• International Journal of Highway Engineering
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• v.18 no.5
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• pp.11-19
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• 2016

PURPOSES : This study identifies the causes and the mechanism of the occurrence of underground cavities. METHODS : A case study on cave-in and a series of model tests with a small soil chamber were conducted. RESULTS : A hypothesis about the mechanism of the cave-in in road was established, and the basic influencing factors on underground cavity expansion were identified. CONCLUSIONS : It was found that the characteristics of shear strength of soil and direction of water flow had a larger influence on cavity formation and expansion than the characteristics of internal erosion. In addition, large cavities suddenly expanded when cavities were caused owing to breakage of buried sewer pipe.

• Journal for History of Mathematics
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• v.26 no.4
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• pp.277-299
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• 2013

It was not until the early twentieth century that statistics emerged as an independent academic discipline. The developments of statistical theory and methods would not have been possible without heated controversies among founding fathers. One of them, controversy on the statistical test between R. A. Fisher and J. Neyman, E. S. Pearson had been very fierce and long-lasting. On the other hand it was in the early twentieth century that psychologists began to utilize statistical test which was a hybrid of tests developed by Fisher and Neyman-Pearson. By considering the history of fields such as psychology, we can see distinctive characteristics specific to the history of statistics.

• Geotechnical Engineering
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• v.3 no.2
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• pp.41-54
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• 1987

Although natural soil deposits hat.e been consolidated under Ko-stress system, the soil behavior has been predicted in laboratory from the results of tests performed on specimens consolidated under an isotropic stress s).stem. A series of undrained triaxial compression tests are performed on remolded specimens of clay consolidated under both types of stress systems, and the results at.e compared. One dimensional consolidation history induces anisotropy in clalrs, which is called as the stress induced anisotropy. However, if the clays would be reconsolidated under isotropic stress system. the anisotropy of undrained stress비h would be decreased with decrease of overconsolidation ratio. Undrained shear strength of norma]Iy consolidated clay depends on consolidation methods. Both the Rutledge hypothesis and the study of Henkel and Sowa do not agree with the test results obtained in this paper. In addition, a new theory is explained about the relationships between consolidation stresses, water contents and undiained shear strength.

• The Korean Journal of Financial Management
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• v.26 no.4
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• pp.103-140
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• 2009

This paper investigates various channels through which liquidity can affect stock returns and examines whether behavioral explanation for liquidity risk is reasonable. First, we examine whether liquidity level (average liquidity) plays a significant role in determining asset returns. The result is consistent with the hypothesis that a stock with higher average illiquidity will have a higher expected return. Second, we focus on the argument that liquidity has a non-diversifiable systematic component. If systemic liquidity has a different impact across individual securities, a stock that is more sensitive to systematic liquidity will have a higher expected return. The results of various tests are inconsistent with each other, not completely supporting the argument. Finally, the intra-market tests in Korea support the behavioral explanation for the liquidity premium, and the effect is stronger in the liquidity level than in the liquidity beta related to systematic liquidity.

• Journal of the Korean Statistical Society
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• v.31 no.4
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• pp.415-431
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• 2002

A unified framework for statistical inference for the mean of the normal distribution to derive point estimates, confidence intervals and statistical tests is proposed. This optimal design is justified after investigating the basic information and requirements that are possible and impossible to control when specifying practical and statistical requirements. Point estimation is only credible when viewed in the larger context of interval estimation, since the information required for optimal point estimation is unspecifiable. Triple sampling is proposed and justified as a reasonable sampling vehicle to achieve the specifiable requirements within the unified framework.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11b
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• pp.235-239
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• 2000

For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are 'active zone' and 'passive zone'. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain distribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

• International Journal of Reliability and Applications
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• v.11 no.2
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• pp.139-151
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• 2010

The main objective of this study is to present a new approach to obtain moment inequalities for the new better than renewal used (NBRU) class of life distributions. In order to achieve our main objective, the moment inequalities for NBRU class of life distribution using the new approach has been derived and then a new test for testing exponentiality against NBRU class based on these inequalities has been constructed. Then we calculate the Pitman asymptotic efficiency for the proposed test using some alternative distributions and comparing it with the other tests. Moreover, we make a comparison between Pittman asymptotic efficiencies (PAE's) and PAE's of some other tests. A simulation study is conducted to calculate the upper critical values and the power estimate of the proposed test for some common alternatives. Finally, we apply the suggested test to some real data.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.6
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• pp.809-813
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• 2009

We want to show that the construct of best fuzzy tests for certain fuzzy situations of Poisson distribution. Due to Neyman and Pearson theorem, if we have ${\theta}_0$ and ${\theta}_1$ be distinct fuzzy values of ${\Omega}=\{{\theta}\;:\;{\theta}\;=\;{\theta}_0,\;{\theta}_1\}$ such that $L({\theta}_0\;:\;X)/L({\theta}_1\;:\;X)$ < k, then k is a fuzzy number. For each fuzzy random samples point $X\;{\subset}\;C$, we have most power test for fuzzy critical region C by agreement index.

• Journal of the Korean Geophysical Society
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• v.8 no.1
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• pp.39-43
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• 2005

For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are 'active zone' and 'passive zone'. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain istribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

• Journal of the Korean Statistical Society
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• v.19 no.2
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• pp.128-138
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• 1990

In this paper we study the properties of nonparametric tests for testing the null hypothesis of no changes against one sided and two sideds alternatives in scale parameter at unknown point. We first propose two types of nonparametric tests based on linear rank statistics and rank-like statistics, respectively. For these statistics, we drive the asymptotic distributions under the null and contiguous alternatives. The main theoreticla tools used for derivation are the stochastic process representation of the test staistic and the Brownian bridge approximation. We evaluate the Pitman efficiencies of the test for the contiguous alternatives, and also compute empirical power by Monte Carlo simulation.