• Pediatric Infection and Vaccine
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• v.25 no.3
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• pp.170-175
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• 2018

Actinomyces are anaerobic, Gram-positive bacteria that are part of the endogenous flora of mucous membranes in humans. Infection caused by these bacteria is termed actinomycosis. The 3 most common types of actinomycosis are cervicofacial, abdominopelvic, and pulmonary. A previously healthy 6-year-old boy presented with the emergency room with fever, vomiting, and abdominal pain and initially diagnosed with acute appendicitis. Exploratory laparoscopy was done. Histologic finding demonstrated acute gangrenous appendicitis complicated by perforation and sulfur granules compatible with actinomycosis. Subsequently, he was diagnosed with abdominal actinomycosis and received long-term antibiotic therapy. Abdominal actinomycosis is uncommon in children and difficult to diagnose because of its nonspecific symptoms and of difficulties in growing Actinomyces in the clinical setting. It is necessary to include abdominal actinomycosis as a differential diagnosis of children presenting with abdominal pain.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.664-671
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• 2019

This study was conducted to investigate the environmental impact of the construction of the Yeongju Dam, located near the upper stream of the Nakdong River, on benthic macroinvertebrates. The investigation was conducted four times from 2015 to 2016 and the composition of the benthic macroinvertebrate fauna from the four surveyed sites was compared. After the dam construction, the number of benthic macroinvertebrate species decreased and the species composition ratio of the E.P.T taxa(Ephemeroptera, Plecoptera, and Trichoptera) decreased, which favored the previous environment and the large riverbed structure. However, the species composition ratio of the O.C.H taxa (Odonata, Coleoptera, and Hemiptera), which favored the reservoir environment, increased. For the pattern of changes in the functional habitat groups, the proportion of 'Clinger(CL)' taxa decreased and the 'Burrower(BU), Climber(CB), Sprawler(SP), Swimmer(SW)' taxa increased in all surveys after the dam construction. A cluster stability comparison showed that the 'Stability Group II' species of St.2 and St.3 showed a drastic decrease. The average Benthic Macroinvertebrate Index(BMI) of all the survey sites in 2016 was lower than that in 2015. This research confirmed the temporal and spatial changes in the habitat type and community structure of the benthic macroinvertebrates resulting from the dam construction.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.997-1001
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• 2009

GIS 기반의 HEC-HMS를 이용하여 유량자료가 있는 소하천인 정자천 유역을 대상으로 장기 강우 유출 분석을 하였다. 일반적으로 홍수량 산정은 단기해석으로 분석하나 평 갈수기와 홍수기 때의 하천 유황이 다르기 때문에 매개변수가 불일치할 것이라 생각되고, 이에 대한 보정이 필요한지 판단이 필요하다. 이를 위해 장기 연속모의를 통하여 매개변수의 보정 필요성을 검토하였다. 연구는 수치지도를 조합하여 ARC-VIEW로부터 Map파일 및 Basin파일을 생성하였고, 토지이용도와 토양도를 ARC-VIEW를 이용하여 CN value를 추출하였다. 계산조건중 손실량 산정방법은 SCS Curve Number법으로 하였고, 단위도 방법은 Clark UH법, 하도추적방법은 Muskingum방법, 기저유량산정방법은 Constant monthly로 설정하였다. 유역면적, 도달시간자료, 저류상수 값 등의 추출은 GIS기법을 이용하여 추출하였다. HEC-HMS의 장기 연속모의(Continuous Simulation)로 얻어진 Element Graph를 보면 대략적인 형태가 일치하나 2006년도에 대한 모의에서는 홍수기의 결과만 일치하는 것으로 보이고, 2007년도에 대한 모의에서는 평 갈수기와 홍수기의 그래프 형태가 유사하게 나타났다. 실측 유량보다 유량 값이 약간 크게 산출되어 홍수량 산정에서 볼 때 안정성에 무리가 없다고 판단되지만, 평 갈수기 기간에서 볼 때 연마다 하천의 매개변수가 일치하지 않는다고 생각되며, 홍수 후 유역의 변화로 매개변수가 변화한 것이라 생각된다. 향후 정자천유역의 보다 많은 강우사상과 실측유량을 통해 HEC-HMS의 유출량을 비교 분석하면 보다 더 정확한 해석이 가능할 것이며, 홍수가 빈번한 지역의 경우 유수지의 검토와 저수지의 시간당 방류량을 알 수 있다면 오차의 범위를 줄일 수 있다고 생각된다. 더 나아가 우리나라에 적합한 매개변수와 GIS 프로그램이 개발된다면 보다 쉽고 정확한 해석이 가능할 것이라고 생각된다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.11
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• pp.949-954
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• 2016

When a snowplow is operating in the up or down direction, the sensor stops the movement automatically and the wire could be broken from an endless drive in the reverse direction impact or conversely winding wire. In the present study, a new bobbin was designed to ensure the durability of snowplows; in this design, the bobbin plays the role of a clutch during power transfer or idling. This will protect the blade of the snowplow during an impact and maintain close contact of the blade with the road. Therefore, the new technology to eliminate the tension and fatigue of the wire is suggested by winding a chain instead of the wire in the newly designed bobbin. From these, it was developed to extend the life of the snowplow without causing damages to the vehicle.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.259-266
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• 1999

In case that pile cap is in direct contact with underlying soil, the bearing mechanism for pile groups, including direct bearing effect of cap and its induced influence on pile-soil-cap interaction, should be properly considered. In this paper, the effects of pile caps on behaviors of pile groups in sandy soils were investigated by model tests, which consist of tests on 3 by 3 pile groups with/without contact on subsoil, single pile with/without contact and cap as a shallow foundation. Also, the influences of pile spacing in group piles on contact effects were investigated. The test results showed that the load carrying capacity of pile cap was large enough not to be ignored. However, the interaction effects due to contact between cap and subsoils were not revealed obviously in working load range. And in the design of pile groups, the bearing effect of pile cap when contacted with subsoils, can be reflected by simply summing up load settlement behaviors of each cap and group piles without contact.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.262-262
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• 2004

수정란이식의 수태율을 높이기 위해서 가급적 자궁각 심부에 이식하려고 한다. 그러나 자궁경관경유법에 의한 수정란이식에서 자궁각 심부에 무리하게 이식하면 출혈 또는 이식지연으로 수태율이 저하된다. 수정란이식시 자궁내 이식기의 조작은 자궁내 PG 분비를 촉진하며, 자궁내에 분비된 PGF₂a는 수정란의 발육에 악영향을 준다고 보고하고 있다. 따라서 수태율 향상을 위해 수정란이식 직전에 PGF₂a 분비억제 제제를 투여하면 수태율을 높일 수 있다고 Schrick 등(Theriogenology, 2001;55:370)은 보고하였다. (중략)

• The Science & Technology
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• v.12 no.4 s.119
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• pp.29-39
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• 1979

과학화 운동의 대상은 학생층ㆍ일반시민ㆍ농어민등 사회와 연령의 계층별로 조직적으로 집중전개해야 한다. 이중 가장 주력해야할 대상은 초등료육과정의 청소년층이다. 전통적인 인습과 생활양식에 젖어온 기성세대에 비하면 이들은 과학환경과 여건만 조성해주면 과학을 생활화할 수 있는 세대로 성장할 수 있다. 이들을 위한 과학화사업은 교육사업의 일환으로 장기적인 안목에서 상당한 투자와 꾸준한 추진력등이 필요하다. 이러한 노력이 아무리 어렵고 많은 재정을 필요로 한다해도 그보다 더 가치있는 사업은 찾기어렵다. 과학적인 의식구조로 세련된 오늘의 국민학생들이 다음 세대의 주인공이 되어 가장 진취성있고 창의적인 국민으로 등장할 때 민족중흥의 대과업이 이루어 질것이다. 이것은 기성세대가 물려 줄 수 있는 가장 고귀한 귀산이라고 할 수 있을 것이다. 그러면 이들을 위한 올바른 과학화전개방안은 무엇이며 과학과 친근할 수 있는 기회를 어떻게 마련해 주어야 하는가를 고대 김시중교수ㆍ문교부 문찬고과학교육연구관 및 서울사대부속국민학교 김겸렬 교감(과학주임)ㆍ서울연가국민학교 송연휘 과학주임ㆍ홍사대부속국민학교 이종화 과학주임에게서 들어본다. <편집자주>

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.245-252
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• 2000

Model tests on free standing pile groups and piled footings with varying a pile spacing in two layered soils are carried out. The influence of pile cap on the behaviors of end bearing pile groups is analyzed by comparing the bearing behavior in piled footings with those in a single pile, a shallow footing(cap alone) and free standing pile groups. From the test results, it is found that the bearing characteristics of cap-soil-pile system are related with load levels and pile spacings. Before yield, the bearing resistance by cap is not fully mobilized, however, as the applied load increases, the bearing resistance of cap approaches to that of cap alone and settlement hardening occurs after yield due to the compaction caused by the contact pressure between cap and soil. By the cap-soil-pile interaction, shaft friction and point resistance of piles considerably increase with dependency of pile spacings. In two layered soil, the increasing effect of dilatancy in dense sandy soil adjacent to pile tips, increases the point resistance of pile.

• Tunnel and Underground Space
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• v.10 no.3
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• pp.481-485
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• 2000

Vibration screening trench is very effective to reduce the ground vibration, but to construct the trench in the rock mass is not easy. Various line drilling methods have been tried to replace the trenching. In this study, UDEC was applied to simulate the screening effect of drilling holes in 2 dimensional ground model. Field measurement was conducted and compared to numerical analysis.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2000.09a
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• pp.235-239
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• 2000

Vibration screening trench is very effective to reduce the ground vibration, but to construct the trench in the rock mass is not easy. Various line drilling methods have been tried to replace the trenching. In this study, UDEC was applied to simulate the screening effect of drilling hopes in 2 dimensional ground model. Field measurement was conducted and compared to numerical analysis.