• 한국공간구조학회논문집
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• 제1권1호
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• pp.117-124
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• 2001

In Single-layer latticed domes with rectangular network which is composed of ring of circumferential direction and rafter of longitudinal direction, that is, rib domes, if we use the cross-membered junction's method for the advantage in fabrication and construction, the eccentricity is occurred in the nodal point of crossing members. This paper is aimed at investigating the buckling characteristics for the effect of eccentricity according to rise-span ratios and distance of eccentricity. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems. The conclusion were given as follows: 1. The maximum decreasing ratio of buckling strength due to the junction's eccentricity is about 60% in models of this paper. 2. In the increasing ratio of buckling strength for rise-span ratio, that of Type 3 models is larger than that of type 2 models. On the other hand, that of Type 2 mode is larger than that of Type 3 for eccentricity-distance. 3. In the viewpoint of the value of buckling strength, that of Type 2 models is larger than that of type 3 models. The effect of the junction's rigidity on buckling strength is not great for overall models. Therefore if we use the cross-membered junction's method for the advantage in fabrication and construction, the method of Type 2 will have the great advantage of that of Type 3.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 추계 학술논문 발표대회
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• pp.47-50
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• 2009

The existing techniques used to estimate and manage the compressive strength of concrete do not include the environmental factors that influence the development of compressive strength and the compressive strength itself. Thus, it is necessary to develop a reasonable yet simple way to measure the compressive strength of concrete structures at construction sites by considering concrete's mechanical properties and curing environment. This study was conducted to propose an acrylic form and a junction isolation mold with crack-inducing boards that uses non-destructive methods to create and collect concrete test samples that are cured in the same condition as the actual concrete structures. junction isolation molds were used in high-strength and super high-strength concrete to evaluate the reliability of compressive strength evaluation on the test sample. The following were the findings of this study:

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 가을 학술발표회논문집
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• pp.74-78
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• 1993

Compared with rigid-jointed latticed dome, in pinned-joint latticed dome, results of Ref.1 showed reduction of buckling strength by decline of junction's rotational rigidity. Moreover, with decline of junction's rotational rigidity, geometrical initial imperfection incurs more and more reduction of buckling-strength. This study, subsequently the case of rigid-joint domes, is aimed at analyzing buckling-characteristics of pinned-joint single-layer latticed domes with triangular network subjected to initial imperfection.

• 한국지반공학회논문집
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• 제28권7호
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• pp.55-65
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• 2012

지오그리드의 장기허용강도를 산출할 때 사용되는 총 감소계수는 내시공성 감소계수($RF_{ID}$), 내화학성 감소계수($RF_D$), 크리프 감소계수($RF_{CR}$) 등이 적용된다. 지오그리드의 단기인장강도에 대한 감소계수를 고려한 허용인장강도 산출 모델의 경우 감소계수들 사이의 상호 작용력을 고려하지 않는 한계를 가지고 있다. 접점강도는 인장강도와 마찬가지로 시공 시 손상이나 화학적 분해에 의하여 감소하게 된다. 기존의 단일접점강도 시험 방법은 치수효과를 고려할 수 없기에 결과의 편차가 큰 시공 시 손상된 시험편의 접점강도를 측정하는데 적합하지 않다. 또한 시공 시 손상에 의한 전단강도 변화에 대한 연구도 전혀 이루어지지 않은 실정이다. 따라서 본 연구에서는 다양한 조건을 고려하여 지오그리드의 장기성능에 영향을 미치는 감소계수들을 재평가하고 감소계수 사이의 상호 작용을 고려하여 정확한 장기허용강도를 구하려고 한다. 내시공성 시험과 내화학성 시험 후 크리프 시험결과 총 감소계수는 GRI GG-4 시험값보다 작게 나타났다. 내시공성 시험과 내화학성 시험 후 접점강도의 감소계수는 인장강도 감소계수보다 더 작게 나타났다. 내시공성 시험후 전단강도 차이가 나타나지 않거나 증가함을 나타내었다.

• 동의생리병리학회지
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• 제32권2호
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• pp.106-112
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• 2018

The aim of this research was to determine the diverse effects of Sappan Lignum extract and brazilin on human keratinocyte HaCaT cells. We confirmed the antioxidant effect of Sappan Lignum extract and brazilin was analyzed by using an ABTS assay, confirming the efficacy of water extraction method. Also, we examined effect of Sappan Lignum extract and brazilin on the cell viability, using the MTS assay in HaCaT cells. mRNA expression levels of tight junction-related genes associated with skin barrier in HaCaT cells were analyzed using quantitative real-time PCR analysis. Sappan Lignum extract increased the cellular activity of HaCaT cells and the expression of the tight junction-related genes claudin 3, claudin 6, and ZO-2. Brazilin displayed the same effects as that of the extract on HaCaT cells activity and tight junction-related genes expression. Furthermore, dispase assay demonstrated altered cell-cell adhesion strength of Sappan Lignum extract or brazilin treated HaCaT cells. Sappan Lignum extract or brazilin might be an useful ingredient in skin-mosturizinng and anti-wrinkle cosmetics, given its effects of altering mRNA expression of tight junction-related genes and enhancing cell-cell adhesion strength of HaCaT cells.

• 대한본초학회지
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• 제34권1호
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• pp.99-107
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• 2019

Objectives : Cudrania tricuspidata (C. tricuspidata) is well-known traditional herbal remedy and its root, leaf and fruit were used for treatment of inflammation, tumor and painkilling. However, effect of C. tricuspidata fruit on tight junction is still unknown. The aim of this research was to determine the effect of C. tricuspidata fruit extract on human keratinocyte HaCaT cells. Methods : The antioxidant effects of water extract of C. tricuspidata (WECT) and ethanol extract of C. tricuspidata (EECT) were analyzed by using an ABTS assay. To confirm the cytotoxicity of WECT and EECT, MTS assay was performed. The mRNA expression levels of tight junction related genes were analyzed using quantitative RT-PCR analysis. Furthermore, dispase assay was used to investigate the alteration of cell-cell adhesion strength of EECT treated HaCaT cells. Results : WECT and EECT showed strong antioxidant activity. No obvious cytotoxicity was observed in both WECT and EECT until $2.0mg/m{\ell}$ concentration. The mRNA expression level of Claudin 6 were significantly increased by EECT treatment, whereas the WECT did not affect the expression of Claudin 6. Furthermore, EECT treatment enhances cell-cell adhesion strength. Conclusions : In this study, we investigated the physiological activities of the extracts of Cudrania tricuspidata fruit extracts on human keratinocytes by two different extraction methods. EECT might have an anti-aging activity on the skin by reducing oxidative stress. Moreover, it may be a useful ingredient in atopic dermatitis and skin-moisturizing, given its effects of altering Claudin 6 gene expression and enhancing cell-cell adhesion strength.

• Journal of Welding and Joining
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• 제16권2호
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• pp.111-121
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• 1998

It is well recognized that a excessive temperature gradient from the junction of head to skirt in axial direction in a hot pressure vessel can cause unpredicted high thermal stress at the junction and/or in axial direction of a skirt. this thermal stress resulting from axial thermal gradient may be a major cause of unsoundness of structural integrity. In case of cyclic operation of hot pressure vessels, the thermal stress becomes one of the primary design consideration because of the possibility of fracture as a result of cyclic thermal fatigue and progressively incremental plastic deformation. To perform thermal stress analysis of the junction and cylindrical skirt of a vessel, or, at least, to inspect quantitatively the magnitude and effect of thermal stress, the temperature profile of the vessel and skirt must be known. This paper demonstrated the temperature distribution and thermal stress analysis for the junction of skirt to head using F.E. analysis. Effect of air pocket in crotch space was quantitatively investigated to minimize the temperature gradient causing the thermal stress in axial direction. Effect of the skirt height on thermal stresses was also studied. Analysis results were compared with theoretical formulas to verify th applicability to the strength calculation in design field.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 가을 학술발표회논문집
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• pp.63-67
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• 1993

In single-layer latticed domes with two-way grid, if we use the cross-membered junction's method for the advantage in fabrication and construction, the eccentricity is occurred in the nodal point of crossing members. This paper is aimed at investigating the buckling characteristics for the effect of eccentricity. Analysis method is based on FEM dealing with the geometically nonlinear deflection problems. As a result of the study, in the case of having eccentricity, the values of buckling strength are about 0.7 times than or not but the characteristics of buckling and deflection except buckling strength have a similar tendency each other.

• 열처리공학회지
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• 제32권1호
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• pp.29-35
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• 2019

The remedial junction is found in the network of single walled carbon nanotubes after the irradiation of protons not only for the better mechanical strength but also for the higher property of electrical conductivity. The irradiated proton formed a beam transferred sufficient energy to change the sp2 structure of atomic carbon as much as damage of crystalline formation, however it is shown the cross bonding while recovery of structure. This improved network in 2-D atomic chain of carbon is expected to use in a critical part in space energy harvesting system related with the solar radiation.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.4-5
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• 2021

In this study, in the coating-sheet composite waterproofing method, a specimen was formed to prevent the transmission of the no-node tensile stress occurring under the junction between sheets by forming an insulating structure when the junction was formed, and to compare the effect of preventing breakage with the existing common junction. For this, tensile performance evaluation was conducted. As a result of the evaluation, it was confirmed that it exhibited higher tensile strength compared to the existing joint and at the same time exhibited a large width of displacement characteristics, and thus, had an effect of preventing breakage.