• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.365-368
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• 2003

Despite of the simple equipment and operation, DMT has been widely used to obtain various soil parameters and those parameters have been successfully applied to geotechnical design practice. Among them, the estimation of horizontal coefficient of consolidation is so useful that many researchs recently have been carried out. However, simulation of the penetration of the DMT blade is complex due to the inherent difficulty on analyzing a plane strain deformation of the soil around blade. Therefore, empirical and semi-empirical methods that use the theoretical solution developed fur piezocone with some assumptions have been used to estimate the coefficient of consolidation from Dilatometer dissipation test. In this paper, coefficients of consolidation c$\_$h/ which were obtained using equivalent radius that is same area with the DMT blade and optimization technique are compared with those obtained from Oedometer test and other interpretation methods. It was found that a new method used in this study can give more precise horizontal coefficient of consolidation than other methods do.

• Journal of Korean Society for Quality Management
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• v.33 no.3
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• pp.59-70
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• 2005

The purpose of this research is to identify the impact of trust on user acceptance of mobile banking and to identify if causalities among these factors are different between Internet and mobile banking. To test this model, this research applies the technology acceptance model(TAM) that incorporates trust. Additionally, this research use structural equation modeling to test the model and examine cross-group differences using a multi-group comparison method. The empirical results indicate that all path is significant expect the path from trust to intention to use. The results of a multi-group comparison test indicated that the path from trust to attitude, from trust to intention to use, from perceived usefulness to attitude and from perceived to intention to use are different between Internet and mobile banking.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.656-665
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• 2010

Shear modulus has been recognized as one of the important soil properties in dynamic analysis of ground and can be calculated from in situ measurement of shear wave velocity. Field seismic tests are the most accurate but expensive methods to investigate dynamic ground characteristics. Due to that reason, empirical equations for estimating the shear wave velocity are widely used rather than conducting in-situ tests. The most common equations are based on the N value obtained in conjuctions with a standard penetration test. In this paper, the field datas of standard penetration test and suspension PS logging measured in 126 sites of Korea were summarized and the correlation equations between N value and shear wave velocity are suggested.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.777-783
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• 2006

The coarse grained materials are used in various construction field such as express way back fill, Dam etc. Especially, for dam construction, a huge mount of rock fill materials are needed, so around domestic stony mountains are generally developed to produce materials. Not an accurate theory, but design criteria is based on empirical factors that were constructed in advance for design of dam especially Concrete Face Rockfill Dam(CFRD). Considering the post facts, the modified design criteria are essential in the future with more theoretical and experimental ways. In this study, large scale direct shear tests are performed with various relative density conditions on coarse grained material of Yecheon area to compare test results and general CFRD design factors.

• Communications for Statistical Applications and Methods
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• v.23 no.3
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• pp.215-230
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• 2016

The powers of some tests for independence hypothesis against positive (negative) quadrant dependence in generalized Farlie-Gumbel-Morgenstern distribution are compared graphically by simulation. Some of these tests are usual linear rank tests of independence. Two other possible rank tests of independence are locally most powerful rank test and a powerful nonparametric test based on the $Cram{\acute{e}}r-von$ Mises statistic. We also evaluate the empirical power of the class of distribution-free tests proposed by Kochar and Gupta (1987) based on the asymptotic distribution of a U-statistic and the test statistic proposed by $G{\ddot{u}}ven$ and Kotz (2008) in generalized Farlie-Gumbel-Morgenstern distribution. Tests of independence are also compared for sample sizes n = 20, 30, 50, empirically. Finally, we apply two examples to illustrate the results.

• Communications for Statistical Applications and Methods
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• v.19 no.1
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• pp.129-134
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• 2012

In this paper we review a bi-aspect nonparametric test for the two-sample problem under the location translation model and propose a new one to accommodate a more broad class of underlying distributions. Then we compare the performance of our proposed test with other existing ones by obtaining empirical powers through a simulation study. Then we discuss some interesting features related to the bi-aspect test with a comment on a possible expansion for the proposed test as concluding remarks.

• Journal of applied mathematics & informatics
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• v.8 no.2
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• pp.669-682
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• 2001

In this paper a nonparametric test for the parallelism of k regression lines against ordered alternatives, when the independent variables are positive and all regression lines have a common intercept is proposed. The proposed test is based on a Jonckheere-type statistic applied to residuals. Under some conditions the proposed test statistic is asymptotically distribution-free. The small-sample powers of our test are compared with other tests by a Monte Carlo study. The simulation results show that the proposed test has significantly higher empirical powers than the other tests considered in this paper.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.1-9
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• 2022

In this study, for development of the MDO (Multi Disciplinary Optimization) framework, the flight dynamic characteristic parameters of the ChangGong-91, a light aircraft, were extracted by an analytical method based on various semi-empirical methods, and the flight test method was compared and evaluated. The semi-empirical analysis methods for comparative subjects were the Perkins method, McCormick method, and Smetana method. The major stability/control derivatives and dynamic factors were calculated, using each method. As the comparison criteria, the flight test derivative estimates and dynamic factors were processed, using the output error method. Additionally, the flight characteristics of the light aircraft were analyzed and evaluated according to the provisions of the Korean Airworthiness Standard (KAS) of the Ministry of Land, Infrastructure and Transport, and MIL-F-8785C for the U.S. military.

• Journal of the Korean Geotechnical Society
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• v.24 no.10
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• pp.161-174
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• 2008

To investigate the characteristics of the shear wave velocity of cohesive soils and residual soils in Korea, Standard Penetration Test (SPT), Suspension PS Logging tests (SPS) and other soil tests were performed to analyze the shear wave velocity at each layer For these purposes, 2 study sites are selected: one is cohesive soils and the other is residual soils. As a results, new empirical formulas are proposed from the relationship between strength of the ground (N value) and shear wave velocity from the test data at each layer. In the case of cohesive soils, the proposed relationships are nearly similar to empirical formulas, however, in the case of residual soils there was a little difference between the empirical formulas and measured velocities in this study. Case examples for shear wave velocites are presented with depth, N-values and compared with Ohta et al. (1978) empirical formula.

• The Journal of Fisheries Business Administration
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• v.45 no.1
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• pp.1-16
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• 2014

The study attempts to show that the theory of critical environmental variation quantum(CEVQ) has a sound logical basis and empirical support. It is well known that the theory of critical environmental variation quantum is derived from the theory of biological probability distibution function and the central limit theorem(CLT) in statistics. The study uses the case study of fisheries damages compensation caused br the public marine construction undertaken in the area do Anjeong Bay in the city of Tongyeong for empirical test of theory of CEVQ. The results shows that the CEVQ theory perfoms a good job in measuring quantatively fjsheries damages caused by outflow of cold water due to the operation of LNG company since 2002. Therefore the study proves that the CEVQ theory is a good theory having internal consistency and empirical applicability.