• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.383-391
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• 1993

In this paper, a new automatic cardiac output control algorithm without any pressure sensors for the motor-driven electromechanical total artificial heart(TAH) was developed using motor current information. In the previous studies, many transducers were utilized to obtain informations of hemodynamic states for the automatic cardiac output control. But. such automatic control with sensors has some problems. To solve these problems, I proposed a new "sensorless" automatic cardiac output control algorithm providing the adequate cardiac output to the time-varying physiological demand without right atrial collapse. In-vitro tests were performed to evaluate the performance of a new algorithm and it satisfied the basic three requirements on the pump output response through the mock circulation tests.

• Nuclear Engineering and Technology
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• 제41권3호
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• pp.295-306
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• 2009

The subchannel grade void distributions in the NUPEC (Nuclear Power Engineering Corporation) BFBT (BWR Full-Size Fine-Mesh Bundle Tests) facility were evaluated with the subchannel analysis code MATRA and the system code MARS. Fifteen test series from five different test bundles were selected for an analysis of the steady-state subchannel void distributions. Two transient cases, a turbine trip without a bypass as a typical power transient and a re-circulation pump trip as a flow transient, were also chosen for this analysis. It was found that the steady-state void distributions calculated by both the MATRA and MARS codes coincided well with the measured data in the range of thermodynamic qualities from 5% to 25%. The results of the transient calculations were also similar and were highly feasible. However, the computational aspects of the two codes were clearly different.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1411-1414
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• 2008

It is reported that mechanical stimulation takes a role in improving cell growth in skeletal system. And various research groups have showed that developed bioreactor to stimulate cell-seeded and threedimensional scaffold. In this study, we designed a custom-made bioreactor capable of applying controlled compression to cell-seeded agarose gel. This device consisted of a circulation system and compression system. In circular system, culture chamber was sealed for prohibiting contamination and media solution was circulated by pump. In compression system, mechanical stimuli were controlled by LabVIEW software and mechanical transfer system. Cell-encapsulated agarose gels were cultured for up to 7 days. There were significant differences between the number of cells grown in dynamic cell culture and in static cell culture from 3 days to 7 days.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 춘계 학술대회논문집
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• pp.75-81
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• 1998

A new advanced integral reactor of 330 MWt capacity named SMART(System-integrated Modular Advanced ReacTor) is currently under development at KAERI(Korea Atomic Energy Research Institute). One of the major design features of the integral reactor is locating the steam generators(SG) inside reactor vessel and eliminating the possibility of LB LOCA(large Break Loss of Coolant Accident). Orifices are fitted at the low part of steam generator cassette to stabilize and balance coolant flow distribution in the MCP (Main Circulation Pump) pressure header. A sensitivity analysis is conducted to determine the optimum orifice size using computer code 'CFX'.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.245-249
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• 2003

Vapor-liquid equilibrium data were obtained for system of propane + R227ea (Heptafluoropropane) over the temperature range from 253.15 K to 323.15 K at 10 K intervals. Experiments were performed in a circulation type apparatus by injecting vapor through liquid pool using a magnetic pump. This system forms azeotrope in the temperature range of this study. The experimental results were correlated with the Peng-Robinson (PR) equation of state and Redlich-Kwong-Soave (RKS) equation of state using the van der Walls one-fluid mixing rule and were compared with each other.

• 한국산업융합학회 논문집
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• 제6권2호
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• pp.103-108
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• 2003

This study was performed to find out drying characteristics and develop waste heat recovery dryer. this system was initiated in order to recover discharged waste heat of drying air from drying chamber in agricultural products dryer and recycle for additional heat source that could save drying cost. The system consists of drying chamber, fan, burner, circulation pump and heat exchanger made of fins and tubes. For the system performance, drying experiments with fresh pepper were conducted, and comparisons on fuel consumption amount and drying performance were made between conventional dryer and the heat recovery system attached dryer.

• 태양에너지
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• 제18권3호
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• pp.113-118
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• 1998

This project studied a new generator utilizing the Seebeck effect. The major objective of this study was to prove the baseline concept through experimental studies. The important results from this study included design and fabrication of a laboratory scale generating system. The generating capacity of the TE-generator was 500Watt. The preliminary testing results showed the system efficiency of close to 20%. The experimental testing system has been built to include heating element, circulation pump and the instrumentation system included watt-hour meter, temperature sensor, and data acquisition system by the Hewlett-Packard 75000 Series.

• 한국태양에너지학회 논문집
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• 제25권2호
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• pp.1-8
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• 2005

On-off differential controller is one of the very important components which affect the system performance of the active solar thermal system. In this study, analyses were made regarding the influence of "on-off" setting temperature on the system efficiency and on the electrical consumption by circulation pump. This study was performed by experiment as well as the computer simulation using TRNSYS program. The simulation system was developed in this study was verified the its reliability by the experimental results. As a results, the turn off temperature(${\Delta}T_{off}$) is much more influence than the turn on temperature(${\Delta}T_{on}$) on the system efficiency. It is more clear and sensitivity in winter season. Finally the optimum on-off setting value and the system on-off pattern according to the several different kind of system was also represented.

• 한국압력기기공학회 논문집
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• 제7권3호
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• pp.30-39
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• 2011

URANUS (Ubiquitous, Robust, Accident-forgiving, Non-proliferating, Ultra-lasting and Sustainer) has been developed with 35MWe (100MWth) operating without primary coolant pump, capitalizing on natural circulation capability of lead-bismuth eutectic (LBE) for long-life small and robust power units. To ensure the structural integrity, the large safety margin against Safe Shutdown Earthquake, 0.3g, and furthermore the cost effectiveness for URANUS, three-dimensional seismic base isolation design has been developed. The analytical model has been developed and seismic time history analyses have been carried out. The advantage for using three-dimensional seismic base isolation for URANUS has been discussed.

• 대한의용생체공학회:의공학회지
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• 제18권1호
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• pp.51-64
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• 1997

A dynamic model of the Korean total artificial heart(TAH) which contains a brushless DC motor, all of mechanical components, the pump system with integrated variable volume space(WS) and the circulatory system model including the bronchial circulation were established Two different sets of seven differential equations were separately derived for the left and right systolic period of the Korean TAH operation. Throughout the computer simulation, a full-state fEedback optimal controller that minimizes the power consumption of the Korean TAH and drives the end stage velocity of the energy converter to zero was developed based upon the optimal control theory. Robustness of the controller were also analyzed with the dynamic model of the Korean TAH.