• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1711-1720
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• 2001

In this study, the heat transfer characteristics of a U-shape heat pipes were investigated. Heat is supplied to the U heat pipe through its middle zone(evaporator), and is released to the environment through its both arms(condensers). Both heat transfer coefficients and heat transport limitations were measured and compared with correlations previously developed for straight type heat pipes. Special concerns were focused to the cases, when each of condensers were submitted to a different cooling conditions, relatively. As a result. the heat transfer limitation of a U-shape heat pipe was found out to be 10∼15% less than the value for a straight heat pipe with an equivalent size.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.109-113
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• 2011

Recently, according to the development of ubiquitous computing, the u-GIS which not only used in u-Transport, u-Care, u-Fun, u-Green, u-Business, u-Government, and u-City but also used to provides various spatial information such as the location of user is being the core technology of the ubiquitous computing environment. In this paper, we implemented an mobile spatio-temporal Query Processing Systems for handling the Spatio-Temporal Data in mobile equipment.The mobile spatio-temporal Query Processing Systems provides the spatio-temporal data type and the spatio-temporal operator that is expanded by the spatial data type and the spatial operator from OepenGIS "Simple Feature Specification for SQL". It supports arithmetic coding compression techniques that is considered with a spatio-temporal data specific character. It also provides the function of data cashing for improving the importation and exportation of the spatio-temporal data between a embedded spatio-temporal DBMS and u-GIS server.

• 한국ITS학회지
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• v.4 no.1
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• pp.7-16
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• 2007

• 한국ITS학회지
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• v.4 no.1
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• pp.25-29
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• 2007

• Journal of the Korean Society of Combustion
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• v.13 no.1
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• pp.23-30
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• 2008

An analytical expression for the turbulent burning velocity is derived from the asymptotic zone conditional transport equation at the leading edge. It is given as a sum of laminar and turbulent contributions, the latter of which is given as a product of turbulent diffusivity in unburned gas and inverse scale of wrinkling at the leading edge. It was previously shown that the inverse scale is equal to four times the maximum flame surface density in the wrinkled flamelet regime [1]. The linear behavior between $U_T$ and u' shows deviation with the inverse scale decreasing due to the effect of a finite flamelet thickness at higher turbulent intensities. DNS results show that $U_T/S^0_{Lu}$ may be given as a function of two dimensionless parameters, $u'/S^0_{Lu}$ and $l_t/\delta_F$, which may be transformed into another relationship in terms of $u'/S^0_{Lu}$, and Ka. A larger $l_t/{\delta}_F$ or a smaller Ka leads to a smaller scale of wrinkling, hence a larger turbulent burning velocity in the limited range of $u'/S^0_{Lu}$. Good agreement is achieved between the analytical expression and the turbulent burning velocities from DNS in both wrinkled and thickened-wrinkled flame regimes.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.1
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• pp.100-111
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• 2011

u-City(ubiquitous city) pursuing competitiveness of city and improvement the quality of life needs high cost to build and operate it. But not all people get a benefit by u-City. It is important that low-income people have experienced information divide gain practical benefits in u-City. In this paper, first we selected suitable item of u-service for low-income people and then drew a order of priority using AHP method about legal and institutional conditions, possibility of technical realization, and the generalization. As a result, we prioritize to u-service for low-income people, that is the order is prevention for missing a dotard, safety of street, and information providing about job and employment.

• Membrane Journal
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• v.4 no.2
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• pp.96-105
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• 1994

Theoretical model for membrane transport of large polye!ectroiyte is presented. When the electric field is applied, the molecular conformation quickly orients in the field direction showing overshooting orientation. the predicted dependence of overshoot time and orientation upon field intensity and molecular size aids to understand the dynamic motion of molecules in membrane transport. The dynamics of the overshoot is associated with self-trapping conformations of molecule. The understanding of these effects supports evidences for the electrophoretic filtration of polydectrolyte in the polymeric membrane. This paper shows one example for molecular study in the theoretical review paper of membrane transport.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.2
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• pp.45-52
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• 2008

Contaminant transport has been widely studied in rigid porous media, but there are some cases where a large volumetric stain occurs such as dewatering of dredged contaminated sediment, landfill liner, and in-situ capping. This paper presents a numerical investigation of contaminant transport coupled with large strain consolidation. Consolidation test was performed with contaminated sediments collected in Gary, Indiana, U.S. to obtain constitutive relationships, which are required for numerical simulations. Numerical results using CST2 show an excellent agreement with measured settlement and excess pore pressure. CST2 is then used to simulate contaminant transport during and after in-situ capping. Numerical simulations provide that transient advective flows caused by consolidation significantly increase the contaminant transport rate. In addition, the numerical simulations revealed that active capping with Reactive Core Mat (RCM) significantly decelerates consolidation-induced contaminant transport.

• Journal of Aerospace System Engineering
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• v.5 no.1
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• pp.24-29
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• 2011

The industry related to commercial space transport is growing rapidly as a futurity industry all over the world and America is leading them. If this trend continues, domestic individuals or private enterprises may plan for the commercial space transport business by adopting the advanced technology. Therefore it is necessary to make a law to control the business in our country for the industrial development and the growth related to commercial space transport. This paper provides outline for domestic commercial space transport law by the study and analysis of U.S. commercial space transport laws.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.4
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• pp.415-421
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• 2008

The purpose of this study is to provide a sensor based service model for traffic facilities in u-City through analysing the present condition of urban infrastructure, especially traffic facilities management. In order to achieve this purpose, we did a comparative analysis of internal and external situation of ITS(Intelligent Transport System) and classified service for traffic facilities to 3 categories, namely traffic flow management, traffic information offering, formation of road structure. Also, we examined technological trend of USN(Ubiquitous Sensor Network). Through this process, we present a sensor based service model of traffic facilities for building sustainable road environment.