Browsing by Author "Chang, K. -H."

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Optical Properties Study in Qusai Three Dimensional Aluminum Metallic Photonic Crystal
(2007-01-01)
Wu, S-C
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Lee, Y. -J.
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Chang, K. -H.
;
Lin, S. -Y
;
Cho, A. -T.
A qusai three dimensional aluminum metallic photonic crystal (Q-3D Al MPC) composed with five layers of Al rod arrays was fabricated from IC foundry. The qusai means that MPC was made out under constrain of the traditional metallization processes in IC manufacture during current foundry model, in that the vertical distance between layers is about 1 mu m while the horizontal pitch is about 350 nm. The aim of this study is to evaluate the feasibility of mass production of MPC by using the modern IC technology. The novel optical properties are investigated in order to estimate the photonic band gap (PBG) behavior under this qusai structure. There exists an obvious PBG effect ranging from 3.5 to 7.5 mu m and some other sharp period of transmission region.
Reliability assessment of an aircraft propulsion system using IFS and OWA tree
(2008)
Chang, K. -H.
;
Cheng, C. -H.
;
Chang, Y. -C.
;
工業工程與管理學系
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Department of Industrial Engineering and Management
In conventional system reliability analysis, the failure probabilities of components of a system are treated as exact values when the failure probability of the entire system is estimated. However, it may be difficult or even impossible to precisely determine the failure probabilities of components as early as the product design phase. Therefore, an efficient and simplified algorithm to assess system reliability is needed. This article proposes a deductive top-down estimation methodology, which combines intuitionistic fuzzy set (IFS) and ordered weighted averaging (OWA) operators to evaluate system reliability. A case of an aircraft propulsion system from an aerospace company is presented to further illustrate the proposed approach. After comparing results from the proposed method and two other approaches, this research found that the proposed approach provides a more accurate and reasonable reliability assessment.