• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.220-226
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• 2011

This paper proposes a straightforward method of analyzing the operation characteristics for the capacitor run single-phase induction motor from the traditional equivalent circuit based on the revolving field theory. The proposed method consists of five procedures as follows: mechanical loss segregation, iron loss segregation and calculation of the equivalent circuit parameters, recalculation of parameters of the main winding side, calculation of the auxiliary winding magnetizing reactance and effective turn ratio, and analyzing the operation characteristics for this motor. When the characteristics are analyzed, the segregated mechanical and iron losses are considered as a loss resistance across input terminals of the equivalent circuit for the analysis. The validity of the proposed method is verified from the comparison between the computed results and the experimental ones for the operation characteristics.

• Journal of Advanced Marine Engineering and Technology
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• v.14 no.3
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• pp.34-41
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• 1990

Mode Synthesis Method is applied to analyize the vibration characteristics of the press machine sold at present. Vibration analysis of the machine has not been done thoroughly as far, because of its complicated structure and much bigger unlinearity of its vibration characteristics. The press was disassembled by parts, and it was experimented by the exciting techniques and curve fitting methods, and analyzed by the Mode Synthesis Method. The 2 results were showed good agreements at each part. We confirming it, the machine was assembled, and experimented and analyzed by the same method. Also good agreements between 2 methods were obtained. In addition, impact responses of the actual moving press were agreed with the analyzed values by the Mode Synthesis Method. And we found that the first bending mode of the slide was ruling the vibration characteristics of the press.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.1
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• pp.56-61
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• 2023

The characteristics of write discharge were investigated when the conventional driving method with the unipolar sustain voltages, and the single sustain driving method applying the bipolar sustain voltage were applied in an AC plasma display. In the case of having a single sustain waveform, the strength of the write discharge is weakened compared to the conventional driving method during the address period, because the wall charge inside the panel is more dissipated by the lower scanning voltage. In the driving method with a single sustain waveform, the bias voltage of the other electrodes was changed to improve the write discharge characteristics. As a result, the intensity of the discharge was enhanced by 32% and the delay time was shortened by 60 ㎲.

• 전기의세계
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• v.22 no.1
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• pp.42-51
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• 1973

The contriving equivalent circuit of single phase induction motor which does not separate the primary leakage reactance and the secondary leakage reactance by the revolving field theory, and the graphically calculating method of the characteristics with T-type circle diagram of three phase induction motor which does not suppose the primary leakage reactance can be drawn up only by the no load test, the lock test, and measuring the resistance of stator winding are suggested in this paper. The method which can calculate the parameters of the equivalent circuit and the characteristics with no load test, lock test and measuring resistance of stator windings is suggested in this paper. Considered the exciting current in lock test, we could calculate very accurate characteristics of the single phase induction motor.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.154-160
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• 1998

This study describes a theoretical and experimental investigation of gas wave propagation in the pipe system. Most calculations of compressible flows in the pipe have been based on the method of characteristics. This technique has propensity to truncate waves and is difficult to apply to non-perfect gas. A method that describes the application of a two-step Lax-Wendroff acheme to solution of the unsteady one-dimentional flow in the pipe was developed. Theoretical calculations using both the method of characteristics and the two-step Lax-Wendroff method are presented including a realistic model for heat transfer and friction processes. In the present work, account is taken of the nonlinear behavior. For sections of parallel pipe, an one dimensional unsteady homentropic analysis is employed, and a numerical solution is obtained with the aid of a digital computer, using the method of characteristics and two-step Lax-Wendroff method. This analysis is then combined with boundary models, based on a quasi-steady flow approach, to give a complete treatment of the flow behavior in the pipe system.

• Journal of Korean Society for Quality Management
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• v.31 no.4
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• pp.150-163
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• 2003

The purpose of this paper is to propose an interactive method using the concept of Signal­to­Noise (SN) ratios and cutting ranges for selecting the most preferred alternatives of Multiple­attribute Decision­Making(MADM) with the­smaller­the­better or the­larger­the­better characteristics. In this method the decision makers could make a grouping of attributes by their priorities. This research is based on the assumption of an equality between the attributes of MADM with the characteristics of Taguchi method. As a result, this interactive method could transform the characteristic value of Taguchi method into the size of SN ratios which are relatively easy to understand by decision makers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.311-314
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• 2007

The experimental method of measuring dynamic properties of structures was presented. The method is based on the flexural wave propagation characteristics. Using the method, change in structural dynamic properties due to damage is measured. The crack has much more significant impact on the strain energy than the inertial effects. From this, the sensitivity of the dynamic stiffness on the crack location is estimated by calculating the strain energy. When the wave propagates, the strain and kinetic energies shows cyclic changed over space. The crack that occurred at locations where the wave energy is in the form of the potential energy affected most significantly the wave propagation characteristics. The effects of crack location on the wave propagation were used to determine the crack location.

• Journal of computational fluids engineering
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• v.8 no.4
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• pp.26-33
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• 2003

Smart UAV Development Program, one of the 21c Frontier R&D Program sponsored by MOST(Ministry of Science and Technology), was launched in 2002 As an air vehicle for the Smart UAV, CRW(Canard Rotor/wing) concept was one of the candidates compared in trade-off study. The CRW concept has not only been proven completely but its aerodynamic characteristics not known in detail yet. Two calculation methods were adopted in this study to obtain aerodynamic data for the CRW First method was the superpose DATCOM method which is capable of three lifting sufaces, and second one is the full Navier-Stokes computation around CRW configuration using overset grid method. Basic aerodynamic characteristics of the CRW configuration was analyzed and the minimum drag level with lift to drag ratio is presented. The peculiar flow characteristics around rotor/wing and hub were also examined and considered in the configuration design.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.27-33
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• 2001

Linear harmonic analysis is a convenient and generally accurate method to use for the acoustic analysis of intake and exhaust silencers for IC engines. The major uncertainty in this form of modelling is the characterisation of the source, which is inherently nonlinear and time-variant. Experimental methods are generally used to determine the source characteristics, and in particular the indirect method is most suitable for an IC-engine source. With reference to an idealised linear time-variant source, it is found that the characteristics of a time-variant source as determined by the indirect method have no physical relevance. The direct method of experimental measurement appears to have some advantage over the indirect method, although in practice it is difficult to apply to an IC engine source. Again, an idealised linear time-variant source can be used to indicate that the characteristics of a time-variant source as determined by the direct method also have no physical relevance. Strangely, these meaningless measured source properties can nevertheless be used to accurately predict the radiated noise from an IC engine and silencer system.

• Journal of Power System Engineering
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• v.7 no.2
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• pp.11-16
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• 2003

Because of the advancement of digital computers and software technologies, simulation methods have been used to reduce time and costs. A lot of simulation methods have been developed for the improvement of charging efficiency on the intake and exhaust system of engines. In this study, as a basic step for the development of the gas flow simulation program for the intake and exhaust system, the gas flow in a pipe-orifice system was calculated with three algorithms(Method of Characteristics, MacCormack Method for conservation, and MacCoramck Method for nonconservation). The calculated results using three numerical algorithms were compared with measured result to verify the calculation accuracy.