• 제목/요약/키워드: A. affine

검색결과 502건 처리시간 0.026초

SOME PROPERTIES OF VERMA MODULES OVER AFFINE LIE ALGEBRAS

  • Kim, Wan-Soon
    • 대한수학회논문집
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    • 제10권4호
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    • pp.789-795
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    • 1995
  • For nonintegrable weight $-\rho$, some weight multiplicities of the irreducible module $L(-\rho)$ over $A^{(1)}_{(1)}$ affine Lie algebras are expressed in terms of the colored partition functions. Also we find the multiplicity of $L(-\rho)$ in ther Verma module $M(-\rho)$ for any affine Lie algebras.

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CURVATURE OF MULTIPLY WARPED PRODUCTS WITH AN AFFINE CONNECTION

  • Wang, Yong
    • 대한수학회보
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    • 제50권5호
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    • pp.1567-1586
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    • 2013
  • In this paper, we study the Einstein multiply warped products with a semi-symmetric non-metric connection and the multiply warped products with a semi-symmetric non-metric connection with constant scalar curvature, we apply our results to generalized Robertson-Walker spacetimes with a semi-symmetric non-metric connection and generalized Kasner spacetimes with a semi-symmetric non-metric connection and find some new examples of Einstein affine manifolds and affine manifolds with constant scalar curvature. We also consider the multiply warped products with an affine connection with a zero torsion.

MEGH: A New Affine Invariant Descriptor

  • Dong, Xiaojie;Liu, Erqi;Yang, Jie;Wu, Qiang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권7호
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    • pp.1690-1704
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    • 2013
  • An affine invariant descriptor is proposed, which is able to well represent the affine covariant regions. Estimating main orientation is still problematic in many existing method, such as SIFT (scale invariant feature transform) and SURF (speeded up robust features). Instead of aligning the estimated main orientation, in this paper ellipse orientation is directly used. According to ellipse orientation, affine covariant regions are firstly divided into 4 sub-regions with equal angles. Since affine covariant regions are divided from the ellipse orientation, the divided sub-regions are rotation invariant regardless the rotation, if any, of ellipse. Meanwhile, the affine covariant regions are normalized into a circular region. In the end, the gradients of pixels in the circular region are calculated and the partition-based descriptor is created by using the gradients. Compared with the existing descriptors including MROGH, SIFT, GLOH, PCA-SIFT and spin images, the proposed descriptor demonstrates superior performance according to extensive experiments.

다목적 비디오 부호화를 위한 고속 어파인 움직임 예측 방법 (Fast Affine Motion Estimation Method for Versatile Video Coding)

  • 정승원;전동산
    • 한국산업융합학회 논문집
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    • 제25권4_2호
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    • pp.707-714
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    • 2022
  • Versatile Video Coding (VVC) is the most recent video coding standard, which had been developed by Joint Video Expert Team (JVET). It can improve significant coding performance compared to the previous standard, namely High Efficiency Video Coding (HEVC). Although VVC can achieve the powerful coding performance, it requires the tremendous computational complexity of VVC encoder. Especially, affine motion compensation (AMC) was adopted the block-based 4-parameter or 6-parameter affine prediction to overcome the limit of translational motion model while VVC require the cost of higher encoding complexity. In this paper, we proposed the early termination of AMC that determines whether the affine motion estimation for AMC is performed or not. Experimental results showed that the proposed method reduced the encoding complexity of affine motion estimation (AME) up to 16% compared to the VVC Test Model 17 (VTM17).

AFFINE TRANSFORMATION OF A NORMAL ELEMENT AND ITS APPLICATION

  • Kim, Kitae;Namgoong, Jeongil;Yie, Ikkwon
    • Korean Journal of Mathematics
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    • 제22권3호
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    • pp.517-527
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    • 2014
  • In this paper, we study affine transformations of normal bases and give an explicit formulation of the multiplication table of an affine transformation of a normal basis. We then discuss constructions of self-dual normal bases using affine transformations of traces of a type I optimal normal basis and of a Gauss period normal basis.

Growth rates and nitrate uptake of co-occurring red-tide dinoflagellates Alexandrium affine and A. fraterculus as a function of nitrate concentration under light-dark and continuous light conditions

  • Lee, Kyung Ha;Jeong, Hae Jin;Kang, Hee Chang;Ok, Jin Hee;You, Ji Hyun;Park, Sang Ah
    • ALGAE
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    • 제34권3호
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    • pp.237-251
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    • 2019
  • The dinoflagellate genus Alexandrium is known to often form harmful algal blooms causing human illness and large-scale mortality of marine organisms. Therefore, the population dynamics of Alexandrium species are of primary concern to scientists and aquaculture farmers. The growth rate of the Alexandrium species is the most important parameter in prediction models and nutrient conditions are critical parameters affecting the growth of phototrophic species. In Korean coastal waters, Alexandrium affine and Alexandrium fraterculus, of similar sizes, often form red-tide patches together. Thus, to understand bloom dynamics of A. affine and A. fraterculus, growth rates and nitrate uptake of each species as a function of nitrate ($NO_3$) concentration at $100{\mu}mol\;photons\;m^{-2}s^{-1}$ under 14-h light : 10-h dark and continuous light conditions were determined using a nutrient repletion method. With increasing $NO_3$ concentration, growth rates and $NO_3$ uptake of A. affine or A. fraterculus increased, but became saturated. Under light : dark conditions, the maximum growth rates of A. affine and A. fraterculus were 0.45 and $0.42d^{-1}$, respectively. However, under continuous light conditions, the maximum growth rate of A. affine slightly increased to $0.46d^{-1}$, but that of A. fraterculus largely decreased. Furthermore, the maximum nitrate uptake of A. affine and A. fraterculus under light : dark conditions were 12.9 and $30.1pM\;cell^{-1}d^{-1}$, respectively. The maximum nitrate uptake of A. affine under continuous light conditions was $16.4pM\;cell^{-1}d^{-1}$. Thus, A. affine and A. fraterculus have similar maximum growth rates at the given $NO_3$ concentration ranges, but they have different maximum nitrate uptake rates. A. affine may have a higher conversion rate of $NO_3$ to body nitrogen than A. fraterculus. Moreover, a longer exposure time to the light may confer an advantage to A. affine over A. fraterculus.

라이트필드 영상 압축을 위한 Affine 움직임 보상 분석 (Analysis of Affine Motion Compensation for Light Field Image Compression)

  • ;;;전병우
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송∙미디어공학회 2019년도 하계학술대회
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    • pp.216-217
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    • 2019
  • Light Field (LF) image can be understood as a set of images captured by a multi-view camera array at the same time. The changes among views can be modeled by a general motion model such as affine motion model. In this paper, we study the impact of affine coding tool of Versatile Video Coding (VVC) on LF image compression. Our experimental results show a small contribution by affine coding tool in overall LF image compression of roughly 0.2% - 0.4%.

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AFFINE MANIFOLD WITH MEASURE PRESERVING PROJECTIVE HOLONOMY GROUP

  • Park, Yeong-Su
    • 대한수학회보
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    • 제38권1호
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    • pp.157-161
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    • 2001
  • In this paper, we prove that an affine manifold M is finitely covered by a manifold $\overline{M}$ where $\overline{M}$ is radiant or the tangent bundle of $\overline{M}$ has a conformally flat vector subbundle of the projective holonomy group of M admits an invariant probability Borel measure. This implies that$x^M$is zero.

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GEOMETRIC INEQUALITIES FOR AFFINE CONNECTIONS ON RIEMANNIAN MANIFOLDS

  • Huiting Chang;Fanqi Zeng
    • 대한수학회보
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    • 제61권2호
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    • pp.433-450
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    • 2024
  • Using a Reilly type integral formula due to Li and Xia [23], we prove several geometric inequalities for affine connections on Riemannian manifolds. We obtain some general De Lellis-Topping type inequalities associated with affine connections. These not only permit to derive quickly many well-known De Lellis-Topping type inequalities, but also supply a new De Lellis-Topping type inequality when the 1-Bakry-Emery Ricci curvature is bounded from below by a negative function. On the other hand, we also achieve some Lichnerowicz type estimate for the first (nonzero) eigenvalue of the affine Laplacian with the Robin boundary condition on Riemannian manifolds.