• Title/Summary/Keyword: Hyperbolic

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REAL HYPERSURFACES IN THE COMPLEX HYPERBOLIC QUADRIC WITH CYCLIC PARALLEL STRUCTURE JACOBI OPERATOR

  • Jin Hong Kim;Hyunjin Lee;Young Jin Suh
    • Journal of the Korean Mathematical Society
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    • v.61 no.2
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    • pp.309-339
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    • 2024
  • Let M be a real hypersurface in the complex hyperbolic quadric Qm*, m ≥ 3. The Riemannian curvature tensor field R of M allows us to define a symmetric Jacobi operator with respect to the Reeb vector field ξ, which is called the structure Jacobi operator Rξ = R( · , ξ)ξ ∈ End(TM). On the other hand, in [20], Semmelmann showed that the cyclic parallelism is equivalent to the Killing property regarding any symmetric tensor. Motivated by his result above, in this paper we consider the cyclic parallelism of the structure Jacobi operator Rξ for a real hypersurface M in the complex hyperbolic quadric Qm*. Furthermore, we give a complete classification of Hopf real hypersurfaces in Qm* with such a property.

A two-dimensional hyperbolic spring model for mat foundation in clays subjected to vertical load

  • Der-Wen Chang;Tzu-Min Chou;Shih-Hao Cheng;Louis Ge
    • Geomechanics and Engineering
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    • v.37 no.5
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    • pp.527-538
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    • 2024
  • This study proposes a two-dimensional hyperbolic soil spring model for mat foundations in clays subjected to vertically uniform loads to simplify the complexity of three-dimensional finite element analysis on mat foundations. The solutions from three-dimensional finite element analysis were examined to determine the hyperbolic model parameters of the soil springs underneath the slab. Utilizing these model parameters, normalized functions across the middle section of the mat were obtained. The solutions from the proposed model, along with the approximate finite difference analysis of the mat in clays under vertical load, were found to be consistent with those from the three-dimensional finite element analysis. The authors conclude that the proposed method can serve as an alternative for the preliminary design of mat foundations.

MIXED PROBLEM OF SEMILINEAR HYPERBOLIC SYSTEMS

  • EI-Sayed, Ahmed M.
    • Kyungpook Mathematical Journal
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    • v.27 no.1
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    • pp.43-46
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    • 1987
  • In this paper we consider the semilinear hyperbolic symmetric system of the first-order. The existence and uniqueness of the solution are proved, under certain conditions, some properties of the solution are investigated.

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A study on Applying Hyperbolic Social Discount Rate onto the Benefit-Cost Analysis: Focused on Appropriate Analytical Time Span (쌍곡선함수 방식의 사회적할인율 적용에 대한 연구: 적정 분석기간의 설정을 중심으로)

  • Kim, Sang Kyum
    • Environmental and Resource Economics Review
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    • v.24 no.1
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    • pp.85-107
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    • 2015
  • This study analyzes the effect of applying hyperbolic social discount rate onto the results of benefit-cost analysis of environmental public investment projects in Korea. In order to check the application possibility to the actual feasibility study, the discount factors generated by hyperbolic function, rather than traditional exponential one, would be applied to the benefit and cost data from the pre-feasibility studies which peformed for environmental public investment projects. The results of this study shows that using hyperbolic social discount rate is effective for enhancing test results, only under the condition of which the full expansion of the time periods of analysis is satisfied. According to the simulation results of this study, to achieve higher benefit/cost ratio by using hyperbolic social discount rate, the period should be increased up to 120 to 150 years at least.