Browsing by Issue Date, starting with "2011-02-14"

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A master equation approach to the dynamics of zero electron kinetic energy (ZEKE) states and ZEKE spectroscopy
(2011-02-14)
Wang, Yi-Hsieh
;
Mineo, H.
;
Chao, S. D.
;
Selzle, H. L.
;
Neusser, H. J.
We have theoretically studied important dynamic processes involved in zero electron kinetic energy (ZEKE) spectroscopy using the density matrix method with the inverse Born-Oppenheimer approximation basis sets. In ZEKE spectroscopy, the ZEKE Rydberg states are populated by laser excitation (either a one- or two- photon process), which is followed by autoionizations and l-mixing due to a stray field. The discrimination field is then applied to ionize loosely bound electrons in the ZEKE states. This is followed by using the extraction field to extract electrons from the ZEKE levels which have a strength comparable to that of the extraction field. These extracted electrons are measured for the relative intensities of the ion states under investigation. The spectral positions are determined by the applied laser wavelength and modified by the extraction electric field. In this paper, all of these processes are conducted within the context of the density matrix method. The density matrix method can provide not only the dynamics of system's population and coherence (or phase) but also the rate constants of the processes involved in the ZEKE spectroscopy. Numerical examples are given to demonstrate the theoretical treatments. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3547363]
Beamlike photon-pair generation for two-photon interference and polarization entanglement
(2011-02-14)
Lo, Hsin-Pin
;
Yabushita, Atsushi
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Luo, Chih-Wei
;
Chen, Pochung
;
Kobayashi, Takayoshi
Beamlike photon pairs were generated by spontaneous parametric down-conversion using a type-II beta-BaB2O4 crystal. A pump laser generated photon pairs when it transmitted through the crystal and was reflected back into the crystal by a mirror to generate more photon pairs. The photon pairs generated when the pump laser first transmitted through the crystal (first photon pairs) were also reflected back into the crystal to overlap with the light path of the photon pairs generated in the second transmission of the pump laser through the crystal (second photon pairs). We observed interference between the first and second photon pairs modulated with a half period of the wavelength of the photon pairs, which demonstrates two-photon interference using the beamlike photon pairs. The fringe period confirms that the observed interference is not classical interference but quantum two-photon interference. Through rotating the angles of quarter-wave plates in the light paths of the photon pairs, we generated beamlike photon pairs with entangled polarization. The phase between the first and second photon pairs could be tuned by changing the position of mirrors reflecting the pump pulses and photon pairs. The fringes of coincidence counts showed that the beamlike photon pairs have polarization entanglement.
Balanced carrier transport in organic solar cells employing embedded indium-tin-oxide nanoelectrodes
(2011-02-14)
Hsu, Min-Hsiang
;
Yu, Peichen
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Huang, Jen-Hsien
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Chang, Chia-Hua
;
Wu, Chien-Wei
In this paper, we present evidence of balanced electron and hole transport in polymer-fullerene based solar cells by means of embedded indium-tin-oxide nanoelectrodes. Enabled by a controllable electrochemical deposition, the individual nanoelectrodes are uniformly enclosed by a poly (3,4-ethylenedioxythiophene) hole-conducting layer, allowing a relatively short route for holes to reach the anode and hence increasing the effective hole mobility. Consequently, the power conversion efficiency and photogenerated current are maximized with a deposition condition of 50 mu C, where the ratio of the electron to hole mobility is nearly unity. (C) 2011 American Institute of Physics. [doi:10.1063/1.3556565]
Etching method for nitride semiconductor
(2011-02-15)
Lee
;
Wei-I
;
Huang
;
Hsin-Hsiung
;
Zeng
The invention discloses etching method for the nitride semiconductor. Firstly dielectric layer is formed on gallium nitride. The line pattern or dot pattern is formed on the dielectric layer by using the exposure, development, and etching processes. The dielectric layer is used as the mask for the epitaxial lateral overgrowth of follow-up gallium nitride layer. The thick gallium nitride film is grown on the dielectric layer. Then the wet etching process is used to remove the dielectric layer, and the thick gallium nitride film on the dielectric layer is etched to form the specific shape as required.
Predicting and analyzing DNA-binding domains using a systematic approach to identifying a set of informative physicochemical and biochemical properties
(2011-02-15)
Huang, Hui-Lin
;
Lin, I-Che
;
Liou, Yi-Fan
;
Tsai, Chia-Ta
;
Hsu, Kai-Ti
Background: Existing methods of predicting DNA-binding proteins used valuable features of physicochemical properties to design support vector machine (SVM) based classifiers. Generally, selection of physicochemical properties and determination of their corresponding feature vectors rely mainly on known properties of binding mechanism and experience of designers. However, there exists a troublesome problem for designers that some different physicochemical properties have similar vectors of representing 20 amino acids and some closely related physicochemical properties have dissimilar vectors. Results: This study proposes a systematic approach (named Auto-IDPCPs) to automatically identify a set of physicochemical and biochemical properties in the AAindex database to design SVM-based classifiers for predicting and analyzing DNA-binding domains/proteins. Auto-IDPCPs consists of 1) clustering 531 amino acid indices in AAindex into 20 clusters using a fuzzy c-means algorithm, 2) utilizing an efficient genetic algorithm based optimization method IBCGA to select an informative feature set of size m to represent sequences, and 3) analyzing the selected features to identify related physicochemical properties which may affect the binding mechanism of DNA-binding domains/proteins. The proposed Auto-IDPCPs identified m=22 features of properties belonging to five clusters for predicting DNA-binding domains with a five-fold cross-validation accuracy of 87.12%, which is promising compared with the accuracy of 86.62% of the existing method PSSM-400. For predicting DNA-binding sequences, the accuracy of 75.50% was obtained using m=28 features, where PSSM-400 has an accuracy of 74.22%. Auto-IDPCPs and PSSM-400 have accuracies of 80.73% and 82.81%, respectively, applied to an independent test data set of DNA-binding domains. Some typical physicochemical properties discovered are hydrophobicity, secondary structure, charge, solvent accessibility, polarity, flexibility, normalized Van Der Waals volume, pK (pK-C, pK-N, pK-COOH and pK-a(RCOOH)), etc. Conclusions: The proposed approach Auto-IDPCPs would help designers to investigate informative physicochemical and biochemical properties by considering both prediction accuracy and analysis of binding mechanism simultaneously. The approach Auto-IDPCPs can be also applicable to predict and analyze other protein functions from sequences.
Immunopathogenic behaviors of canine transmissible venereal tumor in dogs following an immunotherapy using dendritic/tumor cell hybrid
(2011-02-15)
Pai, Chien-Chun
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Kuo, Tzong-Fu
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Mao, Simon J. T.
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Chuang, Tien-Fu
;
Lin, Chen-Si
Canine transmissible venereal tumor (CTVT) is a naturally occurring tumor that can be transmitted between dogs via live tumor cell inoculation. It is also a spontaneous self-regression tumor and its behavior is closely related to host immune responses. Since CTVT had been widely used for tumor models in canine cancers, whether this self-regression may overtake the immunity elicited from an exogenous tumor vaccine remains unclear and certainly worthwhile to be investigated. In this study, we used DCs/tumor hybrids as a tumor vaccine to evaluate the CTVT model. We prepared mature allogeneic dendritic cells from bone marrow and then assessed their phenotype (CD80, CD83, CD86, CD1a, CD11c, CD40 and MHC II), antigen uptake and presenting abilities. Fused dendritic cell/CTVT hybrids were then used as a vaccine, administered three times at two-week intervals via subcutaneous injection near the bilateral auxiliary and inguinal lymph nodes. In comparison with unvaccinated dogs (spontaneous regressed group), within a period of 2.5 months, the vaccinations substantially inhibited tumor progression (p<0.05) and accelerated the rate of regression by a mechanism involving amplification of the host tumor-specific adaptive immune responses and NK cytotoxicity (p<0.001). Pathologic examination revealed early massive lymphocyte infiltration resulting in final tumor necrosis. In addition, there are not any detectable effects on routine physical, body temperature or blood chemistry examinations. In conclusion, our data furnishes a reference value showing that CTVT is a model of potential use for the study of immunity elicited by vaccines against tumors, and also enable early-phase evaluation of the dendritic cell/tumor vaccine in terms of raising host immunity. (C) 2010 Elsevier B.V. All rights reserved.
iGEMDOCK: a graphical environment of enhancing GEMDOCK using pharmacological interactions and post-screening analysis
(2011-02-15)
Hsu, Kai-Cheng
;
Chen, Yen-Fu
;
Lin, Shen-Rong
;
Yang, Jinn-Moon
;
生物科技學系
Background: Pharmacological interactions are useful for understanding ligand binding mechanisms of a therapeutic target. These interactions are often inferred from a set of active compounds that were acquired experimentally. Moreover, most docking programs loosely coupled the stages (binding-site and ligand preparations, virtual screening, and post-screening analysis) of structure-based virtual screening (VS). An integrated VS environment, which provides the friendly interface to seamlessly combine these VS stages and to identify the pharmacological interactions directly from screening compounds, is valuable for drug discovery. Results: We developed an easy-to-use graphic environment, iGEMDOCK, integrating VS stages (from preparations to post-screening analysis). For post-screening analysis, iGEMDOCK provides biological insights by deriving the pharmacological interactions from screening compounds without relying on the experimental data of active compounds. The pharmacological interactions represent conserved interacting residues, which often form binding pockets with specific physico-chemical properties, to play the essential functions of a target protein. Our experimental results show that the pharmacological interactions derived by iGEMDOCK are often hot spots involving in the biological functions. In addition, iGEMDOCK provides the visualizations of the protein-compound interaction profiles and the hierarchical clustering dendrogram of the compounds for post-screening analysis. Conclusions: We have developed iGEMDOCK to facilitate steps from preparations of target proteins and ligand libraries toward post-screening analysis. iGEMDOCK is especially useful for post-screening analysis and inferring pharmacological interactions from screening compounds. We believe that iGEMDOCK is useful for understanding the ligand binding mechanisms and discovering lead compounds. iGEMDOCK is available at http://gemdock.life.nctu.edu.tw/dock/igemdock.php.
Expert system based parallel multi-1D block matching algorithm with implementation for motion estimation
(2011-02-15)
Lin, Shin-Yeu
;
Su, Chong-Wei
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Huang, Jung-Shou
;
電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, we propose an expert-system based parallel multi-1-dimensional block matching algorithm (ESPM-1D-BMA) for motion estimation (ME). Instead of the conventional 2D block matching, we employ the parallel multi-1D blocks matching to improve the computing speed. To improve the ME accuracy, we design a knowledge base and inference engine to determine the true motion vector (MV) from the results of parallel multi-1D blocks matching. To speed up the computing speed further, we present a hardware architecture for implementing the ESPM-1D-BMA. We have demonstrated that the MV estimation accuracy achieved by the proposed ESPM-1D-BMA is much better than the comparing fast block matching algorithms and is close to the 2 dimensional full search block matching algorithm (2D-FSBMA). We also demonstrate that the computing speed of the proposed ESPM-1D-BMA is about two times as fast as the mixed-signal 2D-FSBMA (MS-2D-FSBMA). (C) 2011 Elsevier Ltd. All rights reserved.
Transition State in a Prevented Proton Transfer Observed in Real Time
(2011-02-15)
Iwakura, Izumi
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Yabushita, Atsushi
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Kobayashi, Takayoshi
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電子物理學系
;
Department of Electrophysics
Direct observation of the molecular structural change during chemical reactions including transition states is desirable to fully clarify the mechanism of chemical reactions. Time-dependent frequency variations in molecular vibration modes reflect structural change in transition states. Ultrafast changes in molecular structure during bond breaking and bond reformation can be clearly visualized using ultrafast spectroscopy. This study elucidated molecular structural information in states along the chemical reaction including transition state in the proton transfer of indigodisulfonate salt. The photoexcited proton transfer was found to follow a stepwise pathway. The monoalcohol intermediate generated by the proton transfer was found to return immediately to the original indigo without proton-transfer configuration. This back reaction of this is the reason for the ultra-photostability of indigo over extremely long exposure to light. This shows that real-time vibrational spectroscopy by a few femtosecond pulse laser enables the observation of dynamic behavior of molecular vibrations during chemical reactions, leading to the clarification of reaction mechanisms or the development of new chemical reactions.
The Rayleigh-Ritz method, refinement and Arnoldi process for periodic matrix pairs
(2011-02-15)
Chu, Eric King-Wah
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Fan, Hung-Yuan
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Jia, Zhongxiao
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Li, Tiexiang
;
Lin, Wen-Wei
We extend the Rayleigh-Ritz method to the eigen-problem of periodic matrix pairs. Assuming that the deviations of the desired periodic eigenvectors from the corresponding periodic subspaces tend to zero, we show that there exist periodic Ritz values that converge to the desired periodic eigenvalues unconditionally, yet the periodic Ritz vectors may fail to converge. To overcome this potential problem, we minimize residuals formed with periodic Ritz values to produce the refined periodic Ritz vectors, which converge under the same assumption. These results generalize the corresponding well-known ones for Rayleigh-Ritz approximations and their refinement for non-periodic eigen-problems. In addition, we consider a periodic Arnoldi process which is particularly efficient when coupled with the Rayleigh-Ritz method with refinement. The numerical results illustrate that the refinement procedure produces excellent approximations to the original periodic eigenvectors. (C) 2010 Elsevier B.V. All rights reserved.
Class-D driving method for stereo load
(2011-02-15)
Hu
;
Jwu-Sheng
;
Chen
;
Keng-Yuan
The present invention provides a class D amplifier and method for driving a tri-wired stereo amplifier. Additionally, the class D amplifier includes a first filter, a second filter, a processor, a 2D-quantitizer, a signal generator, and a logic circuit. The class D amplifier and method of the invention can reduce cost of production and increase processing efficiency. More particularly, the class D amplifier and method of the invention are processed in an optimal feedback mode, so as to reduce the reciprocal effect between the two channels, and avoid mismatch of the two amplifiers.
Light-emitting device and method for making the same
(2011-02-15)
Chiu
;
Ching-Hua
;
Huang
;
Hung-Wen
;
Kuo
A light-emitting device is capable of emitting a light having a wavelength ranging from 300 to 550 nm, and includes: a substrate; a p-type semiconductor layer disposed on the substrate; an active layer disposed on the p-type semiconductor layer; a n-type semiconductor layer disposed on the active layer and having a waveguide-disposing surface; and a waveguide structure formed on the waveguide-disposing surface of the n-type semiconductor layer and having a plurality of spaced apart nanorods extending from the waveguide-disposing surface.
A priori estimate for non-uniform elliptic equations
(2011-02-15)
Yeh, Li-Ming
;
應用數學系
;
Department of Applied Mathematics
A priori estimate for non-uniform elliptic equations with periodic boundary conditions is concerned. The domain considered consists. of two sub-regions, a connected high permeability region and a disconnected matrix block region with low permeability. Let c denote the size ratio of one matrix block to the whole domain. It is shown that in the connected high permeability sub-region, the Holder and the Lipschitz estimates of the non-uniform elliptic solutions are bounded uniformly in epsilon. But Holder gradient estimate and L(P) estimate of the second order derivatives of the solutions in general are not bounded uniformly in epsilon. (c) 2010 Elsevier Inc. All rights reserved.
Device and method for integrating sound effect processing and active noise control
(2011-02-15)
Bai
;
Mingsian R.
;
Ou
;
Kuen-Ying
;
Lin
A device and a method for integrating 3D sound effect processing and active noise control are proposed. A digital signal processor incorporates an artificial reverberator and a 3D spatial audio processor into an audio module. The audio signal is presented via an earphone. Next, a microphone embedded in the vicinity of the loudspeaker inside the headset is used to sense an external noise while playing, and feed it back to an active noise controller, which generates an anti-noise to eliminate the external noise. Therefore, the signal to noise ratio can be increased and the 3D sound field effect can be significantly enhanced. In addition, a head-related transfer function is more efficiently implemented on the basis of an interaural transfer function in the spatial audio processing to reduce the filter order lower and hence the computation loading.
Constructing a yield model for integrated circuits based on a novel fuzzy variable of clustered defect pattern
(2011-02-15)
Lin, Jun-Shuw
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工業工程與管理學系
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Department of Industrial Engineering and Management
As the wafer size increases, the clustering phenomenon of defects becomes significant. In addition to clustered defects, various clustering patterns also influence the wafer yield. In fact, the recognition of clustering pattern usually exists fuzziness. However, the wafer yield models in previous studies did not consider the fuzziness of clustering pattern belonging to which shape in recognition. Therefore, the objective of this study is to develop a new fuzzy variable of clustering pattern (FVCP) by using fuzzy logic control, and predict the wafer yield by using back-propagation neural network (BPNN) incorporating ant colony optimization (ACO). The proposed method utilizes defect counts, cluster index (CI), and FVCP as inputs for ACO-BPNN. A simulated study is utilized to demonstrate the effectiveness of the proposed model. (C) 2011 Elsevier Ltd. All rights reserved.
Changed epitopes drive the antigenic drift for influenza A (H3N2) viruses
(2011-02-15)
Huang, Jhang-Wei
;
Yang, Jinn-Moon
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生物科技學系
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生物資訊及系統生物研究所
;
Department of Biological Science and Technology
Background: In circulating influenza viruses, gradually accumulated mutations on the glycoprotein hemagglutinin (HA), which interacts with infectivity-neutralizing antibodies, lead to the escape of immune system (called antigenic drift). The antibody recognition is highly correlated to the conformation change on the antigenic sites (epitopes), which locate on HA surface. To quantify a changed epitope for escaping from neutralizing antibodies is the basis for the antigenic drift and vaccine development. Results: We have developed an epitope-based method to identify the antigenic drift of influenza A utilizing the conformation changes on epitopes. A changed epitope, an antigenic site on HA with an accumulated conformation change to escape from neutralizing antibody, can be considered as a "key feature" for representing the antigenic drift. According to hemagglutination inhibition (HI) assays and HA/antibody complex structures, we statistically measured the conformation change of an epitope by considering the number of critical position mutations with high genetic diversity and antigenic scores. Experimental results show that two critical position mutations can induce the conformation change of an epitope to escape from the antibody recognition. Among five epitopes of HA, epitopes A and B, which are near to the receptor binding site, play a key role for neutralizing antibodies. In addition, two changed epitopes often drive the antigenic drift and can explain the selections of 24 WHO vaccine strains. Conclusions: Our method is able to quantify the changed epitopes on HA for predicting the antigenic variants and providing biological insights to the vaccine updates. We believe that our method is robust and useful for studying influenza virus evolution and vaccine development.
Low-Power High-Performance Non-Volatile Memory on a Flexible Substrate with Excellent Endurance
(2011-02-15)
Cheng, Chun-Hu
;
Yeh, Fon-Shan
;
Chin, Albert
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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
Very high performance Ni/GeO(x)/HfON/TaN non-volatile resistive memory is fabricated using the covalently bonded dielectric GeO(x) and metal oxynitride HfON, as well as low cost electrodes. The device shows low set and reset powers, good 85 degrees C retention, and 10(5) endurance, which are near to the characteristics of existing commercial flash memory.
On the common mean of several inverse Gaussian distributions based on a higher order likelihood method
(2011-02-15)
Lin, S. H.
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Wu, I. M.
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統計學研究所
;
Institute of Statistics
An interval estimation method for the common mean of several heterogeneous inverse Gaussian (IG) populations is discussed. The proposed method is based on a higher order likelihood-based procedure. The merits of the proposed method are numerically compared with the signed log-likelihood ratio statistic, two generalized pivot quantities and the simple t-test method with respect to their expected lengths, coverage probabilities and type I errors. Numerical studies show that the coverage probabilities of the proposed method are very accurate and type I errors are close to the nominal level. 05 even for very small samples. The methods are also illustrated with two examples. (C) 2010 Elsevier Inc. All rights reserved.
Mobile merchandise evaluation service using novel information retrieval and image recognition technology
(2011-02-15)
Lo, Chi-Chun
;
Kuo, Ting-Huan
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Kung, Hsu-Yang
;
Kao, Hsiang-Ting
;
Chen, Chi-Hua
Consumers' purchasing behavior has obviously changed in recent years with developments in social economics. This change has been evident in the decreased ratio of planned purchases but not in the increase of planned (or spontaneous) purchases. This act of spontaneous or otherwise unplanned purchasing is called "impulse buying". However, buying under these conditions costs more money always comes with negative responses, such as complaints and regret. Therefore, we propose and have designed a new merchandise recommendation system, the Mobile Merchandise Evaluation Service Platform (MMESP). This is a three-tier system composed of Real-time Merchandise Identifying System (RMIS), Real-time Merchandise Evaluation System (RMES), and Real-time Merchandise Recommendation System (RMRS). With this system, Mobile Users (MUs) take pictures of merchandise and send them to MMESP. RMIS integrates Region Adjacency Graph (RAG) and Self-Organizing Maps (SOM) to gather information on the merchandise through those photographs, and. RMES and RMRS provide Intelligence Agents (IAs) and Multiple Document Summarization (MDS) to summarize recommendations on merchandise for MUs, all in real time. (C) 2010 Elsevier B.V. All rights reserved.
Generalized synchronization of chaotic systems with different orders by fuzzy logic constant controller (vol 38, pg 2302, 2011)
(2011-02-15)
Li, Shih-Yu
;
Ge, Zheng-Ming
;
機械工程學系
;
Department of Mechanical Engineering