• KSTLE International Journal
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• v.2 no.2
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• pp.127-132
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• 2001

The steady state performance of the counterrotating floating ring journal bearings is analyzed with isothermal finite bearing theory. The effect of counterrotating speed of the sleeve on the performance of the bearing is investigated. It is shown that counterrotating floating ring journal bearings can have considerable load capacity at the same counterrotating speeds, while conventional circular journal bearings with one fluid film cannot. Investigating the relationship between the frictional torques exerted on the ring due to the inner and outer films and the rotational speed of the ring, the stability of the equilibrium state is identified and the operating characteristics of the counterrotating floating ring journal bearing according to the method of acceleration or deceleration of the rotational speeds of the journal and sleeve are clarified. It is theoretically confirmed that floating ring journal bearings can be used in counterrotating journal-bearing system and become good substitutes for rolling bearings in counterrotating systems.

• Journal of Korean Society of Rural Planning
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• v.14 no.2
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• pp.99-110
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• 2008

The purposes of this paper are first, to develop and adapt auditing methodology of rural amenity resource investigation and second, to propose strategic planning of amenity web data base system. Relating with auditing methodology, we make the life cycle of rural amenity resource investigation based on value chain method. we make 8 stage of auditing process and 105 auditing items in details. We adapt these guidelines in real world and then improve developed methodology. Therefore we expect to promote the quality and accuracy of investigation project using these guidelines. Relating with blue print of strategic planning, we first analyse external environment about Competitors, Suppliers, New entrants, Buyers, Substitutes with 5 force model for amenity information system. We second make the blue print of strategic planning of amenity web data base system project. Then we propose the FIRST, BEST, MOST strategy of amenity web data base system and the web hub system.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.1
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• pp.121-129
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• 1994

A study focused on the implication of the blue and black colors in Korean traditional costume is presented. The presented study shows that the blue color in most of literatures regarding Korean traditional costume implies not only green and blue colors, but also dark blue and black colors. In a broad sense, the blue color implies a color category which includes green, indigo, blue, dark blue and black. On the other hand, the color includes blue, dark blue and black in a narrow sense. The rotor black, however, should not be interpreted as blue and dark blue because it has two bypes of black colors with and without reddish tone. Four reasons that the color blue was understood as the color black were discussed in this paper. The fundamental reason was that the blue color looked like black because of dark shadows. Secondly, there was a difference of color awareness between the color blue in Korea and in China. Thirdly, there was a color difference related to the type of textiles. Finally, other substitutes were used because of the lack of blue dyes.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.217-222
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• 2002

The purposes of this study are to investigate the material characteristics and strength properties of concrete mixed with waste incinerated bottom ash(BA), and to evaluate the leaching of environmentally harmful heavy metals from the bottom ash itself and from hardened concrete mixed with bottom ash. For this purpose, two reference mixes with W/C ratios of 0.45 and 0.55 were used, and the replacement proportion of BA was varied with the ratios of 0%, 30%, 50%, 70%, and 100% by volume of fine aggregate in the reference mixes. The variation of compressive and splitting tensile strength, workability and unit weight of concrete were considered. Test results showed that the strengths, workability and unit weight decreased with increase in proportion of BA replaced. Leaching test results showed that there would be no environmentally harmful problem from using BA as the substitutes of fine aggregates in concrete.

• Culinary science and hospitality research
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• v.22 no.6
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• pp.14-23
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• 2016

This purpose of this study is to examine the antioxidant and antimicrobial activities of Persicaria hydropiper L. extract in 70% ethanol and in water, a medicinal herb, as an effort to examine the potential of medicinal herbs for development of antioxidants and natural preservative substitutes. The total poly-phenol content in the 70% ethanol extract and in the water extract were 19.88 mg/g and 7.46 mg/g, respectively. The DPPH radical scavenging activity was 90.99% and 64.98% in the 70% ethanol extract and water extract, in which 70% ethanol extract showed a higher activity. The antioxidant effect of Persicaria hydropiper L. extract appears to be very good and due to its excellent growth inhibitory effect on food-poisoning-causing microorganisms in the food, it is thought to be utilized as a potential natural preservative substitute in many areas.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.313-313
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• 2016

Transparent conductive oxide (TCO) films have many disadvantages, such as rarity, possible exhaustion, process temperature limitations, and brittleness on a flexible substrate. In particular, as display technology moves toward flexible displays, TCO will become completely unsuitable due to its brittleness. To address theses issue, many researchers have been studying TCO substitutes. In recent efforts, metal nanowires, conducting polymers, carbon nanotube networks, graphene films, hybrid thin films, and metal meshes/grids have been evaluated as candidates to replace TCO electrodes. In this study, we fabricated the TCO film with Ag meshes shape using polystyrene (PS) beads monolayer on the substrate. The PS beads were used as a template to create the mesh pattern. We fabricated the monolayer on the flexible substrate (PES) with the well-aligned PS beads. Electrodes with Ag mesh shape were formed using this patterned monolayer. We could fabricated the Ag mesh electrode with the sheet resistance with $8ohm{\Omega}/{\Box}$.

• International Journal of Fluid Machinery and Systems
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• v.8 no.3
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• pp.124-131
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• 2015

The good performance of a vortex shedder is defined by strong and stable vortex generated under the condition of most linearity in Strouhal number and low power loss. In this paper, the flow past a bluff body of circular cylinder with a slit normal to the flow has been analyzed focusing on drag coefficient, linearity of Strouhal number and flow resistance (K-factor). The ANSYS/FLUENT package is used for flow simulation and the integration method of computational code to iSIGHT platform is employed for automated design cycle. This study results the design with (0.20~0.267) blockage ratio and 0.10 slit ratio as the best shedder for vortex flowmeter and this results are in well agreement with the experiment. As the combination of GAMBIT, FLUENT, and iSIGHT substitutes the design parameters automatically according to the input data, this method designs effectively the vortex shedder with less design cycle time and low manufacturing cost eliminating the human intervention bottleneck.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.217-220
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• 2005

In this paper describes novel m antenna using aperture matched type slot structure. It substitutes edge diffractions by curved-surface diffractions which have a tendency to provide an undisturbed energy flow across the junction, around the curved surface, and into free-space. The proposed antenna is composed of a CPW feed structure, exponential tapered slot and the curved sectional at the edge. experimental resulte show that aperture matched type slot improve the performance of the UWB antenna.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.164-168
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• 2003

Fatty acid methyl esters (FAMEs) show large potential applications as diesel substitutes, and they are known as biodiesel fuel. Biodiesel fuel as a renewable energy is an alternative that can reduce energy dependence on petroleum and air pollution. Several processes for the production of biodiesel fuel have been developed. Transesterification process under alkali-catalysis and short-chain alcohol gives high level yield of methyl esters in short reaction times. In this research, transesterification of rapeseed oil was investigated to produce the FAMEs. Experimental reaction conditions included molar ratio of oil to alcohol, concentration of catalyst, types of catalysts, reaction time, and reaction temperature. The conversion ratio of rapeseed oil enhanced with the alcohol-oil mixing ratio and with the reaction temperature.

• Preventive Nutrition and Food Science
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• v.2 no.4
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• pp.291-295
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• 1997

Some sensory properties of synthetic sweeteners are limiting factors for use in low calorie foods of soft drinks. By combining synthetic sweeteners(Neohesperidin dihydrochacone(NHDC), stevioside) with sucrose, sorbitol or xylitol, these limitations can be overcome. Using trained taste panelists and magnitude estimation methods, synergistic effects were investigated in binary sweetener mixtures, The results showed that synergism, as much as 28% to 69%,was noted at all concentration in xylitol-stevioside, NHDC-stevioside mixtures. Synergistic effects were found only at high concentration levels in mixtures of sucrose-NHDC, sucrose-stevioside, and sorbitol-stevioside, ranging from 11% to 22%.By taking advantage of synergistic effects, ginseng tea and orange flavored beverages, sweetened with either xylitol-stevioside of NHDC-stevioside, were prepared and the sensory quality was compared with that of sucrose containing beverages. It was found that sensory characteristics were judged to be very similar for all formulations. The result suggests the possibility of using of using these sweetener mixtures as sugar substitutes in ginseng tea and orange drink.