• The Journal of Engineering Geology
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• v.15 no.2 s.42
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• pp.185-199
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• 2005

Properties of sliding materials are dependent on the lithology because debris is the product of rock weathering processes. In order to characterize transportation behavior of debris dependent of debris types, this study selected 26 debris flows over three areas composed with different rock weathering types and topographic conditions. Analyses of lithology, weathering, and topographic characteristics were performed by detailed field survey. Based on the field survey data, transportation behavior of debris was studied at the aspect of the relationship of grain size and volume of debris as well as topographic conditions. According to the study results, change of slope angle is very influential factor on runout distance of debris among the topographic factors. Because the sliding velocity and the energy of debris are frequently changed and more irregular on an undulating slope, the unout distance of debris is larger than that of an uniformly dipping slope. Runout distance of debris is also influenced by volume and grain size of debris. Volume of debris in the gabbro is four or five times larger than that of the granite area because it is controlled by the lithology. Considered with grain size distribution, runout distance of debris is longer in the gabbro area which is composed with irregular grain size bearing large corestones than that in the medium grained granite area.

• The Journal of Engineering Geology
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• v.15 no.2 s.42
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• pp.145-154
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• 2005

This study conducted to develop an assessment method of runout distance of debris flow that is a major type of landslides in Korea. In order to accomplish the objectives, this study performed detailed field survey of runout distance and laboratory soil tests using 24 landslides over three pilot sites. Based on the data of the field survey and the laboratory tests, an assessment method of runout distance was suggested using the artificial neural network. The input data for the analysis of artificial neural network are change rate of slope angle, Permeability coefficient of in-situ soil, dry density, void ratio, volume of debris and the measured runout distance. The analyzed results using the artificial neural network show low error rate of inference distributing lower than $10\%$. Some cases have $5\%$ and $2\%$ of error rates of inferences. The results can be thought as excellent teaming rates. However, it is difficult to be accepted as excellent results if it is considered with the results derived using only 24 landslide data. Therefore, more landslide data should be surveyed and analyzed to increase the confidence in the assessment results.

• Journal of Science and Technology Studies
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• v.7 no.1
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• pp.67-90
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• 2007

Could STS throw another-colored light on the Hwang's Affair, the scientific fraud committed by Hwang Woo-Suk and his research team in Korea? And could analytic tools of STS unfold another meanings which have been overlooked in most of the traditionally social-sciences-oriented analyses? In this essay, I try to answer these questions by analyzing the Hwang's Affair in the view of STS, especially by using some concepts of actor-network theory(ANT): movement, translation and displacement. I want to say that the Hwang's Affair seems to be a part of normal scientific activity, not an abnormal phenomenon, and as an evidence, focus on the similarities of their life styles between "pure/real scientist" Louis Pasteur and "impure/political scientist" Hwang Woo-Suk. I try to mobilize some concepts of ANT, especially movement, and find out why scientists came to move toward the opposed direction on the pure/real-impure/political line. I suggest that there exists "laboratory politics" as the key factor in this bifurcation. My tentative conclusion is that Pasteur can take a position to make his great world, so-called the Pasteurian world, owing to the success of "double movement" in which he treated his laboratory as a fulcrum to lift up the world, but Hwang degrades himself to "ugly scientific politician" due to the loss of the momentum of his movement; Hwang treated his laboratory only as the symbolic resources and in turn failed to solidify material entities, his real political resources, even though he knew the importance of laboratory.