• Geomechanics and Engineering
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• 제11권6호
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• pp.821-845
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• 2016

Extensive researches on distribution of earthquake induced damages in different regions have shown that geological and geotechnical conditions of the local soils significantly influence behavior of alluvial areas under seismic loading. In this article, the site of Babol city which is formed up of saturated fine alluvial soils is considered as a case study. In order to reduce the uncertainties associated with earthquake resistant design of structures in this area (Babol city), the required design parameters have been evaluated with consideration of site's dynamic effects. The utilized methodology combines experimental ground ambient noise analysis, expressed in terms of horizontal to vertical (H/V) spectral ratio, with numerical one-dimensional response analysis of soil columns using DEEPSOIL software. The H/V spectral analysis was performed at 60 points, experimentally, for the region in order to estimate both the fundamental period and its corresponding amplification for the ground vibration. The investigation resulted in amplification ratios that were greater than one in all areas. A good agreement between the proposed ranges of natural periods and alluvial amplification ratios obtained through the analytical model and the experimental microtremor studies verifies the analytical model to provide a good engineering reflection of the subterraneous alluviums.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권1호
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• pp.24-33
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• 2021

Analysis of long term affecting factors on water quality items of gas emission form (BOD, COD) and leachate emission form (T-N, non-bio-degradable COD (NBDCOD)) was performed for the SUDOKWON 1st Landfill Site (LS1) and 2nd Landfill Site (LS2). As landfill gas was generated, BOD and COD decreased from 6,887 and 20,025 mg/L in 1993 to 49.5 and 670.2 mg/L in 2019, respectively. TN and NBDCOD increased with waste decomposition but gradually decreased after landfill closure because of the precipitation infiltration effect. Due to the drastic decline of carbon in the leachate, the BOD/TN ratios of LS1 and LS2 declined from 13.0 and 17.0 during early stage of the landfill to 0.07 and 0.16 in 2019, respectively; LS2 and NBDCOD/COD increased from 0.25 to 0.65 during the same period. These conditions caused carbon deficiency in denitrification treatment and a chemical post-treatment request for NBDCOD. The different behaviors of gas emission and leachate emission items suggest the necessity of different strategic approaches in the long term perspective.

• 한국산림과학회지
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• 제99권1호
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• pp.144-152
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• 2010

본 연구는 경기도 광릉시험림에 위치한 노령 느티나무 인공림의 생장특성과 지상부 탄소저쟝량을 구명하기 위해 실시하였다(조사지1:IX영급, 조사지2:VIII영급). 임분구조분석을 위해 수형급을 구분하였고, 수형급별 연륜생장과 우세목의 수간석해를 통해 생장특성을 파악하였다. 직경급은 조사지1에서 8~62 cm, 조사지2에서 14~40 cm의 분포범위를 보였고 수고급은 조사지1에서 8~26 m, 조사지2에서 12~26 m의 분포범위를 보였으며, 이에 따른 수형급간 생장특성이 다르게 나타났다. 그 중 조사지1의 우세목은 최근 5년간 평균 연륜생장량(3.3 mm)이 생장기간 전체의 평균 연륜생장량(2.3 mm)보다 높았고, 조사지2의 우세목은 최근 5년간 평균 연륜생장량(2.2 mm)과 생장기간 전체의 평균 연륜생장량(2.2 mm)이 같았다. 또한, 2개 조사지 모두 우세목과 타 수형급간 연륜생장량의 차이가 큰 것으로 나타났다(p<0.01). 우세목의 수간석해 결과, 단재적이 2개 조사지에서 각각 1.106 $m^3$와 1.035 $m^3$으로 나타나 유사하였으며, 2개 조사지 모두 노령임에도 불구하고 최근에도 연간재적생장량이 지속적으로 증가하였다. 한편, 총탄소저장량은 조사지1에서 65.6 Mg C $ha^{-1}$, 조사지2에서 56.1 Mg C $ha^{-1}$로 나타나 조사지1이 더 많았고, 총탄소저장량에 대한 우세목과 준우세목의 비율이 2개 조사지 모두 90% 이상으로 나타났다. 개체목의 탄소저장량은 2개 조사지 모두 우세목이 가장 많았으나, 우세목의 평균흉고직경 차이로 인해 조사지1의 우세목이 0.054 Mg C $tree^{-1}$정도 더 많았다. 이러한 결과들은 느티나무인공림의 시업적 관리를 위한 기초자료로서 의미가 있을 것으로 사료된다.

• 헤리티지:역사와 과학
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• 제42권4호
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• pp.172-197
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• 2009

미륵사지와 정림사지 석탑은 한국석탑의 시원인 동시에 현재 유일하게 남아있는 백제석탑이다. 따라서 이 둘의 특징을 살펴보는 작업은, 넓게는 한국석탑, 좁게는 백제양식석탑을 이해할 수 있는 바탕이 된다. 백제의 뛰어난 건축술은 기록에도 전하듯이 아비지가 신라의 국가적인 사업인 황룡사목탑의 건립에 초청된 것을 통해서 알 수 있고, 그 과정에서 석탑과 관련된 기술과 양식이 신라에 전파되었음도 짐작된다. 그러나 신라통일을 맞이하여 백제석탑의 양식을 공유하는 석탑들이 일순간에 단절되었다고 보는 것은, 문화와 예술이 계승 발전된다는 측면에서 쉽게 수긍이 가지 않는다. 현재 학계에서는 여타의 백제지역 석탑들을 모두 고려시대 건립된 백제계 석탑이라는 틀로 규정하여, 일률적인 편년 아래 두고 있다. 등장요인으로는 불교의 대중화, 지방 호족의 지원, 문화의 복고적 경향 등을 들고 있는데, 과연 이것만으로 백제양식석탑이 약 300년간의 공백을 깨고 한 순간에 등장할 수 있었는지는 확신하기 어렵다. 물론 경주지역처럼 활발하지는 않았지만, 백제양식석탑이 일부 지역에 한정되어 전개되었을 가능성이 있다. 본 논문에서는 전개의 시발점에 초점을 맞추어, 백제양식석탑이 미륵사지와 정림사지 석탑을 통해서 형성되고, 그후 왕궁리 석탑을 통해서 전개가 시작되었음을 고찰해 보았다.

• 한국전통조경학회지
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• 제33권1호
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• pp.12-20
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• 2015

문무대왕이 674년에 동궁과 월지를 조성한 후, 1922년에 측량이 이루어지기까지 1249년 동안 어떻게 변형되었는지 자료가 없어 원형경관을 추정 할 수 없다. 그래서 본 연구는 월지 경관변화를 좀 더 심도 있게 추정하기 위하여 그동안 연구되지 않았던 Hara(1932)의 연구와 일제강점기의 사진 등을 분석하였으며 그 결과는 다음과 같다. 1922년 측량도면과 1975년 측량도면을 비교해 본 결과 53년 동안, 섬을 제외한 월지 전 지역에서 2~4m가 낮아졌으며, 심한 곳은 10m나 낮아진 조산(造山)지역도 있었다. 제1 건물지 남쪽 호안에는 산을 연상시킬 만큼 많은 경석이 놓여 있었으며 이곳에 입수로가 있었음이 1922년 측량도면과 1950년대 사진자료를 통해 확인할 수 있었으며, 이러한 유구는 발굴 직전까지 남아 있었음을 확인 할 수 있었다. 건물지 3, 5는 건물지 1, 2, 4에 비해 봉우리 형상으로 더 높았다. 따라서 높은 기단 위에 건축물이 세워져 있었을 가능성이 매우 높으며, 현재와 같이 제 3, 5 건물지가 여타 건물지와 함께 같은 높이로 정비된 것은 잘못된 것이며, '경주 임해전지 조경정비계획(2009)'과 '종합정비기본계획(2012)'은 잘못된 것이다. 월지 발굴 이전의 사진을 통해 경관변화를 추정해 본 결과, 도면상에서 많은 변화가 있었던 조산 지역의 경관변화와 경석의 변화를 확인할 수 있었다. 이번 연구에서는 지면 관계상 제한적이었지만 좀 더 많은 사진자료를 분석한다면 월지 원형경관 추정에 도움이 될 것으로 판단된다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.593-598
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• 2005

At-site analysis is not appropriate if the record length is shorter than target return period T. If the record length is longer than 27 years, then at-site analysis may be sufficient(Institute of Hydrology, 1999). However, in such a case, regional frequency analysis is recommended for purpose of comparison. Record lengths of annual maximum rainfall data in Korea are usually shorter than 50 years. It is therefore essential to apply regional frequency analysis for estimating rainfall quantiles of more than 100 years return period. In this research, regional rainfall frequency analysis is performed for hourly rainfall data of South Korea. Homogeneous regions are idntified by clusgter analysis which is a standard method of statistical multivariate analysis for dividing a data set into groups. An appropriate distribution is chosen by goodness-of-fit test. GLO is found to be an appropriate distribution as a result of goodness-of-fit measure (Hosking & Wallis, 1997). Simulation experiments are performed to check the performance of frequency analysis techniques. The effects of discordant sites on quantiles are considered.

• 한국농공학회논문집
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• 제47권3호
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• pp.69-76
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• 2005

An Absorbent Biofilter System (ABS) combined with the recirculation process was investigated for the feasible application in additional removing of organics (BOD, SS) as well as nutrients (TN, TP) from small Community wastewater in Korea. Polyurethane biofilter media with high porosity and large surface area were /used for the aerobic system. A part of treated wastewater was recirculated into the anoxic septic tank to promote removal of nutrients. The concentrations of BOD and SS of treated wastewater satisfied the regulations for small on-site wastewater treatment facility (10 mg/L) during the overall experimental period. The effluent concentrations of BOD and SS were decreased with enhancement of removal efficiencies of 95.7 and $96.7\%$. The nitrogen and phosphorus removal efficiencies by the recirculation increased to $52.9\%\;and\;43.2\%$ in average during the overall experimental period, respectively. With the improvement, these values were increased as much as additional 42 and $18\%$ compared with those of non-recirculation. The rates of nitrification and denitrification were enhanced showing $65\~77\%\;and\;42\~92\%$, respectively. The described process modification is a low cost and effective method of enhancing nitrogen and phosphorus removal, especially on existing systems without changing major design components of a treatment facility.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제42권4호
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• pp.182-186
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• 2016

Objectives: The purpose of this study was to analyze the incidence of indications for the removal of mini-plates over a five-year period in maxillofacial trauma patients. Materials and Methods: The medical records of 530 patients who underwent treatment with mini-plate fixation after maxillofacial trauma were reviewed for a five-year period (May 2007 to May 2012). Patients were evaluated concerning the number of mini-plates removed, age and gender distributions, time between insertion and removal, indication for removal, and site of removal. Results: The plates of 120 patients were removed (26 females and 94 males). The removal rate was 22.6%. The most frequent indication for removal was patient demand (81.7%), followed by tooth extraction (7.5%), and pain (3.3%). The most frequent removal site was the mandible (95.0%). Conclusion: The number of mini-plates removed was small, and the most common indication for removal was patient demand. There is no evidence to support a recommendation for the routine removal of titanium mini-plates.

• 한국주거학회논문집
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• 제26권6호
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• pp.139-146
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• 2015

In this study, the plane type of main building relics of unified Silla period house site which excavated in Gyeongju city after 1990s was classified and the architectural characteristic of them was investigated. The chronology of building relics in Silla capital city site was mostly known as 8-9th century, and by standard of column arrangement, the plane types of them could be classified as grid type, front veranda-grid type, outer column type. The outstanding characteristic of plane is wide span and open front veranda. In most relics the span were over 4 meters, and inner foundations for small post and strip foundation were found between columns. The front veranda added type buildings were composited of enclosed main room and open front veranda, and column arrangement of them dose not fall into line in most case. Thus it thought that the structures of enclosed main room and open front veranda were independent. The interior space of enclosed main room were divided two rooms by partition wall in some case. In this case, one room is enclosed by wall, and the other room has open front side. This plane is considered for the pleasant life in cold winter and hot summer.

• 대한간호학회지
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• 제30권1호
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• pp.29-38
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• 2000

To determine whether personal history of lactation in premenopausal women influence bone mineral density, a cross-sectional study was conducted. One hundred eighty-four premenopausal women were selected from women who had been checked for bone mineral density by dual energy x-ray absortiometry in lumbar spine, femoral neck, Ward's triangle, and trochanteric site at general hospitals in Seoul and Pusan. They completed a questionnaire including life style factors and reproductive history. In the data analysis, Pearson correlation coefficients were used to test any association between individual variables and bone mineral density and a statistical comparisons between long term lactation(>24 months) and short term lactation(<24 months) were made by one way analysis of covariance. The results were summarized as follows: 1) There was no significant difference in the bone mineral density of the lumbar vertebrae in premenopausal women between the long term lactation group(>24months) and the short term lactation group(<24months). 2) There was no significant difference in the bone mineral density of the femur neck, Ward's triangle, and trochanteric site in premenopausal women between the long term lactation group (>24months) and the short term lactation group (<24months). Considering these results, we suggest prospective studies that measure bone mineral density before and after, in addition to those during lactation. We also suggest the further study with premenopausal women less than 35 who have achieved peak adult bone mass.