• 대한기계학회논문집
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• 제18권2호
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• pp.372-379
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• 1994

In this study, the describing function is adopted to represent nonlinearity in the system equations. The compliance can be obtained by solving nonlinear simultaneous algebraic quations for multi-degrees-of-freedom system with multinonlinearities. When the technique is applied, the nonlinearity of the system can be identified from the compliance which is obtained from the sinusoidal excitation of the system. By employing the describing function in the Building Block Analysis, we can extensively develop the BBA into investigation of the continuous systems with nonlinearities. The evaluated compliance can quantitatively show the effects of nonlinearity such as the transfer of the natural frequency, the variance of the compliance at the natural frequency, and the jump phenomena which occur during sweeping of the excitation frequency.

• 대한기계학회논문집A
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• 제20권1호
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• pp.53-67
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• 1996

The dynamic characteristics of mechanical structure are strongly affected by the properties of joint parameters. In this study, the test structures are constructed with two beams which are clamped by bolts, and a bolted joint which is modelled as a lumped stiffness element. To idientify the dynamic joint parameters with variance of clamping torque of bolts, the sensitivity analysis and the mode energy analysis methods are investigated experimentally. As a reult of these two methods, stiffnesses of bolted joint are experimentally found to increase as the clamping torque increases. These stiffnesses identified from the sensitivity analysis and the mode energy analysis method have some difference.

• 한국통신학회논문지
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• 제19권7호
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• pp.1407-1413
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• 1994

레이다에서 정확한 표적 정보를 얻기 위해서는 우선 클러터나 간섭 신호를 효율적으로 제거하고 표적을 검출하여야 한다. 본 논문에서는 신호를 제한 조건에 의해 구별되는 직교 부공간으로 투사함으로써 최분산 기분을 갖는 최적 검출기를 제한 조건을 갖지 않는 검출기로 변형하였다. 제안된 방법은 기존의 최적검출 알고리듬과 등가이며, 역행렬을 구하지 않고서도 빠른 수렴속도를 얻기위한 Gram-Schmidt 적교화가 가능한 구조를 가지게 된다. 모의 실험을 통해 제안된 검출기가 공간과 주파수 영역에서 적응적으로 잘 동작하고 있음을 보였다.

• Journal of the Korean Statistical Society
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• 제25권2호
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• pp.255-263
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• 1996

Let $(X_{1j}, X_{2j}, … , X_{nj}, Y_j/)$j = 1, 2, … , n, be a sample of size n on an (m + l)-dimensional vector $(X_1, X_2, … , X_m, Y)$, m .geq. 1. If $Y_{(r)}$ denote the rth order statistic from Y, then the $X_{[r:n]}$ paired with $Y_(r)$ is termed the concomitant vector of the order statistics. The general distributions of concomitant of order statistics will be found. The mean, variance and covariance of$X_{[r:n]}$ Will be studied. Then we will apply the results to the multivariate normal variate case.e.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.638-642
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• 2003

This paper presents a parameter design of an Electrorheological(ER) panel for noise reduction using Taguchi method. Taguchi method is a robust design method that determines control parameters in the presence of noise effect. Host structure thickness, spacer thickness, base oil viscosity and the weight ratio of ER particles are chosen for the control factors. A test setup in an SAE J1400 facility is used to analyze the sound transmission loss. The sensitivity of each factor with signal-to-noise(S/N) ratio and analysis of variance are investigated. The analysis results show that the weight ratio of ER particle and base oil viscosity of the ER fluid mostly affects the noise reduction in the presence of electric field. Based on the Taguchi method, an optimal configuration was designed and comparison is made with experimental result fer the verification.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.422-422
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• 2009

This paper describes the structural design of small wind turbine blade by using design of experiments. Blade structure consists of skin, spar and foam. The materials for skin and spar are a kind of Glass/Epoxy and form is polyurethane. It has 7 lay-ups with different ply angle. A factorial design is applied to design the ply angles considering manufacturing constraints and to investigate the safety factor which is calculated by structural analysis. In order to perform the structural analysis, the commercial software ABAQUS is used. Tsai-Wu failure criterion is chosen to compute safety factor. The determination of the significance of effects in the experiments is made through the analysis of variance. The results show that ply angle at skin affects the safety factor of wind turbine blade. And from this result, optimal ply angles of composite blade are achieved.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2018년도 춘계학술대회
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• pp.25-25
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• 2018

• 한국의류학회지
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• 제21권7호
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• pp.1109-1116
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• 1997

This study was designed to investigate the image of show window displays. The specific objectives of the study are as follows; 1) Construct a semantic differential scale to evaluate the images of show window displays; 2) Identify the factor structure of the show window displays; 3) Cluster the brands according to the images of show window displays; 4) Examine how the images of show window displays differ according to the different brand clusters; and 5) Identify by brand clusters, how the different show window display images affect the purchasing desires. The following conclusions were made from this study; 1.25 pairs of adjectives for show window displays were found to include five factor dimensions (total variance 67.7%) such as evaluation, interest, hardness and softness, maturity, and modernity. 2. The brands were divided into six clusters according to the show window display images. 3. There were significant differences in the visual evaluation of the brand clusters in the show window display images. 4. There were significant differences in the show window display images that affect the Purchasing desires among the brand clusters.

• 한국자동차공학회논문집
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• 제8권5호
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• pp.173-180
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• 2000

European side impact analysis of an electric vehicle was done using robust design. Locations and section properties of some of the vehicle structure components which influence the european side impact characteristics were chosen as the main factors for the robust design. Eight factors were considered for the analysis: one with two level and seven with three level combinations comprising the L18(21$\times$37) orthogonal array. It is shown that the sensitivities of the factors and the best combination of the factors can be obtained, and that the location of the main components were as much sensitive as the section properties of those. Also it is shown that the interactions were existed between some factors.

• 아동학회지
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• 제26권1호
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• pp.75-90
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• 2005

The structure of fears was identified and measured by Q methodology. Subjects were 40 school-aged children with emotional and behavioral problems. Subjectivity of children's fears was classified into 3 types by the QUANL program. Three types occupied 52% of all variance and correlations ranged between .31 and.52. The first type is "imaginative-sensitive perception" where children are fearful about unreal and imaginative objects related to death. The second type is "rational-empirical perception" where children are concerned about the impact of fearful objects and authoritative figures based on their own personal experience. The last type is "realistic-egocentric perception" where children are fearful of possible violence, crime, and disease.