Browsing by Issue Date, starting with "2009-02-11"

Now showing 1 - 20 of 51421

Different effects of probiotic species/strains on infections in preschool children: A double-blind, randomized, controlled study
(2009-02-11)
Lin, Jun-Song
;
Chiu, Yi-Han
;
Lin, Nien-Tsung
;
Chu, Chia-Hsiang
;
Huang, Kuo-Chin
Treatment and prevention of pediatric infectious diseases of three commercial probiotic products were evaluated by a double-blind, randomized, controlled trial. Test subjects under age 5,1062 in total, were distributed randomly into four groups. This investigation showed that L. casei rhamnosus can control bacterial, viral and respiratory infections; a multi-species probiotic reduced gastrointestinal disease significantly. Long-term consumption of L. rhamnosus T cell-1 decreased the incidence of bacterial infection. (C) 2008 Elsevier Ltd. All rights reserved.
Single-electron effects in non-overlapped multiple-gate silicon-on-insulator metal-oxide-semiconductor field-effect transistors
(2009-02-11)
Lee, W.
;
Su, P.
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper systematically presents controlled single-electron effects in multiple- gate silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistors (MOSFETs) with various gate lengths, fin widths, gate bias and temperature. Our study indicates that using the non-overlapped gate to source/drain structure as an approach to the single-electron transistor (SET) in MOSFETs is promising. Combining the advantage of gate control and the constriction of high source/drain resistances, single-electron effects are further enhanced using the multiple- gate architecture. From the presented results, downsizing multiple- gate SOI MOSFETs is needed for future room-temperature SET applications. Besides, the tunnel barriers and access resistances may need to be further optimized. Since the Coulomb blockade oscillation can be achieved in state-of-the-art complementary metal-oxide-semiconductor (CMOS) devices, it is beneficial to build SETs in low-power CMOS circuits for ultra-high-density purposes.
Highest Urgency First (HUF): A latency and modulation aware bandwidth allocation algorithm for WiMAX base stations
(2009-02-12)
Lin, Yi-Neng
;
Lin, Ying-Dar
;
Lai, Yuan-Cheng
;
Wu, Che-Wen
;
交大名義發表
The mobile WiMAX systems based on IEEE 802.16e-2005 provide high data rate for mobile wireless networks. However, the link quality is frequently unstable owing to mobility and air interference and therefore impacts the latency requirement of real-time applications. In the WiMAX standard, the modulation/coding scheme and the boundary of uplink/downlink sub-frames could be adjusted subject to channel quality and the traffic volume, respectively. This provides us a chance to design a MAC-layer uplink/downlink bandwidth allocation algorithm that is QoS/PHY-aware. This work takes into account the adaptive modulation and coding scheme (MCS), uplink and downlink traffic volume, and QoS parameters of all five defined service classes to design a bandwidth allocation algorithm that calculates the slot allocation in two phases. The first phase decides the boundary of uplink and downlink sub-frames by satisfying requests with pending latency violation and proportionating according to traffic volume, while the second phase allocates slots to mobile stations considering urgency, priority and fairness. Simulation results show our algorithm achieves zero latency violation and higher system throughput compared to existing non-QoS/PHY-aware or less-QOS/PHY-aware approaches. (C) 2008 Elsevier B.V. All rights reserved.
Increasing wide-area download throughputs on the roads by trunking multiple cellular channels over a vehicular ad hoc network
(2009-02-12)
Wang, S. Y.
;
Chou, C. L.
;
Lin, C. C.
;
資訊工程學系
;
Department of Computer Science
To obtain infotainment services (e.g., traffic, maps, accidents, weather, etc.) on the roads, vehicle drivers and back-seat passengers may want to use wide-area networks (e.g., GPRS) to download useful information from the Internet when needed. In this paper. we design and implement a scheme to increase GPRS download throughput for a vehicle user while he (she) is moving on the roads. This scheme integrates inter-vehicle communication with trunking mechanisms to achieve this goal. This scheme can be readily deployed for any real-world GPRS network or any 3G network without any support from the network operator. Our field trial results show that when this scheme is applied in a motorcade of four vehicles and all of the GPRS channel provided by each vehicle are used to download a file simultaneously, the download speed is 3.92 times faster than that achieved when only one GPRS channel is used. (C) 2008 Elsevier B.V. All rights reserved.
Thermally or Magnetically Induced Polarization Reversal in the Multiferroic CoCr2O4
(2009-02-13)
Choi, Y. J.
;
Okamoto, J.
;
Huang, D. J.
;
Chao, K. S.
;
Lin, H. J.
We report the unexpected evolution, with thermal and magnetic-field (H) variations, of the interrelation between the polarization P, magnetization M, and spiral wave vector Q in CoCr2O4, which has a ferrimagnetic conical-spiral magnetic order. For example, P suddenly jumps and changes its sign at the magnetic lock-in transition (T-L) with thermal variation, or with isothermal variation of H (without changing its direction) at T-L, which surprisingly occurs without change in spiral handedness (i.e., the sign of Q). The presence of multiple spiral sublattices may be behind this unusual behavior.
Thermally or Magnetically Induced Polarization Reversal in the Multiferroic CoCr(2)O(4)
(2009-02-13)
Choi, Y. J.
;
Okamoto, J.
;
Huang, D. J.
;
Chao, K. S.
;
Lin, H. J.
We report the unexpected evolution, with thermal and magnetic-field (H) variations, of the interrelation between the polarization P, magnetization M, and spiral wave vector Q in CoCr(2)O(4), which has a ferrimagnetic conical-spiral magnetic order. For example, P suddenly jumps and changes its sign at the magnetic lock-in transition (T(L)) with thermal variation, or with isothermal variation of H (without changing its direction) at T(L), which surprisingly occurs without change in spiral handedness (i.e., the sign of Q). The presence of multiple spiral sublattices may be behind this unusual behavior.
Quantitative Assessment of Hepatic Fat of Intact Liver Tissues with Coherent Anti-Stokes Raman Scattering Microscopy
(2009-02-15)
Wu, Yao-Ming
;
Chen, Hung-Che
;
Chang, Wei-Tien
;
Jhan, Jhen-Wei
;
Lin, Hung-Lung
A fatty liver might progress from being a benign fatty liver, to steatohepatitis, cirrhosis, or even hepatocellular carcinoma. The great prevalence and severe outcome have warranted much investigation of the pathology and the development of effective therapies, which involve animal studies requiring critical evaluation of the hepatic fatty change. Histological examination and wet chemical analysis of liver biopsy specimens are generally employed for this purpose despite numerous procedures being involved. Using coherent anti-Stokes Raman scattering (CARS) microscopy, we have demonstrated the specific imaging of fat droplets in intact liver tissues and extracted the hepatic fat content through image analysis while eliminating laborious procedures required by traditional histopathological. examination. The content of hepatic fat measured with CARS imaging was correlated strongly with that determined by biochemical analysis (R(2) = 0.89) over a pathologically significant range of the hepatic fat (from 2% to 20% of the total mass of tissue). Our work validates the quantitative assessment of fat in intact tissue through the use of CARS microscopy. When combined with the increasingly diverse animal models of diseases related to metabolic disorders of lipids, our approach is extensible to enable acquiring important insight into the genetic, environmental, and dietary factors affecting the uptake and accumulation of fat within tissues.
Numerical study on micro-reformer performance and local transport phenomena of the plate methanol steam micro-reformer
(2009-02-15)
Hsueh, Ching-Yi
;
Chu, Hsin-Sen
;
Yan, Wei-Mon
;
機械工程學系
;
Department of Mechanical Engineering
The objective of this work is to investigate the transport phenomena and performance of a plate steam methanol micro-reformer. Micro channels of various height and width ratios are numerically analyzed to understand their effects on the reactant gas transport characteristics and micro-reformer performance. In addition, influences of Reynolds number and geometric size of micro channel on methanol conversion of micro-reformer and gas transport phenomena are also explored. The predicted results demonstrated that better performance is noted for a micro channel reformer with lower aspect-ratio micro channel. This is due to the larger the chemical reaction surface area for a lower aspect-ratio channel reformer. It is also found that the methanol conversion decreases with increasing Reynolds number Re. The results also indicate that the smaller micro channel size experiences a better methanol conversion. This is due to the fact that a smaller micro channel has a much more uniform temperature distribution, which in turn, fuel utilization efficiency is improved for a smaller micro channel reformer. (C) 2008 Elsevier B.V. All rights reserved.
Ultrafast optical probes of polaron dynamics in La0.7Ca0.3MnO3 thin films
(2009-02-15)
Wu, K. H.
;
Hsu, T. Y.
;
Shih, H. C.
;
Chen, Y. J.
;
Luo, C. W.
In this work, we use ultrafast optical pump-optical probe spectroscopy to probe the polaron dynamics in La0.7Ca0.3MnO3 (LCMO) thin films. The temporal evolution in transient reflectivity change Delta R/R exhibits two relaxing components: a fast component with a time constant of subpicosecond and a slow component with time constant ranging from tens of picoseconds to hundreds of picoseconds. The amplitude of the fast component, though has been seldom discussed before, exhibits the similar temperature dependence with that of the resistivity and the neutron scattering intensity due to nanoscale correlated polarons. The results strongly suggest that the fast photoinduced reflectivity change may have been due to the photoexcitation and trapping process of correlated Jahn-Teller polarons in the paramagnetic and ferromagnetic phases and, thus, implies the presence of electronic inhomogeneity in LCMO manganites.
Using C-band erbium-doped fiber amplifier with two-ring scheme for broadly wavelength-tuning fiber ring laser
(2009-02-15)
Yeh, C. H.
;
Shih, F. Y.
;
Wen, S.
;
Chow, C. W.
;
Chi, S.
In this demonstration, we propose and experimentally investigate a broad and stable wavelength-tuning fiber laser employing a C-band erbium-doped fiber amplifier (EDFA) and coupled-ring cavity scheme. Based on the proposed laser scheme, the wavelength-tuning range can be tuned in S- to C-bands (from 1510.0 to 1562.0 nm) due to the properly control of cavity loss. In addition, the performances of side-mode suppression ratio (SMSR), optical signal to noise ratio (OSNR), and output power and wavelength are also discussed and analyzed over the wavelength-tuning range. (C) 2008 Elsevier B.V, All rights reserved.
Organic light-emitting devices based on solution-processible quinolato-complex supramolecules
(2009-02-15)
Cheng, Jung-An
;
Chen, Chin H.
;
Shieh, Han-Ping D.
;
光電工程學系
;
顯示科技研究所
This paper discusses a new type of supramolecular material tris{5-N-[3-(9H-carbazol-9-yl)propyl]-N-(4-methylphenyl)aminesulfonyl-8-hydroxyquinolato} aluminum(III), Al(SCarq)(3), which we synthesized using three 5-N-[3-(9H-carbazol-9-yl)propyl]-N-(4-methylphenyl)aminesulfonyl-8-hydroxyquinoline as bidentate ligands. The peak photoluminescence in the solid phase appears at 488 nm. In cyclic voltammetric measurement, two oxidation peaks, which were obtained at -5.6 and -5.9eV, correspond to HOMO sites of carbazoyl and aluminum quinolates, respectively. in the investigation of solid morphological thin film, the flat surface was investigated using an atomic force microscope. The root mean square (rms) and mean roughness (R(a)) were respectively measured to be 0.427 and 0.343 nm. For the fabrication of organic light-emitting devices (OLEDs) using spin-coating techniques, the turn-on voltage and maximum luminescence of the optimized electroluminescence device, glass/ITO (20 nm)/PEDOT: PSS (75 nm)/Al(SCarq)(3) (85 nm)/BCP (8 nm)/LiF (1 nm)/Al (200 nm), were respectively 9.6 V and 35.0 cd m(-2). Due to the electroplex formation between the carbazole (electron-donor) and the aluminum quinolates (electron-acceptor) moieties under an applied DC bias, the chromaticity of electroluminescence shifted to green-yellow with 1931 CIE(x,y) (0.40, 0.47). (C) 2008 Elsevier B.V. All rights reserved.
Functional analysis of the evolutionarily conserved cis-regulatory elements on the sox17 gene in zebrafish
(2009-02-15)
Chan, Tzu-Min
;
Chao, Chung-Hao
;
Wang, Horng-Dar
;
Yu, Yen-Ju
;
Yuh, Chiou-Hwa
The Sox17 is an important transcription factor for endodermal cells (Danio rerio). According to the predictions of the GRNs, based on perturbation experiments and literature search, the sox17 gene is engaged with two other regulatory genes, sox32 and pou5f1. Nodal signaling operated on several endoderm-specific transcription factors to determine the endoderm specification. In addition, endoderm specification requires the Fgf and Bmp signaling pathways to be repressed in the cells which will become endoderm. It is predicted that Nodal activates sox32 and works synergistically with Pou5f1 to activate sox17 Bmp represses the expression of sox17 on the ventral side and Fgf represses it on the dorsal side. The regulatory inputs of sox17 at the genomic sequence level are not known. Here, we have uncovered the relevant sox17 cis-regulatory elements, and examined the specific input predictions of the GRNs. We discovered three conserved modules, A, 13, and C, with a synergistic effect among them. We revealed that the Pou5f1-binding element on the B module and the Sox32-binding element on the C module work synergistically. Furthermore, an evolutionarily non-conserved R module exhibits a repressive effect on both the ventral and dorsal side. We have directly demonstrated the structural and functional relationships of the genomic code at this key node of the endoderm GRNs in zebrafish development. This information provides new insight into the complexity of endoderm formation and serves as a valuable resource for the establishment of a complete endoderm gene regulatory network. (c) 2008 Elsevier Inc. All rights reserved.
Long paths in hypercubes with conditional node-faults
(2009-02-15)
Kueng, Tz-Liang
;
Liang, Tyne
;
Hsu, Lih-Hsing
;
Tan, Jimmy J. M.
;
資訊工程學系
Let F be a set of f <= 2n - 5 faulty nodes in an n-cube Q(n) such that every node of Q(n) still has at least two fault-free neighbors. Then we show that Q(n) - F contains a path of length at least 2(n) - 2f - 1 (respectively, 2(n) - 2f - 2) between any two nodes of odd (respectively, even) distance. Since the n-cube is bipartite, the path of length 2(n) - 2f - 1 (or 2(n) - 2f - 2) turns out to be the longest if all faulty nodes belong to the same partite set. As a contribution, our study improves upon the previous result presented by [J.-S. Fu, Longest fault-free paths in hypercubes with vertex faults, Information Sciences 176 (2006) 759-771] where only n - 2 faulty nodes are considered. (c) 2008 Elsevier Inc. All rights reserved.
Study of Al-Ti/Si bi-layer as the recording media for write-once HD-DVD optical disks
(2009-02-15)
Mai, Hung-Chuan
;
Hsieh, Tsung-Eong
;
Jeng, Shiang-Yao
;
Chen, Chong-Ming
;
Wang, Jen-Long
Optimum structure for HD-DVD optical disks containing Al-Ti/Si bi-layer recording system was identified by reflectivity simulation and dynamic test of disk samples. For the disk sample with optimized structure, the maximum partial response signal-to-noise ratio (PRSNR) of 19.1 dB, minimum simulated bit error rate (sbER) of 1.7 X 10(-7) and modulation >0.6 were achieved at the writing power (P(W)) = 11.2 mW. Transmission electron microscopy (TEM) revealed that the polycrystalline granular clusters constitute the recording marks. Subsequent analyses evidenced that element mixing/alloy reactions occur in between Si and Al-Ti layers and the formation of Al(3.21)Si(0.47) crystalline phase is responsible for the signal recording in the disk samples. (C) 2008 Elsevier B.V. All rights reserved.
Ultrafast optical probes of polaron dynamics in La(0.7)Ca(0.3)MnO(3) thin films
(2009-02-15)
Wu, K. H.
;
Hsu, T. Y.
;
Shih, H. C.
;
Chen, Y. J.
;
Luo, C. W.
In this work, we use ultrafast optical pump-optical probe spectroscopy to probe the polaron dynamics in La(0.7)Ca(0.3)MnO(3) (LCMO) thin films. The temporal evolution in transient reflectivity change Delta R/R exhibits two relaxing components: a fast component with a time constant of subpicosecond and a slow component with time constant ranging from tens of picoseconds to hundreds of picoseconds. The amplitude of the fast component, though has been seldom discussed before, exhibits the similar temperature dependence with that of the resistivity and the neutron scattering intensity due to nanoscale correlated polarons. The results strongly suggest that the fast photoinduced reflectivity change may have been due to the photoexcitation and trapping process of correlated Jahn-Teller polarons in the paramagnetic and ferromagnetic phases and, thus, implies the presence of electronic inhomogeneity in LCMO manganites.
螢光材料與發光裝置
(2009-02-16)
陳登銘
;
周怡君
一種螢光材料,其化學通式如下:A(B1-mEum^2+)PO4;其中A係選自Li、Na、K所組成之族群至少其中之一;B係選自Ca、Sr、Ba所組成之族群至少其中之一;其中0.0001≦m≦0.8。
Observation and analysis of coherent optical waves emitted from large-Fresnel number degenerate cavities
(2009-02-16)
Lu, T. H.
;
Lin, Y. C.
;
Chen, Y. F.
;
Huang, K. F.
;
電子物理學系
We demonstrate that the coherent optical waves emitted from large-Fresnel-number degenerate cavities persistently display a sort of salient intensity variations. We use the representation of the coherent states to explore the origin of the salient intensity variations and find that these coherent laser waves arise from a quadrature superposition of two degenerate coherent states. With the analytical representation of the superposed coherent states, we verify that these coherent laser waves possess a large angular momentum per photon. (c) 2009 Optical Society of America
Organic light-emitting diodes using 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane as p-type dopant
(2009-02-16)
Mi, Bao Xiu
;
Gao, Zhi Qiang
;
Cheah, Kok Wai
;
Chen, Chin H.
;
友訊交大聯合研發中心
We demonstrate that 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane (F2-HCNQ) can serve as an excellent electrical doping material for hole transport materials with the highest occupied molecular orbital level as high as 5.4 eV, such as N,N(')-di(naphthalene-1-yl)-N,N(')-diphenyl-benzidine (NPB). With its relatively strong electron-accepting ability and high thermal stability, F2-HCNQ doped NPB organic light-emitting diode (OLED) showed improved power efficiency with low driving voltage. The tris(8-hydroxyquinoline)aluminum based OLED with F2-HCNQ doped NPB layer and Cs(2)O doped bathophenanthroline electron transport layer exhibits power efficiency of 3.6 lm/W with driving voltage of 3.2 V at 100 cd/m(2).
Investigation of Ni-based thermal bimaterial structure for sensor and actuator application
(2009-02-16)
Huang, Chia-Sheng
;
Cheng, Yu-Ting
;
Chung, Junwei
;
Hsu, Wensyang
;
機械工程學系
Thermal bimaterial structures made of Ni and Ni-diamond nanocomposite for sensor and actuator application are proposed, fabricated, and tested. Two deflection types of thermal bimaterial structures, including upward and downward bending types, can be easily fabricated by controlling electroplating sequence of Ni and Ni-diamond nanocomposite. According to thermal performance measurement, the tip deflection of upward and downward types can reach about 82.5 mu m and -22.5 mu m for a temperature change of 200 degrees C, respectively. In the condition, the thermomechanical sensitivity and Output force are 412.5 nm/K and 97.0 mu N for upward type thermal bimaterial structure: and -112.5 nm/K and -26.5 mu N for downward type one. Due to the low electroplating process temperature (similar to 50 degrees C) for both Ni-based layers, diminutive pre-deformation of as-fabricated structure and strong interlaminar bonding strength are verified by SEM and vibrational test. The resonant frequency of the structure remains unchanged after 10(9) cycles. (C) 2008 Elsevier B.V. All rights reserved.
於矽基板上形成三族氮化物半導體磊晶層的方法
(2009-02-16)
張俊彥
;
楊宗
;
張哲榮
;
辜瑞泰
;
沈詩國
本發明為一種於矽基板上形成三族氮化物半導體磊晶層的方法,首先以氫氟酸溶液去除矽基板氧化物,再以高溫去除氟離子及污染物,產生平坦及重構之矽表面。接著以低溫沉積鋁原子層於矽基板上。在適當條件下,利用低射頻功率、低溫梯度變化等單一步驟同時形成單晶氮化矽絕緣層及氮化鋁成核層。且在富含鎵的條件下,以高溫成長氮化鎵層。