• 대한산업공학회지
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• 제38권2호
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• pp.74-79
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• 2012

An efficient separation heuristic for the rank-1 Chvatal-Gomory cuts for the binary knapsack problem is proposed. The proposed heuristic is based on the decomposition property of the separation problem for the fixedcharge 0-1 knapsack problem characterized by Park and Lee [14]. Computational tests on the benchmark instances of the generalized assignment problem show that the proposed heuristic procedure can generate strong rank-1 C-G cuts more efficiently than the exact rank-1 C-G cut separation and the exact knapsack facet generation.

• International Journal of Oral Biology
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• 제30권4호
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• pp.117-123
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• 2005

Various aspects of antioxidant activity in vitamin C were evaluated in this study. Relatively high level of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was detected in vitamin C, but not in non-antioxidative vitamin, vitamin B1. Vitamin C also reduced the production of lipid peroxidation in Chinese hamster lung fibroblast (V79-4) cells with $IC_{50}$ value of $4{\mu}g/ml$. Vitamin B1 showed comparable reduction in lipid peroxidation products ($IC_{50}$ value was about $10{\mu}g/ml$). It was shown that vitamin C also dose-dependently enhanced the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in V79-4 cells, and these effects were not observed in vitamin Bl-treated cells. Our data suggest that well-known antioxidant vitamin C involved in direct activation of SOD, CAT and GPX.

• 한국자원식물학회지
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• 제25권4호
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• pp.363-371
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• 2012

본 연구에서는 딱총나무의 항산화 활성을 조사해 보았다. 딱총나무 잎과 줄기의 물추출물에는 6.6 mg/g과 2.0 mg/g의 phenolic compound가 함유되어 있었다. 추출물의 항산화 활성 실험에서 전자공여능은 딱총나무 잎의 물과 에탄올 추출물 phenolic 200 ${\mu}g/mL$의 함량에서는 99.5%, 89.7%, 줄기의 물과 에탄올 추출물 phenolic 200 ${\mu}g/mL$의 함량에서는 92.2%, 94.3%의 높은 항산화 효과를 나타내었다. 또한 ABTS radical cation decolorization 측정에서도 딱총나무 잎의 물과 에탄올 추출물 phenolic 200 ${\mu}g/mL$의 함량에서는 79.8%, 99.1%, 줄기의 물과 에탄올 추출물 phenolic 200 ${\mu}g/mL$의 함량에서 90.8%, 97.2%의 매우 높은 항산화 효과를 나타내었다. Antioxidant protection factor에서는 딱총나무 잎의 물과 에탄올 추출물 phenolic 200 ${\mu}g/mL$의 함량에서는 1.1과 1.1 PF, 줄기의 물과 에탄올 추출물 phenolic 200 ${\mu}g/mL$의 함량에서는 1.4와 1.0 PF의 항산화효과를 나타내었다. Thiobarbituric acid reaction substance 측정에서도 딱총나무 잎의 물과 에탄올 추출물 phenolic 200 ${\mu}g/mL$의 함량에서는 88.7%, 98.1%, 줄기의 물과 에탄올 추출물 phenolic 200 ${\mu}g/mL$의 함량에서는 93.6%, 90.6%로 positive control인 BHT 및 vitamin C보다 우수한 항산화 효과를 나타내었다. 본 연구의 결과로 딱총나무의 항산화 활성을 이용한 천연 기능성 식품소재로서의 활용이 가능할 것으로 판단되었다.

• 소성∙가공
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• 제29권5호
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• pp.257-264
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• 2020

This paper is concerned with the influence of the plastic property of the rivet on the numerical prediction of the Self-Piercing Rivet (SPR) Joining. In order to predict the plastic property of the rivet, a ring compression specimen was directly fabricated from the rivet used for the mechanical joining of dissimilar materials, and the FE analysis together with the ring compression test was iteratively carried out by changing the plastic property of the rivet. For reliable FE analysis, a friction coefficient was estimated based on a friction calibration curve, measuring the reductions in inner diameter and height of the ring specimen after the compression test. From each simulation result, the force-displacement curves were then compared from each other so as to obtain the rivet plastic property that shows good agreement with the experimental result. The SPR joining between GA590 1.0t and Al5052 2.0t was conducted, and the numerical prediction was performed with the use of the plastic property evaluated based on the inverse analysis and the one referred from Mori et al. [11]. Comparison of the experiment and the numerical predictions in terms of the interlock and bottom thickness revealed that the reliable evaluation of the plastic property of the rivet is necessary for the trustworthy numerical prediction of the SPR joining.

• 대한공업교육학회지
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• 제40권2호
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• pp.155-174
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• 2015

본 연구의 목적은 중등단계 직업교육에서의 발명 지식재산 교육내용에 대한 교사의 교육요구도 우선 순위를 분석하여, 중등단계 직업교육에서의 발명 지식재산교육이 효과적으로 이루어 질 수 있는 토대가 되는 교원의 역량 개발을 위한 직무 연수 프로그램 개발에 기초 자료를 제공하는 것이다. 이를 위해서 담당 교사 인식에 기반한 중등단계 직업교육에서의 발명 지식재산 교육내용에 대한 교육요구도와 이러한 교육요구도의 우선 순위를 분석하여 제시하였다. 본 연구의 구체적인 결과를 제시하면 다음과 같다. 첫째, 중등단계 직업교육에서 발명 지식재산 교육내용에 대한 담당 교사의 교육 요구도 평균은 5.02로 나타났다. 교육요구도가 전체 평균보다 높은 교육내용 항목은 23개이고, 이들 항목과 항목별 평균은 F4(특허 청구 범위) 6.72, F5(명세서 수정 및 보충) 6.46, F2(특허 도면 작성) 6.39, F3(특허명세서와 요약서 작성) 6.31, A5(발명 기법과 활동) 6.27, E6(발명 디자인 프로젝트) 6.15, H3(발명품 사업화) 5.97, F1(특허 정보 및 출원) 5.90, E5(디자인 권리화) 5.78, E3(발명 디자인의 디자인 과정) 5.77, A4(발명과 문제 해결) 5.57, G2(특허 조사 및 분류) 5.47, C2(발명 문제 해결 사고 기법) 5.45, E4(발명 디자인 제품 제작) 5.45, B5(발명특허 프로젝트) 5.42, A2(창의성 개발) 5.26, C4(발명 문제 해결 프로젝트) 5.26, H4(발명품 마케팅) 5.26, H2(발명품 사업성 분석) 5.20, D4(발명과 경영) 5.16, C3(문제 해결 활동) 5.14, E2(발명 디자인의 발상과 표현) 5.11, B3(발명기법의 실제) 5.08 순으로 나타났다. 둘째, 중등단계 직업교육에서 발명 지식재산 교육내용에 대한 담당 교사의 교육 요구도 우선 순위는 1순위에 해당하는 교육내용 항목은 13개, 2순위는 10개, 3순위는 17개로 나타났다. 1순위에 해당하는 교육내용 항목은 A4(발명과 문제 해결), A5(발명 기법과 활동), B5(발명특허 프로젝트), C2(발명 문제 해결 사고 기법), C4(발명 문제 해결 프로젝트), E3(발명 디자인 과정), E4(발명 디자인 제품 제작), E5(디자인 권리화), E6(발명 디자인 프로젝트), F1(특허 정보 및 출원), F2(특허 도면 작성), F3(특허명세서와 요약서 작성), H3(발명품 사업화)이다. 2순위에 해당하는 교육내용 항목은 A2(창의성 개발), B3(발명기법의 실제), C3(문제 해결 활동), D4(발명과 경영), E2(발명 디자인의 발상과 표현), F4(특허 청구 범위), F5(명세서 수정 및 보충), G2(특허 조사 및 분류), H2(발명품 사업성 분석), H4(발명품 마케팅)이다. 3순위는 1, 2 순위를 제외한 교육내용이다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2006년도 공동학술대회 논문집
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• pp.17-22
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• 2006

Shear modulus is directly linked to material's stiffness and is one of the most critical engineering parameters. Seismically, shear-wave velocity (Vs) is its best indicator. Although methods like refraction, down-hole, and cross-hole shear-wave surveys can be used, they are generally known to be tougher than any other seismic methods in field operation, data analysis, and overall cost. On the other hand, surface waves, commonly known as ground roll, are always generated in all seismic surveys with the strongest energy, and their propagation velocities are mainly determined by Vs of the medium. Furthermore, sampling depth of a particular frequency component of surface waves is in direct proportion to its wavelength and this property makes the surface wave velocity frequency dependent, i.e., dispersive. The multichannel analysis of surface waves (MASW) method tries to utilize this dispersion property of surface waves for the purpose of Vs profiling in 1-D (depth) or 2-D (depth and surface location) format. The active MASW method generates surface waves actively by using an impact source like sledgehammer, whereas the passive method utilizes those generated passively by cultural (e.g., traffic) or natural (e.g., thunder and tidal motion) activities. Investigation depth is usually shallower than 30 m with the active method, whereas it can reach a few hundred meters with the passive method. Overall procedures with both methods are briefly described.

• 한국염색가공학회지
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• 제21권2호
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• pp.1-6
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• 2009

Recently, polyester is widely used in textile fabrics due to its application potentials in various fields. It is known that askin fabric is prepared with mainly polyester and is enjoyed with various end uses such as marine clothing, underwear, shirts, swimming suits and so on. For this purpose, color fastness should be considered with great importance during its wet processing step. In this context, vat dyes were very much attracted due to the advantage of superior fastness property. Thus, we have used indigo dye towards askin fabric dyeings and investigated corresponding properties namely, dyeing temperature, concentration of dye, reducing agent amount and alkali amount. The results showed that higher color strengths of indigo dyeing on askin fabric were obtained at $110^{\circ}C$, 8% o.w.f, 3g/l, 5g/l, respectively. The color fastness to washing was considerable generally.

• 한국자원식물학회지
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• 제29권3호
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• pp.313-321
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• 2016

Persimmon has long been established as one of the major fruits in Korea. The southern parts of Korea were traditionally the pocket areas for good persimmon production; however, rising temperatures have gradually rendered the southern regions unsuitable for successful harvest. Ecology of fruit growing areas affects the productivity of various types of crops, including fruit trees such as persimmon. The quality characteristics of the fruit of persimmon cv. Dongchul grown in Gangwondo, which lies in the northern part of South Korea, were investigated. Different physicochemical, nutritional, and antioxidant properties of fruit were evaluated to assess the locational effect on the quality of persimmon fruits grown in Gangwondo. The results of this study showed that persimmon cv. Dongchul grown in Gangwondo maintains many of the physicochemical (4.33% crude protein and 4.32% crude fiber), nutritional (total mineral content: 461.51 and vitamin C content: 15.28 ㎎/100 g), and antioxidant properties (polyphenol content: 633.1 ㎎ gallic acid equivalent/100 g) those are found in other three commercial cultivars ‘Daebong’, ‘Kyengsan Bansi’, and ‘Sangju Doongsi’ grown in Korea. Overall results of this study imply that ‘Dongchul’ cultivar of persimmon could commercially be grown in Kangwondo, Korea.

• 산업식품공학
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• 제15권2호
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• pp.169-174
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• 2011

This study was performed to analyze the effects of ultra fine pulverization (UFP) on the physicochemical properties of sweet potato starch (SPS). The average diameter and specific surface area of the SPS was decreased from 22.94 to 10.25 $\mu$m and from 0.879 to 1.909 $m^2$ /g throughout UFP, respectively, and the damaged starch content was increased from 13.7 to 99.2%. The pulverized sweet potato starch (PSPS) had higher swelling power, solubility, and transmittance values than the SPS. X-ray diffractograms revealed that the SPS had a C-type pattern, which disappeared in PSPS. The rapid visco analysis (RVA) characteristics, peak viscosity, break down, and set back of SPS ceased to exist in PSPS. According to differential scanning calorimetry (DSC) curves, the peak temperature ($T_p$) and gelatinization enthalpy ($\Delta$E) of SPS were $71.95^{\circ}C$ and 10.40 J/g, respectively, while these remained undetected in PSPS. The enzymatic digestibilities of SPS and PSPS were 61.7 and 84.7%, respectively.

• 한국환경과학회지
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• 제21권7호
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• pp.805-813
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• 2012

The removal property of Cu and Zn ions by chemical precipitation and adsorption using zeolite(Z-C1) prepared from coal fly ash(CFA) were evaluated in this study. Adsorption kinetic and equilibrium mechanisms described to analyze parameters and correlation factors with Lagergen $1^{st}$ and $2^{nd}$ order model and Langmuir and Freundlich model. Analysis of adsorption kinetics data revealed that the pseudo $2^{nd}$ order kinetics mechanism was predominant. The equilibrium data in pH 3 - 5 were able to be fitted well to a Langmuir model, by which the maximum adsorption capacities($q_{max}$) were determined at 124.9 - 140.1 mg $Cu^{2+}/g$ and 153.2 - 166.9 mg $Zn^{2+}/g$, respectively. We found that Z-C1 has a potential application as absorbents in metal ion recovery with low pH.