• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.109-112
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• 1995

This paper is a study on the detection of the significant point in ECG signal. ECG signal consists of two components; one is high frequency component to be detected and the other is low frequency component to be removed. AR model is appropriate for modelling and removing the low frequency component. AR model coefficients are updated by artificial neural network algorithm. We can remove the background noise(low frequency) by passing through the AR filter. The remaining signals which include high frequency noise are sent to the matched filter to pass only the signal which we want to extract. The template used in matched filter is updated adaptively.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.35-39
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• 2003

Effort has been given to improve demand forecast methodology of rail system since it can have great impact on project evaluation of rail system investment. However most of demand forecast softwares developed in western countries where concerns have been provided mostly to private transport and they should be updated in order to reflect our country's situation accurately. Therefore, this paper aims, especially focusing on rail system, to do comparison analysis of oversea's passenger demand forecast softwares and provide some ideas to develop the updated demand forecast system which enables to reflect our country's situation accurately. Main conclusions are that we will need to have well described model for real situation. So we will have to study for these aspects for travel demand forecasting system and develop the package architecture.

• Transactions on Control, Automation and Systems Engineering
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• v.2 no.3
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• pp.189-195
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• 2000

The mathematical solutions of the stability convergence are important problems in system control. In this paper such problems are analyzed and resolved for system control using multilayer neural networks. We describe an algorithm to control an unknown nonlinear system with a disturbance, using a multilayer neural network. We include a disturbance among the modeling error, and the weight update rules of multilayer neural network are derived to satisfy Lyapunov stability. The overall control system is based upon the feedback linearization method. The weights of the neural network used to approximate a nonlinear function are updated by rules derived in this paper . The proposed control algorithm is verified through computer simulation. That is as the weights of neural network are updated at every sampling time, we show that the output error become finite within a relatively short time.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.5
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• pp.767-774
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• 1990

Successive images can be reconstructed without great degradation by using one codebook in vector quantization, because statistics of successive images are sinilar. In this paper, we propose a method to update vector centroids in one slot of an image sequence and reconstruct images with the codebook replenished with the updated vector centroids. To remove the overhead required to transmit the updated vector centroids, we catagorize image blocks into changing blocks and nonchanging blocks, and then transmit only the labels of the changing blocks. Therefore, we can assign the remaining bits to the replenishment of a codebook. By the proposed method, almost the same image as the same image as the one reconstructed by LBG algorithm can be obtained and the bit rate can be reduced to below 0.5 bit/pixel.

• ETRI Journal
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• v.42 no.3
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• pp.333-340
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• 2020

We consider a hybrid combiner design for downlink massive multiple-input multiple-output systems when there is residual inter-user interference and each user is equipped with a limited number of radio frequency (RF) chains (less than the number of receive antennas). We propose a hybrid combiner that minimizes the mean-squared error (MSE) between the information symbols and the ones estimated with a constant amplitude constraint on the RF combiner. In the proposed scheme, an iterative alternating optimization method is utilized. At each iteration, one of the analog RF and digital baseband combining matrices is updated to minimize the MSE by fixing the other matrix without considering the constant amplitude constraint. Then, the other matrix is updated by changing the roles of the two matrices. Each element in the RF combining matrix is obtained from the phase component of the solution matrix of the optimization problem for the RF combining matrix. Simulation results show that the proposed scheme performs better than conventional matrix-decomposition schemes.

• Pediatric Infection and Vaccine
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• v.15 no.1
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• pp.12-19
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• 2008

Varicella is a highly infectious disease caused by the varicella zoster virus. The varicella vaccine was developed by Michiaki Takahashi in Japan in 1974. Despite the worldwide distribution of efficient vaccines, varicella vaccination policy is extremely variable from country to country. Although varicella vaccine is not currently recommended for universal vaccination in Japan, most countries throughout Europe, and developing countries, it had been introduced into Korea in 1988 and 20 years have elapsed since its use. Currently, varicella vaccine has been most extensively used in the United States where routine 2-dose vaccination program has been recently implemented for children. Recent 2-dose schedule in the United States and the availability of combination measles-rubella-varicella vaccines may lead to future varicella vaccination policy changes in many countries. With this background, this article summarizes the current status of varicella vaccination policies worldwide and presents provisional updated recommendation of varicella vaccination in Korea.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.10a
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• pp.150-156
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• 1995

In the finite element analysis of metal forming processes, the updated Lagrangian approach has been widely and effectively used to simulate the non-steady state problems. However some difficulties have arisen from abrupt flow change as in extrusion through square dies. In the present work, a ALE(arbitrary Lagrangian-Eulerian) finite element formulation for deformation analysis are presented for rigid viscoplastic materials. The developed finite element program is applied to the analysis of square die extrusion of a square section. The computational results are compared with those from the updated Lagrangian finite element analysis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.4
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• pp.11-18
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• 2007

A moving object detection algorithm for surveillance video is here proposed which employs background initialization based on two-stage median filtering and a background updating method based on state transition diagram. In the background initialization, the spatiotemporal similarity is measured in the subinterval. From the accumulated difference between the base frame and the other frames in a subinterval, the regions affected by moving objects are located. The median is applied over the subsequence in the subinterval in which regions share similarity. The outputs from each subinterval are filtered by a two-stage median filter. The background of every frame is updated by the suggested state transition diagram The object is detected by the difference between the current frame and the updated background. The proposed method showed good results even for busy, crowded sequences which included moving objects from the first frame.

• Journal of information and communication convergence engineering
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• v.13 no.4
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• pp.280-285
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• 2015

Double random phase encryption (DRPE) is one of the well-known optical encryption techniques, and many techniques with DRPE have been developed for information security. However, most of these techniques may not solve the fundamental security problem caused by using fixed phase masks for DRPE. Therefore, in this paper, we propose a key phase mask updating scheme for DRPE to improve its security, where a spatial light modulator (SLM) is used to implement key phase mask updating. In the proposed scheme, updated key data are obtained by using previous image data and the first phase mask used in encryption. The SLM with the updated key is used as the second phase mask for encryption. We provide a detailed description of the method of encryption and decryption for a DRPE system using the proposed key updating scheme, and simulation results are also shown to verify that the proposed key updating scheme can enhance the security of the original DRPE.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.3
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• pp.13-19
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• 1989

A system of coupled differential equations governing the lateral-torsional buckling of thin-walled arches subjected to pure bending moment is presented. The governing differential equations are derived using incremental form of principle of virtual displacement based on updated Lagrangian procedure. The differential equations are solved for the critical end moments of arches with I section, and then comparative studies are made with existing solutions.