• Structural Engineering and Mechanics
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• v.88 no.4
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• pp.323-334
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• 2023

The submerged floating tunnel (SFT) infrastructure has been regarded as an emerging technology that efficiently and safely connects land and islands. The SFT route problem is an essential part of the SFT planning and design phase, with significant impacts on the surrounding environment. This study aims to develop an optimization model considering transportation and structure factors. The SFT routing problem was optimized based on two objective functions, i.e., minimizing total travel time and cumulative strains, using NSGA-II. The proposed model was applied to the section from Mokpo to Jeju Island using road network and wave observation data. As a result of the proposed model, a Pareto optimum curve was obtained, showing a negative correlation between the total travel time and cumulative strain. Based on the inflection points on the Pareto optimum curve, four optimal SFT routes were selected and compared to identify the pros and cons. The travel time savings of the four selected alternatives were estimated to range from 9.9% to 10.5% compared to the non-implemented scenario. In terms of demand, there was a substantial shift in the number of travel and freight trips from airways to railways and roadways. Cumulative strain, calculated based on SFT distance, support structure, and wave energy, was found to be low when the route passed through small islands. The proposed model helps decision-making in the planning and design phases of SFT projects, ultimately contributing to the progress of a safe, efficient, and sustainable SFT infrastructure.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.204-210
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• 2004

Most auto-body members fabricated by the sheet metal forming process. During this process the thickness and material properties of the sheet metal are changed with the residual stress and plastic strain. This paper deals with the material properties of the sheet metal at the high strain rate considering the pre-strain effect. Specimens are selected from sheet metals for outer panels and inner members, such as SPCEN, SPRC45E, SPRC35R and EZNCD. The specimens are prepared with the pre-strain of 2, 5 and 10 % by tensile elongation in Instron 5583, which could be equivalent to the plastic strain in sheet metal forming. High speed tensile tests are then carried out with the pre-stained specimens at the strain rate of 1 to 100/sec. The experimental result informs that the material properties are noticeably influenced by the pre-strain when the yield stress of the specimens is moderate as SPCEN, SPRC35R and EZNCD. The result also demonstrates that the ultimate tensile strength as well as the yield stress is increased as the amount of the pre-strain is increased.

• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.215-220
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• 1990

Prophage cured strain derivatives from Luctobacillirs araei YIT 9018 were isolated from thermoinducible mutant of the parent lysogenic strain. Two thermoinducible mutants were isolated from L. casei YIT 9018 strain treated with N-methyl-N'-nitro-N-nitrosoguanidine. Prophage cured strains were selected after heat induction of thermoinducible strains at $42^{\circ}C$ for 30 min in MRT medium containing anti- 4 FSV serum. The prophage cured strains, L. casei HYM 1213 and L. casei HYM 4024, could be used an indicator strain for temperate phage $\phi$ FSW. The growth, lactic acid producing ability and carbohydrates fermentation of L. casei HYM 1213 were similar to the parent L. cmei YIT 9018 strain, but A. casei HYM 4024 was not. One of the prophage cured strain, L. cmei HYM 1213, could be used industrially .to produce lactic acid beverages because this strah could not induce the virulent phage$\phi$FSV. The physiological characterization of L. casei HYM 1213 strain was similar to the parent L. casei YIT 9018 strain.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.54-62
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• 1998

20 bacterial strains capable of growing on phenol minimal medium were isolated from soil and wastewater by the enrichment culture technique, and among them, one isolate which was the best in the cell growth was selected and identified as Bacillus sp. SH3 by its characteristics. Strain SH3 could grow with phenol as the sole carbon source up to 15 mM, but did not grow in minimal medium containing above 20 mM of phenol. The optimal conditions of temperature and initial pH for growth and phenol degradation were 30$^{\circ}$C and 7.5, respectively. This strain could grow on various aromatic compounds such as catechol, protocatechuic acid, gentisic acid, o-, m-, p-cresol, benzoic acid, p-hydroxybenzoic acid, anthranilic acid, phenyl acetate and pentachlorophenol, and the growth-limiting log P value of strain SH3 on organic solvents was 3.1. In batch culture, strain SH3 degraded 97% of 10 mM phenol in 48 hours. In continuous culture under the conditions of 20 mM of influent phenol concentration and 0.050 hr$^{-1}$ of dilution rate, the treatment rate of phenol was 94%.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.50-55
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• 2013

In order to understand the biomaterial like the blood vessel of artery, there is a need to quantify the biomechanical behavior of the vessel. However, theoretical framework to describe and quantify the behaviour of blood vessel was not well established so far. For studying the biomechanical behavior of artery, Rubber-liked material which is similar to passive artery is selected since conventional theoretical interpretation is very limited to understand and predict the behavior of biomaterial. Rubber-like material is assumed to be very similar to artery and has properties of isotropy, homogeneity and is undergoing large deformation. Based on this assumption, stress developed on Rubber-like material is described by strain energy function and strain invariants which are required to understand the nonlinear elastic behavior of biomaterial. The descriptor which would be used for understanding the biomechanical behavior of artery is studied in this work.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.439-444
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• 1996

Microorganisms were collected to isolate the microbes producing Kochujang flavor from 3 kinds of traditional Kochujang. The strain B7 and Y20 which scored the highest sensory evaluation value among 400 microorganisms were finally selected. Also, they showed the most similar flavor pattern to the traditional Kochujang's by comparison of GC chromatogram after sniffing test. As the result of the result of the morphological and physiological experiments, the bacterial strain B7 could be identified Bacillus licheniformis and the yeast strain Y20 Saccaromyces dairensis. Especially, the bacterial strain B7 could grow in anaerobic condition and was able to hydrolysis the starch that was the major component in Kochujang.

• Interaction and multiscale mechanics
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• v.4 no.2
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• pp.155-164
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• 2011

The lattice strain evolution within polycrystalline solids is influenced by the crystal orientation and grain interaction. For multi-phase polycrystals, due to potential large differences in properties of each phase, lattice strains are even more strongly influenced by grain interaction compared with single phase polycrystals. In this research, the effects of the grain interaction and crystal orientation on the lattice strain evolution in a two-phase polycrystals are investigated. Duplex steel of austenite and ferrite phases with equal volume fraction is selected for the analysis, of which grain arrangement sensitivity is confirmed in the literature through both experiment and simulation (Hedstr$\ddot{o}$m et al. 2010). Analysis on the grain interaction is performed using the results obtained from the finite element calculation based on the model of restricted slip within crystallographic planes. The dependence of lattice strain on grain interactions as well as crystal orientation is confirmed and motivated the need for more in-depth analysis.

• Journal of Microbiology and Biotechnology
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• v.4 no.4
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• pp.338-342
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• 1994

The bacterium producing EPA was isolated from the intestines of the marine fishes. The strains were studied for their identification and their culture conditions. The selected strain was gram negative, rod(0.7 $\times$ 2.4 $\mu m$ in size) and motile with a single polar flagellum. This strain was identified as a Pseudomonas sp. on the basis of its morphological, cultural and physiological characteristics. The strain showed a maximum productivity of phospholipid at $20^{\circ}C$ after 48 hours of culture time with an initia1 pH of 7.0 in the PYM-glucose medium. Under these culture conditions, the production of phospholipid was about 0.3 mg/ml and 0.06 mg/mg dry cell weight.

• YAKHAK HOEJI
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• v.37 no.5
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• pp.483-489
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• 1993

Bifidobacterium bifidum, one strain of medical preparations being on the market for human intestinal disorder, is very sensitive to rifampicin. If this preparation is taken with rifampicin, its therapeutic effect can't be expected. To develope rifampicin resistant mutants, B. bifidum was treated with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG). All of thirty strains grown on the plates containing 10 $\mu\textrm{g}$/ml rifampicin were over 1, 000 times more resistant to rifampicin than parental strain and they were identified as B. bifidum by fructose-6-phosphoate phosphoketolase test. Three strains out of thirty, which produced almost same amount of organic acid as parental strain, were selected for further studies. They showed identical growth inhibition activity aganist E. coli compared with that of parental strain. And rifampicin was not inactivated.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.103-110
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• 1997

The objective of this study is to provide the information on the small-scale model mix proportion when the behavior of prototype concrete pavement is studied through small-scale model experiments. However it is difficult to obtain a model material to simulate the prototype concrete by scaling the individual components according to the laws of similitude. In this paper, the stress-strain behavior in uniaxial compression is used as a means to correlate materials similitude between the prototype and the model concrete. Based on th results of experiments, We compared the stress-strain curves of prototype and model concrete mixes using a nondimensional basis. In order to simulate the stress-strain curves of prototype concrete, it is important that various mix as of model concrete selected properly which are varied from aggregate grading, cement-aggregate and sand-aggregate ratio.