• 한국지반공학회지:지반
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• 제13권2호
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• pp.101-124
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• 1997

풍화토 및 모래질 충적토가 암반위에 쌓인 형태로 구성된 국내 수도권 도심 지역에서, 깊은 굴착 공사로 인하여 발생하는 인접 지표의 침하에 대해 현장 측정을 중심으로 연구를 수행하였다. 먼저, 토류벽 설치, 중간 말뚝 설치 등 본격적인 굴토 공사가 진행되기 이전의 공정으로 인한 인접 지표침하량, 침하 영향거리 등을 측정, 분석하였으며 다음으로, 본격적인 굴토로 인하여 발생하는 인접 지표의 침하에 대해 침하량, 침하 영향거리 등을 측정, 분석하고 균질한 사질토 지반이나 단단한 점토 지반에 대해 기존에 제시된 연구 결과와 비교하였다. 또한 굴착 공사시 과도한 변형으로 인하여 인접 지표 및 구조물에 균열 등의 피해가 발생한 7개 현장 사례를 통하여 굴착 공사로 인한 인접 지표의 균열 발생 범위에 대하여 분석하였다.

• 대한기계학회논문집B
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• 제21권9호
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• pp.1139-1148
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• 1997

Compression waves propagating in a high-speed railway tunnel develops large pressure fluctuations on the train body or tunnel structures. The pressure fluctuations would cause an ear discomfort for the passengers and increase the aerodynamic resistance of trains. As a fundamental research to resolve the pressure wave phenomenon in the tunnel, experiments were carried out by using a shock tube with an open end. A blockage to model trains inside the tunnel was installed on the lower wall of shock tube, thus forming a sudden cross-sectional area reduction. The compression waves were obtained by the fast opening gate valve instead of a conventional diaphragm of shock tube and measured by the flush mounted pressure transducers with a high sensitivity. The experimental results were compared with the previous theoretical analyses. The results show that the ratio of the reflected to the incident compression wave at the sudden cross-sectional area reduction increases but the ratio of the passing to the incident compression wave decreases, as the incident compression wave becomes stronger. This experimental results are in good agreements with the previous theoretical ones. The maximum pressure gradient of the compression wave abruptly increases but the width of the wave front does not vary, as it passes over the sudden cross-sectional area reduction.

• 국제초고층학회논문집
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• 제9권3호
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• pp.283-300
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• 2020

The Lakhta Center is a Multifunction Complex Development (MFCD) consisting of 1) an 86 story office tower rising 462 m above the ground to provide high-end offices for Gazprom Neft and Gazprom Group affiliates 2) a Multi-Function Building (MFB) that includes, a scientific/educational center, a sport center, a children's technopark, a planetarium, a multi-transformable hall, an exhibition center, shops, restaurants, and other public facilities 3) a Stylobate 4) "The Arch, which forms the main entrance to the tower, restaurants, and cafes 5) underground parking and 6) a wide range of large public plazas. While each of the MFCD buildings is technically challenging in its own right, the focus of the paper is to present the development and integration of the structural and foundation systems of the bowed, tapered, and twisted shape of the tower into the fabric of the tallest Tower in Europe.

• 대한토목학회논문집
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• 제32권3A호
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• pp.171-181
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• 2012

지중에 매설된 원형강관으로 보강된 FRP 개인하수 처리시설에 대한 설계를 수행하고 실물 현장 재하실험을 통하여 보강의 형태 및 종류에 따른 극한거동을 분석하였다. 현행 개인하수 처리시설의 설계 기준의 문제점 파악하고 강관으로 보강된 하수처리시설에 대한 구조설계절차를 정립하였다. 본체 두께 및 보강링, 격벽을 고려한 제품을 설계하고 안전성을 검토하였다. 원통형 쉘의 구조재료로 사용되는 박막의 FRP에 대해 휨실험과 인장실험을 수행하여 재료특성을 파악하였다. 개인하수처리시설을 무보강, 강재 보강링 보강, 격벽 보강으로 설계한 제품의 현장실험을 통하여 본체의 변위와 응력의 변화를 계측 하여 파괴거동을 분석하였고 유한요소해석 결과와 비교, 검토하였다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제22권6호
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• pp.608-612
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• 2019

Gastric volvulus (GV) is an uncommon pathology, with 10-20% of cases occurring in children, typically before one year of age. It often occurs in people with congenital diaphragmatic hernias, intestinal malrotation, eventration of the diaphragm, paraesophageal hernias, wandering spleens, asplenism, or intra-abdominal adhesions. We report a rare case of chronic GV after left hemihepatectomy for hepatoblastoma in a child. The patient was a 9-year-old boy who complained of upper abdominal pain and postprandial upper abdominal distension for one year. At the age of 4 months, he was diagnosed with hepatoblastoma and had undergone left hemihepatectomy. The upper gastrointestinal contrast study revealed chronic organoaxial gastric volvulus. After a surgical procedure involving adhesiolysis and an anterior wall gastropexy, the patient improved and the symptoms resolved. Although GV is a rare disease, it should be suspected in a patient with a previous abdominal surgical history who is complaining of abdominal distension and pain.

• 한국추진공학회지
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• 제22권5호
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• pp.97-106
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• 2018

본 논문은 충격파 터널을 이용한 이중압축램프 흡입구 형상의 모델 스크램제트 시험에서 나타난 기술적 난제 및 그 해결 방안들을 정리하였다. 시험 설비 불시동, 격막 파편에 의한 유동 교란 및 모델 손상, 다중 분사에 따른 연료 제트 미발달, 그리고 짧은 시험 시간이 이에 해당한다. 파악된 기술적 난제들을 해결한 이후, 개선된 결과를 쉐도우그래프 이미지 및 저압관 끝단 전압력 측정 결과를 통해 확인하였다.

• Journal of Chest Surgery
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• 제34권6호
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• pp.441-446
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• 2001

배경: 전기 자극에 의한 호흡조율장치는 인공호흡기에 비하여 많은 장점이 있으나 임상적으로 제한된 환자에게만 적용이 되어왔고 일시적인 조율장치는 별로 보고가 없는 실정이다. 본 실험의 목적은 일시적 호흡보조장치가 개흉술 환자에서 임상응용이 가능한지를 알고자 동물실험을 하였다. 대상 및 방법: 전신마취 하에 5마리의 개를 대상으로 하였다. 좌측 5번째 늑간을 열고 자체 고안한 일시적 사용 가능한 전극을 좌측 횡격 신경 주위에 설치하고 근자극기에 연결하였다. 흉벽을 봉합하고 흉관을 수면 아래로 배관되게 설치하였다. 대동맥과 우심방에 Millar 카테터를 삽입하고 Swan-Ganz 카테터를 폐동맥에 삽입하였다. 마취가 깊게되어 자기 호흡이 약해진 경우 자극기를 작동하여 혈역학적 변화와 일회호흡량을 관찰하였다. 결과 일회호흡량은 143.3$\pm$51.3ml에서 272.3$\pm$87.4ml(p=0.004)로 증가하였고 우심방 이완기압은 0.7$\pm$4.0mmHg에서 -10.5$\pm$4.7mmHg(p=0.005)로 감소하였다. 폐동맥 이완기압도 6.1$\pm$2.5mmHg에서 1.2$\pm$4.8mmHg(p<0.001)로 감소하였다. 흉강내압의 변화를 알 수 있는 흉관의 물기등 높이는 10.3$\pm$6.7cmH$_{2}$O에서 20.0$\pm$5.3cmH$_{2}$O로 증가하였다. 결론: 일시적인 횡격막 조율장치는 개흉술 예에서 일시적으로 호흡을 보조해주는 간편한 방법이다. 자체 고안한 전극은 삽입 및 제거가 가능하며 이러한 음압을 이용한 호흡보조장치는 혈액순환에도 도움을 준다. 임상적으로 개흉술 환자에서 일시적인 호흡보조장치를 응용하면 호흡 및 순환기에도 도움을 줄 수 있을 것으로 사료된다.

• Wind and Structures
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• 제16권1호
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• pp.93-115
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• 2013

This paper describes a study of the influence of a dynamically flexible building structure on pressures inside and net pressures on the roof of low-rise buildings with a dominant opening. It is shown that dynamic interaction between the flexible roof and the internal pressure results in a coupled system that is similar to a two-degree-of-freedom mechanical system consisting of two mass-spring-damper systems with excitation forces acting on both the masses. Two resonant modes are present, the natural frequencies of which can readily be obtained from the model. As observed with quasi-static building flexibility, the effect of increased dynamic flexibility is to reduce the first natural frequency as well as the corresponding peak value of the admittance, the latter being the result of increased damping effects. Consequently, it is found that the internal and net roof pressure fluctuations (RMS coefficients) are also reduced with dynamic flexibility. This model has been validated from experiments conducted using a cylindrical model with a leeward end flexible diaphragm, whereby good match between predicted and measured natural frequencies, and trends in peak admittances and RMS responses with flexibility, were obtained. Furthermore, since significant differences exist between internal and net roof pressure responses obtained from the dynamic flexibility model and those obtained from the quasi-static flexibility model, it is concluded that the quasi-static flexibility assumption may not be applicable to dynamically flexible buildings. Additionally, since sensitivity analyses reveal that the responses are sensitive to both the opening loss coefficient and the roof damping ratio, careful estimates should therefore be made to these parameters first, if predictions from such models are to have significance to real buildings.

• 한국동물위생학회지
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• 제38권3호
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• pp.199-203
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• 2015

An 8-year old intact female poodle was presented to clinics due to abdominal distension, anorexia, and labored breath associated with pleural effusion. Intra-operative findings revealed multiple neoplasm of the greater omentum, involving anterolateral abdominal wall, sterna surface in the pleural cavity and diaphragm. These masses were 0.1~0.5 cm in diameter and extended to ovaries, pancreas, and serosal surface of stomach. Microscopically, most neoplastic cells had oval nuclei with prominent nucleoli and abundant eosinophilic cytoplasm. In deeper area, neoplastic acinus or glandular structures showed invaginated growth resembling adenocarcinoma. High mitotic figures were observed. By immunohistochemistry, the neoplastic cells were strong positive both cytokeratin and vimentin. The present case described for malignant mesothelioma in a dog. Our findings might be helpful for diagnosis and information and helped the clinics choose the treatment including chemotherapy such as cisplatin.

• Structural Engineering and Mechanics
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• 제17권3_4호
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• pp.527-537
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• 2004

Consequence-Based Engineering (CBE) is a new paradigm proposed by the Mid-America Earthquake Center (MAE) to guide evaluation and rehabilitation of building structures and networks in areas of low probability - high consequence earthquakes such as the central region of the U.S. The principal objective of CBE is to minimize consequences by prescribing appropriate intervention procedures for a broad range of structures and systems, in consultation with key decision makers. One possible intervention option for rehabilitating unreinforced masonry (URM) buildings, widely used for essential facilities in Mid-America, is passive energy dissipation (PED). After the CBE process is described, its application in the rehabilitation of vulnerable URM building construction in Mid-America is illustrated through the use of PED devices attached to flexible timber floor diaphragms. It is shown that PED's can be applied to URM buildings in situations where floor diaphragm flexibility can be controlled to reduce both out-of-plane and in-plane wall responses and damage. Reductions as high as 48% in roof displacement and acceleration can be achieved as demonstrated in studies reported below.