• 한국지반공학회논문집
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• 제30권12호
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• pp.63-72
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• 2014

측방유동 지반 속에 설치된 매설관의 측방이동과 이에 대한 성토지지말뚝의 방지효과를 관찰하기 위하여 일련의 현장 실험시공을 시행하였다. 매립중인 서해안 연약지반에 지하매설관(H.P:400mm)를 부설하고 인접 위치에 성토를 3단계로 시행하여 침하판과 지중경사계를 이용하여 지하매설관의 수직변위(침하)와 수평변위를 확인하였다. 성토에 따른 측방유동 억지대책으로는 성토지지말뚝을 설치하였다. 실험시공 결과 성토도중에는 매설관이 미미하게 융기하는 현상이 발생하였고 추후 침하하다 점차 수렴하는 거동으로 나타났다. 성토지지말뚝 보강 효과는 약 2.0배로 확인되었다. 또한, 침하와 변위는 상부지반에서는 크고 하부지반에서는 적게 침하가 발생하였고 변위는 비례하여 발생하는 것으로 나타났다.

• 상하수도학회지
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• 제24권4호
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• pp.407-412
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• 2010

The purpose of this study was to investigate removal efficiencies of contaminants in night soil treatment plant using the B3 system. The samples were collected from retaining tank and settlement tank in Yechon night soil plant. We experimented concentrations of BOD, COD, SS, TN and TP. Concentration data were processed using removal efficiencies by season and correlation analysis with pilot running parameters. Removal efficiencies of total organic carbon was over 96%, TN was 98% during summer, 80.9% during winter. In the case of TP, the highest removal efficiencies was 94.1% during fall and the lowest removal efficiencies was 82% during spring. Results of correlation analysis showed two positive correlation groups and one negative group. Positive correlations were among temperature, BOD and TN. The others were pH, BOD, COD, SS, TN and TP. Negative correlation were among MLSS, BOD, COD, SS, TN, TP.

• 한국환경과학회지
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• 제29권3호
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• pp.299-306
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• 2020

This study analyzed the changes in the concentrations of the pollutants of constructed treatment wetlands which come from the discharge water of a sewage treatment plant. According to the results of budgets in constructed wetlands, the net production of the organic carbon, nitrogen and phosphorus were 368 kgC/month, 306 kgN/month and -49 kgP/month, respectively. The high particle form of pollutants are mostly removed due to settlement and absorption when passing through wetlands, but because a low processing efficiency for pollutants was shown when sewage treatment plant wastewater flows in, there is a need for a water management system that can reduce the organic matter load through monitoring. The low removal efficiency of constructed wetlands were caused by both structural and operational problems. Therefore, to enable to play a role as a reduction facility of pollutants, an appropriate design and operation manuals for constructed wetlands is urgently needed.

• 생태와환경
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• 제56권4호
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• pp.384-392
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• 2023

식물의 기공은 이산화탄소와 수증기가 대기와 식물 사이를 이동하는 통로로 광합성 및 증산작용과 밀접하게 연관되는 중요한 생리적 기능 형질이다. 본 연구에서는 낙동강변에 서식하는 초본 식물종을 대상으로 자생식물과 외래식물 사이에 기공 형질에 차이가 있는지 조사 분석함으로써 낙동강변 식물 군집 내 기공 형질의 변이 양상을 파악하고, 또한 외래식물이 성공적으로 정착하는 이유를 알아보고자 하였다. 조사 결과, 같은 신장 모양 기공 형태를 가진 외래식물과 자생식물의 경우 기공밀도, 기공지수, 기공크기에 차이가 없었고, 이는 외래식물의 성공적 정착에 비어있는 생태적 지위가 꼭 필요한 것은 아님을 시사하였다. 기공밀도는 잎의 두께와 음의 상관관계를, 잎건조중량(LMDC)과는 양의 상관관계를 보였으며, 잎면적비(SLA)와는 상관관계가 없었다. 신장 모양기공을 가진 식물은 모두 양면기공형 잎을 가지고 있었고, 아령 모양 기공의 밀도 및 크기가 신장 모양 기공보다 작았다.

• Earthquakes and Structures
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• 제4권5호
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• pp.557-585
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• 2013

The recent huge earthquake ground motion records in Japan result in the reconsideration of seismic design forces for nuclear power stations from the view point of seismological research. In addition, the seismic design force should be defined also from the view point of structural engineering. In this paper it is shown that one of the occurrence mechanisms of such large acceleration in recent seismic records (recorded in or near massive structures and not free-field ground motions) is due to the interaction between a massive building and its surrounding soil which induces amplification of local mode in the surface soil. Furthermore on-site investigation after earthquakes in the nuclear power stations reveals some damages of soil around the building (cracks, settlement and sand boiling). The influence of plastic behavior of soil is investigated in the context of interaction between the structure and the surrounding soil. Moreover the amplification property of the surface soil is investigated from the seismic records of the Suruga-gulf earthquake in 2009 and the 2011 off the Pacific coast of Tohoku earthquake in 2011. Two methods are introduced for the analysis of the non-stationary process of ground motions. It is shown that the non-stationary Fourier spectra can detect the temporal change of frequency contents of ground motions and the displacement profile integrated from its acceleration profile is useful to evaluate the seismic behavior of the building and the surrounding soil.

• 한국응용곤충학회지
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• 제47권1호
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• pp.107-110
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• 2008

Tropical fire ant로 알려진 Solenopsis geminata (Fabricius)는 열대 및 온대지역에 분포하는 잡식성 개미로서, 식물에 피해를 주기도 하지만 야외활동을 하는 사람들이 물릴 경우 심하게 부어오르고 통증을 유발하는 위생해충으로 유명하며 우리나라에 침입 시 제주도 및 남부지방의 농경지 및 산림에 피해를 줄 것으로 예상되어 현재 식물방역법상 관리해충으로 지정된 종이다. 이 개미는 선박을 통하여 항구주위에서 먼저 정착하여 확산되고 있으며, 현재 동남아, 중국남부지역에서 급격히 확산되고 있다. 우리나라에서는 1990년대에는 수입식물검역 과정에서 검출실적이 1건이었으나 2000년부터 검출빈도가 증가추세에 있어 2006년도에는 7건이 검출되어 국내 침입이 우려되고 있다. 따라서, 동종에 대한 형태, 분포, 기주식물, 생태 등에 대한 자료를 정리하여 금후 수입식물검역시 참고하고 국내 침입시 조기 박멸하기 위한 자료로 이용하고자 한다.

• 무역상무연구
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• 제57권
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• pp.79-108
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• 2013

International transactions of plant and construction project need to time to time for completing the contract. During the performing the contract there may arise many claims and disputes it should be settled rapidly for processing schedule of works. However, arbitration and litigation for settlement of dispute are inappropriate in time and expense under the specifications of plant and construction project. Dispute boards are one of the successful resolution method of dispute prior to litigation or arbitration. If the dispute board was failed, of course, it may be allowed to continue into litigation or arbitration. As the creative methods of parties agreement, dispute boards may be expected to avoid claims and dispute in long and medium international contract. The purpose of this paper is to explore the specification and limitations of dispute boards that may clear disputes under long and medium contract of construction and procurement. It needs to be understand to determine whether is the useful methods for resolving dispute in the international project. This paper considers the specific natures of dispute board and its rules, procedures and problems including ICC and FIDIC for the contract of long and medium transaction.

• 대한전자공학회논문지TC
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• 제43권5호
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• pp.45-50
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• 2006

광가입자망의 궁극적인 목표라 할 수 있는 FTTH 서비스가 2005년을 시작으로 본격 추진되고 있다. FTTH 서비스를 위해서는 시스템 개발과 동시에 국사에서 가입자까지 이르는 다양한 자재로 구성되는 광선로시설의 효율적이고, 경제적인 구축 기술 및 시공품질 확보를 필요로 한다. 본 논문에서는 일반주택지역을 대상으로 FTTH 구축에 소요되는 선로시설에 대한 기술적 특징을 조사 분석하고, 주요 시설별 기능요구사항 및 선로시설 구축에 요구되는 특성 등을 분석하였다.

• Journal of Plant Biology
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• 제17권4호
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• pp.18-22
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• 1974

Counts of herb stems were made with each systematic grid sized 10cm by 1300cm within six apparently homogeneous herb layers under the open young Japanese red pine, Pinus densiflora, stands. The stands had often been subjected to strong human interferences such as burning, cutting, grazing, and denuding since human settlement until the conservation scheme practiced in these stands for last decade. In addition, amounts of loss of ignition and field capacity were determined to detect soil heterogeneity among and within the stands. The values of information measure of diversity(H), and Hurlbert's probability of interspecfic encounter(Δ), obtained here do not show any consistent correlation. The amount of interspecific competetion(Δ1), the ratio of interspecific to intraspecific competetion(Δ4), Levin's niche breadth(Sh), and species evenness(V), increase, while the amount of intraspecific competetion decrease, as the soil factors become favorable. One stand examined does not follow the above trends, which is more young and shows strong within site heterogeneity of the soil factors. The stand includes pioneer species which is not detectable without detailed observation. It is argued that in stable or favorable environment more intense interspecific competetion and less intraspecific competetion might occur, but this situation does not necessarily always bring smaller niche breadth. In this connection, the results support Hurlbert's contention that the two components of diversity should be analyzed separately.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.809-814
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• 2009

Deep mixing method has been used for ground improvement and foundation system for embankment, port and harbor foundations, retaining wall, and liquefaction mitigations. It has attractive benefits because it is not only improved strength of soft ground but superior for prevention of settlement. However, the quality controls of improved mass affect to the efficiency of the deep mixing method is not properly established. These effects vary depending upon the construction environments and conditions of agitation in consideration of an agitator. The strength and shape of the improved column are not unique and these are affected by mechanical properties of agitators. In this study, in order to investigate the efficiency of deep mixing method for ground improvement on a soft clay ground, experimental studies are performed considering mechanical properties of agitator; the location of exit-hole of admixtures, an angle of mixing wing and a speed of revolution. The experiments are conducted with the simulated apparatus for deep mixing plant that reduced the scale in 1:8 of the real plant. According to the results, the diameter and shape of improved column mass vary depending on the mechanical properties and operating conditions of agitator. Its quality is better when the exit-hole of admixtures is located in the mixing wing, when an angle of mixing wing is large, and when the speed of revolution is rapid.