• Structural Engineering and Mechanics
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• 제45권2호
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• pp.169-182
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• 2013

The mechanical behavior of rectangular foundation plates with perimetric beams and internal stiffening beams of the plate is herein analyzed, taking the foundation design into account. A series of dimensionless parameters related to the geometry of the studied elements were defined. In order to generalize the problem statement, an initial settlements was considered. A numeric procedure was developed for the resolution by means of the Finite Differences Method that takes into account the stiffness of the plate, the perimetric and internal plate beams and the soil reaction module. Iterative algorithms were employed which, for each of the analyzed cases, made it possible to find displacements and reaction percentages taken by the plate and those that discharge directly into the perimetric beams, practically without affecting the plate. To enhance its mechanical behavior the internal stiffening beams were prestressed and the results obtained with and without prestressing were compared. This analysis was made considering the load conditions and the soil reaction module constant.

• Tuberculosis and Respiratory Diseases
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• 제46권3호
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• pp.420-425
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• 1999

저자들은 심한 청색증을 동반한 만성 간질환에서, 폐 내 동정맥 단락과 동맥혈 저산 소혈증을 보인 간폐증 후군 1예를 경험하였기에 문헌고찰과 함께 보고한다. 단순흉부 X-선 사진에는 망상결절이 하엽 기저부에 주로 분포하였고 고해상 전산화 단층영상에서 확장된 폐혈관이 늑막까지 연장되어 보이고, 특히 비정상적으로 증가된 폐혈관종말지의 확장이 늑막하 폐에 분포하였다. 핵의학 관류검사 및 조영 심초음파 검사를 통해 폐내 단락을 진단하여 보고하는 바이다.

• Structural Engineering and Mechanics
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• 제84권6호
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• pp.767-782
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• 2022

In this paper, the nonlinear vibration behavior of the spiral stiffened multilayer functionally graded (SSMFG) cylindrical shells exposed to the thermal environment and a uniformly distributed harmonic loading using a semi-analytical method is investigated. The cylindrical shell is surrounded by a nonlinear viscoelastic foundation consisting of a two-parameter Winkler-Pasternak foundation augmented by a Kelvin-Voigt viscoelastic model with a nonlinear cubic stiffness. The distribution of temperature and material constitutive of the stiffeners are continuously changed through the thickness direction. The cylindrical shell has three layers consisting of metal, FGM, and ceramic. The interior layer of the cylindrical shell is rich in metal, while the exterior layer is rich in ceramic, and the FG material is located between two layers. The nonlinear vibration problem utilizing the smeared stiffeners technique, the von Kármán equations, and the Galerkin method has been solved. The multiple scales method is utilized to examine the nonlinear vibration behavior of SSMFG cylindrical shells. The considered resonant case is 1:3:9 internal resonance and subharmonic resonance of order 1/3. The influences of different material and geometrical parameters on the vibration behavior of SSMFG cylindrical shells are examined. The results show that the angles of stiffeners, temperature, and elastic foundation parameters have a strong effect on the vibration behaviors of the SSMFG cylindrical shells.

• 한국산학기술학회논문지
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• 제17권10호
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• pp.331-337
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• 2016

높이가 5m와 10m인 사면부와 사면하부지반으로 이루어진 지반조건에 대하여 여러 가지 강도정수를 갖는 사면하부지반을 가정하고 안정해석을 수행한 결과 사면하부 끝단에 억지말뚝을 설치할 수 있는 사면하부지반의 강도정수의 범위를 얻을 수 있었고 표로써 제시하였다. 사면높이가 5m인 경우 사면하부지반의 점착력이 10kPa일 때 내부마찰각은 $15^{\circ}$인 경우까지 억지말뚝의 설치가 가능하며 점착력이 20kPa와 25kPa인 경우 내부마찰각이 $0^{\circ}$일 때만 억지말뚝의 설치가 가능하였다. 사면높이가 10m인 경우 사면하부지반의 점착력이 10kPa일 때 내부마찰각은 $20^{\circ}$인 경우까지 억지말뚝의 설치가 가능하며 점착력이 40kPa, 45kPa 그리고 50kPa인 경우에는 내부마찰각이 $0^{\circ}$인 경우만 억지말뚝의 설치가 가능함을 알 수 있었다. 가정한 사면에 적용한 억지말뚝에 대한 해석결과에 따르면 억지말뚝의 길이와 최대 휨모멘트의 크기는 내부마찰각의 존재여부에 큰 영향을 받음을 알 수 있었다. 사면하부지반의 내부마찰각이 $0^{\circ}$인 경우 필요한 억지말뚝의 길이 $D_s$와 d는 각각 내부마찰각이 $5^{\circ}$인 경우에 비해 4.6배와 8.0배 컸다. 사면하부지반의 내부마찰각이 $0^{\circ}$인 경우 억지말뚝에 발생하는 최대 휨모멘트는 내부마찰각이 $5^{\circ}$인 경우에 비해 24.6배 컸다. 억지말뚝을 적용한 사면하부지반의 내부마찰각이 $0^{\circ}$인 경우 억지말뚝의 길이 및 억지말뚝에 발생하는 최대 휨모멘트의 크기가 상당히 커서 억지말뚝의 적용을 어렵게 함을 알 수 있었다. 본 연구결과를 통해 볼 때 비배수상태에 있는 포화점토지반상에 성토를 하는 경우에는 압밀이 발생하는 시간적 여유를 갖도록 완속 성토함으로써 억지말뚝의 길이와 발생 최대 휨모멘트를 대폭적으로 감소시킬 수 있을 것으로 기대된다.

• 문화기술의 융합
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• 제7권4호
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• pp.67-74
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• 2021

본 연구는 장애인평생교육의 내부 토대를 탐색하는 데 목적을 두어 실시되었다. 이를 위한 내용 의미의 구성체계에 대해 장애인평생교육을 기준으로 주체를 의미하는 '의(of)', 목적을 의미하는 '을 위한(for)', 실천적 주요 기반을 의미하는 '으로부터(from)'와 같이 세 가지 요소로 분류 구성하였다. 연구 방법은 장애인평생교육 지원체제의 내부 토대를 형성하기 위해 학문적 근거나 실천적 적용 모델 및 방안을 논의하거나 실제화한 선행연구를 통한 문헌분석이 일차적으로 고려되었으며, 이차적으로는 문헌분석의 근거를 기초로 하여 연구 내용의 구체성을 제고하기 위해 전문가 회의를 실시하였다. 연구 내용은 장애인평생교육의 내부 토대를 형성하기 위하여 요구되는 주체, 목적, 실천적 주요기반을 종합하여 발달장애 토대화와 학교 토대화와 같이 크게 두 가지로 제시되었다. 위 두 가지 토대 요인에 의하여 장애인평생교육 지원체제의 내부적 보편성을 일차적으로 확립하고, 연계적으로 감각장애 유형 및 일반평생교육 분야와 융합하는 측면이 반영되었다. 연구 결과, 장애인평생교육 지원체제 전반의 장기적 안정성 측면이 분석되었다.

• Geomechanics and Engineering
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• 제38권4호
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• pp.381-395
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• 2024

With the wide application of urban subway tunnels, the foundation pits of new stations and existing subway tunnels are becoming increasingly close, and even zero-distance close-fitting construction has taken place. To optimize the construction support scheme, the existing tunnel's vertical displacement is theoretically analyzed using the two-stage analysis method to understand the action mechanism of the construction of zero-distance deep large foundation pits on both sides of the existing stations; a three-dimensional numerical calculation is also performed for further analysis. First, the additional stress field on the existing tunnel caused by the unloading of zero-distance foundation pits on both sides of the tunnel is derived based on the Mindlin stress solution of a semi-infinite elastic body under internal load. Then, considering the existing subway tunnel's joints, shear stiffness, and shear soil deformation effect, the tunnel is regarded as a Timoshenko beam placed on the Kerr foundation; a sixth-order differential control equation of the tunnel under the action of additional stress is subsequently established for solving the vertical displacement of the tunnel. These theoretical calculation results are then compared with the numerical simulation results and monitoring data. Finally, an optimized foundation pit support scheme is obtained considering the pit corner effect and external corner failure mode. The research shows a high consistency between the monitoring data,analytical and numerical solution, and the closer the tunnel is to the foundation pit, the more uplift deformation will occur. The internal corner of the foundation pit can restrain the deformation of the tunnel and the retaining structure, while the external corner can cause local stress concentration on the diaphragm wall. The proposed optimization scheme can effectively reduce construction costs while meeting the safety requirements of foundation pit support structures.

• Geomechanics and Engineering
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• 제34권1호
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• pp.17-27
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• 2023

Taking a subway shield tunnel in a certain section of Zhengzhou Metro Line 5 as an example, the field tests of shield cutting cement-soil monopile composite foundation were carried out. The load and internal force of the tunnel lining under the action of composite foundation were tested on-site and the distribution characteristics and variation laws of earth pressure around the tunnel under the load holding state of the composite foundation were analyzed. Five different load combinations (i.e., overburden load theory + q₀, Terzaghi's theory + q₀, Bierbaumer's theory + q₀, Xie's theory + q₀, and the proposed method (the combination of compound weight method and Terzaghi's theory) + q₀) were used to calculate the internal force of the tunnel structure and the obtained results were compared with the measured internal force results. The action mode of earth pressure on the tunnel lining structure was evaluated. Research results show that the earth pressure obtained by the calculation method proposed in this paper was more consistent with the measured value and the deviation between the two was within 5%. The distribution of the calculated internal force of the tunnel structure was more in line with the distribution law of field test data and the deviation between the calculated and measured values was small. This effectively verified the rationality and applicability of the proposed calculation method. Research results provided references for the design and evaluation of shield tunnels under the action of composite foundations.

• 대한한방내과학회지
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• 제36권2호
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• pp.189-199
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• 2015

Objectives: The marker substances of cultivated wild ginseng pharmacopuncture that may not be detected during the process of steaming remain controversial. We developed a combined cultivated wild ginseng pharmacopuncture that contains all the marker substances. The aim of this experiment was to investigate the marker substances and test the toxicity of the combined cultivated wild ginseng pharmacopuncture. Methods: The marker substances were detected using HPLC. Intravenous injection toxicity studies were conducted at Medvill, an authorized institution for non-clinical studies, under the regulations of Good Laboratory Practice. We observed survival rates, abnormal behaviors, weight changes, gross findings in autopsy, blood biochemical properties, and histological abnormalities of organs such as the liver and kidney. Results: HPLC data showed that ginsenosides Rg1, Rb1, and Rg3 were detected at concentrations of 19.29, 47.64, and 3.02 μ g /ml, respectively. Administration of combined cultivated wild ginseng pharmacopuncture resulted in no dead animals or significant toxicological changes. Conclusions: The combined cultivated wild ginseng pharmacopuncture contains all the marker substances and is a relatively safe treatment medium. Further studies should be conducted to confirm the present findings.

• KEPCO Journal on Electric Power and Energy
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• 제2권3호
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• pp.461-467
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• 2016

부유 이송식 해상풍력 기초를 목표 지점에 설치하기 위해서는 내부의 중공부에 해수를 주입하여 착저 시키게 되는데, 그 과정에서 중량 및 무게 중심과 부력중심이 변하게 되어 부유식 기초가 불안정해 질 수 있다. 부유 이송식 기초의 동적안정성 해석은 기초 외부의 수력학적 하중과 6-자유도 운동을 하게 되는 기초에 작용하는 파도와 조류 하중 및 설치 과정에서 기초 내부의 중공부로 투입되는 해수의 무게중심 이동까지 동시에 고려해야 하는 복잡한 문제이다. 따라서 본 연구에서는 3차원 비정상 CFD 기법과 다물체 동역학 기법을 연성 (coupling)한 정밀 해석기법을 적용하여 부유 이송식 기초 내부 물의 슬로싱 운동까지 고려한 동적안정성 해석을 수행하고 특성을 분석하였다.

• Nutrition Research and Practice
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• 제8권1호
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• pp.94-102
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• 2014

Diet attrition and failure of long term treatment are very frequent in obese patients. This study aimed to identify pre-treatment variables determining dropout and to customise the characteristics of those most likely to abandon the program before treatment, thus making it possible to modify the therapy to increase compliance. A total of 146 outpatients were consecutively enrolled; 73 patients followed a prescriptive diet while 73 followed a novel brief group Cognitive Behavioural Treatment (CBT) in addition to prescriptive diet. The two interventions lasted for six months. Anthropometric, demographic, psychological parameters and feeding behaviour were assessed, the last two with the Italian instrument VCAO Ansisa; than, a semi-structured interview was performed on motivation to lose weight. To identify the baseline dropout risk factors among these parameters, univariate and multivariate logistic models were used. Comparison of the results in the two different treatments showed a higher attrition rate in CBT group, despite no statistically significant difference between the two treatment arms (P = 0.127). Dropout patients did not differ significantly from those who did not dropout with regards to sex, age, Body Mass Index (BMI), history of cycling, education, work and marriage. Regardless of weight loss, the most important factor that determines the dropout appears to be a high level of stress revealed by General Health Questionnaire-28 items (GHQ-28) score within VCAO test. The identification of hindering factors during the assessment is fundamental to reduce the dropout risk. For subjects at risk, it would be useful to dedicate a stress management program before beginning a dietary restriction.