• Bulletin of the Korean Mathematical Society
• /
• v.50 no.5
• /
• pp.1415-1432
• /
• 2013

We consider the value distribution of a class of the functions analytic in the exterior of a disc and their applications to complex oscillation theory of differential equations with periodic coefficients in the complex plane.

• Journal of the Korean Statistical Society
• /
• v.26 no.3
• /
• pp.309-317
• /
• 1997

A sequential procedure for estimating a linear function of two normal means which satisfies the two requirements, i.e. one is a condition of coverage probability, the other is a condition of $\beta$-protection, is proposed when the variances are unknown and not necessarily equal. We give asymptotic behaviors of the proposed stopping time.

• Communications for Statistical Applications and Methods
• /
• v.9 no.1
• /
• pp.101-113
• /
• 2002

In this paper we introduce a new score generating (unction for the rank regression in the linear regression model. The score function compares the $\gamma$'th and s\`th power of the tail probabilities of the underlying probability distribution. We show that the rank estimate asymptotically converges to a multivariate normal. further we derive the asymptotic Pitman relative efficiencies and the most efficient values of $\gamma$ and s under the symmetric distribution such as uniform, normal, cauchy and double exponential distributions and the asymmetric distribution such as exponential and lognormal distributions respectively.

• Journal of the Korean Data and Information Science Society
• /
• v.16 no.2
• /
• pp.371-382
• /
• 2005

The paper compares the performance of some widely used Bayesian estimators such as Bayes estimator, empirical Bayes estimator, constrained Bayes estimator and constrained Bayes estimator by means of a new measurement under squared error loss function for the typical normal-normal situation. The proposed measurement is a weighted sum of the precisions of first and second moments. As a result, one can gets the criterion according to the size of prior variance against the population variance.

• Journal of the Korean Statistical Society
• /
• v.19 no.2
• /
• pp.139-144
• /
• 1990

For the first-order bilinear time series model $X_t = aX_{t-1} + e_i + be_{t-1}X_{t-1}$ where ${e_i}$ is a sequence of independent normal random variables with mean 0 and variance $\sigma^2$, the asymptotic distribution of sample autocarrelation function is obtained and shown to follow a normal distribution. The variance of the asymptotic distribution is of a complicated form and hence a bootstrap estimate of the variance is proposed for large sample inference. This result can be used to distinguish between different bilinear models.

• Communications of the Korean Mathematical Society
• /
• v.26 no.2
• /
• pp.229-235
• /
• 2011

In this paper, a continuous real function on the real line is considered. The necessary and sufficient conditions for the convergence of the Ishikawa iteration with error terms for the functional are obtained.

• Journal of Korean Society for Atmospheric Environment
• /
• v.1 no.1
• /
• pp.17-23
• /
• 1985

In order to study the effect of air pollution on the ventilatory function of lung, pulmonary function studies were carried out in middle school students (male) living isn Sasang industrial area more than 10 years, and were compared with those of control group. The following results were obtained; 1. Lung capacities were normal in observed & control group, and were not significantly different between two groups. 2. The respective parameters of ventilatory function test of observed group were smaller than that of control group, but FVC, $FEV_1$, $FEV_1/FVC$, FEF 25-75%, Vmax 50, MVV of two groups were normal. 3. PEFR, Vmax 25, Vmax 75 of observed group were significantly decreased, and there were statistically significant differences between two groups in FEF 25-75% (p < 0.01), Vmax 25 (p < 0.05), Vmax 50 (p < 0.01), Vmax 75 (p < 0.05), PEFR (p < 0.05) and MVV (p < 0.02).

• Journal of applied mathematics & informatics
• /
• v.7 no.1
• /
• pp.61-82
• /
• 2000

In this paper two so-called regularized Green's functions are introduced to derive the optimal maximum norm error estimates for the unknown function and the adjoint vector-valued function for mixed finite element methods of Laplacian operator. One contribution of the paper is a demonstration of how the boundedness of $L^1$-norm estimate for the second Green's function ${\lambda}_2$ and the optimal maximum norm error estimate for the adjoint vector-valued function are proved. These results are seemed to be to be new in the literature of the mixed finite element methods.

• The Journal of Korean Physical Therapy
• /
• v.22 no.6
• /
• pp.91-98
• /
• 2010

Neurostimulation approaches have been developed and explored to modulate neuroplastic changes of cortical function in human brain. As one of the most primary noninvasive tools, transcranial direct current stimulation (tDCS) was extensively studied in the field of neuroscience. The alternation of cortical neurons depending on the polarity of the tDCS has been used for improving cognitive processing including working memory, learning, and language in normal individuals, as well as in patients with neurological or psychiatric diseases. In addition, tDCS has great advantages: it is a non-invasive, painless, safe, and cost-effective approach to enhance brain function in normal subjects and patients with neurological disorders. Numerous previous studies have confirmed the efficacy of tDCS. However, tDCS has not been considered for clinical applications and research in the field of physical therapy. Therefore, this review will focus on the general principles of tDCS and its related application parameters, and provide consideration of motor behavioral research and clinical applications in physical therapy.

• The Pure and Applied Mathematics
• /
• v.30 no.1
• /
• pp.43-65
• /
• 2023

In this paper, by using the difference analogue of Nevanlinna's theory, the authors study the shared-value problem concerning two higher order difference operators of a transcendental entire function with finite order. The following conclusion is proved: Let f(z) be a finite order transcendental entire function such that λ(f - a(z)) < ρ(f), where a(z)(∈ S(f)) is an entire function and satisfies ρ(a(z)) < 1, and let 𝜂(∈ ℂ) be a constant such that ∆_𝜂ⁿ⁺¹ f(z) ≢ 0. If ∆_𝜂ⁿ⁺¹ f(z) and ∆_𝜂ⁿ f(z) share ∆_𝜂ⁿ a(z) CM, where ∆_𝜂ⁿ a(z) ∈ S ∆_𝜂ⁿ⁺¹ f(z), then f(z) has a specific expression f(z) = a(z) + Be^Az, where A and B are two non-zero constants and a(z) reduces to a constant.