• Title/Summary/Keyword: engineering site

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Estimation of Pollution Sources of Oenam Watershed in Juam Lake using Nitrogen Concentration and Isotope Analysis (주암호 외남천 유역 하천수의 질소농도와 동위원소비 분석을 이용한 오염원 평가)

  • Choi, Yujin;Jung, Jaewoon;Choi, Woojung;Yoon, Kwangsik;Choi, Dongho;Lim, Sangsun;Jeong, Juhong;Lim, Byungjin;Chang, Namik
    • Journal of Korean Society on Water Environment
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    • v.27 no.4
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    • pp.467-474
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    • 2011
  • In an effort to investigate water pollution characteristics of Juam lake, water samples were collected from three sites (Sites A, B, and C) of Oenam stream which is a typical tributary of rural watershed in the lake and analyzed for N concentration and the corresponding isotope ratio (${\delta}^{15}N$) of ${NO_3}^-$. Concentrations of ${NO_3}^-$ were not dramatically different among the sites; $0.8{\pm}0.2mgNL^{-1}$ (range: $0.0{\sim}4.3mgNL^{-1}$) for Site A, $1.1{\pm}0.2mgNL^{-1}$ ($0.0{\sim}4.3mgNL^{-1}$) for Site B, and $1.1{\pm}0.1mgNL^{-1}$ ($0.1{\sim}2.6mgNL^{-1}$) for Site C. Meanwhile, ${\delta}^{15}N$ tended to decrease with river flow; it was highest for Site A ($45.5{\pm}5.3$‰) followed by Site B ($19.7{\pm}2.0$‰) and Site C ($8.7{\pm}1.5$‰). Such high ${\delta}^{15}N$ values of ${NO_3}^-$ in Site A suggested that ${NO_3}^-$ derived from livestock feedlot (specifically livestock excrete of which ${\delta}^{15}N$ is higher than 10‰) is the predominant pollution sources despite mountainous area occupied the most of land-use in the watershed. Using the two-sources isotope mixing model, it was estimated that the contribution of cropping activities (i.e. fertilization) became greater in down-stream area (Sites B and C) due to the higher agricultural land-use than the up-stream area (Site A). Particularly, during the active cropping season, the low contribution of organic pollution sources indicated that domestic sewage was not the predominant pollution source. Therefore, it was suggested that agricultural sources such as livestock farming and cropping rather than mountainous and residential are the dominant sources of water pollution in the study area. These results could be effectively utilized in elucidating water pollution sources in rural areas and selecting water management practices.

A Case Study of Cross Site Script attack and defence measures (사례연구를 통한 Cross Site Script 공격 및 방어대책)

  • Son, Kang-Won;Kim, Ji-Hun;Cho, Doosan;Youn, JongHee
    • Annual Conference of KIPS
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    • 2015.04a
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    • pp.499-500
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    • 2015
  • 최근 인터넷 기술 발전에 따라 웹 시장이 커지고 웹 사이트 범죄가 급증하고 있다. 통계에 따르면 악성코드 주요 전파경로로 웹 사이트가 가장 높은 비율을 차지 할 정도로 조심해야 할 전파경로 중 하나이다. 그 중에서 이 논문은 웹 사이트 관련 공격 기술 중 하나인 크로스 사이트 스트립트(Cross Site Script, XSS)취약점을 알아본다. 먼저 XSS에 대해 알아보고, 실제 공격 예시를 살펴본다. 그리고 XSS를 막기위한 방어대책으로 화이트 리스트와 필터링에 대해 알아본다.

Derivation of preliminary derived concentration guideline levels for surface soil at Kori Unit 1 by RESRAD probabilistic analysis

  • Byon, Jihyang;Park, Sangjune;Ahn, Seokyoung
    • Nuclear Engineering and Technology
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    • v.50 no.8
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    • pp.1289-1297
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    • 2018
  • Preliminary surface soil Derived Concentration Guideline Levels (DCGLs) were derived conforming to the Multi-Agency Radiation Site Survey and Investigation Manual (MARSSIM) procedure for the site release and reuse of Kori Unit 1 in Korea. Based on the decommissioning experiences of the U.S. nuclear power plants, a suite of residual radionuclides was determined, and uncertainties contributed to the resultant dose by the input parameters were quantified via the sensitivity analysis of parameters. The peak of the mean dose was obtained via the probabilistic analysis of the RESRAD (RESidual RADioactivity)-ONSITE code. Consequently, $DCGL_w$ of Kori Unit 1 in accordance with two scenarios, industrial worker and residential farmer scenario, were derived and the results were compared respectively with other NPPs. It could be used as a basic guideline for establishing regulatory standards for reuse planning, designing the site characterization surveys and implementing final status survey (FSS).

Verification of 2-Parameters Site Classification System and Site Coefficients (I) - Comparisons with Well-known Seismic Code and Site Response Characteristics (2-매개변수 지반분류 방법 및 지반 증폭계수의 검증 (I) - 국외 내진설계기준 및 부지응답특성과의 비교)

  • Lee, Sei-Hyun;Sun, Chang-Guk;Ha, Jeong-Gon;Kim, Dong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.28 no.3
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    • pp.25-34
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    • 2012
  • In order to verify that the recently proposed two-parameters site classification system and the corresponding site coefficients are suitable for the local geological conditions in Korea, a comparison was conducted with current Korean seismic code, Eurocode-8, NYC DOT seismic code. The design spectrum of the current Korean seismic code is significantly amplified in the long-period range, whereas the other response spectra, including the proposed two-parameters approach, are significantly amplified in the short-period range, which is a typical geological condition in Korea. In addition, based on the results of site response analyses in the specific $10km{\times}10km$ area of Gyeongju, spatial distributions of site coefficients from site-specific seismic response analyses were compared with the proposed site coefficients, as well as those specified in the current Korean seismic code. The site coefficients ($F_a$ and $F_v$) from the current Korean seismic codes show significantly high spatial error distributions compared with those specified by the two-parameters site classification system. Therefore, the proposed system is suitable for regions of shallow bedrock including the Korean peninsula.

Factor Analysis of the Aircraft Noise Impact Assessment in the Building Site Development District Around of Gimpo Airport (김포공항 주변 택지개발지구 항공기소음 영향평가에 미치는 요인분석)

  • Kim, Heung-Sik;Ju, Si-Woong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.6 s.99
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    • pp.718-723
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    • 2005
  • The purpose of this study is to present a fundamental data for evaluating aircraft noise of building site development. By the field experiments and the predicted equal noise level contours using the INM program, actual condition in the building site development arranged district was investigated. In order to get the results, Analysis of factors effected on noise level, sound level on the rate of increase to aircraft demand and difference on the aircraft noise levels according to floor level in apartment house was carried out. As a result the influence of the take-off and landing direction were appeared greatly. The influences of the height at receiving point, movement number of aircraft and increase to aircraft demand were appeared small And the influence of 1 day average WECPNL must be considered.

Implementation of the virtual reforestation system using spatial data

  • Kim Sung-Jae;Jo Myung-Hee;Kim Joon-Bum;Lee Myung-Bo;Lim Joo-Hoon
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.77-80
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    • 2004
  • In this study the spatial distribution characters of burnt forest site was first considered by analyzing spatial data and monitoring forest landscape before/after lire to restore the site. Then suitable tree species on each forest site should be selected through the weighted score analysis of GIS analysis methods. Finally. the best forest stand arrangement method could be simulated on the system for the advanced reforestation technology in Korea. For this purpose, the virtual reforestation system was implemented by using the concept of virtual GIS and CBD (Component Based Development) method. By use of this system the change of forest landscape of burnt forest area some years after reforestation practice could be detected and monitored by applying the site index and 3D modeling method.

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CFD evaluation of a suitable site for a wind turbine on a trapezoid shaped hill

  • Unchai, Thitipong;Janyalertadun, Adun
    • Wind and Structures
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    • v.19 no.1
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    • pp.75-88
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    • 2014
  • The computational fluid dynamic is used to explore new aspects of the hill flow. This analysis focuses on flow dependency and the comparison of results from measurements and simulations to show an optimization turbulent model and the possibility of replacing measurements with simulations. The first half of the paper investigates a suitable turbulence model for determining a suitable site for a wind turbine. Results of the standard k-${\varepsilon}$ model are compared precisely with the measurements taken in front of the hilltop, The Reynolds Stress Model showed exact results after 1.0 times of hill steepness but the standard k-${\varepsilon}$ model and standard k-${\omega}$ model showed greater underestimation. In addition, velocity flow over Pha Taem hill topography and the reference geometry shape were compared to find a suitable site for a turbine in case the actual hill structure was associated with the trapezoid geometric shape. Further study of geometry shaped hills and suitable sites for wind turbines will be reported elsewhere.

Dynamic simulation models for seismic behavior of soil systems - Part II: Solution algorithm and numerical applications

  • Sahin, Abdurrahman
    • Geomechanics and Engineering
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    • v.9 no.2
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    • pp.169-193
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    • 2015
  • This paper is the second part of the study for determining the seismic behavior of soil systems. The aim of this part is to present solution approaches for determining seismic site amplification. For this purpose, two solution techniques are used. The first technique is equivalent linear analysis which is mostly used in literature. The other technique is real time parameter updating approach and this approach uses the possibilities of Simulink effectively. A graphical user interfaced (GUI) program called DTASSA standing for Discrete-Time Analysis of Seismic Site Amplification is developed. In DTASSA, automatic block diagram producing system is developed and seismic site amplification for multiple soil layers may easily be investigated in real time. Numerical applications have been carried out to check the reliability of developed algorithm. The results of DTASSA are compared with SUA, EERA and NERA programs for the particular example problems.

Crash of a small construction site accident analysis and Risk Assessment Study -Focusing on project value of less than 20 billion small construction sites- (소규모 건설현장의 추락 재해분석 및 위험성 평가연구 -공사금액 20억 미만 소규모 건설현장을 중심으로-)

  • Shin, Sung Su;Bae, Young Bok;Ha, Haeng Bong;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.16 no.4
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    • pp.41-51
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    • 2014
  • Share of total accidents in construction accidents construction site accident 70% of small embroidery Reducing the rate of Construction of the entire construction accidents decreased overall is a very meaningful work. Disaster reduction continues to increase despite the efforts of a small construction site(Amount less than 2,000,000,000) for Disaster Reduction In order to identify more clearly the cause of the system and provide the urgently needed measures.

Consciousness of Safety Engineer for Foreign Workers at a construction site (안전관리자의 건설현장 외국인 근로자에 대한 의식조사)

  • Son, Ki-Sang;Lee, Seung-Young
    • Journal of the Korea Safety Management & Science
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    • v.10 no.1
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    • pp.41-47
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    • 2008
  • Safety training for foreign workers should be thoroughly done. But it has not been done well even if field safety manager understand that the training has not been well provided. 72% of responders (Safety Managers) at field thinks that safety training has not been well provided at a site. It is shown that there are not any additional measures to correct this problem. Eventually, the reasons of that the training is not well provided, and foreign workers do not understand safe condition at site, well lead to an accident at construction site.