• Environmental Analysis Health and Toxicology
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• v.18 no.1
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• pp.33-44
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• 2003

The possibility that liver and kidney function is adversely affected by current levels of environmental exposure to cadmium (Cd) as investigated in adult men and women in the general population in Seoul. From February to August in 2001, blood and morning spot urine samples were collected from 136 not occupationally exposed group (age range 20∼75 years) at 4 survey sites throughout seoul. Liver and kidney function parameters in serum and urine were examined by conventional methods. The questionnaire included factors, i.e. sex, age, smoking, alcohol, diet habit etc. The geometric mean values for Cd in blood (Cd-B) were 1.43 $\mu\textrm{g}$/1, It seemed prudent to conclude that liver and kidney function as not disturbed by the current environmental exposure to Cd in study.

• Journal of Korean Neurosurgical Society
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• v.45 no.3
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• pp.133-142
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• 2009

The advent of endovascular therapy for intracranial aneurysms and the rapid advances in that field have supplanted microsurgical treatment for many intracranial aneurysms. Applying current outcome data and other parameters, nuances of selecting the modality of treatment for intracranial aneurysms are reviewed. Patient factors, such a age, co-morbidities, vasospasm and other medical conditions, are addressed. A custom-tailored multimodality treatment paradigm for the management of ruptured and unruptured aneurysms will maximize the favorable results seen in this difficult patient population.

• Journal of the Korean Statistical Society
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• v.16 no.2
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• pp.92-101
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• 1987

Our interest is to access in some way teh relative odds or probability that a multivariate observation Z belongs to one of k multivariate normal populations with unequal covariance matrices. We derived the empirical Bayes posterior odds ratio for the classification rule when population parameters are unknown. It is a generalization of the posterior odds ratio suggested by Gelsser (1964). The classification rule does not have complicated distribution theory which a large variety of techniques from the sampling viewpoint have. The proposed posterior odds ratio is compared to the Gelsser's posterior odds ratio through a Monte Carlo study. The results show that the empiricla Bayes posterior odds ratio, in general, performs better than the Gelsser's. Especially, for large dimension of Z and small training sample, the performance is prominent.

• Speech Sciences
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• v.10 no.2
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• pp.35-43
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• 2003

General speaker verification systems improve their recognition performances by normalizing log likelihood ratio, using a speaker model and its background speaker model that are required to be verified. So these systems rely heavily on the availability of much speaker independent databases for background speaker model design. This constraint, however, may be a burden in practical and portable devices such as palm-top computers or wireless handsets which place a premium on computations and memory. In this paper, new approach for the GMM-based background model design used in portable speaker verification system is presented when the enrollment data is available. This approach is to modify three parameters of GMM speaker model such as mixture weights, means and covariances along with reduced mixture order. According to the experiment on a 20 speaker population from YOHO database, we found that this method had a promise of effective use in a portable speaker verification system.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.384-386
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• 2009

This paper introduces an effectively optimized Fuzzy model identification by means of complex and nonlinear system applying PSO algorithm. In other words, we use PSO(Particle Swarm Optimization) for identification of Fuzzy model structure and parameter. PSO is an algorithm that follows a collaborative population-based search model. Each particle of swarm flies around in a multidimensional search space looking for the optimal solution. Then, Particles adjust their position according to their own and their neighboring-particles experience. This paper identifies the premise part parameters and the consequence structures that have many effects on Fuzzy system based on PSO. In the premise parts of the rules, we use triangular. Finally we evaluate the Fuzzy model that is widely used in the standard model of gas data and sew data.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.135-138
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• 2002

High-speed ejection of burnt gases from the resonator cavity is essential for performance optimization of the chemical laser system. Additionally, to maintain the population of lasing species at a level for maximum optical power, the pressure within the cavity must be of order of 10 torr. In the present study, a small-scale ejector was designed and built for parametric study of its performance. High-pressure air was used as a motive gas. Measurements include schlieren visualization and pressure distribution trace near the ejector nozzle and along the diffuser downstream of the ejector. preliminary tests showed performance of the ejector is a function of parameters including mass flow rate and stagnation pressure of the motive gas, ejector nozzle area ratio, throat area of the diffuser downstream of the ejector.

• Economic and Environmental Geology
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• v.28 no.4
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• pp.425-431
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• 1995

Genetic algorithms are so named because they are analogous to biological processes. The model parameters are coded in binary form. The algorithm then starts with a randomly chosen population of models called chromosomes. The second step is to evaluate the fitness values of these models, measured by a correlation between data and synthetic for a particular model. Then, the three genetic processes of selection, crossover, and mutation are performed upon the model in sequence. Genetic algorithms share the favorable characteristics of random Monte Carlo over local optimization methods in that they do not require linearizing assumptions nor the calculation of partial derivatives, are independent of the misfit criterion, and avoid numerical instabilities associated with matrix inversion. An additional advantage over converntional methods such as iterative least squares is that the sampling is global, rather than local, thereby reducing the tendency to become entrapped in local minima and avoiding the dependency on an assumed starting model.

• Journal of the Korean Data and Information Science Society
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• v.12 no.1
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• pp.51-59
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• 2001

We propose the Bayesian testing for the equality of two Lognormal population means. Specially we use the fractional Bayesian factors suggested by O'Hagan (1995) based on the noninformative priors for the parameters. In order to investigate the usefulness of the proposed Bayesian testing procedures, we compare it with classical tests via both real data analysis and simulations.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.1
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• pp.3-15
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• 1996

An approximation algorithm is presented for cyclic queueing networks with finite buffers. The algorithm decomposes the queueing network into individual queues with revised arrival and service process and revised queue capacity. Then, each queue is analyzed in isolation. The service process reflects the additional delay a unit might undergo due to blocking and the arrival process is described by a 2-phases Coxian ($C_2$) distribution. The individual queues are modelled as $C_2/C_2$/1/B queues. The parameters of the individual queues are computed approximately using an iterative scheme. The population constraint of the closed network is taken into account by ensuring that the sum of the average queue lengths of the individual queues is equal to the number of customers of the network. Extensive numerical experiments show that this method provides a fairly good estimation of the throughput.

• Journal of Korean Physical Therapy Science
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• v.24 no.2
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• pp.53-60
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• 2017

Purpose: This study aimed to investigate the effect of physiotherapy on the range of motion (ROM) of patients with hemophilic arthropathy after total knee replacement (TKR) during treadmill gait. Method: Nineteen patients (age range, 30-61 years) who received physiotherapy at the Korea Hemophilia Foundation (KHF) Clinic in Seoul between 2011 and 2013 after TKR were recruited. Protocol rehabilitation was performed (KHF Clinic, Department of Physiotherapy) with an average follow-up of 70 days (range, 6-141 days). Result: Physiotherapy after TKR improved the ROM parameters, including the post-operative average ROM. The post-operative and follow-up ROM also significantly increased. Conclusion: Patients with hemophilia require different physiotherapeutic techniques and need dedicated post-operative care in comparison with the general population.