• 동력기계공학회지
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• 제4권2호
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• pp.40-45
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• 2000

Some engineering materials are often known to have considerable spatial variation in their resisting strength and other properties. The objective of this study is to investigate the averaging effect and the applicability of extremal statistic for the statistical size effect. In the present study, it is assumed that the material property is a stationary random process in space. The theoretical autocorrelation function of the material strength are discussed for several correlation lengths. And, in order to investigate the statistical size effect, the material properties was simulated by using the non-Gaussian random process method. The material properties were plotted on the Weibull probability papers. The main results are summarized as follows: The autocorrelation function of the material properties are almost independent of the averaging length. The variance decreases with increasing the averaging length. As correlation length is smaller, the slope is larger. And also, it was found that Weibull statistics based on the weakest-link model could not explain the spatial variation of material properties with respect to the size effect satisfactory.

• 한국전기전자재료학회논문지
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• 제18권4호
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• pp.363-369
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• 2005

we compared the operating characteristics between flux-lock type and resistive type superconducting fault current limiters(SFCLs). Flux-lock type SFCL consists of two coils, which are wound in parallel each other through an iron core, and a high-Tc superconducting(HTSC) element is connected with coil 2 in series. The the flux-lock type SFCL can be divided into the subtractive polarity winding and the additive polarity winding operations according to the winding directions between the coil 1 and coil 2. It was confirmed from experiments that flux-lock type SFCL could improve both the quench characteristics and the transport capacity compared to the resistive type SFCL, which means, the independent operation of HTSC element.

• 한국전기전자재료학회논문지
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• 제16권9호
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• pp.775-782
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• 2003

In the study, the total conductivies in [(Ce $O_2$)$_{1-x}$ (Zr $O_2$)$_{x}$]$_{0.8}$(Sm $O_{1.5}$)$_{0.2}$ (x- 0, 0.05, 0.1, 0.2) solid solution were measured as a function of temperature and oxygen partial pressure between 80$0^{\circ}C$ and 1,00$0^{\circ}C$ using 4-probe d.c method. Under pure oxygen atmospere, the oxygen ionic conductivity of [(Ce $O_2$)$_{1-x}$ (Zr $O_2$)$_{x}$]$_{0.8}$(Sm $O_{1.5}$)$_{0.2}$ decreased with the concentration of Zr $O_2$At high oxygen partial pressure, the electrical conductivity is almost independent of oxygen partial pressure and decreased with the increase in Zr content. However, the electrical conductivity increase with decreasing oxygen partial pressure and is almost independent of Zr content at low oxygen partial pressure. Empirically, Total conductivity( $\sigma$ ) was expressed by the p$o_{2}$ -independent conductivity as $\sigma$$_{i}$, and the $p_{-1/4}$ $o_{2}$sup -dependent part as $\sigma$$_{e}$. Total, ionic and electronic conductivities fitted by data enabled to determine the transference number. The ionic transference number( $t_{i}$ ) decreased while the electronic transference( $t_{e}$ ) increase with the increase in Zr content and p$o_{2}$.

• 분석과학
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• 제20권6호
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• pp.502-507
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• 2007

X 선 회절법은 물질 내부에 원자의 배열 상태를 연구하는데 널리 사용되는 실험 방법으로써 넓은 응용 범위를 가지고 있다. 특히 분말 X 선 회절법은 비파괴적으로 다양한 형태의 시료에 대한 측정이 가능하기 때문에 결정의 배향성, 결정의 크기, 결정 내부의 응력 측정 등에 널리 이용되고 있다. 분말 X 선 회절 방법을 이용하여 혼합물의 성분을 정량적으로 측정하기 위해서는 시료를 구성하고 있는 source 스펙트럼을 도출하고 혼합된 시료의 XRD 스펙트럼에 회귀식을 적합시켜 혼합물 구성비를 얻는 방법이 제안된 바 있다. 그러나 구성성분의 특성상 스펙트럼의 피이크가 폭이 좁고 민감한 경우에는 노이즈의 영향을 받아 도출된 source 스펙트럼이 원래의 순수성분의 형태와 달리 나타날 수 있다. 특히 순수성분 시료를 구할 수 없거나 측정이 불가능한 경우 혼합물 구성비 측정에 어려움이 있다. 본 연구에서는 노이즈 간섭에 의한 source 스펙트럼 도출의 문제를 해결하는 방안으로 비음독립성분분석을 이용하여 혼합된 미지시료로부터 순수한 성분에 해당하는 스펙트럼을 분리해내는 방법을 제안하고자 한다.

• Genomics & Informatics
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• 제19권4호
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• pp.39.1-39.8
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• 2021

Tamoxifen (TAM) is an anticancer drug used to treat estrogen receptor (ER)-positive breast cancer. However, its ER-independent cytotoxic and antifungal activities have prompted debates on its mechanism of action. To achieve a better understanding of the ER-independent antifungal action mechanisms of TAM, we systematically identified TAM-sensitive genes through microarray screening of the heterozygous gene deletion library in fission yeast (Schizosaccharomyces pombe). Secondary confirmation was followed by a spotting assay, finally yielding 13 TAM-sensitive genes under the drug-induced haploinsufficient condition. For these 13 TAM-sensitive genes, we conducted a comparative analysis of their Gene Ontology (GO) 'biological process' terms identified from other genome-wide screenings of the budding yeast deletion library and the MCF7 breast cancer cell line. Several TAM-sensitive genes overlapped between the yeast strains and MCF7 in GO terms including 'cell cycle' (cdc2, rik1, pas1, and leo1), 'signaling' (sck2, oga1, and cki3), and 'vesicle-mediated transport' (SPCC126.08c, vps54, sec72, and tvp15), suggesting their roles in the ER-independent cytotoxic effects of TAM. We recently reported that the cki3 gene with the 'signaling' GO term was related to the ER-independent antifungal action mechanisms of TAM in yeast. In this study, we report that haploinsufficiency of the essential vps54 gene, which encodes the GARP complex subunit, significantly aggravated TAM sensitivity and led to an enlarged vesicle structure in comparison with the SP286 control strain. These results strongly suggest that the vesicle-mediated transport process might be another action mechanism of the ER-independent antifungal or cytotoxic effects of TAM.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1997년도 Proceedings of the 12th KACG Technical Meeting and the 4th Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.45-48
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• 1997

ZrO$_2$ coated flake graphite powders were prepared by the controlled hydrolysis of zirconium oxichloride. The stirring process plays an important role in the coating process. There are two types of coated ZrO$_2$ particles: (a)primary particles with few nm size were obtained by the direct formation of the shell by precipitation of the surface of the graphite and (b) Secondary particles of ZrO$_2$ with ∼0.1$\mu\textrm{m}$ size were obtained by the independent formation of primary particles ZrO$_2$ and subsequent heterocoagulation at the graphites surface.

• 복식문화연구
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• 제8권2호
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• pp.315-333
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• 2000

The purpose of this study is to find out how the aesthetic values and characters of the Avant-garde fashion through semantics analysis of Avant-garde experiments in the early 20th century. Inner expressions of Avant-garde fashion in future dynamism, alien-hostile, and surreal-experimentalism are as followings (1) Reject tradition of existing fashion concept, (2) Dismantle costume material and inter-text characteristics in fashion field, (3) Laugh at material civilization and elite fashion, (4) Pursue primitive and fundamental sensibility on non-civilized world (5) Express human estrangement due to material civilization, (6) Remove the barrier of fashion between luxury and cheap ones, (7) Time, space and purpose is mixed, (8) Open concept as space structure independent of human body, (9) Complicatedness, ambiguity and expression of irregularity as changeableness, (10) Dismantle concept of beauty and ugliness. As you see, fashion design in modern Avan-garde is pursuing newness as beauty of open concept, rejecting all modern tradition and allowing extremity such as experimental, illogic, unreasonable and non-formatted expressions.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1994년도 봄 학술발표회 논문집
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• pp.181-188
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• 1994

Generally, the structural material shows rate dependent behaviors, which require to constitute different strain-stress relations according to strain rates. Conventional rate- independent constitutive equations used in general purpose finite analysis programs are inadequate for dynamic finite strain problems. In this paper, a rate dependent constitutive equation for elastic-plastic material was developed. The plastic stretch rate was modeled based on slip model with dislocation velocity and density so that there is no yielding condition, and no loading conditions. Non-linear hardening rule was also introduced for finite strain. Material constants of present constitutive equation were determined by experimental data of mild steel. The constitutive equation was applied to uniaxile tension. It was appeared that the present constitutive equation well simulates rate dependent behaviors of mild steel.

• Structural Engineering and Mechanics
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• 제56권1호
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• pp.85-106
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• 2015

Postbuckling of thick plates made of functionally graded material (FGM) subjected to in-plane compressive, thermal and thermomechanical loads is investigated in this work. It is assumed that the plate is in contact with a Pasternak-type elastic foundation during deformation. Thermomechanical non-homogeneous properties are considered to be temperature independent, and graded smoothly by the distribution of power law across the thickness in the thickness in terms of the volume fractions of constituents. By employing the higher order shear deformation plate theory together the non-linear von-Karman strain-displacement relations, the equilibrium and compatibility equations of imperfect FGM plates are derived. The Galerkin technique is used to determine the buckling loads and postbuckling equilibrium paths for simply supported plates. Numerical examples are presented to show the influences of power law index, foundation stiffness and imperfection on the buckling and postbuckling loading capacity of the plates.

• Steel and Composite Structures
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• 제11권2호
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• pp.115-130
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• 2011

Considering the randomness of material parameters in the laminated composite plate, a scheme of stochastic finite element method to analyze the displacement response variability is suggested. In the formulation we adopted the concept of the weighted integral where the random variable is defined as integration of stochastic field function multiplied by a deterministic function over a finite element. In general the elastic modulus of composite materials has distinct value along an individual axis. Accordingly, we need to assume 5 material parameters as random. The correlations between these random parameters are modeled by means of correlation functions, and the degree of correlation is defined in terms of correlation coefficients. For the verification of the proposed scheme, we employ an independent analysis of Monte Carlo simulation with which statistical results can be obtained. Comparison is made between the proposed scheme and Monte Carlo simulation.