R.O.C Military Academy

About: R.O.C Military Academy is a government organization based out in Kaohsiung City, Taiwan. It is known for research contribution in the topics: Monopole antenna & Antenna efficiency. The organization has 136 authors who have published 236 publications receiving 3553 citations. The organization is also known as: Republic of China Army Officer School & Whampoa Military Academy.

A self-heating gas sensor with integrated NiO thin-film for formaldehyde detection

Abstract: This study develops a MEMS-based formaldehyde gas sensor based on a suspended silicon nitride microstructure with an integrated micro Pt heater, a thin-film NiO sensing layer and Pt interdigitated electrodes (IDEs) to measure the resistance changes of the NiO layer in the presence of formaldehyde. A specific orientation of the NiO layer is observed as the substrate temperature in the sputtering process is increased. The increase in substrate temperature assists in the formation of a NiO layer with the correct stoichiometric ratio (1:1). When formaldehyde is present in the atmosphere, oxidation occurs near the heated NiO sensing layer. This oxidization causes a change in the electrical conductivity of the NiO film, and hence changes the measured resistance between the interdigitated electrodes. The formaldehyde concentration is then determined from the change in the measured resistance. The application of a voltage to the Pt heaters causes the temperature of the micro-hotplate to increase, which in turn enhances the sensitivity of the sensor. The current experimental results show that the sub-micrometer grain sizes of the sputtered oxide thin film yield a high degree of sensitivity (0.33 Ω ppm−1), a low hysteresis value (0.7 ppm), a detection capability of less than 0.8 ppm, a quick response time (13.2 s), a quick recovery time (40.0 s) and a high selectivity over a wide range of formaldehyde concentrations in the presence of interfering species, such as acetone, ethanol and methanol. The novel micro formaldehyde gas sensor developed in this study is ideal for applications aimed at preventing and controlling sick building syndrome (SBS).

Evaluating the risk of failure using the fuzzy OWA and DEMATEL method

Abstract: Most current risk assessment methods use the risk priority number (RPN) value to evaluate the risk of failure. However, traditional RPN methodology has been criticized to have several shortcomings. Therefore, an efficient, simplified algorithm to evaluate the orderings of risk for failure problems is proposed in this paper, which utilizes fuzzy ordered weighted averaging (OWA) and the decision making trial and evaluation laboratory (DEMATEL) approach to rank the risk of failure. The proposed approach resolves some of the shortcomings of the traditional RPN method. In numerical verification, a failure mode and effects analysis (FMEA) of the thin film transistor liquid crystal display (TFT-LCD) product is presented to further illustrate the proposed approach. The results show that the proposed approach can reduce duplicated RPN numbers and get a more accurate, reasonable risk assessment. As a result, the stability of product and process can be assured.

A novel efficient approach for DFMEA combining 2-tuple and the OWA operator

Abstract: Design Failure Mode and Effect Analysis (DFMEA) is the application of the Failure Mode and Effects Analysis (FMEA) method specifically to product design. DFMEA is not only an important risk assessment technique but also a major task for enterprises in implementing production management. The purpose is to ensure that the product can achieve its designed functions under specific operating conditions. Most current DFMEA methods use the Risk Priority Number (RPN) value to evaluate the risk of failure. However, conventional RPN methodology has the serious problem of measurement scales and loses some valued information, which experts have to provide. In order to improve the method of RPN evaluation, this paper proposes a novel technique, combining 2-tuple and the Ordered Weighted Averaging (OWA) operator for prioritization of failures in a product DFMEA. A case of the Color Super Twisted Nematic (CSTN) that has been drawn from a midsized manufacturing factory is presented to further illustrate the proposed approach. After comparing the result that was obtained from the proposed method with the other two listed approaches, it was found that the proposed approach can effectively solve the problem of measurement scales and has not lost any expert to provide the useful information. As a result, stability of the product and process can be assured.