• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.359-362
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• 2006

Infra-red thermography was conducted to understand a heat transfer characteristic on a surface protruded to a supersonic flowfield. Surface temperature distribution was obtained under the constant heat flux condition with a infra-red camera and the convective heat transfer coefficient distribution was calculated. Finally, two dimensional distribution of heat transfer coefficient on a surface around a cylinder body was derived.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.5
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• pp.383-388
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• 2019

It is essential to reduce the Infra-red signature for increasing ship's survivability in ship design stage. However the ship's IR signature is quite sensitive to the maritime and atmosphere. Therefore, it is very important to select the marine meteorological data to be applied to the signature analysis. In this study, we selected the three meteorological sample sets from the population of the Korea Meteorological Administration's marine environment data in 2017. These samples were selected through the two-dimensional stratified sampling method, taking into account the geopolitical threats of the Korean peninsula and the effective area of the buoy. These sample sets were applied to three naval ships classified by their tonnage, and then the IR signature analysis was performed to derive the Contrast Radiant Intensity (CRI) values. Based on the CRI values, the validity of each sample set was determined by comparing Cumulative Distribution Function (CDF), and Probability Density Function (PDF). Also, we checked the degree of scattering in each sample set and determined the efficiency of analysis time and cost according to marine meteorological sample sets to confirm the possibility of a probabilistic method. Through this process, we selected the standard for optimization of marine meteorological sample for ship IR signature analysis. Based on this optimization sample, by applying probabilistic method to the management of IR signature for naval ships, the robust design is possible.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.337-338
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• 2008

In this paper, propagation analysis method in using Walfish-Ikegami propagation model in wireless cell planning is proposed. Through Walfish-Ikegami model, we can predict the distribution of propagation loss of the received signal. For correct and low complex analysis, quick LOS search method and path loss offset calibration using measured data are included in Walfish-Ikegami model. In CellTREK that is developed by KT, it is showed that the proposed model outperforms Modified HATA model when comparing with measured data in Wibro system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.627-628
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• 2011

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.515-524
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• 2014

In this paper, The investment prioritization model was investigated for keeping the service level of mooring facilities more than the target level of management with a limited budget in the right time. Network level prioritization criteria of the national scale was developed to take into criteria index and quantitative evaluation, management authority's opinion. Delphi method was conducted maintenance exports of mooring facilities over twice for verifying the validity and adequacy. In order to improve the objectivity of criteria, the criteria for evaluating the utilization of port facilities is presented form yearly facility traffic/facility's length, the result of the analysis of facility traffic data. The investment prioritization criteria of mooring facilities is expected to be utilized for more efficient and national budget distribution applied to the maintenance budget plan of nationwide.

• International Commerce and Information Review
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• v.10 no.3
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• pp.101-116
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• 2008

Future e-Trade RFID/USN distribution should satisfy the new needs of reasonable customers such as efficient supply of goods, presentation of information, and communication by developing intermediate and long-term strategies through analysis of industrial conditions and customers' needs. Through preferential application of new technology, knowledge-based e-Trade RFID/USN distribution environment and DB of industrial portal sites should be developed, RFID/USN infra such as Supply Chain Management(SCM) should be expanded, future-oriented knowledge-based services should be developed to prepare specific and realistic plans for proper UT(Ubiquitous Technology). Such change in e-Trade distribution environment should have historical and environmental backgrounds to suggest specific tasks and directions as a conversion of structural concept of engineering and trade theory for new u-Trade. Accordingly, this study is to present all the problems available in RFID/USN distribution, develop an organized and technological estimate model and provide a foundation to apply it efficiently. This study aims to present an interpretational foundation of RFID/USN distribution, rather than technical directions.

• Journal of Korea Port Economic Association
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• v.20 no.2
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• pp.187-216
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• 2004

Northeast Asia logistics hub strategy was undertaken by Korean Government to gain a national competitive advantage in Northeast Asia. Current Government has Northeast Asian Economic Hub Strategy including construction of SOC in Northeast Asia for promoting peace, promotion of formation of Northeast Asia Community, logistics hub, Financial hub and national innovation for R&D Cluster. To realize Northeast Asian logistics hub, the Northeast Asia logistics hub road map has undertaken as follows: expansion of logistics infra in Incheon Airport, Busan Port and Gwangyang Port, systematic improvements such as adjustment of investment distribution, special logistics companies, transparent customs in logistics transactions, logistics manpower, improvement of system supporting global logistics and attraction of international logistics companies to the logistics center, construction of seamless and paperless logistics information network, Northeast Asia railway infra. The purpose of this paper is to study investment priority and improvements in the Northeast Asia Logistics Hub Road Map and to contribute to gain the national competitive advantage as logistics hub in Northeast Asia

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.371-374
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• 2006

Heat transfer characteristic near a sharp fin in a supersonic flow was studied. Infra-red thermography was used to obtain the variation of surface heat transfer coefficient distribution. The attack angle of fin is ranged from $10^{\circ}\;to\;20^{\circ}$ and the oil flow method was also conducted to understand a flow field near a sharp fin.

• Proceedings of the KWS Conference
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• 1996.10a
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• pp.142-144
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• 1996

This paper discusses the application of infra-red thermography in monitoring the robotic arc welding process, and it's potential for weld bead dimension and seam tracking control. Thermal images illustrating weld pool formation dynamics and heat distribution phenomena are digitized and their characteristics are measured. At each sampling point the maximum depth of penetration is recorded together with additional information regarding weld bead placement in relation to the seam location. Deficiencies such as incomplete penetration and lack of side wall fusion are readily identified and can be remained during the process. The technique can help an increase in productivity and weld quality by minimizing the amount of post process rework and inspection efforts needed otherwise.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.717-726
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• 2022

This study was conducted to assess the geochemical contamination degree of As, Cd, Cu, Pb, Sb, and Zn in the soil and water samples from an abandoned gold mine. Enrichment Factor (EF), Geoaccumulation Index (Igeo), and Pollution Load Index (PLI) were carried out to assess the geochemical contamination degree of the soil samples. Variations of sulfate and heavy metals concentration in water samples were determined to identify the geochemical distribution with respect to the distance from the mine tailing dam. Geochemical pollution indices indicated significant contaminated with As, Cd, Pb, and Zn in the soil samples that areas close to the mine tailing dam, while, Sb showed similar indices in all soil samples. These results indicated that the As, Cd, Pb, and Zn dispersion has occurred via anthropogenic sources, such as mining activities. In terms of water samples, anomalies in the concentrations of As, Cd, Zn, and SO₄^2- was determined at specific area, in addition, the concentrations of the elements gradually decreased with distance. This result implies the heavy metals distribution in water has carried out by the weathering of sulfide minerals in the mine tailing and soil. The study area has been conducted the remediation of contaminated soil in the past, however, the geochemical dispersion of heavy metals was supposed to be occurred from the potential contamination source. Therefore, continuous monitoring of the soil and water is necessary after the completion of remediation.