Browsing by Author "Chiu, YC"

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Alkaline and ultrasonic pretreatment of sludge before anaerobic digestion
(1997)
Chiu, YC
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Chang, CN
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Lin, JG
;
Huang, SJ
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環境工程研究所
Pretreatment of waste activated sludge (WAS) results in an improved efficiency of the subsequent anaerobic biotransformation of the organic matter to volatile fatty acids. The pretreatment process has been carried out using alkaline treatment, ultrasonic treatment (20 KHz, 120 W) and different combination of these two methods: alkaline followed by ultrasonic, as well as the combining method in which ultrasonic treatment is applied to WAS samples dosed with alkaline, The hydrolysis efficiency was evaluated based on the quantity of soluble COD (SCOD) and organic nitrogen in the pretreated WAS as well as the production of total volatile fatty acids (TVFA) in the following biochemical acid potential (BAP) test. For WAS samples with described pretreatments, the released SCOD varied from 36% to 89% of the total COD (TCOD) and soluble organic nitrogen from 34% to 42%. The TVFA/TCOD ratio of the raw WAS used in this study was less than 10%. For the alkaline pretreated WAS, the TVFA/TCOD ratio increased to 30%, and the following ultrasonic treatment enhanced the ratio 66%. Further, WAS samples pretreated using simultaneous ultrasound and alkaline treatment in which ultrasonic was applied to WAS samples dosed with 40 meq/L NaOH for 14.4 sec/mL could achieve a maximum TVFA/TCOD ratio of 84% in 21 hours, Therefore, the combination of simultaneous alkaline and ultrasound pretreatment is efficient in enhancing the production of volatile acids in WAS in order to achieve recovery of volatile fatty acids from the WAS. (C) 1997 IAWQ. Published by Elsevier Science Ltd.
Assessment of recoverable forms of sulfur particles used in bioleaching of contaminated sediments
(2003-01-01)
Chen, SY
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Chiu, YC
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Chang, PL
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Lin, JG
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環境工程研究所
The use of recoverable sulfur particles will enhance the feasibility and reduce the cost of bioleaching process. Three different forms of sulfur particles, powder, pastilles and pellets were used to study the utilization and recovery of sulfur, used as energy source for thiobacilli in the bioleaching process. The Langmuir isotherm was used to explain the adsorption equilibrium existing between the sorbed and suspended bacteria and the maximum adsorption capacity obtained from the Langmuir isotherm was utilized to determine the specific surface area of the sulfur particles. The specific surface area of sulfur particles was found to be the determining factor in the bioleaching process and not the particle size. The rates of pH reduction, sulfate production and metal solubilization increased with increasing specific surface area of the particles. The pH reduction and metal solubilization were significantly enhanced by the reuse of recovered sulfur particles. The efficiency of metal solubilization with recovered sulfur pastilles was comparable to that with sulfur powder. This study revealed the practicability of reusing the recovered sulfur pastilles in the bioleaching process. (C) 2002 Elsevier Science Ltd. All rights reserved.
Copyright protection against print-and-scan operations by watermarking for color images using coding and synchronization of peak locations in frequency domain
(2006-05-01)
Chiu, YC
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Tsai, WH
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資訊工程學系
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Department of Computer Science
A watermarking method for copyright protection of color images against print-and-scan operations is proposed. A watermark is embedded in an input image as coefficient-value peaks that are circularly and symmetrically distributed ill a middle band of the discrete Fourier transform (DFT) domain of the input image. By detecting the robust peaks in the DFT domain of a reproduced image obtained by scanning a printed version of a watermarked image, we can extract the embedded watermark to verify the copyright of the reproduced image. Experimental results are given to prove the feasibility of the proposed method.
Innovation capacity comparison of China's information technology industrial clusters: The case of Shanghai, Kunshan, Shenzhen and Dongguan
(2005-09-01)
Lai, HC
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Chiu, YC
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Leu, HD
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科技管理研究所
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Institute of Management of Technology
The aim of this paper is twofold: first, to explore the effects of industrial cluster on innovation capacity, and second, to study the impact of external resources on firms' innovation capacity especially under Chinese regional economic policy. This is a critical subject that lacks sufficient analysis. Through years of investment and effort, several IT industrial clusters have developed in China with Shanghai, Kunshan, Shenzhen and Dongguan the better-known examples. These IT industrial clusters were chosen for an empirical study on the disparities in China's innovation capacity. All of the innovation capacity determinants at these four IT industrial clusters were different. It was confirmed that the regional dimension of Chinese economic policy affects firms' innovation capacity in the industrial cluster. The results also show whether the regional policy differences will moderate the cluster effect on innovation.
Innovation policy for developing Taiwan's competitive advantages
(2002-09-01)
Shyu, JZ
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Chiu, YC
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科技管理研究所
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Institute of Management of Technology
Innovation is a prerequisite for every nation and business facing the emergence of a knowledge-based economy and globalization. For small and medium firms in developing countries with limited resources and relatively low national advantage innovation is much more difficult. Government innovation policy, stemming from three sides - supply, demand, and environment, has been shown to play a major role in assisting firms to conduct innovation activities, especially in developing countries. This paper first summarizes recent tends and issues relevant to Taiwan's innovation structure and policy. Then, considering the present situation of Taiwan, analyzes the effect of government policy and current problems. Recommendations are presented systematically, based upon innovation policy.
The market acceptance of electric motorcycles in Taiwan experience through a stated preference analysis
(1999-03-01)
Chiu, YC
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Tzeng, GH
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運輸與物流管理系註：原交通所+運管所
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Department of Transportation and Logistics Management
The environmental and energy concerns of using motorcycles in urban areas have fostered the rapid development development of electric motorcycles (EMs) in Taiwan in recent years. EMs' zero-emission, low noise level and high energy efficiency features provide the promising potential to alleviate the severe environmental pollution problem caused by the existing gasoline motorcycles. This study summarizes the recent development of the EM. More specifically, this study aims to analyze the potential demand for EMs based on an interview survey using stated preference modeling approaches. Study results show that female motorists are the potential target market for EMs. Developmental and energy-use issues of EMs are also discussed in this study. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.