• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.716_717
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• 2009

This paper deals with the characteristic analysis & optimum design of Permanent Magnet Assisted Synchronous Reluctance Motor(PMASynRM) for Premium Efficiency Performance. The focus of this paper is characteristic analysis of d and q-axis inductances and torque according to magnetizing quantity of interior permanent magnet for PMASynRM. The d and q-axis current component ratios, load angles of a PMASynRM are investigated quantitatively on the basis of the proposed analysis method and the experimental test. Comparisons are given with output characteristic curves of normal SynRM and those according to the load in PMASynRM, respectively. And optimum design of PMASynRM is performed by Response Surface Methodology(RSM).

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.35-38
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• 2006

Using the repeaters is indispensable to WiBro services. Repeater types are distinguished by usage, output power and required performance. In the paper, we have studied on the WiBro digital optic repeater design which has excellent performance characteristic than any other repeaters. WiBro has specific characteristic on modulation method TDD(Time Division Duplex)/OFDMA(Orthogonal Frequency Division Multiple Access) so that it demands specified H/W to design WiBro repeater. Switching technique has been introduced because of TDD characteristic in each amplifier on the repeater. Time Advance technique has been considered because of OFDM characteristic among RAS(Radio Access Station) and repeater. In this paper, we have studied on these techniques to increase repeater cell coverage and distance between RAS and repeater.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.641-643
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• 2000

Because of high torque and easiness of speed control, Direct Current(DC) motors are used long time. But, its applications are limited in circumstance and performance, since they contained brush and commutator. The commutation characteristic gives effect to life and performance of DC motor. Naturally, the commutation characteristic analysis is strongly required. In this paper, With the result of finite element analysis. The inductance is calculated each rotor position and applied to the voltage equations coupled with commutation equation. The time derivative term in the differential equation is solved in time difference method. This algorithm was applied to 2-pole shunt DC motor. We considered commutation characteristic by changing contact resistance between brush and commutator segment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.57-62
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• 2013

Because of high torque and easiness of speed control, Direct Current(DC) motors have been used for a long time. But, its applications are limited in circumstance and performance, since they contained brush and commutator. The commutation characteristic gives effect to life and performance of the DC motor. Naturally, the commutation characteristic analysis is strongly required. In this paper, With the result of finite element analysis, The inductance is calculated each rotor position and applied to the voltage equations coupled with commutation equation. Also, contact resistances of brush/commutator assembly are considered using contact area and brush width converted with commutator segments. The time derivative term in the differential equation is solved in time difference method. This algorithm was applied to 2-pole shunt DC motor. We considered commutation characteristic by changing contact resistance between brush and commutator segment.

• Journal of Broadcast Engineering
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• v.5 no.2
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• pp.211-219
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• 2000

The IBAC DAB system was interfered by existing FM broadcasting signal as was used guardband within existing FM broadcasting. The FM interference signals are very important parameter in performance evaluation of IBAC DAB system. We got the characteristic of FM PSD in according to instantaneous change and average characteristic of FM broadcasting signal in according to characteristic of FM channel. In this paper, based on proposed IBAC DAB system, we analyze effects of FM interference for occupied bandwidth and performance of IBAC DAB modeling various FM interference signals with sum of sinusoid function using C language, suggest FM interference ratio that can maintain performance. We was know that IBAC DAB system have a great performance variation in according to average characteristic of FM PSD by simulation results, also, FM interference ration that can maintain performance of system is 10dB.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.331-337
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• 2005

This study aims at evaluation of component performance of a commercial micro gas turbine by detailed measurements of various system parameters. A test facility to measure performance of a micro gas turbine was set up. Performance parameters such as turbine exit temperature, exhaust gas temperature, engine inlet temperature, compressor discharge pressure and fuel flow rate were measured. Variations in measured data and estimated performance parameters were analyzed. In addition to overall engine performance, component characteristic parameters including the turbine inlet temperature, the compressor efficiency, the turbine efficiency, the recuperator effectiveness were estimated. Behaviors of the estimated characteristic parameters with operating condition change were examined.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.50-62
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• 2011

In this paper, analytical techniques for performance characteristics analysis of wind power generator with outer permanent magnet rotor are proposed. Furthermore, the proposed analytical techniques are validated by performance experiments of the manufactured generator. In this part, characteristic equations of losses such as copper loss, core loss are derived. Using the derived loss characteristic equations, electrical parameters obtained in [15] and d-q axes method, constant load and constant speed characteristics of wind power generator are analyzed. And then, to analyze performance of wind power system according to wind speed, d-q analysis model considering wind turbine characteristics is proposed. Finally, the obtained performance characteristics results are validated in comparison with those by experiments.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.1
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• pp.42-49
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• 2014

Performance evaluation was carried out for the 70 N-class hydrazine thruster whose design performance had been already verified. The pulse-mode firing test was conducted for the development model thrusters with various thrust chamber diameters. Evaluation was made by the performance parameters such as specific impulse, impulse bit, and characteristic velocity, etc: specific impulse and characteristic velocity were deteriorated as the thrust chamber diameter deviates from a standard model. Consequently, it is revealed that the performance characteristics of standard model is most superior among the test models.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.186-193
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• 2014

This paper presents characteristic analysis of underwater bearing for canned type electric water pump. Characteristic analysis of underwater bearing was performed using self-developed performance tester, which capable of torque change, noise change, motor speed change and abrasion loss test with respect to temperature change of underwater bearing. The performance tester can be monitored in real time by designing the control unit using the Labview program. The performance experiment was performed through comparison of the silicon carbide (SIC) and the carbon bearing. From the experiment results, performance of SIC bearing was better than carbon bearing at the abrasion and temperature experiment.

• Journal of Power System Engineering
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• v.17 no.6
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• pp.88-94
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• 2013

As the results of analysis that are applying a heat pump using underground water as heat source of facility horticulture house, temperature change in house, growth of cultivated plants and the crop characteristic, the conclusion can be acquired as follows. It was possible to maintain the chamber temperature through operating heat pump with setting goal temperature at $16^{\circ}C$ and temperature variation at ${\pm}3^{\circ}C$. And cooling and heating coefficient of performance in heat pump system are different from setting room temperature and operation condition of equipment, totally in case that the setting temperature in house is low, the coefficient of performance and the in case that temperature departure is low. In case that the house does not heated, the result of the growth characteristic of cucumber planted last 50days is that cucumber grown in house equipped with heat pump is the most favorable growth characteristic due to maintaining a constant room temperature. After 90 days, the quantity and weight cucumber harvested in each house are averagely 9.8%, 13.1% increase and more heavy weight respectively. So it is researched that crop characteristic is superior.