• The KIPS Transactions:PartA
• /
• v.10A no.4
• /
• pp.381-388
• /
• 2003

Location tracking is used to keep track of the location information of a mobile terminal in an idle state for a cail setup between mobile terminals. In this paper, we introduce a location update algorithm based on the call arrival history, which is appropriate for a variable call arrival rate over time. The location tracking strategy which uses the proposed algorithm can find changes in the call arrival rate by maintaining a call arrival history of a mobile terminal, from which a mobile terminal can calculate an appropriate timeout interval for a variable call arrival rate. We show that the proposed scheme is appropriate for a variable call arrival rate by presenting a simple analytical model and analytical results to investigate its performance for both a fixed and a variable call arrival rate.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1998.06a
• /
• pp.634-639
• /
• 1998

A methodology based on the concept of variable string length GA(VGA) is developed for determining automatically the number of hyperplanes and their appropriate arrangement for modeling the class boundaries of a given training data set in RN. The genetic operators and fitness functionare newly defined to take care of the variability in chromosome length. Experimental results on different artificial and real life data sets are provided.

• Communications for Statistical Applications and Methods
• /
• v.11 no.1
• /
• pp.49-58
• /
• 2004

In this talk we proposed an asymptotic test for dimensionality in the latent variable model for probabilistic principal component analysis with missing values at random. Proposed algorithm is a sequential likelihood ratio test for an appropriate Normal latent variable model for the principal component analysis. Modified EM-algorithm is used to find MLE for the model parameters. Results from simulations and real data sets give us promising evidences that the proposed method is useful in finding necessary number of components in the principal component analysis with missing values at random.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.6 no.4
• /
• pp.277-281
• /
• 2006

Cyber counseling, one of the most compatible type of consultation for the information society, enables people to reveal their mental agonies and private problems anonymously, since it does not require face-to-face interview between a counsellor and a client. However, there are few cyber counseling centers which provide high quality and trustworthy service, although the number of cyber counseling center has highly increased. Therefore, this paper is intended to enable an appropriate consultation for each client by analyzing client propensity using Bayesian variable selection. Bayesian variable selection is superior to stepwise regression analysis method in finding out a regression model. Stepwise regression analysis method, which has been generally used to analyze individual propensity in linear regression model, is not efficient since it is hard to select a proper model for its own defects. In this paper, based on the case database of current cyber counseling centers in the web, we will analyze clients' propensities using Bayesian variable selection to enable individually target counseling and to activate cyber counseling programs.

• Proceedings of the KIEE Conference
• /
• 1990.07a
• /
• pp.376-379
• /
• 1990

This parer presents a cycloconverter with a LC resonant circuit for a induction motor drive. The cycloconverter can provide variable voltage and frequency three phase output while keeping the input displacement factor at 1.0. The input current wave for is are sinusoidal,and the wide output frequency range is appropriate for variable speed AC motor drives.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.16 no.28
• /
• pp.137-143
• /
• 1993

Generally there are three methods to derive an approximation formula: 1) approching standard normal distribution by appropriate changing variable 2) using standardization variable for expansion 3) deriving approximation formula by direct method. This paper present correction terms having the form of $C_{1/v^{n/2}}/{\;}+{\;}C_2{\;}(n=1,2)$ with respect to $x^2_{\alpha}(v)$ distribution (${\nu}{\;}{\leq}{\;}30$), which minimize the error by EDA method and least square method.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.9
• /
• pp.870-877
• /
• 2009

This study provides how the Dimension Reduction (DR) method as an efficient technique for reliability analysis can acquire its increased efficiency when it is applied to highly nonlinear problems. In the highly nonlinear engineering systems, 4N+1 (N: number of random variables) sampling is generally recognized to be appropriate. However, there exists uncertainty concerning the standard for judgment of non-linearity of the system as well as possibility of diverse degrees of non-linearity according to each of the random variables. In this regard, this study judged the linearity individually on each random variable after 2N+1 sampling. If high non-linearity appeared, 2 additional sampling was administered on each random variable to apply the DR method. The applications of the proposed sampling to the examples produced the constant results with increased efficiency.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.11a
• /
• pp.35-36
• /
• 2011

Recently, an irregular-shaped super tall building has been increased, aiming toward landmarks of cityscape. However, the complex floor plan derived from an irregular shape requires considerable resources including time, cost, and effort to meet complex structural framework. Based on the motivation, the study proposes a table-form system that is variable slab form appropriate to an irregular shaped floor through improving limitations of an existing table-form system. The variable table-form is expected to reduce construction resources and improve constructability on an irregular floor plan of super tall buildings as well.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1162-1168
• /
• 2008

This study provides how the Dimension Reduction (DR) method as an efficient technique for reliability analysis can acquire its increased efficiency when it is applied to highly nonlinear problems. In the highly nonlinear engineering systems, 4N+1 (N: number of random variables) sampling is generally recognized to be appropriate. However, there exists uncertainty concerning the standard for judgment of non-linearity of the system as well as possibility of diverse degrees of non-linearity according to each of the random variables. In this regard, this study judged the linearity individually on each random variable after 2N+1 sampling. If high non-linearity appeared, 2 additional sampling was administered on each random variable to apply the DR method. The applications of the proposed sampling to the examples produced the constant results with increased efficiency.

• Journal of Yeungnam Medical Science
• /
• v.39 no.4
• /
• pp.278-284
• /
• 2022

Headache is one of the most common neurological disorders in children and adults and can cause significant distress and disability in children and their families. The spectrum of pediatric headaches is broad, and the underlying etiology is variable. The symptoms and phenotypes of headaches in children may differ slightly from those in adults. It is important to have a good understanding of headaches in children and to distinguish between primary and secondary headaches through appropriate history assessment and neurological examination. Accurate diagnosis and appropriate drug selection are helpful for effective treatment. This article reviews headaches in children and adolescents, focusing on approaches for diagnosis and management.