• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 추계학술대회 논문집
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• pp.177-181
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• 1992

For this study, a new hydraulic control unit which designed in compact compared to the currently manufactured hydraulic control unit for ABS has been introduced and its experimental model has been made. Based on the basic principle as ABS using braking force characteristics against slip ratio of tire, half car model bench tester were designed and made to make an analysis of braking effect of the new hydraulic control unit. Experiment for slip ratio characteristics of tire has been carried out using half car model bench tester and with the results of this experiment and control experiment of the new hyraulic control unit, the experiment result of the characteristics of tire and control experiment were compared to find out their correspondence. And furthermore, slip ratio characteristics of the new hydraulic control unit has been studied based on the experiment result of slip ratio characteristics of tire through simulation and compared with experiment result.

• 한국생산제조학회지
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• 제19권6호
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• pp.797-803
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• 2010

A method has been developed to tune the static stiffness at a rotation joint considering the whole machine tool system by interactive use of finite element method and experiment. This paper describes the procedure of this method and shows the results. The method uses the static experiment on measurement model which is set-up so that the effects of uncertain factors can be excluded. For FEM simulation, the rotation joint model is simplified using only spindle, bearing and spring. At the rotation joint, the damping coefficient is ignored, The spindle and bearing is connected by only spring. By static experiment, 500 N is forced to the front and behind portion of spindle and the deformation is measured by capacitive sensor. The deformation by FEM simulation is extracted with changing the static stiffness from the initial static stiffness considering only rotation joint. The tuning static stiffness is obtained by exploring the static stiffness directly trusting the deformation from the static experiment. Finally, the general tuning method of the static stiffness of machine tool joint is proposed using the force stream and the modal analysis of machine tool.

• 한국콘텐츠학회논문지
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• 제13권11호
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• pp.1046-1057
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• 2013

본 연구의 목적은 일개 대학 간호과 3학년 학생 145명을 대상으로 학습유형별 시뮬레이션 교육 전 후 자기효능감, 문제해결능력, 임상수행능력 차이를 파악하여 학습유형별 시뮬레이션 교육을 제공하기 위한 기초자료를 마련하고자 실시하였다. 본 연구는 시뮬레이션교육 후 학습유형별로 효과를 검증하기 위한 단일군 전후설계 실험연구이다. 본 연구 결과 간호학생의 학습유형은 적응자가 가장 많았으며, 시뮬레이션 교육 후 문제해결능력(F=5.015, p=.02)과 임상수행능력(F=3.288, p=.02)은 유의한 차이를 나타냈으며, 문제해결능력은 융합자와 분사자가 적응자보다, 임상수행능력은 융합자가 적응자보다 유의하게 높게 나타나 학습유형별 시뮬레이션 교육의 효과에 차이가 있음을 확인하였다. 그러나 자기효능감은 통계적으로 유의한 차이를 나타나지 않았다. 이상의 연구결과를 바탕으로 학습유형별로 시뮬레이션교육을 제공할 수 있을 것으로 기대된다.

• 보건의료산업학회지
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• 제9권3호
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• pp.127-143
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• 2015

Objectives : This study is a quasi-experiment with a pre-post design and a nonequivalent control group performed from May 1 to June 2, 2013 to verify the effects of a simulation based education program on nursing students' self-confidence, and clinical performance ability. Methods : The subjects of the study were a total of 60 students in their fourth year of a nursing program at a university located in G city and they were assigned to an experimental group of 30 students and a control group of 30 students by convenience sampling. Results : After being offered education, self-confidence, and clinical performance ability were significantly more improved than before in each group. In the comparison of the two groups, the self-confidence (t=3.00, p=.004) and clinical performance ability(t=3.14, p=.003) of the experiment group were significantly higher than those of the control group. Conclusions : The results indicated that instructional methods using a simulation-based emergency care program should be adopted maximize the effects of advanced cardiopulmonary life support education.

• 한국주거학회논문집
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• 제21권2호
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• pp.41-48
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• 2010

This study shows how the water space outside the housing impacts the indoor thermal environment. CFD simulation was used for this experiment to analyze the interior environment focusing on the effect of temperature control and the thermal comfort. A shape of perfect square, which creates the very basic space formation, was used and the simulation was processed looking at the size, distance, and the location of the water space. The results of the experiment are as follows. Firstly, introducing a water space with the same floor area size of the simulation model decreased the indoor temperature by 1 Celsius (3.72%). It was determined the interior environment was considered as a comfort zone when the water space was greater than 70% of the floor area. Secondly, there was not much influence to the level of thermal comfort of the interior environment when the distance to the water space from the housing was greater than 2 meters. Lastly, interpreting the location of water space, the effect of controlling the total areas' temperature was the greatest following with the surrounding of the formation. There barely was any change to the temperature considering the side and the rear of the area.

• 산업공학
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• 제17권1호
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• pp.22-32
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• 2004

The most complicated and difficult area in the simulation of evacuation process is the area of human behavior. However, it is generally very difficult to understand and quantify human behaviors since the factors involved vary significantly according to the types of accidents and the environment. The walking speed of passenger is especially affected by dynamic effect and list due to damage and ship motion in wave. There are various methods to get the useful data for evacuation simulation. The onboard experimental approach is one of the strongest method. This paper discusses the onboard experimental results of human mobility of passengers in evacuation from ship. To realize ship trim and heel due to maritime casuality, the passage model for experiment is made. The experiment was carried out at dynamic and static condition respectively using the ship with passage model. The result was evaluated and it will be reflected in evacuation simulation tool.

• 한국분무공학회지
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• 제21권1호
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• pp.47-52
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• 2016

This paper describes the modeling of CNG direct injection using gaseous sphere injection model. Simulation of CNG direct injection does not need break up and evaporation model compared to that of liquid fuel injection. And very fine mesh is needed near the injector nozzle to resolve the inflow boundary. Therefore it takes long computation time for gaseous fuel injection simulation. However, simulation of CNG direct injection could be performed with the coarse mesh using gaseous sphere injection model. This model was integrated in KIVA-3V code and RNG $k-{\varepsilon}$ turbulence model needs to be modified because this model tends to over-predict gas jet diffusion. Furthermore, we preformed experiments of gaseous fuel injection using PLIF (planar laser induced fluorescence)method. Gaseous fuel injection model was validated against experiment data. The simulation results agreed well with the experiment results. Therefore gaseous sphere injection model has the reliability about gaseous fuel direct injection. And this model was predicted well a general tendency of gaseous fuel injection.

• 대한기계학회논문집A
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• 제25권2호
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• pp.214-219
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• 2001

In this paper, the nonlinear behavior of ultrasonic wave in partially degraded material is considered. For this aim, FDM(finite difference method) model for the nonlinear wave equation was developed with the restriction to the 1-D longitudinal wave motion and how the partial degradation in material contributes to the detected nonlinear parameter was analyzed quantitatively. In order to verify the rightness of this simulation method, the relation between the detected nonlinear parameter and the continuous distribution of degradation obtained from simulation was compared with experiment results and the simulation and experiment results showed similar tendency. It can be known from simulation result that the degree of degradation, the range of degradation and the continuous distribution of degradation have strong correlation with the detected nonlinear parameter. As it was possible in these simulations that only special part is assumed as degraded one, the quantitative evaluation of partially degraded material may be obtained by using this method.

• 상하수도학회지
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• 제27권2호
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• pp.177-184
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• 2013

This study analyzed the hydraulic characteristics of a venturi flume with a circular cone using a 3-D numerical model which uses RANS(Reynolds-Averaged Navier-Stokes Equation) as the governing equation. The venturi flume with the circular cone efficiently measures the discharge in the low-flow to high-flow range and offers the advantage of accurate discharge measurements in the case of a low flow. With no influence of the tail-water depth, the stage-discharge relationship and the flow behaviors were analyzed to verify the numerical simulation results. Additionally, this study reviewed the effect of the tail-water depth on the flow. The stage-discharge relationship resulting from a numerical simulation in the absence of an effect by the tail-water depth showed a maximum margin of error of 4 % in comparison to the result of a hydraulic experiment. The simulation results reproduced the overall flow behaviors observed in the hydraulic experiment well. The flow starts to become influenced by the tail-water depth when the ratio of the tail-water depth to the total head exceeds approximately 0.7. As the ratio increases, the effect on the flow tends to grow dramatically. As shown in this study, a numerical simulation is effective for identifying the stage-discharge relationship of a venturi flume with various types of venturi bodies, including a venturi flume with a circular cone.

• 한국화재소방학회논문지
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• 제23권5호
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• pp.133-137
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• 2009

화재 시뮬레이션용 전산유체역학 모델인 Fire Dynamics Simulator(FDS)을 이용한 수직벽 화재 시뮬레이션의 정확성을 확인하기 위해 FDS를 프로필렌 수직벽 화재에 적용하였다. 단위면적당 연소율 $7.0{\sim}29.29g/m^2-s$의 범위에서 버너중심에서의 경계층 내 온도분포를 실험결과와 비교하였다. 또 수직벽면 위 수직중심선을 따라 계산한 열유속(heat flux) 분포도 실험과 비교하였다. 경계층 내 온도분포는 비교적 잘 예측됨을 확인하였다. 그러나 벽면근처의 최고온도는 측정치보다 낮았고, 수직벽면의 열유속은 지나치게 높게 나타났다. 이에 따라 수직벽 화재의 시뮬레이션에 있어서 FDS를 개선할 필요가 있음을 확인하였다.