• Proceedings of the KOSOMBE Conference
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• v.1990 no.11
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• pp.110-113
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• 1990

A new approach to impulsive noise rejection and background normalization of digitized electrocardiogram signals is presented using mathematical morphological operators that incoporate the shape information of a signal. A brief introduction to these nonlinear signal processing operators, as well as detailed description of the new algorithm, is presented. Empirical results show that the new algorithm has good performance in impulsive noise rejection and background normalization.

• Proceedings of the KIEE Conference
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• 2000.07e
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• pp.129-131
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• 2000

The moving vehicle with disturbances has the 6 degree of freedom motion in the pitching, Yawing, and rolling directions of two independent axes. The control system in such a moving vehicle has to perform disturbance rejection. This paper present PID controller with disturbance rejection function, low sensitivity filter and notch filter for bending frequency rejection. The performance of a designed system has been certified by the simulation and experiment and experiment results.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.65-68
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• 2001

In the rehabilitation robotic arm systems for the disabled with spinal code injury, EMG signals are used in the control of the robotic arm. EMG signals are corrupted by many kinds of noises such as ECG signal, power noise and contact noise of electrode. Noise rejection improves the performance of the EMG pattern classification. In this paper, a variable bandwidth filter (VBF) and wavelet transform are used for the noise rejection of EMG signals and the comparison of SNR is given. Also, some statistical characteristics of features are investigated.

• Journal of IKEEE
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• v.24 no.3
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• pp.877-882
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• 2020

This paper presents performance comparison study of current control methods for grid connected inverter (GCI) system. Different current control methods have been developed for GCI systems and each controller has its own advantages and limitations. Steady state and transient dynamic performance of the GCI current controllers are compared in this paper. The performance of the proposed command feedforward control (CFFC) and disturbance rejection control (DRC) is analyzed before and after application to all GCI current controllers. The proposed CFFC and DRC control algorithms is analyzed in a frequency domain and the simulation and experiment models of each GCI current control methods are developed for verification of the performance.

• Membrane and Water Treatment
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• v.6 no.5
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• pp.379-392
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• 2015

Polyvinyl chloride (PVC) ultrafiltration membrane was prepared by blending 12 wt.% of PVC in N, N-dimethylacetimide (DMAc) with polyethylene glycol 400 (PEG400) as an additive. The influence of PEG400 concentration on the PVC membrane morphology, permeability, fouling and rejection were investigated. Fouling and rejection of the PVC membrane were characterized by dextran T-100 filtration. The results showed that membrane water flux was increased up to $682Lm^{-2}h^{-1}$ when 28 wt.% of PEG400 was added into the PVC membrane solution. The best membrane performance with a low fouling and a high selectivity was achieved by adding 12 wt.% concentration of PEG400, which resulted in 90% rejection of dextran and 90% of flux recovery ratio. At further addition of PEG400 concentration, irreversible fouling was starting to increase. A 90% of irreversible fouling was formed in the PVC membrane when more than 22 wt.% of PEG400 is added.

• Macromolecular Research
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• v.16 no.7
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• pp.590-595
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• 2008

The pressure driven membrane process has been a breakthrough in the removal of pollutants from drinking water. These experiments examined the removal of chlorophenol compounds from water using low pressure membranes. The removal performance of the membranes was based primarily on size exclusion. Apart from size exclusion, the polarity and pKa of the compounds also influences the membrane performance. The molecular size and dipole moments of the respective molecules were calculated using a quantum chemical method. The rejection of pollutants also followed the same trend as salt rejection by the membranes.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.5
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• pp.505-508
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• 2006

This paper presents a new analytical approach for designing multiloop PI controllers for disturbance rejection in multivariable processes with time delay. The proposed method is based on IMC-PID design approach. To overcome a sluggish load response by dominant pole in the process, the IMC filter is modified to compensate the dominant pole effect. Based on the modified IMC filter, an analytical tuning rule for multiloop PI controller is driven by extending the generalized IMC-PID method for single input/single output (SISO) systems [1] to multi input/multi output (MIMO) systems. Simulation results show that the proposed method gives a satisfactory load performance as well as servo performance in the multiloop system.

• Journal of the Korean Society of Safety
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• v.8 no.4
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• pp.133-138
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• 1993

The stable and safe operation of a boiler system is essential for ensuring stability of the chemical processes. A dynamic simulation of a boiler drum was performed to identify the dynamics of the boiler drum. The obtained results represented that the variation of process variables disturb boiler system. So, disturbance rejection with tracking and constraints handing was necessary for stable operation of boiler drum. Among many controller, GPC has been known to show good performance in set point tracking than disturbance. In order to improve disturbance rejection performance measurable disturbance term was Introduced in basic GPC model. The controller which had tracking and disturbance rejection was designed for Improving the stable operation of a boiler system.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.43-48
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• 2012

This paper presents an iterative single-frequency continuous-wave signal-based I/Q regeneration method for improving image-rejection performance of multi-port junction-based direct receivers (MPDRs). This paper analyzes I/Q regeneration in MPDRs as I/Q mismatch compensation for direct conversion receivers. Based on the analysis, this paper evaluates the accuracy of I/Q regeneration in terms of the image-rejection ratio (IRR). The proposed method improves the IRR performance more than 20 dB compared to existing I/Q regeneration methods. Simulation results show that MPDRs using the proposed method can achieve an IRR of more than 70 dB, and that the bit error rate performances are almost the same as those of conventional coherent demodulators, even in fading channels.

• Membrane and Water Treatment
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• v.8 no.6
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• pp.613-623
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• 2017

We report the novel thin film composite RO membrane modified by graphene oxide. The thin film composite RO membrane was exposed to 2000 mg/l sodium hypochloride; thereafter it was subjected to different graphene oxide concentration ranging from 50 mg/l to 1000 mg/l in water. The resultant membrane was crosslinked with 5000 mg/l N-hydroxysuccinimide. The performance of different membranes were analysed by solute rejection and water-flux measurement. It was found that 100 mg/l graphene oxide exposure followed by 5000 mg/l N-hydroxysuccinimide treatment resulted in the membrane with the highest solute rejection of 97.78% and water-flux of 4.64 Liter per sqm per hour per bar g. The membranes were characterized by contact angle for hydrophilicity, scanning electron micrographs for surface morphology, energy dispersive X-Ray for chemical composition of the surface, Atomic force microscope for surface roughness, ATR-FTIR for chemical structure identification. It was found that the graphene oxide modified membrane increases the salt rejection performance after exposure to high-fouling water containing albumin. Highly hydrophilic, antifouling surface formation with the nanomaterial led to the improved membrane performance. Moreover, the protocol of incorporating nanomaterial by this post-treatment is simple and can be applied to any RO membrane after it is manufactured.