• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.1256-1263
• /
• 2010

Suction Drain Method is soft ground improvement technique, in which a vacuum pressure can be directly applied to the Vertical Drain Board to promote consolidation and strengthening the soft ground. This method does not require a surcharge load, different to embankment or Preloading Method. In this study, ground improvement efficiency of suction drain method was estimated when duplex loading pressure with vacuum and pressure. During suction drain method process, surface settlement and pore pressure were monitored, and cone resistance test as well as water content were also measured after the completion of Suction Drain Method treatment.

• Journal of The Korean Digital Architecture Interior Association
• /
• v.4 no.1
• /
• pp.1-9
• /
• 2004

Greg Lynn has been watched as a future architect that we have known him as a digital architect. As a result, this study tried to understanding his architectural concept by researching his works. The objects of this study were his thirteen projects selected in his website, have been already built, been constructing, their experimental value have been highly evaluated. In conclusion, first, Greg Lynn understood the architecture is animated. Secondly, he actively uses digital technology that creates unexpected new design for his works. Lastly, he intends the consolidation of a design process and building system as a whole.

• Journal of Powder Materials
• /
• v.14 no.1 s.60
• /
• pp.32-37
• /
• 2007

Using spark plasma sintering process (SPS), Ti-6Al-4V alloy powders were successfully consolidated without any contamination happened due to reaction between the alloy powders and graphite mold. Variation of microstructure and mechanical properties were investigated as a function of SPS temperature and time. Compared with hot isostatic pressing (HIP), the sintering time and temperature could be lowered to be 10 min. and $900^{\circ}C$, respectively. At the SPS condition, UTS and elongation were about 890 MPa and 24%, respectively. Considering the density of 98.5% and elongation of 24%, further improving the tensile strength would obtain by increasing the SPS pressure.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2005.10a
• /
• pp.139-142
• /
• 2005

Cu-Ni-Zr-Ti bulk amorphous thin strips were produced by multi-pass warm rolling of the amorphous powder at temperatures in the supercooled liquid region. Process variables for rolling of the bulk amorphous strips were properly controlled to prevent onset of crystallization and failure during rolling up to three passes. During rolling of the amorphous powder, both the deformation and densification took place and the newly developed surface on the deformed amorphous particles enhances the consolidation leading to an increase in the strength. The strain state during rolling was analyzed by FEM.

• Journal of Powder Materials
• /
• v.14 no.6
• /
• pp.399-404
• /
• 2007

The Cu-based bulk metallic glass (BMG) composite was fabricated by spark plasma sintering (SPS) using of gas-atomized metallic glass powders and ductile brass powders. No defect such as pores and cavities was observed at the interface between the brass powder and the metallic glass matrix, suggesting that the SPS process caused a severe viscous flow of the metallic glass and brass phases in the supercooled liquid region, resulting in a full densification. The BMG composites shows some macroscopic plasticity after yielding, although the levels of strength decreased.

• Journal of the Korean Society of Industry Convergence
• /
• v.12 no.1
• /
• pp.35-42
• /
• 2009

In Taguchi's quadratic expected loss function used as robustness metric of performance characteristics, the mean and variance contributions are confounded. The consolidation of the mean and variance in the expected loss function may not always be the ideal approach. This paper presents a procedure for multi-attributes design optimization, where the mean and variance of performance characteristics are considered as separate attributes having designer's relative preferences for them and Technique for Order Preference by Similarity to Ideal Solution(TOPSIS) is introduced to attain robust optimal design. The effectiveness of proposed approach is shown with an example of a weld line minimization problem in the injection molding process.

• Journal of The Korean Association For Science Education
• /
• v.24 no.1
• /
• pp.171-182
• /
• 2004

The purpose of this study is to analyze lesson plans from third to sixth grades of science and to find out teaching strategies in respects of learning functions provided by preservice elementary teachers in education university. On the whole, to control students' learning process preservice teachers used more shared-regulation strategy than strong teacher-regulation one. Teaching activities for regulative learning function were most used in strategy of strong teacher-regulation, and in strategy of shared-regulation those for cognitive learning functions were most used. But teaching activities for affective learning functions were used a little considered in both teaching strategies. In introduction step of instruction, affective and regulative learning functions were more instructed by strong teacher-regulation strategy and cognitive learning functions were more instructed by shared-regulation strategy. The affective, cognitive, and regulative learning functions were largely planned by shared-regulation teaching strategy in development. The regulative learning functions were planned by strong teacher-regulation strategy than by shared-regulation strategy and affective learning functions were considered a little bit in consolidation. There was a tendency that strong teacherregulation strategy was increased in lessons for fifth and sixth grade.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.1290-1291
• /
• 2006

Fabrication of $Fe_3AlC$ matrix in-situ composite, reinforced by a FeAl phase, was studied by using the powder metallurgical processing route. Especially, in order to disperse the second phase more finely, we chose the mechanical alloying process. We investigated the microstructural and mechanical properties of the consolidated material. After consolidation by vacuum hot pressing, the compact showed almost full density and consisted of a $Fe_3AlC$ matrix and FeAl second phase (average particle size was less than 1m). The compact showed HV746, which was higher than that of the arc melted $Fe_3AlC$ monolithic material, HV603.

• Journal of Powder Materials
• /
• v.18 no.5
• /
• pp.401-405
• /
• 2011

Half-heusler phase ZrNiSn is one of the potential thermoelectric materials for high temperature application. In an attempt to investigate the effect of Sb doping on thermoelectric properties, half-heusler phase $ZrNiSn_{1-x}Sb_x$ ($0{\leq}x{\leq}0.08$) was synthesized by mechanical alloying of stoichiometric elemental powder compositions, and consolidated by vacuum hot pressing. Phase transformations during mechanical alloying and hot consolidation were investigated using XRD. Sb doped ZrNiSn was successfully produced in all doping ranges by vacuum hot pressing using as-milled powders without subsequent annealing. Thermoelectric properties as functions of temperature and Sb contents were evaluated for the hot pressed specimens. Sb doping up to x=0.04 in $ZrNiSn_{1-x}Sb_x$ was shown to be effective on thermoelectric properties and the figure of merit (ZT) was shown to reach to the maximum at x=0.02 in this study.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.10a
• /
• pp.681-688
• /
• 2002

Study was peformed to develop the‘environmental double pile’for the remediation of low-permeable contaminated soil. This technique is similar in function to‘sand drain pile’But this applies recyclable oyster shell treated as waste materials to a drain material and the pile is consisted of two layers. Inner metal pile is located in center and oyster shells are filled around it. By this technology, contaminated ground water is pumped out through the oyster shell and purified by drainage, adsorption, and reaction processes. Afterwards, the grout material is injected through the inner pile for the effect of the solidification / stabilization. As a result, the concept of this technique is a development of one-step process technology. Through the test, a consolidation characteristic by radial drain is going to be evaluated and the optimum standard of this technology will be calculated.