• Journal of the Korean Data and Information Science Society
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• v.9 no.2
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• pp.173-177
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• 1998

This paper presents the asymptotic relative efficiency of the nonparametric estimator relative to the parametric maximum likelihood estimator of the reliability function under the proportional hazards model of random censorship. Also we examine the efficiency loss due to censoring proportions and misson times.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.171-176
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• 1995

In recent years, Hith Performance Concrete has attracted world wide attention for its workability, strength and long-term durability. A field test was conducted to confirm the properties of high performance Concrete in situconditions. This paper describes the concrete materials, mix proportions, fresh state properties, some aspects of placability and qualty control results for field test. From the result, it was found that it is possible to produce High Performance Concrete with self-compactable and high strength.

• Proceedings of the Korea Concrete Institute Conference
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• 1990.04a
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• pp.16-19
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• 1990

The effect of superplasticizers on the fluidity performance in fresh concrete and physical properties in hardened concrete have been analyzed and investigated under mix proportions of water cement ratio of 0.4, 0.6, crushed stone aggregates, and addition rates of superplasticizers of 0.0, 0.5, 1.0 and 1.5 in the practical range. It is the aim of this study to provide the fundamental data on the workability improvement and engineering properties of crushed stone concrete using superplasticizers comparing with conventional concrete for the practical use and research data accumulation of superplastized concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.360-363
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• 2004

The effectiveness of Meta-Kaolin to prevent detrimental expansion due to alkali-silica reaction was investigated through the ASTM C 1260 method. Reactive aggregate used is a metamorphic rock. The replacement proportions of portland cement by Meta-Kaolin were 0, 5, 10, 15, 25 and 35 percent, respectively. The results indicate that 25 percent replacement of portland cement by Meta-Kaolin seems to be most effective to reduce alkali-silica reaction expansion under this experimental conditions.

• The Korean Journal of Applied Statistics
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• v.6 no.1
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• pp.53-66
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• 1993

A Bayesian approach is suggested to the multi-proportions randomized response model. O'Hagan's (1987) Bayes linear estimator is extended to the inference of unrelated question-type randomized response model. Also some numerical comparisons are provided to show the performance of the Bayes linear estimator under the Dirichlet prior.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.19-22
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• 1998

This study is investigate the properties of high performance concrete at W/B of 35%, used with silica fume and CSA expansive additives, which is used to improve the concrete qualities and prevent the drying-shrinkage. According to the results, the fluidity of concrete shows a decline with the increase of replacement percentage of silica fume and proportions of expansive additives. A higher strength is obtained at 5% of replacement percentage of silica fume, while the compensation achieves in drying-shrinkage of concrete at 5% of expansive additives.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.329-330
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• 2010

For the computerization of structural lightweight concrete mix design, mix design theories of ACI211.2-98(Standard Practice for Selecting Proportions for Structural Lightweight Concrete) are investigated and the mix design process is mathematized by Table Curve 2D and 3D software of Jandel company.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.142-147
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• 2000

Durability characteristics of controlled low strength material(flowable fill) with high volume fly ash content was examined. The mix proportions used for flowable fill are selected to obtain low-strength material in the 10 to 15kgf/㎥ range. The optimized flowable fill was consisted of 60kgf/㎥ cement content, 280kgf/㎥ fly ash content, 1400kgf/㎥sand content, and 320kgf/㎥water content. Subsequently, durability tests including permeability warm water immersion, repeated wetting & drying, freezing & thawing for high volume fly ash-flowable fill are conducted The test results indicated that flowable fill has has acceptable durability characteristics.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.59-64
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• 2003

As the economy of a country develops, the necessity for social overhead capital such as railroad, highway and other transportation infrastructures becomes an utmost issue as the volume of traffic increases. As the standard of living has been raised the needs for ecological road pavement also increase. As a matter of fact, the concrete and asphalt pavement have been constructed without considering the harmony with nature. The Road Compound pavement is constructed with local soils from optimum mixture proportions that did not contaminate the surroundings and represent the ecological pavement.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1543-1550
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• 2013

In this paper, we study Bayesian estimation for the finite population proportion in binary data under selection bias. We use a Bayesian nonignorable selection model to accommodate the selection mechanism. We compare four possible estimators of the finite population proportions based on data analysis as well as Monte Carlo simulation. It turns out that nonignorable selection model might be useful for weekly biased samples.