• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.383-389
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• 2011

In this paper, a statistical calibration method is proposed in order to identify the variability of complex modulus for a rubber material due to operational temperature and experimental/model errors. To describe temperature- and frequency-dependent material properties, a fractional derivative model and a shift factor relationship are used. A likelihood function is defined as a product of the probability density functions where experimental values lie on the model. The variation of the fractional derivative model parameters is obtained by maximizing the likelihood function. Using the proposed method, the variability of a synthetic rubber material is estimated and applied to a rubber mount problem. The dynamic characteristics of the rubber mount are calculated using a finite element model of which material properties are sampled from Monte Carlo simulation. The calculated dynamic stiffnesses show very large variation.

• Electrical & Electronic Materials
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• v.6 no.3
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• pp.200-206
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• 1993

유기재료의 Electronic에 관련하는 물성과 구조와의 관계를 전자의 공역계분자와 vander waals상호작용과 Coulomb상호작용과의 조합에 의해서 설명하여 왔다. 앞에서 기술한 바와 같이 Electronic에 관련한 유기재료의 응용은 점점 넓어 지고 있는 추세에 있다. 따라서 이를 위한 유기재료의 전자물성의 평가 및 유기재료의 합성에 관한 많은 연구가 요구된다. 또한 유기재료의 미시적인 연구를 통하여 분자 Level의 기능소자도 가능할 것으로 기대되고 고차구조의 제어에 의한 전자물성의 향상 및 기능의 도출을 통한 그의 응용이 더욱 넓어질 것으로 보인다.

• Science of Emotion and Sensibility
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• v.10 no.3
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• pp.299-306
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• 2007

The purpose of this study is to analyze physical properties of foreign famous worsted fabrics to realize improvements in qualities of the domestic men's worsted fabrics and to make an comparison between foreign worsted fabrics and domestic ones. For this purpose, this study carries out both objective and subjective fabric hand measurements using KES-FB system and Blind field test, to evaluate physical properties of worsted fabrics and finally is aiming to make an comparison between the results from the two measurements for enhancing the quality of the domestic worsted fabrics using the 14 specimens of 7 types as worsted fabrics manufactured in Italy, UK and Korea.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.134.2-134
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• 2003

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.63-65
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• 2012

플라즈마 물성데이터는 플라즈마 내에서 일어나는 입자(전자, 원자, 이온분자 등) 들의 충돌에 의해 발생되는 데이터로써 플라즈마 현상을 이해하는 필수 데이터이며, 다양한 분야에서 응용되고 있다. 플라즈마 물성데이터를 산업계에서 지속적으로 참조하여 사용할 수 있도록 만든 수치데이터나 통계자료를 플라즈마 물성 참조데이터라고 한다. 기존 플라즈마 물성데이터 센터의 플라즈마 물성 참조데이터 수집평가 시스템은 사용자가 이용하고자 하는 플라즈마 물성 참조데이터를 일일이 자신의 시스템에 맞춰 데이터를 다시 가공해야 하는 어려움이 있어 데이터를 효율적인 관리하고 다양한 분야에 적용하기 위한 XML Schema 설계 대해 논의한다.

• Geophysics and Geophysical Exploration
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• v.24 no.1
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• pp.6-19
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• 2021

Subsurface physical properties can be obtained and imaged by seismic exploration, and various algorithms have been developed for this purpose. In this regard, root mean square error (RMSE) has been widely used to quantitatively evaluate the accuracy of the developed algorithms. Although RMSE has the advantage of being numerically simple, it has limitations in assessing structural similarity. To supplement this, full-reference image quality assessment (FR-IQA) techniques, which reflect the human visual system, are being investigated. Therefore, we selected six FR-IQA techniques that could evaluate the obtained physical properties. In this paper, we used the full-waveform inversion, because the algorithm can provide the physical properties. The inversion results were applied to the six selected FR-IQA techniques using three benchmark models. Using salt models, it was confirmed that the inversion results were not satisfactory in some aspects, but the value of RMSE decreased. On the other hand, some FR-IQA techniques could definitely improve the evaluation.

• Composites Research
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• v.26 no.5
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• pp.303-308
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• 2013

Carbon fiber (CF) reinforced polypropylene (PP) compositeis was increased to amount consumed. In this study, recycle of composites by recycle times. CF was containing 20%. Mechanical and interfacial propertis of CF/PP was evaluation for number of recycle time. Mechanical assessment of CF/PP was tension, bending, fatigue tension test and izod test method. Interfacial assessment of CF/PP was wettability test and FE-SEM of fracture surface method. Fiber and matrix was changed to recycle time. The more recycle of CF/PP, the more interfacial bonding was decreased. Because fiber and matrix was damaged to thermal damage. And then reinforced CF was shorter than original shape.

• Elastomers and Composites
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• v.43 no.3
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• pp.183-190
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• 2008

In this study, we have investigated mechanical properties and scratch resistance of polypropylene compounds by two types of masterbatch with different molecular weight of PP. Masterbatches were prepared with polypropylene(PP) and polydimethylsiloxane(PDMS) by melt mixing. Mechanical properties and scratch behavior were examined with UTM and polarizing microscope. The morphology surface of grain pattern was investigated Color 3D Laser Scanning Microscope. Mechanical properties of two masterbatches containing PP compounds showed a little bit difference in accordance with amount of M/B. Scratch resistance was much improved by adding masterbatches used high-molecular weight PP. Scratch resistance was excellent when grain pattern of the surface is deep, large, round and irregular.

• The Korean Journal of Rheology
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• v.10 no.2
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• pp.74-81
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• 1998

사출성형품의 설계는 그 내부의 기계적 물성 변화보다는 전통적으로 용도에 부합하 는 형상을 위주로 하여 이루어져 왔기 때문에 설계조건의 개선을 통하여 성능이 우수한 제 품을 얻기까지 많은 시행착오가 요구되고 있다. 그런데 사출성형 실험이나 물성평가 시험을 하기 전에 성형품의 부위별 기계적 물성을 알수있다면 제품의 설계나 금형 설계에 많은 도 움이 될 수 있으므로 최근에 물성 예측을 위한 방법론들의 개발이 다양하게 시도되고 있다. 따라서 본 연구에서는 학습시스템, 사출성형 수치모사와 기계적 물성과의 상관관계를 밝히 는 방법을 만들어 사출물이 제작되기 전에 그들의 기계적 물성을 사출성형 수치모사에서 얻 어진 열적·기계적 이력으로부터 예측하고자 하였다. 이때 성형품의 기계적 물성과 열적· 기계적 이력 사이에는 매우 복잡하고 비선형적인 상관관계를 보이기 때문에 이들 사이를 비 매개변수적으로 연관짓기 위하여 역전파 인공신경망 알고리듬을 사용하였으며 열적·기계적 이력은 사출성형용 수치모사 소프트웨어를 이용하여 구하였다. 학습과정에서 전역최소값에 도달하지 못하는 인공신경망의 문제점을 해결하기 위하여 모멘텀변수와 잡음지수를 포함하 는 일련의 항을 첨가하여 연결가중치를 보정하였다. 그 결과 어떤 초기값에 의하여 학습이 되더라도 전역최소값에 도달하는 것을 확인하였으며 이를 이용하여 다른 사출조건에서 사출 물의 기계적 물성을 잘 예측할수 있었다.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.4
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• pp.418-430
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• 2012

The present paper reviews the micro and nano nondestructive evaluation(NDE) technique that is possible to investigate the surface and measure the acoustic properties. The technical theory, features and applications of the ultrasonic atomic force microscopy(UAFM) and scanning acoustic microscopy(SAM) are illustrated. Especially, these technologies are possible to evaluate the mechanical properties in micro/nano structure and surface through the measurement of acoustic properties in addition to the observation of surface and subsurface. Consequently, it is thought that technique developments and applications of these micro/nano NDE in advanced industrial parts together with present nondestructive industry are widely possible hereafter.