Browsing by Issue Date, starting with "2014-01-25"

Now showing 1 - 20 of 27751

New free-air and Bouguer gravity fields of Taiwan from multiple platforms and sensors
(2014-01-25)
Hwang, Cheinway
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Hsu, Hung-Jui
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Chang, Emmy T. Y.
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Featherstone, W. E.
;
Tenzer, Robert
We construct 1' x 1' grids of free-air and Bouguer gravity anomalies around Taiwan with well-defined error estimates for quality assessment. The grids are compiled from land, airborne and shipbome gravity measurements, augmented with altimeter gravity at sea. Three sets of relative land gravity measurements are network-adjusted and outlier-edited, yielding accuracies of 0.03-0.09 mGal. Three airborne gravity sets are collected at altitudes 5156 and 1620 m with accuracies of 2.57-2.79 mGal. Seven offshore shipborne gravity campaigns around Taiwan and its offshore islands yield shallow-water gravity values with 0.88-2.35 mGal accuracies. All data points are registered with GPS-derived geodetic coordinates at cm-dm accuracies, allowing for precise gravity reductions and computing gravity disturbances. The various datasets are combined by the band-limited least-squares collocation in a one-step procedure. In the eastern mountainous (or offshore) region, Bouguer anomalies and density contrasts without considering the oceanic (or land) topographic contribution are underestimated. The new grids show unprecedented tectonic features that can revise earlier results, and can be used in a broad range of applications. (C) 2013 Elsevier B.V. All rights reserved.
Forming-free bipolar resistive switching in nonstoichiometric ceria films
(2014-01-27)
Ismail, Muhammad
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Huang, Chun-Yang
;
Panda, Debashis
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Hung, Chung-Jung
;
Tsai, Tsung-Ling
The mechanism of forming-free bipolar resistive switching in a Zr/CeO (x) /Pt device was investigated. High-resolution transmission electron microscopy and energy-dispersive spectroscopy analysis indicated the formation of a ZrO (y) layer at the Zr/CeO (x) interface. X-ray diffraction studies of CeO (x) films revealed that they consist of nano-polycrystals embedded in a disordered lattice. The observed resistive switching was suggested to be linked with the formation and rupture of conductive filaments constituted by oxygen vacancies in the CeO (x) film and in the nonstoichiometric ZrO (y) interfacial layer. X-ray photoelectron spectroscopy study confirmed the presence of oxygen vacancies in both of the said regions. In the low-resistance ON state, the electrical conduction was found to be of ohmic nature, while the high-resistance OFF state was governed by trap-controlled space charge-limited mechanism. The stable resistive switching behavior and long retention times with an acceptable resistance ratio enable the device for its application in future nonvolatile resistive random access memory (RRAM).
Polarized emission of quantum dots in microcavity and anisotropic Purcell factors
(2014-01-27)
Lee, Yi-Shan
;
Lin, Sheng-Di
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
We study the polarization properties of quantum dot (QD) emission coupled with the fundamental cavity modes. A rotation of polarization axis and a change of polarization degree are observed as the coupling is varied. To explain this observation, we derive an analytical model considering the polarization misalignment between QD dipole and cavity mode field. Our model also provides a new approach to extract the anisotropic Purcell factors by analyzing the polarization of detected quantum dot emission coupled to the cavity mode, which paves the way to develop high-efficiency polarized single photon sources. (C) 2014 Optical Society of America
Resonant modes of 12-fold symmetric defect free photonic quasicrystal
(2014-01-27)
Chen, Minfeng
;
Li, Yun-Jing
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Cheng, Yuh-Jen
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Chang, Yai-Chung
;
Chang, Chun-Yen
This work investigates the resonant modes of a 12-fold symmetric defect free photonic quasicrystal (PQC) nanorod array using finite difference time domain (FDTD) simulation. Localized modes can exist in PQC without introducing defects due to the lack of translational symmetry. The resonant modes of the unit cell PQC and the one time expanded PQC from unit cell are systematically examined. The resonant spectrum is that of a single rod modified by the interaction among PQC nanorods. The mode confinement is contributed by guided resonance and destructive interference scattering. The self-scaling similarity of resonant spectrum and mode profile are also investigated. (C) 2014 Optical Society of America
Method for carry estimation of reduced-width multipliers
(2014-01-28)
Liao Yen-Chin
;
Chang Hsie-Chia
A low-error reduced-width multiplier is provided by the present invention. The multiplier can dynamically compensate the truncation error. The compensation value is derived by the dependencies among the multiplier partial products, and thus, can be analyzed according to the multiplication type and the multiplier input statistics.
Elliptic flow from thermal photons with magnetic field in holography
(2014-01-28)
Mueller, Berndt
;
Wu, Shang-Yu
;
Yang, Di-Lun
;
物理研究所
;
丘成桐中心
We compute the elliptic flow v(2) of thermal photons in a strongly coupled plasma with constant magnetic field via gauge/gravity duality. The D3/D7 embedding is applied to generate the contributions from massive quarks. By considering the cases in 2 + 1 flavor super Yang-Mills analogous to the photon production in quark gluon plasma, we obtain the thermal photon v(2), which is qualitatively consistent with the direct photon v(2) measured at the relativistic heavy ion collider at intermediate energy. However, due to the simplified setup, the thermal photon v(2) in our model should be regarded as the upper bound for the v(2) generated by solely a magnetic field in the strongly coupled scenario.
Communication: Three-dimensional model for phonon confinement in small particles: Quantitative bandshape analysis of size-dependent Raman spectra of nanodiamonds
(2014-01-28)
Korepanov, Vitaly I.
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Witek, Henryk
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Okajima, Hajime
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Osawa, Eiji
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Hamaguchi, Hiro-O
Raman spectroscopy of nano-scale materials is facing a challenge of developing a physically sound quantitative approach for the phonon confinement effect, which profoundly affects the phonon Raman band shapes of small particles. We have developed a new approach based on 3-dimensional phonon dispersion functions. It analyzes the Raman band shapes quantitatively in terms of the particle size distributions. To test the model, we have successfully obtained good fits of the observed phonon Raman spectra of diamond nanoparticles in the size range from 1 to 100 nm. (C) 2014 AIP Publishing LLC.
Coupling between Protein Conformation and Local Unfolding Highlights the Role of Disorder in Protein Function and Suggests a New Target for Tuberculosis Treatment
(2014-01-28)
Morrell, Thomas E.
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Rafalska-Metcalf, Ilona U.
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Chu, Jhih-Wei
;
Yang, Haw
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交大名義發表
Live Cell Imaging with Rab-Gtpases Elucidates Intracellular Pathways of RGD and iRGD Tagged Cationic Lipid-DNA Nanoparticles
(2014-01-28)
Majzoub, Ramsey N.
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Ewert, Kai K.
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Kotamraju, Venkata R.
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Chan, Chia-Ling
;
Liang, Keng S.
A Single-Step Digital Nucleic Acid Amplification Platform by Digital Plasma Separation on a Chip
(2014-01-28)
Yeh, Erh-Chia
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Yeh, Chi-Cheng Fu
;
Hu, Lucy
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Huang, Meng-Yao
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Lee, Luke P.
Kinetic Ising Model Study of Protein Aggregation
(2014-01-28)
Tsai, Min-Yeh
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Yuan, Jian-Min
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Lin, Sheng-Hsien
;
應用化學系
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Department of Applied Chemistry
Method for Making Porous Materials
(2014-01-30)
LEU Jih-Perng
;
CHEN Yu-Han
A method for manufacturing a porous material is disclosed, which comprises the following steps: providing a substrate; coating the substrate with a precursor solution to form a precursor film, wherein the precursor solution includes a precursor compound, a porogen, and a solvent, and the porogen is modified by a surface modification to have an absolute surface electric potential of >25 mV; and treating the precursor film with a thermal curing profile to remove the porogen and form a porous material.
METHOD FOR MANUFACTURING A NOZZLE PLATE CONTAINING MULTIPLE MICRO-ORIFICES FOR CASCADE IMPACTOR
(2014-01-30)
TSAI Chuen-Jinn
;
CHEN Sheng-Chieh
;
CHEN Hong-Dar
A nozzle plate containing multiple micro-orifices for the cascade impactor and a method for manufacturing the same are disclosed. The nozzle plate is formed by a series of semiconductor processes, including lithography, etching and electroplating. The nozzle plate comprises a plate body and a plurality of micro-orifices formed on the plate body. The orifice has a diameter which gradually expands in the direction away from the bottom of the plate body to achieve a smooth inner surface, allowing particles to pass therethrough smoothly without being clogged in the nozzle plate.
MOTION PARAMETER ESTIMATING METHOD, ANGLE ESTIMATING METHOD AND DETERMINATION METHOD
(2014-01-30)
Huang Chung-Jung
;
Dai Chia-Wei
;
Tsai Tsung-Yu
;
Lee Ta-Sung
A motion parameter estimating method, an angle estimating method and a determination method are provided. The methods are adapted for an electronic device. In the angle estimating method, a first frequency modulation continuous wave signal is first transmitted, and at least one antenna receives a second frequency modulation continuous wave signal resulted by a target reflecting the first frequency modulation continuous wave signal. Multiple motion parameters associated with the target are then obtained according to the first frequency modulation continuous wave signal and the second frequency modulation continuous wave signal. Multiple measured values corresponding to the at least one antenna are obtained according to the motion parameters and configuration parameters of the at least one antenna, respectively. Afterwards, the measured values are substituted into a formula to obtain an estimated angle between a preset direction of the electronic device and the target.
METHOD OF PROTEIN PURIFICATION
(2014-01-30)
LI Yaw-Kuen
;
WU Yue-Jin
A method for producing a target protein is provided, which includes steps described below. A crude extract including a fusion protein is provided. The fusion protein includes a tag, a target protein and a linker inserted between the tag and the target protein. The fusion protein and magnetic particles are then bound to form a magnetic particle-binding fusion protein. Finally, the linker of the magnetic particle-binding fusion protein undergoes autocleavage by using a cleavage buffer solution to release the target protein. A one-pot process for producing a purified target protein is also provided.
An efficient synthesis of the C27-C45 fragment of lagunamide A, a cyclodepsipeptide with potent cytotoxic and antimalarial properties
(2014-01-31)
Liu, Hui-Ming
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Chang, Chieh-Yu
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Lai, Ya-Chi
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Yang, Mei-Due
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Chang, Ching-Yao
An efficient and stereoselective synthesis of the entire C27-C45 moiety of lagunamide A has been achieved from 1-[(4S)-4-benzyl-2-thioxothiazolidin-3-yl]propan-1-one in six steps with 22% overall yield. The key step in the synthesis is an asymmetric acetal aldol reaction featuring the enantioselective addition of a chiral thiazolidinethione-derived titanium enolate to an acetal to establish the stereochemistry at C39. (C) 2013 Elsevier Ltd. All rights reserved.
Efficient Multiply-by-3 and Divide-by-3 Algorithms and Their Fast Hardware Implementation
(2014-02-01)
Wey, Chin-Long
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Jui, Ping-Chang
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Sung, Gang-Neng
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電機工程學系
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Department of Electrical and Computer Engineering
This study presents efficient algorithms for performing multiply-by-3 (3N) and divide-by-3 (N/3) operations with the additions and subtractions, respectively. No multiplications and divisions are needed. Full adder (FA) and full subtractor (FS) can be implemented to realize the N3 and N/3 operations, respectively. For fast hardware implementation, this paper introduces two basic cells UCA and UCS for 3N and N/3 operations, respectively. For 3N operation, the UCA-based ripple carry adder (RCA) and carry lookahead adder (CLA) designs are proposed and their speed performances are estimated based on the delay data of standard cell library in TSMC 0.18 mu m CMOS process. Results show that the 16-bit UCA-based RCA is about 3 times faster than the conventional FA-based RCA and even 25% faster than the FA-based CLA. The proposed 16-bit and 64-bit UCA-based CLAs are 62% and 36% faster than the conventional FA-based CLAs, respectively. For N/3 operations, ripple borrow subtractor (RBS) is also presented. The 16-bit UCS-based RBS is about 15.5% faster than the 16-bit FS-based RBS.
Optimality of Frame Aggregation-Based Power-Saving Scheduling Algorithm for Broadband Wireless Networks
(2014-02-01)
Liu, Wen-Jiunn
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Feng, Kai-Ten
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Tseng, Po-Hsuan
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電機資訊學士班
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Undergraduate Honors Program of Electrical Engineering and Computer Science
The limitation on battery lifetime has been a critical issue for the advancement of mobile computing. Different types of power-saving techniques have been proposed in various fields. In order to provide feasible energy-conserving mechanisms for the mobile subscriber stations (MSSs), three power-saving types have been proposed for the IEEE 802.16e broadband wireless networks. However, these power-saving types are primarily targeting for the cases with a single connection between the base station (BS) and the MSS. With the existence of multiple connections, the power efficiency obtained by adopting the conventional scheduling algorithm can be severely degraded. In this paper, with the consideration of multiple connections and their quality-of-service (QoS) constraints, a frame aggregation-based powersaving scheduling (FAPS) algorithm is proposed to enhance the power efficiency by aggregating multiple under-utilized frames into fully-utilized ones. The optimality on the minimum number of listen frames in the proposed FAPS algorithm is also provided, and is further validated via the correctness proofs. Performance evaluation of proposed FAPS scheme is conducted and compared via simulations. Simulation results show that the power efficiency of FAPS algorithm outperforms the other existing protocols with tolerable frame delay.
Solution-processable bismuth iodide nanosheets as hole transport layers for organic solar cells
(2014-02-01)
Boopathi, Karunakara Moorthy
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Raman, Sankar
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Mohanraman, Rajeshkumar
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Chou, Fang-Cheng
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Chen, Yang-Yuang
In this paper we demonstrate the use of low-temperature-solution-processable bismuth iodide (BiI3) nanosheets as hole transport layers in organic photovoltaics with an active layer comprising poly(3-hexylthiophene) (P3HT) mixed with a fullerene derivative. The performance of the resulting devices was comparable with that of corresponding conventionally used systems incorporating polyethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS). UV-vis spectroscopy revealed that the transparency of a BiI3 layer in the visible ( > 620 nm) and near-infrared range is greater than that of a PEDOT:PSS layer. X-ray photoemission spectroscopy of a BiI3 film revealed signals at 158.8, 164, 618.6, and 630 eV-characteristic of Bi 4f(7/2), Bi 4f(5/2), I 3d(5/2), and I 3d(3/2), respectively-that indicated a stoichiometric BiI3 film. Wet milling of BiI3 crystals resulted in the formation of nanosheets, the presence of which we confirmed using scanning electron microscopy. The resultant power conversion efficiency of the device was approximately 3.5%, with an open-circuit voltage of 0.56 V, a short-circuit current density of 10.4 mA cm(-2), and a fill factor of 60.1% under AM1.5G irradiation (100 mW cm(-2)). (C) 2013 Elsevier B.V. All rights reserved.
Tri-Resistive Switching Behavior of Hydrogen Induced Resistance Random Access Memory
(2014-02-01)
Chu, Tian-Jian
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Tsai, Tsung-Ming
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Chang, Ting-Chang
;
Chang, Kuan-Chang
;
Zhang, Rui
In this letter, the special role of hydrogen ions in hafnium doped silicon oxide resistive random access memory (RRAM) is presented. In addition to the more typical oxygen ion-dominated resistive switching, hydrogen ions were also observed to trigger a resistance transformation phenomenon, producing a tri-resistive device. Unlike a normal RRAM device, a hydrogen plasma-treated device is operated with a reversed voltage polarity, and the direction of hydrogen ion migration results in the chemical bonds breaking and repairing. By changing the voltage polarity and stop voltage, this tri-resistive behavior can be achieved. This particular hydrogen-induced switching behavior suggests a different RRAM switching mechanism and is finally explained by our model.