摘要 :
A pictorial approach to modeling poor-quality cost (PQC) is proposed. The approach is patterned after that used in a computer-based information system design. It includes two major steps: (1) specifying the PQC variables as well a...
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A pictorial approach to modeling poor-quality cost (PQC) is proposed. The approach is patterned after that used in a computer-based information system design. It includes two major steps: (1) specifying the PQC variables as well as the significant relationship among the variables, and mapping the variables and relationships into an influence diagram showing the structure of a PQC system: and (2) converting the structure into a well-defined entity-relationship diagram showing the input-output functions and their associated properties. Two major benefits of using the pictorial approach are that the influence diagram can provide an easy-to-understand PQC system for quality management practitioners and the entity-relationship diagram can provide an effective framework for maintaining and revising the PQC system.
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摘要 :
The erratic p-type conductivity in nitrogen-doped ZnO film is still under investigation and has been debated up to now. In this study, the authors have studied the effect of rapid thermal process (RTP) on the properties of N-doped...
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The erratic p-type conductivity in nitrogen-doped ZnO film is still under investigation and has been debated up to now. In this study, the authors have studied the effect of rapid thermal process (RTP) on the properties of N-doped ZnO films grown by metal-organic chemical vapor deposition. Hall-effect measurements show that the sample is of p-type as the RTP temperature is lower than 350 °C while, as the RTP temperature increased up to 550 °C or higher, the conduction-type of the sample changed to be n-type. Correspondingly, obvious D and G peaks, which are related to graphite clusters, are observed to increase their intensity with RTP temperature, indicating that interstitial or substitutional carbon atoms may migrate to form carbon clusters in the grain boundary during RTP. RTP is also found to lead to significant changes on the photoluminescence of the samples, with enhanced visible emissions observed as RTP temperature increased. Similar changes are observed on the intensity ratios of the D over G peaks and the visible emission around 600 nm over the near-band-edge emission. This indicates that besides zinc vacancy (VZn) and oxygen vacancy (VO), which are popularly ascribed as the origins of the visible emissions around 500 and 550 nm, carbon clusters may be a possible origin of the visible emission around 600 nm. Finally, carbon clusters formed in the grain boundary are also supposed to at least partly be responsible for the type transition caused by RTP.
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摘要 :
We report a systematic study of the switching and recording characteristics of perpendicular magnetic recording media in which the exchange coupling between granular oxide and continuous cap layers was varied. The interfacial exc...
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We report a systematic study of the switching and recording characteristics of perpendicular magnetic recording media in which the exchange coupling between granular oxide and continuous cap layers was varied. The interfacial exchange coupling strength was controlled by adjusting the magnetization $({rm M}_{rm s})$ and the thickness (t) of the exchange control layer (ECL) between granular oxide and cap layers. The media switching mechanism highly depends on the oxide-to-cap exchange coupling strength as well as the relative moment ratio of cap and oxide layers. Reversal process is coherent for medium with only granular oxide layer and becomes incoherent with incorporation of ECL and continuous cap layers. Optimizing granular oxide-to-cap exchange coupling improves the media writeability as well as the media signal-to-noise ratio $({rm SNR}_{rm m})$. At optimum exchange coupling condition, the switching field is significantly reduced even with higher thermal stability factor (${rm K}_{rm u} {rm V/k}_{rm B}$ T). However, when the interlayer coupling strength is too weak, independent switching of oxide and cap layers occurs, resulting in poor writeability and high media noise. An optimum design of oxide-to-cap exchange coupling is critical in attaining recording properties for high density recording through selection of appropriate ECL and cap materials.
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