• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.411-418
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• 2009

So far the Limit Equilibrium Method has been widely used by way of 2-D slope stability analysis for the evaluation of land slides and slope failures. However recently the evaluation of 3-D slope stability analysis has been comparatively possible owing to the developments of obtaining the terrain data and geological data and of 3-D slope stability analysis softwares. In Japan the evaluation of the 3-D slope stability analysis has been necessary for the stability analysis of the tunnel mouth. In this study we inspected the economic effects introducing the 3-D slope stability analysis for larger scale landslides and slope failures. In case of 3-D slope stability analysis of landslides we acquired the results that we reduce the cost of the countermeasure work of pile work by 40% comparing the 2-D slope stability analysis. Moreover in case of the stability analysis of slope failures we figured out the results that we reduce the cost of the countermeasure work of anchor works by 20%. Furthermore we proved that 3-D slope stability analysis is effective for the stability analysis of tunnel mouths around the sides of landslides and large scale embankment which we could have not evaluated by conventional 2-D section stability analysis.

• The Journal of the Petrological Society of Korea
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• v.24 no.3
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• pp.233-252
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• 2015

This research are systematic and scientific approaches to obtain the distribution, occurrence and quality of granite stone for building purposes. The process of dimension stone exploration must be carried out to know the underground potentiality of granitic body using the basic data collection and study, field mapping, detailed drilling survey, televiewer technique, and physical and chemical tests in the Geochang area. Televiewer data obtained in drilling boreholes can be accurately distinguished from the discontinuous face, strike and inclination, extension which is difficult to obtain in a core logging. 3D joint images will be helpful to establish a quarry exploitation plan because the 3D joint images give quite accurate information down to depth below the outcrop surface. Through the process of the quality estimation on the Geochang site, the proven reserve estimated as dimensional building stone are calculated with good quality in petrologic and physical properties.

• Journal of Korea Water Resources Association
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• v.33 no.5
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• pp.611-622
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• 2000

In this study, MODFLOW model is used to analyze the groundwater flow system of Seoguipo area in Cheju island, The final parameters of permeability coefficient and storage coefficient of target area can be obtained by trial and error method using the measured data of pumping rate as initial values. And it is found that the applicability for groundwater flow system is reflected well from the simulation result of the model. Seoguipo area spring water is thought to appear by relatively stable groundwater recharge below EL. 400m according to head distribution through the analysis of observed data considering topographic and geological characteristics, Lee's study(996), and the simulation result. Also it is known that point II, III, and VI show relatively large velocity vectors, and groundwater flows through the movement path which is distributed in various directions of I, II, III, IV, V, VI, and VIl form the result of velocity vector analysis using head distribution result values to analyze the groundwater flow path under unsteady flow condition.dition.

• Korean Journal of Ichthyology
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• v.18 no.1
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• pp.12-19
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• 2006

To examine the relationship of geological distribution and phylogenetic tree of O. latipes in the Far East, we analyzed cytochrome b (cyt b) gene in the mitochondrial genome. In this study we employed the entire sequence of cyt b of 53 samples collected from nine Korean locations and 117 cyt b data retrieved from the GenBank. From 170 Oryzias latipes cyt b sequence data, 142 different haplotypes were identified and phylogenetic relationship was reconstructed based on the dataset. According to the phylogeny, haplotypes were divided into three major haplogroups A, B and C, and their relationships were well correlated to their distributional patterns. Haplogroup A which is widely distribute in the southern part of Korea is separated in the geographical distribution from the haplogroup B which is found from China to the western part of Korea. Haplogroup C is only found in Japan.

• Geotechnical Engineering
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• v.13 no.1
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• pp.19-34
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• 1997

Applications of geostatistical method to cone penetrometer data have been performed at the overconsolidated clay site. Randomlylocated 28 electronic CPT soundings (Location A) and consistently-located 38 CPT soundings(Location B) are investigated geostatistically. Variograms for Locations A and B have been developed for q, from the CPT data by using "kriging" principles, which establish the horizontal and vertical correlation distrances at this site. These vertical and horizontal correlation distances can be used to optimal sampling design, where, if one needs to compare two test results, sampling must be made within these vertical and horizontal correlation distances. Analysis of the variograms indicated that the geological formation between two locations are not very different in both vertical direction and horizontal direction.direction.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.148-148
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• 2018

Land subsidence caused by excessive groundwater pumping is a serious hydro-geological hazard. The spatial variability in land use, unbalanced groundwater extraction and aquifer characteristics are the key factors which make the problem more difficult to monitor using conventional methods. This study uses the European Space Agency (ESA) Sentinel satellites to investigate and monitor land subsidence varying with different land covers and groundwater use in the arid Quetta valley, Pakistan. The Persistent Scattering Differential Interferometry of Synthetic Aperture Radar (PS-DInSAR) method was used to develop 28 subsidence interferograms of the study area for the period between 16 Oct 2014 and 06 Oct 2016 using ESA's Sentinel-1 SAR data. The uncertainty of DInSAR result is first minimized by removing the dynamic effect caused by atmospheric factors and then filtered using the radar Amplitude Dispersion Index (ADI) to select only the stable pixels. Finally the subsidence maps were generated by spatially interpolating the land subsidence at the stable pixels, the comparison of DInSAR subsidence with GPS readings showed an R 2 of 0.94 and mean absolute error of $5.7{\pm}4.1mm$. The subsidence maps were also analysed for the effect of aquifer type and 4 land covers which were derived from Sentienl-2 multispectral images. The analysis show that during the two year period, the study area experienced highly non-linear land subsidence ranging from 10 to 280 mm. The subsidence at different land covers was significantly different from each other except between the urban and barren land. The barren land and seasonally cultivated area show minor to moderate subsidence while the orchard and urban area with high groundwater extraction rate showed excessive amount of land subsidence. Moreover, the land subsidence and groundwater drawdown was found to be linearly proportional to each other.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.269-281
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• 2021

Land creeping is the imperceptibly slow, steady, downward movement o f slope-forming soil or rock. Because creep-related failures occur frequently on a large scale without notice, they can be hazardous to both property and human life. Korea Forest Service has operated the prevention and response system from land creeping which has been on the rise since 2018. We categorized and proposed three survey steps (e.g., preliminary, regional, detailed) for investigation of creeping susceptibility site with a focus on geophysical mapping of a selected test site, Yongheung-dong, Pohang, Korea. The combination of geophysical (dipole-dipole electrical resistivity tomography and reciprocal seismic refraction technique, well-logging), geotechnical studies (standard penetrating test, laboratory tests), field mapping (tension cracks, uplift, fault), and comprehensive interpretation of their results provided the reliable information of the subsurface structures including the failure surface. To further investigate the subsurface structure including the sliding zone, we performed high-resolution geophysical mapping in addition to the regional survey. High-resolution seismic velocity structures are employed for stability analysis because they provided more simplified layers of weathering rock, soft rock, and hard rock. Curved slip plane of the land creeping is effectively delineated with a shape of downslope sliding and upward pushing at the apex of high resistive bedrock in high-resolution electrical resistivity model with clay-mineral contents taken into account. Proposed survey steps and comprehensive interpretation schemes of the results from geological, geophysical, and geotechnical data should be effective for data sets collected in a similar environment to land-creeping susceptibility area.

• Journal of the Korea Convergence Society
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• v.10 no.6
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• pp.25-31
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• 2019

Because of its physical characteristics, earthquake has a great impact on a wide area in a short time, so it needs a resilience based seismic countermeasures to restore the community function. For this reason, in this study, the seismic damages of urban buildings were assessed stochastically by virtual earthquakes using public data information and disaster management program(Ergo-EQ). A geographical map reflecting geological characteristics of the target area was created with the buildings and topographic data in Dalseo-gu, Daegu City. In addition, an integrated database including building characteristics was modified to be linked with the Ergo-EQ program. The seismic damages for the buildings were evaluated through the exceedance probability of four different damage levels. From the damage results, it can be identified not only the seismic damage of each building, but also the major factors affecting earthquake damage.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.8
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• pp.3917-3941
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• 2019

The recent interest in artificial intelligence and machine learning has partly contributed to an interest in the use of such approaches for hyperspectral remote sensing (HRS) imagery classification, as evidenced by the increasing number of deep framework with deep convolutional neural networks (CNN) structures proposed in the literature. In these approaches, the assumption of obtaining high quality deep features by using CNN is not always easy and efficient because of the complex data distribution and the limited sample size. In this paper, conventional handcrafted learning-based multi features based on expert knowledge are introduced as the input of a special designed CNN to improve the pixel description and classification performance of HRS imagery. The introduction of these handcrafted features can reduce the complexity of the original HRS data and reduce the sample requirements by eliminating redundant information and improving the starting point of deep feature training. It also provides some concise and effective features that are not readily available from direct training with CNN. Evaluations using three public HRS datasets demonstrate the utility of our proposed method in HRS classification.

• Journal of Climate Change Research
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• v.7 no.2
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• pp.143-155
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• 2016

Present work aims to establish the countermeasure for the better maintenance and preservation of insular floristic diversity at the South Sea of Jeollanamdo Province, ROK, where unique ecosystems are under threat due to climate change, anthropogenic disturbance and habitat destruction. Numerous flora reports from 15 inhabited islands and 60 uninhabited islands as well as field survey data are collated for the compilation of floristic data base and island biogeographical analysis. Out of the 1,940 vascular plant species from 180 families occurring in studies areas, 30.1 percentage or 584 plant species are physiognomically belonging to arboreal plants. Average number of species at individual island is numbered about 222 species, but it varies from about 591 species at the inhabited islands to 129 species at the uninhabited islands. Only 0.15 percentage of species with high proportion above 0.9 in its relative occurrence rate occurs at 68 islands and it includes three species, such as Pinus thunbergii, Eurya japonica and Pteridium aquilinum var. latiusculum. However, about 68 percentage of plant species occurring in study area is confined their distribution to less than seven islands. Presence of high proportion of notable plants in small islands, i.e., 10 critically endangered species compared with 5.5 species in average, 9 endangered species (average 4.2 spp.) at Sonjookdo, and 7 critically endangered species, 8 endangered species at Sokomundo may due to existence of diverse geological and topographical environmental diversity as well as lower human population density and remoteness from the mainland. Since island is small in size and geographically isolated, minor environmental and ecological burdens can cause the critical damages to the diversity of flora and vegetation, urgent island biogeographical research is needed for the scientific conservation and management of island biodiversity.