• Korean Management Science Review
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• v.32 no.3
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• pp.105-118
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• 2015

This study examines the relationship between city slogan modifiers and slogan attitudes from the perspective of residents in other cities. To examine this relationship, the study focuses on two important characteristics of slogan modifiers : the preference for a slogan modifier and the fit of a slogan modifier. To test the hypotheses, a 2 (low vs. high city knowledge)${\times}2$ (low vs. high slogan modifier preference)${\times}2$ (low vs. high slogan modifier fit) between-subjects factorial design was adopted. A total of 254 undergraduate students at the authors' college participated in the study. Their ages ranged from 19 and 30 (average = 22.3), and 58.3% of the participants were male. According to the results, the high-preference slogan modifier had a greater positive effect on slogan attitudes than the low-preference one. Similarly, the high-fit slogan modifier had a greater positive effect on slogan attitudes than the low-fit one. Also, it was shown that the fit of the slogan modifier had a greater effect on purchase intentions than the preference for the slogan modifier when city knowledge was high. However, contrary to expectations, when city knowledge was low, the standardized coefficient of the preference for the slogan modifier was not significantly different from that of its fit.

• Tribology and Lubricants
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• v.18 no.2
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• pp.133-137
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• 2002

This paper reports on the effect of fuel additive friction modifier on the engine friction and fuel consumption. The test of engine friction and fuel consumption is performed for the each oils and fuels. The TFA4724 friction modifier is added in test oil and fuel. The test results show that total engine friction is a decrease of 0.7-2.0% compared with base fuel, and fuel consumption is improved by 0.3%. The amount of friction reduction corresponds to that of boundary friction loss term in ring-pack friction losses. From the results, it is thought that the additive friction modifier in the fuel is effective to reduce the boundary friction in ring-pack.

• Journal of Preventive Medicine and Public Health
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• v.23 no.3 s.31
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• pp.247-254
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• 1990

짝짓기 방법은 교란변수를 통제하기 가장 좋은 방법으로 알려져 있으나, 모수추정시 그 계산방법이 복잡하고, 포함된 모든 정보를 이용할 수 없다는 단점을 갖고 있다. 그럼에도 불구하고, conditional 모델을 이용한 matched 분석법은 짝지은 자료 분석시 가장 좋은 방법으로 인정되고 있다. 그러나 명확한 confounding 현상을 통제할 목적이 아닌 상태에서 짝지워진 자료를 matched 분석법으로 모수추정하는 경우나, 올바로 짝지워진 자료를 분석법의 편이성 때문에 unmatched 분석을 시도하는 경우, 오히려 estimation bias가 야기될 수 있다. 이러한 estimation bias의 통제능력을 몇 가지 분석방법을 이용하여 비교하고자, 1:2로 대응된 한 환자-대조군 자료를 이용하여 Mantel-Haenszel 분석법, 두가지의 unconditional model을 이용한 다변량분석법의 결과를 conditional model을 이용한 matched 분석법의 결과와 비교하였다. 1. Matched 분석법의 대용방법으로 사용된 세 가지 방법들은 모수추정면에서나 가설검정능력면에서 차이를 서로 보이지 않았다. 2. 짝짓기에 사용된 변수가 분석자료내에서 confounder나 effect modifier로 작용되지 않았음이 명백한 경우에는 이들 세 가지 통제 방법과 matched 분석법간에 차이가 없었다. 3. 짝짓기에 사용된 변수가 분석자료내에서 effect modifier로 작용하지는 않았으나, Confounder로 작용한 것으로 추정되는 경우, unmatched 분석법으로 인해 야기된 estimation bias의 통제능력이 이들 세 가지 대용방안 모두에서 인정되었다. 4. 짝짓기에 사용된 변수가 분석자료내에서 effect modifier로 작용하고 있음을 직접 확인할 수 있는 경우에는, overmatching에 의한 estimation bias를 의심할 수 있었으며, 이들 세 가지 통제방법은 오히려 unmatched 분석 방법에 가까운 모수를 추정하였다.

• Korean Journal of Pharmacognosy
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• v.30 no.2
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• pp.99-104
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• 1999

During the screening for inhibitors of nitric oxide production in LPS-activated macrophage, RAW 264.7 cells. Five coumarins were isolated from chloroform extract of the root of Peucedanum japonicum. They were identified as praeruptorin A (1), xanthotoxin (2), psoralen (3), isopimpinellin (4), bergapten (5) on the basis of spectroscopic methods. The $IC_{50}$ values for nitrite production by activated macrophages were about $1.5\;{\mu}g/ml$ (1), $0.3\;{\mu}g/ml$ (2), $1.0\;{\mu}g/ml$ (3), $25\;{\mu}g/ml$ (4), $25\;{\mu}g/ml$ (5), respectively. However, the inducible nitric oxide synthase (iNOS) was not inhibited by treatment with these compounds. Their inhibitory effect on nitric oxide production was resulted from the supperssion of iNOS expression.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.5
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• pp.39-45
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• 2012

For a fundamental study for high concentration pigment coating, the effects of alkali swellable emulsion (ASE) type rheology modifier and surface adsorption emulsion (SAE) type rheology modifier on both the stability and the viscoelastic behavior of a coating color were elucidated. The coating color prepared with SAE type rheology modifier showed superior thermal and mechanical stability than that with ASE type. In the high concentration and high speed coating process, the mechanical stability of a coating color was a key parameter since both impact force and shear force were increased with the increase of coating color concentration and coating speed, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.2
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• pp.126-133
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• 2013

This paper presents a study on the dispersion effect of the X-Ray diffraction, glass transition and DMA properties of organic modifier clay/epoxy nanocomposites produced in a homogenizer. Several experiments were conducted including different types of dispersion condition with varying processing conditions such as homogenizer rotor speed and applied time of homogenizer. The effects of these variables on the dispersion properties of nanocomposites were then studied. In order to fully understand the experimental results, a X-ray diffraction, DSC and DMA were used to investigate the effect of above mentioned variables on microstructure and intercalation/exfoliation of organic modifier clay/epoxy nanocomposites. The results from this work could be used to determine the best processing condition to obtain appropriate levels of d-spacing, glasss transition temperature and storage modulus in organic modifier clay/epoxy nanocomposites.

• Journal of Environmental Science International
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• v.10 no.4
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• pp.311-314
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• 2001

The asphalt mixture with CRM(Crumb Rubber Modifier) is known to show a better performance in resisting thermal cracking, fatigue cracking and rutting compared with the conventional mixture. The laboratory tests on the physical characteristics of indirect tensile strength, density, flow and Marshall value of the CRM asphalt were conducted. The test results show that CRM asphalt has better physical characteristics than that of conventional asphalts. And the analysis on the noise reduction effect, penetration capacity from the field test on the national road in Haksan of Chungbuk, and recycling of tire waste were conducted. From this study, the results show that 1% CRM asphalt has higher the noise reduction effect and penetration capacity that those of conventional asphalts. And, optimal contents of crumb rubber modifier in the asphalt binder is one percent. In this case, crumb rubber modifier were used 10 kg to make the asphalt binder of one cubic meter. So it was named as Eco-asphalt.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.121-126
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• 1994

To elucidate the effect on the reactive extraction of acetic acid, various carriers and modifiers were investigated. Carriers used were secondary and tertiary amines and solvation extractant. Diluent was n-butylacetate. Modifiers were 4-nonylphenol, TBP(Tti-n-butyl phospate) and isodecanol. Besides the effect of temperature and pH in aqueous phase were studied. The mixture of 50% tri-n-octyl/n-decylamine tertiary amine, gave higher degree of extraction and selectivity than other extractants in the extraction of acetic acid. It was found that 4-nonylphenol as modifier fairly good. The degree of extraction was higher with decreasing the pH in aquous phase and the temperature of extraction system.

• Journal of Powder Materials
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• v.25 no.6
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• pp.501-506
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• 2018

With the recent remarkable improvements in the average speeds of contemporary trains, a necessity has arisen for the development of new friction modifiers to improve adhesion characteristics at the wheel-rail interface. The friction modifier must be designed to reduce slippage or sliding of the trains' wheels on the rails under conditions of rapid acceleration or braking without excessive rolling contact wear. In this study, a novel composite material consisting of metal, ceramic, and polymer is proposed as a friction modifier to improve adhesion between wheels and rails. A blend of Al-6Cu-0.5Mg metallic powder, $Al_2O_3$ ceramic powder, and Bakelite-based polymer in various weight-fractions is hot-pressed at $150^{\circ}C$ to form a bulk composite material. Variation in the adhesion coefficient is evaluated using a high-speed wheel-rail friction tester, with and without application of the composite friction modifier, under both dry and wet conditions. The effect of varying the weighting fractions of metal and ceramic friction powders is detailed in the paper.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.99-106
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• 2018

The modifier proposed in this research is for enhancing the affinity of the glass component with the high polymer resin and the molecular weight. The particle packing, tensile strength and shielding performance of the shielding sheet made of the tungsten oxide were evaluated. The best effect can be obtained when 20% of the modifier PMMA used to improve the shielding performance and maintain the affinity and strength with the sealant is mixed. The fusion of the materials presented in this study and the mass production of the shielding sheet through the modifier are possible and will contribute to the production of lightweight shielding sheets in the future.