An understanding of the pad surface state and its effect on the tribological regime of the polishing process is critical to understanding the fundamental mechanism of Chemical Mechanical Polishing (CMP). The focus of this study is the measurement of pad surface roughness evolution during the polishing process and its characterization, which has a critical relation to the polishing rate and decay phenomena of the polishing rate during polishing when conditioning is suspended. Research reveals that the average roughness parameters R a or R q have a weak relation to the removal rate, which contradicts the general idea about the relation between polishing rate and roughness. However, it was found that the reduced peak height R pk has the most significant influence on the removal rate. Considering the theoretical concept of the real area of contact, a reasonable explanation about the phenomena is that the reduced peak height, rather than the average roughness, dominates the real area of contact.

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This study is a parametric investigation of the application of a compact type of pre-swirl duct for a slender aft-body 158k crude oil carrier. The International Maritime Organization (IMO) has created the Energy Efficiency Design Index (EEDI), which is an index related to carbon dioxide emissions, to enforce regulations on newly built ships; many solutions have been proposed, including an increase in propulsion efficiency. In the present study, a new type of energy-saving device (pre-swirl duct), the so-called ring stator, is proposed for 158k crude oil carriers, the hull form of which has been developed as a slender after-body full form to reduce the resistance by delaying separation. A conventional pre-swirl duct is no longer effective at the slender aft-body hull forms because of the small radial flow to the propeller. A parametric study was conducted through Computational Fluid Dynamics (CFD) analysis using the commercial program Star-CCM+, and an improvement of approximately 3% in the propulsion efficiency was achieved in the present study. The efficiency gain was validated through a comparison with the experimental results. The developed ring stator may become applicable to container ships through further parametric studies in the near future.

f i e software metrics are widely advocated as a fundamental elements of an engineering approach to planning and controlling software developnent. n e y are o f especial importance with the objectoriented program. In this paper, we propose the new software cmplexity model which consists of the class cmplexity, the inter-object cmplexity, and the total cmplexity for the objectoriented progran. We measure the cmplexities based on the entropy concept. The class cmplexity for a class measures the information flows in a class based on the information passing relationship an-mmber data and member functions. The inter-object cmplexity for a program measures the information flows between objects. The total cmplexity for a program i s measured by the class canplexity and the inter-object cmplexity. W e evaluate the proposed metrics by the cmplexity properties proposed by Weyuh-er. Experimental results of C++ classes show the effectiveness o f the proposed metrics. W e assert that the class canplexity and the inter-object cmplexity are considerately correlated to other metrics for object-oriented concepts.