• Geomechanics and Engineering
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• v.3 no.4
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• pp.285-290
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• 2011

This article employs Multivariate Adaptive Regression Spline (MARS) for determination of friction capacity of driven piles in clay. MARS is non-parametric adaptive regression procedure. Pile length, pile diameter, effective vertical stress, and undrained shear strength are considered as input of MARS and the output of MARS is friction capacity. The developed MARS gives an equation for determination of $f_s$ of driven piles in clay. The results of the developed MARS have been compared with the Artificial Neural Network. This study shows that the developed MARS is a robust model for prediction of $f_s$ of driven piles in clay.

• Journal of Korea Technology Innovation Society
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• v.4 no.2
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• pp.127-142
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• 2001

This paper presents an econometric model for measuring basic research capacity index(BRCI) of each OECD countries and analyses the gap in terms of time lag measured and forecasted in connection with factor analysis and BRCI progress function. Based on the analysis, gross domestic expenditure on R&D(GERD), total R&D personnel higher education expenditure on R&D(HERD) and number of science and technical papers based on SCI are more effective than other factors to BRCI. Also, BRCI progress function shows that 29 years is needed for Korea to catch up the level of German's BRCI of year 1998. But, it's impossible for Korea to catch up US and Japan. Therefore, with restricted scientific resources, Korea's own strategy for strengthening basic research capacity is going to be more important in 21st century.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.319-324
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• 1999

This study is to investigate the properties on the load-deflection and fracture behaviors of the steel fiber reinforced concrete(SFRC) slab model specimens, Steel fibers of indent, crimp, and end hook shape were considered to reinforce the matrix under various mixing conditions and proportions. Initial cracking load, maximum load, and energy absorption capacity(load carrying capacity) of SFRC panel specimen increased with increase of steel fiber contents. And the plain concrete slab was fractured abruptly after maximum load but SRFC slabs were fractured smoothly by steel fibers in concrete matrix operated as cracking resistance force after maximum load. Indent, crimp and end hook shape steel fibers were effective in reinforcing the matrices but end hook type fiber were superior to indent and crimp type fibers.

• Journal of Food Hygiene and Safety
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• v.9 no.1
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• pp.23-30
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• 1994

When three systems commonly used for screening(washed platelets suspended in uffer containing Ca2+, washed platelets in buffer without Ca2+and platelet rich plasma) are compared by studying the anti-aggregating capacity of garlic extract, platelet rich plasma was the least sensitive system. The most sensitive assay system, based on the IC50s of garlic extract and 2 other platelet aggregation-inhibiting agents(vitamin K3 and propranolol), was the platelet preparation without Ca2+in the suspension buffer. This system was confirmed as the most sensitive during subsequent investigation of garlic extract's capacity to inhibit platelet ATP release. These results suggest that applying the system with washed platelet without Ca2+is most effective to screen for the anti-affregating capacity of natural food.

• Journal of the Korean Society for Heat Treatment
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• v.10 no.3
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• pp.188-197
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• 1997

Effect of martensite morphology on damping capacity and hardness of Fe-Ni-C martensitic alloys were studied. The morphologies of martensite such as lath, butterfly, lenticular and thin plate were prepared by adjusting nickel content and austenite grain size. The hardness increased in order of lath, lenticular, thin plate, butterfly. The damping capacities of the lath and butterfly martensites were higher than those of the other two morphologies, indicating that the dislocation substructure is more effective in the damping capacity than the twin substructure. Especially, the butterfly martensite showed the highest damping capacity among these morphologies because of presence of not tangled but free dislocations in there.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.523-528
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• 2001

The Capacity Spectrum Method (CSM) was first introduced in the 1970's as rapid evaluation procedure. The procedure compares the capacity of the structure (in the form of a pushover curve) with the demands on the structure (in the form of a response spectrum). The graphical intersection of the two curves approximates the response of the structure. In order to account for nonlinear inelastic behavior of the structural system, effective ductility ratios(μ) are applied to the elastic-linear response spectrum to imitate an inelastic response spectrum. CSM in ATC-40 has deficiencies such as performance point does not converge and the peak deformation of inelastic systems is to be inaccurate when compared against results of nonlinear response history analysis. The purpose of this paper is to investigate the variation of performance points of Capacity Spectrum Method (CSM) are investigated with respect to the different sets of earthquake ground motions. The earthquake sets were used in this study selected by Miranda(1993), Riddell(1991), Seed et al. (1976).

• Journal of Power System Engineering
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• v.22 no.1
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• pp.87-93
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• 2018

Specimens were machined out from hot-rolled AZ31 magnesium alloy, and deformed at 623K with rolling reduction of 30%. After hot rolling, specimens were annealed at various range of temperature and time. In this study, static recrystallization was occurred during heat treatment, however, variation of main component and intensity of texture was not revealed. The results of microstructure observation, damping capacity test and dislocation mechanism indicated that increasing of damping capacity was caused by grain growth. It means that grain size is effective factor to damping capacity.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2001.05a
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• pp.473-492
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• 2001

This paper presents an econometric model for measuring basic research capacity index(BRCI) of each OECD countries and analyses the gap in terms of time lag measured and forecasted in connection with factor analysis and BRCI progress function. Based on the analysis, gross domestic expenditure on R&D(GERD), total R&D personnel, higher education expenditure on R&D(HERD) and number of science and technical papers based on SCI are more effective than other factors to BRCI. Also, BRCI progress function shows that 29 years is needed for Korea to catch up the level of German's BRCI of year 1998. But, it's impossible for Korea to catch up US and Japan. Therefore, with restricted scientific resources, Korea's own strategy for strengthening basic research capacity is going to be more important in 21st century.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.65-68
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• 2004

In the seismical capacity evaluation for RC structure wall-slab joint is very important factor. Because lateral load is resistance element and gravity load resistance element are acted mutually in the wall-slab joint. In this paper, to improve the seismic capacity of the wall-slab joint in the existing wall type apartments experiment which improve and retrofit a seismic capacity by unequal angle bracing and carbon sheet attachment are carried out. These methods are also economic and simple in mitigating seismic hazard, improve earthquake-resistance performance, and reduce risk level of building occupants. From the experimental results, the change of strength, degration of stiffness, and energy dissipation are evaluated. It can be concluded that these methods are effective in improving the seismic performance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.1-10
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• 1995

The allocation of files is essential to the efficiency and effectiveness of a distributed system that must meet geographically dispersed data processing demands. In this paper, we address an optimization model that generates optimal file migration policies in distributed database systems. The proposed model is a more generalized model that includes system's capacity constraints - computing sites' storage capacity and communication networks' capacity - which have not taken into consideration in previous researches. Using this model, we can establish initial file allocation, file reallocation and file migration polices that minimize a system operating cost under system's capacity constraints at an initial system design or reorganization point The proposed model not only can be adopted by small-sized systems but also provides a foundation for effective and simple heuristics for adaptive file migration in large systems.