• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.925-934
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• 2005

The dynamic response due to the unbalance and crack and the quasi-static response due to gravity are analytically derived based on the complex transfer matrix. The additional slope is expressed as function of the bending moment at crack position based on the fracture mechanics concept, and inversely the bending moment is expressed as function of the additional slope at the crack position. At each angle step during the shaft revolution, the additional slope and bending moment are calculated by an iterative method. The transient behavior is considered by introducing Fourier series expansion concept for the additional slope. Simulation is carried out for a simple rotor similar to those available in the literature and comparison of the basic crack behavior is shown. Using the additional slope, the cracked rotor behavior is explained with the crack depth increased: the magnitude of the additional slope increases and the closed crack duration during a revolution decreases as the crack depth increases. The direction of unbalance is also shown as a factor to affect the crack breathing. Whirl orbits are shown near the sub-critical speed ranges of the rotor.

• 한국소음진동공학회논문집
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• 제15권10호
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• pp.1137-1147
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• 2005

The dynamic response due to the unbalance and crack and the quasi-static response due to gravity are analytically derived based on the complex transfer matrix. The additional slope is expressed as function of the bending moment at crack position based on the fracture mechanics concept, and inversely the bending moment is expressed as function of the additional slope at the crack Position. At each angle step during the shaft revolution, the additional slope and bending moment are calculated by an iterativemethod. The transient behavior is considered by introducing Fourier series expansion concept for the additional slope. Simulation is carried out for a simple rotor similar to those available in the literature and comparison of the basic crack behavior is shown. Using the additional slope, the cracked rotor behavior is explained with the crack depth increased: the magnitude of the additional slope increases and the closed crack duration during a revolution decreases as the crack depth increases. The direction of unbalance is also shown as a factor to affect the crack breathing. Whirl orbits are shown near the sub-critical speed ranges of the rotor.

• 조명전기설비학회논문지
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• 제12권2호
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• pp.1-6
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• 1998

INSNA에서 제시하고 있는 환경등급에 따른 광속유지율 산정법에 기초하여, 각 고속도로의 교통량, 주변 지역의 오염 정도에 따라 세분화된 보수율을 산정하는 방법을 제시함으로써 고속도로 조명설계에 있어서 보수율 적용을 손쉽게 할 수 있도록 하였다. 또한, 그러나 기존의 보수율 개념만 가지고는 실제적인 광손실률 값을 얻을 수 없으므로 장치적용률로서 0.9 정도를 고려해야 실제 현장에서 적용하고 있는 보수율에 근사한 값을 얻을 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.122-125
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• 2005

A novel torque ripple reduction scheme of single-phase SRM with high power factor is presented. The proposed SRM drive has one additional active switches in the conventional asymmetric inverter. In order to get a higher power factor, the source current is controlled sinusoidal, And additional excitation current is added from charge capacitor due to torque ripple reduction. The switching period of source and charged voltage is controlled properly to get unity power factor and torque ripple reduction. The characteristics and validity of the proposed scheme is discussed with some simulation results.

• The Journal of the Acoustical Society of Korea
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• 제23권2E호
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• pp.40-43
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• 2004

In moving jammer environments, the performance of conventional adaptive beamformer is severely degraded and the robust adaptive beamformer requires additional sensors to obtain desired performances. Therefore, it is necessary to develop efficient algorithm without any additional requirement of the number of sensors, etc. In this paper, we introduce a fast adaptive algorithm with variable forgetting factor, which does not have any additional requirements. From the computer simulations, we obtain the better performances than those of other techniques for the arrays with various aperture lengths.

• 한국식생활문화학회지
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• 제22권5호
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• pp.575-581
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• 2007

The purpose of this study was to investigate the influence of additional marketing mix on overall satisfaction of customers at family restaurants in Seoul and Kyongki-province. In this research frequency analysis, reliability analysis, factor analysis, multiple-regression analysis were employed to analyze the data. Additional marketing mix were divided into 3 factors. Employee(${\beta}=0.352$, t(p)=7.221(0.000) had the most positive impact on overall satisfaction. And physical evidence(0.160, t(p)=3.271(0.001) and process(${\beta}=0.114$, t(p)=2.338(0.020) influenced positively(+) in order. As a result, all factors of additional marketing mix influenced significantly overall satisfaction of customers. These additional marketing mix are regarded as effective marketing tactic to reduce intangibility of food-service business. Therefore restaurant company needs to manage additional marketing mix sufficiently to maintain of customers' satisfaction at family restaurants.

• 한국통신학회논문지
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• 제41권9호
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• pp.1141-1145
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• 2016

일반적으로 RLS 알고리즘에서 비정재성(non-stationary) 환경에서 시간에 따라 변하는 파라메터를 좀 더 잘 추정하기 위해서 가변 망각인자를 사용한다. RLS 알고리즘에서 가변 망각인자를 사용할 때는 연산량이 많이 증가하는 단점이 수반된다. 본 논문에서는 연산량이 적은 가우스 뉴턴 가변망각인자 RLS 알고리즘을 제안한다. 본 방법은 기존 가우스 뉴턴 가변망각인자 RLS와 거의 유사한 성능을 보유하고 있을 뿐만 아니라 부가로 요구되는 연산량을 $O(N^2)$에서 O(N)으로 줄이는 효과도 준다.

• 품질경영학회지
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• 제38권1호
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• pp.42-51
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• 2010

For the fractional factorial designs, the resolution-IV designs can be used when we want to estimate the main effects and to investigate the structure of the non-negligible two-factor interaction effects, when the three-factor and higher order interaction effects are all negligible. However we need to add the additional treatment combinations in order to identify the influential interactions for the resolution-IV fractional factorial designs. In this paper we investigate the statistical structure for 3-level resolution-IV designs constructed by fold-over scheme and introduce a method for analyzing the influential two-factor interactions.

• 한국관개배수논문집
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• 제18권2호
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• pp.66-75
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• 2011

Multivariate statistical analysis was applied to 110 dam heightening reservoir to classify the building conditions for waterfront centered around cultivated area using data of land cover, landscape, additional water quantity, local economic, tourism resources, and accessibility related variables. Five factors were extracted through factor analysis based on eigen value criteria of more than one. These five factors together account for 68.2% of the total variance. Characteristics of five factors for the downstream of dam heightening reservoirs are building conditions of waterfront, economic conditions, additional water quantity, eco-tours, and accessibility of tourism resources respectively. Five clusters were classified through cluster analysis based on factor score. The classified result shows that third cluster has remunerative terms for building waterfront.

• Steel and Composite Structures
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• 제33권5호
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• pp.629-640
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• 2019

This paper presents a theoretical and finite element (FE) study on the stress intensity factors of double-edged cracked steel beams strengthened with carbon fiber reinforced polymer (CFRP) plates. By simplifying the tension flange of the steel beam using a steel plate in tension, the solutions obtained for the stress intensity factors of the double-edged cracked steel plate strengthened with CFRP plates were used to evaluate those of the steel beam specimens. The correction factor α₁ was modified based on the transformed section method, and an additional correction factor φ was introduced into the expressions. Three-dimensional FE modeling was conducted to calculate the stress intensity factors. Numerous combinations of the specimen geometry, crack length, CFRP thickness and Young's modulus, adhesive thickness and shear modulus were analyzed. The numerical results were used to investigate the variations in the stress intensity factor and the additional correction factor φ. The proposed expressions are a function of applied stress, crack length, the ratio between the crack length and half the width of the tension flange, the stiffness ratio between the CFRP plate and tension flange, adhesive shear modulus and thickness. Finally, the proposed expressions were verified by comparing the theoretical and numerical results.