• Clinical and Experimental Reproductive Medicine
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• 제49권3호
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• pp.202-209
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• 2022

Objective: The aim of this study was to assess the correlation of oocyte number with serum anti-Müllerian hormone (AMH) levels measured by two automated methods (Access or Elecsys) in fresh stimulated in vitro fertilization (IVF) cycles. Methods: In this retrospective study at a university hospital, data were collected from 243 fresh stimulated IVF cycles performed from August 2016 to December 2020. The serum AMH level was measured by Access in 120 cycles and by Elecsys in 123 cycles. The cut-off of serum AMH for prediction of poor responders (three or fewer oocytes) or high responders (15 or more oocytes) was calculated by the receiver operating characteristic curve analysis. Results: For the two automated methods, the following equations were derived: total oocyte number=2.378+1.418×(Access-AMH) (r=0.645, p<0.001) and total oocyte number=2.417+2.163×(Elecsys-AMH) (r=0.686, p<0.001). The following combined equation could be derived: (Access-AMH)=0.028+1.525×(Elecsys-AMH). To predict poor responders, the cut-off of Access-AMH was 1.215 ng/mL (area under the curve [AUC], 0.807; 95% confidence interval [CI], 0.730-0.884; p<0.001), and the cut-off of Elecsys-AMH was 1.095 ng/mL (AUC, 0.848; 95% CI, 0.773-0.923; p<0.001). To predict high responders, the cut-off of Access-AMH was 3.450 ng/mL (AUC, 0.922; 95% CI, 0.862-0.981; p<0.001), and the cut-off of Elecsys-AMH was 2.500 ng/mL (AUC, 0.884; 95% CI, 0.778-0.991; p<0.001). Conclusion: Both automated methods for serum AMH measurement showed a good correlation with oocyte number and good performance for predicting poor and high responders in fresh stimulated IVF cycles. The Access method usually yielded higher measured serum AMH levels than the Elecsys method.

• Journal of applied mathematics & informatics
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• 제4권1호
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• pp.1-16
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• 1997

In this paper we study efficient parallel implementation for hybrid iterative methods BICGSTAB and BICGSTAB $(\ell)$ with ${Well}=2$ on the CRAY C90 and the efficiency of their parallel performance is evaluated. numerical experiments suggest that on the CRAY C90 a parallel inner product algorithm called PDOTB be used for the par-allelization of hybrid iterative methods containing sensitive values of inner products. Lastly it is shown that the number of iterations in which parallel hybrid iterative methods satisfy a certain convergence criterion depends on the number of processors to be used.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1999년도 KOBA 방송기술 워크샵 KOBA Broadcasting Technology Workshop
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• pp.125-131
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• 1999

In this paper, we address practical methods for calculating camera lens distortion for real time applications. Although the lens distortion problem can be easily ignored for constant-parameter lenses, in the field of real-time camera calibrations, for zoom lenses a large number of calculations are needed to calculate the distortion. However, if the distortion can be calculated independently of the other camera parameter, we can easily calibrate a camera without the need for a large number of calculations. Based on Tsai's camera model, we propose two different methods for calculating lens distortion. These methods are so simple and require so few calculations that the lens distortion can be rapidly calculated even in real-time applications. The first method is to refer to the focal length - lens distortion Look Up Table(LUT), which is constructed in the initialization process. The second method is to use the relationship between the feature points found in the image. Experiments were carried out for both methods, results of which show that the proposed methods are favorably comparable in performance with non-real full optimization method.

• 한국정보시스템학회지:정보시스템연구
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• 제9권1호
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• pp.27-44
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• 2000

The structure of neural networks is represented by a weighted directed graph with nodes representing units and links representing connections. Each link is assigned a numerical value representing the weight of the connection. In learning process, the values of weights are adjusted by errors. Following experiment results, the interval of adjusting weights, that is, epoch size influenced neural networks＇ performance. As epoch size is larger than a certain size, neural networks＇performance decreased drastically. And the number of hidden layer＇s node also influenced neural networks＇performance. The networks＇performance decreased as hidden layers have more nodes and then increased at some number of hidden layer＇s node. So, in implementing of neural networks the epoch size and the number of hidden layer＇s node should be decided by systematic methods, not empirical or heuristic methods.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.518-523
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• 2001

Vortex methods were originally conceived as a tool to model the evolution of unsteady, incompressible, high Reynolds number flows of engineering interest. Recently various methods have been proposed for simulating the diffusion in vortex methods for two-dimensional incompressible flows. We test the diffusion schemes of vortex methods. In this paper we directly compare the particle strength exchange scheme with the vorticity redistribution scheme in tenus of their accuracy and computational efficiency. Comparisons between both viscous models described are presented for short-time runs of impulsively started flows past a circular cylinder for Reynolds number of 60. The particle strength exchange scheme has been shown more accurate and efficient than the vorticity redistribution scheme.

• 제어로봇시스템학회논문지
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• 제20권3호
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• pp.372-379
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• 2014

This paper surveys past and state-of-the-art SLAM technologies. The standard methods for solving the SLAM problem are the Kalman filter, particle filter, graph, and bundle adjustment-based methods. Kalman filters such as EKF (Extended Kalman Filter) and UKF (Unscented Kalman Filter) have provided successful results for estimating the state of nonlinear systems and integrating various sensor information. However, traditional EKF-based methods suffer from the increase of computation burden as the number of features increases. To cope with this problem, particle filter-based SLAM approaches such as FastSLAM have been widely used. While particle filter-based methods can deal with a large number of features, the computation time still increases as the map grows. Graph-based SLAM methods have recently received considerable attention, and they can provide successful real-time SLAM results in large urban environments.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2000년도 춘계 학술대회논문집
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• pp.33-38
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• 2000

A Numerical study of laminar vortex-shedding past a circular cylinder has been performed widely by many researchers. Many factors, such as numerical technique and domain size, number and shape of grid, affected predicting vortex shedding and Strouhal number. In the present study, the effect of convection scheme, time discretization methods and grid dependence were investigated. The present paper presents the finite volume solution of unsteady flow past circular cylinder at Re=200, 400. The Strouhal number was predicted using UDS, CDS, Hybrid, Power-law, LUDS, QUICK scheme for convection term, implicit and crank-nicolson methods for time discretization. The grid dependence was investigated using H-type mesh and O-type mesh. It also studied that the effect of mesh size of the nearest adjacent grid of circular cylinder. The effect of convection scheme is greater than the effect of time discretization on predicting Strouhal. It has been found that the predicted Strouhal number changed with mesh size and shape.

• 한국멀티미디어학회논문지
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• 제7권12호
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• pp.1665-1670
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• 2004

The general fractal image compression provides a high compression rate, but it requires a large encoding time. In order to overcome this disadvantage, many researchers have introduced various methods that reduce the total number of domain blocks considering their block similarities or control the number of searching domain block depending on its distribution. In this paper, we propose a method that can reduce the number of searching domain blocks employing the variance coherence of intensity values and also the number of range blocks requiring the domain block search through the classification of range blocks. This proposed method effectively reduces the encoding time and also a negligible drop of the quality as compared with the previous methods requiring the search of all range blocks.

• 한국멀티미디어학회논문지
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• 제19권10호
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• pp.1747-1758
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• 2016

In this paper, we propose a new fast Hough transform to improve the processing time and line detection of Hough transform that is widely used in various vision systems. First, for the fast processing time, we reduce the number of features by using multi-statistical methods and also reduce the dimension of angle through six separate directions. Next, for improving the line detection, we effectively detect the lines of various directions by designing the line detection method which detects line in proportion to the number of features in six separate directions. The proposed method was evaluated with previous methods and obtained the excellent results. The processing time was improved in about 20% to 50% and line detection was performed better in various directions than conventional methods with experimental images.

• Communications for Statistical Applications and Methods
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• 제11권3호
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• pp.609-617
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• 2004

To present graph of probability densities, many softwares and graphical tools use methods that link points or straight lines. However, the methods can't display exactly and smoothly the graph and are not efficient from the viewpoint of process time. One method to overcome these shortcomings is utilizing interpolation methods. In these methods, selecting the number and location of knots is an important factor. This article proposes an algorithm to select knots for graphically presenting densities and implements graph components based on the algorithm.