Mobile QR Code QR CODE : The Transactions of the Korean Institute of Electrical Engineers

다변수 제어성능 최적화를 위한 유전자 알고리즘 기반 발전소 제어 파라미터 튜닝 기법 PID Control Parameters Tuning Technique of Power Plant Based on Genetic Algorithm for Multivariable Control Performance Optimization

https://doi.org/10.5370/KIEE.2020.69.1.1

윤수용(SooYong Yun) ; 이학성(Hak-Sung Lee) ; 우주희(JooHee Woo) ; 변승현(Seung-Hyun Byun) ; 최인규(InKyu Choi) ; 이주현(JooHyun Lee) ; 서인용(In-Yong Seo)

PID controllers are widely used in the power plant control system. Generally, to calculate PID control parameters, the dynamic characteristics should be identified by investigating the variation of the process value according to the variation of the controller output. Based on this characteristics, several tuning methods can be applied to minimize the cumulative error based performance index. The applicability of ITAE(Integral Time Absolute Error) tuning method which has been studied for decades is determined by the range of time-delay/time-constant ratio. By using this method the fast rising time can be expected, but overshoot and oscillation are inevitable. These effects may lead to shorter life spans of the power plant materials because of excessive movement of the parts. To solve these problems, this paper proposed a PID tuning technique that minimizes cumulative error and overshoot simultaneously by applying genetic algorithm. The performance of the proposed PID tuning technique was verified using power plant simulator, and the performance was excellent compared with ITAE tuning method.

배전계통 모의운영 기반의 변동성 전원 수용한계 산정방법 Hosting Capacity Calculation Method for Variable Energy Resources based on the Operation Simulation of Distribution System

https://doi.org/10.5370/KIEE.2020.69.1.9

노승길(Seung Gil Noh) ; 최우영(Woo Yeong Choi) ; 유한님(Han Nim Yu) ; 국경수(Kyung Soo Kook)

As the connections of variable energy resources (VER) to the distribution system are recently delayed due to the limited expansion of the network facilities, the accurate calculation of the hosting capacity for VER has become an issue in the distribution system. The utilities would decide to integrate additional VER in a similar way as they have done for the conventional distributed resources. However, this method can be too conservative for VER. The capacity factors of VER are usually low due to their dependency on the weather and the correlation with the electric loads is quite high. Therefore, the criteria for allowing those connection should be based on the probable operating conditions rather than the maximum output based operation condition. For doing this, this paper proposes the method of calculating the capacity of the distribution system for hosting VER considering the probable operating conditions based on the time-series based operation simulation.

공급신뢰도 측면에서의 신재생에너지발전단지와 연계된 의 운용 알고리즘 개발 Development of Operational Algorithm of BESS linked with Renewable Energy Complex in terms of Power System Reliability

https://doi.org/10.5370/KIEE.2020.69.1.16

오웅진(Ungjin Oh) ; 이연찬(Yeonchan Lee) ; 임진택(Jin-Taek Lim) ; 최재석(Jaeseok Choi)

This paper proposes a probabilistic reliability evaluation model and algorithm for the power system considering wind turbine generator (WTG) and battery energy storage system (BESS) in viewpoint of power system reliability. A large-scale wind turbine generator (WTG) can creates significant power fluctuations and should affect the stability, frequency control and then reliability of the power system. Therefore, wind power should be limited to supply the percentage of load. The output of WTG cannot be predicted accurately and so results in significant fluctuations in power supply balance. Therefore, it is difficult to control the power balance between supply and demand. However, it can be controlled by installing the BESS. The BESS may smooth the fluctuation of the WTG power output. This paper proposes reliability based alternative algorithm in order to simulate the effects of the interaction of multiple WTG and BESS newly. Additionally, this paper presents sample system studies that single BESS as well as multi-BESS are simulated by handwork very clearly. Futhermore, the reliability effects of BESS according to a couple of different BESS operation rules and conditions are demonstrated in sample system case study.

대역 통과 필터를 이용한 3상 계통 연계 인버터의 저차 고조파 소거 기법 Low-Order Harmonics Cancellation for Three-Phase Grid-Connected Inverters Using a Band Pass Filter

https://doi.org/10.5370/KIEE.2020.69.1.27

안상원(Sang-Won An) ; 김석민(Seok-Min Kim) ; 조성준(Sungjoon Cho) ; 이교범(Kyo-Beum Lee)

This paper proposes a novel control method to effectively reduce the low-order harmonics contained in the grid current. When different kinds of loads or non-linear loads are connected to the Point of Common Coupling(PCC), harmonics are generated in the grid voltage, which causes output current distortion of inverter. This current distortion causes reduced efficiency and resonance of the power converter. In general, to reduce the current distortion, a low-order harmonic cancellation technique is used using proportional-integral control and low-pass filter. This method cannot effectively remove the harmonic component of the grid current due to the effect of the fundamental wave. In this paper, an effective harmonic control method is proposed, in which the effects by fundamental wave components have been removed. Simulation and experimental results verify the effectiveness and validity of proposed method

광대역 수중 음향센서 구동 시스템 소형화를 위한 매칭용 변압기 활용 설계 방안 Design of Matching Transformer for Miniaturization of Wideband Underwater Acoustic Sensor Drive System

https://doi.org/10.5370/KIEE.2020.69.1.37

박상욱(Sang-Uk Park) ; 이주찬(Ju-Chan Lee) ; 윤홍우(Hong-Woo Yoon) ; 안병선(Byoung-Sun Ahn) ; 이승훈(Seung-Hun Lee) ; 박재영(Jae-Young Park) ; 목형수(Hyung-Soo Mok)

To drive the sonar sensor, it consists of a power converter that supplies power, a filter to attenuate harmonics of the power converter, and a matching transformer to attenuate the reactive components caused by the magnitude of the voltage and the structural characteristics of the sensor. In general sonar sensors, filters and matching transformers are designed based on one fundamental wave component to attenuate reactive components. However, sonar sensors in the operating frequency range have difficulty in selecting a standard in the design of a system for driving the same, and there is a problem of overdesigning the power converter more than necessary for the overall operation. In this paper, I propose a design standard for broadband sensors to solve these problems, and propose a method of volume reduction, one of the important factors for sensors mounted in a limited space.

HVDC 하프브리지 서브모듈의 고장나무분석 기반 수명 예측 Fault-tree Analysis Based Life-cycle Expectation for Half-bridge Submodule in HVDC

https://doi.org/10.5370/KIEE.2020.69.1.42

강필순(Feel-soon Kang) ; 송성근(Sung-Geun Song)

This paper proposes an application of artificial neural networks for analyzing electricity market that has insufficient information for calculating equilibrium. Neural networks are constructed and trained on two representative cases in the electricity market. One is for calculating equilibrium price in perfect competition market and the other is for determining whether the transmission congestion occurs. The neural network uses a multilayer structure and learns with backpropagation algorithms for training. The neural networks trained in the case studies calculate the market price with a high probability and also determines an occurrence of the transmission congestion accurately.

DFIG 풍력터빈의 계통 저전압 발생 시 빠른 과도상태자속 감쇄를 위한 컨버터 제어 방법 Converter Control Method of DFIG Wind Turbine for Fast Transient Flux Attenuation Under Voltage Dips

https://doi.org/10.5370/KIEE.2020.69.1.50

김태형(Tae-Hyeong Kim) ; 송승호(Seung-Ho Song)

The high penetration of large power capacity of wind power plants connected to the grid directly can lead to serious problem of power system stability. Wind turbines should control active and reactive power according to the requirements of grid code and should stay connected to the grid during grid voltage disturbance. Doubly fed induction generator(DFIG) provides the advantage of variable speed operation and control of rated active and reactive power using a small rated power of converter approximately 30% power capacity of the generator. But the main drawback of this type of wind turbine is large sensitivity to the grid voltage disturbance, because the stator of a DFIG is directly connected to the grid. In this paper, based on theoretical study, the dynamic behavior of DFIG under grid voltage dips is analyzed and a control method of rotor current injection is proposed for the fast decrease of the transient natural stator flux. The proposed control strategy focuses on the mitigation of the transient natural stator flux for the reduction of high voltage on rotor-side and the injection of the reactive current for grid voltage support simultaneouly. For the verification of the proposed control strategy, a complete simulation model for 2MW DFIG is implemented and its performance is extensively examined using PSCAD.

폐열에너지로 구동되는 자성나노유체 버블 상유동 사이클 나노발전 시스템 Cycle Nanogenerating System Due to Two-phase Flow of Magnetic Nanofluid-Bubble Driven by Waste Heat Energy

https://doi.org/10.5370/KIEE.2020.69.1.60

김수헌(Su-Hun Kim) ; 이세희(Se-Hee Lee)

As a part of energy conversion technology, we proposed a cycle nanogenerator to produce electric energy through magnetic nanofluid (MNF) flow using waste heat energy from the industry. In the proposed nanogenerator, a heat source causes self-circulation of working fluid by thermosiphon method, and two-phase flow of MNF-bubbles resulting in density difference in the gas-liquid phase. For this reason, the spatial discretization of the magnetic field occurs under an external magnetic field and the induced electromotive force is generated in a solenoid coil by Faraday's law. The power generation test was carried out using magnetic nanofluid containing the iron oxide (Fe3O4) nanoparticles were dispersed in a volume ratio of 2% in the distilled water as the base fluid. The effective voltage was generated at the generating part, which was composed of permanent magnet and solenoid coil, by the two-phase flow of MNF-bubbles from 300W heat source.

전기추진 항공기를 위한 급 공심형 초전도 발전기의 설계 타당성 연구 A Study on the Design Feasibility of 10MW Fully Air-Cored Super Conducting Generator for Electric Propulsion Aircraft

https://doi.org/10.5370/KIEE.2020.69.1.66

방태경(Tae-Kyoung Bang) ; 장강현(Gang-Hyeon Jang) ; 이정인(Jeong-In Lee) ; 공한울(Han-Ul Gong) ; 최장영(Jang-Young Choi) ; 조한욱(Han-Wook Cho)

In this paper, a study on the design feasibility of superconducting electric machine using HTS(High Temperature Superconducting) wire for electric propulsion aircraft was carried out. NASA(National Aeronautics and Space Administration) is developing electric propulsion aircraft and electric machine for electric propulsion aircraft and aims at 41.4kW/kg specific power by 2035. Based on research trends, this paper proceeds with the design of superconducting electric machine using fully air-cored superconducting field coil to achieve high power density. Electromagnetic design was performed for fully air-cored machine. Also, the superconducting field magnet and armature rotor design were performed to satisfy the generator requirements. The analysis result confirmed that the design target 10MW output was satisfied. The results of this study can be applied to the design and research of superconducting electric machine for electric propulsion aircraft

HVDC용, 실리콘/나노실리카 콤포지트의 경화조건을 위한 전기적, 기계적 특성 Electrical and Mechanical Properties for Curing Conditions of HVDC, Silicone / Nano Silica Composite

https://doi.org/10.5370/KIEE.2020.69.1.76

박재준(Jae-Jun Park) ; 홍영기(Young-Gi Hong) ; 이재영(Jae-Young Lee)

Silica / Nano Silica_20wt% Composite, a new material for power for HVDC, which has excellent electrical and mechanical properties, was manufactured. Electrical and mechanical experiments were carried out to determine the optimum mole ratio of the amount of the silicone resin and the cross-linking agent through the stoichiometric Si-H / Vinyl mole ratio. The hardening conditions were set using the results. Electrical HVDC breakdown characteristics and mechanical tensile strengths were studied at the optimum molar ratio 2, and the curing conditions were determined according to the characteristics.

스마트 시티 서비스를 위한 채널 보상 지도 기반 광역 가시 광 통신 기법 Wide Access Visible Light Communication Technique based on Channel Compensation Map for Smart City Indoor Service

https://doi.org/10.5370/KIEE.2020.69.1.82

이용업(Yong Up Lee)

The conventional visible light (VL) communication signals based on the LED array and photodiode in the VL channel are severely distorted at the receiving point far away from VL transmitter because of the channel effect of path loss, multipath diffraction, or cochannel interference, and the insufficient compensation of the VL receiver, which results in failure of long-range VL communication for smart city service. In this paper, we consider the wide access VL communication technique that the compensation extent of the channel effect is basically provided in advance by channel compensation map, and proposes the optimal transceiver circuit for wide access VL communication. And so we can see that the proposed wide access VL communication technique overcomes the signal distortion problem through channel compensation by utilizing the optimal threshold voltage of VL receiver, and attains the successful wide access VL communication test in the overall range to 1070 cm distance.

지적 PID 제어기를 위한 파라미터 α의 설정 Optimal Value of Parameter α for iPID Control Systems

https://doi.org/10.5370/KIEE.2020.69.1.90

최연욱(Yeon-Wook Choe)

This paper is concerned with the problem of determining the intelligent PID (iPID) controller’s 4 parameters, that is,  &      . The iPID was recently proposed by Fliss and Join, and many successful cases of using it have been reported. Although these parameters, especially , is known to have a significant effect on control performance, few studies have been done on an optimal value or setup methods for in relation to the characteristics of the plants. First, using the Anischronic model, the control performances according to the increase and decrease of  are assessed and based on these results, the optimal values of iPID’s four parameters are given based on the seven plants of various formats. The parameter optimization technique is adopted to determine parameters for iPID controller. Second, check the usefulness of the optimal values proposed with various types of plants.

멀티 포인트 센싱 방법을 이용한 편광 특성 추정 Estimating Linear Polarization with Multi-Point Optic Sensing

https://doi.org/10.5370/KIEE.2020.69.1.99

백의현(Eui-Hyun Baek) ; 김대은(DaeEun Kim)

Polarized light studies have been conducted on polarized light images using three or four cameras at the concurrent time. It has been a challenging issue to find how angle of linear polarization and degree of polarization are effectively estimated. We investigate a feasible solution to handle the problem with a single webcam. Multiple optic samples can be taken with polarized film by a servo motor, and the collection helps find the characteristics of linear polorization. The multi-point optic sensing with a single camera can improve the resolution of polarization angle and estimate the degree of polarization more correctly. The method is based on the phase analysis with the fundamental frequency of a rotation of polarization angle. This paper shows a potential of extracting polarization information effectively through multiple polarized snapshot images. It greatly improves reading the polarization angle and degree over light images, compared to the conventional method with four snapshot images.

위 내시경 영상에서의 비정상 분류를 위한 머신러닝 기반 컴퓨터 보조 진단 시스템 Computer-aided Diagnosis System for Abnormalities Classification in Gastric Endoscopy Images using Machine Learning

https://doi.org/10.5370/KIEE.2020.69.1.107

이신애(Sin-ae Lee) ; 조현진(HyunChin Cho) ; 조현종(Hyun-chong Cho)

Gastric cancer is the most common cancer and has been the number one incidence since 1999 in Korea(as of 2016). Gastrointestinal symptoms and functional gastrointestinal disorders comprise a large proportion of primary care and gastroenterology practice. We propose a Computer-aided Diagnosis (CADx) system that analyzing the traditional gastroscope images and help the medical experts improve the accuracy of medical diagnosis. The data set we used consists of 400 normal images and 285 abnormal images from 103 volunteers. We also extracted four color features and two texture features from each image. The Least Square Support Vector Machine(LS-SVM) classifier was used for normal and abnormal classification. LS-SVM finds the solution by solving a set of linear equations instead of a convex quadratic programming problem for classical SVMs. The AUC value was 0.85, which is 0.02 higher than that of normal SVM.

운동 후 회복 조건에서 초단기 심박변이도 활용 가능성 연구 Feasibility Study of Ultra-Short-Term Heart Rate Variability in Recovery Condition after Exercise

https://doi.org/10.5370/KIEE.2020.69.1.114

김진웅(Jin Woong Kim) ; 신항식(Hangsik Shin)

As the application of heart rate variability extends to mobile and wearable devices, time required for analysis is becoming a major issue. There have been many research investigating whether ultra-short-term heart rate variability can replace traditional 5-minute heart rate variability, however, every study is limited to resting condition and are not suitable for application in mobile devices that lies on dynamic condition. The aim of this study is to evaluate the feasibility of the ultra-short-term heart rate variability in dynamic condition such as recovery after an exercise. We analyzed time- and frequency-domain variables of ultra-short-term heart rate variability at 240-, 180-, 120-, 60-, 30- and 10-second Electrocardiogram in recovery condition after exercise. Then, we compared the result of ultra-short-term heart rate variability with the results of 5-minute heart rate variability statistically. Results showed that more than 180-second is required for AVNN, 120-second is required for VLF, 60-second is required for SDNN, SDSD, RMSSD, pNN50, TP and LF, and 30-second is required for HF and LF/HF in recovery conditions.

이중 주파수 대역 검출기반의 강인한 시스템 A Robust Audio Fingerprinting System based on Duplex Frequency Band Detection

https://doi.org/10.5370/KIEE.2020.69.1.120

손희수(Heusu Son) ; 이석필(Soek-Pil Lee)

In this paper, we present a new audio identification system which is robust to various attacks. The types of attacks employed are modification such as changes of tempo, pitch and speed and noise addition also low and high pass filtering. We proposed a two-dimensional representation for the audio signal called FFMAP. This consists of pitch components and frame components. We also employ Pearson’s correlation score to calculate similarity between original audio data and query. Experimental results show that the proposed algorithm has a high performance.

딥러닝 모델 기반의 수두 발생 예측 Chicken pox Prediction Using Deep Learning Model

https://doi.org/10.5370/KIEE.2020.69.1.127

이미란(Miran Lee) ; 김종욱(Jong Wook Kim) ; 장백철(Beakcheol Jang)

Chicken pox is a highly diffuse disease, and the need for surveillance research to predict it is increasing. Initially used CDC data takes at least a week to a month for this data to be confirmed. So there is a need to predict chicken pox using web data that can be collected in real time. Chicken pox, unlike other infectious diseases, appears frequently in web data regardless of actual outbreak data. Therefore, their linear relationship is not clear enough to be applied to existing linear regression models. In this paper, we predict chicken pox through deep learning model that can model nonlinear relationship. In addition, the prediction accuracy is improved by extracting the keyword related to the outbreak of chicken pox. Finally, the LSTM prediction model was able to predict the chicken pox for a longer period of time and had the highest correlation coefficient of 0.97114. The root mean square error was 341.01547, which was overwhelmingly smaller than the linear regression model

실시간 객체 검출기를 이용한 동적 객체 및 행동 결합 학습 방법 비교 연구 Comparison of the Methods for Jointly Learning Objects and Actions Using Realtime Object Detector

https://doi.org/10.5370/KIEE.2020.69.1.138

홍성준(Sungjun Hong) ; 이희성(Heesung Lee)

Most of visual detection in videos are limited to focus on objects or human actions separately. In this work, changing the classification loss of well-known realtime object detector, we introduce a detection model to jointly detect object-action pairs in videos. For detecting objects-actions in videos, we present two methods to label object-action pairs, called Cartesian product (CP) and valid Cartesian product (VCP). In experiments on the A2D dataset, we compares results on detection of object-action pairs in terms of the mean average precision.

충격 추진력 변화의 표준편차를 이용한 지진 파 검출 알고리즘 P The Seismic P-wave Detection Algorithm Using Standard Deviation of Impact Momentum Variations

https://doi.org/10.5370/KIEE.2020.69.1.144

허경용(Gyeongyoung Heo) ; 최훈(Hun Choi)

In this paper, we propose a new seismic P-wave detection algorithm using the variation of impact movement and the variable threshold. In the proposed algorithm, the seismic P-wave is detected using a sudden change in the impact momentum calculated from the seismic jerk. The threshold to be the reference for sudden change is set from the mean and the standard deviation of the impact momentum changes. In addition, the mean and standard deviation estimated by the iterative method adjust the threshold value according to the SNR of the seismic wave. Using the observed real earthquakes and measured noise in the living area, computer simulations were performed to compare the conventional algorithms with the seismic P-wave detection performance of the proposed algorithm. From the experimental results, it is possible to confirm the superior detection performance of the proposed method and the effectiveness of the threshold adjustment.

웨이블릿 평면의 픽셀별 가중 결합을 이용한 위성 영상 융합 Pixel-wise Weighted Composition of Wavelet Planes for Satellite Image Fusion

https://doi.org/10.5370/KIEE.2020.69.1.152

김기백(Gibak Kim)

We propose a wavelet-based method for fusing satellite images. The proposed scheme is based on the wavelet decomposition. A linear combination of wavelet planes is presented, which includes terms for avoiding overlapping high frequency component and enhancing details. To consider the local characteristics of image, weights are imposed on each pixel of the image and the high resolution image is synthesized in a pixel-wise fusion. The weights are estimated by least squares method with lowered resolution images and multiplied by a proper scaling factor. In the experiments, using IKONOS and QuickBird satellite image data, we demonstrated that the proposed method outperforms conventional methods in terms of various objective quality measures.

듀얼 마이크를 이용한 교차 파워 스펙트럼 위상 기반의 음성 구간 검출 알고리즘 Dual-microphone Voice Activity Detector based on Cross Power Spectrum Phase

https://doi.org/10.5370/KIEE.2020.69.1.158

김기백(Gibak Kim)

To detect voice activity in adverse noisy environment, multichannel signal processing can be considered to exploit spatial selectivity. In this paper, a dual-microphone voice activity detection method is proposed to cope with the presence of strong coherent interference. Under the assumption that the direction of the target speech signal is known and the time delay between the two microphones is compensated, it is shown that the maximum of windowed averaging of real coherence function provides a reliable feature for the voice activity detection even in low signal-to-interference ratio case. The coherence function is based on the cross power spectrum phase between the two microphones. In the experiments, isolated digit utterances are convolved with impulse responses to simulate dual-microphone signals. The experimental results show that the proposed method provides more reliable feature for the voice activity detection in the presence of strong coherent interference.

합성 샴 신경망을 이용한 화자 인식 Speaker Recognition Using Convolutional Siamese Neural Networks

https://doi.org/10.5370/KIEE.2020.69.1.164

정희승(Heeseung Jung) ; 윤상혁(Sanghyeuk Yoon) ; 박능수(Neungsoo Park)

Recently, machine learning has been applied in a variety of fields. Speaker recognition is one of attractive applications of machine learning. In this paper, we propose a convolutional Siamese neural network for speaker recognition. The proposed model generates feature vectors through the identical two convolutional neural networks for speech data of two speakers. The similarity is measured by calculating the Euclidean distance of two output feature vectors. If the calculated similarity is less than the threshold, it is judged that two speakers are the same. The experimental result of the proposed speaker recognition based on the convolutional Siamese neural network showed its accuracy was achieved up to 96%. The accuracy of one-shot classification using the trained convolutional Siamese neural network was evaluated also. For the evaluation, the 10-way one-shot classification for 10 speakers not used for learning stages were tested, resulting in 92% accuracy.

특징 선택을 활용한 머신 러닝 기반의 위암 컴퓨터 보조 진단 시스템 Machine Learning based Gastric Cancer Computer-aided Diagnosis System using Feature Selection

https://doi.org/10.5370/KIEE.2020.69.1.170

김윤지(Yun-ji Kim) ; 이신애(Sin-ae Lee) ; 김동현(Dong-hyun Kim) ; 채정우(Jung-woo Chae) ; 함현식(Hyun-sik Ham) ; 조현진(Hyun Chin Cho) ; 조현종(Hyun-chong Cho)

Gastric cancer is a kind of cancer that is difficult to detect at an early stage because it has almost no symptoms at the beginning. In this study, we propose a Computer-aided Diagnosis(CADx) system that detects gastric cancer from the endoscopy. The data set we used consist of 93 normal images and 93 gastric images. We extracted 6 features in 449 dimensions from the gastric endoscopy images and reduced them to 10 dimensions through feature selection algorithms. Algorithms that we use to dimension reduction are Pearson Correlation, Chi-Squared Test, Recursive Feature Elimination, and Model-based Feature Selection, which are provided by the Sci-kit Learn library. A method was also used to select the top 10 features with a higher number of times selected by these four algorithms. Normal images and gastric cancer images were classified using support vector machine(SVM). Recursive feature elimination algorithm has the highest performance among the five feature selection algorithms, with an accuracy of 0.92.

보정 기법을 이용한 하수처리 활성오니 공정의 입출력 데이터 유효성 검증 및 전력절감에 관한 연구 A Study on Validity Verification of Input/Output Process Data and Energy Saving in Water Treatment System Using Calibration

https://doi.org/10.5370/KIEE.2020.69.1.177

남의석(Eui-Seok Nahm)

There are two major issues for activated sludge process in sewage treatment plant. One is how to make sewage be more clean and the other is the energy saving in sewage treatment process. In order to solve these issues, many studies has developed the model of activated sludge process in sewage treatment plant. But, these models was not effective in real field as to inaccurate or non-verified process data which is used in the model. So, this paper is aimed to verify process data for the performance enhancement of model and real field applications. The major monitoring data of activated sludge process are chemical oxygen demand, phosphorus, nitrogen, suspended solid in effluent. These are transmitted to the national TMS(Telemetry Monitoring System) at every hour. If these exceed the environmental standard, the environmental charges imposed in regular. So, these water qualities are to be controlled below the environmental standards and are very accurate in operation of sewage treatment plant. NH4, DO(Dissolved Oxygen), MLSS(Mixed Liquid Suspended Solid) are major process data in activated sludge process. But these process data are not verified in the field because of long-using without calibrations. Many operators of the activated sludge process has no confidence in these data as to these reasons and so many research model has not be applied to field. Almost researches are only to focus on the performance of modeling in activated sludge process. Model structures or decision of input-output of model, parameter tuning are the major research theme. All these are need to pre-process input-output data which are to be used in modeling. So, data verification is to be performed before modeling. So, we propose the real-time calibration that the process data NH4, DO, MLSS is to be verified by compensation method. The validity of the method is proved by applying to the fuzzy model of activated sludge process which was developed in previous research. The result show that the performance of the fuzzy model was improved.

리눅스 커널 영역 응용 모듈을 이용한 네트워크의 동작 주기 개선 Cycle Time Improvement of EtherCAT Networks Using Linux Kernel Space Application Module

https://doi.org/10.5370/KIEE.2020.69.1.184

박성문(Sung-Mun Park) ; 최준영(Joon-Young Choi)

We propose a method to improve the cycle time of EtherCAT networks by implementing the EtherCAT application as a kernel space application module. Commonly, the EtherCAT application has been implemented as an application program in the user space of Linux, which causes time-consuming memory copies of EtherCAT frames between the kernel and user space and deteriorates the performance of cycle time. In order to deal with this problem, we move the EtherCAT application from the user space to the kernel space by implementing the EtherCAT application as a kernel space application module. Consequently, the time-consuming memory copies are prevented between the kernel and user space, and the performance of cycle time is significantly improved. We demonstrate the performance of the proposed method by performing experiments using an EtherCAT network composed of the off-the-shelf slaves and IgH EtherCAT master for Linux. The experimental results confirm that the cycle time is significantly improved, which verifies the effect of the master application implementation in the kernel space.

α-안정화 파라미터를 사용한 분산 파티클 기반 차량 추적 시스템 Distributed Particle Filter based Vehicle Tracking System with α-stable Parameter

https://doi.org/10.5370/KIEE.2020.69.1.190

박재성(Jaesung Park) ; 윤창용(Changyong Yoon)

This paper proposes a system with multiple sensors to track vehicles in real time while driving. Environmental information on real-time roads has the characteristics of nonlinear, non-gaussian distributions, and the performance of tracking systems tends to decrease if sudden changes occur and outliers are included. To overcome these shortcomings from vehicle tracking systems, we proposes algorithms that maintain stable and robust characteristics in real-time road environments using distributed particle filters and symmetrical-stability parameters. The distributed particle filter adopts a Gaussian mixed model exchanging parameters between adjacent sensor nodes to approximate the posterior distribution of the weighted particles. The average consensus filter is used to enable each sensor node to interact with the neighboring node. Also, outliers such as impulse, the state estimation method applied to the particle filter-based tracking system is likely to result in degraded performance. To resolve these problems, this paper proposes the method to use a probability density function approximated by the particles generated, as using -stability distribution value appropriate to the circumstances. The experimental results show that the proposed method has better performance than other traditional particle methods, even when multiple sensors are used to detect multiple objects in nonlinear environment where rapid changes occur.

집적 영상에서 시점 영상 배열 변환에 기반 둔 요소 영상 압축 Compression of Elemental Images based on View Image Array Transform in Integral Imaging

https://doi.org/10.5370/KIEE.2020.69.1.197

오은주(Eun-Ju Oh) ; 유훈(Hoon Yoo)

This paper proposes a compression method for elemental images based on the view image array transform in integral imaging. As three-dimensional images start to get attention, the integral imaging as an three-dimensional imaging method has been studied actively. Elemental images have a large amount of data since they offer lots of different view points than regular images. For this reason, studies on pre-processing and compression for elemental images are required. In this paper, we proposed a compression method for elemental images based on view image array. An experiment is conducted to evaluate our method. The experimental results indicate that proposed method is effective for the elemental image compression.

IEC61850을 이용한 원자력 발전소 전력 보호 시스템의 연속되는 고장 방지 Cascading failure Prevention in Electrical Power Protection System of Nuclear Power Plant using IEC61850

https://doi.org/10.5370/KIEE.2020.69.1.203

무스타파압델라흐만무스타파(Moustafa Abdelrahman Moustafa) ; 장중구(Choong-koo Chang)

Cascading failure is the main mechanism of large blackouts in electrical power systems; this paper analyzes a cascading failure in Hanbit nuclear power plant unit (2) caused by a circuit breaker (CB) operation failure. This malfunction has been expanded to the loss of offsite power (LOOP). In this study, current practices are reviewed and then the methodologies of how to mitigate cascading failures in protection power systems are introduced. A description of the implementation-as a key solution-of the IEC61850 GOOSE message, together with zone selectivity interlocking was described. In consideration of ZSI blocking time, attention should be paid to all contributing factors such as circuit breaker tripping time, relay responding time and communications traveling time in the communication network. The aim of this paper is to establish the influence of cascading failure in NPP electrical protection power system and propose preventive actions of this failures. Finally, the expected advantages and challenges are elaborated.

대면적 초고주파 용량결합 플라즈마 전극의 전기장 균일도 개선 The study on improving the electric field uniformity in large scale VHF-CCP reactors

https://doi.org/10.5370/KIEE.2020.69.1.211

구교욱(Kyo-Woog Koo) ; 김일중(Il-Jung Kim) ; 구경완(Kyung-Wan Koo)

Large area PECVD processes have been evolved from HF to VHF technology. The larger the substrate and the higher the frequency, the stronger the standing wave is created at the center of the electrode. In this paper, a seven steps of design process were proposed to improve the standing waves by the shape deformation of electrode concave structure. Sheath thickness of 2 mm and cutting depth of 3.4 mm were simulated under the conditions of circular electrode of 1.1 m diameters, excitation frequency of 40.68MHz and gap of electrode 15mm at 4Torr. The non-uniformity was improved from 9.9%. to 1.1% adapting the processes. The same method was applied to the rectangular electrode to improve the electric field uniformity by cutting the upper electrode by making a mock up in proportion to the processing depth in the direction of the center axis using electric field analysis.

IoT /OCF 표준기반 모드버스 연동지원 자가용 전기설비 상태 모니터링 시스템 An IoT Standards-Based Electrical Equipment Status Monitoring System Supporting Modbus/OCF Bridging

https://doi.org/10.5370/KIEE.2020.69.1.217

정상진(Sangjin Jeong) ; 안윤영(Yoon-Young An) ; 강현주(Hyunjoo Kang) ; 심태형(Taehyoung Shim) ; 김성혜(Sung-Hei Kim)

With the spread of IoT technology and the convergence of power facility technology and IoT technology, IoT-based electrical facility management systems are being developed to support real-time monitoring and advanced prediction of abnormal behaviors. Currently, many IoT-based electrical facility management systems use a non-standard-based information model that defines its own IoT information model representing the state information for various electrical facilities. Therefore, it is difficult to guarantee interworking between different electrical safety management systems, and it is also difficult to develop and disseminate various electrical safety-related advanced services based on electrical safety big data. In addition, legacy electrical facilities that do not support IoT functionality are not integrated with IoT-based electrical safety management systems. In this paper, to solve these problems, we propose the architecture of IoT standard based electrical safety management system. The proposed electrical safety management system can support interworking with non-IoT electrical equipment by providing a data model conversion function that can convert Modbus data models into IoT data models. A testbed was constructed and operational tests were conducted to test the proposed electrical safety management system prototype system. The proposed system in this paper is expected to effectively manage not only IoT-supported electrical facilities but also non-IoT facilities.