• 제목/요약/키워드: R-Factor

검색결과 5,375건 처리시간 0.046초

ON THE MATCHING NUMBER AND THE INDEPENDENCE NUMBER OF A RANDOM INDUCED SUBHYPERGRAPH OF A HYPERGRAPH

  • Lee, Sang June
    • 대한수학회보
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    • 제55권5호
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    • pp.1523-1528
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    • 2018
  • For $r{\geq}2$, let ${\mathcal{H}}$ be an r-uniform hypergraph with n vertices and m hyperedges. Let R be a random vertex set obtained by choosing each vertex of ${\mathcal{H}}$ independently with probability p. Let ${\mathcal{H}}[R]$ be the subhypergraph of ${\mathcal{H}}$ induced on R. We obtain an upper bound on the matching number ${\nu}({\mathcal{H}}[R])$ and a lower bound on the independence number ${\alpha}({\mathcal{H}}[R])$ of ${\mathcal{H}}[R]$. First, we show that if $mp^r{\geq}{\log}\;n$, then ${\nu}(H[R]){\leq}2e^{\ell}mp^r$ with probability at least $1-1/n^{\ell}$ for each positive integer ${\ell}$. It is best possible up to a constant factor depending only on ${\ell}$ if $m{\leq}n/r$. Next, we show that if $mp^r{\geq}{\log}\;n$, then ${\alpha}({\mathcal{H}}[R]){\geq}np-{\sqrt{3{\ell}np\;{\log}\;n}-2re^{\ell}mp^r$ with probability at least $1-3/n^{\ell}$.

WEAKLY DUO RINGS WITH NIL JACOBSON RADICAL

  • KIM HONG KEE;KIM NAM KYUN;LEE YANG
    • 대한수학회지
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    • 제42권3호
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    • pp.457-470
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    • 2005
  • Yu showed that every right (left) primitive factor ring of weakly right (left) duo rings is a division ring. It is not difficult to show that each weakly right (left) duo ring is abelian and has the classical right (left) quotient ring. In this note we first provide a left duo ring (but not weakly right duo) in spite of it being left Noetherian and local. Thus we observe conditions under which weakly one-sided duo rings may be two-sided. We prove that a weakly one-sided duo ring R is weakly duo under each of the following conditions: (1) R is semilocal with nil Jacobson radical; (2) R is locally finite. Based on the preceding case (1) we study a kind of composition length of a right or left Artinian weakly duo ring R, obtaining that i(R) is finite and $\alpha^{i(R)}R\;=\;R\alpha^{i(R)\;=\;R\alpha^{i(R)}R\;for\;all\;\alpha\;{\in}\;R$, where i(R) is the index (of nilpotency) of R. Note that one-sided Artinian rings and locally finite rings are strongly $\pi-regular$. Thus we also observe connections between strongly $\pi-regular$ weakly right duo rings and related rings, constructing available examples.

신경교종에서 표피성장인자수용체의 발현도와 자기공명영상 소견의 상관관계 (Correlation Between the Expression of Epidermal Growth Factor Receptor and MR Features in Glioma)

  • 김범수;신경섭
    • Investigative Magnetic Resonance Imaging
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    • 제1권1호
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    • pp.125-129
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    • 1997
  • 목적: 신경고종의 자기공명영상 소견과 표피성장인자수용체의 발현 사이의 상관관계를 알아보고자 본 실험을 시행하였다. 대상 및 방법: 수술적 제거 혹은 생검으로 확진된 41예의 신경교종(저등급 성상세포종 8예, 역형성 성상세포종 12예, 다형성 교아세포종 21예) 환자에서 시행한 자기공명영상을 종양의 경계, 괴사, 균질도, 출혈, 조영증강, 그리고 종괴주위의 부종에 대하여 분석하여 각 소장인자수용체의 염색을 시행한 후 그 염색 분포 및 강도에 대한 등급값을 정하였다. 각 환자에서 얻어진 종양 조직을 면역조직화학법으로 표피성 장인자수용체의 염색을 시행한 후 그 염색 분포 및 강도에 대해 등급값을 정했다. 각 자기공명소견과 표피성장인자수용체 발현의 상관관계를 통계적으로 알아보았다. 결과: 자기공명영상에서 종괴주위 부종만이 표피성장인자수용체의 염색 분포(r=0.71, p=0.00) 및 염색 강도(r=0.69, p=0.00)와 유의한 상관관계를 보이는 소견이었다. 나머지 소견은 표피성장인자수용체의 발현과 통게적으로 유의한 상관관계를 보이지 않았다. 결론: 자기공명영상은 신경교종의 진단에 있어 유용한 방법이며, 신경교종에서 종괴주위 부종은 그 조직병리학적 악성도의 예측 뿐만 아니라, 표피성장인자수용체의 발현을 예측하는 데에도 도움이 되는 소견이다.

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선형열원법에 의한 지중유효열전도도와 보어홀 전열저항 해석 (Analysis of Effective Soil Thermal Conductivities and Borehole Thermal Resistances with a Line Source Method)

  • 이세균;우정선;노정근
    • 한국태양에너지학회 논문집
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    • 제30권4호
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    • pp.71-78
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    • 2010
  • Investigation of the effective soil thermal conductivity(k) is the first step in designing the ground loop heat exchanger(borehole) of a geothermal heat pump system. The line source method is required by New and Renewable Energy Center of Korea Energy Management Corporation in analyzing data obtained from thermal response tests. Another important factor in designing the ground loop heat exchanger is the borehole thermal resistance($R_b$). There are two methods to evaluate $R_b$ : one is to use a line source method, and the other is to use a shape factor of the borehole. In this study, we demonstrated that the line source method produces better results than the shape factor method in evaluating $R_b$. This is because the borehole thermal resistance evaluated with the line source method characteristically reduces the temperature differences between an actual and a theoretical thermal behaviors of the borehole. Evaluation of $R_b$ requires soil volumetric heat capacity. However, the effect of the soil volumetric heat capacity on the borehole thermal resistance is very small. Therefore, it is possible to use a generally accepted average value of soil volumetric heat capacity($=2MJ/m^3{\cdot}K$) in the analysis. In this work, it is also shown that an acceptable range of the initial ignoring time should be in the range of 8~16hrs. Thus, a mean value of 12 hrs is recommended.

ICT융합 유형별 스타트업 기업의 성공요인에 관한 연구 -사례연구를 중심으로- (A study on the success factors of ICT Convergence type-specific start-up enterprise - mainly the case study -)

  • 이서한;노승훈
    • 디지털융복합연구
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    • 제12권12호
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    • pp.203-215
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    • 2014
  • 창업에 관한 많은 연구들이 있지만 ICT융합 스타트업 기업을 대상으로 하는 연구는 거의 없다. 본 연구에서는 급속히 성장하고 있는 ICT융합분야에서 스타트업 기업을 대상으로 성공요인을 분석하고자 한다. 10개의 성공한 스타트업 기업의 사례를 바탕으로 ERIS모델을 활용하여 총 29가지의 성공요인을 도출하였다. ICT융합 사업화 형태를 소프트웨어 R&D 중심, 소프트웨어 마케팅 중심, 소프트웨어와 하드웨어를 결합한 R&D 중심, 소프트웨어와 하드웨어를 결합한 마케팅 중심으로 구분하였다. 성공요인 가운데 창업자와 연관된 역량이 가장 많았으며 전문적인 지식, 패러다임 속에서 사업기회의 포착 등을 들 수 있다. ICT융합이라는 기존의 스타트업 기업과 다른 형태의 사업화 과정에서 나타난 성공요인을 도출하였으며 스타트업 기업을 4가지 형태로 유형화하는 데 기여하였다.

Growth hormone-releasing peptide-biotin conjugate stimulates myocytes differentiation through insulin-like growth factor-1 and collagen type I

  • Lim, Chae Jin;Jeon, Jung Eun;Jeong, Se Kyoo;Yoon, Seok Jeong;Kwon, Seon Deok;Lim, Jina;Park, Keedon;Kim, Dae Yong;Ahn, Jeong Keun;Kim, Bong-Woo
    • BMB Reports
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    • 제48권9호
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    • pp.501-506
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    • 2015
  • Based on the potential beneficial effects of growth hormone releasing peptide (GHRP)-6 on muscle functions, a newly synthesized GHRP-6-biotin conjugate was tested on cultured myoblast cells. Increased expression of myogenic marker proteins was observed in GHRP-6-biotin conjugate-treated cells. Additionally, increased expression levels of insulin-like growth factor-1 and collagen type I were observed. Furthermore, GHRP-6-biotin conjugate-treated cells showed increased metabolic activity, as indicated by increased concentrations of energy metabolites, such as ATP and lactate, and increased enzymatic activity of lactate dehydrogenase and creatine kinase. Finally, binding protein analysis suggested few candidate proteins, including desmin, actin, and zinc finger protein 691 as potential targets for GHRP6-biotin conjugate action. These results suggest that the newly synthesized GHRP-6-biotin conjugate has myogenic stimulating activity through, at least in part, by stimulating collagen type I synthesis and several key proteins. Practical applications of the GHRP-6-biotin conjugate could include improving muscle condition. [BMB Reports 2015; 48(9): 501-506]

공간스케일 변화에 따른 생물다양성 평가 -강원도 백두대간 보호구역을 대상으로- (Evaluation of Biodiversity Based on Changes of Spatial Scale -A Case Study of Baekdudaegan Area in Kangwondo-)

  • 심우담;박진우;이정수
    • Journal of Forest and Environmental Science
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    • 제30권1호
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    • pp.91-100
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    • 2014
  • This research was conducted on the conservation area of Baekdudaegan, Kangwondo under the purpose of evaluating bio-diversity according to the changes of spatial scale, using GIS data and spatial filtering method. The diversity index was calculated based on the information of species of The $5^{th}$ forest type map using Shannon-weaver index (H'), evenness index ($E_i$) and richness index ($R_i$). The diversity index was analyzed and compared according to the changes of 12 spatial scales from Kernel size $3{\times}3$ to $73{\times}73$ and basin unit. As for H' and $R_i$, spatial scale increased as diversity index decreased, while $E_i$ decreases gradually. H' and $R_i$ was highest; each 1.1 and 0.6, when the Kernel size was $73{\times}73$, while $E_i$ was 0.2, the lowest. When you look at according to the basin unit, for large basin unit, 'YeongDong' region shows higher diversity index than 'YeongSeo' region. For middle basin unit, 'Gangneung Namdaecheon' region, and for small basin unit, 'Gangneung Namdaecheon' and 'Gangneung Ohbongdaem' region shows high diversity index. When you look at the relationship between diversity index and Geographic factors, H' shows positive relation to curvature and sunshine factor while shows negative to elevation, slope, hillshade, and wetness index. Also $E_i$ was similar to the relationship between H' and Geographic factor. Meanwhile, $R_i$ shows positive relationship to curvature and sunshine factor, while negative to elevation, slope, hillshade, and wetness index. macro unit diversity index evaluation was possible through the GIS data and spatial filtering, and it can be a good source for local biosphere conservation policy making.

중복된 멀티캐리어 DS-CDMA 시스템의 서브밴드 중복율 변화에 따른 성능개선에 관한 연구 (A Study on the Performance Improvement with Subband Overlapping Variation for Overlapped Multicarrier DS-CDMA Systems)

  • 오정헌;박광철;김기두
    • 대한전자공학회논문지TC
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    • 제37권9호
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    • pp.11-23
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    • 2000
  • 멀티캐리어 DS-CDMA는 다중경로 페이딩 채널에서 광대역 시스템의 구현에 효과적인 방법이다. 본 논문에서는 콘볼루션 코딩을 적용한 중복된 멀티캐리어 DS-CDMA 시스템을 제안하고, 중복율 변화에 대한 성능을 분석하여 정해진 서브밴드 캐리어 수에 따라 최적의 성능을 제공하는 중복율을 제시한다. 특히 전체 서브캐리어 수에 따라 최적의 성능을 제공하는 중복율을 제시한다. 특히 전체 서브캐리어 수 M*R 값이 같다면 콘볼루션 코딩율 1/M과 반복 코딩율 1/R 값에 관계없이 칩 성형필터의 rolloff인자 β값이 같으면 중복율 변화에 따른 BET의 변화 형태가 거의 동일함을 보인다. 그리고 서브밴드의 중복인자 (0<β≤2) 변화와 rolloff인자(0<β≤1)의 변화에 따른 MUI를 분석하여 기존의 멀티태리어 시스템과 성능을 비교하고, 제안한 시스템의 중복율 변화에 따른 성능 개서 정도를 보인다.

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NF-κB 조절을 통한 오매추출물의 항염효과 및 작용기작에 관한 연구 (Study on the Anti-inflammatory Effect and Mechanism of Prunus mume Extract Regarding NF-κB)

  • 서원상;오한나;박우정;엄상용;이대우;강상모
    • KSBB Journal
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    • 제29권1호
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    • pp.50-57
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    • 2014
  • NF-${\kappa}B$ is a transcriptional factor which is involved in many biological processes including immunity, inflammation, and cell survival. Many investigators studied on the mechanism involved in activation of NF-${\kappa}B$ signalling pathway via ubiquitination and degradation of $I{\kappa}B$ regarding skin disease. Some specific molecules including Akt, MEK, p38 MAP Kinase, Stat3, et al. represent convergence points and key regulatory proteins in signaling pathways controlling cellular events such as growth and differentiation, energy homeostasis, and the response to stress and inflammation. Ultraviolet (UV) irradiation has many adverse effects on skin, including inflammation, alteration in the extracellular matrix, cellular senescence, apoptosis and skin cancer. Prunus mume, a naturally derived plant extract, has beneficial biological activities as blood fluidity improvement, anti-fatigue action, antioxidative and free radical scavenging activities, inhibiting the motility of Helicobacter pyolri. Previous reports on various beneficial function prompted us to investigate UVB-induced or other immunostimulated biological marker regarding P. mume extract. P. mume extract suppresses UVB-induced cyclooxygenase-2 (COX-2) expression in mouse skin epidermal JB6 P+ cells. The activation of activator protein-1 and nuclear factor-${\kappa}B$ induced by UVB was dose-dependently inhibited by P. mume extract treatment. This results suggest that P. mume extracts might be used as a potential agents for protection of inflammation or UVB induced skin damage.