• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1430-1433
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• 2003

Transducers, which are incorporated in control devices for fixed wing aircraft, land vehicles. and weapon systems were designed and manufactured by use of semiconductor strain gages. These transducers consist of three parts; flange mounts, sensing rods, and semiconductor strain gages. In this investigation, we designed cylindrical sensing rods with high sensitivity and developed installation procedures of semiconductor strain gages. The semiconductor strain gage has hish gage factor such that it can produce high resistance change in spite of low strain, but it is so small and fragile that one should handle carefully and sophisticated installation method is needed for good performances. The prototype transducers are manufactured, and then tested about three important factors: sensitivity, linearity, and hysteresis. We got results or 0.084 V/N sensitivity, 0.2% nonlinearity, and 0.5% hysteresis.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.3 s.96
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• pp.222-232
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• 1999

This paper describes the development of a precision 3-component load cell with plate beams which may be used for measuring forces Fx, Fy and moment Mz simultaneously in industry. We have derived equations to predict the bending strains on the surface of the beams under forces or moment. We have also determined the attachment location of strain gages of each sensor and fabricated 3-component load cell. To evaluate the rated strain and interference error of each sensor, we have carried out characteristic test of precision 3-component load cell. It reveals that the rated strain calculated from the derived equations are good agreement with the results from Finite Element Method analysis.

• Food Science and Preservation
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• v.24 no.6
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• pp.778-785
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• 2017

This study was conducted to develop a predictive model for the growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds. We collected E. coli kinetic growth data during red kohlrabi seed sprouting under isothermal conditions (10, 15, 20, 25, and $30^{\circ}C$). Baranyi model was used as a primary order model for growth data. The maximum growth rate (${\mu}max$) and lag-phase duration (LPD) for each temperature (except for $10^{\circ}C$ LPD) were determined. Three kinds of secondary models (suboptimal Ratkowsky square-root, Huang model, and Arrhenius-type model) were compared to elucidate the influence of temperature on E. coli growth rate. The model performance measures for three secondary models showed that the suboptimal Huang square-root model was more suitable in the accuracy (1.223) and the suboptimal Ratkowsky square-root model was less in the bias (0.999), respectively. Among three secondary order model used in this study, the suboptimal Ratkowsky square-root model showed best fit for the secondary model for describing the effect of temperature. This model can be utilized to predict E. coli behavior in red kohlrabi sprout production and to conduct microbial risk assessments.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.627-632
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• 2010

Recently the research for lightening the railway vehicle is actively made according to the demand of the environment-friendly technology development contributing to the energy cost reduction and the green growth. The railway vehicle lightweight research is expanded to the load-supporting first structure from the secondary structure which doesn't support the load. After the composite car body development used in the Korean tilting train is completed, the composite bogie frame development in which the weight reduction efficiency is large is progressed. In this paper, distributed strain was monitored when the train load was added to the central part of the composite bogie side-frame. By using the optical fiber which was attached to the lower part of the side-frame and the developed Brillouin correlation domain analysis (BOCDA) system, the strain distribution could be measured with 3cm step over 3m section. This strain distribution was compared with the design value by the FE analysis when the load of 14ton and 18ton added. This experiment can verify the manufactured composite bogie side-frame.

• Korean Journal of Materials Research
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• v.14 no.10
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• pp.713-718
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• 2004

To study the dynamic strain aging behavior of Zr-0.4Sn-1.5Nb-0.2Fe sample tube for nuclear fuel cladding in the range of pressurized water reactor (PWR) operation temperature, the tensile tests of the tube specimens, which had been finally heat-treated at $470^{\circ}C\;and\;510^{\circ}C$, had been carried out with the strain rate $1.67{\times}10^{-2}/s\;and\;8.33{\times}10^{-5}/s$ at the various temperatures from room temperature to $500^{\circ}C$. It was observed that the elongation of the specimens got shortened as the temperature increased from $200^{\circ}C\;to\;340^{\circ}C$. The specimens that were finally heat-treated at $470^{\circ}C$ showed a plateau more remarkably on the plot of yield strength-temperature than those heat-treated at $510^{\circ}C$. In the range of $310\sim400^{\circ}C$, the strain rate sensitivity of the specimens finally heat-treated at $510^{\circ}C$ was $30.4\%\sim33.7\%$ lower but the work hardening exponent index of the specimens was a little higher than that without dynamic strain aging effect.

• The Korean Journal of Mycology
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• v.39 no.1
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• pp.31-38
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• 2011

In this study, 81 commercial strains of Pleurotus species cultivated in South Korea were analyzed with randomly amplified polymorphic DNA (RAPD) technique. Sequence characterized amplified region (SCAR) markers were developed by designing from one RAPD polymorhic band specific to Suhan strain. The SCAR primer pair 'S-OPA13-1' amplified a 590-bp fragment in the varieties originated from Suhan strain. The Blast search of S-OPA13-1 showed high homology to the POMFBO1 P. ostreatus cDNA clone MFB02-A05 and Laccaria bicolor S238N-H82. The results showed that this SCAR marker can clearly distinguish Suhan strains from Pleurotus spp.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.148-152
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• 2014

A mutant strain of Lactobacillus paracasei (ML-7) was derived by ultraviolet irradiation of the parent L. paracasei LS-2 strain, followed by colony selection on pH 3.5 MRS agar plates, on which L. paracasei LS-2 cannot grow. The L. paracasei ML-7 mutant strain produced an increased amount of organic acids compared to the L. paracasei LS-2 parent strain. Broiler chickens were randomly fed with one of three experimental diets: a basal diet as a control, and basal diets supplemented with 0.3% of the L. paracasei LS-2 and L. paracasei ML-7 strains. When concluding the study, the final body weights of the broilers fed with the supplemented basal diets were found to be significantly higher (1.9% for LS-2 and 6.2% for ML-7) than the control broiler group. Broilers fed with basal diet supplemented with the mutant L. paracasei ML-7 strain showed increased body weight and food intake, compared to broilers fed with the basal diet with or without the parent L. paracasei LS-2 strain.

• Journal of Mushroom
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• v.3 no.1
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• pp.31-34
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• 2005

This experiment was carried out to examine on the physiological and cultural characteristics of commercial strain Kunneutari #3 of Pleurotus eryngii. The optimal medium suitable for mycelial growth was YM, and followed by MCM and PDA. Also this strain more faster mycelial growth as 6.1 cm/7days compared with commercial strain P. eryngii #1. The optimal mycelial growth temperature was $25{\sim}30^{\circ}C$. The fruitbody yield was increased 54% with $117{\pm}16g/850m{\ell}$ and the fruitbody shape and qualities of this strain was good. And individual weight was $41{\pm}27g$. Spawn run of P. eryngii #3 in bottle cultivation took 30 days and also it took 21 days from scratching of inoculum to harvest that was shorter 3 days than P. eryngii #1, respectively. Therefore, it is expected that cultivation for P. eryngii #3 strain will improve farmer's income by enhancing efficiency of facilities and shorten 6 days on cultivation period, in addition, getting more growing cycle of P. eryngii.

• Computers and Concrete
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• v.7 no.2
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• pp.191-202
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• 2010

A laboratory investigation was conducted to characterize the constitutive property behavior of Cor-Tuf, an ultra-high-performance composite concrete. Mechanical property tests (hydrostatic compression, unconfined compression (UC), triaxial compression (TXC), unconfined direct pull (DP), uniaxial strain, and uniaxial-strain-load/constant-volumetric-strain tests) were performed on specimens prepared from concrete mixtures with and without steel fibers. From the UC and TXC test results, compression failure surfaces were developed for both sets of specimens. Both failure surfaces exhibited a continuous increase in maximum principal stress difference with increasing confining stress. The DP tests results determined the unconfined tensile strengths of the two mixtures. The tensile strength of each mixture was less than the generally assumed tensile strength for conventional strength concrete, which is 10 percent of the unconfined compressive strength. Both concretes behaved similarly, but Cor-Tuf with steel fibers exhibited slightly greater strength with increased confining pressure, and Cor-Tuf without steel fibers displayed slightly greater compressibility.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.8
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• pp.70-75
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• 2010

The aim of this study is to evaluate the axial residual stress in multi-pass drawn high carbon steel wire by using FE analysis and XRD. When FE analysis is applied to evaluate the residual stress in drawn wire of multi-pass drawing process, obtaining the reliable effective stress-strain curve at high strain is very important. In this study, a model, which can express the reliable effective stress-strain curve at high strain, is introduced based on the Bridgman correction and tensile test for multi-pass drawn high carbon steel wires. By using the introduced model, FE analysis was carried out to evaluate the axial residual stress in the drawn wires. Finally, the effectiveness of the FE analysis with the introduced stress-strain relation was verified by the measurement of residual stress in the drawn wires through XRD. As a result, the evaluated residual stress of FE analysis shows good agreement with the measured residual stress.