• Communications for Statistical Applications and Methods
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• v.27 no.1
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• pp.97-108
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• 2020

This paper compares several methods for estimating parameters of normal inverse Gaussian distribution. Ordinary maximum likelihood estimation and the method of moment estimation often do not work properly due to restrictions on parameters. We examine the performance of adjusted estimation methods along with the ordinary maximum likelihood estimation and the method of moment estimation by simulation and real data application. We also see the effect of the initial value in estimation methods. The simulation results show that the ordinary maximum likelihood estimator is significantly affected by the initial value; in addition, the adjusted estimators have smaller root mean square error than ordinary estimators as well as less impact on the initial value. With real datasets, we obtain similar results to what we see in simulation studies. Based on the results of simulation and real data application, we suggest using adjusted maximum likelihood estimates with adjusted method of moment estimates as initial values to estimate the parameters of normal inverse Gaussian distribution.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.8-12
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• 1999

The erythrocyte sedimentation rate (ESR) test could be applied well in clinic of men, horses or dogs. But the ESR test was not applied to clinic ruminants except for buffaloes since it was too low measure. To overcome this problem angled tube method was developed. This method was found to be useful for making diagnosis and prognosis. The results were summarized as follows. 1. In the early pregnancy condition, corrected ESR did not changed when compared with normal valures. 2. In the middle pregnancy condition, corrected ESR was increased when compeared with normal valures. 3. In the latter pregnancy condition, corrected ESR was increased when compeared with normal valures. 4. After parturition condition, corrected ESR did not changed when compeared with normal valures.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.375-375
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• 2006

The preparation methods are to be used as "melting method" and "absorption method", respectively. The reaction mixture in the reaction container was heating up the reaction mixture to $200^{\circ}C$ for 2 hour. The mixing time of lab scale preparation should be provided quit long, instead of the short working time in a compounder vessel. And The PP-PCM mixture in the reaction container was heating up the mixture around $60-80^{\circ}C$ for 2 hour. A melting method of frozen gel with 50/50 weight ratio of polypropylene-normal octadecane was prepared by adding PP chip and normal octadecane. An absorption method of frozen gel with 70/30 weight ratio of PP 4.8-normal n-octadecane was prepared by adding PP powder and normal octadecnae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.386-392
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• 1996

A numerical method based on genetic algorithms was introduced to characterize the grain-size distribution more effectively. This technique was proved significant particularly for multimodal size distributions, as was verified for samples from Korea Strait continental shelf. Sediment samples collected from the Korea Strait continental shelf revealed that $96\%$ of the grain-size distributions were multimodal. Therefore, the use of grain-size parameters was not the ideal method. As an alternative method, the decomposition of sue curves into elementary normal component curves was used. Means and standard deviations of 593 decomposed normal components were calculated by a numerical method from 268 size curves of Korea Strait sediments. The mean values of decomposed normal components showed peaks at $1\~3\phi\;and\;7\~9\phi$ size classes. The plot of mean and standard deviation values of the coarse fraction normal components on the map showed a characteristic areal distribution. The characteristic distribution was found to derive from underlying Pleistocene sediment on the basis of sea bottom geologic distribution of the area. The method of decomposition into normal components was found to be more effective than the analysis using traditional grain-size parameters in investigation of multimodal size distribution of Korea Strait shelf sediment.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.24 no.3
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• pp.305-320
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• 2020

This study aims to generalize MINRES-N2 method [1]. It means that we tend to obtain an algorithm to transfer each normal matrix - that its eigenvalues belong to an algebraic curve of low degree k- to its condensed form through using a unitary similarity transformation. Then, we aim to obtain a method to solve a system of linear equations that its coefficient matrix is equal to such a matrix by utilizing it. Finally this method is compared to the well-known GMRES method through using numerical examples. The results obtained through examples show that the given method is more efficient than GMRES.

• Annals of Clinical Neurophysiology
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• v.12 no.1
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• pp.16-20
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• 2010

Background: The medial plantar nerve (MPN) is a distal branch of the posterior tibial nerve, and various methods of nerve conduction study for MPN have been introduced so far. Hemmi et al described a new method (Hemmi's method) for recording medial plantar sensory nerve action potentials (SNAPs), which is considered as a simple and reliable method for measuring medial plantar SNAPs. This study was aimed to establish the normal values for the MPN conduction study among Koreans and to compare the sensitivities of three different methods for MPN conduction study (Hemmi, Oh, and Saeed's method) in detecting evidence of peripheral neuropathy among diabetic patients. Methods: In 27 healthy subjects, MPN conduction study using Hemmi's method was performed and normal values were calculated. In 54 diabetic patients who showed normal routine nerve conduction studies, three different methods for MPN conduction study were performed and diagnostic sensitivity of each method were compared. Results: In normal subjects, the mean medial plantar SNAP amplitude and conduction velocities measured by Hemmi's method were $4.3{\pm}1.0$ uV and $38.3{\pm}6.8$ m/s respectively. Among 54 patients with diabetes who showed normal routine nerve conduction studies, medial plantar SNAP was not obtainable in 28, 31, and 6 patients by Hemmi, Oh and Saeed's method respectively. Conclusions: In terms of the diagnostic sensitivity for detecting diabetic neuropathy, there had been no significant statistical difference between three different methods. Our study suggested that MPN conduction study using Hemmi's method is simple and useful screening test for early diabetic neuropathy, and is comparable with Oh's method.

• Structural Engineering and Mechanics
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• v.62 no.3
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• pp.365-372
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• 2017

Reliability analysis is a probabilistic approach to determine a safety level of a system. Reliability is defined as a probability of a system (or a structure, in structural engineering) to functionally perform under given conditions. In the 1960s, Basler defined the reliability index as a measure to elucidate the safety level of the system, which until today is a commonly used parameter. However, the reliability index has been formulated based on the pivotal assumption which assumed that the considered limit state function is normally distributed. Nevertheless, it is not guaranteed that the limit state function of systems follow as normal distributions; therefore, there is a need to define a new reliability index for no-normal distributions. The main contribution of this paper is to define a sophisticated reliability index for limit state functions which their distributions are non-normal. To do so, the new definition of reliability index is introduced for non-normal limit state functions according to the probability functions which are calculated based on the convolution theory. Eventually, as the state of the art, this paper introduces a simplified method to calculate the reliability index for non-normal distributions. The simplified method is developed to generate non-normal limit state in terms of normal distributions using series of Gaussian functions.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.11 no.1
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• pp.300-318
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• 1998

Background : The vasoreactivity of cerebral artery is currently the subject of increasing interest. Transcranial Doppler Sonography(TCD) is an accurate method of monitoring the blood flow velocities of the cerebral artery. We wished to assess the vasoreactivity between age-matched normal and cerebral infarction group. Method : We performed TCD findings in 40 normals and 20 cb-inf. subjects who arrived at hospital during 48 hours after attack. The former were devided into twenties normal group and fifties normal group. Result : 1. Fibrinogen levels showed significant changes between age-matched normal and cb-inf. group. 2. $V^{MEAN}$ of the both side Carotid Siphon during rest state increased significantly in cb-inf. group as compared with the age-matched normal group. 3. $V^{MEAN}and\;V^{MAX}$ of the both side carotid siphon during breath-hold state increased significantly in cb-inf. group as compared with the age-matched normal group. 4. Vasoreactivity of cerebral artery increased significantly in cb-inf. group as compared with the age-matched normal group. 5. $V^{MEAN}and\;V^{MAX}$ of the both side Radial artery during heat-stimuration state increased significantly in cb-inf. group as compared with the age-matched normal group. 6. Vasoreactivity of Radial artery increased significantly in cb-inf. group as compared with the age-matched normal group.

• Journal of Korean Society for Quality Management
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• v.42 no.2
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• pp.209-219
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• 2014

Purpose: The purpose of this study is to develop the statistical test for process capability index $C_p$ based on mixture normal process. Methods: This study uses Bootstrap method to calculate the approximate P-value for various simulation conditions under mixture normal process. Results: This study indicates that our proposed method is effective way to test for process capability index $C_p$ based on mixture normal process. Conclusion: This study finds out that statistical test for process capability index $C_p$ based on mixture normal process is useful for real application.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.461-466
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• 2006

In this paper, an algorithm with a new Armijo-type line search is proposed that ensure global convergence of a correlative Polak-Ribiere conjugate method for the unconstrained minimization of non-convex differentiable function.