• 한국지반공학회지:지반
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• 제11권4호
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• pp.75-86
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• 1995

내관과 외관으로 구성된 모형 개단 말뚝을 압력 토조속에 상이한 설치방법으로 관입한 후,실제 지진 기록을 이용하여 모델링시킨 유사 지진을 작용시켜 개단 말뚝에서의 지지력 저감 특성을 고찰하였다. 유사 지진 진동에 의한 극한 지지력 감소율은, 타격 관입 말뚝에서 약 20%였으며, 진동 관입 말뚝의 경우 약 40%에 달하였다. 또한,외주변 마찰력의 감소는 극한 지지력 감소의 대부분을 차지하여 약 80%였으며, 선단 강재부 지지력과 관내토 폐색력은 각각 약 10%였으며, 이러한 경향은 말뚝의 설치방법에 따라 크게 달라지지 않았다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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• pp.91-97
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• 2000

Once a response spectrum is estimated for the site, if there is a need of generating realistic earthquakes time histories considering seismic sources and path effects, one alternative is to use statistical phase characteristics based on real earthquake records other than assuming arbitrary duration and envelope curves. In this study, statistics of group delay times derived from Japanese strong earthquake data were used for phase generation to fully capture the stochastic property of earthquakes. The result shows that simulated earthquake time histories can be generated according to earthquake magnitude and distances with target response spectrum.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1989년도 봄 학술발표회 논문집
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• pp.66-70
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• 1989

Methods for identification of modal properties of linear structures are presented. The extended Kalman filtering technique is empolyed. The state equation is formulated by two different ways, namely by the time domain and frequency domain approaches. Verifications are carried out by using simulated records of ground acceleration and structural response. Then the techniques are applied to the estimation of modal parameters of a scaled model for a 3-story building which is installed on a shaking table.

• Communications for Statistical Applications and Methods
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• 제20권1호
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• pp.29-39
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• 2013

This paper derives maximum likelihood estimators (MLEs) and some approximate MLEs (AMLEs) of unknown parameters of the generalized exponential distribution when data are lower record values. We derive approximate Bayes estimators through importance sampling and obtain corresponding Bayes predictive intervals for unknown parameters for lower record values from the generalized exponential distribution. For illustrative purposes, we examine the validity of the proposed estimation method by using real and simulated data.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.39-43
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• 1998

The objective of the study is to develop attenuation equations of groud motions in the southern part of the Korean Peninsula. The earthquake source characteristics and the medium properties were estimated from available instrumental earthquake records and used as input parameters. The peak ground accelerations (PGA) and pseudo-velocty response spectra(PSV) were simulated by the random vibration theory. The attenuation equations for the PGA were constructed in terms of local magnitudes and hypocentral distances.

• 한국지반공학회지:지반
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• 제12권2호
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• pp.19-32
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• 1996

시간영역의 지진 가속도-시간 이력을 주파수 영역의 courier 진폭-주파수 이력으로 변화시키는 Trifunac의 경험적 모델을 기초로 하여 지진 관측소에서 측정된 임의 규모의 실제 지진기록들을 필요한 규모의 지진기록으로 유사화시키는 지진 확대 (scaling) 기법을 제안하였다. 또한, 지진 규모(M) 5.6의 지진기록을 이용하여 지진 규모(M) 8.0의 유사지진을 작성하여 동적 재하 시험 장치에 적용가능하도록 하였다. 지진 확대 (scaling) 기법은 MMI(modified mercalli intensity), 지진기록 부지의 조건,진앙거리,지진 가속도 성분의 방향, 해석의 신뢰도 등을 고려할 수 있으며, 다양한 지진 기록들에 적용가능하였다.유사지진은 수평방향의 성분들만을 고려하여 작성되었다. 압력토조내에 설치된 모형인장말뚝과 개단압출말뚝에 대한 유사지진 진동에 의한 동적 말뚝재하시험이 가능하였다. 정적 말뚝재하시험시 인장말뚝과 압축말뚝의 거동은 매우 상이하였는데, 인장말뚝은 2~3회의 급작스런 미끄러짐 변위를 수반하였다. 또한, 유사 지진 진동중 인장말뚝과 개단압축말뚝의 거동특성은 매우 상이하였으며, 지지력 감소특성도 크게 달랐다.

• 한국문헌정보학회지
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• 제49권3호
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• pp.135-154
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• 2015

본 연구는 개화기 방한 서양인 기록물의 디지털 아카이브를 구축하여 지역문화콘텐츠로 활용하기 위하여 수행되었다. 수집대상 자료는 서양인 기록물 11권이고, 주제분류체계로부터 10개의 대주제와 120개의 소주제를 추출하였다. 37개 메타데이터 항목에 맞추어 텍스트 내용의 분석과 입력자료 유형을 분류하고 엑셀로 된 데이터베이스를 구축하였다. 그리고 디지털 아카이브 시스템 모델과 5개의 메뉴로 구성된 홈페이지 구축(안)을 제시하였다. 추후연구를 위해 아카이빙 구축을 위한 데이터의 지속적인 발굴과 아카이브 확대 방안, 아카이브 시스템간의 활발한 연계, 시스템 표준화, 시스템 호환성과 사용자 편의성을 고려한 시스템 설계를 제언하였다.

• 한국대기환경학회지
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• 제7권3호
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• pp.208-218
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• 1991

To compare the resistance of landscape trees by acid rain, simulated acid rain was treated on the seeds of 6 coniferous species (Pinus densiflora, Pinus thunbergii, Pinus koraiensis, Taxus cuspidata, Cedrus deodara, Thuja occidentalis) and 6 broad-leafed species (Ligustrum obtusifolium, Acer Buergerianum, Acer Ginnala, Styrax obassia, Cornus Kousa, Magnolia obovata). The experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agri-Tech Junior College. The seeds of 12 tree species were planted on the nursery soil in the early spring of 1991. The regime of artificial acid rain, in terms of spray frequency per monthly and spray amount at year records. Simulated acid rain (pH 2.0, pH 4.0, pH 5.6 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (April 8 to August 31) in 1991. Seedling establishment, seedling growth and nutrient contents in needles and leaves were measured and compared among the treatment. The results were summerized as follows; 1. In general, coniferous species were more resistant than broad-leafed species in the resistant comparisons of landscape trees by simulated acid rain. But there were resistant tree species to acid rain among the broad-leafed species. 2. Among 6 coniferous species used in this experiment, Pinus densiflora, Pinus koraiensis, Taxus cuspidata, Cedrus deodara and Pinus thunbergii revealed the resistant tree species to acid rain. But Thuja occidentalis was very susceptible to acid rain, because of no germination in pH 2.0 treatment plot of acid rain. 3. Among 6 broad-leafed species used in this study, Magnolia obovata, Styrax obassia and Ligustrum obtusifolium showed relative resistant tree species to acid rain. But Acer Buergerianum, Acer Ginnala and Cornus Kousa were very susceptible to acid rain, because of no germination in pH 2.0 plot of acid rain treatment.

• 한국대기환경학회지
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• 제4권1호
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• pp.33-44
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• 1988

For the purpose of examining the effects of simulated acid rain on the chemical properties of the experimental soil in Pinus densiflora seedlings and Forsythia koreana rooted cuttings, the experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agricultural Junior College. One-year-old Pinus densiflora seedlings and Forsythia koreana cuttings were planted in the pots filled the mixed soils (nursery soil: forest soil of siliceous sandy loam = 1 : V/V)in the early spring of 1985. The regime of artificil acid rain, in terms of spray frequency per monthly and spray amount at single treatment per plot, was simulated on the basis of climatological data averaged from 30 years records. Simulated acid rain (pH 2.0, pH4.0, and pH 5.5 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (May 1 to August 31) in 1985. THe results obtained in this study were as follows; 1. Soil acidity was dropped, and exchangeable aluminum contents in the soil was dramatically increased in both species, with decreasing pH levels of acid rain. 2. Exchangeable potassium, clacium, magnesium contents, and base saturation degree of the soil were highly drcreased in two species as the pH levels of acid rain decreased. 3. In two species, sulfate concentrations in the soil were decreased of pH 4.0 treatment, and remarkably increased at pH 2.0 treatment of acid rain in comparison with control. 4. Total nitrogen and available phosphate contents of the soil were not affected by acid rain treatment in the both species, and Fe contents at pH 2.0 treatment were highest among three acid rain treatments.

• 한국농공학회지
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• 제42권1호
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• pp.57-65
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• 2000

The objective of this paper are to present a realistic methodology to estimate the daily water supply rates form irrigation pumping stattions, to validate it with the field data, and to report the daily irrigation pumping rates from the Han river basin. Five-year historical pumping records were collected from seventy-three pumping stations in the Han river basin. And the daily pumping rates were estimated from the electrical consumption records. The pumping patterns from the stations were analyzed and the results were applied to ungauged pumping stations in the basin. The method was appliedto five stations which were field monitored during the irragation periods in 1998. The relative errors between the observed and simulated water pumpage ranged from 1.4 to 7.0 percent. This indicates that the proposed method is valid to apply for estimating the pumping rates for agricultural lands. During 1993 to 1997, the annual average water pumpaging from the Han river and the tributaries were 350 million cubic meter. The annual water supply from the pumping stations varied from 973 to 1.377 mm in depth and the mean was 1,170 mm. The major factor affecting the annual variations was attributed to the rainfall during the growing seasons.