• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.298-304
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• 2012

The development of low rolling resistance tire with weight reduction in tire and vehicle may induce high level of tire/road noise, especially the rumble road noise on rough road. In this paper, the design factor for good rumble noise is considered in view of tire and vehicle. For the 3 mid-sized sedans, the rumble noise is very sensitive to the test vehicle. And it is concluded that the tire with high tread part stiffness and low sidewall part stiffness shows best rumble noise performance, and the rumble noise is in trade-off relation with cavity resonance noise. So, it is desirable to select and change proper construction design factors to have good tire/vehicle rumble noise.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.281-286
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• 1997

Recent construction activities and maintenance of marine facilities have been accelerating to keep up with rapid economic growth in Korea. Marine concrete structures are exposed to salts an chloride from ocean environments. The corrosion of reinforcement steel caused by chloride-penetration into concrete may severely effect the durability of concrete structures. The objective of this research is to develop a durable concrete by investigating the corrosion resistance of various corrosion protection systems utilizing different water/cement ratio, silica fumes, corrosion inhibitors and etc. A tow-year verification test on various corrosion protection systems has been doing in the laboratory and at the seaside. Corrosion investigations on reinforcement steel are now under progress for more than 180 concrete specimen. Corrosion-related measurements include macrocell corrosion current, instant-off voltage between corroding and noncorroding reinforcement, chloride contents, the corroded surface areas on the reinforcement steel, and etc. A low level of corrosion is investigated on reinforcement steels in concrete specimen made with corrosion inhibitors or applied aqueous impregnating corrosion inhibitors into their surface, even though high chloride contents of concrete specimen.

• Structural Engineering and Mechanics
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• v.46 no.5
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• pp.595-613
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• 2013

A new effective model for calculation of the equivalent uniform blast load for non-uniform blast load such as close-in explosion of a one-way square and rectangle reinforced concrete slab is proposed in this paper. The model is then validated using single degree of freedom (SDOF) system with the experiments and blast tests for square slabs and rectangle slabs. Test results showed that the model is accurate in predicting the damage level on the tested RC slabs under the given explosive charge weight and stand-off distance especially for close-in blast load. The results are also compared with those obtained by conventional SDOF analysis and finite element (FE) analysis using solid elements. It is shown that the new model is more accurate than the conventional SDOF analysis and is running faster than the FE analysis.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1303-1308
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• 2004

This paper proposes a reduction method for the mis-operation analysis of the DC High Speed Circuit Breaker(HSCB) in electric railway substation system. The analysis method is based on present condition of operation which is a method for accuracy level up. There is reason to operation of HSCB that it is mis-operation of fault detection relay(50F), operation of ground fault relay(64P), and trouble of electric car. A countermeasure is relay resetting through field test, induction of GTOCB(Gate Turn Off Thyristor Circuit Breaker), HSVCB(High Speed Vacuum Circuit Breaker), coordination with electric car. The results presented in the paper can be used as a reference for maintenance free in electric railway substation system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.265-267
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• 2013

Tire labeling is an important issue to reduce $CO_2$ and to secure the safety of tire/vehicle on wet road. A basic study on the effects of tire basic stiffness design on tire labeling performance has been done through experimental test. The pass-by noise is affected by tire structural design. The tire with lower side part stiffness and lower tread part stiffness has the lowest PBN level and the best wet grip. And the tire with higher tread part stiffness and higher side part stiffness has the better RR performance. Also it is observed that the trade-off between RR and wet grip exists for various tire stiffness design.

• Journal of the Korean Society of Tobacco Science
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• v.28 no.1
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• pp.58-66
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• 2006

Threshold limit value (TLV) test between expert and consumer panel was conducted about absolute, recognition and difference threshold respectively. And we tried to suggest appropriate and minimum acceptable menthol concentration level by consumer panel. Determination of threshold value was based on ASTM E 679-79 method by forced-choice ascending concentration series. In addition, a semi-ascending paired difference method was referred to conduct test. The group threshold value was determined as the value of geometric mean individual threshold. The smokers were dividend by two groups, trained and consumer panel. Trained panel was selected according to sensitivity to menthol discrimination. Consumer panel wasrecruited in proportion as population ratios including female smokers. They were all over twenty years old volunteers and summed up thirty four persons. In terms of sensor evaluation, overall difference test with seven-category scale by both trained and consumer panelists were done. On judging correct or incorrect answer, two by three cut-off levels applied to. Every test was conducted with two sessions, before smoking and during smoking period. And, only two samples served each paneI per test with regard to sensory fatigue and reliable results. All tests were replicated, and in total 32 times per panelist. In conclusion, the recognition threshold about consumer and expert panel was 358 ppm/cig. and 276 ppm/cig. in separately. Besides, absolute and difference thresholds were obtained also. And, we conduct difference threshold test with two different ways, upward and downward. And, The results of each method were 246, 195 ppm/cig., 1414, 1336 ppm/cig. and 1047, 972 ppm/cig.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.301-303
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• 2001

In this paper we present a Capacitor Charging Power Supply (CCPS) using a series-resonant three-level inverter topology to improve voltage regulation and use semiconductor switches having low blocking voltage capability such as MOSFETs. This inverter can be operated with two modes, Full Power Mode (FPM) and Half Power Mode (HPM). In FPM inverter supplies the high frequency step up transformer with full DC-link voltage and in HPM with half DC-link voltage. HPM switching method will be adopted when CCPS output voltage reaches the preset target value and operates in refresh mode-charge is maintained on the capacitor. In this topology each semiconductor devices blocks a half of the DC-link voltage[2]. A 15kW, 30kV CCPS has been built and will be tested for an electric precipitator application. The CCPS operates from an input voltage of 500VDC and has a variable output voltage between 10 to 30kV and 1kHz repetition rate at 44nF capacitive load [3]. A resonant frequency of 67.9kHz was selected and a voltage regulation of $0.83\%$ has been achieved through the use of half power mode without using the forced cut off the switch current [1]. The theory of operation, circuit topology and test results are given.

• Korean journal of food and cookery science
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• v.24 no.6
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• pp.849-855
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• 2008

DPPH radical scavenging activities were 66.80% by hot water extract and 41.86% by 80% methanol extract. Inhibitions of angiotensin I-converting enzyme (ACE) were 91.09% by hot water extract and 75.20% by 80% methanol extract. In this study, Sulgidduk samples were prepared with 1, 3, 5, and 7% concentrated sweet pumpkin powder (CSPP), and a control were examined for quality characteristics such as moisture content, water activity, color, textural characteristics, and sensory qualities, in order to determine the optimal ratio of CSPP in the formulation. The samples containing CSPP exhibited significantly higher moisture content than the control group. Water activity was not significantly different among the Sulgidduk samples. For the color, the control group presented significantly higher lightness as compared to the samples containing CSPP. The samples containing 1 and 3% CSPP had significantly higher greenness than the samples containing 5 and 7% CSPP. Yellowness increased as the level of CSPP content increased. In terms of textural characteristics, hardness, gumminess, and chewiness were highest at the 1% substitution level, while lowest at the 3% level. The CSPP samples presented significantly higher adhesiveness, springiness, and cohesiveness than the control group. In the consumer acceptance and characteristic intensity rating test, the control group showed significantly higher color and flavor as compared to the CSPP samples. Pumpkin flavor, delicious taste, and off-flavor increased with increasing amounts of CSPP. Softness, overall acceptability, and gumminess were not significantly different among the various samples tested. Sweetness was highest at the 5% substitution level, while lowest at the 1% level. In conclusion, the results indicate that substituting $3{\sim}5%$ CSPP to Sulgidduk is optimal, providing good DPPH radical scavenging activity and inhibition of ACE as well as reasonably high overall acceptability.

• The Research Journal of the Costume Culture
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• v.23 no.6
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• pp.972-986
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• 2015

This study seeks to explore the relationship between clothing adaptation and acculturation for married Chinese immigrant women. In addition, it aims to analyze the differences in their clothing consumption behaviors according to acculturation level. To achieve these purposes, a quantitative research study was conducted on 291 wives of Korean-Chinese multicultural families in Seoul and Gyeonggi. The data was analyzed using factor analysis, cluster analysis, ANOVA, and the Duncun test. The findings were as follows. First, the women were divided into three groups based on their level of acculturation, which was defined as 'assimilated', 'marginalized' and 'segregated'. Second, the relationship between their acculturation level and their clothing adaptation was identified. The marginalized group had the lowest level of clothing adaptation. Third, the groups' differences in clothing selection criteria were analyzed. The segregated group considered the practical aspects (price, color, quality) of clothing to be more important than the other groups. The marginalized group scored the lowest in valuing the aesthetic factors (design, style, trendiness) of clothing. Finally, conformity of clothing consumption varied significantly based on acculturation level. The assimilated and marginalized groups showed higher levels conformity than did the segregated group. Clothing purchase location also varied significantly between the three groups. The assimilated and marginalized groups preferred online shopping, but members of the segregated group preferred to carry out their shopping off-line. This study showed that clothing adaptation and clothing consumption behaviors play key roles in understanding the acculturation of multicultural families.

• Management & Information Systems Review
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• v.4
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• pp.225-255
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• 2000

The basic purpose of this research is to analyse a relationship between the integration level of AMT(ILAMT) and manufacturing performance (cost, quality, flexibility, delivery) and to identify the moderating effects of organizational structure in the relationship. First research question(hypothesis 1) was to examine the relationship between ILAMT and manufacturing performance. We tested this question using simple regression analysis. All of the correlation were positive and significant at the level of 1%(two-tail test). Therefore, hypothesis 1 was supported by the results. It means that firms that have high ILAMT are to exhibit high level of all manufacturing performance(cost, flexibility, quality, delivery). Namely, It is that the integration of AMT can solve the trade-off among manufacturing performance. Second research question (hypothesis 2) was to identify the moderating effects of organizational structure on the relationship between ILAMT and manufacturing performance. we tested this question using moderated regression analysis. According to the results, hypothesis 2 was partially supported. In other words, formalization and decentralization were accepted, but complexity was rejected. It means that firms with high ILAMT and an organic organizational structure are more likely to exhibit high level of manufacturing performance. To the practitioners, this research provided the answer to what they ought to do make AMT work in their organizations. To increase the effectiveness of AMT, first of all, they should take notice of the importance of integrated use of AMT, and the implementation of AMT should take into consideration the characteristics of organizational structure manufacturing strategy so that the effect of AMT may be multiplied by using AMT.