Browsing by Issue Date, starting with "2015-07-16"

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Incidence of Non-Traumatic Subconjunctival Hemorrhage in a Nationwide Study in Taiwan from 2000 to 2011
(2015-07-16)
Hu, Dan-Ning
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Mou, Chih-Hsin
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Chao, Shih-Chun
;
Lin, Ching-Yang
;
Nien, Chan-Wei
Objective To determine the nationwide incidence of non-traumatic subconjunctival hemorrhage (NTSCH) in Taiwan from 2000-2011 and to analyze the risk factors for NTSCH using a case-control analysis. Methods This is a population-based cohort administrative database study. Randomly selected 1,000,000 residents from the Taiwan National Health Insurance Research Database in 2000 and followed for 12 years to determine the population incidence of NTSCH. Individuals with the first diagnosis of subconjunctival hemorrhage were identified by the corresponding International Classification of Diseases code (ICD) 372.72. Traumatic subconjunctival hemorrhages (ICD-9 codes 921, 871, 850-854 and 959.01) were excluded. The association of NTSCH with various demographic factors, comorbidities and use of medications was studied by a population based case-control analysis using data of 2008-2011. Results A total of 67,720 patients with a first-time diagnosis of NTSCH were identified during the 12 years period. The mean annual incidence was 65 per 10,000 individuals (crude incidence) and 60 per 10,000 individuals (age-and sex-standardized incidence). The incidence rate of NTSCH was higher in women than in men, [men-women ratio: 0.80 (95% confidence interval: 0.78-0.81)]. The age-specific incidence decreased from childhood to the group of teenagers, after which it increased to a maximal value of 136.2 per 10,000 people in the age group of 60-69 years. Case-control analysis showed that comorbidities of hypertension, purpura and thrombocytopenia, and the use of aspirin were significantly associated with the risk of NTSCH. Conclusions This study indicates that NTSCH is a common eye disease that occurs once in 167 individuals in a general East Asian population per year. It occurs more often in women than in men and the age-specific incidence peaked in the age group of 60-69 years. Hypertension, purpura and thrombocytopenia, and the use of aspirin are the major risk factors for NTSCH.
Ab Initio Chemical Kinetics for the CH3 + O(P-3) Reaction and Related Isomerization-Decomposition of CH3O and CH2OH Radicals
(2015-07-16)
Xu, Z. F.
;
Raghunath, P.
;
Lin, M. C.
;
應用化學系
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Department of Applied Chemistry
The kinetics and mechanism of the CH3 + O reaction and related isomerization-decomposition of CH3O and CH2OH radicals have been studied by ab initio molecular orbital theory based on the CCSD(T)/aug-cc-pVTZ//CCSD/aug-cc-pVTZ, CCSD/aug-cc-pVDZ, and G2M//B3LYP/6-311+G(3df,2p) levels of theory. The predicted potential energy surface of the CH3 + O reaction shows that the CHO + H-2 products can be directly generated from CH3O by the TS3 -> LM1 -> TS7 -> LM2 -> TS4 path, in which both LM1 and LM2 are very loose and TS7 is roaming-like. The result for the CH2O + H reaction shows that there are three low-energy barrier processes including CH2O + H -> CHO + H-2 via H-abstraction and CH2O + H -> CH2OH and CH2O + H -> CH3O by addition reactions. The predicted enthalpies of formation of the CH2OH and CH3O radicals at 0 K are in good agreement with available experimental data. Furthermore, the rate constants for the forward and some key reverse reactions have been predicted at 200-3000 K under various pressures. Based on the new reaction pathway for CH3 + O, the rate constants for the CH2O + H and CHO + H-2 reactions were predicted with the microcanonical variational transition-state/Rice-Ramsperger-Kassel-Marcus (VTST/RRKM) theory. The predicted total and individual product branching ratios (i.e., CO versus CH2O) are in good agreement with experimental data. The rate constant for the hydrogen abstraction reaction of CH2O + H has been calculated by the canonical variational transition-state theory with quantum tunneling and small-curvature corrections to be k(CH2O + H -> CHO + H-2) = 2.28 x 10(-19) T-2.65 exp(-766.5/T) cm(3) molecule(-1) s(-1) for the 200-3000 K temperature range. The rate constants for the addition giving CH3O and CH2OH and the decomposition of the two radicals have been calculated by the microcanonical RRKM theory with the time-dependent master equation solution of the multiple quantum well system in the 200-3000 K temperature range at 1 Torr to 100 atm. The predicted rate constants are in good agreement with most of the available data.
Two HCI-Elimination Channels and Two CO-Formation Channels Detected with Time-Resolved Infrared Emission upon Photolysis of Acryloyl Chloride [CH2CHC(O)Cl] at 193 nm
(2015-07-16)
Lee, Pei-Wen
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Scrape, Preston G.
;
Butler, Laurie J.
;
Lee, Yuan-Pern
;
應用化學系
Following photodissociation of gaseous acryloyl chloride, CH2CHC(O)Cl, at 193 nm, temporally resolved vibration-rotational emission spectra of HCl (v <= 7, J <= 35) in region 2350-3250 cm(-1) and of CO (v <= 4, J <= 67) in region 1865-2300 cm(-1) were recorded with a step-scan Fourier-transform spectrometer. The HCl emission shows a minor low-J component for v <= 4 with average rotational energy E-rot = 9 +/- 3 kJ mol(-1) and vibrational energy E-vib = 28 +/- 7 kJ mol(-1) and a major high-J component for v <= 7 with average rotational energy E-rot = 36 +/- 6 kJ mol(-1) and vibrational energy E-vib = 49 +/- 9 kJ mol(-1); the branching ratio of these two channels is similar to 0.2:0.8. Using electronic structure calculations to characterize the transition states and each intrinsic reaction coordinate, we find that the minor pathway corresponds to the four-center HCl-elimination of CH2ClCHCO following a 1,3-Cl-shift of CH2CHC(O)Cl, whereas the major pathway corresponds to the direct four-center HCl-elimination of CH2CHC(O)Cl. Although several channels are expected for CO produced from the secondary dissociation of C2H3CO and H2C=C=C=O, each produced from two possible dissociation channels of CH2CHC(O)Cl, the CO emission shows a near-Boltzmann rotational distribution with average rotational energy E-rot = 21 +/- 4 kJ mol(-1) and average vibrational energy E-vib = 10 +/- 4 kJ mol(-1). Consideration of the branching fractions suggests that the CO observed with greater vibrational excitation might result from secondary decomposition of H2C=C=C=O that was produced via the minor low-J HCl-elimination channel, while the internal state distributions of CO produced from the other three channels are indistinguishable. We also introduce a method for choosing the correct point along the intrinsic reaction coordinate for a roaming HCl elimination channel to generate a Franck-Condon prediction for the HCl vibrational energy.
Uridylation of RNA Hairpins by Tailor Confines the Emergence of MicroRNAs in Drosophila
(2015-07-16)
Reimao-Pinto, Madalena M.
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Ignatova, Valentina
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Burkard, Thomas R.
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Hung, Jui-Hung
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Manzenreither, Raphael A.
Uridylation of RNA species represents an emerging theme in post-transcriptional gene regulation. In the microRNA pathway, such modifications regulate small RNA biogenesis and stability in plants, worms, and mammals. Here, we report Tailor, an uridylyltransferase that is required for the majority of 3\' end modifications of microRNAs in Drosophila and predominantly targets precursor hairpins. Uridylation modulates the characteristic two-nucleotide 3\' overhang of microRNA hairpins, which regulates processing by Dicer-1 and destabilizes RNA hairpins. Tailor preferentially uridylates mirtron hairpins, thereby impeding the production of non-canonical microRNAs. Mirtron selectivity is explained by primary sequence specificity of Tailor, selecting substrates ending with a 3\' guanosine. In contrast to mirtrons, conserved Drosophila precursor microRNAs are significantly depleted in 3\' guanosine, thereby escaping regulatory uridylation. Our data support the hypothesis that evolutionary adaptation to Tailor-directed uridylation shapes the nucleotide composition of precursor microRNA 3\' ends. Hence, hairpin uridylation may serve as a barrier for the de novo creation of microRNAs in Drosophila.
Computing cutoff times of birth and death chains
(2015-07-18)
Chen, Guan-Yu
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Saloff-Coste, Laurent
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應用數學系
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Department of Applied Mathematics
Earlier work by Diaconis and Saloff-Coste gives a spectral criterion for a maximum separation cutoff to occur for birth and death chains. Ding, Lubetzky and Peres gave a related criterion for a maximum total variation cutoff to occur in the same setting. Here, we provide complementary results which allow us to compute the cutoff times and windows in a variety of examples.
交大e-News第190期-頂大不是夢想　經濟弱勢生進交大
(2015-07-20)
國立交通大學秘書室
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Secretariat
Synthesis and Characterization of Ba[CoSO]: Magnetic Complexity in the Presence of Chalcogen Ordering
(2015-07-20)
Valldor, Martin
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Roessler, Ulrich K.
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Prots, Yurii
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Kuo, Chang-Yang
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Chiang, Jen-Che
Barium thio-oxocobaltate(II), Ba[CoS2/2O2/2], was synthesized by the reaction of equimolar amounts of BaO, Co, and S in closed silica ampoules. The title compound (Cmcm, a=3.98808(3), b=12.75518(9), c=6.10697(4)angstrom) is isostructural to Ba[ZnSO]. The use of soft X-ray absorption spectroscopy confirmed that cobalt is in the oxidation state +2 and tetrahedrally coordinated. Its coordination consists of two sulfur and two oxygen atoms in an ordered fashion. High-temperature magnetic susceptibility data indicate strong low-dimensional spin-spin interactions, which are suggested to be closely related to the layer-type crystal structure and perhaps the ordered distribution of sulfur and oxygen. Antiferromagnetic ordering below T-N=222K is observed as an anomaly in the specific heat, coinciding with a significant lowering of the magnetic susceptibility. Density functional theory calculations within a generalized-gradient approximation (GGA)+U approach identify an antiferromagnetic ground state within the square-like two-dimensional layers of Co, and antiferromagnetic correlations for nearest and next nearest neighbors along bonds mediated by oxygen or sulfur. However, this magnetic state is subject to frustration by relatively strong interlayer couplings.
Enhanced switching uniformity in AZO/ZnO1-x/ITO transparent resistive memory devices by bipolar double forming
(2015-07-20)
Simanjuntak, Firman Mangasa
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Panda, Debashis
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Tsai, Tsung-Ling
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Lin, Chun-An
;
Wei, Kung-Hwa
The influence of single and double forming on the switching stability of AZO/ZnO1-x/ITO transparent resistive memory devices was investigated. Devices that underwent single forming exhibited severe switching instability, where as those that underwent double forming exhibited excellent switching uniformity. The quantity of conducting filaments can be limited by applying the two-step forming process. Consequently, the set/reset process can be controlled, enhancing switching stability. Satisfactory endurance with an acceptable ON/OFF ratio of 10(2) and satisfactory retention behavior of 10(4)s at room temperature confirmed the reliability of optimized devices. Furthermore, highly transparent devices (transparency of approximately 85% in visible range) have been fabricated. (C) 2015 AIP Publishing LLC.
Novel Wire-on-Plate Electrostatic Precipitator (WOP-EP) for Controlling Fine Particle and Nanoparticle Pollution
(2015-07-21)
Li, Ziyi
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Liu, Yingshu
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Xing, Yi
;
Thi-Minh-Phuong Tran
;
Thi-Cuc Le
A new wire-on-plate electrostatic precipitator (WOP-EP), where discharge wires are attached directly on the surface of a dielectric plate, was developed to ease the installation of the wires, minimize particle deposition on the wires, and lower ozone emission while maintaining a high particle collection efficiency. For a lab-scale WOP-EP (width, 50 mm; height, 20 mm; length, 180 mm) tested at the applied voltage Of 18 kV, experimental total particle collection efficiencies were found as high as 90.9-99.7 and 98.8-99.9% in the particle size range of 30-1870 nm at the average air velocities of 0.50 m/s (flow rate, 30 L/min; residence time, 0.36 s) and 0.25 m/s (flow rate, 15 L/min; residence time, 0.72 s), respectively. Particle collection efficiencies calculated by numerical models agreed well with the experimental results. The comparison to the traditional wire-in-plate EP showed that, at the same applied voltage, the current WOP-EP emitted 1-2 orders of magnitude lower ozone concentration, had cleaner discharge wires after heavy particle loading in the EP, and recovered high particle collection efficiency after the grounded collection plate was cleaned. It is expected that the current WOP-EP can be scaled up as an efficient air-cleaning device to control fine particle and nanopartide pollution.
三角積分調變器及其校正方法
(2015-07-21)
吳書豪
;
吳介琮
一種三角積分調變器，包括：一迴路濾波器，接收一輸入訊號、一回授訊號與一校正訊號，該迴路濾波器包括N個積分器，該些積分器相互串聯，其中N為正整數；一量化器，耦接該迴路濾波器，數位化該迴路濾波器之一輸出訊號以輸出一數位資料；一數位類比轉換器，耦接該量化器，轉換從該量化器接收的該數位資料以輸出該回授訊號；以及一校正處理器，包括N個校正單元，各該校正單元耦接相對應之各該積分器，其中第i個校正單元利用第(i-1)個積分器輸出的一偵測訊號以產生一誤差訊號至第i個積分器，第i個積分器根據該誤差訊號調整一操作極點，i為大於1且小於等於N的整數。
工程變更之保持時間修復方法
(2015-07-21)
江蕙如
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楊喻名
;
何松庭
一種工程變更之保持時間修復方法，其係對一已佈局及繞線設計藉由塞入最少的電容來填補完該已佈局及繞線設計的短路徑，該方法包含：一填補數值決定步驟，接收該已佈局及繞線設計，依據一元件庫、一時序限制及一時序分析報告，以決定並輸出該已佈局及繞線設計之每一個閘所需填補的數量與位置；以及一負載/緩衝配置步驟，依據一備用元件資訊、一虛擬金屬資訊、及該已佈局及繞線設計之每一個閘所需填補的數量與位置，以填補完該已佈局及繞線設計的短路徑；其中，該填補數值決定步驟包含：一填補資源收集步驟，依據該備用元件資訊及該虛擬金屬資訊，以收集該已佈局及繞線設計之一個閘其扇出網絡的一有界盒子中的對應備用元件資訊及對應虛擬金屬資訊；一扇出填補靈活性計算/靈活性檢查步驟，計算該已佈局及繞線設計之一個閘的扇出填補靈活性PF (i)；一填補值決定步驟，依據該一個閘的該扇出填補靈活性PF (i)以計算該一個閘的一填補值；一判斷步驟，其判斷該已佈局及繞線設計之每一個閘的短路徑之保持違反是否均已解決或是違反已無法再刪減，若否，則重回扇出填補靈活性計算/靈活性檢查步驟；以及一填補值再精鍊步驟，若判定該已佈局及繞線設計之每一個閘的短路徑之保持違反均已解決或是違反已無法再刪減時，以反向拓樸次序計算該已佈局及繞線設計之一個閘的再精鍊填補值，以再刪減該已佈局及繞線設計之一個閘的填補值；其中，該負載/緩衝配置步驟包含：一找尋備用元件候選者步驟，對該已佈局及繞線設計之需要進行填補的閘/走線產生備用元件候選者，其係將每個需要進行填補的閘的扇出網絡的一有界盒子中的對應備用元件規劃為需要進行填補的閘能夠使用的資源；一備用元件選擇步驟，其係將每個需要進行填補的閘/走線選擇最佳的次集合加總解，填補完該已佈局及繞線設計的短路徑；以及一虛擬金屬配置步驟，利用虛擬金屬插置，填補完該已佈局及繞線設計的短路徑；其中，該已佈局及繞線設計係以一有向圖K{K=(G,E)}表示，該有向圖的每個節點gi (giG)係為該已佈局及繞線設計中的一個閘，並在該節點gi 上以D(i)表示對應於該閘的閘延遲，每一條邊e(i,j){e(i,j)E}表示連著該閘的導線，節點gi 的輸出端之建立到達時間A(i)係以下列公式表示：節點gi 的輸出端之建立需要時間R(i)係以下列公式表示：節點gi 的輸出端的保持到達時間a(i)係以下列公式表示：節點gi 的輸出端之保持需要時間r(i)係以下列公式表示：
基於線上遞回獨立成分分析之即時多通道腦波訊號處理器
(2015-07-21)
方偉騏
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石偉業
;
廖瑞傑
;
黃冠儒
;
陳秋國
一種基於線上遞回獨立成分分析(ORICA)之即時多通道腦波訊號處理器，係包括：逆開方根矩陣計算單元，係用於提供特徵值、特徵向量及逆開方根矩陣之運算；白化處理單元，係耦接該逆開方根矩陣計算單元，用於將所接收之取樣訊號進行共變異數計算以產生共變異數矩陣，該共變異數矩陣藉由該逆開方根矩陣計算單元之運算以產生白化矩陣；ORICA計算單元，係耦接該逆開方根矩陣計算單元及該白化處理單元，用於將該取樣訊號與該白化矩陣進行計算以得到白化後取樣訊號，並將該白化後取樣訊號與所預設之一解混合矩陣進行獨立成分分析運算，以得到獨立成分資料；以及ORICA訓練單元，係耦接該逆開方根矩陣計算單元及該ORICA計算單元，用以根據該獨立成分資料對該解混合矩陣進行訓練，以藉由該逆開方根矩陣計算單元之計算而得到該解混合矩陣之逆矩陣，並將該解混合矩陣以及該解混合矩陣之逆矩陣進行運算以產生新的解混合矩陣，其中，該新的解混合矩陣係供該ORICA計算單元將下一個該白化後取樣訊號與該新的解混合矩陣進行另一次獨立成分分析運算，以得到新的獨立成分資料，且其中，該ORICA訓練單元更包含：非線性模組，係用於計算該獨立成分資料以得到非線性轉換函數；峰度估計模組，係用於識別該獨立成分資料為超高斯訊號或次高斯訊號並產生一峰度數值；多工器，係耦接該非線性模組及該峰度估計模組，用以依據該高斯訊號或該次高斯訊號以及該峰度數值，以得到獨立成分分布資料的非線性轉換函數；學習率模組，係用於計算學習率，該學習率決定該解混合矩陣在訓練時的收斂性和穩態效能；及權重訓練模組，係利用該獨立成分資料、該獨立成分分布資料的非線性轉換函數、該學習率與該解混合矩陣進行疊代運算，以產生該新的解混合矩陣。
Multifunctional 3D Patternable Drug-Embedded Nanocarrier-Based Interfaces to Enhance Signal Recording and Reduce Neuron Degeneration in Neural Implantation
(2015-07-22)
Huang, Wei-Chen
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Lai, Hsin-Yi
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Kuo, Li-Wei
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Liao, Chia-Hsin
;
Chang, Po-Hsieh
Quantitative Characterization and Mechanism of Formation of Multilength-scale Bulk Heterojunction Structures in Highly Efficient Solution-Processed Small-Molecule Organic Solar Cells
(2015-07-23)
Huang, Yu-Ching
;
Tsao, Cheng-Si
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Huang, Tzu-Yen
;
Cha, Hou-Chin
;
Patra, Dhananjaya
In this study we used simultaneous grazing-incidence small- and wide-angle X-ray scattering (GISAXS and GIWAXS, respectively) to probe the multilength-scale structures of thin active layers comprising the linear A-D-A-type pi-conjugated donor molecule TBDTCNR and the fullerene acceptor molecule PC61BM for use in solution-processed small-molecule-based organic solar cells (SMOSCs). We found that the pseudo-two-dimensional fractal-like networks in the bulk heterojunction (BHJ) structure were determined by mutual interactions between the small-molecule (SM) crystallites and the nanoscale PC61BM clusters during their formation and phase separation, and deduced quantitatively, at multiple length scales, the BHJ structures comprising these SM crystallites and PC61BM clusters. We also conducted in situ GIWAXS measurements to study the temporal behavior and kinetics of SM crystallization from solution to the solid film state. Our GISAXS/GIWAXS study revealed that the multilength-scale BHJ structures in the thin films could be tuned effectively by varying the amount of incorporated PC61BM and the annealing temperature. This study provides fundamental information relating to the mechanism of formation of hierarchical BHJ structures through relatively rapid crystallization of a highly crystalline SM, as well as the relationships among the hierarchical structure, the photovoltaic performance, and the mechanism of formation, thereby allowing greater control over BHJ structures in SMOSCs with optimized fabrication and performance.
METHOD FOR SELECTING MUSIC BASED ON FACE RECOGNITION, MUSIC SELECTING SYSTEM AND ELECTRONIC APPARATUS
(2015-07-23)
Song Kai-Tai
;
Lin Chao-Yu
A method for selecting music based on face recognition, a music selecting system and an electronic apparatus are provided. The method includes the following steps: accessing a database to retrieve a plurality of song emotion coordinates corresponding to a plurality of songs; mapping the song emotion coordinates to an emotion coordinate graph; capturing a human face image; identifying an emotion state corresponding to the human face image, and transforming the emotion state to a current emotion coordinate; mapping the current emotion coordinate to the emotion coordinate graph; updating a song playlist according to a relative position between the current emotion coordinate and a target emotion coordinate, wherein the song playlist includes a plurality of songs to be played that direct the current emotion coordinate to the target emotion coordinate.
Time-resolved magnetophotoluminescence studies of magnetic polaron dynamics in type-II quantum dots
(2015-07-24)
Barman, B.
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Oszwaldowski, R.
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Schweidenback, L.
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Russ, A. H.
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Pientka, J. M.
We used continuous wave photoluminescence (cw-PL) and time-resolved photoluminescence (TR-PL) spectroscopy to compare the properties of magnetic polarons (MP) in two related spatially indirect II-VI epitaxially grown quantum dot systems. In the ZnTe/(Zn, Mn)Se system the holes are confined in the nonmagnetic ZnTe quantum dots (QDs), and the electrons reside in the magnetic (Zn, Mn)Se matrix. On the other hand, in the (Zn, Mn)Te/ZnSe system, the holes are confined in the magnetic (Zn, Mn)Te QDs, while the electrons remain in the surrounding nonmagnetic ZnSe matrix. The magnetic polaron formation energies E-MP in both systems were measured from the temporal redshift of the band-edge emission. The magnetic polaron exhibits distinct characteristics depending on the location of the Mn ions. In the ZnTe/(Zn, Mn)Se system the magnetic polaron shows conventional behavior with E-MP decreasing with increasing temperature T and increasing magnetic field B. In contrast, E-MP in the (Zn, Mn)Te/ZnSe system has unconventional dependence on temperature T and magnetic field B; E-MP is weakly dependent on T as well as on B. We discuss a possible origin for such a striking difference in the MP properties in two closely related QD systems.
Synthesis, characterization and analysis of the acrylamide- and glycidamide-glutathione conjugates
(2015-07-25)
Luo, Yu-Syuan
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Long, Tai-Ying
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Shen, Li-Ching
;
Huang, Shou-Ling
;
Chiang, Su-Yin
Acrylamide (AA) is reported present in high-temperature-processed food and classified as a possible human carcinogen. In vivo metabolic activation of AA by CYP 2E1 to glycidamide (GA) may play an important role on AA carcinogenicity. AA and GA can be detoxified by glutathione-S-transferase to form AA and isomeric GA glutathione conjugates (M-, GA2- and GA3-GSH, respectively), which can be further metabolized to mercapturic acids (MAs). Although many studies analyzed MAs in urine of rodents and humans, few studies have characterized and analyzed the GSH conjugates. The objectives of this study were to synthesize, purify, and characterize AA-GSH, GA2-GSH, GA3-GSH, (C-13(3))-AA-GSH, (C-13(3))-GA2-GSH, and (C-13(3))-GA3-GSH to develop an isotope-dilution liquid chromatography tandem mass spectrometry (LC-MS/MS) method to analyze AA- and GA-GSHs in blood of rats treated with AA. After purification and characterization of these conjugates, the LC-MS/MS method was developed and validated. This method reveals a limit of detection (S/N= 3) at 0.017 and a limit of quantitation (S/N = 10) at 0.05 ng/mL of serum for AA-GSH, 0.075 and 0.25 ng/mL for GA2-GSH, and 0.15 and 0.5 ng/mL for GA3-GSH. Analyzed with this method, AA-GSH, GA2-GSH and GA3-GSH were 1651.1 +/- 374.5, 18.4 +/- 6.3 and 75.3 +/- 31.3 ng/mL in blood of male rats at 2 h after treatment with 5 mg/kg bw of AA by ip injection. These results showed that the LC-MS/MS method was successfully developed to analyze AA-GSH, GA2-GSH and GA3-GSH with satisfying sensitivity of AA and GA which were conjugated by glutathione in vivo. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
Three-phase behavior-based detection and classification of known and unknown malware
(2015-07-25)
Lin, Ying-Dar
;
Lai, Yuan-Cheng
;
Lu, Chun-Nan
;
Hsu, Peng-Kai
;
Lee, Chia-Yin
To improve both accuracy and efficiency in detecting known and even unknown malware, we propose a three-phase behavior-based malware detection and classification approach, with a faster detector in the first phase to filter most samples, a slower detector in the second phase to observe remaining ambiguous samples, and then a classifier in the third phase to recognize their malware type. The faster detector executes programs in a sandbox to extract representative behaviors fed into a trained artificial neural network to evaluate their maliciousness, whereas the slower detector extracts and matches the LCSs of system call sequences fed into a trained Bayesian model to calculate their maliciousness. In the third phase, we define malware behavior vectors and calculate the cosine similarity to classify the malware. The experimental results show that the hybrid two-phase detection scheme outperforms the one-phase schemes and achieves 3.6% in false negative and 6.8% in false positive. The third-phase classifier also distinguishes the known-type malware with an accuracy of 85.8%. Copyright (c) 2015 John Wiley & Sons, Ltd.
Light extraction from electroluminescent devices using micro-rod array embedded within glass substrate
(2015-07-27)
Wang, Yi-Jun
;
Ouyang, Shi-Hong
;
Lu, Jian-Gang
;
Shieh, Han-Ping D.
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光電工程學系
The total internal reflection (TIR) effect in conventional electroluminescent devices causes a large amount of light energy trapped in the devices and result in heat energy that adversely affects the performance of the device. In order to enhance the light out-coupling efficiency without sacrificing the electrical properties, a micro-rod array (MRA) structure fabricated by a femtosecond laser was demonstrated. Green, blue, and red organic light-emitting diodes were employed to verify the effect of the proposed method, which increases out-coupling efficiencies by a factor of 1.9, 1.7, and 1.82, respectively, compared with conventional devices. This highly effective method is compatible with current device fabrication processes and is applicable to full-color electroluminescent devices. (C) 2015 Optical Society of America
Synchronous-asynchronous laser mode-locking transition
(2015-07-27)
Wu, Shang-Ying
;
Hsiang, Wei-Wei
;
Lai, Yinchieh
;
光電工程學系
;
光電工程研究所
Synchronous-asynchronous mode-locking transition in a hybrid active and passive mode-locked laser is investigated theoretically. Three distinct mode-locking states are found and their transition diagram under varying detuning frequency and modulation strength is determined. By examining the steady-state lasing gain as a function of the detuning modulation frequency, we also clarify why the laser will become unstable near the transition points and why the nonlinear saturable absorption effect is crucial for the stable asynchronous mode-locking operation.