• Proceedings of the Korea Concrete Institute Conference
• /
• 1998.10b
• /
• pp.603-608
• /
• 1998

This study was performed to examine the effect of time dependent properties on RC columns in subway structures subjected to high filled soil layer. By using Program TCC which is a modified version of CPF for the present purpose, a typical column in subway structure was analyzed. Four different model equations for predicted time dependent concrete properties(ACI, CEB-FIP, Bazant & Panula and Korea Bridge Specification) was employed, and the results were compared. It was found that a relevant creep coefficient is recommended to be 1.0 for designing columns in subway structure, and the sol filling work would be performed at least 3 months later after the concrete casting in order to ensure durability by reducing the negative effect of concrete time dependent properties.

• Honam Mathematical Journal
• /
• v.33 no.4
• /
• pp.591-602
• /
• 2011

In this paper we establish the central limit theorem and the strong law of large numbers for linear random fields generated by identically distributed linear negative quadrant dependent random variables on $\mathbb{Z}^2$.

• Honam Mathematical Journal
• /
• v.36 no.3
• /
• pp.679-688
• /
• 2014

The notion of asymptotically negative dependence for collection of random variables is generalized to a Hilbert space and the almost sure convergence for these H-valued random variables is obtained. The result is also applied to a linear process generated by H-valued asymptotically negatively dependent random variables.

• Journal of the Korean Mathematical Society
• /
• v.45 no.1
• /
• pp.289-300
• /
• 2008

For an array of dependent random variables satisfying a new notion of uniform integrability, weak laws of large numbers are obtained. Our results extend and sharpen the known results in the literature.

• Communications for Statistical Applications and Methods
• /
• v.7 no.1
• /
• pp.291-296
• /
• 2000

Petrov(1996) examined the connection between general moment conditions and the applicability of the strong law lf large numbers to a sequence of pairwise independnt and identically distributed random variables. In this note wee generalize Theorem 1 of Petrov(1996) and also show that still holds under assumption of pairwise negative quadrant dependence(NQD).

• Transactions of Materials Processing
• /
• v.13 no.7
• /
• pp.600-607
• /
• 2004

This paper addresses a viscoplastic constitutive model that allows a consistent way of modeling positive and negative rate sensitivities of flow stress concerned with dynamic strain aging. Based on the concept of continuum mechanics, a phenomenological constitutive model includes the use of a yield surface within the framework of unified viscoplasticity theory. To model negative rate sensitivity, rate-dependent back stress is introduced and flow stress in fully developed inelastic deformation regime is thus decomposed into the plastic contribution of rate independency and the viscous one of rate dependency.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.762-766
• /
• 2001

The nar promoter of Escherichia coli was known to induce maximally under anaerobic or microaerobic conditions in the presence of nitrate. In this study, the nar promoter was tested to see whether the expression level of a reporter gene which fused lacZ gene at nar promoter's downstream, in the some gram negative host strains(Agrobacterium, Pseudomonas and Rhizobium). A nar promoter system(Combination of nar promoter and gram negative strain) was grown under aerobic conditions to absorbance at 600 nm of nearly 2.0 and then, the nar promoter was induced by lowering DO to 1-2% with alternating microaerobic and aerobic condition in the fermentor cultures, using different gram negative hosts. For a wild type nar promoter (pNW61), it was possible to maintain production of ${\beta}-galactosidase$ activity per cell(specific ${\beta}-galactosidase$ activity) at 14,000, 9600, 45 Miller units in the presence of 1% nitrate. and for a nitrate - independent nar promoter (pNW618) at 12,000, 10,400 and 58 Miller units in the absence of nitrate ion, respectively.

• Investigative Magnetic Resonance Imaging
• /
• v.21 no.4
• /
• pp.199-209
• /
• 2017

Purpose: Caffeine is the most widely consumed psychostimulant. It is often adopted as a tool to modulate brain activations in fMRI studies. However, its pharmaceutical effect on task-induced deactivation has not been fully examined in fMRI. Therefore, the purpose of this study was to examine the effect of caffeine on both activation and deactivation under sustained attention. Materials and Methods: Task fMRI was acquired from 26 caffeine naive healthy volunteers before and after taking caffeine pill (200 mg). Results: Statistical analysis showed an increase in cognition-load dependent task activation but a decrease in load dependent de-activation after caffeine ingestion. Increase of attention and memory task activation and its load-dependence suggest a beneficial effect of caffeine on the brain even though it has no overt behavior improvement. The reduction of deactivation by caffeine and its load-dependence indicate reduced facilitation from task-negative networks. Conclusion: Caffeine affects brain activity in a load-dependent manner accompanied by a disassociation between task-positive network and task-negative network.

• 한국체육학회지인문사회과학편
• /
• v.54 no.4
• /
• pp.111-121
• /
• 2015

The purpose of this study was 1) to investigate professional sports fans' perception of immigrants and changes of athletes' nationalities, and 2) to examine how the fans' perception affected the perception of changes of athletes' nationalities. Results indicated that first the fan showed a neutral attitude toward the immigrants. In the results of the regression analysis containing foreign athletes naturalized as Korean citizens as the dependent variable, independent variables (i.e., gender and acceptance) explained 39.1% and 38% of the dependent variable, respectively, within [naturalization positive]. Within [naturalization negative] female fan and exclusive perception of immigrants positively predicted the objection to changes of athletes' nationalities. Lastly, in the results of the regression analysis containing Korean athletes who naturalized as foreign citizens as the dependent variable, fans who were older and rated higher on exclusive perception of immigrants had more negative perception of the dependent variable. Female fans perceived changes of athletes nationalities as personal choice.

• Journal of the Korean GEO-environmental Society
• /
• v.21 no.8
• /
• pp.15-27
• /
• 2020

In the current paper, a series of advanced 3D finite element analyses have been performed on existing pieces of work of negative skin friction from a geotechnical centrifuge test and full-scale field measurements. From these analyses, key features of pile behaviour under the influence of negative skin friction which, previously, were not fully understood in existing studies, have been meticulously discussed. As such, it has been possible to successfully address several numerical modelling issues such as negative skin friction induced pile settlements and group effects (the shielding effect), the effect of sacrificial piles in groups and the interaction between the pile head and the cap, the effect of interface elements at the pile-soil interface and the time-dependent pile behaviour. During a geotechnical centrifuge test, substantial amounts of negative skin frictions were mobilised when centrifugal acceleration increased from 1g to a certain g-level due to an increase in the self-weight of soil. The behaviour of piles inside a group were heavily affected by the sacrificial piles and the connectivity between the pile head and the pile cap. In particular, as negative skin friction has time dependent qualities associated with consolidation, it was logical to perform coupled analyses when analysing piles in consolidating grounds. From the current work, several insufficiencies of previous researches have been addressed, and the engineering pile behaviour subjected to negative skin friction has been clarified.