• 한국산업융합학회 논문집
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• 제7권4호
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• pp.355-361
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• 2004

The finite element method were used to determine the stress intensity factor of cracked plate. The stress method, displacement method and J Integral are most popular finte element method. ANSYS proposed another a kind of displacement method. In this paper, it was examined that the accuracy and utility of the ANSYS method could believable to determine the stress intensity factors of centered inclined crack. Generally, inclined crack has two portion of stress intensity factors, tensile mode F1 and shear mode F2. For the purpose of increasing the accuracy of stress intensity factors, examined the effect of the numbers of nodes and elements, crack tip element size and number of partition of the crack tip vicinity. It was found that the method proposed by ANSYS is useful and has high accuracy. Accuracy of calculated stress intensity factors was increased by increase of the number of nodes and elements, and at the small size of crack tip elements can get more highly accuracy.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.1138-1141
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• 2002

In this study, the ISO 15186-1 “Measurement of sound insulation in buildings and of building elements using sound intensity - Part 1 : Laboratory conditions” was reviewed in order to make it as a new Korean Industrial Standard. Several main contents are discussed.

• Earthquakes and Structures
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• 제4권1호
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• pp.109-132
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• 2013

Current codes incorporate simplified methods for the prediction of acceleration demands on secondary structural and non-structural elements at different levels of a building. While the use of simple analysis methods should be advocated, damage to both secondary structural and non-structural elements in recent earthquakes have highlighted the need for improved design procedures for such elements. In order to take a step towards the formation of accurate but simplified methods of predicting floor spectra, this work examines the floor spectra on elastic and inelastic single-degree of freedom systems subject to accelerograms of varying seismic intensity. After identifying the factors that appear to affect the shape and intensity of acceleration demands on secondary structural and non-structural elements, a new series of calibrated equations are proposed to predict floor spectra on single degree of freedom supporting structures. The approach uses concepts of dynamics and inelasticity to define the shape and intensity of the floor spectra at different levels of damping. The results of non-linear time-history analyses of a series of single-degree of freedom supporting structures indicate that the new methodology is very promising. Future research will aim to extend the methodology to multi-degree of freedom supporting structures and run additional verification studies.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.961-964
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• 2002

A KS draft of the measurement of sound insulation in buildings and of building elements using sound intensity: laboratory conditions is proposed. It is based on ISO 15186-1. In order to make it as a KS, some contents are carefully tested.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.251-255
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• 2012

Structural intensity has been mainly utilized to identify vibration energy flow in a vessel. In this paper, the structural intensity of a shuttle tanker subjected to H-moment of the main engine was calculated using a finite element model. From the analysis, it was found that the top-bracing elements, which support the main engine onto the hull structure to prevent the excessive transverse vibration of the main engine, play the role of the dominant path and sink for vibration energy flow from the main engine. Therefore, the structural intensity was controlled by the modification of stiffness and damping characteristics of the top-bracing elements. As a result, it is observed that the transverse vibration level at the center of navigation bridge deck decreased after the control of structural intensity.

• 감성과학
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• 제16권2호
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• pp.187-194
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• 2013

본 연구는 컬러영상에서 특정소리를 연상시킬 수 있는 공감각 인지현상에 기반하여 컬러이미지에서 음악요소로 변환하는 시스템의 구현을 최종 목표로 한다. 이는 빛과 소리의 물리적 주파수정보사이의 유사도를 기반으로 이루어진다. 입력 컬러영상은 우선 컬러모델변환이론에 기초하여 색상(Hue), 채도(Saturation) 및 명도(Intensity)영역으로 변환된다. 음계, 옥타브, 크기 및 시간길이 등의 음악적 성분들이 HSI 컬러모델의 각 영역으로부터 추출된다. 기본주파수(F0, Fundamental Frequency)는 색상 및 명도 히스토그램에서 추출되고, 크기 및 시간길이성분은 명도와 채도 히스토그램에서 추출된다. 실험에서, 제안된 시스템은 표준 C 및 VC++ 기반에서 실현되었고, 최종적으로 WAV 포맷의 사운드파일이 생성되었다. 시뮬레이션 결과를 통해서 입력 컬러영상에서 추출된 음악적 요소들이 출력 사운드신호에 반영됨을 알 수 있었다.

• Journal of the Optical Society of Korea
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• 제5권3호
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• pp.93-98
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• 2001

In order to verify the performance of the two-stage iterative Fourier transform algorithm[Hankook Kwanghak Hoeji 11, 47 (2000)], a number of phase-only diffractive pattern elements which produce simple 16x16-pixel intensity patterns useful in the field of optical information processing have been designed and their performance has been compared with that from the nonlinear least-squares algorithm[Appl. Opt. 36, 7297(1977)] which is computationally intensive. for all intensity patterns, elements designed by the former algorithm show better overall signal-to noise ratio and uniformity, although they show essentially the same diffraction efficiency. In the case of continuous phase elements, they show far superior uniformity. Computationally,. the former algorithm is far more efficient than the latter.

• Journal of Advanced Marine Engineering and Technology
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• 제6권1호
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• pp.41-48
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• 1982

One of the important subjects in fracture mechanics study is to analyze the stress intensity factor. In this paper, the stress intensity factor in Mode I ($K^{I}$) is determined by J-integral using the finite element method. In this investigation, the values of $K^{I}$ are computed for distorted and undistorted elements of 8-noded isoparametric finite elements. The numerical results obtained are summarized as follows. (1) Through a relatively coarse mesh, the $K^{I}$ values obtained by this method are fairly good accuracy. (2) The $K^{I}$ values for the distorted elements appear to be better than those obtained using the undistorted mesh. (3) Within the limits of these analyses, the solutions obtained through the integral paths in the medium region of elements approach to the analytical solution most closely.

• Journal of the Korean Wood Science and Technology
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• 제21권1호
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• pp.15-20
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• 1993

X-ray diffractograms of the vessel elements and the wood fibers of Quercus variabilis BLUME were recorded and resolved into characteristic reflections of cellulose I. Some differences were observed in the ratio of integrated intensity and crystallinity index between vessel elements and wood fibers. Present results suggest that cellulose crystal structure in the hardwood species was varied with the elements of wood.

• Structural Engineering and Mechanics
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• 제35권3호
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• pp.283-299
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• 2010

This paper addresses the numerical simulation of fatigue crack growth in arbitrary 2D geometries under constant amplitude loading by the using a new finite element software. The purpose of this software is on the determination of 2D crack paths and surfaces as well as on the evaluation of components Lifetimes as a part of the damage tolerant assessment. Throughout the simulation of fatigue crack propagation an automatic adaptive mesh is carried out in the vicinity of the crack front nodes and in the elements which represent the higher stresses distribution. The fatigue crack direction and the corresponding stress-intensity factors are estimated at each small crack increment by employing the displacement extrapolation technique under facilitation of singular crack tip elements. The propagation is modeled by successive linear extensions, which are determined by the stress intensity factors under linear elastic fracture mechanics (LEFM) assumption. The stress intensity factors range history must be recorded along the small crack increments. Upon completion of the stress intensity factors range history recording, fatigue crack propagation life of the examined specimen is predicted. A consistent transfer algorithm and a crack relaxation method are proposed and implemented for this purpose. Verification of the predicted fatigue life is validated with relevant experimental data and numerical results obtained by other researchers. The comparisons show that the program is capable of demonstrating the fatigue life prediction results as well as the fatigue crack path satisfactorily.