• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.9
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• pp.1033-1038
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• 2015

Complementary Filter is commonly used in signal processing method for real-time position measurement. Butterworth filter characteristic has a uniform gain in the pass band, the blocking band has a good blocking characteristics. Therefore, we propose a method of designing a complementary filter having a characteristic of Butterworth filter characteristic. By setting the appropriate filter coefficients in the simulation it appears to improve the performance of the filter. In the experiment it shows a real-time signal processing is possible by using the calculated filter coefficients in the simulation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.62-63
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• 2018

Oyster shell is produce by shucking process in oyster farming in southern coast of Korea. In average, about 6.7kg of oyster shell is produced as an industrial waste for 1kg of oyster flesh, and even only in last year, it is estimated that about 150,000 ton of oyster shell is produced. Oyster shell is light weighted and the strength characteristic of it is similar to send. So we produced mortar test piece using grounded oyster shell according to aggregate and reviewed strength characteristic. Therefore, in this study, the strength characteristics of the test specimen are evaluated by artificially altering fineness modulus and curing method by processing oyster shells.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.440-445
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• 2011

Dynamic characteristic analysis is required in developing SMT mounter system with high installation speed and position precision, because of vibration source occurred by positioning head. This paper presents the method of improving dynamic characteristic of SMT(Surface Mount Technology) mounter with finite element method and modal test. The design direction is that natural frequencies of SMT mounter must be higher than the vibration source. In addition, the effect of input shaping on residual vibration reduction is investigated by simulating the response of a first-order system.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.811-813
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• 2002

This paper deals with the design of vaccum pump using moving magnet type linear oscillaory actuator based on the design procedure and the characteristic analysis. To improve the starting characteristic, the optimum spring constant is detected and redesigned. The parameter was calculated by Finite Element Method(FEM). In order to dynamic characteristic analysis, Time difference method with voltage and kinetic equation is used. The propritey of the improved model is verified through the experimental.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1067-1068
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• 2011

This paper deals with the method of starting characteristic analysis of a single-phase line-start permanent magnet (LSPM)motor. The starting characteristic such as current, torque and is important in LSPM because of demagnetizing of the permanent magnet. In this paper, the characteristic analysis is performed using finite element method.

• Journal of the Semiconductor & Display Technology
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• v.11 no.2
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• pp.59-62
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• 2012

This test method covers a procedure for measuring particle removal characteristic of equipment fan filter unit(EFFU) installed inside of semiconductor process equipments, FPD manufacturing equipments and so on. Since EFFU is a combination of air filter and the assembly of fan, motor and frame, the integrity of these parts is very important for the performance of EFFU. So a conventional particle removal test method for air filters is not suitable for EFFU particle removal performance. This test method defines an evaluation method for EFFU which is installed inside an enclosed space to remove particles that are generated inside process equipment. The particle removal performance of EFFUs is usually depending on the performance of filter media and air flow rate. To understand a performance of an EFFU, the filter media characteristic, air flow rate and the integrity of EFFU parts should be considered simultaneously. This test method is intended to demonstrate the system performance of an EFFU and successfully evaluated EFFU performance characteristics.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.04a
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• pp.95-99
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• 1996

In this paper, we proposed a method to measure the gap between the magnetic pole and the levitated object applying the inductance characteristic which vary according to gap. We made a driving circuit which supply the control input PWM(Pulse Width Modulation) signal and the carrier PWM signal to estimate the gap. Because the inductance is a function of gap, and the current of the carrier signal is a function of the inductance. We investigated the validity of the proposed method through the experimental results.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.10 no.4
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• pp.253-258
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• 2010

The causal network represents the knowledge related to the dependency relationship between all attributes. If the causal network is available, the dependency relationship can be employed to estimate the missing values for improving the estimation performance. However, the previous method had a limitation in that it did not consider the bidirectional characteristic of the causal network. The proposed method considers the bidirectional characteristic by applying prior and posterior conditions, so that it outperforms the previous method.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.53-57
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• 1989

Until now, method of equivalent circuit is generally used in analyzing the characteristic of the synchronous alternator. But this method can't apply when loads are connected to alternator. In this paper, we analyzed the load characteristic of the synchronous alternator with permanant magnet using 2-dimensional finite element method having voltage source. The loads of a alternator are battary and diodes which are used to rectify. also, we used half periodic boundary condition in the F.E.M calculation

• International Journal of Control, Automation, and Systems
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• v.1 no.1
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• pp.127-133
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• 2003

This paper proposes a new numerical method to check the stability of a general class of time delay systems. The proposed method checks whether there are characteristic roots whose real values are nonnegative through two steps. Firstly, rectangular bounds of characteristic roots whose real values are nonnegative are computed. Secondly, the existence of roots inside the bounds are checked using the numerical computation of argument principles. An adaptive discretization is proposed for the numerical computation of argument principles.