• Fibers and Polymers
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• 제6권4호
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• pp.339-342
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• 2005

In this paper, a hand-operating method (tiled test method) of the wool-blending sample is made out, and make use of the method, the test of wool-blending bundle in different blending ratio is accomplished. According to the test data, the synthesis method of the stretch curve is worked out and the synthesis software for the typical stretch curve of wool-blending bundle is designed. Through laboratory hand-operating method, the blending fasciculus applying to fiber bundle test can be obtained in a short time. Calculation for sampling is accomplished in the article. We bring up 9 new signs to describe the characteristics of the curve behind peak for the first time: elongation behind peak (HE), elongation percentage behind peak (HEP), relative elongation rate behind peak (RHE), total break work $(W_a)$, break work behind peak (HW), break work coefficient behind peak (HWC), elongation percentage of half-load behind peak (HEL), load percentage of half-elongation behind peak (HLE), break efficiency behind peak (HEC).

• 전기전자학회논문지
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• 제22권3호
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• pp.585-589
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• 2018

Consumer demand for high quality image/video services led to growing trend in image quality enhancement study. Therefore, recent years was a period of substantial progress in this research field. Through careful observation of the image quality after processing by image enhancement algorithms, we perceived that the dark region in the image usually suffered loss of contrast to a certain extent. In this paper, the low-light stretch preprocessing algorithm is, hence, proposed to resolve the aforementioned issue. The proposed approach is evaluated qualitatively and quantitatively against the well-known histogram equalization and Photoshop curve adjustment. The evaluation results validate the efficiency and superiority of the low-light stretch over the benchmarking methods. In addition, we also propose the 255MHz-capable hardware implementation to ease the process of incorporating low-light stretch into real-time imaging systems, such as aerial surveillance and monitoring with drones and driving aiding systems.

• 한국해양공학회지
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• 제32권4호
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• pp.253-260
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• 2018

Recently, the application of non-steel materials in ships and offshore plants is increasing because of the development of various nonlinear materials and the improvement of performance. Especially, hyper-elastic materials, which have a nonlinear stress-strain relationship, are used mainly in marine plant structures or ships where impact relaxation, vibration suppression, and elasticity are required, while elasticity must be maintained, even under high strain conditions. In order to simulate and evaluate the behavior of the hyperelastic material, it is very important to select an appropriate material model according to the strain of the material. This study focused on the selection of material models for hyperelastic materials, such as rubber used in the marine and offshore fields. Tension and compression tests and finite element simulations were conducted to compare the accuracy of the nonlinear material models due to variations in the stretch ratio of hyper-elastic material. Material coefficients of nonlinear material models are determined based on the curve fitting of experimental data. The results of this study can be used to improve the reliability of nonlinear material models according to stretch ratio variation.

• 전자공학회논문지
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• 제52권4호
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• pp.56-61
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• 2015

고주파에서 이상적인 커패시턴스-전압 곡선과 결함이 존재하여 늘어진 커패시턴스-전압 곡선을 SiGe p-FinFET 시뮬레이션을 이용하여 보였다. 두 곡선이 게이트 전압 축으로 늘어진 전압 차이를 이용하여 평균적인 계면 결함 밀도를 구할 수 있었다. 또한 같은 특성을 이용하는 Terman의 방법으로 에너지에 따른 계면 결함 밀도를 추출하고, 동일한 에너지 구간에서 평균값을 구하였다. 전압 차이로 구한 평균 계면 결함 밀도를 Terman의 방법으로 구한 평균값과 비교하여, 두 방법의 결과가 거의 비슷한 평균 계면 결함 밀도를 나타낸다는 것을 검증하였다.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.277-280
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• 2011

We studied the relative stability and atomic structure of five $C_{20}^{2+}$ isomers obtained by two-electron ionization of a $C_{20}$ cage (the smallest fullerene). All the isomers are bond-stretch isomers, i.e., they differ in bond length. In particular, in one of the isomers with Ih symmetry, all the bond lengths are equal. Full geometry optimizations of the dipositive ion $C_{20}^{2+}$ were performed using the hybrid density functional (B3LYP/6-31G(d)) methods. All isomers were found to be true minima by frequency analysis at the level of B3LYP/6-31G(d) under the reinforced tight convergence criterion and a pruned (99,590) grid. The zero-point correction energy for the cage bond-stretch isomers was in the increasing order $D_{2h}<C_{2h}<C_2<T_h<I_h$ of $C_{20}^{2+}$. The energy difference among the isomers of cage dipositive ions was less than that among neutral cage isomers. Our results suggest that these isomers show bond-stretch isomerism and that they have an identical spin state and an identical potential energy curve. Although the predominant electronic configurations of the isomers are similar, the frontier orbital characteristics are different, implying that we could anticipate an entirely different set of characteristic chemical reactions for each type of HOMO and LUMO.

• 한국의류산업학회지
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• 제8권3호
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• pp.357-362
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• 2006

This study is to evaluate the objective sensibility of the commercial lining fabrics. Five kinds of the linings were collected by adding taffetas with four kinds of fibers (polyester, nylon, rayon, and acetate) to one polyester stretch fabric. The six basic mechanical and hand properties were studied by using KES-FB system (Kawabata Evaluation System). The result of measuring the mechanical properties shows that polyester has high bending rigidity (B), that polyester-stretch has a high value of linearity of load-extension curve (LT), tensile energy (WT), tensile resilience (RT), and coefficient of friction (MIU) and a low value of bending rigidity(B), shear property, and geometrical roughness (SMD). The nylon has a high value of bending rigidity (B), shear property, and compression resilience (RC). The rayon has a high value of coefficient of friction (MIU) and linearity of compression-thickness curve (LC) and a low value of shear property, and the acetate has a low value of shear property. The result of hand value shows that polyester, nylon, and acetate are a high value of KOSHI (stiffness), NUMERI (smoothness), and FUKURAM (fullness & softness), and they feel stiff and massive, that rayon has a low value of NUMERI and FUKURAMI. The total result of hand value shows that polyester taffeta and polyester stretch fabric are about the same as the best material for the lining of a woman's dress for spring and summer, and the next thing is acetate, but nylon and rayon are somewhat inferior materials. This provides a fundamental data for the comfortable clothing production of a higher value-added product through the study on the mechanical and hand properties of the lining as well as the right side of fabrics.

• 한국해양공학회지
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• 제14권1호
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• pp.44-51
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• 2000

Safety and integrity are required for reactor pressure vessels because they are operated in high temperature. There are single specimen method multiple specimen method and load ratio analysis method which used as evaluation of safety and integrity for reactor pressure vessels. In this study the fracture resistance curve(J-R curve) elastic-plastic fracture toughness($J_{IC}$) and material tearing modulus ($T_{mat}$) of SA 508 class 3 alloy steel used as reactor pressure vessel steel are measured and evaluated at room temperature 20$0^{\circ}C$ and 30$0^{\circ}C$ according to unloading compliance method and load ration analysis method. And then the comparison with experimental $J_{IC}$ and theoretical$J_{IC}$ by local fracture strain is managed.

• 대한수의학회지
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• 제36권1호
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• pp.65-74
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• 1996

Atrial Natriuretic Peptide(ANP) is a hormone with potent natriuretic, diuretic and relaxing properties of vascular smooth muscle. Specific chemical modulator responsible for the ANP secretion has not yet been found. Although atrial stretch of stretch-release is to be a major stimulus for the secretion of ANP, the precise mechano-molecular transduction mechanism responsible for its evoked secretion remains to be elucidated. It is interested to clarify the effect of superoxide anion in the stretch-induced ANP secretion. In order to investigate the effectg of $H_2O_2$ in the regulation of ANP secretion, a perfused model of left atrium of rats was used. The results obtained were as follows; 1. The ANP secretion and the extracellular fluid(ECF) translocation were accentuated by the effect of repetitive atrial distension-reduction volume at atrial pressure($4cmH_2O$). 2. The dilution curve showed to be in parallel between pure atriopeptin III (AP III) and perfusated buffer. 3. $H_2O_2(5{\times}10^{-4}M)$ accenturated a strectch-release induced increase of the ANP secretion. The amount of released ANP was significantly(p<0.01) increased. These results suggest that the superoxide anion may be involved in the regulatory mechanism of mechanically activated ANP release.

• 대한가정학회지
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• 제42권8호
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• pp.203-218
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• 2004

Recently, knitted materials are used more often than ever before in fashion. Therefore it is necessary to study their application into garment patterns. The purpose of this study was to develop a system by which the tensile property of knitted fabrics can be applied. In this study, 5 different distribution methods of tensile property were tested on 2 sample fabrics which have a lower and higher tensile property than moderate-stretch. The subjects were five women within an age range from 18 to 24 who showed average body figures. The major findings derived from this investigation were as follows; The 4th method was regarded as the most valid. The 4th method was fixed proportional alteration based on the reduction amount of bust girth, i.e. front (back) width and shoulder width reduced by 60％ of the bust girth reduction and neck point reduced by 28％ of the bust girth reduction. When the reduction was based on the proportion of the actual measurements, the alteration was too severe, so that the armhole curve was changed into a very uncomfortable curve.

• 감성과학
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• 제24권2호
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• pp.49-56
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• 2021

본 연구의 목적은 생체 신호 측정 압력 및 인장 직물 센서의 전극을 자수 공정을 이용하여 제작할 때 전도사의 필요 물성을 파악하는 것이다. 스마트 웨어러블 제품의 전극을 전도사를 이용한 자수 공정을 통해 전극 및 회로 등을 제작하면 불필요한 재료 손실이 없고 복잡한 전극 모양이나 회로 디자인을 컴퓨터 자수기를 이용하여 추가 공정 없이 제작할 수 있다. 하지만 보통의 전도사는 자수 공정 내의 부하를 못 이기고 사절 현상이 발생하기에 본 연구에서는 silver coated multifilament yarn 3종류의 기계적 물성인 S-S curve, 두께, 꼬임 구조 등을 분석하고 동시에 자수기의 실의 부하를 측정하여 자수 공정 내 전도사의 필요 물성을 분석하였다. 실제 샘플 제작에서 S-S curve의 측정 결과가 가장 낮은 silver coated polyamide/polyester가 아닌 silver coated multifilament의 사절이 발생하였으며 그 차이는 실의 꼬임 구조와 사절이 일어난 부분을 관찰한 결과 수직으로 반복적인 부하가 일어나는 자수 공정에서 꼬임이 풀리면서 사절이 일어나는 것을 알 수 있었다. 추가적으로 압저항 압력/인장 센서를 제작하여 생체 신호 측정용 지표인 gauge factor를 측정하였으며 스마트 웨어러블 제품의 대량 생산화에 중요한 부분인 자수 전극 제작으로의 적용 가능성을 확인하였다.