• 제목/요약/키워드: Xi

검색결과 2,159건 처리시간 0.056초

ON SUBMANIFOLDS OF A SPHERE WITH BOUNDED SECOND FUNDAMENTAL FORM

  • Matsuyama, Yoshio
    • 대한수학회보
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    • 제32권1호
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    • pp.103-113
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    • 1995
  • Let $S^{n+p}$(c) be the (n + p)-dimensional Euclidean sphere of constant curva ture c and let M be an n-dimensional compact minimal submanifold isometric ally immersed in $S^{n+p}$(c). Let $A_\xi$ be the second fundamental form of M in the direction of a normal $\xi$ and T the tensor defined by $T(\xi, \eta) = traceA_\xi A_\eta$.

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Explainable radionuclide identification algorithm based on the convolutional neural network and class activation mapping

  • Yu Wang;Qingxu Yao;Quanhu Zhang;He Zhang;Yunfeng Lu;Qimeng Fan;Nan Jiang;Wangtao Yu
    • Nuclear Engineering and Technology
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    • 제54권12호
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    • pp.4684-4692
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    • 2022
  • Radionuclide identification is an important part of the nuclear material identification system. The development of artificial intelligence and machine learning has made nuclide identification rapid and automatic. However, many methods directly use existing deep learning models to analyze the gamma-ray spectrum, which lacks interpretability for researchers. This study proposes an explainable radionuclide identification algorithm based on the convolutional neural network and class activation mapping. This method shows the area of interest of the neural network on the gamma-ray spectrum by generating a class activation map. We analyzed the class activation map of the gamma-ray spectrum of different types, different gross counts, and different signal-to-noise ratios. The results show that the convolutional neural network attempted to learn the relationship between the input gamma-ray spectrum and the nuclide type, and could identify the nuclide based on the photoelectric peak and Compton edge. Furthermore, the results explain why the neural network could identify gamma-ray spectra with low counts and low signal-to-noise ratios. Thus, the findings improve researchers' confidence in the ability of neural networks to identify nuclides and promote the application of artificial intelligence methods in the field of nuclide identification.

Protective Effects of Scutellaria barbata Against Rat Liver Tumorigenesis

  • Dai, Zhi-Jun;Wu, Wen-Ying;Kang, Hua-Feng;Ma, Xiao-Bin;Zhang, Shu-Qun;Min, Wei-Li;Lu, Wang-Feng;Lin, Shuai;Wang, Xi-Jing
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권1호
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    • pp.261-265
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    • 2013
  • Scutellaria barbata D. Don (S. barbata), a traditional Chinese medicine, is used to treat cancers, inflammation, and urinary diseases. This study aimed to determine any protective effects of S. barbata crude extract (CE-SB) against rat liver tumorigenesis induced by diethylnitrosamine (DENA). Liver malfunction indices in serum were measured by biochemical examination. Hematoxylin and eosin staining was performed to examine liver pathology. Contents of malondialdehyde (MDA) and superoxide dismutase (SOD) were measured in liver homogenates to evaluate oxidative stress. The levels of liver malfunction indices in the CE-SB groups, especially in the CE-SB high dose group, were lower than that of the model group (P<0.05). The results from histological examination indicated that the number of liver nodules in the CE-SB groups decreased compared with the model group (P<0.05). Content of MDA determined in liver was significantly decreased, and level of SOD elevated by CE-SB. CE-SB can inhibit experimental liver tumorigenesis and relieve hepatic injury in rats.

보습상태에서 피부각질의 구조 모델링에 관한 연구 (A study of structure modeling of the stratum corneum on the hydration)

  • 김정래;김혜주
    • 문화기술의 융합
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    • 제3권3호
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    • pp.31-36
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    • 2017
  • 본 연구는 보습상태에서 피부의 각질층에 변화상태를 구조적으로 모델링한다. 피부구조에 따라 진행되는 형태는 세포사이와 세포횡단의 조건으로 조절 할 수 있도록 하였고, 구조적인 모델링으로 시스템의 변화상태를 확인하였다. 보습조건에서 크기 형태 조합의 모형을 구성하고, 결과적으로 보습상태의 피부 임피던스는 각층에 따라 피부에 측정 임피던스가 ${\xi}-R-SC-RH$, ${\xi}-R-SL-RH$, ${\xi}-R-SG-RH$, ${\xi}-R-SS-RH$${\xi}-R-SB-RH$ 로 다른 형태로 나타났다. 보습조건에서 S-Corneum, S-Lucidum, S-Granulosum, S-Spinosum 과 S-Basale의 변화의 차가 있고, 변환을 제어하는 전달시스템을 구성과 변환모델을 세분화하여 구축하였다. 이를 통하여 보습상태에서 피부의 기능적 효능조절이 가능한 보습조절시스템이 구성되어 지속적인 피부의 개선효과가 진행 될 것으로 예상된다. 투과 조절시스템이 구성되어 지속적인 피부의 개선효과가 진행 될 것으로 예상된다.

IMPROVED MULTIPLICITY RESULTS FOR FULLY NONLINEAR PARABOLIC SYSTEMS

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
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    • 제17권3호
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    • pp.283-291
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    • 2009
  • We investigate the existence of multiple solutions (${\xi},{\eta}$) for perturbations of the parabolic system with Dirichlet boundary condition $$(0.1)\;\begin{array}{lcr}{\xi}_t=-L{\xi}+g_1(3{\xi}+{\eta})-s{\phi}_1-h_1(x,t)\;in\;{\Omega}{\times}(0,\;2{\pi}),\\{\eta}_t=-L{\eta}+g_2(3{\xi}+{\eta})-s{\phi}_1-h_2(x,t)\;in\;{\Omega}{\times}(0,\;2{\pi}).\end{array}$$ We show the existence of multiple solutions (${\xi},{\eta}$) for perturbations of the parabolic system when the nonlinearity $g^{\prime}_1,\;g^{\prime}_2$ are bounded and $3g^{\prime}_1(-{\infty})+g^{\prime}_2(-{\infty})<{\lambda}_1,\;{\lambda}_n<3g^{\prime}_1(+{\infty})+g^{\prime}_2(+{\infty})<{\lambda}_{n+1}$.

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REEB FLOW INVARIANT UNIT TANGENT SPHERE BUNDLES

  • Cho, Jong Taek;Chun, Sun Hyang
    • 호남수학학술지
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    • 제36권4호
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    • pp.805-812
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    • 2014
  • For unit tangent sphere bundles $T_1M$ with the standard contact metric structure (${\eta},\bar{g},{\phi},{\xi}$), we have two fundamental operators that is, $h=\frac{1}{2}{\pounds}_{\xi}{\phi}$ and ${\ell}=\bar{R}({\cdot},{\xi}){\xi}$, where ${\pounds}_{\xi}$ denotes Lie differentiation for the Reeb vector field ${\xi}$ and $\bar{R}$ denotes the Riemmannian curvature tensor of $T_1M$. In this paper, we study the Reeb ow invariancy of the corresponding (0, 2)-tensor fields H and L of h and ${\ell}$, respectively.

OBSERVATIONS ON A FURTHER IMPROVED ($\frac{G}{G}$) - EXPANSION METHOD AND THE EXTENDED TANH-METHOD FOR FINDING EXACT SOLUTIONS OF NONLINEAR PDES

  • Zayed, E.M.E.
    • Journal of applied mathematics & informatics
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    • 제30권1_2호
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    • pp.253-264
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    • 2012
  • In the present article, we construct the exact traveling wave solutions of nonlinear PDEs in the mathematical physics via the (1+1)-dimensional Boussinesq equation by using the following two methods: (i) A further improved ($\frac{G}{G}$) - expansion method, where $G=G({\xi})$ satisfies the auxiliary ordinary differential equation $[G^{\prime}({\xi})]^2=aG^2({\xi})+bG^4({\xi})+cG^6({\xi})$, where ${\xi}=x-Vt$ while $a$, $b$, $c$ and $V$ are constants. (ii) The well known extended tanh-function method. We show that some of the exact solutions obtained by these two methods are equivalent. Note that the first method (i) has not been used by anyone before which gives more exact solutions than the second method (ii).