• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.4
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• pp.65-77
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• 2007

Site response analyses were performed based on equivalent linear technique using shear wave velocity profiles of 162 sites collected around the Korean peninsula. The site characteristics, particularly the shear wave velocities and the depth to the bedrock, are compared to those in the western United States. The results show that the site-response coefficients based on the mean shear velocity of the top 30m ($V_{S30}$) suggested in the current code underestimates the motion in short-period ranges and overestimates the motion in mid-period ranges. The current Korean code based on UBC is required to be modified considering site characteristics in Korea for the reliable estimation of site amplification. From the results of numerical estimations, new regression curves were derived between site coefficients ($F_{a}\;and\;F_{v}$) and the fundamental site periods, and site coefficients were grouped based on site periods with reasonable standard deviations compared to site classification based on $V_{S30}$. Finally, new site classification system and modification of design response spectra are recommended considering geotechnical characteristics in Korea.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.63-71
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• 2001

PM 2.5/ samples were measured at two sites, Hadan(suburban site) and Anrak (roadside site) in Busan area. PM 2.5/ sampling was performed for 24-hour intervals by the FH9.5 particulate sampler. Aerosol samples were collected on PTFE filter. A total of 60 particulate samples were collected, dad samples were measured for Particulate mass concentration, metallic elements (Cr, Mn, Ni. Cu. Se, Fe, Pb, and Zn) and waer-soluble elements (C $l^{[-10]}$ , N $O_{3}$$^{[-10]}$ ,S $O_{4}$$^{2-}$, N $H_{4}$$^{+}$, $Ca_{2}$$^{+}$, $Mg_{2}$$^{+}$ and $^{+}$.Mass concentration in Hadan ranged 24.23~57.12 $\mu\textrm{g}$/㎥ and 60.22~72.12 $\mu\textrm{g}$/㎥m Yellow Sand Events. Major cations in Hadan and Anrak site is N $H_{4}$$^{+}$and N $a^{+}$ respectively. SO42$^{[-10]}$ was the abundant specie in the PM 2.5 fraction for Hadan site an dAnrak site. Hadan site showed igher concentration in S $O_{4}$$^{2.1}$ and N $H_{4}$ $^{+}$ In Anrak site the concentration of S $O_{4}$/sip 2-/and N $a^{+}$ was higher than other ions Prominent metallic elements were Fe and Pb in two sites. Principal component analysis showed that main source of PM 2.5 aerosol particles was non-metal related source which was resulted in relating elements as Cr, Ni, and Pb at Hadan site, Anrak site also has resulted PM2.5 aerosol paricles source, which was related its element like Zn, and Ni,. The SAS package analysis also showed that long-range transport effect at Hadan area due to Yellow Sand Event by the prevailing weaterlies.ling weaterlies.

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.111-115
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• 2009

In Korea, the probabilistically developed seismic hazard maps are used with deterministically derived seismic site coefficients in developing the design response spectrum of a specific site. Even though the seismic hazard maps and seismic site coefficients are incompatible, the current design code ignores such incompatibility. If the seismic hazard map and seismic coefficients are both developed in identical probabilistic framework, such problems can be solved. Unfortunately, the available method cannot be use to derive "true" probabilistic site coefficients. This study uses the ground motion time histories, which were developed as the result of a new probabilistic seismic hazard analysis in the companion paper, as input motions in performing one-dimensional equivalent linear site response analyses, from which the uniform hazard response spectra are generated. Another important characteristic of the hazard response spectra are that the uncertainties and randomness of the ground properties are accounted for. The uniform hazard spectra are then used to derive probabilistic site coefficients. Comparison of probabilistic and deterministically site coefficients demonstrate that there is a distinct discrepancy between two coefficients.

• Earthquakes and Structures
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• v.15 no.2
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• pp.193-202
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• 2018

This paper studied the probability of pounding occurred between decks and abutments of a long span high-pier continuous rigid fame bridge subjected to ground motions with local soil effect. A pounding probability analysis methodology has been proposed using peak acceleration at bedrock as intensity measure (IM) for multi-support seismic analysis. The bridge nonlinear finite element (FE) models was built with four different separation distances. Effect of actual site condition and non-uniform spatial soil profiles on seismic wave propagating from bedrock to ground surface is modelled. Pounding probability of the high-pier bridge under multi-support seismic excitations (MSSE) is analyzed based on the nonlinear incremental dynamic analysis (n-IDA). Pounding probability results under uniform excitations (UE) without actual local site effect are compared with that under MSSE with site effect. The study indicates that the required design separation length between deck and abutment under uniform excitations is larger than that under MSSE as the peak acceleration at bedrock increases. As the increase of both separation distance between deck and abutment and the peak acceleration, the probability of pounding occurred at a single abutment or at two abutments simultaneously under MSSE is less than that under UE. It is of great significance considering actual local site effect for determining the separation distance between deck and abutment through the probability pounding analysis of the high-pier bridge under MSSE.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.550-555
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• 2005

In vicinity of Seoul, there has been water service tunnel that classified into 1st grade facility by special act for the safety control of public structures and with providing capacity equals to $1,543{\times}10^3$(ton/day) and inner pressure equals to $2.5-3.5kg/cm^2$. In this research, site investigation and stability analysis for water tunnel caused by new construction of road tunnel were carried out. the ground near water tunnel were zoned into spatial area having similar geotechnical characteristics and estimating geotechnical properties for each area. The site for analysis consists of banded biotite gneiss, biotite schist and granite gneiss with spatial non-homogeneity, and for that reason weathering and fault zone were distributed with large scale. It's important thing to consider spatial ground zone and their geotechnical properties properly into stability analysis at design and construction stage. Also, using results of site investigation, stability of existing tunnel have been analyzed for Hydraulic Fracture/Jacking and deformation in detail.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.35.2-35.2
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• 2011

A wind turbine power performance test is very important to wind turbine manufacturers because a wind farm developer or planner must want to define power performance characteristics and reliability of new wind turbines. Based on the IEC 61400-12-1, A wind turbine test site has to be nicely installed at flat terrain for testing. We are developing the wind power system which is IEC wind class IIa model with rated power of 3MW. KEPCO's Gochang power testing center was considered as candidates to build the test site without site calibration. This paper aims to verify the validity of the test site by using implement site assessment result that was based on IEC 61400-12-1.

• Journal of Ecology and Environment
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• v.32 no.2
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• pp.115-121
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• 2009

In order to elucidate the mechanisms affecting plant distributions in the reclaimed dredging area in the Gwangyang steelworks, in the Gwangyang Bay, Korea, we examined soil characteristics and plant distributions in four study sites and a control site in the study area. Desalination occurring along a gradient with increasing elevation, resulting in decrease of soil pH, EC, P, K, Cl, Ca, Mg, and salt and an increase in soil T-N, silt, clay contents. From site 1 (the lowest-elevation site) to site 5 (the highest-elevation site), halophytes decreased in abundance and nonhalophytes increased. The dominant species in each site were: Phragmites communis, Limonium tetragonum, and 12 additional species at site 1, Carex pumila, Suaeda japonica, and 15 additional species at site 2, Spergularia marina, Scirpus planiculmis, and 22 additional species at site 3, Miscantus sinensis, Lespedeza bicolor, and 26 additional species at site 4 and Pinus thunberii, Rhododendron mucronulatum, and 39 additional species at site 5, which resembled a naturally-occurring P. thinbergii community. Cluster analysis of the vegetation data matrix grouped the 35 plots into 5 major groups, and cluster analysis using the soil environment data matrix revealed 4 major groups. CCA of the floristic and environmental data matrix showed a positive relationship of SAR, EC, Na, Cl, and Ca, which are related to salt, in the $1^{st}$ axis and $2^{nd}$ axis, but negative relationships for altitude, organic contents, silt, and clay contents. Notably, plant species in the reclaimed dredging area that were separated along the $1^{st}$ axis showed strong relationships with factors that related to salt. Long-term exposure to natural rainfall in the reclaimed dredging area changed the soil characteristics, such as salinity. This change in soil characteristics might alter the SAR, which affects plant survival strategies in a given habitat. These results strongly indicated that factors related to salt and elevation play important roles in determining the overall plant distribution in the reclaimed dredging area.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.457-462
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• 2009

In this study, seismic analysis is performed using simplified method, analytical solution and numerical analysis based on one-dimensional seismic site response analysis. The results show that analytical solution of tunnel response is predicted more conservative than numerical solution. And simplified method is not appropriate for seismic analysis of tunnel response. In addition, it is reasonable to determine shear-modulus reduction ratio performing seismic site response analysis to consider ground nonlinear-behavior.

• Journal of Software Assessment and Valuation
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• v.17 no.2
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• pp.125-142
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• 2021

Reports of rampant cross-site scripting (XSS) vulnerabilities raise growing concerns on the effectiveness of current Static Analysis Security Testing (SAST) tools as an internet security device. Attentive to these concerns, this study aims to examine seven open-source SAST tools in order to account for their capabilities in detecting XSS vulnerabilities in PHP applications and to determine their performance in terms of effectiveness and analysis runtime. The representative tools - categorized as either text-based or graph-based analysis tools - were all test-run using real-world PHP applications with known XSS vulnerabilities. The collected vulnerability detection reports of each tool were analyzed with the aid of PhpStorm's data flow analyzer. It is observed that the detection rates of the tools calculated from the total vulnerabilities in the applications can be as high as 0.968 and as low as 0.006. Furthermore, the tools took an average of less than a minute to complete an analysis. Notably, their runtime is independent of their analysis type.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.4
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• pp.47-64
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• 2019

The purpose of this study is to present the basic data for the management of National Park by surveying and analysing the change of vegetation of forest fire damaged area in Sogeumgang District, Gyeongju National Park. The covergae ratio, a number of species and dominant species changed overall in forest fire damaged area. The final result of the change is as follows. In case of coverage ratio in the shrub layer, Site 1 was 30%, 40% in Site 2, 50% in Site 3, 60% in Site 4 and 30% in Site 5. In the herb layer, Site 1 was 90%, 80% in Site 2, 90% in Site 3, 60% in Site 4 and 20% in Site 5. In case of the number of species in the shrub layer, Site 1 was 11 species, 8 species in Site 2, 6 species in Site 3, 10 species in Site 4, 7 species in Site 5, and in the herb layer, Site 1 was 22 species, 25 species in Site 2, 12 species in Site 3 and Site 4 each and 11 species in Site 5. In the dominant species, the shrub layer was Lespedeza maritima(Site 1, 2), Quercus serrata(Site 3), Quercus serrata and Lespedeza bicolor(Site 4) and Styrax japonicus(Site 5), the herb layer was Miscanthus sinensis var. purpurascens(Site 1, 3), Pteridium aquilinum var. latiusculum and Carex humilis var. nana(Site 2), Quercus serrata(Site 4) and Carex humilis var. nana andS tyrax japonicus(Site 5). The number of vascular plants was summarized as 91 taxa including 35 families, 69 genera, 78 species, 2 subspecies, 10 varieties and 1 form.