• Journal of the Korean Wood Science and Technology
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• 제49권5호
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• pp.453-461
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• 2021

In wood-based composite panels, low-molar ratio (LMR) urea-formaldehyde (UF) resins usually result in reduced formaldehyde emission (FE) at the expense of poor adhesion. However, the FE and adhesion of medium-density fiberboard (MDF) bonded with LMR UF resins were both improved in this study. The modified LMR UF resins with transition metal ion-modified bentonite (TMI-BNT) nanoclay simultaneously improved the FE and adhesion of MDF panels. The modified LMR UF resins with 5% TMI-BNT resulted in a 37.1% FE reduction and 102.6% increase in the internal bonding (IB) strength of MDF panels. Furthermore, thickness swelling and water absorption also significantly decreased to 13.0% and 24.9%, respectively. These results imply that TMI-BNT modification of LMR UF resins could enhance the formation of a three-dimensional network rather than crystalline domains, resulting in improved cohesion.

• 대한방사선기술학회지:방사선기술과학
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• 제10권1호
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• pp.25-29
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• 1987

To compensate density of abnormal lung field for density of normal lung field, used each cellulose paper calculated sensitometry and contrast. As apply clinic part to the result: We are able to compensate density of abnormal lung that is pleural effusion atelectasis, etc for normal lung. We believe this method is good one because the method is simple to change exposure and the material is cheap enough to be accessible to every one and easily buyable and we need not be afraid of loss of image quality.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권2호
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• pp.39-52
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• 2003

This paper deals with an automatic design procedure for the maximum torque density and power factor in a synchronous reluctance motor (SynRM). The focus of this paper is the design relative to the number of flux barrier and the ratio Kw of flux barrier width to iron sheet width of a SynRM under the mechanical constraint. The Finite Elements Analysis (FEA) has been used to evaluate the maximum torque density and power factor with each rotor shape. The proposed procedure allows to define the rotor geometric dimensions starling from an existing mootor or a preliminary design. The maximum torque density and power factor of a SynRM has been resulted with the rotor design variation. To prove the propriety of the designed SynRM, the Digital Signal Processor (DSP) installed experimental devices are equipped and the efficiency characteristic test is Performed.

• Earthquakes and Structures
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• 제4권4호
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• pp.383-396
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• 2013

In earthquake engineering area, the critical excitation method is an approach to find the most severe earthquake subjected to the structure. However, given some earthquake constraints, such as intensity and power, the critical excitations have spectral density functions that often resonate with the first modes of the structure. This paper presents a non-stationary critical excitation that is capable of exciting the main modes of the structure using a non-uniform power spectral density (PSD) that is similar to natural earthquakes. Thus, this paper proposes a new method to estimate the power and intensity of earthquakes. Finally, a new method for the linear seismic design of structures using a modified non-stationary critical excitation is proposed.

• 전기학회논문지
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• 제59권3호
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• pp.549-554
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• 2010

This paper deals with optimum design criteria for maximum torque density & minimum torque ripple of Flux Switching Motor (FSM) using RSM & FEM. The focus of this paper is to find a design solution through the comparison of torque density and torque ripple according to rotor shape variations. And then, a central composite design(CCD) mixed resolution is introduced, and analysis of variance (ANOVA) is conducted to determine the significance of the fitted regression model.

• 대한교통학회지
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• 제29권3호
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• pp.83-91
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• 2011

이 논문은 확률론적인 방법을 이용하여 동적 통행시간(dynamic travel time) 모형을 도출한다. 동적 통행시간 모형은 차량의 통행시간은 도로 공간상에서의 교통흐름 분포에 따라, 또는 통행구간 출발점에서 시간에 대한 교통흐름의 분포에 따라 결정된다고 가정하여 얻어진다. 이 모형들에서 교통흐름의 분포가 차량의 통행시간에 미치는 정도를 나타내는 확률밀도함수(probability density function)는 여러 가지 형태의 도입될 수 있으나 지수분포를 따른다고 가정한다.

• 한국전기전자재료학회논문지
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• 제16권10호
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• pp.952-957
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• 2003

The purpose of this paper is analyses about in 12kV/50kA vacuum interrupter with an axial magnetic field type electrode system through the studies of electromagnetic phenomena. Vacuum interrupter is important in electric safety part. In this paper, we performed analysis of electric field, magnetic field, current density in AMF electrode using the Maxwell 3D simulation. The current distribution and magnetic field in simple models are analyzed to verify its efficiency and accuracy. In addition the validity of FEM is confirmed by performing the analyses of distribution in current density and magnetic flux density.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.179-182
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• 1998

This paper is proposed a selection method of the major design dimension which constrain the maximum acceleration capability and minimum power loss of surface-mounted brushless do motor with NdFeB permanent magnet for servo drives. Expressions are derived from the air-gap flux density and the linear current density around the stator periphery and design dimensions. The linear current density is limited by the need to avoid demagnetization. In this paper, We compute the optimum design dimensions of 2KW BLDC motor with maximum acceleration capability and minimum power loss by using genetic algorithm.

• Communications for Statistical Applications and Methods
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• 제13권3호
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• pp.503-512
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• 2006

In this paper, the Inverse Weibull distribution parameters have been estimated using a new estimation technique based on the non-parametric kernel density function that introduced as an alternative and reliable technique for estimation in life testing models. This technique will require bootstrapping from a set of sample observations for constructing the density functions of pivotal quantities and thus the confidence intervals for the distribution parameters. The performances of this technique have been studied comparing to the conditional inference on the basis of the mean lengths and the covering percentage of the confidence intervals, via Monte Carlo simulations. The simulation results indicated the robustness of the proposed method that yield reasonably accurate inferences even with fewer bootstrap replications and it is easy to be used than the conditional approach. Finally, a numerical example is given to illustrate the densities and the inferential methods developed in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.414.1_415.1
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• 2009

This paper deals with optimum design criteria for maximum torque density & minimum torque ripple of Flux Switching Motor (FSM) using RSM & FEM. The focus of this paper is to find a design solution through the comparison of torque density and torque ripple according to rotor shape variations. And then, a central composite design(CCD) mixed resolution is introduced, and analysis of variance (ANOVA) is conducted to determine the significance of the fitted regression model.