• The Journal of Information Systems
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• v.25 no.4
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• pp.121-139
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• 2016

Purpose In this study, we propose the special purposed R package named ""new_Noun()" to process nonstandard texts appeared in various social networks. As the Big data is getting interested, R - analysis tool and open source software is also getting more attention in many fields. Design/methodology/approach With more than 9,000 R packages, R provides a user-friendly functions of a variety of data mining, social network analysis and simulation functions such as statistical analysis, classification, prediction, clustering and association analysis. Especially, "KoNLP" - natural language processing package for Korean language - has reduced the time and effort of many researchers. However, as the social data increases, the informal expressions of Hangeul (Korean character) such as emoticons, informal terms and symbols make the difficulties increase in natural language processing. Findings In this study, to solve the these difficulties, special algorithms that upgrade existing open source natural language processing package have been researched. By utilizing the "KoNLP" package and analyzing the main functions in noun extracting command, we developed a new integrated noun processing package "new_Noun()" function to extract nouns which improves more than 29.1% compared with existing package.

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

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.3
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• pp.103-109
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• 2016

The purpose of this study is to perform comparative economic evaluation for the systems of ground source heat pump (GSHP) and district heating and cooling (DHC) by focusing on the analysis of operation case of GSHP. The adapted research object is a public office building located in Seoul. The capacity of ground source pump is about 3,900 kW. Ground heat exchanger is closed loop type. The analysis period for life cycle cost is 30 years. Economic evaluation is assessed from the viewpoints of the following four parts: initial cost, energy cost, maintenance and replacement cost, and environment cost. The total life cycle cost of GSHP is approximately 8,447 million won. The cost of the DHC System is approximately 3,793 million won. The cost of the DHC is approximately 46% lower than GSHP system under the condition of current rate for GSHP and DHC.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.96-102
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• 2019

The study of thermal effect on the structure is carried out in the case of Guss asphalt which is paved at the temperature of $240^{\circ}C$ or higher in the bridge pavement of the steel deck bridges. However, studies on the heat source data applicable to numerical analysis are insufficient, the temperature load is used as a joint load. In this study, the heat source equations that can be directly loaded on the plate elements, although limited, are presented using the measured temperature data in the Guss asphalt pavement and its validity is confirmed by a brief numerical analysis.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.609-611
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• 2008

Eddy current is usually generated in material with high conductivity by time-varying source such as AC current and also is induced in the moving source with relative velocity. The contactless magnetic brakes make use of the braking force from the eddy current generated by moving source and currently used for the secondary brakes of heavy trucks, buses and rail vehicles. This study aims to design the magnetization pattern of a permanent magnet type eddy current brake system to maximize the braking force. The analysis of the brake system is based on the two-dimensional finite element analysis. We use the sequential linear programming as the optimizer and the adjoint variable method for the sensitivity analysis.

• The Journal of the Korean life insurance medical association
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• v.29 no.2
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• pp.22-28
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• 2010

Medical risk selection or mortality analysis is very important in insurance medicine. Among many kind of source articles there have been several limitations. There are few long-term follow-up studies in rare disease, as Romeo's article. We can do mortality analysis of this type using cause of death within the article and assumption of expected mortality q'. In the case of article which is published in foreign country such as Tikkanen et al, we can use comparative group from the control group within source article. It is another way for mortality analysis of limited article. However Retrospective study even performed in Korea, is unusable for estimation of extra-mortality.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.7
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• pp.658-663
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• 2009

Eddy current is usually generated in the material with high conductivity by time-varying source such as AC current and also is induced by the moving source with relative velocity. The contactless magnetic brake makes use of the braking force from the eddy current generated by the moving source and currently used for the secondary brakes of heavy trucks, buses and rail vehicles. This study aims to design the magnetization pattern of the eddy current brake system of a permanent magnet type where the design aim is to maximize the braking force. The analysis of brake systems is based on the two-dimensional finite element analysis. We use the sequential linear programming as the optimizer and the adjoint variable method is applied for the sensitivity analysis.

• Journal of Auto-vehicle Safety Association
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• v.12 no.4
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• pp.70-77
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• 2020

In this study, we estimate the vehicle speed by analyzing the acoustic data recorded in a single microphone of a surveillance camera. The frequency analysis of the acoustic data corrects the Doppler effect, which is a characteristic of the moving sound source, and reflects the geometric relationship according to the location of the sound source and the microphone on the two-dimensional plane. The acoustic data is selected from the horn sound that is mainly observed in an urgent situation among various sound sources that may occur in a traffic accident, and the characteristics of the monotone source are considered. We verified the reliability of the proposed method by time domain acoustic analysis and actual vehicle evaluation. This method is effective and can be used for traffic accident analysis in the blind spot of the camera using a single microphone built into the existing surveillance camera.

• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.761-767
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• 2010

This study introduces a model of territorial analysis on Chungcheongnam-do Nonsan-chun valley area, which gives an example of a method of selecting the management area for non-point pollution source from land use to help eliminate its source. High discharge load per unit area signify high level of land ratio with high level of basic unit of development load (including factory sites, school sites, roadways), which mean that there are a significant level of urbanization. It is these areas with the examination of the water quality of the nearby river that should be considered as the management area for non-point pollution source. Thus, the management area for non-point pollution source should be sought in areas with high discharge load per unit area and high density of water pollution area. When level of drainage is high the pollution density level is relatively lower, and when the level of drainage is low the density level is relatively higher. The level of pollution from non-point pollution source is much lower with more water flowing through. The possible non-point pollution source areas that were selected with these standards were then examined with the distance from the river, the slope angle, land usage, elevation, BOD discharge density load, T-N discharge density load, T-P discharge density load, and were given a level one through five. Out of the possible areas Nonsan-si Yeonmu-eup Anshim-li was the densest area, and it was given level one. The level one area should be examined further with the field analysis to be selected as the actual management area for non-point pollution source.

• Journal of Environmental Science International
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• v.19 no.8
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• pp.971-981
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• 2010

The objectives of this study were to measure ambient total gaseous mercury (TGM) concentrations in Seoul, to analyze the characteristics of TGM concentration, and to identify of possible source areas for TGM using back-trajectory based hybrid receptor models like PSCF (Potential Source Contribution Function) and RTWC (Residence Time Weighted Concentration). Ambient TGM concentrations were measured at the roof of Graduate School of Public Health building in Seoul for a period of January to October 2004. Average TGM concentration was $3.43{\pm}1.17\;ng/m^3$. TGM had no notable pattern according to season and meteorological phenomena such as rainfall, Asian dust, relative humidity and so on. Hybrid receptor models incorporating backward trajectories including potential source contribution function (PSCF) and residence time weighted concentration (RTWC) were performed to identify source areas of TGM. Before hybrid receptor models were applied for TGM, we analysed sensitivities of starting height for HYSPLIT model and critical value for PSCF. According to result of sensitivity analysis, trajectories were calculated an arrival height of 1000 m was used at the receptor location and PSCF was applied using average concentration as criterion value for TGM. Using PSCF and RTWC, central and eastern Chinese industrial areas and the west coast of Korea were determined as important source areas. Statistical analysis between TGM and GEIA grided emission bolsters the evidence that these models could be effective tools to identify possible source area and source contribution.