• 대한기계학회논문집A
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• 제26권4호
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• pp.775-786
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• 2002

A Mixed Volume and Boundary Integral Equation Method is applied for the effective analysis of elastic wave scattering problems and plane elastostatic problems in unbounded solids containing general anisotropic inclusions and voids or isotropic inclusions. It should be noted that this newly developed numerical method does not require the Green's function for anisotropic inclusions to solve this class of problems since only Green's function for the unbounded isotropic matrix is involved in their formulation for the analysis. This new method can also be applied to general two-dimensional elastodynamic and elastostatic problems with arbitrary shapes and number of anisotropic inclusions and voids or isotropic inclusions. In the formulation of this method, the continuity condition at each interface is automatically satisfied, and in contrast to finite element methods, where the full domain needs to be discretized, this method requires discretization of the inclusions only. Finally, this method takes full advantage of the pre- and post-processing capabilities developed in FEM and BIEM. Through the analysis of plane elastostatic problems in unbounded isotropic matrix with orthotropic inclusions and voids or isotropic inclusions, and the analysis of plane wave scattering problems in unbounded isotropic matrix with isotropic inclusions and voids, it will be established that this new method is very accurate and effective for solving plane wave scattering problems and plane elastic problems in unbounded solids containing general anisotropic inclusions and voids/cracks or isotropic inclusions.

• 한국식품영양과학회지
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• 제34권6호
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• pp.869-874
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• 2005

녹차 및 발효정도에 따른 약발효차, 중발효차, 홍차 가루를 첨가하여 제조한 식빵의 일반성분, 수분결합력, 무게, 부피, 색도, texture 및 관능검사 측정한 결과는 다음과 같다. 차가루 첨가식빵의 수분함량은 $36.02\~36.44\%$로 대조구 $36.98\%$와 거의 차이가 없었다. 조단백질과 회분 함량은 대조구보다 차첨가구가 높게 나타났다 수분결합력은 녹차 첨가구가 가장 높았고, 발효차 첨가구, 대조구 순으로 높게 나타났다 식빵의 부피와 비용적은 대조구가 가장 높게 나타났고, 발효 차 첨가구, 녹차첨가구 순으로 높게 나타났다. 색도는 대조구에 비하여 발효가 많이 진행된 차가루를 첨가한 식빵일수록 L값은 낮고, a값과 b값은 높게 나타났다. 식빵의 견고성은 발효가 많이 진행된 차가루 첨가구일수록 높게 나타난 반면, 응집성은 발효가 많이 진행된 차가루를 첨가할수록 낮게 나타났다 접착성과 씹힘성은 홍차가루 첨가식빵이 가장 높았다. 관능검사 결과, 색깔, 외관, 질감은 대조구가 가장 높은 기호도를 보였고, 향미와 맛은 녹차 및 약발효차 가루 첨가구의 기호도가 높았으며, 전체적인 기호도는 약발효차 가루 첨가구의 선호도가 가장 높게 나타났다.

• 한국위성정보통신학회논문지
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• 제4권2호
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• pp.52-56
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• 2009

본 논문에서는 그린 함수(Green's function) 방법을 이용하여 하나의 페라이트 디스크를 사용하는 4 단자 스트립라인 서큘레이터 설계 방법을 제안한다. 통신 시스템 설계의 유연성을 높일 수 있는 4 단자 서큘레이터는 이제까지 2개의 3 단자 서큘레이터를 연결하여 사용하고 있다. 이를 하나의 페라이트 디스크를 사용하는 4 단자 서큘레이터로 대체하면 무게와 부피를 감소시킬 수 있어서 위성용으로 장점을 갖는다.

• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2557-2560
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• 2010

To assay for antioxidant capacity of natural products considered important in producing human health benefits, a practical and economical method using pellet techniques was developed. A standard visualizing reagent, 1,1diphenyl-2-picryl-hydrazyl (DPPH), was mixed with a water-miscible polyvinyl alcohol (PVA), serving as a solid phase support for the DPPH reagent. A DPPH pellet was prepared by dropping a small volume of the DPPH solution onto PET film, and drying in an oven. The PVA-based DPPH pellet was dissolved into water, in which the water-miscible PVA plays as a non-ionic surfactant to help the DPPH reagent to be dissolved into the solvent. Using the DPPH assay, the antioxidant capacity of water-soluble extracts of black soybean, barley, green tea, and green gram was examined. Among the natural products tested, green tea showed the highest antioxidant capacity. This PVA-based DPPH antioxidant assay can be further applied in the natural food, raw plant material, and health product inspection field.

• 한국식품영양과학회지
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• 제15권4호
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• pp.47-50
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• 1986

These studies were carried out to investigate effects of Leonurus sibiricus green juice on gastric secretion of rats and acute toxicity in mice ; $LD_50(mg/kg)$ of Leonurus sibiricus extract was 625mg/kg intraperitoneally in mice. The groups administered green juice and water extract of Leonurus sibiricus showed more excellent increasing effect in total acidity and peptic activity, and decreasing effect on gastric volume than control group. But any differences were not found between sample and control group in gastric pH. It is suggested that Leonurus sibiricus can he used as the bitter stomachics to promote the gastric digestion.

• East Asian mathematical journal
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• 제34권5호
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• pp.577-585
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• 2018

For the purpose of characterizing subharmonic or ${\mathcal{M}}$-subharmonic Hardy classes in the unit ball of ${\mathbb{C}}^n$, we establish fundamental identities between integral means in terms of volume integrals and Green's functions.

• 대한기계학회논문집A
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• 제23권11호
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• pp.1993-2006
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• 1999

A Volume Integral Equation Method (VIEM) is applied for the effective analysis of elastic wave scattering problems and plane elastostatic problems in unbounded solids containing general anisotropic inclusions. It should be noted that this newly developed numerical method does not require the Green's function for anisotropic inclusions to solve this class of problems since only Green's function for the unbounded isotropic matrix is involved in their formulation for the analysis. This new method can also be applied to general two-dimensional elastodynamic and elastostatic problems with arbitrary shapes and number of anisotropic inclusions and voids. Through the analysis of plane elastodynamic and elastostatic problems in unbounded isotropic matrix with orthotropic inclusions and voids, it will be established that this new method is very accurate and effective for solving plane elastic problems in unbounded solids containing general anisotropic inclusions and voids.

• 아시안잔디학회지
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• 제16권2호
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• pp.107-114
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• 2002

본 연구는 토지피복현황과 식재의 계층구조가 다양한 도시녹지를 대상으로 기온저감효과에 미치는 영향을 파악하기 위해 녹지 내의 기온을 관측하였다. 그 테이터를 바탕으로 녹지내의 토지피복현황과 기온분포, 식재지율(식재의 면적비율)과 기온, 식재의 계층구조비율과 기온, 수목그루 및 녹적량(수목의 체적)과 기온 저감효과와의 관련성을 회귀분석 등에 의해 해석하였다. 그 결과, 고온역은 인공구조물과 나지 주변에서, 저온역은 식재지와 수면 주변에서 형성되었다. 또한, 식재의 계층구조가 2, 3층으로 덮여있는 구역과 수면을 핵으로 그 주변이 식재로 둘러싸인 구역이 상대적으로 낮은 기온을 나타냈다. 수목그루 및 녹적량의 증가는 어떤 수고라도 기온저감에 효과적이고 그 효율은 교목, 소교목, 관목의 순이다.

• Structural Engineering and Mechanics
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• 제81권5호
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• pp.575-589
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• 2022

In order to enhance the greenness in the strain-hardening composites and to reduce the high cost of typical polyvinyl alcohol fiber reinforced engineered cementitious composite (PVA-ECC), an affordable strain-hardening composite with green binder content has been proposed. For optimizing the strain-hardening behavior of cementitious composites, this paper investigates the effects of polypropylene fibers on the first cracking strength, fracture properties, and micromechanical parameters of cementitious composites. For this purpose, digital image correlation (DIC) technique was utilized to monitor crack propagation. In addition, to have an in-depth understanding of fiber/matrix interaction, scanning electron microscope (SEM) analysis was used. To understand the effect of fibers on the strain hardening behavior of cementitious composites, ten mixes were designed with the variables of fiber length and volume. To investigate the micromechanical parameters from fracture tests on notched beam specimens, a novel technique has been suggested. In this regard, mechanical and fracture tests were carried out, and the results have been discussed utilizing both fracture and micromechanical concepts. This study shows that the fiber length and volume have optimal values; therefore, using fibers without considering the optimal values has negative effects on the strain-hardening behavior of cementitious composites.

• 대한기계학회논문집A
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• 제32권2호
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• pp.148-161
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• 2008

A volume integral equation method (VIEM) is used to calculate the plane elastostatic field in an isotropic elastic half-plane containing multiple isotropic or anisotropic inclusions subject to remote loading. A detailed analysis of stress field at the interface between the matrix and the central inclusion in the first column of square packing is carried out for different values of the distance between the center of the central inclusion in the first column of square packing of inclusions and the traction-free surface boundary in an isotropic elastic half-plane containing multiple isotropic or anisotropic inclusions. The method is shown to be very accurate and effective for investigating the local stresses in an isotropic elastic half-plane containing multiple isotropic or anisotropic inclusions.