• Journal of the Korean Society for information Management
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• v.36 no.4
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• pp.83-105
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• 2019

This study aims to suggest an effective method for the automatic classification of keywords with similar patterns by calculating pattern similarity of temporal data. For this, large scale news on the Web were collected and time series data composed of 120 time segments were built. To make training data set for the performance test of the proposed model, 440 representative keywords were manually classified according to 8 types of trend. This study introduces a Dynamic Time Warping(DTW) method which have been commonly used in the field of time series analytics, and proposes an application model, MA-DTW based on a Moving Average(MA) method which gives a good explanation on a tendency of trend curve. As a result of the automatic classification by a k-Nearest Neighbor(kNN) algorithm, Euclidean Distance(ED) and DTW showed 48.2% and 66.6% of maximum micro-averaged F1 score respectively, whereas the proposed model represented 74.3% of the best micro-averaged F1 score. In all respect of the comprehensive experiments, the suggested model outperformed the methods of ED and DTW.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.2
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• pp.159-163
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• 2006

In order to tune the speed controller in the linear servo applications an accurate information of a mover mass including a load mass is always required. This paper suggests the mass estimation method of a permanent magnet linear synchronous motor(PMLSM) 4y using the parameter estimation method of Least-Squares algorithm. First, the deterministic autoregressive moving average(DARMA) model of the mechanical dynamic system is derived. Then the application of the Least-Squares algorithm shows that the mass can be accurately estimated both in the simulation results and in the experimental results.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.5
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• pp.193-198
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• 1986

In this paper, 1-168 hours ahead load prediction algorithm is developed for power system economic weekly operation. Total load is composed of three components, which are base load, week load and weather-sensitive load. Base load and week load are predicted by moving average and exponential smoothing method, respectively. The days of moving average and smoothing constant are optimally determined. Weather-sensitive load is modeled by linear form. The paramiters of weather load model are estimated by exponentially weighted recursive least square method. The load prediction of special day is very tedious, difficult and remains many problems which should be improved. Test results are given for the day of different types using the actual load data of KEPCO.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.3
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• pp.101-108
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• 2016

I propose a hybrid fuzzy controller with a look-up table to improve the performance of the FARMA(Fuzzy Auto-regressive Moving Average) fuzzy controller. The hybrid structure of the proposed method is composed of a fuzzy controller with a look-up table of the PD type and the FARMA fuzzy controller. The proposed method improves poor performance due to the lack of I/O data to calculate predictive output and shows robust performance over the FARMA fuzzy controller when a incorrect Dmax value is selected by trial and error. I executed some computer simulations on the regulation problem of an inverted pendulum system and compared the results with those of the FARMA fuzzy controller.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.56 no.4
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• pp.173-178
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• 2007

As development of industry is accelerated, most electricity load system requires power supply that could be high precision and effective control. Among supply and control unit of suitable power supply in these load characteristic, inverter systems of constant current regulate is used widely control of lighting & beaconing of aerodromes and electric heating system. Therefore, in this paper proposed a inverter systems of constant current regulate that using improved measurement and switching techniques. Proposed measure techniques that used moving average method of instantaneous r.m.s. for measuring current sensing improved response and precision. Also, in this paper proposed improved high effectiveness switching techniques that get high efficiency of inverter by the double-carrier modulation. Results of an experiment proved effect of proposed system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.57-65
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• 2011

Monitoring auto correlated processes is prevalent in recent manufacturing environments. As a proactive control for manufacturing processes is emphasized especially in the semiconductor industry, it is natural to monitor real-time status of equipment through sensor rather than resultant output status of the processes. Equipment's sensor data show various forms of correlation features. Among them, considerable amount of sensor data, statistically autocorrelated, is well represented by Box-Jenkins autoregressive moving average (ARMA) model. In this paper, we present a design method of statistical process control (SPC) used for monitoring processes represented by the ARMA model. The proposed method shows benefits in the power of detecting process changes, and considers robustness to ARMA modeling errors simultaneously. We prove benefits through Monte carlo simulation-based investigations.

• Journal of Multimedia Information System
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• v.7 no.3
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• pp.231-238
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• 2020

This work presents a fully analog baseline wander tracking and removal circuitry using high-pass filter (HPF) based R-peak detection and quadratic interpolation that does not require digital post processing, thus suitable for compact and low power long-term ECG monitoring devices. The proposed method can effectively track and remove baseline wander in ECG waveforms corrupted by various motion artifacts, whereas minimizing the loss of essential features including the QRS-Complex. The key component for tracking the baseline wander is down sampling the moving average of the corrupted ECG waveform followed by quadratic interpolation, where the R-peak samples that distort the baseline tracking are excluded from the moving average by using a HPF based approach. The proposed circuit is designed using CMOS 0.18-㎛ technology (1.8V supply) with power consumption of 19.1 ㎼ and estimated area of 15.5 ㎟ using a 4^th order HPF and quadratic interpolation. Results show SNR improvement of 10 dB after removing the baseline wander from the corrupted ECG waveform.

• Journal of the Korean Data and Information Science Society
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• v.21 no.3
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• pp.503-511
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• 2010

The goal of this paper is to suggest an algorithm to get the number of student on the elementary, meddle and high-school for the forecasting of the numbers of student by the moving average method using a proportional expression. Comparing with the results of Korean education statistical system 2005, 2006, and 2007, the results of this paper are better than those of the Korean education statistical system.

• The Journal of Society for e-Business Studies
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• v.9 no.2
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• pp.17-31
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• 2004

It is very important that sellers provide reasonable reserve prices for auction items in internet auction systems. Recently, an agent has been proposed to generate reserve prices automatically based on the case similarity of information retrieval theory. However, one of its drawbacks is that the recent trend of auction prices is not reflected in the generated reserve prices, because it suggests the bid price of the most similar item from the past auction data. In this paper, in order to overcome the problem, we propose a new method that generates reserve prices based on the moving average of time series analysis, in which more weight is provided to the recent bid prices. Through performance experiments, we show that the successful bid rate can be increased by preventing sellers from making unreasonable reserve prices.

• Journal of Korean Physical Therapy Science
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• v.17 no.3_4
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• pp.51-58
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• 2010

Purpose: The purpose of this study was to examine changes of postural sway between the normal group and treatment group of same people through COP movements. Methods: Fifty men with no history of sensory, neurological and orthopedic disorders were participated in this study. Participants were tested on single limb balance during 30 seconds on EMED system with bared foot. Each of them performed two methods and 5 trials totally each method: (1) non-treated group (2) treated group(with big toe flexion limitation). Data on the moving length, average velocity, instantaneous maximum velocity, mediolateral(x axis) maximum velocity, and anteroposterior(y axis) maximum velocity of COP were measured in single limb standing position. Results: The moving length and average velocity of COP were significant difference between normal and treatment group(p<0.05). On correlation of parameters, the faster average velocity of COP, the higher moving length, instantaneous maximum velocity, mediolateral maximum velocity, and anteroposterior maximum velocity of COP increase. The more Instantaneous maximum velocity of COP, the faster is anteroposterior maximum velocity of COP. Conclusions: Limitation of big toe flexors function affected single limb balance of the normal.