• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.2090-2092
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• 2004

In this paper, the new measurement methodology of characteristics of the vibratory micro gyroscope using Quality factor and the resonant displacement was proposed. Because the Quality factor has a large error under the high Quality factor condition, it is difficult to analyze the characteristics of the vacuum packaged vibratory micro gyroscopes with the Quality factor. We analyzed mechanical characteristics of gyroscope with the value of Quality factor. We described measurement errors of mechanical characteristics of micro gyroscopes. The measured value of Quality factor is 47532 and error range of Quality factor is from -29.8 % to 73.9 %. The value of resonant displacement is 3.4${\mu}m$ and the measurement error is 2.9 %. From the result of Quality factor degradation and resonant displacement degradation, 1698 days and 1503 days were estimated as Time To Failure (TTF), respectively. The range of estimation error of Quality factor degradation and resonant displacement degradation is calculated from 1246 days to 1832 days and from 1456 days to 1537 days, respectively. We can analyze the characteristics of the vibratory gyroscope using the quality factor when the Quality factor is smaller than 10,000. Also we can analyze that using the resonant displacement when the Quality factor is larger than 10,000.

• 한국콘텐츠학회논문지
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• 제9권9호
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• pp.380-392
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• 2009

본 연구는 도시축제인 2008광주충장축제를 대상으로 지각된 환경단서 중 어떠한 요인들이 방문객의 만족과 행동의도에 영향을 미치는지 알아보고 자 한다. 설문조사는 축제기간중인 2008년 10월 7일부터 10월 12일의 기간 중에 도시축제인 2008광주 충장 축제를 마친 방문객 300명을 대상으로 실시하였다. 300부전부 회수 되었으나 불성실한 설문지를 제외한 270부를 분석에 이용하였다. 수집된 자료의 통계적 처리는 데이터 코딩(Data Coding)과정을 거쳐, SPSS 12.0 for Windows를 활용하여 빈도분석, 신뢰도분석, 요인분석, 다중회귀분석을 실시하였다. 연구결과 첫째, 도시축제 환경단서 요인이 만족도의 3가지 차원에 따라 다르게 나타났다. 즉 축제만족에는 '음식요인',이 중요한 영향 요인으로 나타났다. 둘째, 도시축제 환경단서 요인이 만족의 후속변수인 행동의도인 재방문의도에는 '편의시설요인' '접근성과 홍보요인',이 추천의도에는 '홍보안내요인'이 중요한 영향요인으로 나타났다. 반면에 '음식요인',은 유의한 영향을 미치지 않는 것으로 나타났다. 셋째, 축제만족이 행동의도인 재방문의도와추천의도에 미치는 영향에 대한 분석결과 축제만족이 중요한 영향요인으로 나타났다. 본 연구는 2008광주충장축제에 대한 발전전략 제시를 연구 목적으로 삼고자 한다. 도시축제를 추진하는 시점에 시기적절한 연구라고 사료되며 연구의 시사점은 발전방향추진에 있어 많은 도움이 되리라 판단된다.

• 대한두경부종양학회지
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• 제20권1호
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• pp.13-18
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• 2004

Objectives: Cancer lethality is usually the result of local invasion and metastasis of neoplastic cell from the primary tumor. Because of their ability to degrade extracellular matrix components, matrix metalloproteinases (MMPs) and basic fibroblast growth factor (bFGF) have been implicated in the breakdown of basement membrane and underlying stroma, thereby facilitating tumor growth and invasion. It has been well established that MMPs and bFGF expression correlate with cervical lymph node metastasis, but studies on expression in the metastatic cervical lymph node itself are not enough. We have analyzed matrix metalloproteinases (MMPs) and basic fibroblast growth factor (bFGF) in squamous cell carcinoma of the head and neck and metastatic cervical lymph node, and evaluated their relationship and clinicophathologic significance. Material and Methods: 20 cases of squamous cell carcinoma of the head and neck were entered on the study of immunohistochemical stains for MMP-9 and bFGF in the obtained tissue from primary tumor and metastatic cervical lymph node. We analyzed the relationship between MMP-9, bFGF expression of the primary tumor and metastatic node with age, sex, T-stage, N-stage, histologic grade, pathologic stage and disease free survival. Results: Expression of MMP-9 and bFGF in cancer cell and metastatic lymph node was higher than that in normal cell and lymph node. According to histologic differentiation, expression of MMP-9 of the metastatic cervical lymph node was higher than primary tumor. Considering to other clinicopathologic factor, no statistical significance was seen in MMP-9 and bFGF. Conclusion: We found that expression of MMP-9 is higher in the metastatic lymph node than primary tumor in the poorly differentiated squamous cell carcinoma. But we don't find out the statistical significance in relation between bFGF and clinical factors. So we guess that some different mechanism of MMP-9 and bFGF in Head & Neck squamous cell carcinoma exist. Further studies will be necessary to establish their pathogenesis in the Head and Neck cancer.

• Journal of Applied Biological Chemistry
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• 제63권1호
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• pp.75-82
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• 2020

본 연구에서는 한국에서 육종한 신육성품종 그린볼 사과 껍질 추출물(GBE)이 피부 광노화 인자조절에 대한 억제효과를 확인하였다. 피부에서 광노화 인자 조절에 대한 억제 효과를 확인하기 위해 CCD986sk fibrobalst cell에 UVB로 광노화를 유도시킨 후 세포에 GBE를 처리하였다. 광노화 인자 조절 효과를 측정한 결과 GBE가 COL1A2, MMP-1, MMP-9, TIMP-1 단백질 발현량에서 UVB에 의해 자극된 MMP-1, MMP-9 단백질 합성을 억제하였으며, COL1A2, TIMP-1 단백질의 경우 발현량이 유의적으로 증가하는 것을 확인하였다. Photoaging-related factors인 COL1A2, MMP-1, MMP-9, HAS2, TGF-β, TIMP-1의 mRNA 발현량을 측정한 결과 GBE에 의해 MMP-1, MMP-9 단백질 발현을 효과적으로 억제하였으며, MMPs와 type procollagen 발현에 관여하는 조절인자인 TIMP-1과 TGF-β의 발현량이 증가함에 따라 COL1A2의 생성량이 증가하는 것을 확인할 수 있었다. 또한 피부를 구성하는 구조 단백질 중 하나인 hyaluronic acid 생성에 관여하는 HAS2의 발현량 증가도 확인하였다. 따라서 GBE는 광노화의 인자 억제 조절에 대한 우수한 효능을 가졌으며, 피부 노화를 예방하는 기능성 소재로서 활용이 가능할 것으로 판단되었다.

• 생명과학회지
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• 제26권10호
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• pp.1189-1195
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• 2016

Vascular endothelial growth factor (VEGF)와 hepatocyte growth factor (HGF)는 강력한 혈관신생 유도인자로 알려져 있다. 세포가 이동하고 침윤하기 위해서는 세포의 증식과 더불어 주변의 세포외기질을 분해하는 단백질분해효소의 분비가 선행되어야 한다. 본 연구에서는 인간의 악성신경교종 유래 세포주인 U-373-MG 세포에 VEGF와 HGF를 처리하여 세포의 증식, matrix metalloproteinase-2 (MMP-2)와 MMP-9 및 플라스민의 분비, 세포의 이동 및 침윤에 미치는 효과를 조사하였다. 또한 단백질분해효소 억제제 처리를 통하여 세포의 증식, 이동 및 침윤에 미치는 단백질분해효소의 역할을 조사하였다. 연구 결과, VEGF와 HGF의 병용처리 시 VEGF와 HGF의 단독 처리 시보다 세포의 증식, MMP-2, MMP-9 및 플라스민의 분비, 세포의 이동 및 침윤이 유의할만하게 증가되었다. 한편 VEGF와 HGF 처리에 의한 U-373-MG 세포의 증식, 이동 및 침윤 증가에 미치는 단백질분해효소의 효과를 MMPs 억제제인 BB-94를 처리하여 조사한 결과 최대 이동 효과를 나타낸 HGF와 VEGF의 병용처리군 보다 세포의 이동이 32% 억제되었고 플라스민 억제제인 α2AP에 의해서도 29% 억제되었다. 또한 U-373-MG 세포의 침윤 역시 BB-94와 α2AP 처리에 의해 유의할 만하게 억제되었다. 이러한 결과는 VEGF와 HGF에 의한 MMP-2, MMP-9 및 플라스민의 분비증가에 의해 직접 또는 간접적인 경로를 통하여 U-373-MG 세포의 증식, 이동 및 침윤을 증가시킨다고 여겨진다.

• Molecules and Cells
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• 제40권12호
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• pp.906-915
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• 2017

Impairment of wound healing is a common problem in individuals with diabetes. Adiponectin, an adipocyte-derived cytokine, has many beneficial effects on metabolic disorders such as diabetes, obesity, hypertension, and dyslipidemia. C1q/TNF-Related Protein 9 (CTRP9), the closest paralog of adiponectin, has been reported to have beneficial effects on wound healing. In the current study, we demonstrate that CTRP9 regulates growth, differentiation, and apoptosis of HaCaT human keratinocytes. We found that CTRP9 augmented expression of transforming growth factor beta 1 ($TGF{\beta}1$) by transcription factor activator protein 1 (AP-1) binding activity and phosphorylation of p38 in a dose-dependent manner. Furthermore, siRNA-mediated suppression of $TGF{\beta}1$ reversed the increase in p38 phosphorylation induced by CTRP9. siRNA-mediated suppression of $TGF{\beta}1$ or p38 significantly abrogated the effects of CTRP9 on cell proliferation and differentiation while inducing apoptosis, implying that CTRP9 stimulates wound recovery through a $TGF{\beta}1$-dependent pathway in keratinocytes. Furthermore, intravenous injection of CTRP9 via tail vein suppressed mRNA expression of Ki67 and involucrin whereas it augmented $TGF{\beta}1$ mRNA expression and caspase 3 activity in skin of type 1 diabetes animal models. In conclusion, our results suggest that CTRP9 has suppressive effects on hyperkeratosis, providing a potentially effective therapeutic strategy for diabetic wounds.

• Journal of Periodontal and Implant Science
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• 제35권3호
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• pp.675-685
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• 2005

Bone resorption involves sequential stages of osteoclast precursor migration and differentiation of osteoclast precursors into multinucleated osteoclasts. Stromal cell derived factor (SDF)-1 is a chemotactic factor for osteoclast precursor migration. Matrix metalloproteinase (MMP)-9 is involved in migration of osteoclast precursors and activation of $interleukin(IL)-1{\beta}$. Alveolar bone destruction is a characteristic feature of periodontal disease. Treponema lecithinolyticum is a oral spirochete isolated from the periodontal lesions. The effect of lipopolysaccharide(LPS) from T. lecithinolyticum on expression of SDF-1 and MMP-9 was examined in cocultures of bone marrow cells and osteblasts derived from mouse calvariae. T. lecithinolyticum LPS increased expression of MMP-9 in the coculture. Polymyxin B, an inhibitor of LPS, abolished the increase of MMP-9 mRNA expression by LPS. LPS did not increase the expression of SDF-1, $IL-1{\beta}$ and tumor necrosis $factor(TNF)-{\alpha}$ mRNA in cocultures. Prostaglandin $E_2(PGE_2)$ up-regulated the expression of MMP-9 and NS398, an inhibitor of $PGE_2$ synthesis, down-regulated the induction of MMP-9 expression by T. lecitbinolyticm LPS. These results suggest that T. lecitbinolyticm LPS increases MMP-9 expression in bone cells via $PGE_2$ and that the induction of MMP-9 expression by T. lecitbinolyticm LPS is involved in alveolar bone destruction of periodontitis patients by the increase of osteoclast precursor migration and the activation of bone resorption-inducing cytokine.

• East Asian mathematical journal
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• 제36권5호
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• pp.583-591
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• 2020

In [8, 9] they introduced a new finite element method for accurate numerical solutions of Poisson equations with corner singularities. They consider the Poisson equations with corner singularities, compute the finite element solutions using standard Finite Element Methods and use the extraction formula to compute the stress intensity factor(s), then they posed new PDE with a regular solution by imposing the nonhomogeneous boundary condition using the computed stress intensity factor(s), which converges with optimal speed. From the solution they could get an accurate solution just by adding the singular part. The error analysis was given in [5]. In their approaches, the singular functions and the extraction formula which give the stress intensity factor are the basic elements. In this paper we consider the biharmonic problems with the cramped and/or simply supported boundary conditions and get the singular functions and its duals and find properties of them, which are the cornerstones of the approaches of [8, 9, 10].

• 대한기계학회논문집A
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• 제24권9호
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• pp.2252-2258
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• 2000

In order to investigate the effect of nozzle on stress concentration in pressure vessels, three dimensional finite element analyses were performed. The results were compared with those for corresponding two dimensional axisymmetric finite element analyses. A three dimensional finite element model with a surface crack was also designed to evaluate the effect of internal pressure and heat transfer on crack face, and the resulting stress intensity factors from the finite element analyses were compared with those for ASME Sec. XI and Raju-Newman's stress intensity factor solution. As a result, the validity of currently available stress intensity factor solutions for a surface crack was reviewed in the presence of geometrical complexity, heat transfer and internal pressure.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.178-183
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• 2014

This paper presents a motor characteristics analysis method using an equivalent circuit. Motor characteristics analysis via equivalent circuit is very important for designing a high efficiency single phase induction motor. The accuracy of the motor characteristics depends on the accuracy of the parameters, especially saturation factor, which determines the cyclical relationship in the analysis process. Therefore, using the proposed method, the saturation factor was calculated using the iteration routine and numerical technique. The proposed method was verified by comparing the finite element method results and the dynamo test results of manufactured prototype model.