Browsing by Issue Date, starting with "2017-09-21"

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Direct infrared observation of hydrogen chloride anions in solid argon
(2017-09-21)
Huang, Tzu-Ping
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Chen, Hui-Fen
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Liu, Meng-Chen
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Chin, Chih-Hao
;
Durrant, Marcus C.
To facilitate direct spectroscopic observation of hydrogen chloride anions (HCl-), electron bombardment of CH3Cl diluted in excess Ar during matrix deposition was used to generate this anion. Subsequent characterization were performed by IR spectroscopy and quantum chemical calculations. Moreover the band intensity of HCl fi decays slowly when the matrix sample is maintained in the dark for a prolonged time. High-level ab inito calculation suggested that HCl fi is only weakly bound. Atom-in-molecule charge analysis indicated that both atoms of HCl fi are negatively charged and the Cl atom is hypervalent. Published by AIP Publishing.
Remarkable nonlinear optical response of excess electron compounds: theoretically designed alkali-doped aziridine M-(C2NH5)(n)
(2017-09-21)
Li, Bo
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Xu, Chao
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Xu, Xuan
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Zhu, Chaoyuan
;
Gu, Feng Long
Theoretically designed alkali-doped aziridine M-(C2NH5)(n) (M = Li, Na and K; n = 1, 2, 3, and 4) are investigated by density functional theory (DFT) and time-dependent TD-DFT. The interaction energies at optimized electronic structures indicate that alkali-doped aziridine are quite stable. The natural population analysis of charges on alkali atoms show that all positive and electronic transitions to LUMO orbitals are large, so that the designed compounds not only have electride features, but also have large flexible ligands. This leads to a high-performance nonlinear optical response (NLO) and this remarkable NLO response mainly comes from alkali atoms. By calculating the first hyperpolarizabilities for M-(C2NH5)(4) with M@ Calix[4] pyrrole for comparison, we demonstrate that enhancements of the NLO response of M-(C2NH5)(4) are 10 to 100 times larger than those of M@ Calix[ 4] pyrrole, and in particular, the largest first hyperpolarizability values of Na-(C2NH5)(4) is up to 3.4 x 10(6) (a. u.).
Spin filtering of a termination-controlled LSMO/Alq(3) heterojunction for an organic spin valve
(2017-09-21)
Lam, Tu-Ngoc
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Huang, Yen-Lin
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Weng, Ke-Chuan
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Lai, Yu-Ling
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Lin, Ming-Wei
La1-xSrxMnO3 (LSMO) is weLL known as an efficient spin-injection electrode in ferromagnetic organic hybrid-based organic spin valves (OSV). Herein, we examine the influence of three terminating Layers of LSMO fiLms (mixed-, MnO2-, and LaSrO- (LSO-) terminated) on the spin filter at the bottom interface of tri (8-hydroxyquinoLine) aluminum (ALq(3)) deposited on these substrates. Angle-dependent X-ray photoelectron spectra (XPS) demonstrated the presence of SrO segregation at the outermost Layer for three types of LSMO fiLms but in different amounts that might contribute to their magnetic properties. A weak surface coupling between LSMO and Alq(3) was obtained through a small increase of Mn L-edge X-ray magnetic circular dichroism (XMCD) but it does not vary the bulk magnetic properties of LSMO fiLms upon Alq(3) adsorption (LSMO/Alq(3)). The surface dipoles due to the interaction between LSMO fiLms and Alq(3) were found to be 0.5, 0.5, and 0.7 eV for the mixed-ter/Alq(3), MnO2-ter/Alq(3), and LSO-ter/Alq(3) interfaces, respectively. Our results indicate that the segregated SrO Layer Ways an important role in the surface electronic and magnetic properties at LSMO/Alq(3) interfaces, which contributes to a fundamental understanding of the spin injection and transport in LSMO-Alq(3) hybrid-based OSV devices.
SEMICONDUCTOR DEVICE FOR ULTRA-HIGH VOLTAGE OPERATION AND METHOD FOR FORMING THE SAME
(2017-09-21)
Chun-Yen CHANG
;
Chun-Hu CHENG
;
Yu-Pin LAN
A semiconductor device for ultra-high voltage (UHV) operation disclosed in the present invention includes a substrate having a normally-on channel, a negative capacitance material layer, an electrode, a source and a drain. The negative capacitance material layer is disposed over the substrate and capable of adjusting the threshold voltage of the semiconductor device so as to transform the normally-on channel into a normally-off channel and change the transistor characteristics of the semiconductor device from a depletion mode to an enhance mode. In addition, the semiconductor device also includes a gate dielectric layer made of high-k material between the negative capacitance material layer, a gate layer between the gate dielectric layer and the negative capacitance material layer and an ion implantation layer in the substrate under the gate. Furthermore, the aforementioned technical features or structures can be formed in a semiconductor device having a gate-recessed structure.
A Solution to Modeling Multilevel Confirmatory Factor Analysis with Data Obtained from Complex Survey Sampling to AvoidConflated Parameter Estimates
(2017-09-22)
Wu, Jiun-Yu
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Lin, John J. H.
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Nian, Mei-Wen
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Hsiao, Yi-Cheng
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教育研究所
The issue of equality in the between-and within-level structures in Multilevel Confirmatory Factor Analysis (MCFA) models has been influential for obtaining unbiased parameter estimates and statistical inferences. A commonly seen condition is the inequality of factor loadings under equal level-varying structures. With mathematical investigation and Monte Carlo simulation, this study compared the robustness of five statistical models including two model-based (a true and a mis-specified models), one design-based, and two maximum models (two models where the full rank of variance-covariance matrix is estimated in between level and within level, respectively) in analyzing complex survey measurement data with level-varying factor loadings. The empirical data of 120 3rd graders' (from 40 classrooms) perceived Harter competence scale were modeled using MCFA and the parameter estimates were used as true parameters to perform the Monte Carlo simulation study. Results showed maximum models was robust to unequal factor loadings while the design-based and the miss-specified model-based approaches produced conflated results and spurious statistical inferences. We recommend the use of maximum models if researchers have limited information about the pattern of factor loadings and measurement structures. Measurement models are key components of Structural Equation Modeling (SEM); therefore, the findings can be generalized to multilevel SEM and CFA models. Mplus codes are provided for maximum models and other analytical models.
Investigating degradation behaviors induced by mobile Cu ions under high temperature negative bias stress in a-InGaZnO thin film transistors
(2017-09-25)
Chiang, Hsiao-Cheng
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Chang, Ting-Chang
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Liao, Po-Yung
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Chen, Bo-Wei
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Tsao, Yu-Ching
This letter investigates the effect of negative bias temperature stress (NBTS) on amorphous InGaZnO4 thin film transistors with copper electrodes. After 2000 s of NBTS, an abnormal subthreshold swing and on-current (I-on) degradation is observed. The recovery of the Id-Vg curve after either annealing or positive bias temperature stress suggests that there are some native mobile copper ions in the active layer. Both the existence of copper and the degradation mechanism can be confirmed by AC stress with different frequencies and by transmission electron microscope energy-dispersive X-ray spectroscopy analysis. Published by AIP Publishing.
A structural health monitoring system based on multifractal detrended cross-correlation analysis
(2017-09-25)
Lin, Tzu-Kang
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Chien, Yi-Hsiu
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土木工程學系
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Department of Civil Engineering
In recent years, multifractal-based analysis methods have been widely applied in engineering. Among these methods, multifractal detrended cross-correlation analysis (MFDXA), a branch of fractal analysis, has been successfully applied in the fields of finance and biomedicine. For its great potential in reflecting the subtle characteristic among signals, a structural health monitoring (SHM) system based on MFDXA is proposed. In this system, damage assessment is conducted by exploiting the concept of multifractal theory to quantify the complexity of the vibration signal measured from a structure. According to the proposed algorithm, the damage condition is first distinguished by multifractal detrended fluctuation analysis. Subsequently, the relationship between the q-order, q-order detrended covariance, and length of segment is further explored. The dissimilarity between damaged and undamaged cases is visualized on contour diagrams, and the damage location can thus be detected using signals measured from different floors. Moreover, a damage index is proposed to efficiently enhance the SHM process. A seven-story benchmark structure, located at the National Center for Research on Earthquake Engineering (NCREE), was employed for an experimental verification to demonstrate the performance of the proposed SHM algorithm. According to the results, the damage condition and orientation could be correctly identified using the MFDXA algorithm and the proposed damage index. Since only the ambient vibration signal is required along with a set of initial reference measurements, the proposed SHM system can provide a lower cost, efficient, and reliable monitoring process.
Solving Lauricella string scattering amplitudes through recurrence relations
(2017-09-26)
Lai, Sheng-Hong
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Lee, Jen-Chi
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Lee, Taejin
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Yang, Yi
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電機學院
We show that there exist in finite number of recurrence relations valid for all energies among the open bosonic string scattering amplitudes (SSA) of three tachyons and one arbitrary string state, or the Lauricella SSA. Moreover, these in finite number of recurrence relations can be used to solve all the Lauricella SSA and express them in terms of one single four tachyon amplitude. These results extend the solvability of SSA at the high energy, fixed angle scattering limit and those at the Regge scattering limit discovered previously to all kinematic regimes.
Identification of neuraminidase inhibitors against dual H274Y/I222R mutant strains
(2017-09-26)
Hsu, Kai-Cheng
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Hung, Hui-Chen
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HuangFu, Wei-Chun
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Sung, Tzu-Ying
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Lin, Tony Eight
Influenza is an annual seasonal epidemic that has continually drawn public attentions, due to the potential death toll and drug resistance. Neuraminidase, which is essential for the spread of influenza virus, has been regarded as a valid target for the treatment of influenza infection. Although neuraminidase drugs have been developed, they are susceptible to drug-resistant mutations in the sialic-binding site. In this study, we established computational models (site-moiety maps) of H1N1 and H5N1 to determine properties of the 150-cavity, which is adjacent to the drug-binding site. The models reveal that hydrogen-bonding interactions with residues R118, D151, and R156 and van der Waals interactions with residues Q136, D151, and T439 are important for identifying 150-cavitiy inhibitors. Based on the models, we discovered three new inhibitors with IC50 values <10 mu M that occupies both the 150-cavity and sialic sites. The experimental results identified inhibitors with similar activities against both wild-type and dual H274Y/I222R mutant neuraminidases and showed little cytotoxic effects. Furthermore, we identified three new inhibitors situated at the sialic-binding site with inhibitory effects for normal neuraminidase, but lowered effects for mutant strains. The results suggest that the new inhibitors can be used as a starting point to combat drug-resistant strains.
Interplay of Nanoscale, Hybrid P3HT/ZTO Interface on Optoelectronics and Photovoltaic Cells
(2017-09-27)
Lai, Jian-Jhong
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Li, Yu-Hsun
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Feng, Bo-Rui
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Tang, Shiow-Jing
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Jian, Wen-Bin
Photovoltaic effects in poly(3-hexylthiophene-2,5-diyl) (P3HT) have attracted much attention recently. Here, natively p-type doped P3HT nanofibers and n-type doped zinc tin oxide (ZTO) nanowires are used for making not only field-effect transistors (FETs) but also p-n nanoscale diodes. The hybrid P3HT/ZTO p-n heterojunction shows applications in many directions, and it also facilitates the investigation of photoelectrons and photovoltaic effects on the nanoscale. As for applications, the heterojunction device shows a simultaneously high on/off ratio of n-and p-type FETs, gatable p-n junction diodes, tristate buffer devices, gatable photodetectors, and gatable solar cells. On the other hand, P3HT nanofibers are taken as a photoactive layer and the role played by the p-n heterojunction in the photoelectric and photovoltaic effects is investigated. It is found that the hybrid P3HT/ZTO p-n heterojunction assists in increasing photocurrents and enhancing photovoltaic effects. Through the controllable gating of the heterojunction, we can discuss the background mechanisms of photocurrent generation and photovoltaic energy harvesting.
SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF
(2017-09-28)
Chao-Hsin CHIEN
;
Chi-Wen LIU
;
Chen-Han CHOU
A semiconductor device including a Fin FET device includes a fin structure extending in a first direction and protruding from a substrate layer. The fin structure includes a bulk stressor layer formed on the substrate layer and a channel layer disposed over the bulk stressor layer. An oxide layer is formed on the substrate layer extending away from the channel layer. A source-drain (SD) stressor structure is disposed on sidewalls of the channel layer over the oxide layer. A gate stack including a gate electrode layer and a gate dielectric layer covers a portion of the channel layer and extends in a second direction perpendicular to the first direction.
Intermetallic compounds in 3D integrated circuits technology: a brief review
(2017-09-28)
Annuar, Syahira
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Mahmoodian, Reza
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Hamdi, Mohd
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Tu, King-Ning
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材料科學與工程學系
The high performance and downsizing technology of three-dimensional integrated circuits (3D-ICs) for mobile consumer electronic products have gained much attention in the microelectronics industry. This has been driven by the utilization of chip stacking by throughSi- via and solder microbumps. Pb-free solder microbumps are intended to replace conventional Pb-containing solder joints due to the rising awareness of environmental preservation. The use of low-volume solder microbumps has led to crucial constraints that cause several reliability issues, including excessive intermetallic compounds (IMCs) formation and solder microbump embrittlement due to IMCs growth. This article reviews technologies related to 3D-ICs, IMCs formation mechanisms and reliability issues concerning IMCs with Pb-free solder microbumps. Finally, future outlook on the potential growth of research in this area is discussed.
Enantiospecific Synthesis of Imidazoquinazolin-2-ones via Base-Catalyzed Tandem Cyclization
(2017-09-29)
Kumar, Sunil
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Ho, Pei-Heng
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Barve, Indrajeet J.
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Sun, Chung-Ming
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應用化學系
A facile protocol for the enantiospecific synthesis of novel (S)-3-substituted imidazo[2,l-b]quinazoline-2-ones via tandem reaction of substituted (S)-3-amino-4-aminomethylbenzoates and cyanogen bromide under basic conditions is explored. This tandem process involves addition reaction of substituted (S)-3-amino-4-aminomethylbenzoates to CNBr to yield 2-imino tetrahydroquinazoline carboxylate intermediates followed by insitu intramolecular aminolysis to afford the triheterocyclic imidazo[2,l-b]quinazoline-2-ones in good yields and high enantiomeric purity.
A 41.3/26.7 pJ per Neuron Weight RBM Processor Supporting On-Chip Learning/Inference for IoT Applications
(2017-10-01)
Tsai, Chang-Hung
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Yu, Wan-Ju
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Wong, Wing Hung
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Lee, Chen-Yi
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電子工程學系及電子研究所
An energy-efficient restricted Boltzmann machine (RBM) processor (RBM-P) supporting on-chip learning and inference is proposed for machine learning and Internet of Things (IoT) applications in this paper. To train a neural network (NN) model, the RBM structure is applied to supervised and unsupervised learning, and a multi-layer NN can be constructed and initialized by stacking multiple RBMs. Featuring NN model reduction for external memory bandwidth saving, low power neuron binarizer (LPNB) with dynamic clock gating and area-efficient NN-like activation function calculators for power reduction, user-defined connection map (UDCM) for both computation time and bandwidth saving, and early stopping (ES) mechanism for learning process, the proposed system integrates 32 RBM cores with maximal 4k neurons per layer and 128 candidates per sample for machine learning applications. Implemented in 65nm CMOS technology, the proposed RBM-P chip costs 2.2 M gates and 128 kB SRAM with 8.8 mm(2) area. Operated at 1.2 V and 210 MHz, this chip achieves 7.53G neuron weights (NWs) and 11.63G NWs per second with 41.3 and 26.7 pJ per NW for learning and inference, respectively.
Exploring Parents' Conceptions of Augmented Reality Learning and Approaches to Learning by Augmented Reality With Their Children
(2017-10-01)
Cheng, Kun-Hung
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傳播與科技學系
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Department of Communication and Technology
With the increasing attention to the role of parents in children's learning, what issues parents consider and how they behave when learning with their children when confronted with the emerging augmented reality (AR) technology may be worth exploring. This study was therefore conducted to qualitatively understand parents' conceptions of AR learning and approaches to learning by AR with their children. A total of 90 pairs of parents and children were invited to participate in an AR book reading activity held in 2015; all of the parents were then interviewed to acquire the research data. Through the phenomenographic method, this study generated several categories of the parents' conceptions of and approaches to AR learning. Further analysis identified the relationships between parents' conceptions and approaches. For example, the parents holding cohesive conceptions (e.g., learning by AR as attaining in-depth understanding) tended to use deep approaches (e.g., offering guidance to connect life experiences with the book content for thorough reading). Based on the findings, a framework of interactive AR book systems for child-parent shared reading is proposed. This study was expected to initiate research in the area of learning by AR in informal learning environments.
Strong-Form Formulated Generalized Displacement Control Method for Large Deformation Analysis
(2017-10-01)
Yang, Judy P.
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Chen, Jian-Yu
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土木工程學系
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Department of Civil Engineering
The traditional analysis of geometric nonlinearity is mostly based on the weak-formulated Galerkin method such as the finite element method. The element nature has limited its application as a result of numerical integration in the governing equation and quality control of deformed mesh. In the middle of 1990s, the meshfree methods have been developed and become one leading research topic in computational mechanics. Especially, the strong form collocation methods require no additional efforts to process numerical integration and impose Dirichlet boundary condition, thereby making the collocation methods computationally efficient. In the incremental-iterative process, how to accurately reflect the change in the slope of the load-deflection curve of the structure and remain numerically stable are of major concerns. Thus, we propose a strong-form formulated generalized displacement control method to analyze geometric nonlinear problems, where the radial basis collocation method is adopted. The numerical examples demonstrate the ability of the proposed method for large deformation analysis.
Formation and characterization of high-performance silicon thin-film transistors with and without location-controlled grain boundary
(2017-10-01)
Liao, Chan-Yu
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Lin, Hsiao-Chun
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Wang, Chao-Lung
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Lee, I-Che
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Chou, Chia-Hsin
This paper reports the demonstration of structural effects on excimer laser crystallization (ELC) for the Si strip with a recessed-channel structure on the silicon nitride under-layer (RCS-ULN). We revealed that a single location-controlled grain boundary (GB) oriented normal to the Si strip in the middle site without any other GB in the recessed region can be attained via ELC for the RCS-ULN structures with a short recessed region between neighboring long thick regions in a narrow Si strip. This can be attributed to the effective production of a significant 2D lateral thermal gradient in the recessed region and neighboring thick regions. Consequently, the RCS-ULN TFTs fabricated at the position one-half of such an optimal recessed region can achieve a superior field-effect mobility of 670 cm(2) V-1 . s(-1) with minor performance variations since the single-crystal-like Si channel has been adopted.
評張崑將教授之《電光影裏斬春風：武士道分流與滲透的新詮釋》
(國立陽明交通大學出版社, 2017-10-01)
簡曉花
Optimization of carbofuran degradation in microwave-granular activated carbon system using response surface methodology
(2017-10-01)
Remya, Neelancherry
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Lin, Jih-Gaw
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環境工程研究所
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Institute of Environmental Engineering
Present study revealed tremendous improvement in carbofuran degradation in a Microwave - Granular Activated carbon (MW-GAC) system compared to natural hydrolysis process and the degradation half-life was 12 and 0.189 min at a pH of 6 and 10 respectively at a reaction temperature of 80 degrees C. In addition, the effect of several operating parameters such as carbofuran concentration, MW output power and reaction time was modelled using Central composite design (CCD) and response surface methodology (RSM) with 17 experimental runs. Carbofuran degradation/mineralization process was described in terms of carbofuran concentration, MW output power and reaction time. The experimental outcomes from CCD indicated improved degradation and mineralization of carbofuran with the increase in reaction time. On the other hand, lower MW output power resulted in poor degradation and mineralization of carbofuran. RSM showed highest correlation coefficient for carbofuran removal per MW output power, R-w (0.92) and COD removal efficiency, eta(COD) (0.82). Therefore, quadratic models were developed using regression analysis to predict R-w and eta(COD). Good correlation between the observed values and predicted values by the developed models indicated that the developed models can be used to design required R-w and eta(COD) within the experimental conditions.
An Efficient Hierarchical Banking Structure for Algorithmic Multiported Memory on FPGA
(2017-10-01)
Lai, Bo-Cheng Charles
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Huang, Kun-Hua
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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
Algorithmic multiported memory supports concurrent accesses by cooperating block RAMs (BRAMs) with algorithmic operations, and demonstrates the better performance per resource usage on FPGA when compared with register-based designs. However, the current approaches still use significant amount of FPGA resources and pose great design challenges when increasing the access ports. This paper proposes HB-NTX with a resource efficient hierarchical banking structure for nontable-based multi-ported memory design on FPGA. The regular design style enables a systematic flow to scale both read and write ports. When compared with the previous approaches, HB-NTX can reduce 62.03% BRAMs when composing a 2R4W memory with 32K depth. This paper further extends the HB-NTX to alleviate the complexity of the table-based memory designs. When compared with the previous table-based TBLVT approach, the proposed design for a 2R4W memory with 8K depth attains the cost reduction of 39.9%, 14.3%, and 15.6%, for registers, lookup tables, and BRAMs, respectively.