Browsing by Issue Date, starting with "2012-11-30"

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Facile Synthesis of Radial-Like Macroporous Superparamagnetic Chitosan Spheres with In-Situ Co-Precipitation and Gelation of Ferro-Gels
(2012-11-30)
Yang, Chih-Hui
;
Wang, Chih-Yu
;
Huang, Keng-Shiang
;
Yeh, Chen-Sheng
;
Wang, Andrew H. -J.
Macroporous chitosan spheres encapsulating superparamagnetic iron oxide nanoparticles were synthesized by a facile and effective one-step fabrication process. Ferro-gels containing ferrous cations, ferric cations and chitosan were dropped into a sodium hydroxide solution through a syringe pump. In addition, a sodium hydroxide solution was employed for both gelation (chitosan) and co-precipitation (ferrous cations and ferric cations) of the ferro-gels. The results showed that the in-situ co-precipitation of ferro-ions gave rise to a radial morphology with non-spheroid macro pores (large cavities) inside the chitosan spheres. The particle size of iron oxide can be adjusted from 2.5 nm to 5.4 nm by tuning the concentration of the sodium hydroxide solution. Using Fourier Transform Infrared Spectroscopy and X-ray diffraction spectra, the synthesized nanoparticles were illustrated as Fe3O4 nanoparticles. In addition, the prepared macroporous chitosan spheres presented a super-paramagnetic behaviour at room temperature with a saturation magnetization value as high as ca. 18 emu/g. The cytotoxicity was estimated using cell viability by incubating doses (0 similar to 1000 mu g/mL) of the macroporous chitosan spheres. The result showed good viability (above 80%) with alginate chitosan particles below 1000 mu g/mL, indicating that macroporous chitosan spheres were potentially useful for biomedical applications in the future.
k-Angle Object Coverage Problem in a Wireless Sensor Network
(2012-12-01)
Tseng, Yu-Chee
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Chen, Po-Yu
;
Chen, Wen-Tsuen
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資訊工程學系
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Department of Computer Science
One of the fundamental issues in sensor networks is the coverage problem, which reflects how well a field is monitored or tracked by sensors. Various versions of this problem have been studied, such as object, area, barrier, and hole coverage problems. In this paper, we define a new k-angle object coverage problem in a wireless sensor network. Each sensor can only cover a limited angle and range, but can freely rotate to any direction to cover a particular angle. Given a set of sensors and a set of objects at known locations, the goal is to use the least number of sensors to k-angle-cover the largest number of objects such that each object is monitored by at least k sensors satisfying some angle constraint. We propose centralized and distributed polynomial-time algorithms to solve this problem. Simulation results show that our algorithms can be effective in maximizing coverage of objects. A prototype system is developed to demonstrate the usefulness of angle coverage.
Item Selection for the Development of Parallel Forms From an IRT-Based Seed Test Using a Sampling and Classification Approach
(2012-12-01)
Chen, Pei-Hua
;
Chang, Hua-Hua
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Wu, Haiyan
;
應用化學系
;
管理科學系
Two sampling-and-classification-based procedures were developed for automated test assembly: the Cell Only and the Cell and Cube methods. A simulation study based on a 540-item bank was conducted to compare the performance of the procedures with the performance of a mixed-integer programming (MIP) method for assembling multiple parallel test forms. The study investigated the statistical equivalence of the forms generated by the three test assembly methods (Cell Only, Cell and Cube, and MIP) in terms of test information functions, test characteristic curves, mean square deviations, and practical constraints, such as content balancing and nonoverlap among forms. The results indicated that the 13-point MIP method outperformed the other two methods in terms of the "closeness" test information functions between the reference form and the assembled parallel tests. Regarding test characteristic curves, the Cell Only and Cell and Cube methods yielded more similar test characteristic curves than the MIP method. Constraining test information functions apparently does not guarantee that the assembled forms will yield similar test characteristic curves. Overall, the Cell Only and Cell and Cube methods have the potential to provide results similar to the optimization approach.
毛語言及其批判之可能
(深河出版有限公司, 2012-12-01)
黃子平
變動中的集體聽覺：模糊的訊號
(深河出版有限公司, 2012-12-01)
王明輝
Enhanced carrier extraction efficiency in organic solar cells with reduced space-charge limited transport by engineered vertical compositional profile
(2012-12-01)
Lee, Ming-Kun
;
Kuo, Tsung-Han
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Kong, Kuo-Wen
;
Hong, Yun-Ru
;
Wang, Jen-Chun
A multi-layered polymer solar cell (PSC) with a graded compositional profile to reduce space-charge limited (SCL) transport was designed and analyzed in details. We found that by increasing the effective carrier lifetime for the slower photo-carriers. SCL effects that degrade the fill factor and the power conversion efficiency can be alleviated in PSCs with a thick active layer. The reduction of SCL effects was evidenced by a diminished dependence of the incident photon-to-electron conversion efficiency (IPCE) on light bias, which also indicates the importance of light bias in characterizing the operating IPCE of PSCs with thick active layers which operate in SCL region. Based on our results, device architecture to enhance FF was proposed. (C) 2012 Elsevier B.V. All rights reserved.
頂尖男子桌球選手比賽技術比較分析
(國立交通大學體育室, 2012-12-01)
郭山本
;
陳金海
;
游鳳芸
;
郭明珍
;
Shan-Ben Kuo
目的：分析頂尖男子桌球選手綜合技術表現並比較我國與世界頂尖男子桌球選手綜合技術表現差異。方法：採用觀察法蒐集2008年參加世界盃桌球賽的各國頂尖選手11場比賽22筆資料，以桌球比賽綜合技術統計表為研究工具，所得資料以敘述統計、t檢定等方法來進行分析。結果：一、頂尖男子桌球選手各項綜合技術得分率及使用率最多的都是正手側發球搶攻。二、我國與世界頂尖男子桌球選手各項綜合技術得分率與使用率差異比較，只有蔣澎龍在正手側推攻使用率與世界頂尖男子桌球選手達顯著差異，其他各項綜合技術都未達顯著差異。結論：頂尖男子桌球選手比賽最重要綜合技術為正手側發球搶攻。
一個台灣人的紅衛兵印象
(深河出版有限公司, 2012-12-01)
鄭鴻生
阿妹／台妹：關於流行音樂研究的一點想法
(深河出版有限公司, 2012-12-01)
蔡孟哲
Optimization of the Single-Phased White Phosphor of Li2SrSiO4:Eu2+, Ce3+ for Light-Emitting Diodes by Using the Combinatorial Approach Assisted with the Taguchi Method
(2012-12-01)
Chen, Lei
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Luo, Anqi
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Zhang, Yao
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Liu, Fayong
;
Jiang, Yang
The best performance of the phosphor Li2SrSiO4: Eu2+, Ce3+ in terms of luminescence efficiency (LE), color rendering index (CRI) and color temperature (Tc) for light-emitting diode application was optimized with combinatorial approach. The combinatorial libraries were synthesized with solution-based method and the scale-up samples were synthesized with conventional solid-reaction method. Crystal structure was investigated by using the X-ray diffraction spectrometer. The emission spectra of each sample in combinatorial libraries were measured in situ by using a fiber optic spectrometer. Fluorescence spectrometers were used to record excitation and emission spectra of bulk samples. White light generation was tuned up by tailoring Eu2+ and Ce3+ concentrations in the single-phased host of Li2SrSiO4 under near-ultraviolet excitation, but it exhibited low efficiency of luminescence and poor color rendering index. The effects of each level of the Eu2+ and Ce3+ concentrations on LE, CRI, and Tc were evaluated with the Taguchi method. The optimum levels of the interaction pairs between Eu2+ and Ce3+ concentration on LE, CRI, and Tc were [2,1] (0.006 M, 0.003 M), [1, 2] (0.003 M, 0.006 M), and [3, 1] (0.009 M, 0.00 3M), respectively. The thermal stability of luminescence, the external quantum efficiency (QE), luminance, chromaticity coordinates, correlated color temperature, color purity including the composition ratio of RGB in white light, and color rendering index of the white light emission of phosphor were evaluated comprehensively from a bulk sample.
Resonance fluorescence spectra near a photonic bandgap
(2012-12-01)
Lai, Yinchieh
;
光電工程學系
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Department of Photonics
兩種民族主義：讀了劉大任〈反芻民族主義〉
(深河出版有限公司, 2012-12-01)
何懷碩
投籃輔助器對投籃時籃球軌跡與旋轉圈數之影響
(國立交通大學體育室, 2012-12-01)
陳忠強
;
Chiang-Chung Chen
本研究之目的：是在探討籃球選手投籃時籃球軌跡與旋轉圈數之研究，瞭解選手佩帶與未佩帶投籃輔助器時的投籃軌跡與球體轉數的差異性。方法：以不同位置的男子籃球選手為對象（小前鋒、大前鋒、中鋒），分別以未佩帶與佩帶投籃輔助器的方式進行20次的罰球線投籃試驗，並以高速攝影機從受測者的側面與背面進行拍攝，再利用影像分析來觀察從出手之後至碰到籃框間籃球的軌跡及轉數。結論：受測者佩戴投籃輔助器投籃時，籃球的軌跡高於未佩戴時，球的轉數變異係數也降低。由此現象我們推估，戴上投籃輔助器之後，投籃的出手姿勢的穩定度增加了。未來研究與實際應用建議詳見內文。
Molecular engineering of cocktail co-sensitization for efficient panchromatic porphyrin-sensitized solar cells
(2012-12-01)
Wu, Hui-Ping
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Ou, Zih-Wei
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Pan, Tsung-Yu
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Lan, Chi-Ming
;
Huang, Wei-Kai
Co-sensitization of two or more dyes with complementary absorption spectra on a semiconductor film is an effective approach to enhance the performance of a dye-sensitized solar cell (DSSC). Porphyrin sensitizer YD2-oC8 showed outstanding photovoltaic performance co-sensitized with an organic dye to cover the entire visible spectral region, 400-700 nm. To promote the light-harvesting capability beyond 700 nm, a porphyrin dimer (YDD6) was synthesized for a co-sensitized system. We report a systematic approach for engineering of molecular co-sensitization of TiO2 films in a cocktail solution containing YD2-oC8, an organic dye (CD4) and YDD6 in a specific molar ratio to optimize the photovoltaic performance of the device. The resulting device showed panchromatic spectral features in the IPCE action spectrum in the region 400-700 nm attaining efficiencies of 75-80%; the spectrum is extended to the near-IR region attaining 40-45% in 700-800 nm region, giving J(SC)/mA cm(-2) = 19.28, V-OC/mV = 753, FF = 0.719, and eta = 10.4% under standard AM 1.5 G one-sun irradiation. This performance is superior to what is obtained from the individual single-dye devices and the two-dye co-sensitized systems. The shifts of TiO2 potential upon dye uptake and the kinetics of charge recombination were examined through measurements of the charge extraction (CE) and intensity-modulated photovoltage spectroscopy (IMVS), respectively. Five co-sensitized systems were investigated to demonstrate that suppression of dye aggregation of YDD6 in the co-sensitized film is a key factor to further improve the device performance.
Large-area non-close-packed nanosphere deposition by blade coating for vertical space-charge-limited transistor
(2012-12-01)
Chao, Yen-Chu
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Wang, Kai-Ruei
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Meng, Hsin-Fei
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Zan, Hsiao-Wen
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Hsu, Yung-Hsuan
In this work, we proposed a fast and controllable blade coating process to form non-close-packed nanosphere structures. We investigated the key to obtain well-distributed non-close-packed PS spheres with blade coating. We utilized the blade-coated nanosphere structure to realize colloidal lithography and fabricate a vertical channel polymer transistor, the space-charge-limited transistor (SCLT). We demonstrated that SCLT utilizing blade-coated nanospheres delivered 13.9 mA/cm(2) at 1.8 V with an on/off current ratio as 45,000. The process of blade-coating nanospheres may facilitate the commercialization of low-cost colloidal lithography. (C) 2012 Elsevier B.V. All rights reserved.
Comparison of the clinical outcomes between fresh blastocyst and vitrified-thawed blastocyst transfer
(2012-12-01)
Ku, Pei-Yun
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Lee, Robert Kuo-Kuang
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Lin, Shyr-Yeu
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Lin, Ming-Huei
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Hwu, Yuh-Ming
To compare the clinical outcomes between fresh and vitrified-thawed day 5 blastocyst transfers. Retrospective case control study. Tertiary referral center. Patients 38 years of age or less who underwent IVF/ICSI cycles with fresh or frozen-thawed blastocysts transferred from June 1, 2009 to November 30, 2011 Vitrification and thawing of day 5 blastocysts using the Cryotop method. (Kitazato BioPharma Co., Ltd., Fuji city, Shizuoka, Japan) Clinical pregnancy rate, implantation rate, ongoing pregnancy rate, and multiple pregnancy rates. Of the 118 cycles in the fresh transfer group, 234 blastocysts were transferred. The clinical pregnancy rate was 66.1 % and implantation rate was 50.9 %. The ongoing pregnancy rate was 56.8 % and the rates for singleton and twin pregnancies were 53.7 % and 44.8 %. Of the 59 cycles in the vitrified-thawed group, 111 blastocysts were transferred. The clinical pregnancy rate was 59.3 % and implantation rate was 43.2 %. The ongoing pregnancy rate was 47.5 % and the rates for singleton and twin pregnancies were 60.7 % and 39.3 %. The clinical pregnancy rate, implantation rate and ongoing pregnancy rate did not differ significantly between the two groups. The implantation rates were not significantly different between the fresh and the vitrified-thawed groups. Thus, single embryo transfer may be considered in fresh cycles to decrease multiple pregnancy rates. The surplus embryos should be vitrified for the frozen embryo transfer to improve the cumulative pregnancy rate.
A computerized system of nail-fold capillaroscopy for dry eye disease diagnosis
(2012-12-01)
Hou, Mark C.
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Huang, Sheng-Chieh
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Wang, Hui-Min
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Tseng, Cheng-Lung
;
Lo, Lun-Chien
Nail-fold Capillaroscopy is a convenient and non-invasive tool to evaluate peripheral circulation. Rheumatic diseases such as Raynaud's disease and systemic sclerosis are investigated mostly by nail-fold capillaroscopy. However, it has not been used popularly due to the lack of golden standard in both measurement procedure and objective quantity analysis. This study proposes a computerized system of nail-fold capillaroscopy (CNC). CNC includes standard measurement procedures and three criterions of microcirculation which are capillary density, capillary width and blood flow velocity. CNC is applied to the images of 36 normal subjects and seven patients of dry eye disease (DED). We found density and width of afferent capillary were the better parameters to identify DED (p < 0.05). CNC could be a good auxiliary diagnostic tool for DED.
Anodic TiO2 Nanotube Arrays for Dye-Sensitized Solar Cells Characterized by Electrochemical Impedance Spectroscopy
(2012-12-01)
Wu, Hui Ping
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Li, Lu Lin
;
Chen, Chien Chon
;
Diau, Eric Wei Guang
;
土木工程學系
This paper reports on the microstructure of anodic titanium oxide (TiO2) and its use in a dye-sensitized solar cell (DSSC) device. When voltages of 60 V were applied to titanium foil for 2 hr under 0.25 wt% NH4F + 2 vol% H2O+C2H4(OH)(2), TiO2 with a nanotube structure was formed. The film, which had a large surface area, was used as an electron transport film in the DSSC. The DSSC device had a short-circuit current density (J(sc)) of 12.52 mA cm(-2), a fill factor (FF) of 0.65, an open-voltage (V-oc) of 0.77 V, and a photocurrent efficiency of 6.3% under 100% AM 1.5 light. The internal impedance values under 100%, 64%, 11%, and 0% (dark) AM 1.5 light intensities were measured and simulated using the electrical impedance spectroscopy (EIS) technique. The impedance characteristics of the DSSC device were simulated using inductors, resistors, and capacitors. The Ti/TiO2, TiO2/Electrolyte, electrolyte, and electrolyte/ (Pt/ITO) interfaces were simulated using an RC parallel circuit, and the bulk materials, such as the Ti, ITO and conducting wire, were simulated using a series of resistors and inductors. The impedance of the bulk materials was simulated using L-0+R-0+R-b, the impedance of the working electrode was simulated using (C-1//R-1)//(R-a+(C-2//R-2), the electrolyte was simulated using C-3//R-3, and the counter electrode was simulated using C-4//R-4. (C) 2012 Elsevier Ltd and Techna Group Sri. All rights reserved.
Image Saturation Improvement for 180 Hz Stencil-FSC LCD With Side-Lit LED Backlight
(2012-12-01)
Lin, Fang-Cheng
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Huang, Yi-Pai
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Teng, Chang-Yi
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Shieh, Han-Ping D.
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光電工程學系
The green-based 180 Hz Stencil-FSC method was proposed to effectively suppress color breakup for a field-sequential-color liquid crystal display (FSC-LCD). Nevertheless, this method has an issue on green color desaturation. Therefore, we further propose the "limited backlight signal ratio" (LBSR) to determine a proper backlight signal to increase image color saturation and simultaneously suppress color breakup. To realize a thin and high image quality eco-display, in addition, the light spread function model and the number of backlight divisions for a side-lit backlight are optimized and combined with the LBSR stencil-FSC method.
A comparison of two indices for the intraclass correlation coefficient
(2012-12-01)
Shieh, Gwowen
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管理科學系
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Department of Management Science
In the present study, we examined the behavior of two indices for measuring the intraclass correlation in the one-way random effects model: the prevailing ICC(1) (Fisher, 1938) and the corrected eta-squared (Bliese & Halverson, 1998). These two procedures differ both in their methods of estimating the variance components that define the intraclass correlation coefficient and in their performance of bias and mean squared error in the estimation of the intraclass correlation coefficient. In contrast with the natural unbiased principle used to construct ICC(1), in the present study it was analytically shown that the corrected eta-squared estimator is identical to the maximum likelihood estimator and the pairwise estimator under equal group sizes. Moreover, the empirical results obtained from the present Monte Carlo simulation study across various group structures revealed the mutual dominance relationship between their truncated versions for negative values. The corrected eta-squared estimator performs better than the ICC(1) estimator when the underlying population intraclass correlation coefficient is small. Conversely, ICC(1) has a clear advantage over the corrected eta-squared for medium and large magnitudes of population intraclass correlation coefficient. The conceptual description and numerical investigation provide guidelines to help researchers choose between the two indices for more accurate reliability analysis in multilevel research.