Browsing by Issue Date, starting with "2012-02-02"

Now showing 1 - 20 of 37321

OPTICAL IMAGING SYSTEM
(2012-02-02)
Cheng Chu-Ming
;
Chern Jyh-Long
An optical imaging system including an imaging lens and a spatial light modulator is provided. The imaging system has an aperture stop position. The spatial light modulator is disposed at the aperture stop position of the imaging system to serve as a pupil of the imaging lens. The spatial light modulator is adapted to modulate the light transmission rate of the spatial light modulator to change an amplitude and a phase of a light intensity of the pupil.
A rule-based inter-session network coding scheme over IEEE 802.16(d) mesh CDS-mode networks
(2012-02-02)
Wang, Shie-Yuan
;
Lin, Chih-Che
;
Chang, Yu-Chi
;
資訊工程學系
;
Department of Computer Science
In the literature, an opportunistic inter-session network coding scheme needs to exchange extra control messages to maintain traffic flow states to operate. However, such a requirement increases the implementation complexity of a network coding scheme. In this paper, we propose a rule-based network coding scheme (RNC) that performs opportunistic intersession network coding using a stateless design. By exploiting this stateless design, the proposed coding scheme is easy to implement and deploy. In addition, in this paper based on RNC we study the hidden terminal problems between different coding structures. Such a problem may result in severe packet collisions in a network-coding-based network and thus degrade network coding performance. To alleviate this problem, based on RNC we propose a smart handshake procedure (called RNC-SHP) over the IEEE 802.16(d) mesh coordinated distributed scheduling (CDS) mode to reduce the number of hidden terminals between pairwise network coding structures. Our simulation results show that the proposed RNC schemes can greatly outperform the original routing-based scheme on end-to-end flow goodputs and packet delays. (C) 2011 Elsevier B.V. All rights reserved.
Interfacial Charge Carrier Dynamics of the Three-Component In2O3-TiO2-Pt Heterojunction System
(2012-02-02)
Chen, Yu-Chih
;
Pu, Ying-Chih
;
Hsu, Yung-Jung
;
材料科學與工程學系
;
Department of Materials Science and Engineering
The interfacial charge carrier dynamics of the three-component semiconductor semiconductor-metal heterojunction system were investigated and presented for the first time. The samples were prepared by selectively depositing Pt nanoparticles on the TiO2 surface of In2O3-decorated TiO2 nanobelts (In2O3-TiO2 nanobelts (NBs)) using the typical photodeposition method. For In2O3-TiO2 NBs, because of the difference in band structures between In2O3 and TiO2, the photoexcited electrons of In2O3 nanocrystals would preferentially transfer to TiO2 NBs to cause charge carrier separation. With the introduction of Pt on TiO2 surface, a fluent electron transfer from In2O3, through TiO2, and eventually to Pt was achieved, giving rise to the increasingly pronounced charge separation property for the as-prepared In2O3-TiO2-Pt NBs. The remarkable charge separation of the samples was revealed with the corresponding photocurrent measurements. Time-resolved photoluminescence spectra were measured to quantitatively analyze the electron transfer event between In2O3 and TiO2 for In2O3-TiO2 NBs and its dependence on Pt deposition. Upon the deposition of Pt, In2O3-TiO2 NBs showed an increased apparent electron-scavenging rate constant, fundamentally consistent with the result of their performance evaluation in photocatalysis. The current study provides a new paradigm for designing highly efficient three-component nanoheterojunction photocatalysts which can effectively produce chemical energy from absorbing light.
Protein Secondary Structure Imaging with Ultrabroadband Multiplex Coherent Anti-Stokes Raman Scattering (CARS) Microspectroscopy
(2012-02-02)
Bito, Kotatsu
;
Okuno, Masanari
;
Kano, Hideaki
;
Tokuhara, Shihomi
;
Naito, Satoru
Protein secondary structures in human hair have been studied with ultrabroadband multiplex coherent anti-Stokes Raman scattering (CARS) microspectroscopy. The CARS peak-shift mapping method has been developed and applied to hair samples with and without treatments by chemical reduction and mechanical extension. It clearly visualizes the treatment induced changes in protein secondary structures and their spatial distributions. Using the new imaging technique, we found a multilayered structure in the human hair cortex.
Level statistics and eigenfunctions of square torus billiards: Manifesting the transition from regular to chaotic behaviors
(2012-02-02)
Tuan, P. H.
;
Yu, Y. T.
;
Chiang, P. Y.
;
Liang, H. C.
;
Huang, K. F.
We thoroughly analyze the level statistics and eigenfunctions in concentric as well as nonconcentric square torus billiards. We confirm the characteristics of quantum and classical correspondence and the existence of scarred and superscarred modes in concentric square torus billiards. Furthermore, we not only verify that the transition from regular to chaotic behaviors can be manifested in nonconcentric square torus billiards, but also develop an analytical distribution to excellently fit the numerical level statistics. Finally, we intriguingly observe that numerous eigenstates commonly exhibit the wave patterns to be an ensemble of classical diamond trajectories, as the effective wavelengths are considerably shorter than the size of internal hole.
ENHANCEMENT-MODE HIGH-ELECTRON-MOBILITY TRANSISTOR AND THE MANUFACTURING METHOD THEREOF
(2012-02-02)
CHANG EDWARD YI
;
CHANG CHIA-HUA
;
LIN YUEH-CHIN
This invention discloses an enhancement-mode high-electron-mobility transistor and the manufacturing method thereof. The transistor comprises an epitaxial buffer layer on a substrate, a source and drain formed in the buffer layer, a PN-junction stack formed on the buffer layer and located between the source and drain, and a gate formed on the PN-junction stack, wherein the PN-junction stack is composed of alternating layers of a P-type semiconductor and an N-type semiconductor.
An adaptive hybrid dynamic power management algorithm for mobile devices
(2012-02-02)
Shih, Hung-Cheng
;
Wang, Kuochen
;
資訊工程學系
;
Department of Computer Science
We propose a novel power efficient adaptive hybrid dynamic power management (AH-DPM) algorithm. To adapt well to bursty request arrival patterns with self-similarity and a service provider (SP, i.e., hard disk or WLAN NIC, in this paper) with multiple inactive states, the proposed AH-DPM first derives the average idle time of the SP in the bursty (ON) period and non-bursty (OFF) period separately. Then, to achieve better power saving, we use the average idle time in the ON period to adjust the timeout value more precisely and use the average idle time in the OFF period to decide which inactive state the SP should be switched to. Experimental results based on real traces show that, for the hard disk, the average power consumption of the proposed AH-DPM is better than that of the Adaptive Timeout (ATO), Machine Learning (ML), Predictive, Static Timeout (STO), and Stochastic algorithms. In addition, the average response time of the proposed AH-DPM algorithm is still lower than that specified in a typical hard disk specification. As to the WLAN NIC, experimental results show that the average power consumption of the proposed AH-DPM is comparable to that of the Oracle (theoretically optimal), ATO, and Predictive algorithms, and is better than that of the ML, STO, and Stochastic algorithms. However, the average packet transmission delay of the proposed AH-DPM is better than that of the ATO and Predictive algorithms. Therefore, by providing a better tradeoff between average power consumption and average response time (or average packet transmission delay), the proposed AH-DPM algorithm is very feasible for extending the battery lifetime of ever increasing mobile devices that are equipped with hard disks and WLAN NICs. (C) 2011 Elsevier B.V. All rights reserved.
Method for producing indole derivative
(2012-02-02)
Chiu Hsien-Tai
The present invention provides a method for in vitro producing an indole derivative in a one-pot reaction. The method for producing a rhamnosylated indolocarbazole compound includes the steps of transforming a plasmid carrying a gene encoding N-glycosyltransferase into a bacterial strain; expressing the gene encoding N-glycosyltransferase in the bacterial strain; lysing the bacterial strain to obtain a crude enzyme extract; and adding TDP-glucose, an indolocarbazole aglycone and a metal ion in the crude enzyme extract for performing an enzymatic reaction to form the rhamnosylated indolocarbazole compound. Alternatively, the method for producing an indole-3-carboxaldehyde analog includes the steps of transforming a plasmid carrying a gene encoding NokA of Nocardiopsis sp. K-252 into a bacterial strain; expressing the gene encoding NokA in the bacterial strain; lysing the bacterial strain to obtain a crude enzyme extract; and adding an L-tryptophan analog for performing an enzymatic reaction to form the indole-3-carboxaldehyde analog.
High efficiency GaN-based light-emitting diodes with embedded air voids/SiO(2) nanomasks
(2012-02-03)
Chiu, Ching-Hsueh
;
Lin, Chien-Chung
;
Han, Hau-Vei
;
Liu, Che-Yu
;
Chen, Yan-Hao
In this paper, the high performance GaN-based light-emitting diodes (LEDs) with embedded microscale air voids and an SiO(2) nanomask by metal-organic chemical vapor deposition (MOCVD) were demonstrated. Microscale air voids and an SiO(2) nanomask were clearly observed at the interface between GaN nanorods (NRs) and the overgrown GaN layer by scanning electron microscopy (SEM). From the reflectance spectra we show strong reflectance differences due to the different refractive index gradient between the GaN grown on the nanotemplate and sapphire. It can increase the light extraction efficiency due to additional light scattering. The transmission electron microscopy (TEM) images show the threading dislocations were suppressed by nanoscale epitaxial lateral overgrowth (NELOG). The LEDs with embedded microscale air voids and an SiO(2) nanomask exhibit smaller reverse-bias current and large enhancement of the light output (65% at 20 mA) compared with conventional LEDs.
High efficiency GaN-based light-emitting diodes with embedded air voids/SiO2 nanomasks
(2012-02-03)
Chiu, Ching-Hsueh
;
Lin, Chien-Chung
;
Han, Hau-Vei
;
Liu, Che-Yu
;
Chen, Yan-Hao
In this paper, the high performance GaN-based light-emitting diodes (LEDs) with embedded microscale air voids and an SiO2 nanomask by metal-organic chemical vapor deposition (MOCVD) were demonstrated. Microscale air voids and an SiO2 nanomask were clearly observed at the interface between GaN nanorods (NRs) and the overgrown GaN layer by scanning electron microscopy (SEM). From the reflectance spectra we show strong reflectance differences due to the different refractive index gradient between the GaN grown on the nanotemplate and sapphire. It can increase the light extraction efficiency due to additional light scattering. The transmission electron microscopy (TEM) images show the threading dislocations were suppressed by nanoscale epitaxial lateral overgrowth (NELOG). The LEDs with embedded microscale air voids and an SiO2 nanomask exhibit smaller reverse-bias current and large enhancement of the light output (65% at 20 mA) compared with conventional LEDs.
交大e-News第111期
(2012-02-06)
Secretariat
;
國立交通大學秘書室
Phase structure of the Kerr-AdS black hole
(2012-02-06)
Tsai, Yu-Dai
;
Wu, X. N.
;
Yang, Yi
;
電子物理學系
;
Department of Electrophysics
We study the critical phenomena of Kerr-AdS black hole. Phase structures are observed at different temperatures, T-L, T-c1 and T-c2 with various features. We discuss the thermal stability considering the isothermal compressibility and how phase transitions related to each other. The asymptotic value of the angular momentum also has an implication on separating stable and unstable part. Near critical temperature T-c1, the order parameter is determined to calculate the critical exponents. All the critical exponents (alpha, beta, gamma, delta) = (0, 1/2, 1, 3) are identical to that of mean field systems. We plot the phase diagram near this critical point, and discuss the scaling symmetry of the free energy.
Electrically driven nanopyramid green light emitting diode
(2012-02-06)
Chang, S. -P.
;
Chen, Y. -C.
;
Huang, J. -K.
;
Cheng, Y. -J.
;
Chang, J. -R.
An electrically driven nanopyramid green light emitting diode (LED) was demonstrated. The nanopyramid arrays were fabricated from a GaN substrate by patterned nanopillar etch, pillar side wall passivation, and epitaxial regrowth. Multiple quantum wells were selectively grown on the facets of the nanopyramids. The fabricated LED emits green wavelength under electrical injection. The emission exhibits a less carrier density dependent wavelength shift and higher internal quantum efficiency as compared with a reference c-plane sample at the same wavelength. It shows a promising potential for using nanopyramid in high In content LED applications. (C) 2012 American Institute of Physics. [doi:10.1063/1.3681363]
Intruder detection system and method
(2012-02-07)
Song Kai-Tai
;
Lin Chia-Hao
;
Lin Chih-Sheng
;
Yang Su-Hen
This invention is an intruder detection system which integrates wireless sensor network and security robots. Multiple ZigBee wireless sensor modules installed in the environment can detect intruders and abnormal conditions with various sensors, and transmit alert to the monitoring center and security robot via the wireless mesh network. The robot can navigate in the environment autonomously and approach to a target place using its localization system. If any possible intruder is detected, the robot can approach to that location, and transmit images to the mobile devices of the securities and users, in order to determine the exact situation in real time.
Device for accurately measuring amplifier's open-loop gain with digital stimuli
(2012-02-07)
Hong Hao-Chiao
A device capable of receiving one or more digital stimulus signals and accurately measuring an open-loop gain of an amplifier comprises: a digital charge converter (DCC), a charge integrator, an A/D converter, a control logic circuit and an arithmetic logic unit (ALU). The DCC and the charge integrator are composed of a plurality of switches, one or more sampling capacitor, at least one integrating capacitor and an operational amplifier under test (OPAUT) with a single-ended output or differential-ended outputs. The DCC, the charge integrator, and the A/D converter are controlled by control signals generated by the logic control circuit and can be reconfigured as a first-order Sigma-Delta modulator capable of receiving at least one of the digital input stimulus signals. The ALU calculates the open-loop gain of the OPAUT with single-ended output or differential-ended outputs according to the digital stimulus signals and the digital output of the first-order Sigma-Delta modulator.
LIQUID CRYSTAL LENS AND MANUFACTURING METHOD THEREOF
(2012-02-09)
LIAO LIN-YAO
;
HUANG YI-PAI
;
LIN YU-MIN
;
SHIEH HAN-PING D.
The present invention discloses a liquid crystal lens and a manufacturing method thereof. At least one first electrode is disposed on a first substrate, a first alignment layer is disposed on the first electrode, a liquid crystal layer is disposed on the first alignment layer, a second alignment layer is disposed on the liquid crystal layer, an electric field uniformization layer is disposed on the second alignment layer, at least one second electrode and at least one third electrode are disposed on the electric field uniformization layer, and the second electrode is arranged around the third electrode. A second substrate is disposed on the second electrode and the third electrode. The third electrode which matches up with the second electrode produces an electric field gradient and the liquid crystal layer is affected uniformly by the electric field uniformization layer so as to achieve rapid focus purpose by the liquid crystal.
A T3 and T7 Recombinant Phage Acquires Efficient Adsorption and a Broader Host Range
(2012-02-09)
Lin, Tiao-Yin
;
Lo, Yi-Haw
;
Tseng, Pin-Wei
;
Chang, Shun-Fu
;
Lin, Yann-Tsyr
It is usually thought that bacteriophage T7 is female specific, while phage T3 can propagate on male and female Escherichia coli. We found that the growth patterns of phages T7M and T3 do not match the above characteristics, instead showing strain dependent male exclusion. Furthermore, a T3/7 hybrid phage exhibits a broader host range relative to that of T3, T7, as well as T7M, and is able to overcome the male exclusion. The T7M sequence closely resembles that of T3. T3/7 is essentially T3 based, but a DNA fragment containing part of the tail fiber gene 17 is replaced by the T7 sequence. T3 displays inferior adsorption to strains tested herein compared to T7. The T3 and T7 recombinant phage carries altered tail fibers and acquires better adsorption efficiency than T3. How phages T3 and T7 recombine was previously unclear. This study is the first to show that recombination can occur accurately within only 8 base-pair homology, where four-way junction structures are identified. Genomic recombination models based on endonuclease I cleavages at equivalent and nonequivalent sites followed by strand annealing are proposed. Retention of pseudo-palindromes can increase recombination frequency for reviving under stress.
FLEXIBLE MICRO-SYSTEM AND FABRICATION METHOD THEREOF
(2012-02-09)
CHAO TZU-YUAN
;
LIANG CHIA-WEI
;
CHENG YU-TING
A fabrication method for integrating chip(s) onto a flexible substrate in forming a flexible micro-system. The method includes a low-temperature flip-chip and a wafer-level fabrication process. Using the low-temperature flip-chip technique, the chip is bonded metallically onto the flexible substrate. To separate the flexible substrate from the substrate, etching is used to remove the sacrificial layer underneath the flexible substrate. The instant disclosure applies standardized micro-fabrication process for integrating chip(s) onto the flexible substrate. Without using special materials or fabrication procedures, the instant disclosure offers a cost-effective fabrication method for flexible micro-systems.
III-V METAL-OXIDE-SEMICONDUCTOR DEVICE
(2012-02-09)
CHANG Edward Yi
;
LIN Yueh-Chin
A barrier layer, hafnium oxide layer, between a III-V semiconductor layer and an lanthanum oxide layer is used to prevent interaction between the III-V semiconductor layer and the lanthanum oxide layer. Meanwhile, the high dielectric constant of the lanthanum oxide can be used to increase the capacitance of the semiconductor device.
VARIATION-TOLERANT WORD-LINE UNDER-DRIVE SCHEME FOR RANDOM ACCESS MEMORY
(2012-02-09)
Chuang Ching-Te
;
Lin Yi-Wei
;
Chen Chia-Cheng
;
Shih Wei-Chiang
A Random Access Memory (RAM) is provided. The RAM includes a plurality of word-line drivers, at least a first tracking transistor and a second tracking transistor. Each word-line driver has an input node receiving a decoding signal, a power node receiving an operation voltage and a driving node driving a word-line. In an embodiment, the first tracking transistor has two channel terminal nodes respectively coupled to the driving node of one of the word-line driver and a channel terminal node of the second tracking transistor; wherein the first tracking transistor has electronic characteristics tracking those of a driving transistor of word-line driver, and the second tracking transistor has electronic characteristics tracking those of pass-gate transistor(s) in each cell of the RAM.