spatial and temporal EEG dynamics of dual-task driving performance
(2011-02-18)
Lin, Chin-Teng
;
Chen, Shi-An
;
Chiu, Tien-Ting
;
Lin, Hong-Zhang
;
Ko, Li-Wei
Background: Driver distraction is a significant cause of traffic accidents. The aim of this study is to investigate Electroencephalography (EEG) dynamics in relation to distraction during driving. To study human cognition under a specific driving task, simulated real driving using virtual reality (VR)-based simulation and designed dual-task events are built, which include unexpected car deviations and mathematics questions. Methods: We designed five cases with different stimulus onset asynchrony (SOA) to investigate the distraction effects between the deviations and equations. The EEG channel signals are first converted into separated brain sources by independent component analysis (ICA). Then, event-related spectral perturbation (ERSP) changes of the EEG power spectrum are used to evaluate brain dynamics in time-frequency domains. Results: Power increases in the theta and beta bands are observed in relation with distraction effects in the frontal cortex. In the motor area, alpha and beta power suppressions are also observed. All of the above results are consistently observed across 15 subjects. Additionally, further analysis demonstrates that response time and multiple cortical EEG power both changed significantly with different SOA. Conclusions: This study suggests that theta power increases in the frontal area is related to driver distraction and represents the strength of distraction in real-life situations.
道路角度估測系統及其方法
(2011-02-21)
陳宗麟
;
許齡元
一種道路角度估測系統及其方法，其中，該系統包含：一感測模組及一估測計算模組。該感測模組裝設於一移動體上以量測出一組包括一懸掛系統位移量、一側向加速度、一縱向速度及一橫擺角之系統量測參數。而該估測計算模組包括一擴增卡曼濾波器且具有實施一儲存記憶褪去法及一描述移動體動態方程式之功能，並用來接收該組系統量測參數、一組包括一假設傾斜角及一假設坡度角之待估參數，及一組包括一操縱角度、一油門力道值及一煞車力道值之操作參數的輸入，並產生一道路角度資訊。藉此，僅利用較少感測設備達成同時且精確的道路角度變化估測。
交大e-News第088期
(2011-02-21)
Secretariat
;
國立交通大學秘書室
Synthesis and Physicochemical Characterization of Carbon Backbone Modified [Gd(TTDA)(H2O)](2-) Derivatives
(2011-02-21)
Chang, Ya-Hui
;
Chen, Chiao-Yun
;
Singh, Gyan
;
Chen, Hsing-Yin
;
Liu, Gin-Chung
The present study was designed to exploit optimum lipophilicity and high water-exchange rate (k(ex)) on low molecular weight Gd(III) complexs to generate high bound relaxivity (r(1)(b)), upon binding to the lipophilic site of human serum albumin (HSA). Two new carbon backbone modified TTDA (3,6,10-tri(carboxymethyl)-3,6,10-triazadodecanedioic acid) derivatives, CB-TTDA and Bz-CB-TTDA, were synthesized. The complexes [Gd(CB-TTDA)(H2O)](2-) and [Gd(Bz-CB-TTDA)(H2O)](2-) both display high stability constant (log K-GdL = 20.28 and 20.09, respectively). Furthermore, CB-TTDA (log K-(Gd/Zn) = 4.22) and Bz-CB-TTDA (log K-(Gd/Zn) = 4.12) exhibit superior selectivity of Gd(III) against Zn(II) than those of TTDA (log K-(Gd/Zn) = 2.93), EPTPA-bz-NO2 (log K-(Gd/Zn) = 3.19), and DTPA (log K-(Gd/Zn) = 3.76). However, the stability constant values of [Gd(CB-TTDA)(H2O)](2-) and [Gd(Bz-CB-TTDA)(H2O)](2-) are lower than that of MS-325. The parameters that affect proton relaxivity have been determined in a combined variable temperature O-17 NMR and NMRD study. The water exchange rates are comparable for the two complexes, 232 x 10(6) s(-1) for [Gd(CB-TTDA)(H2O)](2-) and 271 x 10(6) s(-1) for [Gd(Bz-CB-TTDA)(H2O)](2-). They are higher than those of [Gd(TTDA)(H2O)](2-) (146 x 10(6) s(-1)), [Gd(DTPA)(H2O)](2-) (4.1 x 10(6) s(-1)), and MS-325 (6.1 x 10(6) s(-1)). Elevated stability and water exchange rate indicate that the presence of cyclobutyl on the carbon backbone imparts rigidity and steric constraint to [Gd(CB-TTDA)(H2O)](2-) and [Gd(Bz-CB-TTDA)(H2O)](2-). In addition, the major objective for selecting the cyclobutyl is to tune the lipophilicity of [Gd(Bz-CB-TTDA)(H2O)](2-). The binding affinity of [Gd(Bz-CB-TTDA)(H2O)](2-) to HSA was evaluated by ultrafiltration study across a membrane with a 30 kDa MW cutoff, and the first three stepwise binding constants were determined by fitting the data to a stoichiometric model. The binding association constants (K-A) for [Gd(CB-TTDA)(H2O)](2-) and [Gd(Bz-CB-TTDA)(H2O)](2-) are 1.1 x 10(2) and 1.5 x 10(3), respectively. Although the K-A value for [Gd(Bz-CB-TTDA)(H2O)](2-) is lower than that of MS-325 (K-A = 3.0 x 10(4)), the r(1)(b) value, r(1)(b) = 66.7 mM(-1) s(-1) for [Gd(Bz-CB-TTDA)(H2O)](2-), is significantly higher than that of MS-325 (r(1)(b) = 47.0 mM(-1) s(-1)). As measured by the Zn(II) transmetalation process, the kinetic stabilities of [Gd(CB-TTDA)(H2O)](2-), [Gd(Bz-CB-TTDA)(H2O)](2-), and [Gd(DTPA)(H2O)](2-) are similar and are significantly higher than that of [Gd(DTPA-BMA)(H2O)](2-) High thermodynamic and kinetic stability and optimized lipophilicity of [Gd(CB-TTDA)(H2O)](2-) make it a favorable blood pool contrast agent for MRI.
Synthesis and Physicochemical Characterization of Carbon Backbone Modified [Gd(TTDA)(H(2)O)](2-) Derivatives
(2011-02-21)
Chang, Ya-Hui
;
Chen, Chiao-Yun
;
Singh, Gyan
;
Chen, Hsing-Yin
;
Liu, Gin-Chung
The present study was designed to exploit optimum lipophilicity and high water-exchange rate (k(ex)) on low molecular weight Gd(III) complexs to generate high bound relaxivity (r(1)(b)), upon binding to the lipophilic site of human serum albumin (HSA). Two new carbon backbone modified TTDA (3,6,10-tri(carboxymethyl)-3,6,10-triazadodecanedioic acid) derivatives, CB-TTDA and Bz-CB-TTDA, were synthesized. The complexes [Gd(CB-TTDA)(H(2)O)](2-) and [Gd(Bz-CB-TTDA)(H(2)O)](2-) both display high stability constant (log K(GdL) = 20.28 and 20.09, respectively). Furthermore, CB-TTDA (log K((Gd/Zn)) = 4.22) and Bz-CB-TTDA (log K((Gd/Zn)) = 4.12) exhibit superior selectivity of Gd(III) against Zn(II) than those of TTDA (log K((Gd/Zn)) = 2.93), EPTPA-bz-NO(2) (log K((Gd/Zn)) = 3.19), and DTPA (log K((Gd/Zn)) = 3.76). However, the stability constant values of [Gd(CB-TTDA)(H(2)O)](2-) and [Gd(Bz-CB-TTDA)(H(2)O)](2-) are lower than that of MS-325. The parameters that affect proton relaxivity have been determined in a combined variable temperature (17)O NMR and NMRD study. The water exchange rates are comparable for the two complexes, 232 x 10(6) s(-1) for [Gd(CB-TTDA)(H(2)O)](2-) and 271 x 10(6) s(-1) for [Gd(Bz-CB-TTDA)(H(2)O)](2-). They are higher than those of [Gd(TTDA)(H(2)O)](2-) (146 x 10(6) s(-1)), [Gd(DTPA)(H(2)O)](2-) (4.1 x 10(6) s(-1)), and MS-325 (6.1 x 10(6) s(-1)). Elevated stability and water exchange rate indicate that the presence of cyclobutyl on the carbon backbone imparts rigidity and steric constraint to [Gd(CB-TTDA)(H(2)O)](2-) and [Gd(Bz-CB-TTDA)(H(2)O)](2-). In addition, the major objective for selecting the cyclobutyl is to tune the lipophilicity of [Gd(Bz-CB-TTDA)(H(2)O)](2-). The binding affinity of [Gd(Bz-CB-TTDA)(H(2)O)](2-) to HSA was evaluated by ultrafiltration study across a membrane with a 30 kDa MW cutoff, and the first three stepwise binding constants were determined by fitting the data to a stoichiometric model. The binding association constants (K(A)) for [Gd(CB-TTDA)(H(2)O)](2-) and [Gd(Bz-CB-TTDA)(H(2)O)](2-) are 1.1 x 10(2) and 1.5 x 10(3), respectively. Although the K(A) value for [Gd(Bz-CB-TTDA)(H(2)O)](2-) is lower than that of MS-325 (K(A) = 3.0 x 10(4)), the r(1)(b) value, r(1)(b) = 66.7 mM(-1) s(-1) for [Gd(Bz-CB-TTDA)(H(2)O)](2-), is significantly higher than that of MS-325 (r(1)(b) = 47.0 mM(-1) s(-1)). As measured by the Zn(II) transmetalation process, the kinetic stabilities of [Gd(CB-TTDA)(H(2)O)](2-), [Gd(Bz-CB-TTDA)(H(2)O)](2-), and [Gd(DTPA)(H(2)O)](2-) are similar and are significantly higher than that of [Gd(DTPA-BMA)(H(2)O)](2-) High thermodynamic and kinetic stability and optimized lipophilicity of [Gd(CB-TTDA)(H(2)O)](2-) make it a favorable blood pool contrast agent for MRI.
An electrically tunable focusing liquid crystal lens with a built-in planar polymeric lens
(2011-02-21)
Lin, Hung-Chun
;
Lin, Yi-Hsin
;
光電工程學系
;
Department of Photonics
An electrically tunable focusing liquid crystal (LC) lens with a built-in planar polymeric lens with a short focal length (similar to 4.41 to 8.82 cm) is demonstrated. The focal length of the LC lens is contributed by two parts: one is the LC layer and the other is planar polymeric layer. In the image system, the object can be continuously imaged by the LC lens when the object is at the objective distance from 360 to 17 cm as the voltage is switched from 0 to 35 V(rms). The image performance is also demonstrated. The applications are cell phones, and cameras (C) 2011 American Institute of Physics. [doi: 10.1063/1.3559622]
Direct measurement of versatile surface plasmon polaritons excited by split polarization
(2011-02-21)
Lan, Tzu-Hsiang
;
Ho, Chen-Yeh
;
Tien, Chung-Hao
;
光電工程學系
;
顯示科技研究所
We report on the concept, generation, and observation of versatile excited surface plasmon polariton (SPP) patterns via focused split polarization. Unlike the conventional subwavelength features such as holes array, grating, or other protrusion to satisfy the phase matching condition for SPP excitation, we utilized a structured focus to form either counterpropagating interference or a multiple casting plasmonic pattern by means of the arrangement of split polarization and corresponding focus position. The characteristics of the near-field SPP image are in close agreement with the finite-difference time-domain calculation and confirm its feasibility associated with SPP excitations in many areas. (C) 2011 American Institute of Physics. [doi:10.1063/1.3552673]
Transport current carrying superconducting film with periodic pinning array under strong magnetic fields
(2011-02-22)
Rosenstein, B.
;
Shapiro, I.
;
Shapiro, B. Ya.
;
電子物理學系
;
Department of Electrophysics
The transport current carrying dissipative (flux flow) and dissipationless (pinned) vortex configurations and their dynamics are investigated numerically in the framework of the time-dependent Ginzburg-Landau approach. Assuming that magnetic induction is nearly uniform, the model is generalized to include strong inhomogeneous electric fields. Hexagonal array nanoholes of the size of coherence length and density n(pin) was considered for various filling factors [defined as f = B/(Phi(0)n(pin))]. The vortex depinning is closely associated with the appearance of a strongly varying electric field. For the matching field, f = 1, the critical current is maximal and the transition to the resistive state occurs as a coherent depinning of the entire vortex lattice. For a system with interstitial vortices, f > 1, the mechanism of depinning depends on the current direction with respect to the pinning array. There are two qualitatively distinct geometries: the obstacle and channel geometries. In the obstacle geometry lines of interstitial vortices are blocked by strongly pinned vortices, while in the channel geometry the lines move unimpeded confined in channels. It was found that slightly above the critical current the trajectories of the moving vortices are not straight, but rather acquire a snakelike shape enveloping the system of pins. In contrast to f = 1, the transition to a resistive state is not coherent and is going through formation of "snakelike" vortex trajectories. The critical current in the obstacle geometry is significantly larger than in the channel one.
Sensing device
(2011-02-22)
Cheng
;
Pi-Ying
;
Wong
;
Kian-Poh
The present invention discloses a sensing device, wherein a hemispherical container containing a liquid dielectric, and the hemispherical container has more than two pairs of electrodes, and the liquid dielectric can trigger the conduction states of the electrodes. A corrosion-resistant material envelops the container. A precision valve is arranged in the container and used to adjust the level of the liquid dielectric and the sensitivity of the sensing device. A buffer necking part is also arranged in the container and used to prevent from non-expected vibration-induced contact between the electrodes and the liquid dielectric. A leakage-proof detection device envelops the hemispherical container, the liquid dielectric, the precision valve, and the buffer necking part and functions to prevent from the leakage of the liquid dielectric. Thus, the present invention can provide an adjustable multi-directional tilt-sensing device for level control.
ON-CHIP INDUCTOR STRUCTURE AND METHOD FOR MANUFACTURING THE SAME
(2011-02-24)
CHAO, TZU-YUAN
;
HSU, MING-CHIEH
;
CHENG, YU-TING
;
CHEN, CHIH
;
LIU, CHIEN-MIN
The present invention relates to a an on-chip inductor structure and a method for manufacturing the same. The an on-chip inductor structure according to the present invention comprises a substrate, a porous layer, a plurality of conductors, and an inductor. The porous layer is disposed on the substrate and has a plurality of voids; each of the plurality of conductors is disposed in the plurality of voids, respectively; and the inductor is disposed on the porous layer. Because the plurality of conductors is used as the core of the inductor, the inductance is increased effectively and the area of the an on-chip inductor is reduced. Besides the manufacturing method according to the present invention is simple and compatible with the current CMOS process, the manufacturing cost can be lowered.
SURFACE-EMITTING LASER DEVICE
(2011-02-24)
Chen, Shih-Wei
;
Lu, Tien-Chang
;
Kuo, Hao-Chung
;
Wang, Shing-Chung
A surface-emitting laser device includes: a substrate; a low refractive index layer with a refractive index nL and disposed on the substrate; a light emitting layered structure with a refractive index nH, where nH>nL, the light emitting layered structure being formed on the low refractive index layer and having first and second semiconductor layers and a multi-quantum well (MQW) disposed between the first and second semiconductor layers and capable of generating photons having a wavelength λ0; and a two-dimensional photonic crystal (2DPC) formed in the light emitting layered structure and having optical nanostructures arranged into a periodic pattern with a lattice constant a. The nanostructures extend from the first semiconductor layer through the MQW. The 2DPC has a normalized frequency, which is defined as a/λ0, ranging from 0.25 to 0.70.
Sodium chloride on Si(100) grown by molecular beam epitaxy
(2011-02-25)
Chung, Jen-Yang
;
Li, Hong-Dao
;
Chang, Wan-Heng
;
Leung, T. C.
;
Lin, Deng-Sung
Sodium chloride (NaCl) films were grown on an Si(100)-(2 x 1) surface at near room temperature by molecular beam epitaxy (MBE). The atomic structure and growth mode of the prototypical ionic materials on the covalent bonded semiconductor surface is examined by synchrotron core-level x-ray photoemission spectrum (XPS), scanning tunneling microscopy (STM), and first-principles calculations. The Si 2p, Na 2p, and Cl 2p core-level spectra together indicate that adsorbed NaCl molecules at submonolayer coverage [i.e., below 0.4 monolayer (ML)] partially dissociate and form Si-Cl species, and that a significant portion of the dangling-bond characteristics of the clean surface remains after NaCl deposition of 1.8 MLs. The deposition of 0.65-ML NaCl forms a partially ordered adlayer, which includes NaCl networks, Si-Cl species, adsorbed Na species, and isolated dangling bonds. The STM results revealed that the first adlayer consists of bright protrusions which form small c(2 x 4) and (2 x 2) patches. Above 0.65 ML, the two-dimensional NaCl double-layer growth proceeds on top of the first adlayer.
Ultra fast self-corrected polarization modulated ellipsometer
(2011-02-28)
Tsai, Hsiu-Ming
;
Chen, Leng-Chun
;
Chao, Yu-Faye
;
光電工程學系
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Department of Photonics
A high speed self-corrected algorithm is proposed for the polarization modulated ellipsometry (PME). In this post-flight analysis, we prove that a set of optimized ellipsometric parameters (EPs) can be obtained by using the intensities at 4 specific temporal phases. The correction ability to its initial phase by this technique has been demonstrated through a twisted nematic liquid crystals (TN-LC) cell under the driving of a square wave. Furthermore, the optimal modulation amplitude in obtaining the accurate and precise set of EPs will be discussed in this work. (C) 2011 Elsevier B.V. All rights reserved.
Characterization of write-once blu-ray disk containing Cu-Al/Si recording layer using transmission electron microscopy
(2011-02-28)
Mai, Hung-Chuan
;
Hsieh, Tsung-Eong
;
Jeng, Shiang-Yao
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Microstructure change in write-once blu-ray disk containing Cu-Al/Si recording layer was investigated by transmission electron microscopy. Nanoscale crystallites were found to comprise of the Cu-Al/Si recording layer before and after signal writing and the energy dispersive spectroscopy revealed insignificant composition fluctuation in disk sample. Analytical results indicated the signal properties of disk samples are correlated with a moderate improvement of crystallinity and the formation of Cu and Si solid-solution phases due to element mixing in mark area, rather than the formation of Cu(3)Si silicide and recrystallization of recording layer as reported by previous studies. (C) 2011 American Institute of Physics. [doi:10.1063/1.3560053]
Characteristics of exciton-polaritons in ZnO-based hybrid microcavities
(2011-02-28)
Chen, Jun-Rong
;
Lu, Tien-Chang
;
Wu, Yung-Chi
;
Lin, Shiang-Chi
;
Hsieh, Wen-Feng
Wide bandgap semiconductors are promising materials for the development of polariton-based optoelectronic devices operating at room temperature (RT). We report the characteristics of ZnO-based microcavities (MCs) in the strong coupling regime at RT with a vacuum Rabi splitting of 72 meV. The impact of scattering states of excitons on polariton dispersion is investigated. Only the lower polariton branches (LPBs) can be clearly observed in ZnO MCs since the large vacuum Rabi splitting pushes the upper polariton branches (UPBs) into the scattering absorption states in the ZnO bulk active region. In addition, we systematically investigate the polariton relaxation bottleneck in bulk ZnO-based MCs. Angle-resolved photoluminescence measurements are performed from 100 to 300 K for different cavity-exciton detunings. A clear polariton relaxation bottleneck is observed at low temperature and large negative cavity detuning conditions. The bottleneck is suppressed with increasing temperature and decreasing detuning, due to more efficient phonon-assisted relaxation and a longer radiative lifetime of the polaritons. (C) 2011 Optical Society of America
Impact of static and dynamic stress on threshold voltage instability in high-k/metal gate n-channel metal-oxide-semiconductor field-effect transistors
(2011-02-28)
Dai, Chih-Hao
;
Chang, Ting-Chang
;
Chu, Ann-Kuo
;
Kuo, Yuan-Jui
;
Lo, Wen-Hung
This letter investigates the impact of static and dynamic stress on threshold voltage (V(th)) instability in ultrathin n-channel metal-oxide-semiconductor field-effect transistors with hafnium-based gate stacks. Experimental results indicate V(th) shift under dynamic stress is more serious than that under static stress due to charge trapping within the high-k dielectric. Capacitance-voltage techniques demonstrated that electron trapping under dynamic stress was located in the high-k dielectric near the source/drain overlap region rather than throughout the overall dielectric layer. This implies in real circuit operation, the phenomenon of electrons trapped in high-k near the source/drain overlap is the main issue affecting V(th) instability. (C) 2011 American Institute of Physics. [doi:10.1063/1.3560463]
An electrically tunable optical zoom system using two composite liquid crystal lenses with a large zoom ratio
(2011-02-28)
Lin, Yi-Hsin
;
Chen, Ming-Syuan
;
Lin, Hung-Chun
;
光電工程學系
;
Department of Photonics
An electrically tunable-focusing optical zoom system using two composite LC lenses with a large zoom ratio is demonstrated. The optical principle is investigated. To enhance the electrically tunable focusing range of the negative lens power of the LC lens for a large zoom ratio, we adopted two composite LC lenses. Each composite LC lens consists of a sub-LC lens and a planar polymeric lens. The zoom ratio of the optical zooming system reaches similar to 7.9:1 and the object can be zoomed in or zoomed out continuously at the objective distance of infinity to 10 cm. The potential applications are cell phones, cameras, telescope and pico projectors. (C) 2011 Optical Society of America
Phase-modulated ellipsometry for probing the temperature-induced phase transition in ruthenium-doped lead zinc niobate-lead titanate single crystal
(2011-02-28)
Chuang, Chun-I
;
Marinova, Vera
;
Lin, Shiuan-Huei
;
Chao, Yu-Faye
;
電子物理學系
Phase-modulated ellipsometry was applied to measure changes in the refractive index of pure and ruthenium (Ru)-doped 0.9Pb (Zn(1/3)Nb(2/3))O(3)(PZN)-0.1 PbTiO(3) (PT) during the heating process in real time. Both samples were heated from room temperature to 200 degrees C in a thermally insulated chamber. In both samples, the phase transitions were observed to change from tetragonal to cubic. The temperature region at which the phase transition (Curie region) of Ru-doped 0.9PZN-0.1PT occurred not only broadened but also shifted to a lower temperature. The refractive indices were extremely stable in this region, meaning that Ru-doped 0.9PZN-0.117 is a more favorable medium for the fabrication of optical memories. (C) 2011 Elsevier B.V. All rights reserved.
Design and analysis of radial imaging capsule endoscope (RICE) system
(2011-02-28)
Ou-Yang, Mang
;
Jeng, Wei-De
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this study, a radial imaging capsule endoscope (RICE) system is designed, which differs from a conventional front imaging capsule endoscope (FICE) system. To observe the wrinkled intima of the intestine, which spreads without folding around the circumference of the capsule when a capsule endoscope with a diameter that slightly exceeds that of the intestine passes through it, the RICE uses a cone mirror, a radial window shell, and a focus optical module that comprise the radial imaging system. This concept was demonstrated in a packaged optical simulator. The RICE optical model also has been established and verified by many simulations and experiments. In minimizing the sagittal and tangential aberrations, the optical module of the RICE has achieved an F-number of 4.2, a viewing angle of 65.08 degrees, and an RMS radius of the 4th to 6th fields of less than 17 um. A comparison of these characteristics with those of the focus optical module that is used in FICE lenses reveals that the spot size is 50% larger for each field, and the modulation transfer function (MTF) is remarkably improved from 7% to 36% at 100 lp/mm on the 5th field of the sagittal plane. (C) 2011 Optical Society of America
Anticorrelation between the splitting and polarization of the exciton fine structure in single self-assembled InAs/GaAs quantum dots
(2011-02-28)
Lin, Chia-Hsien
;
You, Wen-Ting
;
Chou, Hsiang-Yu
;
Cheng, Shun-Jen
;
Lin, Sheng-Di
We report on a systematic correlation between the fine-structure splitting and polarization anisotropy of excitons in InAs/GaAs quantum dots, but with an unexpected reversal in order of the polarization eigenaxes. Such an anticorrelation is explained by a large valence-band-mixing induced splitting due to the shape and strain anisotropies. The strength and phase of valence band mixing are also found to play an important role in the tuning of fine structure splitting using an in-plane magnetic field.