Zobrazeno 1 - 10
of 146
pro vyhledávání: '"JaeYoung Chung"'
Autor:
Jaeyoung Chung, Yu-Min Ju
Publikováno v:
Journal of Function Spaces, Vol 2016 (2016)
Let X be a real normed space and Y a Banach space and f:X→Y. We prove the Ulam-Hyers stability theorem for the quartic functional equation f(2x+y)+f(2x-y)-4f(x+y)-4f(x-y)-24f(x)+6f(y)=0 in restricted domains. As a consequence we consider a measure
Externí odkaz:
https://doaj.org/article/633e8f5b0958485aa32054cc56372002
Publikováno v:
Journal of Function Spaces, Vol 2016 (2016)
Let G be a uniquely 2-divisible commutative group and let f,g:G→C and σ:G→G be an involution. In this paper, generalizing the superstability of Lobačevskiǐ’s functional equation, we consider f(x+σy)/22-g(x)f(y)≤ψ(x) or ψ(y) for all x,y
Externí odkaz:
https://doaj.org/article/3d111a5835a84346bf5443a2b6d5963b
Autor:
Jaeyoung Chung, Soon-Yeong Chung
Publikováno v:
Journal of Function Spaces, Vol 2015 (2015)
We prove the Ulam problem for the cosine addition formula in the spaces of Schwartz distributions and Sato hyperfunctions with respect to bounded distributions and bounded hyperfunctions.
Externí odkaz:
https://doaj.org/article/831fff287e1c4c5dac4c071b1053dad7
Publikováno v:
Journal of Function Spaces, Vol 2015 (2015)
Let S and G be a commutative semigroup and a commutative group, respectively, C and R+ the sets of complex numbers and nonnegative real numbers, respectively, and σ:S→S or σ:G→G an involution. In this paper, we first investigate general solutio
Externí odkaz:
https://doaj.org/article/11c8c1b101cb43ad9fcbd512573951ba
Autor:
Jaeyoung Chung
Publikováno v:
Journal of Function Spaces, Vol 2014 (2014)
Let S be a commutative semigroup with no neutral element, Y a Banach space, and ℂ the set of complex numbers. In this paper we prove the Hyers-Ulam stability for Pexider equation fx+y-gx-h(y)≤ϵ for all x,y∈S, where f,g,h:S→Y. Using Jung’s
Externí odkaz:
https://doaj.org/article/9b89dfdaba61473d9bb3a26502ba1c8c
Autor:
Jaeyoung Chung, Soon-Yeong Chung
Publikováno v:
Journal of Function Spaces, Vol 2014 (2014)
Let S be a commutative semigroup if not otherwise specified and f:S→ℝ. In this paper we consider the stability of exponential functional equations |f(x+σ(y))-g(x)f(y)|≤ϕ(x) or ϕ(y), |f(x+σ(y))-f(x)g(y)|≤ϕ(x) or ϕ(y) for all x,y∈S and
Externí odkaz:
https://doaj.org/article/72a1dd9870424a2ab42749b39c3d3222
Autor:
Jaeyoung Chung, Prasanna K. Sahoo
Publikováno v:
Abstract and Applied Analysis, Vol 2014 (2014)
Let S be a nonunital commutative semigroup, σ:S→S an involution, and C the set of complex numbers. In this paper, first we determine the general solutions f,g:S→C of Wilson’s generalizations of d’Alembert’s functional equations fx+y+fx+σy
Externí odkaz:
https://doaj.org/article/65e7d4f2d7964f12b3b45147cf20b1c9
Autor:
Jaeyoung Chung
Publikováno v:
Abstract and Applied Analysis, Vol 2014 (2014)
Let S be a commutative semigroup, f,g:S→C and σ:S→S an involution. In this paper we consider the stability of involution-exponential functional equations fx+σy-gxfy≤ϕxresp., ϕy, |f(x+σy)-f(x)g(y)|≤ϕ(x) [resp., ϕ(y)] for all x,y∈S, wh
Externí odkaz:
https://doaj.org/article/bc70743c39404bc2836754be2da0c439
Autor:
Jaeyoung Chung, Jeongwook Chang
Publikováno v:
Abstract and Applied Analysis, Vol 2013 (2013)
We consider the Hyers-Ulam stability for a class of trigonometric functional equations in the spaces of generalized functions such as Schwartz distributions and Gelfand hyperfunctions.
Externí odkaz:
https://doaj.org/article/924bb113b7374b0889957efb66ebbc64
Autor:
Jaeyoung Chung, Prasanna K. Sahoo
Publikováno v:
Abstract and Applied Analysis, Vol 2013 (2013)
Let be the set of real numbers, , , and . As classical and versions of the Hyers-Ulam stability of the logarithmic type functional equation in a restricted domain, we consider the following inequalities: , and in the sectors . As consequences of the
Externí odkaz:
https://doaj.org/article/4632f1c6262c4ba5873427f3ddcb1809