• Journal of information and communication convergence engineering
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• 제10권1호
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• pp.91-95
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• 2012

The photoplethysmography (PPG) signal measured from a mobile healthcare device contains various motion artifacts occurring from a patient’s movements. Recently, to reject the motion artifacts, the method of using an acceleration sensor was suggested, but such sensors are very expensive. Therefore, this study deals with a novel sensor device to replace the acceleration sensor, and evaluated the performance of the proposed sensor experimentally. In the results of the experiments, it is shown that the proposed sensor device can reconstruct the PPG signal despite the occurrence of motion artifacts, and also that the variation rate in heart rate analysis was 1.22%. According to the experimental results, the proposed method can be applied to design a low-cost device.

• 한국막학회:학술대회논문집
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• 한국막학회 1995년도 제3회 하계분리막 Workshop (환경과 막분리 공정의 역할)
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• pp.39-50
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• 1995

The membrane processes that are commonly uscd in water and wastewater treatment are reverse osmosis (Ro), ultrafiltration (UF) and microfiltration (MF), which utilize pressure differentials. There is also nano-filtration (NF), or low-pressure reverse osmosis, which is positioned midway between conventional reverse osmosis and ultrafiltration. Reverse osmosis membranes reject dissolved ions, while ultrafiltration can be used to reject relatively larger molecules, such as protein, polysacchalides and so on. Microfiltration is capable of eliminating particles at submicron level. This paper summarizes the characteristics of MSAS process first, as it is the main membrane process applied to wastewater treatment. Two successful examples of the applications, the cases of individual building reuse system and nightsoil treatment, are then shown. The latest trend of new membrane applications, i.e., immersed-type MSAS is also introduced.

• 펄프종이기술
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• 제31권1호
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• pp.10-16
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• 1999

Air froth flotation was applied to OCC recycling process as a new pulp fractionation method and the effects of strength and drainage properties of testliner were also investigated. Fines including inks, stickies, and inorganic substances in OCC stock furnish were efficiently separated by the flotation. After the flotation, selective enzymatic treatment on the flotation reject was separately preformed, and then, the refined long fiber(flotation accept) portion was combined again with the fines(flotation reject) fraction for papermaking. This combination process was found to be effective in improving strength and drainage properties of testliner based on 100% OCC.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.58-62
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• 1998

In the industrial motor drive systems, a torsional vibration is often generated because of the elastic elements in torque transmission. One of general methods for the system is H$\infty$ controller to suppress the torsional vibration and reject the torque disturbance. vibration and reject the torque disturbance. Moreover, the two-degrees-of-freedom controller, which includes the H$\infty$ controller, is designed in order to improve the command following property. In this paper, we propose a new H$\infty$ controller with partial state feedback. This method having simple structure satisfies with the fast command following property and the attenuation of disturbances and vibrations simultaneously, just like the complicated TDOF H$\infty$ controller

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.178-179
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• 2017

In this study, the fundamental properties of cement mortar in relation to the change of the replacement ratio of the RA(Reject-Ash) were analyzed by mixing RA to the mixed aggregate consisting of poorly graded fine rock aggregate and marine aggregate for quality improvement. It was found that replacing 5% of the mixed aggregate with RA could improve the quality of the aggregate to the degree of fine rock aggregates.

• 수산해양교육연구
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• 제22권4호
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• pp.633-646
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• 2010

The purpose of this study was to actually analyze students' sociability using sociometry and effectiveness of students' sociability improvement. To accomplish this purpose, subjects of this study were selected as follow. First, how students' sociability style are actually identified. And second, when teachers give additional concern, opportunity, care, praise to experiment group(reject, isolate, neglectee), what is the effectiveness of students' sociability improvement. As sampling, from fourth to sixth grades 270 students(215 control group, 55 experiment group) of 8 classrooms of 8 elementary schools were sampled. As a tool of investigation, questionnaires about students' sociability style and effectiveness of sociability improvement had made by researcher of this study were used. And as processing of data, ANCOVA were used. The result of this study is as follow. When teachers gave additional concern, opportunity, care, praise to experiment group(reject, isolate, neglectee), students' sociability were improved. In other words, student's self-concept, proactive behavior, human relationship were improved significantly.

• 재무관리연구
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• 제15권2호
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• pp.401-419
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• 1998

This paper examines the international arbitrage pricing model (IAPM) in regional equity markets setting. Factor analyses are used to estimate the international common risk factors. And the cross-sectional regression analyses are used to test the validity of regional IAPMs and Chow tests are used to evaluate the integration of regional equity markets. The results of factor analyses show that the number of common factors in each regional group is seven. The cross-sectional regression results lead us not to reject that the IAPMs are regionally valid but Chow test results lead us to reject that regional equity markets are integrated.

• East Asian Economic Review
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• 제20권4호
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• pp.493-517
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• 2016

This paper examines the persistent properties of 12 sectoral relative prices between Korea and Japan obtained following the Classification of Individual Consumption according to Purpose (COICOP) over the period of 1985-2016. Applying a new econometric method developed by Pesaran which controls for the cross-section dependence in a panel, we are not able to reject the hypothesis that the sectoral real exchange rates contain a common stochastic trend. On the other hand, the well-known panel unit root tests such as the IPS and LLC tests widely used by previous studies strongly reject the unit root hypothesis. Since the error term of the regression for our panel exhibits significant cross-section dependence, these opposite results justify that the use of the new econometric method is appropriate.

• 대한의용생체공학회:의공학회지
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• 제14권2호
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• pp.137-145
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• 1993

Time domain analysis as well as frequency domain analysis of signal conditioning filters is very useful for practical applications. Time domain analysis of digital filters for noise cancelling in ECG signals is presented. Several band pass and band reject filters are designed for the analysis. Computer simulations are performed to compare the distortions of the Butterworth type filters and linear phase optimal FIR filters which are widely used for ECG signal processing. Band reject filters are applied to power line interference cancelling in ECG signals.

• 한국기계가공학회지
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• 제20권4호
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• pp.66-72
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• 2021

Since the behavior of an autonomous underwater vehicle (AUV) is influenced by disturbances and moments that are not accurately known, the depth control law of AUVs must have the ability to track the input signal and to reject disturbances simultaneously. Here, we proposed robust tracking control for controlling the depth of an AUV. An augmented closed-loop system is represented by an error dynamic equation, and we can easily show the asymptotic stability of the overall system by using a Lyapunov function. The robust tracking controller is consisted of the internal model of the command signal and a state feedback controller, and it has the ability to track the input signal and reject disturbances. The closed-loop control system is robust to parameter uncertainties. Simulation results showed the control performance of the robust tracking controller to be better than that of a P + PD controller.