• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.143-149
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• 2003

This experiment was carried out to confirm the stability of bar gene introduced into petunia plant through Agrobacerium-mediated transformation. Twenty-five transgenic plants T$_{0}$ plants, back cross (BC$_1$) populations to wild type and F$_1$plants between different T$_{0}$ plants were prepared, and polymerase chain reaction(PCR), PCR-Southern blot analysis, and field test with 0.1% Basta treatment were done. The results of PCR, PCR-Southern blot hybridization, and field test indicated that NPTII and bar gene introduced into the genome of petuina plants were stably transmitted to their progenies, and conferred the plants resistance to herbicide, Basta.sta.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.4
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• pp.498-507
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• 1992

This study was to investigate the retentive force changes according to repeated insertion and withdrawal of Cr-Co alloy clasps, commonly used in this country, and the differences in retentive capacities between Aker's clasp and I-bar clasp. The author selected 4 kinds of Cr-Co alloys and Type IV gold alloy, and measured the retentive force changes of each clasp type in undercut depth of 0.25mm and analyzed statistically. The following results were obtained. 1. In both Aker's and I-bar clasps, there were no statistically significant differencies in retentive forces among 4 Cr-Co alloys. 2. Cr-Co alloys exerted greater retentive forces than those of gold alloy, 2 times greater in Aker's clasps and 2.5 times in I-bar clasps. 3. In all test specimens, I-bar clasps exerted greater retentive forces than Aker's clasps. 4. In all test specimens, there were trends of second order relationships in retentive force changes.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.10-13
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• 2010

Low pressure combustion tests for TDM(Technology Demonstration Model) of 75 tonf thrust chamber were performed. It has design chamber pressure of 60 bar, propellant mass flow rate of 243.6 kg/s. Due to the limitation of the current firing test facility in Korea, the combustion tests were conducted to verify the operation and the combustion performance at low pressure condition (30 bar, 121.8 kg/s). All the tests had been successfully executed without the damage of the hardware. These test results can be used as fundamental data to predict the combustion performance at design point condition for 75 tonf thrust chamber.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.9
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• pp.791-799
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• 2016

To ensure the reliability and safety of various mechanical systems in accordance with their high-speed usage, it is necessary to evaluate the dynamic deformation behavior of structural materials under impact load. However, it is not easy to understand the dynamic deformation behavior of the structural materials using experimental methods in the high strain-rate range exceeding $10^4\;s^{-1}$. In this study, the Taylor bar impact test was conducted to investigate the dynamic deformation behavior of metallic materials in the high strain-rate region, using a high-speed photography system. Numerical analysis of the Taylor bar impact test was performed using AUTODYN S/W. The results of the analysis were compared with the experimental results, and the material behavior in the high strain-rate region was discussed.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.1
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• pp.1-6
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• 2012

This study is damage evaluation for CNG fuel tank during the burst test through the analysis of acoustic emission signals. Kaiser effect until the pressure 420 bar appears, but More than 420 bar by the creep effect appears significantly damaged vessels, and 480 bar pressure, the Kaiser effect of the rising phase was missing. Resonant transducer at 540 bar than 480 bar decreased activity such as energy and count Continually, but increased wideband transducer. In addition, through the rise time or frequency analysis of composite pressure vessels in order to observe the damage mechanisms wideband transducer is more effective than resonant transducer.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.3
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• pp.73-82
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• 2015

A high altitude test facility which includes supersonic diffuser and ejector has been developed to simulate atmospheric pressure at 25 km using a 500 N class small scale liquid rocket engine. Also high altitude simulation test for the small scale liquid rocket engine was performed to verify the facility's performance. The experimental facility consists of high altitude simulation device, propellants supply system and coolant supply system. Low pressure condition corresponding to about 27 km(0.021 bar) altitude atmosphere was successfully simulated and a small scale liquid rocket engine thrust level was confirmed at the simulated condition by the high altitude test facility verification test.

• Culinary science and hospitality research
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• v.23 no.1
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• pp.58-65
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• 2017

This study performed to test the effect of food neophobia on the formulated model on the relationships among perceived service attributes(food, employee, and physical attributes), brand trust, satisfaction and behavioral intention as perceived by franchise snack bar consumers. Total 299 respondents were used for statistical analysis and SPSS 21.0 and AMOS 21.0 program were employed. The findings of current study verified that food attribute among perceived service attributes has positively influence on brand trust and satisfaction, and the employee attribute has only effect on the brand trust. Additionally, the brand trust was critical predictor of satisfaction, but it was not significant antecedent of behavioral intention in context of franchise snack bar restaurant. Furthermore, this study found the moderating effect according to level of food neophobia on the designed hypothesizes, so it has been identified the importance of people's propensity about food neophobia can significantly effect on brand trust and satisfaction in franchise snack bar restaurant. These findings will contribute to provide meaningful suggestion to develop marketing strategic in franchise snack bar business as well as provide the theoretical evidence in the new segmentation.

• Journal of IKEEE
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• v.20 no.2
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• pp.200-204
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• 2016

In this paper, we have estimated the performance of an overflow valve for EURO type CRDI(common rail direct injection) engine. In order to implement the overflow valve with friendly circumstance, it is necessity for considering spring load. Especially, the performance evaluation of diesel car with accuracy control will be considered a mileage improvement and circumstance regulation. In order to evaluate the performance of overflow valve, The leak test system checks the pressure, switching time and operating time under 3.0 bar below 100 cc, 3.3 bar among 150 cc and 200 cc, finally 4.0 bar upper 250 cc.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.6
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• pp.96-103
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• 2002

The objective of this study is to adjust the roll gap fur the dimension accuracy of bar in hot bar rolling process considering roll wear. In this study hot bar rolling processes fur round and oval passes have been investigated. In order to predict the roll wear, the wear model is reformulated as an incremental from and then wear depth of roll is calculated at each deformation step on contact area using the results of finite element analysis, such as relative sliding velocity and normal pressure at contact area. Archard's wear model was applied to predict the roll wear. To know the effects of thermal softening of DCI (Ductile Cast Iron) roll material according to operating conditions, high temperature micro hardness test is executed and a new wear model has been proposed by considering the thermal softening of DCI roll expressed in terms of the main tempering curve. The new technique developed in this study for adjusting roll gap can give more systematically and economically feasible means to improve the dimension accuracy of bar with full usefulness and generality.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.1
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• pp.56-62
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• 2003

The objective of this study is to adjust the roll gap for the dimension accuracy of bar in hot bar rolling process considering roll wear. In this study hot bar rolling processes for round and oval passes have been investigated. In order to predict the roll wear, the wear model is reformulated as an incremental form and then wear depth of roll is calculated at each deformation step on contact area using the results of finite element analysis, such as relative sliding velocity and normal pressure at contact area. Archard's wear model was applied to predict the roll wear. To know the effects of thermal softening of DCI (Ductile Cast Iron) roll material according to operating conditions, high temperature micro hardness test is executed and a new wear model has been proposed by considering the thermal softening of DCI roll expressed in terms of the main tempering curve. The new technique developed in this study for adjusting roll gap can give more systematically and economically feasible means to improve the dimension accuracy of bar with full usefulness and generality.