• Asian-Australasian Journal of Animal Sciences
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• v.19 no.4
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• pp.475-481
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• 2006

The genetic polymorphism and relationships of Muscovy, Cherry Valley Meat ducks, Partridge ducks and their crossbreds $F_1$ and $F_2$, respectively, were studied using a random amplified polymorphic DNA (RAPD) technique. The results showed that RAPD markers were effective for the analysis of genetic relationships among ducks. Amplification with 20-primers gave 760 reproducible amplified fragments. The percentage of polymorphic marker band was 74.70%, which indicates that the RAPD technique had higher efficiency of polymorphism detection and sensitivity in studying the genetic variations among ducks and showed that the genetic polymorphism was abundant between two species of duck populations. The average index of genetic distance in hybrid $F_2$ was 0.2341 and higher than that of its parents, which indicates that the genetic diversity was improved by crossbreeding with Muscovy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.12a
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• pp.109-111
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• 2006

This paper presents characterization and analysis of integrated ferromagnetic inductors in RF regime. Two different materials (CoFe/NiFe) are used as ferromagnetic material. Systematic studies of the inductance (L), the Q-factor (Q) and the structure of the inductor have been performed.

• Structural Engineering and Mechanics
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• v.46 no.4
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• pp.459-486
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• 2013

A novel damage classification method based on wavelet packet transform and statistical analysis is developed in this study for structural health monitoring. The response signal of a structure under an impact load is normalized and then decomposed into wavelet packet components. Energies of these wavelet packet components are then calculated to obtain the energy distribution. Statistical similarity comparison based on an F-test is used to classify the structure from changes in the wavelet packet energy distribution. A statistical indicator is developed to describe the damage extent of the structure. This approach is applied to the test results from simply supported reinforced concrete beams in the laboratory. Cases with single and two damages are created from static loading, and accelerations of the structure from under impact loads are analyzed. Results show that the method can be used with no reference baseline measurement and model for the damage monitoring and assessment of the structure with alarms at a specified significance level.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.797-799
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• 1996

This paper presents a simple method for evaluating of voltage stability using the line flow equation. Line flow equations($P_{ij}$, $Q_{ij}$) are comprised of state variable, $V_i$, ${\delta}_i$, $V_j$ and ${\delta}_j$, and line parameter, r and x. Using the feature of polar coordinate, these equations become one equation with two variables, $V_i$ and $V_j$. Moreover, if bus j is slack bus or generator bus, which is specified voltage magnitude, it becomes One equation with one variable $V_i$, that is, may be formulated with the second-order equation for $V_i^2$. Therefore, solutions are obtained with simple computation. Solutions obtained are used for evaluating of voltage stability through sensitivity analysis. Also, considering of reactive power source, method for evaluating the voltage stability is introduced. The proposed method was validated to 2-bus and IEEE 6-bus system.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1638-1640
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• 2003

In the recent years, UHF PD measuring technique for detecting partial discharges was proved the effective method for Gas Insulated Switchgear (GIS). However, in case of GIS with a metal flange around insulating spacer, UHF PD measurement using typical external UHF PD sensor is difficult. In this paper, a novel hole-type UHF PD sensor based on Archimedean spiral antenna theory has been proposed and realized. All spacers with metal flange have small hole in order to inject epoxy. Using the novel hole-type UHF PD sensor, it makes detection possible to PD signal that are emitted through the epoxy injection hole. Additionally, the measuring characteristic of UHF PD signals from several artificial defects in GIS and the novel ${\Phi}$-f-q pattern analysis technology are discussed.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.683-691
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• 2019

In this paper, we propose a novel method to quantify the neural synchronization between subjects in the collaborative process through electroencephalogram (EEG) hyperscanning. We hypothesized that the neural synchronization in EEGs will increase when the communication of the operators is smooth and the teamwork is better. We quantified the EEG signal for multiple subjects using a representative EEG quantification method, and studied the changes in brain activity occurring during collaboration. The proposed method quantifies neural synchronization between subjects through bispectral analysis. We found that phase synchronization between EEGs of multi subjects increased significantly during the periods of collaborative work. Traditional methods for a human error analysis used a retrospective analysis, and most of them were analyzed for an unspecified majority. However, the proposed method is able to perform the real-time monitoring of human error and can directly analyze and evaluate specific groups.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.1
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• pp.1-12
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• 1995

In order to seek various relationships among many design parameters employed in the design of the axial-flow fans the program which generates acoustic spectrum has been developed and its validity verified. Outputs of the program, with other outputs from a formerly developed performance prediction program, have been used to form a multi-objective function, for which an optimal design process was carried out. The present analysis shows that overall noise level and efficiency has contrasting trends, and the chord length turns out to be the most critical design variable. In the chosen design case of requirements $Q=2000m^2/min$, ${\Delta}P_s=67mmAq$, D=1.4m, the chord length of 0.2059m minimizes the overall noise level, while chord length of 0.1254m maximizes the efficiency. The resulting chord length in the balanced optimization is 0.1809m.

• Structural Engineering and Mechanics
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• v.23 no.1
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• pp.97-113
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• 2006

A simply supported hybrid plate consisting of top and bottom functionally graded elastic layers and an intermediate actuating or sensing homogeneous piezoelectric layer is investigated by an elasticity (piezoelasticity) method, which is based on state space formulations. The general spring layer model is adopted to consider the effect of bonding adhesives between the piezoelectric layer and the two functionally graded ones. The two functionally graded layers are inhomogeneous along the thickness direction, which are approached by laminate models. The effect of interlaminar bonding imperfections on the static bending and free vibration of the smart plate is discussed in the numerical examples.

• Journal of the Optical Society of Korea
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• v.6 no.3
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• pp.83-86
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• 2002

Nanoscopic emission from periodic nano-hole arrays in thick metal films is studied experimentally. The experiments give direct evidence for SP excitations in such structures. We show that the symmetry of the emission is governed by polarization and its shape is defined the interference of SP waves of different diffraction orders. Near-Held pattern analysis combined with the far-Held reflection and transmission measurements suggests that the SP eigenmodes of these arrays may be understood as those of ionic plasmon molecules.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.305-306
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• 2019

본 논문에서는 고전압 커패시터 충전용 3상 LCC 공진형 컨버터를 설계하고 제작하였다. 고전압 커패시터 충전시간과 충전전압간에 선형성을 확보하기 위하여 컨버터는 충전 전 구간에서 정전류원으로 동작하도록 설계되었다. 공진탱크 설계를 위해서 FHA(Fundamental Harmonic Analysis) 기법을 이용하여 첨예도(Q; Quality factor)와 기저 주파수 변동에 따른 입출력 전류이득특성을 도출하였고 이를 바탕으로 28.8kJ/s의 충전속도를 가지며 최대 충전전압은 10kV 인 3상 LCC 공진형 컨버터를 제작하였다. 제작된 컨버터는 10kV, 600kJ 규격의 12mF 고전압 커패시터를 이용한 충전 실험을 통해 설계의 타당성을 확인하였다.