General exponential dichotomies on time scales and parameter dependence of roughness

On the Robustness of Exponential Dichotomies

For linear evolution families in Banach spaces, we establish the robustness of a weaker notion of exponential dichotomy. This notion allows the contraction and expansion along the stable and unstable subspaces to be nonuniform and requires nothing from the angles between these subspaces.

Exponential Stability of Linear Time-Invariant Systems on Time Scales

Several notions of exponential stability of linear time-invariant systems on arbitrary time scales are discussed. We establish a necessary and sufficient condition for the existence of uniform exponential stability. Moreover, we characterize the uniform exponential stability of a system by the spectrum of its matrix. In general, exponential stability of a system can not be characterized by the ...

the effects of time planning and task complexity on accuracy of narrative task performance

هدف اصلی این تحقیق بررسی تاثیر برنامه ریزی زمانی، هم چنین افزایش میزان پیچیدگی تکالیف در نظر گرفته شده بصورت همزمان، بر دقت و صحت و پیچیدگی عملکرد نوشتاری زبان آموزان می باشد. بدین منظور، 50 نفر از دانش آموزان دختر در رده ی سنی 16 الی 18 سال به عنوان شرکت کنندگان در این زمینه ی تحقیق در نظر گرفته شدند و به دو گروه آزمایشی و کنترل بصورت اتفاقی تقسیم شدند. اعضای گروه آزمایشی هر دو تکلیف ساده و پی...

Exponential and Polynomial Dichotomies of Operator Semigroups on Banach Spaces

Let A generate a C0–semigroup T (·) on a Banach space X such that the resolvent R(iτ, A) exists and is uniformly bounded for τ ∈ R. We show that there exists a closed, possibly unbounded projection P on X commuting with T (t). Moreover, T (t)x decays exponentially as t → ∞ for x in the range of P and T (t)x exists and decays exponentially as t→ −∞ for x in kernel of P . The domain of P depends ...

Lyapunov Function and Exponential Trichotomy on Time Scales