• 한국환경과학회지
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• 제20권10호
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• pp.1309-1317
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• 2011

This study selected 6 river reach, which have various curved-channel, included in an object of study as making the Nakdong River, which is a real nature river, as a point of an object of study by using SMS RMA-2 model, a 2D numerical analysis model, and applied project flood and analyzed and examined characteristic of hydrological property and super-elevation, which includes characteristic of the velocity of a moving fluid. As a result, in a river reach, whose width is wide, angle of curved-channel has impact on the velocity of a moving fluid of inside of curved-channel and in a river reach, whose width is narrow, the radius of curvature and width of the river have impact on the velocity of a moving fluid of inside of curved-channel. Also it found out that the ratio of reduction in water-level of inside of curved-channel is more bigger than ratio of increasing in water-level of outside of curved-channel when project flood is increasing and angle of curve is increasing. Based on this, this study would be used as a expectation of danger and preliminary data in planning real river or a business, that creates an environment.

• Advances in nano research
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• 제2권2호
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• pp.121-133
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• 2014

Polymer nanocomposites are advanced nanomaterials which exhibit dramatic improvements in various mechanical, thermal and barrier properties as compared with the neat polymer. Polystyrene/ alumina nanocomposites were prepared by an ultrasound-assisted solution casting method at filler loadings ranging from 0.2 to 2% and also at different ultrasonic frequencies, viz. 58 kHz, 192/58 kHz, 430 kHz, 470 kHz and 1 MHz. The composites were subjected to mechanical property tests (tensile and impact tests) and cavitation erosion tests to study the enhancement in functional properties. Filler dispersion in the polymer matrix was observed by SEM analysis. The effect of frequency on filler dispersion in the matrix was studied by SEM analysis and functional property enhancement of the composite material. The composites prepared at dual (high/ low) frequency (192/58 kHz) were found to show better property enhancement at low filler loadings as compared with neat polymer and also with composites prepared without ultrasound, thus reinforcing the finding that ultrasound-assisted synthesis is a promising method for the synthesis of nanocomposites.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.77-81
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• 2010

This study deals with the analysis of color-difference and physical property of anti-corrosion coatings using at inside of concrete tank for drinking water. Because anti-corrosion coatings are effected by chemical attack, color and physical property are changed. So in this study when epoxy resin coatings of 3 types were received chemical attack by Cl- and NaOH, we present the co-relationship between color-difference and bond strength. For this study, we used the colorimetry, which can measure the degree of color difference on surface of materials. As the results, in case of Cl-, color change is appeared, bond strength also is decreased. From this experiment, we could know that color change due to chemical aging has the deep relationship with physical performance(bond strength) materials. further researches are needed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.546-552
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• 2012

This paper is a study on squeal noise simulation under the consideration of temperature and pressure dependent material properties of friction material. For this, data of pressure and temperature dependent material properties of lining is achieved by using lining data base and exponential curve fit. Complex eigenvalue analysis is performed for predicting squeal noise frequency and instability and chassis dynamo test is performed for achieving squeal noise frequency, sound pressure level, occurrence temperature & pressure. Initial multi models are composed for considering complex interface conditions such as pad ear-clip, piston-housing and guide pin-torque member. The simulation result of base models is compared with the test result. Squeal noise simulation under the consideration of temperature and pressure dependent material properties of friction material is performed and analyzed using multi models. And additional condition is disc material property variation. Entire simulation conditions are combined and analyzed. Finally, this paper proposes direction of the warm squeal noise model.

• 복식문화연구
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• 제18권5호
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• pp.824-841
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• 2010

In 21st century, subordinated relationship of fashion from the body has been disappearing, and fashion is understood as variable and creative field. This research aims at analysis about the relationship between the body and fashion depending on the theories about the authority and the desire. So, this utilizes between theoretical study and empirical analysis. For concentrated study, research period limits from 2000 to the present time 2010. Contemporary body and fashion have being changed into various forms and values, become complex and de-territory. Especially, body is symbol of ambivalence eroticism that gives point to sexual property, and the object of fetishism and machine having a desire. This study's purpose draw a parallel with between the limits of contemporary body that couldn't be rid of the capital and desire, and the liberty of fashion that escape from the body's influence has being changed independent and fluid space. This research's results are as follow as; contemporary de-territory fashion is expressed as 1) symbol of the object and physical material property, 2) self-transcendental instrument fashion, 3) independent spatial molding, 4) de-centering fashion.

• 대한산업공학회지
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• 제13권2호
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• pp.65-77
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• 1987

Congestion occurs whenever users interfere with each other, while competing for scarce resources. In a congested market, such as a telecommunication service market, users of telecommunication services incur costs in using the service in addition to the price. The user's own time costs involved in learning to use the service, waiting for the service, and making use of the service are typically greater than the price of telecommunication services. A market equilibrium analysis is performed in which a method for user demand aggregation is developed. The effects of price changes on user demands and market demands for congested services are examined. It is found that total market demands may increase as the price for less-congested services increase under certain demand conditions. This suggests that a nonuniform pricing scheme for a congested service may improve the utilization of the congested system. The sign of price cross-elasticity for congested services is show to vary with demand conditions. A possible complementary property of congested services is found and the implication of such a property is discussed. It is argued that such a complementary property may lead to a cross subsidy in a market with congestion. Finally, comparisons between uniform pricing and nonuniform pricing policies are made. A specific numerical example is given to show that a nonuniform pricing policy may be Pareto superior to a uniform pricing policy.

• 한국자동차공학회논문집
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• 제9권3호
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• pp.51-59
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• 2001

A diesel engine oil formulated in KRICT and a commercial diesel engine oil (API CG-4) were tested by car and their Kinematic Viscosity, TAN, TBN, metal content, additive depletion, anti-wear property and IR analysis were analyzed. From the research, both of the tested oils had almost the same properties f3r the change of TAN and TBN, but the change of Kinematic Viscosity of formulated oil was slightly higher than that of commercial oil. The iron content in the commercial oil increased rapidly from 7000 km while that of the formulated oil was still low. These results were confirmed by the anti-wear test with a 4-ball wear test machine for the each samples. Also, for the commercial oil, the depletion factor of the Zn-DTP which was added as an anti-wear property did not change any more after 7000 km. But, that of the formulated oil changed continuously to 8000 km, which means that the ability to prevent wear of the sliding pairs exists for the formulated oil. From the analysis results of oil properties obtained by field test, it was found that the commercial oil could be used only within 7000 km, but the formulated oil could be used more than 8000 km without severe wear of the sliding parts in the diesel engine.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.745-745
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• 2002

Both geophysical and geospatial data provide important information in the establishment of the optimal telecommunication systems especially in the mobile telecommunication environment. The objective of this study is to utilize geophysical properties and geospatial information in the analysis of the telecommunication environment through point-to-point wave property modeling. Geophysical properties associated with wave propagation parameters of the earth surface were analyzed based on hierarchical land classification using Landsat ETM＋ and IKONOS images. Three-dimensional geospatial information was obtained by processing stereo aerial images. The results show that the accurate geospatial information and reliable geosphysical property of the surface improve the prediction of receiving power of the receivers located near corners of the buildings where diffractions occur. The wave property model developed from accurate telecommunication environment could be applied to optimal cell planning and delay time analysis.

• Journal of Electrochemical Science and Technology
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• 제9권4호
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• pp.330-338
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• 2018

The adhesion strength as well as the electrochemical properties of $LiNi_{0.4}Mn_{0.4}Co_{0.2}O_2$ electrodes containing various conductive carbons (CC) such as fiber-like carbon, vapor-grown carbon fiber, carbon nanotubes, particle-like carbon, Super P, and Ketjen black is compared. The morphological properties is investigated using scanning electron microscope to reveal the interaction between the different CC and the active material. The surface and interfacial cutting analysis system is also used to measure the adhesion strength between the aluminum current collector and the composite film, and the adhesion strength between the active material and the CC of the electrodes. The results obtained from the measured adhesion strength points to the fact that the structure and the particle size of CC additives have tremendous influence on the binding property of the composite electrodes, and this in turn affects the electrochemical property of the configured electrodes.

• 헤리티지:역사와 과학
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• 제34권
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• pp.4-18
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• 2001

Paekche black potteries are earthenwares begun to be produced at the beginning of Paekche Dynasty, around 3-century. They have typical Paekche style. Representative Paekche earthenwares are burnished black pottery, long oval shaped pots and shoulder pots. Among these, burnished black potteries are limited to Paekche in the occurrence site and age. Their numbers are a few. To reproduce black pottery, their compositions were analyzed. As a result of X-Ray analysis, quarts, feldspar, illite, muscovite, and anorthite were found on their surfaces and imsides spinel and vermiculite were found on their surfaces. Since same constituent minerals were found on surfaces and their insides, special other materials were not added to make surface black. With the showing vermiculite, they were made higher than $800^{\circ}C$. As a result of analysis, fine grained clay bad been influenced by the black smoke. Its luster was appeared by polishing with a big flat wooden spoon. The black color was made of smoking when the hot pot taken off from burning oven was covered with the wet pine leaves.