• Title/Summary/Keyword: normal vector

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MYLLER CONFIGURATIONS IN FINSLER SPACES. APPLICATIONS TO THE STUDY OF SUBSPACES AND OF TORSE FORMING VECTOR FIELDS

  • Constantinescu, Oana
    • Journal of the Korean Mathematical Society
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    • v.45 no.5
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    • pp.1443-1482
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    • 2008
  • In this paper we define a Myller configuration in a Finsler space and use some special configurations to obtain results about Finsler subspaces. Let $F^{n}$ = (M,F) be a Finsler space, with M a real, differentiable manifold of dimension n. Using the pull back bundle $({\pi}^{*}TM,\tilde{\pi},\widetilde{TM})$ of the tangent bundle $(TM,{\pi},M)$ by the mapping $\tilde{\pi}={\pi}/TM$ and the Cartan Finsler connection of a Finsler space, we obtain an orthonormal frame of sections of ${\pi}^{*}TM$ along a regular curve in $\widetilde{TM}$ and a system of invariants, geometrically associated to the Myller configuration. The fundamental equations are written in a very simple form and we prove a fundamental theorem. Important lines in a Finsler subspace are defined like special lines in a Myller configuration, geometrically associated to the subspace: auto parallels, lines of curvature, asymptotes. Torse forming vector fields with respect to the Cartan Finsler connection are characterized by means of the invariants of the Frenet frame of a versor field along a curve, and the new notion of torse forming vector fields in the sense of Myller is introduced. The particular cases of concurrence and parallelism in the sense of Myller are completely studied, for vector fields from the distribution $T^m$ of the Myller configuration and also from the normal distribution $T^p$.

Wide Air-gap Control for Multi-module Permanent Magnet Linear Synchronous Motors without Magnetic Levitation Windings

  • Bang, Deok-Je;Hwang, Seon-Hwan
    • Journal of Power Electronics
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    • v.16 no.5
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    • pp.1773-1780
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    • 2016
  • This paper proposes a wide air-gap control method for the multi-module permanent magnet linear synchronous motor (MM-PMLSM) based on independent vector control. In particular, the MM-PMLSM consists of symmetrical multi-module and multi-phase structures, which are basically three-phase configurations without a neutral point, unlike conventional three-phase machines. In addition, there are no additional magnetic levitation windings to control the normal force of the air-gap between each stator and mover. Hence, in this paper, a dq-axis current control applying a d-q transformation and an independent vector control are proposed for the air-gap control between the two symmetric stators and mover of the MM-PMLSM. The characteristics and control performance of the MM-PMLSM are analyzed under the concept of vector control. As a result, the proposed method is easily implemented without additional windings to control the air-gap and the mover position. The effectiveness of the proposed independent vector control algorithm is verified through experimental results.

SMS Text Messages Filtering using Word Embedding and Deep Learning Techniques (워드 임베딩과 딥러닝 기법을 이용한 SMS 문자 메시지 필터링)

  • Lee, Hyun Young;Kang, Seung Shik
    • Smart Media Journal
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    • v.7 no.4
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    • pp.24-29
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    • 2018
  • Text analysis technique for natural language processing in deep learning represents words in vector form through word embedding. In this paper, we propose a method of constructing a document vector and classifying it into spam and normal text message, using word embedding and deep learning method. Automatic spacing applied in the preprocessing process ensures that words with similar context are adjacently represented in vector space. Additionally, the intentional word formation errors with non-alphabetic or extraordinary characters are designed to avoid being blocked by spam message filter. Two embedding algorithms, CBOW and skip grams, are used to produce the sentence vector and the performance and the accuracy of deep learning based spam filter model are measured by comparing to those of SVM Light.

Determination of Intrusion Log Ranking using Inductive Inference (귀납 추리를 이용한 침입 흔적 로그 순위 결정)

  • Ko, Sujeong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.1
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    • pp.1-8
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    • 2019
  • Among the methods for extracting the most appropriate information from a large amount of log data, there is a method using inductive inference. In this paper, we use SVM (Support Vector Machine), which is an excellent classification method for inductive inference, in order to determine the ranking of intrusion logs in digital forensic analysis. For this purpose, the logs of the training log set are classified into intrusion logs and normal logs. The associated words are extracted from each classified set to generate a related word dictionary, and each log is expressed as a vector based on the generated dictionary. Next, the logs are learned using the SVM. We classify test logs into normal logs and intrusion logs by using the log set extracted through learning. Finally, the recommendation orders of intrusion logs are determined to recommend intrusion logs to the forensic analyst.

Variational surface design under normal field guidance

  • Wu, Weidong;Yang, Xunnian
    • Journal of Computational Design and Engineering
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    • v.2 no.3
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    • pp.129-136
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    • 2015
  • This paper proposes a novel method for shape design of a Bezier surface with given boundary curves. The surface is defined as the minimizer of an extended membrane functional or an extended thin plate functional under the guidance of a specified normal field together with an initial prescribed surface. For given boundary curves and the guiding normal field, the free coefficients of a Bezier surface are obtained by solving a linear system. Unlike previous PDE based surface modeling techniques which construct surfaces just from boundaries, our proposed method can be used to generate smooth and fair surfaces that even follow a specified normal field. Several interesting examples are given to demonstrate the applications of the proposed method in geometric modeling.

Constructions of a Transfer Vector Containing the gX Signal Sequence of Pseudorabies Virus and a Recombinant Baculovirus

  • Lee, Hyung-Hoan;Kang, Hyun;Kim, Jung-Woo;Hong, Seung-Kuk;Kang, Bong-Joo;Song, Jae-Young
    • Journal of Microbiology and Biotechnology
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    • v.9 no.5
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    • pp.541-547
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    • 1999
  • Constructions of a transfer vector and a recombinant baculovirus using the thymidine kinase gene of the Herpes simplex virus type 1 strain F (HSV -1) were carried out. Newly cloned transfer vector, pHcgXIIIB, was constructed by insertion of the glycoprotein gX gene signal peptide sequence of Pseudorabies virus into the baculovirus vector pHcEV-IV. The gX sequence was inserted just downstream from the promoter for the polyhedrin gene of the Hyphantria cunea nuclear polyhedrosis virus (HcNPV). HSV-1 thymidine kinase(tk) gene (1.131 kb) was used as a candidate gene for transferring into the baculovirus expression system. The tk gene was inserted into a BamHI site downstream from the gX sequence-promoter for the polyhedrin gene in the pHcgXIIIB transfer vector and was transferred into the infectious lacZ-HcNPV expression vector. Recombinant virus was isolated and was named gX-TK-HcNPV. The recombinant virus produced a 45 kDa gX-TK fusion protein in Spodoptera frugiperda cells, which was confirmed by Western blot analysis. Microscopic examination of gX-TK-HcNPV-infected cells revealed normal multiplication. Fluorescent antibody staining indicated that the gX-TK fusion protein was present in the cytoplasm. These results indicated that the transfer vector successfully transferred the gX-tk gene into the baculovirus expression system.

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SEMI-INVARIANT SUBMANIFOLDS OF CODIMENSION 3 SATISFYING 𝔏ξ∇ = 0 IN A NONFLAT COMPLEX SPACE FORM

  • AHN, SEONG-SOO;LEE, SEONG-BAEK;LEE, AN-AYE
    • Honam Mathematical Journal
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    • v.23 no.1
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    • pp.133-143
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    • 2001
  • In this paper, we characterize some semi-invariant submanifolds of codimension 3 with almost contact metric structure (${\phi}$, ${\xi}$, g) satisfying 𝔏ξ∇ = 0 in a nonflat complex space form, where ${\nabla}$ denotes the Riemannian connection induced on the submanifold, and 𝔏ξ is the operator of the Lie derivative with respect to the structure vector field ${\xi}$.

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ON TIMELIKE BERTRAND CURVES IN MINKOWSKI 3-SPACE

  • Ucum, Ali;Ilarslan, Kazim
    • Honam Mathematical Journal
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    • v.38 no.3
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    • pp.467-477
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    • 2016
  • In this paper, we study the timelike Bertrand curves in Minkowski 3-space. Since the principal normal vector of a timelike curve is spacelike, the Bertrand mate curve of this curve can be a timelike curve, a spacelike curve with spacelike principal normal or a Cartan null curve, respectively. Thus, by considering these three cases, we get the necessary and sufficient conditions for a timelike curve to be a Bertrand curve. Also we give the related examples.

ON SPACELIKE ROTATIONAL SURFACES WITH POINTWISE 1-TYPE GAUSS MAP

  • Dursun, Ugur
    • Bulletin of the Korean Mathematical Society
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    • v.52 no.1
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    • pp.301-312
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    • 2015
  • In this paper, we study a class of spacelike rotational surfaces in the Minkowski 4-space $\mathbb{E}^4_1$ with meridian curves lying in 2-dimensional spacelike planes and having pointwise 1-type Gauss map. We obtain all such surfaces with pointwise 1-type Gauss map of the first kind. Then we prove that the spacelike rotational surface with flat normal bundle and pointwise 1-type Gauss map of the second kind is an open part of a spacelike 2-plane in $\mathbb{E}^4_1$.

ON THE APPLICATION OF MIXED FINITE ELEMENT METHOD FOR A STRONGLY NONLINEAR SECOND-ORDER HYPERBOLIC EQUATION

  • Jiang, Ziwen;Chen, Huanzhen
    • Journal of applied mathematics & informatics
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    • v.5 no.1
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    • pp.23-40
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    • 1998
  • Mixed finite element method is developed to approxi-mate the solution of the initial-boundary value problem for a strongly nonlinear second-order hyperbolic equation in divergence form. Exis-tence and uniqueness of the approximation are proved and optimal-order $L\infty$-in-time $L^2$-in-space a priori error estimates are derived for both the scalar and vector functions approximated by the method.