• Title/Summary/Keyword: kernels

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Evaluation of the Efficiency of an Inverse Exponential Kernel Estimator for Spherical Data

  • Park, Hyun Suk
    • Communications for Statistical Applications and Methods
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    • v.20 no.1
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    • pp.77-84
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    • 2013
  • This paper deals with the relative efficiency of two kernel estimators $\hat{f}_n$ and $\hat{g}_n$ by using spherical data, as proposed by Park (2012), and Bai et al. (1988), respectively. For this, we suggest the computing flows for the relative efficiency on the 2-dimensional unit sphere. An evaluation procedure between two estimators (given the same kernels) is also illustrated through the observed data on normals to the orbital planes of long-period comets.

Variable selection in the kernel Cox regression

  • Shim, Joo-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.4
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    • pp.795-801
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    • 2011
  • In machine learning and statistics it is often the case that some variables are not important, while some variables are more important than others. We propose a novel algorithm for selecting such relevant variables in the kernel Cox regression. We employ the weighted version of ANOVA decomposition kernels to choose optimal subset of relevant variables in the kernel Cox regression. Experimental results are then presented which indicate the performance of the proposed method.

탄성학 문제의 경계적분방정식에서 초특이해 커널의 해법

  • 윤승원
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.04a
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    • pp.573-577
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    • 1995
  • An integration method for the hypersingular kernels, in the boundary integralequations used for the solution of crack-like problems in elasticity, has been developed. To isolate the stronger singularities, the actual boundaries are replaced by the smoothly curved auxiliary boundaries which provide the detoured, non-singular integration paths. The auxiliary boundary can be interpreted as a contracted form of the actual boundaries except for the singular element where the collocating point is located. For an optimal integration path for every singular collocation point, the auxiliary boundary may have different shape depending on the position of the collocation point on the singular element.

A NOTE ON GENERALIZED PARAMETRIC MARCINKIEWICZ INTEGRALS

  • Liu, Feng
    • Bulletin of the Korean Mathematical Society
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    • v.56 no.5
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    • pp.1099-1115
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    • 2019
  • In the present paper, we establish certain $L^p$ bounds for the generalized parametric Marcinkiewicz integral operators associated to surfaces generated by polynomial compound mappings with rough kernels in Grafakos-Stefanov class ${\mathcal{F}}_{\beta}(S^{n-1})$. Our main results improve and generalize a result given by Al-Qassem, Cheng and Pan in 2012. As applications, the corresponding results for the generalized parametric Marcinkiewicz integral operators related to the Littlewood-Paley $g^*_{\lambda}$-functions and area integrals are also presented.

REPRODUCING KERNEL HILBERT SPACE BASED ON SPECIAL INTEGRABLE SEMIMARTINGALES AND STOCHASTIC INTEGRATION

  • Sababe, Saeed Hashemi;Yazdi, Maryam;Shabani, Mohammad Mehdi
    • Korean Journal of Mathematics
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    • v.29 no.3
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    • pp.639-647
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    • 2021
  • In this paper, we consider the integral of a stochastic process with respect of a sequence of square integrable semimartingales. By this integrals, we construct a reproducing kernel Hilbert space and study the correspondence between this space with the concepts of arbitrage and viability in mathematical finance.

ON THE MIXED RADIAL-ANGULAR INTEGRABILITY OF LITTLEWOOD-PALEY FUNCTIONS

  • Zhang, Xiao
    • Bulletin of the Korean Mathematical Society
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    • v.58 no.2
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    • pp.403-417
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    • 2021
  • This note is devoted to establishing the boundedness for some classes of Littlewood-Paley square operators defined by the kernels without any regularity on the mixed radial-angular spaces. The corresponding vector-valued versions are also presented. As applications, the corresponding results for the Littlewood-Paley g∗λ function and the Littlewood-Paley function related to the area integrals are also obtained.

INVERSE PROBLEM FOR STOCHASTIC DIFFERENTIAL EQUATIONS ON HILBERT SPACES DRIVEN BY LEVY PROCESSES

  • N. U., Ahmed
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.4
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    • pp.813-837
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    • 2022
  • In this paper we consider inverse problem for a general class of nonlinear stochastic differential equations on Hilbert spaces whose generating operators (drift, diffusion and jump kernels) are unknown. We introduce a class of function spaces and put a suitable topology on such spaces and prove existence of optimal generating operators from these spaces. We present also necessary conditions of optimality including an algorithm and its convergence whereby one can construct the optimal generators (drift, diffusion and jump kernel).

ON CERTAIN ESTIMATES FOR ROUGH GENERALIZED PARAMETRIC MARCINKIEWICZ INTEGRALS

  • Daiqing, Zhang
    • Bulletin of the Korean Mathematical Society
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    • v.60 no.1
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    • pp.47-73
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    • 2023
  • This paper is devoted to establishing certain Lp bounds for the generalized parametric Marcinkiewicz integral operators associated to surfaces generated by polynomial compound mappings with rough kernels given by h ∈ ∆γ(ℝ+) and Ω ∈ Wℱβ(Sn-1) for some γ, β ∈ (1, ∞]. As applications, the corresponding results for the generalized parametric Marcinkiewicz integral operators related to the Littlewood-Paley g*λ functions and area integrals are also presented.

Antitumor Toxic Protein Abrin and Abrus Agglutinin

  • Liu, Chao-Lin;Lin, Jung-Yaw
    • Toxicological Research
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    • v.17
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    • pp.109-115
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    • 2001
  • Abrus agglutinin was purified from the kernels of Abrus precatorius by Sepharose 4B affinity column chromatography followed by Sephadex G-100 gel filtration column chromatography. About 1.25 g of abrus agglutinin was obtained from 1 kg of the kernels. The LD$_{50}$ of abrus agglutinin is 5 mg/kg of body weight, which is less toxic than that of abrin, 20$\mu\textrm{g}$/kg body weight. The amino acid sequence of abrus agglutinin was determined by protein sequencing techniques and deduced from the nucleotide sequence of a cDNA clone encoding full length of abrus agglutinin. There are 258 residues, 2 residues and 267 residues in the A-chain, the linker peptide and the B-chain of abrus agglutinin, respectively. Abrus agglutinin had high homology to abrin-a (77.8%). The 13 amino acid residues involved in catalytic function, which are highly conserved among abrin and ricin, were also conserved within abrus agglutinin. The protein synthesis inhibitory activity of abrus agglutinin ($IC_{50}$/ = 3.5 nM) was weaker than that of abrin-a (0.05 nM). By molecular modeling followed by site-directed mutagenesis showed that Pro199 of abrus agglutinin A-chain located in amphipathic helix H and corresponding to Asn200 of abrin A-chain, can induce bending of helix H. This bending would presumably affect the binding of abrus agglutinin A-chain to its target sequence GpApGpAp, in the tetraloop structure of 285 r-RNA subunit and this could be one of major factors contributing to the relatively weak protein synthesis inhibitory activity and toxicity of abrus agglutinin.n.

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