Low-loss low-ripple SAW filters using three bidirectional centrosymmetric transducers

Low-loss, low-ripple and high out-of-band rejection SAW filters have been constructed using a three transducer configuration with symmetric/antisymmetric end transducers. The filter on 128°-cut LiNbO3 has an insertion loss of 5.2 dB, a passband ripple of 0.3 dB (peak to peak) and an out-of-band rejection of 55 dB.     

Cyclic fatigue crack growth of SiCw/Y-TZP composites: long- and short-crack behaviour

Cyclic fatigue crack growth behaviour has been investigated for 10 vol % SiC_w/Y-TZP composites with grain sizes varying from 1.50–2.00 m in a residual stress field. To investigate the effect of precracking procedure, cyclic fatigue tests were performed on unannealed specimens using the four-point bending method under two conditions: (a) with a sharp crack and precracking procedure, and (b) with a natural sharp flaw. For all specimens in both conditions, an overall V-shaped da/dN versus K _app relation was obtained. However, for the specimens without precracking, the da/dN had an unusual dependence on the applied stress intensity, giving a zigzag V-shaped curve. Explanations for these different results for the two conditions are discussed in terms of crack-tip shielding effects and residual stress field.     

Gate effects on DNA translocation through silicon dioxide nanopore

The effects of gate voltage on the translocation of DNA molecules through a nanopore are studied. A twenty-fold increase in the translocation time is observed with a positive gate voltage applied, without changing too much of the ionic current. The amplitude of the current blockage by the DNA molecules was reduced by roughly the same factor. At the same time, the number of the blocking events decreases significantly. The applied gate voltage also modulates the scatter plot of the amplitude of the current blockage against the dwell time. The observations are consistent with the recent theoretical results.     

Rapid on-site multiplex assays for total and toxigenic Microcystis using real-time PCR with microwave cell disruption

A quantitative real-time polymerase chain reaction (qPCR) is a robust means by which to monitor toxin-producing cyanobacteria. However, qPCR usually requires DNA extraction, which is a time-consuming, labor-intensive pretreatment. To be able to quickly determine the potential of cyanotoxin contamination in the field, a rapid pretreatment method for DNA extraction and a portable qPCR device are needed. In this study, we applied a microwave-based method for the qPCR pretreatment and a multicolor portable qPCR with UPL and TaqMan probes to quantify toxigenic and total Microcystis. The method was tested using laboratory cultures of toxigenic Microcystis aeruginosa PCC7820. The qPCR results showed the cycle thresholds value (Ct value) correlated well with cell numbers, with detection limit at about 1,000 cells/ml. This scheme was applied in 22 environmental samples from six drinking water reservoirs (DWRs) in Taiwan. Although the results for qPCR were about four times higher than those of microscopic observation, good correlation between qPCR and microscope methods were obtained (r-square: 0.79, P < 0.01). The ratios of toxigenic Microcystis to total Microcystis in two reservoirs, Sin-Shan Reservoir and Shih-men Reservoir, were less than 10%. In three other reservoirs, Ren-Yi-Tan Reservoir, Nan-Hua Reservoir and Bao-Shan Reservoir, much higher (>46.1%) ratios were obtained. The scheme may assist quick assessment of the risk associated with toxic cyanobacteria in DWRs.     

Understanding domain registration abuses

The ability to monetize domain names through resale or serving ad content has contributed to the rise of questionable practices in acquiring them, including domain-name speculation, tasting, and front running. In this paper, we perform one of the first comprehensive studies of these domain registration practices. In order to characterize the prevalence of domain-name speculation, we derive rules describing “hot” topics from popular Google search queries and apply these rules to a dataset containing all .com registrations for an eight-month period in 2008. We also study the extent of domain tasting throughout this time period and analyze the efficacy of ICANN policies intended to limit tasting activity. Finally, we automatically generate high-quality domain names related to current events in order to measure domain front running by registrars. The results of our experiments shed light on the methods and motivations behind these domain registration practices and, in some cases, underscore the difficulty in definitively measuring these questionable behaviors.     

An analysis of IT/IS outsourcing provider selection for small- and medium-sized enterprises in Taiwan

Outsourcing is important in highly diversified business environments, but while there have been many studies on outsourcing, none have explicitly tackled the problem of how SMEs should assess and select their outsourcer. Numerous benefits might be gained if SMEs could utilize evaluation models to help select their IT/IS outsourcer effectively. Prejudices arising from selection through impartial analysis could be avoided and a more accurate and an objective decision could be made. We investigated the selection process of an enterprise needing an IT/IS outsourcing provider in Taiwan. Our recommended process quantitatively sorts the criteria using the AHP. An evaluation model was developed based on the needs of the SME who should use it to obtain a better outsourcing provider resulting from improved information vital to maintain outsourcing efficiency. Use of our model should reduce costs and potential risks in adopting new IT/IS applications and promote an objective standard with which to evaluate IT/IS outsourcing providers.     

Identifying the signs of fraudulent accounts using data mining techniques

In today’s technological society there are various new means to commit fraud due to the advancement of media and communication networks. One typical fraud is the ATM phone scams. The commonality of ATM phone scams is basically to attract victims to use financial institutions or ATMs to transfer their money into fraudulent accounts. Regardless of the types of fraud used, fraudsters can only collect victims’ money through fraudulent accounts. Therefore, it is very important to identify the signs of such fraudulent accounts and to detect fraudulent accounts based on these signs, in order to reduce victims’ losses. This study applied Bayesian Classification and Association Rule to identify the signs of fraudulent accounts and the patterns of fraudulent transactions. Detection rules were developed based on the identified signs and applied to the design of a fraudulent account detection system. Empirical verification supported that this fraudulent account detection system can successfully identify fraudulent accounts in early stages and is able to provide reference for financial institutions.     

Migrating from WCAG 1.0 to WCAG 2.0 - A comparative study based on Web Content Accessibility Guidelines in Taiwan

The primary purpose of this research was to explore a comparative analysis of the “Web Content Accessibility Guidelines (WCAG)” standard in Taiwan and the international WCAG standards (WCAG 1.0/WCAG 2.0). The WCAG in Taiwan was established by the Research, Development and Evaluation Commission (RDEC), Executive Yuan in 2002. The WCAG 1.0 was established by the Web Accessibility Initiative (WAI, an organization that created the Web Content Accessibility system) of the World Wide Web Consortium (W3C), and became a W3C standard on May 5, 1999. The WCAG 2.0 became a W3C standard on December 11, 2008.The WCAG in Taiwan was established based on the contents of the WCAG 1.0. However, as the WCAG 2.0 was announced in 2008, check standards based on the WCAG 1.0 were facing revision in all aspects. Therefore, this study aimed at analyzing and comparing the differences between the WCAG 2.0 and the WCAG standards in Taiwan. Utilizing “human check” based on the WCAG 2.0 standard, this study assessed disabilities-related websites conforming to the WCAG standard in Taiwan. Results suggested that migrating from WCAG in Taiwan (based on WCAG 1.0) to WCAG 2.0 does not require a full range revision of webpage design. Suggestions given to disabilities-related websites in Taiwan for developing and providing more complete web accessibility included: (1) websites without accessible design should directly follow the WCAG 2.0 standard in developing web accessibility; (2) future promotion of web accessibility should include all educational institutes and related associations/organizations.For future studies, the resource availability for the disabled and the government achievement in web accessibility after WCAG 2.0 is implemented in Taiwan are topics worth of investigation. Expert opinions and user feedbacks should be included to reflect the actual needs of people with disabilities.