• The Journal of Engineering Geology
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• v.23 no.2
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• pp.149-160
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• 2013

Volcanic activity commonly creates a highly complicated volcanic complex due to the admixture of lava flow and sedimentation of volcanic ash. The Song-Gok site is composed of volcanic rocks that collapsed at the lower part of the slope, in combination with several discontinuities in and around a fault. The results of projection analysis indicated the possibility of plane, wedge, and toppling failure in the failure section. The results of discontinuity modeling using the Distinct Element Method (DEM) revealed a total displacement of 207 mm and a joint shear displacement of 114 mm. The yield surface zone was verified at the fault plane of the failure section. In geotechnical terms, volcanic rock slopes are characteristically vulnerable to failure because of differential weathering among the various rock types, the effect of groundwater based on the permeability of the rocks, and the presence of systematic joints generated by the cooling and contraction of lava. When considering the stability of a volcanic rock slope, it is necessary to consider data such as the geological features of the rock, as obtained through detailed geological survey, and variations in discontinuities and rock blocks.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.1
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• pp.51-64
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• 2020

The purpose of this study is to present a method for quantitative analysis of flooding at the flood plain in an ungauged area using satellite rainfall and global geographic data. For this, flooding of the Tumen/Namyang area in the Duman-gang(Riv.) was simulated and the flood conditions were quantitatively analyzed. The IMERG data, a rainfall data derived from satellite images, was used as rainfall data. The GRM model was applied to the watershed runoff simulation, and the G2D model was applied to the flooding simulation of the Tumen/Namyang area. Flood event caused by Typhoon Lionrock in August 2016 was applied. Recorded peak discharge of the Tumen/Namyang region was used to verify the runoff simulation results. To verify the result of the inundation simulation, the flood situation collected through field survey and satellite image data before and after the flood were used. The peak flow rates by the runoff simulation and flood record were 7,639㎥/s and 7,630㎥/s, respectively, with a relative error of about 0.1%. In the flood simulation, the results were similar to the flooding ranges identified in the survey data and satellite images. And the changes of flooding depth and flooding time in the flood plain in Tumen/Namyang area could also be assessed. The methods and results of this study will be useful for the quantitative assessment of floods in the ungauged areas.

• Journal of the Korean Geotechnical Society
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• v.28 no.4
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• pp.23-33
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• 2012

Recently, landslide disasters caused by severe rain storms and typhoons have been frequently reported. Due to the geomorphologic characteristics of Korea, considerable portion of urban area and infrastructures such as road and railway have been constructed near mountains. These infrastructures may encounter the risk of landslide and debris flow. It is important to evaluate the highly risky locations of landslide and to prepare measures for the protection of landslide in the process of construction planning. In this study, a landslide-risk prediction equation is proposed based on the statistical analysis of 423 landslide data set obtained from field surveys, disaster reports on national road, and digital maps of landslide area. Each dataset includes geomorphologic characteristics, soil properties, rainfall information, forest properties and hazard history. The comparison between the result of proposed equation and actual occurrence of landslide shows 92 percent in the accuracy of classification. Since the input for the equation can be provided within short period and low cost, and the results of equation can be easily incorporated with hazard map, the proposed equation can be effectively utilized in the analysis of landslide-risk for large mountainous area.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.462-466
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• 2006

Close-to-nature stream evaluation is one of the processing to make the streams over in order to keep them natural. It is integral to evaluate and make an accurate analysis of them on the purpose of maintaining streams healthy. For many instances, there are, stream organization evaluation for restoration by German government, evaluation for ecosystem protection in natural preserves by New Zealand government, and stream-view evaluation for restoration by Britain government so on. In case of the country there are analysis and evaluation of stream physical organization by Cho, Yong-hyun, Close-to-nature stream evaluation for restoration by Kim, Dong-chan, evaluation of stream properties in korea by Park, Bong-jin. Close-to-nature evaluation by Lim, Chan-uk, that is advanced version of Park, Bong-jin's, shows form of stream including waterway curve, sand bar, diversity of flow, river bed material, diversity of minor bed, minor bed bank protection works, bank protection material. It also does environment of stream including side of minor bed vegetation, width of surface of the water/width of the river etc.. By the way, this evaluation does not have free access to apply those details above in the field, it often happens that you get various outcome from the one spot. so you must need more realistic testing method to obtain more accurate data. Remote sensing method is highly recommended because this is very useful for collecting realistic data of vegetation index. what is more, it can not only scan even the minimum area within its resolving power but also do obtain data anytime. Vegetation index indicates Ratio vegetation index, Normalized difference vegetation index, Soil adjusted vegetation index, Atmospherically resistant vegetation index etc.. The research is focusing on Cheokgwa stream which is the branch of Taehwa river and shows 19 sectioned Close-to-nature stream performed according to the method by Lim, chan-uk. Besides let you know vegetation index came from image data of satellite landsat 7 with the variation of buffering area, of the day 9. may. 2003. Of all, the outcome 0.758 at 200m buffer-zone of NDVI was the best we have got so far.

• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.255-265
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• 2017

The study analyzed previous studies on traditional markets and market modernization projects to analyze research trends and content related to traditional markets. Next, the study selected 4 traditional markets throughout the nation where there was promotion of market modernization projects to conduct field research and interviews about store modules, line of flow, facility configuration, and types of businesses. Empirical comparative analysis was conducted on construction hardware status through measurement and observation and data was collected on business environment and requirement characteristics by business type through interviews with merchant associations of the corresponding markets. Consistent standard was applied as much it was possible to comparatively analyze the 4 market modernization cases and on the unique characteristics of individual markets, the cause was determined in conjunction to the history of the business promotion process and regional characteristics. After the study, basic data to suggest guidelines in store modules by business type in traditional markets could be acquired and the study identified the facilities equipment standards that must be considered in future market modernization projects. Through this it will be possible to derive policy implications to minimize trial and error and guarantee business efficiency in future market modernization projects.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.7
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• pp.371-378
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• 2017

Recently, with the spread of smart device and the introduction of web services, the data is rapidly increasing online, and it is utilized in various fields. In particular, the emergence of social media in the big data field has led to a rapid increase in the amount of unstructured data. In order to extract meaningful information from such unstructured data, interest in big data technology has increased in various fields. Big data is becoming a key resource in many areas. Big data's prospects for the future are positive, but concerns about data breaches and privacy are constantly being addressed. On this subject of big data, where positive and negative views coexist, the research of analyzing people's opinions currently lack. In this study, we compared the changes in peoples perception on big data based on unstructured data collected from the social media using a text mining. As a results, yearly keywords for domestic big data, declining positive opinions, and increasing negative opinions were observed. Based on these results, we could predict the flow of domestic big data.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.1
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• pp.1-10
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• 2018

The importance of entrepreneurship has been emphasized recently from academia and government officials and studies trying to investigate entrepreneurial alertness as core competence of entrepreneurial mindset in the research field of entrepreneurship continue. In domestic academic research, research on entrepreneurial alertness has not yet been conducted in earnest, unlike the active flow of research overseas. This paper aims to investigate what factors influence entrepreneurial alertness in the Korean environment, we conducted an empirical analysis through a questionnaire survey for CEOs of small and medium enterprises in Seoul, Gyeonggi province. In this study, we selected prior knowledge of markets and technology, positive attitude, social network, number of books per month as independent variables on entrepreneurial agility based on Ardichvili's Alertness model, and as control variables respondents' Demographic characteristics, such as gender, age, founding career were selected. According to the results of the empirical analysis, prior knowledge of markets and technology, positive attitudes, number of books per month as independent variables, showed positive influence on entrepreneurial alertness, showing statistical significance. However, the social network picked up measured variables by the number of regular meetings which are quantitative indicators, but found that there is no statistically significant effect on entrepreneurial alertness. Despite several limitations of this research, we investigate what factors influence entrepreneurial alertness through empirical research on entrepreneurial alertness impact factors that have not been explained in the domestic academic research. Although you saw it, it can be said that there is academic contribution.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1931-1938
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• 2012

This study evaluated whether the installed location of air quality monitoring stations is at an optimal level in an effort to improve the health and environmental quality of the surrounding areas of the Pohang Steel Complex. As a result of analyzing the atmospheric flow field, it was found that the location of air quality monitoring stations was acceptable in case of Daesong-myeon(The 1st Division of Local Wind Sector) and Jukdo-dong(The 3rd Division of Local Wind Sector). However, the air quality monitoring stations installed at Daedo-dong and Jukdo-dong is judged to have made an overlapped measurement because the stations existed at the Division of the same Wind Sector. Accordingly, this study suggests that the further air quality monitoring stations should be additionally installed at Buk-gu areas of Pohang where more than 50% of the population of Pohang is living presently. As a result of the analysis of air contaminant concentration distribution, the Jangheung-dong area showed higher concentration distribution than other areas in case of $PM_{10}$ while the Daesong-myeon area showed a comparatively higher concentration distribution in case of $O_3$. Conclusively, this study indicates that it is high time to prepare an aggressive management of $PM_{10}$ and $O_3$ which causes a harmful impact on the life and health of the residents of the target areas.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.97-104
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• 2015

Apartment Housing 25 in the field of construction since 2000 collected by types of labor: reinforced concrete, plaster, internal, equipment, electrics communication, the other work. And the performance of labor input was collected in the amount of construction work performed on a monthly basis. After changing the construction period in the standardization work that is 100% of the construction period, the amount was converted into labor ratio by type. Analysis of the input flow rate and the amount of labor conclusions were as follows: (1) The size of the labor rate is reinforced concrete work (38.25%), plastering work (5.10%), internal work (5.67%), equipment work (9.10%), electrics communication (8.76%), the other works (33.12%) and the size of labor rate is the largest work in reinforced concrete work. (2) The peak of labor input ratio was from 52.5% month to 62.5% month. This was when the labor rate of 3.6%. (3) The period month of the largest labor ratio% is 35% month by reinforced concrete construction, and this time it was 2.12% per month labor rate, and reinforced concrete construction is finishing from 65% month to 80% month. This showed the greatest congestion of mutual interference between each works is being continue. The results of this study are the greatest congestion in apartment housing construction has informed the high period(%months), which is essential to a successful project.

• Journal of the Korean Ceramic Society
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• v.56 no.2
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• pp.178-183
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• 2019

A process of fabricating the foamed glass that has closed pores with 8 ~ 580 ㎛ sizes without a blowing agent by sintering 10 ㎛ boron-free glass powder composed of CaO, MgO, SO₃, Al₂O₃-83 wt% SiO₂ at a molding pressure of 0 ~ 120 MPa and a sintering temperature of 750 ~ 1000℃ was investigated. To analyze the glass transition temperature of glass powder, thermogravimetric analysis-differential thermal analysis (TGA-DTA) method were used. The microstructure and pore size of foamed glass were examined using the optical microscopy and field emission scanning electron microscopy (FE-SEM). For the thermal diffusivity and color of the fabricated samples, a heat flow meter and ultraviolet-visible-near-infrared (UV-VIS-NIR)-colormetry were used, respectively. In the TGA-DTA result, the glass transition temperature of glass powder was confirmed to be 626℃. In the microstructure result, closed pores of 7 ~ 20 ㎛ were formed at 750 ~ 900℃, and they were not affected by the molding pressure and sintering temperature. However, at 1,000℃, when there was 0 MPa molding pressure, closed pores of 580 ㎛ were confirmed, and the pore size decreased as the molding pressure increased. Moreover, at a molding pressure of 30 MPa or higher, closed pores of approximately 400 ㎛ were formed. The porosity showed an increasing trend of smaller molding pressure and larger sintering temperature, and it was controllable in the range of 5.69 ~ 68.45%. In the thermal diffusivity result, there was no change according to the molding pressure, and, by increasing the sintering temperature, up to 0.115 W/m·K could be obtained. The Lab color index (CIE-Lab) results all showed a similar translucent white color regardless of molding pressure and sintering temperature. Therefore, based on the foamed glass without boron and blowing agent, it was confirmed that white foamed glass, which has closed pores of 8 ~ 580 ㎛ and a thermal diffusivity characteristic of 0.115 W/m·K, can be fabricated by changing the molding pressure and sintering temperature.