• 제목/요약/키워드: differential inequalities

검색결과 84건 처리시간 0.028초

STABILITIES FOR NONLINEAR FUNCTIONAL DIFFERENTIAL EQUATIONS

  • Choi, Sung Kyu;Koo, Nam Jip;Song, Sse Mok
    • 충청수학회지
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    • 제9권1호
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    • pp.165-174
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    • 1996
  • Using the comparison principle and inequalities we obtain some results on boundedness and stabilities of solutions of the nonlinear functional differential equation $y^{\prime}=f(t,y)+g(t,y,Ty)$.

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ON INEQUALITIES OF GRONWALL TYPE

  • Choi, Sung Kyu;Kang, Bowon;Koo, Namjip
    • 충청수학회지
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    • 제20권4호
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    • pp.561-568
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    • 2007
  • In this paper, we improve the results of [9] and give an application to boundedness of the solutions of nonlinear integro-differential equations.

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Existence and Uniqueness Theorems for Certain Fourth-order Boundary Value Problems

  • Minghe, Pei;Chang, Sung Kag
    • Kyungpook Mathematical Journal
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    • 제45권3호
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    • pp.349-356
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    • 2005
  • In this paper, by using the Leray-Schauder continuation theorem and Wirtinger-type inequalities, we establish the existence and uniqueness theorems for two-point boundary value problems of a certain class of fourth-order nonlinear differential equations.

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남녀 노인의 사회경제적 우울 불평등: 사회적 지지 자원의 기여 (Socioeconomic Inequalities in Depressive Symptoms among Korean Older Men and Women: Contribution of Social Support Resources)

  • 이정;최경원;전경숙
    • 지역사회간호학회지
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    • 제31권1호
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    • pp.13-23
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    • 2020
  • Purpose: This study explored the contribution of social support resources to the explanation of socioeconomic inequalities in depressive symptoms of older Korean men and women. Methods: Data were derived from Living Profiles of Older People Survey (LPOPS), which comprises a nationally representative sample of non-institutionalized Korean older adults living in the community. The data were analyzed by using multiple logistic regression. The sample consisted of 4,046 men and 6,036 women aged ≥65 years. The Korean version of the Geriatric Depression Scale-Short form (SGDS-K) was employed as an outcome variable. Results: Compared to the older men and women who were in higher socioeconomic status, those in lower socioeconomic status had significantly higher risk of depressive symptoms after adjusting for other covariates. When social support resources were individually included in the base model, each factor contributed to inequalities in depressive symptoms. Social networks explained about 20% of the differential impact of education and 10% to 15% of the differential impact of household income for depressive symptoms in men. Among women, it mitigated 23.6% to 39.0% of education and household income inequalities for depressive symptoms. Social participation contributed to buffer depressive symptom inequalities of 24.0% to 46.3% among men and those of 11.7% to 45.3% among women. Conclusion: Our findings suggest community care nurses acknowledge the value of social support resources to alleviate socioeconomic inequality in depressive symptoms among older men and women.

ON SOME NEW NONLINEAR DELAY AND WEAKLY SINGULAR INTEGRAL INEQUALITIES

  • Ma, Qing-Hua;Debnath, L.
    • Journal of applied mathematics & informatics
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    • 제26권5_6호
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    • pp.877-888
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    • 2008
  • This paper deals with some new nonlinear delay and weakly singular integral inequalities of Gronwall-Bellman type. These results generalize the inequalities discussed by Xiang and Kuang [19]. Several other inequalities proved by $Medve{\check{d}}$ [15] and Ou-Iang [17] follow as special cases of this paper. This work can be used in the analysis of various problems in the theory of certain classes of differential equations, integral equations and evolution equations. A modification of the Ou-Iang type inequality with delay is also treated in this paper.

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장애물 접촉문제에서의 지역 A Posteriori 오차계산 (Local A Posteriori Error Estimates for Obstacle Contact Problems)

  • 이춘열
    • 한국정밀공학회지
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    • 제15권5호
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    • pp.120-127
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    • 1998
  • Differential inequalities occurring in problems of obstacle contact problems are recast into variational inequalities and analyzed by finite element methods. A new a posteriori error estimator, which is essential in adaptive finite element method, is introduced to capture the errors in finite element approximations of these variational inequalities. In order to construct a posteriori error estimates, saddle point problems are introduced using Lagrange parameters and upper bounds are provided. The global upper bound is localized by a special mixed formulation, which leads to upper bounds of the element errors. A numerical experiment is performed on an obstacle contact problem to check the effectivity index both in a local and a global sense.

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CERTAIN GRONWALL TYPE INEQUALITIES ASSOCIATED WITH RIEMANN-LIOUVILLE k- AND HADAMARD k-FRACTIONAL DERIVATIVES AND THEIR APPLICATIONS

  • Nisar, Kottakkaran Sooppy;Rahman, Gauhar;Choi, Junesang;Mubeen, Shahid;Arshad, Muhammad
    • East Asian mathematical journal
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    • 제34권3호
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    • pp.249-263
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    • 2018
  • We aim to establish certain Gronwall type inequalities associated with Riemann-Liouville k- and Hadamard k-fractional derivatives. The results presented here are sure to be new and potentially useful, in particular, in analyzing dependence solutions of certain k-fractional differential equations of arbitrary real order with initial conditions. Some interesting special cases of our main results are also considered.

Gender, Professional and Non-Professional Work, and the Changing Pattern of Employment-Related Inequality in Poor Self-Rated Health, 1995-2006 in South Korea

  • Kim, Il-Ho;Khang, Young-Ho;Cho, Sung-Il;Chun, Hee-Ran;Muntaner, Carles
    • Journal of Preventive Medicine and Public Health
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    • 제44권1호
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    • pp.22-31
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    • 2011
  • Objectives: We examined gender differential changes in employment-related health inequalities according to occupational position (professional/nonprofessional) in South Korea during the last decade. Methods: Data were taken from four rounds of Social Statistical Surveys of South Korea (1995, 1999, 2003, and 2006) from the Korean National Statistics Office. The total study population was 55435 male and 33913 female employees aged 25-64. Employment arrangements were divided into permanent, fixed-term, and daily employment. Results: After stratification according to occupational position (professional/nonprofessional) and gender, different patterns in employment - related health inequalities were observed. In the professional group, the gaps in absolute and relative employment inequalities for poor self-rated health were more likely to widen following Korea's 1997 economic downturn. In the nonprofessional group, during the study period, graded patterns of employment-related health inequalities were continuously observed in both genders. Absolute health inequalities by employment status, however, decreased among men but increased among women. In addition, a remarkable increase in relative health inequalities was found among female temporary and daily employees (p = 0.009, < 0.001, respectively), but only among male daily employees (p = 0.001). Relative employment-related health inequalities had clearly widened for female daily workers between 2003 and 2006 (p = 0.047). The 1997 Korean economic downturn, in particular, seemingly stimulated a widening gap in employment health inequalities. Conclusions: Our study revealed that whereas absolute health inequalities in relation to employment status increased in the professional group, relative employment-related health inequalities increased in the nonprofessional group, especially among women. In view of the high concentration of female nonstandard employees, further monitoring of inequality should consider gender specific patterns according to employee's occupational and employment status.