• Journal of the Korean earth science society
• /
• v.25 no.1
• /
• pp.10-21
• /
• 2004

Recently, spatial data integration for geoscientific application has been regarded as an important task of various geoscientific applications of GIS. Although much research has been reported in the literature, quantitative assessment of the spatial interrelationship between input data layers and an integrated layer has not been considered fully and is in the development stage. Regarding this matter, we propose here, methodologies that account for the spatial interrelationship and spatial patterns in the spatial integration task, namely a multi-buffer zone analysis and a statistical analysis based on a contingency table. The main part of our work, the multi-buffer zone analysis, was addressed and applied to reveal the spatial pattern around geological source primitives and statistical analysis was performed to extract information for the assessment of an integrated layer. Mineral potential mapping using multi-source geoscience data sets from Ogdong in Korea was applied to illustrate application of this methodology.

• Journal of the Korea Institute of Building Construction
• /
• v.9 no.4
• /
• pp.75-83
• /
• 2009

Although a range of machine excavation methods are in wide use, including casing, earth drill and reverse circulation drilling, deterioration in pile quality and faulty construction can be often found these days because of trouble in the construction field. For this study, research was conducted in the form of a survey of construction engineers working in the field in order to identify the types and the causes of trouble by focusing on all casing, earth drilling and reverse circulation drilling. By analyzing the causes of trouble, countermeasures could be presented. The data and the analysts presented in this study could be effectively used for minimizing trouble in future machine excavation work during construction.

• Journal of Soil and Groundwater Environment
• /
• v.27 no.2
• /
• pp.41-49
• /
• 2022

To abate the environmental burdens arising from CO₂ emissions, biochar offers a strategic means to sequester carbons due to its recalcitrant nature. Also, biochar has a great potential for the use as carbon-based adsorbent because it is a porous material. As such, developing the surface properties of biochar increases a chance to produce biochar with great adsorption performance. Given that biochar is a byproduct in biomass pyrolysis, characteristics of biochar are contingent on pyrolysis operating parameters. In this respect, this work focused on the investigation of surface properties of biochar by controlling temperature and reaction medium in pyrolysis of pine sawdust as case study. In particular, CO₂ was used as reaction medium in pyrolysis process. According to pyrolytic temperature, the surface properties of biochar were indeed developed by CO₂. The biochar engineered by CO₂ showed the improved capability on CO₂ sorption. In addition, CO₂ has an effect on energy recovery by enhancing syngas production. Thus, this study offers the functionality of CO₂ for converting biomass into engineered biochar as carbon-based adsorbent for CO₂ sorption while recovering energy as syngas.

• Nuclear Engineering and Technology
• /
• v.55 no.12
• /
• pp.4664-4670
• /
• 2023

Radiation is the main safety issue for almost all nuclear applications, which must be controlled to protect living organisms and the surrounding materials. In this context, radiation shielding materials have been investigated and used in nuclear technologies. The choice of materials depends on the radiation usage area, type, and energy. Polymer materials are preferred in radiation shielding applications due to their superior characteristics such as chemical inertness, resistivity, low weight, flexibility, strength, and low cost. In the presented work, ABS polymer material, which is possibly the most commonly used material in 3D printers, is mixed with Gd₂O₃ and Er₂O₃ nanoparticles. ABS filaments containing these rare-earth elements are then produced using a filament extruder. These produced filaments are used in a 3D printer to create shielding samples. Following the production of shielding samples, SEM, EDS, and gamma-ray shielding analyses (including experiments, WinXCOM, GEANT4, and FLUKA) are performed. The results show that 3D printing technology offers significant enhancements in creating homogeneous and well-structured materials that can be effectively used in gamma-ray shielding applications.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.1
• /
• pp.72.2-72.2
• /
• 2015

Wolf-Rayet galaxies, galaxies which show spectral features produced by Wolf-Rayet stars, are thought to be the place of recent massive star formation since the Wolf-Rayet phase covers relatively short timescale in the life of massive O and B type stars. Studying these galaxies provides a unique chance to understand how massive star formation occurs in a galaxy within a short timescale. In this work, we present the intermediate resolution optical spectra of 12 Wolf-Rayet galaxies obtained using longslit spectrograph on Bohyunsan Optical Astronomy Observatory. We derived the emission line ratios for a number of star-forming knots in each Wolf-Rayet galaxy. Star formation properties in these galaxies are discussed.

• Journal of the Korea Institute of Building Construction
• /
• v.5 no.4 s.18
• /
• pp.139-144
• /
• 2005

A ground anchor system is used as a load carrying element in soil work. The conventional systems with ground anthers bring about the anchorage loss of wedges when anchors are installed for the support of soil structures. Hence we developed the new type of anchor system using both the spacing apparatus and spring (length 60mm, diameter 6mm). In this system, we tan directly check the condition of wedges and PS strands and modify the problems with the slip and anchorage of wedges under construction. For demonstrating the superiority of this system, we carried out a series of the laboratory test. Consequently, we can obtain satisfactory result (18.99$\%$ reduction to the loss of conventional systems). Moreover, the replacement of wedges is easy and simple when retensioning of strands.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.04a
• /
• pp.195-198
• /
• 2002

Nitrogen pollution in urban and rural groundwater is a common problem and poses a major threat to drinking water supplies based on groundwater. In this work, the kinetics of nitrification-denitrification coupled reactions are modeled and new reaction modules for the RT3D code (Clement, 1997) describing the fate and transport nitrogen species, dissolved oxygen, dissolved organic carbon, and biomass are developed. The proposed nitrogen transformations and transport model showed very good match with results of a conceptual model. However, the model simulation results for the major reactive species should be tested for validation using experimental and field data.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1998.02a
• /
• pp.18-18
• /
• 1998

F First I will introduce our works how to improve the crystal growth t technique for Rare earth pnictides and chalcogenides. All these substances h have hi양1 vapor pressure and high melting print up to 3$\alpha$)()C. 까len we employ m the tungsten or molybden crucibles and enclose the sample by 빼e welding of m the lid with high current electron beam. We cannot elevate the temperature up t to 3$\alpha$)()C without suitable radiation shield because rate of radiation loss r rapidly increase in such a high temperature regions. There were no good r radiation shield but we discovered that the p-BN could work as an excellent r radiation shield after checking of the many substances. S Secondly I will show several interesting and unusual 뻐ysical properties of obtained crystals under high magnetic field, hi양1 pressure and also i including angle resolve photoemission spectroscopy. I will stress the p properties of the low carrier concentration with strong correlation on C댐, U USb and Yb4As3

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2005.04a
• /
• pp.110-113
• /
• 2005

The objective of this study was to examine the effect of proposed permeable eobarrier system for removal of PCE from groundwater. The materials used for the natural geobarrier are gravel bean and silty clay. In addition, the effect of Pyeongtaek soil on PRB assessed in this experiments. It was observed that the adsorption of PCE in natural geobarrier system is eligible for real site. However, natural geobarrier system has various factors based on using materials. Therefore, more laboratory work is needed to study about permeable geobarrier.

• Current Industrial and Technological Trends in Aerospace
• /
• v.9 no.1
• /
• pp.90-101
• /
• 2011

In this article, we introduce the technologies and trend of technical evolution of Payload Data Handling Unit (PDHU) for Earth Observation Satellites. As well, we review the efforts for the Koreanization of PDHU so far, and conclude with some suggestions for future work.