• Title/Summary/Keyword: sudden damage

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Clinical Evaluation of Mitral Valve Replacement (승모판 치환술의 임상적 고찰)

  • Kim, Sang-Hyeong;Jeong, Jeong-Gi
    • Journal of Chest Surgery
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    • v.24 no.9
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    • pp.861-869
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    • 1991
  • From August, 1986 to December, 1989, mitral valve replacement was performed in 93 patients. Of the valve implanted, 42 were Duromedics, 35 St. Jude Medical, 15 Carpenter-Edwards and 1 Ionescu-Shiley. The hospital mortality rate was 3.2%[3 patients] and the late mortality rate was 4.3% [4 patients]. The causes of hospital death were LV rupture in 1, renal failure in 1 and hypoxic brain damage in l. The causes of late death were congestive heart failure in 1 and sudden death in 3. Follow-up was done on 78 surviving patients; mean follow-up period was 29.22$\pm$9.09 months. The actual survival rate was 91.8% at 4 years. We concluded, therefore, that good clinical results could be achieved with mitral valve replacement in short-term follow-up, and long-term follow-up is also necessary.

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A Study on the Noise and Vibration Reduction Effect Depending on Dynamic Property of Slab (바닥판의 동적특성에 따른 소음진동 저감성능에 관한 연구)

  • 황재승;김선우;송진규;서재란
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.04a
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    • pp.259-266
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    • 2004
  • The vibration of slab causes a sudden change of air pressure in the interface between slab and air to create structure home sound. Floor impact noise induced from the vibration of slab became one of the hottest social issues in these day, and it took the biggest parts of the cause of damage in environmental dispute. Because the structure borne sound of slab is different from the dynamic characteristic of slab, it is required more precise vibroacaustic analysis. In this study, we was trying to understand by what mechanism the slab noise is induced from the slab vibration and the relationship between the dynamic propety of slab and the noise is shown by the numerical simulation.

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Acute Rotator Cuff Tears due to Low Voltage Electrical Injury: A Case Report

  • Yoo, Jae Hyun;Rhee, Sung-Min;Shim, Ho Yong;Lee, Jae Sung
    • Clinics in Shoulder and Elbow
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    • v.21 no.2
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    • pp.101-104
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    • 2018
  • Since shoulder have a higher proportion of muscle which would have low electrical resistance, there could be more electrical damage to the rotator cuff muscles. We present a patient with acute rotator cuff tear by sudden uncontrolled jerking contractions caused by an electrical shock. A case of 42-year-old man with acute rotator cuff tear due to electrical injury to the shoulder was presented. Magnetic resonance imaging showed a full thickness tear and an undulating appearance of the peripheral end of the torn supraspinatus and infraspinatus muscle, suggesting an acute complete rupture. By arthroscopic surgery, the torn rotator cuff tendons were repaired with a suture bridge technique. At the final follow-up, the patient had a full, pain-free range of motion and had fully recovered shoulder muscle power.

Patch load resistance of longitudinally stiffened webs: Modeling via support vector machines

  • Kurtoglu, Ahmet Emin
    • Steel and Composite Structures
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    • v.29 no.3
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    • pp.309-318
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    • 2018
  • Steel girders are the structural members often used for passing long spans. Mostly being subjected to patch loading, or concentrated loading, steel girders are likely to face sudden deformation or damage e.g., web breathing. Horizontal or vertical stiffeners are employed to overcome this phenomenon. This study aims at assessing the feasibility of a machine learning method, namely the support vector machines (SVM) in predicting the patch loading resistance of longitudinally stiffened webs. A database consisting of 162 test data is utilized to develop SVM models and the model with best performance is selected for further inspection. Existing formulations proposed by other researchers are also investigated for comparison. BS5400 and other existing models (model I, model II and model III) appear to yield underestimated predictions with a large scatter; i.e., mean experimental-to-predicted ratios of 1.517, 1.092, 1.155 and 1.256, respectively; whereas the selected SVM model has high prediction accuracy with significantly less scatter. Robust nature and accurate predictions of SVM confirms its feasibility of potential use in solving complex engineering problems.

Effects of Sodium Cyanide (NaCN) on the Endogenous Rhythm of the Oxygen Consumption Rate in the Black Rockfish Sebastes schlegeli

  • Kim, Wan-Soo;Kim, Jong-Wook;Lee, Jae-Hak;Huh, Sung-Hoe
    • Ocean Science Journal
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    • v.43 no.2
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    • pp.107-113
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    • 2008
  • Laboratory bioassays were conducted to test the acute toxicity effects of sudden exposure to sodium cyanide (NaCN) on the endogenous rhythm of the oxygen consumption rate (OCR) in the black rockfish Sebastes schlegeli. The OCR of the black rockfish(n = 14, total length = $20.4{\pm}1.16\;cm$, wet weight = $158{\pm}25\;g$) was measured with an automatic intermittent-flow-respirometer. OCR decreased significantly when experimental fish were exposed to NaCN. When exposed to 10 ppb NaCN, fish were able to recover their OCR rhythmic activities. When fish were exposed to 20 ppb, however, the metabolic activity rhythms were not recovered. These results suggest that exposure to NaCN concentrations over 20 ppb cause severe physiological damage to the endogenous rhythms of black rockfish.

Fatigue Life Prediction using Fuzzy Reliability theory (퍼지신뢰성이론에 의한 피로수명 예측)

  • 심확섭;이치우;장건의
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.672-675
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    • 1995
  • Because of a sudden growth of the research of fatigue failure, recent machines or structures have been designed by damage tolerance design in many fields. Consequently, it is the most primary factor to clarity the specific character of fatique failure in the design of machines or structures considering reliability. A statistical analysis is required to analyze the outcome of an experiment or a life estimate by reason of that fatigue failure contains lots of random elements. Reliability analysis which has tukenn the place of the existing analyses in the consideration of the uncertainty of a material, is a very efficient way. Even reliability analysis, however, is not a perfect way to analyses the uncertainties of all the materials. This thesis would refer to a newly conceived data analysis that the coefficient of a system could cause the ambiguity of the relationship of an input and output.

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A Seismic Design of RC Underground Subway Structure (지중 RC 도시지하철고 구조물의 내진설계)

  • Jeong, Jae-Pyoung;Im, Tong-Won;Lee, Seong-Lo;Kim, Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.357-362
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    • 2000
  • This Paper presents dynamic analysis of underground R/C Subway Structure, subjected to seismic actions. Earthquakes brought serious damage to RC subway Structure. Foe studying the collapse mechanism of underground RC Subway, seismic of a subway station is simulated in using FEM program ASP2000 of two-dimension based on the path dependent RC elastic model, soil foundation and interfacial models. The shear failure of intermediate vertical columns is founds to be the major cause of the structural collapse. According to FEM simulation of the failure mechanism, it is considered that the RC column would lose axial load carrying capacity after the occurrence of the localized diagonal shear cracks , and sudden failure of the outer frame would be followed. Specially, the shear stress in the middle slab reaches maximum shear capacity. So, the Structure would fail in the middle slab as a result of erasing the vertical ground motion computation.

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Clinical Results of Mitral Valve Replacement (승모판 치환술의 임상 성적)

  • Na, Guk-Ju;Kim, Sang-Hyeon;Kim, Gwang-Hyu
    • Journal of Chest Surgery
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    • v.28 no.12
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    • pp.1113-1121
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    • 1995
  • From August, 1986 to December, 1993, mitral valve replacement was performed in 178 patients. Of the valve implanted, 114 were St.Jude Medical, 47 Duromedics, 16 Carpenter-Edward and 1 Ionesc-Shiley. The hospital mortality rate was 2.8%[5 patients and the late mortality rate was 7.5%[13 patients . The causes of hospital death were LV rupture in 1, renal failure in 1, cardiac tamponade in 1, valve malfunction in 1 and hypoxic brain damage in 1. The causes of late death were sudden death in 6, congestive heart failure in 4, brain ischemic injury in 3. Follow-up was done on 155 surviving patients : mean follow-up period was 50.94$\pm$8.04 months. The actual survival rate was 88.2% at 8 years. We concluded, therefore, that good clinical results could be achieved with mitral valve replacement in mid-term follow-up, and long-term follow-up is also necessary.

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Thermal Shock Behavior of Barium Titanate Ceramics

  • Jae Yeon Kim;Young Wook Kim;Kyeong Sik Cho;June Gunn Lee
    • The Korean Journal of Ceramics
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    • v.3 no.3
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    • pp.195-198
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    • 1997
  • Post-firing process of electronic ceramic, such as electroding and encapsultion with resin, often causes damage by thermal shock. The thermal shock behavior of $BaTiO_3$ ceramics was investigated by the down-quench test, where the relative strength retained is determined after the sample is quenched from an elevated temperature into a fixed temperature bath. The critical temperature drop, $\DeltaTc$, was evaluated for three kinds of sintered $BaTiO_3$ ceramics, which were formed by extrustioin, uniaxial pressing using granules, and uniaxial pressing using powders. A drastic loss in strength caused by microcracking was observed for the specimens quenched with $\DeltaT\geq150^{\circ}C$. This concentp can be adopted as a method of the quality control by monitoring the sudden drop of the strength of capacitor products after each exposure to heat.

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Sink holes material damage and mental harm analysis and risk assessment studies -Focusing on the incidents surrounding the construction site- (씽크홀의 물적손상과 정신적 피해분석 및 위험성 평가연구 -건설현장 주변의 사고사례를 중심으로-)

  • Lim, Jin Sang;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.17 no.4
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    • pp.153-160
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    • 2015
  • Recent News patrons of incidents can be called sinkhole that occurred one after another (Sink Hole). Due to this anytime, anywhere I do not know how the land is turned off worry and anxiety is the reason why you can never be dismissed as exaggerated. As we have seen today through the video, the vehicle was traveling on a road or pedestrian who was walking down the street they look out of the basement of a sudden they still come to mind vividly. Here, examples and corresponding measures to prevent the sinkhole off the ground, including the causes and impact on society because of this that occurred, and policy measures and abroad are evaluated with respect to what it is.