Browsing by Issue Date, starting with "2012-05-01"

Now showing 1 - 20 of 36637

Chromosome 15q21-22-Related Polymorphisms and Haplotypes Are Associated with Susceptibility to Type-2 Diabetic Nonproliferative Retinopathy
(2012-05-01)
Hsieh, Yao-Yuan
;
Huang, Yu-Chuen
;
Chang, Chi-Chen
;
Wang, Yu-Kuo
;
Lin, Wen-Hsin
Objective: Diabetic retinopathy (DR) is a microvascular complication of diabetes with a complex multifactorial pathogenesis. We aimed to investigate whether chromosome 15q21-22-related gene polymorphisms could be used as markers of DR susceptibility in type 2 diabetic (T2D) individuals. Methods: Individuals were divided into three groups: (1) T2D with nonproliferative DR (NPDR; n = 102); (2) T2D with proliferative DR (PDR; n = 72); (3) T2D without DR (n = 573). Six single-nucleotide polymorphisms (SNPs) (rs7174997, rs3751624, rs8025011, rs17818837, rs2922220, and rs2414520) lying within chromosome 15q21-22 region were genotyped by using Illumina HumanHap550-Duo BeadChips. Genotypes/allelic frequencies and haplotypes for these polymorphisms in each group were compared. Results: The MYO5C related SNP (rs3751624)*A related genotype and allele are associated with higher susceptibilities to DR, including PDR and NPDR. The rs3751624*GG/AA + AG percentages in each group are (1) 75.5%/24.5%, (2) 73.6%/26.4%, and (3) 82.5%/17.5%. In contrast, the other five SNPs in each group were not significantly different. One haplotype (G-A-G-G-T-G) appears significantly different between T2D individuals with and without DR. Other haplotype distributions were not significantly different between each group. Conclusion: The MYO5C related SNP (rs3751624)*A related genotype/allele and haplotype (G-A-G-G-T-G) might be associated with susceptibility for retinopathy in T2D individuals. Some chromosome 15q21-22* related genetic variations might contribute to the pathogenesis of DR.
A Scalable High-Performance Virus Detection Processor Against a Large Pattern Set for Embedded Network Security
(2012-05-01)
Cheng, Chieh-Jen
;
Wang, Chao-Ching
;
Ku, Wei-Chun
;
Chen, Tien-Fu
;
Wang, Jinn-Shyan
Contemporary network security applications generally require the ability to perform powerful pattern matching to protect against attacks such as viruses and spam. Traditional hardware solutions are intended for firewall routers. However, the solutions in the literature for firewalls are not scalable, and they do not address the difficulty of an antivirus with an ever-larger pattern set. The goal of this work is to provide a systematic virus detection hardware solution for network security for embedded systems. Instead of placing entire matching patterns on a chip, our solution is a two-phase dictionary-based antivirus processor that works by condensing as much of the important filtering information as possible onto a chip and infrequently accessing off-chip data to make the matching mechanism scalable to large pattern sets. In the first stage, the filtering engine can filter out more than 93.1% of data as safe, using a merged shift table. Only 6.9% or less of potentially unsafe data must be precisely checked in the second stage by the exact-matching engine from off-chip memory. To reduce the impact of the memory gap, we also propose three enhancement algorithms to improve performance: 1) a skipping algorithm; 2) a cache method; and 3) a prefetching mechanism.
Thermally activated state transition technique for femto-Newton-level force measurement
(2012-05-01)
Chen, Feng-Jung
;
Wong, Jhih-Sian
;
Hsu, Ken Y.
;
Hsu, Long
;
電子物理學系
We develop and test a thermally activated state transition technique for ultraweak force measurement. As a force sensor, the technique was demonstrated on a classical Brownian bead immersed in water and restrained by a bistable optical trap. A femto-Newton-level flow force imposed on this sensor was measured by monitoring changes in the transition rates of the bead hopping between two energy states. The treatment of thermal disturbances as a requirement instead of a limiting factor is the major feature of the technique, and provides a new strategy by which to measure other ultraweak forces beyond the thermal noise limit. (C) 2012 Optical Society of America
Diagnostic test-pattern generation targeting open-segment defects and its diagnosis flow
(2012-05-01)
Chen, Y. -H.
;
Chang, C. -L.
;
Wen, C. H. -P.
;
電機工程學系
;
Department of Electrical and Computer Engineering
As an open defect occurs in one wire segment of the circuit, different logic values on the coupling wires of the physical layout may result in different faulty behaviours, which are so called the Byzantine effect. Many previous researches focus on the test and diagnosis of open defects but the pattern diagnosability has not properly addressed. Therefore in this study, a high-resolution diagnostic framework for open defects is proposed and consists of a diagnostic test-pattern generation (DTPG) and its diagnosis flow. The branch-and-bound search associated with controllability analysis is incorporated in satisfiability-based DTPG to generate patterns for the target segment. Later, a precise diagnosis flow constructs the list of defect candidates in a dictionary-based fashion followed by an inject-and-evaluate analysis to greatly reduce the number of candidates for silicon inspection. Experimental results show that the proposed framework runs efficiently and deduces nearly one candidate for each open-segment defect on average among all ISCAS'85 benchmark circuits.
Ionic liquid-supported synthesis of dihydroquinazolines and tetrahydroquinazolines under microwave irradiation
(2012-05-01)
Hsu, Hai-Yuan
;
Tseng, Chih-Chun
;
Matii, Banrali
;
Sun, Chung-Ming
;
應用化學系
An efficient microwave-assisted and water-soluble ionic liquid (IL)-supported synthesis of medicinally important dihydro- and tetrahydroquinazolines has been developed. The protocol involves the S(N)2 substitution reaction of IL-bound 4-bromomethyl-3-nitrobenzoic acid with various primary amines to provide IL-bound 4-((alkylamino) methyl)-3-nitrobenzoate under microwave irradiation. Further elaboration followed by sequential cyclization with various isothiocyanates and aldehydes furnished IL-bound target compounds. Cleavage of the IL support by methanolysis gave dihydro- and tetrahydroquinazolines with high purity and excellent yields. The new protocol has the advantages of shorter reaction time, easy workup process, excellent yields, reduced environmental impact, wide substrate scope, and convenient procedure.
使用共用傳導層傳送晶片間多重信號之系統
(2012-05-01)
蘇朝琴
;
何盈杰
;
黃博祥
本發明提供一種使用共用傳導層傳送晶片間多重信號之系統,其包括一第一晶片、一第二晶片、及一共用傳導層。該第一晶片至少具有第一晶片之第一金屬層墊及一第二金屬層墊。該第二晶片至少具有第二晶片之第一金屬層墊及一第二金屬層墊。該共用傳導層為導電材料,該共用傳導層直接黏合該第一晶片及該第二晶片,其中,第二晶片之第一金屬層墊係對齊該第一晶片之第一金屬層墊,以透過該共用傳導層而接收來自該第一晶片之第一金屬層墊之訊號,而不受來自其它該第一晶片及第二晶片之金屬層墊之訊號的影響。
Application of 2-Azido-2-deoxythioglycosides for beta-Glycoside Formation and Oligosaccharide Synthesis
(2012-05-01)
Mong, Kwok-Kong Tony
;
Yen, Yu-Fang
;
Hung, Wei-Cheng
;
Lai, Yen-Hsun
;
Chen, Jiun-Han
Most natural 2-acetamido-2-deoxyglycosides exist in a 1,2-trans-beta-glycosidic configuration. This study investigated the use of 2-azido-2-deoxythioglycosides for 1,2-trans-beta-glycosidic bond formation under low-concentration glycosylation conditions. Further application of the 2-azido-2-deoxythioglycosyl substrates for one-pot oligosaccharide synthesis was demonstrated in the synthesis of protected beta-(1?6)-N-acetylglucosamine trimer, core-6serine conjugate, and F1a serine conjugate.
Dual-reflected-structure erbium-doped fiber laser in single-longitudinal-mode for wavelength-tuning
(2012-05-01)
Yeh, C. H.
;
Chow, C. W.
;
Sung, J. Y.
;
Lu, S. S.
;
Wu, Y. F.
In this work, we propose and demonstrate a dual-reflected-structure erbium-doped fiber (EDF) laser with a linear cavity using a passive saturable-absorbor-based (SAB) filter to achieve single-longitudinal-mode (SLM) lasing. Here, we can observe the wavelength tuning range between 1530.0 and 1562.0 nm with the output powers of -13.7 to -7.6 dBm and optical signal to noise ratios (OSNRs) of 35.4 and 47.9 dB/0.05 nm, respectively. Moreover, when the lasing wavelength is tuned to the longer wavelength gradually, the obtained output power and SNR increase. This is because the Er+ gain can be suppressed and moves to the longer wavelength via the proposed fiber laser structure. In addition, the output stability of the proposed laser has also been analyzed and studied.
GUIDING CENTER DRIFT INDUCED BY HOMOGENIZATION
(2012-05-01)
Jiang, Jiann-Sheng
;
Lin, Chi-Kun
;
應用數學系
;
數學建模與科學計算所(含中心)
;
Department of Applied Mathematics
The guiding center drift induced by the homogenization of the Lorentz forces is studied. It generates memory effects. The memory (or nonlocal) kernel is described by the Volterra integral equation. The memory kernel can be characterized explicitly in terms of a Radon measure. It describes the extra velocity drift. By way of velocity drift, we view the Gauss's law with polarization charges.
Air-side performance of herringbone wavy fin-and-tube heat exchangers under dehumidifying condition - Data with larger diameter tube
(2012-05-01)
Wang, Chi-Chuan
;
Liaw, Jane-Sunn
;
機械工程學系
;
Department of Mechanical Engineering
This study examines the airside performance of the herringbone wavy fin-and-tube heat exchangers in dehumidifying condition having a larger diameter tube (D-c = 16.59 mm) with the tube row ranging from 2 to 12. Test results are compared to that of dry conditions and plain fin geometry. Upon the influence of surface condition (dry or wet) on the heat transfer performance, the heat transfer performance in dehumidifying condition normally exceeds that in dry condition, and is more pronounced with the rise of tube row or reduction of fin pitch. By contrast, it is found that the heat transfer coefficient for plain fin geometry in dehumidifying condition is slightly lower than that in dry condition. The pressure drops in wet condition is much higher than that in dry condition. However, the difference in pressure drop amid dry and dehumidifying condition for wavy fin configuration is less profound as that of plain fin geometry. (C) 2012 Elsevier Ltd. All rights reserved.
A frequency bin-wise nonlinear masking algorithm in convolutive mixtures for speech segregation
(2012-05-01)
Chi, Tai-Shih
;
Huang, Ching-Wen
;
Chou, Wen-Sheng
;
電機工程學系
;
Department of Electrical and Computer Engineering
A frequency bin-wise nonlinear masking algorithm is proposed in the spectrogram domain for speech segregation in convolutive mixtures. The contributive weight from each speech source to a time-frequency unit of the mixture spectrogram is estimated by a nonlinear function based on location cues. For each sound source, a non-binary mask is formed from the estimated weights and is multiplied to the mixture spectrogram to extract the sound. Head-related transfer functions (HRTFs) are used to simulate convolutive sound mixtures perceived by listeners. Simulation results show our proposed method outperforms convolutive independent component analysis and degenerate unmixing and estimation technique methods in almost all test conditions. (C) 2012 Acoustical Society of America
Assessing attitude error of FORMOSAT-3/COSMIC satellites and its impact on orbit determination
(2012-05-01)
Tseng, Tzu-Pang
;
Hwang, Cheinway
;
Yang, Shan Kuo
;
土木工程學系
;
Department of Civil Engineering
An attitude determination and control system (ADCS) is critical to satellite attitude maneuvers and to the coordinate transformation from the inertial frame to the spacecraft frame. This paper shows specific sensors in the ADCS of the satellite mission FORMOSAT-3/COSMIC (F3/C) and the impact of the ADCS quality on orbit accuracy. The selection of main POD antenna depends on the beta angles of the different F3/C satellites (for FM2 and FM4) during the inflight phase. In particular, under the eclipse, alternative attitude sensors are activated to replace the Sun sensors, and such a sensor change leads to anomalous GPS phase residuals and a degraded orbit accuracy. Since the nominal attitude serves as a reference for ADCS, the 3-dimensional attitude-induced errors in reduced dynamic orbits over selected days in 2010 show 9.35, 10.78, 4.97, 5.48, 7.18, and 6.89 cm for FM1-FM6. Besides, the 3-dimensional velocity errors induced by the attitude effect are 0.10, 0.10, 0.07, 0.08, 0.09, and 0.10 for FM1-FM6. We analyze the quality of the observed attitude transformation matrix of F3/C and its impact on kinematic orbit determination. With 249 days of GPS in 2008, the analysis leads to the following averaged 3-dimensional attitude-induced orbit errors: 2.72, 2.62, 2.37, 1.90, 1.70, and 1.99 cm for satellites FM1-FM6. Critical suggestions of geodetic payloads for the follow-on mission of F3/C are presented based on the current result. (C) 2012 COSPAR. Published by Elsevier Ltd. All rights reserved.
Limit Theorems for Subtree Size Profiles of Increasing Trees
(2012-05-01)
Fuchs, Michael
;
應用數學系
;
Department of Applied Mathematics
Simple families of increasing trees were introduced by Bergeron, Flajolet and Salvy. They include random binary search trees, random recursive trees and random plane-oriented recursive trees (PORTs) as important special cases. In this paper, we investigate the number of subtrees of size k on the fringe of some classes of increasing trees, namely generalized PORTs and d-ary increasing trees. We use a complex-analytic method to derive precise expansions of mean value and variance as well as a central limit theorem for fixed k. Moreover, we propose an elementary approach to derive limit laws when k is growing with n. Our results have consequences for the occurrence of pattern sizes on the fringe of increasing trees.
A calibrated direct conversion front-end transmitter with resonant matching techniques for mobile WiMAX/WiBro applications
(2012-05-01)
Chang, Chia-Hung
;
Jou, Christina F.
;
電機工程學系
;
Department of Electrical and Computer Engineering
A direct conversion front-end transmitter with the properties of high linearity and high single sideband rejection ratio is described in this paper. The transmitter employs two resonant matching techniques to improve its operating bandwidth. The first resonant circuit design is applied at the inter-stage of the LO input buffer in order to achieve a wideband frequency response which ranges from dc to 6 GHz. The second resonant circuit is applied at the power amplifier (PA) driver output stage to increase the matching bandwidth and meet both the Worldwide Inter-operability for Microwave Access (WiMAX) and Wireless Broadband (WiBro) applications simultaneously. In addition, the sideband signal and carrier leakage of this transmitter are further minimized by a proposed calibration circuit design to achieve the error vector magnitude (EVM) specifications. The measured single sideband performance with calibration mechanism demonstrates approximately 15 dB improvement on sideband and carrier suppression. The rejected sideband and carrier signals can be up to 55.19 and 56.31 dBc, respectively. The measured dynamic gain range of the transmitter is 53 dB in 1-dB step with a maximum relative gain error lower than 0.4 dB. The transmitter delivers +0.766 dBm output power with EVM of -34.687 dB for the orthogonal frequency division multiple access (OFDMA) 64QAM-3/4 modulated signals. The measured constellation is minimized to be < 1.5% with output power from -2.3 to -36.2 dBm.
Diffuser-Aided Diffuse Optical Imaging for Breast Tumor: A Feasibility Study Based on Time-Resolved Three-Dimensional Monte Carlo Modeling
(2012-05-01)
Chuang, Ching-Cheng
;
Lee, Chia-Yen
;
Chen, Chung-Ming
;
Hsieh, Yao-Sheng
;
Liu, Tsan-Chi
This study proposed diffuser-aided diffuse optical imaging (DADOI) as a new approach to improve the performance of the conventional diffuse optical tomography (DOT) approach for breast imaging. The 3-D breast model for Monte Carlo simulation is remodeled from clinical MRI image. The modified Beer-Lambert's law is adopted with the DADOI approach to substitute the complex algorithms of inverse problem for mapping of spatial distribution, and the depth information is obtained based on the time-of-flight estimation. The simulation results demonstrate that the time-resolved Monte Carlo method can be capable of performing source-detector separations analysis. The dynamics of photon migration with various source-detector separations are analyzed for the characterization of breast tissue and estimation of optode arrangement. The source-detector separations should be less than 4 cm for breast imaging in DOT system. Meanwhile, the feasibility of DADOI was manifested in this study. In the results, DADOI approach can provide better imaging contrast and faster imaging than conventional DOT measurement. The DADOI approach possesses great potential to detect the breast tumor in early stage and chemotherapy monitoring that implies a good feasibility for clinical application.
[3+2] Cycloaddition of Dialkyl (E)-Hex-2-en-4-ynedioates to [60]Fullerene by Phosphane-Promoted Tandem alpha(delta ')-Michael Additions
(2012-05-01)
Chuang, Shih-Ching
;
Deng, Jie-Cheng
;
Chan, Fu-Wei
;
Chen, Sheng-Yuan
;
Huang, Wei-Je
Organophosphanes promote the [3+2] cycloaddition reactions of dialkyl (E)-hex-2-en-4-ynedioates and [60]fullerene, giving a series of cyclopenteno-fullerenes 3ak bearing phosphorus ylides. This cycloaddition reaction is initiated by the attack of nucleophilic phosphanes at the a(d')-C atom of the dialkyl (E)-hex-2-en-4-ynedioate, which generates a 1,3-dipolar species. These 1,3-dipoles then react with C60 followed by intramolecular cyclization to give cyclopenteno-fullerenes in moderate-to-good yields. In a cyclic voltmmetry study, these novel fullerenes show a larger cathodic shift in their first reduction potential relative to [6,6]phenyl-C61 methyl butyrate, which indicates that these new derivatives possess higher LUMO energy levels.
Social networking and adjustments among international students
(2012-05-01)
Lin, Jih-Hsuan
;
Peng, Wei
;
Kim, Mijung
;
Kim, Sung Yeun
;
LaRose, Robert
How do social media facilitate adjustment to changes in social structure and culture? This research examines the impact of online social networking on online and offline social capitals and adjustment of international students in the United States. A survey of 195 international students in a major Midwestern university showed that students' interactions with Americans and home country friends using Facebook, extroversion, and horizontal collectivism were positively related to international students' social adjustment and online bridging capital. Facebook usage mediated the relationship between extroversion and online social capital. The implications of social network site use, personality, and cultural difference on social capital and adjustment are discussed.
Exploiting Multi-Spatial Correlations of Motion Data in a Body Sensor Network
(2012-05-01)
Wu, Chun-Hao
;
Tseng, Yu-Chee
;
資訊工程學系
;
Department of Computer Science
Human body motions usually exhibit a high degree of coherence and correlation in patterns. This allows exploiting spatial correlations of motion data being captured by a body sensor network. Since human bodies are relatively small, earlier work has shown how to compress motion data by allowing a node to overhear at most kappa = 1 node's transmission and exploit the correlation with its own data for data compression. In this work, we consider multi-spatial correlations by extending kappa = 1 to kappa > 1 and constructing a partial-ordering directed acyclic graph (DAG) to represent the compression dependencies among sensor nodes. While a minimum-cost tree for kappa = 1 can be found in polynomial time, we show that finding a minimum-cost DAG is NP-hard even for kappa = 2. We then propose an efficient heuristic and verify its performance by real sensing data.
Performance Evaluation of Inter-Processor Communication for an Embedded Heterogeneous Multi-Core Processor
(2012-05-01)
Tsao, Shiao-Li
;
Lee, Sung-Yuan
;
資訊工程學系
;
Department of Computer Science
Embedded systems often use a heterogeneous multi-core processor to improve performance and energy efficiency. This multi-core processor is composed of a general purpose processor (GPP), which manages the program flow and I/O, and a digital. signal processor (DSP), which processes mass data. An inter-processor communication (IPC) mechanism is thus required to exchange data between a GPP and a DSP. This paper uses comprehensive experiments to evaluate the IPC performance of an embedded heterogeneous multi-core processor under different design strategies. We further develop the IPC performance model and suggest dynamic adjustment of IPC strategies under environmental parameters and system resource constraints. Based on the results and findings, we improve the IPC performance of a voice over IP (VoIP) phone. Experimental results demonstrate that the GPP workload decreases significantly by 35% without sacrificing the functionalities and voice quality of the VolP system. Moreover, we apply the concept of dynamic adjustment of IPC strategies to an embedded media gateway. The simulation results demonstrate that the dynamic IPC strategy can considerably improve the system performance of the media gateway compared with the static IPC design approach.
具有氮化鎵層的多層結構基板及其製法
(2012-05-01)
張翼
;
蕭佑霖
;
呂榮淇
一種具有氮化鎵層的多層結構基板之製法,其係先在承載板上形成具有複數開孔之網狀層,並於該開孔內的承載板上依序形成緩衝層、三層不同鋁濃度之氮化鋁鎵層與氮化鎵層。本發明之三層不同鋁濃度之氮化鋁鎵層係能有效釋放應力、減少氮化鎵層表面裂痕與控制內部缺陷,因此可形成較大面積、較大厚度、無裂痕且較高品質的氮化鎵層,進而有利於高效能電子元件的製作。本發明復提供一種具有氮化鎵層的多層結構基板。