• Journal of the Korean Statistical Society
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• v.35 no.2
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• pp.115-142
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• 2006

This paper studies the problem of option hedging when the underlying asset price process is a compound Poisson process. By adopting an asymptotic approach to let the security price converge to a continuous process, we find a closed-form hedging strategy that improves the classical Black-Scholes hedging strategy in a quadratic sense. We first show that the scaled Black-scholes hedging error has a limit in law, and that limit is decomposed into a part that can be traded away and a part that is purely unreplicable. The Black-Scholes hedging strategy is then modified by adding the replicable part of its hedging error and by adding the mean-variance hedging strategy to the nonreplicable part. Some results of simulation experiment s are also provided.

• Korean Journal of Logic
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• v.8 no.1
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• pp.23-46
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• 2005

The purpose of the paper Is to discuss and estimate early Popper's theory of probability, which is presented in his book, The Logic of of Scientific Discovery. For this, Von Mises' frequency theory shall be discussed in detail, which is regarded as the most systematic and sophisticated frequency theory among others. Von Mises developed his theory to response to various critical questions such as how finite and empirical collectives can be represented in terms of infinite and mathematical collectives, and how the axiom of randomness can be mathematically formulated. But his theory still has another difficulty, which is concerned with the inconsistency between the axiom of convergence and the axiom of randomness. Defending the objective theory of probability, Popper tries to present his own frequency theory, solving the difficulty. He suggests that the axiom of convergence be given up and that the axiom of randomness be modified to solve Von Mises' problem. That is, Popper introduces the notion of ordinal selection and neighborhood selection to modify the axiom of randomness. He then shows that Bernoulli's theorem is derived from the modified axiom. Consequently, it can be said that Popper solves the problem of inconsistency which is regarded as crucial to Von Mises' theory. However, Popper's suggestion has not drawn much attention. I think it is because his theory seems anti-intuitive in the sense that it gives up the axiom of convergence which is the basis of the frequency theory So for more persuasive frequency theory, it is necessary to formulate the axiom of randomness to be consistent with the axiom of convergence.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.4
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• pp.36-44
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• 2012

Electrical impedance tomography is a relatively new imaging modality in which the internal conductivity (or resistivity) distribution of a object is reconstructed based on the injected currents and measured voltages through the electrodes placed on the surface of the object. In this paper, it is assumed that the relationship between the resistivity distribution and the resistance of electrodes is linear. From this linear relation, the weighting matrix can be obtained and modified iterative Landweber method is applied to estimate the internal resistivity distribution. Additionally, to accelerate the convergence rate and improve the spatial resolution of the reconstructed image, optimal step lengths for the iterative Landweber method are computed from the objective function in the least-square sense. The numerical experiments have been performed to illustrate the superior reconstruction performance of the proposed scheme.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.571-577
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• 2016

Recently problems and issues of career-interrupted women were emerging as major social agenda in modern general and female society. This study modified and restructured REBT career group counseling and intended to testify the effects of REBT career group counseling program on self-efficacy and career attitude maturity of career discontinued married women in thirties. The subjects were career-interrupted married women in thirties living in J city, who have elementary school students as their children and applied to our study with 3 groups. 45 subjects were randomly assigned to experimental group(REBT Group), control group1(education group for vocational counselor) and control group2(general parental education group) by the number of 15. To assess effects of 3 groups, pre-test and post-test were carried out. Results showed that the participants of REBT group showed more self-efficacy, social efficacy and total self-efficacy scores than them of 2 control groups. And they had tendency to have more sense of reality, preparedness and total career attitude maturity scores. It seems that REBT career counseling program changed their irrational beliefs into rational beliefs about course and career, increasing their self-efficacy and career attitude maturity. The meaning, limitation and future tasks were discussed.