• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.404-410
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• 2001

A new thermal type fluid level transmitter was designed and tested at the HITROL R&D institute. The relation of heat transfer and electric resistance was adopted as an operation principle. The length of a fabricated level transmitter was two meters and a water under normal temperature was used as a working fluid for the experiment Finally, the new product could have a high precision, acceptable accuracy and reasonable response time. Foreign-made level transmitter of this type is under in use for measuring water level of containment building in nuclear power plants so far. It is expected that new product will substitute it.

• 한국전산유체공학회:학술대회논문집
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• 2009.11a
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• pp.1-1
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• 2009

In this presentation, I talk about various fluid simulation methods that have been developed for computer graphics special effects since 1996. They are all based on CFD but sacrifice physical reality for visual plausability and time. But as the speed of computer increases rapidly and the capability of GPU (graphics processing unit) improves, methods for more physical realism have been tried. In this talk, I will focus on four aspects of fluid simulation methods for computer graphics: (1) particle level-set methods, (2) particle-based simulation, (3) methods for exact satisfaction of incompressibility constraint, and (4) GPU-based simulation. (1) Particle level-set methods evolve the surface of fluid by means of the zero-level set and a band of massless marker particles on both sides of it. The evolution of the zero-level set captures the surface in an approximate manner and the evolution of marker particles captures the fine details of the surface, and the zero-level set is modified based on the particle positions in each step of evolution. (2) Recently the particle-based Lagrangian approach to fluid simulation gains some popularity, because it automatically respects mass conservation and the difficulty of tracking the surface geometry has been somewhat addressed. (3) Until recently fluid simulation algorithm was dominated by approximate fractional step methods. They split the Navier-Stoke equation into two, so that the first one solves the equation without considering the incompressibility constraint and the second finds the pressure which satisfies the constraint. In this approach, the first step introduces error inevitably, producing numerical diffusion in solution. But recently exact fractional step methods without error have been developed by fluid mechanics scholars), and another method was introduced which satisfies the incompressibility constraint by formulating fluid in terms of vorticity field rather than velocity field (by computer graphics scholars). (4) Finally, I want to mention GPU implementation of fluid simulation, which takes advantage of the fact that discrete fluid equations can be solved in parallel.

• Tuberculosis and Respiratory Diseases
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• v.39 no.3
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• pp.278-281
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• 1992

Air fluid level in a large ring shadow poses a diagnostic problem. But a new development of fluid level in preexisting bullous lesion is another problem. A 60 year old man with chronic obstructive lung disease was noticed to have multiple bullae. A few years later fluid level was newly developed in some of the bullae. Fluid level persisted for several months and later completely filled the space. Surgical exploration revealed pus collection in the bullae and epidermoid carcinoma in the nearby bronchi.

• Smart Media Journal
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• v.4 no.2
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• pp.9-16
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• 2015

Fluids appear in innumerable phenomena; therefore, it is interesting to reproduce those phenomena by computer graphics techniques. However, this process is not trivial. We work with a fluid simulation that uses Navier-Stokes equations to model the fluid, a semi-Lagrangian approach to solve it and the level set method to track the surface of the fluid. Modified versions of the Navier-Stokes equations for computer graphics allow us to create a wide diversity of effects. In this paper, we propose a technique that allows us to integrate a force inspired by surface tension into the model. We describe which information we need and how to modify the model with this new approach. We end up with a modified simulation that has additional effects that might be suitable for computer graphics purposes. The effects that we are able to recreate are small waves and droplet-like formations close to the surface of the fluid. This model preserves the overall behavior governed by the Navier-Stokes equations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1073-1078
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• 2003

This paper presents the vibration characteristics of a cantilever beam in contact with a fluid using a PZT actuator and PVDF film. dynamic behaviors of a flexible beam-water interaction system are examined. The effect of the liquid level on free vibration of the composite beam in a partially liquid-filled circular cylinder is investigated. The coupled system is subject to an undisturbed boundary condition un the fluid domain. In the vibration analysis of a wetted beam. the decoupled analyses between beam and fluid have been conventionally employed by considering first the composite beam vibration in the all and secondly Performing the correction taking account for surrounding fluid effects. That is, this investigation was to look at how natural frequencies, mode shapes. and damping are affected by liquid level variations. The signals from the sensor according to the applied input voltage are digitalized and filtered in order to obtain the dynamic characteristics of the composite beam in contact with fluid. It was found that the coupled natural frequencies decreased with the fluid level for the identical composite beam due to added mass effect. In case of the free-free boundary condition, the natural frequency gently decreased at fluid water level between 20% and 80% in the first tending mode and we found out the bends of stair shape for added mass effect of the fluid.

• Interaction and multiscale mechanics
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• v.5 no.3
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• pp.287-318
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• 2012

We apply a partitioned-solution (iterative-staggered) coupling method based on a fixed Eulerian mesh with the level set function to a large-deformation fluid-structure interaction (FSI) problem where a large-deformable thin structure moves in a high-speed flow field, as an airbag does during deployment. This method combines advanced fluid and structure solvers-specifically, the constrained interpolation profile finite element method (CIP-FEM) for fluid Eulerian mesh and large-deformable structural elements for Lagrangian structural mesh. We express the large-deformable interface as a zero isosurface by the level set function, and introduce virtual nodes with level sets and structural normal velocities to generate the level set function according to the large-deformable interfacial geometry and enforce the kinematic condition at the interface. The virtual nodes are located in the direction normal to the structural mesh. It is confirmed that application of the method to unfolded airbag deployment simulation shows the adequacy of the method.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.6
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• pp.744-752
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• 2003

A level set method is combined with the volume-of-fluid method so that the coupled method can not only calculate an interfacial curvature accurately but also can achieve mass conservation well. The coupled level set and volume-of-fluid(CLSVOF) method is efficiently implemented by employing an interface reconstruction algorithm which is based on the explicit relationship between the interface configuration and the fluid volume function. The CLSVOF method is applied for numerical simulation of droplet impact on solid surfaces with variable contact angles. The numerical results are found to preserve mass conservation and to be in good agreement with the data reported in the literature. Also, the present method proved to be applicable to the complex phenomena such as breakup and rebound of a droplet.

• Journal of Nutrition and Health
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• v.38 no.2
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• pp.117-124
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• 2005

We investigated the effects of prolonged exposure in hot environmental condition and ingestion of fluid on various physiological variables including plasma glucose, lactate, the rating of perceived exertion (RPE), and heart rate as well as golf putting performance. Six male professional golfers were voluntarily participated in three different putting trials which were separated by seven days of time interval period. Three different putting trials were conducted at either 20℃ or 32℃, or 32℃ + Fluid ingestion. Performing 32℃ + Fluid ingestion trial, all subject ingested sport drink as much as their body mass was decreased. For each experiment, all subjects were undertaken total 48 putting, which separated by four x 12 putting in four different time points (i.e., Rest, 1 hr, 2 hr, and 3 hr). Plasma glucose concentration was significantly decreased with hot ambient condition but it was almost fully recovered by fluid ingestion. Plasma lactate concentration was significantly higher when subjects were exposed in hot environmental condition, and it did not change with fluid ingestion. There was a no different in putting performance and psychological fatigue level (performed by GRID test) at any environmental conditions. The RPE, commonly used for evaluating of physical fatigue level, was significantly dropped by fluid ingestion which indicates lower physical fatigue level. In addition to this, heart rate (HR) was also significantly decreased after fluid ingestion. Based on these results, it was concluded that the ingestion of fluid during prolonged exposure in hot ambient condition decrease the degree of physical fatigue levels and heart rate, which will possibly improve the golf performance when exposed in extreme weather condition in summer. (Korean J Nutrition 38(2): 117～124, 2005)

• The Journal of Korean Society for School & Community Health Education
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• v.15 no.3
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• pp.17-30
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• 2014

Objectives: The purpose of this study was to investigate the status of exposure to blood and body fluid and factors affecting on blood and body fluid exposure of nursing students including knowledge, performance regarding standard precautions. Methods: 280 nursing students in D-city and S-city participated in this study. Data collection was conducted from January to March 2012. Students' knowledge and performance on standard precautions of infection control in hospitals were measured using the measurement developed by Hong(2010). Data analysis was performed using descriptive statistics, t-test, one way-ANOVA, ${\chi}^2-test$, Pearson correlation coeficient, logistic regression by the SPSS WIN 18.0 program. Results: 58.6 percent of subjects experienced a exposure to blood and body fluid. The level of nursing students' knowledge level regarding standard precautions was $22.44{\pm}2.11$ and performance level was $4.31{\pm}0.50$. The factors affecting on blood and body fluid exposure of nursing students were knowledge level and education type about infection control. Conclusions: Based on the findings of this study, to decrease the exposure to blood and body fluid of nursing students, a proper education need to be stressed to improve nursing students' infection control knowledge and awareness.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.97.3-97
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• 2002

This paper presents the vibration characteristics of an intelligent cantilever beam in contact with a fluid using a PZT actuator and PVDF film. The dynamic behaviors of a flexible beam-water interaction system are examined. The effect of the liquid level on free vibration of the composite beam in a partially liquid-filled circular cylinder is investigated. The coupled system is subject to an undisturbed boundary condition in the fluid domain. It was found that the coupled natural frequencies decreased with the fluid level for the identical composite beam due to added mass effect. In case of the free-free boundary condition, the natural frequency gently decreased at fluid water level betw...