Browsing by Author "Chen, I-Ching"

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Benchmarking handheld graphical user interface: Smoothness quality of experience
(2018-05-01)
Lin, Ying-Dar
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Chu, Edward T. -H.
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Wen, Chien-Ling
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Lai, Yuan-Cheng
;
Chen, I-Ching
With the rapid growth of smartphones in the market, the smoothness of smartphones, how quickly and well smartphones react to a user's input, becomes a crucial factor consumers consider when making buying decisions. However, there is no benchmark for comparing the smoothness of one phone against another. In this paper, a handheld smoothness evaluation over regression (HSER) model was developed to make a fair evaluation. A video was first made and the several key indexes were extracted to represent behavior-based smoothness quality of services (BQoS). We built up a relationship between BQoS and behavior-based smoothness quality of experience (BQoE), and converted BQoE to handheld smoothness quality of experience. Our experiment results show that maximal frame interval and number of frame intervals are the two most critical indexes that indicate smoothness. The proposed HSER model is able to fairly evaluate the smoothness of smartphones because the error rate of the HSER model is less than 9% for a single behavior.
Cloning and characterization of monacolin K biosynthetic gene cluster from Monascus pilosus
(2008-07-23)
Chen, Yi-Pei
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Tseng, Ching-Ping
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Liaw, Li-Ling
;
Wang, Chun-Lin
;
Chen, I-Ching
Monacolin K is a secondary metabolite synthesized by polyketide synthases (PKS) from Monascus, and it has the same structure as lovastatin, which is mainly produced by Aspergillus terreus. In the present study, a bacterial artificial chromosome (BAC) clone, mps01, was screened from the BAC library constructed from Monascus pilosus BCRC38072 genomic DNA. The putative monacolin K biosynthetic gene cluster was found within a 42 kb region in the mps01 clone. The deduced amino acid sequences encoded by the nine genes designated as mokA-mokl, which share over 54% similarity with the lovastatin biosynthetic gene cluster in A. terreus, were assumed to be involved in monacolin K biosynthesis. A gene disruption construct designed to replace the central part of mokA, a polyketide synthase gene, in wild-type M. pilosus BCRC38072 with a hygromycin B resistance gene through homologous recombination, resulted in a mokA-disrupted strain. The disruptant did not produce monacolin K, indicating that mokA encoded the PKS responsible for monacolin K biosynthesis in M. pilosus BCRC38072.
Direct encapsulation of organic light-emitting devices (OLEDs) using photo-curable co-polyacrylate/silica nanocomposite resin
(2007-08-01)
Wang, Yu-Young
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Hsieh, Tsung-Eong
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Chen, I-Ching
;
Chen, Chin-Hsin
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材料科學與工程學系
Direct encapsulation of organic light-emitting devices (OLEDs) was realized by using highly transparent, photo-curable co-polyacrylate/silica nanocomposite resin. Feasibility of such a resin for OLED encapsulation was evaluated by physical/electrical property analysis of resins and driving voltage/luminance/lifetime measurement of OLEDs. Electrical property analysis revealed a higher electrical insulation of photocured nanocomposite resin film at 3.20 x 1012 9 in comparison with that of oligomer film at 1.18 x 10(12) Omega at 6.15 V to drive the bare OLED. This resulted a lower leakage current and the device driving voltage was efficiently reduced so that the nanocomposite-encapsulated OLED could be driven at a lower driving voltage of 6.09 V rather than 6.77 V for the oligomer-encapsulated OLED at the current density of 20 mA/cm(2). Luminance measurement revealed a less than 1.0% luminance difference of OLEDs encapsulated by various types of resins, which indicates that the photo-polymerization takes very little effect on the light-emitting property of OLEDs. Lifetime measurement of OLEDs found that t(80), the time span for the normalized luminance of device drops to 80%, for nanocomposite-encapsulated OLED is 350.17 h in contrast to 16.83 h for bare OLED and 178.17 h for the oligomer-encapsulated OLED. This demonstrates that nanocomposite resin with optimum properties is feasible to OLED packaging and a compact device structure could be achieved via the method of direct encapsulation.
Selection of an Effective Red-Pigment Producing Monascus pilosus by Efficient Transformation with Aurintricarboxylic Acid
(2008-11-01)
Chen, Yi-Pei
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Chen, I-Ching
;
Hwang, Ing-Er
;
Yuan, Gwo-Fang
;
Liaw, Li-Ling
The filamentous fungus Monascus pilosus was genetically transformed with a reporter plasmid, pMS-1.5hp, by aurintricarboxylic acid (ATA) treatment to obtain an efficient red-pigment producing mutant. The transformation efficiency of Monascus pilosus was higher with the ATA-treatment than with either a non-restriction enzyme-mediated integration (REMI) or a REMI method. This valid and convenient random mutagenesis method shows that ATA can be applied in fungi for efficient genetic transformation.