• 한국산업융합학회 논문집
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• 제3권4호
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• pp.337-343
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• 2000

Physical properties of matt georgette knitted fabrics, which has been developed recently, were investigated to provide fundamental information for the textile industry. Dimensional characteristics were examined with three different loop lengths, where the plain knitted fabrics were knitted with cotton yam and polyester yarn. The matt georgette plain knitted stitch was fully relaxed after wet relaxation treatment at $130^{\circ}C$ for 30minutes and subsequent tumble dry treatment at $70^{\circ}C$ for 90minutes. As the treatment temperature of wet relaxation became higher and the loop length did shorter, all of stitch density, course density and wale density were increased with 31 of $K_1$ 8.3 of $K_2$ and 3.8 of $K_3$. Also, The higher value of $K_4$ could be obtain with shorter loop length. When the loop length became longer, the $K_4$ value was varied in a wide range with the treatment of wet relaxation and subsequent tumble dry.

• Steel and Composite Structures
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• 제35권2호
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• pp.199-213
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• 2020

This paper proposes a Global-Local Analysis Method (GLAM) to assess the progressive collapse of steel framed structures under fire-induced column failure. GLAM obtains the overall structural response by combining dynamic analysis of the heated column (local) with static analysis of the overall structure (global). Test results of two steel frames which explicitly consider the dynamic effect during fire-induced column failure were employed to validate the proposed GLAM. Results show that GLAM gives reasonable predictions to the test frames in terms of both whether to collapse and the displacement verse temperature curves. Besides, several case studies of a two-dimensional (2D) steel frame and a three-dimensional (3D) steel frame with concrete slabs were conducted by using GLAM. Results show that GLAM gives the same collapse predictions to the studied cases with nonlinear dynamic analysis of the whole structure model. Compared with nonlinear dynamic analysis of the whole structure model, GLAM saves approximately 70% and 99% CPU time for the cases of 2D and 3D steel frame, respectively. Results also show that the load level of a structure has notable effects on the restraint condition of a heated column in the structure.

• Journal of Microbiology and Biotechnology
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• 제32권8호
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• pp.976-981
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• 2022

Phenanthrenes are bioactive phenolic compounds found in genus Dioscorea, in which they are distributed more in peel than in flesh. Recent studies on phenanthrenes from Dioscorea sp. peels have revealed the potential for valuable biomaterials. Herein, an analytical method using high-performance liquid chromatography (HPLC) for quantitation of bioactive phenanthrenes was developed and validated. The calibration curves were obtained using the phenanthrenes (1-3) previously isolated from Dioscorea batatas concentrations in the range of 0.625-20.00 ㎍/ml with a satisfactory coefficient of determination (R²) of 0.999. The limit of detection (LOD) and the limit of quantification (LOQ) values of the isolated phenanthrenes ranged from 0.78-0.89 and 2.38-2.71 ㎍/ml, respectively. The intraday and interday precision ranged from 0.25-7.58%. The recoveries of the isolated phenanthrenes were from 95 to 100% at concentrations of 1.25, 2.5, and 5.0 ㎍/ml. Additionally, phenanthrenes (1-3) were found in all investigated peel extracts. Hence, the developed method was encouraging for the quantitative analysis of phenanthrenes in genus Dioscorea.

• Human Ecology Research
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• 제59권2호
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• pp.275-286
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• 2021

In this study, we produced kimchi with cooked Dioscorea batatas yam based on the its outstanding nutritional value, biological activity, and pharmacological action. Sliced kimchi cabbage, processed white radish kimchi (kkakdugi), and whole kimchi cabbage were prepared with 3% Dioscorea batatas, and the physicochemical and bioactivity characteristics were analyzed. In three kinds of Dioscorea batatas. The pH of the kimchi decreased and its acidity increased as the storage period was extended. The period of the maximum total viable cell count of the sliced cabbage and the processed white radish kimchi (kkakdugi) was 14 days, while the period for whole kimchi cabbage was 21 days. The period of maximum lactic acid bacteria count was 14 days for all three kinds. For physiological activities, polyphenol and flavonoid contents and DPPH elimination were highest immediately after production of the kimchi. Also, anthocyanin content increased as the storage period extended. The pH, acidity, total viable cell count, lactic acid bacteria count, and physiological activities were shown to be different according to the type of kimchi and the storage period.

• Structural Engineering and Mechanics
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• 제82권5호
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• pp.611-628
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• 2022

Energy-dissipative rocking (EDR) columns are a class of seismic mitigation device capable of dissipating seismic energy and preventing weak-story failure of moment resisting frames (MRFs). An EDR consists of two hinge-supported steel columns interconnected by steel dampers along its height. Under earthquakes, the input seismic energy can be dissipated by plastic energy of the steel dampers in the EDR column. However, the unrecoverable plastic deformation of steel dampers generally results in residual drifts in the structural system. This paper presents a proof-of-concept study on an innovative device, namely self-centring energy-dissipative rocking (SC-EDR) column, aiming at enabling self-centring capability of the EDR column by installing a set of shape memory alloy (SMA) tension braces. The working mechanism of the SC-EDR column is presented in detail, and the feasibility of the new device is carefully examined via experimental and numerical studies considering the parameters of the SMA bar diameter and the steel damper plate thickness. The seismic responses including load carrying capacities, stress distributions, base rocking behaviour, source of residual deformation, and energy dissipation are discussed in detail. A rational combination of the steel damper and the SMA tension braces can achieve excellent energy dissipation and self-centring performance.

• Steel and Composite Structures
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• 제47권1호
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• pp.103-117
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• 2023

This paper presents an investigation on the shear resistance of corrugated web steel beams (CWBs) with a circular web opening. A total of five specimens with different diameters of web openings were designed and tested with vertical load applied on the top flange at mid-span. The ultimate strengths, failure modes, and load versus middle displacement curves were obtained from the tests. Following the tests, numerical models of the CWBs were developed and validated against the test results. The influence of the web plate thickness, steel grade, opening diameter, and location on the shear strength of the CWBs was extensively investigated. An XGBoost machine learning model for shear resistance prediction was trained based on 256 CWB samples. The XGBoost model with optimal hyperparameters showed excellent accuracy and exceeded the accuracy of the available design equations. The effects of geometric parameters and material properties on the shear resistance were evaluated using the SHAP method.

• Structural Engineering and Mechanics
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• 제81권1호
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• pp.39-50
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• 2022

Layer separation (delamination) is an essential threat to fiber-reinforced polymer (FRP) plates under dynamic, static, and fatigue loads. Under compressive load, the growth of delamination will lead to structural instability. The aim of this paper is to present a method using shape memory alloy (SMA) stitches to suppress the delamination growth in a FRP plate and to improve the buckling behavior of the plate with a rectangular hole. The present paper is divided into two parts. Firstly, a closed-form (CF) formulation for evaluating the buckling load of the FRP plate is presented. Secondly, the finite element method (FEM) will be employed to calculate the buckling loads of the plates which serves to validate the results obtained from the closed-form method. The novelty of this work is the development of the closed-form solution using the p-Ritz energy approach regarding the stress-dependent phase transformation of SMA to trace the equilibrium path. For the FEM, the Lagoudas constitutive model of the SMA material is implemented in FORTRAN programming language using a user material subroutines (VUMAT). The model is simulated in ABAQUS/Explicit solver due to the nature of the loading type. The cohesive zone model (CZM) is applied to simulate the delamination growth.

• Steel and Composite Structures
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• 제44권4호
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• pp.587-602
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• 2022

In this study, the classical J₂ flow theory is explicitly proved to be inappropriate to describe the plastic behaviour of structural steels under different stress states according to the reported test results. A numerical framework of the characterization of the strain hardening and ductile fracture initiation involving the effect of stress states, i.e., stress triaxiality and Lode angle parameter, is proposed based on the mechanical response of structural steels under monotonic loading. Both effects on strain hardening are determined by correction functions, which are implemented as different modules in the numerical framework. Thus, other users can easily modify them according to their test results. Besides, the ductile fracture initiation is determined by a fracture locus in the space of stress triaxiality, Lode angle parameter, and fracture strain. The numerical implementation of the proposed model and the corresponding code are provided in this paper, which are also available on GitHub. The validity of the numerical procedure is examined through single element tests and the accuracy of the proposed model is verified by existing test results.

• 한국작물학회지
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• 제30권2호
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• pp.131-139
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• 1985

이모작재배에 적합한 극조숙 양질 다수성 소맥품종육성을 위하여 등수기간에 관여하는 유전자 작용에 대한 연구는 매우 중요하다. 추파성품종 Yam-hill과 Hyslop, 춘파성품종 Red Bobs와 Siete Cellos를 사용하여 4 $\times$ 4 complete diallel crosses F$_1$, F$_2$, BC$_1$ 및 BC$_2$를 작성, Jinks-Hay-man model를 이용하여 등숙기간에 관여하는 유전자 작용을 분석하였다. 본 시험은 오레곤 주립대학교에서 실시되었다. 그 결과의 개요는 다음과 같다. 전등숙기간인 출수에서 생리적 성숙기까지의 기간과 출수에서 개화까지의 기간에서 maternal effect 가 인정되지 않았으며 비대립유전자간 상호작용도 발현되지 않았다. 개화에서 생리적 성숙기까지의 기간에서는 비대립유전자간에 상호작용이 인정되었다. 춘파성 품종인 Red Bobs와 Siete Cellos는 전등숙기간과 출수에서 개화까지의 기간을 지배하는 우성유전자들을 가지고 있었으며 짧은 쪽에 비하여 긴쪽이 우성으로 발현되고 있었다. 대조적으로 추파성 품종인 Yamhill 과 Hyslop은 개화에서 생리적 성숙기까지의 기간을 지배하는 우성유전자들을 가지고 있었으며 긴쪽이 우성으로 작용하고 있었다. 그리고 이 유전자들은 문배친들간에 독립적으로 분포되어 있었다.

• 한국의상디자인학회지
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• 제8권3호
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• pp.17-25
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• 2006

We performed the objective sensibility evaluation on knitted fabrics by the following procedures: setting acrylic fabrics with knitted fabrics as basis, knitted five kinds of blended spun yarns and four kinds of twisted filament yams made by different twisting methods(the amount and direction of twist) then, measuring mechanical properties in the use Kawabata Evaluation System, obtaining hand values and total hand values. The results are as follows: First, A(F)/W acrylic/wool spun knits obtain high scores in bending, compressing, shear properties, MMD, and thickness among five kinds of acrylic-blended knit fabrics. A(S)/W acrylic/wool blended knit represented prominent values at compressing properties and thickness and so wool-blended yams demonstrated superior characters comparing other blended yarns. To contrast, acrylic/rayon blended knits showed low scores in bending properties, shear properties and thickness, so that it affects to total hand values. On the one hand, among the four kinds of acrylic filament knitted fabrics, they do not exhibit any notable dynamic differences such as tensile properties of knitted fabrics by the twist number and direction of filament yarns, bending, shear, compressing properties, weight and thickness except surface properties. Second, fabrics showed the most high score at FUKURAMI (fullness and softness) among the hand values. A(S)/W acrylic/wool blended knits obtaining the lowest values at SAHRI (crispness) outrank at total hand values, so that it was the predominant knitted fabric in objective sensibility evaluation. In total hand values, five kinds of acrylic blended knits got a higher score than four kinds of acrylic filament knits, and the amount and direction of twist did not influence on total hand values among the four kinds of acrylic filaments.