• Geomechanics and Engineering
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• 제36권6호
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• pp.527-543
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• 2024

In the implementation of most civil structures, especially underground, deep excavations with a vertical slope are required. Using flexible retaining walls is applied as one of the ways to stabilize vertical holes. Therefore, it is necessary to know the parameters affecting the performance of such walls in reducing their horizontal movement. In this research, by building a suitable laboratory model, the parameters of the amount of flexibility, the embedment depth of the wall, the type and number of tieback in the wall were investigated for 42 static laboratory models. The purpose of this research is to study the flexible retaining wall with helical tieback compared to simple tieback at different heights, which shows the best performance in terms of reducing horizontal displacement in proportion to increasing or decreasing flexibility. On the other hand, one of the parameters affecting the flexibility of the wall, which is its bending stiffness, was extracted by numerical software outputs and studied on the results such as relative flexibility, stiffness, safety and numerical stability of the wall.The results of this study show that among the parameters, in the first place, the effect of the type of tieback is inhibited and in the second place, the ratio of thickness to wall height is known as the most important parameter. the best performance for walls with the helical tiebacks in reducing their horizontal displacement can be economically, flexibly and stability assigned to a wall that tiebacks is in the range of H2/t to H4/t and its flexibility ratio is 2/3.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.618-621
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• 2003

이 연구의 목적은 현장 상황에 적절한 컨설턴트의 참여방안을 제안하는 것이다. 주의 깊게 고려된 컨설턴트의 참여는 공사비용과 기간을 단축시키고 공사 품질을 향상 시킬 수 있다. 연구의 첫 번째 단계는 커튼월 공사과정에 대한 문헌조사이다. 연구의 두 번째 단계는 공사에 관련된 전문가(설계자, 시공자. 전문시공업체, 컨설턴트)들에 대한 면담을 통한 커튼월 공사의 문제점을 분석하는 것이다. 이 때 우리는 컨설턴트가 이떻게 커튼일 공사의 문제를 해결할 수 있는지, 컨설턴트의 참여방안은 무엇인지 연구한다. 참여방안은 세 가지 방안으로 구성된다. 첫 번째 방안은 설계${\cdot}$시공단계 참여이고 두 번째 방안은 설계단계 참여, 참여, 세 번째 방안은 시공 단계 참여이다. 이러한 참여방안에 대한 검증은 전문가들의 면담을 통해 이루어졌다.

• Structural Engineering and Mechanics
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• 제11권6호
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• pp.605-616
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• 2001

The purpose of this study is to investigate the effect of the shear wall location in rigid frames on the dynamic behavior of a roof structure due to vertical and horizontal earthquake motions. The study deals with a gabled long span beam supported by two story rigid frames with shear walls. The earthquake response analysis is carried out to study the responses of the roof: vibration mode, natural period, bending moment and horizontal shear force of the bearings. The study results in the following conclusions: First, a large horizontal stiffness difference between the side frames is caused by the shear wall location, which results in a large vertical vibration of the roof and a large shear force at the side bearings. Second, in this case, the seismic design method for ordinary buildings is not useful in determining the distribution of the static equivalent loads for the seismic design of this kind of long span structures.

• IEIE Transactions on Smart Processing and Computing
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• 제6권2호
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• pp.76-84
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• 2017

This paper presents an efficient method for generating spatiotemporal images in order to detect leukocyte motion in microvessels. Leveraging the constraint that leukocytes move along the contour line of the blood vessel wall, our proposed method efficiently generates spatiotemporal images for leukocyte motion detection. To that end, translational motion caused by in vivo movement is first removed by a template matching method. Second, the blood vessel region is detected by an automatic threshold selection method in order to binarize temporal variance images. Then, the contour of the blood vessel wall is expressed via B-spline function. Finally, using the detected blood vessel wall's contour as an initial curve, the plasma layer for the most accurate position is determined in order to find the spatial axis via snake, and the spatiotemporal images are generated. Experimental results show that the spatiotemporal images are generated effectively through comparison of each step with three images.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.624-629
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• 2001

An experimental study was performed to investigate adiabatic wall temperature and heat transfer coefficient around on a module with longitudinal fin heat sink cooled by forced air flow. In the first method, inlet air flow(1-7m/s) and input power(3-5W) was varied after a heated module were placed on an adiabatic floor($320{\times}550{\times}1mm^{3}$). An adiabatic wall temperature was determinated to use liquid crystal film(LCF). In the second method to determinate heat transfer coefficient, inlet air flow(1-7m/s) and the heat flux of rubber heater($0.031-0.062\;W/cm^{2}$) was varied after an adiabatic module was placed on rubber heater covering up an adiabatic floor. In addition, surface oil-film visualization were performed to characterize the macroscopic flow-field around a module.

• 대한기계학회논문집B
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• 제24권2호
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• pp.224-232
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• 2000

Four turbulent $k-{\varepsilon}$ models (i.e., standard model, modified models with streamline curvature modification and/or preferential dissipation modification) are applied in order to analyze the turbulent flow of wall-attaching offset jet. For numerical convergence, this paper develops a method of slowly increasing the convective effect induced by skew-velocity in skew-upwind scheme (hereafter called Partial Skewupwind Scheme). Even though the method was simple, it was efficient in view of convergent speed, computer memory storage, programming, etc. The numerical results of all models show good prediction in first order calculations (i.e., reattachment length, mean velocity, pressure), while they show some deviations in ·second order (i.e., kinetic energy and its dissipation rate). Like the previous results obtained by upwind scheme, the streamline curvature modification results in better prediction, while the preferential dissipation modification does not.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.265-273
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• 2016

A water wall system is one of the most important components of a boiler in a thermal power plant, and it is a nonlinear Multi-Input and Multi-Output (MIMO) system, with 6 inputs and 3 outputs. Three models are developed and comp for the controller design, including a linear model, a multilayer feed-forward neural network (MFNN) model and an Echo State Network (ESN) model. First, the linear model is developed by linearizing a given nonlinear model and is analyzed as a function of the operating point. Second, the MFNN and the ESN are developed by using training data from the nonlinear model. The three models are validated using Matlab with nonlinear input-output data that was not used during training.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.65-69
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• 2007

Recently, the method of the apartment building design is changing from wall type to moment structure. Because of this reason, dry wall systems are used plentifully. This study examines the sound insulation performance of the light weight concrete panel using bottom ash. There is the difference of airborne sound isolation between laboratory and field test. For the purpose of searching deviation, we use the prediction tool(Insul 6.0). First, we calculated the prediction data and measured the sound isolation in the wall at the lab. Then, we measured it in the field and compared them. At the base of these datum, we measured the difference.

• Structural Engineering and Mechanics
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• 제52권6호
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• pp.1177-1191
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• 2014

Reinforced concrete (RC) shear walls are one of the most commonly used lateral-load resisting systems in high-rise buildings. RC Parallel redundancy walls studied herein consist of two parts nested to each other. These two parts have different mechanical behaviors and energy dissipation mechanisms. In this paper, experimental studies of four 1/2-scale specimens representing this concept, which are subjected to in-plane cyclic loading, are presented and test results are discussed. Two specimens consist of a wall frame with barbell-shaped walls embedded in it, and the other two consist of a wall frame and braced walls nested each other. The research mainly focuses on the failure mechanism, strength, hysteresis loop, energy dissipation capacity and stiffness of these walls. Results show that the RC parallel redundancy wall is an efficient lateral load resisting component that acts as a "dual" system with good ductility and energy dissipation capacity. One main part absorbs a greater degree of the energy exerted by an earthquake and fails first, whereas the other part can still behave as an independent role in bearing loads after earthquakes.

• Journal of Chest Surgery
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• 제25권10호
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• pp.1107-1111
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• 1992

Extraskeletal Ewing`s sarcoma was first reported by L. Angervall and F.M. Enzinger in 1975. Clinically the tumor affects mainly young adults and children The extraskeletal Ewing`s sarcoma are mainly involved the soft tissues of the trunk and lower extremity. Microscopically. extraskeletal Ewing`s sarcoma is indistinguishable from the Ewing`s sarcoma of bone. We recently experienced a case of extraskeletal Ewing`s sarcoma of the anterior chest wall in a 13-year old female. The patient underwent local wide excision and postoperative radiation and combind chemotherapy were done. This group of tumors has been rarely reported in Korea. We presented a case of extraskeletal Ewing`s Sarcoma in the anterior chest wall with reviw of world literature.