• 제목/요약/키워드: contractive conditions

검색결과 58건 처리시간 0.02초

흙의 변형국지화 편재에 관한 연구 (Omnipresence of Strain Localization in Soils)

  • 권태혁;조계춘
    • 한국지반공학회논문집
    • /
    • 제19권5호
    • /
    • pp.199-210
    • /
    • 2003
  • 흙이 변형하는 동안 전단지역 내에서 변형국지화가 자주 관찰된다. 사실상, 그 현상은 예외적이라기보다는 전형적으로 보인다. 개념적으로, 행해진 일의 증가가 음인 경우 변형국지화가 쉽게 발생한다. 이러한 현상을 검증하기 위해서, 본 연구에서는 배수상태의 조밀한 흙, 비배수상태의 느슨한 흙, 비배수전단하의 조밀한 흙에서의 공동화, 비균질한 흙, 판상형의 입자로 된 흙에서의 입자배열, 입자 깨짐을 가지는 흙, 그리고 낮은 함수비나 약한 시멘트결합이 된 흙 등 다양한 흙과 다양한 조건에 대하여 조사를 수행하였다. 이러한 경우들의 각각을 독립적으로 시험할 수 있도록 시료를 제작하였고 실험절차를 구상하였다. 실험결과에 의하면, 최고점후 변형연화거동을 가지는 흙은 변형국지화, 전단대형성, 그리고 점진적 파괴가 되기 쉽다. 응력상태, 흙밀도, 흙입자의 고유적인 역학적$.$지형학적인 특성, 저함수비, 그리고 비균질성이 변형국지화를 일으키는데 공헌을 하였다. 국지화가 가능한 모든 경우들을 고려해 볼 때, 실내시험으로부터 한계상태정수를 결정하는 최선의 방법은 배수전단하의 느슨하고 균일한 포화시료를 사용하는 것으로 나타났다.

COMPLETION OF HANKEL PARTIAL CONTRACTIONS OF NON-EXTREMAL TYPE

  • KIM, IN HYOUN;YOO, SEONGUK;YOON, JASANG
    • 대한수학회지
    • /
    • 제52권5호
    • /
    • pp.1003-1021
    • /
    • 2015
  • A matrix completion problem has been exploited amply because of its abundant applications and the analysis of contractions enables us to have insight into structure and space of operators. In this article, we focus on a specific completion problem related to Hankel partial contractions. We provide concrete necessary and sufficient conditions for the existence of completion of Hankel partial contractions for both extremal and non-extremal types with lower dimensional matrices. Moreover, we give a negative answer for the conjecture presented in [8]. For our results, we use several tools such as the Nested Determinants Test (or Choleski's Algorithm), the Moore-Penrose inverse, the Schur product techniques, and a congruence of two positive semi-definite matrices; all these suggest an algorithmic approach to solve the contractive completion problem for general Hankel matrices of size $n{\times}n$ in both types.

STRONG CONVERGENCE OF HYBRID ITERATIVE SCHEMES WITH ERRORS FOR EQUILIBRIUM PROBLEMS AND FIXED POINT PROBLEMS

  • Kim, Seung-Hyun;Kang, Mee-Kwang
    • 한국수학교육학회지시리즈B:순수및응용수학
    • /
    • 제25권2호
    • /
    • pp.149-160
    • /
    • 2018
  • In this paper, we prove a strong convergence result under an iterative scheme for N finite asymptotically $k_i-strictly$ pseudo-contractive mappings and a firmly nonexpansive mappings $S_r$. Then, we modify this algorithm to obtain a strong convergence result by hybrid methods. Our results extend and unify the corresponding ones in [1, 2, 3, 8]. In particular, some necessary and sufficient conditions for strong convergence under Algorithm 1.1 are obtained.

On ϑ-quasi-Geraghty Contractive Mappings and Application to Perturbed Volterra and Hypergeometric Operators

  • Olalekan Taofeek Wahab
    • Kyungpook Mathematical Journal
    • /
    • 제63권1호
    • /
    • pp.45-60
    • /
    • 2023
  • In this paper we suggest an enhanced Geraghty-type contractive mapping for examining the existence properties of classical nonlinear operators with or without prior degenerates. The nonlinear operators are proved to exist with the imposition of the Geraghty-type condition in a non-empty closed subset of complete metric spaces. To showcase some efficacies of the Geraghty-type condition, convergent rate and stability are deduced. The results are used to study some asymptotic properties of perturbed integral and hypergeometric operators. The results also extend and generalize some existing Geraghty-type conditions.

CONTROL FUNCTION BASED COUPLED AND COMMON COUPLED FIXED POINT THEOREMS IN PARTIAL METRIC SPACES

  • H. K. Nashine;G. S. Saluja;G. V. V. Jagannadha Rao;W. H. Lim
    • Nonlinear Functional Analysis and Applications
    • /
    • 제29권2호
    • /
    • pp.559-580
    • /
    • 2024
  • In this paper, we aim to prove coupled and common coupled fixed point theorems for contractive type conditions in the context of partial metric spaces by means of a control function, and to provide some corollaries of the established results. This paper presents a number of results that generalize and extend previous work in the field. In order to better illustrate the process, we provide examples.

COMMON FIXED POINT AND INVARIANT APPROXIMATION RESULTS

  • Abbas, Mujahid;Kim, Jong-Kyu
    • 대한수학회보
    • /
    • 제44권3호
    • /
    • pp.537-545
    • /
    • 2007
  • Necessary conditions for the existence of common fixed points for noncommuting mappings satisfying generalized contractive conditions in the setup of certain metrizable topological vector spaces are obtained. As applications, related results on best approximation are derived. Our results extend, generalize and unify various known results in the literature.

COMMON FIXED POINT AND INVARIANT APPROXIMATION IN MENGER CONVEX METRIC SPACES

  • Hussain, Nawab;Abbas, Mujahid;Kim, Jong-Kyu
    • 대한수학회보
    • /
    • 제45권4호
    • /
    • pp.671-680
    • /
    • 2008
  • Necessary conditions for the existence of common fixed points for noncommuting mappings satisfying generalized contractive conditions in a Menger convex metric space are obtained. As an application, related results on best approximation are derived. Our results generalize various well known results.