• Journal of applied mathematics & informatics
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• 제20권1_2호
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• pp.133-147
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• 2006

In this paper, by using the Riccati transformation technique we establish some new oscillation criteria for second-order nonlinear perturbed dynamic equation on time scales. An example illustrating our main results is also given.

• Journal of applied mathematics & informatics
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• 제28권3_4호
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• pp.945-952
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• 2010

In this paper, existence criteria of one solution to a nonlinear first-order periodic boundary value problem of impulsive dynamic equation on time scales are obtained by using the well-known Schaefer fixed-point theorem.

• Kyungpook Mathematical Journal
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• 제47권3호
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• pp.425-438
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• 2007

In this paper, we establish some new oscillation criteria for a second-order delay dynamic equation $$u^{{\Delta}{\Delta}}(t)+p(t)u(\tau(t))=0$$ on a time scale $\mathbb{T}$. The results can be applied on differential equations when $\mathbb{T}=\mathbb{R}$, delay difference equations when $\mathbb{T}=\mathbb{N}$ and for delay $q$-difference equations when $\mathbb{T}=q^{\mathbb{N}}$ for q > 1.

• 충청수학회지
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• 제25권1호
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• pp.127-133
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• 2012

In this paper we give a necessary and sufficient condition for characterizing $h$-stability for linear dynamic systems on time scales by using Lyapunov functions.

• East Asian Economic Review
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• 제19권2호
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• pp.189-220
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• 2015

Multi-scale representations are effective in characterising the time-frequency characteristics of financial return series. They have the capability to reveal the properties not evident with typical time domain analysis. Given the aforesaid, this study derives crucial insights from multi scale analysis to investigate the co-movements between Indian and emerging Asian equity markets using wavelet correlation and wavelet coherence measures. It is reported that the Indian equity market is strongly integrated with Asian equity markets at lower frequency scales and relatively less blended at higher frequencies. On the other hand the results from cross correlations suggest that the lead-lag relationship becomes substantial as we turn to lower frequency scales and finally, wavelet coherence demonstrates that this correlation eventually grows strong in the interim of the crises period at lower frequency scales. Overall the findings are relevant and have strong policy and practical implications.

• 천문학회지
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• 제17권1호
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• pp.15-22
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• 1984

The transverse velocities of the gravitational lens system (galaxy plus a 'disturbing star') and their dependences on unkown properties of the source and the deflecting object are discussed. We have derived an analytic expression for the transverse velocity in terms of the velocities of the light source, the gravitational lensing galaxy and the 'disturbing star', and the observer. The results are then further applied to an estimate of the expectation value of the absolute transverse velocity and of the probable time scales of flux changes of the double QSO 0957+561A, B.

• 대한수학회보
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• 제48권5호
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• pp.1047-1061
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• 2011

In this paper, a class of second-order boundary value problems with Sturm-Liouville boundary conditions or multi-point conditions is considered. Some existence and uniqueness theorems of positive solutions of the problem are obtained by using monotone iterative technique, the iterative sequences yielding approximate solutions are also given. The results are illustrated with an example.

• Journal of applied mathematics & informatics
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• 제33권1_2호
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• pp.1-12
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• 2015

This paper is concerned with boundary value problems for systems of n-th order dynamic equations on time scales. Under the suitable conditions, the existence and multiplicity of positive solutions are established by using abstract fixed-point theorems.

• 충청수학회지
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• 제27권4호
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• pp.661-674
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• 2014

In this paper, we define the $M_{\alpha}$-delta integral and investigate the relation between the $M_{\alpha}$ and $M_{\alpha}$-delta integrals on time scales.

• Kyungpook Mathematical Journal
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• 제56권2호
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• pp.529-539
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• 2016

In this paper, we obtain solution for the first order matrix dynamical system and also we provide set of necessary and sufficient conditions for complete controllability and complete observability of the Sylvester matrix dynamical system.