Browsing by Issue Date, starting with "2016-11-01"

Now showing 1 - 20 of 16228

Study of Inherent Gate Coupling Nonuniformity of InAs/GaSb Vertical TFETs
(2016-11)
Hsu, Ching-Yi
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Zeng, Yuping
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Chang, Chen-Yen
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Hu, Chenming
;
Chang, Edward Yi
An electrostatic nonuniformity in the cantilever vertical tunneling FETs intrinsically exists in the InAs/GaSb junction to InAs cantilever transition region. The effects of the coupling ratio (CR) nonuniformity are investigated in this paper. The results show that the switching characteristics are degraded by the CR nonuniformity, especially in the case of large InAs/GaSb band offset. This paper also reveals that the nonuniformity in InAs/GaSb vertical tunneling FETs can be mitigated with the optimized band offset of heterojunction, scaling of oxide thickness, and acute angle etching profile.
Mechanical properties of nanocomposites with functionalized graphene
(2016-11)
Lee, Ming-Wei
;
Wang, Tai-Yuan
;
Tsai, Jia-Lin
;
機械工程學系
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Department of Mechanical Engineering
The research investigated the thermal and mechanical properties of graphene/epoxy nanocomposites. Pristine graphene and functionalized graphene were used as nano-reinforcement in the nanocomposites. The graphene loadings employed in the nanocomposites were 0.1, 0.3, 0.5, and 1.0wt%. The functional groups grafted on the functionalized graphene were characterized through Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). Results indicated that two kinds of functional groups are grafted on the functionalized graphene surfaces: one contains only COOH group and the other contains both COOH and NH2 groups. Moreover, from mechanical and thermal testing, it was found that the nanocomposites with functionalized graphene demonstrate better mechanical and thermal properties than those with pristine graphene. The graphene containing NH2 and COOH functional groups exhibits superior mechanical and thermal properties than the graphene with only COOH functional group. In addition, Young\'s modulus and thermal conductivity of the nanocomposites increase as the graphene loading increases. However, the fracture toughness and tensile strength of the nanocomposites attain peak values when the functionalized graphene loading is 0.1wt%. The effects of the functional groups on the mechanical and thermal properties of nanocomposites were elaborated using molecular dynamics (MD) simulation. It was revealed that the interfacial thermal conductance and normalized interaction energy increase between the functionalized graphene and epoxy matrix, which may be responsible for the enhanced mechanical properties in the functionalized graphene/epoxy nanocomposites.
Synthesis, characterization, and photovoltaic applications of donor-acceptor alternating and random copolymers based on a ladder-type nonacyclic structure
(2016-11)
Liang, Wei-Wei
;
Lin, Yu-Shun
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Lai, Yu-Ying
;
Cheng, Yen-Ju
;
應用化學系
A nonacylic building block TPTPT with the alternate thiophene and benzene subunits fastened by four bridging methylene groups was connected with various acceptors including diphenylquinoxaline (QX), thieno[3,4-c]pyrrole-4,6(5H)-dione (TPD), thieno[3,44]thiophene (TT) to afford donor-acceptor (D-A) alternating copolymers - PTPTPTQX, PTPTPTTPD, and PTPTPTTT and random copolymers - PTPTPTQX11,PTPTPTQX12, PTPTPTTPD11, PTPTPTTPD12, PTPTPTTT11, and PTPTPTTT12. The thermal, optical, and electrochemical properties of these copolymers were measured and compared. The random copolymers all have higher glass transition temperature (T-g) than the corresponding alternating copolymers. ONIOM (our own n-layered integrated molecular orbital and molecular mechanics) calculations suggest that the increase of planarity in the random copolymers arises from the introduction of thiophene units intercalating between donor and acceptor moieties. Bulk heterojunction (BHJ) polymer solar cells (PSCs) were fabricated on the basis of ITO/PEDOT:PSS/polymer:PC71BM/Ca/Al device configuration. When the acceptor is QX or TPD, the resultant alternating copolymers performed superior than the random counterparts. When the acceptor is TT, the high content of TT seems to be harmful to the device efficiency, which may relate with the strong quinoidal character of the TT unit. Overall, for the win core structure, in the used acceptors, the alternating-copolymer arrangement appears to be a better construction manner for the purpose of BHJ PSC applications. (C) 2016 Published by Elsevier B.V.
Bounds on the price of anarchy for a more general class of directed graphs in opinion formation games
(2016-11)
Chen, Po-An
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Chen, Yi-Le
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Lu, Chi-Jen
;
資訊工程學系
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資訊管理與財務金融系註：原資管所+財金所
In opinion formation games with directed graphs, a bounded price of anarchy is only known for weighted Eulerian graphs. Thus, we bound the price of anarchy for a more general class of directed graphs with conditions intuitively meaning that each node does not influence the others more than she is influenced, where the bounds depend on such difference (in a ratio). We also show that there exists an example just slightly violating the conditions with an unbounded price of anarchy. (C) 2016 Elsevier B.V. All rights reserved.
Circulating miR-148b-3p and miR-409-3p as biomarkers for heart failure in patients with mitral regurgitation
(2016-11-01)
Chen, Mien-Cheng
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Chang, Tzu-Hao
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Chang, Jen-Ping
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Huang, Hsien-Da
;
Ho, Wan-Chun
Background: MicroRNAs (miRs) regulate gene expression in heart failure. Circulating miRs as biomarkers for heart failure in mitral regurgitation patients (MR) remain unexplored. Methods: This case-control study enrolled 32 MR patients with heart failure, 16 asymptomatic MR patients, and 12 control subjects without heart failure. We used next generation sequencing to study the gene expression profiles in the sera, and quantitative RT-PCR to study serum and tissue miRs in the left atria. Results: Next generation sequencing analysis and enrichment analysis showed that 25 miRs were differentially expressed in the sera of MR patients with heart failure compared to control subjects. The circulating miR-148b-3p (p = 0.002) and miR-409-3p (p = 0.010) were significantly down-regulated in the MR patients with heart failure compared to control subjects. However, only circulation miR-148b-3p was significantly down-regulated in the MR patients without heart failure compared to control subjects (p = 0.009). The tissue miR-409-3p was significantly down-regulated in the MR patients with heart failure compared to 3 purchased normal controls (p = 0.041). Notably, the tissue RASGRP3 mRNA, target gene of miR-409-3p, was significantly upregulated in the MR patients with heart failure compared to normal controls (p = 0.010). The tissue FRY (p = 0.010) and GADD45A (p = 0.010) mRNAs, target genes of miR-148b-3p, were significantly up-regulated in the MR patients with heart failure compared to normal controls. Conclusions: Circulating miR-148b-3p might serve as biomarker for future development of heart failure and miR-409-3p might serve as biomarker for incident heart failure in MR patients. (C) 2016 Elsevier Ireland Ltd. All rights reserved.
Phospholamban is concentrated in the nuclear envelope of cardiomyocytes and involved in perinuclear/nuclear calcium handling
(2016-11)
Wu, Adonis Z.
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Xu, Dongzhu
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Yang, Na
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Lin, Shien-Fong
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Chen, Peng-Sheng
Aims: Phospholamban (PLB) regulates the cardiac Ca2+-ATPase (SERCA2a) in sarcoplasmic reticulum (SR). However, the localization of PLB at subcellular sites outside the SR and possible contributions to Ca2+ cycling remain unknown. We examined the intracellular distribution of PLB and tested whether a pool of PLB exists in the nuclear envelope (NE) that might regulate perinuclear/nuclear Ca2+ (nCa(2+)) handling in cardiomyocytes (CMs). Methods and results: Using confocal immunofluorescence microscopy and immunoblot analyses of CMs and CM nuclei, we discovered that PLB was highly concentrated in NE. Moreover, the ratio of PLB levels to SERCA levels was greater in NE than in SR. The increased levels of PLB in NE were a consistent finding using a range of antibodies, tissue samples, and species. To address a possible role in affecting Ca2+ handling, we used Fluo-4 based con focal Ca2+ imaging, with scan-lines across cytosol and nuclei, and evaluated the effects of PLB on cytosolic and nCa(2+) uptake and release in mouse CMs. In intact CMs, isoproterenol increased amplitude and decreased the decay time of Ca2+ transients not only in cytosol but also in nuclear regions. In saponin-permeabilized mouse CMs ([Ca2+]; = 400 nM), we measured spontaneous Ca2+ waves after specific reversal of PLB activity by addition of the Fab fragment of an anti-PLB monoclonal antibody (100 mu g/ml).This highly selective immunological reagent enhanced Ca2+ uptake (faster decay times) and Ca2+ release (greater intensity) in both cytosol and across the nuclear regions. Conclusions: Besides SR, PLB is concentrated in NE of CMs, and may be involved in modulation of nCa(2+) dynamics. (C) 2016 Elsevier Ltd. All rights reserved.
Simple approach to three-color two-photon microscopy by a fiber-optic wavelength convertor
(2016-11-01)
Li, Kuen-Che
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Huang, Lynn L. H.
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Liang, Jhih-Hao
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Chan, Ming-Che
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光電學院
A simple approach to multi-color two-photon microscopy of the red, green, and blue fluorescent indicators was reported based on an ultra-compact 1.03-mu m femtosecond laser and a nonlinear fiber. Inside the nonlinear fiber, the 1.03-mu m laser pulses were simultaneously blue-shifted to 0.6 similar to 0.8 mu m and red-shifted to 1.2 similar to 1.4 mu m region by the Cherenkov radiation and fiber Raman gain effects. The wavelength-shifted 0.6 similar to 0.8 mu m and 1.2 similar to 1.4 mu m radiations were co-propagated with the residual non-converted 1.03-mu m pulses inside the same nonlinear fiber to form a fiber-output three-color femtosecond source. The application of the multi-wavelength sources on multi-color two-photon fluorescence microscopy were also demonstrated. Overall, due to simple system configuration, convenient wavelength conversion, easy wavelength tunability within the entire 0.7 similar to 1.35 mu m biopenetration window and less requirement for high power and bulky light sources, the simple approach to multi-color two-photon microscopy could be widely applicable as an easily implemented and excellent research tool for future biomedical and possibly even clinical applications. (C) 2016 Optical Society of America
A Unified Ant Agent Framework for Solving DoS and QoS Problems
(2016-11)
Chen, Hsia-Hsiang
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Lee, Chien-Hua
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Huang, Shih-Kun
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資訊工程學系
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資訊技術服務中心
Anomalous traffic volume can be used for identifying network threats and faults. Denial of service (DoS) and quality of service (QoS) are two contrasting problems of anomalous network traffic. DoS exploits malicious traffic to hinder service availability to normal users, whereas QoS determines if the service provision quality has reached the preset agreement. This paper proposes a unified ant agent framework for identifying the source of these problems: IP traceback for DoS attacks and fault localization for QoS violations. Numerous studies have investigated IP traceback techniques for identifying spoofed IP addresses of attackers. These techniques can identify the attack path from the victim to the attacker. Metaheuristic algorithms that consider slight increments in traffic volume (SITV) are rarely studied for solving the IP traceback problem of DoS attacks. We investigated the malicious and nonmalicious situations for the QoS attack and QoS fault localization problem. This paper proposes a novel ant colony optimization (AGO) method for fast filtering, DoS threat source identification, and QoS fault localization (unified threat identification and fault localization by using ACO, UTFACO). The UTFACO framework was compared with the probabilistic packet marking approach and conventional ant system algorithms. We compared the efficiency of UTFACO with and without a bloom filter (BF). The framework was verified in the QoS attack and QoS fault experiment environments. This study showed that attack or fault detection and identification procedures can be designed and implemented practically. The tests used the dataset of the network topology from the DARPA repository with two cases: one is a general experiment, and the other has various levels of SITV. Perfect accuracy can be achieved for the general experiment, and more than 90% accuracy can be obtained for various levels of SITV. The datasets of the QoS attack and QoS fault were obtained from a real network. Precise fault localization is achieved due to the high detection rate obtained. The results show that UTFACO is an efficient and accurate framework. Moreover, the computation time is considerably reduced by using UTFACO with the BF, and the time is less than five seconds in the framework. Our proposed framework is robust and can solve the problem of identifying the IP address of an attacker and detecting the fault location.
Annealing-induced phase transition in zinc phthalocyanine ultrathin films
(2016-11-01)
Ahn, Hyeyoung
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Chu, Ting-Chang
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光電工程學系
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Department of Photonics
We report the evidence of post-annealing-induced phase transition in zinc phthalocyanine (ZnPc) ultrathin (similar to 20 nm) films upon annealing at 200 degrees C. The signatures of phase transition are observed in their morphological, structural, and ultrafast spectroscopic properties. X-ray diffraction measurement shows that alpha-phase nanospheres transform to beta-phase nanorods that have a high degree of crystallinity with an excellent ordering along the c-direction in a monoclinic arrangement. Tight packing of molecules in the beta-crystallites allows a red-shift and intensity gain of the lowest-energy subband in the Q-band and subsequently increases the electronic coupling in both intercolumn and intracolumn paths. (C) 2016 Optical Society of America
Single domain non-polar (12(3)over-bar0)ZnO epitaxy on (118)LaAlO3 by pulsed laser deposition
(2016-11-01)
Yen, Tzu-Chun
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Ho, Yen-Teng
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Peng, Chun-Yen
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Tian, Jr-Sheng
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Shih, Yi-Sen
An unconventional non-polar (12 (3) over bar0)ZnO epitaxial film is grown on (118)LaAlO3(LAO) substrate by pulsed laser deposition. X-ray diffraction pole figures and transmission electron microscopy show that the crystal orientation relationships between non-polar (1230)ZnO and (118)LAO substrate are (0001)ZnO // (110)LAO and (1120)ZnO // (001)LAO. The Raman spectrum with a significant E2 peaked at 439 cm(-1) clearly indicates the formation of non-polar ZnO film. Photoluminescence measurement of the non-polar ZnO film shows a strong near band-edge emission located at 3.3 eV with negligible green-yellow emission. (C) 2016 Elsevier B.V. All rights reserved.
Exploring Coupled Plasmonic Nanostructures in the Near Field by Photoemission Electron Microscopy
(2016-11)
Yu, Han
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Sun, Quan
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Ueno, Kosei
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Oshikiri, Tomoya
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Kubo, Atsushi
The extraordinary optical properties of coupled plasmonic nanostructures make these materials potentially useful in many applications; thus, they have received enormous attention in basic and applied research. Coupled plasmon modes have been characterized predominantly using far-field spectroscopy. In near-field spectroscopy, the spectral response of local field enhancement in coupled plasmonic nanostructures remains largely unexplored, especially experimentally. Here, we investigate the coupled gold dolmen nanostructures in the near field using photoemission electron microscopy, with wavelength tunable femtosecond laser pulses as an excitation source. The spatial evolution of near-field mapping of an individual dolmen structure with the excitation wavelength was successfully obtained. In the near field, we spatially resolved an anti-bonding mode and a bonding mode as the result of plasmon hybridization. Additionally, the quadrupole plasmon mode that could be involved in the formation of a Fano resonance was also revealed by spatially resolved near-field spectra, but it only contributed little to the total near-field enhancement. On the basis of these findings, we obtained a better understanding of the near-field nanostructures, where the plasmon hybridization and the plasmonic Fano resonance were mixed.
An agent-based model for queue formation of powered two-wheelers in heterogeneous traffic
(2016-11-01)
Lee, Tzu-Chang
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Wong, K. I.
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運輸與物流管理系註：原交通所+運管所
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Department of Transportation and Logistics Management
This paper presents an agent-based model (ABM) for simulating the queue formation of powered two-wheelers (PTWs) in heterogeneous traffic at a signalized intersection. The main novelty is that the proposed interaction rule describing the position choice behavior of PTWs when queuing in heterogeneous traffic can capture the stochastic nature of the decision making process. The interaction rule is formulated as a multinomial logit model, which is calibrated by using a microscopic traffic trajectory dataset obtained from video footage. The ABM is validated against the survey data for the vehicular trajectory patterns, queuing patterns, queue lengths, and discharge rates. The results demonstrate that the proposed model is capable of replicating the observed queue formation process for heterogeneous traffic. (C) 2016 Elsevier B.V. All rights reserved.
Gas outflow and dust transport of comet 67P/Churyumov-Gerasimenko
(2016-11-01)
Lai, Ian-Lin
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Ip, Wing-Huen
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Su, Cheng-Chin
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Wu, Jong-Shinn
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Lee, Jui-Chi
Because of the diurnal thermal cycle and the irregular shape of the nucleus, gas outflow of comet 67P/Churyumov-Gerasimenko could be highly anisotropic as indicated by the colliminated dust jet structures on the sunlit side. Based on the OSIRIS imaging observations of the outgassing effect, a simple model of surface sublimation can be constructed by taking into account the dependence on the solar insolation. With preliminary information on the time variability of the global gas production rate, a sequence of gas coma models can be generated at different epochs before and after perihelion. We also investigate different patterns of dust particle dynamics under the influences of nuclear rotation and gas drag. From these considerations, a consistent picture of the spatial distribution of dusty materials across the surface of comet 67P as it moves around the perihelion can be developed. It is found that because of the redeposition of the ejected dust from the Southern hemisphere to the Northern hemisphere during the southern summer season the Hapi region could gain up to 0.4 m while the Wosret region would lose up to 1.8 m of dust mantle per orbit.
Secret image sharing with smaller shadow sizes for general access structures
(2016-11)
Chen, Ying-Ru
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Chen, Ling-Hwei
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Shyu, Shyong Jian
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資訊工程學系
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Department of Computer Science
In the area of secret image sharing (SIS), most papers focused on the schemes for threshold or some special access structures. Regarding general access structures (GAS), few results have been found in the literature. Two SIS schemes for GAS were proposed in 2001 and 2010, both are based on qualified sets. However, one distorts the reconstructed secret image, and some extra information is needed in both schemes. Here, we propose three polynomial based SIS schemes for GAS. Considering either qualified or forbidden sets, these schemes can reconstruct the secret image perfectly without any extra information needed. Some proof and analysis on the shadow sizes of the three schemes are given to lead us to choose the one with the smallest size. In addition, we also give some comparisons with two existing schemes, and security issue is also addressed in conclusion.
See-Through Image Blurring of Transparent Organic Light-Emitting Diodes Display: Calculation Method Based on Diffraction and Analysis of Pixel Structures
(2016-11)
Qin, Zong
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Tsai, Yu-Hsiang
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Yeh, Yen-Wei
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Huang, Yi-Pai
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Shieh, Han-Ping David
In this paper, the issue of see-through image blurring of transparent organic light-emitting diodes display is demonstrated, and a systematic method is proposed to calculate blurred see-through image based on diffraction theory. In the calculation, distances of background object and the viewer are considered to correct Fresnel diffraction and chromatic image can be finally synthesized. Calculated and actually captured see-through images match well by using different background distances and pixel structures to verify, as error ratio of only 2.3% and 4.3%, respectively, in the term of blurred image\'s fringe length. Based on the calculation results, see-through image qualities corresponding to four pixel structures are evaluated and two structures are verified to have better image quality. Finally, higher resolutions that lead to much more significant see-through image blurring are discussed.
客家族譜線上書寫：以資訊視覺化技術建置客家族譜數位平臺
(國立交通大學客家文化學院, 2016-11)
張陳基
;
李國兆
;
Chen-Chi Chang and Kuo-Chao Lee
客家族譜具有三項視覺化特性，包括遷徙路線圖、風水地理記錄、世系圖錄。客家人所重視的世系表需要以動態視覺化方式呈現，遷徙圖與墳塋風水也需要結合Google Map 視覺資訊建構家族動態遷徙路線圖以及風水位置繪製功能。透過資訊科技撰寫客家族譜，保存客家文化，引領家族尋根，強化族群認同。以資訊視覺化技術建置客家族譜數位平臺，透過雛型系統開發法，建構客家族譜文獻內容，並藉由使用者經驗評估，瞭解系統成效。視覺化後的客家族譜透過世系圖表、遷徙地圖、地理風水的視覺化書寫，可以呈現客家人的族譜特色，以釐清客家族群的地理脈絡以及家族歷史發展。
Adjustable Extended Discontinuous Reception Cycle for Idle-State Users in LTE-A
(2016-11)
Chang, Chia-Wei
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Chen, Jyh-Cheng
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資訊工程學系
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Department of Computer Science
In the long term evolution advanced, a user in idle state can activate the discontinuous reception (DRX) to save its energy, and the 3GPP extends the length of a DRX cycle. Therefore, how to configure the extended DRX (eDRX) cycle is a tradeoff between the tracking area update (TAU) cost (the cost of updating a user\'s location) and the paging cost (the cost of waking up a user). In this letter, we analyze the tradeoff and determine the optimal length for the eDRX cycle under the latency constraint. The objective function is to minimize the total signaling cost considering the tradeoff between TAU cost and paging cost. The analytical and simulation results demonstrate that the proposed mathematical model can mitigate the signaling cost for the networks.
Low-Leakage and Low-Trigger-Voltage SCR Device for ESD Protection in 28-nm High-k Metal Gate CMOS Process
(2016-11)
Lin, Chun-Yu
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Wu, Yi-Han
;
Ker, Ming-Dou
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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
To effectively protect integrated circuits from electrostatic discharge (ESD) damage, this letter proposes a silicon-controlled rectifier (SCR) device with low trigger voltage, low leakage current, low parasitic capacitance, and which requires no additional process step. The proposed device uses two metal gates to separate the anode and cathode of the SCR to reduce the leakage current. These two gates are well controlled to trigger the SCR device. The test devices have been implemented and verified in a 28-nm high-k metal gate CMOS process. Experimental results show that the proposed SCR exhibits a low trigger voltage (<3 V), low leakage current (<5 nA), low parasitic capacitance (<40 fF), and sufficient ESD robustness (>1 kV in human-body-model tests). Based on its good performances during ESD stress and normal circuit operating conditions, the proposed SCR device is very suitable for ESD protection in advanced CMOS processes.
新加坡大埔客視覺化認同表述：一個比較分析的視野
(國立交通大學客家文化學院, 2016-11)
陳雪薇
;
Hsuen Wei Chin
自上世紀末，新加坡地緣組織對史料價值改觀，轉向物質及視覺文化，既重視保存文物，更用物件圖像鋪陳敘事，拓寬溝通空間，視覺化回應政府重委傳承本族傳統之重任。本文細讀新加坡茶陽（大埔）會館文物館展示，分析其如何藉物質展陳形構表意系統，表述社群多元認同。其視覺論述表達的當地大埔客乃至客家社群認知原鄉、認同本土的立場，相較於中國客家博物館旨在召喚全球客家共同體，和大埔縣博物館之展演地方，有其個別和共同性。三者表述主從有別的認同：國族─族群認同；世界客家共同體認同；地方─中央認同；分別建構「新加坡客家」、「世界客家」、「大埔地方」主體性，唯皆展示「發展」「進步」的歷史，並以線性結構其視覺語言實踐主軸。
Modifying Indium-Tin-Oxide by Gas Cosputtering for Use as an Insulator in Resistive Random Access Memory
(2016-11)
Chen, Po-Hsun
;
Chang, Kuan-Chang
;
Chang, Ting-Chang
;
Tsai, Tsung-Ming
;
Pan, Chih-Hung
In this paper, indium-tin-oxide (ITO) was used to act as both insulator and top electrode in resistive random access memory (RRAM) on identical bottom substrates. This is achieved by cosputtering an ITO target with nitride (N-2) or oxygen (O-2) gas as the insulator; then capping by an ITO electrode, such that both the rectifier and RRAM characteristics can be achieved before and after a forming process, respectively. In contrast, using pure ITO as an insulator does not exhibit RRAM behavior. To verify the rectifier and RRAM characteristics, material analyses and electrical measurements at various temperatures were conducted. Reliability tests including retention and endurance were also applied to verify the resistance switching stability. Finally, the rectifier and RRAM conduction models were proposed to examine the resistance switching behaviors. By applying the ITO material as both electrode and insulator, the resistance switching characteristic with high reliability is thus obtained.