• Title/Summary/Keyword: non-existence

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THE NUMBER OF LINEAR SYSTEMS COMPUTING THE GONALITY

  • Coppens, Marc
    • Journal of the Korean Mathematical Society
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    • v.37 no.3
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    • pp.437-454
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    • 2000
  • Let C be a smooth k-gonal curve of genus g. We study the number of pencils of degree k on C. In case $g\geqk(k-a)/2$ we state a conjecture based on a discussion on plane models for C. From previous work it is known that if C possesses a large number of pencils then C has a special plane model. From this observation the conjectures are split up in two cases : the existence of some types of plane curves should imply the existence of curves C with a given number of pencils; the non-existence of plane curves should imply the non-existence of curves C with some given large number of pencils. The non-existence part only occurs in the range $k(k-1)/2\leqg\leqk(k-1)/2] if k\geq7$. In this range we prove the existence part of the conjecture and we also prove some non-existence statements. Those result imply the conjecture in that range for $k\leq10$. The cases $k\leq6$ are handled separately.

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EXISTENCE OF NON-CONSTANT POSITIVE SOLUTIONS FOR A RATIO-DEPENDENT PREDATOR-PREY SYSTEM WITH DISEASE IN THE PREY

  • Ryu, Kimun
    • Journal of the Chungcheong Mathematical Society
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    • v.31 no.1
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    • pp.75-87
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    • 2018
  • In this paper, we consider ratio-dependent predator-prey models with disease in the prey under Neumann boundary condition. We investigate sufficient conditions for the existence and non-existence of non-constant positive steady-state solutions by the effects of the induced diffusion rates.

A Study of Image Target Tracking Using ITS in an Occluding Environment (표적이 일시적으로 가려지는 환경에서 ITS 기법을 이용한 영상 표적 추적 알고리듬 연구)

  • Kim, Yong;Song, Taek-Lyul
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.4
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    • pp.306-314
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    • 2013
  • Automatic tracking in cluttered environment requires the initiation and maintenance of tracks, and track existence probability of true track is kept by Markov Chain Two model of target existence propagation. Unlike Markov Chain One model for target existence propagation, Markov Chain Two model is made up three hypotheses about target existence event which are that the target exist and is detectable, the target exists and is non-detectable through occlusion, and the target does not exist and is non-detectable according to non-existing target. In this paper we present multi-scan single target tracking algorithm based on the target existence, which call the Integrated Track Splitting algorithm with Markov Chain Two model in imaging sensor.

THE NON-EXISTENCE AND EXISTENCE OF POSITIVE SOLUTION TO THE COOPERATION MODEL WITH GENERAL COOPERATION RATES

  • Kang, Joon Hyuk;Lee, Jungho
    • Korean Journal of Mathematics
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    • v.16 no.3
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    • pp.259-269
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    • 2008
  • The non-existence and existence of the positive solution for the generalized cooperation biological model for two species of animals $${\Delta}u+u(a-bu+g(v))=0\;in\;{\Omega}\\{\Delta}v+v(d+h(u)-cv)=0\;in\;{\Omega}\\u=v=0\;on\;{\partial}{\Omega}$$ are investigated. The techniques used in this paper are elliptic theory, upper-lower solutions, maximum principles and spectrum estimates. The arguments also rely on some detailed properties for the solution of logistic equations.

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AN EXISTENCE OF THE SOLUTION TO NEUTRAL STOCHASTIC FUNCTIONAL DIFFERENTIAL EQUATIONS UNDER SPECIAL CONDITIONS

  • KIM, YOUNG-HO
    • Journal of applied mathematics & informatics
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    • v.37 no.1_2
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    • pp.53-63
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    • 2019
  • In this paper, we show the existence of solution of the neutral stochastic functional differential equations under non-Lipschitz condition, a weakened linear growth condition and a contractive condition. Furthermore, in order to obtain the existence of solution to the equation we used the Picard sequence.

EXISTENCE OF NON-CONSTANT POSITIVE SOLUTION OF A DIFFUSIVE MODIFIED LESLIE-GOWER PREY-PREDATOR SYSTEM WITH PREY INFECTION AND BEDDINGTON DEANGELIS FUNCTIONAL RESPONSE

  • MELESE, DAWIT
    • Journal of applied mathematics & informatics
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    • v.40 no.3_4
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    • pp.393-407
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    • 2022
  • In this paper, a diffusive predator-prey system with Beddington DeAngelis functional response and the modified Leslie-Gower type predator dynamics when a prey population is infected is considered. The predator is assumed to predate both the susceptible prey and infected prey following the Beddington-DeAngelis functional response and Holling type II functional response, respectively. The predator follows the modified Leslie-Gower predator dynamics. Both the prey, susceptible and infected, and predator are assumed to be distributed in-homogeneous in space. A reaction-diffusion equation with Neumann boundary conditions is considered to capture the dynamics of the prey and predator population. The global attractor and persistence properties of the system are studied. The priori estimates of the non-constant positive steady state of the system are obtained. The existence of non-constant positive steady state of the system is investigated by the use of Leray-Schauder Theorem. The existence of non-constant positive steady state of the system, with large diffusivity, guarantees for the occurrence of interesting Turing patterns.