• Korean Journal of Hydrosciences
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• 제5권
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• pp.115-124
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• 1994

This paper presents the results of a study conducted to improve the understanding of the characteristics of cylindrical capsule flow in a pipeline by taking into account of the effect of capsule density uniformity. The effect fo capsule density variation in the axial direction was studied both experimentally and analytically. The experiments were conducted in a 190mm diameter straight pipe 17m long. The velocity, gap and tilt of capsules were measured under various conditions. In order to interpret the data on various capsule density conditions, the stability index given in the dimensionless number was introduced. The motion of capsules in pipelines is strongly affected by the stability of the capsules characterized by the statility index. The experiments conducted proved that the stability index is a vaild criterion for explaining and correlating data on the capsule motion and the capsule denisity uniformity.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1993년도 수공학연구발표회논문집
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• pp.483-490
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• 1993

본 논문은 캡슐밀도의 균일성의 영향을 고려하여 관로내에서의 원통형 캡슐 흐름의 특성을 이해하기 위하여 수행된 연구결과를 기술한다. 캡슐의 중심 축방향으로의 밀도변화 영향을 실험적으로나 분석적인 방법으로 연구하였다. 실험은 직경 190mm, 길이 18m인 관에서 수행되었으며, 속도, 캡슐의 기울기, 캡슐바닥과 관과 간격이 여러가지 실험조건하에서 측정되었다. 실험데이타를 해석하기 위하여 무차원 변수로 주어지는 안정성지수(Stability Index)가 유도되었다. 관로에서의 캡슐의 거동은 안정성지수에 크게 영향을 받는다. 실험결과는 안정성지수가 캡슐거동과 캡슐밀도의 균일성과의 상관관계를 잘 설명하여주는 유효한 기준임을 증명하였다.

• 물과 미래
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• 제26권4호
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• pp.97-105
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• 1993

본 논문은 캡슐밀도의 균일성의 영향을 고려하여 관로내에서의 원통형 캡슐 흐름의 특성을 이해하기 위하여 수행된 연구결과를 기술한다. 캡슐의 중심 축방향으로의 밀도변화 영향을 실험적으로나 분석적인 방법으로 연구하였다. 실험은 직경 190mm, 길이 17m인 관에서 수행되었으며, 속도, 캡슐의 기울기, 캡슐바닥과 관과의 간격이 여러 가지 실험 조건하에서 측정되었다. 실험데이타를 해석하기 위하여 무차원 변수로 주어지는 안정성지수(Stability Index)가 유도되었다. 관로에서의 캡슐의 거동은 안정성 지수에 크게 영향을 받는다. 실험결과는 안정성 지수가 캡슐거동과 캡슐밀도의 균일성과의 상관관계를 잘 설명하여주는 유효한 기준임을 증명하였다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.367-368
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• 2002

The design of capsule body for self-propelled endoscope is important from the frictional resistance point of view. The capsule should be able to overcome the frictional resistance in order to move along the intestine. The motivation of this work was to gain a better understanding of the capsule body design on the frictional resistance of the capsule inside an intestine. A special experimental set-up was built to measure the frictional resistance as the capsule was being pulled inside the pig intestine specimen. Tests were performed with open and closed intestine specimens. Experimental data showed that smooth cylindrical capsule geometry resulted in the least frictional resistance. The resistance inside the closed intestine specimen was about four times higher than that of the open specimen. It is expected that the results of this work will be used to design the optimum propulsion system for the microendoscope.

• 설비공학논문집
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• 제26권7호
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• pp.301-307
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• 2014

This paper presents a numerical study on the constrained melting of a phase change material inside various capsule containers, using water and HDPE (High Density Polyethylene) as a PCM and a capsule material, respectively. The computations are based on an iterative, finite-volume numerical procedure that incorporates a single-domain enthalpy formulation for simulation of the phase change phenomenon. Using the enthalpy method, various capsule configurations, such as a capsule from E company, an isochoric cylinder capsule, an equivalent diameter sphere capsule, and an isochoric sphere capsule, are used to investigate the effect of capsule configurations on the charging and discharging performance. A transient three-dimensional model is used for each case. The simulation results show that the capsule from E company results in a higher melting and solidification rate of the PCM, than the other capsule configurations considered in this research.

• 한국가시화정보학회지
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• 제17권1호
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• pp.19-25
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• 2019

We report a study on the dynamics of the transport of a capsule immersed in a vertical pipe. Techniques to convey objects through liquid flow pipes using a hydraulic mean are used to transport sludge and hazardous materials. For the better understanding of the techniques, we developed a theoretical model to predict the transport speed of a cylindrical capsule in a vertical pipe. The comparison of the model prediction with the experiments shows that our model using the lubrication approximation precisely describes the experimental observations in cases where the gap between the capsule and pipe wall is sufficiently small. Our study suggests parameters to control the falling speed and thus enable an accurate control of the capsule speed in hydraulic transport systems.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.142-145
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• 2002

In order to develop a self-propelled microendoscope, the frictional resistance of the capsule-type endoscope inside the intestine should be understood. In this work the frictional resistance behaviors of capsules with different designs were experimentally investigated using a pig intestine. It was found that cylindrical capsule design had the least frictional resistance. Also, the resistance increased as the speed of the capsule motion was decreased. It is expected that the results of this work will be used to design the optimum propulsion system for the microendoscope.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 춘계학술발표회요약집
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• pp.249-249
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• 1999

• 대한의용생체공학회:의공학회지
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• 제29권3호
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• pp.187-190
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• 2008

This paper presents two dimensional receiving coils to provide hundreds of milli-watt power via inductive link to in vivo robotic capsules, whose orientation are practically undetermined. The wireless power transmission system consists of a transmitter powered by class E power amplifier, and a receiver with three dimensional antenna, rectifier, and voltage regulator. As the 2D lateral antenna construction is more critical for the receiving antenna, two types of 2D antennas are introduced and evaluated by theoretic and experimental analyses. Experimental results verifies that the cross-type construction show better directional performance for receiving power than the cylindrical one for the 2D antenna. The former could deliver the power homogeneously regardless of its orientation, with less than 20 % of variation from the possible maximum power.

• 대한기계학회논문집B
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• 제24권1호
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• pp.50-59
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• 2000

An experimental study has been carried out in order to investigate the heat storage characteristics for a latent heat storage tank with horizontal shell and tube type. The heat exchanger consisted of horizontal cylindrical capsules with a staggered tube bank layout. Based on the obtained data, the effects of flow rate and inlet fluid temperature on the melting time and heat storage rates were examined. It is found that the melting time decreased with increase of the flow rate and the inlet temperature. Results also show that at the initial stage of heat transfer the heat storage rate represents the maximum value and rapidly decreases.