• The Journal of the Petrological Society of Korea
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• v.10 no.1
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• pp.1-12
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• 2001

A small of carbonate rocks and spatially-associated ultramafic rocks uniquely occur in the ulsan iron-serpentine mine of the sourtheastern Kyungsang basin. The study of field geology, core drilling data and stable isotope analysis suggest that the carbonate rocks are carbonatite formed from the melt reflecting intrusive natures. Based on this study, the geology of the Ulsan iron-serpentinite mining area consists of Cretaceous sedimentary, volcanic, granitic ultramafic and carbonate rocks in ascending order. The carbonate and ultramafic rocks show concentric and ellipsoidal shapes at the outcrop and a funnel shape in the cross sectional view. Carbon and oxygen stable isotope analysis show a bimodal pattern rather than a typical mantle pattern, which may indicate that the melt was a secondary melt generated within the crus not in the mantle directly. The uprising of ultramafic melts would have melted lime-contained rocks forming a secondary carbonate melt in the upper crus. Then, the intrusion of the ultramafic melts would have melted lime-contained rocks forming a secondary carbonate melt in the upper crust. Then, the intrusion of the ultramafic melt was followed by the intrusion of the carbonate melt along deep-seated fractures. Well-developed major fractures in this area, fluid inclusion characteristics of the carbonate rocks, the spatial relation between the ultramafic and carbonate rocks and stable isotope data support interpreting the Ulsan carbonate rocks as carbonatite.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.520-525
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• 2019

Mines are an important infrastructure for securing resources, but safety problems can arise in the course of operation. Recently, the mining process is very complicated due to the large scale and mechanization. Therefore, it is necessary to construct accurate geospatial information on mine for systematic and safe mine operation. The geospatial information construction using the existing total station has a disadvantage that a lot of work time is required because the target must be collimated and measured. In this study, the data of the mines were acquired with the total station and the 3D laser scanner, and the mine spatial information was constructed by using the shape based registration method. By using the static scanner data of some area applying the reference point surveying result of the total station, it was possible to construct the accurate result on the wide area acquired by the mobile scanner effectively. Also, the accuracy of the constructed geospatial information was evaluated and the deviation of mean 0.083m was shown. Point cloud products constructed through the research can contribute to the efficiency improvement of mine management by enabling quantitative analysis such as visualization of mine shape, distance, area and slope, and automation of drawing creation for cross section shape.

• Journal of Environmental Impact Assessment
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• v.32 no.6
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• pp.556-576
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• 2023

This study attempted to find a way to utilize idle spaces in rural areas as a way to respond to rural extinction. Based on the keywords "startup," "youth start-up," and "youth start-up+rural," start-up+rural," the study sought to identify the perception of idle facilities in rural areas through the keywords "Idle facilities" and "closed schools." The study presented basic data for policy direction and plan search by reviewing frequency analysis, major keyword analysis, network analysis, emotional analysis, and domestic and foreign cases. As a result of the analysis, first, it was found that idle facilities and school closures are acting importantly as factors for regional regeneration. Second, in the case of youth startups in rural areas, it was found that not only education on agriculture but also problems for residence should be solved together. Third, in the case of young people, it was confirmed that it was necessary to establish digital utilization for agriculture by actively starting a business using digital. Finally, in order to attract young people and revitalize the region through best practices at home and abroad, policy measures that can serve as various platforms such as culture and education as well as startups should be presented in connection with local residents. These results are significant in that they presented implications for youth start-ups in rural areas by reviewing start-up recognition for the influx of young people as one of the alternatives for the use of idle facilities and regional regeneration, and if additional solutions are presented through field surveys, they can be used to set policy goals that fit the reality.

• Journal of the Korean earth science society
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• v.37 no.2
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• pp.89-106
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• 2016

The Gochang open-coast intertidal flat is located in the southwestern coast of Korea (the eastern part of the Yellow Sea), characterized by macro-tidal range, an open-coast type, and sand substrates. This study has investigated seasonal variation in sedimentary facies of surface sediments in the Gochang intertidal flat. In the four seasons of February, May, August, and November, 2014, surface sediments of 252 sites in total were sampled and analyzed along three survey lines. The surface sediments of the Gochang intertidal flat in 2014 consisted mainly of fine-grained sand sediments showing a trend in grain size to be coarser in winter and finer in summer. Based on seasonal wave and tidal level data recorded near the study area, it was interpreted that the seasonal effects of wave were stronger than those of tide as a factor controlling surface sedimentation. High waves in winter resulted in the coarsening trend of grain size in surface sediments, whereas, during summer time, the sediments became finer by relatively low waves. Spatial sedimentary facies of the Gochang intertidal flat in 2014 represented that seasonal deviation of the upper tidal zone was larger than that of the lower tidal zone, hence sediments getting coarser in grain size and poorly sorted in the upper tidal zone. From upper to lower tidal zone, the grain size became finer and sediments were better-sorted, showing smaller seasonal deviations.

• Journal of KIISE:Databases
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• v.31 no.5
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• pp.468-478
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• 2004

It is essential in various application areas of data mining and bioinformatics to effectively retrieve the occurrences of interesting patterns from sequence databases. For example, let's consider a network event management system that records the types and timestamp values of events occurred in a specific network component(ex. router). The typical query to find out the temporal casual relationships among the network events is as fellows: 'Find all occurrences of CiscoDCDLinkUp that are fellowed by MLMStatusUP that are subsequently followed by TCPConnectionClose, under the constraint that the interval between the first two events is not larger than 20 seconds, and the interval between the first and third events is not larger than 40 secondsTCPConnectionClose. This paper proposes an indexing method that enables to efficiently answer such a query. Unlike the previous methods that rely on inefficient sequential scan methods or data structures not easily supported by DBMSs, the proposed method uses a multi-dimensional spatial index, which is proven to be efficient both in storage and search, to find the answers quickly without false dismissals. Given a sliding window W, the input to a multi-dimensional spatial index is a n-dimensional vector whose i-th element is the interval between the first event of W and the first occurrence of the event type Ei in W. Here, n is the number of event types that can be occurred in the system of interest. The problem of‘dimensionality curse’may happen when n is large. Therefore, we use the dimension selection or event type grouping to avoid this problem. The experimental results reveal that our proposed technique can be a few orders of magnitude faster than the sequential scan and ISO-Depth index methods.hods.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.233-254
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• 2017

The purpose of this study is to analyze the main factors influencing the severity of traffic accidents and to visualize spatiotemporal characteristics of traffic accidents in Seoul. To do this, we collected the traffic accident data that occurred in Seoul for four years from 2012 to 2015, and classified as slight, serious, and death traffic accidents according to the severity of traffic accidents. The analysis of spatiotemporal characteristics of traffic accidents was performed by kernel density analysis, hotspot analysis, space time cube analysis, and Emerging HotSpot Analysis. The factors affecting the severity of traffic accidents were analyzed using decision tree model. The results show that traffic accidents in Seoul are more frequent in suburbs than in central areas. Especially, traffic accidents concentrated in some commercial and entertainment areas in Seocho and Gangnam, and the traffic accidents were more and more intense over time. In the case of death traffic accidents, there were statistically significant hotspot areas in Yeongdeungpo-gu, Guro-gu, Jongno-gu, Jung-gu and Seongbuk. However, hotspots of death traffic accidents by time zone resulted in different patterns. In terms of traffic accident severity, the type of accident is the most important factor. The type of the road, the type of the vehicle, the time of the traffic accident, and the type of the violation of the regulations were ranked in order of importance. Regarding decision rules that cause serious traffic accidents, in case of van or truck, there is a high probability that a serious traffic accident will occur at a place where the width of the road is wide and the vehicle speed is high. In case of bicycle, car, motorcycle or the others there is a high probability that a serious traffic accident will occur under the same circumstances in the dawn time.