• Journal of electromagnetic engineering and science
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• 제10권4호
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• pp.290-295
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• 2010

In this paper, an interference analysis method with a site-specific path loss model for a wireless personal area network (WPAN) is proposed. The site-specific path loss model is based on geometrical optics and geometric probability to consider both site-specific radio propagation characteristics and a closed-form expression to obtain the mean interference from which the uniformly distributed multiple interferers are derived. Therefore, the proposed interference analysis method can achieve more computational simplicity than the Monte-Carlo (MC) simulation, which uses the ray-tracing (RT) technique. In addition, better accuracy than the conventional interference analysis model that uses stochastic method can also be achieved. To evaluate the proposed method, a signal to the interference-noise ratio with a mean interference concept for uniformly distributed interferers is calculated and compared in two simulation scenarios. As a result, the proposed method produces not only better matched results with the MC simulation using the RT technique than the conventional interference analysis model, but also simpler and faster calculation, which is due to the site-specific path loss model and closed-form expression for interference calculation.

• 한국방재학회 논문집
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• 제7권5호
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• pp.139-150
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• 2007

컴퓨터 기술이 급속히 발전됨에 따라, 최근에는 많은 분야에서 지리정보시스템(GIS)이 활용되고 있다. 이 연구에서는 서울 내의 한 시범 지역을 대상으로 지하 지반 조건에 따라 영향을 받는 부지 효과에 관련된 지진피해 가능성을 GIS 기법을 이용하여 평가하였다. 시범 지역에서의 지역적 부지고유 지진 응답의 평가를 위하여 서울 대도시 지역에 대한 기존 시추 조사 자료의 분포를 파악하였다. GIS 토대의 지반 정보 시스템(GTIS)을 구축하여 시범 지역 전체에 대한 공간 지층 정보를 예측하였다 서울 시법 지역의 부지고유 지진응답 예측을 위한 부지 주기$(T_G)$의 정밀구역화를 GTIS 내에서 수행하였다. 공간 분포 정밀구역화 지도로부터 시범 지역 내 2 층에서 4 층 건물들의 지진 취약성을 확인하였다. 또한, GTIS 내에서 $T_G$ 분포를 토대로 설계 지반 운동 결정을 위한 지반 분류 지도를 작성하였으며, 그로부터 대상 시범 지역 부지의 거의 대부분이 현행 지반 분류 C 와 D로 분류됨을 확인하였다. 이와 같은 서울 시범 지역에 대한 지진 정밀구역화 적용 구조 체계는 특별히 기존 시추 자료를 활용하여 대도시 서울 지역 전체에 대해 적용 가능할 것으로 판단된다.

• 대한수학회지
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• 제51권4호
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• pp.817-836
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• 2014

We develop a topological model of site-specific recombination that applies to substrates which are the connected sum of two torus links of the form T(2, n)#T(2, m). Then we use our model to prove that all knots and links that can be produced by site-specific recombination on such substrates are contained in one of two families, which we illustrate.

• 미생물학회지
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• 제29권4호
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• pp.209-214
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• 1991

The PRD1 DNA polymerase is a small multi-functional enzyme containing conserved amino acid sequences shared by family B DNA polymerases. Thus the PRD1 DNA polymerase provides an useful model system with which to study structure-functional relationships of DNA polymerase molecules. In order to investigate the functional and structural roles of the highly conserved amino acid sequences, we have introduced three mutations into a conserved amino acid of the PRD1 DNA polymerase. Genetic complememtation study indicated that each mutation inactivated DNA polymerase catalytic activity.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권3호
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• pp.65-73
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• 2020

Exposure assessment methodology for outdoor air inhalation pathways (i.e., inhalation of volatile compounds and fugitive dust in outdoor air) was investigated. Default values of several parameters currently used in Korea (e.g., Q/C; inverse value of concentration per unit flux, and frs; soil fraction in PM10) may not be suitable and lack site-specificity, as they have been adopted from the risk assessment guidance of the United States or the Netherlands. Such limitation can be addressed to a certain degree by incorporating the volatilization factor (VF) and the particulate emission factor (PEF) with Box model. This approach was applied to an exposure assessment of a site contaminated with petroleum hydrocarbons in Korea. The result indicated that the suggested methodology led to more accurate site-specific exposure assessment for outdoor inhalation pathways. Further work to establish methodology to determine site-specific Q/C values in Korea needs to be done to secure the reliability of the exposure assessment for outdoor air inhalation pathways.

• 한국지리정보학회지
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• 제9권2호
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• pp.1-10
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• 2006

이 연구의 목적은 주요 조림수종의 적지적수 및 투자효율성을 분석하기 위한 GIS 응용모델을 개발하는데 있다. 이 모델은 잠재적 임분생장력과 투자효율성을 동시에 만족시킬 수 있는 수종을 선정할 수 있도록 개발되었다. 즉, 임분의 잠재적 생장력은 지위지수의 추정을 통해 그리고 산림투자에 대한 효율성은 내부투자수익율을 산출하여 수종을 선발하게 된다. 산림경영 여건과 지위지수는 일련의 FGIS 수치도면들의 처리과정을 통해 추출되는 산림입지환경인자들의 함수로 평가된다. 이와 같은 분석 과정을 거쳐서 결정된 수종별 지위지수를 토대로 잠재적 임분생장량이 높게 예측되는 수종들을 우선 선발하고, 이 수종들을 조림하여 경영하는 경우의 내부투자수익율을 산출하게 된다. 내부투자수익율이 가장 높은 것이 결국 임분의 생장량 측면과 수익성 측면을 동시에 만족시키는 수종으로 볼 수 있다. 이 모델을 서울대학교 태화산학술림에 적용하여 6개 수종에 대한 입지 여건별 적합도 판정을 위한 사례분석을 수행하였고 그 결과를 제시하였다.

• 통상정보연구
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• 제8권4호
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• pp.3-22
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• 2006

Recently, the use of digital contents and demand have been increased with expanding users of internet. Thus, the importance of digital contents distribution site's has been increased that deal in commercially. The model that measuring acceptance of web sites is studying lively, however, the web sites that dealing and distributing specific goods to be called digital contents have insufficient theoretical base and model about acceptance of customers. Also, the research that acceptance of existing commercial web sites have limitation to explain systematically which influence on acceptance of digital contents distribution sites. Because, those research connect directly the feature of web sites, the purchase of web sites or the feature of buyers and acceptance. For that reason, it's hard to reflect the feature of digital contents. In this research, to measure customers' acceptance of web sites that distribute digital image, it is based on Technology Acceptance Model by Davis. This research find out the significant cause from survey by users of digital image distribution site. and TAM which has been adapted the analyzation of new site's acceptance can explain the state of digital image distribution site use. This research let us know the evaluation of digital image distribution site and operating strategy as a new business model.

• Water Engineering Research
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• 제1권1호
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• pp.11-23
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• 2000

Regional flood frequency analysis has been developed by employing the nearby site's information to improve a precision in estimating flood quantiles at the site of interest. In this paper, single site and regional flood frequency analyses were compared based of the 2-parameter Weibull model. For regional analysis, two approaches were employed. The First one is to use the asymptotic variances of the quantile estimators derived based of the assumption that all sites including the site of interest are independent each other. This approach may give the maximum regional gain due to the spatial independence assumption among sites. The second one in Hosking's regional L-moment algorithm. These methods were applied to annual flood data. As the results, both methods generally showed the regional gain at the site of interest depending on grouping the sites as homogeneous. And asymptotic formula generally shows smaller variance than those from Hosking's algorithm. If the shape parameter of the site of interest from single site analysis is quite different from that from regional analysis then Hosking's results might be better than the asymptotic ones because the formula was derived based on the assumption that all sites have the same regional shape parameter. Furthermore, in such a case, regional analysis might be worse than single site analysis in the sense of precision of flood quantile estimation. Even though the selected sites may satisfy Hosking's criteria, regional analysis may not give a regional gain for specific and nonexceedance probabilities.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권2_spc호
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• pp.70-85
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• 2020

This paper introduces the 'Smart Scoping for Environmental Investigations Technical Guide' issued by the US Environmental Protection Agency in 2018, which describes the use of smart scoping during lifecycle of remedial investigation projects. This paper also briefly summarizes the guidelines of soil and groundwater contamination investigation of South Korea. The smart scoping practices can support the development of a robust and realistic conceptual site model that is very useful for investigations and evaluations of the contaminated site. The application of evaluation tools relevant for the site-specific characteristics is important for the development of a conceptual site model. The smart scoping recommends the use of previous investigation data and implementation of best proven strategies for successful remedial investigation project. The use of smart scoping in contaminated site investigation will provide better management of contaminated sites.

• Steel and Composite Structures
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• 제26권2호
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• pp.197-211
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• 2018

The study presents the earthquake performance of the Bosphorus Bridge under multi-point earthquake excitation considering the spatially varying site-specific earthquake motions. The elaborate FE model of the bridge is firstly established depending on the new considerations of the used FEM software specifications, such as cable-sag effect, rigid link and gap elements. The modal analysis showed that singular modes of the deck and the tower were relatively effective in the dynamic behavior of the bridge due to higher total mass participation mass ratio of 80%. The parameters and requirements to be considered in simulation process are determined to generate the spatially varying site-specific ground motions. Total number of twelve simulated ground motions are defined for the multi-support earthquake analysis (Mp-sup). In order to easily implement multi-point earthquake excitation to the bridge, the practice-oriented procedure is summarized. The results demonstrated that the Mp-sup led to high increase in sectional forces of the critical components of the bridge, especially tower base section and tensile force of the main and back stay cables. A close relationship between the dynamic response and the behavior of the bridge under the Mp-sup was also obtained. Consequently, the outcomes from this study underscored the importance of the utilization of the multi-point earthquake analysis and the necessity of considering specifically generated earthquake motions for suspension bridges.