• Nonlinear Functional Analysis and Applications
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• v.28 no.2
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• pp.407-420
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• 2023

In this manuscript, we study the sufficient conditions for controllability of Volterra-Fredholm type fractional integro-differential systems in a Banach space. Fractional calculus and the fixed point theorem are used to derive the findings. Some examples are provided to illustrate the obtained results.

• Journal of applied mathematics & informatics
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• v.40 no.1_2
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• pp.305-316
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• 2022

We study the existence and uniqueness of solutions for a class of boundary value problems of nonlinear fractional order differential equations involving the Caputo fractional derivative by employing the Banach's contraction principle and the Schauder's fixed point theorem. In addition, an example is given to demonstrate the application of our main results.

• Journal of the Korean Statistical Society
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• v.34 no.2
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• pp.85-98
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• 2005

A Bayesian analysis for the product of different powers of k independent Poisson rates, written ${\theta}$, is developed. This is done by considering a prior for ${\theta}$ that satisfies the differential equation due to Tibshirani and induces a proper posterior distribution. The Gibbs sampling procedure utilizing the rejection method is suggested for the posterior inference of ${\theta}$. The procedure is straightforward to specify distributionally and to implement computationally, with output readily adapted for required inference summaries. A salient feature of the procedure is that it provides a unified method for inferencing ${\theta}$ with any type of powers, and hence it solves all the existing problems (in inferencing ${\theta}$) simultaneously in a completely satisfactory way, at least within the Bayesian framework. In two examples, practical applications of the procedure is described.

• Journal of the Korean Society of Combustion
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• v.16 no.3
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• pp.21-26
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• 2011

Thermal analyses are conducted to measure chemical kinetic parameters of an unknown liquid fuel with various components. Thermal Analyses are divided into two different methods such as TGA(Thermo-Gravimetric Analysis) and DSC(Differential Scanning Calorimety). Non-isothermal experimental results are analyzed by adopting TGA and they are filtered by Freeman-Carroll method. As a results of the analysis, chemical parameters of the activation temperature and the reaction order are measured to be 6128.2 K and 1.4, respectively. Furthermore, the chemical kinetic parameters are obtained by a variety of mathematical processing methods. It has been found that they show a little difference depending on the processing method.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.9
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• pp.578-583
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• 2000

We introduce the systematization design method using analogical analysis. The design method can make us predict the characteristic experiment for the magnitude we desire as the expression equation applied continuously. We can induce the design sample the users demand with the verification of the data on optimum design previously. Therefore in case of designing and developing the products systematization design method is very useful for the standardization of the developed goods compatability the reduction of construction time and price. In this paper we present the analogical algorithms of systematization design using similarity theory design factors and processing method of the restriction factors. Also we analyze the output voltage in terms of input voltage and displacement as choosing a differential transformer as the model.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.2
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• pp.122-129
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• 2016

Current differential protection relaying with second harmonic restraint is the main protection for large capacity power transformer. PSCAD simulation program is widely used for modeling of dynamic varying transients phenomena. This paper deals with a power transformer model and transients analysis using PSCAD software to develop IED for power transformer. Simulation was carried out using a three phase 40MVA, 154/22.9kV, 60Hz, two-winding transformer with Y-Y connection used in actual fields. The paper analyzed transformer magnetizing inrush, external fault, and internal fault conditions with this model in the time domain. In addition, we performed an analysis in the frequency domain using FFT during several conditions.

• Steel and Composite Structures
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• v.22 no.1
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• pp.161-182
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• 2016

A state space differential reproducing kernel (DRK) method is developed for the three-dimensional (3D) analysis of functionally graded material (FGM) axisymmetric circular plates with simply-supported and clamped edges. The strong formulation of this 3D elasticity axisymmetric problem is derived on the basis of the Reissner mixed variational theorem (RMVT), which consists of the Euler-Lagrange equations of this problem and its associated boundary conditions. The primary field variables are naturally independent of the circumferential coordinate, then interpolated in the radial coordinate using the early proposed DRK interpolation functions, and finally the state space equations of this problem are obtained, which represent a system of ordinary differential equations in the thickness coordinate. The state space DRK solutions can then be obtained by means of the transfer matrix method. The accuracy and convergence of this method are examined by comparing their solutions with the accurate ones available in the literature.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.70-75
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• 2012

LED-64 is a 64-bit block cipher proposed in CHES 2011 and suitable for the efficient implementation in constrained hardware environments such as WSN. In this paper, we propose a differential fault analysis on LED-64. In order to recover the secret key of LED-64, this attack requires only one random nibble fault and an exhaustive search of $2^8$. This work is the first known cryptanalytic result on LED-64.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.16 no.2
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• pp.21-27
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• 2008

An inverse method is introduced to construct the problem for the error analysis of the numerical solution of initial value problem. These problems constructed through this method have a known exact solution, even though analytical solutions are generally not obtainable. The process leading to the exact solution makes use of an initially available approximate numerical solution. A smooth interpolation of the approximate solution is forced to exactly satisfy the differential equation by analytically deriving a small forcing function to absorb all of the errors in the interpolated approximate solution. Using this special case exact solution, it is possible to investigate the relationship between global errors of a candidate numerical solution process and the associated tuning parameters for a given problem. Under the assumption that the original differential equation is well-posed with respect to the small perturbations, we thereby obtain valuable information about the optimal choice of the tuning parameters and the achievable accuracy of the numerical solution.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.246-248
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• 2001

In this paper, the fault analysis program that is convenient to analyse fault records of a digital relay and to set a digital relay is described. The key feature of this fault analysis program is as follows. - analysing fault records stored in a local PC and/or a digital relay - analysing events - setting a digital relay. This program is for a digital bus protection relay using a conventional variable percentage current differential relaying algorithm. So this program adds a function analysing the characteristic of each variable percentage current differential function and the connection state of the transmission lines at double-bus system.