• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.317-318
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• 1998

The purpose of this study is to design and develop the circuit of the dual mode syringe pump. Syringe pump is used in intensive care unit, delivery room, pediatric room, operating theater and other fields of hospital at present. Normally the syringe pump delivers one medicine in one case, but in case of intensive care unit, it is necessary to deliver more than two kinds of medicines at a time. Therefore we have designed dual mode syringe pump. We used RISC type microcontroller, PIC17C44 as master controller, and PIC16C73 as slave cpu using for the low power consumption. The performance of system is evaluated by analysis of the linearity and accuracy which is the most important factors in application. While the proposed system shows a acceptable linearity and accuracy, a further research about reducing the errorr should be done.

• Progress in Superconductivity and Cryogenics
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• v.23 no.4
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• pp.19-24
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• 2021

The low normal zone propagation velocity (NZPV) of high-temperature superconducting (HTS) tape leads to a quench protection problem in HTS magnet applications. To overcome this limitation, various studies were conducted on HTS coils without turn-to-turn insulation (NI coils) that can achieve self-protection. On the other hand, NI coils have some disadvantages such as slow charging and discharging time. Previously, the HTS coils with turn-to-turn insulation (INS coils) were operated in power supply (PS) driven mode, which requires physical contact with the external PS at room-temperature, not in persistent current mode. When a quench occurs in INS coils, the low NZPV delays quench detection and protection, thereby damaging the coils. However, the rotary HTS flux pump supplies the DC voltage to the superconducting circuit with INS coils in a non-contact manner, which causes the INS coils to operate in a persistent current mode, while enabling quench protection. In this paper, a new protection characteristic of HTS coils is investigated with INS coils charging through the rotary HTS flux pump. To experimentally verify the quench protection characteristic of the INS coil, we investigated the current magnitude of the superconducting circuit through a quench, which was intentionally generated by thermal disturbances in the INS coil under charging or steady state. Our results confirmed the protection characteristic of INS coils using a rotary HTS flux pump.

• Progress in Superconductivity and Cryogenics
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• v.3 no.2
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• pp.15-20
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• 2001

This paper describes a model flux pump experiment recently performed at the MIT Francis Bitter Magnet Laboratory. The results of the model flux pump will be used in the development of a prototype flux pump that will be couple to a high-temperature superconductor (HTS) insert coil of a high-field NMR (Nuclear Magnetic Resonance) magnet, Such an HTS insert is unlikely to operate in persistent model because of the conductors low index(n) The flux pump can compensate fro field decay in the HTS insert coil and make the insert operate effectively in persistent mode . The flux pump, comprised essentially of a transformer an two switches. all made of superconductor, transfers into the insert coil a fraction of a magnetic energy that is first introduced in the secondary circuit of the transformer by a current supplied to the primary circuit. A model flux pump has been designed. fabricated, and operated to demonstrate that a flux pump can indeed supply a small metered current into a load superconducting magnet. A current increment in the range of microamperes has been measured in the magnet after each pumping action. The superconducting model flux pump is made of Nb$_3$ Sn tape, The pump is placed in a gaseous environment above the liquid helium level to keep its heat dissipation from directly discharged in the liquid: the effluent helium vapor maintains the thermal stability of the flux pump.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.626-629
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• 2007

Vibration originated from the fuel pump is transmitted to the fuel pump module and fuel tank. Fuel tank transmits it to chassis of vehicle. Also, noise perturbed through fuel and fuel tank is radiated out. Dynamic characteristics of fuel tank are composed of tank structure and containing fuel quantity. Therefore, this study is focused at fuel tank with various quantity. As a result, characteristics of vibration for various fuel quantity in a tank are identified as the more mass of fuel is, the less the 1st resonance frequency decrease. Also, between acoustic camera and mode shape of modal analysis are used for searching the positions of radiated noise and are found to be in accordance with each other.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1301_1302
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• 2009

Recently, there has been increased incessantly an interest in research area on micro-fluidic pump for electronic and biological applications. The proposed pump takes an unobtrusive operation into the simple displacing mechanism using peristaltic traveling waves without the physical moving valves. And, this piezopump makes up a panel type design. The ATILA simulation was performed to estimate the operating frequency of the vibrating wave mode, to optimize the design conditions of piezopump such as structure, elastic body material, piezoelectric ceramics, and to analyze the distribution of vibration displacement. The best measured value of the pumping rate is about $118{\mu}l$/min under the following parameters : 4-wave mode, 50kHz operating frequency, $200V_p$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.36-40
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• 2007

It uses a tank to store, purify and feed lube oil in power plants, which is made by steel plate. Several pumps to feed lube oil are installed on the top plate of the oil tank. In this case if pumps on the top plate are removed or added, the dynamic characteristics of the structure will be changed. In this paper, we present that we analyze in detail the similar case with a finite element model for tank & pump structure coupled with oil and that we set plan to change mode shapes on the top plate of the tank.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.4
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• pp.340-348
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• 2004

The air and refrigerant side heat transfer performances are key parameters to improve heat transfer efficiency of the heat exchanger including the fan performance. Design of the fins, treatment of the tube inside, tube diameter and tube array effect heat transfer performance of the heat exchanger. The heat exchanger is used as a condenser at cooling mode and used as an evaporator at heating mode in the heat pump system. The heat pump system uses R410A as the refrigerant. The heat exchangers are consisted with 7 mm diameter tubes with slit-type fins. The study was conducted with variation of arrangement of the refrigerant path and air flow rate and refrigerant pressure drop and heat transfer rate were measured with a code tester. The capacity of the 3 path heat exchanger is more efficient than 2 or 4 path heat exchangers in heating or cooling modes.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.307-308
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• 2007

At present, there are unnecessary electrical consumes and a lot of fuel-losses by the vaporized gas due to the rising of fuel temperature because the fuel pump of the fuel supply system rotates regularly regardless to the driving condition. In this paper, we designed the multi-step controller for controlling fuel pump to supply fuel according to RPM of each moment by measuring the real time RPM of the engine at ECU of the vehicle. Also, it can judge the existence or nonexistence of disorder by measuring the pressure of the fuel supply line, in case of abnormal state, it can supply the fuel intelligently by changing the mode to self-compensation mode.

• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.324-333
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• 2009

This paper presents a numerical simulation study of the transient behavior of a $2{\times}340MW$ pump-turbine power plant, where the results show an unstable behavior at runaway. First, the modeling of hydraulic components based on equivalent schemes is presented. Then, the 2 pump-turbine test case is presented. The transient behavior of the power plant is simulated for a case of emergency shutdown with servomotor failure on Unit 1. Unstable operation at runaway with a period of 15 seconds is properly simulated using a 1-dimensional approach. The simulation results points out a switch after 200 seconds of the unstable behavior between a period of oscillations initially of 15 seconds to a period of oscillation of 2.16 seconds corresponding to the hydraulic circuit first natural period. The pressure fluctuations related to both the rigid and elastic water column mode are presented for oscillation mode characterization. This phenomenon is described as a switch between a rigid and an elastic water column oscillation mode. The influence of the rotating inertia on the switch phenomenon is investigated through a parametric study.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.7
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• pp.481-486
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• 2015

This paper provides how to solve the problems analytically and experimentally that occur for testing the water injection pump under development. First of all, water injection pump, based on shaft system dynamic analysis, is verified by measuring the behavior of the shaft system. After the water injection pump is measured, the structural resonances which can cause excessive noise, degradation the equipment life and malfunction are found. Therefore, by changing the structural design, the reso- nance should be avoided. Application of the design variables to the experimentally resonance avoid- ance is difficult. So analytically, with application of the design variables, the design will be changed with mode analysis using FEM.