Browsing by Issue Date, starting with "2018-08-01"

Now showing 1 - 20 of 10255

On the number of rainbow spanning trees in edge-colored complete graphs
(2018-08-01)
Fu, Hung-Lin
;
Lo, Yuan-Hsun
;
Perry, K. E.
;
Rodger, C. A.
;
應用數學系
A spanning tree of a properly edge-colored complete graph, K, is rainbow provided that each of its edges receives a distinct color. In 1996, Brualdi and Hollingsworth conjectured that if K-2m is properly (2m 1)-edge-colored, then the edges of K-2m,, can be partitioned into m rainbow spanning trees except when m = 2. By means of an explicit, constructive approach, in this paper we construct [root 6m+9/3] mutually edge-disjoint rainbow spanning trees for any positive value of m. Not only are the rainbow trees produced, but also some structure of each rainbow spanning tree is determined in the process. This improves upon best constructive result to date in the literature which produces exactly three rainbow trees. (C) 2018 Elsevier B.V. All rights reserved.
Defect-Rich Brown TiO2-x Porous Flower Aggregates: Selective Photocatalytic Reversibility for Organic Dye Degradation
(2018-08-01)
Ullattil, Sanjay Gopal
;
Ramakrishnan, Resmi M.
;
應用化學系
;
Department of Applied Chemistry
A low-temperature, Mn(II)-assisted sol-solvothermal strategy has been developed for the synthesis of positively surface-charged defective brown TiO2-x flower aggregates with porous nature. The porous structure possessed enormous surface defect states such as trivalent titanium ion (TO3+) and oxygen vacancy (V-o) sites. The defect states present in the brown TiO2-x facilitated enhanced absorption even in the NIR region of the solar spectrum, whereas for the negatively surface-charged TiO2 sample, synthesized in the absence of Mn(II), the absorption was limited to the visible region. Obviously, band-gap narrowing occurred for brown TiO2-x as compared to the yellow TiO2 synthesized in the absence of Mn(II). Interestingly, studying the photocatalytic efficiency of these materials using a methyl orange-methylene blue (MO-MB) dye mixture model system under solar illumination revealed selective photocatalytic reversibility, with MB and MO photodegradation performed by yellow TiO2 and brown TiO2-x, respectively. This is the first report on the use of surface-charged brown TiO2-x with porous flower aggregate morphology for selective photocatalysis.
ON STATISTICALLY-SECURE QUANTUM HOMOMORPHIC ENCRYPTION
(2018-08-01)
Lai, Ching-Yi
;
Chung, Kai-Min
;
電信工程研究所
;
Institute of Communications Engineering
Homomorphic encryption is an encryption scheme that allows computations to be evaluated on encrypted inputs without knowledge of their raw messages. Recently Ouyang et al. constructed a quantum homomorphic encryption (QHE) scheme for Clifford circuits with statistical security (or information-theoretic security (IT-security)). It is desired to see whether an information-theoretically-secure (ITS) quantum FHE exists. If not, what other nontrivial class of quantum circuits can be homomorphically evaluated with IT-security? We provide a limitation for the first question that an ITS quantum FHE necessarily incurs exponential overhead. As for the second one, we propose a QHE scheme for the instantaneous quantum polynomial-time (IQP) circuits. Our QHE scheme for IQP circuits follows from the one-time pad.
Efficient Progressive Radiance Estimation Engine Architecture and Implementation for Progressive Photon Mapping
(2018-08-01)
Chiu, Ching-Chieh
;
Van, Lan-Da
;
Lin, Yu-Shu
;
資訊工程學系
;
Department of Computer Science
We propose a progressive radiance estimation engine (PREE) hardware architecture to accelerate the processing of the progressive photon mapping with satisfactory graphic quality. The presented PREE architecture consists of four progressive radiance estimation units (PREUs), approximate full task schedule-oriented hit-point update operation controller (AFTSO-HpUOC) and approximate data-independent schedule-oriented radiance evaluation controller (ADISO-REC). The PREUs accelerate the radiance estimation computation by a pipeline technique and share and configure the hardware resource for hit-point update operation and radiance evaluation. Through AFTSO-HpUOC and ADISO-REC, the data can be efficiently dispatched to achieve better parallelism and the data dependence can be alleviated within the four PREUs, respectively. The core area of the proposed PREE architecture implemented in TSMC 90-nm CMOS process is 1.78 mm(2). According to the post-layout simulation results, the implementation achieves 496.79 million hit-point update operations per second (MHpUO/s) and consumes 184 mW at 125 MHz for Cornell box with three balls.
詹澈訪談側記：從花園新城談起
(深河出版有限公司, 2018-08-01)
郭佳
Glycosaminoglycan-based hybrid hydrogel encapsulated with polyelectrolyte complex nanoparticles for endogenous stem cell regulation in central nervous system regeneration
(2018-08-01)
Jian, Wei-Hong
;
Wang, Huan-Chih
;
Kuan, Chen-Hsiang
;
Chen, Ming-Hong
;
Wu, Hsi-Chin
The poor regenerative capability of stem cell transplantation in the central nervous system limits their therapeutic efficacy in brain injuries. The sustained inflammatory response, lack of structural support, and trophic factors deficiency restrain the integration and long-term survival of stem cells. Instead of exogenous stem cell therapy, here we described the synthesis of nanohybrid hydrogel containing sulfated glycosaminoglycan-based polyelectrolyte complex nanoparticles (PCN) to mimic the brain extracellular matrix and control the delivery of stromal-derived factor-1 alpha (SDF-1 alpha) and basic fibroblast factor (bFGF) in response to matrix metalloproteinase (MMP) for recruiting endogenous neural stem cells (NSC) and regulating their cellular fate. Bioactive factors are delivered by electrostatic sequestration on PCN to amplify the signaling of SDF-1 alpha and bFGF to regulate NSC in vitro. In in vivo ischemic stroke model, the factors promoted neurological behavior recovery by enhancing neurogenesis and angiogenesis. These combined strategies may be applied for other tissue regenerations by regulating endogenous progenitors through the delivery of different kinds of glycosaminoglycan-binding molecules. (C) 2018 Elsevier Ltd. All rights reserved.
專號－馬來亞與印尼－群島的多元思想與疆界想像（續）：林清祥對馬來亞的願景：團結統一、非暴力、主權在民
(深河出版有限公司, 2018-08-01)
覃炳鑫
;
劉璧嘉
10月22日現場討論
(深河出版有限公司, 2018-08-01)
陳冉涌
;
郭佳
Secure and Fast Encryption (SAFE) with Classical Random Number Generators
(2018-08-01)
Deng, Lih-Yuan
;
Shiau, Jyh-Jen Horng
;
Lu, Henry Horng-Shing
;
Bowman, Dale
;
統計學研究所
Pseudo-random number generators (PRNGs) play an important role in both areas of computer simulation and computer security. Currently, there appears to be a huge divide between the types of PRNGs used in these two areas. For PRNGs in computer security applications, the security concern is extremely important. For PRNGs in computer simulation applications, the properties of high-dimensional equi-distribution, efficiency, long period-length, and portability are important. In recent years, there have been many PRNGs proposed in the area of computer simulation satisfying these nice properties. However, most of them are linear generators, thus sharing the same weakness in predictability. The major aim of this article is to propose a general class of secure generators, called SAFE (secure and fast encryption) generators, by properly "mixing" two baseline generators with the aforementioned properties to obtain a secure generator that would inherit these nice properties. Specifically, we propose applying a general mutual-shuffling method to certain linear generators, such as the currently most popular MT19937 generator and large-order multiple recursive generators, as well as outputting certain nonlinear transformations of the generated variates to construct secure PRNGS.
Integrated Portfolio Risk Measure: Estimation and Asymptotics of Multivariate Geometric Quantiles
(2018-08-01)
Sun, Edward W.
;
Wang, Yu-Jen
;
Yu, Min-Teh
;
管理學院
;
College of Management
Portfolio management and integrated risk management are more commonly applied toward enterprise risk management, requiring multivariate risk measures that capture the dependence among many risk factors. In this paper we propose the non-parametric estimator for multivariate value at risk (MVaR) and multivariate average value at risk (MAVaR) based on the multivariate geometric quantile approach and derive the symptotic properties of the proposed estimators for MVaR. We also present their performances under both simulated data and high-frequency financial data from the New York Stock Exchange. In addition, we compare our method with the delta normal approach and order statistics approach. The overall empirical results confirm that the multivariate geometric quantile approach significantly improves the risk management performance of MVaR and MAVaR.
Mixed yeast infections in Taiwan
(2018-08-01)
Yang, Yun-Liang
;
Chu, Wen-Li
;
Lin, Chih-Chao
;
Zhou, Zi-Li
;
Chen, Pei-Ning
Clinically significant yeast isolates were collected via Taiwan Surveillance of Antimicrobial Resistance of Yeasts (TSARY) in 2014, and mixed infections were investigated. Among 44 out of 1092 specimens containing multiple species, 17, 11, 5, 3, and 8 were from urine, sputum, blood, ascites, and 6 others, respectively. There predominant combinations of mixed infection were 14 Candida albicans/Candida glabrata, 13 C. albicans/Candida tropicalis, and 9 C. glabrata/C. tropicalis. Furthermore, we also detected fluconazole resistant isolates Candida norvegensis and Candida krusei. Hence, it is important to accurately identify the species with different drug susceptibilities when they are in the same specimen.
Surface Analysis and Optical Properties of Cu-Doped ZnO Thin Films Deposited by Radio Frequency Magnetron Sputtering
(2018-08-01)
Chen, Guo-Ju
;
Jian, Sheng-Rui
;
Juang, Jenh-Yih
;
電子物理學系
;
Department of Electrophysics
In this study, Cu-doped ZnO (CZO) thin films were grown on glass substrates by using the radio frequency magnetron sputtering technique. The effects of Cu doping on the structural, surface morphological, optical properties, and wettability behaviors of CZO thin films were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), UV-Visible spectroscopy, and contact angle measurement, respectively. The XRD results indicated that all CZO thin films were textured, having a preferential crystallographic orientation along the hexagonal wurtzite (002) axis. The average transmittance in the visible wavelength region was above 80% for all CZO thin films. The optical band gap of the CZO films decreased from 3.18 to 2.85 eV when the Cu-doping was increased from 2% to 10%. In addition, the water contact angle measurements were carried out to delineate the Cu-doping effects on the changes in the surface energy and wettability of the films.
影像選輯
(深河出版有限公司, 2018-08-01)
阿里．艾巴拉
;
陳冉涌
Democracy under Siege: Xiangmin Politics in Sunflower Taiwan
(2018-08-01)
Chuang, Ya-Chung
;
人文社會學系含：族群與文化碩士班
;
Department of Humanities and Social Sciences, Graduate Program of Ethnicity and Culture
Exciton Localization of High-Quality ZnO/MgxZn1-x Multiple Quantum Wells on Si (111) with a Y2O3 Buffer Layer
(2018-08-01)
Liu, Wei-Rein
;
Huang, Wei-Lun
;
Wu, Yung-Chi
;
Lai, Liang-Hsun
;
Hsu, Chia-Hung
We report the structural and optical properties of ten-period ZnO/MgxZn1-x multiple quantum wells (MQWs) prepared on the most widely used semiconductor material, Si. The introduction of a nanometer thick high-k Y2O3 transition layer between Si (111) substrate and a ZnO buffer layer significantly improves the structural perfection of the MQWs grown on top of it. The high structural quality of the ZnO/MgxZn1-xO MQWs is evidenced by the appearance of pronounced high order satellite peaks in X-ray crystal truncation rods; high resolution cross-sectional transmission electron microscopy images also confirmed the regularly arranged well and barrier layers. When the well width is less than similar to 2.7 nm, the quantum-confined Stark effect in MQWs can be negligible. Not only the increasing exciton-binding energy but also reducing exciton-phonon coupling determined in temperature-dependent photoluminescence spectra indicate quantum-size effect. Our results demonstrate that ZnO/MgxZn1-xO MQWs integrated on Si have great potential in UV optoelectronic device applications.
Paradoxical Effects of Sodium-Calcium Exchanger Inhibition on Torsade de Pointes and Early Afterdepolarization in a Heart Failure Rabbit Model
(2018-08-01)
Chang, Po-Cheng
;
Lu, Yu-Ying
;
Lee, Hui-Ling
;
Lin, Shien-Fong
;
Chu, Yen
Calcium homeostasis plays an important role in development of early afterdepolarizations (EADs) and torsade de pointes (TdP). The role of sodium-calcium exchanger (NCX) inhibition in genesis of secondary Ca2+ rise and EAD-TdP is still debated. Dual voltage and intracellular Ca2+ optical mapping were conducted in 6 control and 9 failing rabbit hearts. After baseline electrophysiological and optical mapping studies, E4031 was given to simulate long QT syndrome. ORM-10103 was then administrated to examine the electrophysiological effects on EAD-TdP development. E4031 enhanced secondary Ca2+ rise, EADs development, and TdP inducibility in both control and failing hearts. The results showed that ORM-10103 reduced premature ventricular beats but was unable to suppress the inducibility of TdP or EADs. The electrophysiological effects of ORM-10103 included prolongation of action potential duration (APD) and increased APD heterogeneity in failing hearts. ORM-10103 had a neutral effect on the amplitude of secondary Ca-1 rise in control and heart failure groups. In this model, most EADs generated from long-short APD junction area. In conclusion, highly selective NCX inhibition with ORM-10103 reduced premature ventricular beat burden but was unable to suppress secondary Ca2+ rise, EADs development, or inducibility of TdP. The possible electrophysiological mechanisms include APD prolongation and increased APD heterogeneity.
Resonant Wavelength Shift Detection System Based on a Gradient Grating Period Guided-Mode Resonance
(2018-08-01)
Chang, Chih-Wei
;
Chen, Shi-Ting
;
Lin, Yi-Ming
;
Huang, Cheng-Sheng
;
機械工程學系
A resonant wavelength detection system based on a gradient grating period guided-mode resonance (GGP-GMR) filter and a linear charge-coupled device is demonstrated. The GGP-GMR used in this work consists of a subwavelength grating structure with a grating period that varies from 250 to 550 nm in increments of 2 nm. We successfully demonstrate that by using this system, we can monitor the shift in a sensor's dip wavelength caused by different sucrose concentrations. This technology has the potential to replace the spectrometer used in most optical biosensor systems. Given its compactness, the system can be integrated with lab-on-a-chip systems for numerous biosensing applications.
Enhanced Photocatalysis from Truncated Octahedral Bipyramids of Anatase TiO2 with Exposed {001}/{101} Facets
(2018-08-01)
Lee, Tzu-Yuan
;
Lee, Chi-Young
;
Chiu, Hsin-Tien
;
應用化學系
;
Department of Applied Chemistry
In this study, we develop a new synthetic method to grow anatase TiO2 crystals composed of truncated octahedral bipyramids (TOBs) with exposed {001} and {101} facets by a vaporsolid reaction growth (VSRG) method. The VSRG method employs TiCl4(g) to react with CaO(s)/Ca(OH)(2(s)) at 8231043 K under atmospheric pressure. The O-deficient pale-blue TOB TiO2 crystals display high amount of both {001} and {101} facets. Together, they decompose methylene blue photocatalytically under UVvisible (UVvis) light irradiation. The most-efficient TOB catalyst VT923 (grown at 923 K, average edge length 400 nm, average thickness 200 nm, and surface area 4.20 m2/g) shows a degradation rate constant k, 0.0527 min(1). This is close to that of the P25 standard 0.0577 min(1). However, the surface area of P25 (46.8 m(2)/g) is about 12 times that of VT923. The extraordinary performance of VT923 is attributed to the presence of high amount of coexisting {001} and {101} facets to form effective surface heterojunctions. They would separate photogenerated electrons and holes effectively on {101} and {001} surfaces, respectively. For VT923, the {001}/{101} ratio is 0.764, which is close to 1, the highest value observed for all TOB samples grown in this study. The surface heterojunctions prolong the electronhole separation so that VT923 demonstrates the excellent photocatalytic capability. In addition, residual Cl atoms on the exposed faces are easily removed to show clean TiO surface layers with sufficient amount of O-deficient sites in the current samples.
VOICE/VIDEO QUALITY MEASUREMENT FOR LTE SERVICES
(2018-08-01)
Sung, Yingrong Coral
;
Ho, Yung-Sheng
;
Lin, Yi-Bing
;
Chen, Jyh-Cheng
;
Rao, Herman Chung-Hwa
LTE is a broadband wireless communication standard with the core network technology including voice service, which will be enhanced and evolved into 5G. In this article, we elaborate on performance issues of VoLTE and ViLTE. We investigate VoLTE voice quality with measurement experiments performed in the ITRI VoLTE testing environment. We also present the multimode and multiband interworking ViLTE call with a trial in a FET commercial mobile network. Our study provides references for the operators to measure the quality of VoLTE and ViLTE services.
Investigation of boundary layer thickness and turbulence intensity on film cooling with a fan-shaped hole by direct numerical simulation
(2018-08-01)
Fu, Wu-Shung
;
Chao, Wei-Siang
;
Tsubokura, Makoto
;
Li, Chung-Gang
;
Wang, Wei-Hsiang
Effects of the mainstream boundary layer thickness and the turbulence intensity on film cooling under low Reynolds number conditions are studied in this work by the direct numerical simulation (DNS). In other to solve low-speed compressible flow problems, several methods of Roe scheme, preconditioning, dual time stepping, and LUSGS are adopted to solve governing equations. Results reveal that a horseshoe vortex appears with a thicker mainstream boundary layer, and thus the lateral coverage of the coolant fluid has increased significantly. In addition, the existence of turbulence intensity eliminates the blow-off phenomenon, which happens in a thin mainstream boundary layer condition and enhances the film cooling effectiveness.