• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.4
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• pp.410-416
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• 2009

In recent years, the rollover accident of large class of vehicles has become important safety issue. Even though the rollover form a small percentage of all traffic accidents, they have a fatal effect upon the driver and passenger. Among the traffic accidents occurred in driving, the rollover is the major cause of traffic fatalities. Therefore, it is required to develop the analytical and experimental techniques for predicting rollover propensity of vehicles and also to improve the vehicle suspension design in the viewpoint of rollover resistance. In this study, the parameter sensitivities for the roll angle of SUV suspension are analyzed, and then the determined design parameters are optimized by using the regression model function of the response surface methods. The analysis results show that the roll angle of the optimized vehicle is decreased as compared with the initial vehicle and also the rollover possibility is decreased when the roll rate of the front suspension is larger than the roll rate of the rear suspension.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.48-53
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• 2006

A methodology is described for predicting the fatigue life of the resistance spot weldment including strain rate effect. Because it is difficult to perform a physical failure test with high strain rate, an analytical method is necessary to get the mechanical properties of various strain rate, To this end, quasi-static tensile-shear tests at several strain rate were performed on spot weldments of SPC. These test provided the empirical data with the strain rate. With these results, we formulated the function of fatigue life prediction using the lethargy coefficient which is the global material property from tensile test. And, we predicted the fatigue life of spot weldment at dynamic strain rate. To confirm this method for fatigue life prediction, analytical results were compared with the experimental fatigue data.

• Journal of electromagnetic engineering and science
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• v.16 no.1
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• pp.57-65
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• 2016

In this paper, based on the mode analysis of four-conductor lines, the extended mixed-mode chain-parameters and S-parameters of four-conductor lines are estimated using current division factors. The extended mixed-mode chain-parameters of cascaded four-conductor lines are then obtained with mode conversion. And, the extended mixed-mode S-parameters of cascaded four-conductor lines can be predicted from the transformation of the extended chain-parameters. Compared to the extended mixed-mode S-parameters of four-conductor lines, the cross-mode S-parameters are induced in the extended mixed-mode S-parameters of cascaded four-conductor lines, due to the imbalanced current division factors of cascaded two sections. The generated cross-mode S-parameters make the equivalent different- and common-mode conductors not independent from each other again. In addition, a new mode conversion, which applies the imbalanced current division factors, between the extended mixed-mode S-parameters and standard S-parameters is also proposed in this paper. Finally, the validity of the proposed extended mixed-mode S-parameters and mode conversion is confirmed by a comparison of the simulated and estimated results of shielded cable.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.63-65
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• 1994

In this paper, the design, fabrication and test of inside notched superconducting coil are described. The inside notched coil is one of the basic configurations, producing homogeneous magnetic field. This magnet is a primitive version of MRI or NMR magnet in Korea Electromagnetic Research Institute. To test the magnetic field distribution inside the magnet, a X-Z scanner was made and the homogeneity was about $1.8{\times}10^{-3}$in 5 cm dsv (Diameter of Spherical Volume).

• Journal of the Korea Society of Computer and Information
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• v.21 no.8
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• pp.85-94
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• 2016

The purpose of this research is to clarify the effect that group art therapy with ceramics affects aggression and impulse for juvenile delinquent. The experimental domain of this study was implemented with 24 juvenile delinquent suspended from protective dispositions for them who were in long-term juvenile sheltered housing about for 12 years. These subjects were selected from among juvenile delinquent between 14 to 20 years age who were entrusted from court to the Juvenile Protection Education Institute located in G area. 12 people were randomly assigned each experimental domain and control domain; experimental group was implemented group art therapy with ceramics whereas there was anything to control group. The program was designed once a week and 90minutes each 12 sessions. The result of this study show that control group at variable related aggression was not significantly changed at posttest. In case of experimental group, here was significantly changed as a whole, also sub factor such as physical aggression showed considerable change so that the first hypothesis was supported In addition, experimental group showed the considerable change at sub factor of motor impulsiveness so that the second hypothesis was supported whereas control group at impulse variable was not significantly changed during pretest and posttest. This study results conclude that the juvenile delinquent participating group art therapy with ceramics represents the effect on reduction of aggression and motor impulsiveness. We expect this result will be used as further base line data for juvenile delinquent.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.2
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• pp.151-155
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• 2020

In this paper, a new experimental method to determine the thermal resistance of building wall was proposed by improving the heat flow method (HFM) based on the air-surface temperature ratio theory. This technique measures the thermal resistance of the wall excluding the inner and outer surface heat transfer resistance. Unlike conventional HFM, this value can be compared directly with the theoretical reference value. Its performance was verified using three mock-up structures with a theoretical thermal transmittance of 0.5, 3.3, and 0.18 W/㎡·K respectively. After measuring the variations in the temperature and heat transfer rate of the mock-ups for 383 hours, the thermal transmittances were determined to be 0.47, 3.10, and 0.18 W/㎡·K, which corresponded to errors of 5.2, 6.2 and 0.5%, respectively, compared to the theoretical values. It was concluded that this technique can directly compare the thermal resistance of the wall between the existent stage and initial stage after construction.

• Archives of Pharmacal Research
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• v.28 no.11
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• pp.1302-1310
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• 2005

Glucosylated polyethylenimine (GPEI) was synthesized as a tumor-targeting gene carrier through facilitative glucose metabolism by tumor glucose transporter. Particle sizes of GPEI/DNA complex increased in proportion to glucose content of GPEI, whereas surface charge of the complex was not dependent on glucosylation, partially due to inefficient shielding of the short hydrophilic group introduced. GPEI with higher glucosylation (36 mol-$\%$) had no cytotoxic effect on cells even at polymer concentrations higher than 200 $\mu$g/mL. Compared to unglucosylated PEl. glucosylation induced less than one-order decrease of transfection efficiency. Transfection of GPEI/DNA complex into tumor cells possibly occurred through specific interaction between glucose-related cell receptors and glucose moiety of GPEI. Gamma imaging technique revealed GPEI/DNA complex was distributed in liver. spleen. and tumors.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.281-286
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• 1995

Tooth length determination is a crucial step in endodontic treatment. Traditionally, radiographs are used to confirm working length of the root length. This study was performed to evaluate the radiographic distortion(magnification) and calculate correction coefficients for the object-film distance. Ninty-six radiographs were made of eight extracted teeth(two upper first premolars, two lower first premolars, two upper first molars, and two lower first molars) by using the 16 inch long cone paralelling techniques with 1mm interval from 5 to 16mm tooth-film distance. The results were as follows. 1. The least mean radiographic distortion from 5 to 16mm tooth-film distance was 2.42±0.68％(the length of mesiobuccal cusp-mesial root of lower first molars), the greatest distortion was 4.74±1.36％(the length of mesiobuccal cusp-mesiobuccal root of upper first molars). 2. The greatest correction coefficient was 0.986(the mesiobuccal cusp-mesial root of lower first molars, the lowest one was 0.937(the mesiobuccal cusp-mesiobuccal root of upper first molars).

• Imaging Science in Dentistry
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• v.33 no.2
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• pp.91-95
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• 2003

Purpose : To compare the diagnostic accuracy of proximal caries detection between Kodak Insight film and the Biomedisys CDX2000HQ digital (CCD) sensor. Materials and Methods: 156 proximal surfaces of extracted teeth, 78 of which had chemical artificial caries, were used in this study. Four observers interpreted the radiographs using a five-point confidence rating scale to record their diagnoses. The results were analyzed by receiver operating characteristic curves, ANOVA and Kappa values. Result: Analysis using receiver operating characteristic curves revealed the areas under each curve which indicated a diagnostic accuracy of 0.951 in Insight and 0.952 in CDX2000HQ digital sensor. ANOVA revealed no significant differences between the two images with respect to caries detection. Kappa values indicated that the mean intra-observer agreement was 0.85 and inter-observer agreement 0.71 in conventional radiography. In digital radiography, the mean intra-observer agreement was 0.84 and inter-observer agreement 0.72. Conclusion: The results suggest that no significant difference exists between the two modalities for artificial caries detection and that CDX2000HQ was as good as Insight film for this purpose.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.131-137
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• 2011

This paper analyzes EM(Electromagnetic) characteristic in the high voltage connector for the hybrid electric vehicle. The connector bridges the electrical components and helps transferring electrical power and signal through it. The necessity of the high voltage and current connector development is emphasized because the hybrid electric vehicle recently uses the high voltage and current more than 500V and 80A. So far there has not been international EMC (Electromagnetic Compatibility) standards to limit the RE(Radiation Emission) from the connector for the hybrid electric vehicle. In this paper we analyzed EM characteristic of the 288V, 65A connector to check if the RE from the high voltage connector could be within the RE limit standard of vehicle. Three-dimensional modeling and simulation was conducted by using MWS(Microwave Studio) of the CST corporation, and the result was compared with the measured RE data, which showed good coincidence each other.